horizontal homogeneity does not apply and the understanding of slope and basin flows is a
necessity. Here a double fold approach is made. On one hand, a ten-year climatology is
made for an ensemble of stations in the Lleida area of the Ebro basin, with a typical
separation of 10 kilometers between stations. The climatology is restricted to stably
stratified nights and an effort has been made to develop suitable filters for the
database. Interpretation of the statistics with time along night and situation gives
hints on the flow patterns within the basin.
On the other hand, a high resolution mesoscale simulation is made for a clear skies night
with weak synoptic winds, in the hope that it reproduces the typical basin circulations
during that night. Comparison with the data for that night, radiative surface temperature
from satellite and the conditioned climatology will be used for validation and inspection
of the model outputs to understand the slope and basin flows.