Correlation of vorticity advection values and grey shade values in infra-red satellite images

Abstract

A statistical analysis of the correlation between vorticity advection values and grey shade values in infra-red satellite images is presented. Average correlation coefficients for six-month data set in all four chosen levels were found positive. This means that higher vorticity advection values result in brighter grey shades in satellite images. The best correlation was found for vorticity advection in 500 and 300 hPa levels. Absolute values of average coefficients are below 0.2 meaning that correlation is not good in all synoptic situations. The results were significantly improved when only those images were considered in which comma cloud structures, enhanced cumuli clouds or frontal intensifications were found. Statistics for the 16 selected cases indicated satisfactory correlation between vorticity advection and pixel values. This enables forecasting of cloud paths and development by following the vorticity advection maxima related to the mentioned cloud structures.