monsoon trough

The monsoon trough is a low-pressure area at sea level that marks the leading edge of the summer monsoon. This feature is associated with the seasonal reversal of wind systems, primarily caused by the differing warming and cooling rates of land and sea.12

During the summer, continents heat up more rapidly than oceans, creating areas of lower pressure over land. This draws moist air onshore, leading to the monsoon trough and often significant rainfall. Conversely, winter monsoons are characterized by winds blowing from land to sea, which tend to diverge and subside, potentially causing drought. The most prominent monsoons occur in South Asia, Africa, Australia, and Central America.123