GEOL 108 Final Exam Study Guide

What about supercell storms keeps them from dissipating as quickly as ordinary thunderstorms?

Because there are strong winds high above, that tilts the upper portion of the storm. Therefore, as the updraft comes in, it allows the down draft to shoot off the back. Therefore, they don't cut each other off and cancel each other out.

How do clouds form?

Clouds form when the invisible water vapor in the air condenses into visible water droplets or ice crystals. For this to happen, the parcel of air must be saturated, i.e. unable to hold all the water it contains in vapor form, so it starts to condense into a liquid or solid form.

In the Midwest, and across latitudes from 30 and 60 degrees, what is the direction of the prevailing wind? And how does this wind flow? a. West; west to east b. West; east to west c. East; west to east d. East; east to west

a. West; west to east

What are the layers of the atmosphere?

(From lowest altitude to highest altitude) 1. Troposphere 2. Stratosphere 3. Mesosphere 4. Thermosphere 5. Exosphere

What is the eye of a hurricane?

20-50km in diameter, marked by high pressure, air is sinking, very few clouds, and wind velocity is low

What is the eye wall of a hurricane?

A hurricane's most devastating region. Located just outside of the eye is the eye wall. This is the location within a hurricane where the most damaging winds and intense rainfall is found

What is the difference between a severe weather watch and warning?

A severe thunderstorm watch is issued by the National Weather Service in Norman, OK when the weather conditions are such that a severe thunderstorm is likely to develop: A severe thunderstorm warning is issued by local National Weather Service office (Detroit forecasts for Adrian) when a severe thunderstorm has been sighted or indicated by weather radar.

How does fog form?

A warm surface at night or early evening, IR radiation is given off by the planet's surface. As energy is being given off, water from soil is being carried up from the atmosphere. If the air is cold enough in the air, the cool air will cause the water to condense into clouds on the ground.

How do we name winds?

A wind is always named according to the direction from which it blows

How does wind flow geographically?

Air flows horizontally at top of the troposphere; horizontal flow is called advection. The air cools until it descends. Where it reaches the ground, it creates a high pressure zone. Air flowing from areas of high pressure to low pressure creates winds. (kind of unsure, am going to ask in the review)

How do air masses form?

Air masses form over large areas of flat land where there is little to no fluctuation in wind, humidity, temperature, and pressure.

What are some of the minor gases that make up Earth's atmosphere?

Ar, CO2, Ne, He, SO2, CH4 (methane), H2, O3 (ozone), and CFC's

What is the adiabatic process?

As air warms it expands. Expansion occurs from molecules moving in an outward direction. Outward movement decreases density of air and it rises. When air rises, the pressure within parcel decreases and the air molecules slow and cool. In simple terms, adiabatic cooling happens when air rises. The air will cool and condense. Adiabatic heating occurs as air falls.

How does hail lead to the production of lightning?

As hail is lifted and falls it collides with cloud droplets that cool instantly and release latent heat. Ions exchange between hail and ice crystals making the hail (-) and ice crystals (+). Ice crystals are lifted with updrafts and hail falls to lower portion of cloud. This stratifies the charges within a storm cloud.

How does the eye of a hurricane differ from the eye wall?

The eye of the hurricane has very high pressure, very few clouds, and a low wind velocity whereas the eyewall is very dangerous, has very high winds, horrible weather, and very low pressure.

What does it mean when the isobars on a weather map are closely spaced together?

The faster wind is blowing

In what ways does our Sun warm our atmosphere (Sun to atmosphere and ground to atmosphere)?

The heat energy from the Sun's rays hit the planet directly or indirectly, causing different types of warming to occur.

What is the Coriolis Force?

The pattern of deflection taken by objects not firmly connected to the ground as they travel long distances around Earth.

What is weather?

The state of the atmosphere at a place and time with regards to temperature, precipitation, wind, etc. Weather is short term

Where do the majority of gases reside in the atmosphere?

The troposphere

How do mid-latitude cylcones form?

They beegin as a stationary front sandwiched between two high pressure systems. Rotation begins as a result of shear movement. A low pressure system develops at the center of the shear as a cold front starts to push a newly developed warm front. The low intensifies as warm air is lifted and cold air pushes underneath. This along with latent heat of condensation gives energy to intensify the low pressure. Precipitation advances ahead of the warm front and forms "comma shape." Eventually the cold front catches the warm front and becomes an occluded front hitting its peak. Once the storm becomes even more occluded, the low is enveloped in cold air and is "starved."

Do hurricanes ever hit the west coast of the U.S.? Why or why not?

They do not hit the west coast of the United States. This is because warm water and wind direction are two of the biggest reasons why the Gulf Coast of the United States has so many hurricanes. On the west coast, the wind direction moves opposite that of the East Coast and the coastal waters are significantly colder as a result. Therefore, while it isn't entirely impossible, it is highly unlikely that a hurricane would happen on the West Coast because it doesn't have the proper conditions to fuel a large storm.

When do tornadoes occur most during the year, and during the day?

They occur most during the spring and summer months. They occur most often during the late afternoon/early evening of a day

What are tornadoes?

Tight counterclockwise (NH) rotating columns of air around a low pressure system. 100-600 m in diameter. Avg. storm speed 25-50 mph. Wind speed ranges 65 to 300 mph. Typically last a few minutes, but can last hours

Where are tornadoes worst in the U.S.?

Tornado Alley This area includes many midwest states; such as Kansas, Missouri, Texas, Illinois, Indiana, Oklahoma, Arkansas, Louisiana, and others

How do tornadoes form?

Tornadoes form when warm, humid air collides with cold, dry air. The denser cold air is pushed over the warm air, usually producing thunderstorms. The warm air rises through the colder air, causing an updraft. ... When it touches the ground, it becomes a tornado.

Where do tropical cyclones form?

Tropical cyclones form between 23.5˚ N and S with tropic winds moving from E to W.

True or False A hurricane has never made landfall on the west coast of the United States

True

True or False In a sea breeze, low pressure develops over land and high pressure develops over the sea during the summer and on hot days.

True

True or False Lightening requires hail and ice crystals to form so thunderstorms only develop when they grow large enough to reach freezing temperatures aloft

True

True or False Tropical cyclones are called Hurricanes in North America

True

How does pressure affect temperature?

Unsure of answer, asking in review

How does temperature affect pressure?

Unsure of answer, asking in review

How does pressure change with regard to temperature aloft and at the surface?

Unsure of answer. Will ask at the review

What are blizzards?

Violent snowstorm, common in the northeast, upper Midwest, and Great Plains of the United States. They have 35 mph+ winds, temperatures under 20 degrees Fahrenheit, decreased visibility to 400m (1/4 mile) due to blowing or falling snow, and they last for at least 3 hours.

What causes a tropical cyclone to build or dissipate?

Warm water is the primary ingredient for the growth of a tropical cyclone. When the storm system is over land, there is no water to help it grow causing it to dissipate.

What is lake effect snow?

When cold air blows over warm water causing snow to fall on the lee side of a lake

How do supercell thunderstorms form?

When environmental winds are favourable, the updraft and downdraft of a storm become organized and twist around and reinforce each other. The result is a long-lived supercell storm. These storms are the most intense type of thunderstorm.

When is relative humidity higher regarding dewpoint and air temperature?

When the dew point and the air temperature are closer, that will create a higher relative humidity.

What is the most abundant gas in the atmosphere? a. Nitrogen b. Oxygen c. Water d. Argon

a. Nitrogen

All of the following are ingredients required for the formation of a tropical cyclone, EXCEPT: a. Strong surface winds over the ocean b. Latitudes of between 5 and 20 degrees c. Warm water d. Low pressure

a. Strong surface winds over the ocean

How and why was New Orleans so terribly affected by Katrina?

1. 25 ft. storm surges 2. Most of the city lies 6.5 ft below sea level 3. Mississippi River and Lake Pontchartrain are both dammed with artificial levees and flood walls. 4. The city was not equipped with proper infrastructure to handle a disaster of this magnitude.

What are the two types of humidity discussed?

1. Absolute humidity: mass of water/volume of air 2. Relative humidity: absolute humidity/air's capacity for humidity or (dewpoint temperature/air temperature) * 100

What are the different types of air masses?

1. Arctic 2. Tropical 3. Polar 4. Equatorial

What types of severe weather can mid-latitude cyclones produce?

1. Gales (50 mph+ winds) 2. Blizzards 3. Thunderstorms 4. Tornadoes

What are the processes involved in changing states of matter?

1. Heating 2. Freezing 3. Condensation 4. Evaporation 5. Sublimation 6. Deposition

What are factors that can cause problems during evacuations?

1. High volume of citizens trying to evacuate 2. If you evacuate too late, could get caught in the storm or not be able to navigate flooded roads 3. Debris in the road 4. Road damage 5. Expensive 6. Storms are very unpredictable

What are the primary hazards associated with hurricanes?

1. Storm surge 2. Flooding 3. Rain 4. Tornado 5. Wind

Why does storm surge occur?

1. The atmospheric pressure pushing down on the water surface is less 2. Prolonged winds push sea water into huge mounds 3. The surge moves at the same speed as the storm

What forces affect wind flow?

1. The pressure gradient force (PGF) 2. The Coriolis Force 3. Friction 4. Gravity 5. Centrifugal Force

Why was Hurricane Katrina so devastating?

1. There was not as much notice to prepare for the storm because it did not develop from Easterly wave into a tropical depression until reaching the Bahamas. 2. 25 ft. storm surges 3. People and the government did not have time to evacuate or prepare properly

What are the two primary front types?

1. Warm Front 2. Cold Front

What are the ingredients for a hurricane?

1. Warm water (78-80 F) 2. Low pressure for uplift (the lower the pressure, the higher the wind speeds) 3. Light steering wind (too strong of winds will cause the storm to dissipate) 4. Coriolis affect (needs rotation to deepen low pressure and grow)

Besides gases, what else can be found in the Earth's atmosphere?

1. Water Vapor: 0-4% of atmosphere 2. Aerosols: suspended solid particles (3 nm to 3 μm) Sea salt, volcanic ash, clay dust, soot, viruses, bacteria, decaying organics, and pollen

How do the fronts differ?

Cold Fronts: 1. Steep 2. Rapid Pressure Increase 3. High Clouds 4. Short Rainfall Duration 5. Rapid Temperature Decrease 6. Winds Blow in Direction of Front Movement Warm Fronts 1. Shallow Slope 2. Gradual Pressure Decrease 3. Low Clouds at Front 4. Long Periods of Rainfall and High Humidity 5. Gradual Increase in Temperature 6. Winds Blow in Opposite Direction of Front Movement

What are the two ways rain forms?

Collision Coalescence: droplets collide and form larger drops Bergeron Process: Higher vapor pressure around water droplets forces H20 molecules towards ice crystals, thereby depleting water droplets and growing ice crystals. Liquid to gas to solid. High vapor pressure to low vapor pressure. Ice crystals may drop as snow flakes, ice pellets, sleet, and even rain. Useful chart in powerpoint

What should you do if you think you are about to get struck by lightning?

Cover your ears, crouch on the balls of your feet like a baseball catcher, and touch your heels together

How do ordinary thunderstorms form?

Developing stage: Moist, unstable air rises and a cumulus cloud builds. Mature state: Updrafts cause the cloud to billow higher and the storm begins. Downpours start downdrafts Dissipating Stage: Downdrafts cut off the supply of warm, moist air. Without field, the storm dissipates.

What is the difference between direct and inclined Sun rays?

Direct rays of sun occur when the Sun is directly overhead and strike perpendicular to the Earth's surface.. Indirect rays of sun occur when the Sun is NOT directly overhead and strike the Earth at some angle.

In general, are there more EF 1 tornadoes or more EF 5 tornadoes annually?

EF 1 Tornadoes are more common

Other than size, why was Hurricane Dorian so devastating to the Bahamas?

It hovered over the Bahamas for 3 days, resulting in paramount destruction. Several towns destroyed No power, no potable water, >9000 homes gone, and 7 schools. 5.1 Billion dollars in damage.

How do tropical cyclones form?

Easterly wave forms as wind converges over high pressure inland and then diverges over water. Light winds indicate that the ocean is warm and the air is saturated with water. Because of this, a low pressure system is created. This area of low pressure yields storm clouds, also known as a tropical disturbance. From there, the winds quicken to 23-39mph and the pressure to continue to lower creating a tropical depression. This depression then rotates as a result of the Coriolis effect. As the low pressure continues to deepen, wind speeds increase to 40-74mph creating a tropical storm. If the water temperature continues to stay warm and feed the storm, the low pressure system deepens, allowing wind speeds to surpass 74mph winds. Therefore, creating the conditions for a tropical cyclone to form.

What is always involved in the process of changing states of matter?

Energy

What scale talks about the intensity of tornadoes?

Enhanced Fujita scale

How does pressure create wind?

Even at similar elevations, the barometric pressure is not distributed evenly across the east. Therefore, we have wind. The air is attempting to equalize pressure.

True or False Earth's seasons are produced from its orbit around the Sun, and when we are closer to the sun, we have summer.

False

True or False You can have thunder without lightening

False

What type of wind occurs ABOVE the surface?

Geostrophic Winds: Happens when Pressure Gradient Force combines with the Coriolis Force

What are the global winds?

Global winds are winds that occur in belts that go all around the planet. Like local winds, global winds are caused by unequal heating of the atmosphere. Winds blow on a diagonal over the surface due to Coriolis effect.

What type of wind occurs AT the surface?

Gradient Wind is because of Pressure Gradient Force

What are the ways in which tornadoes and hurricanes differ? How are they similar?

I know the differences but just want to see what Mack says in class.

How do Atlantic Ocean cyclones form?

In the case of hurricanes that form in the Atlantic Ocean, the wind blowing westward across the Atlantic from Africa provides the necessary ingredient. As the wind passes over the ocean's surface across 23.5 degrees N and S, it interacts with very warm water, creating the perfect fuel for a cyclone to form. They need to form over large bodies of water. You need to have the Coriolis force to allow the storm to rotate and gain traction. This creates a rotating mass of thunderstorms. As long as low pressure remains over low water, the cyclone will develop as follows. Easterly wave ---> tropical disturbance ---> tropical depression---> tropical storm---> hurricane (this is really the same thing as the question of how to tropical cyclones form)

What are lines of equal pressure on a weather map?

Isobars

How does wind flow?

It blows from high-pressure areas to low-pressure areas

Why is the atmosphere constantly in a state of flux and change?

It is a very dynamic region constantly trying to achieve equilibrium regarding pressure, temperature, and humidity. Because of the constant reactions taking place and the addition of green house gases, the atmosphere is constantly changing and reacting to these new forces at play.

Why does Earth have four seasons?

It is because of the 23 ½∞ tilt of the Earth's rotational axis. It causes the angle that the Sun's rays hit the earth to change throughout the year. This in turn affects how efficiently the Earth's surface is heated.

How does thunder form?

Lightning instantly heats the air surrounding it to ~ 50,000∞F. The heat causes a violent expansion of the air and that expansion releases sound.

About how many tornadoes form in the U.S. every year?

More than 1200 tornadoes every year

What are the two major gases that make up Earth's atmosphere?

Nitrogen (78%) and Oxygen (21%)

What is the atmosphere composed of?

Nitrogen, Oxygen, Argon, Carbon DiOxide, Ne, He, SO2, CH4 (methane), H2, O3 (ozone), and CFC's

What hemisphere is facing the Sun when Adrian has summer?

Northern Hemisphere

Centrifugal Force Definition

Objects in motion tend to travel in straight lines, unless acted upon by an outside force.

What is storm surge?

Occurs when the low atmospheric pressure over an area of a major storm permits the sea level to rise.

How does pressure change with height?

Pressure decreases with hight

What hemisphere is facing the Sun when Adrian has Winter?

Southern Hemisphere

What is dewpoint temperature?

Temperature at which air must be cooled to be saturated. Higher dewpoints indicate higher moisture present in the air

Where does the energy for our atmosphere come from?

The Sun

When do clouds grow higher and higher?

The Sun heats the ground, which then heats the air. This warm air is lighter and less dense than the surrounding air, so it begins to rise. When this air rises, it expands because of the lower pressures that exists at higher levels in the atmosphere.

Why do Atlantic Ocean hurricanes move travel the way they do?

The average hurricane moves from east to west due to the tropical trade winds that blow near the equator (where hurricanes start). When a hurricane is still in the Caribbean, the tropical jet blows east to west, and the hurricane moves west to gain power.

What is climate?

The composite or generally prevailing weather conditions of a region throughout the year, averaged over a series of years. Long term

Where do cyclones develop? a. Around high pressure b. Around low pressure c. Only at sea-level pressure d. Only in the tropics

b. Around low pressure

What of the following is NOT a control on temperature for a given location? a. Proximity to water b. Composition of surrounding bedrock c. latitude d. elevation

b. Composition of surrounding bedrock

What can be said about energy? a. It is never conserved b. It flows from high to low c. It flows from low to high d. It is wasted more often than transferred

b. It flows from high to low

On average, when are tornadoes most likely to occur during the day? a. First thing in the morning when the sun rises b. Late afternoon to early evening c. Late evening after the sun goes down d. Late morning after the dew evaporates

b. Late afternoon to early evening

What is used with air temperature to determine heat index? a. Wind speed b. Relative humidity c. Air pressure d. Time of day

b. Relative humidity

What type of severe weather cannot form with mid-latitude cyclones? a. Tornadoes b. Severe thunderstorms c. Hurricanes d. Blizzards

c. Hurricanes

Why was the destruction in New Orleans so devastating following Hurricane Katrina making landfall? a. Hurricane Katrina hit landfall as a category 5 storm b. The eye of the storm ran directly into New Orleans c. Most of New Orleans lies 6.5 feet below sea level making it highly susceptible to storm surge d. Hurricane Katrina hit New Orleans, curved back out into the Gulf of Mexico, and then hit New Orleans a second time

c. Most of New Orleans lies 6.5 feet below sea level making it highly susceptible to storm surge

What tropical cyclone hazard is associated with the highest percentage of death and destruction? a. Severe rain b. Wind c. Lightening d. Storm surge

d. Storm surge

How is relative humidity calculated?

dewpoint temperature/air temperature