Weather Flashcards
water and weather
water can absorb or release substantial quantities of heat without any significant change in temperature
specific heat (heat capacity)
very high, water takes a long time to heat up
latent heat
energy released or absorbed during change of state
calorie
unit of energy
what is humity
amount of water in the atmosphere, a measure of the amount of moisture in air
which can hold more water warm or cold air
cold air
relative humidity
amount of water point relative to the max can be held
dew point
straturation point of atmosphere.
atmospheric pressure
decreases with increasing altitude, local variation related to density,
cold dry air
sinks and compresses
high pressure rotates which way
clock wise
low pressure rotates which way
counter clock wise
warm moist air
rises and expands
lower the pressure =
bad weather
why does the wind blow
air moves from high to low pressure, always moves from high to low pressure, widely spaced circles from the west
atmospheric circulation
southern hemisphere deflected to left, northern hemisphere deflected to right
parts of atmospheric circulation
circulation cells, wind bands, polar easeries, westerlies, trade winds,
weather systems track from
the west/ to east, because of westerlies
why do weather patterns track from west to east?
westerlies
why do tropical storms track from east to west?
following the trade winds
air masses
changes in weather are the result of interaction between moving air masses, source area and temperature.
martime and continental
most interesting weather
air masses change from
temp, topography
front
boundary between moving air masses
cold front
heavy rainfall, weather changes for the worst, on a weather map has teeth, moves faster
warm front
light rainfall, redline, half circle, warm air behind, cold air front
continental polar and maritime tropical air mass
most weather system in us are this type
what influences where storm systems track?
jet stream, curvature
jet stream
strong, focused, high altitude winds, follow westerly winds. west to east
curvature
get weather, curves up and down
down curvature
cyclonic circulation, low pressure, counter clockwise
up curvature
anticyclonic cirulation, high pressure, clockwise
thunderstorms
happen during summer, cold fronts produce super cells, latent heat, as it rains out it loses energy
3 stages of Thunder storm
cumulus, mature, and dissipating
mature
rain dissipating
what causes lighting?
strong up drafts, strong down drafts, up and down drafts pass each other and friction happens. cause electrostatic charges to separate
pilot leader
negative charge goes towards the ground, electrical discharge
how does a tornado happen
cold front produces super cells, jet stream moving along cold front, extreme pressure gradinets,
3 stages of tornado
early, updraft, and tornado
updraft
bringing in air from all over friction starts to create vortex
spin
funnel cloud
Types of air masses
cA, cP, cT, mP, mT
air masses
identified by the temp and moisture characteristics of the underlying surface
midlatitude cyclone
large center of low pressure with an associated cold front and often a warm front. frequently accompanied by abundant precipitation. moves counter clockwise
front
boundary from one air mass and another
study page
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trade winds
two belts of winds that blow almost constantly from easterly directions and are located on the equatorial sides of the subtropical highs
westerlies
winds between 30 degrees and 60 degrees latitude that move west to east and greatly influence weather in North America
occluded front
a composite front formed when a cold front overtakes a warm front and forces it aloft. purple line on map
