Monsoon In India
Monsoon Onset Map
Monsoon is basically a periodic wind, especially in the Indian Ocean and southern Asia. Monsoon has become the synonym of the season in which wind blows from the southwest in India and adjacent areas which brings rainfall to the Indian Sub-continent.
The word "monsoon" is known to have originated from the Arabic word "mausem", which means season.
It is often applied to the seasonal movements of wind along the shores of the Indian Ocean, especially in the Arabian Sea and the Bay of Bengal, that blow from the southwest during June-September and from the northeast during December to March.
The annual monsoon cycle can be physically described as a result of the annual variation of incoming solar radiation and the differential heating at the surface of land and water. Simply stated, sections of the earth's surface heat and cool at different rates depending on their ability to absorb solar radiation and the time of year. Bodies of water, which can absorb sunlight at varying depths (and consequently reflect less back to the atmosphere), store energy more efficiently than land and therefore retain heat longer than a land mass. Land surfaces gain or lose heat at a quicker rate due to the shallowness of their absorbing surfaces. To maintain an energy balance, heat is transferred from areas of surplus to deficit, and in the case of a land-water differential, this is accomplished through a phenomenon known as the "land-sea breeze". For example, on a sunny day at the beach, the land warms more quickly than the ocean. As the hot air rises over the land, it is replaced by the cooler air over the water. At night, however, the land cools at a quicker rate than the water, so the wind shifts, blowing from the land to the warmer water.
The word "monsoon" is known to have originated from the Arabic word "mausem", which means season.
It is often applied to the seasonal movements of wind along the shores of the Indian Ocean, especially in the Arabian Sea and the Bay of Bengal, that blow from the southwest during June-September and from the northeast during December to March.
The annual monsoon cycle can be physically described as a result of the annual variation of incoming solar radiation and the differential heating at the surface of land and water. Simply stated, sections of the earth's surface heat and cool at different rates depending on their ability to absorb solar radiation and the time of year. Bodies of water, which can absorb sunlight at varying depths (and consequently reflect less back to the atmosphere), store energy more efficiently than land and therefore retain heat longer than a land mass. Land surfaces gain or lose heat at a quicker rate due to the shallowness of their absorbing surfaces. To maintain an energy balance, heat is transferred from areas of surplus to deficit, and in the case of a land-water differential, this is accomplished through a phenomenon known as the "land-sea breeze". For example, on a sunny day at the beach, the land warms more quickly than the ocean. As the hot air rises over the land, it is replaced by the cooler air over the water. At night, however, the land cools at a quicker rate than the water, so the wind shifts, blowing from the land to the warmer water.
On a larger scale, such as a continent surrounded by oceans, heat builds up on land over time results in lower density air masses, or areas of low pressure.
On the contrary, denser air associated with high pressure dominates
ocean surfaces. Wind and ocean currents that result from air flowing
from high to low pressure mix areas of warmer and colder air and water,
contributing to the global energy balance. This exchange is evident at
different levels of the atmosphere. Air converging into a low pressure
center at the surface rises, leading to moisture condensation and the
subsequent release of heat into the upper atmosphere. Diverging air at
the surface in a high pressure center is associated with subsiding air
from the upper atmosphere and evaporation, a mechanism for energy
storage.
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Just as energy imbalances develop between land and water surfaces,
the variation in space and time of solar heating due to the earth's
tilt create seasonal hemispheric energy imbalances. The hemisphere
receiving the most direct radiation (during the summer months)
experiences a net radiative heating (more energy is gained from the
sun than is lost to space). The winter hemisphere is at the same time
experiencing net radiative cooling. As part of a global compensation,
heat is transported from warmer to cooler areas by ocean and wind
currents. Since the areas of heat surplus and deficit change throughout
the year, as in the sea breeze example, the direction of transport
must change as well. As noted earlier, climates dominated by monsoons
experience the most pronounced seasonal wind shifts, indicative of a
pronounced land-sea effect. In the South Asian example, the rainy
season, typically beginning in June, is preceded by nearly two months
of scorching temperatures, cooled only with the commencement of the
summer rains brought by the south-westerly winds and the monsoon.
January is the peak of the dry season, which is marked by cool, dry
northeasterly flow over most of the region.
Indian economy which is still mainly an agricultural
economy – is dependent on the amount of monsoon rains as a large part of
the agricultural produce comes from the monsoon fed crops. Good monsoon
always means a good harvest and brings in cheers all around India. A
weak or bad monsoon is always considered as a big set back to India’s
economy and always results in a big loss in the country GDP levels.
To understand monsoon –it’s definition has to be be broadened to include the phenomena associated with the annual weather cycle within the tropical and subtropical continents of Asia, Australia, and Africa and the adjacent seas and oceans.
It is within these regions that the most significant, vigorous and dramatic cycles of weather events on the globe takes place.
To understand monsoon –it’s definition has to be be broadened to include the phenomena associated with the annual weather cycle within the tropical and subtropical continents of Asia, Australia, and Africa and the adjacent seas and oceans.
It is within these regions that the most significant, vigorous and dramatic cycles of weather events on the globe takes place.
Features Of Monsoon Rains
Monsoon Burst Over Mumbai
There are some unique features about the rains that Monsoon brings to the Indian subcontinent.
- "Bursting" of Monsoon Rains
- Monsoon Rain Variability ("Vagaries")
Background Music ( Played during monsoon mood only): Dr. Ranjan Kumar on Mohan on Veena