Abstract. Satellite cloud observations have become an indispensable tool for evaluatinggeneral circulation models (GCMs). To facilitate the satellite and GCMcomparisons, the CFMIP (Cloud Feedback Model Inter-comparison Project)Observation Simulator Package (COSP) has been developed and is nowincreasingly used in GCM evaluations. Real-world clouds and precipitation canhave significant sub-grid variations, which, however, are often ignored oroversimplified in the COSP simulation. In this study, we use COSP cloudsimulations from the Super-Parameterized Community Atmosphere Model (SPCAM5)and satellite observations from the Moderate Resolution ImagingSpectroradiometer (MODIS) and CloudSat to demonstrate the importance ofconsidering the sub-grid variability of cloud and precipitation when usingthe COSP to evaluate GCM simulations. We carry out two sensitivity tests:SPCAM5 COSP and SPCAM5-Homogeneous COSP. In the SPCAM5 COSP run, the sub-gridcloud and precipitation properties from the embeddedcloud-resolving model (CRM) of SPCAM5 are used to drive the COSP simulation, while inthe SPCAM5-Homogeneous COSP run only grid-mean cloud and precipitationproperties (i.e., no sub-grid variations) are given to the COSP. We find thatthe warm rain signatures in the SPCAM5 COSP run agree with the MODIS andCloudSat observations quite well. In contrast, the SPCAM5-Homogeneous COSPrun which ignores the sub-grid cloud variations substantially overestimatesthe radar reflectivity and probability of precipitation compared to thesatellite observations, as well as themore »
High-frequency precipitation variance is calculated in 12 different free-running (non-data-assimilative) coupled high resolution atmosphere–ocean model simulations, an assimilative coupled atmosphere–ocean weather forecast model, and an assimilative reanalysis. The results are compared with results from satellite estimates of precipitation and rain gauge observations. An analysis of irregular sub-daily fluctuations, which was applied by Covey et al. (Geophys Res Lett 45:12514–12522, 2018.
- Award ID(s):
- Publication Date:
- NSF-PAR ID:
- Journal Name:
- Climate Dynamics
- Page Range or eLocation-ID:
- p. 2887-2913
- Springer Science + Business Media
- Sponsoring Org:
- National Science Foundation
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