Microphysical Characteristics of DYNAMO Convective Systems using In-Situ Airborne Cloud and Precipitation Imaging Probe Data

The NOAA P-3 instrumented aircraft provided in-situ cloud and precipitation microphysical observations during the DYNAMO (Dynamics of the Madden-Julian Oscillation) field experiment. The Particle Measuring System 2D cloud (2D-C) and precipitation (2D-P) probes collected data for particles between 12.5 μm – 1.55 mm (25 μm resolution) and 100 μm – 6.2 mm (100 μm resolution), respectively. Spectra from each instrument are combined to provide a broad distribution of precipitation particle sizes. Analysis of the drop size distribution (DSD) spectra, which were modeled by fitting a three-parameter gamma model, indicates that the characteristic shape of the mean spectrum is similar to previous measurements of maritime convective/stratiform systems. DSD variability will be presented with respect to the temporal evolution of cloud populations during a Madden-Julian Oscillation (MJO) event, as well as during an active and inactive MJO phase. In addition, complementary measurements from the airborne platform, such as in-situ aircraft vertical wind velocity measurements, will be used to contextualize the DSD observations. Comparisons to DSD distributions and Z-R (reflectivity factor-rainfall rate) relationships obtained during the TOGA COARE field experiment in the Western Pacific will be discussed. These results address an important focus to the DYNAMO project, to improve the understanding of cloud population characteristics in the climatological MJO region. Improved representation of the cloud characteristics on the microphysical scale will serve as a check to model parameterizations, helping to improve numerical simulations.