Convective Storm Life Cycle Parameters Derived from Radar Reflectivity Data

Weather radar is one of the important tools of severe storm warning. It is important to depict the density and evolution of whole storm using weather radar reflectivity data for storm identification and tracking. Therefore, based on 3-demension CHINRAD/SA radar reflectivity, cell gravity potential energy (CEPE), a new physical parameter, is defined, which is relevant to storm life cycle. Its expression is derived and characteristic is studied. In addition, the vertical reflectivity profile of the cell is built and analyzed. The results show that the density of whole storm cell can be compactly and objectively described by the CEPE, and the cell evolvement trend is reflected by its change. If using CEPE to describe cell life cycle, there are two basic processes during the entire life cycle of the cell, namely developing process and weakening process. In spite of the overview single-peak distribution pattern, sometimes there is a little pulse in the pattern which occurs mostly at developing phase. At mature phase, the value of the CEPE is marked different among different cell types. The largest is for supper cell, the second is for multi cell, and the least is for ordinary cell. Accordingly, cell type can be distinguished by CEPE to some extent. The characteristics of vertical reflectivity profile (VPR) of the storm cell are different from initiative to dissipated phases, which help to identify the evolution of the storm cell. But these differences can not be opened out to 150 km and in 30 km, as the effects of the earth curvature and radar blind area respectively. Comparing these two methods, it is obvious that the VPR is not as concise and objective as the CEPE.