A Study of the Spatial and Temporal Variation of Temperature in the Atmospheric Boundary Layer.

摘要

The horizontal uniformity of minimum temperature during quiescent intervals for unstable convection is shown to be on the order of a few hundreds of a degree celsuis over a fifty meter array for periods on the order of fifteen minutes. One interpretation of this characteristic is that the minimum temperature during the quiescent interval is characteristic of the potential temperature at planetary boundary layer heights at which the potential temperature is constant with height. Examination of the quiescent temperature during unstable and stable periods of the same day, shows that the spatially uniform quiescent temperatures go from cold during unstable conditions to warm during stable conditions. The latter is consistent with the hypothesis that elements from height ranges of uniform potential temperature are advected into the surface layer by mechanical mixing during these stable conditions.