Sensitivity of Remotely Sensed Effective Radius of Cloud Droplets to Changes in LOWTRAN Version

Abstract

A method of retrieving effective radius and optical depth of stratocumulus from narrowband near-infrared radiances was recently presented by Rawlins and Foot. Their retrieval scheme used LOWTRAN 5 to calculate atmospheric corrections, and the results showed that the remotely retrieved effective radii were significantly larger than those measured in situ with a PMS Forward Scattering Spectrometer Probe. LOWTRAN 7 has recently been developed and is used in this work for all atmospheric corrections. In this note, the major differences between LOWTRAN 5 and LOWTRAN 7 at near-infrared wavelengths are discussed, and it is shown that the retrieved effective radii using LOWTRAN 7, for two flights during the FIRE87 campaign, are in much better agreement with the in situ measurements.