Aerosol Extinction over the Ocean: A Field Evaluation of the Wells-Munn- Katz Model

• Main Author: Fairall, Christopher W.
• Other Authors: BDM CORP MONTEREY CA
• Format: Text
• Language: English
• Published: 1981
• Subjects: Atmospheric Physics; *INFRARED SPECTRA; *ATMOSPHERE MODELS; *AEROSOLS; *METEOROLOGY; *LIGHT TRANSMISSION; *VISIBLE SPECTRA; MARINE METEOROLOGY; SEA WATER; SPECTRAL ENERGY DISTRIBUTION; AIR MASS ANALYSIS; COEFFICIENTS; GRAPHS; EXTINCTION; TABLES(DATA); WELLS-MUNN-KATZ MODEL; Pacific; North Atlantic
• Online Access: http://www.dtic.mil/docs/citations/ADA096599; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA096599

Aerosol and Meteorological data from cruises in the East Pacific (CEWCOM-78) and the North Atlantic (JASIN) were used to evaluate the predictive performance of the Wells-Munn-Katz aerosol model. Under given meteorological conditions (wind speed and relative humidity), the model gave very good predictions of the average aerosol extinction coefficient at 10.6 micron wavelength (the standard deviation was about a factor of three). The model did not perform well when asked to predict specific aerosol extinction values. The model continental coefficient, B = 1.7, was found to be too large -- the average open ocean value should be B = 0.24. The continental coefficient was found to be important for predicting IR band extinction from visible band extinction estimates. Further analysis demonstrated that much of the variance of continental aerosol spectral density was due to air-mass history and that much of the variance of sea salt aerosol spectral density was due to changes in the marine layer mixing height.