Geo Ch 4
Normal sea level pressure has a value of
1013.2 millibars or 29.92 inches of mercury in a barometer.
The average height of a column of mercury (Hg) in a barometer at sea level is
760 mm (76 cm).
The normal range for air pressure at sea level is
980 to 1050 mb.
Which of the following is true of high pressure areas?
Air descends and diverges within high pressure systems.
Which of the following describes the Coriolis force?
It causes the apparent deflection of winds from a straight path.
Which of the following describes the pressure gradient force?
It drives air from areas of higher to lower barometric pressure.
Which of the following refers to tertiary circulation?
Landd-sea breezes
Which of the following is true of upwelling zones?
They are nutrient-rich, They occur along the west coasts of continents, They are most common above deep ocean basins, They are nutrient-rich and along the west coasts only.
On a weather map of air pressure, what can you infer from a closer spacing of isobars?
a steep pressure gradient creating a faster flow of air
An instrument used to measure air pressure is
an aneroid barometer.
An isoline of equal pressure plotted on a weather map is known as
an isobar.
The winds that blow off the ice sheets of Antarctica and Greenland are
called katabatic winds.
The intertropical convergence zone is characterized by
convergence and uplift of warm surface air
Air flow in a Northern Hemisphere high pressure zone is
downward, outward and clockwise.
Ocean currents are produced by
friction, Coriolis force, and water density differences only.
Which of the following refers to primary circulation?
general circulation of the atmosphere
In the absence of friction, the combined effect of the Coriolis force and the pressure gradient
geostrophic winds at high altitudes above the ground.
As air temperature increases, the speed of the molecules in a mass of air ________ and the air pressure ________.
increases; increases
Within the upper-air westerly wind flow are great waving undulations
known as Rossby waves that involve contact between cooler and warmer air masses
Which of the following refers to secondary circulation?
migratory high and low pressure systems
Land-sea breezes are caused by
onshore (toward the land) air flows that develop in the afternoon as the land heats faster than neighboring water surfaces.
Air flows ________ a surface high pressure area because the density of the air in the high pressure zone is ________ than that of the surrounding air.
out of; more dense
If Earth did not rotate, air would flow
perpendicular to the isobars, i.e., straight across the isobars.
Air flow is initiated by the
pressure gradient force.
Monsoonal winds are
regional wind systems that seasonally vary.
An increase in air pressure will cause the mercury in a barometer to ________.
rise
The deflection produced by the Coriolis force is caused by
the fact that Earth's rotation decreases in speed toward the poles.
The jet streams help control
the movement of high and low pressure systems, the movement of storms, the boundary between cold polar air to the north and warm air to the south.
Between 20° to 35° north latitude and 20° to 35° south latitude are
the world's arid and semi-arid desert regions.
Winds that blow predominantly from the northeast and the southeast are the
trade winds.
Mountain-valley breezes are caused by
warm air rising upslope during the day and cooler air descending the slopes at night.
If you were between 40° and 50° north latitude and you wanted to stand with the average winds blowing in your face, you would stand facing
west
The dominant surface winds from the subtropics to high latitudes are the
westerlies.
The horizontal motion of air relative to Earth's surface is
wind
