Lesson 3 Flashcards
What is meant by the term weather
- it is a hour to hour and day to day variability in atmospheric conditions
- > this includes precipitatation, humidity, air pressure and wind at any specific location
- > these conditions can change rapidly
What is meant by the term climate
- climate is the long-term average of weather and its extremes
- > more predictable than weather
What are mountain climates characterized by
-they are characterized by extremes in temperatures, precipitation, wind and radiation
What are the three primary forces determining and regulating mountain climates
1) Latitude or distance from the equator
2) Elevation or height above sea level
3) Continentality
- >proximity or distance to large water bodies such as oceans
Why are climates warmer near the equator
- because the Sun’s ray hit the Earth directly
- > concentrating solar radiation
- > in contrast, at higher latitudes, the Sun’s rays hit the Earth at an angle casing the same solar radiation to be spread over a larger area
What is seasonality
-the control of temperature fluctuation is controlled through latitude
Is the Earth closer to the Sun during the winter and further away during the summer in the northern hemisphere
-yes
Why is there greater seasonality at higher latitudes
1) The tilt of the earth on its axis
- >the Earth is tilted on its axis at an angle of 23.5 degrees
- >so as Earth completes its annual orbit around the Sun
- >the Northern and Southern Hemispheres are angled towards the Sun at opposite times of the year
- >whichever hemisphere is tilted towards the Sun receives solar radiation most directly and has more hours of daylight(southern hemisphere)
2) Revolution of the Earth around the Sun
3) greater variation in solar radiation
Is seasonality weaker at the equator than the higher latitudes
-yes
What is the exception to the rule that temperature decreases with increasing latitude
- during the summer in the northern hemisphere, solar radiation strikes the Earth most directly near the Tropic of Cancer around the latitude of 23.5 degrees North
- > here temperatures are higher during the summer than in the tropics near the equator
- opposite patterns occur during the the summer in the Southerh Hemispher
- > where the temperatures are often warmers near the Tropic of Capricorn
What is air temperature
- how hot or cold the air is
- >hot air is less dense than cool air
What is atmospheric pressure
- it is the downward force of air in the atmosphere
- >caused by gravity pulling molecules of air towards the air
How is wind generated
-by air moving along pressure gradients from areas of high to low pressure
What is the intertropical convergence zone
- near the equator, high temperatures create an area of low atmospheric pressure
- > this is the intertropical convergence zone
What are circulation cells
- they are belts that encircle the Earth in which prevailing winds occur
- > if the Earth did not rotate, there would only be two circulation cells
- > one in each hemisphere
- > but with the rotation of the Earth on its axis, there is three circulation cells within each hemisphere
Describe the Hadley cells
- rising air near the equator flowes toward the poles
- > 10-15 kilometers above the surface
- > it then descends in the subtropics before returning to the equator closer to the surface
What is the Coriolis effect
- the rotation of the Earth deflects winds so they do not flow directly north and south
- > it provides an explanation for why object curve on Earth and do not move in a straight line