Anil Deo, a PhD student in the School of Earth Sciences at the University Of Melbourne mentored by Professor Kevin Walsh, recently spent two weeks at the Goddard Space Flight Centre (GSFC, NASA) to collaborate with Dr Stephen Munchak on an active research project that examines the representation of convective and stratiform precipitation in tropical cyclones (TCs).
During his visit to GSFC, Anil worked on a project that examines some of the important characteristics of precipitation such as the radar reflectivity, the rainfall drop size distribution (DSD) parameter and the rainfall rate which are estimated from different instruments such as the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR), a combined TRMM Microwave Imager (TMI)-PR algorithm and a C-Band dual polarised radar, during the passage of tropical cyclones over Darwin, Australia. The combined algorithm that is being used by Anil was developed by Dr Munchak and his colleagues and the visit provided Anil with an opportunity to work more closely with him on this topic.
Figure 1: Matched reflectivity profiles from the ground radar (GR; left), PR (middle) and Combined (COM; right) for four events (dates given in left panel) at the 1.3º GR elevation sweep. Picture (top left): Anil Deo (left) and Dr. Stephen Munchak (right) beside a model of the Global Precipitation Measurement (GPM) based satellite at the GSFC, Greenbelt, USA (Photo courtesy of Jasmine Smith, GSFC)
Our analysis shows that the reflectivity estimate of the combined algorithm is close to the PR and both compares well with the ground radar, which is taken as the reference. Also, the median volume rain-drop diameter estimate of the combined algorithm appears to be better than the PR. However, for the rainfall estimates, the combined algorithm usually has a larger bias than the PR (the ground radar is taken as the reference). Anil and Dr Munchak used the time to perform a sensitivity analysis of the combined algorithm. The sensitivity analysis shows that the inclusion of the TMI does increase the bias in the rainfall estimates.
Anil and Dr Munchak also worked on a draft paper for this project and the results obtained from this visit will be included to finalise the paper which would then be put for publication.
Anil and his collaborators would like to thank the Centre of Excellence for financially supporting this important visit.