References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-10-6527-2010

A comparison of ship and satellite measurements of cloud properties with global climate model simulations in the southeast Pacific stratus deck

Brunke

M. A.

¹ de Szoeke

S. P.

² Zuidema

³ Zeng

The University of Arizona, Department of Atmospheric Sciences, Tucson, Arizona, USA

Oregon State University, College of Oceanic and Atmospheric Sciences, Corvallis, Oregon, USA

University of Miami, Rosentiel School of Marine and Atmospheric Science, Miami, Florida, USA

16 07 2010

10 14 6527 6536

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/10/6527/2010/acp-10-6527-2010.html

The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/6527/2010/acp-10-6527-2010.pdf

Here, liquid water path (LWP), cloud fraction, cloud top height, and cloud base height retrieved by a suite of A-train satellite instruments (the CPR aboard CloudSat, CALIOP aboard CALIPSO, and MODIS aboard Aqua) are compared to ship observations from research cruises made in 2001 and 2003–2007 into the stratus/stratocumulus deck over the southeast Pacific Ocean. It is found that CloudSat radar-only LWP is generally too high over this region and the CloudSat/CALIPSO cloud bases are too low. This results in a relationship (LWP~h9) between CloudSat LWP and CALIPSO cloud thickness (h) that is very different from the adiabatic relationship (LWP~h2) from in situ observations. Such biases can be reduced if LWPs suspected to be contaminated by precipitation are eliminated, as determined by the maximum radar reflectivity Zmax>−15 dBZ in the apparent lower half of the cloud, and if cloud bases are determined based upon the adiabatically-determined cloud thickness (h~LWP1/2). Furthermore, comparing results from a global model (CAM3.1) to ship observations reveals that, while the simulated LWP is quite reasonable, the model cloud is too thick and too low, allowing the model to have LWPs that are almost independent of h. This model can also obtain a reasonable diurnal cycle in LWP and cloud fraction at a location roughly in the centre of this region (20° S, 85° W) but has an opposite diurnal cycle to those observed aboard ship at a location closer to the coast (20° S, 75° W). The diurnal cycle at the latter location is slightly improved in the newest version of the model (CAM4). However, the simulated clouds remain too thick and too low, as cloud bases are usually at or near the surface.

References 1

Albrecht, B. A., Fairall, C. W., Thomson, D. W., White, A. B., Snider, J. B., and Schubert, W. H.: Surface-based remote sensing of the observed and the adiabatic liquid water content of stratocumulus clouds, Geophys. Res. Lett., 17, 89–92, 1990.

Austin, P., Wang, Y., Pincus, R., and Kujula, V.: Precipitation in stratocumulus clouds: Observational and modeling results, J. Atmos. Sci., 52, 2329–2352, 1995.

Bony, S., Colman, R., Kattsov, V. M., et al.: How well do we understand and evaluate climate change feedback processes?, J. Climate, 19, 3445–3482, 2006.

Bretherton, C. S., Uttal, T., Fairall, C., Yuter, S. E., Weller, R. A., Baumgardner, D., Comstock, K., Wood, R., and Raga, G. B.: The EPIC 2001 stratocumulus study, Bull. Amer. Meteor. Soc., 85, 967–977, 2004.

Comstock, K. K., Wood, R., Yuter, S. E., and Bretherton, C. S.: Reflectivity and rain rate in and below drizzling stratocumulus, Q. J. Roy. Meteorol. Soc., 130, 2891–2918, 2004.

de Szoeke, S. P., Fairall, C. W., and Pezoa, S.: Ship observations of the tropical Pacific Ocean along the coast of South America, J. Climate, 22, 458–464, 2009.

de Szoeke, S. P., Fairall, C. W., Wolfe, D. E., Bariteau, L., Zuidema, P.: Surface flux observations on the southeastern tropical Pacific Ocean and attribution of SST errors in coupled ocean-atmopshere models, J. Climate, in press, 2010.

Duynkerke, P. G. and Teixeira, J.: Comparison of the ECMWF reanalysis with FIRE I observations: Diurnal variation of marine stratocumulus, J. Climate, 14, 1466–1478, 2001.

Haynes, J. M., L'Ecuyer, T. S., Stephens, G. L., Miller, S. D., Mitrescu, C., Wood, N. B., and Tanelli, S.: Rainfall retrieval over the ocean with spaceborne W-band radar, J. Geophys. Res., 114, D00A22, doi:10.1029/2008JD009973, 2009.

Klein, S. A. and Hartmann, D. L.: The seasonal cycle of low stratiform clouds, J. Climate, 6, 1587–1606, 1993.

Kollias, P., Fairall, C. W., Zuidema, P., Tomlinson, J., and Wick, G. A.: Observations of marine stratocumulus in SE Pacific during the PACS 2003 cruise, Geophys. Res. Lett., 31, L22110, doi:10.1029/2004GL020751, 2004.

Leon, D. C., Wang, Z., and Liu, D.: Climatology of drizzle in marine boundary layer clouds based on 1 year of data from CloudSat and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), J. Geophys. Res., 113. D00A14, doi:10.1029/2008JD009835, 2008.

Li, J.-L. F., Waliser, D., Woods, C., Teixeira, J., Bacmeister, J., Chem, J., Shen, B.-W., Tompkins, A., Tao, W.-K., and Köhler, M.: Comparisons of satellites liquid water estimates to ECMWF and GMAO analyses, 20th century IPCC AR4 climate simulations, and GCM simulations, Geophys. Res. Lett., 35, L19710, doi:10.1029/2008GL035427, 2008.

Ma, C.-C., Mechoso, C. R., Robertson, A. W., and Arakawa, A.: Peruvian stratus clouds and the tropical Pacific circulation: A coupled ocean-atmosphere GCM study, J. Climate, 9, 1635–1645, 1996.

Matrosov, S. Y., Uttal, T., and Hazen, D. A.: Evaluation of radar reflectivity-based estimates of water content in stratiform marine clouds, J. Appl. Meteor., 43, 405–419, 2004.

O'Dell, C. W., Wentz, F. J., and Bennartz, R.: Cloud liquid water path from satellite-based passive microwave observations: A new climatology over the global oceans, J. Climate, 21, 1721–1739, 2008.

Pawlowska, H., Brenguier, J. L., and Burnet, F.: Microphysical properties of stratocumulus clouds, Atmos. Res., 55, 15–33, 2000.

Rahn, D. A. and Garreaud, R.: Marine boundary layer over the subtropical southeast Pacific during VOCALS-REx – Part 1: Mean structure and diurnal cycle, Atmos. Chem. Phys., 4491–4506, doi:10.5194/acp-10-4491-2010, 2010.

Räisänen, P., Isaac, G. A., Barker, H. W., and Gultepe, I.: Solar radiative transfer for stratiform clouds with horizontal variations in liquid-water path and droplet effective radius, Q. J. R. Meteorol. Soc., 129, 2135–2149, 2003.

Reynolds, R. W., Rayner, N. A., Smith, T. M., Stokes, D. C., and Wang, W.: An improved in situ and satellite SST analysis for climate, J. Climate, 15, 1609–1625, 2002.

Serpetzoglou, E., Albrecht, B. A., Kollias, P., and Fairall, C. W.: Boundary layer, cloud, and drizzle variability in the southeast Pacific stratocumulus regime, J. Climate, 21, 6191–6214, 2008.

Siebesma, A. P., Jakob, C., Lenderink, G., Neggers, R. A. J., Teixeira, J., Van Meijgaard, E., Calvo, J., Chlond, A., Grenier, H., Jones, C., Köhler, M., Kitagawa, H., Marquet, P., Lock, A. P., Müller, F., Olmeda, D., and Severijns, C.: Cloud representation in general-circulation models over the northern Pacific Ocean: A EUROCS intercomparison study, Q. J. Roy. Meteorol. Soc., 130, 324–3267, 2004.

Stephens, G. L., Vane, D. G., Tanelli, S., Im, E., Durden, S., Rokey, M., Reinke, D., Partain, P., Mace, G. G., Austin, R., L'Ecuyer, T., Haynes, J., Lebsock, M., Suzuki, K., Waliser, D., Wu, D., Kay, J., Gettelman, A., Wang, Z., and Marchand, R.: CloudSat mission: Performance and early science after the first year of operation, J. Geophys. Res., 113, D00A18, doi:10.1029/2008JD009982, 2008.

Wang, J. and Geerts, B.: Identifying drizzle within marine stratus with W-band radar reflectivity, Atmos. Res., 69, 1–27, 2003.

Wentz, F. J.: A well-calibrated ocean algorithm for special sensor microwave/imager, J. Geophys. Res., 102, 8703–8718, 1997.

White, A. B., Fairall, C. W., and Snider, J. B.: Surface-based remote sensing of marine boundary-layer cloud properties, J. Atmos. Sci., 52, 2827–2838, 1995.

Winker, D. M. and Vaughan, M. A.: Vertical distribution of clouds over Hampton, Virginia observed by lidar under the ECLIPS and FIRE ETO programs, Atmos. Res., 34, 117–133, 1994.

Winker, D. M., Hunt, W. H., and McGill, M. J.: Initial performance assessment of CALIOP, Geophys. Res. Lett., 34, L19803, doi:10.1029/2007GL030135, 2007.

Wood, R. and Field, P. R.: Relationships between total water, condensed water, and cloud fraction in stratiform clouds examined using aircraft data, J. Atmos. Sci., 57, 1888–1905, 2000.

Zhou, M., Zeng, X., Brunke, M., Zhang, Z., and Fairall, C.: An analysis of statistical characteristics of stratus and stratocumulus over eastern Pacific, Geophys. Res. Lett., 33, L02807, doi:10.1029/2005GL024796, 2006.

Zuidema, P. and Hartmann, D. L.: Satellite determination of stratus cloud microphysical properties, J. Climate, 8, 1638–1657, 1995.

Zuidema, P., Westwater, E. R., Fairall, C., and Hazen, D.: Ship-based liquid water path estimates in marine stratocumulus. J. Geophys. Res., 110, D20206, doi:10.1029/2005JD005833, 2005.