The climate of Asia is dry across its southwestern region. Some of the largest daily temperature ranges on Earth occur in the western part of Asia. The monsoon circulation dominates across the southern and eastern regions, due to the Himalayas forcing the formation of a thermal low which draws in moisture during the summer. The southwestern region of the continent experiences low relief as a result of the subtropical high pressure belt; they are hot in summer, warm to cool in winter, and may snow at higher altitudes. Siberia is one of the coldest places in the Northern Hemisphere, and can act as a source of arctic air mass for North America. The most active place on Earth for tropical cyclone activity lies northeast of the Philippines and south of Japan, and the phase of the El Nino-Southern Oscillation modulates where in Asia landfall is more likely to occur. Many parts of Asia are being impacted by climate change.
The Southern sections of Asia are mild to hot, while far northeastern areas such as Siberia are very cold, and East Asia has a temperate climate. The highest temperature recorded in Asia was 54 °C (at Ahvaz Airport, Iran on June 29, 2017 and at Tirat Zvi, Israel on June 21, 1942). [2] West-central Asia experiences some of the largest diurnal temperature ranges on Earth. The lowest temperature measured was −67.8 °C (−90.0 °F) at Verkhoyansk and Oymyakon, both in Sakha Republic of Russia on February 7, 1892 and February 6, 1933 respectively. [3]
A large annual rainfall minimum, composed primarily of deserts, stretches from the Gobi Desert in Mongolia west-southwest through the Taklamakan Desert in Western China, the Thar Desert in Western India and Iranian Plateau into the Arabian Desert in the Arabian Peninsula. Rainfall around the continent is across its southern portion from Eastern India and Northeast India across the Philippines, Indochina, Malay Peninsula, Malay Archipelago and Southern China into Korean Peninsula Taiwan and Japan due to the Monsoon advecting moisture primarily from the Indian Ocean into the region. [4] The monsoon trough can reach as far north as the 40th parallel in East Asia during August before moving southward thereafter. Its poleward progression is accelerated by the onset of the summer monsoon which is characterized by the development of lower air pressure (a thermal low) over the warmest part of Asia.Mawsynram in Meghalaya received annually 11872 cm of rainfall [5] [6] [7] Cherrapunji. The highest recorded rainfall in a single year was 22,987 mm (904.9 in) in 1861. The 38-year average at Mawsynram, Meghalaya, India is 11,872 mm (467.4 in). [8] Lower rainfall maxima are found around Turkey and central Russia.
In March 2008, La Niña caused a drop in sea surface temperatures around Southeast Asia by an amount of 2 °C. It also caused heavy rains over Malaysia, Philippines and Indonesia. [9]
The Asian monsoons may be classified into a few sub-systems, such as the South Asian Monsoon which affects the Indian subcontinent and surrounding regions, and the East Asian Monsoon which affects southern China, Korea and parts of Japan. The southwestern summer monsoons occur from June through September. The Thar Desert and adjoining areas of the northern and central Indian subcontinent heats up considerably during the hot summers, which causes a low pressure area over the northern and central Indian subcontinent. To fill this void, the moisture-laden winds from the Indian Ocean rush into the subcontinent. These winds, rich in moisture, are drawn towards the Himalayas, creating winds blowing storm clouds towards the subcontinent. The Himalayas act like a high wall, blocking the winds from passing into Central Asia, thus forcing them to rise. With the gain in altitude of the clouds, the temperature drops and precipitation occurs. Some areas of the subcontinent receive up to 10,000 mm (390 in) of rain. The moisture-laden winds on reaching the southernmost point of the Indian subcontinent, due to its topography, become divided into two parts: the Arabian Sea Branch and the Bay of Bengal Branch.
The Arabian Sea Branch of the Southwest Monsoon first hits the Western Ghats of the coastal state of Kerala, India, thus making it the first state in India to receive rain from the Southwest Monsoon. This branch of the monsoon moves northwards along the Western Ghats with precipitation on coastal areas, west of the Western Ghats. The eastern areas of the Western Ghats do not receive much rain from this monsoon as the wind does not cross the Western Ghats. The Bay of Bengal Branch of Southwest Monsoon flows over the Bay of Bengal heading towards northeast India and Bengal, picking up more moisture from the Bay of Bengal. The winds arrive at the Eastern Himalayas with large amounts of rain. Mawsynram, situated on the southern slopes of the Eastern Himalayas in Shillong, India, is one of the wettest places on Earth. After the arrival at the Eastern Himalayas, the winds turns towards the west, travelling over the Indo-Gangetic Plain at a rate of roughly 1–2 weeks per state[ citation needed ], pouring rain all along its way. June 1 is regarded as the date of onset of the monsoon in India, as indicated by the arrival of the monsoon in the southernmost state of Kerala.
The monsoon accounts for 95% of the rainfall in India[ citation needed ]. Indian agriculture (which accounts for 25% of the GDP and employs 70% of the population) is heavily dependent on the rains, for growing crops especially like cotton, rice, oilseeds and coarse grains. A delay of a few days in the arrival of the monsoon can badly affect the economy, as evidenced in the numerous droughts in India in the 1990s. The monsoon is widely welcomed and appreciated by city-dwellers as well, for it provides relief from the climax of summer heat in June. [10] However, the condition of the roads take a battering each year. Often houses and streets are waterlogged and the slums are flooded in spite of having a drainage system. This lack of city infrastructure coupled with changing climate patterns causes severe economical loss including damage to property and loss of lives, as evidenced in the 2005 Maharashtra floods. Bangladesh and certain regions of India like Assam and West Bengal, also frequently experience heavy floods during this season. And in the recent past, areas in India that used to receive scanty rainfall throughout the year, like the Thar Desert, have surprisingly ended up receiving floods due to the prolonged monsoon season.
The influence of the Southwest Monsoon is felt as far north as in China's Xinjiang. It is estimated that about 70% of all precipitation in the central part of the Tian Shan Mountains falls during the three summer months, when the region is under the monsoon influence; about 70% of that is directly of "cyclonic" (i.e., monsoon-driven) origin (as opposed to "local convection"). [11]
Around September, with the sun fast retreating south, the northern land mass of the Indian subcontinent begins to cool off rapidly. With this air pressure begins to build over northern India, the Indian Ocean and its surrounding atmosphere still holds its heat. This causes the cold wind to sweep down from the Himalayas and Indo-Gangetic Plain towards the vast spans of the Indian Ocean south of the Deccan peninsula. This is known as the Northeast Monsoon or Retreating Monsoon.
While traveling towards the Indian Ocean, the dry cold wind picks up some moisture from the Bay of Bengal and pours it over peninsular India and parts of Sri Lanka. Cities like Madras, which get less rain from the Southwest Monsoon, receives rain from this Monsoon. About 50% to 60% of the rain received by the state of Tamil Nadu is from the Northeast Monsoon. [12] In Southern Asia, the northeastern monsoons take place from December to early March when the surface high-pressure system is strongest. [13] The jet stream in this region splits into the southern subtropical jet and the polar jet. The subtropical flow directs northeasterly winds to blow across southern Asia, creating dry air streams which produce clear skies over India. Meanwhile, a low pressure system develops over South-East Asia and Australasia and winds are directed toward Australia known as a monsoon trough.
The East Asian monsoon affects large parts of Indochina, Philippines, China, Korea and Japan. It is characterised by a warm, rainy summer monsoon and a cold, dry winter monsoon. The rain occurs in a concentrated belt that stretches east-west except in East China where it is tilted east-northeast over Korea and Japan. The seasonal rain is known as Meiyu in China, Changma in Korea, and Bai-u in Japan, with the latter two resembling frontal rain. The onset of the summer monsoon is marked by a period of premonsoon rain over South China and Taiwan in early May. From May through August, the summer monsoon shifts through a series of dry and rainy phases as the rain belt moves northward, beginning over Indochina and the South China Sea (May), to the Yangtze River Basin and Japan (June) and finally to North China and Korea (July). When the monsoon ends in August, the rain belt moves back to South China.
Bangladesh and the eastern parts of India are very exposed to destructive tornadoes. Bangladesh, the Philippines, and Japan have the highest number of reported tornadoes in Asia. The single deadliest tornado ever recorded struck the Manikganj District of Bangladesh on 26 April 1989, killing an estimated 1,300 people, injuring 12,000, and leaving approximately 80,000 people homeless. [14] Throughout China, an estimated 100 tornadoes may occur per year with a few exceeding F4 in intensity, with activity most prevalent in eastern regions. [15] During the period of 1948 until 2013, 4763 tornadoes were confirmed in China. [16]
Many portions of Asia bordering the Indian and Pacific oceans are regularly affected by tropical cyclones. In southern Asia, Bangladesh is vulnerable to storm surge flooding from landfalling tropical cyclones. The low-lying and populated country has a history of the deadliest tropical cyclones. On November 12, 1970, a cyclone struck Bangladesh, then known as East Pakistan, producing a 6.1 m (20 ft) storm surge that killed at least 300,000 people. This made it the deadliest tropical cyclone on record. [17] The cyclone wrecked about 400,000 houses, 99,000 boats, and 3,500 schools. The local government's lack of response to the storm was a partial factor in the Bangladesh Liberation War, one of the first instances in which a natural disaster led to a civil war. [18] In neighboring Myanmar, Cyclone Nargis struck the low-lying Irrawaddy Delta in May 2008 with strong winds and a 3.7 m (12 ft) storm surge. Nargis killed an estimated 140,000 people, becoming the country's worst natural disaster on record, and left more than US$10 billion in damage, with more than 700,000 homes damaged or destroyed, leaving more than 1 million people homeless. [19] [20] [21] Cyclones in the Indian Ocean have hit Asia as far west as Yemen, as demonstrated by Cyclone Chapala striking the country in October 2015. [22] [23] The strongest cyclone on record in the Bay of Bengal was a super cyclonic storm in 1999, which made landfall in the eastern Indian province of Odisha in October 1999 with winds of 260 km/h (160 mph). The cyclone killed 9,887 people across Odisha, with 1.6 million houses damaged or destroyed, causing US$1.5 billion in damage. [24] [25] [26]
The Pacific Ocean north of the equator is the most active tropical cyclone basin on Earth, accounting for roughly one-third of all storms annually. [27] Most tropical cyclones form on the side of the subtropical ridge closer to the equator, then move poleward past the ridge axis before recurving into the main belt of the Westerlies. [28] Each year, an average of nine tropical cyclones strike the Philippines, mostly along Luzon and the eastern Visayas. Tropical cyclones contributed to more than half of the annual rainfall in western Luzon. [29] [30] [31] Typhoons – the regional name for an intense tropical cyclone – affect southeastern Asia more often during La Niña years, due to the westward position of the subtropical ridge. During El Niño years, the position of the subtropical ridge increases the threat to Japan. [27]
Climate change occurs all over the world, and it is particularly important in Asia, as it accounts for the majority of the human population. Warming since the 20th century is increasing the threat of heatwaves across the entire continent. [34] : 1459 Heatwaves lead to increased mortality, and the demand for air conditioning is rapidly accelerating as the result. By 2080, around 1 billion people in the cities of South and Southeast Asia are expected to experience around a month of extreme heat every year. [34] : 1460 The impacts on water cycle are more complicated: already arid regions, primarily located in West Asia and Central Asia, will see more droughts, while areas of East, Southeast and South Asia which are already wet due to the monsoons will experience more flooding. [34] : 1459
The waters around Asia are subjected to the same impacts as elsewhere, such as the increased warming and ocean acidification. [34] : 1465 There are many coral reefs in the region, and they are highly vulnerable to climate change, [34] : 1459 to the point practically all of them will be lost if the warming exceeds 1.5 °C (2.7 °F). [35] [36] Asia's distinctive mangrove ecosystems are also highly vulnerable to sea level rise. [34] : 1459 Asia also has more countries with large coastal populations than any other continent, which would cause large economic impacts from sea level rise. [34] : 1459 Water supplies in the Hindu Kush region will become more unstable as its enormous glaciers, known as the "Asian water towers", gradually melt. [34] : 1459 These changes to water cycle also affect vector-borne disease distribution, with malaria and dengue fever expected to become more prominent in the tropical and subtropical regions. [34] : 1459 Food security will become more uneven, and South Asian countries could experience significant impacts from global food price volatility. [34] : 1494
Historical emissions from Asia are lower than those from Europe and North America. However, China has been the single largest emitter of greenhouse gases in the 21st century, while India is the third-largest. As a whole, Asia currently accounts for 36% of world's primary energy consumption, which is expected to increase to 48% by 2050. By 2040, it is also expected to account for 80% of the world's coal and 26% of the world's natural gas consumption. [34] : 1468 While the United States remains the world's largest oil consumer, by 2050 it is projected to move to third place, behind China and India. [34] : 1470 While nearly half of the world's new renewable energy capacity is built in Asia, [34] : 1470 this is not yet sufficient in order to meet the goals of the Paris Agreement. They imply that the renewables would account for 35% of total energy consumption in Asia by 2030. [34] : 1471
Climate change adaptation is already a reality for many Asian countries, with a wide range of strategies attempted across the continent. [34] : 1534 Important examples include the growing implementation of climate-smart agriculture in certain countries or the "sponge city" planning principles in China. [34] : 1534 While some countries have drawn up extensive frameworks such as the Bangladesh Delta Plan or Japan's Climate Adaptation Act, [34] : 1508 others still rely on localized actions that are not effectively scaled up. [34] : 1534India is situated north of the equator between 8°4' north to 37°6' north latitude and 68°7' east to 97°25' east longitude. It is the seventh-largest country in the world, with a total area of 3,287,263 square kilometres (1,269,219 sq mi). India measures 3,214 km (1,997 mi) from north to south and 2,933 km (1,822 mi) from east to west. It has a land frontier of 15,200 km (9,445 mi) and a coastline of 7,516.6 km (4,671 mi).
A monsoon is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscillation of the Intertropical Convergence Zone (ITCZ) between its limits to the north and south of the equator. Usually, the term monsoon is used to refer to the rainy phase of a seasonally changing pattern, although technically there is also a dry phase. The term is also sometimes used to describe locally heavy but short-term rains.
Bangladesh is a densely populated, low-lying, mainly riverine country located in South Asia with a coastline of 580 km (360 mi) on the northern littoral of the Bay of Bengal. The delta plain of the Ganges (Padma), Brahmaputra (Jamuna), and Meghna Rivers and their tributaries occupy 79 percent of the country. Four uplifted blocks occupy 9 percent and steep hill ranges up to approximately 1,000 metres (3,300 ft) high occupy 12 percent in the southeast and in the northeast. Straddling the Tropic of Cancer, Bangladesh has a tropical monsoon climate characterised by heavy seasonal rainfall, high temperatures, and high humidity. Natural disasters such as floods and cyclones accompanied by storm surges periodically affect the country. Most of the country is intensively farmed, with rice the main crop, grown in three seasons. Rapid urbanisation is taking place with associated industrial and commercial development. Exports of garments and shrimp plus remittances from Bangladeshis working abroad provide the country's three main sources of foreign exchange income.
The climate of India consists of a wide range of weather conditions across a vast geographic scale and varied topography. Based on the Köppen system, India hosts six major climatic sub types, ranging from arid deserts in the west, alpine tundra and glaciers in the north, and humid tropical regions supporting rain forests in the southwest and the island territories. Many regions have starkly different microclimates, making it one of the most climatically diverse countries in the world. The country's meteorological department follows the international standard of four seasons with some local adjustments: winter, summer, monsoon or rainy season, and a post-monsoon period.
Cherrapunji or Sohra is a sub-divisional town East Khasi Hills district in the Indian state of Meghalaya. It was the traditional capital of ka hima Sohra.
In the Indian Ocean north of the equator, tropical cyclones can form throughout the year on either side of the Indian subcontinent, although most frequently between April and June, and between October and December.
The 2005 North Indian Ocean cyclone season caused much devastation and many deaths in Southern India despite the storms’ weakness. The basin covers the Indian Ocean north of the equator as well as inland areas, sub-divided by the Arabian Sea and the Bay of Bengal. Although the season began early with two systems in January, the bulk of activity was confined from September to December. The official India Meteorological Department tracked 12 depressions in the basin, and the unofficial Joint Typhoon Warning Center (JTWC) monitored two additional storms. Three systems intensified into a cyclonic storm, which have sustained winds of at least 63 km/h (39 mph), at which point the IMD named them.
The 1992 North Indian Ocean cyclone season was unofficially the most active year on record for the basin, with 10 tropical storms developing, according to the Joint Typhoon Warning Center (JTWC). There are two main seas in the North Indian Ocean – the Bay of Bengal to the east of the Indian subcontinent – and the Arabian Sea to the west of India. The official Regional Specialized Meteorological Centre in this basin is the India Meteorological Department (IMD), while the JTWC releases unofficial advisories. An average of four to six storms form in the North Indian Ocean every season with peaks in May and November. Cyclones occurring between the meridians 45°E and 100°E are included in the season by the IMD.
The monsoon trough is a portion of the Intertropical Convergence Zone in the Western Pacific, as depicted by a line on a weather map showing the locations of minimum sea level pressure, and as such, is a convergence zone between the wind patterns of the southern and northern hemispheres.
Natural calamities in India, many of them related to the climate of India, cause massive losses of life and property. Droughts, flash floods, cyclones, avalanches, landslides brought by torrential rains, and snowstorms pose the greatest threats. A natural disaster might be caused by earthquakes, flooding, volcanic eruption, landslides, hurricanes etc. In order to be classified as a disaster, it will need to have a profound environmental effect and/or human loss and frequently incurs a financial loss. Other dangers include frequent summer dust storms, which usually track from north to south; they cause extensive property damage in North India and deposit large amounts of dust and dirt from arid regions. Hail is also common in parts of India, causing severe damage to standing crops such as rice and wheat and many more crops and effects many people.
A western disturbance is an extratropical storm originating in the Mediterranean region that brings sudden winter rain to the northwestern parts of the Indian subcontinent, which extends as east as up to northern parts of Bangladesh and South eastern Nepal. It is a non-monsoonal precipitation pattern driven by the westerlies. The moisture in these storms usually originates over the Mediterranean Sea, the Caspian Sea and the Black Sea. Extratropical storms are a global phenomena with moisture usually carried in the upper atmosphere, unlike their tropical counterparts where the moisture is carried in the lower atmosphere. In the case of the Indian subcontinent, moisture is sometimes shed as rain when the storm system encounters the Himalayas. Western disturbances are more frequent and stronger in the winter season.
The 2003 North Indian Ocean cyclone season was the last season that tropical cyclones were not publicly labeled by India Meteorological Department (IMD). Also was mostly focused in the Bay of Bengal, where six of the seven depressions developed. The remaining system was a tropical cyclone that developed in the Arabian Sea in November, which was also the only system that did not affect land. There were three cyclonic storms, which was below the average of 4–6. Only one storm formed before the start of the monsoon season in June, although it was also the most notable. On May 10, a depression formed in the central Bay of Bengal, and within a few days became a very severe cyclonic storm. After it stalled, it drew moisture from the southwest to produce severe flooding across Sri Lanka, killing 254 people and becoming the worst floods there since 1947. Damage on the island totaled $135 million (2003 USD). The storm eventually made landfall in Myanmar on May 19. It is possible that the storm contributed to a deadly heat wave in India due to shifting air currents.
The 1990 North Indian Ocean cyclone season featured a below average total of twelve cyclonic disturbances and one of the most intense tropical cyclones in the basin on record. During the season the systems were primarily monitored by the India Meteorological Department, while other warning centres such as the United States Joint Typhoon Warning Center also monitored the area. During the season, there were at least 1,577 deaths, while the systems caused over US$693 million in damages. The most significant system was the 1990 Andhra Pradesh cyclone, which was the most intense, damaging, and the deadliest system of the season.
The Philippines has five types of climates: tropical rainforest, tropical monsoon, tropical savanna, humid subtropical and oceanic. The country overall is characterized by relatively high temperature, oppressive humidity and plenty of rainfall. There are two seasons in the country: the wet season and the dry season, based upon the amount of rainfall. This is also dependent on location in the country as some areas experience rain all throughout the year. The warm months of the year are March through October; the winter monsoon brings cooler air from November to February. May is the warmest month, and January, the coolest.
Earth rainfall climatology Is the study of rainfall, a sub-field of meteorology. Formally, a wider study includes water falling as ice crystals, i.e. hail, sleet, snow. The aim of rainfall climatology is to measure, understand and predict rain distribution across different regions of planet Earth, a factor of air pressure, humidity, topography, cloud type and raindrop size, via direct measurement and remote sensing data acquisition. Current technologies accurately predict rainfall 3–4 days in advance using numerical weather prediction. Geostationary orbiting satellites gather IR and visual wavelength data to measure realtime localised rainfall by estimating cloud albedo, water content, and the corresponding probability of rain.
The Monsoon of South Asia is among several geographically distributed global monsoons. It affects the Indian subcontinent, where it is one of the oldest and most anticipated weather phenomena and an economically important pattern every year from June through September, but it is only partly understood and notoriously difficult to predict. Several theories have been proposed to explain the origin, process, strength, variability, distribution, and general vagaries of the monsoon, but understanding and predictability are still evolving.
The 2017 North Indian Ocean cyclone season was a below average yet deadly season in the annual cycle of tropical cyclone formation. This season produced only three named storms, of which one only intensified into a very severe cyclonic storm. The North Indian Ocean cyclone season has no official bounds but cyclones tend to form between April and December with the two peaks in May and November. These dates conventionally delimit the period of each year when most tropical cyclones form in the northern Indian Ocean. The season began with the formation Cyclone Maarutha on April 15 and ended with the dissipation of a deep depression on December 9.
The 2018 North Indian Ocean cyclone season was one of the most active North Indian Ocean cyclone seasons since 1992, with the formation of fourteen depressions and seven cyclones. The North Indian Ocean cyclone season has no official bounds, but cyclones tend to form between April and December, with the two peaks in May and November. These dates conventionally delimit the period of each year when most tropical cyclones form in the northern Indian Ocean.
During 2017 tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 146 tropical cyclones had formed. 88 tropical cyclones had been named by either a Regional Specialized Meteorological Center (RSMC) or a Tropical Cyclone Warning Center (TCWC). The strongest and deadliest tropical cyclone was Hurricane Maria with a minimum barometric pressure of 908 mbar and killing 3,000 people in Puerto Rico and Dominica. The costliest tropical cyclone of the year was Hurricane Harvey in the Atlantic, which struck Houston metropolitan area in August causing US$125 billion in damage, tying with Hurricane Katrina as the costliest tropical cyclone worldwide.
The following is a list of weather events that occurred on Earth in the year 2015. There were several natural disasters around the world from various types of weather, including blizzards, cold waves, droughts, heat waves, tornadoes, and tropical cyclones.