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Direct measurement of evapotranspiration from a forest using a superconducting gravimeter
Author(s) -
Van Camp Michel,
Viron Olivier,
PajotMétivier Gwendoline,
Casenave Fabien,
Watlet Arnaud,
Dassargues Alain,
Vanclooster Marnik
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl070534
Subject(s) - gravimeter , evapotranspiration , environmental science , mesoscale meteorology , flux (metallurgy) , atmosphere (unit) , hydrology (agriculture) , atmospheric sciences , geology , meteorology , geophysics , physics , climatology , ecology , materials science , casing , geotechnical engineering , metallurgy , biology
Evapotranspiration (ET) controls the flux between the land surface and the atmosphere. Assessing the ET ecosystems remains a key challenge in hydrology. We have found that the ET water mass loss can be directly inferred from continuous gravity measurements: as water evaporates and transpires from terrestrial ecosystems, the mass distribution of water decreases, changing the gravity field. Using continuous superconducting gravity measurements, we were able to identify daily gravity changes at the level of, or smaller than, 10 −9 nm s −2 (or 10 −10 g) per day. This corresponds to 1.7 mm of water over an area of 50 ha. The strength of this method is its ability to enable a direct, traceable and continuous monitoring of actual ET for years at the mesoscale with a high accuracy.