Top of Altitude Flux and Cloud Radiative Forcing (CRF) From Cirrus Clouds: Effect of Subvisual Clouds
Abstract
Ice clouds are a source of large uncertainty in studies of the energy budget of the atmosphere and are estimated to have an average global coverage of 30%. Cirrus clouds, in particular, can have either positive or negative cloud radiative forcing, depending on their optical thickness. However, passive sensors, such as NASA's Moderate Resolution Imaging Spectrometer (MODIS), have difficulty in detecting ice clouds with low optical thicknesses, while active sensors are better able to detect these clouds and retrieve their microphysical and optical properties. We seek to show that where an active sensor retrieval (2C-ICE for our study) records a single layer, optically thin, nonprecipitating ice cloud and MODIS classifies a collocated pixel as clear, donating those active retrieval cloud products to the MODIS pixel will help reduce differences between calculated fluxes and CERES benchmark fluxes. Shortwave and longwave broadband radiative fluxes are estimated using the Atmosphere and Environmental Research (AER) Rapid Radiative Transfer Model (RRTMG), in conjunction with incorporating MODIS C6 ice cloud microphysical properties, and utilizing the two-stream process for multiple scattering. Cloud properties are taken from CloudSat Data Processing Center (DPC) radar-lidar synergy products (2B-CLDCLASS-LIDAR, 2C-ICE, 2C-PRECIP) and collocated auxiliary products (MODIS-1KM-AUX, ECMWF-AUX). Preliminary results are presented.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A21Q2631M
- Keywords:
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- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES;
- 3359 Radiative processes;
- ATMOSPHERIC PROCESSES;
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES;
- 3367 Theoretical modeling;
- ATMOSPHERIC PROCESSES