Estimation of marine boundary layer depth and relative humidity with multispectral satellite measurements

Abstract

estimating marine boundary layer depth and relative humidity structure from satellite inferred measurements of aerosol optical depth, total water vapor and sea-surface temperature. The data originate from radiance measurements by channels 1, 4 and 5 of NOAA's AVHRR instrument. The technique assumes that the atmospheric optical depth and total water vapor are primarily confined within the boundary layer, and that the layer is well-mixed. These inputs are combined through the relative humidity dependent variables of extinction and vapor density. Relative humidity is parameterized as an increasing linear function wit h height, resulting in an equation for the near-surface relative humidity. This equation is solved, enabling estimation of boundary layer depth and humidity structure. The technique is iterative in nature, requiring 5 to 10 iterations for convergence.