Search results
Results from the WOW.Com Content Network
The other major effect of altitude is due to lower ambient temperature. The oxygen saturation of hemoglobin determines the content of oxygen in blood. After the human body reaches around 2,100 metres (6,900 ft) above sea level, the saturation of oxyhemoglobin begins to decrease rapidly. [2]
By contrast, the women of long-resident, high-altitude populations are known to give birth to heavier-weight infants than women of the lowland. This is particularly true among Tibetan babies, whose average birth weight is 294–650g (~470) g heavier than the surrounding Chinese population, and their blood-oxygen level is considerably higher. [24]
The variation in temperature that occurs from the highs of the day to the cool of nights is called diurnal temperature variation. Temperature ranges can also be based on periods of a month or a year. The size of ground-level atmospheric temperature ranges depends on several factors, such as: Average air temperature; Average humidity; The regime ...
Temperature lag, also known as thermal inertia, is an important factor in diurnal temperature variation. Peak daily temperature generally occurs after noon, as air keeps absorbing net heat for a period of time from morning through noon and some time thereafter. Similarly, minimum daily temperature generally occurs substantially after midnight ...
At 11,900 m (39,000 ft), breathing pure oxygen through an unsealed face mask, one is breathing the same partial pressure of oxygen as one would experience with regular air at around 3,600 m (11,800 ft) above sea level [citation needed]. At higher altitudes, oxygen must be delivered through a sealed mask with increased pressure, to maintain a ...
The division of the atmosphere into layers mostly by reference to temperature is discussed above. Temperature decreases with altitude starting at sea level, but variations in this trend begin above 11 km, where the temperature stabilizes over a large vertical distance through the rest of the troposphere.
Therefore, in order to breathe in the same amount of oxygen per minute, the person has to inhale a proportionately greater volume of air per minute at altitude than at sea level. This is achieved by breathing deeper and faster (i.e. hyperpnea) than at sea level (see below). Fig. 13 Aerial photo of Mount Everest from the south, behind Nuptse and ...
In the region from sea level to around 3,000 m (10,000 ft), known as the physiological-efficient zone, oxygen levels are usually high enough for humans to function without supplemental oxygen and altitude decompression sickness is rare. The physiological-deficient zone extends from 3,600 m (12,000 ft) to about 15,000 m (50,000 ft).