An analytical framework for the modelling of the spatial interaction between the soil moisture and the atmosphere

Abstract Soil moisture-atmosphere interaction is recognized to play a role in the dynamics of long-lasting spatial anomalies of continental climates. A simple analytical model is formulated and analysed, which represents the soil moisture balance subjected to atmospheric forcing. The interaction between the soil moisture and the atmosphere is included in the form of a convolution integral, whose kernel represents the space-time feedbacks of the soil state on its own forcing. The conditions under which the model predicts the birth and growth of long-lasting spatial soil moisture anomalies are studied. Particular properties of the feedback kernel, such as the requirement of the simultaneous presence of an activation and an inhibition component, are identified. The existence of specific feedbacks of soil moisture on precipitation, as the main moisture forcing, is then addressed on the basis of some examples from the existing literature, with particular reference to the unforced convective and frontal-stratiform precipitation dynamics.

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