文章基本信息

标题：Modulation of Land Photosynthesis by the Indian Ocean Dipole: Satellite‐Based Observations and CMIP6 Future Projections
本地全文：下载
作者：Jun Wang ; Meirong Wang ; Jin‐Soo Kim 等
期刊名称：Earth's Future
电子版ISSN：2328-4277
出版年度：2021
卷号：9
期号：4
页码：e2020EF001942
DOI：10.1029/2020EF001942
出版社：John Wiley & Sons, Ltd.
摘要：Indian Ocean Dipole (IOD), a major climate variability in the tropics which drives the abiotic stress associated with heavy rainfalls and severe droughts, is not much understood in terms of its role in the carbon cycle, while El Niño‐Southern Oscillation (ENSO)‐related terrestrial carbon cycle variation has been intensively studied. Here, we investigate IOD's impact on land photosynthesis over the Indian ocean rim countries during austral spring using satellite‐based gross primary productivity (GPP) and Earth System Model simulations produced in the Coupled Model Intercomparison Project Phase 6 (CMIP6). IOD independently affects GPP with significant positive partial correlation coefficients ( ) over most of Africa and India, and negative over southern China, Indo‐China peninsula, maritime continent, and Australia, mostly driven by precipitation variations; this obviously differs from the widespread significant negative pattern induced by ENSO. The recent extremely positive IOD in 2019 caused the canonical IOD‐affected GPP patterns, however, with its extreme impacts. Furthermore, though large inter‐model spreads exist, the CMIP6 multimodel median can basically capture the main characteristics of IOD‐affected precipitation and GPP patterns. Importantly, IOD is predicted to occur more frequently in future warming scenarios. Model future projections suggest that it will exert larger impacts on GPP variations over central and eastern Africa, Sumatra, western and southeastern Australia with stronger and enhanced explained variance, but less impacts over southern Africa, east India, Indo‐China peninsula, and northeastern Australia. Therefore, besides ENSO, understanding the IOD impacts can provide us new insights into regional and global carbon cycle interannual variability. Plain Language Abstract Indian ocean dipole (IOD) is a major climate variability in the tropics, acting as an important determinant of regional climate variations. However, its role in the carbon cycle received less attention. Here we explore the impact of IOD events on land photosynthesis over the Indian ocean rim countries during austral spring based on satellite‐based gross primary productivity (GPP) and historical and future simulations in 10 Earth System models. We suggest that IOD can positively impact on GPP over most of Africa and India, but negatively impact over southern China, Indo‐China peninsula, maritime continent, and Australia, which are mostly driven by heavy rainfalls and severe droughts associated with its two sea surface temperature poles. The recent extremely positive IOD in 2019 resulted in the canonical but extreme IOD‐affected GPP patterns. Furthermore, multimodel future projections suggest that the occurrence of IOD events will be more frequent in future warming scenario. IOD will exert larger impacts on GPP variations over the central and eastern Africa, Sumatra, western and southeastern Australia, but lower impacts over southern Africa, east India, the Indo‐China peninsula, and northeastern Australia. Understanding the IOD impacts can provide us new insights into regional and global carbon cycle interannual variability.
关键词：CMIP6;future projections;Indian Ocean Dipole;land photosynthesis;precipitation