Revisiting the contribution of transpiration to global terrestrial evapotranspiration
Revisiting the contribution of transpiration to global terrestrial evapotranspiration
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DOI：
10.1002/2016gl072235
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发表时间：
2017-03
影响因子：
5.2
通讯作者：
Zhongwang Wei;K. Yoshimura;Lixin Wang;D. Miralles;S. Jasechko;X. Lee
中科院分区：
文献类型：
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作者：
Zhongwang Wei;K. Yoshimura;Lixin Wang;D. Miralles;S. Jasechko;X. Lee
尽管了解蒸腾(T)、土壤和开阔水域蒸发(E)以及截留(I)对陆地蒸散(ET=T+E+I)的贡献对于理解水文循环及其与生态过程的关系是至关重要的，但通过传统的大尺度测量技术无法获得T的比例。以前报告的来自多个独立来源的全球平均T/(E+T+I)，包括基于卫星的估计、再分析、陆地表面模型和同位素测量，基本上从24%到90%不等。在这里，我们开发了一种新的ET划分算法，该算法结合了全球蒸散估计和不同植被类型的叶面积指数(LAI)和T/(E+T)之间的关系，以扩大已发表的广泛的立地尺度测量结果。结果表明，蒸腾作用约占全球陆地蒸腾总量的57.2%(标准差±6.8%)。我们的方法弥合了现场测量和全球模式模拟之间的比例差距，并且可以简单地应用到当前的全球气候模型中，以改进生物二氧化碳通量模拟。
Even though knowing the contributions of transpiration (T), soil and open water evaporation (E), and interception (I) to terrestrial evapotranspiration (ET = T + E + I) is crucial for understanding the hydrological cycle and its connection to ecological processes, the fraction of T is unattainable by traditional measurement techniques over large scales. Previously reported global mean T/(E + T + I) from multiple independent sources, including satellite‐based estimations, reanalysis, land surface models, and isotopic measurements, varies substantially from 24% to 90%. Here we develop a new ET partitioning algorithm, which combines global evapotranspiration estimates and relationships between leaf area index (LAI) and T/(E + T) for different vegetation types, to upscale a wide range of published site‐scale measurements. We show that transpiration accounts for about 57.2% (with standard deviation ± 6.8%) of global terrestrial ET. Our approach bridges the scale gap between site measurements and global model simulations,and can be simply implemented into current global climate models to improve biological CO2 flux simulations.