气候变化领域集成服务门户(CCPortal): Small anomalies in dry-season greenness and chlorophyll fluorescence for Amazon moist tropical forests during El Niño and La Niña

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DOI	10.1016/j.rse.2020.112196
	Small anomalies in dry-season greenness and chlorophyll fluorescence for Amazon moist tropical forests during El Niño and La Niña
	Doughty R.; Xiao X.; Qin Y.; Wu X.; Zhang Y.; Moore B.; III
发表日期	2021
ISSN	00344257
卷号	253
英文摘要	The Amazon Basin, a major driver of atmospheric CO2 fluxes, is composed of moist tropical forest (> 2000 mm mean annual precipitation), seasonally moist tropical forests (< 2000 mm mean annual precipitation), croplands, and pastures. It is debated whether there is a dry-season increase in photosynthesis for moist forest and a large reduction in photosynthesis of tropical South America was recently cited as a major driver of the historically high atmospheric CO2 growth rate during the 2015/2016 El Niño. To address this debate and to gain insight into changes in dry-season greenness, SIF, and photosynthesis during El Niño-Southern Oscillation (ENSO) events, here we investigate (1) dry-season changes in satellite-based greenness, solar-induced chlorophyll fluorescence (SIF), and photosynthesis during 2007–2017 and (2) anomalies of satellite-based dry-season greenness, SIF, and photosynthesis for two El Niño events (2009/2010 and 2015/2016) and two La Niña events (2007/2008 and 2010/2011). We hypothesize that satellite-based greenness, SIF, and photosynthesis of moist tropical forests should increase during the dry season, and find this to be the case using two MODIS BRDF-adjusted vegetation indices (EVI and NDVI), GOME-2 SIF data, and the Vegetation Photosynthesis Model (VPM). We also hypothesize that dry-season greenness, SIF, and photosynthesis should be anomalously high during the El Niños, due to anomalously high photosynthetically active radiation (PAR) and a relatively normal preceding wet season, and anomalously low during the La Niñas because these dry seasons were preceded by anomalously low amounts of wet-season precipitation. For this hypothesis, we present results for moist tropical forest and at the basin scale to determine if and by how much their anomalies differ. We find dry-season greenness, SIF, and photosynthesis of moist tropical forest and at the basin scale were statistically significantly lower than normal during the La Niñas, significantly higher than normal during the 2009/2010 El Niño, and were mixed for the 2015/2016 El Niño. Although statistically significant, the magnitudes of the dry-season anomalies were not substantial. Our findings provide additional evidence that photosynthesis of moist tropical Amazon forest increases during the dry season and narrows the potential drivers of perturbations to the atmospheric CO2 growth rate during the last four ENSO events, as anomalies in dry-season greenness, SIF, and photosynthesis during these ENSO events were minute. © 2020 Elsevier Inc.
英文关键词	Drought; El Niño–southern oscillation; GOME-2; Gross primary productivity; MAIAC; MODIS; OCO-2; Solar-induced chlorophyll fluorescence
语种	英语
scopus关键词	Atmospheric pressure; Carbon dioxide; Chlorophyll; Climatology; Drought; Fluorescence; Forestry; Growth rate; Lanthanum; Photosynthesis; Satellites; Tropics; Vegetation; Amazon forests; Chlorophyll fluorescence; Mean annual precipitation; Moist forests; Photosynthetically active radiation; Southern oscillation; Tropical forest; Vegetation index; Nickel compounds; chlorophyll; dry season; El Nino; fluorescence; growth rate; La Nina; MODIS; photosynthetically active radiation; spatiotemporal analysis; tropical forest; Amazon Basin
来源期刊	Remote Sensing of Environment
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179036
作者单位	Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK 73019, United States; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States; Department of Environmental Science, Policy and Management, University of California Berkeley, Berkeley, CA 94720, United States; College of Atmospheric and Geographic Sciences, University of Oklahoma, Norman, OK 73019, United States
推荐引用方式 GB/T 7714	Doughty R.,Xiao X.,Qin Y.,et al. Small anomalies in dry-season greenness and chlorophyll fluorescence for Amazon moist tropical forests during El Niño and La Niña[J],2021,253.
APA	Doughty R..,Xiao X..,Qin Y..,Wu X..,Zhang Y..,...&III.(2021).Small anomalies in dry-season greenness and chlorophyll fluorescence for Amazon moist tropical forests during El Niño and La Niña.Remote Sensing of Environment,253.
MLA	Doughty R.,et al."Small anomalies in dry-season greenness and chlorophyll fluorescence for Amazon moist tropical forests during El Niño and La Niña".Remote Sensing of Environment 253(2021).