18 
ESTIMATION OF THE SEA SURFACE WIND FIELD FROM 
THE AIRBORNE REFLECTANCE DATA 
Y. KAWATA AND A. YAMAZAKI 
ENVIRONMENTAL RESEARCH AND INFORMATION LABORATORY 
KANAZAWA INSTITUTE OF TECHNOLOGY 
NONOICHI, ISHIKAWA 921, JAPAN 
Tel: 81-762-48-1100 Fax: 81-762-48-7753 
Email: kawata@infor.kanazawa-it.ac.jp 
ABSTRACT 
In this paper we have made the estimation of the sea surface wind field using the reflectance data 
measured over Mediterrenean Sea ( referred as the Medimar data ) by the airborne POLDER 
sensor. Assuming an atmosphere-ocean system with a Cox-Munk type reflecting sea surface [ 1], 
the reflectance, including radiance contributions from multiple scatterings and reflections have 
been computed by using the adding and doubling method [2] for several different atmospheric 
models. We have made the theoretical study on two basic aerosol size distribution models, 
namely, a log-normal size distribution function [3], and a power law size distribution function by 
Junge[4], Our results based on this study are summarized as follows: 
1) The anisotropic Cox-Munk model was adopted to estimate the sea surface wind field from the 
airborne POLDER's reflectance data. The estimated ranges of the wind field are 9.0 m/s ^ V ^ 
14.0 m/s and 215 ^ W d ^ 240 , where V and W d are the wind speed and its direction, 
respectively. We should note here that the observed wind field values were V =14.4 m/s and W 
d 
=220° at the time of the airborne experiment. 
2) The range of aerosol refractive index, m= n -i k was examined by assuming the Junge type size 
distnbution with 3.5 ^ v ^ 4.0 and the log-normal size distnbution functions (such as an oceanic 
aerosol model and a water soluble aerosol model).