Rapid Non-LTE Analysis of CO_2 Limb Emission from the Upper Mesosphere to Obtain Kinetic Temperature and Pressure

摘要

The SABER instrument aboard the TIMED satellite is providing highly resolved and precise broadband limb emission measurements. Inverting these measurements to temperature profiles that extend into the lower thermosphere (90+ kilometers) is a complicated and often unstable process. NLTE (Non-Local Thermodynamic Equilibrium) models must be employed to model the upper atmosphere physics that thwarts the normal limb measurement advantages available to lower atmosphere retrievals. Maintaining hydrostatic pressure constraints while accurately modeling the effects of upwelling radiation can induce instabilities in attempts at iterative relaxation. We show that the limb geometry can be used to apply boundary conditions during "bottom-up" procedures that stabilize the process and allow rapid convergence by minimizing the required calculations of upwelling flux.