Elevated stratified layers observed with sodar during VTMX

Summary

A combination of low frequency sodar, radar wind profiler and in-situ balloon-borne measurements of temperature and water vapor have been used to investigate the structure of elevated stratified layers within the transition layer above the nocturnal boundary layer during the Vertical Transport and Mixing Field Campaign in Salt Lake City Utah, during October, 2000. Elevated layers determined from sodar and radar vertical time sections were penetrated with a balloon-born instrument package to determine the fine scale temperature and moisture structure of the layers. As expected a potential temperature increase was found in the upper half of the layers; however the magnitude was considerably smaller than found above the daytime well-mixed layer and the vertical distance of the increase was quite variable. Mixing ratio, in the mean was found to have a relative maximum in the lower portion of the layers. It was found that the potential temperature within the layers decreased with time relative to background values, regardless of whether the layer descended or ascended.