Local Winds

Wind Shear
Southeast Indian Ocean

Wind shear, Indian Ocean

5 I-39-0195
Flight 51I; 28S, 111.4E, 06:54:14 GMT, 2 Sept 1985

Even in countries where extensive networks of meteorological stations are present, local winds may be unobserved when they occur between stations. Usually, however, they soon reach a weather station that can monitor their progress. At sea, it is a totally different story. The number of weather/oceanography buoys is relatively small, and there are vast areas of the ocean rarely frequented by ships. Geostationary weather satellites do not yet have the resolution to sense local winds over the oceans, and polar orbiting satellites do not have the capability to continuously monitor any given area of the ocean.
    A perfect example of the effect of a wind shear on the sea's surface, from what is thought to have started as a squall line, was observed by the crew aboard Discovery as they approached Perth, Australia. Spiral eddies along the edge of the West Australian Current were visible in the sun's glitter pattern. Laid on top of the eddy field was a horizontal wind shear extending east to west across the orbital path of the shuttle. On the south, the wind was blowing easterly; on the north side, to the west. Wind slicks were observed on either side, as well as along the boundary line formed in the ocean by the sharply shearing winds.
    Mesoscale wind features of this sort are ubiquitous over the world's oceans, but because of the lack of routine detailed observations, the magnitude of their influence on the upper layers of the sea is unknown.

Download 57.tiff high resolution TIFF file (8.8 MB)

Contents Local Winds prev: Sea Breeze, Sumba next: Dust, Sun Glitter