A Longwave Broadband QME Based on ARM Pyrgeometer and AERI Measurements

Accurate modeling of the downwelling longwave flux at the surface is critical to our understanding of a number of important issues: the earth’s energy balance; processes at the atmosphere’s lower boundary including ice melt and ocean forcing; and evaluating our ability to model atmospheric fluxes for dynamical models including numerical weather prediction and climate models. Under the Atmospheric Radiation Measurement (ARM) Program, there has been a concerted effort (Brown et al. 1998) to evaluate the modeling of the downwelling zenith spectral radiances using Atmospheric Emitted Radiance Interferometer (AERI) measurements (Revercomb et al. 1997) and the line-by-line radiative transfer model (LBLRTM) (Clough and Iacono 1995). Up to this point, there has not been a comparable effort to extend this type of analysis to the downwelling fluxes at the surface, which are of interest to the broader community.