Weather and Climate Final
Terms
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- How the current weather state affects our lives
-
-human beings - how we feel
-commerce - gas, crops, flying
-food prices - raise up, dry, freeze - climate
-
the collective state of the Earth's atmosphere over a long period of time (natural and man-made changes)
-constantly changing - How long of a period is considered for climate
- 30 years or more
- atmosphere
-
-a mixture of many different gases
-the composition of the atmosphere is NOT constant...as it changes from place to place and time to time
-includes ALL atmosphere-all planets are part of the atmosphere (Pluto included) - meteorology
- the study of the Earth's atmosphere that is a nonperfect science
- 340 BC
- Aristotle - Father of Meteorology
- 1593
- thermometer developed by Torricelli
- late 1700s
- hygrometer developed
- 1843
- telegraph invented
- 1850
- 4 cup anemometer built by Robinson
- 1870
- Department of Telegrams and Reports for the Benefit of Commerce under Signal Corporation (Department of War)
- 1891
- Civilian U.S. Weather Bureau developed in the Department of Agriculture
- around 1920
- air mass/frontal theories developed (Norwegian meteorologist)
- 1940
- U.S. Weather Bureau transferred to the Department of Commerce
- 1940s
- upper air balloons and atmospheric multi-dimensional view (growing aviation importance during World War II)
- 1950s
- high speed computers developed (age of atmospheric modeling begins)
- 1957
- conventional weather radars developed (based on reflectivity)
- 1960
- first weather satellite - TIROS I
- 1970
- U.S. Weather Bureau name changed to the National Weather Service (still in the Department of Commerce)
- April 3 and 4, 1974
- worst tornado outbreak in U.S. history (100 1/2 tornadoes touched down in 24 hours in states such as: Alabama, Mississippi, Michigan, etc.)
- 1980s
- development and use of ground based lightning detection systems
- 1960s and 1970s
- Weather Bunny Era - women did weather reports on TV no matter how much they knew about weather
- 1970s
- after tornadoes more meteorologists on the air to explain effects
- late 1980s into the 1990s
- development and deployment of Automated Surface Weather Observing Systems (ASOS/AWOS)
- 1990s
- materialization and restructuring of National Weather Service
- air temperature
- hotness or coldness of air
- humidity
- amount of moisture in the air
- wind direction
- horizontal movement of air from the origin
- wind speed
- force which air blows
- clouds
- nature's handwriting
- precipitation
- ice or water droplets falling from the sky
- atmospheric pressure
- the mass/weight of the air above us (high or low pressure)(clouds and rain-low pressure, good weather-high pressure)
- visibility
- how far you can see
- satellite
- cloud cover
- radar
- precipitation
- atmospheric profilers
- atmospheric information from temperature
- rawinsondes/radiosonders
- up high (pressure, precipitation)
- surface aviation weather observations
- worldwide aviation safety
- lightning networks
- observations of lightning
- surface weather map
- 4 or 5 feet off the ground
- upper air weather map
- upper levels of the atmosphere
- isolines
- lines of equal or constant values of a given property (with respect to place and time)
- isobars
- lines of equal pressure - only used on surface weather maps
- isotherm
- lines of equal temperature
- isohyet
- lines of equal rainfall - especially after big storms
- isallobar
- lines connecting points of equal pressure over a period of time
- isodrosotherm
- lines of equal dew point temperature
- isotach
- lines of equal wind speed
- surface weather maps
-
model in Fahreheit (U.S.) which is located in upper left corner
-bottom left corner-dew point - upper air weather maps
-
model in Celsius which is located in upper left corner
-dots-rain
-big circle-clouds
-flag points in wind direction
-pendants on flag-wind speed (knots)
-dew point depression-lower left number (Celsius-dew point dep.=dew point) - Stanley Gedzelman's Seven Causes of Weather
-
1.sun's heating varies over Earth and with seasons
2.difference in air temperatures over Earth causes wind
3.rotation of Earth destroys simple wind patterns...twisting the wind, produces spirals...high/low pressure
4.since less moisture can coexist in colder air, precipitation is generally cause by cooling the air
5.pressure in the atmosphere ALWAYS decreases with increasing height while temperature GENERALLY decreases
-the process of decreasing air pressure...temperature drops
-the process of increasing air pressure...temperatures rise
6.clouds/precipitation are caused by sinking air (high pressure) and clear skies are caused by sinking air (high pressure)
7.rising air expands and cools - hydrosphere
- water part of the planet (70-75% of the Earth's surface)
- lithosphere
- land part of the planet (land heats and cools quickly)
- biosphere
- living part of the planet (made up of all spheres)
- composition of the atmosphere
-
permanent gases (about 98% by volume)
-nitrogen - 78.08%
-oxygen - 20.95%
-hydrogen - 0.93%
-neon - 0.001%
variable gases (about 2% by volume) - most of these are Greenhouse gases
-water vapor
-methane
-ozone
-aerosols/particulates
-carbon dioxide
-nitrous oxide
-CFCs
-water vapor in the atmosphere is the most variable gas (0-4% by volume) - in colder regions there is not much moisture
- moisture can't coexist
- in desert regions it is very dry
- no moisture
- in rain forests
- tons of moisture
- ozone is a very unstable compound
-
good ozone found in the Stratosphere
-effective screen for UV rays from the sun
-unstable
-ozone holes-raise in skin cancer
bad ozone found in the Troposphere
-form of pollution
-fumes find sun light and form 3O-fill up at night (no light)
-unstable - How do computers draw isolines?
- by interpelating data
- atmospheric origins
-
-particles in solar winds formed Earth...and then they cooled
-out gassing (including water vapor)
-clouds formed...rain fell
-at first, rain "boiled" away
-after cooling, oceans filled with water - formation of oxygen
-
-first atmpsohere contained little amounts of oxygen
-UV radiation through chemical reactions produced some oxygen
-largely though...most came from photosynthesis - thermal structure of the atmosphere
-
thermosphere (about 55 miles and up)
-mesopause
mesosphere (30 to 55 miles up)
-stratopause
stratosphere (15 to 30 miles up)
-tropopause (highes near equator/lowest near poles)
troposphere (surface to 10 or 15 miles up) - If a thunderstorm breaks through the __________ - it is a bad storm
- tropopause
- Why does the temperature rise in the stratosphere?
- because of the ozone
- Just because temperature increases in mesosphere and thermosphere doesn't mean it is hot because ________
- of such few molecules present
- homosphere
- surface to 55/60 miles up (through stratosphere)-well mixed region
- heterosphere
- 55/60 miles and upward (above stratosphere)-due to small number of atoms/molecules, layering takes place with heavier atoms/molecules (O/N) setting on bottom layers; lighter atoms (H/He) on top
- ionosphere
-
45/50 miles and higher-not really a layer by electrified region-molecules (N) and atoms (O) are readily ionized with high energy SW radiation-D,E,F layers (lowest to highest)
-daytime-all layers present
-nighttime-D and E disappear, F remains - Aurora Borealis/Australis
- another structural layer with electrical properties
- The Earth intercepts less than __________ of all the Sun's energy.
- 2 billionths
- The solar energy represents ____% of the energy that heats the Earth's surface
- 99.9%
- if the sun stops shining...
- global scale winds would cease...
- The atmosphere is a poor absorber of the sun's radiation
- The Earth heats the lower level of the atmosphere
- rotation
- spinning of the Earth on its axis once every 24 hours
- revolution
- movement of Earth in orbit around the sun occurs about every 365 1/4 days
- tilting
- causes seasons
- the most direct rays from the sun are at __________
- 90 degrees overhead
- "atmosphere"
- the number of atmospheres the sun rays have to shine through to get to us
- More of an angle determines the number of "atmospheres" that the sun rays must traverse
-
-1 "atmosphere" - 90 degrees overhead
-2 "atmospheres" - 30 degrees above horizon
-11 "atmospheres" - 5 to 10 degrees above horizon - 21st of March
-
Vernal Equinox (first day of spring)
-sun directly above the equator - 21st of June
-
Summer Solstice (first day of summer)
-sun directly above the Tropic of Cancer - 21st of September
-
Autumnal Equinox (first day of fall)
-sun directly above the equator - 21st of December
-
Winter Solstice (first day of winter)
-sun directly above the Tropic of Capricorn - When do the lows and highs for the days occur?
-
lows - 30 minutes after sunrise
highs - 4 or 5 pm
The highs and lows for the day are called the march/lay of temperatures - When do the hottest and coldest parts of the year occur?
-
hottest - a couple weeks after the summer solstice
coldest - a couple weeks after the winter solstice - circle of illumination
-
the boundary separating the light part of the planet from the dark part of the planet
-poles - depending on which way the axis is tilted they will be light for about 2 months or dark for about 2 months - Of 100% of incoming solar radiation...
-
-20% is scattered and reflected by clouds
-51% is absorbed by the earth (most important)
-6% is scatterred from the atmosphere
-19% is absorbed by the atmosphere and the clouds
-4% is reflected by the surface - conduction
-
transfew of energy from a hot end to a cooler end (pot and spoon)
-not an efficient way of transferring energy in the atmosphere (only an inch or two off the surface) - convection
-
the vertical transfer of heat energy through the atmosphere
-air pockets in the air (invisible)
-clouds form due to convection - advection
- the horizontal movement of an object (cloud, moisture, temperatures) across the atmosphere
- radiation
-
shortwave (solar) radiation vs. long wave (terrestrial) radiation
-hot to cool areas - Dust and other particles redirect radiation...
- which results in light (bright daytime sky)
- Small gas molecules scatter radiation...
- resulting in the blue/violet sky
- Rayleigh scattering (short wave)
- gases (blue sky)
- Mei scattering (lower levels of atmosphere)
- pollen, dust, smoke, clouds, fog
- Non-selective scattering
-
haze (largest particles)
-pollution - albedo
- total fraction of total radiation that is reflected by a given surface
- albedo varies...
-
-place to place/time to time
-due to cloud cover/particlate matter
-due to angle of the sun's rays
-due to nature of the Earth's surface - What is the average planetary albedo?
- 30%
- albedo for fresh fallen snow
- 80 to 85%
- albedo for thick clouds
- 70 to 80 %
- albedo for water (low sun angle)
- 50 to 80%
- albedo for old "dirty" snow
- 50 to 60%
- albedo for thin clouds
- 25 to 50%
- albedo for sand surfaces
- 20 to 30%
- albedo for green grassy areas
- 20 to 25%
- albedo for dry Earth
- 15 to 25%
- albedo for wet Earth
- 10%
- albedo for forested areas
- 5 to 10%
- albedo for water (directly overhead)
- 3 to 5%
- What does higher albedo equal?
- lower temperatures (reflects more light)
- atmospheric "greenhouse" effect
- the relatively easy transmission of short wave (solar) radiation by the atmosphere coupled with the selective absorption of long waves (terrestrial) radiation (especially by carbon dioxide and water vapor)
- absorption and emission
-
-very important as far as energy is concerned
-if an object radiates more energy than it absorbs...it'll turn cooler (equator)
-if an object absorbs more energy than it radiates...it'll turn warmer (poles)
-hurricanes redistribute energy - a "black body" object
-
-a perfect absorber (all the radiation it receives, it absorbs) or a perfect emitter (emits the max radiation possible at a given temperature)
-doesn't have to be black
-Earth: day (absorbs), night(emits)
-the radiative equilibrium temperature is reached
-not being a "black body" the atmosphere selectively absorbs and emits radiation
-without the gases (water and carbon dioxide) the Earth's surface would be 59 degrees cooler - energy
- the property of a system that enables it to do work
- temperature
- "hotness"/"coldness" of an object
- heat
- form of kinetic energy transferred between objects by virtue of temperature differences
- heat capacity
- ratio of heat absorbed (or released) by a system compared to the corresponding temperature rise (or fall)
- latent heat
-
-heat energy required for change of state
-latent means "hidden"
-a very important source of atmospheric energy
-latent heat of condensation is very important in the concept of atmospheric stability - melting
-
ice to liquid
-333 J/g or 80 cal/g - evaporation
-
liquid to vapor
-2500 J/g or 600 cal/g - sublimation
-
ice to vapor
-2833 J/g or 680 cal/g - condensation
-
vapor to liquid
-2500 J/g or 600 cal/g - deposition
-
vapor to ice
-2833 J/g or 680 cal/g - freezing
-
liquid to ice
-333 J/g or 80 cal/g - Worldwide, average short wave (solar) radiation is balanced by average long wave (terrestrial) radiation
- This is NOT true of each latitude N and S