DOI: 10.1002/2017MS001248
Scopus记录号: 2-s2.0-85043368073
论文题名: A Comparison of the Diel Cycle of Modeled and Measured Latent Heat Flux During the Warm Season in a Colorado Subalpine Forest
作者: Burns S ; P ; , Swenson S ; C ; , Wieder W ; R ; , Lawrence D ; M ; , Bonan G ; B ; , Knowles J ; F ; , Blanken P ; D
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2018
卷: 10, 期: 3 起始页码: 617
结束页码: 651
语种: 英语
英文关键词: Forestry
; Latent heat
; Surface measurement
; Community land models
; Friction velocity
; Hydrological cycles
; Land surface models
; Physiological characteristics
; Precipitation change
; Subalpine forests
; Subcanopy
; Heat flux
英文摘要: Precipitation changes the physiological characteristics of an ecosystem. Because land-surface models are often used to project changes in the hydrological cycle, modeling the effect of precipitation on the latent heat flux λE is an important aspect of land-surface models. Here we contrast conditionally sampled diel composites of the eddy-covariance fluxes from the Niwot Ridge Subalpine Forest AmeriFlux tower with the Community Land Model (CLM, version 4.5). With respect to measured λE during the warm season: for the day following above-average precipitation, λE was enhanced at midday by ≈40 W m−2 (relative to dry conditions), and nocturnal λE increased from ≈10 W m−2 in dry conditions to over 20 W m−2 in wet conditions. With default settings, CLM4.5 did not successfully model these changes. By increasing the amount of time that rainwater was retained by the canopy/needles, CLM was able to match the observed midday increase in λE on a dry day following a wet day. Stable nighttime conditions were problematic for CLM4.5. Nocturnal CLM λE had only a small (≈3 W m−2) increase during wet conditions, CLM nocturnal friction velocity u∗ was smaller than observed u∗, and CLM canopy air temperature was 2°C less than those measured at the site. Using observed u∗ as input to CLM increased λE; however, this caused CLM λE to be increased during both wet and dry periods. We suggest that sloped topography and the ever-present drainage flow enhanced nocturnal u∗ and λE. Such phenomena would not be properly captured by topographically blind land-surface models, such as CLM. © 2018. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75632
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: Department of Geography, University of Colorado, Boulder, CO, United States; National Center for Atmospheric Research, Boulder, CO, United States; Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO, United States; School of Geography and Development, University of Arizona, the College of Social and Behavioral Sciences, Tucson, AZ, United States
Recommended Citation:
Burns S,P,, Swenson S,et al. A Comparison of the Diel Cycle of Modeled and Measured Latent Heat Flux During the Warm Season in a Colorado Subalpine Forest[J]. Journal of Advances in Modeling Earth Systems,2018-01-01,10(3)