The Life Cycle of Anvil Clouds and the Top-of-Atmosphere Radiation Balance over the Tropical West Pacific

Journal Article · 30 November 2018 · Journal of Climate

DOI: https://doi.org/10.1175/JCLI-D-18-0154.1 · OSTI ID:1483738

Wall, Casey J. ^[1]; Hartmann, Dennis L. ^[1]; Thieman, Mandana M. ^[2]; Smith, Jr., William L. ^[3]; Minnis, Patrick ^[2]

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1. Department of Atmospheric Sciences, University of Washington, Seattle, Washington
2. Science Systems and Applications, Inc., Hampton, Virginia
3. NASA Langley Research Center, Hampton, Virginia

Observations from a geostationary satellite are used to study the life cycle of mesoscale convective systems (MCS), their associated anvil clouds, and their effects on the radiation balance over the warm pool of the tropical western Pacific Ocean. In their developing stages, MCS primarily consist of clouds that are optically thick and have a negative net cloud radiative effect (CRE). As MCS age, ice crystals in the anvil become larger, the cloud top lowers somewhat, and cloud radiative effects decrease in magnitude. Shading from anvils causes cool anomalies in the underlying sea surface temperature (SST) of up to −0.6°C. MCS often occur in clusters that are embedded within large westward-propagating disturbances, and therefore shading from anvils can cool SSTs over regions spanning hundreds of kilometers. Triggering of convection is more likely to follow a warm SST anomaly than a cold SST anomaly on a time scale of several days. This information is used to evaluate hypotheses for why, over the warm pool, the average shortwave and longwave CRE are individually large but nearly cancel. The results are consistent with the hypothesis that the cancellation in CRE is caused by feedbacks among cloud albedo, large-scale circulation, and SST.

• Research Organization: Univ. of Washington, Seattle, WA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: SC0012580
• OSTI ID: 1483738
• Journal Information: Journal of Climate, Journal Name: Journal of Climate Journal Issue: 24 Vol. 31; ISSN 0894-8755
• Publisher: American Meteorological SocietyCopyright Statement
• Country of Publication: United States
• Language: English