As the height above sea level (elevation) increases, the atmospheric pressure decreases. This relationship is fundamental to understanding weather patterns, aviation, and even human physiology at different altitudes.
Understanding the Relationship
Atmospheric pressure is the force exerted by the weight of air above a given point. At sea level, you have the entire column of air in the atmosphere pressing down. As you move higher, there is less air above you, and therefore, less weight, resulting in lower pressure.
Pressure and Altitude: Key Points
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Decreasing Pressure: As altitude increases, atmospheric pressure consistently decreases.
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Non-Linear Relationship: The decrease in pressure isn't linear. Pressure drops more rapidly at lower altitudes than at higher altitudes.
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Reference Range: According to the reference, at sea level the atmospheric pressure is 101 kPa (kilopascals), whereas at 30,000 m, it's near 0 kPa. This illustrates the significant drop in pressure with increasing altitude.
Practical Implications
The inverse relationship between atmospheric pressure and altitude has several important practical implications:
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Aviation: Aircraft altimeters use atmospheric pressure to determine altitude. Changes in pressure due to weather systems can affect altimeter readings.
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Weather Forecasting: Atmospheric pressure is a crucial factor in weather forecasting. Low-pressure systems are often associated with stormy weather, while high-pressure systems usually bring clear skies.
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Human Physiology: Lower atmospheric pressure at high altitudes means less oxygen is available. This can lead to altitude sickness.
Table: Altitude and Atmospheric Pressure (Approximate)
| Altitude (m) | Atmospheric Pressure (kPa) | Notes |
|---|---|---|
| 0 (Sea Level) | 101 | Standard atmospheric pressure |
| 3,000 | 70 | Significant drop from sea level |
| 5,500 (approx. Everest Base Camp) | 50 | Roughly half of sea level pressure |
| 8,848 (Mount Everest Summit) | 33 | Very low pressure; supplemental oxygen required. |
| 30,000 | Near 0 | Edge of space |
