APES CHAPTER 4 REVIEW

WEATHER

short term conditions of the atmosphere in a local area. these conditions include: - temperature - humidity - clouds - precipitation - wind speed - atmospheric pressure

IN WHAT WAYS ARE ATMOSPHERIC AND OCEANIC CIRCULATION PATTERNS SIMILAR? HOW ARE THEY DIFFERENT?

similar because they both move by the earth's rotation and heating causes currents in both patterns different because in the atmosphere there are winds and cells and in the ocean there are hot/cold currents and upwelling

DESCRIBE THE FORMATION OF HADLEY CELLS

solar energy warms humid air in the tropics. the warm air rises and eventually cools below its saturation point. the water vapor it contains condenses into clouds and precipitation. the now dry air sinks to earth's surface at approximately 30 degrees N and S. as the air descends it is warmed by adiabatic heating. this descent of hot, dry air causes desert environments to develop at those latitudes. 1. at the ITZC, the sun heats moist tropical air causing it to rise 2. the rising air experiences adiabatic cooling, which causes water vapor to condense into rain and fall back to earth 3. the condensation of water vapor produces latent heat release. this causes the air to expand and rise farther up into the atmosphere 4. the warm rising air displaces the cooler, drier air above it to the north and south 5. the cool, dry air sinks and experiences adiabatic heating. it reaches earth's surface as warm, dry air, and then flows back towards the equator

ITCZ (INTERTROPICAL CONVERGENCE ZONE)

the area of the earth that receives the most intense sunlight, where ascending branches of the two cells converge. it is typified by dense clouds and intense thunderstorm activity. the latitude along which the ITCZ is located is not fixed. instead over the course of a year, it moves north and south of the equator, following the path of the sun's most direct rays. because the earth's axis of rotation is tilted, the area receiving the most intense sunlight shifts between approximately 23.5 degrees N and 23.5 degrees S as the Earth orbits the sun. as a result, the tropics experience seasonal patterns of precipitation.

WHAT THREE PHENOMENA CAUSE WIND PATTERNS WORLDWIDE?

the atmospheric convection currents of tropical and polar latitudes, the mixing of air currents in the mid-latitudes and the Coriolis effect cause the prevailing wind patterns that occur worldwide, although local features, such as mountain ranges, can alter wind directions significantly.

CLIMATE

the average weather that occurs in a given region over a long period - typically several decades

CORIOLIS EFFECT

the deflection of an object's path due to the earth's rotation. as the earth rotates, its surface moves faster at the equator than in mid-latitude and polar regions earth's surface moves at 1,670 km per hour at the equator and 1,445 km per hour at 30 N or S and 291 km per hour at 80 N or S the prevailing wind systems of the world are produced by a combination of atmospheric convection currents and the Coriolis effect explains the prevailing wind directions between 30 and 60 degrees. closer to 30 degrees, the air tends to move along earth's surface away from the equator. given that the air is rotating faster at 30 than at 60 the air is deflected to the east. helps us understand the prevailing wind directions in the polar regions. at the earth's surface, polar cells move air away from the poles and towards 60 degrees latitude. given that the earth is rotating faster at 60 than at 90, the air movement is deflected to the west.

WHAT DOES AIR DENSITY DO?

the density of air determines its movement: less dense air rises, whereas denser air sinks. at a constant atmospheric pressure, warm air has a lower density that cold air. because of this density difference, warm air rises.

TROPOSPHERE

the layer closest to the earth's surface. extends roughly 16 km above earth. the densest layer of the atm (most of the atm's nitrogen, oxygen, and water vapor occur in this layer). characterized by a great deal of circulation and mixing of liquids and gases, and it is the layer where earth's weather occurs. air temp. in this layer decreases with distance from earth's surface and varies with latitude. temp. can fall as low as -52 degrees celsius near the top.

SUMMARIZE HOW THE EARTH'S OCEANS HELP REGULATE TEMPERATURE ON THE PLANET

the ocean current known as the gulf stream originates in the tropics near the gulf of mexico and flows northeast across the atlantic ocean towards western europe. as it transports warm tropical waters northward the gulf steam brings vast amounts of heat energy to cooler regions, moderating temperatures latitudes that would otherwise be much colder

ALBEDO

the percentage of incoming sunlight that is reflected from a surface

WHAT EFFECT DOES THE EARTH'S ROTATION HAVE ON ATMOSPHERIC CIRCULATION AND OCEAN CURRENTS?

the rotation causes the water to flow east and west.

KEY IDEAS

- the processes that affect heat and precipitin around the globe are unequal heating of earth by the sun, atmospheric convection currents, the rotation of the earth, earth's orbit around the sun on a tilted axis, and ocean currents - 4 layers of earth's atmosphere are the troposphere, stratosphere, mesosphere, and thermosphere. the exosphere is space - different types of ocean currents are gyres, upwelling, thermohaline circulation, heat transport, and ENSO (el nino southern oscillation)

LATENT HEAT RELEASE

- the production of heat when water vapor condenses from a gas to a liquid when water vapor in the atmosphere condenses into liquid water, energy is released. important because it means that wherever water vapor in the atmosphere condenses, the air will become warmer and this warm air will rise.

WHAT ARE THE 3 CAUSES OF UNEQUAL WARMING/HEATING OF THE EARTH?

1. variation in the angle at which the sun's rays strike the earth. in the tropics (the region nearest to the equator) the sun strikes at a perpendicular or right angle. in the mid latitude/polar regions, the sun's rays strike at a more oblique angle. as a result the sun's rays travel a shorter distance through the atmosphere to reach earth's surface in the tropics. because solar energy is lost as it passes through the atmosphere, more solar energy reaches the equator than the mid-latitude and polar regions. 2. variation in the amount of surface area over which the sun's rays are distributed. the perpendicular angle of the sun's rays in the tropics causes solar energy to be distributed 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. 3. some areas of the earth reflect more solar energy than others. the higher the albedo of a surface, the more solar energy it reflects and the less it absorbs. a white surface area has a higher albedo than a black one so it tends to stay cooler

WHICH OF THE BELOW IS AN EXAMPLE OF WEATHER? A. A LARGE AREA CHANGES FROM A GRASSLAND TO A DESERT B. WHILE CLIMBING A MOUNTAIN, ONE MOVE THROUGH SEVERAL DIFFERENT BIOMES C. A THUNDERSTORM FORM AND DROPS 1.5 CM OF RAIN D. INCREASED GREENHOUSE GASES IN THE ATMOSPHERE CAUSE ATMOSPHERIC WARMING E. DESERTIFICATION OF AN AREA CAUSES THE AREA TO SEE INCREASED ANNUAL TEMPERATURE

C. A THUNDERSTORM FORM AND DROPS 1.5 CM OF RAIN

EXPLAIN THE FORCES THAT DRIVE GLOBAL CIRCULATION PATTERNS AND HOW THOSE PATTERNS DETERMINE WEATHER AND CLIMATE

Global climate patterns are driven by a combination of unequal heating of Earth by the Sun, atmospheric convection currents, the rotation of Earth and the Coriolis effect, Earth's orbit around the Sun on a tilted axis, and ocean currents. The unequal heating of Earth is the driver of atmospheric convection currents. These air circulation patterns are further modified by the deflecting action of the Coriolis effect. The tilt of Earth's axis of rotation causes seasonal changes in temperature and precipitation as Earth orbits the Sun. Ocean currents are driven by a combination of temperature, gravity, prevailing winds, the Coriolis effect, and the locations of continents. Together, prevailing winds and ocean currents distribute heat and precipitation around the globe.

WHAT ARE THE 5 PROCESSES THAT DETERMINE CLIMATE?

REGIONAL DIFFERENCES IN TEMPERATURE AND PRECIPITATION COLLECTIVELY HELP DETERMINE WHICH ORGANISM CAN SURVIVE IN EACH REGION. - to understand this we need to look at the processes that affect the distribution of heat and precipitation across the globe. these processes include: - the unequal heating of the Earth by the Sun - atmospheric convection currents - the rotation of the Earth - Earth's orbit around the sun on a tilted axis - ocean currents

WHAT IS THE DIFFERENCE BETWEEN WEATHER AND CLIMATE?

WEATHER: short term conditions of the atmosphere in a local area. these conditions include: - temperature - humidity - clouds - precipitation - wind speed - atmospheric pressure CLIMATE: the average weather that occurs in a given region over a long period - typically several decades

RAIN SHADOW

[SEE WINDWARD VS. LEEWARD FOR 1ST PART] this now warm, dry air produces arid conditions on the leeward side of the range, forming a region called a rain shadow. in tropical areas, rain shadows tend to be on the western side of the mountain range because of the prevailing trade winds moving from east to west. in mid-latitude zones, such as North America, rain shadows are commonly on the eastern sides of the mountain ranges because the prevailing westerlies move from west to east.

STRATOSPHERE

above troposphere. extends roughly 16 to 50 km above the earth's surface. because of its greater distance from the earth's gravitational pull, the stratosphere is less dense then the troposphere.in stratosphere, because UV radiation reaches higher altitudes first and warms them, the higher altitudes are warmer than the lower altitudes. ozone forms a layer within the stratosphere. ozone absorbs most of the sun's ultraviolet-C (UV-C) radiation.

THERMOHALINE CIRCULATION

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

HADLEY CELL

air near the top of the troposphere is chilled by adiabatic cooling.this air contains relatively little water vapor. as warmer air rises from below, this cold, dry air is displaced horizontally both north and south of the equator. this displaced air eventually begins to sink back to earth's surface at approximately 30 degrees N and S. as the air sinks it experiences higher atmospheric pressures and its reduction in volume causes adiabatic heating. by the time the air reaches the earth's surface, it is hot and dry. as a result regions at 30 degrees N and S are typically hot and dry deserts. much of this desert air then moves along earth's surface towards the equator to replace the air that is rising there, completing the cycle. the convection currents that cycle between the equator and 30 degrees N and S.

ADIABATIC HEATING

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

POLAR CELLS

convection currents that are formed by air that rises at 60 degrees N and S and sinks at the poles (90 degrees N and S). At 60 degrees N and S, 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 Earth's surface. at the poles, the air moves back toward 60 degrees N and S, completing the cycle.

LIST THE 4 PROPERTIES OF AIR

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

DESCRIBE NORMAL VS. EL NINO CONDITIONS IN THE TROPICAL PACIFIC OFF THE COAST OF PERU. WHAT EFFECTS DOES THIS HAVE ON WEATHER PATTERNS IN THE US AND SOUTH AMERICA?

first the trade winds near South America weaken. this weakening allows warm equatorial water from the western pacific to move eastward towards the west coast of south america. the movement of warm water and air towards south america suppresses upwelling off the coast of Peru and decreases productivity there, reducing fish populations near the coast. the impact of ENSO includes cooler and wetter conditions in the southeastern US and unusually dry weather in southern Africa and southeast Asia.

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

ATMOSPHERIC CONVECTION CURRENT

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

WESTERLIES

in the Northern Hemisphere, the combined effect of the Coriolis effect and the air currents causes regions just N of 30 degrees to experience prevailing winds from the southwest. in the southern hemisphere, the prevailing winds are from the northwest

GYRES

in the northern hemisphere, the trade winds near the equator push water from the northeast to the southwest and the Coriolis effect deflects this wind driven current so that water actually moves from east to west. when winds in the northern mid-latitude regions push water from the southwest to the northeast the Coriolis effect deflects this current so that the water actually moves from west to east. ocean surface currents rotate in a clockwise direction in the northern hemisphere and a counter-clockwise direction in the southern hemisphere. these large scale patterns of water circulation are called gyres. gyres redistribute heat in the ocean just as atmospheric convection currents redistribute heat in the atmosphere. cold water from the polar regions moves along the west coasts of the continents and the transport of cool air from immediately above these water causes cooler temperatures on land.

HOW ARE ATMOSPHERIC CONVECTION CURRENTS FORMED?

in the tropics, the warming of humid air at the earth's surface decreases its density. as a result the air begins to rise. when air rises it begins to experience lower atmospheric pressures and adiabatic cooling. the cooling causes the air to reach its saturation point. this leads to condensation, which causes cloud formation and precipitation. condensation also causes latent heat release, which offsets some of the adiabatic cooling and becomes a strong driving force to make the air expand further and rise more rapidly through the troposphere. these processes cause air to rise continuously from the earth's surface near the equator, forming a river of air flowing upward into the troposphere.

ENSO

occurs approximately every 3 to 7 years. these interactions cause surface currents in the tropical pacific ocean to reverse direction. called el nino because it often begins around the December 25 Christmas holiday. can last from a few weeks to a few years. it is a periodic change in winds and ocean currents.

UPWELLING

ocean currents also help explain why some regions of the ocean support highly productive ecosystems. along the west coasts of most continents, the surface currents diverge or separate from one another causing deeper waters to rise and replace the water that has moved away. the upward movement of water toward the surface. the deepwater bring with them nutrients from the ocean bottom that support large populations of producers. these producers in turn support large populations of fish that have long been important to commercial fisheries.

WHAT DRIVES OCEAN CURRENTS?

ocean currents are driven by a combination of temperature, gravity, prevailing winds, the Coriolis effect, and the locations of the continents

EASTERLIES

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

THERMOSPHERE

the thermosphere is important to life on earth because it can block harmful X-ray and UV radiation. the thermosphere also contains charged gas molecules that when hit by solar energy begin to glow and produce light (aurora borealis).

SATURATION POINT

warm air also has a higher capacity for water vapor than cold air. that is why hot summer days are associated with high humidity: the warm air contains a lot of water vapor. the maximum amount of water vapor that can be in the air at a given temperature increases with temperature. when air cools, its saturation point drops, water vapor condenses into liquid water that forms clouds. these clouds are ultimately the source of precipitation when the temperature of the air falls, its saturation point decreases and water vapor condenses into liquid water forming clouds and later resulting in precipitation.

WINDWARD VS. LEEWARD

when air meets the windward side of a mountain range, the side facing the wind, it rises and begins to experience adiabatic cooling. because water vapor condenses as air cools, clouds form and precipitation falls and this condensation then causes latent heat to release which helps to accelerate the upward movement of the air. thus the presence of a mountain range causes large amounts of precipitation to fall on the windward side. the cold dry air then travels to the other side of the mountain range, the leeward side, where it descends and experiences higher pressures, which cause adiabatic heating.

ADIABATIC COOLING

when air sinks towards the earth's surface, the pressure on it increases. the higher pressure forces the air to decrease volume and this decrease raises the temperature of the air.