Barometertryck

Barometertryck, or atmospheric pressure as measured by a barometer, is the force exerted by the column of air above a location. It results from the weight of the Earth's atmosphere pressing down on the surface. Barometertryck is usually expressed in hectopascals (hPa) or kilopascals (kPa); 1 hPa equals 100 pascals. At sea level, the standard barometertryck is about 1013.25 hPa. Pressure decreases with increasing altitude according to the hydrostatic balance of the atmosphere, a relationship that varies with temperature and weather conditions.

Instruments used to measure barometertryck include the mercury barometer, which balances atmospheric force against a column of mercury; the aneroid barometer, which uses a sealed flexible chamber whose shape changes with pressure; and digital barometers that sense pressure electronically. In meteorology and aviation, pressure readings are often adjusted to a reference level. Sea-level-adjusted values are commonly used (QNH), while aviation uses QFE (local surface pressure) or QFF (obtainable from standard atmospheric conditions).

Weather interpretation relies on barometertryck trends. Generally, rising pressure indicates an approaching high-pressure system and clearer skies, whereas falling pressure suggests a low-pressure system and the potential for clouds and precipitation. Rapid drops in barometertryck can signal storms or fronts. Spatially, pressure is not uniform; isobars connect locations with equal barometertryck and help forecasters assess wind patterns and the movement of weather systems.

Barometertryck is a fundamental parameter in meteorology, aviation, and outdoor planning, reflecting the dynamic state of the Earth's atmosphere.