Santander Meteorology Group

A multidisciplinary approach for weather & climate

Interactions between the land surface and the atmosphere play a fundamental role in the weather
and climate system. Here we present a comparison of summertime land-atmosphere coupling strength found
in a subset of the ERA-Interim-driven European domain Coordinated Regional Climate Downscaling Experiment
(EURO-CORDEX) model ensemble (1989–2008). Most of the regional climate models (RCMs) reproduce the
overall soil moisture interannual variability, spatial patterns, and annual cycles of surface exchange fluxes for
the different European climate zones suggested by the observational Global Land Evaporation Amsterdam
Model (GLEAM) and FLUXNET data sets. However, some RCMs differ substantially from FLUXNET observations
for some regions. The coupling strength is quantified by the correlation between the surface sensible and
the latent heat flux, and by the correlation between the latent heat flux and 2 m temperature. The first
correlation is compared to its estimate from the few available long-term European high-quality FLUXNET
observations, and the latter to results from gridded GLEAM data. The RCM simulations agree with both
observational datasets in the large-scale pattern characterized by strong coupling in southern Europe and weak
coupling in northern Europe. However, in the transition zone from strong to weak coupling covering large parts
of central Europe many of the RCMs tend to overestimate the coupling strength in comparison to both
FLUXNET and GLEAM. The RCM ensemble spread is caused primarily by the different land surface models
applied, and by the model-specific weather conditions resulting from different atmospheric parameterizations.