气候变化领域集成服务门户(CCPortal): Influence of surface water variations on VOD and biomass estimates from passive microwave sensors

CCPortal

DOI	10.1016/j.rse.2021.112345
	Influence of surface water variations on VOD and biomass estimates from passive microwave sensors
	Bousquet E.; Mialon A.; Rodriguez-Fernandez N.; Prigent C.; Wagner F.H.; Kerr Y.H.
发表日期	2021
ISSN	00344257
卷号	257
英文摘要	Vegetation optical depth (VOD) is a remotely sensed indicator characterizing the attenuation of the Earth's thermal emission at microwave wavelengths by the vegetation layer. At L-band, VOD is used to estimate the global biomass, a key component of the Earth's surface and of the carbon cycle. This study focuses on the behaviour of L-band VOD (L-VOD) retrieval algorithm over seasonally inundated areas, as some previous observations have shown an unexpected decline in VOD during flooding events. To analyse such variations, a passive microwave model was used to simulate the signal emitted by a mixed scene composed of soil and standing water. The retrieval over this inundated scene led to an overestimation of soil moisture (SM) and an underestimation of L-VOD. The phenomenon is more pronounced over grasslands than over forests, since low vegetation is mostly submerged under water and becomes invisible to the sensor; and since more standing water is visible to the sensor. The estimated L-VOD is typically reduced by ~10% over flooded forests and up to 100% over flooded grasslands. Such effects can distort the analysis of aboveground biomass (AGB) and aboveground carbon (AGC) dynamics based on L-VOD estimates. We evaluated that AGB can be underestimated by 15/20 Mg ha−1 in the largest seasonal wetlands, which can represent more than 50% of the actual AGB of these fields, and up to higher values during exceptional meteorological years. Consequently, to better estimate the global biomass, surface water seasonality has to be taken into account in passive microwave retrieval algorithms. © 2021 The Author(s)
英文关键词	Biomass; L-band; Passive microwaves; Retrievals; SMOS; VOD; Water fraction
语种	英语
scopus关键词	Biomass; Carbon; Floods; Forestry; Microwaves; Soil moisture; Surface waters; Vegetation; Video on demand; Above-ground carbons; Aboveground biomass; Microwave wavelengths; Passive microwave sensors; Passive microwaves; Retrieval algorithms; Thermal emissions; Vegetation optical depth; Microwave sensors; aboveground biomass; algorithm; biomass; estimation method; flooding; grassland; microwave radiation; optical depth; remote sensing; sensor; soil moisture; standing wave; surface water; wavelength; Indicator indicator
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/178912
作者单位	Centre d'Etudes Spatiales de la Biosphère (CESBIO), Université de Toulouse (CNES/CNRS/INRAE/IRD/UPS), 18 av. Edouard Belin, bpi 2801, Toulouse CEDEX 9, 31401, France; CNRS, Sorbonne Université, Observatoire de Paris, Université PSL, LERMA, 61 avenue de l'Observatoire, Paris, 75014, France; GeoProcessing Division, Foundation for Science, Technology and Space Applications—FUNCATE, São José dos Campos, SP 12210-131, Brazil
推荐引用方式 GB/T 7714	Bousquet E.,Mialon A.,Rodriguez-Fernandez N.,et al. Influence of surface water variations on VOD and biomass estimates from passive microwave sensors[J],2021,257.
APA	Bousquet E.,Mialon A.,Rodriguez-Fernandez N.,Prigent C.,Wagner F.H.,&Kerr Y.H..(2021).Influence of surface water variations on VOD and biomass estimates from passive microwave sensors.Remote Sensing of Environment,257.
MLA	Bousquet E.,et al."Influence of surface water variations on VOD and biomass estimates from passive microwave sensors".Remote Sensing of Environment 257(2021).