On the Importance of a Geostationary View for Tropical Cloud Feedback

This study shows that geostationary satellites are critical to estimate the accurate cloud feedback strength over the tropical western Pacific (TWP). Cloud feedback strength was calculated by the simultaneous relation between cloud cover and sea surface temperature (SST) over the TWP [120°E–170°E, 20°S–20°N]. During 2011–2018, the cloud cover was obtained by geostationary earth orbit satellite (GEO) and low-level earth orbit satellite (LEO) (A^GEO, A^LEO), and the NOAA's all-sky SST (T_o) was weighted with the clear-sky fraction observed by GEO and LEO (T_w^GEO; T_w^LEO). The linear regression coefficients between clouds and SST are very different: −7.93%K⁻¹ (A^GEO/T_w^GEO), −6.94%K⁻¹ (A^LEO/T_w^GEO), −1.35%K⁻¹ (A^GEO/T_w^LEO), −0.69%K⁻¹ (A^LEO/T_w^LEO), −0.02 %K⁻¹ (A^GEO/T_o), and −0.50 %K⁻¹ (A^LEO/T_o). Among these, only the T_w^GEO values provided a valid cloud feedback signal. This is because GEO's field of view is large enough to simultaneously capture cloud cover over the entire TWP.