Sensitivity of Infrared Radiances to Changes in Planetary Boundary Layer Water Vapor

Planetary boundary layer processes have been highlighted by the decadal survey as key variables, and the science community must better understand critical processes such as energy, momentum, and mass exchanges. One observation that is necessary to understand these exchanges is the routine measurement of water vapor with high vertical sensitivity and accuracy. Retrieval of boundary layer water from space presents many challenges and will require investigation into single and multi-instrument missions to accomplish this goal. This study looks at the spectral sensitivity of boundary layer water vapor in the region from 650 – 2800 cm^-1 (3-15 microns) for the possible development of a retrieval system. We will examine the degrees of freedom, Jacobians, and possible interference from other state vectors as a function of spectral resolution, signal to noise, and error covariances. The spectral range will be broken up into long, mid, and shortwave so we can evaluate different infrared instrument configurations.