Evapotranspiration estimates using the eddy covariance technique
Citation
Desjardins, R.L. 2016. Evapotranspiration estimates using the eddy covariance technique. China-Canada Water Resource Workshop, Ottawa, ON 2016/11/15.
Plain language summary
The eddy covariance (EC) approach is one of the primary and minimally invasive methods of directly measuring the flux of water from the ground surface. In this presentation, tower and aircraft-based EC methods to estimate the flux of water vapour are described. Using examples from past research, the comparability of tower-based and aircraft-based measurements is demonstrated, and the related problem of lack of energy budget closure is discussed. Wavelet analysis is presented as one potential analysis technique that could be used to try and reduce the lack of energy budget closure, by being able to resolve longer-wavelength (greater than 2 km) flux contributions. The development of Environmental Response Functions, a technique that employs wavelet and footprint analysis to relate a flux measurement with satellite-based measurements is presented, and an example of the prediction of water vapour flux from a large area in the agricultural region of northern Saskatchewan is given.
Abstract
The eddy covariance (EC) approach is one of the primary and minimally invasive methods of directly measuring the flux of water from the ground surface. In this presentation, tower and aircraft-based EC methods to estimate the flux of water vapour are described. Using examples from past research, the comparability of tower-based and aircraft-based measurements is demonstrated, and the related problem of lack of energy budget closure is discussed. Wavelet analysis is presented as one potential analysis technique that could be used to try and reduce the lack of energy budget closure, by being able to resolve longer-wavelength (greater than 2 km) flux contributions. The development of Environmental Response Functions, a technique that employs wavelet and footprint analysis to relate a flux measurement with satellite-based measurements is presented, and an example of the prediction of water vapour flux from a large area in the agricultural region of northern Saskatchewan is given.