Measuring and Estimating Atmospheric Stability

Abstract

The only way to estimate atmospheric stability at a given place and time is to understand the vertical profile of temperature. There are several mechanisms for assessing the stability condition based on the temperature profile. A global network of sites where instrument packages called radiosondes are launched synchronously twice daily measure, among other variables, the vertical temperature profile. A less accurate, precise, and expensive method is to rank stability using observed wind speed, intensity of incoming solar radiation, and cloud cover, in the Pasquill stability type scheme. Local-scale stability can be measured using the vertical gradient of potential temperature and wind speed to compute the gradient Richardson number. These methods are important because they assist in the determination of the extent to which vertical motion in the atmosphere is enhanced or suppressed in a given situation.