Retrieval of temperature and pressure using broadband solar occultation: SOFIE approach and results

Abstract

Measurement of atmospheric temperature as a function of pressure, <i>T(P)</i>, is key to understanding many atmospheric processes and a prerequisite for retrieving gas mixing ratios and other parameters from solar occultation measurements. This paper gives a brief overview of the solar occultation measurement technique followed by a detailed discussion of the mechanisms that make the measurement sensitive to temperature. Methods for retrieving <i>T(P)</i> using both broadband transmittance and refraction are discussed. Investigations using measurements of broadband transmittance in two CO₂ absorption bands (the 4.3 and 2.7 μm bands) and refractive bending are then presented. These investigations include sensitivity studies, simulated retrieval studies, and examples from SOFIE.