[A-CG36] Satellite Earth Environment Observation

[ACG36-P13] Cloud Top Temperature and Cloud Optical Thickness Can Effectively Identify Convective Clouds Over the Tibetan Plateau

*Letu Husi¹ (1.Aerospace Information Research Institute, Chinese Academy of Sciences)

Keywords:Convective Clouds, Tibetan Plateau, Himawari-8/AHI

Large inaccuracies remain in the traditional convective cloud identification system over the plateau area as struggle to capture the mid-level and low-level clouds caused by the use of cloud pressure under the complex topographic effects. Besides, the lack of efficient nighttime cloud-type products hinders progress in the research on the diurnal cycle and seasonal variation in convective clouds over the Tibet Plateau (TP). In this study. we developed a 24-hour convective cloud detection algorithm using cloud top temperature and optical thickness data derived from the Himawari-8 infrared channels, which specifically addresses the issue of the water cloud underestimation and ice cloud overestimation in plateau area. This innovative product enables capturing important processes of deep convection and especially for cumulus clouds, facilitating a comprehensive spatial-temporal analysis of the entire TP region. The verification results confirm that the new algorithm shows significant improvements in cumulus detection compared to the official cloud product of Himawari-8. Additionally, the deep convective clouds have also improved from 36.93% to 71.63% for hit rate value. The analysis reveals a notable diurnal variation in convective cloud activity over the TP, predominantly occurring from noon to night. This finding underscores the influential heating role of the TP in convective activity.