Using Radar and Ozone Observations Collected During GoAmazon2014/5 to Identify Characteristics of Convective Downdrafts

Three-dimensional reflectivity measurements collected during the Green Ocean Amazon experiment (GoAmazon2014/5) by the Sistema de Proteção da Amazônia (SIPAM) S-band, Doppler radar located at the Manaus-AM airport will be used to give insight into the occurrences and properties of precipitation-laden downdrafts that reach the surface during convective events. Contoured frequency by altitude diagrams (CFADs) of SIPAM radar reflectivity centered over an instrument site located north of Manaus (T0 or ZF2) were previously shown to have descending bands of high reflectivity that strongly correlate with surface observations of enhanced ozone and decreased equivalent potential temperature (i.e., surface downdraft identifiers). The enhanced reflectivity, which we refer to as “descending arms”, typically originate 4-7 km above the surface and are present for both isolated and organized convective events. Profiler measurements of vertical velocity and surface ozone measurements collected west of Manaus at Manacapuru (T3) will be compared to the SIPAM radar CFADs centered over T3 to determine if the descending arms observed over ZF2 are a robust feature that can be used across the radar domain to identify convective downdrafts and their characteristics. We will then examine the microphysical properties of the descending arms nearby the T3 site with the CHUVA X-band, polarimetric radar.