气候变化领域集成服务门户(CCPortal): Assimilation of Cosmic-Ray Neutron Counts for the Estimation of Soil Ice Content on the Eastern Tibetan Plateau

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DOI	10.1029/2019JD031529
	Assimilation of Cosmic-Ray Neutron Counts for the Estimation of Soil Ice Content on the Eastern Tibetan Plateau
	Mwangi S.; Zeng Y.; Montzka C.; Yu L.; Su Z.
发表日期	2020
ISSN	2169897X
卷号	125 期号:3
英文摘要	Accurate observations and simulations of soil moisture phasal forms are crucial in cold region hydrological studies. In the seasonally frozen ground of eastern Tibetan Plateau, water vapor, liquid, and ice coexist in the frost-susceptible silty-loam soil during winter. Quantification of soil ice content is thus vital in the investigation and understanding of the region's freezing-thawing processes. This study focuses on the retrieval of soil ice content utilizing the in situ soil moisture (i.e., liquid phase) and cosmic ray neutron measurements (i.e., total water including liquid and ice), with Observing System Simulation Experiments. To derive the total soil water from neutron counts, different weighting methods (revised, conventional, and uniform) for calibrating the cosmic-ray neutron probe (CRNP) were intercompared. The comparison showed that the conventional nonlinear method performed the best. Furthermore, to assimilate fast neutrons using the particle filter, the STEMMUS-FT (Simultaneous Transfer of Energy, Mass and Momentum in Unsaturated Soil) model was used as the physically based process model, and the COSMIC model (Cosmic-ray Soil Moisture Interaction Code) used as the observation operator (i.e., forward neutron simulator). Other than background inputs from disturbed initializations in the STEMMUS-FT, model uncertainties were predefined to assimilate fast neutrons. We observed that with enough spread of uncertainties, the updated states could mimic the CRNP observation. In all setups, assimilating CRNP measurements could enhance total soil water analyses, which consequently led to the improved detection of soil ice content and therefore the freezing thawing-process at the field scale. ©2020. The Authors.
英文关键词	cosmic-ray neutron probe; data assimilation; freezing-thawing; soil ice content; Tibetan Plateau
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186192
作者单位	Faculty of Geo-information Science and Earth Observation (ITC), University of Twente, Enschede, Netherlands; Institute of Bio- and Geosciences: Agrosphere (IBG-3), Forschungszentrum Jülich GmbH, Jülich, Germany; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, School of Water and Environment, Chang'an University, Xi'an, China
推荐引用方式 GB/T 7714	Mwangi S.,Zeng Y.,Montzka C.,et al. Assimilation of Cosmic-Ray Neutron Counts for the Estimation of Soil Ice Content on the Eastern Tibetan Plateau[J],2020,125(3).
APA	Mwangi S.,Zeng Y.,Montzka C.,Yu L.,&Su Z..(2020).Assimilation of Cosmic-Ray Neutron Counts for the Estimation of Soil Ice Content on the Eastern Tibetan Plateau.Journal of Geophysical Research: Atmospheres,125(3).
MLA	Mwangi S.,et al."Assimilation of Cosmic-Ray Neutron Counts for the Estimation of Soil Ice Content on the Eastern Tibetan Plateau".Journal of Geophysical Research: Atmospheres 125.3(2020).