PNNL

Abstract

This study characterizes the wide range of deep convective cloud lifecycles and their relationships with ambient environments observed during the Cloud, Aerosol and Complex Terrain Interactions (CACTI) field campaign near the Sierras de Córdoba (SDC) range in central Argentina. We develop a novel convective cell tracking database for the entire field campaign using C-band polarimetric radar observations. The cell tracking database includes timing, location, area, depth, merge/split information, microphysical properties, collocated satellite-retrieved cloud properties, and sounding-derived environmental conditions. Results show that the SDC exerts a strong control on convection initiation (CI) and growth. CI preferentially occurs east of the SDC ridge during the afternoon, and cells often undergo upscale growth through the evening as they travel eastward towards the plains. Larger and more intense cells tend to occur in more unstable and humid low-level environments, and surface-based cells are stronger than elevated cells. Mid-tropospheric relative humidity and vertical wind shear also jointly affect the size and depth of the cells. Evolution of convective cell macro- and microphysical properties are strongly influenced by instability and low-level humidity, as well as the presence of other cells in their vicinity. This cell tracking database demonstrates a framework that ties measurements from various platforms centering around convective lifecycles to facilitate process understanding of factors that control convective evolution.