The Loo ( hi, लू,

Urdu Urdu (;"Urdu"
''

wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hou ...

from the west which blows over the

Indo-Gangetic Plain The Indo-Gangetic Plain, also known as the North Indian River Plain, is a fertile plain encompassing northern regions of the Indian subcontinent, including most of northern and eastern India, around half of Pakistan, virtually all of Bangla ...

region of

North India North India is a loosely defined region consisting of the northern part of India. The dominant geographical features of North India are the Indo-Gangetic Plain and the Himalayas, which demarcate the region from the Tibetan Plateau and Central ...

and

Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...

. It is especially strong in the months of May and June. Due to its very high temperatures (45 °C–50 °C or 115 °F–120 °F), exposure to it often leads to fatal heatstrokes. Since it causes extremely low humidity and high temperatures, the ''Loo'' also has a severe drying effect on vegetation leading to widespread browning in the areas affected by it during the months of May and June.

Origin and ending

The Loo mainly originates in the large desert regions of the northwestern Indian subcontinent: the Great Indian Desert, the

Cholistan Desert The Cholistan Desert ( ur, ; Punjabi: ), also locally known as Rohi (), is a desert in the southern part of Punjab, Pakistan that forms part of the Greater Thar Desert, which extends to Sindh province and the Indian state of Rajasthan. It is ...

and the

desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...

areas of Southern

Balochistan Balochistan ( ; bal, بلۏچستان; also romanised as Baluchistan and Baluchestan) is a historical region in Western and South Asia, located in the Iranian plateau's far southeast and bordering the Indian Plate and the Arabian Sea coastline. ...

. The Loo ends in late summer, with the arrival of the Indian

monsoon 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 oscil ...

. In some areas of North India and Pakistan, there are brief, but violent, dust storms known as

Kali Andhi Black storms, locally called Kali Andhi , Kali Nheri in South Asia ( hi, काली आँधी, pnb, , ur, , literal meaning: ''Black Storm'') are violent dust squalls that occur in the late-spring in the northwestern parts of the Indo-Gan ...

(or ''black Storm'') before the monsoon sets in. The arrival of monsoon clouds in any location is frequently accompanied with

cloudburst A cloudburst is an extreme amount of precipitation in a short period of time, sometimes accompanied by hail and thunder, which is capable of creating flood conditions. Cloudbursts can quickly dump large amounts of water, e.g. 25 mm of prec ...

s, and the sudden transformation of the landscape from brown to green can seem "astonishing" as a result of the ongoing deluge and the abrupt cessation of the Loo.

Dwelling adaptation

Since the plains of North India and Pakistan are both very hot and extremely dry during this season, water evaporates quite readily. Although this leads to the drying out of many ponds and lakes, the extreme dryness of the air is also easily exploited to create evaporation-based cooling systems. Windows shielded with fiber-screens of the fragrant ''khas'' (ख़स/خس or

vetiver ''Chrysopogon zizanioides'', commonly known as vetiver and khus, is a perennial bunchgrass of the family Poaceae. Vetiver is most closely related to ''Sorghum'' but shares many morphological characteristics with other fragrant grasses, such as ...

) dry-grass that are kept damp with a simple water-pumping mechanism are quite effective as an inexpensive form of air conditioning, and have been in common use throughout the plain portions of the northern

Indian subcontinent The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian O ...

for centuries. Because evaporation proceeds at a very rapid rate in the extreme dryness, the cooling effect can be quite dramatic and result in dwellings where the interior feels chilly. The water in the screens evaporates very rapidly, however, so it must constantly be replenished from raised tanks or with pumps (that can sometimes be driven by the ''Loo'' itself). Any water reservoir used must also be shielded from the Loo and the sun, or it can rapidly be depleted.

Ecological effects

Many birds and animals succumb to the Loo in the summer months, especially in deforested areas where the Loo blows unhindered and shelter is unavailable. Certain insect-borne diseases, such as

malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...

, have historically registered dips during the Loo season as insects populations also plummet during this season. Even prior to the 1897 discovery that mosquitoes transmitted malaria, officials in Asia had noticed the strong winds in the plains of Northernmost India naturally made the region relatively free of the disease.

In popular culture

Due to the dangerous, and potentially fatal, effects of the loo on vegetation, humans and animals, it is sometimes referred to as an evil wind in popular Indo-Pakistani culture. Avoiding exposure to the ''Loo'' is strongly recommended for children and the elderly, as well as pets. Most people attempt to stay indoors as much as possible during afternoons in the Loo-affected months. Heatstrokes are commonly referred to as ''loo lagna'' (

Hindi Hindi (Devanāgarī: or , ), or more precisely Modern Standard Hindi (Devanagari: ), is an Indo-Aryan language spoken chiefly in the Hindi Belt region encompassing parts of northern, central, eastern, and western India. Hindi has been de ...

: लू लगना,

Urdu Urdu (;"Urdu"
''

Certain

sharbat Sharbat ( fa, شربت, ; also transliterated as ''shorbot'', ''šerbet'' or ''sherbet'') is a drink prepared from fruit or flower petals. It is a sweet cordial, and usually served chilled. It can be served in concentrated form and eaten with a ...

s, which are popularly believed to have a cooling effect on the body and provide some protection against Loo-caused heatstrokes, are widely consumed during the Loo-season. These include sherbets of

rose A rose is either a woody perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred species and tens of thousands of cultivars. They form a group of plants that can be ...

, khus-khus, shahtoot,

bel BEL can be an abbreviation for: * The ISO 3166-1 alpha-3 country code for Belgium * ''BEL'' or bell character in the C0 control code set * Belarusian language, in the ISO 639-2 and SIL country code lists * Bharat Electronics Limited, an Indian stat ...

and

phalsa ''Grewia asiatica'', commonly known as phalsa or falsa,Flora of Indi''Grewia asiatica''/ref> is a species of flowering plant in the mallow family Malvaceae. It was first found in Varanasi, India, and was taken by Buddhist scholars to other Asian ...

. A specific

Unani Unani or Yunani medicine (Urdu: ''tibb yūnānī'') is Perso-Arabic traditional medicine as practiced in Muslim culture in South Asia and modern day Central Asia. Unani medicine is pseudoscientific. The Indian Medical Association describes U ...

recipe called

Rooh Afza Rooh (English: Soul) is an Indian one hour horror supernatural thriller television series which was broadcast on Zee TV from 6 November 2004 to 6 August 2005. It used to air every Saturday at 8 P.M. Each story has a different cast and crew. Shi ...

combines several of these popularly believed cooling agents, and is sold commercially as a syrup to flavor sherbets, cold milk drinks, ices and cold desserts, such as the popular

falooda A ''falooda'' is a Mughlai Indian version of a cold dessert made with noodles. It has origins in the Persian dish ''faloodeh'', variants of which are found across West, Central, and South Asia. Traditionally it is made by mixing rose syrup, ...

Lassi Lassi () is a regional name for buttermilk, the traditional dahi (yogurt)–based drink, consumed in the South Asian region. Lassi is a blend of yogurt, water, spices, and sometimes fruit. Salty lassi is similar to doogh, while modern sweet la ...

, a

yogurt Yogurt (; , from tr, yoğurt, also spelled yoghurt, yogourt or yoghourt) is a food produced by bacterial Fermentation (food), fermentation of milk. The bacteria used to make yogurt are known as ''yogurt cultures''. Fermentation of sugars in t ...

-based drink of North India and Pakistan, is also extremely popular and believed to confer some protection against the Loo. Additionally in the desert state of Rajasthan '' Kairi Ka Panna'' ( hi, कैरी का पन्ना) (drink of raw/unripe mango) is a very popular way of remaining cool and resilient to Loo.

References

External links

American Meteorological Society's glossary of Meteorology
{{Wiktionary pipe, loo#Etymology 4, loo Winds Climate of Pakistan Climate of India