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

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

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

4. How a Barometer works

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

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

7. 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.

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

9. Strong Wind Gust 5/12/14

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

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

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