Semi-arid regions, of which the Mediterranean is one, are known hot-spots for biases in model parameters/variables such as land surface temperature and components of the surface energy balance. These model biases exist across diurnal and seasonal time-scales. These inadequacies in land surface models demonstrate the need for a better understanding of the physical processes represented in such models. Understanding the processes that drive the hydrological cycle in the Mediterranean region is a key challenge and dedicated working groups including HyMEX (HYdrological cycle in the Mediterranean EXperiment) and WACMOS_MED (Water Cycle Multi-mission Observation Strategy for the Mediterranean) aim to address these scientific challenges.

Little is known of the impact of drought onset on seasonal weather prediction. Climate projections suggest that semi-arid regions may extend further into Europe and may play an increasingly important role on components of regional climate in the future.

The overarching motivation for this session is an improved understanding of processes such as evapotranspiration, precipitation and soil moisture and the subsequent feedbacks to the Mediterranean boundary layer. This session aims to bring together observational and modelling studies investigating land-atmosphere interactions in semi-arid regions, particularly the Mediterranean region. In particular, we invite contributions which can include, but are not limited to,

1) Observational studies of the surface energy balance and the hydrological cycle in the Mediterranean region.
2) Modelling studies demonstrating strengths and weaknesses of these semi-arid environments.