Meterology 1050 Lupo Online Exam 2 -

An atmospheric condition is defined as stable when a parcel of air that has been vertically displaced

returns to its original position after being displaced

In unstable atmospheric conditions, a parcel of lifted air finds itself in a new environment where the parcel is

Less dense and warmer than environemtnal air

An adiabatic temperature change occurs when a mass (or parcel) of air experiences

Change in pressure

If an air parcel is given a small push upward and it falls back to its original position, the atmosphere is said to be

stable

In a conditionally unstable atmosphere, the environmental lapse rate will be __________ than the moist adiabatic rate and __________ than the dry adiabatic rate.

greater; less

Which two sets of conditions, working together, will make the atmosphere more stable?

Cool the surface and warm the air aloft

As seen in a cumulonimbus cloud, the anvil develops and appears. This is due to a(n) _________ layer of air at the tropopause level.

Stable

What is the term for the mixing of outside air into a cloud or a rising parcel of air?

Entrainment

When temperature decreases more rapidly with height than the dry adiabatic rate, the atmosphere is _______________.

Absolutely Unstable

What is the diameter of a typical raindrop in relation to a typical cloud droplet?

100 times larger

What is the temperature of supercooled liquid water in clouds?

-40°C to 0°C

For the ice-crystal (Bergeron) process to be effective, the region of the cloud where the rain is initiated must be at temperatures __________ 0°C and contain __________.

Below; a mixture of water drops and ice crystals

Which of the following statements is true concerning condensation nuclei and ice nuclei?

Condensation nuclei are abundant but ice nucei are not

Freezing rain occurs under what atmospheric conditions?

temperatures below 0°C in the middle of the cloud and near the surface but above 0°C in a region between these layers.

Which form of precipitation begins as an ice element and is carried up and down in the portion of the cloud with temperatures below 0°C until it becomes so large it falls from the cloud and reaches the ground?

Hail

Which of the following phrases best describes the solute effect?

dissolving of hygroscopic particles in pure water droplets so that condensation will begin when the relative humidity of the air is less than 100%

Curvature Effect

When the relative humidity inside a cloud is 100%, small cloud droplets evaporate more quickly than do large cloud droplets.

At what temperature would you expect a cloud to become completely glaciated?

-40°C (-40°F)

What is an aggregate of ice crystals?

Snowflake

What does radar measure to gather information about precipitation in clouds?

Amount of energy scattered back to a transmitter

What is the proper term for precipitation measuring less than .001 inch (0.025 cm)?

Trace

What is the proper term for rain falling from a cloud but evaporating before reaching the surface?

Virga

Which is the best description of the station pressures used in Missouri?

Lower than sea level pressure

An isobar is a line on the weather map connecting points of equal _____________

Pressure

What is Newton's first law?

An object in motion will continue to move at the same speed and direction until acted on by other forces.

The pressure gradient force acts from __________ pressure and is greatest where isobars are __________.

higher to lower; closest together

With one's back to the wind, the Coriolis force (CF) in the Northern Hemisphere is directed toward the ____________________.

right

In the Northern Hemisphere, the air movement (gradient wind) around a high-pressure area (anticyclone) is _____________________.

clockwise, while the air movement around a low-pressure area is counterclockwise.

For geostrophic wind, what are the forces in balance?

pressure gradient and Coriolis

For the gradient wind, what are the forces in balance along with pressure gradient?

Coriolis and Centripetal

Meridional flow occurs when the trajectory of the air movement is _____________.

North and South

Zonal flow occurs when the trajectory of the air movement is ________________.

West to east

What is the wind speed if, at a given time and place, the horizontal distance between isobars that are curved around a high-pressure area is identical to the horizontal distance between the isobars curved around a low-pressure area at the same place?

Greter for the time with the high pressure Area

How does a steep (or strong) pressure gradient appear on a weather map?

Closely spaced isobars

The atmosphere around Earth would rush off into space if the vertical pressure gradient force were not balanced by _________________.

Gravity

To obtain station pressure with a mercury barometer, normally you must make a correction for any instrumental error and which of the following?

Temperature and GravityOn an upper-level chart, the wind tends to blow at __________ to the contours or isobars.

On an upper-level chart, the wind tends to blow at __________ to the contours or isobars.

Course Parallel

Which force initially causes the wind to blow?

PGF

If in the Northern Hemisphere the upper-level winds above you are blowing from the south, then it is a good bet that a trough of low pressure is to your __________.

West

The surface air around a low-pressure area normally __________, while the air normally __________ aloft, above the system.

Converges; diverges

In which direction does the wind around an area of high pressure on the surface weather map in the Southern Hemisphere blow?

counterclockwise and outward from the center

What scale of motion would be used when evaluating the circulation patterns over North America?

Synoptic scale

The effect of friction as air moves over Earth's surface extends above the surface to a height of _______________.

1000 meters

How is the wind blowing if it is reported to be 330°?

Northwest

A wind speed of 20 knots is equal to how many miles per hour?

23

When are turbulent winds most likely to occur in places like the Great Plains and the Midwest?

Hours just after noon

During times when the PGF is weak, what is the wind circulation near the seacoasts?

from the sea toward the land during the day and from the land toward the sea at night

During times when the PGF is weak, what is the air movement along the slope of a mountain?

Upslope during the day and downslope at night

Where are the doldrums found?

Near the equator

Where are the semipermanent subtropical highs (anticyclones) found?

Near 30 lattitude

Where are the westerlies found?

30 and 60 Latitudes

The anticyclone found over Siberia is a feature of the circulation system in which season(s)?

Winter

Why are the subtropical highs known as "semipermanent"?

They experience broad seasonal shifts that tend to be farther from the equator, with greater intensity in summer than in winter.

Which is the best description of the wind speed of jet streams?

100 knots at 10-13 km above sea level

When does the El Niño current along the west coast of South America regularly occur?

annually and usually lasts only a few weeks or a month

What occurs in the Intertropical Convergence Zone (ITCZ)?

the northeast trades meet the southeast trades

In terms of the three-cell model of the general circulation, where should areas of surface low pressure be found?

30° latitude and 60° latitude

On a weather map of the Northern Hemisphere, where would you observe the westerlies?

Between sub polar lows and subtropical highs

On a weather map of the Northern Hemisphere, where would the trade winds be observed?

between the equator and northern subtropical highs

What prevents the average winter temperature in Great Britain and Norway from being colder than it is?

North Atlantic Drift

Which of the following statements is false regarding the polar front jet stream?

It is normally found at a higher elevation than the subtropical jet.

In terms of the three-cell general circulation model, where should the driest regions of Earth be near?

30° latitude and polar regions

How does the jet stream flow?

Wavy, west to east pattern

What is the ocean current that flows southward parallel to the west coast of North America?

California Current

On the surface weather map during the month of July, what is the type of pressure system found over the desert Southwest (United States)?

Thermal Low

What pressure system often is associated with polar front

Subpolar low