The word “monsoon” comes from an Arab word meaning “season”. It has to do with a type of climate in which winds blow from sea to land (onshore) during the warm season, and from land to sea (offshore) during the cool season. The warm season of onshore winds is often very rainy, while the cool season of offshore winds may be dry.
What causes this seasonal chaflge in winds and rainfall? It is due to the fact that large continents or land masses heat and cool more rapidly than the surrounding oceans. Central and Southern Asia grow warm rapidly in the spring, and during the summer they are much warmer than the Indian Ocean on the south, or the Pacific Ocean on the east.
The warmer temperatures inland create lower atmospheric pressures, and therefore the wind blows inland from the surrounding seas. This is the onshore or summer monsoon.
In the autumn, interior Asia cools rapidly, and during the winter it has much lower temperatures than the surrounding oceans. These lower temperatures create high atmospheric pressures, and therefore the winter monsoon winds blow outward from the dry interior regions toward the sea.
Why Is It Called Monsoon?
The word “monsoon” comes from the Arabic word Muslim, meaning “season.” The seasonal wind shift is usually accompanied by a dramatic change in precipitation.