globalchange  > 气候变化与战略
DOI: 10.5194/hess-24-5015-2020
论文题名:
Averaging over spatiotemporal heterogeneity substantially biases evapotranspiration rates in a mechanistic large-scale land evaporation model
作者: Freund E.R.; Zappa M.; Kirchner J.W.
刊名: Hydrology and Earth System Sciences
ISSN: 1027-5606
出版年: 2020
卷: 24, 期:10
起始页码: 5015
结束页码: 5025
语种: 英语
Scopus关键词: Earth (planet) ; Estimation ; Evaporation ; Evapotranspiration ; Surface measurement ; Atmospheric dynamics ; Hydrological cycles ; Hydrological process ; Land surface modeling ; Land surface models ; Land surface properties ; Mathematical approach ; Spatiotemporal heterogeneities ; Agglomeration ; evapotranspiration ; heterogeneity ; numerical model ; simulation ; spatiotemporal analysis
英文摘要: Evapotranspiration (ET) influences land-climate interactions, regulates the hydrological cycle, and contributes to the Earth's energy balance. Due to its feedback to large-scale hydrological processes and its impact on atmospheric dynamics, ET is one of the drivers of droughts and heatwaves. Existing land surface models differ substantially, both in their estimates of current ET fluxes and in their projections of how ET will evolve in the future. Any bias in estimated ET fluxes will affect the partitioning between sensible and latent heat and thus alter model predictions of temperature and precipitation. One potential source of bias is the so-called "aggregation bias"that arises whenever nonlinear processes, such as those that regulate ET fluxes, are modeled using averages of heterogeneous inputs. Here we demonstrate a general mathematical approach to quantifying and correcting for this aggregation bias, using the GLEAM land evaporation model as a relatively simple example. We demonstrate that this aggregation bias can lead to substantial overestimates in ET fluxes in a typical large-scale land surface model when sub-grid heterogeneities in land surface properties are averaged out. Using Switzerland as a test case, we examine the scale dependence of this aggregation bias and show that it can lead to an average overestimation of daily ET fluxes by as much as 10% across the whole country (calculated as the median of the daily bias over the growing season). We show how our approach can be used to identify the dominant drivers of aggregation bias and to estimate sub-grid closure relationships that can correct for aggregation biases in ET estimates, without explicitly representing sub-grid heterogeneities in large-scale land surface models. © 2020 Author(s).
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/162568
Appears in Collections:气候变化与战略

Files in This Item:

There are no files associated with this item.


作者单位: Freund, E.R., Laboratory of Hydrology and Water Management, Ghent University, Ghent, Belgium, Department of Hydrology, Faculty of Environment and Natural Resources, University of Freiburg, Freiburg, Germany, Department of Environmental Systems Science, ETH Zurich, Zurich, 8092, Switzerland; Zappa, M., Swiss Federal Research Institute WSL, Birmensdorf, 8903, Switzerland; Kirchner, J.W., Department of Environmental Systems Science, ETH Zurich, Zurich, 8092, Switzerland, Swiss Federal Research Institute WSL, Birmensdorf, 8903, Switzerland, Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, United States

Recommended Citation:
Freund E.R.,Zappa M.,Kirchner J.W.. Averaging over spatiotemporal heterogeneity substantially biases evapotranspiration rates in a mechanistic large-scale land evaporation model[J]. Hydrology and Earth System Sciences,2020-01-01,24(10)
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[Freund E.R.]'s Articles
[Zappa M.]'s Articles
[Kirchner J.W.]'s Articles
百度学术
Similar articles in Baidu Scholar
[Freund E.R.]'s Articles
[Zappa M.]'s Articles
[Kirchner J.W.]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[Freund E.R.]‘s Articles
[Zappa M.]‘s Articles
[Kirchner J.W.]‘s Articles
Related Copyright Policies
Null
收藏/分享
所有评论 (0)
暂无评论
 

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.