New gap-filling and partitioning technique for H<sub>2</sub>O eddy fluxes measured over forests
The continuous measurement of H<sub>2</sub>O fluxes using the eddy covariance (EC) technique is still challenging for forests because of large amounts of wet canopy evaporation (<i>E</i><sub>WC</sub>), which occur during and following rain events when the EC sy...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-01-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/15/631/2018/bg-15-631-2018.pdf |
| Summary: | The continuous measurement of H<sub>2</sub>O fluxes using the
eddy covariance (EC) technique is still challenging for forests because of
large amounts of wet canopy evaporation (<i>E</i><sub>WC</sub>), which occur during and
following rain events when the EC systems rarely work correctly. We propose
a new gap-filling and partitioning technique for the H<sub>2</sub>O fluxes: a
model–statistics hybrid (MSH) method. It enables the recovery of the missing
<i>E</i><sub>WC</sub> in the traditional gap-filling method and the partitioning of the
evapotranspiration (ET) into transpiration and (wet canopy) evaporation. We
tested and validated the new method using the data sets from two flux towers,
which are located at forests in hilly and complex terrains. The MSH
reasonably recovered the missing <i>E</i><sub>WC</sub> of 16–41 mm yr<sup>−1</sup> and separated it from the ET (14–23 % of the
annual ET). Additionally, we illustrated certain advantages of the proposed
technique which enable us to understand better how ET responds to
environmental changes and how the water cycle is connected to the carbon
cycle in a forest ecosystem. |
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| ISSN: | 1726-4170 1726-4189 |