Estimating convective momentum fluxes using geostationary satellite data

Research and case studies have shown that convection plays a large role toward the feedbacks of momentum to the large-scale environment. Convective momentum fluxes have been studied for many years using in situ and aircraft measurements, along with numerical simulations. However, little work has been conducted on developing a method to use satellite remote sensing as a tool to diagnose these fluxes. Using this as motivation, a case study-based approach is used to determine if information derived from Geostationary Operational Environmental Satellites (GOES) data, such as cloud-drift winds and brightness temperature differences, can be used to diagnose these fluxes. Using satellite-derived winds for mesoscale atmospheric motion vectors (MAMVs), one can obtain the appropriate winds occurring within a convective environment. Outflow boundaries and upper tropospheric anvil outflow produce "perturbation" winds on convective scales (similar to 1-3 km) that the MAMV algorithm can measure. Using a computed background wind field from the MAMVs (smoothed and averaged over a larger region), horizontal perturbations, u' and v', associated with the mesoscale flow are calculated. To compute w', an algorithm was developed using IR satellite temperature differences, along with convective available potential energy profiles, to diagnose mass fluxes which can be used to infer vertical motion. Using these methods resulted in area-averaged convective momentum fluxes between +/- 1 m(2) s(-2), which were similar in magnitude and sign to those computed using a cloud-resolving model.