APES Chapter 4

Atmospheric convection currents

Global patterns of air movement that are initiated by the unequal heating of Earth.

Regions at 30 degrees N and S are typically?

Hot, dry deserts

Intertropical convergence zone (ITCZ)

The area of Earth that receives the most intense sunlight, where the ascending branches of the two Hadley cells converge. It's typified by dense clouds and intense thunderstorm activity.

Climate

The average weather that occurs in a given region over a long period

What is the fifth global process that influences weather and climate?

The circulation of ocean waters, both at the surface and in the deep ocean.

Hadley cells

The convection currents that cycle between the equator and 30N and S

Coriolis effect

The deflection of an object's path due to Earth's rotation

Saturation point

The maximum amount of water vapor that can be in the air at a given temperature.

El Nino

The movement of warm water and air toward South America suppresses upwelling off the coast of Peru and decreases productivity there, reducing fish populations near the coast. Occurs every 3 to 7 years.

Albedo

The percentage of incoming sunlight that is reflected from a surface.

Easterlies

The polar winds come out of the northeast in the Northern Hemisphere and out of the southeast in the Southern Hemisphere.

Windward

The side facing the wind

What layers are beyond the stratosphere?

the mesosphere, thermosphere, and exosphere. Given the weaker gravitational pull on molecules at these greater distances from Earth, the atmospheric pressure and density in each of these layers decreases as it extends out into space. The thermosphere is particularly important to organisms on Earth because of its ability to block harmful X-ray and UV radiation. It also contains charged gas molecules that, when hit by solar energy, begin to glow and produce light. These glowing gases are known as the northern lights, or aurora borealis.

Rain shadow

the now warm, dry air produces arid conditions on the leeward side of the range, forming the rain shadow region.

Leeward side

the other side of the mountain range

How fast does the Earth's surface move per hour?

1,670 km per hour.

Uneven warming of the Earth's three main primary causes

1. variation in the angle at which the Sun's rays strike Earth. 2. Variation in the amount of surface area over which the Sun's rays are distributed. 3. Some areas of Earth reflect more solar energy than others.

Tropical regions have an average albedo of?

10 to 20%

What is the tilt of Earth's axis of rotation?

23.5 degrees

What is the average albedo or Earth?

30%

Snow-covered polar regions have an average albedo of?

80 to 95%

Stratosphere

Above the troposphere, which extends roughly 16 to 50 km above Earth's surface. It is less dense than the troposphere. Because UV radiation reaches the higher altitudes first and warms them, the higher altitudes are warmer than the lower altitudes. Ozone forms a layer within the stratosphere, which absorbs most of the Sun's ultraviolet-B (UV-B) radiation and all of its ultraviolet-C (UV-C) radiation.

Thermohaline Circulation

Another oceanic circulation pattern that drives the mixing of surface water and deep water. Scientists believe this process is crucial for moving heat and nutrients around the globe. It appears to be driven by surface waters that contain unusually large amounts of salt. It helps to mix the waters of all the oceans.

Adiabatic cooling

It's response to changes in pressure. Ex. As air rises the pressure decreases. The lower pressure allows the rising air to expand in volume, and this expansion lowers the temperature of the air.

Gyres

Large-scale patterns of water circulation. They redistribute heat in the ocean (cold water from polar regions moves along the west coast of continents, warm waters from the tropics moves along the east coasts of continents).

December Solstice

The Northern Hemisphere is maximally tilted away from the Sun and experiences the shortest day of the year. Winter begins in the Northern Hemisphere. Summer begins in the Southern Hemisphere.

June solstice

The Northern Hemisphere is maximally tilted toward the sun and experiences the longest day of the year. summer begins in the Northern Hemisphere. Winter begins in the Southern Hemisphere.

September Equinox

The Sun is directly overhead at the equator and all regions of Earth receive 12 hours of daylight and 12 hours of darkness. Fall begins in the Northern Hemisphere. Spring begins in the Southern Hemisphere.

Troposphere

The layer closest to the Earth's surface. It extends roughly 16 km above Earth. It's the densest layer of the atmosphere: most of the atmosphere's nitrogen, oxygen and water vapor occur in this layer. It can be characterized by a great deal of circulation and mixing of liquids and gases, and it's the layer where Earth's weather occurs.

March equinox

The sun is directly overhead at the equator and all regions of Earth receive 12 hours of daylight and 12 hours of darkness. Spring begins in the Northern Hemisphere. Fall begins in the southern hemisphere.

Westerlies

The winds made from the combined effect of the air currents and the Coriolis effect cause regions just north of 30 degrees to experience prevailing winds from the southwest. In the Southern hemisphere, the prevailing winds are from the northwest.

Polar cells

These convection currents are formed by air that rises at 60N and S and sinks at the poles (90N and S).

Adiabatic Heating

When air sinks towards Earth's surface, the pressure increases. The higher pressure forces the air to decrease in volume, and this decrease raises the temperature of the air.

latent heat release

When water vapor in the atmosphere condenses into liquid water, energy is released.

Upwelling

Where the surface currents diverge/separate from one another, causing deeper waters to rise an replace the water that has moved away. The upward movement of water toward the surface is the upwelling. The deep waters bring with them nutrients from the ocean bottom that support large populations of producers.

What are the properties of air?

density, water vapor capacity, adiabatic heating or cooling, and latent heat release.

The density of air determines?

it's movement: less dense air rises, whereas dense air sinks. War air also has a higher capacity for water vapor.