Intraseasonal vertical cloud regimes based on CloudSat observations over the tropics
Journal
Remote Sensing
Journal Volume
12
Journal Issue
14
Pages
-
Date Issued
2020
Author(s)
Abstract
This study identifies the evolution of tropical vertical cloud regimes (CRs) and their associated heating structures on the intraseasonal time scales. Using the cloud classification retrievals of CloudSat during boreal winter between 2006 and 2017, the CR index is defined as the leading pair of the combined multivariate empirical orthogonal functions of the daily mean frequency of deep, high, and low clouds over the tropical Indian Ocean,Maritime Continents, and theWestern Pacific. The principal components of the CR index exhibit robust temporal variance in the 30 to 80 day intraseasonal band. Based on the propagation stages of the CRs, the coherent vertical structures of cloud composition and large-scale moisture and vertical motion exhibit a westward-tilted structure. The associated Q1-QR diabatic heating and cloud radiative forcing are consistent with the key characteristics of the Madden Julian Oscillation (MJO) documented in the previous studies. Lastly, anMJO case study showcases that the presented approach characteristically captures the propagation of moisture, cloud vertical structure, and precipitation activity across spatial and temporal scales. The current results suggest that the CR index can potentially serve as an evaluationmetric to cloud-associated processes in the simulated tropical intraseasonal variability in global climate models. © 2020 by the authors.
SDGs
Other Subjects
Atmospheric radiation; Climate models; Climatology; Clouds; Moisture; Orthogonal functions; Tropics; Cloud radiative forcing; Cloud vertical structure; Empirical Orthogonal Function; Intraseasonal time scale; Madden-Julian oscillation; Spatial and temporal scale; Tropical Indian ocean; Tropical intraseasonal variability; Precipitation (meteorology)
Type
journal article