OFFSHORE

Cloudiness along the coast of Brazil is unusually high because of the blocking influence of the Serra do Mar, but the effect does not extend more than a hundred kilometers or so offshore. Conditions improve farther out to sea. Figure 8 shows that the area along the track is quite promising for several hundred kilometers beyond the coast. While the Atlantic coast of Brazil was very close to the edge of the satellite images examined to develop the statistics in Figure 9, it appeared that offshore weather systems were spotted with numerous breaks and holes. These holes and the patchy nature of the disturbances are probably due to the influence of the anticyclone which resides off the African coast. Ships have excellent mobility with which to exploit these breaks, and a water-borne eclipse chase should be quite promising. Weather forecasts and satellite images can provide enough information to select a promising location on the track, but leave lots of time to reach it in case the distance to clear skies is large.

Wave heights are a major concern for ship-board eclipse observers since they make photography difficult (and interfere with lunch!). Mean wave heights off Brazil range between 1 and 1.5 meters in November, a low value for the latitude. This is comparable to wave heights in waters near the Philippines for those who caught the 1988 eclipse from the ocean surface. The standard deviation of the wave height is close to one meter along the east coast of South America. This means there is a 66% chance that wave heights will lie between one-half and 2.5 meters on eclipse day. Of course the exact value on eclipse day will depend on prevailing winds and the location of nearby storms.

Wave heights, cloudiness and dismal prospects for the eclipse all increase along the eclipse track as it moves onto the African side of the South Atlantic. Gough Island off of South Africa has a high mean cloudiness and few sunshine hours for the month. Once around Cape Horn however, brighter weather begins to return, though Figure 8 is only marginally encouraging.


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