Further study of terrain effects on the mesoscale spectrum of atmospheric motions

Abstract

Wind and temperature data collected on commercial airliners are used to investigate the effects of underlying terrain on mesoscale variability, focusing on the coupling of variance with the roughness of the underlying terrain over mountainous regions. Earlier results, showing that variances are larger over mountains than over oceans or plains, with greatest increases at wavelengths below about 80km, are confirmed. Statistical tests are used to confirm that these differences are highly significant. Over mountainous regions the roughness of the underlying terrain was parameterized from topographic data and it was found that variances are highly correlated with roughness and, in the troposphere, with background wind speed. Average variances over the roughest terrain areas range up to about ten times larger than those over the oceans. -from Authors