Publications

Yang, K; Wang, Z; Deng, M; Dettmann, B (2023). Combining CloudSat/CALIPSO and MODIS measurements to reconstruct convective cloud structure. REMOTE SENSING OF ENVIRONMENT, 287, 113478.

Abstract
Tropical convective clouds are a crucial component of the Earth's weather and climate system. However, there are still large uncertainties in model simulations of tropical convective clouds and precipitation. In this study, CloudSat/CALIPSO and MODIS measurements are combined to provide vertical convective cloud structures under horizontal storm context and structures of convective cores. Convective cells are identified with MODIS brightness temperature at 11 mu m (BT11) and convective centers are determined for each cell by finding the minimum BT11 (BT11min). The difference between BT11 and BT11min is calculated to provide the distance to the convective center as in brightness temperature. Therefore, detailed convective cloud structures from centers to the stratiform regions could be shown as in the contoured frequency by temperature diagram (CFTD) of radar reflectivity factor (Ze). A group of strongly attenuated Ze profiles is identified near the convective center in Africa during daytime, and the occurrence of this group of profiles is much smaller in the west Pacific during daytime. The out-of-phase day/night variations of convective system structures over ocean and over land are also analyzed. It is shown that over ocean regions, rather than land regions, nighttime convective clouds have larger Ze than daytime ones between 210 K to 260 K, but they have smaller Ze at temperatures colder than 210 K near the cloud top. The convective cores are analyzed by separating and classifying those strongly attenuated Ze profiles as group one convective cores representing the developing stage, and the rest regular profiles as group two convective cores representing the later stage. As BT11min decreases for group one, the cores grow stronger with the maximum Ze shifts into lower temperature; and as BT11min decreases for group two, the CFTD for the cores gradually shifts to larger Ze for temperatures colder than 273.15 K and smaller Ze for temperatures warmer than 273.15 K. These observed composite structures of convective clouds and land/ocean and day/night vari-ations provide crucial information for model evaluations.

DOI:
10.1016/j.rse.2023.113478

ISSN:
1879-0704