Intercomparison of local evapotranspiration estimates at high latitudes

The main motivation for this study is to improve knowledge about the actual evapotranspiration in cold environments. Erlandsen et al (2021) summarize evapotranspiration estimates that range from 175 – 500 mm/year, i.e. between 13 and 31% of mean annual precipitation for Norway. The study is part of the LATICE (Land-ATmosphere Interactions in Cold Environments) strategic research initiative at the University of Oslo. Here we have launched a new initiative, LATICE MIP-ET that aims to compare model estimates of evapotranspiration (ET) in a high latitude environment.

In this study, we compare local observations of evapotranspiration with local estimates from two land surface models (CLM and SURFEX) and three hydrological models (SHYFT, HBV and Lisflood). Observations are available at five eddy covariance flux sites with a gradient in climate across Norway, from low altitude forested and grassland sites to high mountain and high latitude sites. To run the models three sets of forcing data will be used.

The presentation will summarize the models’ ability to capture diurnal and seasonal variations in evapotranspiration as compared to the observations. We will also compare how models simulate the relationship between potential and actual evapotranspiration and assess the models’ sensitivity to the choice of vegetation-and soil parameters and forcing data used.

References:

Erlandsen, H.B., Beldring, S., Eisner, S., Hisdal, H., Huang, S., Tallaksen, L.M. (2021) Constraining the HBV model for robust water balance assessments in a cold climate. Hydrology Research 2021; nh2021132. doi: https://doi.org/10.2166/nh.2021.132