The research results of Professor xuweixin from the school of atmosphere of Sun Yat sen University on extreme precipitation caused by weak convection were reported by science highlights

Research background

01

It is generally believed that extreme precipitation is mainly caused by strong convection , However, many extreme precipitation cases in reality do not show any strong convective characteristics . From the perspective of monitoring and Forecasting , Since there are no extreme features or drastic development trends to be based on , Such extreme precipitation events are more challenging , The potential disaster causing possibility is greater , It is urgent to pay attention to business and research .

research findings

02

The team of Professor xuweixin of our college has utilized nearly 17 Spaceborne radar detection data and Multi-source Satellite Data in , Explored “ Weak convection ” The contribution of the system to extreme precipitation events and its dynamic structure and environmental characteristics . Global tropical - Subtropical extreme precipitation events , According to the development height of the strong radar echo in the convection Center （ chart -1）, It is classified as weak convection 、 Moderate convective and strong convective events . The results reveal , Weak Convective Events account for nearly 30%, It is equivalent to the contribution of strong convection events ( chart -1), Highlight its importance to extreme precipitation . Weak convection - The cloud top height of heavy precipitation events is low 、 The ice phase particle layer is shallow 、 No significant lightning activity , They occur most frequently on the windward slopes of coastal mountains in the ocean and monsoon regions . The spaceborne radar data reveal that the raindrops of these systems grow very rapidly in the process of falling , It shows that the radar profile increases from the frozen layer to the near ground 50%; Relatively speaking , The increase of radar vertical profile of strong convection is not obvious . It shows that the , The direct cause of extreme precipitation caused by weak convective system is that its warm rain process is very active . The reanalysis data shows that , Weak convection - The main environmental feature of heavy precipitation events is that the convective effective potential energy is low 、 The moist layer of the atmosphere is very deep 、 The low-level water vapor convergence is very strong and the terrain uplift is significant .

chart -1, Examples of extreme precipitation （a） And its radar vertical profile （b）; The frequency distribution of extreme precipitation events includes all （c）, Weak convection （d）, And strong convection （e）.

Results published

03

The research results are 2022 year 3 It was published in the authoritative journal of Geoscience 《Geophysical Research Letters》, titled “Extreme Precipitation Produced by Relatively Weak Convective Systems in the Tropics and Subtropics”. Professor xuweixin of our college is the first author and corresponding author , Chen Hao, a doctoral student, is the second author , Researcher Luo Yali of the Academy of Meteorological Sciences is a collaborator . The study was Science The latest issue of the magazine was selected as the research highlight (Research Hightlights) To report on , Titled “Overlook not the weak”.

Thesis link ：

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GL098048

Science Report link （“Overlook not the weak”）：

https://www.science.org/doi/full/10.1126/science.abq4271?adobe_mc=MCMID%3D79147834146328814981961441378931300621%7CMCORGID%3D242B6472541199F70A4C98A6%2540AdobeOrg%7CTS%3D1650325109

---ATMOS---

source ： Xuweixin

edit ： Qianpengsheng

editor ： Lijiaqian

Preliminary examination ： Linbofu

to examine ： Hewenping

Audit release ： Zheng Hui

Welcome to contribute

[email protected]

Statement ： Welcome to reprint 、 Forward the original content of this number , You can leave a message in the message area or contact the editor in the background for authorization . Meteorologists official account for information dissemination. , The content is the responsibility of the author , Doesn't represent this point of view . Some of the pictures in this article come from the Internet , If it involves the content of the work 、 Copyright and other issues , Please contact Xiaobian in the background for processing .