metr 121 quiz 6

a station at an altitude of 300 m (about 1000 feet) above sea level measures an air pressure of 920 mb. under normal conditions, which of the values below do you think would be the most realistic sea level pressure for this station

950 mb

A station at an elevation of 220 m (about 722 feet) above sea level measures an air pressure of 951 mb at ground level. Under normal conditions, which of the values below do you think would be the most realistic sea level pressure for this station?

973 mb

an anticyclone in either the Northern or Southern Hemisphere is defined as ____

a high pressure system

a cyclone in either the northern or Southern Hemisphere is defined as

a low pressure system

the reason for altitude correction to obtain sea-level pressure from station observations is that ____

air pressure changes more rapidly in the vertical direction than in the horizontal

centripetal force keeps objects to move

along a curved oath

horizontal air pressure change is usually ____ the vertical change

at a smaller rate than

the pressure gradient force is directed from higher pressure toward lower pressure

at all places on earth

in the vertical, the pressure gradient force points ____ and gravity points ____

away from earth; toward earth

in the vertical, the pressure gradient force points ____ and gravity points ___

away from earth; towards earth

in the pressure and wind fields, as well as four locations a, b, c, d shown below, the direction of the pressure gradient force (PGF) at point c is pointing towards ____, and is ____ than PGF at point a

b, stronger

which of the following instruments measures pressure

barometer

in the pressure and wind fields, as well as four locations a, b, c, and d shown below, the direction of the pressure gradient force (PGF) at point b is pointing towards ____, and is ____ than that at point c

c, weaker

Cyclonic flow means in either the Northern or Southern Hemisphere.

circulation around a low pressure center

cyclonic flow means ____ in either the Northern or Southern Hemisphere

circulation around a low pressure center

in Southern Hemisphere, wind around a cyclone blows

clockwise and inward

in northern hemisphere, wind around an anticyclone blows ____

clockwise and outward

in the northern hemisphere, wind around an anticyclone blows ____

clockwise and outward

the wind around a surface high pressure center in the northern hemisphere blows

clockwise and outward from the center

a surface low pressure center is generally associated with ____

cloudy or rainy weather

the earth's atmosphere is ordinarily ____

conditionally unstable

meteorologists often refer the vertical motion of air as

convection

the surface air around a strengthening low pressure area normally ____ and ____

converges; rises

in northern hemisphere, wind around a cyclone blows

counterclockwise and inward

in the northern hemisphere, wind around a cyclone blows

counterclockwise and inward

the large red l's on a surface weather map represents centers of low pressure, also known as ____

cyclones

if upper-level divergence (air flow out of column) exceeds surface convergence, the air pressure at the center of the low will ____ and isobars will be ____ tightly packed

decrease, more

The surface pressures at the bases of warm and cold columns of air are equal. Air pressure in the warm column of air will with increasing height than in the cold column.

decrease, more slowly

the surface pressures at the bases of warm and cold columns of air are equal. air pressure in the warm column of air will ____ with increasing height ____ than in the cold column

decrease, more slowly

suppose that the winds aloft in the northern hemisphere are geostrophic and blowing from the north. low pressure is located to the ____

east

which of the following combinations produces the strongest Coriolis force

fast winds and high altitude

the simple air column model can be used to explain thermal circulation. at surface, the resulting wind is ____

from cold column to warm column

a ____ wind blows at a constant speed parallel to straight line isobars, with the pressure gradient force (PGF) and the Coriolis force in balance

geostrophic

a wind blowing at a constant speed parallel to straight line isobars with the pressure gradient force (PGF) and the Coriolis force in balance is called a

geostrophic wind

a wind that blows at a constant speed parallel to curved isobars or contour lines is called a

gradient wind

which of the following forces does not have a direct effect on horizontal winds

gravitational force

In a vertical direction, the balance between ____ results in the hydrostatic equilibrium status, which keeps the air not rushing out to space or crash down to surface

gravitational force and pressure gradient force

The atmosphere around Earth would rush off into space if the upward-directed pressure gradient force were not exactly balanced by ____.

gravity

low ____ on a constant pressure chart corresponds to low ____ on a constant height chart

heights; pressures

which combination produces the strongest Coriolis force

high latitude and faster earth rotation

On an upper-air chart, normally we find warm air associated with ____ pressure, and cold air associated with ____ pressure.

high; low

when the upward-directed pressure gradient force is in balance with the downward pull of gravity, the atmosphere is in

hydrostatic equilibrium

if the earth's gravitational force were to increase, atmospheric pressure at the ground would

increase

lines connecting points of equal pressure are called

isobars

which of the statements below is not correct concerning the pressure gradient force

it does not change wind speed, only changes wind direction

which statement below is not correct concerning the Coriolis force

it is strongest at the equator

which of the following is not a unit for measuring pressure

kelvin

suppose that the winds aloft are geostrophic and blowing from the north. with the same orientation of isobars at the surface, the winds would blow from the ____

northwest

which of the following is not correct regarding the pressure gradient force

parallel to isobars

upper-level geostrophic winds

parallel to the contours

on an upper-level chart the wind tends to blow

parallel to the isobars or contour lines of height

the scale on an altimeter indicates altitude, but an altimeter actually measures

pressure

which of the following atmospheric variables always decreases with increasing height

pressure

the amount of pressure change that occurs over a given horizontal distance is called the

pressure gradient

the force that causes the wind to blow is the ____ force

pressure gradient

the force that would cause a stationary parcel of air to begin to move horizontally is called the

pressure gradient force

in the upper-level atmosphere, the balance between ____ results in geostrophic winds

pressure gradient force and Coriolis force

at upper-level, ____ and ____ keep the air moving parallel to contour lines or isobars

pressure gradient force; Coriolis force

centripetal force for gradient winds (curved winds) is provided by the difference of ____ and ____

pressure gradient force; Coriolis force

upper-level geostrophic wind is the result of the balancing forces of ____ and ____

pressure gradient force; Coriolis force

the surface pressures at the bases of warm and cold columns of air are equal. which of the following statements is not correct

pressure will decrease with increasing height at the same rate in both columns

on an upper-level chart, moving along the wind, high pressure is on your ____ and low pressure is on your ____

right; left

we can generally expect the air to be ____ above areas of surface low pressure and ____ above areas of surface high pressure

rising, sinking

we can generally expect the air to be ____ in a warm air column and ____ in a cold air column

rising; sinking

when an object is moving unexpectedly, one would think that there must be ____

some other forces working on it

if, at your home in the northern hemisphere, the surface wind is blowing from the northwest, then the region of lowest pressure will be to the ____ of your home

southeast

what are the two things for describing wind

speed and direction

we can generally expect the weather to be ____ in the areas of surface low pressure and ____ in the areas of surface high pressure

stormy, fair

suppose a column of air has constant air temperature. what would happen is we force more air into the column

the air would become more dense, and the surface air pressure would increase

the wind direction is defined as the direction where ____

the wind comes from

According to the simple air column model, surface low pressure forms in the ____ column and surface high pressure forms in the _____ column.

warm, cold