Mesoscale Spatial Variability of Lower Thermospheric Winds During the Anomalous Transport Rocket Experiment

We present observations and analysis of seven horizontal wind profiles obtained by the trimethyl aluminum (TMA) tracer method on 27 March 2012 over the Atlantic ocean near Wallops Island, Virginia (37.9 degrees N, 75.4 degrees W). Payloads were launched in order to produce quasi-simultaneous trails separated by tens to hundreds of kilometers. Tracer positions evolving in time and space were triangulated from three locations along the Atlantic seaboard and wind profiles between 90 and 140 km calculated. The wind profiles present a coherent wind structure dominated by very strong diurnal and semidiurnal tides up to 110 km and an upward propagating inertia-gravity wave between 110 and 140 km. Properties such as horizontal and vertical wavelength could be extracted from the simultaneous observations at separate locations. A statistical analysis of the wind differences was performed to estimate power-law coefficients of the second structure function at mesoscales. They show scale-independence in the region of the largest wind shears, 100-110 km, and a scaling coefficient characteristic for isotropic wind fluctuations above and below this region.