What are barometers?
Barometers are instruments used to predict short term changes in weather patterns by measuring air pressure. There are two types of barometers: mercury and aneroid.
How do barometers work?
Mercury barometers: Atmospheric pressure balances the column of mercury inside the barometer, the height of which is measured to give air pressure.
Aneroid barometers: An evacuated capsule deflects with changes in atmospheric pressure. Amount of deflection is coupled to and indicating needle.
What is a barograph?
- A barograph is a barometer that records changes in barometric pressure over time. This device usually uses aneroid barometers.
For a more in-depth description of how barometers work, try these sources.
- Barometers Topic GuideContent from multiple reference sources on barometers, plus links out to research articles, books, and more.
- Barometer: Encyclopædia Britannica
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- Atmospheric Pressure: Encyclopædia Britannica
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Where can I find data?
One of the primary sources of weather data is the National Climatic Data Center (NCDC) which includes air pressure data.
- National Centers for Environmental InformationFormerly called the National Climate Data Center (NCDC), this site is the place to go if you need climate data, including precipitation, temperature, and other measures.
For international data on air pressure, try the Monthly Climatic Data for the World publication by NCDC.
- Monthly Climate Data for the WorldContains monthly mean temperature, pressure, precipitation, vapor pressure, and sunshine for ~ 2000 surface data collection stations worldwide and monthly mean dew point depressions, upper air temperatures, and wind Velocities for ~500 observing sites.
See also...
The Gould Library Climate and Weather Data guide lists many more sources of weather data.
Attribution
This page developed by Maddy Menard '17 in spring 2016.
