Does a Dry Winter Have the Opposite Wind Direction From a Monsoon?

About Monsoons

• Monsoon winds are seasonal winds that occur in low-latitude or tropical and subtropical climates. These seasonal winds change their direction during the winter and summer months due to differences in air pressure that is caused by heat in the Earth's atmosphere. The southwesterly moving wind during summer and the northeasterly moving wind during winter happen mainly over the Arabian Sea in Eastern and Southern Asia. Other areas where monsoons occur are West Africa, Australia, the Amazon Valley of South America and islands of the Pacific Ocean.

Why Monsoons Happen

• During the summer the heat that rises from the surface of the land is hotter than the heat that rises from the water. This creates a difference in air pressure that causes the winds to blow from the land to the sea to maintain a temperature balance in the air. This atmospheric balancing act causes humid winds to come in from the ocean to the continent. The humid air mixes with the drier western winds and moves over the mountains, where rain clouds develop that cause storms and heavy pouring rains. During the winter months, the air over the continents is colder than that over the oceans and the winds reverse their course and flow from the land to the sea. This creates a big area of high air pressure that forms over Siberia, which causes the air to move over South China and the Indian Ocean, creating clear skies and dry air for East and South Asia.

Monsoon Seasons

• The dry winter monsoon winds happen for six months and comes from the northeast. The wet summer monsoon occurs for six months and comes from the southwest. The rain season that the summer monsoon brings starts in April and ends in September. The dry winter season lasts from October to March.

Their Importance

• Monsoons have an impact on the circulation of the atmosphere. They influence the tropic and subtropical areas of the world by carrying humid air from the oceans to make rain on land. Monsoons strongly influence the climates of these regions. The areas of the world where the monsoons occur tend to be agricultural areas that depend on the heavy rains that monsoons bring in during the summer months. The main characteristic of the summer monsoon is its burst of storms and rain showers. These rain showers are so intense that they can cause rapid flooding of areas.