Exam 2 (Ch 5-8) Flashcards
The amount of pressure change that occurs over a given horizontal distance
Pressure gradient
Low ________ on a constant height chart corresponds to low ________ on a constant pressure chart.
Pressures, heights
A station at an altitude of 300 m (about 1000 feet) above sea level measures an air pressure of 920 mb. Under normal conditions, what value below do you think would be the most realistic sea level pressure for this station?
950 mb
To correctly monitor horizontal changes in air pressure, the most important correction for a mercury barometer measurement is the correction for
Altitude
Cyclonic flow means circulation around a _____ pressure center in either the Northern or Southern Hemisphere.
Low
Which statement below is NOT correct concerning the Coriolis force?
It is strongest at the equator.
The scale on an altimeter indicates altitude, but an altimeter actually measures
Pressure
On an upper-level chart, the wind tends to blow:
Parallel to the isobars or contours
The pressure gradient force is directed from higher pressure toward lower pressure
At all places on earth
The force that would cause a stationary parcel of air to begin to move horizontally
Pressure gradient force
Which of the statements below is not correct concerning the pressure gradient force?
Pressure gradient
A surface low pressure center is generally associated with ________ on an upper level isobaric chart.
A trough
We can generally expect the air to be ________ above areas of surface low pressure and ________ above areas of surface high pressure.
Rising; sinking
When the upward-directed pressure gradient force is in balance with the downward pull of gravity, the atmosphere is in
Hydrostatic equilibrium
Which of the following combinations produces the strongest Coriolis force?
Fast winds, high latitude
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 more ________ than in the cold column.
Decrease, slowly
Two air columns extend from sea level up to an altitude of 10 km. If one column is cold and the other is warm, the air pressure in the cold column will ________ ________ with increasing height than the air pressure in the warm column.
Decrease more rapidly
Which of the following forces does not have a direct effect on horizontal wind motions?
Gravitational force
The net force on air moving in a circle at constant speed is
Inward toward the center of rotation
The contour lines drawn on a 500 mb chart are lines of constant
Altitude
Lines connecting points of equal pressure
Isobars
If the earth’s gravitational force were to increase, atmospheric pressure at the ground would
Increase
Pressure changes more ________ in the horizontal direction than in the vertical.
Rapidly
A wind blowing at a constant speed parallel to straight line isobars with the pressure gradient force (PGF) and the Coriolis force in balance
Geostrophic wind
On an upper-level chart, normally we find warm air associated with _____ pressure, and cold air associated with _____ pressure.
High, low
Which of the following instruments measures pressure?
Barometer
The net force acting on air which is blowing parallel to straight contours at constant speed is
Zero
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.
The wind around a surface high pressure center in the Northern Hemisphere blows
Clockwise and outward from the center
A wind that blows at a constant speed parallel to curved isobars or contour lines
Gradient wind
Surface low pressure becomes best developed over the Asian continent in the
Summer
Which below does not describe the polar front jet stream?
Is normally found at a higher elevation than the subtropical jet.
Which of the following associations is most accurate?
Mesoscale - land scale
Which of the following conditions favor the development of dust devils?
Hot, dry days
The majority of the United States lies within a ________ wind belt.
Westerly
The summer monsoon in eastern and southern Asia is characterized by
Wet weather and winds blowing from sea to land.
The jet stream blows
In a wavy pattern from west to east.
An example of mesoscale motion is
Winds blowing through a city.
The heat from a chinook wind is generated mainly by
Compressional heating
A sea breeze circulation is caused by ________ differences.
Temperature
A katabatic wind is a ________, ________ wind.
Cold, downslope
Upwelling occurs along the northern California coast because
Winds cause surface waters to move away from the coast.
The name given to a wind system that seasonally changes direction is
Monsoon
In the three-cell model of the general circulation, areas of surface low pressure should be found at
The equator and 60o latitude
Warm southwesterly and cold northeasterly surface winds meet at the
Subpolar low
According to the three-cell general circulation model, at the equator we would NOT expect to find
A ridge of high pressure
A chinook wall cloud is a
Bank of clouds that form over the mountains and signal the possible onset of a chinook.
Which below is usually NOT true concerning a sea breeze circulation?
They mainly occur at night.
The intertropical convergence zone (ITCZ) is a region where
Northeast trades meet the southeast trades
In the 3-cell model, converging surface winds and rising air motions are found at
The equator and 60o latitude
During the summer along the coast, a sea breeze is usually strongest and best developed
In the afternoon.
While fly fishing in a mountain stream, you notice that the wind is blowing upstream. From this you might deduce that the wind is a
Valley breeze
Which of the following would NOT be associated with a major El Niño event?
Record fish catch in the ocean off the coasts of Peru and Ecuador.
The Santa Ana wind is a _____, _____ wind that blows into southern California.
Warm, dry
A dust- or sandstorm that forms along the leading edge of a thunderstorm is a
Haboob
Which is NOT a characteristic of a thermal low?
Becomes stronger with increasing height
Cumulus clouds that appear above isolated mountain peaks are often the result of
Valley breezes
Strong Santa Ana winds develop in Los Angeles during the fall when
a ________ pressure center forms to the ________ of Los Angeles over the Great Basin.
High, northeast
Clouds and precipitation are frequently found on the downwind side of a large lake. This would indicate that the air on the downwind side is
Converging and rising
On the eastern side of the Rocky Mountains, chinook winds are driest when
Clouds form and precipitation falls on the upwind side of the mountains.
Most thunderstorms do not extend very far into the stratosphere because the air in the stratosphere is:
Stable
Which set of conditions, working together, will make the atmosphere the most stable?
Cool the surface and warm the air aloft
If you observe the large raindrops hitting the ground, you could probably say that the cloud overhead was _____ and had _____ updrafts.
Thick, strong
The most common ice crystal shape is
A dendrite
Two air columns extend from the sea level up to an altitude of 10 km. if one column is cold and the other is warm, the air pressure in the cold column will ________ ________ ________ than the air pressure in the warm column.
Decrease more rapidly (with increasing height)
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
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
A station at an altitude of 900 m (about 3000 feet) about sea level measures an air pressure of 950 mb. Under normal conditions, which of the values below do you think would be the most realistic sea level pressure for this station?
1020 mb
Note: Remember 1 mb/10 m.
To correctly monitor horizontal changes in air pressure, the most important correction for a mercury barometer measurement is the correction for
Altitude
Low pressure on a constant height chart corresponds to _____ _____ on a constant pressure chart.
(????)
The contour lines drawn on a 500 mb chart are lines of constant:
Pressure
Cumulus clouds that appear above isolated mountain peaks are often the result of
Valley breezes
Which of the following associations is most accurate?
Mesoscale: land breeze
Clouds and precipitation are frequently found on the downwind side of a large lake. This would indicate that the air on the downwind side is
Converging and rising
Which below does not describe the polar front jet stream?
Is normally found at a higher elevation than the subtropical jet.
Strong Santa Ana winds develop in Los Angeles during the fall with a ________ pressure center forms to the ________ of Los Angeles over the Great Basin.
High, northeast
Which of the following would NOT be associated with a major El Niño event?
Record fish catch in the ocean off the coasts of Peru and Ecuador.
A dust- or sandstorm that forms along the leading edge of a thunderstorm is a
Haboob
The name given to a wind system that seasonally changes direction is
Monsoon
According to the 3-cell general circulation model, at the equator we would NOT expect to find
A ridge of high pressure
A chinook wall cloud
Bank of clouds that form over the mountains and signal the possible onset of a chinook.
Which is NOT a characteristic of a thermal low?
Becomes stronger with increasing height.
Surface low pressure becomes best developed over the Asian continent in the:
Summer
Warm southwesterly and cold northeasterly surface winds meet at the
Subpolar low
A sea breeze circulation is caused by ________ differences.
Temperature
The heat from a chinook wind is generated mainly by:
Compressional heating
During the summer along the coast, a sea breeze is usually strongest and best developed
In the afternoon
A katabatic wind is a _____, _____ wind.
Cold, downslope
In the 3-cell model, converging surface winds and rising air motions are found at:
The equator and 60o latitude
The summer monsoon in eastern and Southern Asia is characterized by:
Wet weather and winds blowing from sea to land.
The Santa Ana wind is a _____, _____ wind that blows into Southern California.
Warm, dry
In the 3-cell model of the general circulation, areas of surface low pressure should be found at
The equator and 60o latitude
The majority of the U.S. lies within a ________ wind belt.
Westerly
An example of mesoscale motion is
Winds blowing through a city
Which of the following conditions favor the development of dust devils?
Hot, dry days
The intertropical convergence zone (ITCZ) is a region where:
Northeast trades meet the southeast trades.
On the eastern side of the Rocky Mountains, chinook winds are driest when:
Clouds form and precipitation falls on the upwind side of the mountains.
The jet stream blows:
In a wavy pattern from west to east.
Which below is usually NOT true concerning a sea breeze circulation?
They mainly occur at night.
Upwelling occurs along the Northern California coast because:
Winds cause surface waters to move away from the coast.
While fish flying in a mountain stream, you notice that the wind is blowing upstream. From this you might deduce that the wind is a
Valley breeze
A ________ parcel of air expands and cools, while a ________ parcel is compressed and warms.
Rising; sinking
When a parcel of air expands and cools, or compresses and warms, with no interchange of heat with its outside surroundings.
Adiabatic process
The rate of cooling or warming that only applies to unsaturated air.
Dry adiabatic rate
The rate of cooling or warming that applies to saturated air.
Moist adiabatic rate
The rate at which the air temperature surrounding us would be changing if we were to climb upward into the atmosphere.
Environmental lapse rate
When the lifted parcel of air is colder and heavier than the air surrounding it
Absolutely stable
Since stable air strongly resists upward vertical motion, it will, if forced to rise, tend to spread out ________.
Horizontally
The cooling of the surface air may be due to:
- Nighttime radiational cooling of the surface.
- An influx of cold surface air brought in by the wind.
- Air moving over a cold surface.
An inversion that forms by slow, sinking air
Subsidence inversion
An atmospheric conditions that exists when the environmental lapse rate is greater than the dry adiabatic rate. This results in a lifted parcel of air being warmer than the air around it.
Absolutely unstable atmosphere
An atmospheric conditions that exists when the environmental lapse rate is less than the dry adiabatic rate. This results in a lifted parcel of air being colder than the air around it.
Absolutely stable atmosphere
The elevation above the surface where the cloud first forms
Condensation level
An atmospheric condition that exists when the environmental lapse rate is less than the dry adiabatic rate but greater than the moist adiabatic rate. (Also called conditional instability)
Conditionally unstable atmosphere
The atmosphere is ordinarily in a state of ________ ________.
Conditional instability
A hot “bubble” of air
Thermal
Forced lifting along a topographic barrier
Orographic uplift
Clouds formed by orographic uplift
Orographic clouds
The region on the leeward side of a mountain where precipitation is noticeably low, and the air is often drier
Rain shadow
Wave clouds that often have a characteristic lens shape
Lenticular clouds
The process of producing precipitation by liquid particles (cloud droplets and raindrops) colliding and joining (coalescing)
Collision-coalescence process
The constant speed at which a raindrop falls
Terminal velocity
Larger drops fall ________ than smaller drops.
Faster
Merging of cloud droplets by collision
Coalescence
The forces that hold a tiny droplet together
Surface tension
Sticking together
Coalesce
The process that ice crystals and liquid cloud droplets must co-exist in clouds at temperatures below freezing
Ice crystal (or Bergeron) process
When water droplets exist at temperatures below freezing
Supercooled
Ice-forming particles
Ice nuclei
Process of ice crystals growing larger as they collide with supercooled cloud droplets
Accretion
Snow pellets
Graupel
An aggregate of ice crystals
Snowflake
Injecting a cloud with small particles that will act as nuclei, so the cloud particles will grow large enough to fall to the surface as precipitation
Cloud seeding
Any falling drop of liquid water
Rain
Fine uniform drops of water whose diameters are smaller than 0.5 mm
Drizzle
Evaporating streaks of precipitation
Virga
Suspended drops that fall to the ground
Shower
When the shower is excessively heavy
Cloudburst
When ice crystals and snowflakes fall from high cirrus clouds
Fallstreaks
Snow falling from developing cumulus clouds
Flurries
A more intense snow shower
Snow squall
Low temperatures and strong winds bearing large amounts of fine, dry, powdery particles of snow
Blizzard
Tiny transparent ice pellet
Sleet
Glaze, or drops that spread and almost immediately freeze into a thin veneer of ice
Freezing rain
An accumulation of white or milky granular ice
Rime
Small, opaque grains of ice; the solid equivalent of drizzle
Snow grains
White, opaque grains of ice about the size of an average raindrop
Snow pellets
Pieces of ice either transparent of partially opaque
Hailstones
A funnel-shaped collector attached to a long measuring tube
Standard rain gauge
An amount of rainfall less than one-hundredth of an inch
Trace
Radio detection and ranging
Radar
Similar to conventional radar units that were put into service shortly after WWII
Doppler radar
Principle of having the capacity to measure the speed at which falling rain is moving horizontally toward or away from the radar antenna
Doppler shift
