Monsoon
[Class / Course]
[Professor]
[Student Name]
[Date]
Introduction
The Columbia Encyclopedia defines monsoon as the
“wind that changes direction with change of season, notably in India and SE
Asia.” It originated from the Arabic
word mausium which means
‘season.’ Monsoons likewise develop
albeit less notable in other parts of the world with the exception of
Antarctica. (32270) The term also
serves as a label for a season “in which this wind blows from the southwest in
India and adjacent areas that is characterized by very heavy rainfall, and
specifically the rainfall that is associated with this wind.” (“Monsoon”) However, the term ‘monsoon’ is often misused
“to refer to INDIVIDUAL thunderstorms.” (“The Arizona Monsoon”) The formation of sea and land breezes explains
how monsoons are formed.
Formation of Sea and Land Breezes
Land changes temperature faster than water as it
takes longer for water to warm up and cool down. Therefore, during the summer, there is higher temperature over the
land as compared to that of the ocean. The
high temperature causes hot air to rise from the land which then creates an
area of low pressure. Due to this, a
constant wind blows toward the land.
The humid ocean air is then directed upwards by the mountains, which
cools the air and causes condensation, which will result in rainfall.
(“Monsoons”) The higher the differences
in temperature, the more extensive the monsoon winds get.
During winter, the ocean maintains heat longer while
the land cools off rapidly. The ocean
then produces hot air that rises and creates a low pressure area and breeze
travel from land to ocean. The winter
monsoon wind is not as regular as compared to summer monsoon as differences
between the temperature of land and ocean is lesser during winter. (“Monsoons”)
The wind shifts during the season generally cause “a
dramatic increase in moisture, and associated shower and thunderstorm activity,
to the affected region.” The reverse
happens when the winds once more shift, ending the monsoon, when “much drier
air” then moves into the region. (“The
Arizona Monsoon”)
The Indian sub continent commonly surface in the
discussion of monsoons as it is considered the best example of a monsoon. “During the months of April through October,
a moist southwest wind brings heavy rains to this region...while a dry
northeast wind is prevalent during the remainder of the year.” (“The Arizona
Monsoon”) The chart below shows the seasonal
cumulated monsoon rainfall pattern in India.
Source: Monsoon On Line,
http://www.tropmet.res.in/~kolli/MOL/Monsoon/frameindex.html
Source: Monsoon On Line,
http://www.tropmet.res.in/~kolli/MOL/Monsoon/frameindex.html
The cumulated data in the charts relate to the “daily
rainfall, corresponding long-term normal and percentage departures from the
long-term mean for the period specified” as to the “36 meteorological
subdivisions of India, computed from real-time reports and published in the
Weekly Weather Reports issued by the India Meteorological Department.” (Stephenson,
Kumar, Black, and Revadekar)
North America likewise has monsoons, which mostly
occurs in Mexico. “[I]n Acapulco,
rainfall averages 51.8 inches during the months of June through October...while
only 3.3 inches falls during the remainder of the year.” (“The Arizona Monsoon”) According to studies, the monsoon depends
largely upon the “relative location of the typical northward-migrating
subtropical ridge during the summer months.” (“About the North American Monsoon”)
According to Peter Combs:
“When viewed as a continuous event, the
Mexican/Arizona monsoon can be pictured as a stair-stepped, regional wind. At
each step, the moist surface-flow is forced upwards, creating thunderstorms. We
took advantage of this sequence to study how the competing effects of clouds
change as they move higher. These effects, called feedbacks, are both a
substantial warming from trapped terrestrial heat, and a reflective cooling
that increases as cloud water increases. The feedbacks can cancel one another
out or one can predominate.”
Source: About the North American
Monsoon, http://geography.asu.edu/azclimate/aboutmon.htm
Benefits
Monsoon winds may seem depressing for some as heavy
rainfalls connote flash floods and losses.
However, there are also benefits that are acknowledged in the regions
where they occur. As Combs said, “The
monsoon is the lifeblood to a cattle rancher's rangeland and the answer to a
forest ranger's prayers...” As cattle
ranchers have wide stretches of land, monsoons allow grass and plants to live
as the land absorbs the rainfall. On
the other hand, monsoons keep the forest from drying and drought which could
upset life within the forest and cause the plants and animals to die.
Conclusion
Low pressure areas brought about by heat either from
land or the ocean causes the seasonal shifting of the wind either towards the
sea during summer or the land in winter.
These, therefore, causes the monsoon associated by rainfall. The differences in temperature between land
and the ocean determine the extent of the monsoon. India is one of the best examples in the discussion of monsoons
as they occur annually between the months of April to October. North America likewise experience monsoons from
June to October. Monsoons are
considered a blessing for cattle ranchers and forest rangers as they provide
water to wide stretches of land that keep them from drying up.
Cited Works
“About the North American Monsoon.” geography.asu.edu.
17 Jul. 2005. <http://geography.asu.edu/azclimate/aboutmon.htm>
Stephenson, D.B., Kumar, K. Rupa, Black, E. and Revadekar,
J.V. “The 2005 Indian Summer Monsoon.” Monsoons
Online. 15 Jul. 2005. 17 Jul. 2005. <http://www.tropmet.res.in/~kolli/MOL/Monsoon/frameindex.html>
“Monsoon.” Wikipedia. 12 Jul. 2005. 17 Jul.
2005. <http://en.wikipedia.org/wiki/Monsoon>
“The Arizona Monsoon.” wrh.noaa.gov. National
Weather Service Forecast Office Phoenix, AZ. 18 Jul. 2005 <http://www.wrh.noaa.gov/psr/general/monsoon/index.php>
The Columbia Encyclopedia 6th Edition. New York: Columbia University Press, 2004.