Observed Southern Ocean Cloud Properties and Shortwave Reflection. Part I: Calculation of SW Flux from Observed Cloud Properties*

• DOI: 10.1175/jcli-d-14-00287.1
• Publication Date: 2014-10-14T19:25:20Z
• Authors: Daniel T. McCoy; Dennis L. Hartmann; Daniel P. Grosvenor
• Keywords: Cloud fraction; Effective radius; Liquid water content; Cloud top; Moderate-resolution imaging spectroradiometer; Shortwave; Liquid water path; Shortwave radiation; Cloud forcing; Cloud height; Solar zenith angle; Cloud albedo; Earth's energy budget

Abstract The sensitivity of the reflection shortwave radiation over Southern Ocean to cloud properties there is estimated using observations from a suite passive and active satellite instruments in combination with radiative transfer modeling. A composite property observational data description constructed that consistently incorporates mean liquid water content, ice particle radius information, vertical structure, overlap, spatial aggregation as measured by optical depth versus cloud-top pressure histograms. datasets used are Moderate Resolution Imaging Spectroradiometer (MODIS) effective filtered mitigate solar zenith angle bias, Multiangle (MISR) height–optical (CTH–OD) histogram, path University Wisconsin dataset, CloudSat. This database compute reflected function month location ocean 40° 60°S, which compares well radiation. calculation then test seasonal variation observed properties. Effective decreases during summer season, results an increase 4–8 W m−2 compared what would be if remained constant at its annual-mean value. Summertime increases low fraction similarly summertime 9–11 m−2. In-cloud less summertime, causing 1–4 less.