ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-7-3353-2007 Global statistics of liquid water content and effective number concentration of water clouds over ocean derived from combined CALIPSO and MODIS measurements Hu Y. 1 Vaughan M. 2 McClain C. 3 Behrenfeld M. 4 Maring H. 5 Anderson D. 5 Sun-Mack S. 2 Flittner D. 1 Huang J. 2 Wielicki B. 1 Minnis P. 1 Weimer C. 6 Trepte C. 1 Kuehn R. 2 NASA Langley Research Center, Hampton, Virginia, USA Science Systems and Applications, Inc., Hampton, Virginia, USA NASA Goddard Space Flight Center, Greenbelt, Maryland, USA Oregon State University, Corvallis, Oregon, USA NASA Headquarter, Washington, DC, USA Ball Aerospace & Technologies Corp., Builder, Colorado, USA 27 06 2007 7 12 3353 3359 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/7/3353/2007/acp-7-3353-2007.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/7/3353/2007/acp-7-3353-2007.pdf

This study presents an empirical relation that links the volume extinction coefficients of water clouds, the layer integrated depolarization ratios measured by lidar, and the effective radii of water clouds derived from collocated passive sensor observations. Based on Monte Carlo simulations of CALIPSO lidar observations, this method combines the cloud effective radius reported by MODIS with the lidar depolarization ratios measured by CALIPSO to estimate both the liquid water content and the effective number concentration of water clouds. The method is applied to collocated CALIPSO and MODIS measurements obtained during July and October of 2006, and January 2007. Global statistics of the cloud liquid water content and effective number concentration are presented.

 References Breon, F. M. and Goloub, P.: Cloud droplet, effective radius from spaceborne polarization. measurements, Geophys. Res. Lett., 25, 1879–1992, 1998. Charlson, R. J., Lovelock, J. E., Andreae, M. O., and Warren, S. G.: Oceanic phytoplankton, atmospheric sulfur, cloud albedo and climate, Nature, 326, 655–661, 1987. Chu, S., Elliott, S., and Maltrud, M.: Ecodynamic and Eddy-Admitting Dimethyl Sulfide Simulations in a Global Ocean Biogeochemistry/Circulation Model, Earth Interact., 8, 11, doi:10.1175/1087-3562, 2004. Gerber, H., Jensen, J. B., Davis, A. B., Marshak, A., and Wiscombe, W. J.: Spectral Density of Cloud Liquid Water Content at High Frequencies, J. Atmos. Sci., 58, 497–503, 2001. Han, Q., Rossow, B., Chou, J., and Welch, R.: Global Survey of the Relationships of Cloud Albedo and Liquid Water Path with Droplet Size Using ISCCP, J. Climate, 11, 1616–1528, 1998. Hanson, J.: Multiple Scattering of Polarized Light in Planetary Atmospheres, J. Atmos. Sci., 28, 1400–1426, 1971. Hu, Y. and Stamnes, K.: An accurate parameterization of cloud radiative properties suitable for climate models, J. Climate, 6, 728–742, 1993. Hu, Y., Winker, D., Yang, P., Baum, B., L. Poole, and L. Vann: Identification of cloud phase from PICASSO-CENA lidar depolarization: A multiple scattering sensitivity study, J. Quant. Spectros. Radiat. Trans., 70, 569–579, 2001. Hu, Y., Liu, Z., Winker, D., Vaughan, M., Noel, V., Bissonnette, L., Roy, G., and McGill, M.: A simple relation between lidar multiple scattering and depolarization for water clouds, Opt. Lett., 31, 1809–1811, 2006. Meskhidze, N. and Nenes, A.: Photoplankton and cloudness in the southern ocean, Science, 314, 1919, 2006. Miles, N. J., Verlinde, J., and Clothiaux, E. E.: Cloud droplet size distributions in low-level stratiform clouds, J. Atmos. Sci., 57, 295–311, 2000. Minnis, P., Kratz, D. P., Coakley Jr., J. A., et al.: Cloud Optical Property Retrieval (Subsystem 4.3), Clouds and the Earth's Radiant Energy System (CERES) Algorithm Theoretical Basis Document, Volume III: Cloud Analyses and Radiance Inversions (Subsystem 4), NASA RP 1376 Vol 3, edited by: CERES Science Team, December, 135–176, 1995. Minnis, P., Garber, D. P., Young, D. F., Arduini, R. F., and Takano, Y.: Parameterization of reflectance and effective emittance for satellite remote sensing of cloud properties, J. Atmos. Sci., 55, 3313–3339, 1998. Minnis, P., Geier, E., Wielicki, B., et al.: Overview of CERES cloud properties from VIRS and MODIS, Proc. AMS 12th Conf. Atmos. Radiation, Madison, WI, July 10–14, CD-ROM, J2.3., 2006. Shaw, G.: Aerosols as climate regulators: a climate-biosphere linkage, Atmos. Environ., 21, 985–986, 1983.