Articles | Volume 18, issue 22
https://doi.org/10.5194/acp-18-16537-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-18-16537-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
22 Nov 2018
Research article |
| 22 Nov 2018
| 22 Nov 2018
Building a cloud in the southeast Atlantic: understanding low-cloud controls based on satellite observations with machine learning
Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
Institute of Photogrammetry and Remote Sensing, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
Jan Cermak
Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
Institute of Photogrammetry and Remote Sensing, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
Hendrik Andersen
Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
Institute of Photogrammetry and Remote Sensing, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
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Related subject area
Subject: Clouds and Precipitation | Research Activity: Remote Sensing | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
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Extensive coverage of ultrathin tropical tropopause layer cirrus clouds revealed by balloon-borne lidar observations
The effects of warm-air intrusions in the high Arctic on cirrus clouds
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Climatologically invariant scale invariance seen in distributions of cloud horizontal sizes
Variability and properties of liquid-dominated clouds over the ice-free and sea-ice-covered Arctic Ocean
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The evolution of deep convective systems and their associated cirrus outflows
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For decades the earth's temperature has been rising. The Arctic regions are warming faster. Cirrus clouds can contribute to this phenomenon. During warm-air intrusions, air masses are transported into the Arctic from the mid-latitudes. The HALO-(AC)3 campaign took place to measure cirrus during intrusion events and under normal conditions. We study the two cloud types based on these measurements and find differences in their geometry, relative humidity distribution and vertical structure.
Huige Di and Yun Yuan
Atmos. Chem. Phys., 24, 5783–5801, https://doi.org/10.5194/acp-24-5783-2024, https://doi.org/10.5194/acp-24-5783-2024, 2024
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We observed the seeder–feeder process among double-layer clouds using a cloud radar and microwave radiometer. By defining the parameters of the seeding depth and seeding time of the upper cloud affecting the lower cloud, we find that the cloud particle terminal velocity is significantly enhanced during the seeder–feeder period, and the lower the height and thinner the thickness of the height difference between double-layer clouds, the lower the height and thicker the thickness of seeding depth.
Kristofer S. Tuftedal, Bernat Puigdomènech Treserras, Mariko Oue, and Pavlos Kollias
Atmos. Chem. Phys., 24, 5637–5657, https://doi.org/10.5194/acp-24-5637-2024, https://doi.org/10.5194/acp-24-5637-2024, 2024
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This study analyzed coastal convective cells from June through September 2018–2021. The cells were classified and their lifecycles were analyzed to better understand their characteristics. Features such as convective-core growth, for example, are shown. The study found differences in the initiation location of shallow convection and in the aerosol loading in deep convective environments. This work provides a foundation for future analyses of convection or other tracked events elsewhere.
Michie Vianca De Vera, Larry Di Girolamo, Guangyu Zhao, Robert M. Rauber, Stephen W. Nesbitt, and Greg M. McFarquhar
Atmos. Chem. Phys., 24, 5603–5623, https://doi.org/10.5194/acp-24-5603-2024, https://doi.org/10.5194/acp-24-5603-2024, 2024
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Tropical oceanic low clouds remain a dominant source of uncertainty in cloud feedback in climate models due to their macrophysical properties (fraction, size, height, shape, distribution) being misrepresented. High-resolution satellite imagery over the Philippine oceans is used here to characterize cumulus macrophysical properties and their relationship to meteorological variables. Such information can act as a benchmark for cloud models and can improve low-cloud generation in climate models.
William K. Jones, Martin Stengel, and Philip Stier
Atmos. Chem. Phys., 24, 5165–5180, https://doi.org/10.5194/acp-24-5165-2024, https://doi.org/10.5194/acp-24-5165-2024, 2024
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Storm clouds cover large areas of the tropics. These clouds both reflect incoming sunlight and trap heat from the atmosphere below, regulating the temperature of the tropics. Over land, storm clouds occur in the late afternoon and evening and so exist both during the daytime and at night. Changes in this timing could upset the balance of the respective cooling and heating effects of these clouds. We find that isolated storms have a larger effect on this balance than their small size suggests.
Shaoyue Qiu, Xue Zheng, David Painemal, Christopher R. Terai, and Xiaoli Zhou
Atmos. Chem. Phys., 24, 2913–2935, https://doi.org/10.5194/acp-24-2913-2024, https://doi.org/10.5194/acp-24-2913-2024, 2024
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The aerosol indirect effect (AIE) depends on cloud states, which exhibit significant diurnal variations in the northeastern Atlantic. Yet the AIE diurnal cycle remains poorly understood. Using satellite retrievals, we find a pronounced “U-shaped” diurnal variation in the AIE, which is contributed to by the transition of cloud states combined with the lagged cloud responses. This suggests that polar-orbiting satellites with overpass times at noon underestimate daytime mean values of the AIE.
Irene Bartolomé García, Odran Sourdeval, Reinhold Spang, and Martina Krämer
Atmos. Chem. Phys., 24, 1699–1716, https://doi.org/10.5194/acp-24-1699-2024, https://doi.org/10.5194/acp-24-1699-2024, 2024
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How many ice crystals of each size are in a cloud is a key parameter for the retrieval of cloud properties. The distribution of ice crystals is obtained from in situ measurements and used to create parameterizations that can be used when analyzing the remote-sensing data. Current parameterizations are based on data sets that do not include reliable measurements of small crystals, but in our study we use a data set that includes very small ice crystals to improve these parameterizations.
Wenyue Wang, Klemens Hocke, Leonardo Nania, Alberto Cazorla, Gloria Titos, Renaud Matthey, Lucas Alados-Arboledas, Agustín Millares, and Francisco Navas-Guzmán
Atmos. Chem. Phys., 24, 1571–1585, https://doi.org/10.5194/acp-24-1571-2024, https://doi.org/10.5194/acp-24-1571-2024, 2024
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The south-central interior of Andalusia experiences complex precipitation patterns as a result of the semi-arid Mediterranean climate and the influence of Saharan dust. This study monitored the inter-relations between aerosols, clouds, meteorological variables, and precipitation systems using ground-based remote sensing and in situ instruments.
Francisco Lang, Steven T. Siems, Yi Huang, Tahereh Alinejadtabrizi, and Luis Ackermann
Atmos. Chem. Phys., 24, 1451–1466, https://doi.org/10.5194/acp-24-1451-2024, https://doi.org/10.5194/acp-24-1451-2024, 2024
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Marine low-level clouds play a crucial role in the Earth's energy balance, trapping heat from the surface and reflecting sunlight back into space. These clouds are distinguishable by their large-scale spatial structures, primarily characterized as hexagonal patterns with either filled (closed) or empty (open) cells. Utilizing satellite observations, these two cloud type patterns have been categorized over the Southern Ocean and North Pacific Ocean through a pattern recognition program.
Julian Hofer, Patric Seifert, J. Ben Liley, Martin Radenz, Osamu Uchino, Isamu Morino, Tetsu Sakai, Tomohiro Nagai, and Albert Ansmann
Atmos. Chem. Phys., 24, 1265–1280, https://doi.org/10.5194/acp-24-1265-2024, https://doi.org/10.5194/acp-24-1265-2024, 2024
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An 11-year dataset of polarization lidar observations from Lauder, New Zealand / Aotearoa, was used to distinguish the thermodynamic phase of natural clouds. The cloud dataset was separated to assess the impact of air mass origin on the frequency of heterogeneous ice formation. Ice formation efficiency in clouds above Lauder was found to be lower than in the polluted Northern Hemisphere midlatitudes but higher than in very clean and pristine environments, such as Punta Arenas in southern Chile.
Hannes Jascha Griesche, Carola Barrientos-Velasco, Hartwig Deneke, Anja Hünerbein, Patric Seifert, and Andreas Macke
Atmos. Chem. Phys., 24, 597–612, https://doi.org/10.5194/acp-24-597-2024, https://doi.org/10.5194/acp-24-597-2024, 2024
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The Arctic is strongly affected by climate change and the role of clouds therein is not yet completely understood. Measurements from the Arctic expedition PS106 were used to simulate radiative fluxes with and without clouds at very low altitudes (below 165 m), and their radiative effect was calculated to be 54 Wm-2. The low heights of these clouds make them hard to observe. This study shows the importance of accurate measurements and simulations of clouds and gives suggestions for improvements.
Thomas D. DeWitt, Timothy J. Garrett, Karlie N. Rees, Corey Bois, Steven K. Krueger, and Nicolas Ferlay
Atmos. Chem. Phys., 24, 109–122, https://doi.org/10.5194/acp-24-109-2024, https://doi.org/10.5194/acp-24-109-2024, 2024
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Viewed from space, a defining feature of Earth's atmosphere is the wide spectrum of cloud sizes. A recent study predicted the distribution of cloud sizes, and this paper compares the prediction to observations. Although there is nuance in viewing perspective, we find robust agreement with theory across different climatological conditions, including land–ocean contrasts, time of year, or latitude, suggesting a minor role for Coriolis forces, aerosol loading, or surface temperature.
Marcus Klingebiel, André Ehrlich, Elena Ruiz-Donoso, Nils Risse, Imke Schirmacher, Evelyn Jäkel, Michael Schäfer, Kevin Wolf, Mario Mech, Manuel Moser, Christiane Voigt, and Manfred Wendisch
Atmos. Chem. Phys., 23, 15289–15304, https://doi.org/10.5194/acp-23-15289-2023, https://doi.org/10.5194/acp-23-15289-2023, 2023
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In this study we explain how we use aircraft measurements from two Arctic research campaigns to identify cloud properties (like droplet size) over sea-ice and ice-free ocean. To make sure that our measurements make sense, we compare them with other observations. Our results show, e.g., larger cloud droplets in early summer than in spring. Moreover, the cloud droplets are also larger over ice-free ocean than compared to sea ice. In the future, our data can be used to improve climate models.
Grégory V. Cesana, Olivia Pierpaoli, Matteo Ottaviani, Linh Vu, and Zhonghai Jin
EGUsphere, https://doi.org/10.5194/egusphere-2023-2940, https://doi.org/10.5194/egusphere-2023-2940, 2023
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Better characterizing the relationship between sea ice and clouds is key to understanding Arctic climate, because clouds and sea ice affect surface radiation and modulate Arctic surface warming. Our results indicate that Arctic liquid clouds robustly increase in response to sea-ice decrease. This increase has a cooling effect on the surface, because more solar radiation is reflected back to space, and it should contribute to dampening future Arctic surface warming.
Pablo Saavedra Garfias, Heike Kalesse-Los, Luisa von Albedyll, Hannes Griesche, and Gunnar Spreen
Atmos. Chem. Phys., 23, 14521–14546, https://doi.org/10.5194/acp-23-14521-2023, https://doi.org/10.5194/acp-23-14521-2023, 2023
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An important Arctic climate process is the release of heat fluxes from sea ice openings to the atmosphere that influence the clouds. The characterization of this process is the objective of this study. Using synergistic observations from the MOSAiC expedition, we found that single-layer cloud properties show significant differences when clouds are coupled or decoupled to the water vapour transport which is used as physical link between the upwind sea ice openings and the cloud under observation.
Matthew D. Lebsock and Mikael Witte
Atmos. Chem. Phys., 23, 14293–14305, https://doi.org/10.5194/acp-23-14293-2023, https://doi.org/10.5194/acp-23-14293-2023, 2023
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This paper evaluates measurements of cloud drop size distributions made from airplanes. We find that as the number of cloud drops increases the distribution of the cloud drop sizes narrows. The data are used to develop a simple equation that relates the drop number to the width of the drop sizes. We then use this equation to demonstrate that existing approaches to observe the drop number from satellites contain errors that can be corrected by including the new relationship.
George Horner and Edward Gryspeerdt
Atmos. Chem. Phys., 23, 14239–14253, https://doi.org/10.5194/acp-23-14239-2023, https://doi.org/10.5194/acp-23-14239-2023, 2023
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Tropical deep convective clouds, and the thin cirrus (ice) clouds that flow out from them, are important for modulating the energy budget of the tropical atmosphere. This work uses a new method to track the evolution of the properties of these clouds across their entire lifetimes. We find these clouds cool the atmosphere in the first 6 h before switching to a warming regime after the deep convective core has dissipated, which is sustained beyond 120 h from the initial convective event.
Rodanthi-Elisavet Mamouri, Albert Ansmann, Kevin Ohneiser, Daniel A. Knopf, Argyro Nisantzi, Johannes Bühl, Ronny Engelmann, Annett Skupin, Patric Seifert, Holger Baars, Dragos Ene, Ulla Wandinger, and Diofantos Hadjimitsis
Atmos. Chem. Phys., 23, 14097–14114, https://doi.org/10.5194/acp-23-14097-2023, https://doi.org/10.5194/acp-23-14097-2023, 2023
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For the first time, rather clear evidence is found that wildfire smoke particles can trigger strong cirrus formation. This finding is of importance because intensive and large wildfires may occur increasingly often in the future as climate change proceeds. Based on lidar observations in Cyprus in autumn 2020, we provide detailed insight into the cirrus formation at the tropopause in the presence of aged wildfire smoke (here, 8–9 day old Californian wildfire smoke).
Peter Manshausen, Duncan Watson-Parris, Matthew W. Christensen, Jukka-Pekka Jalkanen, and Philip Stier
Atmos. Chem. Phys., 23, 12545–12555, https://doi.org/10.5194/acp-23-12545-2023, https://doi.org/10.5194/acp-23-12545-2023, 2023
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Aerosol from burning fuel changes cloud properties, e.g., the number of droplets and the content of water. Here, we study how clouds respond to different amounts of shipping aerosol. Droplet numbers increase linearly with increasing aerosol over a broad range until they stop increasing, while the amount of liquid water always increases, independently of emission amount. These changes in cloud properties can make them reflect more or less sunlight, which is important for the earth's climate.
Hendrik Andersen, Jan Cermak, Alyson Douglas, Timothy A. Myers, Peer Nowack, Philip Stier, Casey J. Wall, and Sarah Wilson Kemsley
Atmos. Chem. Phys., 23, 10775–10794, https://doi.org/10.5194/acp-23-10775-2023, https://doi.org/10.5194/acp-23-10775-2023, 2023
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This study uses an observation-based cloud-controlling factor framework to study near-global sensitivities of cloud radiative effects to a large number of meteorological and aerosol controls. We present near-global sensitivity patterns to selected thermodynamic, dynamic, and aerosol factors and discuss the physical mechanisms underlying the derived sensitivities. Our study hopes to guide future analyses aimed at constraining cloud feedbacks and aerosol–cloud interactions.
Anne-Claire Billault-Roux, Paraskevi Georgakaki, Josué Gehring, Louis Jaffeux, Alfons Schwarzenboeck, Pierre Coutris, Athanasios Nenes, and Alexis Berne
Atmos. Chem. Phys., 23, 10207–10234, https://doi.org/10.5194/acp-23-10207-2023, https://doi.org/10.5194/acp-23-10207-2023, 2023
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Secondary ice production plays a key role in clouds and precipitation. In this study, we analyze radar measurements from a snowfall event in the Jura Mountains. Complex signatures are observed, which reveal that ice crystals were formed through various processes. An analysis of multi-sensor data suggests that distinct ice multiplication processes were taking place. Both the methods used and the insights gained through this case study contribute to a better understanding of snowfall microphysics.
Rebecca J. Murray-Watson, Edward Gryspeerdt, and Tom Goren
Atmos. Chem. Phys., 23, 9365–9383, https://doi.org/10.5194/acp-23-9365-2023, https://doi.org/10.5194/acp-23-9365-2023, 2023
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Clouds formed in Arctic marine cold air outbreaks undergo a distinct evolution, but the factors controlling their transition from high-coverage to broken cloud fields are poorly understood. We use satellite and reanalysis data to study how these clouds develop in time and the different influences on their evolution. The aerosol concentration is correlated with cloud break-up; more aerosol is linked to prolonged coverage and a stronger cooling effect, with implications for a more polluted Arctic.
Michael S. Diamond
Atmos. Chem. Phys., 23, 8259–8269, https://doi.org/10.5194/acp-23-8259-2023, https://doi.org/10.5194/acp-23-8259-2023, 2023
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Fuel sulfur regulations were implemented for ships in 2020 to improve air quality but may also accelerate global warming. We use spatial statistics and satellite retrievals to detect changes in the size of cloud droplets and find evidence for a resulting decrease in cloud brightness within a major shipping corridor after the sulfur limits went into effect. Our results confirm both that the regulations are being followed and that they are having a warming influence via their effect on clouds.
Hao Luo, Johannes Quaas, and Yong Han
Atmos. Chem. Phys., 23, 8169–8186, https://doi.org/10.5194/acp-23-8169-2023, https://doi.org/10.5194/acp-23-8169-2023, 2023
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Clouds exhibit a wide range of vertical structures with varying microphysical and radiative properties. We show a global survey of spatial distribution, vertical extent and radiative effect of various classified cloud vertical structures using joint satellite observations from the new CCCM datasets during 2007–2010. Moreover, the long-term trends in CVSs are investigated based on different CMIP6 future scenarios to capture the cloud variations with different, increasing anthropogenic forcings.
Gregor Köcher, Tobias Zinner, and Christoph Knote
Atmos. Chem. Phys., 23, 6255–6269, https://doi.org/10.5194/acp-23-6255-2023, https://doi.org/10.5194/acp-23-6255-2023, 2023
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Polarimetric radar observations of 30 d of convective precipitation events are used to statistically analyze 5 state-of-the-art microphysics schemes of varying complexity. The frequency and area of simulated heavy-precipitation events are in some cases significantly different from those observed, depending on the microphysics scheme. Analysis of simulated particle size distributions and reflectivities shows that some schemes have problems reproducing the correct particle size distributions.
Claudia J. Stubenrauch, Giulio Mandorli, and Elisabeth Lemaitre
Atmos. Chem. Phys., 23, 5867–5884, https://doi.org/10.5194/acp-23-5867-2023, https://doi.org/10.5194/acp-23-5867-2023, 2023
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Organized convection leads to large convective cloud systems and intense rain and may change with a warming climate. Their complete 3D description, attained by machine learning techniques in combination with various satellite observations, together with a cloud system concept, link convection to anvil properties, while convective organization can be identified by the horizontal structure of intense rain.
Scott E. Giangrande, Thiago S. Biscaro, and John M. Peters
Atmos. Chem. Phys., 23, 5297–5316, https://doi.org/10.5194/acp-23-5297-2023, https://doi.org/10.5194/acp-23-5297-2023, 2023
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Our study tracks thunderstorms observed during the wet and dry seasons of the Amazon Basin using weather radar. We couple this precipitation tracking with opportunistic overpasses of a wind profiler and other ground observations to add unique insights into the upwards and downwards air motions within these clouds at various stages in the storm life cycle. The results of a simple updraft model are provided to give physical explanations for observed seasonal differences.
Edward Gryspeerdt, Adam C. Povey, Roy G. Grainger, Otto Hasekamp, N. Christina Hsu, Jane P. Mulcahy, Andrew M. Sayer, and Armin Sorooshian
Atmos. Chem. Phys., 23, 4115–4122, https://doi.org/10.5194/acp-23-4115-2023, https://doi.org/10.5194/acp-23-4115-2023, 2023
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The impact of aerosols on clouds is one of the largest uncertainties in the human forcing of the climate. Aerosol can increase the concentrations of droplets in clouds, but observational and model studies produce widely varying estimates of this effect. We show that these estimates can be reconciled if only polluted clouds are studied, but this is insufficient to constrain the climate impact of aerosol. The uncertainty in aerosol impact on clouds is currently driven by cases with little aerosol.
Zackary Mages, Pavlos Kollias, Zeen Zhu, and Edward P. Luke
Atmos. Chem. Phys., 23, 3561–3574, https://doi.org/10.5194/acp-23-3561-2023, https://doi.org/10.5194/acp-23-3561-2023, 2023
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Cold-air outbreaks (when cold air is advected over warm water and creates low-level convection) are a dominant cloud regime in the Arctic, and we capitalized on ground-based observations, which did not previously exist, from the COMBLE field campaign to study them. We characterized the extent and strength of the convection and turbulence and found evidence of secondary ice production. This information is useful for model intercomparison studies that will represent cold-air outbreak processes.
Maria P. Cadeddu, Virendra P. Ghate, David D. Turner, and Thomas E. Surleta
Atmos. Chem. Phys., 23, 3453–3470, https://doi.org/10.5194/acp-23-3453-2023, https://doi.org/10.5194/acp-23-3453-2023, 2023
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We analyze the variability in marine boundary layer moisture at the Eastern North Atlantic site on a monthly and daily temporal scale and examine its fundamental role in the control of boundary layer cloudiness and precipitation. The study also highlights the complex interaction between large-scale and local processes controlling the boundary layer moisture and the importance of the mesoscale spatial distribution of vapor to support convection and precipitation.
Zhenquan Wang, Jian Yuan, Robert Wood, Yifan Chen, and Tiancheng Tong
Atmos. Chem. Phys., 23, 3247–3266, https://doi.org/10.5194/acp-23-3247-2023, https://doi.org/10.5194/acp-23-3247-2023, 2023
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This study develops a novel profile-based algorithm based on the ERA5 to estimate the inversion strength in the planetary boundary layer better than the previous inversion index, which is a key low-cloud-controlling factor. This improved measure is more effective at representing the meteorological influence on low-cloud variations. It can better constrain the meteorological influence on low clouds to better isolate cloud responses to aerosols or to estimate low cloud feedbacks in climate models.
Georgios Dekoutsidis, Silke Groß, Martin Wirth, Martina Krämer, and Christian Rolf
Atmos. Chem. Phys., 23, 3103–3117, https://doi.org/10.5194/acp-23-3103-2023, https://doi.org/10.5194/acp-23-3103-2023, 2023
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Cirrus clouds affect Earth's atmosphere, deeming our study important. Here we use water vapor measurements by lidar and study the relative humidity (RHi) within and around midlatitude cirrus clouds. We find high supersaturations in the cloud-free air and within the clouds, especially near the cloud top. We study two cloud types with different formation processes. Finally, we conclude that the shape of the distribution of RHi can be used as an indicator of different cloud evolutionary stages.
Huazhe Shang, Souichiro Hioki, Guillaume Penide, Céline Cornet, Husi Letu, and Jérôme Riedi
Atmos. Chem. Phys., 23, 2729–2746, https://doi.org/10.5194/acp-23-2729-2023, https://doi.org/10.5194/acp-23-2729-2023, 2023
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We find that cloud profiles can be divided into four prominent patterns, and the frequency of these four patterns is related to intensities of cloud-top entrainment and precipitation. Based on these analyses, we further propose a cloud profile parameterization scheme allowing us to represent these patterns. Our results shed light on how to facilitate the representation of cloud profiles and how to link them to cloud entrainment or precipitating status in future remote-sensing applications.
Luca Lelli, Marco Vountas, Narges Khosravi, and John Philipp Burrows
Atmos. Chem. Phys., 23, 2579–2611, https://doi.org/10.5194/acp-23-2579-2023, https://doi.org/10.5194/acp-23-2579-2023, 2023
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Arctic amplification describes the recent period in which temperatures have been rising twice as fast as or more than the global average and sea ice and the Greenland ice shelf are approaching a tipping point. Hence, the Arctic ability to reflect solar energy decreases and absorption by the surface increases. Using 2 decades of complementary satellite data, we discover that clouds unexpectedly increase the pan-Arctic reflectance by increasing their liquid water content, thus cooling the Arctic.
Yabin Gou, Haonan Chen, Hong Zhu, and Lulin Xue
Atmos. Chem. Phys., 23, 2439–2463, https://doi.org/10.5194/acp-23-2439-2023, https://doi.org/10.5194/acp-23-2439-2023, 2023
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This article investigates the complex precipitation microphysics associated with super typhoon Lekima using a host of in situ and remote sensing observations, including rain gauge and disdrometer data, as well as polarimetric radar observations. The impacts of precipitation microphysics on multi-source data consistency and radar precipitation estimation are quantified. It is concluded that the dynamical precipitation microphysical processes must be considered in radar precipitation estimation.
Hongxia Zhu, Rui Li, Shuping Yang, Chun Zhao, Zhe Jiang, and Chen Huang
Atmos. Chem. Phys., 23, 2421–2437, https://doi.org/10.5194/acp-23-2421-2023, https://doi.org/10.5194/acp-23-2421-2023, 2023
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The impacts of atmospheric dust aerosols and cloud dynamic conditions on precipitation vertical development in southeastern China were studied using multiple satellite observations. It was found that the precipitating drops under dusty conditions grow faster in the middle layer but slower in the upper and lower layers compared with their pristine counterparts. Quantitative estimation of the sensitivity of the precipitation top temperature to the dust aerosol optical depth is also provided.
Zane Dedekind, Jacopo Grazioli, Philip H. Austin, and Ulrike Lohmann
Atmos. Chem. Phys., 23, 2345–2364, https://doi.org/10.5194/acp-23-2345-2023, https://doi.org/10.5194/acp-23-2345-2023, 2023
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Simulations allowing ice particles to collide with one another producing more ice particles represented surface observations of ice particles accurately. An increase in ice particles formed through collisions was related to sharp changes in the wind direction and speed with height. Changes in wind speed and direction can therefore cause more enhanced collisions between ice particles and alter how fast and how much precipitation forms. Simulations were conducted with the atmospheric model COSMO.
Ramon Padullés, Estel Cardellach, and F. Joseph Turk
Atmos. Chem. Phys., 23, 2199–2214, https://doi.org/10.5194/acp-23-2199-2023, https://doi.org/10.5194/acp-23-2199-2023, 2023
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The results of comparing the polarimetric radio occultation observables and the ice water content retrieved from the CloudSat radar in a global and statistical way show a strong correlation between the geographical patterns of both quantities for a wide range of heights. This implies that horizontally oriented hydrometeors are systematically present through the whole globe and through all vertical levels, which could provide insights on the physical processes leading to precipitation.
Ziming Wang, Luca Bugliaro, Tina Jurkat-Witschas, Romy Heller, Ulrike Burkhardt, Helmut Ziereis, Georgios Dekoutsidis, Martin Wirth, Silke Groß, Simon Kirschler, Stefan Kaufmann, and Christiane Voigt
Atmos. Chem. Phys., 23, 1941–1961, https://doi.org/10.5194/acp-23-1941-2023, https://doi.org/10.5194/acp-23-1941-2023, 2023
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Differences in the microphysical properties of contrail cirrus and natural cirrus in a contrail outbreak situation during the ML-CIRRUS campaign over the North Atlantic flight corridor can be observed from in situ measurements. The cirrus radiative effect in the area of the outbreak, derived from satellite observation-based radiative transfer modeling, is warming in the early morning and cooling during the day.
Gerald G. Mace, Sally Benson, Ruhi Humphries, Peter M. Gombert, and Elizabeth Sterner
Atmos. Chem. Phys., 23, 1677–1685, https://doi.org/10.5194/acp-23-1677-2023, https://doi.org/10.5194/acp-23-1677-2023, 2023
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The number of cloud droplets per unit volume is a significantly important property of clouds that controls their reflective properties. Computer models of the Earth's atmosphere and climate have low skill at predicting the reflective properties of Southern Ocean clouds. Here we investigate the properties of those clouds using satellite data and find that the cloud droplet number and cloud albedo in the Southern Ocean are related to the oceanic phytoplankton abundance near Antarctica.
Jianhao Zhang and Graham Feingold
Atmos. Chem. Phys., 23, 1073–1090, https://doi.org/10.5194/acp-23-1073-2023, https://doi.org/10.5194/acp-23-1073-2023, 2023
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Using observations from space, we show maps of potential brightness changes in marine warm clouds in response to increases in cloud droplet concentrations. The environmental and aerosol conditions in which these clouds reside covary differently in each ocean basin, leading to distinct evolutions of cloud brightness changes. This work stresses the central importance of the covariability between meteorology and aerosol for scaling up the radiative response of cloud brightness changes.
Yuxin Zhao, Jiming Li, Lijie Zhang, Cong Deng, Yarong Li, Bida Jian, and Jianping Huang
Atmos. Chem. Phys., 23, 743–769, https://doi.org/10.5194/acp-23-743-2023, https://doi.org/10.5194/acp-23-743-2023, 2023
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Diurnal variations of clouds play an important role in the radiative budget and precipitation. Based on satellite observations, reanalysis, and CMIP6 outputs, the diurnal variations in total cloud cover and cloud vertical distribution over the Tibetan Plateau are explored. The diurnal cycle of cirrus is a key focus and found to have different characteristics from those found in the tropics. The relationship between the diurnal cycle of cirrus and meteorological factors is also discussed.
Qiang Li and Silke Groß
Atmos. Chem. Phys., 22, 15963–15980, https://doi.org/10.5194/acp-22-15963-2022, https://doi.org/10.5194/acp-22-15963-2022, 2022
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The IPCC report identified that cirrus clouds have a significant impact on the radiation balance comparable to the CO2 effects, which, however, is still hard to parameterize. The current study investigates the possible impact of aviation on cirrus properties based on the analysis of 10-year lidar measurements of CALIPSO. The results reveal that there is a significant positive trend in cirrus depolarization ratio in the last 10 years before COVID-19, which is strongly correlated with aviation.
Linda Forster and Bernhard Mayer
Atmos. Chem. Phys., 22, 15179–15205, https://doi.org/10.5194/acp-22-15179-2022, https://doi.org/10.5194/acp-22-15179-2022, 2022
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We present a novel retrieval using ground-based imaging observations of halo displays together with radiative transfer simulations to help improve our understanding of ice crystal properties representative of cirrus clouds. Analysis of 4400 calibrated HaloCam images featuring a 22° halo revealed aggregates of hexagonal columns of 20 µm effective radius with a mixture of about 37 % smooth and 63% severely roughened surfaces as the best match in general.
Yun He, Zhenping Yin, Fuchao Liu, and Fan Yi
Atmos. Chem. Phys., 22, 13067–13085, https://doi.org/10.5194/acp-22-13067-2022, https://doi.org/10.5194/acp-22-13067-2022, 2022
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A method is proposed to identify the sole presence of heterogeneous nucleation and competition between heterogeneous and homogeneous nucleation for dust-related cirrus clouds by characterizing the relationship between dust ice-nucleating particle concentration calculated from CALIOP using the POLIPHON method and in-cloud ice crystal number concentration from the DARDAR-Nice dataset. Two typical cirrus cases are shown as a demonstration, and the proposed method can be extended to a global scale.
Frederic Tridon, Israel Silber, Alessandro Battaglia, Stefan Kneifel, Ann Fridlind, Petros Kalogeras, and Ranvir Dhillon
Atmos. Chem. Phys., 22, 12467–12491, https://doi.org/10.5194/acp-22-12467-2022, https://doi.org/10.5194/acp-22-12467-2022, 2022
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The role of ice precipitation in the Earth water budget is not well known because ice particles are complex, and their formation involves intricate processes. Riming of ice crystals by supercooled water droplets is an efficient process, but little is known about its importance at high latitudes. In this work, by exploiting the deployment of an unprecedented number of remote sensing systems in Antarctica, we find that riming occurs at much lower temperatures compared with the mid-latitudes.
Cited articles
Adebiyi, A. A. and Zuidema, P.: The role of the southern African easterly jet
in modifying the southeast Atlantic aerosol and cloud environments,
Q. J. Roy. Meteor. Soc., 142, 1574–1589,
https://doi.org/10.1002/qj.2765,
2016. a, b
Adebiyi, A. A., Zuidema, P., and Abel, S. J.: The Convolution of Dynamics and
Moisture with the Presence of Shortwave Absorbing Aerosols over the Southeast
Atlantic, J. Climate, 28, 1997–2024,
https://doi.org/10.1175/JCLI-D-14-00352.1,
2015. a, b
Albrecht, B. A.: Aerosols, Cloud Microphysics, and Fractional Cloudiness,
Science, 245, 1227–1230, https://doi.org/10.1126/science.245.4923.1227,
1989. a, b
Andersen, H. and Cermak, J.: How thermodynamic environments control
stratocumulus microphysics and interactions with aerosols, Environ.
Res. Lett., 10, 024004, https://doi.org/10.1088/1748-9326/10/2/024004,
2015. a, b
Andersen, H., Cermak, J., Fuchs, J., and Schwarz, K.: Global observations of
cloud-sensitive aerosol loadings in low-level marine clouds, J.
Geophys. Res.-Atmos., 121, 12936–12946,
https://doi.org/10.1002/2016JD025614, 2016. a
Andersen, H., Cermak, J., Fuchs, J., Knutti, R., and Lohmann, U.:
Understanding the drivers of marine liquid-water cloud occurrence and
properties with global observations using neural networks, Atmos. Chem.
Phys., 17, 9535–9546, https://doi.org/10.5194/acp-17-9535-2017, 2017. a, b, c
Andreae, M. and Rosenfeld, D.: Aerosol-cloud-precipitation interactions. Part
1. The nature and sources of cloud-active aerosols, Earth-Sci. Rev.,
89, 13–41, https://doi.org/10.1016/j.earscirev.2008.03.001, 2008. a
Bond, T. C., Doherty, S. J., Fahey, D. W., Forster, P. M., Berntsen, T.,
DeAngelo, B. J., Flanner, M. G., Ghan, S., Kärcher, B., Koch, D.,
Kinne, S., Kondo, Y., Quinn, P. K., Sarofim, M. C., Schultz, M. G., Schulz,
M., Venkataraman, C., Zhang, H., Zhang, S., Bellouin, N., Guttikunda, S. K.,
Hopke, P. K., Jacobson, M. Z., Kaiser, J. W., Klimont, Z., Lohmann, U.,
Schwarz, J. P., Shindell, D., Storelvmo, T., Warren, S. G., and Zender,
C. S.: Bounding the role of black carbon in the climate system: A scientific
assessment, J. Geophys. Res.-Atmos., 118, 5380–5552,
https://doi.org/10.1002/jgrd.50171, 2013. a
Bony, S. and Dufresne, J.-L.: Marine boundary layer clouds at the heart of
tropical cloud feedback uncertainties in climate models, Geophys.
Res. Lett., 32, L20806, https://doi.org/10.1029/2005GL023851, 2005. a
Boucher, O., Randall, D., Artaxo, P., Bretherton, C., Feingold, G., Forster,
P., Kerminen, V.-M., Kondo, Y., Liao, H., Lohmann, U., Rasch, P., Satheesh,
S. K., Sherwood, S., Stevens, B., Zhang, X. Y., and Zhan, X. Y.: Clouds and
Aerosols, in: Climate Change 2013 – The Physical Science Basis, edited
by:
Intergovernmental Panel on Climate Change, 7, 571–658, Cambridge
University Press, Cambridge, https://doi.org/10.1017/CBO9781107415324.016,
2013. a
Bretherton, C. S. and Wyant, M. C.: Moisture Transport, Lower-Tropospheric
Stability, and Decoupling of Cloud-Topped Boundary Layers, J.
Atmos. Sci., 54, 148–167,
https://doi.org/10.1175/1520-0469(1997)054<0148:MTLTSA>2.0.CO;2,
1997. a
Bretherton, C. S., Blossey, P. N., and Jones, C. R.: Mechanisms of marine low
cloud sensitivity to idealized climate perturbations: A single-LES
exploration extending the CGILS cases, J. Adv. Model. Earth Sy., 5, 316–337, https://doi.org/10.1002/jame.20019, 2013. a, b
Brueck, M., Nuijens, L., and Stevens, B.: On the Seasonal and Synoptic
Time-Scale Variability of the North Atlantic Trade Wind Region and Its
Low-Level Clouds, J. Atmos. Sci., 72, 1428–1446,
https://doi.org/10.1175/JAS-D-14-0054.1,
2015. a, b
Carslaw, D. C. and Taylor, P. J.: Analysis of air pollution data at a mixed
source location using boosted regression trees, Atmos. Environ., 43,
3563–3570, https://doi.org/10.1016/j.atmosenv.2009.04.001, 2009. a
Chand, D., Wood, R., Anderson, T. L., Satheesh, S. K., and Charlson, R. J.:
Satellite-derived direct radiative effect of aerosols dependent on cloud
cover, Nat. Geosci., 2, 181–184, https://doi.org/10.1038/ngeo437, 2009. a
Chen, Y.-C., Christensen, M. W., Stephens, G. L., and Seinfeld, J. H.:
Satellite-based estimate of global aerosol-cloud radiative forcing by marine
warm clouds, Nat. Geosci., 7, 643–646, https://doi.org/10.1038/ngeo2214, 2014. a, b, c
Christensen, M. W., Neubauer, D., Poulsen, C. A., Thomas, G. E., McGarragh,
G. R., Povey, A. C., Proud, S. R., and Grainger, R. G.: Unveiling
aerosol-cloud interactions – Part 1: Cloud contamination in satellite
products enhances the aerosol indirect forcing estimate, Atmos. Chem. Phys.,
17, 13151–13164, https://doi.org/10.5194/acp-17-13151-2017, 2017. a
Costantino, L. and Bréon, F.-M.: Aerosol indirect effect on warm clouds
over South-East Atlantic, from co-located MODIS and CALIPSO observations,
Atmos. Chem. Phys., 13, 69–88, https://doi.org/10.5194/acp-13-69-2013, 2013. a
de Szoeke, S. P., Verlinden, K. L., Yuter, S. E., and Mechem, D. B.: The time
scales of variability of marine low clouds, J. Climate, 29,
6463–6481, https://doi.org/10.1175/JCLI-D-15-0460.1, 2016. a, b, c
Dee, D. P., Uppala, S. M., Simmons, A. J., Berrisford, P., Poli, P.,
Kobayashi, S., Andrae, U., Balmaseda, M. A., Balsamo, G., Bauer, P.,
Bechtold, P., Beljaars, A. C. M., van de Berg, L., Bidlot, J., Bormann, N.,
Delsol, C., Dragani, R., Fuentes, M., Geer, A. J., Haimberger, L., Healy, S.
B., Hersbach, H., Hólm, E. V., Isaksen, L., Kållberg, P., Köhler,
M., Matricardi, M., McNally, A. P., Monge-Sanz, B. M., Morcrette, J.-J.,
Park, B.-K., Peubey, C., de Rosnay, P., Tavolato, C., Thépaut, J.-N., and
Vitart, F.: The ERA-Interim reanalysis: configuration and performance of the
data assimilation system. Q. J. Roy. Meteorol. Soc., 137, 553–597,
https://doi.org/10.1002/qj.828, 2011.
Eastman, R., Wood, R., and Bretherton, C. S.: Time Scales of Clouds and
Cloud-Controlling Variables in Subtropical Stratocumulus from a Lagrangian
Perspective, J. Atmos. Sci., 73, 3079–3091,
https://doi.org/10.1175/JAS-D-16-0050.1,
2016. a
Engström, A. and Ekman, A. M. L.: Impact of meteorological factors on
the correlation between aerosol optical depth and cloud fraction,
Geophys. Res. Lett., 37, L18814, https://doi.org/10.1029/2010GL044361, 2010. a
Fan, J., Wang, Y., Rosenfeld, D., Liu, X., Fan, J., Wang, Y., Rosenfeld, D.,
and Liu, X.: Review of Aerosol-Cloud Interactions: Mechanisms, Significance,
and Challenges, J. Atmos. Sci., 73, 4221–4252,
https://doi.org/10.1175/JAS-D-16-0037.1,
2016. a, b
Friedman, J. H.: Greedy function approximation: A gradient boosting machine,
Ann. Stat., 29, 1189–1232, https://doi.org/10.1214/aos/1013203451, 2001. a, b, c
Grandey, B. S., Stier, P., and Wagner, T. M.: Investigating relationships
between aerosol optical depth and cloud fraction using satellite, aerosol
reanalysis and general circulation model data, Atmos. Chem. Phys., 13,
3177–3184, https://doi.org/10.5194/acp-13-3177-2013, 2013. a
Gryspeerdt, E., Quaas, J., and Bellouin, N.: Constraining the aerosol
influence on cloud fraction, J. Geophys. Res.-Atmos.,
121, 3566–3583, https://doi.org/10.1002/2015JD023744, 2016. a
Hastie, T., Tibshirani, R., and Friedman, J.: The Elements of Statistical
Learning, Springer Series in Statistics, Springer New York, New York, 2
edn., https://doi.org/10.1007/978-0-387-84858-7, 2009. a
Haywood, J. M., Osborne, S. R., and Abel, S. J.: The effect of overlying
absorbing aerosol layers on remote sensing retrievals of cloud effective
radius and cloud optical depth, Q. J. Roy.
Meteor. Soc., 130, 779–800, https://doi.org/10.1256/qj.03.100, 2004. a
Hubanks, P., King, M., Platnick, S., and Pincus, R.: MODIS Atmosphere L3
Gridded Product Algorithm Theoretical Basis Document No. ATBD-MOD-30 for
Level-3 Global Gridded Atmosphere Products (08_D3, 08_E3, 08_M3) and
Users Guide,
available at: https://modis-atmos.gsfc.nasa.gov/sites/default/files/ModAtmo/L3_ATBD_C6_2018_04_11.pdf (last access: 19 November 2018), 2018. a
Huber, P. J.: Robust Estimation of a Location Parameter, Ann.
Math. Stat., 35, 73–101, https://doi.org/10.1214/aoms/1177703732, 1964. a
Johnson, B. T., Shine, K. P., and Forster, P. M.: The semi-direct aerosol
effect: Impact of absorbing aerosols on marine stratocumulus, Q.
J. Roy. Meteor. Soc., 130, 1407–1422,
https://doi.org/10.1256/qj.03.61, 2004. a
Jones, C. R., Bretherton, C. S., and Blossey, P. N.: Fast stratocumulus time
scale in mixed layer model and large eddy simulation, J. Adv. Model. Earth Sy., 6, 206–222, https://doi.org/10.1002/2013MS000289,
2014. a, b, c, d
Kaufman, Y., Remer, L., Tanre, D., Rong-Rong Li, Kleidman, R., Mattoo, S.,
Levy, R., Eck, T., Holben, B., Ichoku, C., Martins, J., and Koren, I.: A
critical examination of the residual cloud contamination and diurnal sampling
effects on MODIS estimates of aerosol over ocean, IEEE T.
Geosci. Remote, 43, 2886–2897,
https://doi.org/10.1109/TGRS.2005.858430, 2005. a
Kaufman, Y. J.: Dust transport and deposition observed from the Terra-Moderate
Resolution Imaging Spectroradiometer (MODIS) spacecraft over the Atlantic
Ocean, J. Geophys. Res., 110, D10S12,
https://doi.org/10.1029/2003JD004436, 2005. a
Kaufman, Y. J.: Smoke and Pollution Aerosol Effect on Cloud Cover, Science,
313, 655–658, https://doi.org/10.1126/science.1126232,
2006. a
Kazil, J., Feingold, G., and Yamaguchi, T.: Wind speed response of marine
non-precipitating stratocumulus clouds over a diurnal cycle in cloud-system
resolving simulations, Atmos. Chem. Phys., 16, 5811–5839,
https://doi.org/10.5194/acp-16-5811-2016, 2016. a
Klein, S. A.: Synoptic Variability of Low-Cloud Properties and Meteorological
Parameters in the Subtropical Trade Wind Boundary Layer, J. Climate,
10, 2018–2039, https://doi.org/10.1175/1520-0442(1997)010<2018:SVOLCP>2.0.CO;2,
1997. a, b
Klein, S. A., Hartmann, D. L., and Norris, J. R.: On the Relationships among
Low-Cloud Structure, Sea Surface Temperature, and Atmospheric Circulation in
the Summertime Northeast Pacific, J. Climate, 8, 1140–1155,
https://doi.org/10.1175/1520-0442(1995)008<1140:OTRALC>2.0.CO;2,
1995. a, b, c
Lacagnina, C. and Selten, F.: A novel diagnostic technique to investigate
cloud-controlling factors, J. Geophys. Res.-Atmos.,
118, 5979–5991, https://doi.org/10.1002/jgrd.50511, 2013. a
Levy, R. C., Mattoo, S., Munchak, L. A., Remer, L. A., Sayer, A. M., Patadia,
F., and Hsu, N. C.: The Collection 6 MODIS aerosol products over land and
ocean, Atmos. Meas. Tech., 6, 2989–3034,
https://doi.org/10.5194/amt-6-2989-2013, 2013. a
Li, J., Von Salzen, K., Peng, Y., Zhang, H., and Liang, X. Z.: Evaluation of
black carbon semi-direct radiative effect in a climate model, J.
Geophys. Res.-Atmos., 118, 4715–4728, https://doi.org/10.1002/jgrd.50327,
2013. a, b, c
Mauger, G. S. and Norris, J. R.: Meteorological bias in satellite estimates of
aerosol-cloud relationships, Geophys. Res. Lett., 34, L16824,
https://doi.org/10.1029/2007GL029952, 2007. a, b, c
Mauger, G. S. and Norris, J. R.: Assessing the Impact of Meteorological
History on Subtropical Cloud Fraction, J. Climate, 23, 2926–2940,
https://doi.org/10.1175/2010JCLI3272.1,
2010. a, b
McCoy, D. T., Eastman, R., Hartmann, D. L., and Wood, R.: The change in low
cloud cover in a warmed climate inferred from AIRS, MODIS, and ERA-interim,
J. Climate, 30, 3609–3620, https://doi.org/10.1175/JCLI-D-15-0734.1, 2017. a, b, c
Medeiros, B., Stevens, B., Held, I. M., Zhao, M., Williamson, D. L., Olson,
J. G., and Bretherton, C. S.: Aquaplanets, Climate Sensitivity, and Low
Clouds, J. Climate, 21, 4974–4991, https://doi.org/10.1175/2008JCLI1995.1,
2008. a
Muhlbauer, A., McCoy, I. L., and Wood, R.: Climatology of stratocumulus cloud
morphologies: microphysical properties and radiative effects, Atmos. Chem.
Phys., 14, 6695–6716, https://doi.org/10.5194/acp-14-6695-2014, 2014. a
Myers, T. A. and Norris, J. R.: Observational evidence that enhanced
subsidence reduces subtropical marine boundary layer cloudiness, J.
Climate, 26, 7507–7524, https://doi.org/10.1175/JCLI-D-12-00736.1, 2013. a, b
Natekin, A. and Knoll, A.: Gradient boosting machines, a tutorial, Front.
Neurorobotics, 7, 21, https://doi.org/10.3389/fnbot.2013.00021,
2013. a, b
Norris, J. R. and Iacobellis, S. F.: North Pacific cloud feedbacks inferred
from synoptic-scale dynamic and thermodynamic relationships, J.
Climate, 18, 4862–4878, https://doi.org/10.1175/JCLI3558.1, 2005. a
Painemal, D. and Zuidema, P.: Microphysical variability in southeast Pacific
Stratocumulus clouds: synoptic conditions and radiative response, Atmos.
Chem. Phys., 10, 6255–6269, https://doi.org/10.5194/acp-10-6255-2010, 2010. a
Painemal, D., Kato, S., and Minnis, P.: Boundary layer regulation in the
southeast Atlantic cloud microphysics during the biomass burning season as
seen by the A-train satellite constellation, J. Geophys.
Res.-Atmos., 119, 11288–11302, https://doi.org/10.1002/2014JD022182, 2014. a, b, c
Pedregosa, F., Varoquaux, G., Gramfort, A., Michel, V., Thirion, B., Grisel,
O., Blondel, M., Louppe, G., Prettenhofer, P., Weiss, R., Dubourg, V.,
Vanderplas, J., Passos, A., Cournapeau, D., Brucher, M., Perrot, M., and
Duchesnay, É.: Scikit-learn: Machine Learning in Python, J. Mach. Learn. Res., 12, 2825–2830, https://doi.org/10.1007/s13398-014-0173-7.2, 2011. a, b
Platnick, S. and Twomey, S.: Determining the Susceptibility of Cloud Albedo to
Changes in Droplet Concentration with the Advanced Very High Resolution
Radiometer, J. Appl. Meteorol., 33, 334–347,
https://doi.org/10.1175/1520-0450(1994)033<0334:DTSOCA>2.0.CO;2,
1994. a
Quaas, J., Boucher, O., Bellouin, N., and Kinne, S.: Satellite-based estimate
of the direct and indirect aerosol climate forcing, J. Geophys.
Res.-Atmos., 113, D05204, https://doi.org/10.1029/2007JD008962, 2008. a
Quaas, J., Stevens, B., Stier, P., and Lohmann, U.: Interpreting the cloud
cover – aerosol optical depth relationship found in satellite data using a
general circulation model, Atmos. Chem. Phys., 10, 6129–6135,
https://doi.org/10.5194/acp-10-6129-2010, 2010. a, b
Rahn, D. A. and Garreaud, R.: Marine boundary layer over the subtropical
southeast Pacific during VOCALS-REx – Part 2: Synoptic variability, Atmos.
Chem. Phys., 10, 4507–4519, https://doi.org/10.5194/acp-10-4507-2010, 2010. a
Sayegh, A., Tate, J. E., and Ropkins, K.: Understanding how roadside
concentrations of NOx are influenced by the background levels, traffic
density, and meteorological conditions using Boosted Regression Trees,
Atmos. Environ., 127, 163–175, https://doi.org/10.1016/j.atmosenv.2015.12.024, 2016.
a
Seinfeld, J. H., Bretherton, C., Carslaw, K. S., Coe, H., DeMott, P. J.,
Dunlea, E. J., Feingold, G., Ghan, S., Guenther, A. B., Kahn, R., Kraucunas,
I., Kreidenweis, S. M., Molina, M. J., Nenes, A., Penner, J. E., Prather,
K. A., Ramanathan, V., Ramaswamy, V., Rasch, P. J., Ravishankara, A. R.,
Rosenfeld, D., Stephens, G., and Wood, R.: Improving our fundamental
understanding of the role of aerosol-cloud interactions in the climate
system, P. Natl. Acad. Sci. USA, 113, 5781–5790,
https://doi.org/10.1073/pnas.1514043113, 2016. a
Stier, P.: Limitations of passive remote sensing to constrain global cloud
condensation nuclei, Atmos. Chem. Phys., 16, 6595–6607,
https://doi.org/10.5194/acp-16-6595-2016, 2016. a
Toniazzo, T., Abel, S. J., Wood, R., Mechoso, C. R., Allen, G., and Shaffrey,
L. C.: Large-scale and synoptic meteorology in the south-east Pacific during
the observations campaign VOCALS-REx in austral Spring 2008, Atmos. Chem.
Phys., 11, 4977–5009, https://doi.org/10.5194/acp-11-4977-2011, 2011. a, b
Twomey, S.: Pollution and the planetary albedo, Atmos. Environ., 8,
1251–1256, https://doi.org/10.1016/0004-6981(74)90004-3, 1974. a
Várnai, T., Marshak, A., and Yang, W.: Multi-satellite aerosol
observations in the vicinity of clouds, Atmos. Chem. Phys., 13, 3899–3908,
https://doi.org/10.5194/acp-13-3899-2013, 2013. a
Wilcox, E. M.: Stratocumulus cloud thickening beneath layers of absorbing
smoke aerosol, Atmos. Chem. Phys., 10, 11769–11777,
https://doi.org/10.5194/acp-10-11769-2010, 2010. a
Winker, D. M., Vaughan, M. A., Omar, A., Hu, Y., Powell, K. A., Liu, Z.,
Hunt, W. H., and Young, S. A.: Overview of the CALIPSO mission and CALIOP
data processing algorithms, J. Atmos. Ocean. Tech., 26, 2310–2323,
https://doi.org/10.1175/2009JTECHA1281.1, 2009.
Wood, R.: Stratocumulus Clouds, Mon. Weather Rev., 140, 2373–2423,
https://doi.org/10.1175/MWR-D-11-00121.1,
2012. a, b, c
Wood, R. and Bretherton, C. S.: On the Relationship between Stratiform Low
Cloud Cover and Lower-Tropospheric Stability, J. Climate, 19,
6425–6432, https://doi.org/10.1175/JCLI3988.1, 2006. a
Yamaguchi, T. and Randall, D. A.: Large-Eddy Simulation of Evaporatively
Driven Entrainment in Cloud-Topped Mixed Layers, J. Atmos.
Sci., 65, 1481–1504, https://doi.org/10.1175/2007JAS2438.1,
2008. a
Zhang, Y., Stevens, B., Medeiros, B., and Ghil, M.: Low-Cloud Fraction,
Lower-Tropospheric Stability, and Large-Scale Divergence, J.
Climate, 22, 4827–4844, https://doi.org/10.1175/2009JCLI2891.1,
2009. a, b
Zuidema, P., Redemann, J., Haywood, J., Wood, R., Piketh, S., Hipondoka, M.,
and Formenti, P.: Smoke and Clouds above the Southeast Atlantic: Upcoming
Field Campaigns Probe Absorbing Aerosol's Impact on Climate, B.
Am. Meteorol. Soc., 97, 1131–1135,
https://doi.org/10.1175/BAMS-D-15-00082.1,
2016. a
Short summary
This study separates the influence of aerosol on cloud properties in the southeast Atlantic region from meteorological conditions in the biomass-burning season. Machine learning is used to link 8-day-averaged satellite and reanalysis data sets. Distinct regimes of aerosol–cloud interactions are identified in the subregions of the southeast Atlantic based on the obtained sensitivities.
This study separates the influence of aerosol on cloud properties in the southeast Atlantic...
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