Weather and Climate - Test Flashcards

Terms Definitions
earth's albedo
prognostic chart
-The computer analyzes the data for it's prediction and draws the projected positions of pressure systems with their isobars or contour lines
-the final forecast representing the atmosphere at a specified future time is called a prognostic chart
*currently, forecast models predict the weather reasonably well 4 to 6 days into the future. These models tend to do a better job of predicting temperature and jetstream patterns than predicting precipitation
when plants release paper
famous lows
-Hatteras Low (North Carolina)
-Alberta Clipper
-Colorado Low
-Gulf Low
-only 0.038% of atmosphere
-enters mainly from decay of vegetation/volcanic eruptions/fossil fuels
-removal through photosynthesis/ocean absorption
-risen more than 20% since '58
-levels were stable before industrial revolution-
-important greenhouse gas
-layer with temperature inversion... b/w tropo and meso
-temp inversion due to ozone... it absorbs UV that warms air
how far you can see
bad ozone
in the troposphere... Pollution
NAO-North Atlantic oscilaation - pressure reversal over atlantic
AO-arctic oscillation
PDO- Pacific Decadial oscillation (every 20-30 years)
roll cloud
-a dense cyclindrical cloud (elongated) that appears to slowly spin about a horizontal axis behind the leading edge of a thunderstorm's gust front
9. Polar
60-90 N/S
short, cool summers
long, cold winters
mean temp. does not reach 10 C
low precipitation
2 Primary ocean movements
1) currents2) upwelling
-tiny solid or liquid suspended particles of various composition (in atmosphere)
absolute zero
-the lowest temperature possible (-273C)
-atoms would theoretically posess no thermal motion
-telegraph was developed by Alexander Bain-transmit signals by Morse code
340 BC
-study of meteorology begins. -Aristotle is known as " father meteorology"
-a linkage between weather changes occuring in widely separated regions of the world
-storms that form along the eastern seaboard of the USA and then move northeastward
-an intense storm of tropical origin with sustained winds exceeding 64 knots (74 mi/hr), which forms over the warm northern Atlantic and eastern North Pacific oceans.
***in the western North Pacific, the same storm is called a TYPHOON, in India, a CYCLONE, and in Australia, a TROPICAL CYCLONE.
****By international agreement, tropical cyclone is the general term for all hurrican-type storms that originate over tropical waters.
outflow boundary
-a surface boundary separating colder more-dense air from warmer less-dense air. Outflow boundaries form by the horizontal spreading of cool air that originates in a thunderstorm
-generally generated by multi-cell storms
5. Warm Temperate
27-37 N/S
abundant precipitation, no extended dry season
small (less than 2mi in diameter), severe downbursts of strong winds
-base of thermosphere to the top (approx 100-500 km)
sea level pressures
inches of mercury: 29.92hectopascals: 1013.25millibars: 1013.25
-lower, well mixed region - ocmposed of air fairly uniform (up to around 100 km, or top of mesosphere)
form of energy that traversed between objects by virtue of temperature differences
Wind shear
-wind changes speed or direction abruptly
Accuracy/Skill in Forecasting
-forecasts b/w 12-24 hours quite accurate
-2-5 days = fairly good
-beyond 7, accuracy falls sharply
-what determines a "right" or "wrong" forecast?
-How does forecast accuracy compare with forecast skill? To show skill, it should be better than one based solely on the current weather (persistence) or the "normal" weather (climatology)
-meteorological forecasts show skill when they are more accurate than a forecast utilizing only persistence or climatology
-though, long range forecasts ususally mean extremely little difference between skill and climatology predictions
filling - weakening of a low pressure system (weak divergence aloft
building- increased high pressure system strength (strong convergence aloft)
Hurricane Winds
-when a hurricane is approaching from the south, its highest winds are usually on its eastern (right) side
-this is because the winds that push the storm along are added on the east side
-even though a hurricane may be moving north, net transfer of water is from east to west
2. Tropical Summer-Rain
10-30 N/S
well-defined wet and dry seasons
Polar Front
frontal zone separating air masses of polar origin from air masses of tropical origin
Continental Arctic (cA)
bitterly cold and very dry; stable
summer solstice
-astronomical first day of summer - june 21
-sun and moon directly overhead
-NH points directly at sun
Types of thermometer(6)
liquid in glass- basic
maximum - showest highest /w zone of constriction
-minimum - index marker shows lowest
-electric thermometers - highly accurate
-radiometer - instruments that measure emitted infrared radiation.. can estimate air T in selected altitudes
-thermograph-measures T by using bimetallic thermometer... 2 different pieces of metal in a single strip - brass expands more than iron and therefore bends the strip to read T
atmospheric origins
particles and solar winds formed the earth and then it cooled.outgassing occurred including water vapor. Clouds formed rain fell. At first rain "boiled away" after completely cooling the Earth the oceans eventually filled with water.and hydraulic cycle began
temperature data uses
temperature data is gathered at thousands of stations worldwide on an hourly basis
heating/cooling degree days
HDD/CDD's were developed by heating engineers* these are considered units of measurement-HDD/CDD's are practical method of evaluating energy, energy demand and consumption-these degree days are based on the assumption that heating/cooling is not required when it's 65°F
isobaric map
-uppoer air map... is a constant pressure chart... shows height variations at given pressure (500mb)
air mass
-an extremely large body of air whose properties of temperature and humidity are fairly similar in any horizontal direction at any given altitude
Hurricane watch/warning
watch- when a hurricane poses a direct threat to an area... typically 24-48 hours before the storm arrives... by the National Hurrican Center (Fl)... or by the Pacific Hurrican Center (Hawaii)
-warning- issued when it appears that the storm will strike an area
-accompanied by a probability
-these are issued for large coastal areas
-much area is "over warned"
storm surge
-an abnormal rise of several meters in the ocean level, which inundates low-lying areas and turns beach front homes into piles of splinters
Fujita scale
F0/F1 - weak tornadoes, and only very few each year go about F3 (violent), with perhaps one or two F5 reported annually.
-violent ones cause death
**as wind doubles, the force of the wind on the object increases by a factor of four
Upper-level divergence
helps draw air upward from the surface and acting as a lifting mechanism above the surface low pressure cell
Causes of lightning
* charges are separated within the clouds as the T-storm develops* positive charges near the top, negative charges at the base* it's the clouds' way of trying to equalize the charge difference or imbalance* to discharged the negative base of the cloud
occluded front
-where cold front has caught up with warm front
local seasonal variations
-in NH, objects facing south will receive more sunlight in a year than thoe facing north
-ski slopes typically face north
-this is important for designing a home!
layers by electrical properties
ionosphere-40/50-not a layer, but no electrical region. Molecules (N) and Atoms(O)are readily ionized with energy from sun's radiation contains the layers (low)D, (mid)E,(high)F
What are mesocale  winds?
These are middle sized phenomenons that generally last minutes to a few hours. These would include thunderstorms and tornadoes.
chinook winds
-warm and dry wind that decends the eastern slope of the rocky mountains
-main cause is the decending compressional heating
-called foehn winds in other parts of the world
mP air masses
-by the time is reaches the pacific coast, from over Asia and frozen polar regions, and then over hundreds or thousands of kilometers, it is cool, moist, and conditionally unstable.
-when the mP air moves inland, it loses much of its moisture as it crosses a series of mountain ranges
-it is slow changed back to cP (referred to as Pacific Air east of the rockies)
-these airs often form chinooks
-due to westerlies, atlantic mP winds are uncommon
Characteristics of Tornadoes
* pressure at the center of vortex often 90-100 mb below the surrounding air = strong pressure gradient (estimated)* high winds are measured on the Enhanced Fujita Scale EF0-EF5* travels horizontally* form in association with thunderstorms & likely to occur in the area of the T-storm adjacent to (behind) the area of large hail, usually the SW section of the T-storm
Characteristics of hurricanes (6)
1) cyclonic storm -- with warm-core low pressure at its center2) average diameter of 360 miles3) form over warm ocean waters4) strong pressure gradient to generate strong winds, strongest in the eye wall & decrease outward* heavy rain, lightning, and sometimes tornadoes* avg. life span of 7-10 days, but can last over 2 weeks
Low pressure cells in the NH basically show _______ ________, while High pressure cells in the NH basically show _______ _________.
positive vorticitynegative vorticity
specific heat
-amount of heat needed to raise 1g of something
What is the symbol for warm front?
A red semi circle.
surface map
on a surface not you will see1.) cold fronts2.) warm fronts3.) station fronts4.) pressures ( hi and low) indicated by isobars**** surface maps have two types... Mono and TV
What are source regions?
Areas where air masses originate and determine the characteristics of the air mass.
Developing Mid-Lat Cyclones/Anticyclones
-For the surface low to develop into a major storm system, upper level divergence of air must be greater than surface convergence of air (ie. more air removed than brought in)
-When this even happens, surface air pressure decreases, and we say that the storm  system is intensifying, or deepening
-if the reverse happen, it is called FILLING (low, becoming weaker)
-*in orer for the surface high to strengthen, upper level convergence of air must exced low level divergence of air
**for a surface mid-latitude cyclone to intensify, the upper level trough of low pressure must be located behind (or to the west of) the surface low
-this means more divergence at top of low pressure system (see Figure 5 pp 228)
Water's effect on climate
1) as a heat source to generate movement within the atmosphere2) as a source of water for latent heat transfer, clouds, & precipitation
daily temp range- humid and cloudy
smaller range- receive less insolation in the day- more LWR re-radiated to the surface at night
What does Weather mean?
Weather is the overall word used to describe the climate at any given time. Warm and dry, wet and windy, etc.
What is a monsoon?
A monsoon is a wind system that exhibits a pronounced seasonal reversal in direction. The most famous of these are the Asian monsoons.
the following criteria are used to locate a front on a surface weather map:
1)sharp temperature changes over a relatively short distance
2)changes in the air's moisture content (marked changes in dewpoint)
3)shifts in wind direction
4)pressure and pressure changes
5)clouds and precipitation patterns
Requirements of Formation of Tornadoes (4)
* T-storm, usually associated with a cold front or squall line* 2 air masses with strong T gradient across the frontal boundary* moist air with high degree of instability* upper level support, jet stream, which helps pull away rising air promoting greater surface uplift
seven causes of weather
1. Suns heat varies over the earth and with seasons2. Difference in air temperatures over the earth causes the wind3. Rotation of the earth destroys simple wind patterns (W to E) twisting the wind producing spirals of high and low pressures4.) since less moisture can coexist in colder air... precipitation is generally caused by cooling the air. cold air cannot contain moisture hence it falls5.)pressure in the atmosphere ALWAYS decreases with hight6.)decreasing air pressure> Temp drops(hairspray)increasing air pressure> Temp rises (football pump)7. Clouds/precipitation are caused by rising air (Low's).... Clear skies are caused by sinking air (highs)
What is the definition of cyclone?
The circulation of air masses around low pressure.
why is it warmer near the equator?
Because the suns rays fall directly perpendicular to the surface throughout the year.
What does the word warm front mean?
The front of an advancing mass of warmer air.
What are the symbols for air mass classification?
m - maritime
c - contential
T - tropical
P - Polar
A - Artic
AA - Antartic
What is a cold front and what weather is associated with it?
A cold front is what happens when a cool air mass occupies space that was formerly occupied by a warm air mass. Weather associated with it include thunderstorms.
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