Barometer

Definition

A barometer is an instrument used to measure atmospheric pressure, which is a crucial factor in weather prediction and understanding the structure of the atmosphere. By measuring pressure changes, a barometer helps identify weather patterns and systems, as well as providing insights into altitude changes, since atmospheric pressure decreases with elevation. This tool is essential for both meteorological studies and understanding air circulation dynamics.

5 Must Know Facts For Your Next Test

1. Barometers come in two main types: mercury barometers, which use mercury to measure pressure, and aneroid barometers, which use a flexible metal capsule that expands or contracts with pressure changes.
2. Changes in atmospheric pressure indicated by a barometer can predict weather changes, such as the approach of storms or fair weather.
3. A rising barometer typically indicates improving weather, while a falling barometer suggests deteriorating conditions.
4. Mercury barometers operate on the principle that the height of mercury in the tube correlates with the weight of the atmosphere pressing down on it.
5. Barometers are also essential tools for climbers and aviators, as they help determine altitude by measuring pressure changes as one ascends or descends.

Review Questions

• How does a barometer function in relation to atmospheric pressure and its changes?
  • A barometer measures atmospheric pressure by using either mercury or an aneroid mechanism. In a mercury barometer, the height of mercury reflects the weight of the air above it; as atmospheric pressure increases, it pushes the mercury higher. In an aneroid barometer, changes in pressure cause a metal capsule to expand or contract, moving a needle on a dial. Both types give important readings that help predict weather patterns based on shifts in pressure.
• Discuss how a barometer's readings can influence our understanding of weather systems and atmospheric circulation.
  • The readings from a barometer are critical for understanding weather systems since they indicate high or low-pressure areas that correlate with different weather patterns. High-pressure systems often lead to clear skies and stable weather, while low-pressure systems are associated with storms and precipitation. This data helps meteorologists make predictions about atmospheric circulation and how it will affect local and regional weather conditions.
• Evaluate the significance of barometers in both meteorological applications and outdoor activities like climbing and aviation.
  • Barometers play a significant role in meteorology by providing essential data for weather forecasts, which can inform public safety and preparedness measures during severe weather events. In outdoor activities like climbing and aviation, barometers serve as altimeters, helping users gauge their altitude by measuring changes in atmospheric pressure. This dual purpose highlights the importance of understanding barometric readings not just for predicting weather but also for ensuring safety in environments where elevation change can impact conditions.

Related terms

Atmospheric Pressure: The force exerted onto a surface by the weight of the air above that surface in the atmosphere of Earth (or that of another planet).

Altimeter: An instrument used to measure altitude by comparing atmospheric pressure at a certain height to a standard reference pressure.

Weather Front: A boundary separating two masses of air of different densities, which can lead to various weather conditions, including storms and precipitation.