APES Atmospheric and ocean circulation; El Nino/La Nina

Nitrogen (N2)

The most abundant gas in Earth’s atmosphere. ~80%

Oxygen (O2)

The second most abundant gas in Earth’s atmosphere. ~20%

Argon (Ar)

The third most abundant gas in Earth’s atmosphere. ~1%

Carbon Dioxide (CO2)

The fourth most abundant gas in Earth’s atmosphere, and the most abundant greenhouse gas. ~0.038%

Neon, Helium, Methane, Water vapor, Krypton, hydrogen, xenon, ozone

Trace gases found in Earth’s atmosphere. Not very abundant.

Relative humidity

Measurement of the relative abundance of water vapor. Decreases with temperature, as hot air can hold more water.

Exosphere

>400 km. Contains rockets.

Thermosphere

80-400 km. Contains satellites, meteors, and auroras. 

Mesosphere

50-80 km. Contains weather balloons

Stratosphere

10-50 km. Contains ozone layer and supersonic jets.

Troposphere

0-10 km. Contains weather, planes, mountains, and life on Earth.

Transitions between atmospheric layers

Defined by changes in temperature trend (ex: going from increasing to decreasing or decreasing to increasing)

Earth’s tilt

~23.5 degrees. Causes seasons due to uneven concentrations of solar radiation (more concentrated at equator)

Earth’s rotation

West to east, counterclockwise if observed from north pole.

Angle of incidence of solar radiation

Decreases at higher latitudes, highest at the equator. Directly correlates with solar radiation concentration, which correlates with air temperature.

Weather

Local atmospheric conditions at a specific time

Climate

Weather patterns averaged over a long time (30 years at least)

Altitude effect on climate

Increasing _______ (ex: going up a mountain) decreases temperature

Latitude effect on climate

Increasing ___________ (ex: traveling to the north pole) decreases temperature

Ocean and large lakes effect on climate

Help moderate weather conditions as wind blows off of these inland remains relatively constant temperature. 

Mountains/topography effect on climate

Create rain shadows (dry regions) on their leeward sides as wind blows over them and is dried out, causing precipitation on the other side. (Relative humidity decreases as temperature decreases, causing precipitation!)

Wind currents effect on climate

These encircle the Earth and redistribute heat around it. 6 main ones.

Lake effect

Causes snow formation as cold air blows over _____, which causes clouds to form and deposit snow on the leeward side (where the wind is blowing to)

Low pressure zone

Area where air is heated and rises (ex: near the equator). Higher precipitation, causes forests.

High pressure zone

Area where air cools and sinks down to the Earth’s surface (ex: 30 degrees N/S). Lower precipitation, causes deserts.

Convection cells

Circular movement of air between latitudes, rising and falling. (0-30, 30-60, 60-90)

Coriolis Effect

Powered by Earth’s rotation which causes deflection of winds. In the northern hemisphere, causes rightward deflection. In the southern hemisphere, causes leftward deflection.

Typhoon/hurricane directions

In the northern hemisphere: counterclockwise. Southern: clockwise.

Thermohaline circulation

Describes how ocean currents move around the world. Driven by density differences in water (ex: salinity (more salty near equator) and temperature (more hot near equator))

Gyres

Circular surface ocean currents. Clockwise in northern hemisphere, counterclockwise in southern hemisphere.

Coastal upwelling

Areas where cold currents run near coastlines, creating nutrient rich zones of high productivity as nutrients are brought up from the seafloor. Also occur where wind is blowing water out to sea. Good for fisheries.

El Nino

Results from a weakening or even reversed trade winds. Pacific becomes warmer, E. Pacific becomes warmer and drier, W. Pacific becomes warmer and wetter. Typically occur every 3-5 years. Decreases S. American upwelling.

La Nina

Results from strengthened trade winds. Pacific becomes cooler, E. Pacific becomes cooler and wetter, W. Pacific becomes cooler and drier. Increases S. American upwelling.