Chapter 4

Distances of layers of the atmosphere

Thermosphere - 480 km Mesosphere - 80 km Stratosphere - 50 km Troposphere - 16 km

Three primary causes of unequal heating of the earth by the sun

Variation in the angle at which the Sun's rays strike the Earth, Variation in the amount of surface area over which the Sun's rays are distributed, Some areas of Earth reflect more solar energy than other

The prevailing winds of the world are produced by

a combination of atmospheric convection currents and the Coriolis effect o If the Earth did not rotate, the air within each convection cell would simply move directly north or south and cycle back again

Latent Heat Release

o When water vapor in atmosphere condenses into liquid water, energy is released o Means that whenever water vapor in the atmosphere condenses, the air will become warmer, and this warm air will rise

Polar Cells

these convection currents are formed by air that rises at 60 degrees North and South and the poles (90 degrees North and South) - At 60 degrees North and South, the rising air cools, and the water vapor condenses into precipitation - The air dries as it moves toward the poles, where it sinks back to the Earth's surface - At the poles, the air moves back toward 60 degrees North and South, completing the cycle

Mesosphere

third most atmospheric layer

Permafrost

underlying subsoil that is an impermeable, permanently frozen layer that prevents water from draining and roots from penetrating; in Alaska, telephone poles tip because as it melts, they tilt; trees work the same way (drunken forests); put Styrofoam in ground to insulate heat to prevent the permafrost from melting; Due to climate change, the temperature of permafrost is getting warmer (it should be the coldest)

Weather

what you get (Short Term)

Explain how thermohaline circulation works

- The sinking of dense, salty water in the North Atlantic drives a deep, cold current that moves slowly around the world - Warm water flows from the Gulf of Mexico to the North Atlantic, where some of it freezes and evaporates - The remaining water, now saltier and denser, sinks to the ocean bottom - The cold water travels along the ocean floor, connecting the world's oceans - The cold, deep water eventually rises to the surface and circulates back to the North Atlantic

Formation of Convection Currents

1. At the ITCZ (intertropical convergence zone) the Sun heats the moist, humid air; this decreases its density and causes it to rise 2. The rising air experiences lower atmospheric pressures and adiabatic cooling, which causes water vapor to condense into rain and fall back into Earth 3. The condensation of water vapor produces latent heat release. This latent heat release offsets some of the adiabatic cooling and causes the air to expand and rise farther up into the atmosphere 4. But as warmer air rises from below, this cold, dry air is displaced horizontally both north and south of the equator and eventually begins to sink back to the Earth's surface at approximately 30 degrees North and South 5. As the air sinks, it experiences higher atmospheric pressures and its reduction in volume causes adiabatic heating. By the time it reaches the Earth's surface, it is hot and dry; Much of this desert air then moves along Earth's surface toward the equator to replace the air that is rising there, completely the cycle.

Prevailing Wind Directions in the polar regions

Air movement is deflected to the west because the polar cells move air away from the poles and toward 60 degrees latitude and the Earth is rotating faster at 60 degrees - Because of this, polar winds come out of the northeast in the Northern Hemisphere and out of the southeast in the Southern Hemisphere (these winds are called easterlies)

Thermohaline Circulation

Another oceanic circulation that drives the mixing of surface water and deep water Scientists believe this is crucial for moving heat and nutrients around the globe

Southeast trade winds

As air travels along Earth's surface toward the equator, Earth's speed increases, which causes the air movement toward the equator to be deflected to the west which causes the air movement of the Hadley cell south of the equator to produce prevailing winds that come from the southeast

Northeast trade wins

As air travels along Earth's surface toward the equator, Earth's speed increases, which causes the air movement toward the equator to be deflected to the west; this causes the Hadley cell north of the equator to produce prevailing winds along Earth's surface that come from the northeast

What causes the Coriolis Effect and what is it?

Because all locations on Earth complete one revolution every 24 hours, and because Earth has a greater circumference near the equator than near the poles, its speed of rotation is much faster at the equator than near the poles This causes the Coriolis Effect = the deflection of objects due to Earth's rotation - Faster rotation speeds closer to the equator cause a deflection of objects that are moving directly North or South

Westerlies

Closer to 30 degrees, air tends to move along Earth's surface away from the equator since the Earth is rotating faster at 30 degrees than at 60 degrees, this air movement is deflected to the east Combined effect of the air currents and the Coriolis effect causes regions in the NH to experience winds (westerlies) from the south west and regions in the SH to experience winds (westerlies) from the northwest

Boreal Forest

Cold temperature, short season • Mainly conifers • Growth limited by temperature not by precipitation • Just south of the tundra • 2 seasons - July and Winter

Density of air

Density of air determines its movement o Less dense air rises o Denser air sinks o At a constant atmospheric pressure, warm air has a lower density than cold air; therefore: warm air rises and cold air sinks

Mean Annual Net Radiation

Effects of incoming and albedo (outgoing) - As you move outwards, more solar energy is being reflected (outgoing energy) - High latitudes - energy deficit - Poleward - heat transfer moves surplus energy from lower to higher latitudes - Equator (warm air rises, flows to poles) advection poles (cold air falls, flows to lower pressures) equator (and the cycle continues)

Name some comparable climates

Moscow and AA China and DC Phoenix and Cairo Scotland and Seattle

Heat Transport; what is it and give an example =

Ocean currents can affect the temperature of nearby land masses For example, the ocean current known as the Gulf Stream originates in the tropics near the Gulf of Mexico and flows northeast across the Atlantic Ocean toward western Europe; as it transports warm tropical waters northward, the Gulf Stream brings vast amounts of heat energy to cooler regions, moderating temperatures in latitudes that would otherwise be much colder

Examples of Rain Shadows

Olympic Peninsula and Cascade Mountain Range in Washington State Hawaii (the main island)

Explain the water and slope of the tropics

Tropics receive most sunlight and thus their waters are generally warm; this warm water, like warm air, expands and rises. This raises the tropical surface about 8 cm higher in elevation than mid-latitude waters; this slight slope is sufficient for the force of gravity to make water flow away from the equator

Upwelling

Upward movement of water toward the surface - Along the west coasts of most continents, for example, the surface currents diverge and cause the upwelling of deeper and more fertile water; this supports large populations of producers which support large populations of fish that have long been important to commercial fisheries

Pipelines in Alaska

above ground; radiators take heat from it and pass it upward so permafrost doesn't melt; goes in snake patterns and doesn't attach to cross bars because of expansion/contraction and earthquakes

Freshwater wetlands

aquatic biomes that are submerged or saturated by water for at least part of each year, but shallow enough to support emergent vegetation through out; they support species of plants that are specialized to live in submerged or saturated soils

Adiabatic cooling

as air rises higher in the atmosphere, the pressure on it decreases. The lower pressures allows the rising air to expand in volume, and this expansion lower the temperature of the air

Third area of air circulation

between the Hadley and the polar cells - Air circulation is driven by the circulation of the Hadley and Polar cells - Wind direction can be quite variable

Streams and rivers

characterized by flowing fresh water that may originate from underground springs as runoff from rain or melting snow; fast moving streams and rivers typically have stretches of turbulent water called rapids, where water and air are mixed together

Patterned ground

collapsed ground

Lakes and ponds

contain standing water; at least some of the standing water is too deep for emergent vegetation to grow

Air has 4 properties that determine its movement

density, water vapor capacity, adiabatic heating/cooling, latent heat release

Orbit is more circular not more....

elliptical; so seasons isn't about where you are in the orbit (i.e. - the farther you are from the sun, the less sunlight you get and that's winter) but if your hemisphere is titled toward or away from the sun

Salt marshes

found along the coast in temperate climes; they contain non-woody emergent vegetation; one of the most productive biomes in the world; many are found in estatuaries

Coral reefs

found in warm, shallow water beyond the shoreline, represent Earth's most diverse marine biome; when a coral digest the food it captures, it releases CO2 and nutrients...the alge use the CO2 during photosynthesis to produce sugars; the nutrients stimulate the agae to release their sugars to the coral and the coral gains energy in the form of sugars; are suffering because of coral bleaching (occurs when algae die inside the corals)

Thermosphere

fourth most atmospheric layer o Blocks UV radiation and harmful X-rays o Where auroras occur; it contains gas molecules that, when hit by solar energy, begin to glow and produce light, in the same way that a light bulb glows when electricity is applied.

Atmosphere

gaseous envelope surrounding the Earth o Made up of a series of connecting 'layers' o Held down by gravity o Most of its mass is near the surface (density of air decreases with altitude) o Earth radius = 6400 km Atmosphere = 99% below 30 km (2 minutes flying straight up in a jet)

Atmospheric convection currents

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

Auroras

glowing, moving lights that are visible at high altitudes in both hemispheres are the product of solar radiation energizing the gases of the thermosphere

What do Gyres redistribute?

heat in the ocean - cold water from the polar regions moves along the west coasts of continents and the transport of cool air from immediately above these waters causes cooler temperatures on land - warm water from the tropics move along the east coasts of continents, and the transport of warm air from immediately above these waters causes warmer temperatures on land

Concern about global warming with relation to thermohaline circulation

is that increased air temperatures could accelerate the melting of glaciers in the NH, which could make the waters of the North Atlantic less salty and less likely to sink; this could shut down the thermohaline circulation and stop the transport of warm water to western Europe, making it a much colder place

Gyres

large-scale patterns of water circulation o Each of the 5 major ocean basins contains a gyre driven by trade winds in the tropics and the westerlies in the mid-latitudes o The result is a clockwise circulation pattern in the NH and a counter-clockwise circulation pattern in the SH

Troposphere

lower-most atmospheric layer o Temperature decreases by 6.4 degrees Celsius (average) per 1000 m in the troposphere o Densest layer of the atmosphere (because gravitational pull weakens as we move father way from the Earth, molecules are more densely packed closer to Earth and less densely packed farther from Earth) o Lots of circulation and mixing of liquids and gases o Where Earth's weather occurs oBounded by the tropopause Immediately above is the stratosphere in which the temperature increases with altitude and a prevalence of ozone absorbs UV radiation

Intertidal zones

narrow band of coastline that exists between the levels of high tide and low rids

some areas of Earth reflect more solar energy than other; what is this called?

o Albedo = the percent of sun's light that is reflect o Earth's average = 30% o Asphalt = 5-10% o Fresh snow = 80-95% o Forest = 10-20% o Water = 10-60% (depends on Sun's angle) o Sea Ice = 50-90%

El Nino - Southern Oscillation

o Every 3-7 years, the interaction of the Earth's atmosphere and ocean cause surface currents in the tropical Pacific Ocean to reverse direction During most years, trade winds push surface water from east to west; deep water moves upward (upwelling) to replace surface water that has moved westward During El Nino years, trade winds weaken or reverse direction; warm surface water moves from west to east; the warm surface builds up along the coast of South America and prevents upwelling of the deep cold water

Explain why there is variation in the angle at which the Sun's rays strike the Earth

o The Sun's rays travel a shorter distance through the atmosphere to reach Earth's surface at the equator o Therefore, more solar energy reaches the equator than the mid-latitude and polar regions because more solar energy is lost as it passes through the atmosphere

Water Vapor Capacity

o Warm air has higher capacity for water vapor than cold o That's why hot summer days are associated with high humidity: the warm air contains a lot of water vapor o Saturation point is the maximum amount of water vapor that can be in the air at a given temperature o When the temperature of air falls, its saturation point decreases, water vapor condenses into liquid water, clouds form, and precipitation occurs

Explain why there is variation in the amount of surface area over which the Sun's rays are distributed

o When sunlight strikes 90 degrees (equator) there is more solar energy over a smaller surface area there than at higher latitudes; thus tropical regions receive more solar energy per square meter than mid-Latitude and polar regions o When it strikes at an oblique angle, solar energy is spread over large surface area (less concentrated)

Ocean Currents are driven by a combination of

o temperature, o gravity, o prevailing winds, o Coriolis effect, o and location of the continent

Mangrove swamps

occur along tropical and subtropical coasts; contain trees whose roots are submerged in water and are salt tolerant; provide sheltered habitat for fish and shellfish

Rain shadows

occur where humid winds blowing inland from the ocean meet a mountain range. On the windward (wind-facing) side of the mountains, air rises and cools, and large amounts of water vapor condense to form clouds and precipitation. On the leeward side of the mountains, cold, dry air descends, warms via adiabatic heating, and causes much drier conditions

Arctic oceans - get warmer when sea ice melts because of less reflection of solar energy, causing more ice to melt; is this a positive or negative thing?

positive thing

Example of a local feature that affects climate

rain shadows

Aquatic Biomes are characterized by

salinity, depth, and water flow

Stratosphere

second most atmospheric layer o Higher altitudes are warmer than lower altitudes because UV radiation reaches the higher altitudes first and warms them o Ozone forms a layer within the stratosphere

Variations in Climate Determine

the Dominant Plant Growth forms of Terrestrial Biomes

Intertropical convergence

the area of the earth that receives the most intense sunlight, where the ascending branches of the 2 Hadley cells converge - Typified by dense clouds and intense thunderstorm activity - Latitude where it's located is not fixes; moves north and south of the equator, following the path of the Sun's most direct rays

Hadley cells

the convections currents that cycle between the equator and 30 degrees North and South

Open Ocean

the deeper water, where no sunlight can reach the ocean bottom; can be divided into several distinct zones

Why do we have seasons?

the tilt of the Earth! Earth's axis tilt = 23.5 degrees

Climate

what you expect (Long Term) ; average over a period of time

Adiabatic heating

when air sinks towards Earth's surface, the pressure on it increases. The higher pressure forces the air to decrease in volume and this decreases the temperature of the air

Subtropical Dessert

• 30 degrees North and South with hot temperatures and extremely dry • Cacti and succulent (water retaining) plants are well adapted • High temperatures • 0 precipitation

Tropical Rainforest

• Average annual temperature > 68 degrees F • Greatest biodiversity • Has about 2/3 of terrestrial species (why they must be preserved)

Temperate Rainforest

• Coastal, mild, wet, long growing season, very large trees • Moderate temperature and really wet, high productivity forest with moss and trees • Cascades, South America, New Zealand, some in Australia

Woodland

• Hot dry summers • Mild rainy winters • "Mediterranean climate" • 12 month growing season but summer is limited by precipitation • Common in San Fran • Wildfires are common

Tundra

• Low annual temperature and low annual precipitation • Treeless • Frozen soil • Short growing season • Highest mountain ranges also • Examples: Himalayas, Andes, Sierras, Greenland • As earth warms, trees in Alaska will be able to grow in areas of Tundra (Tundra biome is decreasing)

Temperate Seasonal Forest

• Lower precipitation • Broadleaf deciduous trees • Warm Summers • Nutrient rich soils

Temperate Grassland/Cold Dessert

• Lowest precipitation of any temperate biome • Cold harsh winters • Hot dry summers • Plants constrained by cold in winter • Lack of precipitation in summer

List the processes that affect weather and climate on a global scale

• Unequal heating of Earth by the Sun • Atmospheric Convection Currents • Rotation of the Earth • Earth's orbit around the Sun on a tilted axis • Ocean currents

Tropical Seasonal Forest/Savanna

• Very warm and dry winters • Some rain in summer • Grasses and scattered deciduous trees • Can be farmed due to fertile soils but precipitation is low