Lake-effect rainfall over Africa’s great lakes and other lakes in the rift valleys
Lake-effect rainfall over Africa’s great lakes and other lakes in the rift valleys
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非洲大湖和裂谷其他湖泊的湖泊效应降雨
DOI：
10.1016/j.jglr.2021.12.004
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发表时间：
2022
影响因子：
2.2
通讯作者：
Nicholson, Sharon E.
中科院分区：
文献类型：
--
作者：
Nicholson, Sharon E.
本文使用 TRMM 3B43 和 3B42 卫星降雨产品检查了东非 27 个湖泊的降雨量，并将其与湖泊流域或周边地区的降雨量进行了比较。对年降雨量和每月降雨量进行比较。还检查了湖泊和集水区/周边地区的降雨日周期。结果表明，几乎所有湖泊的降雨量在所有月份都增加了。湖面和流域降雨之间的对比在夜间和干旱月份最为明显。对于较小的湖泊，夜间和白天降雨量的增加都很明显。在最大的湖泊（维多利亚、坦噶尼喀、马拉维）上，单一降雨量最大值出现在夜间，并且湖泊上空的降雨量通常低于白天流域内的降雨量。大多数其他湖泊都有双峰降雨量最大值，强峰值出现在 03 至 09 LST 之间，第二个峰值通常出现在 18 LST 之间。湖泊上方的白天最大值可能代表了湖泊上方陆地系统的漂移，但湖泊上方的湿度似乎也发挥了作用。除大型湖泊外，湖泊和流域的最大和最小降雨时间（分别为 18 LST 和 12 LST）具有很强的一致性。夜间降雨在湖泊和流域都很常见。陆地上的夜间降雨可能是湖泊上空系统产生的漂移。
This article examines rainfall over 27 lakes in eastern Africa and compares this to rainfall over the lakes' catchments or surrounding regions, using the TRMM 3B43 and 3B42 satellite rainfall products. A comparison is made for annual rainfall and for rainfall in each month. The diurnal cycle of rainfall is also examined over the lakes and over the catchments/surrounding regions. It is shown that rainfall is enhanced over nearly all lakes and in all months. Contrasts between over-lake and catchment rainfall are greatest at night and during the dry months. For the smaller lakes the enhancement is apparent in both nocturnal and daytime rainfall. Over the largest lakes (Victoria, Tanganyika, Malawi) a single rainfall maximum occurs at night and rainfall is generally lower over the lake than over the catchment during the day. The majority of the other lakes have a bimodal rainfall maximum, with a strong peak between 03 and 09 LST and a second peak most generally at 18 LST. The daytime maximum over the lakes might represent a drift of land systems over the lake, but humidity over the lake appears to play a role as well. Except for the large lakes, there is strong uniformity in the times of maximum and minimum rainfall (18 LST and 12 LST, respectively) over both the lakes and the catchments. Nocturnal rainfall is common over both the lakes and the catchments. Nocturnal rainfall over the land might be a drift of the systems generated over the lakes.