A Novel Method for Estimating Shortwave Direct Radiative Effect of Above-cloud Aerosols over Ocean Using CALIOP and MODIS Data
- Oreopoulos, L.
- November 15, 2013.
- Physical Description:
- 1 electronic document
- Additional Creators:
- Lee, D., Yu, H., Meyer, K., Platnick, S., and Zhang, Z.
- Restrictions on Access:
- Unclassified, Unlimited, Publicly available. and Free-to-read Unrestricted online access
- This paper describes an efficient and unique method for computing the shortwave direct radiative effect (DRE) of aerosol residing above low-level liquid-phase clouds using CALIOP and MODIS data. It accounts for the overlapping of aerosol and cloud rigorously by utilizing the joint histogram of cloud optical depth and cloud top pressure. Effects of sub-grid scale cloud and aerosol variations on DRE are accounted for. It is computationally efficient through using grid-level cloud and aerosol statistics, instead of pixel-level products, and a pre-computed look-up table in radiative transfer calculations. We verified that for smoke over the southeast Atlantic Ocean the method yields a seasonal mean instantaneous shortwave DRE that generally agrees with more rigorous pixel-level computation within 4%. We have also computed the annual mean instantaneous shortwave DRE of light-absorbing aerosols (i.e., smoke and polluted dust) over global ocean based on 4 yr of CALIOP and MODIS data. We found that the variability of the annual mean shortwave DRE of above-cloud light-absorbing aerosol is mainly driven by the optical depth of the underlying clouds.
- NASA Technical Reports Server (NTRS) Collection.
- Document ID: 20140011833., GSFC-E-DAA-TN11432., and Atmospheric Measurement Techniques: Discussions; Volume 6; Issue 6; 9993-10020.
- Copyright, Distribution as joint owner in the copyright.
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