Observing convective activities in the complex organizations and their contributions to the precipitation and anvil amount

Wang, Zhenquan

The processes of convection precipitating and producing anvil clouds determine the Earth water and radiative budgets. However, convection could have very complicated organizations and behaviors in the tropics. A bunch of convective activities of various life stages would be connected together in the complex organizations and it is difficult to distinguish their behaviors, e.g., precipitating, producing the anvil, merging and splitting. In this work, from the hourly satellite images of the infrared brightness temperature (BT), the organization segments of a single but variable-BT cold core are identified and tracked. By the segment tracking, the detailed evolution of the organization structures (i.e., variations of the cold-core BT, mergers and splits) and the precipitation and anvil contributions of each organization segment are distinguished from the connected convection complex. The results show that the duration, precipitation and anvil amount of the tracked organization segments have a simple log-linear relationship with the cold-core-peak BT. The organization segments of the core colder than 220 K are the most robust with the duration of 4–16 hours, while the organization segments of the shallow warmer structures disappear rapidly in a few hours but are the most frequent. The frequency of the mergers and splits also increases exponentially with the decrease of the cold-core-peak BT. By the mergers and splits, more high cloud systems are born from convection and the lifetime-accumulated precipitation and anvil amount are strongly enhanced as compared to those of no mergers and splits. Overall, 85.4 % of tropical precipitation are contributed by the long-lived organization segments, in which 67.7 % are accompanied with mergers or splits. The tropical non-precipitating anvil amount are mostly contributed by both long-lived organization segments with mergers or splits (49.1 %) and fragile warm but frequent organization segments (28.7 %).



Wang, Zhenquan: Observing convective activities in the complex organizations and their contributions to the precipitation and anvil amount. 2024. Copernicus Publications.


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Rechteinhaber: Zhenquan Wang

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