Influence of Land Cover and Soil Moisture based Brown Ocean Effect on an Extreme Rainfall Event from a Louisiana Gulf Coast Tropical System
Influence of Land Cover and Soil Moisture based Brown Ocean Effect on an Extreme Rainfall Event from a Louisiana Gulf Coast Tropical System
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DOI：
10.1038/s41598-019-53031-6
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发表时间：
2019-10
影响因子：
4.6
通讯作者：
U. Nair;E. Rappin;E. Foshee;Warren J. Smith;R. Pielke;R. Mahmood;J. Case;C. Blankenship;Marshall Shepherd;J. Santanello;D. Niyogi
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作者：
U. Nair;E. Rappin;E. Foshee;Warren J. Smith;R. Pielke;R. Mahmood;J. Case;C. Blankenship;Marshall Shepherd;J. Santanello;D. Niyogi
2016年8月中旬，路易斯安那州南部的极端洪水是由一个不寻常的热带低气压在陆地上形成并加强造成的。我们使用数值实验来突出“棕色海洋”效应（饱和土壤的功能类似于温暖的海洋表面）对强化的作用及其受土地覆盖变化的调制。一个数值模拟实验，成功地捕捉到洪水事件（控制）进行了修改，以改变水分的可用性转换湿地开放水域，湿农田，干农田。在潮湿的前成土壤的对照实验中，风暴的演变最类似于在海洋上形成和加强的热带低压。不考虑土壤水分条件，湿地转换为农田减少了风暴强度，而且，非饱和土壤减少了20%的降雨量，并导致持续时间较短的高强度风的条件。开发农田，更重要的是恢复湿地，而不是将其转化为开放水域，可以阻碍影响该地区的热带系统的强化。
Extreme flooding over southern Louisiana in mid-August of 2016 resulted from an unusual tropical low that formed and intensified over land. We used numerical experiments to highlight the role of the ‘Brown Ocean’ effect (where saturated soils function similar to a warm ocean surface) on intensification and it’s modulation by land cover change. A numerical modeling experiment that successfully captured the flood event (control) was modified to alter moisture availability by converting wetlands to open water, wet croplands, and dry croplands. Storm evolution in the control experiment with wet antecedent soils most resembles tropical lows that form and intensify over oceans. Irrespective of soil moisture conditions, conversion of wetlands to croplands reduced storm intensity, and also, non-saturated soils reduced rain by 20% and caused shorter durations of high intensity wind conditions. Developing agricultural croplands and more so restoring wetlands and not converting them into open water can impede intensification of tropical systems that affect the area.