Monsoon rains are frequent. Monsoon rain - salvation or destruction? Monsoon rain is a long-awaited event
Monsoon is often associated with heavy rains, hurricane or typhoon. This is not entirely true: the monsoon is not just a storm, but rather a seasonal movement of wind over an area. As a result, there may be heavy summer rains and drought at other times of the year.
What causes monsoons?
Monsoons (from the Arabic mawsim, meaning "season") are caused by temperature differences between land and ocean, explains the National Weather Service. The sun warms the land and water differently, and the air begins to play a tug of war, with colder, more humid air from the ocean winning out. At the end of the monsoon period, the winds reverse.
Wet and dry monsoons
Wet monsoons usually arrive during the summer months (April to September), bringing heavy rainfall. On average, about 75% of the annual rainfall in India and about 50% in the North American region (according to a NOAA study) falls during the summer monsoon season. As mentioned above, wet monsoons bring ocean winds to land.
Dry monsoons occur in October-April. Dry air masses come to India from Mongolia and northwestern China. They are more powerful than their summer counterparts. Edward Guinan, a professor of astronomy and meteorology, states that the winter monsoon begins when "the land cools faster than the water and high pressure builds over the land, displacing ocean air." Drought is coming.
Winds and rains
Every year the monsoons behave differently, bringing either light or heavy rains, as well as winds of varying speeds. The Indian Institute of Tropical Meteorology has compiled data showing the annual monsoon in India over the past 145 years. The intensity of the monsoons appears to vary over 30-40 years. Long-term observations show that there are periods with weak rains, one of which began in 1970, and others with heavy rains. Current records for 2016 showed that from June 1 to September 30, precipitation amounted to 97.3% of the seasonal normal.
The heaviest rainfall occurred in Cherrapunji, Meghalaya state in India, between 1860 and 1861, when the region received 26,470 mm of rainfall. The area with the highest average annual amount (observations lasted for 10 years) is also in the state of Meghalaya, where the average rainfall was 11,872 mm.
Where do monsoons occur?
The places where monsoons occur are the tropics (between 0 and 23.5 degrees north and south latitude) and the subtropics (between 23.5 and 35 degrees north and south latitude). The strongest monsoons are usually observed in India and South Asia, Australia and Malaysia. Monsoons occur in southern North America, Central America, northern South America, and West Africa.
Monsoon influence
Monsoons play a decisive role in many areas of the globe. Agriculture in countries like India is largely dependent on the monsoon. According to National Geographic, hydroelectric power plants also schedule their operations depending on the monsoon season.
During periods when the world's monsoons are limited by weak rains, crops do not receive enough moisture and farm incomes decline. Electricity production decreases, which is only enough for the needs of large enterprises, electricity becomes more expensive and becomes inaccessible to poor families. Due to the lack of domestic food products, imports from other countries are increasing.
During periods of heavy rain, floods are possible, causing damage not only to crops, but also to people and animals. Excess rain contributes to the spread of infections: cholera, malaria, as well as stomach and eye diseases. Many of these infections are spread through water, and overloaded water facilities are unable to clean water for drinking and household use.
The North American monsoon system is also driving a fire season in the southwestern United States and northern Mexico, NOAA said, due to an increase in lightning caused by changes in pressure and temperature. Some regions experience tens of thousands of lightning strikes overnight, causing fires, power outages and severe injuries to people.
Monsoons and global warming
A team of Malaysian scientists warns that global warming could mean more rainfall during the summer monsoon in the next 50 to 100 years. Greenhouse gases such as carbon dioxide help trap even more moisture in the air, which rains down on already flooded areas. During dry monsoons, the land will dry out more due to increased air temperatures.
On small time scales, rainfall during the summer monsoon may vary due to air pollution. El Niño (fluctuations in surface temperature in the Pacific Ocean) also affects the Indian monsoon in both the short and long term, say researchers from the University of Colorado Boulder.
Many factors can influence the monsoon. Scientists are doing their best to predict future rain and winds - the more we know about the behavior of the monsoon, the sooner preparations can begin.
When approximately half of India's population is engaged in agricultural work and agronomy accounts for approximately 18% of India's GDP, shifts in monsoon timing and rainfall can cause great challenges. But research conducted by scientists can turn this problem into a solution.
The name monsoon comes from the Arabic word season and is used to refer to the seasonal winds that prevail in much of the tropics. During dry winters, the prevailing winds blow away from the high pressure centered over the continents. In summer, the earth warms up and a reverse pressure drop occurs. The winds change and heavy rains come.
Summer monsoon. Due to the pressure distribution effect of the Himalayan mountain system, the summer monsoon is particularly strong in South Asia. It brings warm, moist air from the Indian Ocean. The town of Cherrapunji in India receives 8200 mm of rain between May and August.
Winter monsoon. The air moves from a high pressure area over Central Asia and loses moisture as it crosses the Himalayas, bringing dry weather. Cherrapunji receives 152 mm of rainfall between November and February.
Monsoon cities:
1. Mumbai. Previously, this huge metropolis of India was called Bombay. It is directly in the path of the summer southwest monsoon. This city receives only 100 mm of rain between the beginning of October and the end of May, but from June to September it receives more than 1707 mm of precipitation.
2. Lagos. Seasonal variations in this African coastal city are less extreme than in India. Lagos receives an average of 1,740 mm of rain per year, of which 1,490 falls between April and October, and about 50 mm in December and January.
3. Darwin. This tropical city in northern Australia is subject to the Asian monsoon. Of the total annual precipitation of 1575 mm, 970 mm occurs between December and March. During the dry season from May to September, only 40 mm falls, and there is no rain at all in July.
4. Manila. The capital of the Philippines is located on the largest island of the archipelago. The oceanic monsoon climate prevails here. On average, there is 2050 mm of rainfall per year, of which 1460 mm falls between June and September. Less than 50 mm of rainfall occurs from January to March.
5. Hyderabad, India. Sudden heavy downpours during the summer monsoon send city residents scattering for shelter. Such flows can flood roads and railway lines, causing transport problems.
In monsoon regions, farmers and wildlife depend on the timely arrival of rains after a dry winter. If the monsoon is late, the harvest is poor. If the rains are unusually heavy, the torrential torrents can destroy the crop.
Streams and floods. Monsoon torrents often hit Bangladesh, although most do not cause much rising water. Today, such flows cause relatively little damage, as the population is warned.
Plant adaptation. In a monsoon climate, plants “dormant” during the dry period, and grow quickly with the arrival of rains.
African beaks. Monsoon rains bring plenty of water for these African birds, which feed on small animals in open water.
We invite you to go on an unusual journey. Let us follow the winds of the seasons today. “Mausim” - in Arabic - season, time of year, this is where the word “monsoon” comes from. Winds of the seasons that blow from opposite directions in winter and summer.
Let's first Let's look at the situation in the summer: There is a lot of sun and it heats the land to a greater extent. But why? Everything is not so complicated, firstly, water has the property that it is difficult to heat and difficult to cool. Water, of all substances, is the most difficult to heat, so it is said that its heat capacity is equal to unity. The volumetric heat capacity of air is equal to 0.000307, i.e., to heat the air it is necessary to apply 3257 times less heat than is required for water. Conversely, it is 3257 times easier to cool air than water.
Plus, water, unlike land, is also transparent, which means the sun’s rays penetrate into the water column and warm it, and not just the surface layers.
So, we settled on the fact that in the summer the sun heats the land more than the ocean. Therefore, the air over land is heated and rises, leaving behind an area of low pressure. Above the ocean, the air is colder and, therefore, located closer to the ground, and here an area of high pressure arises. That's almost all!!! A holy place is never empty and cold air is directed from the ocean to land to fill the “empty” space. Or in other words, high pressure forces air into areas of lower pressure.
Why is the air humid in summer? Here, too, everything is simple, it came from the ocean, and there is a lot of water there :) In the summer, under the influence of the sun, it evaporates and saturates the air.
Now let's consider what happens in winter. There is little sun here and it does not play an important role. But again, everything happens thanks to the amazing properties of water discussed earlier. Over the long summer, the water has absorbed a lot of heat, and in winter it begins to slowly release it, while the air above the land cools down almost as soon as the sun goes away. Therefore, now, all the air over the ocean is heated due to the heat accumulated in the water, and the air over land without the sun cools down.
And again, where the air is warm, the pressure is low, and where it is cold, the pressure is high. And the wind blows from an area of high pressure to an area of low pressure. Those. in our case, in winter the monsoon winds blow from land to the ocean, and I think it’s clear why they are dry :-).
For a better understanding, also watch the video: “Why does the wind blow?”
Monsoon climate areas.
Summer monsoons come from the sea and bring with them rain and dampness; in winter, the wind blows from the land and gives dry and clear weather.
India is classic monsoon territory. This natural phenomenon has long been known to sailors, because the correct change of winds was very important for navigation.
What does spring mean to us? Awakening of nature, rebirth. The onset of the rainy summer monsoon carries the same significance on the Indian mainland. Many poets have sung this season in their works. In addition to India, the South Asian monsoon also covers Indochina, and then China.
Finally, the Australian monsoon covers northern Australia and the Malay Archipelago. These are the areas of the monsoon country.
Modern Russian physical map of the world with sea currents. Among other things, you can find the monsoon current that goes around India.
And now, we invite you to get acquainted with wet and variable-humid monsoon forests.
Permanently wet forests. Huge humidity and always hot air temperatures. The flora and fauna are very rich. These forests are impenetrable jungles, with several layers of plants that never shed their leaves. The animals are usually small in size, since large individuals would have difficulty making their way through difficult areas. For humans, these forests also pose a challenge. Even today you can find places untouched and unexplored by us.
Variably wet forests. Precipitation does not occur all year round, but only during the rainy season. Plants have to shed their leaves to protect themselves from excess evaporation. Animals also have to adapt, so the diversity of flora and fauna here is inferior to the constantly humid forests.
Unfortunately, these forests are increasingly threatened by our civilization. And restoring their previous appearance takes a lot of time. Therefore, it is worth thinking again about how to preserve this wonderful splendor of nature.
And finally, I suggest watching a video film: BBC: Natural World. Monsoon / Natural World. Monsoon.
MONSOON RAIN - rain that falls during the summer (oceanic) monsoon. M. d. can have a frontal, convective or orographic origin. In the tropics, M. d. is especially abundant; in India, almost all precipitation is a consequence of M. d.
Dictionary of winds. - Leningrad: Gidrometeoizdat.
L.Z. Shit.
1983. See what "MONSOON RAINS" is in other dictionaries:
Heavy Rains in Pakistan (2001)- Heavy rains in Pakistan in 2001 Type of weather anomaly heavy heavy rains Date July 2001 Cause prolonged monsoon rains Coverage area ... Wikipedia Thailand
- Kingdom of Thailand, state in the Southeast. Asia. The national name of the country Muang Thai, the country of Thai, has been established in international use in English, the semi-calque Thailand (Thailand) from the ethnonym Thai and English. land country. Before 1939 and in 1945 1948... ... Geographical encyclopedia Thailand
BRAHMAPUTRA- a river that flows into the Bay of Bengal in the Indian Ocean; China, India, Bangladesh. Starts in the north. slopes of the Himalayas and within China, along the course of the current, the names Matsang, Tsangpo, Dohong are replaced, which in local languages, apparently, simply mean... ...
World Warming- Global warming is the process of a gradual increase in the average annual temperature of the Earth's atmosphere and the World Ocean. Scientific opinion expressed by the UN Intergovernmental Panel on Climate Change (IPCC), and directly supported by... ... Wikipedia
Pakistan flood (2010)- Flood in Pakistan 2010 Type of weather anomaly severe flood Date ... Wikipedia
Somalia (peninsula)- This term has other meanings, see Somalia (meanings). Horn of Africa Coordinates: Coordinates ... Wikipedia
The sky seems to be breaking through. Through the swirling clouds, covering everything to the very horizon, continuous streams of water pour. The rain, not like buckets, but like thousands of buckets, hits the roofs and treetops. Due to the jets of water, visibility is no more than ten meters. From time to time, the twilight is illuminated by bright flashes of lightning, thunder shakes everything around... It is difficult to imagine that such weather can last for several weeks.
This formidable phenomenon is monsoon rain. Dangerous and at the same time beautiful, as it has become the basis of life for the population of many countries. In the countries of South and Southeast Asia, the onset of monsoon rains is awaited with hope and anxiety. Delay in the wet season causes drought. And too intense rains lead to floods. Both are fraught with adverse consequences.
How are monsoon rains formed?
A monsoon is a type of wind that occurs at the interface between an ocean and a large landmass. Their main feature is seasonality, that is, they change direction depending on the time of year. Due to different degrees of heating and cooling of the continents and surrounding waters, areas with different atmospheric pressures are formed. The pressure gradient is what causes the wind to blow from the ocean to the land in summer, and vice versa in winter. The summer monsoon moves from the sea and brings humid air. Clouds arising from these water vapor-rich oceanic air masses become the source of monsoon rains.
Countries with a monsoon climate
The effect of monsoons is most pronounced in the climate of the countries of South Asia: India, Pakistan, Bangladesh, Sri Lanka. Europeans first learned about these winds from Arab travelers. Therefore, the Arabic word "mausim", meaning "season", somewhat modified in French, became the name for the monsoons.
Wet winds, bringing precipitation from the ocean in the summer, are characteristic of both East and Southeast Asia. China, Cambodia, Vietnam and other countries also owe their agricultural development to monsoon rains.
The North American monsoon, which operates in the eastern United States, also stands out. In Russia, the effect of seasonal winds is clearly manifested in the south of the Far East.
Monsoon rain is a long-awaited event
Residents of countries with a monsoon climate always await the arrival of summer rains with trepidation, because the start of agricultural work depends on their timely arrival. Soils that were dried out during the dry period are again saturated with moisture. Water supplies in rivers and lakes are replenished, and large volumes are accumulated in reservoirs. This precious moisture is then used during the dry season to irrigate fields.
The monsoon season begins with joy and rejoicing over the long-awaited freshness, the decline in the heat that lasted for several months. Bright greenery appears and many plants begin to bloom. This is the time when nature flourishes. The main thing is that the monsoon season starts on time. Then there are usually no unpleasant surprises.
Rain is not only a blessing
The monsoon began on time and there was hope for a good harvest. But often the amount of precipitation exceeds all norms. The result is that a joyful event turns into a natural disaster.
In September 2014, much was written about floods in India and Pakistan. The somewhat delayed wet season was marked by incessant monsoon rains for several days, which provoked powerful floods. and its tributaries overflowed their banks, flooding the surrounding area along with hundreds of villages. The number of victims reached several hundred.
Loose rocks saturated with water began to move down the slopes of hills and mountains that were not secured by forest. The result was hundreds of large and small landslides, aggravating the scale of the disaster. Washed out and flooded roads made it difficult for rescuers to arrive from dangerous areas.
Causes of catastrophic consequences
Of course, high intensity monsoon rain led to such unfavorable consequences. But there are several other reasons that are not directly related to precipitation. The first of these is that the majority of the population of these countries lives in the floodplains of large rivers, where the soils are more fertile and where it is easier to provide irrigation to the fields during drought.
The second reason is deforestation of the Himalayan slopes, foothills and steep slopes of the Deccan Plateau. The loose layer of plant litter located under the forests absorbs a lot of moisture, seeping through it and replenishing groundwater supplies. In addition, tree roots hold soil particles together, preventing them from being involved in downslope movement as part of landslide masses or
The conclusion seems simple: stop on the mountain slopes and take measures to restore vegetation cover. But in countries where most rural residents can only use firewood as fuel for cooking and heating their homes in the cold season, a ban on cutting trees will cause new problems.
Monsoons in the Russian Far East
Monsoons are typical for the southern part of the Pacific coast of Russia. The winters here are dry and frosty, and the summers are often cloudy and rainy. The humid ones come from Japan and bring large amounts of precipitation. The monsoon rainy season in the Primorsky and Khabarovsk territories occurs at the end of summer and beginning of autumn. Therefore, the rivers here overflow not in the spring, as in the middle zone, but in August-September.
2013 became a very difficult year for the Far Eastern regions of Russia due to catastrophic flooding on the Amur River and its tributaries. The flood caused enormous damage to the economy and population.
To solve the problem, various measures are proposed, the main ones being the regulation of river flows through the construction of reservoirs and the protection of populated areas with flood dams. It is also necessary to resettle people from the most dangerous areas to flood-free areas.
Monsoon rains are a source of much-needed moisture in different areas of the globe. This is also a formidable natural phenomenon that can be very dangerous. But the beneficial qualities of the monsoons are much more important for people, especially those involved in tropical agriculture.