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349 Cards in this Set

  • Front
  • Back
What percent of the sun's energy is ultraviolet?
What percent of the suns energy is visible
Explain the inside of a cold cloud
The precipitation in a cold cloud has ice in it formed through deposition and supercooled H2O. Deposition nuclei are also inside a cold cloud.
Since deposition nuclei are so rare, what are cold clouds primarily composed of?
supercool H2O
What determines the saturation mixing ratio when the temperature is under 32 degrees F?
The phase of water
What is latent heat?
The energy required to change the phase of H2O at a constant temperature
What is the boiling point of water?
212 degrees F
When water is boiling, what are the bubbles?
Water vapor
If you boil H2O, what will happen to the water?
It will remain at 212 degrees Farenheit until all the water has evaporated
What is water vapor?
Individual molecules suspended in the air. If you can see it, it's NOT VAPOR!!
What is water at its lowest energy state? What is water at its highest energy state?
H2O at its lowest energy state is a solid

H2O at a higher energy state is liquid

H2O at its highest energy state is vapor
Give an example of sublimation
Leaving ice cubes in the freezer a long time, taking them out, and seeing that the ice cubes have shrunk
What is it called when you go from a vapor to a solid?
What is sublimation
Going from the solid state to the vapor state
Are frozen water and deposited water different? If so, how?
Yes; when water freezes, it is frozen water. When water deposits, however, it looks different. It's frost. It's white and has ice crystals. This is different from ice cubes because ice crystals are white, and they have 6 sides.
Given with what you know about deposition, what is deposition responsible for?
the formation of snow and frost
What items are involved in the cooling process?
Describe what happens to the energy and temperatures during the cooling process
For meting, evaporation, and sublimation to occur, energy must be gained. The water temperature does not change but the temperature in the environment around it goes down because it's giving its energy to the water As a result, it is a cooling process
Give an example of the cooling process
You step out of the shower and your body gets colder because water is evaporation and your body is the environment, therefore it gets colder.
What items are involved in the warming process?
Describe what happens to the energy and temperatures in the warming process
For freezing, condensation, and deposition to occur, energy must be lost. The H2O temperature does not change but the temperatures in the environment around it go up because it's taking energy from the water.
In both the cooling and warming processes, what stage is "liquid"?
the intermediate stage
What are the requirements of latent heat?
It is ONLY latent heat during a phase change
Why is latent heat contain the word "latent"?
It's called LATENT heat because latent means hidden. There is a temperature change but nobody would know it because it's hidden. Instead of an obvious temperature change, it's changing phase.
Why is water unique?
It's the only substance that can exist at all 3 phases at the same time
At what temperatures can water exist in all 3 phases at the same time?
-40 degrees F to 32 degrees F
What is the mixing ratio?
gm of vapor/kg of air
If the vapor amount is high, what happens to the mixing ratio?
It will also be high
Say you have a container filled 1/4 full of water. It sits at 68 degrees Farenheit. The volume, other than the liquid, is air. The mixing ratio (r) in this box is 0. What will happen?
The fastest moving molecules will begin to evaporate and they'll suspend into the volume as vapor where the air molecules are moving randomly. At this point, the r goes up. The slowest moving molecules will begin to condense to a liquid state again. Eventually the rate of condensation will equal rate of evaporation. At this point, the amount of vapor stabilizes and does not change anymore. There is a constant mixing ratio, called the equillibrium state. The equillibrium state can ALSO be defined as saturation.
What is the saturation ratio?
The maximum amount of vapor that can be in the air at a given temperature. It is a uniform, equal mixing ratio that occurs when the amount of condensation equals the amount of evaporation
What is important to remember about the saturation mixing ratio?
For every temperature, there is a __________
Saturating mixing ratio
As temperatures increase, the maximum amount of vapor that can be in the air _____________
also increases
True or False. When the amount of vapor that can be in the air increases, the air can hold more vapor.
False. The amount of H2O vapor that can be suspended in the air at a given temperature is the saturation mixing ratio
What is supersaturated?
More vapor in the air than the air can have in it
A point below the curve where the air is NOT saturated is called _____?
Define relative humidity (RH)
The actual amount of vapor in the air (r) relative to the maximum amount of vapor that CAN be in the air (rs) times 100

r/rs * 100
What is a key factor of relative humidity?
It is also temperature dependant
If you have unsaturated air, how do you saturate it?
1)Lower the temperature (cool the air)
2)Add vapor to the air
What is the dewpoint?
The temperature that the air must be cooled to to become saturated
When you drink something in the summer, why does the glass sweat?
It sweats because the dewpoint is higher than your drink
What happens when you cool H2O to its dewpoint?
The result will be liquid H2O
T or F There is less water in vapor than liquid
FALSE. Water can not be created or destroyed. It's still the same amount in a different phase.
When does condensation occur
When the temperature equals the dewpoint temperature and the relative humidity is 100%
What are condensation nuclei?
Surfaces upon which H2O must condense on the environmet
What must be present for condensation to occur and what is 2 things we must remember?
Condensation nuclei; they come in different sizes and amounts
What are 3 types of nuclie (from smallest to largest)
How do we get fog
Fog is a result of vapor condensing on nuclei
What are hygroscopic nuclei
Allow condensation to occur on them when the relative humidity is less than 100%
Give an example of hygroscopic nuclei
In the summer, vapor condensation on salt causes salt to stick together. This is because salt is a hygroscopic nuclei. You add rice to salt shakers because rice absorbs more vapor than salt. Rice is also hygroscopic. This is also why roads are damp after snow. They have residued salt on them
T or F Relative humidity can occur below 100%
True; RH is a gradual process
What are hydrophobic nuclei?
Do not allow condensation on their surfaces, even when the relative humidity=100%
Are most nuclei hygroscopic or hydrophobic?
Majority of nuclei are niether hygroscopic or hydrohobic
Examples of hydrophobic nuclei
oil, was, paraphin, and crayons
When is the air saturated?
When conditions allow condensation to occur on majority of nuclei. This occurs when temperatures are decreased, and this is when the air is saturated. Dewpoint temperature is defined based on the nucleus content
What causes different cloud formation?
Different air circulation that leads to cloud formation
What causes hazy skies in the summer?
The hazy skies in the summer are actually liquid water that has formed hygroscopic nuclei.
What is haze?
It's like a thin fog, but the concentration is not enough to be categorized as fog
What is the formula for haze?
High humidity and condensation of hygroscopic nuclei equals haze
Where doe most nuclei for condensation take place at?
Many times, hygroscopic nuclei will only have condensation __________________________
in the morning when the RH is high
What is fog?
A cloud that is in contact with the ground. Fog has a high droplet content as far as concentration goes. This happens when air is cooled to its dewpoint and the RH is 100%
How can fog differ?
All fog forms when air is cooled to its dewpoint, but exactly how it's formed by the dewpoint can differ
What are the 3 types of fog?
Radiation Fog
Advection Fog
Steam Fog
What is radiation fog?
Forms at night in calm conditions with clear skies
Why must we have clear skies in radiation fog?
We must have clear skies so we can have cooling. If it was not calm, winds would cause the air to mix and temperatures would not be able to cool to their dewpoint
Give an odd example of radiation fog
Fog above cornstalks is radiation fog, but the ground is not cooling the temperatures to their dewpoint, the cornstalks are
How does fog evaporate?
When fog burns off, the sun heats the ground which heats the air which becomes less humid so fog evaporates
Why do you get fog on the bottom of a hill and no fog at the top? Which fog is this an example of?
When you're in a hilly region (especially in the fall) you get a layer of cold air that conforms to the hillsides. It's more dense, causing it to flow down the mountains. As a result, when you drive you experience fog on the ground and it clears on top of the hill. This is an example of radiation fog
Advection fog
Fog that results from the transport of air. Wind is involved
When does advection fog occur?
When a Maritime Tropical air mass moves over us. The snow cools the warm, humid air to its dewpoint and we get advection fog
Steam Fog
Instead of a cold surface, it has a warm surface. The water warms the air and it becomes less dense causing the air to rise. As the air moves away from the heat source it gets colder, but it is almost moist because it's in contact with water. The saturation mixing ratio increases and the mixing ratio increases. As it rises, it's cooled to its dewpoint and we get steam
Example of steam fog
When you eat hot food or a hot drink, it has steam fog
big parcels of rising air that rise ina circular motion. (Handgliders ride on thermals.) Steam rising in swirls is an example of thermals
Warm Cloud
Cloud in which temp. is above 32
cold cloud
any cloud where temperatures inside cloud are below or equal to 32.
What is the freezing point of water?
-40 degrees F
How can liquid water exist below 32?
The droplet size
Supercooled H2O
H2O in the liquid phase at temperatures below 32
After the collision of droplets, what must happen in order for 2 droplets to become 1 bigger droplets?
There must be a coalescence
Will all droplets have coalescence
NO-droplets must have opposite charges
Why do droplets have electrical charges?
1)Because of of the friction between the droplet and the air it is going through
What do coalescence and collision in a cloud produce? How long will this process take?
precipitation; a matter of minutes
In a cloud, through condensation alone, how long would it take before a droplet could fall as a raindrop? What kind of process is this?
1-2 weeks. Tropical process which means it is not responsible for snow, hail, sleet, etc.
Why are deposition nuclei rarer than condensation nuclei
Deposition nuclei have a surface for a phase change to take place. It's special, though, b/c ice crystals are hexagonal and they must form on hexagonal nuclei. As a result, they're rare.
When you cool super-saturated air what happens?
It does not cause condensation. When it becomes liquid H2O, the air does not super-saturate
Imagine you have 2 tanks, both at 25 degrees. The right tank is liquid H2O, and the right tank is ice. Explain what will happen inside the two tanks.
The energy required to EVAPORATE H2O is much less than the energy required to SUBLIMATE H2O. As a result, the rate of evaporation in Tank A is going to be much higher than the rate of sublimation in Tank B. Eventually we'll get condensation in A and deposition in B. The saturation mixing ratio in A is greater than the saturation mixing ratio over B. If the temperature is under 32 degrees, the saturation mixing ratio for water is more than the saturation mixing ratio for ice. In Tank A, saturation means that the rate of evaporation equals condensation. In Tank B, the rate of sublimation equals the rate of deposition at saturation
The amount of vapor that has to surround a ____________ is much greater than the amount of vapor that has to surround a ____________
droplet of H2O;ice crystal
If temperatures in a cloud are over 32 degrees, what will go away
the saturation mixing ratio of ice
When do the saturation mixing ratios for water and the saturation mixing ratios for ice meet? Why is this their meeting point?
32 degrees. They must meet at this point b/c ice must melt at 32. They meet again at -40 b/c it is the freezing point of water and droplets must not freeze
Imagine Tank A and Tank B. A is liquid and B is ice. The temp. is under 32 degrees. If the ice has a RH of 100% (it's at equillibrium) but the air is not saturated, what will happen?
In order to saturate it, we need to add more vapor. When we do this, though, the ice crystal has a RH of more than 100% b/c deposition exceeds sublimation. This causes super-saturation in the ice crystal and with respect to the liquid water, condensation will NOT exceed evaporation. At this point, the droplet is still not at equillibrium so we must add even more vapor to both the droplet and the crystal. As a result, the crystal becomes even more super-saturated BUT the droplet is finally saturated.The amount of vapor required to saturate the air around the droplet is more than the amount of vapor required to saturate the air around the crystal at a constant temperature less than 32 degrees.
Is it possible to get a snowstorm at -40? Why or why not?
You will never get a snowstorm at -40 b/c there is not enough vapor in the air, but it is NEVER too cold to snow
What are the 3 steps?
STEP 1: The RHw=100% and RHi is more than 100% As a result, the ice crystal grows through deposition of surrounding water
STEP 2: The actual vapor content is going down. The mixing ratio decreases and the dot moves down. The RH around the droplets goes under 100% and the RH around the ice crystal also goes down BUT it is still above 100% the droplets then evaporate. As droplets evaporate they add vapor to the air
STEP 3: As vapor gets added to the air, it causes the dot to go up again, so Step 3 means go back to step 1 and do it again
Can the Bergeron process occur in the summer?
Explain the Bergeron Process
H2O will always have to give its vapor to the ice until the liquid H2O is gone. This is called the Bergeron Process. It is the process where ice grows and the expanse of super-cooled H2O in a cold cloud. When the crystal grows to a certain size, it shatters and all the shards of the broken crystals are also 6-sided. As a result, the amound of crystals increase quickly which explains how you can go from mostly droplets to mostly ice crystals. When the crystals increase it accelerates the rate of deposition causing water droplets to evaporate. The whole process then accelerates! The endproduct is snow
Describe dewpoint and explain its relation to temp.
Dewpoint is almost always less than the temperature. Dewpoint indicates how much you have to cool the air to saturate it w/ vapor that is already in the air. The dewpoin temperature relates to the actual vapor content in the air. In the summer, the RH in the morning may be relatively 100% but as temperatures increase in the afternoon, the DP does not change so the RH can drop to almost 50%. A RH of 65% is unbearable
Given a cloud with temperature under 32 and a single mixing ratio value, why is RH around the ice crystal more than the air around the H2O droplet?
It takes a lot less air to saturate a crystal compared to an H2O droplet.
Why are saturation mixing ratios different betweeen rsw and rsi?
Deposition and sublimation are slower than condensation and evaporation
What do differences in phase change rates lead to?
Differences in saturation mixing ratios
What is the difference between the precipitation in warm clouds and cold clouds?
Warm clouds only produce rain. Cold clouds produce it all. Snow is not a result of freezing, it is a result of deposition
Explain how falling snow remains snow until it reaches the ground
As warm air rises over cold air you get overrunning and temperatures decrease b/c there is expansional cooling. If warm air rises over there will be a temp. of less than 32 b/c it has risen that much. The precipitation that falls will not encounter temp. above 32 degrees. As a result, precipitation will be snow. Snow is when it exits the cloud as snow and doesn't encounter temperatures above 32 degrees.
Explain how we get big snowflakes
Every once in awhile when temperatures are right above 32 you get larger snow crystals b/c they're sticky w/ H2O residual
How do you get sleet?
If snow falls in the cold sector, but goes into temp. above 32 and then back under 32, it'll melt but will remain in the ground long enough to freeze. When it is sleeting out, you're still not very close to the warm front
What happens to the precipitation when you get closer to the warm front?
The cold front begins to erode and move to the right. The snow becomes sleet, but by the time it reaches the bottom the cold is so shallow that precipitation remains in liquid form. It dfoes, however, freeze on catact which is why it's called freezing rain
What happens to precipitation when the front goes through?
Precipitation will be rain
Are there always clean transitions between different types of precipitation?
No; sometimes you can have more than 1 kind of precipitation at the same time
Why do temperatures go down at night and up during the day?
During the day the sun is out and energy is being absorbed by the sun. This causes temperatures to increase. During the night, the energy radiating outward from the earth to space is more than the energy being absorbed from the sun causing temperatures to decrease.
When does the earth receive energy from the sun?
During the part of the day where the sun is over the horizon
What happens as temperatures increase?
The earth radiates more energy
In order for temperatures at any location to increase, ____________
more energy must be added
Outgoing Longwave Radiation
Energy the earth is emitting to space
9/21 and 3/21. The point where there are both 12 hours of day and 12 hours of night
6/21 (Summer Solstace) 12/21 (Winter Solstace) The longest day of the year and longest night of the year
On the Dailty temperature cycle, what happens during midnight to 6 a.m.?
Outgoing longwave radiation is more than insolation
On the daily temperature cycle, what does it mean if we are running an energy deficit and when does this deficit occur?
During an energy deficit, temperatures drop and OL is more than INS. This occurs from midnight to 6a.m. and 6p.m. to midnight.
What is an energy surplus and when does it occur?
An energy surplus is when INS is more than OL. Temperatures increase. This takes place from 6 a.m. to 6 p.m.
On the Daily temperature cycle, when does the maximum temperature occur? When does the minimum temperature occur?
Maximum Temp.-30-45 minutes before 6p.m.

Minimum Temp.-30-45 minutes after 6 a.m.
When do temperatures increase most rapidly on the daily temperature cycle?
At what angle is the earth tilted on its axis? What does the earth's axis connect?
23.5 degrees. It connects the North and South Poles
Why do temperatures increase in the summer?
The southern hemisphere receives more radiation than the earth is emitting radiation, so temperatures increase. The sun has no obstacles between the earth and the sun. Because of the tilt, the earth is always illumnating a little of each hemisphere
What is the shortest day of the year?
The Winter Solstace 12/21
What is special about the Tropic of Capricorn and what lattitude is it?
It is the lattitude over which the sun shines directly overhead;(23.5) degrees South
Explain what happens during the winter solstace
More of the southern hemisphere is illuminated in the sun and more of the northern hempisphere is in dark
What would happen if the earth didn't have a tilted axis?
The sun would shine at the equator and we'd have an equinox
How often does the Earth revolve around the sun?
365.25 days
What are Northern seasons called?
What are Southern seasons called?
What is Ohio?
Boreal seasons
Austral seasons
We are Boreal
Explain the importance of the Artic Circle and what lattitude does it lie on
The point where it is dark during the Boreal Winter 24 hours/day. (66.5 North)
Why is there 12 hours of day and 12 hours of night on the equinox?
There is 12 hours of daylight and 12 hours of dark everywhere
What happens during the Boreal Winter?
The Northern hemisphere is tilted away from the sun. The higher lattitudes of the northern hemisphere are in complete darkness. 1/2 of the equator is in dark and 1/2 is in light. As you go north, the upper lattitues get progressively darker. Eventually you reach a latitude where it is dark 24 hours/day. Conversely, if you go farther south it gets lighter, and at the Antarctic Circle the sun never leaves the horizon
What happens during the Boreal Vernal Equinox?
All the earth is illuminated. The Earth's axis is oblique to the sun. Every lattitude is getting 12 hours of light and 12 hours of darkness. The sun shines directly at the Equator. In the spring this is called the Austral Autumnal Equinox
How many hours of light and day does the Equator get year round?
12 hours of light and 12 hours of darkness
Atmosphere refracts energy from the sun that is striking some place near us
When does sunset actually occur?
8 min. before we see it because it takes that long for the sun to reach the earth
Over the year, the average number of daylight and darkness is 12 hours per day no matter what location. Given this, why aren't temperatures the same?
Direct sunshine only happens at the Tropics of Cancer and Capricorn. This is why it never gets as hot at the poles even though we have equals amounts of daylight. When the lights hits at and angle the beams spread out. As a result, it's not the quantity of daylight you receive, it's the quality of daylight you receive. This is why ligher lattitudes are receiving much less energy. The North and South Poles receive the least amount of energy from the sun and the equator receives the most. The Poles emit less energy than the Equator
How can we have a constant temperature year after year if the graph is true?
B/c of atmospheric motion (the wind)
What does wind circulation do?
1)Draws cold air from the poles to the equator causing air modification
2)Draws warm air from the equator to the poles causing air modification. These 2 components equal out big temperature differences that occur b/c of shape of the planet
What 2 factors, taken together, determine whether the temperature at a given location rises or falls? When does the temperature remain constant?
The 2 factors determining whether the temperature at a given location rises or falls are how much Incoming Solar Radiation there is and how much Outgoing Longwave Radiation there is. Incoming SOlar Radiation is how much radiation is being absorbed from the sun. Outgoing longwave radiation is how much radidation the earth is emitting to space. When Incoming Solar Radiation and Outgoing Longwave Radiation are equal, temperatures remain constant. This is called an equillibrium
Why does the earth have seasons?
Because it is moving around the sun which causes changes in season
Why, in general, is the relative humidity of indoor so low during the winter?
The air is cold and saturated outside, but when you walk into your 80 degree room the temperatures increase and the mixing ratio stays the same. As a result, the air in the room is sub-saturated and the relative humidity is low
Combine the principles used to describe parcel motiona nd relative humidity to explainw hy rising air leads to clouds and precipitation.
When you have a parcel of air, you get expansional cooling, which cools the air to its dewpoint. This cooling eventually leads to clouds and precipitation
What are the conditions for absolute stability? Why is it compared to moist air and not dry air?
Environmental adiabatic lapse rate is more than the most adiabatic lapse rate. It is compared to moist air because if moist parcels sink, dry parcels will be even cooler and they'll definitely sink
What is the formula to switch Celsius to Farenheit?
9/5 * C plus 32
If an unsaturated parcel on the ground is 20 degrees Celsius and lift it 1 km, what will the temp. be?
10 degrees Celsius
What marks the upper part of the troposphere?
What percent of the sun's energy is infrared?
Moist Adiabatic Lapse Rate
When the parcel rises it condenses, which is a warming process so the rate will be less. This moist rate only occurs at saturation when it can condense. You get 10 degrees of cooling due to expansion and 4 degrees of warming due to condensation. The Rate is 6 degrees Celsius/km
What does the earth emit most of its energy in?
When do we have the greatest amount of heating during the day?
When the environmental lapse rate is the highest. This is why we have afternoon T-storms
Define latent heat. In waht way does latent heat differ from the heat that was discussed at the beginning of the semester?
Latent heat is the energy required to change the phase of H2O at a given temperature. Latent heat is different from the heat discussed at the beginning of the semester because rather than having an obvious temperature change, latent heat causes an obvious phase change instead
Define pressure and discuss how a barometer is used to measure pressure. Does the pressure tendency give us any indication of what the future weather may be?
Pressure is the amount of weight. The pressure of the atmosphere is the weight of the atmosphere. A barometer measures pressure. A barometer contains a tube. Inside the tube acts like a vaccuum. The bottom of the barometer contains mercury. The weight of the atmosphere presses down on a ball that causes the mercury to go up. If the merury goes up, the pressure is rising. When the pressure drops the weather gets worse
Emission spectrum for the earth is __________ of the sun's emission spectrum
What are the only rates where temperatures can change inside a parcel?
Dry adiabatic lapse rate
Moist adiabatic lapse rate
What characteristics are needed for an air mass thunderstorm?
1)MT air masses
2)conditionally unstable atmosphere
What causes the Earth to have seasons? Where are the Tropics of Concer and Capricorn, The Equator, and the Arctic and Antarctic Circles located?
The Earth has seasons because of the 23/5 degree tilt of the axis. The Tropics of Cancer is located at 23.5 degrees N and the Tropic of Capricorn is located at 23.5 degrees South. The Equator is located at 0 degrees. The Arctic Circle is located at 66.5 degrees N and the Antarctic Circle is located at 66.5 degrees S.
What are condensation nuclei? Define hygroscopic and hydrophobic nuclei. What distinguishes deposition nuclei from condensation nuclei? What is supercooled water and why are cold clouds composed primarily of supercooled water?
Condensation nuclei are surfaces upon which liquid H2O can condense in the environment. Hygroscopic nuclei are nuclei where liquid H2O can condense on at a RH less than 100%. Hydrophobic nuclei are nuclei in which liquid H2O can NOT condense on at a RH of 100% Deposition nuclei are different b/c they're 6-sided. Supercooled water is liquid water that exists at a temp. less than or equal to 32. Cold clouds are composed primarily of supercooled H2O b/c deposition nuclei are so rare b/c they are 6-sided
What is an adiabatic surface? What is the difference between heat and temp.?
An adiabatic surface means that no energy can be exchanged through the boundary. When a parcel is lifted into the air it is adiabatic. The difference between heat and temperature is that temp. is the MEASURE of kinetic energy and heat is the TRANSFER of energy from one object to another. Temperature is also a noun and heat is a verb
What is felt as heat?
Infrared energy
In the real world, we do get mixing air and energy exchange unlike parcels show. Even though we do get energy exchange, why does adiabatic hold true?
Exnergy exchange in the atmosphere is a terrible conductor
Describe the cumulus stage
Clouds begin to form as a result of convection. There is an updraft. The circulation is dominated by updrafts. As soon as cloud forms, air from the outside of the cloud mixes in. The RH outside of the cloud is less than 100% and the cloud has a RH of 100%. When you mix dry air w/ saturated air, the cloud evaporates so the cloud disappears but the vertical transport of moisture moistens up the entire layer where the cloud forms so when the next cloud forms it'll be a little less dry and will be bigger. The process continues until the sky become congested w/ clouds. Eventually clouds will be big enough so we can get precipitation formation. This precipitation is formed by collision and coal. at bottom of cloud and Bergeron process at top of cloud. When droples begin to fall we move to the second stage
Describe the conditions required to produce collision and coalescence within a cloud. Does a collision guarantee that coalescence will occur? Explain
In order for collision and coalescence to occur, it must be a warm cloud, there must be different sizes of dropping at different rates, and the droplets must have different charges in order to coalescence. It does not guarantee that a collision will guarantee coalescence b/c droplets are charged and only those droples of opposite charges will coalescence
Changes in the density of parcel air are governed by what?
A little temp. increase yields a big change in ______
Greenhouse Gases
Water vapor (most abundant greenhouse gas)
How do we find the environmental lapse rate?
1) Start at the surface
2)T for env.=T for parcel
Dewpoint T env.=Dewpoint T of parcel
3)If you raise these, you will have different lapse rates and different pressure
Why are the bottom of clouds flat?
That is the point of the cloud where temp. must be cooled to their dewpoint
How would locations of the important lattitudes change if the tilt of the Earth's axis were 45 degrees. How would the seasons on Earth change from those currently observed?
The Tropic of Capricorn would be 45 degrees and the Tropic of Cancer would be 45 degrees. The poles would also be at 45 degrees. The Tropics and poles would coincide and seasons would be highly amplified in terms of heat and cold
Fully describe the phase changes that water undergoes that cause latent heat to be both absorbed from and released to the environment
Meltion, evaporation, and sublimation are all cooling processes. In order for them to occur, energy must be gained. As a result, temperatures in the surrounding environment decrease because the water is taking energy from the surrounding environment. Freezing, condensation, and deposition are all warming processes. In order for them to occur, the water muts lose energy. The water gives its energy to the surrounding environment causing temperatures in the surrounding environment to increase
The smount of energy an object emits at wavelength lander
What is so special about greenhouse gases
They let visible radiation pass through them
What cause updrafts?
For a given air temperature, define mixing ratio, saturation mixing ratio, and relative humidity (just words, no equations.) Using these 3 quantities, define subsaturation, saturation, and supersaturation
Mixing ratio is the actual amount of vapor in the air. The saturation mixing ratio is the maximum amount of vapor that can be in the air at a given temperature. Relative humidity is the mixing ratio relative to the saturation mixing ratio multiplied by 100%. Subsaturation is when the air has less vapor than the air can have in it at a given temperature. It has a relative humidity of less than 100%. Saturation is when the air has the maximum amount of vapor that the air can have in it at a given temperature. It has a RH of 100%. Supersaturation is when the air has more vapor than the air can have in it at a given temperature. It has a RH over 100%
What is the highest Esablander value
Landasubmax wavelength of maximum emission
Explain what happens during the greenhouse effect
Once visible radiation is absorbed, it makes the earth more energetic and that extra energy goes back to space. Once the earth gets energy from the sun, it is not longer the Sun's energy. Greenhouse gases keep energy from getting out. By absorbing radiation from the earth, the greenhouse gases cause temperatures of the earth to go up
Finding stability in the atmosphere
We lift the parcel 1 km and compare the parcel temperature to environmental temperatures. This allows us to compare densities at 1 km. This is b/c at 1 km we're dealing w/ a single pressure value. If we lift the parcel 1 km and it's colder than the surrounding environment, the parcel will be more dense than the surrounding environment and will be stable. If we lift it and it's warmer than the surrounding environment, the parcel will be less dense than the surrounding environment making it unstable
Mature Stage
Instead of bubbly clouds, clouds begin to fan out. When the rain falls, it's falling from an env. w/ RH of 100% to an env. of RH less than 100%. This is sub-saturated. It begins the evaporation-cooling process. As air is cooled, it becomes mroe dense. It then sinks. We get the development of downdrafts. As raindrops fall they pull cold air down to the surface. T-storms lead to warming of the air and cloud level b/c of condensation. The environmental lapse rate moves to the left and the atmosphere becomes absolutely stable. T-storms are caused by instability but they stabilize the atmosphere. As soon as the atmosphere is stable the updrafts go away. The thunderstorm becomes composed of downdrafts, and it enters into the 3rd stage
Describe the 2 ways that subsaturated air can be changed so that it becomes saturated. Define dewpoint temperature. What happens when saturated air is cooled. Why?
Subsaturated air can be changed to saturated air by addming more vapor to the air or cooling the temperatures to their dewpoint. Dewpoint temperature is the temperature that the air must be cooled to to become super-saturated. When saturated air is cooled it condenses. It condenses b/c the air has more vapor than the air can have in it so it becomes liquid H2O.
Wien's Law
Says that the wavelength of emission is inadversely related to an object's temperature
What is the Natural Greenhouse Effect
Enhanced greenhouse effect is an increase in atmosphere temperature as a result of increased greenhouse gases. This is a direct application of Wien's Law
What are the building blocks of T-storms?
Stability and unstable
Total energy is equal to __________
the sum of E sablandas
Wien's Law can be used to describe:
1)Daily Temperature Cycle
2) Seasons
In order to determine whether atmosphere will be unstable, the only independent variable is?
The environmental lapse rate
During the course of the year, the lower latitudes experience an energy surplus while higher latitudes have a deficit. Why, in reality, don't the tropics become increasingly hot and higher latitudes progressively colder?
The tropics don't become increasingly hot and the higher latitudes don't become progressively colder b/c of atmosphere motion (otherwise known as wind) Wind causes the cold air from the poles to move toward the Equator which causes air modification. In addition, warm air from the Equator moves to the poles, which also caues air modification
Explain the processes that lead to sleet and freezing rain formation when snow falls from a cloud
When snow falls from the ground it'll remain snow, but the overrunning from the warm front will cause temp. over 32. This will cause the snow to melt. Once the droplets reach the cold air, though, they are above the ground long enough to re-freeze. The result is sleet. Freezing rain occurs when you are close to the warm front. The cold air begins to erode and move off to the right. When snow falls from the ground, it eventually comes into contact w/ temp. above 32. This causes the snow to melt. The droplets then go back into the cold air, but the amount of cold air is so shallow that the droplet doesn't have enough time to re-freeze. As a result, the droplets don't freeze until they come into contact w/ a surface. This is freezing rain.
The emission spectrum is huge, but the highest wavelength will be _____. The earth and the sun emit their _______ at ________ wavelengths
small; energy; wavelengths
Why are saturation mixing ratios different in deposition and sublimation than condensation and evaporation
Deposition and sublimation are slower than condensation and evaporation
Downdrafts are caused by:
1)Evaporative cooling
2)Droplets bringing cool air downward
The ratio of rough snow to H2O is?
What are station models?
They appear on surface maps. They provide a great amount of information about the weather. There location on the map corresponds to where the observation was taken
What is the upper-left hand number of the station model?
What is the upper right-hand number on the station model?
What is the bottom left hand number on the station model?
The dewpoint temperature
What is the dewpoint temperature?
The temperature that the air has to be cooled to in order to become saturated.
How do you decode pressure?
If the code is more than 500, add a 9 to the code and place a decimal point between the last 2 digits. EX: 751-975.1 mb. If the code is less than 500, add a 10 and a decimal point. EX: 243=1024.3 mb
The higher the pressure, the more______
Which type of pressure is associated with bad weather?
low pressure
How do we get the dewpoint depression? What happens if T-Td equals 0?
Temperature minus Dewpoint Temperature

IF T-Td=0, the relative humidity is 100%. The higher the dewpoint depression, the smaller the relative humidity
What are numerical models?
They use a set of complex mathematical relationships to generate a replica of the atmosphere. They can look VERY similar to a surface map
What is an analysis?
It is what the atmposphere looks like at the beginning of the day. It is NOT a forecast but a bad analysis can lead to a bad forecast.
What is an isobar?
Curve where the pressure is exactly the same everywhere on it.
What is the difference between isobars? What are these differences called?
4 mb;contour intervals
What are dotted lines on a map? What are there correlations with temperature?
Isotherms; the higher the number of isotherms, the higher the temperature
If the value of temperature is _______ precipitation will consist of snow. If the value of temperature is ______ precipitation will be rain. On radar maps, areas of ____ preddict snow. When we are entrenched in cold air we get light snowfall from ________.
less than 540; more than 540; blue; Canada
What way do the winds surrounding high pressure turn?
What way do the winds surrounding low pressure turn?
How can the speed of wind be roughly determined?
Distance of isobars; the closer the isobars, the stronger the wind
Pressure gradient
The rate at which pressure changes over distance

Delta P/Delta D

If isobars are close together, Delta D is a small value
What does a small Delta P result in?
a larger pressure gradient. The bigger the gradient, the stronger the winds will blow
What does Delta P always equal?
Stationary Front
Is not moving
Cold front
Cold air moving to the south
Reasonable weather
rain, snow, sleet, hail
When there is no frontal boundary around an area, ________________________________
it is normally sunny out
What are clouds and precipitation identified by?
the front
In order to have clouds and precipitation you must have ___________
1) water
2) some mechanism to make the air rise
Mechanisms that cause the air to rise
What intervals do "lines" move in?
intervals of 6
570 line
separates summertime weather from the south with spring temperatures from the north
540 line
Used as an approximate rain/snow line. Below 540 is snow. Above 540 is rain
510 line
Very cool, winter air
When do our coldest night occur?
When it is clear and cold
Pressure tendency
Tells us how much temperature has changed in the past 3 hours.
How do you decode pressure tendency?
Add a decimal point before the last digit. EX: 16 equals 1.6 millibars in 3 hours
What is the bottom right hand number on the station model?
Pressure tendency
What is the diagonal line by the pressure tendancy?
It indicates how the pressure changed. Diagonal means it increased steadily. Checkmark means it decreased then rose. You can never have more than 2 lines
The line extending out of the stationary model is wind. Describe how this works.
The line is the direction from which the wind blows. The long bar corresponds to wind speeds of 10 knots. The short bars correspond to wind speeds of 5 knots.
Nautical mile/hour. A nautical mile is roughly 1.1 miles
What does a clear station model represent?
Clear skies
If the station model is colored in the upper quarter, what does it mean?
partly cloudy skies
If the station model is half-way shaded, what does it represent
At night this is considered partly cloudy. At day this could be partly cloudy or partly sunny. Partly cloudy is typically less than half-shaded and vice-versa
If the station model is 3/4 shaded, what does it represent?
partly sunny/mostly cloudy skies
If the station model is completely shaded, what does it represent?
mostly cloudy skies
If the station model has an X in it what does it represent?
Obscured; when you cannot see the sky. EX: Fog, hard snow, hard rain
current weather
a number of different symbols where each number relates to the weather
What is the symbol for snow shower/flurry
triangle w/ asterick on top of it
light snow (visibility more than .5 mile)
* *
moderate snow (visibility more than or equal to .25 miles and less than or equal to .5 miles)
* *
heavy snow (visibility less than .15 miles)
How are rain symbols and snow symbols different?
Rain symbols are exactly like snow but dots are used instead of astericks
light drizzle
, ,
moderate drizzle
, ,
heavy drizzle
Difference between rain and drizzle
Droplet size. Drizzle size is more than a mist but not rain
light fog
dense fog
What is the symbol for sleet?
Triangle with dot inside of it
What is the symbol for freezing rain?
A squiggly line w/ dot inside the squiggle
What is the symbol for a thunderstorm?
A T with a lightnign bolt extending out of it
What is the symbol for a thunderstorm producing hail
T with lightning bolt extending out of it and a triangle on top
measure of atmosphere's weight
Newton's second law
Force equals mass times acceleration
What does pressure weight?
cumulative weight (from top to bottom)
pressure always _______ w/ height
What is the symbol for calm winds?
Big circle with a smaller circle inside
What is the symbol for calm winds?
Big circle with a smaller circle inside
What is the symbol for calm winds?
Big circle with a smaller circle inside
What is the symbol for calm winds?
Big circle with a smaller circle inside
How does a barometer work?
On the tube of a barometer is a vacuum. As the pressure increases, mercury is forced up the tube by the vacuum.
What measures pressure?
Pressure in millibars is roughly _____
1,000 mb
A measure of an object's mean kinetic energy. As mean kinetic energy increases, the temperature increases. Temperature differences drive the atmosphere
What does a thermometer measure?
The mean kinetic energy of the air
What is our air composed of?
78% nitrogen
21% oxygen
9/10% argon
.1% trace gases (CO2, methane, etc.)
The motion of air molecules is _____
Energy w/ less than .4 wavelengths
What is snow a result of?
What does pink represent on a radar map?


Green or yello?
Mixed precipitation
How does a radar map work?
We send out micro waves, they bounce off the atmosphere and come back to us. If there is a clear sky, waves do NOT come back. If there are clouds, we get a faint energy reflected back. You can tell by the faintness of the echo if there is precipitation.

Strong Echo=More Precipitation
Why is it hard to detect snow on a radar map?
Snow has a high air content, so even if it's snowing hard, there is only a light echo reflected back. We can determine that the precipitation is snow by looking at the temperature profile
Droplets of water under 32
Why can't you take radar maps literally?
The precipitation does not always hit the ground
Winds are parallel to ____
Transport of air with different temperature characteristics
What are the 2 types of advection?
transferring energy through an object an energy is transferred from hot to cold objects
Mass over volume
Why does it get windy before a t-storm?
Downdrafts hits the ground and spreads out ahead of storm. This air is cold and dense which causes temperatures to decrease. It causes a mini cold front between the downdraft air and hot humid air. This is called a gust front.
Wavelengths larger than red
The environmental lapse rate is 3 degrees/km. Temperature is 35, and the parcel is dry. Explain what will happen.
When you raise the parcel 1 km the temp. will be 32. The parcel will be colder than the environment so it's going to be more dense, and it will begin to sink. If the parcel was moist it would still be more dense than the environment so it will sink. This is absolutely stable.
.55 Mm
Green light. This is why vegetation is green
Why is absolutely stable compared to moist air and not dry air?
B/c if moist parcels sink, dry parcels will be even colder and they'll definitely sink
What is visible light
.55 Mm. This is where the sun emits most of its energy
What happens as a parcel rises?
It expands and we get expansional cooling. The temperatures in these parcels decrease at a certain rate
What is the relationship between the environmental lapse rate and temperature?
The smaller the temperature the bigger the environmental lapse rate and vice-versa. This is an inverse change
An idealization, or model, of how volumes of air behave in the atmosphere
Characteristics of a Parcel Interaction With The Surrounding Environment
1)Flexible boundaries
2)No energy exchange across the boundary (This is called adiabatic)
3) There is no air exchange with the surrounding environment
In the parcel on the ground, what is constant?
Energy inside the parcel
How Does Density Change When Lifting A Parcel Into The Atmosphere?
Since you are lifting the parcel, the pressure is NOT a constant. Unlike the parcel on the ground, this IS adiabatic. As the parcel is lifted, density and the pressure decrease. The parcel becomes colder. This is expansional cooling. It gets colder because there is a decrease in kinetic energy and an increase in potential energy. The decrease in pressure is a result of expansion
When you spray a can of deodorant, it gets cold. What causes this temperature change?
When you release pressure from the can, the pressure goes down. This decrease in pressure causes a decrease in temperature. The can is adiabatic.
You are in a jet and you get warm. You turn on the air vent. Does the air have to be cooled or warmed going through the vent?
The pressure inside the jet is the same as the pressure on the ground. The pressure is so much higher in the cabin that air actually has to be cooled before coming into the plane. This is an example of compressional warming
What are high and low pressure centers based on?
Whether they're high or low by the pressure surrounding them
The bottom 6-8 miles of our atmosphere. All our weather takes place in the troposphere
8-15 miles of our atmosphere. Temperatures eventually stop decreasing with height and eventually level out. It is above where the weather occurs
Composition is different than the rest of the atmosphere b/c it contains ozone. Temperatures in the stratosphere increase because of the ozone. Temperatures in strat. can be above 0 degrees F. 99.9 percent of the atmosphere is gone at the top of the stratosphere
Temperatures level out again
Temperatures decrease again w/ height. It is the coldest layer of the atmosphere. Temperature can be -100 to -120 degrees Farenheit.
Temperatures steady again
Temperatures increase. It is the hottest layer of the atmosphere. Temperatures are several hundred degrees. The reason the thermosphere is the hottest layer is b/c all of the lethal radiation is taken out here. The violen radiation is so powerful that it will interact w/ anything that comes along. Since the thermosphere is the most energetic, it has the highest temperatures.
What are the layers of the atmosphere in order?
10 miles up into the atmosphere=____ of the atmosphere's mass
Why is it hotter near the ground and cooler in the upper atmosphere?
Air transparent to energy from the sun. The surface of the atmosphere absorbs sun, so temperatures increase. The further away you are from the ground, the colder it is. This has nothing to do with parcels because the atmosphere is NOT a parcel
What does sunlight emit?
*ultraviolet radiation
*invisible radiatoin (the most common)
*infrared redation (the second most common)
*gamma radiation
*cosmic radiation
What are Ozone Action Days?
Ground ozone does not occur naturally, but we help it along. High levels of ground ozone occur during the summer because of the high temperatures. Ozone is very corrosive, but it does not damage our respiratory system because we have evolved) On Ozone Action Days, busing in cities is free to encourage people from driving. In addition, children and the elderly are encouraged to refrain from going outdoors
When did we have terrestrial life on earth?
When ozone formed.
Air mass
Air that covers an extremely large area, and it has uniform temperature and humidity characteristics
2 Types of Temperature
Tropical (Warm air masses w/ tropical characteristics

Polar (Cold air masses w/ polar characteristics
2 Types of Air dealing w/ humidity
Maritime (humid air masses)

Continental (Dry air masses
Source Region
Where air asses form. They impart weather characteristics to the air. The time it takes an air mass to form is the time it takes the air to reside long enough for characteristics to form
What kind of air masses are in a low lattitude?

What kind of air masses are in a high lattitude?

Air masses can be:
What are the coldest air masses and what is their source region?
Artic Air Masses-CP

Their source region is Siberia
What happens once an air mass becomes a source region?
They move to other areas that do not have source regions.
What are the characteristics of source regions and why isn't Bowling Green a source region
They're typically flat, not mountainous. We are never a source region b/c it is too windy. As a result, our air masses are always modified
As air masses move over new surfaces, those surfaces will influence the characteristics of the air mass
Polar Modification
As polar air masses move, they tend to move over warm air surfaces. The air is still cold, polar air, but it is modified after moving from the original source. The air mass modification keeps the air from becoming too cold.
What prevents air masses from becoming too modified?
snow cover
The boundary between 2 different air masses. Fronts can be based on dewpoint boundaries even though they're referred to as cold or warm fronts
Warm Front
moves over cold air. There is a density difference between warm and cold air. Cold air is much more dense. Warm fronts are drawn as red lines w/ semi-circles pointing to where the air is moving
As warm air approaches the boundary it is forced to run up and over the surface of the cold air. Overrunning causes clouds and precipitation. Overruning precipiation is normally steady and not heavy for very long
When do warm fronts occur?
When cold air or polar air masses retreat to the north. The cold air always determines the outcome. As it retreats, the warm air simply feels the void
When is the air not forced to rise.
When there is no overrunning. In these cases there are clear skies b/c all of the precipitation occurs in the cold air
Cold Front
Cold air is advancing away from the region (toward the southwest normally) Teeth point in the direction the cold front is moving
How does the rate of ascent in warm air compare to cold fronts?
The rate of ascent in warm air is much great in cold fronts than in the ascen tof warm air in a warm front
What is the precipitation like is cold fronts
Much more heavy b/c of the speed of the upward motion of the air. Gradual lift (as in warm fronts) is more steady precipitation
What is the circulation in low pressure?
Counter-clockwise and directed in
What causes fronts?
Low pressure causes air masses to converge. The converging causes fronts
High Pressure
All air eminates from 1 single point (where the high is located) The air in high pressure moves clockwise and out. High pressure systems represent the middle of air masses. You will NEVER have fronts associated w/ high pressure.
What are the characteristic cloud patterns surrounding low pressure?
Comma shaped. The middle of lower pressure is clear
cyclonic circulation
counter-clockwise circulation (low pressure)
anti-cyclonic circulation
Clockwise circulation (high pressure)
The ability to move something
electromagnetic energy
Energy we get from the sun. It changes the air (kinetic energy) When an object receives energy, its total energy increases. The energy from the sun causes temperatures to change
All objects that have mass and temperature radiate _________
electro-magnetic energy
Electromagnetic Radiation (EM)
Emitted by all objects that have temp.
Energy can be expressed in 2 ways
Photon-massless amount of energy emitted through objects

How fast do waves move?
At the speed of light
How do we measure waves
from crest to crest
Speed of light (c)
186,000 miles/second
Number of waves that pass b a point in a given unit of time
Formula for speed of light
wavelenth of energy


frequency of energy
The longer the wavelengths, the _______________________
less frequency there is
Stefan-Boltzmann Law
Some object times its temperature to the 4th power

(The temp. is in KELVINS)
Sigma is a _____
Average temp. of earth in Kelvins

Average temp. of sun in Kelvins

The amount of energy an object emits at wavelength lander
Dry Adiabatic Lapse Rate
10 degrees Celsius/km
Environmental lapse rate is 8 degrees Celsius. Temperature is 35 degrees. What happens?
The dry air is more dense than the environment so it is stable. The moist air will be colder than the parcel so it will be unstable. It's niether absolutely stable or absolutely instable. Instead it is CONDITIONALLY UNSTABLE. It depends if air is saturated unstable saturation and vice-versa. The moist parcel is different b/c it has a latent heat release and the latent heat release is a deciding factor if the atmosphere is stable or unstable. When the atmosphere is absolutely stable or unstable it doesn't matter b/c temperatures are increasing or decreasing w/ height fast or slow enough that it doesn't matter. The only times it matters is in a conditionally unstable atmosphere.
Dissipation Stage
Cloud falls apart b/c all we have are downdrafts. This is b/c we're not adding H2O to storm so it will rain itself out. As air sinks, the saturation mixing ratio goes up, temperatures increase, and humidity decreases. The sinking air is warming and drying so cloud and storm quickly falls apart.
Assume it's extremely cold outside. The temperature inside your home is 68 degrees Farenheit, and outside is 10 degrees. Your home has a large number of poorly insulated windows. Fully explain in words why the relative humidity in your home will be so low. Then explain why using a vaporizer will not lead to an appreciable increase in relative humidity.
When you're outside, the temperature is 10 degrees, and the air is saturated. As you walk indoors, though, you bring the cold air in, but the amount of vapor in the air stays the same. As a result, the air becomes sub-saturated. This causes the RH in your home to remain low. If you have poorly insulated windows, a humidifier will not work b/c the vapor will come into contact w/ the cold air around the windows. This will create more vapor in the air than the air can have in it, causing the air to become super-saturated. As a result, the super-saturated air will condense as liquid water onto your windows.