Download Part I : Temperature Pressure and Wind(126

Part I : Temperature Pressure and Wind(126-132)
Vocabulary:
Weather Variables: Temp, Pressure, Cloud Cover, Dew Point, Relative Humidity…change day to day
Isotherms: Lines that represent equal temperature on a map
Barometric/Atmospheric Pressure: the weight of the air, measured in mb or inches
Barometer: measures barometric pressure
Isobars: lines of equal pressure
Barometric trend: tells you whether the pressure is increasing or falling (which means clear vs. cloudy/rainy weather)
Air Pressure Gradient: The difference in air pressure between two locations divided by distance
Anemometer: measures wind speed
1.) What causes us to experience weather?
Variations in insolation cause an uneven (not equal) distribution of heat. So the movement of heat energy results in the
atmosphere constantly changing (air moving around!)
2.) Explain how a thermometer works
The liquid expands as the temperature increases and it moves up the scale
3.) What are the 5 ways in which the atmosphere is heated?
a.
Conduction: heat from the earth as air touches the grounds surface
b.
Aerosols absorb radiation (insolation) from the sun
c.
Greenhouse gases absorb heat energy (infrared)
d.
Condensation (gl) releases large amounts of stored heat when clouds, fog, dew, and frost forms
e. Coriolois Effect: when winds move their contact with the earth causes friction, which creates heat
absorbed by the atmosphere.
4.) How is energy transferred within the atmosphere?
Heat is transferred by convection currents (cells) in the atmosphere. Mainly in the troposphere. Winds are the
lower and upper parts (parallel) to Earth’s surface.
5.) Explain why air cools as it rises in the troposphere.
As air rises in the atmosphere, it expands as the pressure decreases. As air expands its kinetic energy decreases,
lowering temperature
6.) A. Explain how an increase in temperature affects the barometric pressure.
An increase in temperature causes the pressure to decrease (because air becomes less dense)
b. Explain how a decrease in temperature affects the barometric pressure.
A decrease in temperature causes the air pressure to increase (because air becomes more dense)
7.) Why does more humid/moist air have a lower barometric pressure than dry air?
Humid air has a lower pressure because pressure is the weight of the air on top of you. Water weighs less in
molecular weight than nitrogen or oxygen molecules so when you put more water vapor into the air, you are
replacing N which weighs more!
8.) How does an increase in altitude change the air pressure?
As altitude increases, air pressure decreases (because there is less atmosphere on top of you!)
9.) What causes winds?
Winds are caused by variations in temperature and moisture which in turn create regions of different pressure.
How would a greater pressure gradient be depicted on a weather map? How would this influence the wind
speed?
A greater pressure gradient is depicted by isobars closer togetherfaster wind speed!
10.) What is responsible for the deflection (curving) of winds blowing in otherwise a straight path from regions of
high to low pressure?
The coriolis effect. Winds are deflected to the right in the Northern Hemisphere and to the left in the southern
hemisphere.