11th Conference on Atmospheric Radiation and the 11th Conference on Cloud Physics

Friday, 7 June 2002: 9:30 AM
Evaluation of ocean color and its effects on the polarization of water leaving radiances during the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) experiment
J. Chowdhary, Columbia University, New York, NY; and B. Cairns, J. Laveigne, and L. D. Travis
Poster PDF (238.5 kB)
The Research Scanning Polarimeter was operated onboard a Cessna 210 for six days during the period July 10 to July 17, 2001 at the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) experiment. The main objectives for the RSP participation in this experiment were associated with the retrieval of aerosol properties. However the ability to accurately characterize aerosols is obviously affected by uncertainties in the surface reflectance over land, or scattering within the ocean body.

To provide accurate characterization of the water leaving radiances in the Chesapeake Bay data were acquired at low (200 feet) altitude with a range of relative solar azimuths (0,45,90,135,180) and also during spirals up from 200 feet to 12,000 feet. These flight patterns provide varying scattering geometries at different altitudes within the atmosphere for which the polarized radiances can be dominated by contributions from the radiation upwelling from the ocean body, by contributions from skylight reflected off the ocean surface, or by contributions from molecular and/or aerosol scattering.

In this paper we examine the variation in upwelling polarized radiation over the bright inshore waters of the Chesapeake Bay. Observations were taken over areas where the water appears to be quite clear and also over sediment plumes from creeks and back bays of the Chesapeake Bay. The wide variety of water properties will be used to evaluate the minimal hydrosol model that is required to simulate the intensity and polarization of water leaving radiation for this region. This model will then be used to evaluate how well ocean properties and aerosol properties can be simultaneously retrieved from polarized radiation measurements over bright coastal waters and the effect of observing geometry on the capability of such retrievals to reliably separate the effects of the ocean and atmosphere.

Supplementary URL: http://www.giss.nasa.gov/data/rsp_air