Jennifer Haase, Assistant Professor

The Pre-depression Investigation of Cloud systems in the Tropics (PREDICT) experiment seeks to understand the conditions that lead to the development of hurricanes from favored areas within easterly African waves. Additional measurements of thermodynamic parameters in these areas have the potential to lead to significant improvements in forecasting development or non-development of the systems. For the first time, an airborne GPS radio occultation measurement system has been deployed to contribute to this objective. The GISMOS (GNSS Instrument System for Multistatic and Occultation Sensing) was deployed on the NSF Gulfstream V aircraft on 26 missions to sample easterly African waves in the western and central Atlantic west of -40 longitude during August and September 2010. GISMOS measured continuously during flight, which typically yielded on average one profile from a setting occultation per flight-hour and approximately 8-9 profiles within a typical 1500 km by 1500 km target region. The limb-sounding technique will provide retrieved profiles of refractivity, which is a function of both temperature and water vapor. We will use these preliminary results to determine the large-scale fields and compare them with dropsonde profiles in order to examine where moisture is increasing locally relative to the location of convective activity.