The 2004 Aerosol and Ocean Science Expedition (AEROSE): A unique dataset for infared satellite validation

The 2004 Aerosol and Ocean Science Expedition (AEROSE) was conducted onboard the NOAA Ship Ronald H. Brown (RHB) in the tropical North Atlantic Ocean from 29 February to 26 March 2004 in collaboration with the NOAA Center for Atmospheric Sciences (NCAS) at Howard University. The RHB set out from Bridgetown, Barbados traveling eastward toward Africa. Near the African coast, the ship turned north toward the Canary Islands. After a port-of-call in Las Palmas de Gran Canaria, the ship returned to San Juan, Puerto Rico on 26 March. AEROSE provided unique complementary data on tropospheric aerosols during several significant Saharan dust events. Atmospheric and oceanographic measurements were acquired from a number of in situ and remote sensing sensors. Data collected from the expedition will be used to address key questions pertinent to infrared (IR) satellite remote sensing and radiative transfer modeling. Because aerosols remain a source of bias in satellite IR retrieval products, the AEROSE complementary datasets provide an opportunity for the satellite validation studies overviewed in this paper.

Shipboard radiometric data pertinent to studying the impact of tropospheric dust aerosol upon satellite IR spectra and retrievals include observations from the Marine Atmospheric Emitted Radiance Interferometer (M-AERI) (U. Miami), the Calibrated Infrared In situ Measurement System (CIRIMS) (UW/APL) and Microtops handheld sun photometers (Howard U.). Vaisala RS80/90 radiosondes were launched ~3 hourly including Aqua overpass times, and standard meteorological data and ocean surface temperatures were acquired by the RHB observing platform. Validation studies of satellite derived sea surface skin temperatures (SST) (AVHRR aerosol corrected SST, AIRS, MODIS) have been made possible using the high-accuracy radiometric and in situ SST observations acquired onboard the ship as independent ground-truth. Cross comparisons of the ship radiometric (M-AERI, CIRIMS) and in situ temperatures have also been examined for self-consistency and aerosol impact. Investigations into the AIRS quasi-specular reflectance/emissivity models are being conducted using M-AERI radiance spectra and retrieved skin SST and emissivity, along with Vaisala radiosondes. Validation of AIRS marine temperature and water vapor profile retrievals is possible using coincident Vaisala radiosondes launched during Aqua overpass times, as well as coincident M-AERI uplooking boundary layer profile retrievals. Given co-located hyperspectral downlooking AIRS and uplooking M-AERI observations, along with coincident observations of aerosol (both from the ship as well as from MODIS and AVHRR), detection, and potentially isolation, of the IR spectral signature of dust aerosols is being sought to retrieve IR aerosol optical depth (AOD) from AIRS cloud-cleared radiance spectra.