Atmospheric pressure drops as you go higher up in the atmosphere. Pressure at sea level is around a thousand millibars. Five kilometers (about 16 thousand feet) up pressure is only about half as much.
Click on image for full size
Original artwork by Windows to the Universe staff (Randy Russell).
How Pressure Changes with Altitude in Earth's Atmosphere
Air gets 'thinner' with increasing altitude. That's why mountain climbers sometimes need bottled oxygen to breathe, and why it is so easy to get 'winded' while hiking in high mountains or even visiting someplace at elevation. Atmospheric pressure is around 1,014 millibars (14.7 pounds/inch2) at sea level. At an elevation of 10 km (6 miles or about 30,000 feet), roughly the height of Mt. Everest, pressure drops to 265 millibars. That's less than 30% of the pressure at sea level! Both atmospheric pressure and the density of air decrease with altitude.
Shop Windows to the Universe Science Store!
The Fall 2009 issue of The Earth Scientist
, which includes articles on student research into building design for earthquakes and a classroom lab on the composition of the Earth’s ancient atmosphere, is available in our online store
You might also be interested in:
Rainbows appear in the sky when there is bright sunlight and rain. Sunlight is known as visible or white light and is actually a mixture of colors. Rainbows result from the refraction and reflection of...more
The Earth travels around the sun one full time per year. During this year, the seasons change depending on the amount of sunlight reaching the surface and the Earth's tilt as it revolves around the sun....more
Scientists sometimes travel in specially outfitted airplanes in order to gather data about atmospheric conditions. These research aircraft have special inlet ports that bring air from the outside into...more
An anemometer is a weather instrument used to measure the wind (it can also be called a wind gauge). Anemometers can measure wind speed, wind direction, and other information like the largest gust of wind...more
Thermometers measure temperature. "Thermo" means heat and "meter" means to measure. You can use a thermometer to measure the temperature of many things, including the temperature of...more
Weather balloons are used to carry weather instruments that measure temperature, pressure, humidity, and winds in the atmosphere. The balloons are made of rubber and weigh up to one kilogram (2.2 pounds)....more
Wind is moving air. Warm air rises, and cool air comes in to take its place. This movement creates different pressures in the atmosphere which creates the winds around the globe. Since the Earth spins,...more