Seasonal Variations of Major Global Wind Patterns
Global wind patterns have both an historical and a contemporary significance
for transportation. Historically, wind patterns were linked with the
trade routes of sailships. For instance, there is a relatively stable
wind pattern over the North Atlantic that enabled ships to set sail
from Europe using the westbound dominant wind on the southern part of
the North Atlantic and to come back using the eastbound dominant wind
of the northern part of the North Atlantic. A similar pattern exists
over the North Pacific. The monsoon over the Indian Ocean have also
been linked with maritime trade far in the past, as ships were sailing
from the Middle East to Asia in the winter and undertaking the westbound
voyage back in the summer when the dominant wind direction shifted.
With the progressive abandonment of sailing in the 19th century, wind
patterns have stopped to play a significant role in maritime transportation.
Intercontinental maritime shipping now follows the great circle distance,
regardless of wind direction.
The growing importance of air transportation is constrained
by wind direction, particularly for long distance hauls. Eastbound crossings over the North Atlantic and
the North Pacific are shorter than westbound crossings because of the
cumulative wind effect. For instance, a flight between New York and
London is scheduled to last about 7 hours (from gate to gate) eastbound and about 7
hours and 45 minutes westbound. The scheduled difference of 45 minutes is
accounted by dominant winds. Thus, the westbound transatlantic
flight consumes more energy than the eastbound flight.