This study explores the relationship between water vapor and rainfall intensities over three tropical lands (Amazon Basin, Sahel, southern South America) and three tropical ocean regions (Atlantic Ocean, Indian Ocean, Niño 4). We utilized daily total column water vapor (TCWV) data from the Atmospheric Infrared Sounder (AIRS) and daily precipitation records from the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation. Over tropical land, precipitation shows higher sensitivity to changes in water vapor, with a well-sorted pattern of an increased occurrence of higher daily precipitation as TCWV increases. Precipitation intensity over the Sahel, in particular, is extremely responsive to TCWV change. Over tropical oceans, the precipitation intensity is less sensitive to water vapor, particularly in the Indian Ocean and Niño 4 where precipitation intensities above the 40th percentile are no longer responding to the increasing TCWV. Quantifying water vapor and precipitation intensity aids in forecasting the occurrence of precipitation between tropical land and oceans.

中文翻译：

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卫星观测降水量和总水汽柱

本研究探讨了三个热带陆地（亚马逊盆地、萨赫勒、南美洲南部）和三个热带海洋区域（大西洋、印度洋、尼诺 4 号）水汽与降雨强度之间的关系。我们利用大气红外探测器 (AIRS) 的每日总柱水汽 (TCWV) 数据和热带降雨测量任务 (TRMM) 多卫星降水的每日降水记录。在热带土地上，降水对水汽变化表现出更高的敏感性，随着 TCWV 的增加，日降水量增加的情况也随之增加。特别是萨赫勒地区的降水强度对 TCWV 变化极为敏感。在热带海洋上空，降水强度对水汽不太敏感，特别是在印度洋和厄尔尼诺 4 级地区，40% 以上的降水强度不再对 TCWV 的增加做出响应。量化水蒸气和降水强度有助于预测热带陆地和海洋之间降水的发生。