The phenomenon of monsoon had been known to ancient traders and sailors. To describe seasonal reversal of the wind direction Arabs used the word “mausam”, which means season. The name of the phenomenon brings out the rhythm of changes in wind directions and patterns of rainfall distribution. Monsoon refers specifically to the seasonal winds caused by difference in heating of the land and the ocean (Qazi, 31).
The monsoon occurs because of the different water and land heat up rate. During the summer months continent temperature increases and the air masses that gathered above the land become hot. The low pressure zone develops and, thus, the winds originated over the ocean are drawn into it. Moist surface currents, being caught by upper air flow and turbulence, rise to the colder levels of atmosphere. Heavy precipitation became a cause of the torrential rainfall (Petersen, 126).
The pattern is reversed in winter. Ocean cools off slower than the land, so the masses of air are rising over the ocean and the rush of wind comes from the lands. Continental winds cause high pressure over the land and, generally, dry season.
However, there are more causes of the monsoon phenomenon and its characteristic’s change that cannot be fully explained and deviations in the monsoon cycle is a big concern of the meteorologists.
The monsoon related issues are so important that many researches are being conducted to predict monsoon, with special divisions of the Meteorological Department being created to provide timely information, such as the one in India. To gather the information, many tools are used, including the modern technology. For example, in October 2011 India successfully launched monsoon research satellite (BBC).
The monsoons have great significance on to the economies that depend on agriculture, especially in the countries that receive the majority of the rainfall during monsoon season. In such areas long monsoon outbreaks, withdrawals, delays or other alternations in monsoon cycle affects agriculture, causing not only food shortage, but also deficiency of other agricultural products such as sugarcane, cotton, etc. Variations in the monsoon conditions may also trigger droughts or floods (Qazi, 38).
The monsoons exist not only in equatorial Africa, Southeast Asia and India but also in other locations, such as west Coasts of Chile, some parts of the USA, Mexico, Australia, and the Caribbean Islands. Those regions are often called tropical monsoon regions.
The news concerning India monsoon is aired fairly often. India is a highland, and the agriculture of the country heavily depends on the monsoon.
The example of the monsoon rainfalls effect is the recent floods in Thailand. According to BBC news, excessive monsoon rainfalls caused floods in a third of the South-East Asia since July 2011. By the beginning of November, the floods reached the capital of Thailand, Bangkok. Many citizens have been evacuated, though more than 500 lost their lives (BBC).
The same year monsoon rainfalls brought India a rise of economy by providing conditions for great crops. Four months monsoon season, according to Reuters, brought relief to the world’s second largest country. In 2009, due to monsoon season deviations, India suffered a drought, which affected greatly the economy and people. The crop harvested after monsoon season of 2011 allows plenty of products not only for internal use, but also for the export (Reuters).
Although monsoon can bring welcomed rainfalls for the thirsty ground and a relief from the heat, it may also cause very serious hazards, such as droughts and floods that can severely strain and damage economy and affect people’s life. Further researches are needed to predict and decrease negative effects of monsoons.