Hot season gets hotter due to rainfall delay over tropical land in a warming climate

Abstract Tropical land generally experiences the hottest period (spring) in a year just before the onset of wet season. Previous studies suggested that in a warming climate, the wet season would come later, but its origin is debated and its impact on temperature remains unknown. Here, we find that t...

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Main Authors: Fengfei Song, Hongqiang Dong, Lixin Wu, L. Ruby Leung, Jian Lu, Lu Dong, Peili Wu, Tianjun Zhou
Format: Article
Language:English
Published: Nature Portfolio 2025-03-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-57501-6
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author Fengfei Song
Hongqiang Dong
Lixin Wu
L. Ruby Leung
Jian Lu
Lu Dong
Peili Wu
Tianjun Zhou
author_facet Fengfei Song
Hongqiang Dong
Lixin Wu
L. Ruby Leung
Jian Lu
Lu Dong
Peili Wu
Tianjun Zhou
author_sort Fengfei Song
collection DOAJ
description Abstract Tropical land generally experiences the hottest period (spring) in a year just before the onset of wet season. Previous studies suggested that in a warming climate, the wet season would come later, but its origin is debated and its impact on temperature remains unknown. Here, we find that the warming of hot season would be amplified under global warming, and refer to it as “hot-season-gets-hotter” phenomenon. The amplified hot season warming is closely tied to the amplified warming of hot temperature percentiles. The hot-season-gets-hotter phenomenon is mainly due to the rainfall delay and most evident in the Amazon, where spring is warming by almost 1 K more than the annual mean and the 99th percentile temperatures are warming ~30% more than the mean by the end of 21st century in a high emission scenario. Comparing experiments with and without land-atmosphere coupling, it is further found that the rainfall delay is initially driven by the enhanced effective atmospheric heat capacity and then substantially amplified by positive soil moisture-atmosphere feedback. In the satellite period, observations consistently show that the hot-season-gets-hotter phenomenon has already emerged along with the rainfall delay in the Amazon. Intensified hot and dry spring climate can enhance risks of drought, heatwaves and wildfires, threatening the Amazon forest and habitats in the tropics.
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issn 2041-1723
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spelling doaj-art-aa7cc0f5113f44faaf7461036d360dcb2025-08-20T03:06:00ZengNature PortfolioNature Communications2041-17232025-03-0116111010.1038/s41467-025-57501-6Hot season gets hotter due to rainfall delay over tropical land in a warming climateFengfei Song0Hongqiang Dong1Lixin Wu2L. Ruby Leung3Jian Lu4Lu Dong5Peili Wu6Tianjun Zhou7Frontier Science Center for Deep Ocean Multispheres and Earth System and Physical Oceanography Laboratory, Ocean University of ChinaFrontier Science Center for Deep Ocean Multispheres and Earth System and Physical Oceanography Laboratory, Ocean University of ChinaFrontier Science Center for Deep Ocean Multispheres and Earth System and Physical Oceanography Laboratory, Ocean University of ChinaAtmospheric, Climate, and Earth Sciences Division, Pacific Northwest National LaboratoryAtmospheric, Climate, and Earth Sciences Division, Pacific Northwest National LaboratoryFrontier Science Center for Deep Ocean Multispheres and Earth System and Physical Oceanography Laboratory, Ocean University of ChinaMet Office Hadley CentreLASG, Institute of Atmospheric Physics, Chinese Academy of ScienceAbstract Tropical land generally experiences the hottest period (spring) in a year just before the onset of wet season. Previous studies suggested that in a warming climate, the wet season would come later, but its origin is debated and its impact on temperature remains unknown. Here, we find that the warming of hot season would be amplified under global warming, and refer to it as “hot-season-gets-hotter” phenomenon. The amplified hot season warming is closely tied to the amplified warming of hot temperature percentiles. The hot-season-gets-hotter phenomenon is mainly due to the rainfall delay and most evident in the Amazon, where spring is warming by almost 1 K more than the annual mean and the 99th percentile temperatures are warming ~30% more than the mean by the end of 21st century in a high emission scenario. Comparing experiments with and without land-atmosphere coupling, it is further found that the rainfall delay is initially driven by the enhanced effective atmospheric heat capacity and then substantially amplified by positive soil moisture-atmosphere feedback. In the satellite period, observations consistently show that the hot-season-gets-hotter phenomenon has already emerged along with the rainfall delay in the Amazon. Intensified hot and dry spring climate can enhance risks of drought, heatwaves and wildfires, threatening the Amazon forest and habitats in the tropics.https://doi.org/10.1038/s41467-025-57501-6
spellingShingle Fengfei Song
Hongqiang Dong
Lixin Wu
L. Ruby Leung
Jian Lu
Lu Dong
Peili Wu
Tianjun Zhou
Hot season gets hotter due to rainfall delay over tropical land in a warming climate
Nature Communications
title Hot season gets hotter due to rainfall delay over tropical land in a warming climate
title_full Hot season gets hotter due to rainfall delay over tropical land in a warming climate
title_fullStr Hot season gets hotter due to rainfall delay over tropical land in a warming climate
title_full_unstemmed Hot season gets hotter due to rainfall delay over tropical land in a warming climate
title_short Hot season gets hotter due to rainfall delay over tropical land in a warming climate
title_sort hot season gets hotter due to rainfall delay over tropical land in a warming climate
url https://doi.org/10.1038/s41467-025-57501-6
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