õhurõhu

õhurõhk refers to atmospheric pressure, which is the force exerted by the weight of the air in the Earth's atmosphere on a given surface area. It is a fundamental meteorological variable and is measured in units such as pascals (Pa), hectopascals (hPa), millibars (mbar), or inches of mercury (inHg).

Atmospheric pressure varies with altitude; it decreases as altitude increases because there is less air above to exert pressure. It also changes with temperature and humidity. Warm, moist air is generally less dense than cold, dry air, leading to lower pressure.

Variations in air pressure are crucial for weather patterns. High-pressure systems are typically associated with calm, stable weather, while low-pressure systems often bring clouds, precipitation, and storms. The movement of air from high-pressure to low-pressure areas creates winds.

Weather forecasters use barometers to measure air pressure and track its changes. Isobars, lines connecting points of equal atmospheric pressure on weather maps, help visualize pressure systems and predict future weather. Understanding õhurõhk is essential for meteorology and aviation, as it affects aircraft performance and flight planning.