Exam 2

Question 0

What is the average sea-level pressure is …

Answer 0

1013.25 mb

Question 1

What is sea level pressure expressed in?

Answer 1

1013.25 mb

inches and Pascals.
101,325 Pa
29.9 inches
1mb = .02953 in of Mercury

Question 2

what does a barometer measures

Answer 2

An instrument used to measure air pressure and monitor its changes

Question 3

There is what distance to the top of the atmosphere

Answer 3

None- no set distance

Question 4

sea-level is the base measurement of

Answer 4

Earths pressure

They adjust local air pressure readings to approximately what the air pressure would be if the station were actually located at sea level the simplest adjustment assumes an imaginary column of air having the properties of the standard atmosphere expensing from the station down to sea level= reduction to sea level

Question 5

pressure _______ with height

Answer 5

Decreases

Air pressures decreases with increasing altitude

Question 6

What are characteristics of an air mass

Answer 6

Temperature and humidity

Air mass is a huge volume of air that is relatively uniform horizontally in temperature and water vapor concentration .

Question 7

understand pressure differences and exerted pressure between cold and warm, and dry and moist air.

Answer 7

Hot air- air density decreases, the number of molecules per unit volume decreases

Cold air- air pressure drops more rapidly with altitude within a cold column of air than in a war column of air

Increasing humidity- affects air density in the same way as rising air temp. The greater concentration of water vapor the less dense the air. Water vapor reduces the density of air because the molecular weight of water is less than the average molecular weight of dry air

Question 8

Remember _______ air is less dense, _______ air is more dense.

Answer 8

Warm— cold

Question 9

understand basic info around phase changes … evaporation, sublimation, deposition, and so forth … understand how they relate to each other.

Answer 9

1) Evaporation - if more water me used enter the atmosphere as vapor than as liquid, a net loss occurs in liquid water mass
2) Condensation -If more water molecules return to the water surface as liquid than enter the atmosphere as vapor a new gain of liquid water mass results.
3) Transportation - water that is taken up from the soil by plant roots eventually escapes as vapor through tiny pores in the underside of leaves.
4) Sublimation - ice or snow becomes vapor without first becoming a liquid.
5) Deposition - water vapor becomes ice without first becoming a liquid. (Frost in automobile windows)

Question 10

The maximum pressure that water vapor molecules could exert if the air were saturated is called

Answer 10

the saturation vapor pressure.

The vapor pressure at equilibrium.

Question 11

What is a temperature inversion

Answer 11

Is the inverse of the usual temperature profile of the troposphere

Question 12

stable air means

Answer 12

nice and usually clear weather, suppressed cloud development

Question 13

unstable air enhances

Answer 13

cloud development and vertical lift

Question 14

instability can be caused by

Answer 14

heat / colder temps promote stability

Question 15

leeward side of a mountain is the _____ side and the windward side of a mountain is the ______ side

Answer 15

Leeward=dry

Windward= wet side

Question 16

Clouds have _______ relative humidity or just about ______.

Answer 16

100%

Question 17

know the cloud types and the weather associated with certain clouds …

Answer 17

Cirriform- wispy and fibrous
Stratiform- layered
Cumuli form- heaped or puffy
Cirrus- transparent and occur as delicate silky strands- mares tails
Cirrostratus- nearly transparent- thin white veil or sheet that partially or totally covers the sky.. You see these when approaching middle latitude storm.
Cirrocumulus- small white rounded patches arranged in a wavelike or mackerel pattern.
Altostratus- gray or blueish white layers that totally or partially cover the sky.
Altocumulus- roll-like patches or puffs that often form waves of parallel bands
Stratocumulus- large irregular puffs or rolls separated by areas of clear sky.
Stratus- gray layer stretching from horizon to horizon.
Nimbostratus- drizzle falls from stratus clouds but significant amounts of rain or snow may fall.

Cumulus is a low warn cloud that can be caused by local convection, and “nimbo” means rain.
Stratiform cloud- clouds that form in horizontal layers
Cumuliform cloud- clouds that appear puffy
Cirrus clouds- look fibrous because they are composed of mostly tiny ice crystals
Cumulus clouds- small white clouds that look like puffs of cotton
usually vaporize rapid
Cumulonimbus clouds- cumulus clouds that build vertically and merge laterally and turn into thunder clouds

Question 18

Warm cloud

Answer 18

Precipitation
Droplets grow by colliding and coalescing(merging), with one another in the collision-coalescence process. It happens when a cloud is composed of different size droplets. They have different terminal velocities.. Faster falling then they collide and coalesce with slower droplets in the path. Larger droplets from initially on larger nuclei through random collisions between smaller droplets or via mixing between cloud droplets and the surrounding drier air.

LARGE DROPLETS COLLIDE WITH SMALLER DROPLETS AND COALESCE CREATING DROPLETS LARGE ENOUGH TO SURVIVE THE TO EARTHS SURFACE AS PRECIPITATION

Question 19

Radiation fog

Answer 19

Mist-suspension

Radiation fog- clear night sky, light winds, an air mass that is humid near the ground and relatively dry aloft, radiation all cooling may cause the air near the ground to approach saturation. Ground level cloud. Marshy areas of where soil has been saturated by recent rainfall or snow melt.

Question 20

Condensation nuclei can be made from

Answer 20

several types of particulate matter and several different sources

Question 21

Terminal Velocity is

Answer 21

the maximum rate at which gravity pulls an object towards earth.

Question 22

How many cloud droplets does it make to form 1 raindrop

Answer 22

it takes 1 million cloud droplets

Question 23

drizzle falls from?!

Answer 23

nimbostratus clouds

Question 24

on average … 1 foot of snow equals

Answer 24

1 inch of water.

Question 25

Understand how doppler radar works and know that Doppler radar detects particles moving towards and away from the radar site

Answer 25

X

Question 26

What is pressure gradient force

Answer 26

A force operating in the atmosphere that accelerates air parcels away from regions of high air pressure directly across isobars toward regions of low air pressure in response to an air pressure gradient

Question 27

What is the Coriolis Effect and how does it work and know it’s direction in each hemisphere. Where is it strongest and weakest.

Answer 27

Term
- an apparent reflective force arising from the rotation of the earth on its axis; affects principally synoptic- scale and planetary- scale winds. Winds are deflected to the right of their initial direction in the Northern Hemisphere and to the left in the Southern Hemisphere. Magnitude depends on latitude and speed of the moving object.

Question 28

What is a geostrophic wind

Answer 28

A hypothetical, unaccelerated horizontal wind that flows along a straight path parallel to isobars or height contours about the atmospheric boundary layer; results from a balance between horizontal pressure gradient force and Coriolis effect

Question 29

winds are named for the direction where they ____ ____.

Answer 29

Come from

Question 30

• As space grows between isobars,

Answer 30

pressure gradient force and wind speeds decrease.

Air pressure changes more gradually with distance between, the pressure gradient is weaker

Wind is light

Question 31

know the scales of the atmospheric circulation in order from smallest to largest and largest to smallest ​

Answer 31

Planetary-scale systems- large scale wind belts encircling the planet are global.. Weeks or months

Synoptic- scale systems- are continental or oceanic in scale; extra tropical cyclones, hurricanes, and air masses… Several days to a week or so as they travel over distances of thousands of kilometers.

Horizontal winds are stronger than vertical flow

Mesoscale system- thunderstorms and sea and lake breezes, circulation systems that are small that they may influence the wearer in only a portion of a large city or county… Hours or a day

Microscale systems- a weather system covering a very small area such as several city blocks of a small town represents the smallest spatial subdivision of the atmospheric motion… Minutes or less.

Vertical wind speeds may be comparable in magnitude to horizontal winds.

Question 32

the different types of barometers- 1.

Answer 32

Mercury barometer- invented in 1643 by Evanglista Torricelli an Italian mathematician and student of Galileo. It’s a class tube a little less than 1.0m in length, sealed at one end, open on the other end, and initially filled with Mercury which is 13 times denser than liquid water. The open end is inverted into a small open container of mercury. Mercury settles down the tube until the pressure of Mercury column exactly balances the pressure of the atmosphere acting on the surface of the Mercury in the open container

The average air pressure at sea level will support the Mercury column in the tube to a height of 760mm. The height of the Mercury column changes as air pressure changes. Falling air pressure allows the Mercury column to drop, where as increasing air pressure forces the Mercury column to rise, with the height of the Mercury column directly proportional to air pressure. This is the origin of the common practice of expressing air pressure in units of length or the Mercury column. Air pressure readings by a Mercury barometer require adjustments for 1 the expansion and contraction of Mercury that accompany changes in temp and 2 the slight variation of gravity with latitude and altitude that affects the weight of the Mercury column by convention readings are adjusted to standard conditions of 0C and 32F and 45 degrees latitude at sea level

Question 33

the different types of barometers- 2

Answer 33

Aneroid Barometer
Is more portables. It consists of a flexible seed chamber from which much of the air has been evacuated. An internal spring prevents the chamber from collapsing. As air pressure changes, the chamber flexes, compressing when air pressure rises and expanding when air pressure drops. A series of gears and levers transmits and magnifies these movements to a pointer on a dial, which is calibrated to read in equivalent millimeters or inches of Mercury, or to read directly in units of air pressure. The latest aneroid barometers provide direct digital read outs. Electronic.

Question 34

Advection fog

Answer 34

Advection fog- when the advecting air passes over a relatively cold surface, the air mass may be chilled to saturation in its lower layers. Advection cooling.. Example early spring when miles humid air flows over relatively cold, snow covered ground. Snow on the ground may chill the overlying air to the dew point and fog develops. ADVECTION COOLING

Question 35

Steam fog

Answer 35

(Arctic seam smoke)
Late fall or winter when extremely cold and dry air flows over a large unfrozen body of water. Evaporation and sensible heating cause the lower portion of the air mass to become more humid and warmer than the air above. Heating below destabilizes the air and the consequent mixing of mild humid air with cold dry air brings the aid to saturation and fog forms. Because the air is stabilized fog appears.

Question 36

Cold cloud

Answer 36

Precipitation
Most precipitation falling in middle and high latitudes originates in cold clouds (temps below 0) that contain some ice crystals. Precipitation is most likely to fall from a cloud initially composed of a mixture of supercooled water droplets and ice crystals.
Cloud condensation nuclei are much more abundant than ice forming nuclei and are more efficient in forming a cloud particle so that a mixed cloud consists of far more supercooled water droplets than ice crystals, supercooled water droplets quickly vaporize as ice crystals grow
As it gets colder.. Water freezes into ice crystals, aka SNOW

ICE CRYSTALS GROW BU DEPOSITION SND BECOME LARGE ENOUGH TO FALL