DOI: 10.1002/2015MS000484
Scopus记录号: 2-s2.0-84959545923
论文题名: Incorporating root hydraulic redistribution in CLM4.5: Effects on predicted site and global evapotranspiration, soil moisture, and water storage
作者: Tang J ; , Riley W ; J ; , Niu J
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2015
卷: 7, 期: 4 起始页码: 1828
结束页码: 1848
语种: 英语
英文关键词: Digital storage
; Evapotranspiration
; Forecasting
; Forestry
; Groundwater
; Moisture
; Sensitivity analysis
; Soil moisture
; Soils
; Water supply
; Community land models
; Gravity recovery and climate experiments
; Meteorological forcing
; Numerical implementation
; Pedo-transfer functions
; Root hydraulic redistribution
; Terrestrial water storage
; Water storage
; Soil surveys
; evapotranspiration
; global perspective
; GRACE
; numerical model
; pedotransfer function
; soil moisture
; water storage
; water table
; Amazonia
; Blodgett Forest
; Brazil
; Brazil
; California
; Para [Brazil]
; Santarem [Para]
; United States
英文摘要: We implemented the Amenu-Kumar model in the Community Land Model (CLM4.5) to simulate plant Root Hydraulic Redistribution (RHR) and analyzed its influence on CLM hydrology from site to global scales. We evaluated two numerical implementations: The first solved the coupled equations of root and soil water transport concurrently, while the second solved the two equations sequentially. Through sensitivity analysis, we demonstrate that the sequentially coupled implementation (SCI) is numerically incorrect, whereas the tightly coupled implementation (TCI) is numerically robust with numerical time steps varying from 1 to 30 min. At the site-level, we found the SCI approach resulted in better agreement with measured evapotranspiration (ET) at the AmeriFlux Blodgett Forest site, California, whereas the two approaches resulted in equally poor agreement between predicted and measured ET at the LBA Tapajos KM67 Mature Forest site in Amazon, Brazil. Globally, the SCI approach overestimated annual land ET by as much as 3.5 mm d-1 in some grid cells when compared to the TCI estimates. These comparisons demonstrate that TCI is a more robust numerical implementation of RHR. However, we found, even with TCI, that incorporating RHR resulted in worse agreement with measured soil moisture at both the Blodgett Forest and Tapajos sites and degraded the agreement between simulated terrestrial water storage anomaly and Gravity Recovery and Climate Experiment (GRACE) observations. We find including RHR in CLM4.5 improved ET predictions compared with the FLUXNET-MTE estimates north of 20© N but led to poorer predictions in the tropics. The biases in ET were robust and significant regardless of the four different pedotransfer functions or of the two meteorological forcing data sets we applied. We also found that the simulated water table was unrealistically sensitive to RHR. Therefore, we contend that further structural and data improvements are warranted to improve the hydrological dynamics in CLM4.5. © 2015. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75964
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Earth Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA, United States
Recommended Citation:
Tang J,, Riley W,J,et al. Incorporating root hydraulic redistribution in CLM4.5: Effects on predicted site and global evapotranspiration, soil moisture, and water storage[J]. Journal of Advances in Modeling Earth Systems,2015-01-01,7(4)