Air and Weather Factors Study Guide
Name_____________ Period________
Please review all of your notes and worksheets within you science notebook that are connected with air,
weather factors, or the atmosphere.
Remember that meteorology is the study of weather. The scientist that chooses this as their focus of study is
called a meteorologist. Meteorologists measure weather factors including; temperature, humidity, wind direction,
wind speed, barometric pressure, visibility, and others. Using these measured factors, meteorologists make a
forecast of near future weather conditions. A forecast is a prediction of weather events.
Air is made of a mixture of gases. The most plentiful gases include Nitrogen (78%) and Oxygen (21%). Some gases
are permanent gases (Nitrogen, Oxygen are both permanent gases) and the overall amounts of these gases do not
change in our atmosphere. Other gases are variable gases and amounts in our atmosphere do change over time.
Variable gases include: Water vapor and carbon dioxide. Three gases only found in the Troposphere are water
vapor, carbon dioxide and methane. These gases are byproducts of living organisms.
Gases can be compressed. We proved this by compressing air in a syringe. By using a syringe containing a foam
cube, we learned that compressing air causes the pressure within the syringe to increase. If we could visually see
this happening we would see no increase in the number of air particles within the syringe. We would see a
constant number of air particles being crowded into a smaller space. The gas particles are more crowded in the
syringe and less crowded within the foam cube. This difference causes a pressure difference. We are able to see
this because the foam cube gets smaller. Pressure is a force pushing back.
The atmosphere has different identified regions with some unique features. The Troposphere begins at ground
level. This is the regions were all weather happens, and life exists. Above the Troposphere we find the
Stratosphere. The Stratosphere contains the Ozone layer. This layer shields the Earth’s surface from damaging UV
rays originating from our Sun. Atmospheric temperature also increases in the region of the Ozone layer. The
Stratosphere also contains the jet stream, a fast flowing river of wind. Next we find the Mesosphere which is the
region where shooting stars begin to burn as space objects begin to enter earth’s atmosphere. Above the
Mesosphere is the Thermosphere. This region is not well understood, but we do know that temperatures can get
as high as 1500 degrees Celsius within it. The last region is the Exosphere extending from 300 km into outer space.
Gases are very thin and temperatures are very cold. The Exosphere is the transition to outer space.
Temperature generally decreases in the atmosphere as altitude increases. We experience this when we drive from
the lowlands up into the Cascade Mountains. There are exceptions to this pattern. In the ozone layer
temperatures increase and in the Thermosphere temperatures can get very hot.
Air has mass that can be measured as weight. Meteorologists have developed a tool (barometer) that shows this
property of weight for air. In class using 2 balloons (one full and one empty) and connected straws with a fulcrum
on which the straw pivots, students showed that air has weight.