Relationships between intense convection, lightning, and rainfall over the interior Congo Basin using TRMM data
Relationships between intense convection, lightning, and rainfall over the interior Congo Basin using TRMM data
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DOI：
10.1016/j.atmosres.2022.106164
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发表时间：
2022-08
影响因子：
5.5
通讯作者：
Stephen L. Solimine;Liming Zhou;A. Raghavendra;Yichen Cai
中科院分区：
文献类型：
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作者：
Stephen L. Solimine;Liming Zhou;A. Raghavendra;Yichen Cai
由于缺乏对整个赤道非洲的实地观测，对受极端天气事件影响的区域人口的预报工作带来了挑战，并使刚果盆地内的准确水文监测变得困难。由于这一地区的平均对流强度很高，闪电观测可能对改进卫星地面降水监测和预报特别有用。因此，本研究旨在通过分析1998-2013年高分辨率热带降雨测量使命（TRMM）雷达和闪电观测，量化刚果最强对流事件的相对频率及其相关的闪电-降水关系。闪电和降水测量与观测到的回波被隔离，并分配到四个类别的强烈对流层状回波类型之一。结果表明，只有2.7%的观测回波被归类为强对流层状，但它们产生了36.6%的观测闪电和27.4%的估计降雨总量。强对流层状云降水与总降水量之间存在显著的空间相关性（r =0.56）。闪电和回波雨率之间的线性关系在很大程度上取决于对流类。因此，不能对所有强对流回波进行简单的线性回归。然而，闪电可以用来检索一个下限近似对流降雨率。结果表明，如果实施得当，除了闪电数据可能有助于改善或限制卫星推导的对流强度和降雨量的估计。
The lack of in situ observations across equatorial Africa creates forecasting challenges for regional populations affected by extreme weather events and makes accurate hydrological monitoring within the Congo Basin difficult. Due to the high mean convective intensity in this region, lightning observations may be particularly useful for improving satellite-based surface precipitation monitoring and forecasting. Therefore, this study aims to quantify the relative frequency of the most intense convective events in the Congo and their associated lightning – precipitation relationships through the analysis of high-resolution Tropical Rainfall Measuring Mission (TRMM) radar and lightning observations for the years 1998–2013. Lightning and precipitation measurements associated with observed echoes were isolated and assigned to one of four categories of intense convective-stratiform echo types. Results show that only 2.7% of observed echoes were classified as intense convective-stratiform, yet they produced 36.6% of observed lightning flashes and 27.4% of estimated rain totals. Significant spatial correlations were also found between total rainfall and intense convective-stratiform rain (coefficientr =0.56). Linear relationships between lightning and echo rain rates are shown to depend heavily on the convective category. As a result, a simple linear regression cannot be made for all intense convective echoes. However, lightning can be used to retrieve a lower-bound approximation with respect to convective rain rates. Results suggest that if properly implemented, the addition of lightning data may help to improve or constrain satellite derived convective intensity and rainfall estimations.