Concurrent Radar and Aircraft Reflectivity Comparisons of Florida Thunderstorm Cirrus Clouds

The Citation Research Aircraft conducted measurements of cirrus cloud particles in Florida thunderstorm anvils during 2015 (CAPE2015 field project). During the CAPE2015 field project, ice particles were sampled between an altitude of 29,000 ft and 40,000 ft on eight research flights. In-situ observations were made using a Two-Dimensional Stereographic probe (2D-S) and a Nevzorov Water Content Probe (Nevzorov). Remote sensing observations were made by the United States Navy’s Mid-Course Radar (MCR) with its 37 m resolution (narrowband) and 0.546 m resolution (wideband) beams. The MCR tracked the aircraft, and the wideband beam was positioned just ahead of the aircraft which provided concurrent in-situ and remote observations of the cirrus clouds. The concurrency of the observations allows for the examination of the variation of radar reflectivity that links the cloud microphysics to the large-scale cloud structure and enables the understanding of the cloud evolution over time. Data analysis includes a direct comparison between derived radar reflectivity from in-situ data and measured narrowband MCR radar reflectivity. Radar reflectivity is derived using particle concentration from the 2D-S and particle mass from the Nevzorov. An average ice density during flight legs with constant temperature is evaluated to determine the relationship between ice crystal density and temperature. Results show that a direct comparison between the derived aircraft and measured narrowband radar reflectivity is ineffective due to the large spatial variability, and a statistical comparison between these data sets is used. Results also include a direct comparison between the wideband and aircraft radar reflectivity that is not affected by the large spatial variability.