Probing The Atmosphere Using Remote Sensing Instruments for Deep Convection (Polarimetric Radio Occultation(PRO))

Tropical cyclone observations are difficult to achieve as they develop over the oceans and at high altitudes. However, accurate observations are necessary to improve forecasts, issue early warnings, and refine weather prediction models. A novel remote sensing technique called Polarimetric Radio Occultation (PRO) that uses vertical and horizontal polarized signals, has emerged as a potentially useful method for detection of hydrometeors. The difference in scattering of the vertical and horizontal polarized signals, called delta-phi, is believed to suggest interference in the atmosphere. The interferences may include supercooled liquid, ice, precipitation, or any form of convection occurring within the atmosphere. During this study, the PRO data from SPIRE, collected between June 20th and July 8th, 2023, was analyzed to determine if there is a correlation between regions of deep convection in Hurricane Adrian (observed from June 27th to July 2nd, 2023) and larger than normal variations in delta-phi. All occultations were constrained to the minimum delta-phi threshold of 1.5 mm and bounded within the latitudes and longitudes of the storm area. For verification purposes, NASA’s Integrated Multi-satellite Retrievals for GPM (IMERG) was utilized for rain rates. The coordinates of Hurricane Adrian and its path were compared to the locations of the occultations. Results show there to be no direct correlation between delta-phi and rain rates, however a delta-phi greater than 1.5mm does indicate the presence of hydrometeors. This research assesses PRO's potential to detect tropical cyclone-related interferences which could provide additional ways of examining and understanding tropical meteorology.