Spectroscopic Imaging of Sub-Kilometer Spatial Structure in Lower Tropospheric Water Vapor

Abstract. Understanding the subgrid spatial variability of water vapor is important for parameterizing and simulating cloud processes in General Circulation Models (GCMs). This study maps sub-kilometer spatial structures in total atmospheric column water vapor with Visible to Shortwave Infrared (VSWIR) imaging spectroscopy. We describe our inversion approach and validate its accuracy with coincident measurements by airborne imaging spectrometers and the AERONET ground-based observation network. Next, data from NASA’s AVIRIS-NG spectrometer enables the highest resolution measurement to date of water vapor’s spatial variability and scaling properties. We find second order structure function scaling exponents consistent with prior studies of convective atmospheres. Finally, we conclude by discussing the implications of these measurements and paths toward future campaigns to build upon these results.