Articles | Volume 18, issue 12
Atmos. Chem. Phys., 18, 8909–8927, 2018
https://doi.org/10.5194/acp-18-8909-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Atmos. Chem. Phys., 18, 8909–8927, 2018
https://doi.org/10.5194/acp-18-8909-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article 27 Jun 2018
Research article | 27 Jun 2018
Impact of surface and near-surface processes on ice crystal concentrations measured at mountain-top research stations
Alexander Beck et al.
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Georgios Touloupas, Annika Lauber, Jan Henneberger, Alexander Beck, and Aurélien Lucchi
Atmos. Meas. Tech., 13, 2219–2239, https://doi.org/10.5194/amt-13-2219-2020, https://doi.org/10.5194/amt-13-2219-2020, 2020
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Images of cloud particles give important information for improving our understanding of microphysical cloud processes. For phase-resolved measurements, a large number of water droplets and ice crystals need to be classified by an automated approach. In this study, a convolutional neural network was designed, which exceeds the classification ability of traditional methods and therefore shortens the analysis procedure of cloud particle images.
Fabiola Ramelli, Alexander Beck, Jan Henneberger, and Ulrike Lohmann
Atmos. Meas. Tech., 13, 925–939, https://doi.org/10.5194/amt-13-925-2020, https://doi.org/10.5194/amt-13-925-2020, 2020
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Boundary layer clouds are influenced by many physical and dynamical processes, making accurate forecasting difficult. Here we present a new measurement platform on a tethered balloon to measure cloud microphysical and meteorological profiles. The unique combination of holography and balloon-borne observations allows high-resolution measurements in a well-defined volume. Field measurements in stratus clouds over the Swiss Plateau revealed unique microphysical signatures in the cloud structure.
Alexander Beck, Jan Henneberger, Sarah Schöpfer, Jacob Fugal, and Ulrike Lohmann
Atmos. Meas. Tech., 10, 459–476, https://doi.org/10.5194/amt-10-459-2017, https://doi.org/10.5194/amt-10-459-2017, 2017
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In situ observations of cloud properties in complex alpine terrain are commonly conducted at mountain-top research stations and limited to single-point measurements. The HoloGondel platform overcomes this limitation by using a cable car to obtain vertical profiles of the microphysical and meteorological cloud parameters. In this work example measurements of the vertical profiles observed in a liquid cloud and a mixed-phase cloud at the Eggishorn in the Swiss Alps are presented.
Zane Dedekind, Annika Lauber, Sylvaine Ferrachat, and Ulrike Lohmann
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1326, https://doi.org/10.5194/acp-2020-1326, 2021
Preprint under review for ACP
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The RACLETS campaign combined cloud and snow research to improve the understanding of precipitation formation in clouds. A numerical weather prediction model, COSMO, was used to assess the importance of ice crystal enhancement by ice-ice collisions on cloud properties. We found that the number of ice crystals increased 1 to 3 orders of magnitude when ice-ice collisions were permitted to occur reducing localized regions of high precipitation and thereby improving the model performance.
Ottmar Möhler, Michael Adams, Larissa Lacher, Franziska Vogel, Jens Nadolny, Romy Ullrich, Cristian Boffo, Tatjana Pfeuffer, Achim Hobl, Maximilian Weiß, Hemanth S. K. Vepuri, Naruki Hiranuma, and Benjamin J. Murray
Atmos. Meas. Tech., 14, 1143–1166, https://doi.org/10.5194/amt-14-1143-2021, https://doi.org/10.5194/amt-14-1143-2021, 2021
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The Earth's climate is influenced by clouds, which are impacted by ice-nucleating particles (INPs), a minor fraction of atmospheric aerosols. INPs induce ice formation in clouds and thus often initiate precipitation formation. The Portable Ice Nucleation Experiment (PINE) is the first fully automated instrument to study cloud ice formation and to obtain long-term records of INPs. This is a timely development, and the capabilities it offers for research and atmospheric monitoring are significant.
Claudia Mignani, Jörg Wieder, Michael A. Sprenger, Zamin A. Kanji, Jan Henneberger, Christine Alewell, and Franz Conen
Atmos. Chem. Phys., 21, 657–664, https://doi.org/10.5194/acp-21-657-2021, https://doi.org/10.5194/acp-21-657-2021, 2021
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Most precipitation above land starts with ice in clouds. It is promoted by extremely rare particles. Some ice-nucleating particles (INPs) cause cloud droplets to already freeze above −15°C, a temperature at which many clouds begin to snow. We found that the abundance of such INPs among other particles of similar size is highest in precipitating air masses and lowest when air carries desert dust. This brings us closer to understanding the interactions between land, clouds, and precipitation.
Paolo Pelucchi, David Neubauer, and Ulrike Lohmann
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2020-384, https://doi.org/10.5194/gmd-2020-384, 2021
Preprint under review for GMD
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Stratocumulus are thin clouds whose cloud cover is underestimated in climate models partly due to too-low vertical resolution. We develop a scheme that locally refines the vertical grid based on a physical constraint for the cloud top. Global simulations reveal that the scheme, implemented only in the radiation routine, can increase stratocumulus cloud cover. However, this effect is not propagated to the simulated cloud cover. The scheme could be more effective if implemented in other routines.
Paraskevi Georgakaki, Aikaterini Bougiatioti, Jörg Wieder, Claudia Mignani, Fabiola Ramelli, Zamin A. Kanji, Jan Henneberger, Maxime Hervo, Alexis Berne, Ulrike Lohmann, and Athanasios Nenes
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1036, https://doi.org/10.5194/acp-2020-1036, 2020
Preprint under review for ACP
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Aerosol and cloud observations coupled with a droplet activation parameterization was used to investigate the aerosol-cloud droplet link in mixed-phase Alpine clouds. Predicted droplet number, Nd, agrees with observations, and never exceeds a characteristic
limiting droplet number, Ndlim, which depends solely on σw. Nd becomes velocity-limited when it is to within 50 % of Ndlim. Identifying when dynamical changes control Nd variability is central for understanding aerosol-cloud interactions.
Ulrike Proske, Verena Bessenbacher, Zane Dedekind, Ulrike Lohmann, and David Neubauer
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1145, https://doi.org/10.5194/acp-2020-1145, 2020
Revised manuscript accepted for ACP
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Ice crystals falling out of one cloud can initiate freezing in a second cloud below. We estimate the occurrence frequency of this natural cloud seeding over Switzerland from satellite data and sublimation calculations. We find that such situations with an ice cloud above another cloud are frequent and that the falling crystals survive the fall between two clouds in a significant number of cases, suggesting that natural cloud seeding is an important phenomenon over Switzerland.
Anna J. Miller, Killian P. Brennan, Claudia Mignani, Jörg Wieder, Robert O. David, and Nadine Borduas-Dedekind
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-414, https://doi.org/10.5194/amt-2020-414, 2020
Revised manuscript accepted for AMT
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For characterizing atmospheric ice nuclei, we present (1) the development of our home-built droplet freezing technique (DFT), the Freezing Ice Nuclei Counter (FINC), (2) an intercomparison campaign using NX-illite and an ambient sample with two other DFTs, and (3) the application of lignin as a soluble and commercial ice nuclei standard with three DFTs. We further compiled the growing number of DFTs in use for atmospheric ice nucleation since 2000, to which we add FINC.
Annika Lauber, Jan Henneberger, Claudia Mignani, Fabiola Ramelli, Julie T. Pasquier, Jörg Wieder, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-986, https://doi.org/10.5194/acp-2020-986, 2020
Revised manuscript accepted for ACP
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An accurate prediction of the ice crystal number concentration (ICNC) is important to determine the radiation budget, lifetime, and precipitation formation of clouds. Even though secondary ice processes can increase the ICNC by several orders of magnitude, they are poorly constrained and lack a well-founded quantification. During measurements on a mountain slope, a high ICNC of small ice crystals was observed just below 0 °C, attributed to a secondary ice process and parameterized in this study.
Fabiola Ramelli, Jan Henneberger, Robert O. David, Johannes Bühl, Martin Radenz, Patric Seifert, Jörg Wieder, Annika Lauber, Julie T. Pasquier, Ronny Engelmann, Claudia Mignani, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-772, https://doi.org/10.5194/acp-2020-772, 2020
Revised manuscript under review for ACP
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Orographic mixed-phase clouds are an important source of precipitation, but the ice formation processes within them remain uncertain. Here we investigate the origins of ice crystals in a mixed-phase cloud in the Swiss Alps using aerosol and cloud data from in situ and remote sensing observations. We found that ice formation primarily occurs in cloud top generating cells and low-level feeder clouds. Our results indicate that secondary ice processes occur in both of these regions.
Anna J. Miller, Killian P. Brennan, Claudia Mignani, Jörg Wieder, Assaf Zipori, Robert O. David, and Nadine Borduas-Dedekind
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-361, https://doi.org/10.5194/amt-2020-361, 2020
Preprint withdrawn
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For characterizing atmospheric ice nuclei, we present (1) the development of our home-built droplet freezing technique (DFT), the Freezing Ice Nuclei Counter (FINC), (2) an intercomparison campaign using NX-illite and an ambient sample with three DFTs, and (3) the application of lignin as a soluble and commercial ice nuclei standard with four DFTs. We further compiled the growing number of DFTs in use for atmospheric ice nucleation since 2000, to which we add FINC.
Fabiola Ramelli, Jan Henneberger, Robert Oscar David, Annika Lauber, Julie Thérèse Pasquier, Jörg Wieder, Johannes Bühl, Patric Seifert, Ronny Engelmann, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-774, https://doi.org/10.5194/acp-2020-774, 2020
Revised manuscript accepted for ACP
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Interactions between dynamics, microphysics and orography can enhance precipitation. Yet the exact role of these interactions is still uncertain. Here we investigate the role of low-level blocking and turbulence for hydrometeor growth by combining remote sensing and in situ observations. The observations show that blocked flow can induce the formation of liquid layers and that turbulence can enhance ice growth, demonstrating the importance of local flow effects for orographic precipitation.
Robert J. Allen, Steven Turnock, Pierre Nabat, David Neubauer, Ulrike Lohmann, Dirk Olivié, Naga Oshima, Martine Michou, Tongwen Wu, Jie Zhang, Toshihiko Takemura, Michael Schulz, Kostas Tsigaridis, Susanne E. Bauer, Louisa Emmons, Larry Horowitz, Vaishali Naik, Twan van Noije, Tommi Bergman, Jean-Francois Lamarque, Prodromos Zanis, Ina Tegen, Daniel M. Westervelt, Philippe Le Sager, Peter Good, Sungbo Shim, Fiona O'Connor, Dimitris Akritidis, Aristeidis K. Georgoulias, Makoto Deushi, Lori T. Sentman, Jasmin G. John, Shinichiro Fujimori, and William J. Collins
Atmos. Chem. Phys., 20, 9641–9663, https://doi.org/10.5194/acp-20-9641-2020, https://doi.org/10.5194/acp-20-9641-2020, 2020
Robert O. David, Jonas Fahrni, Claudia Marcolli, Fabian Mahrt, Dominik Brühwiler, and Zamin A. Kanji
Atmos. Chem. Phys., 20, 9419–9440, https://doi.org/10.5194/acp-20-9419-2020, https://doi.org/10.5194/acp-20-9419-2020, 2020
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Ice crystal formation plays an important role in controlling the Earth's climate. However, the mechanisms responsible for ice formation in the atmosphere are still uncertain. Here we use surrogates for atmospherically relevant porous particles to determine the role of pore diameter and wettability on the ability of porous particles to nucleate ice in the atmosphere. Our results are consistent with the pore condensation and freeing mechanism.
Georgios Touloupas, Annika Lauber, Jan Henneberger, Alexander Beck, and Aurélien Lucchi
Atmos. Meas. Tech., 13, 2219–2239, https://doi.org/10.5194/amt-13-2219-2020, https://doi.org/10.5194/amt-13-2219-2020, 2020
Short summary
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Images of cloud particles give important information for improving our understanding of microphysical cloud processes. For phase-resolved measurements, a large number of water droplets and ice crystals need to be classified by an automated approach. In this study, a convolutional neural network was designed, which exceeds the classification ability of traditional methods and therefore shortens the analysis procedure of cloud particle images.
Mattia Righi, Johannes Hendricks, Ulrike Lohmann, Christof Gerhard Beer, Valerian Hahn, Bernd Heinold, Romy Heller, Martina Krämer, Michael Ponater, Christian Rolf, Ina Tegen, and Christiane Voigt
Geosci. Model Dev., 13, 1635–1661, https://doi.org/10.5194/gmd-13-1635-2020, https://doi.org/10.5194/gmd-13-1635-2020, 2020
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A new cloud microphysical scheme is implemented in the global EMAC-MADE3 aerosol model and evaluated. The new scheme features a detailed parameterization for aerosol-driven ice formation in cirrus clouds, accounting for the competition between homogeneous and heterogeneous ice formation processes. The comparison against satellite data and in situ measurements shows that the model performance is in line with similar global coupled models featuring ice cloud parameterizations.
María Cascajo-Castresana, Robert O. David, Maiara A. Iriarte-Alonso, Alexander M. Bittner, and Claudia Marcolli
Atmos. Chem. Phys., 20, 3291–3315, https://doi.org/10.5194/acp-20-3291-2020, https://doi.org/10.5194/acp-20-3291-2020, 2020
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Atmospheric ice-nucleating particles are rare but relevant for cloud glaciation. A source of particles that nucleate ice above −15 °C is biological material including some proteins. Here we show that proteins of very diverse functions and structures can nucleate ice. Among these, the iron storage protein apoferritin stands out, with activity up to −4 °C. We show that its activity does not stem from correctly assembled proteins but from misfolded protein monomers or oligomers and aggregates.
Fabiola Ramelli, Alexander Beck, Jan Henneberger, and Ulrike Lohmann
Atmos. Meas. Tech., 13, 925–939, https://doi.org/10.5194/amt-13-925-2020, https://doi.org/10.5194/amt-13-925-2020, 2020
Short summary
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Boundary layer clouds are influenced by many physical and dynamical processes, making accurate forecasting difficult. Here we present a new measurement platform on a tethered balloon to measure cloud microphysical and meteorological profiles. The unique combination of holography and balloon-borne observations allows high-resolution measurements in a well-defined volume. Field measurements in stratus clouds over the Swiss Plateau revealed unique microphysical signatures in the cloud structure.
Giulia Saponaro, Moa K. Sporre, David Neubauer, Harri Kokkola, Pekka Kolmonen, Larisa Sogacheva, Antti Arola, Gerrit de Leeuw, Inger H. H. Karset, Ari Laaksonen, and Ulrike Lohmann
Atmos. Chem. Phys., 20, 1607–1626, https://doi.org/10.5194/acp-20-1607-2020, https://doi.org/10.5194/acp-20-1607-2020, 2020
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The understanding of cloud processes is based on the quality of the representation of cloud properties. We compared cloud parameters from three models with satellite observations. We report on the performance of each data source, highlighting strengths and deficiencies, which should be considered when deriving the effect of aerosols on cloud properties.
Killian P. Brennan, Robert O. David, and Nadine Borduas-Dedekind
Atmos. Chem. Phys., 20, 163–180, https://doi.org/10.5194/acp-20-163-2020, https://doi.org/10.5194/acp-20-163-2020, 2020
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To contribute to our understanding of the liquid water-to-ice ratio in mixed-phase clouds, this study provides a spatial and temporal dataset of ice-nucleating particle (INP) concentrations in meltwater of 88 snow samples across 17 locations in the Swiss Alps. The impact of altitude, terrain, time since last snowfall and depth on freezing temperatures was also investigated. The measured INP concentrations provide an estimate of cloud glaciation temperatures important for cloud lifetime.
Robert O. David, Maria Cascajo-Castresana, Killian P. Brennan, Michael Rösch, Nora Els, Julia Werz, Vera Weichlinger, Lin S. Boynton, Sophie Bogler, Nadine Borduas-Dedekind, Claudia Marcolli, and Zamin A. Kanji
Atmos. Meas. Tech., 12, 6865–6888, https://doi.org/10.5194/amt-12-6865-2019, https://doi.org/10.5194/amt-12-6865-2019, 2019
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Here we present the development and applicability of the DRoplet Ice Nuclei Counter Zurich (DRINCZ). DRINCZ allows for ice nuclei in the immersion mode to be quantified between 0 and -25 °C with an uncertainty of ±0.9 °C. Furthermore, we present a new method for assessing biases in drop-freezing apparatuses and cumulative ice-nucleating-particle concentrations from snow samples collected in the Austrian Alps at the Sonnblick Observatory.
Franz Friebel, Prem Lobo, David Neubauer, Ulrike Lohmann, Saskia Drossaart van Dusseldorp, Evelyn Mühlhofer, and Amewu A. Mensah
Atmos. Chem. Phys., 19, 15545–15567, https://doi.org/10.5194/acp-19-15545-2019, https://doi.org/10.5194/acp-19-15545-2019, 2019
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We investigated the change in cloud droplet activity of size-selected soot particles after being exposed to atmospheric levels of ozone over the course of 12 h. For this, we operated a 3 m3 aerosol chamber in continuous-flow mode. The results were fed into a climate model (ECHAM-HAM). We found that the oxidation of soot particles with ozone is a significant source of cloud condensation nuclei in the atmosphere.
Anina Gilgen, Stiig Wilkenskjeld, Jed O. Kaplan, Thomas Kühn, and Ulrike Lohmann
Clim. Past, 15, 1885–1911, https://doi.org/10.5194/cp-15-1885-2019, https://doi.org/10.5194/cp-15-1885-2019, 2019
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Using the global aerosol–climate model ECHAM-HAM-SALSA, the effect of humans on European climate in the Roman Empire was quantified. Both land use and novel estimates of anthropogenic aerosol emissions were considered. We conducted simulations with fixed sea-surface temperatures to gain a first impression about the anthropogenic impact. While land use effects induced a regional warming for one of the reconstructions, aerosol emissions led to a cooling associated with aerosol–cloud interactions.
Nadine Borduas-Dedekind, Rachele Ossola, Robert O. David, Lin S. Boynton, Vera Weichlinger, Zamin A. Kanji, and Kristopher McNeill
Atmos. Chem. Phys., 19, 12397–12412, https://doi.org/10.5194/acp-19-12397-2019, https://doi.org/10.5194/acp-19-12397-2019, 2019
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During atmospheric transport, dissolved organic matter (DOM) within aqueous aerosols undergoes photochemistry. We find that photochemical processing of DOM increases its ability to form cloud droplets but decreases its ability to form ice crystals over a simulated 4.6 days in the atmosphere. A photomineralization mechanism involving the loss of organic carbon and the production of organic acids, CO and CO2 explains the observed changes and affects the liquid-water-to-ice ratio in clouds.
André Welti, Ulrike Lohmann, and Zamin A. Kanji
Atmos. Chem. Phys., 19, 10901–10918, https://doi.org/10.5194/acp-19-10901-2019, https://doi.org/10.5194/acp-19-10901-2019, 2019
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The ice nucleation ability of singly immersed feldspar particles in suspended water droplets relevant for ice crystal formation under mixed-phase cloud conditions is presented. The effects of particle size, crystal structure, trace metal and mineralogical composition are discussed by testing up to five different diameters in the submicron range and nine different feldspar samples at conditions relevant for ice nucleation in mixed-phase clouds.
David Neubauer, Sylvaine Ferrachat, Colombe Siegenthaler-Le Drian, Philip Stier, Daniel G. Partridge, Ina Tegen, Isabelle Bey, Tanja Stanelle, Harri Kokkola, and Ulrike Lohmann
Geosci. Model Dev., 12, 3609–3639, https://doi.org/10.5194/gmd-12-3609-2019, https://doi.org/10.5194/gmd-12-3609-2019, 2019
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The global aerosol–climate model ECHAM6.3–HAM2.3 as well as the previous model versions ECHAM5.5–HAM2.0 and ECHAM6.1–HAM2.2 are evaluated. The simulation of clouds has improved in ECHAM6.3–HAM2.3. This has an impact on effective radiative forcing due to aerosol–radiation and aerosol–cloud interactions and equilibrium climate sensitivity, which are weaker in ECHAM6.3–HAM2.3 than in the previous model versions.
Gesa K. Eirund, Anna Possner, and Ulrike Lohmann
Atmos. Chem. Phys., 19, 9847–9864, https://doi.org/10.5194/acp-19-9847-2019, https://doi.org/10.5194/acp-19-9847-2019, 2019
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Low-level mixed-phase cloud (MPC) properties can be highly affected by the ambient aerosol concentration, especially in pristine environments like the Arctic. By employing high-resolution model simulations we investigate the response of a MPC over an open ocean and a sea ice surface to aerosol perturbations. While we find a strong initial sensitivity to changes in aerosol concentration in both cloud regimes, the magnitude as well as the long-term cloud response depends on the surface condition.
Remo Dietlicher, David Neubauer, and Ulrike Lohmann
Atmos. Chem. Phys., 19, 9061–9080, https://doi.org/10.5194/acp-19-9061-2019, https://doi.org/10.5194/acp-19-9061-2019, 2019
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Ice crystals in clouds cover a spectrum of shapes and sizes. We show the first results of a consistent representation of the cloud ice spectrum in the climate model ECHAM6-HAM2. The simulated cloud fields are linked to their sources by new diagnostics. We find that only a small fraction of ice clouds is initiated by freezing of cloud droplets in the mixed-phase temperature regime while most ice forms at temperatures colder than −35 °C.
George S. Fanourgakis, Maria Kanakidou, Athanasios Nenes, Susanne E. Bauer, Tommi Bergman, Ken S. Carslaw, Alf Grini, Douglas S. Hamilton, Jill S. Johnson, Vlassis A. Karydis, Alf Kirkevåg, John K. Kodros, Ulrike Lohmann, Gan Luo, Risto Makkonen, Hitoshi Matsui, David Neubauer, Jeffrey R. Pierce, Julia Schmale, Philip Stier, Kostas Tsigaridis, Twan van Noije, Hailong Wang, Duncan Watson-Parris, Daniel M. Westervelt, Yang Yang, Masaru Yoshioka, Nikos Daskalakis, Stefano Decesari, Martin Gysel-Beer, Nikos Kalivitis, Xiaohong Liu, Natalie M. Mahowald, Stelios Myriokefalitakis, Roland Schrödner, Maria Sfakianaki, Alexandra P. Tsimpidi, Mingxuan Wu, and Fangqun Yu
Atmos. Chem. Phys., 19, 8591–8617, https://doi.org/10.5194/acp-19-8591-2019, https://doi.org/10.5194/acp-19-8591-2019, 2019
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Effects of aerosols on clouds are important for climate studies but are among the largest uncertainties in climate projections. This study evaluates the skill of global models to simulate aerosol, cloud condensation nuclei (CCN) and cloud droplet number concentrations (CDNCs). Model results show reduced spread in CDNC compared to CCN due to the negative correlation between the sensitivities of CDNC to aerosol number concentration (air pollution) and updraft velocity (atmospheric dynamics).
Stephanie Fiedler, Stefan Kinne, Wan Ting Katty Huang, Petri Räisänen, Declan O'Donnell, Nicolas Bellouin, Philip Stier, Joonas Merikanto, Twan van Noije, Risto Makkonen, and Ulrike Lohmann
Atmos. Chem. Phys., 19, 6821–6841, https://doi.org/10.5194/acp-19-6821-2019, https://doi.org/10.5194/acp-19-6821-2019, 2019
Douglas H. Lowenthal, A. Gannet Hallar, Robert O. David, Ian B. McCubbin, Randolph D. Borys, and Gerald G. Mace
Atmos. Chem. Phys., 19, 5387–5401, https://doi.org/10.5194/acp-19-5387-2019, https://doi.org/10.5194/acp-19-5387-2019, 2019
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Snow and liquid cloud particles were measured during the StormVEx and IFRACS programs at Storm Peak Lab to better understand snow formation in wintertime mountain clouds. We found significant interactions between the ice and liquid phases of the cloud. A relationship between large droplet and small ice crystal concentrations suggested snow formation by droplet freezing. Blowing snow can bias surface measurements, but its effect was ambiguous, calling for further work on this issue.
Ina Tegen, David Neubauer, Sylvaine Ferrachat, Colombe Siegenthaler-Le Drian, Isabelle Bey, Nick Schutgens, Philip Stier, Duncan Watson-Parris, Tanja Stanelle, Hauke Schmidt, Sebastian Rast, Harri Kokkola, Martin Schultz, Sabine Schroeder, Nikos Daskalakis, Stefan Barthel, Bernd Heinold, and Ulrike Lohmann
Geosci. Model Dev., 12, 1643–1677, https://doi.org/10.5194/gmd-12-1643-2019, https://doi.org/10.5194/gmd-12-1643-2019, 2019
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We describe a new version of the aerosol–climate model ECHAM–HAM and show tests of the model performance by comparing different aspects of the aerosol distribution with different datasets. The updated version of HAM contains improved descriptions of aerosol processes, including updated emission fields and cloud processes. While there are regional deviations between the model and observations, the model performs well overall.
Yvonne Boose, Philipp Baloh, Michael Plötze, Johannes Ofner, Hinrich Grothe, Berko Sierau, Ulrike Lohmann, and Zamin A. Kanji
Atmos. Chem. Phys., 19, 1059–1076, https://doi.org/10.5194/acp-19-1059-2019, https://doi.org/10.5194/acp-19-1059-2019, 2019
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The role non-mineral components play in the freezing behavior of atmospheric desert dust is not well known. In this study, we use chemical imaging methods to investigate this for airborne and surface-collected desert dust samples. We find that in most cases the ice nucleation behavior is determined by the dust mineralogical composition. However, volatile organic material can coat active sites and decrease the dust ice nucleation ability, while biological particles can significantly increase it.
Mikhail Paramonov, Robert O. David, Ruben Kretzschmar, and Zamin A. Kanji
Atmos. Chem. Phys., 18, 16515–16536, https://doi.org/10.5194/acp-18-16515-2018, https://doi.org/10.5194/acp-18-16515-2018, 2018
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The paper presents an overview of the ice nucleation activity of surface-collected mineral and soil dust. Emphasis is placed on disentangling the effects of mineral, biogenic and soluble components of the dust on its ice nucleation activity. The results revealed that it is not possible to predict the ice nucleation activity of the surface-collected dust based on the presence and amount of certain minerals or any particular class of compounds, such as soluble or proteinaceous/organic compounds.
Emma Järvinen, Olivier Jourdan, David Neubauer, Bin Yao, Chao Liu, Meinrat O. Andreae, Ulrike Lohmann, Manfred Wendisch, Greg M. McFarquhar, Thomas Leisner, and Martin Schnaiter
Atmos. Chem. Phys., 18, 15767–15781, https://doi.org/10.5194/acp-18-15767-2018, https://doi.org/10.5194/acp-18-15767-2018, 2018
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Using light diffraction it is possible to detect microscopic features within ice particles that have not yet been fully characterized. Here, this technique was applied in airborne measurements, where it was found that majority of atmospheric ice particles have features that significantly change the way ice particles interact with solar light. The microscopic features make ice-containing clouds more reflective than previously thought, which could have consequences for predicting our climate.
Harri Kokkola, Thomas Kühn, Anton Laakso, Tommi Bergman, Kari E. J. Lehtinen, Tero Mielonen, Antti Arola, Scarlet Stadtler, Hannele Korhonen, Sylvaine Ferrachat, Ulrike Lohmann, David Neubauer, Ina Tegen, Colombe Siegenthaler-Le Drian, Martin G. Schultz, Isabelle Bey, Philip Stier, Nikos Daskalakis, Colette L. Heald, and Sami Romakkaniemi
Geosci. Model Dev., 11, 3833–3863, https://doi.org/10.5194/gmd-11-3833-2018, https://doi.org/10.5194/gmd-11-3833-2018, 2018
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In this paper we present a global aerosol–chemistry–climate model with the focus on its representation for atmospheric aerosol particles. In the model, aerosols are simulated using the aerosol module SALSA2.0, which in this paper is compared to satellite, ground, and aircraft-based observations of the properties of atmospheric aerosol. Based on this study, the model simulated aerosol properties compare well with the observations.
Fabian Mahrt, Claudia Marcolli, Robert O. David, Philippe Grönquist, Eszter J. Barthazy Meier, Ulrike Lohmann, and Zamin A. Kanji
Atmos. Chem. Phys., 18, 13363–13392, https://doi.org/10.5194/acp-18-13363-2018, https://doi.org/10.5194/acp-18-13363-2018, 2018
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The ice nucleation ability of different soot particles in the cirrus and mixed-phase cloud temperature regime is presented. The impact of aerosol particle size, particle morphology, organic matter and hydrophilicity on ice nucleation is examined. We propose ice nucleation proceeds via a pore condensation freezing mechanism for soot particles with the necessary physicochemical properties that nucleated ice well below water saturation.
Anina Gilgen, Carole Adolf, Sandra O. Brugger, Luisa Ickes, Margit Schwikowski, Jacqueline F. N. van Leeuwen, Willy Tinner, and Ulrike Lohmann
Atmos. Chem. Phys., 18, 11813–11829, https://doi.org/10.5194/acp-18-11813-2018, https://doi.org/10.5194/acp-18-11813-2018, 2018
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Microscopic charcoal particles are fire-specific tracers, which are presently the primary source for reconstructing past fire activity. In this study, we implement microscopic charcoal particles into a global aerosol–climate model to better understand the transport of charcoal on a large scale. We find that the model captures a significant portion of the spatial variability but fails to reproduce the extreme variability observed in the charcoal data.
Wan Ting Katty Huang, Luisa Ickes, Ina Tegen, Matteo Rinaldi, Darius Ceburnis, and Ulrike Lohmann
Atmos. Chem. Phys., 18, 11423–11445, https://doi.org/10.5194/acp-18-11423-2018, https://doi.org/10.5194/acp-18-11423-2018, 2018
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In this study, we investigated the potential impact on clouds and climate by organic particles emitted from the ocean surface, using a global climate model. These particles have previously been found to promote ice crystal formation, which may alter the properties of clouds. Our study, however, found a weak global impact by these particles, which brings into question their relative importance and points to the need for further verification with other models and at more regional scales.
Robin G. Stevens, Katharina Loewe, Christopher Dearden, Antonios Dimitrelos, Anna Possner, Gesa K. Eirund, Tomi Raatikainen, Adrian A. Hill, Benjamin J. Shipway, Jonathan Wilkinson, Sami Romakkaniemi, Juha Tonttila, Ari Laaksonen, Hannele Korhonen, Paul Connolly, Ulrike Lohmann, Corinna Hoose, Annica M. L. Ekman, Ken S. Carslaw, and Paul R. Field
Atmos. Chem. Phys., 18, 11041–11071, https://doi.org/10.5194/acp-18-11041-2018, https://doi.org/10.5194/acp-18-11041-2018, 2018
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We perform a model intercomparison of summertime high Arctic clouds. Observed concentrations of aerosol particles necessary for cloud formation fell to extremely low values, coincident with a transition from cloudy to nearly cloud-free conditions. Previous analyses have suggested that at these low concentrations, the radiative properties of the clouds are determined primarily by these particle concentrations. The model results strongly support this hypothesis.
Anina Gilgen, Wan Ting Katty Huang, Luisa Ickes, David Neubauer, and Ulrike Lohmann
Atmos. Chem. Phys., 18, 10521–10555, https://doi.org/10.5194/acp-18-10521-2018, https://doi.org/10.5194/acp-18-10521-2018, 2018
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Aerosol emissions in Arctic summer and autumn are expected to increase in the future because of sea ice retreat. Using a global aerosol–climate model, we quantify the impact of increased aerosol emissions from the ocean and from Arctic shipping in the year 2050. The influence on radiation of both aerosols and clouds is analysed. Mainly driven by changes in surface albedo, the cooling effect of marine aerosols and clouds will increase. Future ship emissions might have a small net cooling effect.
Ulrike Lohmann and David Neubauer
Atmos. Chem. Phys., 18, 8807–8828, https://doi.org/10.5194/acp-18-8807-2018, https://doi.org/10.5194/acp-18-8807-2018, 2018
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The climate is warming, at the current rate so much so that the 2 ºC target is likely to be exceeded. Uncertainty remains as to when the 2 ºC of warming will be reached. One factor contributing to this uncertainty is how clouds change in the warmer climate. While previously most emphasis was placed on how low clouds change in the warmer climate, here we investigate the importance of mixed-phase and ice clouds.
Martin G. Schultz, Scarlet Stadtler, Sabine Schröder, Domenico Taraborrelli, Bruno Franco, Jonathan Krefting, Alexandra Henrot, Sylvaine Ferrachat, Ulrike Lohmann, David Neubauer, Colombe Siegenthaler-Le Drian, Sebastian Wahl, Harri Kokkola, Thomas Kühn, Sebastian Rast, Hauke Schmidt, Philip Stier, Doug Kinnison, Geoffrey S. Tyndall, John J. Orlando, and Catherine Wespes
Geosci. Model Dev., 11, 1695–1723, https://doi.org/10.5194/gmd-11-1695-2018, https://doi.org/10.5194/gmd-11-1695-2018, 2018
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The chemistry–climate model ECHAM-HAMMOZ contains a detailed representation of tropospheric and stratospheric reactive chemistry and state-of-the-art parameterizations of aerosols. It thus allows for detailed investigations of chemical processes in the climate system. Evaluation of the model with various observational data yields good results, but the model has a tendency to produce too much OH in the tropics. This highlights the important interplay between atmospheric chemistry and dynamics.
Remo Dietlicher, David Neubauer, and Ulrike Lohmann
Geosci. Model Dev., 11, 1557–1576, https://doi.org/10.5194/gmd-11-1557-2018, https://doi.org/10.5194/gmd-11-1557-2018, 2018
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A new cloud scheme was implemented in the aerosol–climate model ECHAM6-HAM2. Unlike traditional schemes, it does not categorize ice particles by in-cloud and precipitation types but uses a single category with prognostic bulk particle properties. The new scheme is not only conceptually simpler but also closer to first principles as it does not rely on weakly constrained conversion rates between predefined categories and resolves falling ice by local sub-time-stepping.
Larissa Lacher, Ulrike Lohmann, Yvonne Boose, Assaf Zipori, Erik Herrmann, Nicolas Bukowiecki, Martin Steinbacher, and Zamin A. Kanji
Atmos. Chem. Phys., 17, 15199–15224, https://doi.org/10.5194/acp-17-15199-2017, https://doi.org/10.5194/acp-17-15199-2017, 2017
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We characterize the new Horizontal Ice Nucleation Chamber HINC to measure ambient ice nucleating particle concentrations at mixed‐phase cloud conditions. Results from winter measurements at the High Altitude Research Station Jungfraujoch compare well to previous measurements. We find increased ice nucleating particle concentrations during the influence of Saharan dust events and marine events, which highlights the importance of these species on ice nucleation in the free troposphere.
David Neubauer, Matthew W. Christensen, Caroline A. Poulsen, and Ulrike Lohmann
Atmos. Chem. Phys., 17, 13165–13185, https://doi.org/10.5194/acp-17-13165-2017, https://doi.org/10.5194/acp-17-13165-2017, 2017
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When aerosol particles take up water their number may seem to be increased optically. However if aerosol particles are removed by precipitation (formation) their numbers will decrease. We applied methods to account for such effects in model and satellite data to analyse the change in cloud properties by changes in aerosol particle number. The agreement of model and satellite data improves when these effects are accounted for.
Sarvesh Garimella, Daniel A. Rothenberg, Martin J. Wolf, Robert O. David, Zamin A. Kanji, Chien Wang, Michael Rösch, and Daniel J. Cziczo
Atmos. Chem. Phys., 17, 10855–10864, https://doi.org/10.5194/acp-17-10855-2017, https://doi.org/10.5194/acp-17-10855-2017, 2017
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This study investigates systematic and variable low bias in the measurement of ice nucleating particle concentration using continuous flow diffusion chambers. We find that non-ideal instrument behavior exposes particles to different humidities and/or temperatures than predicted from theory. We use a machine learning approach to quantify and minimize the uncertainty associated with this measurement bias.
Hendrik Andersen, Jan Cermak, Julia Fuchs, Reto Knutti, and Ulrike Lohmann
Atmos. Chem. Phys., 17, 9535–9546, https://doi.org/10.5194/acp-17-9535-2017, https://doi.org/10.5194/acp-17-9535-2017, 2017
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Aerosol-cloud interactions continue to contribute large uncertainties to our climate system understanding. In this study, we use near-global satellite and reanalysis data sets to predict marine liquid-water clouds by means of artificial neural networks. We show that on the system scale, lower-tropospheric stability and boundary layer height are the main determinants of liquid-water clouds. Aerosols show the expected impact on clouds but are less relevant than some meteorological factors.
Franziska Glassmeier, Anna Possner, Bernhard Vogel, Heike Vogel, and Ulrike Lohmann
Atmos. Chem. Phys., 17, 8651–8680, https://doi.org/10.5194/acp-17-8651-2017, https://doi.org/10.5194/acp-17-8651-2017, 2017
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We compare two chemistry and aerosol schemes – one designed for air-quality, the other for climate applications. For distribution, composition and radiative properties, the choice of aerosol types and processes turns out to be more important than their implementation. For aerosol–cloud interactions, we find cloud processes, in particular ice formation, to be the main obstacle to our understanding.
Anahita Amiri-Farahani, Robert J. Allen, David Neubauer, and Ulrike Lohmann
Atmos. Chem. Phys., 17, 6305–6322, https://doi.org/10.5194/acp-17-6305-2017, https://doi.org/10.5194/acp-17-6305-2017, 2017
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We use observations from 2004 to 2012 to obtain estimates of the aerosol–cloud radiative effect, including its uncertainty, for dust aerosol influencing Atlantic marine stratocumulus clouds (MSc) off the coast of north Africa. Saharan dust modifies MSc in a way that acts to cool the planet. There is a strong seasonal variation, with the aerosol–cloud radiative effect switching from significantly negative during the boreal summer to weakly positive during boreal winter.
Hanna Joos, Erica Madonna, Kasja Witlox, Sylvaine Ferrachat, Heini Wernli, and Ulrike Lohmann
Atmos. Chem. Phys., 17, 6243–6255, https://doi.org/10.5194/acp-17-6243-2017, https://doi.org/10.5194/acp-17-6243-2017, 2017
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The influence of pollution on the precipitation formation in warm conveyor belts (WCBs), the most rising air streams in low-pressure systems is investigated. We investigate in detail the cloud properties and resulting precipitation along these rising airstreams which are simulated with a global climate model. Overall, no big impact of aerosols on precipitation can be seen, however, when comparing the most polluted/cleanest WCBs, a suppression of precipitation by aerosols is observed.
Blaž Gasparini, Steffen Münch, Laure Poncet, Monika Feldmann, and Ulrike Lohmann
Atmos. Chem. Phys., 17, 4871–4885, https://doi.org/10.5194/acp-17-4871-2017, https://doi.org/10.5194/acp-17-4871-2017, 2017
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Cirrus clouds have, unlike other cloud types, a warming impact on climate. Decreasing their frequency therefore leads to a cooling effect. Cirrus ice crystals grow larger when formed on solid aerosols, inducing a shorter cloud lifetime.
We compare simplified simulations of stripping cirrus out of the sky with simulations of seeding by aerosol injections. While we find the surface climate responses to be similar, the changes in clouds and cloud properties differ significantly.
Alexander Beck, Jan Henneberger, Sarah Schöpfer, Jacob Fugal, and Ulrike Lohmann
Atmos. Meas. Tech., 10, 459–476, https://doi.org/10.5194/amt-10-459-2017, https://doi.org/10.5194/amt-10-459-2017, 2017
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In situ observations of cloud properties in complex alpine terrain are commonly conducted at mountain-top research stations and limited to single-point measurements. The HoloGondel platform overcomes this limitation by using a cable car to obtain vertical profiles of the microphysical and meteorological cloud parameters. In this work example measurements of the vertical profiles observed in a liquid cloud and a mixed-phase cloud at the Eggishorn in the Swiss Alps are presented.
Luisa Ickes, André Welti, and Ulrike Lohmann
Atmos. Chem. Phys., 17, 1713–1739, https://doi.org/10.5194/acp-17-1713-2017, https://doi.org/10.5194/acp-17-1713-2017, 2017
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The goal of this study is to find a parameterization scheme for general circulation models to describe immersion freezing with the ability to shift and adjust the slope of the freezing curve compared to homogeneous freezing to match experimental data. We investigated how accurate different formulations of classical nucleation theory reproduce measured immersion freezing curves for different mineral dust types.
Yvonne Boose, André Welti, James Atkinson, Fabiola Ramelli, Anja Danielczok, Heinz G. Bingemer, Michael Plötze, Berko Sierau, Zamin A. Kanji, and Ulrike Lohmann
Atmos. Chem. Phys., 16, 15075–15095, https://doi.org/10.5194/acp-16-15075-2016, https://doi.org/10.5194/acp-16-15075-2016, 2016
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We compare the immersion freezing behavior of four airborne to 11 surface-collected dust samples to investigate the role of different minerals for atmospheric ice nucleation on desert dust. We find that present K-feldspars dominate at T > 253 K, while quartz does at colder temperatures, and surface-collected dust samples are not necessarily representative for airborne dust. For improved ice cloud prediction, modeling of quartz and feldspar emission and transport are key.
Yvonne Boose, Berko Sierau, M. Isabel García, Sergio Rodríguez, Andrés Alastuey, Claudia Linke, Martin Schnaiter, Piotr Kupiszewski, Zamin A. Kanji, and Ulrike Lohmann
Atmos. Chem. Phys., 16, 9067–9087, https://doi.org/10.5194/acp-16-9067-2016, https://doi.org/10.5194/acp-16-9067-2016, 2016
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Mineral dust is known to be among the most prevalent ice-nucleating particles (INPs) in the atmosphere, playing a crucial role for ice cloud formation. We present 2 months of ground-based in situ measurements of INP concentrations in the free troposphere close to the largest global dust source, the Sahara. We find that some atmospheric processes such as mixing with biological particles and ammonium increase the dust INP ability. This is important when predicting INPs based on emissions.
Baban Nagare, Claudia Marcolli, André Welti, Olaf Stetzer, and Ulrike Lohmann
Atmos. Chem. Phys., 16, 8899–8914, https://doi.org/10.5194/acp-16-8899-2016, https://doi.org/10.5194/acp-16-8899-2016, 2016
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The relative importance of contact freezing and immersion freezing at mixed-phase cloud temperatures is the subject of debate. We performed experiments using continuous-flow diffusion chambers to compare the freezing efficiency of ice-nucleating particles for both these nucleation modes. Silver iodide, kaolinite and Arizona Test Dust were used as ice-nucleating particles. We could not confirm the dominance of contact freezing over immersion freezing for our experimental conditions.
Claudia Marcolli, Baban Nagare, André Welti, and Ulrike Lohmann
Atmos. Chem. Phys., 16, 8915–8937, https://doi.org/10.5194/acp-16-8915-2016, https://doi.org/10.5194/acp-16-8915-2016, 2016
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Silver iodide is one of the best-investigated ice nuclei. It has relevance for the atmosphere since it is used for glaciogenic cloud seeding. Nevertheless, many open questions remain. This paper gives an overview of silver iodide as an ice nucleus and tries to identify the factors that influence the ice nucleation ability of silver iodide.
Sarvesh Garimella, Thomas Bjerring Kristensen, Karolina Ignatius, Andre Welti, Jens Voigtländer, Gourihar R. Kulkarni, Frank Sagan, Gregory Lee Kok, James Dorsey, Leonid Nichman, Daniel Alexander Rothenberg, Michael Rösch, Amélie Catharina Ruth Kirchgäßner, Russell Ladkin, Heike Wex, Theodore W. Wilson, Luis Antonio Ladino, Jon P. D. Abbatt, Olaf Stetzer, Ulrike Lohmann, Frank Stratmann, and Daniel James Cziczo
Atmos. Meas. Tech., 9, 2781–2795, https://doi.org/10.5194/amt-9-2781-2016, https://doi.org/10.5194/amt-9-2781-2016, 2016
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The SPectrometer for Ice Nuclei (SPIN) is a commercially available ice nuclei counter manufactured by Droplet Measurement Technologies in Boulder, CO. This study characterizes the SPIN chamber, reporting data from laboratory measurements and quantifying uncertainties. Overall, we report that the SPIN is able to reproduce previous CFDC ice nucleation measurements.
Shipeng Zhang, Minghuai Wang, Steven J. Ghan, Aijun Ding, Hailong Wang, Kai Zhang, David Neubauer, Ulrike Lohmann, Sylvaine Ferrachat, Toshihiko Takeamura, Andrew Gettelman, Hugh Morrison, Yunha Lee, Drew T. Shindell, Daniel G. Partridge, Philip Stier, Zak Kipling, and Congbin Fu
Atmos. Chem. Phys., 16, 2765–2783, https://doi.org/10.5194/acp-16-2765-2016, https://doi.org/10.5194/acp-16-2765-2016, 2016
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The variation of aerosol indirect effects (AIE) in several climate models is investigated across different dynamical regimes. Regimes with strong large-scale ascent are shown to be as important as stratocumulus regimes in studying AIE. AIE over regions with high monthly large-scale surface precipitation rate contributes the most to the total aerosol indirect forcing. These results point to the need to reduce the uncertainty in AIE in different dynamical regimes.
B. Nagare, C. Marcolli, O. Stetzer, and U. Lohmann
Atmos. Chem. Phys., 15, 13759–13776, https://doi.org/10.5194/acp-15-13759-2015, https://doi.org/10.5194/acp-15-13759-2015, 2015
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We determined collision efficiencies of cloud droplets with aerosol particles experimentally and found that they were around 1 order of magnitude higher than theoretical formulations that include Brownian diffusion, impaction, interception, thermophoretic, diffusiophoretic and electric forces. This is most probably due to uncertainties and inaccuracies in the theoretical formulations of thermophoretic and diffusiophoretic processes.
J. Grazioli, G. Lloyd, L. Panziera, C. R. Hoyle, P. J. Connolly, J. Henneberger, and A. Berne
Atmos. Chem. Phys., 15, 13787–13802, https://doi.org/10.5194/acp-15-13787-2015, https://doi.org/10.5194/acp-15-13787-2015, 2015
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This study investigates the microphysics of winter alpine snowfall occurring in mixed-phase clouds in an inner-Alpine valley during CLACE2014. From polarimetric radar and in situ observations, riming is shown to be an important process leading to more intense snowfall. Riming is usually associated with more intense turbulence providing supercooled liquid water. Distinct features are identified in the vertical structure of polarimetric radar variables.
G. Lloyd, T. W. Choularton, K. N. Bower, M. W. Gallagher, P. J. Connolly, M. Flynn, R. Farrington, J. Crosier, O. Schlenczek, J. Fugal, and J. Henneberger
Atmos. Chem. Phys., 15, 12953–12969, https://doi.org/10.5194/acp-15-12953-2015, https://doi.org/10.5194/acp-15-12953-2015, 2015
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The paper explores the microphysical structure of clouds at the high-alpine measurement site Jungfraujoch, Switzerland. High concentrations of ice crystals were measured by a range of instruments. The presence of these high concentrations could not be explained through conventional understanding of ice formation processes in clouds and the possibility that the surface provides a significant source of ice crystals is investigated.
M. Paramonov, V.-M. Kerminen, M. Gysel, P. P. Aalto, M. O. Andreae, E. Asmi, U. Baltensperger, A. Bougiatioti, D. Brus, G. P. Frank, N. Good, S. S. Gunthe, L. Hao, M. Irwin, A. Jaatinen, Z. Jurányi, S. M. King, A. Kortelainen, A. Kristensson, H. Lihavainen, M. Kulmala, U. Lohmann, S. T. Martin, G. McFiggans, N. Mihalopoulos, A. Nenes, C. D. O'Dowd, J. Ovadnevaite, T. Petäjä, U. Pöschl, G. C. Roberts, D. Rose, B. Svenningsson, E. Swietlicki, E. Weingartner, J. Whitehead, A. Wiedensohler, C. Wittbom, and B. Sierau
Atmos. Chem. Phys., 15, 12211–12229, https://doi.org/10.5194/acp-15-12211-2015, https://doi.org/10.5194/acp-15-12211-2015, 2015
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The research paper presents the first comprehensive overview of field measurements with the CCN Counter performed at a large number of locations around the world within the EUCAARI framework. The paper sheds light on the CCN number concentrations and activated fractions around the world and their dependence on the water vapour supersaturation ratio, the dependence of aerosol hygroscopicity on particle size, and seasonal and diurnal variation of CCN activation and hygroscopic properties.
J. C. Corbin, A. Othman, J. D. Allan, D. R. Worsnop, J. D. Haskins, B. Sierau, U. Lohmann, and A. A. Mensah
Atmos. Meas. Tech., 8, 4615–4636, https://doi.org/10.5194/amt-8-4615-2015, https://doi.org/10.5194/amt-8-4615-2015, 2015
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Peak-integration uncertainties in the Aerodyne high-resolution aerosol mass spectrometer (AMS) are analyzed in detail using a combination of empirical data analysis and Monte Carlo approaches. The most general conclusion, applicable to any mass spectrometer, is that non-zero mass accuracy leads to a percentage error in constrained peak fits, even for well-resolved peaks. For overlapping peaks, this mass-accuracy effect may be viewed as a reduction in the effective m/z-calibration precision.
J. C. Corbin, U. Lohmann, B. Sierau, A. Keller, H. Burtscher, and A. A. Mensah
Atmos. Chem. Phys., 15, 11885–11907, https://doi.org/10.5194/acp-15-11885-2015, https://doi.org/10.5194/acp-15-11885-2015, 2015
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The chemical composition of wood-combustion soot is investigated using a soot-particle aerosol mass spectrometer. The analysis elucidates real-time information on BC oxygenated surface functional groups for a real-world source for the first time. Additional insights into the source of organic material in this soot are provided by positive matrix factorization of the data using a new AMS error model.
E. Hammer, N. Bukowiecki, B. P. Luo, U. Lohmann, C. Marcolli, E. Weingartner, U. Baltensperger, and C. R. Hoyle
Atmos. Chem. Phys., 15, 10309–10323, https://doi.org/10.5194/acp-15-10309-2015, https://doi.org/10.5194/acp-15-10309-2015, 2015
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An important quantity which determines aerosol activation and cloud formation is the effective peak supersaturation. The box model ZOMM was used to simulate the effective peak supersaturation experienced by an air parcel approaching a high-alpine research station in Switzerland. With the box model the sensitivity of the effective peak supersaturation to key aerosol and dynamical parameters was investigated.
S. Pousse-Nottelmann, E. M. Zubler, and U. Lohmann
Atmos. Chem. Phys., 15, 9217–9236, https://doi.org/10.5194/acp-15-9217-2015, https://doi.org/10.5194/acp-15-9217-2015, 2015
V. Sant, R. Posselt, and U. Lohmann
Atmos. Chem. Phys., 15, 8717–8738, https://doi.org/10.5194/acp-15-8717-2015, https://doi.org/10.5194/acp-15-8717-2015, 2015
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We have introduced prognostic precipitation for both liquid (drizzle and rain) and solid (snow) phase precipitation into the global circulation model ECHAM5-HAM. This has a significant effect on the clouds and the parameterized collection rates, also reducing the sensitivity of the liquid water path to the anthropogenic aerosol forcing. Altogether the results suggest that the treatment of precipitation in global circulation models has a significant influence on the phase and lifetime of clouds.
S. Fuzzi, U. Baltensperger, K. Carslaw, S. Decesari, H. Denier van der Gon, M. C. Facchini, D. Fowler, I. Koren, B. Langford, U. Lohmann, E. Nemitz, S. Pandis, I. Riipinen, Y. Rudich, M. Schaap, J. G. Slowik, D. V. Spracklen, E. Vignati, M. Wild, M. Williams, and S. Gilardoni
Atmos. Chem. Phys., 15, 8217–8299, https://doi.org/10.5194/acp-15-8217-2015, https://doi.org/10.5194/acp-15-8217-2015, 2015
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Particulate matter (PM) constitutes one of the most challenging problems both for air quality and climate change policies. This paper reviews the most recent scientific results on the issue and the policy needs that have driven much of the increase in monitoring and mechanistic research over the last 2 decades. The synthesis reveals many new processes and developments in the science underpinning climate-PM interactions and the effects of PM on human health and the environment.
A. Possner, E. Zubler, U. Lohmann, and C. Schär
Atmos. Chem. Phys., 15, 2185–2201, https://doi.org/10.5194/acp-15-2185-2015, https://doi.org/10.5194/acp-15-2185-2015, 2015
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For the first time, real-case simulations of ship tracks are performed at the 2km scale and evaluated against observations. Simulations show that ship tracks are quantitatively and qualitatively captured by the model. Therefore, this approach could be used to evaluate the interplay between parameterisations for aerosol–cloud interactions which occur, in the case of ship tracks, in spatially defined regions and under constrained environmental conditions.
D. Neubauer, U. Lohmann, C. Hoose, and M. G. Frontoso
Atmos. Chem. Phys., 14, 11997–12022, https://doi.org/10.5194/acp-14-11997-2014, https://doi.org/10.5194/acp-14-11997-2014, 2014
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Several biases in the representation of clouds in the stratocumulus regime in the ECHAM6-HAM2 global climate model were found by evaluating the model in the stratocumulus cloud regime. Simulations with changes in model resolution and physics to better represent clouds and aerosol in the stratocumulus regime show that the human influence on clouds and thus climate by emission of aerosol particles is sensitive to the representation of (stratocumulus) clouds.
B. Sierau, R. Y.-W. Chang, C. Leck, J. Paatero, and U. Lohmann
Atmos. Chem. Phys., 14, 7409–7430, https://doi.org/10.5194/acp-14-7409-2014, https://doi.org/10.5194/acp-14-7409-2014, 2014
M. Kuebbeler, U. Lohmann, J. Hendricks, and B. Kärcher
Atmos. Chem. Phys., 14, 3027–3046, https://doi.org/10.5194/acp-14-3027-2014, https://doi.org/10.5194/acp-14-3027-2014, 2014
J. C. Corbin, B. Sierau, M. Gysel, M. Laborde, A. Keller, J. Kim, A. Petzold, T. B. Onasch, U. Lohmann, and A. A. Mensah
Atmos. Chem. Phys., 14, 2591–2603, https://doi.org/10.5194/acp-14-2591-2014, https://doi.org/10.5194/acp-14-2591-2014, 2014
A. Baklanov, K. Schlünzen, P. Suppan, J. Baldasano, D. Brunner, S. Aksoyoglu, G. Carmichael, J. Douros, J. Flemming, R. Forkel, S. Galmarini, M. Gauss, G. Grell, M. Hirtl, S. Joffre, O. Jorba, E. Kaas, M. Kaasik, G. Kallos, X. Kong, U. Korsholm, A. Kurganskiy, J. Kushta, U. Lohmann, A. Mahura, A. Manders-Groot, A. Maurizi, N. Moussiopoulos, S. T. Rao, N. Savage, C. Seigneur, R. S. Sokhi, E. Solazzo, S. Solomos, B. Sørensen, G. Tsegas, E. Vignati, B. Vogel, and Y. Zhang
Atmos. Chem. Phys., 14, 317–398, https://doi.org/10.5194/acp-14-317-2014, https://doi.org/10.5194/acp-14-317-2014, 2014
J. Henneberger, J. P. Fugal, O. Stetzer, and U. Lohmann
Atmos. Meas. Tech., 6, 2975–2987, https://doi.org/10.5194/amt-6-2975-2013, https://doi.org/10.5194/amt-6-2975-2013, 2013
L. A. Ladino Moreno, O. Stetzer, and U. Lohmann
Atmos. Chem. Phys., 13, 9745–9769, https://doi.org/10.5194/acp-13-9745-2013, https://doi.org/10.5194/acp-13-9745-2013, 2013
Z. A. Kanji, A. Welti, C. Chou, O. Stetzer, and U. Lohmann
Atmos. Chem. Phys., 13, 9097–9118, https://doi.org/10.5194/acp-13-9097-2013, https://doi.org/10.5194/acp-13-9097-2013, 2013
C. Chou, Z. A. Kanji, O. Stetzer, T. Tritscher, R. Chirico, M. F. Heringa, E. Weingartner, A. S. H. Prévôt, U. Baltensperger, and U. Lohmann
Atmos. Chem. Phys., 13, 761–772, https://doi.org/10.5194/acp-13-761-2013, https://doi.org/10.5194/acp-13-761-2013, 2013
Related subject area
Subject: Clouds and Precipitation | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
Breakup of nocturnal low-level stratiform clouds during the southern West African monsoon season
Effects of thermodynamics, dynamics and aerosols on cirrus clouds based on in situ observations and NCAR CAM6
Towards parameterising atmospheric concentrations of ice-nucleating particles active at moderate supercooling
Meteorological and cloud conditions during the Arctic Ocean 2018 expedition
Long-term deposition and condensation ice-nucleating particle measurements from four stations across the globe
Ship-based measurements of ice nuclei concentrations over the Arctic, Atlantic, Pacific and Southern oceans
Properties of Arctic liquid and mixed-phase clouds from shipborne Cloudnet observations during ACSE 2014
The evolution of cloud and aerosol microphysics at the summit of Mt. Tai, China
Ice-nucleating particle concentrations of the past: insights from a 600-year-old Greenland ice core
Lagrangian matches between observations from aircraft, lidar and radar in an orographic warm conveyor belt
Impact of the Variability in Vertical Separation between Biomass-Burning Aerosols and Marine Stratocumulus on Cloud Microphysical Properties over the Southeast Atlantic
Statistical characteristics of raindrop size distribution over Western Ghats of India: wet versus dry spells of Indian Summer Monsoon
Continuous secondary ice production initiated by updrafts through the melting layer in mountainous regions
The Prevalence of Precipitation from Polar Supercooled Clouds
Influence of low-level blocking and turbulence on the microphysics of a mixed-phase cloud in an inner-Alpine valley
Observed Trends of Clouds and Precipitation (1983–2009): Implications for Their Cause(s)
Measurement report: Ice nucleating abilities of biomass burning, African dust, and sea spray aerosol particles over the Yucatan Peninsula
Vertical Dependence of Horizontal Variation of Cloud Microphysics: Observations from the ACE-ENA field campaign and implications for warm rain simulation in climate models
Captured Cirrus Ice Particles in High Definition
Ice-supersaturated air masses in the northern mid-latitudes from regular in situ observations by passenger aircraft: vertical distribution, seasonality and tropospheric fingerprint
Supercooled drizzle development in response to semi-coherent vertical velocity fluctuations within an orographic-layer cloud
Stratocumulus cloud clearings: statistics from satellites, reanalysis models, and airborne measurements
Supercooled liquid water cloud observed, analysed, and modelled at the top of the planetary boundary layer above Dome C, Antarctica
Open cells exhibit weaker entrainment of free-tropospheric biomass burning aerosol into the south-east Atlantic boundary layer
Small ice particles at slightly supercooled temperatures in tropical maritime convection
Statistical analysis of ice microphysical properties in tropical mesoscale convective systems derived from cloud radar and in situ microphysical observations
Biomass burning aerosol as a modulator of the droplet number in the southeast Atlantic region
Conceptual model of diurnal cycle of low-level stratiform clouds over southern West Africa
The structure of turbulence and mixed-phase cloud microphysics in a highly supercooled altocumulus cloud
Characterization of aerosol particles at Cabo Verde close to sea level and at the cloud level – Part 2: Ice-nucleating particles in air, cloud and seawater
A new look at the environmental conditions favorable to secondary ice production
Spatial and temporal variability in the ice-nucleating ability of alpine snowmelt and extension to frozen cloud fraction
Evaluation of hygroscopic cloud seeding in liquid-water clouds: a feasibility study
The impact of fluctuations and correlations in droplet growth by collision–coalescence revisited – Part 2: Observational evidence of gel formation in warm clouds
The diurnal cycle of the smoky marine boundary layer observed during August in the remote southeast Atlantic
Characterization of aerosol properties at Cyprus, focusing on cloud condensation nuclei and ice-nucleating particles
Subsiding shells and the distribution of up- and downdraughts in warm cumulus clouds over land
Sensitivity of GPS tropospheric estimates to mesoscale convective systems in West Africa
The sensitivity of oceanic precipitation to sea surface temperature
Aerosol influences on low-level clouds in the West African monsoon
Supercooled liquid fogs over the central Greenland Ice Sheet
Droplet inhomogeneity in shallow cumuli: the effects of in-cloud location and aerosol number concentration
On the distinctiveness of observed oceanic raindrop distributions
Ice-nucleating particles in a coastal tropical site
Mixed-phase orographic cloud microphysics during StormVEx and IFRACS
Classification of Arctic multilayer clouds using radiosonde and radar data in Svalbard
Experimental study of the aerosol impact on fog microphysics
Contrasting local and long-range-transported warm ice-nucleating particles during an atmospheric river in coastal California, USA
A novel approach for characterizing the variability in mass–dimension relationships: results from MC3E
New type of evidence for secondary ice formation at around −15 °C in mixed-phase clouds
Maurin Zouzoua, Fabienne Lohou, Paul Assamoi, Marie Lothon, Véronique Yoboue, Cheikh Dione, Norbert Kalthoff, Bianca Adler, Karmen Babić, Xabier Pedruzo-Bagazgoitia, and Solène Derrien
Atmos. Chem. Phys., 21, 2027–2051, https://doi.org/10.5194/acp-21-2027-2021, https://doi.org/10.5194/acp-21-2027-2021, 2021
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Based on a field experiment conducted in June and July 2016, we analyzed the daytime breakup of continental low-level stratiform clouds over southern West Africa in order to provide complementary guidance for model evaluation during the monsoon season. Those clouds exhibit weaker temperature and moisture jumps at the top compared to marine stratiform clouds. Their lifetime and the transition towards shallow convective clouds during daytime hours depend on their coupling with the surface.
Ryan Patnaude, Minghui Diao, Xiaohong Liu, and Suqian Chu
Atmos. Chem. Phys., 21, 1835–1859, https://doi.org/10.5194/acp-21-1835-2021, https://doi.org/10.5194/acp-21-1835-2021, 2021
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A comprehensive, in situ observation dataset of cirrus clouds was developed based on seven field campaigns, ranging from 87° N–75° S. The observations were compared with a global climate model. Several key factors for cirrus cloud formation were examined, including thermodynamics, dynamics, aerosol indirect effects and geographical locations. Model biases include lower ice mass concentrations, smaller ice crystals and weaker aerosol indirect effects.
Claudia Mignani, Jörg Wieder, Michael A. Sprenger, Zamin A. Kanji, Jan Henneberger, Christine Alewell, and Franz Conen
Atmos. Chem. Phys., 21, 657–664, https://doi.org/10.5194/acp-21-657-2021, https://doi.org/10.5194/acp-21-657-2021, 2021
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Most precipitation above land starts with ice in clouds. It is promoted by extremely rare particles. Some ice-nucleating particles (INPs) cause cloud droplets to already freeze above −15°C, a temperature at which many clouds begin to snow. We found that the abundance of such INPs among other particles of similar size is highest in precipitating air masses and lowest when air carries desert dust. This brings us closer to understanding the interactions between land, clouds, and precipitation.
Jutta Vüllers, Peggy Achtert, Ian M. Brooks, Michael Tjernström, John Prytherch, Annika Burzik, and Ryan Neely III
Atmos. Chem. Phys., 21, 289–314, https://doi.org/10.5194/acp-21-289-2021, https://doi.org/10.5194/acp-21-289-2021, 2021
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This paper provides interesting new results on the thermodynamic structure of the boundary layer, cloud conditions, and fog characteristics in the Arctic during the Arctic Ocean 2018 campaign. It provides information for interpreting further process studies on aerosol–cloud interactions and shows substantial differences in thermodynamic conditions and cloud characteristics based on comparison with previous campaigns. This certainly raises the question of whether it is just an exceptional year.
Jann Schrod, Erik S. Thomson, Daniel Weber, Jens Kossmann, Christopher Pöhlker, Jorge Saturno, Florian Ditas, Paulo Artaxo, Valérie Clouard, Jean-Marie Saurel, Martin Ebert, Joachim Curtius, and Heinz G. Bingemer
Atmos. Chem. Phys., 20, 15983–16006, https://doi.org/10.5194/acp-20-15983-2020, https://doi.org/10.5194/acp-20-15983-2020, 2020
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Long-term ice-nucleating particle (INP) data are presented from four semi-pristine sites located in the Amazon, the Caribbean, Germany and the Arctic. Average INP concentrations did not differ by orders of magnitude between the sites. For all sites short-term variability dominated the time series, which lacked clear trends and seasonalities. Common drivers to explain the INP levels and their variations could not be identified, illustrating the complex nature of heterogeneous ice nucleation.
André Welti, E. Keith Bigg, Paul J. DeMott, Xianda Gong, Markus Hartmann, Mike Harvey, Silvia Henning, Paul Herenz, Thomas C. J. Hill, Blake Hornblow, Caroline Leck, Mareike Löffler, Christina S. McCluskey, Anne Marie Rauker, Julia Schmale, Christian Tatzelt, Manuela van Pinxteren, and Frank Stratmann
Atmos. Chem. Phys., 20, 15191–15206, https://doi.org/10.5194/acp-20-15191-2020, https://doi.org/10.5194/acp-20-15191-2020, 2020
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Ship-based measurements of maritime ice nuclei concentrations encompassing all oceans are compiled. From this overview it is found that maritime ice nuclei concentrations are typically 10–100 times lower than over continents, while concentrations are surprisingly similar in different oceanic regions. The analysis of the influence of ship emissions shows no effect on the data, making ship-based measurements an efficient strategy for the large-scale exploration of ice nuclei concentrations.
Peggy Achtert, Ewan J. O'Connor, Ian M. Brooks, Georgia Sotiropoulou, Matthew D. Shupe, Bernhard Pospichal, Barbara J. Brooks, and Michael Tjernström
Atmos. Chem. Phys., 20, 14983–15002, https://doi.org/10.5194/acp-20-14983-2020, https://doi.org/10.5194/acp-20-14983-2020, 2020
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We present observations of precipitating and non-precipitating Arctic liquid and mixed-phase clouds during a research cruise along the Russian shelf in summer and autumn of 2014. Active remote-sensing observations, radiosondes, and auxiliary measurements are combined in the synergistic Cloudnet retrieval. Cloud properties are analysed with respect to cloud-top temperature and boundary layer structure. About 8 % of all liquid clouds show a liquid water path below the infrared black body limit.
Jiarong Li, Chao Zhu, Hui Chen, Defeng Zhao, Likun Xue, Xinfeng Wang, Hongyong Li, Pengfei Liu, Junfeng Liu, Chenglong Zhang, Yujing Mu, Wenjin Zhang, Luming Zhang, Hartmut Herrmann, Kai Li, Min Liu, and Jianmin Chen
Atmos. Chem. Phys., 20, 13735–13751, https://doi.org/10.5194/acp-20-13735-2020, https://doi.org/10.5194/acp-20-13735-2020, 2020
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Based on a field study at Mt. Tai, China, the simultaneous variations of cloud microphysics, aerosol microphysics and their potential interactions during cloud life cycles were discussed. Results demonstrated that clouds on clean days were more susceptible to the concentrations of particle number, while clouds formed on polluted days might be more sensitive to meteorological parameters. Particles larger than 150 nm played important roles in forming cloud droplets with sizes of 5–10 μm.
Jann Schrod, Dominik Kleinhenz, Maria Hörhold, Tobias Erhardt, Sarah Richter, Frank Wilhelms, Hubertus Fischer, Martin Ebert, Birthe Twarloh, Damiano Della Lunga, Camilla M. Jensen, Joachim Curtius, and Heinz G. Bingemer
Atmos. Chem. Phys., 20, 12459–12482, https://doi.org/10.5194/acp-20-12459-2020, https://doi.org/10.5194/acp-20-12459-2020, 2020
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Ice-nucleating particle (INP) concentrations of the last 6 centuries are presented from an ice core in Greenland. The data are accompanied by physical and chemical aerosol data. INPs are correlated to the dust signal from the ice core and seem to follow the annual input of mineral dust. We find no clear trend in the INP concentration. However, modern-day concentrations are higher and more variable than the concentrations of the past. This might have significant atmospheric implications.
Maxi Boettcher, Andreas Schäfler, Michael Sprenger, Harald Sodemann, Stefan Kaufmann, Christiane Voigt, Hans Schlager, Donato Summa, Paolo Di Girolamo, Daniele Nerini, Urs Germann, and Heini Wernli
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1019, https://doi.org/10.5194/acp-2020-1019, 2020
Revised manuscript accepted for ACP
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Warm conveyor belts (WCBs) are important airstreams in extratropical cyclones, often leading to the formation of intense precipitation. We present a case study that involves aircraft, lidar and radar observations of water and clouds in a WCB ascending from western Europe across the Alps towards the Baltic Sea during the field campaigns HyMeX and T-NAWDEX-Falcon in October 2012. A probabilistic trajectory measure and an airborne tracer experiment were used to confirm the long pathway of the WCB.
Siddhant Gupta, Greg M. McFarquhar, Joseph R. O'Brien, David J. Delene, Michael R. Poellot, Amie Dobracki, James R. Podolske, Jens Redemann, Samuel E. LeBlanc, Michal Segal-Rozenhaimer, and Kristina Pistone
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1039, https://doi.org/10.5194/acp-2020-1039, 2020
Revised manuscript accepted for ACP
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Observations from the 2016 NASA ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) field campaign examine how biomass-burning aerosols from southern Africa affect marine stratocumulus cloud decks over the southeast Atlantic. Instances of contact and separation between aerosols and clouds are examined to quantify the impact of aerosol mixing into cloud top on cloud drop numbers and sizes. This information is needed for improving Earth system models and satellite retrievals.
Uriya Veerendra Murali Krishna, Subrata Kumar Das, Ezhilarasi Govindaraj Sulochana, Bhowmik Utsav, Sachin Madhukar Deshpande, and Govindan Pandithurai
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1011, https://doi.org/10.5194/acp-2020-1011, 2020
Revised manuscript accepted for ACP
Annika Lauber, Jan Henneberger, Claudia Mignani, Fabiola Ramelli, Julie T. Pasquier, Jörg Wieder, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-986, https://doi.org/10.5194/acp-2020-986, 2020
Revised manuscript accepted for ACP
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An accurate prediction of the ice crystal number concentration (ICNC) is important to determine the radiation budget, lifetime, and precipitation formation of clouds. Even though secondary ice processes can increase the ICNC by several orders of magnitude, they are poorly constrained and lack a well-founded quantification. During measurements on a mountain slope, a high ICNC of small ice crystals was observed just below 0 °C, attributed to a secondary ice process and parameterized in this study.
Israel Silber, Ann M. Fridlind, Johannes Verlinde, Andrew S. Ackerman, Grégory V. Cesana, and Daniel A. Knopf
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-993, https://doi.org/10.5194/acp-2020-993, 2020
Revised manuscript accepted for ACP
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Long-term ground-based radar and sounding measurements over Alaska (Antarctica) indicate that more than 85 % (75 %) of supercooled clouds are precipitating at cloud base, and 75 % (50 %) are precipitating to the surface. Such high prevalence is reconciled with lesser spaceborne estimates by considering radar sensitivity. Results provide a strong observational constraint for polar cloud processes in large-scale models.
Fabiola Ramelli, Jan Henneberger, Robert Oscar David, Annika Lauber, Julie Thérèse Pasquier, Jörg Wieder, Johannes Bühl, Patric Seifert, Ronny Engelmann, Maxime Hervo, and Ulrike Lohmann
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-774, https://doi.org/10.5194/acp-2020-774, 2020
Revised manuscript accepted for ACP
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Interactions between dynamics, microphysics and orography can enhance precipitation. Yet the exact role of these interactions is still uncertain. Here we investigate the role of low-level blocking and turbulence for hydrometeor growth by combining remote sensing and in situ observations. The observations show that blocked flow can induce the formation of liquid layers and that turbulence can enhance ice growth, demonstrating the importance of local flow effects for orographic precipitation.
Xiang Zhong, Shaw Chen Liu, Run Liu, Xinlu Wang, Jiajia Mo, and Yanzi Li
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-577, https://doi.org/10.5194/acp-2020-577, 2020
Revised manuscript accepted for ACP
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The spatial distributions of the linear trends of total cloud cover and precipitation are both characterized by the widening of Hadley circulation and poleward shifts of the jet streams associated with global warming. Global warming, AMO and PDO can explain 67 %, 49 % and 38 % of the spatial variabilities of the linear trends in cloud cover, respectively. The reduction of total cloud cover in China is primarily driven by the moisture-convection-latent heat feedback cycle under global warming.
Fernanda Córdoba, Carolina Ramirez-Romero, Diego Cabrera, Graciela B. Raga, Javier Miranda, Harry Alvarez-Ospina, Daniel Rosas, Bernardo Figueroa, Jong S. Kim, Jacqueline Yakobi-Hancock, Talib Amador, Wilfrido Gutierrez, Manuel Garcia, Allan K. Bertram, Darrel Baumgardner, and Luis A. Ladino
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-783, https://doi.org/10.5194/acp-2020-783, 2020
Revised manuscript accepted for ACP
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Most precipitation from deep clouds over the continents and in the intertropical convergence zone is strongly influenced by the presence of ice crystals, whose formation requires the presence of aerosol particles. In the present study the ability of three different aerosol types (i.e., marine aerosol, biomass burning, and African dust) to facilitate ice particle formation was assessed in the Yucatan Peninsula, Mexico.
Zhibo Zhang, Qianqian Song, David Mechem, Vincent Larson, Jian Wang, Yangang Liu, Mikael Witte, Xiquan Dong, and Peng Wu
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-788, https://doi.org/10.5194/acp-2020-788, 2020
Revised manuscript accepted for ACP
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Tis study investigates the small-scale variations and covariations of cloud microphysical properties, namly, cloud liquid water content and cloud droplet number concentration, in marine boundary layer clouds based on in situ observation from the ACE-ENA campaign. We discuss the dependence of cloud variations on vertical location in cloud and the implications for warm rain simulations in the global climate models.
Nathan Magee, Katie Boaggio, Samantha Staskiewicz, Aaron Lynn, Xuanyi Zhao, Nicholas Tusay, Terance Schuh, Manisha Bandamede, Lucas Bancroft, David Connolly, Kevin Hurler, Bryan Miner, and Elissa Khoudary
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-486, https://doi.org/10.5194/acp-2020-486, 2020
Revised manuscript accepted for ACP
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The cryo-electron microscopy images and analysis in this paper result from the first balloon-borne capture, preservation, and high-resolution imaging of ice particles from cirrus clouds. The images show cirrus particle complexity in unprecedented detail, revealing unexpected morphology, a mixture of surface roughness scales and patterns, embedded aerosols, and a large variety of habits within a single cloud. The results should inform ongoing efforts to refine modeling of cirrus radiative impact.
Andreas Petzold, Patrick Neis, Mihal Rütimann, Susanne Rohs, Florian Berkes, Herman G. J. Smit, Martina Krämer, Nicole Spelten, Peter Spichtinger, Philippe Nédélec, and Andreas Wahner
Atmos. Chem. Phys., 20, 8157–8179, https://doi.org/10.5194/acp-20-8157-2020, https://doi.org/10.5194/acp-20-8157-2020, 2020
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The first analysis of 15 years of global-scale water vapour and relative humidity observations by passenger aircraft in the MOZAIC and IAGOS programmes resolves detailed features of water vapour and ice-supersaturated air in the mid-latitude tropopause. Key results provide in-depth insight into seasonal and regional variability and chemical signatures of ice-supersaturated air masses, including trend analyses, and show a close link to cirrus clouds and their highly important effects on climate.
Adam Majewski and Jeffrey R. French
Atmos. Chem. Phys., 20, 5035–5054, https://doi.org/10.5194/acp-20-5035-2020, https://doi.org/10.5194/acp-20-5035-2020, 2020
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The study reports formation of supercooled drizzle drops in response to repeating kilometer-wide updrafts and downdrafts within a mixed-phase, mountain-layer cloud containing very little ice despite cold cloud top temperatures (T ~ -30°C). The discrete, embedded hydrometeor growth layers and downwind transition to drizzle production at cloud top indicates the relative importance of kinematic mechanisms in determining the location of precipitation development in cloud.
Hossein Dadashazar, Ewan Crosbie, Mohammad S. Majdi, Milad Panahi, Mohammad A. Moghaddam, Ali Behrangi, Michael Brunke, Xubin Zeng, Haflidi H. Jonsson, and Armin Sorooshian
Atmos. Chem. Phys., 20, 4637–4665, https://doi.org/10.5194/acp-20-4637-2020, https://doi.org/10.5194/acp-20-4637-2020, 2020
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Clearings in the marine-boundary-layer (MBL) cloud deck of the Pacific Ocean were studied. Remote sensing, reanalysis, and airborne data were used along with machine-learning modeling to characterize the spatiotemporal nature of clearings and factors governing their growth. The most significant implications of our results are linked to modeling of fog and MBL clouds, with implications for societal and environmental issues like climate, military operations, transportation, and coastal ecology.
Philippe Ricaud, Massimo Del Guasta, Eric Bazile, Niramson Azouz, Angelo Lupi, Pierre Durand, Jean-Luc Attié, Dana Veron, Vincent Guidard, and Paolo Grigioni
Atmos. Chem. Phys., 20, 4167–4191, https://doi.org/10.5194/acp-20-4167-2020, https://doi.org/10.5194/acp-20-4167-2020, 2020
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Thin (~ 100 m) supercooled liquid water (SLW, water staying in liquid phase below 0 °C) clouds have been detected, analysed, and modelled over the Dome C (Concordia, Antarctica) station during the austral summer 2018–2019 using observations and meteorological analyses. The SLW clouds were observed at the top of the planetary boundary layer and the SLW content was always strongly underestimated by the model indicating an incorrect simulation of the surface energy budget of the Antarctic Plateau.
Steven J. Abel, Paul A. Barrett, Paquita Zuidema, Jianhao Zhang, Matt Christensen, Fanny Peers, Jonathan W. Taylor, Ian Crawford, Keith N. Bower, and Michael Flynn
Atmos. Chem. Phys., 20, 4059–4084, https://doi.org/10.5194/acp-20-4059-2020, https://doi.org/10.5194/acp-20-4059-2020, 2020
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In situ measurements of a free-tropospheric (FT) biomass burning aerosol plume in contact with the boundary layer inversion overriding a pocket of open cells (POC) and surrounding stratiform cloud are presented. The data highlight the contrasting thermodynamic, aerosol and cloud properties in the two cloud regimes and further demonstrate that the cloud regime plays a key role in regulating the flow of FT aerosols into the boundary layer, which has implications for the aerosol indirect effect.
Gary Lloyd, Thomas Choularton, Keith Bower, Jonathan Crosier, Martin Gallagher, Michael Flynn, James Dorsey, Dantong Liu, Jonathan W. Taylor, Oliver Schlenczek, Jacob Fugal, Stephan Borrmann, Richard Cotton, Paul Field, and Alan Blyth
Atmos. Chem. Phys., 20, 3895–3904, https://doi.org/10.5194/acp-20-3895-2020, https://doi.org/10.5194/acp-20-3895-2020, 2020
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Measurements of liquid and ice cloud particles were made using an aircraft to penetrate fresh growing convective clouds in the tropical Atlantic. We found small ice particles at surprisingly high temperatures just below freezing. At colder temperatures secondary ice processes rapidly generated high concentrations of ice crystals.
Emmanuel Fontaine, Alfons Schwarzenboeck, Delphine Leroy, Julien Delanoë, Alain Protat, Fabien Dezitter, John Walter Strapp, and Lyle Edward Lilie
Atmos. Chem. Phys., 20, 3503–3553, https://doi.org/10.5194/acp-20-3503-2020, https://doi.org/10.5194/acp-20-3503-2020, 2020
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This study investigates properties of ice hydrometeors (shape, concentration, density, and size) in deep convective systems. The analysis focuses on similarities and differences over four locations in the tropical troposphere. It shows that measurements as a function of temperature and radar reflectivity factors tend to be similar in the four types of deep convective systems when concentrations of ice are larger than 0.1 g m-3.
Mary Kacarab, K. Lee Thornhill, Amie Dobracki, Steven G. Howell, Joseph R. O'Brien, Steffen Freitag, Michael R. Poellot, Robert Wood, Paquita Zuidema, Jens Redemann, and Athanasios Nenes
Atmos. Chem. Phys., 20, 3029–3040, https://doi.org/10.5194/acp-20-3029-2020, https://doi.org/10.5194/acp-20-3029-2020, 2020
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We find that extensive biomass burning aerosol plumes from southern Africa can profoundly influence clouds in the southeastern Atlantic. Concurrent variations in vertical velocity, however, are found to magnify the relationship between boundary layer aerosol and the cloud droplet number. Neglecting these covariances may strongly bias the sign and magnitude of aerosol impacts on the cloud droplet number.
Fabienne Lohou, Norbert Kalthoff, Bianca Adler, Karmen Babić, Cheikh Dione, Marie Lothon, Xabier Pedruzo-Bagazgoitia, and Maurin Zouzoua
Atmos. Chem. Phys., 20, 2263–2275, https://doi.org/10.5194/acp-20-2263-2020, https://doi.org/10.5194/acp-20-2263-2020, 2020
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A conceptual model of the low-level stratiform clouds (LLSCs), which develop almost every night in southern West Africa, is built with the dataset acquired during the DACCIWA (Dynamics Aerosol Chemistry Cloud Interactions in West Africa) ground-based field experiment. Several processes occur during the four phases composing this diurnal cycle: the cooling of the air until saturation (stable and jet phases), LLSC and low-level jet interactions (stratus phase), and LLSC breakup (convective phase).
Paul A. Barrett, Alan Blyth, Philip R. A. Brown, and Steven J. Abel
Atmos. Chem. Phys., 20, 1921–1939, https://doi.org/10.5194/acp-20-1921-2020, https://doi.org/10.5194/acp-20-1921-2020, 2020
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Here we present new in situ observations from altocumulus clouds made with a research aircraft. By carefully measuring the cloud top height, we are able to study the turbulence and cloud properties in high vertical resolution, something not presented before. The clouds contain both ice particles and liquid drops, even though the temperature is −30 °C. These measurements will hopefully assist future developers of climate models to verify and assess the performance of simulations.
Xianda Gong, Heike Wex, Manuela van Pinxteren, Nadja Triesch, Khanneh Wadinga Fomba, Jasmin Lubitz, Christian Stolle, Tiera-Brandy Robinson, Thomas Müller, Hartmut Herrmann, and Frank Stratmann
Atmos. Chem. Phys., 20, 1451–1468, https://doi.org/10.5194/acp-20-1451-2020, https://doi.org/10.5194/acp-20-1451-2020, 2020
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In this study, we examined number concentrations of ice nucleating particles (INPs) at Cabo Verde in the oceanic sea surface microlayer and underlying seawater, in the air close to both sea level and cloud level, and in cloud water. The results show that most INPs are supermicron in size, that INP number concentrations in air fit well to those in cloud water and that sea spray aerosols at maximum contributed a small fraction of all INPs in the air at Cabo Verde.
Alexei Korolev, Ivan Heckman, Mengistu Wolde, Andrew S. Ackerman, Ann M. Fridlind, Luis A. Ladino, R. Paul Lawson, Jason Milbrandt, and Earle Williams
Atmos. Chem. Phys., 20, 1391–1429, https://doi.org/10.5194/acp-20-1391-2020, https://doi.org/10.5194/acp-20-1391-2020, 2020
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This study attempts identification of mechanisms of secondary ice production (SIP) based on the observation of small faceted ice crystals. It was found that in both mesoscale convective systems and frontal clouds, SIP was observed right above the melting layer and extended to the higher altitudes with colder temperatures. A principal conclusion of this work is that the freezing drop shattering mechanism is plausibly accounting for the measured ice concentrations in the observed condition.
Killian P. Brennan, Robert O. David, and Nadine Borduas-Dedekind
Atmos. Chem. Phys., 20, 163–180, https://doi.org/10.5194/acp-20-163-2020, https://doi.org/10.5194/acp-20-163-2020, 2020
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To contribute to our understanding of the liquid water-to-ice ratio in mixed-phase clouds, this study provides a spatial and temporal dataset of ice-nucleating particle (INP) concentrations in meltwater of 88 snow samples across 17 locations in the Swiss Alps. The impact of altitude, terrain, time since last snowfall and depth on freezing temperatures was also investigated. The measured INP concentrations provide an estimate of cloud glaciation temperatures important for cloud lifetime.
Fei Wang, Zhanqing Li, Qi Jiang, Gaili Wang, Shuo Jia, Jing Duan, and Yuquan Zhou
Atmos. Chem. Phys., 19, 14967–14977, https://doi.org/10.5194/acp-19-14967-2019, https://doi.org/10.5194/acp-19-14967-2019, 2019
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Though many laboratory, modeling, and field experimental studies on cloud seeding have been conducted for more than a half-century, assessing the effectiveness of cloud seeding is still very challenging due to the notorious difficulties in gaining convincing scientific evidences. The goals of this study are to evaluate any consequence of aircraft hygroscopic seeding and to develop a feasible method for analyzing the cloud seeding effect for stratocumulus clouds.
Lester Alfonso, Graciela B. Raga, and Darrel Baumgardner
Atmos. Chem. Phys., 19, 14917–14932, https://doi.org/10.5194/acp-19-14917-2019, https://doi.org/10.5194/acp-19-14917-2019, 2019
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The aim of this paper is to find some observational evidence of gel formation in clouds, by analyzing the distribution of the largest droplet at an early stage of cloud formation, and to show that the mass of the gel (
lucky droplet) is a mixture of Gaussian and Gumbel distributions. The results obtained may help advance the understanding of precipitation formation and are a novel application of the theory of critical phenomena in cloud physics.
Jianhao Zhang and Paquita Zuidema
Atmos. Chem. Phys., 19, 14493–14516, https://doi.org/10.5194/acp-19-14493-2019, https://doi.org/10.5194/acp-19-14493-2019, 2019
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Boundary layer (BL) semi-direct effects in the remote SE Atlantic are investigated using LASIC field measurements and satellite retrievals. Low-cloud cover and cloud liquid water path decrease with increasing smoke loadings in the BL. Daily-mean surface-based mixed layer is warmer by 0.5 K, moisture accumulates near the surface throughout the night, and the BL deepens by 200 m, with LWPs and cloud top heights increasing, in the sunlit morning hours, as part of the smoke-altered BL diurnal cycle.
Xianda Gong, Heike Wex, Thomas Müller, Alfred Wiedensohler, Kristina Höhler, Konrad Kandler, Nan Ma, Barbara Dietel, Thea Schiebel, Ottmar Möhler, and Frank Stratmann
Atmos. Chem. Phys., 19, 10883–10900, https://doi.org/10.5194/acp-19-10883-2019, https://doi.org/10.5194/acp-19-10883-2019, 2019
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For the diverse aerosol on Cyprus, we found the following: new particle formation can be a source of cloud condensation nuclei. Particle hygroscopicity showed that particles ~<100 nm contained mostly organic material, while larger ones were more hygroscopic. Two separate methods obtained similar concentrations of ice-nucleating particles (INP), with mostly no evidence of a local origin. Different parameterizations overestimated INP concentration in this rather polluted region.
Christian Mallaun, Andreas Giez, Georg J. Mayr, and Mathias W. Rotach
Atmos. Chem. Phys., 19, 9769–9786, https://doi.org/10.5194/acp-19-9769-2019, https://doi.org/10.5194/acp-19-9769-2019, 2019
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This study presents airborne measurements in shallow convection over land to investigate the dynamic properties of clouds focusing on possible narrow downdraughts in the surrounding of the clouds. A characteristic narrow downdraught region (
subsiding shell) is found directly outside the cloud borders for the mean vertical wind distribution. The
subsiding shellresults from the distribution of the highly variable updraughts and downdraughts in the near vicinity of the cloud.
Samuel Nahmani, Olivier Bock, and Françoise Guichard
Atmos. Chem. Phys., 19, 9541–9561, https://doi.org/10.5194/acp-19-9541-2019, https://doi.org/10.5194/acp-19-9541-2019, 2019
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A mesoscale convective system (MCS) is a cloud system that occurs in connection with an ensemble of thunderstorms and produces a contiguous precipitation area of the order of 100 km or more. Numerous questions related to MCSs remain poorly answered (e.g., their life cycle, and interactions between physical processes and atmospheric circulations). This work shows how a GPS technique can provide relevant and complementary information on MCSs passing over or in the vicinity of observation stations.
Jörg Burdanowitz, Stefan A. Buehler, Stephan Bakan, and Christian Klepp
Atmos. Chem. Phys., 19, 9241–9252, https://doi.org/10.5194/acp-19-9241-2019, https://doi.org/10.5194/acp-19-9241-2019, 2019
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Sensitivity of precipitation to sea surface temperature over the ocean determines how precipitation potentially changes in a warming climate. This relationship has hardly been studied over ocean due to a lack of long-term oceanic data. Our study shows how the precipitation sensitivity depends on resolution, what process limits oceanic precipitation and how the event duration depends on temperature. This provides valuable information for future climate observations, modeling and understanding.
Jonathan W. Taylor, Sophie L. Haslett, Keith Bower, Michael Flynn, Ian Crawford, James Dorsey, Tom Choularton, Paul J. Connolly, Valerian Hahn, Christiane Voigt, Daniel Sauer, Régis Dupuy, Joel Brito, Alfons Schwarzenboeck, Thierry Bourriane, Cyrielle Denjean, Phil Rosenberg, Cyrille Flamant, James D. Lee, Adam R. Vaughan, Peter G. Hill, Barbara Brooks, Valéry Catoire, Peter Knippertz, and Hugh Coe
Atmos. Chem. Phys., 19, 8503–8522, https://doi.org/10.5194/acp-19-8503-2019, https://doi.org/10.5194/acp-19-8503-2019, 2019
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Low-level clouds cover a wide area of southern West Africa (SWA) and play an important role in the region's climate, reflecting sunlight away from the surface. We performed aircraft measurements of aerosols and clouds over SWA during the 2016 summer monsoon and found pollution, and polluted clouds, across the whole region. Smoke from biomass burning in Central Africa is transported to West Africa, causing a polluted background which limits the effect of local pollution on cloud properties.
Christopher J. Cox, David C. Noone, Max Berkelhammer, Matthew D. Shupe, William D. Neff, Nathaniel B. Miller, Von P. Walden, and Konrad Steffen
Atmos. Chem. Phys., 19, 7467–7485, https://doi.org/10.5194/acp-19-7467-2019, https://doi.org/10.5194/acp-19-7467-2019, 2019
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Fogs are frequently reported by observers on the Greenland Ice Sheet. Fogs play a role in the hydrological and energetic balances of the ice sheet surface, but as yet the properties of Greenland fogs are not well known. We observed fogs in all months from Summit Station for 2 years and report their properties. Annually, fogs impart a slight warming to the surface and a case study suggests that they are particularly influential by providing insulation during the coldest part of the day in summer.
Dillon S. Dodson and Jennifer D. Small Griswold
Atmos. Chem. Phys., 19, 7297–7317, https://doi.org/10.5194/acp-19-7297-2019, https://doi.org/10.5194/acp-19-7297-2019, 2019
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This work looks at how the amount of aerosols contained in cloud affects the spatial orientation of the cloud droplets. Droplet orientation is important because it can lead to changes in the amount of time it takes precipitation to form. The results show that the aerosol amount does not have any effect on the droplet orientation. It is found however that the droplets are spaced closer together (there is increased droplet clustering) at cloud edge and top, as compared to center and bottom.
David Ian Duncan, Patrick Eriksson, Simon Pfreundschuh, Christian Klepp, and Daniel C. Jones
Atmos. Chem. Phys., 19, 6969–6984, https://doi.org/10.5194/acp-19-6969-2019, https://doi.org/10.5194/acp-19-6969-2019, 2019
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Raindrop size distributions have not been systematically studied over the oceans but are significant for remotely sensing, assimilating, and modeling rain. Here we investigate raindrop populations with new global in situ data, compare them against satellite estimates, and explore a new technique to classify the shapes of these distributions. The results indicate the inadequacy of a commonly assumed shape in some regions and the sizable impact of shape variability on satellite measurements.
Luis A. Ladino, Graciela B. Raga, Harry Alvarez-Ospina, Manuel A. Andino-Enríquez, Irma Rosas, Leticia Martínez, Eva Salinas, Javier Miranda, Zyanya Ramírez-Díaz, Bernardo Figueroa, Cedric Chou, Allan K. Bertram, Erika T. Quintana, Luis A. Maldonado, Agustín García-Reynoso, Meng Si, and Victoria E. Irish
Atmos. Chem. Phys., 19, 6147–6165, https://doi.org/10.5194/acp-19-6147-2019, https://doi.org/10.5194/acp-19-6147-2019, 2019
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This study presents results obtained during a field campaign conducted in the tropical village of Sisal located on the coast of the Gulf of Mexico. Air masses arriving in Sisal during the passage of cold fronts have surprisingly higher ice-nucleating particle (INP) concentrations than the campaign average. The high concentrations of INPs at T > −15 C and the supermicron size of the INPs suggest that biological particles may have been a significant contributor to the INP population in Sisal.
Douglas H. Lowenthal, A. Gannet Hallar, Robert O. David, Ian B. McCubbin, Randolph D. Borys, and Gerald G. Mace
Atmos. Chem. Phys., 19, 5387–5401, https://doi.org/10.5194/acp-19-5387-2019, https://doi.org/10.5194/acp-19-5387-2019, 2019
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Snow and liquid cloud particles were measured during the StormVEx and IFRACS programs at Storm Peak Lab to better understand snow formation in wintertime mountain clouds. We found significant interactions between the ice and liquid phases of the cloud. A relationship between large droplet and small ice crystal concentrations suggested snow formation by droplet freezing. Blowing snow can bias surface measurements, but its effect was ambiguous, calling for further work on this issue.
Maiken Vassel, Luisa Ickes, Marion Maturilli, and Corinna Hoose
Atmos. Chem. Phys., 19, 5111–5126, https://doi.org/10.5194/acp-19-5111-2019, https://doi.org/10.5194/acp-19-5111-2019, 2019
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Multilayer clouds are coexisting clouds at different heights. We evaluate measurements and find that Arctic multilayer clouds occur in 29 % of the investigated days at Ny-Ålesund, Svalbard. Multilayer clouds can interact by ice crystals falling from the upper cloud into the lower cloud. This is possible in 23 % of the investigated days, and in 9 % it is not possible. Weather models are still error-prone in the Arctic and we suggest that multilayer clouds should be included more in future work.
Marie Mazoyer, Frédéric Burnet, Cyrielle Denjean, Gregory C. Roberts, Martial Haeffelin, Jean-Charles Dupont, and Thierry Elias
Atmos. Chem. Phys., 19, 4323–4344, https://doi.org/10.5194/acp-19-4323-2019, https://doi.org/10.5194/acp-19-4323-2019, 2019
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In situ microphysical measurements collected during 23 fog events at SIRTA (south of Paris) are examined here. An original iterative method based on the κ-Köhler theory has been used to compute statistics of their activation properties. Useful information is provided to constrain and validate numerical simulations. The paper demonstrates that supersaturation encountered in these fogs is too low to observe a correlation between concentrations of aerosols > 200 nm and droplet concentrations.
Andrew C. Martin, Gavin Cornwell, Charlotte M. Beall, Forest Cannon, Sean Reilly, Bas Schaap, Dolan Lucero, Jessie Creamean, F. Martin Ralph, Hari T. Mix, and Kimberly Prather
Atmos. Chem. Phys., 19, 4193–4210, https://doi.org/10.5194/acp-19-4193-2019, https://doi.org/10.5194/acp-19-4193-2019, 2019
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Aerosols that promote ice formation in clouds were investigated during an atmospheric river that caused significant rain in northern California. We found that biological particles produced by local terrestrial ecosystems greatly enhanced cloud ice when meteorology allowed for their injection to the storm. The local terrestrial particles had greater impact on clouds than particles transported from across the Pacific Ocean, lending additional insight to which aerosols are important for cloud ice.
Joseph A. Finlon, Greg M. McFarquhar, Stephen W. Nesbitt, Robert M. Rauber, Hugh Morrison, Wei Wu, and Pengfei Zhang
Atmos. Chem. Phys., 19, 3621–3643, https://doi.org/10.5194/acp-19-3621-2019, https://doi.org/10.5194/acp-19-3621-2019, 2019
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A new approach describing the relationship between ice crystal mass (m) and dimension (D) is derived, characterizing it as a set of
equally realizableparameters based on the natural variability in cloud conditions observed by aircraft over the Great Plains. Results from this approach address shortcomings of microphysical parameterization schemes and remote sensing retrievals that employ a single m–D relation for a given ice species or environment.
Claudia Mignani, Jessie M. Creamean, Lukas Zimmermann, Christine Alewell, and Franz Conen
Atmos. Chem. Phys., 19, 877–886, https://doi.org/10.5194/acp-19-877-2019, https://doi.org/10.5194/acp-19-877-2019, 2019
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A snow crystal can be generated from an ice nucleating particle or from an ice splinter. In this study we made use of the fact that snow crystals with a particular shape (dendrites) grow within a narrow temperature range (−12 to −17 °C) and can be analysed individually for the presence of an ice nucleating particle. Our direct approach revealed that only one in eight crystals contained such a particle and was of primary origin. The other crystals must have grown from ice splinters.
Cited articles
Baumgardner, D., Brenguier, J., Bucholtz, A., Coe, H., DeMott, P., Garrett, T.,
Gayet, J., Hermann, M., Heymsfield, A., Korolev, A., Krämer, M., Petzold,
A., Strapp, W., Pilewskie, P., Taylor, J., Twohy, C., Wendisch, M., Bachalo,
W., and Chuang, P.: Airborne instruments to measure atmospheric aerosol
particles, clouds and radiation: A cooks tour of mature and emerging
technology, Atmos. Res., 102, 10–29, https://doi.org/10.1016/j.atmosres.2011.06.021,
2011. a
Beck, A., Henneberger, J., Schöpfer, S., Fugal, J., and Lohmann, U.:
HoloGondel: in situ cloud observations on a cable car in the Swiss Alps using
a holographic imager, Atmos. Meas. Tech., 10, 459–476,
https://doi.org/10.5194/amt-10-459-2017, 2017. a, b
Bergeron, T.: On the physics of clouds and precipitation, in: Proces Verbaux de
l'Association de Météorologie, Int. Union of Geodesy and Geophys.,
156–178, 1935. a
Boose, Y., Welti, A., Atkinson, J., Ramelli, F., Danielczok, A., Bingemer,
H. G., Plötze, M., Sierau, B., Kanji, Z. A., and Lohmann, U.: Heterogeneous
ice nucleation on dust particles sourced from nine deserts worldwide – Part
1: Immersion freezing, Atmos. Chem. Phys., 16, 15075–15095,
https://doi.org/10.5194/acp-16-15075-2016, 2016. a
Bromwich, D. H.: Snowfall in high southern latitudes, Rev. Geophys., 26,
149–168, https://doi.org/10.1029/RG026i001p00149, 1988. a
Choularton, T. W., Griggs, D. J., Humood, B. Y., and Latham, J.: Laboratory
studies of riming, and its relation to ice splinter production, Q. J. Roy.
Meteor. Soc., 106, 367–374, https://doi.org/10.1002/qj.49710644809, 1980. a
Comola, F., Kok, J. F., Gaume, J., Paterna, E., and Lehning, M.: Fragmentation
of wind-blown snow crystals, Geophys. Res. Lett., 44, 4195–4203,
https://doi.org/10.1002/2017GL073039, 2017GL073039, 2017. a
Crawford, I., Bower, K. N., Choularton, T. W., Dearden, C., Crosier, J.,
Westbrook, C., Capes, G., Coe, H., Connolly, P. J., Dorsey, J. R., Gallagher,
M. W., Williams, P., Trembath, J., Cui, Z., and Blyth, A.: Ice formation and
development in aged, wintertime cumulus over the UK: observations and
modelling, Atmos. Chem. Phys., 12, 4963–4985,
https://doi.org/10.5194/acp-12-4963-2012, 2012. a
Crosier, J., Bower, K. N., Choularton, T. W., Westbrook, C. D., Connolly,
P. J., Cui, Z. Q., Crawford, I. P., Capes, G. L., Coe, H., Dorsey, J. R.,
Williams, P. I., Illingworth, A. J., Gallagher, M. W., and Blyth, A. M.:
Observations of ice multiplication in a weakly convective cell embedded in
supercooled mid-level stratus, Atmos. Chem. Phys., 11, 257–273,
https://doi.org/10.5194/acp-11-257-2011, 2011. a
DeMott, P. J., Prenni, A. J., Liu, X., Kreidenweis, S. M., Petters, M. D.,
Twohy, C. H., Richardson, M. S., Eidhammer, T., and Rogers, D. C.: Predicting
global atmospheric ice nuclei distributions and their impacts on climate, P.
Natl. Acad. Sci. USA, 107, 11217–11222, https://doi.org/10.1073/pnas.0910818107,
2010. a
Déry, S. J. and Yau, M. K.: A climatology of adverse winter-type weather
events, J. Geophys. Res.-Atmos., 104, 16657–16672,
https://doi.org/10.1029/1999JD900158, 1999. a
Farrington, R. J., Connolly, P. J., Lloyd, G., Bower, K. N., Flynn, M. J.,
Gallagher, M. W., Field, P. R., Dearden, C., and Choularton, T. W.: Comparing
model and measured ice crystal concentrations in orographic clouds during the
INUPIAQ campaign, Atmos. Chem. Phys., 15, 25647–25694,
https://doi.org/10.5194/acpd-15-25647-2015, 2015. a, b, c
Field, P. R., Lawson, R. P., Brown, P. R. A., Lloyd, G., Westbrook, C.,
Moisseev, D., Miltenberger, A., Nenes, A., Blyth, A., Choularton, T.,
Connolly, P., Buehl, J., Crosier, J., Cui, Z., Dearden, C., DeMott, P.,
Flossmann, A., Heymsfield, A., Huang, Y., Kalesse, H., Kanji, Z. A., Korolev,
A., Kirchgaessner, A., Lasher-Trapp, S., Leisner, T., McFarquhar, G.,
Phillips, V., Stith, J., and Sullivan, S.: Secondary Ice Production: Current
State of the Science and Recommendations for the Future, Meteor. Monogr., 58,
7.1–7.20, https://doi.org/10.1175/AMSMONOGRAPHS-D-16-0014.1, 2017. a, b
Findeisen, W.: Kolloid-meteorologische Vorgänge bei Neiderschlagsbildung,
Meteor. Z, 55, 121–133, 1938. a
Geerts, B., Pokharel, B., and Kristovich, D. a. R.: Blowing Snow as a Natural
Glaciogenic Cloud Seeding Mechanism, Mon. Weather Rev., 143, 5017–5033,
https://doi.org/10.1175/MWR-D-15-0241.1, 2015. a, b, c, d
Gordon, M., Savelyev, S., and Taylor, P. A.: Measurements of blowing snow,
part II: Mass and number density profiles and saltation height at Franklin
Bay, NWT, Canada, Cold Reg. Sci. Technol., 55, 75–85,
https://doi.org/10.1016/j.coldregions.2008.07.001, 2009. a
Griggs, D. J. and Choularton, T. W.: A laboratory study of secondary ice
particle production by the fragmentation of rime and vapour-grown ice
crystals, Q. J. Roy. Meteor. Soc., 112,
149–163, https://doi.org/10.1002/qj.49711247109, 1986. a
Gultepe, I., Isaac, G., and Cober, S.: Ice crystal number concentration versus
temperature for climate studies, Int. J. Climatol., 21, 1281–1302,
https://doi.org/10.1002/joc.642, 2001. a
Hallett, J. and Mossop, S.: Production of secondary ice particles during the
riming process, Nature, 249, 26–28, https://doi.org/10.1038/249026a0, 1974. a, b
Hoose, C. and Möhler, O.: Heterogeneous ice nucleation on atmospheric
aerosols: a review of results from laboratory experiments, Atmos. Chem.
Phys., 12, 9817–9854, https://doi.org/10.5194/acp-12-9817-2012, 2012. a
Korolev, A. V., Isaac, G. A., and Hallett, J.: Ice particle habits in Arctic
clouds, Geophys. Res. Lett., 26, 1299–1302,
https://doi.org/10.1029/1999GL900232, 1999. a, b
Korolev, A., Isaac, G. A., and Hallett, J.: Ice particle habits in stratiform
clouds, Q. J. Roy. Meteor. Soc., 126, 2873–2902,
https://doi.org/10.1002/qj.49712656913, 2006. a, b, c
Korolev, A. V., Isaac, G. A., Cober, S. G., Strapp, J. W., and Hallett, J.:
Microphysical characterization of mixed-phase clouds, Q. J. Roy. Meteor.
Soc., 129, 39–65, https://doi.org/10.1256/qj.01.204, 2003. a
Lacher, L., Lohmann, U., Boose, Y., Zipori, A., Herrmann, E.,
Bukowiecki, N., Steinbacher, M., and Kanji, Z. A.: The Horizontal
Ice Nucleation Chamber (HINC): INP measurements at conditions
relevant for mixed-phase clouds at the High Altitude Research
Station Jungfraujoch, Atmos. Chem. Phys., 17, 15199–15224,
https://doi.org/10.5194/acp-17-15199-2017, 2017. a
Lachlan-Cope, T., Ladkin, R., Turner, J., and Davison, P.: Observations of
cloud and precipitation particles on the Avery Plateau, Antarctic Peninsula,
Antarct. Sci., 13, 339–348, https://doi.org/10.1017/S0954102001000475, 2001. a
Lauber, A., Kiselev, A., Pander, T., Handmann, P., and Leisner, T.: Secondary
ice formation during freezing of levitated droplets, J. Atmos. Sci., accepted, 2018. a
Li, L. and Pomeroy, J. W.: Estimates of Threshold Wind Speeds for Snow
Transport Using Meteorological Data, J. App. Meteorol., 36, 205–213,
https://doi.org/10.1175/1520-0450(1997)036<0205:EOTWSF>2.0.CO;2, 1997. a
Lloyd, G., Dearden, C., Choularton, T. W., Crosier, J., and Bower, K. N.:
Observations of the Origin and Distribution of Ice in Cold, Warm, and
Occluded Frontal Systems during the DIAMET Campaign, Mon. Weather Rev., 142,
4230–4255, https://doi.org/10.1175/MWR-D-13-00396.1, 2014. a
Lloyd, G., Choularton, T. W., Bower, K. N., Gallagher, M. W., Connolly, P. J.,
Flynn, M., Farrington, R., Crosier, J., Schlenczek, O., Fugal, J., and
Henneberger, J.: The origins of ice crystals measured in mixed-phase clouds
at the high-alpine site Jungfraujoch, Atmos. Chem. Phys., 15,
12953–12969, https://doi.org/10.5194/acp-15-12953-2015, 2015. a, b, c, d, e, f, g, h, i, j
Lohmann, U., Henneberger, J., Henneberg, O., Fugal, J. P., Bühl, J., and
Kanji, Z. A.: Persistence of orographic mixed-phase clouds, Geophys. Res.
Lett., 43, 10512–10519, https://doi.org/10.1002/2016GL071036, 2016GL071036, 2016. a, b, c
Mahesh, A., Eager, R., Campbell, J. R., and Spinhirne, J. D.: Observations of
blowing snow at the South Pole, J. Geophys. Res.-Atmos., 108, 4707,
https://doi.org/10.1029/2002JD003327, 2003. a, b
Mülmenstädt, J., Sourdeval, O., Delanoë, J., and Quaas, J.: Frequency of
occurrence of rain from liquid-, mixed-, and ice-phase clouds derived from
A-Train satellite retrievals, Geophys. Res. Lett., 42, 6502–6509,
https://doi.org/10.1002/2015GL064604, 2015. a
Murray, B. J., O'Sullivan, D., Atkinson, J. D., and Webb, M. E.: Ice
nucleation by particles immersed in supercooled cloud droplets, Chem. Soc.
Rev., 41, 6519–6554, https://doi.org/10.1039/C2CS35200A, 2012. a
Nishimura, K. and Nemoto, M.: Blowing snow at Mizuho station, Antarctica,
Philos. T. Roy. Soc. A, 363, 1647–1662, https://doi.org/10.1098/rsta.2005.1599, 2005. a, b, c
Palm, S. P., Yang, Y., Spinhirne, J. D., and Marshak, A.: Satellite remote
sensing of blowing snow properties over Antarctica, J. Geophys. Res.-Atmos.,
116, d16123, https://doi.org/10.1029/2011JD015828, 2011. a
Rangno, A. L. and Hobbs, P. V.: Ice particles in stratiform clouds in the
Arctic and possible mechanisms for the production of high ice concentrations,
J. Geophys. Res.-Atmos., 106, 15065–15075, https://doi.org/10.1029/2000JD900286,
2001. a
Roe, G. H.: Orographic Precipitation, Annu. Rev. Earth Pl. Sc., 33, 645–671,
https://doi.org/10.1146/annurev.earth.33.092203.122541, 2015. a
Rogers, D. C. and Vali, G.: Ice Crystal Production by Mountain Surfaces, J.
Clim. Appl. Meteorol., 26, 1152–1168,
https://doi.org/10.1175/1520-0450(1987)026<1152:ICPBMS>2.0.CO;2, 1987. a, b, c
Rotunno, R. and Houze, R. A.: Lessons on orographic precipitation from the
Mesoscale Alpine Programme, Q. J. Roy. Meteor. Soc., 133, 811–830,
https://doi.org/10.1002/qj.67, 2007. a
Schlenczek, O., Fugal, J. P., Lloyd, G., Bower, K. N., Choularton, T. W.,
Flynn, M., Crosier, J., and Borrmann, S.: Microphysical Properties of Ice
Crystal Precipitation and Surface-Generated Ice Crystals in a High Alpine
Environment in Switzerland, J. Appl. Meteorol., 56, 433–453,
https://doi.org/10.1175/JAMC-D-16-0060.1, 2017. a
Schmidt, R. A.: Vertical profiles of wind speed, snow concentration, and
humidity in blowing snow, Bound.-Lay. Meteorol., 23, 223–246,
https://doi.org/10.1007/BF00123299, 1982.
a
Vali, G., Leon, D., and Snider, J. R.: Ground-layer snow clouds, Q. J. Roy.
Meteor. Soc., 138, 1507–1525, https://doi.org/10.1002/qj.1882, 2012. a
Vardiman, L.: The Generation of Secondary Ice Particles in Clouds by
Crystal-Crystal Collision, J. Atmos. Sci., 35,
2168–2180, https://doi.org/10.1175/1520-0469(1978)035<2168:TGOSIP>2.0.CO;2, 1978. a
Vionnet, V., Guyomarch, G., Bouvet, F. N., Martin, E., Durand, Y., Bellot, H.,
Bel, C., and Pugliese, P.: Occurrence of blowing snow events at an alpine
site over a 10-year period: Observations and modelling, Adv. Water Resour.,
55, 53–63, https://doi.org/10.1016/j.advwatres.2012.05.004, 2013. a, b
Wegener, A.: Thermodynamik der Atmosphäre, Barth, Leipzig, 1911. a
Wolf, V., Kuhn, T., Milz, M., Voelger, P., Krämer, M., and Rolf, C.: Ice
particle properties of Arctic cirrus, Atmos. Chem. Phys. Discuss.,
https://doi.org/10.5194/acp-2018-386, in review, 2018. a, b, c
Yang, J. and Yau, M. K.: A New Triple-Moment Blowing Snow Model, Bound.-Lay.
Meteorol., 126, 137–155, https://doi.org/10.1007/s10546-007-9215-4, 2008. a
Short summary
This study assesses the impact of surface processes (e.g. blowing snow) on in situ cloud observations at Sonnblick Observatory. Vertical profiles of ice crystal number concentrations (ICNCs) above a snow-covered surface were observed up to a height of 10 m. The ICNC near the ground is at least a factor of 2 larger than at 10 m. Therefore, in situ measurements of ICNCs at mountain-top research stations close to the surface are strongly influenced by surface processes and overestimate the ICNC.
This study assesses the impact of surface processes (e.g. blowing snow) on in situ cloud...
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