Comparison and Application of Q- vector and Wet-Q-vector to Diagnosis of Storm Rain
Based on some routine observation when a regional storm rain in Jinzhong, Shanxi Province during 26—27 July 2001, the application of quasi-geostrophic Q- and wet-Q-vector are made. The analysis shows that (1) the quasi-geostrophic Q-vector is a good indicator for the heavy rain forecast specially at 700hPa level in the beginning stage of the rainfall, while the wet-Q-vector has a good diagnostic property on each level. (2) The distribution of Q-vector frontogenesis function has typical quasi-geostropic characteristic, but wet-Q-vector ones has apparent mesoscale characteristic. So quasi-geostropic Q-vector adapt to study of atmospheric motion associated with synoptic scale system,and wet-Q-vector adapt to the secondary circulation triggered by synoptic scale system.