Temporal–Spatial Variations of Atmospheric Static Stability: A Comparison of the Influences from Temperature and Its Vertical Difference

Abstract

AbstractThe temporal–spatial variations of the static stability of dry air and the relative importance of their influencing quantities are explored. Derivation shows that while it links to the vertical difference of temperature, static stability also relates to the temperature itself. The static stability is expressed as a nonlinear function of temperature and the vertical difference of temperature. The relative importance of the two influencing quantities is assessed with linear regression. Tests show that the linear fitting method is robust. The results of the dominance rely on the data examined, which include an interannual variation, a seasonal variation, and a spatial variation that consists of the grid points over the globe. It is revealed that in the lower troposphere, while the temporal variations of static stability are dominated by the vertical difference of temperature, the temperature itself may also have considerable influence, especially over the high latitudes of the two hemispheres. In the stratosphere, temperature tends to have more contributions. Over the Antarctic, temperature dominates the seasonal and interannual variations of the static stability. The spatial variation of the static stability of July is influenced by both temperature and its vertical difference before 1980, but after that it is dominated by temperature.