4. Atmosphere & Weather (schoolnet)

Most ultraviolet (UV) rays are deflected or absorbed by the atmosphere, but some of these rays pass easily through the atmosphere and penetrate Earth's surface.

Which substance in the atmosphere absorbs most of the ultraviolet rays?

• chlorofluorocarbon

• ozone

• nitrogen

• water

How does air density affect air pressure in a cyclonic storm?

• Warm air rises, creating an area of low pressure under it.

• Cool air rises, creating an area of low pressure under it.

• Warm air rises, creating an area of high pressure under it.

• Cool air rises, creating an area of high pressure under it.

How does the ocean affect (provide energy for) the formation of hurricanes?

• Ocean water is cool and cools the air above it

• Ocean water is warm and heats the air above it.

• Ocean water contains salt that reacts with air, changing the air pressure.

• Ocean water contains algae that make oxygen, changing the air's composition.

How do hurricanes form and move?

• The storms form at the equator and initially move west.

• The storms form at the equator and initially move south.

• The storms form at the northern mid-latitude and initially move west.

• The storms form at the northern mid-latitude and initially move south.

The air masses that interact to form hurricanes and cyclones rise and fall due to changes in air density and pressure. Why do these storms also spin?

• Ocean currents drag the air above them in circles.

• The Moon's gravity pulls air currents with the tides.

• Low pressure air pushes high pressure air sideways.

• Earth's rotation causes the air to turn as it moves north.

Auroras occur where Earth's magnetosphere traps high-energy particles in which region of the atmosphere?

• Troposphere

• Stratosphere

• Thermosphere

• Exosphere

The average yearly rainfall in Miami, FL is about 58 inches. During the year, Miami goes through a dry period where it receives very little rainfall. Which factor is MOST likely responsible for the dry period?

• cold air moving in from the north

• distance from the Gulf Stream current

• location of latitude north of the equator

• warm air moving in from the Atlantic Ocean

Tornadoes can occur throughout the U.S. One area where most of the tornadoes occur is known as Tornado Alley.

Which environmental factors MOST likely impact the formation of tornadoes in this area?

• high pressure systems colliding with other high pressure systems

• cold dry air and warm dry air moving towards each other

• low evaporation rates and windy conditions

• cool dry air colliding with warm moist air

Hurricanes typically form during predictable times of year and in certain locations on Earth. Which factor BEST enables climatologists to forecast the time and location of hurricane formation?

• ocean currents and temperature

• distance from the Sun

• thickness of the ozone layer

• angle of sunlight on Earth

The arrows on the map represent the movement of air masses across North America.

Air mass 1 would MOST likely bring which weather conditions to a region?

• cool and dry

• warm and dry

• cool and humid

• warm and humid