Chapter 7 (atmosphere) Flashcards
tornado
violently rotating column of air associated with extreme horizontal winds
work
force times distance (joules)
power
rate at which work is done (watts)
current global energy consumption
13 tW per year
potential energy
stored energy
kinetic energy
energy of motion
heat energy
energy of random motion of atoms and molecules
sensible heat
heat that may be sensed or monitored by a thermometer
latent heat
amount of heat that is either absorbed or released when a substance changes phase
latent heat of vaporization
energy required for vaporization of water
conduction
transfer of heat through a substance by means of atomic or molecular interactions
relies on temp differences
convection
transfer of heat by the mass movement of a fluid
convection cell
rising and falling currents due to differences in temperature
radiation
wave like energy that is emitted by any substance that possesses heat
earth’s energy balance
equillibrium between incoming and outgoing energy
wavelength
distance between tops of two successive waves
radiation and absorption of electromagnetic energy is affected by both
temp and reflectivity
hotter objects
emit more electromagnetic energy
if surface temp doubles,
radiated energy increases 16 times
hotter objects radiate energy
more rapidly and at shorter wavelengths
sun emits
short wave radiation
gamma x rays visible UV light
earth’s land surface, oceans, and clouds emit
long wave radiation
infrared
dark or black surfaces
absorb or radiate EM energy readily
light or white surfaces
tend to reflect EM energy rather than absorb it
atmosphere
gaseous envelope that surrounds earth
made up of gas molecules, suspended particles of soild and liquid, and falling precipitation
atmosphere is mainly composes of
nitrogen and oxygen
also argon, water vapor, and carbon dioxide
humidity
amount of water vapor in the atmosphere at a given temperature
relative humidity
ratio of water vapor present in the atmosphere to the maximum amount of water vapor that could be there
lowest layer of the atmosphere
troposphere
troposphere
extends about 8-16km above earths surface
rapid upward decrease in temperature
clouds at the very top
contains most of atmospheric carbon dioxide and methane
ozone is significantly less abundant
tropopause
upper boundary of the troposphere
cumulus clouds
puffy, fair weather, look like cotton
cumulonimbus clouds
thunderstorm clouds, release a lot of energy
atmospheric pressure (barometric pressure)
weight of column of air that is above any given point
force exerted by gas molecules on a surface
atmospheric pressure decreases rapidly at
higher elevations
air rises in areas of
low atmospheric pressure
dry air descends and sky conditions remain clear in
areas of high atmospheric pressure
cold, dry, converging air movement creates
low pressure
warm, moist, diverging air movement results in
high pressure
changes in atmospheric pressure are
a major driving force for wind
parcel
small volume of air
atmospheric stability
tendency of a parcel to remain in place or change its vertical position
an air mass is stable if
its parcels of air resist vertical movement or return to their original position after they have moved
an air mass is unstable if
its parcels rise until they reach air of similar temp and density
atmosphere becomes unstable when
lighter warm air is overlain by denser cold air
coriolis effect
deflects winds to the right in the northern hemisphere and to the left in the southern hemisphere
wind patterns along the equator are not deflected by the coriolis effect
front
boundary between a cooler and warmer air mass
cold front
cold air moves into a mass of warm air
warm front
warm air moves into a mass of cold air
stationary front
boundary shows little movement
most common thunderstorms
colorado, NM, FL, GA, AL, MI, LA
thunderstorms are most common during
afternoon and evening hours
mesoscale convective complexes
roughly circular clusters of storm cells
most common
downdraft of one cell leads to formation of new one nearby
12 hours or more
squall lines
linear belts of thunderstorms
develop parallel to cold fronts or along drylines
supercells
large cells with single updrafts
most damaging
last from 2-4 hours
drylines
air mass boundary between moisture content
outflow boundaries
arcuate lines of thunderstorms that may travel long distances
hailstorms most common in
great plains
tornado
vortex extends downward from a cloud and touches the ground
funnel clouds
funnel shaped vortices that have not touches the ground
tornadoes form where there are
large differences in atmospheric pressure over short distances
mesocyclone
large upward rotating column of air
suction vortices
smaller intense whirls
orbit the center of a large tornado
responsible for greatest damage
how tornadoes are classified
fujita scale (F scale)
tornadic watersprouts
descend from storm clouds over water
develop from downdrafts
fair weather waterspouts
develop upward from water surface
blizzards
large amounts of falling or blowing snow are driven by high winds to create low visibilities for an extended period of time
wind chill effect
moving air rapidly cools exposed skin by evaporation of moisture and by removing warm air from next to the body
ice storms
prolonged periods of freezing rain
drought
extended period of unusually low precipitation
dust storms
strong windstorms in which suspended dust that is carried by the wind reduces visibility for a significant period of time
sand storms
sand is transported over a distance of 30 m at the surface of the land
ridges
elongate areas of high pressure
heat index
measures body’s perception of air temperature (greatly influenced by humidity)
doppler radar
sends out EM radiation that has a wavelength a little longer than a microwave
clouds, raindrops, etc reflect EM waves
doppler effect
wavelengths of the reflected waves changes depending on whether the objects are moving toward or away from the antenna
watch
warns of possibility of event in future
warning
event has been sighted and area is in danger
mitigation
long term actions to prevent or minimize death and damage
conduction
transfer through atomic or molecular interactions
two bodies in contact with one another
convection
transfer through mass movement of a fluid
hot air rises and displaces cool air, which falls
creates a convection cell
radiation
transfer through electromagnetic waves
redirection
reflection back to space by clouds, water, and land
scattering disperses energy in many directions
transmission
energy is passed through atmosphere
albedo
describes the reflectivity of surfaces
dark woodlands reflect
5%-15%
light grasslands reflect
25%
absorption
energy that is not reflected but absorbed
temperature depends on
amount of energy absorbed or reflected
atmospheric composition
composed mostly of N and O
also water vapor, argo, CO2
water vapor
important for cloud formation and circulation
comes from evaporation off of earth’s surface
humidity
describes amount of moisture in atmosphere at particular temperature
troposphere
all of earth’s surface is within this layer
upper boundary is tropopause
temperature decreases with increasing altitude
clouds are present at the tropopause
greenhouse effect
heat trapping gasses (co2, h2o) trap heat in the troposphere
atmospheric pressure decreases with
increasing altitude
air rises in areas of
low atmospheric pressure
cools, condenses, and forms clouds and precipitation
air descends in areas of
high atmospheric pressure
sky conditions are mostly clear
cold air is more
dense
exerts greater pressure on surface
air that converges allows air to increase
pressure
air that diverges lowers the
atmospheric pressure
sea breeze
happens at day
cool breeze from sea to land
land breeze
happens at night
cool breeze from land to sea
3 factors that drive ocean currents
rise and fall of tides
wind
thermohaline circulation
cirrus clouds
made from very small water droplets or ice crystals
cumulus clouds
puffy, fair weather clouds
cumulonimbus clouds
vertically stacked, dark storm clouds
stratus clouds
layered clouds
nimbostratus clouds
layered rain clouds
wind shear
large differences in wind speed and direction
