How close are ground-based Fabry-Perot thermospheric wind and temperature measurements to exospheric values? A simulation study

摘要: Abstract Ground-based Fabry-Perot interferometers (FPIs) have been used extensively to determine thermodynamical and hydrodynamical properties of the upper atmosphere by measuring emission line profiles from O(1D) nightglow at high spectral resolution. The resulting thermospheric winds temperatures are normally referred altitude peak layer, near 250 km, effects wind shear temperature gradations along sight neglected. In order quantify significance these effects, obtain a better understanding “effective” (volume-emission-rate-weighted) FPI measurement, computer simulation measurement technique has performed, incorporating realistic winds, volume rates instrumental line-of-sight. atmospheric for simulations derived recently-developed subroutine based on predictions NCAR general circulation model. code is calculate synthetic spectrograms different viewing geometries station locations, analyzed using standard data reduction techniques derive fitted temperatures. These then compared with as input effective each simulated study differences between recovered corresponding exospheric values. A first investigation geophysical conditions December solstice solar maximum indicated that FPI-derived Doppler may be lower than ∼10% in winter hemisphere ∼15% summer hemisphere. Furthermore, measurements neutral particularly latitudes, can differ appreciably values due weighting altitudes ∼250 km.