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Constraining the Models' Response of Tropical Clouds to SST Forcings Using CALIPSO ObservationsHere we present preliminary results from the analysis of the low cloud cover (LCC) and cloud radiative effect (CRE) interannual changes in response to sea surface temperature (SST) forcings in two GISS climate models, and 12 other climate models. We further classify them as a function of their ability to reproduce the vertical structure of the cloud response to SST change against 10 years of CALIPSO observations: “the constrained models, which match the observation constraint, and the unconstrained models”. The constrained models replicate the observed interannual LCC change particularly well (ΔLCC(sub con)=-3.49 ±1.01 %/K vs. ΔLCC(sub obs)=-3.59 ±0.28 %/K) as opposed to the unconstrained models, which largely underestimate it (ΔLCC(sub unc) = -1.32 ± 1.28 %/K). As a result, the amount of short-wave warming simulated by the constrained models (ΔCRE(sub con)=2.60 ±1.13 W/m2/K) is in better agreement with the observations (ΔCRE(sub obs)=3.05 ±0.28 W/m2/K) than the unconstrained models (ΔCRE(sub con)=0.87 ±2.63 W/m2/K). Depending on the type of low cloud, the observed relationship between cloud/radiation and surface temperature varies. Over the stratocumulus regions, increasing SSTs generate higher cloud top height along with a large decrease of the cloud fraction below as opposed to a slight decrease of the cloud fraction at each level over the trade cumulus regions. Our results suggest that the models must generate sustainable stratocumulus decks and moist processes in the planetary boundary layer to reproduce these observed features. Future work will focus on defining a method to objectively discriminate these cloud types that can be applied consistently in both the observations and the models.
Document ID
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
External Source(s)
Cesana, Gregory
(Columbia Univ. New York, NY, United States)
Del Genio, Anthony D.
(NASA Goddard Inst. for Space Studies New York, NY, United States)
Ackerman, Andrew
(NASA Goddard Inst. for Space Studies New York, NY, United States)
Date Acquired
February 25, 2019
Publication Date
October 23, 2018
Publication Information
Publication: Remote Sensing and Modeling of the Atmosphere, Oceans, and Interactions VII
Publisher: SPIE
Volume: 10782
Subject Category
Meteorology And Climatology
Report/Patent Number
Meeting Information
Meeting: SPIE Asia-Pacific Remote Sensing
Location: Honolulu, HI
Country: United States
Start Date: September 24, 2018
End Date: September 26, 2018
Sponsors: International Society for Optical Engineering
Funding Number(s)
Distribution Limits
Use by or on behalf of the US Gov. Permitted.
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