1. Weather Instruments Once again brought to you by your amazing, insightful and abundantly intelligent teacher, Mr. Harris Once again brought to you by your amazing, insightful and abundantly intelligent teacher, Mr. Harris

2. Weather instruments  The different aspects of the weather require different instruments or tools to measure them.  Before these instruments were invented, scientists had to use their senses and patterns within the weather to understand it. These scientist understood that a tool must be made that would make reading, understanding and predicting the weather more efficient and easier.  Things such as air pressure, humidity, wind speed, precipitation levels and temperature are all measured by both manual and digital instruments or tools.

3. Relative Humidity  Relative humidity is the actual amount of water vapor in the air compared to the total amount of vapor the air can hold.  It is measured as a percentage  Psychrometers are used to measure it. They are comprised of two thermometers: one with a wet bulb and one with a dry bulb.

4. Psychrometers

5. Air pressure  Air pressure is the amount of pressure that the air around us puts on us and the things that surround us. It is measured in pounds per square inch. (lb/in2)  High pressure means good weather, low pressure means cloudy and/or stormy weather.  We use a Barometer to measure the air pressure.

6. Barometers

7. Temperature  Temperature is how much heat is in something. Heat is energy. The absence of heat is cold.  It determines a lot of what the weather actually does. The differences in temperature is one cause of wind.  Thermometers measure temperature. Some are different than others and use different chemicals to measure but they all do the same thing.  The measurement is in degrees Fahrenheit or Celsius. We are used to Fahrenheit.  We can measure temperature of our bodies, the air and other things.

8. Thermometers

9. Precipitation  Precipitation occurs when clouds become saturated and empty out.  Rain gauges measure how much precipitation actually falls at any given time.  We use this information to develop patterns and possibly predict future precipitation levels.  These levels are measured in inches or centimeters.

10. Rain Gauges

11. Where’s Jose?  If Jose was lost in the middle of a hurricane could look at a map and find his exact latitude and longitude, he could enter those coordinates into a GPS (Global Positioning System) and find his way home.  GPS is a computer based unit that can measures distance from one point to another. It uses satellites to triangulate a position on the planet. We use these in our cars and while hunting or hiking.  Some people play a game called GeoCaching.

12. GPS