Atmosphere


CLIMATE

Weather is the day to day fluctuations in the atmosphere while __________ describes temperature and humidity changes over long periods of time. ___________ are not static- they cycle through yearly, centurial and millennial patterns.

Initially the climate on Earth was a deadly mixture of Hydrogen, Helium and ___________ from the volcanic outgassing of molten rock. 3 billion years ago __________ was added to our atmosphere with the evolution of photosynthetic organisms (cyanobacteria).

Milankovitch cycles- animation

  • 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 _____ ______! An average cooling of 10 degrees F is enough to start an ice age.

We know about the past climates from ice cores, tree rings and fossil pollen grains.

The Most Important Factors that Effect Climate are:

Albedo- how much sun is reflected from the Earth. Snow, pollution and volcanic ash reflects a lot of sunlight so these events help _________ the Earth.

Altitude- the higher you go, the cooler the climate

Distance to Oceans- the _____________ to the sea, the smaller the temperature variations

Latitude- the higher the latitude, the colder it gets.

Mountain Ranges- the rain shadow effect causes rain to be dumped on the windward side of a mountain with dry air on the far side.

Greenhouse Effect- Carbon dioxide, methane and nitrous oxide are natural gasses in the atmosphere that help keep us from ___________, but humans are busy adding way more than our fragile ecosystems can handle.

Deforestation, urbanization and pollution are also mankinds' handiwork which impacts the climate. Do you know how these items can change the weather?

Prevailing Wind- Because the Earth rotates and is unevenly heated, wind tends to move in major belts of air in large convection currents. Convection is 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.

Global winds push everything from air masses, airplanes to tropical birds. The most intense solar rays hit the equator causing moist, warm air to move upwards off the earth. Low pressure means lots of rain. The air then cools and sinks at the 30 degree latitude belt (Hadley Cell) only to rise again at the _______ latitude (forming a Ferrel Cell) 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 ___________.

Surface winds cause ocean currents to flow in certain directions while deep sea currents are driven by density differences from temperature variations.

THE CORIOLIS EFFECT

The Coriolis effect is what causes winds and ocean currents to bend to the _________ as they move through the Northern hemisphere and to the left in the Southern Hemisphere.

It happens because the Earth rotates at different ____________ at different latitudes.

The Coriolis effect is caused by the ___________ of the Earth.

 

Air composition

  • ____________- 78%
  • Oxygen- 21%
  • Ozone- <<<1%

(And now for greenhouse gases)

  • Water Vapor- 0-4%
  • Carbon dioxide- <<1%
  • Methane- <<<1%
  • Nitrous Oxide- <<<1%

The Atmosphere has four distinct layers.

________________ (roughly 10 km up)

  • The layer closest to earth. Holds 75% air mass.
  • Gets __________ with altitude
  • Weather happens here, also only layer with water

Stratosphere

  • The top of the stratosphere contains ___________- O3
  • Temperature _____________ with altitude because of UV absorption
    • Ozone absorbs high level UV radiation from the sun. Less UV light hits the Earth.
    • Excessive UV light on the Earth causes skin ___________, cataracts and mutates and kills plankton (the ocean's bread basket).
  • Ozone is caused by UV light and lightning.

Mesosphere

  • Temperature ______________ with height
  • The home of ice clouds and burning meteors.

Thermosphere

  • This layer heats up from gamma rays, X-rays and UV light.
  • Highly ionized gas interacts with magnetosphere to create __________ borealis (Northern Lights)!

 

weather with an attitude

The Coriolis effect causes low pressure systems to spin inwards in a __________ direction. Weather conditions can be very, very unpleasant.

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 ___________.

Why are their no hurricanes in Panama?

Tornadoes- a mini cyclone that begin when the jet streams shear off the top of an especially large _____________ cloud. 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 Weather Changes

____________- 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.

Jet Streams are high altitude, fast moving air currents that push air masses around and when not operating properly can cause a ruckus in the natural state of affairs. Do you remember the 2014 winter snow fall?

 

Changes to the weather after many seasons

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 _____ and Washington is ______

El Nino- ENSO: El Nino Southern Oscillation, occurs every 3-7 years. Used to last 2 weeks to a month, now typically lasts a year!!!

  • 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 several years ago :(