Add To Table of Contents: Weather Tracking Pg. 100 Weather Instruments Pg. 101

Weather Instruments Pg. 101 A. Lower Atmosphere: 1. Thermometer - temperature

What does a barometer measure? 2. Barometer – measures atmospheric pressure.

How a Barometer works

What does a anemometer measure? 3. Anemometer – measures wind speed.

What does a hygrometer measure? 4. Hygrometer – measures humidity = amount of water vapor in the air.

hygrometer uses two basic mercury thermometers, one with a wet bulb one with a dry bulb. Evaporation from the water on the wet bulb causes its temperature reading to drop, causing it to show a lower temperature than the dry bulb. Relative humidity is calculated by comparing the readings using a calculation table that compares the ambient temperature (the temperature given by the dry bulb) to the difference in temperatures between the two thermometers.

What does a weather vane measure? 5. weather vane – measures wind direction

Strong Wind Gust 5/12/14

B. Upper atmosphere: Radiosonde – a helium weather balloon carries weather instruments high into the atmosphere.

2. Radar = radio detection and ranging -reflects radio waves to determine velocity and location of objects.

3. Satellites – use visible, infrared and cloud vapor to show where storms are.