Long description

Figure 18

This is a world map, centred on the Pacific Ocean, showing the global surface wind pattern with blue arrows.

The edges of the map are marked to show longitude and latitude with labels along the top and left sides.

The longitude is marked along the top edge, in intervals of 20°, from 40° E through 180°, 160° W and then to 0° and ending with 20° E.

The latitude ranges from approximately 70° N to 70° S and is marked, along the left edge, from 60° S to 60° N in intervals of 20°.

There are horizontal lines across the entire map at latitudes of 0°, approximately 23° N and S, and approximately 66° N and S.

The map is labelled 'July' in the bottom left corner.

There are two styles of arrows in the map; the key below the map indicates what they represent;

a narrow blue arrow is labelled as 'most frequent wind direction'

a thick blue arrow is labelled as 'prevailing wind direction (greater than or equal to 50 per cent of observations)'.

Some general patterns in the map:

The thick arrows are mostly restricted to the zone between the horizontal lines at 23° N and 23° S and the direction of the arrows is mostly from east to west, with notable exceptions along the coast of Arabia and India where the direction is more to the north and northeast, and over southern Saharan Africa where the direction is from west to east.

High latitudes in the south show a regular west to east pattern of narrow arrows.

High latitudes in the north show clockwise patterns of narrow arrows over the North Atlantic and North Pacific Ocean, but more variable patterns of narrow arrows over the land masses.