PREDICT

Proposal Summary

The prediction and understanding of tropical cyclogenesis remains one of the most challenging aspects of atmospheric science. A multitude of tropical disturbances emerge from the West African coast every year near the Cape Verde islands, but only a few of these develop into tropical depressions, storms, or hurricanes. To further our understanding of these potentially high impact events, the PRE-Depression Investigation of Cloud-systems in the Tropics (PREDICT) field experiment will deploy the NSF/NCAR G-V aircraft in the Atlantic basin in the heart of hurricane season to explore multi-scale interactions in tropical wave-like disturbances that promote or hinder the development of a tropical depression vortex.

Our research in the PREDICT project will focus on the synthesis, analysis and interpretation of the analysis products and the observational dataset obtained by the G-V, NOAA and potential NASA aircraft. The deep tropospheric dropwindsonde observations, radar data, and in situ data at multiple flight levels offer a unique and unprecedented dataset for examining the development and growth of tropical cyclone precursors. By combining data from multiple instruments and platforms, mesoscale and synoptic scale composites of vorticity, divergence, moisture, and even potential vorticity, will be used to diagnose the structure and evolution of these disturbances in the Atlantic. Multiscale analyses of the dataset will be accomplished through the use of objective and variational techniques that allow for quantitative study of the structures and budgets of key quantities related to the primary ‘marsupial’ hypotheses. Multidimensional composites of temperature and humidity have so far been limited or non-existent in most pre-depression disturbances, but the G-V aircraft provides an ideal platform for obtaining the measurements needed to construct these syntheses. The high-resolution vertical structure obtained from the dropsondes and microwave temperature profiler (MTP) complements the significant horizontal coverage of in situ data from the Gulfstream aircraft, allowing for unique compositing opportunities. The cloud and precipitation radar data from the G-V and NOAA aircraft will provide unprecedented possibilities for basic research into the wave-to-vortex transformation process. This research team will also compare and contrast these results with those obtained during the western Pacific T-PARC/TCS-08 field campaign, RAINEX, and BAMEX.

Intellectual Merit: Recent theoretical, logistical, and technological advancements detailed herein and in the supporting EDO allow for testing new dynamical/thermodynamical hypotheses on the role of tropical waves,
mesoscale and convective processes.

Broader Impacts: The proposed research will be in close collaboration with other PREDICT PIs and graduate students in order to obtain the maximum synergy between the observational analyses, theoretical understanding, and numerical modeling and prediction. Detailed analysis of the analysis field and observations during and after the field phase will provide additional quality control and potential targeting opportunities for data assimilation efforts to improve realtime forecasting during the 2010 hurricane season and beyond.