Meteorology Final
the ___ force is an apparent force created by Earth's rotation
Coriolis
Winter Solstice
December 21
studies have shown that on average ozone depletion is greatest over this area
Europe
which of the following statements is an expression of climate?
February is the wettest month in Los Angeles, CA, with an average rainfall of 3.92 inches
A weather warning indicates that ___.
Hazardous weather is either imminent or occurring within the forecast area
the earth is actually the farthest from the sun on
July 4th
Summer Solstice
June 21
Vernal Equinox
March 21
the periodic reversal of atmospheric pressure between the vicinity of the Icelandic low and the region of the Bermuda-Azores high
North Atlantic Oscillation
what is the origin of the cP and cA air masses that enter the U.S.
Northern Canada and Alaska
Over the northern central Pacific and along the west coast of North America the surface water temperature reverses every 20 to 30 years
Pacific Decadal Oscillation
Autumnal Equinox
September 22
Which type of electromagnetic radiation does ozone selectively absorb?
U.V.
Suppose the rising air parcel is warmer and less dense than the air around it. In this case, the atmosphere is ____.
absolutely unstable
A parcel of air expands and cools, or compresses and warms, with no interchange of heat with its outside surroundings. What is this called?
adiabatic process
an instrument that indicates both wind speed and direction
aerovane
radiation fog forms when
air next to the ground is cooled
A dim, "watery" sun visible through a gray sheet-like cloud layer is often a good indication of ____ clouds
altostratus
Radar gathers information about precipitation in clouds by measuring the:
amount of energy reflected back to a transmitter
A final chart created by thousands of observations transmitted onto surface and upper-air charts to forecast weather patterns.
analysis
an instrument that measures wind speed
anemometer
the variation of atmospheric pressure between the Arctic and the North Pacific and the Atlantic.
arctic oscillation
A mathematical model consisting of many equations that describe how atmospheric temperature, pressure, winds, and moisture will change with time
atmospheric model
Cold fronts that move into the United States from the east, or northeast, are called ___ fronts.
back door
On a weather map of the Northern Hemisphere, one would observe the westerlies:
between the subpolar lows and the subtropical highs
a high pressure system that tends to persist in the same geographic location for many days is referred to as a ___ high
blocking
A stationary front does not move because winds on both sides of the front ____.
blow parallel to the front and in opposite directions
what are the ideal conditions for a strong radiational inversion?
calm, dry air, long night, no clouds
Smaller grid spacing ____ the resolution of computer forecasting models.
can increase
Cyclonic flow means ____ in either the Northern or Southern Hemisphere.
circulation around a low pressure center
When viewed from the surface, high clouds that are small, rounded, white puffs occurring individually or in long rows are called ____.
cirrocumulus
Which cloud is LEAST likely to produce precipitation that reaches the ground?
cirrocumulus
dew is most likely to form on
clear, calm nights
the wind around a surface high pressure center in the Northern Hemisphere blows ___ the center.
clockwise and outward from
in the northern hemisphere, ocean currents in the Atlantic and the Pacific move in a generally circular pattern
clockwise;clockwise
Squall lines most often form ahead of a(n) ____ front.
cold
Jet streams play a major role in the global transfer of heat by directing ____.
cold air equatorward
One would expect a cP air mass to be ____.
cold and dry
What type of weather front would be responsible for the following weather forecast? "Increasing high cloudiness and cold this morning. Clouds increasing and lowering this afternoon with a chance of snow or rain tonight. Precipitation ending tomorrow morning. Turning much warmer. Winds light easterly today becoming southeasterly tonight and southwesterly tomorrow."
cold front
the heat from a chinook wind is generated mainly by ____.
compressional heating
gas to liquid
condensation
the elevation above the surface where a cloud first forms is called the
condensation level
an isotherm on a map:
connects points of equal temperature
Air masses that are extremely cold and dry and form over land
continental arctic (cA)
Air masses that are cold and dry and form over land
continental polar (cP)
Air masses that are hot and dry, and are responsible for heat waves of summer in the western half of the United States.
continental tropical (cT)
which set of conditions, working together, will make the atmosphere the most stable?
cooling the surface and warming the air aloft
condensation is more likely to occur when air ____
cools and the speed of the water vapor molecules decreases
hail is usually associated with which cloud type?
cumulonimbus
which cloud type would be most likely to form in an unstable atmosphere
cumulonimbus
which type of cloud shows the greatest vertical growth?
cumulonimbus
the process of integrating surface and upper-air observations of temperature, pressure, moisture, winds, and air density are fed into equation at regular intervals
data assimilation
which of the following correctly describes the equinoxes
days and nights are equal in length in all parts of the world
As the difference between the air temperature and the dew point increases, the relative humidity ____
decreases
gas to solid
deposition
the region with the greatest difference between summer and winter average temperatures would be
eastern Siberia
When atmospheric circulation patterns change over the tropical Pacific, and the trade winds weaken or reverse direction, warm tropical water is able to flow eastward toward South American where it chokes off upwelling
el niño
The forecasting technique that produces several versions of a forecast model, each beginning with slightly different weather information to reflect errors in the measurements, is called ___ forecasting
ensemble
liquid to gas
evaporation
During a major El Niño event
extensive ocean warming occurs in the eastern tropical Pacific
A ___ pressure usually indicates clearing weather or fair weather
fluctuating
clouds that have a ragged or torn appearance; applies only to stratus and cumulus clouds
fractus
liquid to solid
freezing
in the winter, you read in the newspaper that a large section of the Midwest is without power due to downed power lines. Which form of precipitation would most likely produce this situation
freezing rain
What is the best source region for an air mass?
generally flat areas of uniform composition with light surface winds
a ___ wind blows at a constant speed parallel to straight line isobars, with the pressure gradient force I(PGF) and the Coriolis force in balance
geostrophic
in a conditionally unstable atmosphere, the environmental lapse rate will be ____ than the moist adiabatic rate and ____ than the dry adiabatic rate
greater; less
the most important source of the free oxygen in our atmosphere is:
green plants that carry on photosynthesis
On an upper-air chart, normally we find warm air associated with ____ pressure, and cold air associated with ____ pressure.
high;low
which condition most favors the development of dust devils?
hot, dry days
Cirrus clouds are composed primarily of:
ice particles
the diurnal range of temperatures tends to be largest
in dry, cloud-free regions
which of the following factors would have the net effect of making a place warmer in the summer?
in the middle of a landmass
If the earth's gravitational force were to increase, atmospheric pressure at the ground would
increase
which type of electromagnetic radiation is most important to the heating of the atmosphere?
infrared
the daily mean temperature
is the average of the maximum and minimum temperature for a given day
The ideal setting for a ____ wind to form is an elevated plateau surrounded by mountains, with an opening that slopes rapidly downhill.
katabatic
During the night, clouds:
keep the air warmer by absorbing and re-emitting longwave energy back to the surface.
high pressure over the southeastern Pacific and lower pressure near Indonesia produce easterly trade winds along the equator promoting upwelling and cooler ocean water in the eastern Pacific.
la niña
the two types of heat recognized by meteorologists are:
latent heat and sensible heat
clouds having the shape of a lens; often elongated and usually with well-defined outlines, applies mainly to cirrocumulus, altocumulus, and stratocumulus
lenticulus
Water vapor represents what fraction of the air near the earth's surface?
less than 4 percent
the moist adiabatic rate is _____ than the dry adiabatic heat because latent heat is ____ the rising air
less; removed from
What type of air mass would be responsible for hot, muggy summer weather in the eastern half of the United States
mT
baglike clouds that hang like a cow's udder on the underside of a cloud; may occur with cirrus, altocumulus, altostratus, stratocumulus, and cumulonimbus
mammatus
Air masses that are cold and moist, form over water, and are responsible for the cold, damp, and often wet weather along northeastern United States
maritime polar (mP)
Air masses are warm and humid, and are responsible for the hot, muggy weather that frequently plague the eastern United States in summer.
maritime tropical (mT)
solid to liquid
melting
A chart that plots how air temperature has changed over the past five days at a given station is a(n) ____.
meteogram
Light or moderate continuous precipitation is most often associated with ____ clouds.
nimbostratus
the intertropical convergence zone (ITCZ) is a region where the _____.
northeast trades meet the southeast trades
the routine daily forecasting tool with the correct description
numerical weather prediction
Summer temperatures along the California coast are cooler than along the coast of South Carolina, due to the influence of:
ocean currents
A sea breeze circulation will reverse direction and become a land breeze circulation ____.
once per day
When two air masses collide at a front, one air mass may be pushed upward by the other. This is because ____.
one air mass is denser than the other
Santa Ana winds are characteristically dry due to compressional heating and ____.
origination in the desert
Although many thousands of weather observations are taken worldwide each day, what regions still have sparse observations?
over oceans and higher latitudes
the troposphere is most likely to be thickest:
over the equator
the least accurate forecast method of predicting the weather two days into the future during changeable weather conditions is usually the ____.
persistence forecast
ozone is the primary component of
photochemical smog
there are two primary types of weather satellites in use for viewing clouds. The first are geostationary satellites and the second are ____ satellites.
polar-orbiting
the force that causes the wind to blow is the ____ force.
pressure gradient
A final forecast chart made by assimilating data into models repeatedly until a representation of the atmosphere at a specified future time can be made
prognostic chart
the production of dew is mainly the result of ____
radiational cooling
Electromagnetic spectrum from lowest energy to highest energy
radio waves, micro waves, infrared, visible, U.V., x-ray, gamma
a package of weather instruments carried aloft by a balloon is called a
radiosonde
an instrument package designed to measure the vertical profile of temperature, pressure, and humidity
radiosonde
in the northern hemisphere, south-facing slopes
receive more solar radiation than do north-facing slopes
the percentage of water vapor present in the air compared to that required for saturation is the _____
relative humidity
As the air temperature increases, the air's capacity for water vapor ____
remains constant
During a cold occlusion, the cold front forces the warm front to ____.
rise off the ground
The most latent heat would be released in a ____ parcel of ____ saturated air.
rising;warm
A raindrop that freezes before reaching the ground is called ____.
sleet
Which instrument uses wet-bulb and dry-bulb temperatures to obtain relative humidity?
sling psychrometer
the solid equivalent of drizzle is called
snow pellets
on a weather map of the Northern Hemisphere, the northeast trade winds would be observed
south of the subtropical highs
Summertime weather in Northern California often consists of low clouds and fog due to ____.
southerly prevailing winds
A low, lumpy cloud layer that appears in rows, patches, or rounded masses would be classified:
stratocumulus
solid to gas
sublimation
the process of ice transforming directly into water vapor without first going into the liquid phase is termed:
sublimation
the Northern Hemisphere has its maximum tilt toward the sun on the
summer solstice
low pressure systems tend to move toward the region of greatest ___.
surface pressure drop
the dry adiabatic rate is the rate at which
temperature changes in a rising or descending parcel of unsaturated air
Suppose a column of air has constant air temperature. What would happen if we force more air into the column?
the air would become more dense, and the surface air pressure would increase
Polar air is often described as dry even though the relative humidity is high. This is because in polar regions, ____.
the dew point and air temperature are normally close together
A probability forecast that calls for a "40% chance of rain" means that ___.
there is a 40% chance that any random place in the forecast area will receive measurable rainfall
clouds that cover a large part of the sky and are sufficiently transparent to reveal the position of the sun or moon
translucidus
clouds in patches, sheets, or layers showing undulations
undulatus
If an air parcel is given a small push upward and it falls back to its original position, the atmosphere is said to be:
unstable
A nowcast is a weather forecast that extends for ____.
usually not more than 6 hours
Cumulus clouds that appear above isolated mountain peaks are often the result of:
valley breezes
which type of electromagnetic radiation does the sun radiate most of?
visible
the region of air between the cold and warm fronts of an open wave is known as the ___.
warm sector
Compared to an mP air mass, an mT air mass is ____.
warmer and moister
When a mid-latitude cyclone forms and moves along the polar front in a wave-like manner, the developing storm is referred to as a(n) ____.
wave cyclone
the summer monsoon in eastern and southern Asia is characterized by ___ weather and winds blowing from _______.
wet; sea to land
an instrument that obtains the vertical profile of wind speed and direction up to an altitude of 16 km above the ground
wind profile
What term describes air aloft that changes speed or direction?
wind shear
A very old, yet reliable, weather instrument for determining wind direction
wind vane
the polar jet stream is strongest and moves furthest south in the ____.
winter
absolute zero equals
-273 degrees C
standard temperature data must be collected from sensors mounted at a height of
1.5 meters (5 feet)
on average, the atmosphere absorbs roughly this percentage of the solar radiation that reaches the top of the atmosphere
20 percent
the earth's axis of rotation is tilted roughly this number of degrees away from a line perpendicular to the plane of the earth's orbit
23.5
The general area where a tornado is likely to form can often be predicted up to ____ days in advance.
3
Probability forecasts use climatological data that are typically averaged over ___ years.
30
the planetary albedo of the earth is
30%
on a particular day, a place accumulates 15 heating degree days. What was the daily mean temperature on that day?
50 degrees F
