1. Section 12.3 – Gathering Weather Data
8th Grade Earth and Space Science
Class Notes

2. Data from the Earth’s Surface
Quality of the data is important
The greater the accuracy and the greater the amount of data available the more reliable the forecast.

3. Temperature and Pressure
Thermometer – measures temperature
Liquid in glass or bimetallic strip
Barometer – measures air pressure
Barometer
Bimetallic strip thermometer
Liquid in glass thermometer

4. Wind Speed and Relative Humidity
Anemometer – measures wind speed
Hygrometer – measures humidity
Anemometer
Hygrometers

5. Automated Surface Observing System (ASOS)
Created by National Weather Service, Federal Aviation Administration, and Department of Defense
Allows weather
data to be gathered
and analyzed from
various locations
at the same time

6. Data from the Upper Atmosphere
Radiosonde/Rawinsonde - gathers upper atmospheric data using sensors,
a battery powered radio
transmitter, and balloon
Since the 1980s
it has been used
in conjunction
with GPS

7. Weather Observation Systems
Two major types:
Radar – detects precipitation
Satellites – detect clouds
Radar
Satellite

8. Weather Radar Radar = radio detection and ranging
Sends out radio waves programmed to only deflect from particles larger than a specific size
When these waves encounter rain drops they scatter
Doppler radar – uses the Doppler effect to determine speed of precipitation and wind

9. Doppler Radar Image

10. Weather Satellites Use light to image and observe the atmosphere
Infrared imagery – detects cloud cover and the surface temperatures of clouds
Visible light imagery – takes digital pictures of clouds
Water vapor imagery – measures the amount of water vapor in the atmosphere; can be used to look at cloud patterns and air currents

11. Weather Satellite Images
Infrared Imagery – colder clouds are higher
up and more likely to produce strong storms
Water Vapor Imagery
Visible Light Imagery