Erschienen:
American Geophysical Union (AGU), 2017
Erschienen in:Geophysical Research Letters
Sprache:
Englisch
DOI:
10.1002/2016gl072235
ISSN:
0094-8276;
1944-8007
Entstehung:
Anmerkungen:
Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Even though knowing the contributions of transpiration (<jats:italic>T</jats:italic>), soil and open water evaporation (<jats:italic>E</jats:italic>), and interception (<jats:italic>I</jats:italic>) to terrestrial evapotranspiration (<jats:italic>ET = T</jats:italic> + <jats:italic>E</jats:italic> + <jats:italic>I</jats:italic>) is crucial for understanding the hydrological cycle and its connection to ecological processes, the fraction of <jats:italic>T</jats:italic> is unattainable by traditional measurement techniques over large scales. Previously reported global mean <jats:italic>T</jats:italic>/(<jats:italic>E</jats:italic> + <jats:italic>T</jats:italic> + <jats:italic>I</jats:italic>) 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 <jats:italic>ET</jats:italic> partitioning algorithm, which combines global evapotranspiration estimates and relationships between leaf area index (<jats:italic>LAI</jats:italic>) and <jats:italic>T</jats:italic>/(<jats:italic>E</jats:italic> + <jats:italic>T</jats:italic>) 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 <jats:italic>ET</jats:italic>. 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 CO<jats:sub>2</jats:sub> flux simulations.</jats:p>