Near-Surface Temperature Field in a Basin During Nocturnal Drainage Flow

摘要

An empirical analysis of data from 27 surface meteorological stations in a complex basin indicates that the near-surface nighttime temperature patterns can be approximated. A critical pressure or elevation exists each night. Stations above this elevation show an increase in temperature during the night while those below it show a decrease. Cooling rates increase with decreasing elevation in the basin. A possible explanation of this behavior is that we are observing the combined effects of local radiative cooling and advective warming due to entrainment of external air. At sites above the critical elevation the advective effects are dominant and below it radiative effects begin to have the stronger influence. The lower a site is in the basin, the less influence advection has; consequently the observed cooling rates are greater. (ERA citation 08:016011)