Multi-Year Study of GOES-13 Droplet Effective Radius Retrievals for Warm Clouds over South America and Southeast Pacifi

Author(s)

Correia, Alexandre L. ^[1] ; Mendonca, Marina M. ^[2] ; Nobrega, Thiago F. ^[1] ; Pugliesi, Andre C. ^[1] ; Cecchini, Micael A. ^[3]

Affiliation

^[1] Univ Sao Paulo, Inst Phys, BR-05508090 Sao Paulo - Brazil

^[2] Sao Paulo State Univ, Dept Environm Engn, BR-18087180 Sao Paulo - Brazil

^[3] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 - USA

• Document type: Journal article
• Source: TMOSPHER; v. 13, n. 1 JAN 2022.
• Web of Science Citations: 0

Abstract

Geostationary satellites can retrieve the cloud droplet effective radius (re) but suffer biases from cloud inhomogeneities, internal retrieval nonlinearities, and 3-D scattering/shadowing from neighboring clouds, among others. A 1-D retrieval method was applied to Geostationary Operational Environmental Satellite 13 (GOES-13) imagery, over large areas in South America (5 \& LCIRC; N-30 \& LCIRC; S; 20 \& LCIRC;-70 \& LCIRC; W), the Southeast Pacific (5 \& LCIRC; N-30 \& LCIRC; S; 70 \& LCIRC;-120 \& LCIRC; W), and the Amazon (2 \& LCIRC; N-7 \& LCIRC; S; 54 \& LCIRC;-73 \& LCIRC; W), for four months in each year from 2014-2017. Results were compared against in situ aircraft measurements and the Moderate Resolution Imaging Spectroradiometer cloud product for Terra and Aqua satellites. Monthly regression parameters approximately followed a seasonal pattern. With up to 108,009 of matchups, slope, intercept, and correlation for Terra (Aqua) ranged from about 0.71 to 1.17, -2.8 to 2.5 mu m, and 0.61 to 0.91 (0.54 to 0.78, -1.5 to 1.8 mu m, 0.63 to 0.89), respectively. We identified evidence for re overestimation (underestimation) correlated with shadowing (enhanced reflectance) in the forward (backscattering) hemisphere, and limitations to illumination and viewing configurations accessible by GOES-13, depending on the time of day and season. A proposition is hypothesized to ameliorate 3-D biases by studying relative illumination and cloud spatial inhomogeneity. (AU)

• FAPESP's process: 20/13273-9 - Anatomy of Convective Clouds over the Amazon (ACCA)
• Grantee: Micael Amore Cecchini
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 10/15959-3 - SeReNA Project: remote sensing of cloud microphysics and its interaction with atmospheric aerosols
• Grantee: Alexandre Lima Correia
• Support Opportunities: Regular Research Grants