LANDMATE at the European Meteorological Society Annual Meeting 2021 (EMS 2021)

LANDMATE PhD candidate presents the new irrigation parameterization for REMO-iMOVE at the EMS 2021

Figure 1: Irrigation parametrization for REMO-iMOVE

Christina Asmus presented the newly developed irrigation parameterization for REMO-iMOVE at the European Meteorological Society Annual Meeting 2021.

With the parameterization, the study aims to analyze the effects of channel irrigation on the regional and local climate conditions in the Greater Alpine Region. The parameterization is based on the newly implemented irrigated fraction in REMO-iMOVE and an irrigation module, which enables the user to vary properties like irrigation amount and duration, respectively (Figure 1).

Figure 2: Irrigation effects as monthly mean values in June 2017.

The effects of irrigation are calculated as the differences between simulations with the parameterization turned on and off. Since it is known that irrigation effects are most pronounced under dry and warm conditions, the heatwave of the Mediterranean area in June 2017 is simulated with and without irrigation. For irrigated areas the increase of soil moisture leads to an increase in evapotranspiration as well as in the latent heat flux, whereas the sensible heat flux decreases (Figure 2a-c,f). This change in the surface energy balance leads to a decrease in surface and near-surface temperatures (Figure 2d). Under the heatwave conditions, the irrigation effect on the monthly mean value of the 2 m temperature is up to -1 K in areas with a large irrigated fraction (Figure 2e).

Reference: Asmus, C., Hoffmann, P., Pietikäinen, J.-P., Böhner, J., and Rechid, D.: Modeling irrigation effects on the regional climate in the "Greater Alpine Region" using a newly developed parameterization, EMS Annual Meeting 2021, online, 6–10 Sep 2021, EMS2021-176, https://doi.org/10.5194/ems2021-176, 2021.