Articles | Volume 14, issue 17
https://doi.org/10.5194/acp-14-9001-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/acp-14-9001-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
On transition-zone water clouds
E. Hirsch
Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
Department of Environmental Physics, Israel Institute for Biological Research, Nes Ziona, Israel
Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
Department of Geophysical, Atmospheric and Planetary Sciences, Tel-Aviv University, Tel-Aviv, Israel
The Energy, Environment and Water Research Center (EEWRC), The Cyprus Institute, Nicosia, Cyprus
O. Altaratz
Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
E. Agassi
Department of Environmental Physics, Israel Institute for Biological Research, Nes Ziona, Israel
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Huan Liu, Ilan Koren, Orit Altaratz, and Shutian Mu
EGUsphere, https://doi.org/10.5194/egusphere-2025-2574, https://doi.org/10.5194/egusphere-2025-2574, 2025
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Clouds play a crucial role in Earth's climate by reflecting sunlight and trapping heat. Understanding how clouds respond to global warming (cloud feedback) is essential for climate change. However, the natural climate variability, like ENSO, can distort these estimates. Relying on long-term reanalysis data and simulations, this study finds that ENSO with a typical periodicity of 2–7 years can introduce a significant bias on cloud feedback estimates on even decadal to century time scales.
Manuel Santos Gutiérrez, Mickaël David Chekroun, and Ilan Koren
EGUsphere, https://doi.org/10.48550/arXiv.2405.11545, https://doi.org/10.48550/arXiv.2405.11545, 2024
Preprint withdrawn
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This letter explores a novel approach for the formation of cloud droplets in rising adiabatic air parcels. Our approach combines microphysical equations accounting for moisture, updrafts and concentration of aerosols. Our analysis reveals three regimes: A) Low moisture and high concentration can hinder activation; B) Droplets can activate and stabilize above critical sizes, and C) sparse clouds can have droplets exhibiting activation and deactivation cycles.
Huan Liu, Ilan Koren, Orit Altaratz, and Mickaël D. Chekroun
Atmos. Chem. Phys., 23, 6559–6569, https://doi.org/10.5194/acp-23-6559-2023, https://doi.org/10.5194/acp-23-6559-2023, 2023
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Clouds' responses to global warming contribute the largest uncertainty in climate prediction. Here, we analyze 42 years of global cloud cover in reanalysis data and show a decreasing trend over most continents and an increasing trend over the tropical and subtropical oceans. A reduction in near-surface relative humidity can explain the decreasing trend in cloud cover over land. Our results suggest potential stress on the terrestrial water cycle, associated with global warming.
Elisa T. Sena, Ilan Koren, Orit Altaratz, and Alexander B. Kostinski
Atmos. Chem. Phys., 22, 16111–16122, https://doi.org/10.5194/acp-22-16111-2022, https://doi.org/10.5194/acp-22-16111-2022, 2022
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We used record-breaking statistics together with spatial information to create record-breaking SST maps. The maps reveal warming patterns in the overwhelming majority of the ocean and coherent islands of cooling, where low records occur more frequently than high ones. Some of these cooling spots are well known; however, a surprising elliptical area in the Southern Ocean is observed as well. Similar analyses can be performed on other key climatological variables to explore their trend patterns.
Tamir Tzadok, Ayala Ronen, Dorita Rostkier-Edelstein, Eyal Agassi, David Avisar, Sigalit Berkovic, and Alon Manor
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-5, https://doi.org/10.5194/amt-2022-5, 2022
Revised manuscript not accepted
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Wind observations of an advanced doppler lidar are successfully compared to a meteorological mast, a tethered balloon, and free radiosondes. Analysis of boundary layer structure using Lidar observation show Good agreement with WRF model simulations. A specific potential for synergic use of WRF model with the Lidar observations is demonstrated. WRF simulations can be used to indicate atmospheric layers in which Lidar observations are challenged.
Eshkol Eytan, Ilan Koren, Orit Altaratz, Mark Pinsky, and Alexander Khain
Atmos. Chem. Phys., 21, 16203–16217, https://doi.org/10.5194/acp-21-16203-2021, https://doi.org/10.5194/acp-21-16203-2021, 2021
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Describing cloud mixing processes is among the most challenging fronts in cloud physics. Therefore, the adiabatic fraction (AF) that serves as a mixing measure is a valuable metric. We use high-resolution (10 m) simulations of single clouds with a passive tracer to test the skill of different methods used to derive AF. We highlight a method that is insensitive to the available cloud samples and allows considering microphysical effects on AF estimations in different environmental conditions.
Tom Dror, Mickaël D. Chekroun, Orit Altaratz, and Ilan Koren
Atmos. Chem. Phys., 21, 12261–12272, https://doi.org/10.5194/acp-21-12261-2021, https://doi.org/10.5194/acp-21-12261-2021, 2021
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A part of continental shallow convective cumulus (Cu) was shown to share properties such as organization and formation over vegetated areas, thus named green Cu. Mechanisms behind the formed patterns are not understood. We use different metrics and an empirical orthogonal function (EOF) to decompose the dataset and quantify organization factors (cloud streets and gravity waves). We show that clouds form a highly organized grid structure over hundreds of kilometers at the field lifetime.
Tom Dror, J. Michel Flores, Orit Altaratz, Guy Dagan, Zev Levin, Assaf Vardi, and Ilan Koren
Atmos. Chem. Phys., 20, 15297–15306, https://doi.org/10.5194/acp-20-15297-2020, https://doi.org/10.5194/acp-20-15297-2020, 2020
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We used in situ aerosol measurements over the Atlantic, Caribbean, and Pacific to initialize a cloud model and study the impact of aerosol concentration and sizes on warm clouds. We show that high aerosol concentration increases cloud mass and reduces surface rain when giant particles (diameter > 9 µm) are present. The large aerosols changed the timing and magnitude of internal cloud processes and resulted in an enhanced evaporation below cloud base and dramatically reduced surface rain.
Cited articles
Asmi, A., Wiedensohler, A., Laj, P., Fjaeraa, A.-M., Sellegri, K., Birmili, W., Weingartner, E., Baltensperger, U., Zdimal, V., Zikova, N., Putaud, J.-P., Marinoni, A., Tunved, P., Hansson, H.-C., Fiebig, M., Kivekäs, N., Lihavainen, H., Asmi, E., Ulevicius, V., Aalto, P. P., Swietlicki, E., Kristensson, A., Mihalopoulos, N., Kalivitis, N., Kalapov, I., Kiss, G., de Leeuw, G., Henzing, B., Harrison, R. M., Beddows, D., O'Dowd, C., Jennings, S. G., Flentje, H., Weinhold, K., Meinhardt, F., Ries, L., and Kulmala, M.: Number size distributions and seasonality of submicron particles in Europe 2008–2009, Atmos. Chem. Phys., 11, 5505–5538, https://doi.org/10.5194/acp-11-5505-2011, 2011.
Atmospheric sounding: http://weather.uwyo.edu/upperair/sounding.html, last access: October 2013.
Berg, L. K. and Stull, R. B.: Parameterization of Joint Frequency Distributions of Potential Temperature and Water Vapor Mixing Ratio in the Daytime Convective Boundary Layer, J. Atmos. Sci., 61, 813–828, https://doi.org/10.1175/1520-0469(2004)061<0813:POJFDO>2.0.CO;2, 2004.
Bolton, D.: The Computation of Equivalent Potential Temperature, Mon. Weather Rev., 108, 1046–1053, 10.1175/1520-0493(1980)108<1046:tcoept>2.0.co;2, 1980.
Brooks, S. D., Wise, M. E., Cushing, M., and Tolbert, M. A.: Deliquescence behavior of organic/ammonium sulfate aerosol, Geophys. Res. Lett., 29, 1917, https://doi.org/10.1029/2002GL014733, 2002.
Charlson, R. J., Ackerman, A. S., Bender, F. A. M., Anderson, T. L., and Liu, Z.: On the climate forcing consequences of the albedo continuum between cloudy and clear air, Tellus B, 59, 715–727, 2007.
Deng, Z., Zhao, C., Zhang, Q., Huang, M., and Ma, X.: Statistical analysis of microphysical properties and the parameterization of effective radius of warm clouds in Beijing area, Atmos. Res., 93, 888–896, 2009.
Dusek, U., Frank, G., Hildebrandt, L., Curtius, J., Schneider, J., Walter, S., Chand, D., Drewnick, F., Hings, S., and Jung, D.: Size matters more than chemistry for cloud-nucleating ability of aerosol particles, Science, 312, 1375–1378, 2006.
Han, Q., Rossow, W. B., and Lacis, A. A.: Near-global survey of effective droplet radii in liquid water clouds using ISCCP data, J. Climate, 7, 465–497, 1994.
Han, Q., Welch, R., Chou, J., Rossow, W., and White, A.: Validation of satellite retrievals of cloud microphysics and liquid water path using observations from FIRE, J. Atmos. Sci., 52, 4183–4195, 1995.
Hirsch, E., Agassi, E., and Koren, I.: Determination of optical and microphysical properties of thin warm clouds using ground based hyper-spectral analysis, Atmos. Meas. Tech., 5, 851–871, https://doi.org/10.5194/amt-5-851-2012, 2012.
Kawamoto, K., Nakajima, T., and Nakajima, T. Y.: A global determination of cloud microphysics with AVHRR remote sensing, J. Climate, 14, 2054–2068, 2001.
Köhler, H.: The nucleus in and the growth of hygroscopic droplets, T. Faraday Soc., 32, 1152–1161, 1936.
Komppula, M., Lihavainen, H., Kerminen, V. M., Kulmala, M., and Viisanen, Y.: Measurements of cloud droplet activation of aerosol particles at a clean subarctic background site, J. Geophys. Res.-Atmos., 110, D06204, https://doi.org/10.1029/2004JD005200, 2005.
Koren, I., Remer, L. A., Kaufman, Y. J., Rudich, Y., and Martins, J. V.: On the twilight zone between clouds and aerosols, Geophys. Res. Lett., 34, L08805, https://doi.org/10.1029/2007GL029253, 2007.
Koren, I., Oreopoulos, L., Feingold, G., Remer, L. A., and Altaratz, O.: How small is a small cloud?, Atmos. Chem. Phys., 8, 3855–3864, https://doi.org/10.5194/acp-8-3855-2008, 2008.
Lee, I.-Y., and Pruppacher, H.: A comparative study on the growth of cloud drops by condensation using an air parcel model with and without entrainment, Pure Appl. Geophys., 115, 523–545, 1977.
Liu, G., Shao, H., Coakley, J. A., Curry, J. A., Haggerty, J. A., and Tschudi, M. A.: Retrieval of cloud droplet size from visible and microwave radiometric measurements during INDOEX: Implication to aerosols' indirect radiative effect, J. Geophys. Res.-Atmos., 108, 4006, https://doi.org/10.1029/2001JD001395, 2003.
Mason, B. and Chien, C.: Cloud-droplet growth by condensation in cumulus, Q. J. Roy. Meteorol. Soc., 88, 136–142, 1962.
Miles, N. L., Verlinde, J., and Clothiaux, E. E.: Cloud droplet size distributions in low-level stratiform clouds, J. Atmos. Sci., 57, 295–311, 2000.
Mordy, W.: Computations of the growth by condensation of a population of cloud droplets, Tellus, 11, 16–44, 1959.
Pruppacher, H. R. and Klett, J. D.: Microphysics of clouds and precipitation, Springer, 1998.
Reid, J. S., Hobbs, P. V., Rangno, A. L., and Hegg, D. A.: Relationships between cloud droplet effective radius, liquid water content, and droplet concentration for warm clouds in Brazil embedded in biomass smoke, J. Geophys. Res.-Atmos., 104, 6145–6153, 1999.
Reutter, P., Su, H., Trentmann, J., Simmel, M., Rose, D., Gunthe, S. S., Wernli, H., Andreae, M. O., and Pöschl, U.: Aerosol- and updraft-limited regimes of cloud droplet formation: influence of particle number, size and hygroscopicity on the activation of cloud condensation nuclei (CCN), Atmos. Chem. Phys., 9, 7067–7080, https://doi.org/10.5194/acp-9-7067-2009, 2009.
Rogers, R.: A short course in cloud physics, Oxford and Elmsford, N. Y., Pergamon Press, International Series in Natural Philosophy, 96, 246, 1979.
Rose, D., Gunthe, S. S., Mikhailov, E., Frank, G. P., Dusek, U., Andreae, M. O., and Pöschl, U.: Calibration and measurement uncertainties of a continuous-flow cloud condensation nuclei counter (DMT-CCNC): CCN activation of ammonium sulfate and sodium chloride aerosol particles in theory and experiment, Atmos. Chem. Phys., 8, 1153–1179, https://doi.org/10.5194/acp-8-1153-2008, 2008.
Snider, J. R., Guibert, S., Brenguier, J.-L., and Putaud, J.-P.: Aerosol activation in marine stratocumulus clouds: 2. Köhler and parcel theory closure studies, J. Geophys. Res.-Atmos., 108, 8629, https://doi.org/10.1029/2002JD002692, 2003.
Vogelmann, A. M., McFarquhar, G. M., Ogren, J. A., Turner, D. D., Comstock, J. M., Feingold, G., Long, C. N., Jonsson, H. H., Bucholtz, A., and Collins, D. R.: RACORO extended-term aircraft observations of boundary layer clouds, B. Am. Meteorol. Soc., 93, 861–878, 2012.
Wallace, J. M. and Hobbs, P. V.: Atmospheric science: an introductory survey, Academic Press, 2006.
Wood, R., and Field, P. R.: The distribution of cloud horizontal sizes, J. Climate, 24, 4800–4816, 2011.
Zhao, G. and Di Girolamo, L.: Statistics on the macrophysical properties of trade wind cumuli over the tropical western Atlantic, J. Geophys. Res.-Atmos., 112, D10204, https://doi.org/10.1029/2006JD007371, 2007.
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