Mesoscale circulations over complex terrain in the Valencia coastal region, Spain – Part 1: Simulation of diurnal circulation regimes

摘要

We collected ground-based and aircraft vertical profile measurements ofmeteorological parameters during a 2-week intensive campaign over theValencia basin, in order to understand how mesoscale circulations developover complex terrain and affect the atmospheric transport of tracers. Ahigh-resolution version of the RAMS model was run to simulate the campaignand characterize the diurnal patterns of the flow regime: night-timekatabatic drainage, morning sea-breeze development and its subsequentcoupling with mountain up-slopes, and evening flow-veering underlarger-scale interactions. An application of this mesoscale model tothe transport of CO₂ is given in a companion paper. A carefulevaluation of the model performances against diverse meteorologicalobservations is carried out. Despite the complexity of the processesinteracting with each other, and the uncertainties on modeled soil moistureboundary conditions and turbulence parameterizations, we show that it ispossible to simulate faithfully the contrasted flow regimes during thecourse of one day, especially the inland progression and organization of thesea breeze. This gives confidence with respect to future applicability ofmesoscale models to establish a reliable link between surface sources oftracers and their atmospheric concentration signals over complex terrain.