High altitude in the context of "Biocultural diversity"

The troposphere is the lowest layer of the atmosphere of Earth. Pronounced /ˈtrɒpəsfɪərˌ-poʊ-/, the name comes from Ancient Greek τρόπος (trópos) 'turning, change' and -sphere. It contains 80% of the total mass of the planetary atmosphere and 99% of the total mass of water vapor and aerosols, and is where most weather phenomena occur. From the planetary surface of the Earth, the average height of the troposphere is 18 km (11 mi; 59,000 ft) in the tropics; 11 km (6.8 mi; 36,000 ft) in the middle latitudes; and 6 km (3.7 mi; 20,000 ft) in the high latitudes of the polar regions in winter; thus the average height of the troposphere is 13 km (8.1 mi; 43,000 ft).

The term troposphere derives from the Greek words tropos (rotating) and sphaira (sphere) indicating that rotational turbulence mixes the layers of air and so determines the structure and the phenomena of the troposphere. The rotational friction of the troposphere against the planetary surface affects the flow of the air, and so forms the planetary boundary layer (PBL) that varies in height from hundreds of meters up to 2 km (1.2 mi; 6,600 ft). The measures of the PBL vary according to the latitude, the landform, and the time of day when the meteorological measurement is realized. Atop the troposphere is the tropopause, which is the functional atmospheric border that demarcates the troposphere from the stratosphere. As such, because the tropopause is an inversion layer in which air-temperature increases with altitude, the temperature of the tropopause remains constant. The layer has the largest concentration of nitrogen.

The predecessors to the contemporary Army of India were many: the sepoy regiments, native cavalry, irregular horse and Indian sapper and miner companies raised by the three British presidencies. The Army of India was raised under the British Raj in the 19th century by taking the erstwhile presidency armies, merging them, and bringing them under the Crown. The British Indian Army fought in both World Wars.

The armed forces succeeded the military of British India following India's independence in 1947. After World War II, many of the wartime troops were discharged and units disbanded. The reduced armed forces were partitioned between India and Pakistan. The Indian Armed Forces fought in all four wars against Pakistan, and two wars against People's Republic of China in 1962 and 1967. India also fought in the Kargil War with Pakistan in 1999, the highest altitude mountain warfare in history.

Altitude sickness, the mildest form being acute mountain sickness (AMS), is a harmful effect of high altitude, caused by rapid exposure to low amounts of oxygen at high elevation. People's bodies can respond to high altitude in different ways. Symptoms of altitude sickness may include headaches, vomiting, tiredness, confusion, trouble sleeping, and dizziness. Acute mountain sickness can progress to high-altitude pulmonary edema (HAPE) with associated shortness of breath or high-altitude cerebral edema (HACE) with associated confusion. Chronic mountain sickness may occur after long-term exposure to high altitude.

Altitude sickness typically occurs only above 2,500 metres (8,000 ft), though some people are affected at lower altitudes. Risk factors include a prior episode of altitude sickness, a high degree of activity, and a rapid increase in elevation. Being physically fit does not decrease the risk. Diagnosis is based on symptoms and is supported for those who have more than a minor reduction in activities. It is recommended that at high altitude any symptoms of headache, nausea, shortness of breath, or vomiting be assumed to be altitude sickness.