Exponential sum absorption coefficients of phosphine from 2750 to 3550 cm−1 for application to radiative transfer analyses on Jupiter and Saturn

Abstract

PH3 exponential sum k coefficients were computed between 2750 and 3550 cm−1 (2.82–3.64 μm), in view of future application to radiative transfer analyses of Jupiter and Saturn in a phosphine absorption band near 3 μm. The temperature and pressure of this data set cover the ranges from 80 to 350 K and from 10−3 to 101 bars, respectively. Transmission uncertainty incurred by the use of the k coefficients is smaller than a few percent as long as the radiation is confined above an altitude of a few bars in the giant planets. In spectral regions of weak absorption at high pressures close to 10 bars, contributions from far wings of strong absorption lines must be carefully taken into account. Our data set helps map the three‐dimensional distribution of PH3 on the giant planets, revealing their global atmospheric dynamics extending down to the deep interior. The complete k coefficient data set of this work is available at the Web site of the NASA Planetary Data System Atmospheres Node.