Air, Weather and Climate
Weather is the day to day fluctuations in the atmosphere while Climate describes temperature and humidity changes over long periods of time. Climates are not static- they cycle through yearly, centurial (is that a word?) and millennial patterns.
Initially the climate on Earth was a deadly mixture of Hydrogen, Helium and Methane from the outgassing of molten rock. 3 billion years ago oxygen was added to our atmosphere with the evolution of photosynthetic organisms.
Air pressure at sea level 14.5 lbs per square inch known as one Atm. Air pressure decreases with altitude. The surface of the Earth also experiences low pressure when warm air masses rises due to low density.
Air composition
Nitrogen- 78%
Oxygen- 21%
Traces of Water Vapor, Argon and Carbon dioxide
The Atmosphere has four distinct layers.
Troposphere (roughly 10 km up)
The layer closest to earth. Holds 75% air mass.
Gets colder with altitude
Weather happens here, also only layer with water
Stratosphere
The top of the stratosphere contains ozone- O3
Ozone absorbs high level UV radiation from the sun.
Temperature increases with altitude because of UV absorption
Ozone molecules are broken down by CFC (now outlawed ingredient
in aerosol sprays, refrigerator coolants and electrical cleaning
solvents)
Excessive UV light on the Earth causes skin cancer, cataracts
and mutates and kills plankton (the ocean's bread basket).
Mesosphere
Temperature decreases with height
Thermosphere
Highly ionized gas interacts with magnetosphere to create
Aurora borealis (Northern Lights)!
Global Energy Transfer- before _____________ global energy
was in ____________.
Most of the energy from the sun is in the high energy wavelengths-
________ and visible light.
_________% of this energy is absorbed at the surface.
Energy reflected from the surface is _________ (longer wavelengths)
Convection- the transfer of energy of a warm fluid (like gas or water) upwards into a ___________ zone. The cycle of air upwards around and down is called Convection Currents.
Why it rains in a rain forest: The sun's energy is concentrated near the __________. Rising hot air expands and cools (called __________ cooling). Colder air can't hold as much moisture so after a certain altitude, the air dumps out its water vapor in the form of water droplets- the stuff of clouds. Rising air creates low pressure and lots of nasty weather, unless you are a tropical plant in which case you are very happy. As the water vapor condenses it gives up ________ __________ energy- this helps large cloud formations rise higher, cool more and build energy to form large storm systems like hurricanes.
Why it is dry in a desert: At ______ degrees North and South latitude the air is cooling, becoming more dense and sinking. Sinking air creates _______ pressure. High pressure days are cloudless great tanning weather kind of days, unless you are thirsty.
Global winds are caused by the constant balancing act going on in our atmosphere as moist, warm air travels upward from the Equator and then cools and sinks at the 30 degree latitude belt. The air rises again at the _______ latitude and sinks at the poles. When the air moves laterally across the Earth's surface from belt to belt (High to Low pressure) it creates ________- we live in the __________ wind belt which is why all of our weather comes from West to East. Below us are the _______ winds which blow towards the ___________.
All wind belts are curved to the rotation of the Earth knows as the _________ __________. In the Northern hemisphere the air curves to the ________. In the south it curves to the_______. These curving winds are also partially responsible for the direction of the major ocean currents of the world.
The Coriolis effect is also what spins __________ and __________. Cyclones are low pressure centers with winds that blow inwards in a __________ direction. Weather conditions are very _________.
_____________ are high pressure centers with cooler, sinking air that then spin clockwise outwards. Clear skies are created.
______ Streams- 200 km/hr currents of air 10 km up. Responsible for guiding weather systems. Generated by temperature differences in upper atmosphere and the shear from Earth's rotation.
Types of Fronts
Cold Front
_______ air mass moves into ________. Sudden rise in air.
Creates large cumulonimbus rain clouds, lightening and hail
Powerful, but _____ rainstorms
Warm Front
_________ air mass moves into ________
Creates cirrus clouds and later stratus clouds.
Sleet or ________, light, cold rain created.
Occluded Front
________ fronts take over ________ fronts by sandwiching and then
pushing the warm air off the ground. The system begins to spin
(cyclone) and rain like crazy.
Hurricanes (or ___________ in the Pacific Ocean) are a hundred mile wide cyclones that last several weeks. Despite their relatively puny wind speeds (75- _____ mph) hurricanes are much more deadly than tornadoes. Between the heavy rain fall, mud slides and storm surges, people lose their lives by ___________.
Tornadoes- a mini cyclone that begin when the jet streams shear
off the top of an especially large _____________ cloud (cool, huh?).
The cloud tightens as it sinks downward and spins faster due to
angular __________. The fastest tornado winds have been clocked
at 318 mph. Most lives are lost in a tornado due to being struck
by something that has no business flying.
____________- seasonal rains and droughts caused by the differential
temperatures of land and oceans. In the ________, the land heats
up faster than the sea, so a low pressure center develops on land.
Moist air from the ocean rush in to "fill" in the pressure
void and __________ rains last for four months or more. Then, during
the winter, the ocean, which has a higher heat capacity, is now
warmer than the land and winds tend to move towards the sea. A
long term _________ ensues.
Milankovitch cycles-
Periodic shifts in earth's orbit (100,000 year cycle), tilt (40,000
year cycle) and axis wobble (a 26,000 year cycle). The timing
of all three of these phenomenon are such that every __________ years
or so the Earth finds itself very far from the sun- enough to
trigger an _____ ______.
La Nina
The "normal" state of affairs with relatively cool
ocean temperatures on the Equatorial Pacific Ocean. _______ winds
blow warm water in the South Pacific towards the _______ Pacific
Ocean. This causes a low pressure system off of Australia and
Indonesia which leads to lots of _______. Nutrient rich water upwells
off the coast of South America feeding a burgeoning _________ population.
Back in the States we experience warm winters in the _____ and cold
winters in _____ and the Middle Atlantic. Southern California is
_____ (the brats!) and Washington is ______ (poor Kurt).
El Nino- occur every 3-5 years. Used to last 2 weeks to a month,
now last _____ to _____ years!!!
Unusually warm ocean temperatures on Equator (made worse by global
warming) cause the ______ winds to weaken. Warm water is sloshed
back to South America
No upwelling of nutrient rich water occurs off of Peru and the
_______ population falls. Food chain is disturbed and fisherman go broke.
The jet stream splits over America causing lots of weird weather.
New Paltz gets ______ winters while the South West US and Peru
gets _________!!
Seattle goes _______ as does the West Pacific causing large bush
fires in Australia and Borneo- 8 million acres burned just recently
:(
Global Warming (now officially called Climate Change by our
government- doesn't sound as scary)
The burning of ______ ______ creates greenhouse gases- especially
______ _______. Since 1800 we've gone from 280 ppm to _______ ppm
of CO2. Other gases implicated in global warming are water vapor,
methane- mooo! (CH4), N20 (laughing gas) and sulfur hexafluoride.
The massive deforestation around the planet also adds to the greenhouse
effect because our natural carbon dioxide sinks are compromised...
ok, dead.
These greenhouse gases trap infrared heat energy trying to exit the planet and the Earth is heated up- already we've noticed a ______ degree F change. That doesn't sound like much but it only took a reduction of _____ degrees to trigger an ice age.
Effects of Global Warming include:
Glaciers melting and huge icebergs calving off ______ ______. The
Arctic sea is now _____% thinner. Many alpine glaciers are shrinking
quickly or melting altogether.
Creates sea level rise (____ inches projected in next 100 years).
If all of the glaciers/ice sheets melted the sea level would rise _______
feet.
Drought/ fires are more common due to changes in weather patterns.
Crop failure- US _______ basket is now moving to Canada- only problem
is that the soil is thin and not particularly fertile.
More ________ disease will spread due to more tropical areas-
malaria is coming- agghhh!
Extreme weather- contrary to popular misconception- winters get
more ferocious and of course summers get hotter.
Coral reefs are being "_________" by the hotter temperatures.
That means that the algae that lives commensually on the coral
is dying. It is projected that the reefs have ______ years left...
poor Nemo!
Extinctions- animals and plants can't migrate fast enough to
out pace environmental changes especially if you are trapped on
a mountain or if you've reached the limit of your __________.
_________ Protocol
In 1997, 162 countries gathered together in Japan to figure out
how to slow global warming. EVERY COUNTRY agreed to limit their
carbon dioxide production and signed a treaty to that effect,
except for the ______ and ________. It really shocked and disturbed
the world, especially when George Bush senior said, "We are
going to put the interests of our own country first and foremost"
and "The American lifestyle is not up for negotiation."
We tried really hard to create a "CO2 credit" in exchange
for the fair amount of land we have still forested, but the countries
won't go for it. The US produces ______% of the world CO2, and yet
has less than____% of the world's population. Presently the government
has responded to environmentalists' pressure by pledging lots
of money to investigate the NATURAL causes of global warming (okay
volcanoes do make CO2... ). Many people argue that historically
we've seen massive fluctuations in temperature on the Earth, but
the point is that the present _______ of temperature change is unprecedented,
and inconveniently coincides with human-caused increases in _______
levels... The plot thickens.