Objective Method for Analysis and Tracking of Convective Cells as Seen by Radar

Abstract

A special method has been developed for the study of cells that are embedded in convective rain systems. This method consists of a package of computer programs that use pattern recognition techniques on three-dimensional digital radar data to identify the rain cells, track them with time, and calculate their properties. The product of the computations is a comprehensive database of physically meaningful properties of rain cells, which can be used to infer the internal structure and the dynamics of convective rain systems. The cell-tracking method has been applied to the summer convective clouds of south Florida for the following purposes: (i) derivation of the relationship between the echo top height and the precipitation characteristics (e.g., area, water yield, rain intensity and duration of the rain cells); (ii) study of the microphysical behavior of cumulus clouds in relation to their cell properties; (iii) evaluation of the effect of seeding on cumulus clouds on the cell scale; and (iv) examination of cloud-to-ground lightning discharges in relation to convective cell intensity. The cell-tracking method is also currently being used in rain enhancement projects in Texas in the United States, in Israel and in South Africa. The cell-tracking method, its products and their use in meteorological research are described in this paper.