For decades instrument wetting of immersion thermometers placed directly in the airstream has prevented accurate measurements of air temperatures in clouds, resulting in erroneously cool temperatures. These errors have prevented the accurate determination of parcel buoyancy in clouds. Radiometeric thermometers provide an indirect temperature measurement with minimal effects from liquid, and have shown superior operation in clouds. Here we utilize the data from a PRT-5 radiometer(SR) to reconstruct temperature profiles for 362 radial legs in nine Atlantic hurricanes. The SR temperatures are compared to simultaneous temperatures from a Rosemount immersion thermometer (ROSE) and significant differences (approximately >
0.5 degrees C) between the two data sets are considered temperature errors from wetting. From resulting differences, differences of eyewall equivalent potential temperature and buoyancy are calculated from the reconstructed profiles.
The SR dataset is normally distributed, but the ROSE dataset was
skewed toward cooler temperatures, indicating that instrument wetting is occuring. Nearly half of the radial legs contained regions with ROSE temperatures significantly cooler than the SR temperatures. Of these legs, 80% had significant temperature differences associated with the eyewall cloud. Average differences in the eyewall ranged from 1-2 degrees C, with about 10% nearing their theoretical maximum
error of 5-10 degrees C for a completely wetted sensor at typical aircraft speeds. Likewise, the resulting average equivalent potential temperature differences were around 4-7 degrees C in the eyewall. Finally, parcel buoyancy in the eyewall is calculated using classic parcel theory from the SR and ROSE temperatures. On average the SR temperatures indicated postive buoyancy in the eyewall, while the ROSE temperatures indicated negative buoyancy. Thus evidence supports that the eyewall of an average tropical cyclone contains positive buoyancy as opposed to recently-hypothesized conditions of near-neutrality.