Remote measurement of aerosol optical properties using the NOAA POES AVHRR during ACE-1, TARFOX and ACE-2

Abstract

A radiative transfer algorithm in the solar wavelengths for the NOAA POES AVHRR is presented for the cloud-free, marine atmosphere. This algorithm combines linearized, single-scattering theory with an estimate of bi-directional surface reflectance. Phase functions are parameterized using an aerosol distribution model and the ratio of radiance values measured in channels 1 and 2 of the AVHRR. Automated cloud screening and sun glint removal is included. Retrieved satellite aerosol optical depth (AOD) is compared to surface measured sunphotometer AOD collected during the International Global Atmospheric Chemistry (IGAC) Project's Second Aerosol Characterization Experiment (ACE-2) from June 16 to July 25, 1997. The comparison data set has a correlation coefficient of 0.88 with a standard error of 0.02 at both channel 1 and 2 wavelengths. Regional aerosol properties are examined with an emphasis on the differences between the ACE-1, TARFOX and ACE-2 regions. ACE-1 and ACE-2 regions have strong modes at AOD at around 0.1, but ACE-2 tails toward higher values consistent with urban and dust aerosol intrusion. The TARFOX region has a noticeable mode at AOD around 0.2, but has significant spread of AOD values consistent with the varied aerosol constituents in that area.