How does the Monsoon affect life in India?
A monsoon is a wind pattern that reverses direction with the seasons. The term was originally applied to seasonal winds in the and . The word is also used more specifically for the season in which this wind blows from the south-west in India and adjacent areas that is characterised by very heavy rainfall, and especially, for the rainfall associated with this wind.
In terms of total precipitation, total area covered and the total number of people affected, the monsoon affecting the Indian Subcontinent dwarfs the North American monsoon (also called the "Mexican", "south-west", desert or "Arizona" monsoon). Monsoons are caused by the larger amplitude of the seasonal cycle of temperature over land as compared to the adjacent oceans. This differential warming results from the fact that heat in the ocean is mixed vertically through a "mixed layer" that may be 50 meters deep, through the action of wind and buoyancy-generated turbulence, whereas the land surface conducts heat slowly, with the seasonal signal penetrating perhaps a meter or so. Additionally, the specific heat of liquid water is significantly higher than that of most materials that make up land. Together, these factors mean that the heat capacity of the layer participating in the seasonal cycle is much larger over the oceans than over land, with the consequence that land warms faster and reaches a higher temperature than the ocean. The hot air over the land tends to rise, creating an area of . This creates a steady wind blowing toward the land, bringing the moist near-surface air over the oceans with it. Associated is caused by the moist ocean air being lifted upward by mountains, surface heating, convergence at the surface, divergence aloft, or from storm-produced outflows at the surface. However the lifting occurs, the air cools due to adiabatic expansion, which in turn produces condensation. In winter, the land cools off quickly, but the ocean retains heat longer. The hot air over the ocean rises, creating a low-pressure area and a breeze from land to ocean while a large area of high pressure is formed over the land, intensified by wintertime radiation cooling.
