Analysis of mesoscale variability of oceanic surface wind fields: contribution of active microwave sensors

Abstract

The low spatial resolution of conventional observational networks over the ocean have restricted most field investigations to either consideration of large scale (greater than 2000 km) or very small scale (less than 10 km) wind and sea-state variability. However, the energy contained in intermediate scales has been recognized to play an important role in the dynamics of the atmosphere, in the atmospheric forcing of the ocean and in air-sea interaction processes. These intermediate scales can not be resolved by most measuring techniques. In recent years, the use of satellite data from sensors such as scatterometers and radar altimeters has lead to improvements in our knowledge of these intermediate scales. Wind vectors measured by the ERS-1 satellite Scatterometer (SCATT) and wind speed measurements from radar altimeters are analyzed to determine the spatial mesoscale structure of oceanic surface winds over wavelength from /spl sim/10 to 2000 km. The results of these analyses are compared to the two-dimensional isotropic turbulence.