Weather & Climate Systems | Exam #2 | Dr. Lauren Michel

water does not participate easily in hydrogen bonding.

All of the following are properties that make water unique among other substances on Earth EXCEPT:

break hydrogen bonds

Water's temperature increases slowly because some of the energy absorbed is used to _______________ instead of to increase the kinetic energy of the molecules.

absorbed by the evaporating water.

As liquid water is evaporated into the atmosphere, heat energy is:

the mixing ratio.

The formula shown above defines the humidity measure known as:

increases with an increase in temperature. 

The capacity of the air to hold water vapor:

nearness to saturation for the air.

Relative humidity indicates the: 

air temperature.

Relative humidity depends on the water vapor present in the air and the:

condensation

As the temperature of air is reduced to its dew point, which of these is most likely to occur?

expanded to a larger volume.

During the process of adiabatic cooling, the temperature decreases because the air has:

decreases

The temperature of rising air parcels _____________ as they move upward.

latent heat is released inside a parcel of rising saturated air.

The moist adiabatic rate is different from the dry adiabatic rate because:

divergence.

All of the following are lifting mechanisms in the atmosphere EXCEPT:

environmental lapse rate.

The change in the actual air temperature as you go up in to the atmosphere is called:

absolutely stable.

If the environmental lapse rate is less than the wet adiabatic lapse rate, then the atmosphere is:

decrease.

The addition of water vapor will cause the density of air to:

an area of low pressure.

A cyclone is generally defined by meteorologists as:

air moving out of an area.

Divergence in the atmosphere is best defined as:

pressure gradient force.

The primary force which causes ALL winds is:

pressure gradient force and Coriolis effect.

Neglecting friction, the speed and direction of the horizontal wind are determined by:

everywhere. 

The pressure gradient force is directed from higher to lower pressure:

lines connecting points of equal air pressure. 

What do isobars represent on a map?

winds would not be impacted by the Coriolis Effect.

If the Earth were not rotating:

changing the direction of the wind.

The Coriolis effect influences the wind by:

parallel to the isobars.

The geostrophic wind described a situation where the air moves:

If you stand with your back to the wind, there is low pressure on your left and high pressure on the right. 

What does Buys Ballot's Law state? (in the Northern Hemisphere)

outward and counterclockwise.

In the southern hemisphere, anticyclonic winds flow:

microscale winds

• circulation is small and chaotic

• they can last from seconds to minutes

• simple gusts, downdrafts, and small vortices

• don’t cover large distances

mesoscale winds

• can last from minutes to hours

• usually less than 100 km across

• some (thunderstorms and tornadoes) also have strong vertical component

macroscale winds

• largest wind patterns

• planetary scale; can remain unchanged for weeks at a time

• smaller circulation - synoptic scale

  • smaller systems are tropical storms and hurricanes

land and sea breezes

• form in coastal locations in the tropics and midlatitudes

  • arise from differential heating of the land and water

sea breeze

local wind that blows from sea towards land in afternoon in coastal areas

land breezes

blow from land toward sea during night in coastal areas

valley and mountain breezes

results from differential heating of mountain slopes vs valley floors

valley breezes

• daily upslope winds encountered in mountain valleys

  • start in valley floor and move up mountain slope

mountain breezes

• nightly downslope winds commonly encountered in mountain valleys

• start on mountain slopes and winds move into the valley

Chinook winds

• warm, dry winds that move down leeward slopes of mountains

• can bring on drastic changes in temp

Santa Ana winds

• local name for Chinook-like winds in southern California and northwest Mexico

• occur yearly in Fall and Winter

• dry summers + strong [term] = wildfire conditions

Katabatic (fall) winds

• originate when cold, dense air begins to move

  • glacial, cold ahh wind

• better known ones have local names, such as mistral

Country breezes

• mesoscale winds

• caused by uneven heating of urban and country areas

• results in flow from country to urban areas

• Hadley model

  • single-cell circulation model

  • contrast in temps between the poles and equator creates a large convection cell in both the Northern and Southern hemispheres

three-cell circulation model assuming a featureless Earth and no rotation

Hadley Cell

• warm air rises at equator

• as flow moves poleward, begins to cool and sink at 20° - 30° latitude

• somewhat meridional (N - S)

doldrums

region with a weak pressure gradient where trade winds meet at the equator

Ferrel Cell

westerly circulation of surface winds (prevailing westerlies) between 30° and 60° latitude

Polar Easterlies

circulation (60° - 90°) within polar cell; surface flows that move toward equator

equatorial low

an intertropical convergence zone

ITCZ

• intertropical convergence zone

• actual/preferred term for doldrums

subtropical highs (STH)

high-pressure zones in belts around 20° - 35° latitude on either side of equator

polar highs

near poles where polar easterlies originate

monsoon

seasonal reversal of winds; driven by pressure differences

Rossby waves

• longest wave patterns, usually consisting of 4-6 waves that encircle the globe

• have a large impact on weather

Jet Streams

• polar and subtropical

• occur near top of the troposphere

• embedded in westerlies

• widths vary from less than 100 km - more than 500 km

• speeds can attain 100 - 400 kph

polar jet stream

• most prevalent jet stream

• moves faster and is stronger in winter

• occasionally moves north - south in winter

polar front

major frontal zone that the polar jet stream occurs along

subtropical jet stream

• west-to-east current, centered at 25° N and S

• mainly winter phenomenon

• slower than polar

• not on the test

fixes energy imbalance

transfer of heat by winds and ocean currents equalizes the latitudinal energy imbalances

gyres

• “jacking off and tired” - Lou

• nearly circular patterns of ocean currents formed by Coriolis affect deflecting surface currents poleward

poleward moving, warm ocean currents

moderate high latitudes during winter

cold currents

• exert their greatest influence in tropics & during summer in mid-latitudes

• increase aridity in tropical deserts along west coasts of continents

ocean currents

have an impact on climate, help maintain heat balance

cold currents offshore

dry climate

warm currents offshore

warm, moist climate

upwelling

• rising of cold water from deeper layers to replace warmer surface water due to wind-induced vertical movements

  • occurs where winds blow parallel to coast toward equator

El Niño

• gradual warming of Eastern Pacific waters in December or January

  • warm water does not move, it stays there

• noted for potentially catastrophic impact on weather

  • arid areas can get lots of precipitation

  • change in surface water temp can kill fish

Atacama Desert

rain during El Niño year can lead to a superbloom here

La Niña

• opposite of El Niño; refers to colder than normal ocean temperatures

• western Pacific - wetter than normal conditions occur

• more frequent hurricanes in Atlantic

Southern oscillation

seesaw pattern of atmospheric pressure between the eastern and western Pacific

teleconnection

link between weather occurring in widely separated regions of the globe

hydrolic cycle

continuous exchange of water

ice

less dense than liquid

water

has a unique ability to form hydrogen bombs

latent heat

• hidden heat

• calorie is the amount of energy required to raise temp of 1 g of water by 1°C

latent heat of melting

[-] 1 gram of ice requires 80 calories

latent heat of fusion

freezing 1 gram of water releases 80 calories

latent heat of vaporization

energy absorbed by water during evaporation

evaporation

cooling process

condensation

• converting gas to a liquid

• reverse of evaporation

latent heat of condensation

process when water vapor changes to the liquid state

sublimation

• process that turns a solid into a gas

• i.e. disappearing ice cubes in freezer

deposition

• reverse process of changing a vapor to a solid

• i.e. frost accumulating in freezer

humidity

amount of water vapor in the air

absolute humidity

• mass of water vapor in a given volume of air

• = mass of water vapor (g) / volume of air (cubic meter)

mixing ratio

mass of water vapor in a unit of air compared to the remaining mass of dry air

vapor pressure

part of the total air pressure attributable to water vapor content

saturation

equilibrium point between evaporation and condensation

saturation vapor pressure

pressure by the motion of the water vapor molecules when the air is saturated

relative humidity

• how close or far something is to saturation

• ratio of the air’s actual water vapor content & amount of water vapor required for saturation at a certain temp

increase in temp =

decrease in relative humidity

advection

primarily horizontal component of convective flow (wind) that causes temp changes

convection

air moving up

dew point

• temp at which air is cooled to reach saturation

• measure of actual moisture content

saturation pressure is

pressure dependent & that for every 10°C increase in temp, the amount of water vapor needed for saturation doubles

hygrometer

measures moisture content of the air

psychrometer

• consists of two identical thermometers

  • dry thermo measures air temp

  • “wet bulb” measures dryness of air

• the larger the difference in temp, the lower the relative humidity

adiabatic

process is one in which NO HEAT is transferred

changes in pressure

result in temp changes

air compressed

warms

air expands

cools

parcel of air

• imaginary volume of air

• typically few hundred cubic meters in volume

• assumed to act independently of surrounding air

• assumed no heat transferred in or out of

dry adiabatic rate

unsaturated air cools at a rate of 10°C/1000m