ATMO Exam 1
Absorption
trapping of light
Stratosphere
○air temperature begins to increase with height, producing a temperature inversion ○ The inversion region tends to keep the vertical currents of the troposphere from spreading into the stratosphere. & reduces the amount of vertical motion in the stratosphere. The inversion also tends motion in the stratosphere itself; it is a stratified layer ○ Temperature inversion due to absorption of solar radiation by ozone. - Layer is stable (warmer air over cold air) -If the ozone were not present, the air probably would become colder with height as it does in the troposphere.** -Can "fold" and mix with tropospheric air (jet streams)
Above what continent would you find the ozone hole?
Antarctica
What is the Summer (Southern) tropic?
Cancer
Briefly explain the production and natural destruction of carbon dioxide near the earth's surface. Give two reasons for the increase in carbon dioxide over the past 100 years or so.
Carbon dioxide enters the atmosphere through plant decay, volcanic eruptions, exhalation of living things, the burning of fossil fuels, and deforestation. In the past 100 years, carbon dioxide has risen more than 23% and is expected to continue rising.
Climate feedback
Positive feedback- more warming, more water vapor, released into atmosphere, more warming - Negative feedback- more water vapor, more clouds, less warming - Aerosol feedback- more aerosols, less sunlight to the surface, less warming Think about pollution, volcanoes, and wildfires
6. How do the wavelengths of most of the radiation emitted by the sun differ from those emitted by the surface of the earth?
The wavelengths of the earth are much longer than those of the sun.
Convection
Warm to cold with the help of a fluid -transfer of heat by mass movement of a fluid -Buoyancy - vertical motion of air (or fluid) parcels due to density (r) differences -Rising hot air coupled with sinking cool air sets up convection cells
Conduction
Warm to cold within a substance -Transfer of heat from molecule to molecule within a substance -Ability of molecules to transfer vibrational kinetic energy
Transmission
forward scattering of light
Exosphere
the upper limit of our atmosphere. Here molecules can move great distances before they collide with other molecules, and many of the lighter, faster-moving molecules traveling in the right direction actually escape the earth's gravitational pull and shoot off into space.
12. If the earth had no greenhouse effect, would the earth's average surface temperature be higher or lower than it is presently?
It would be lower because heat would leave the atmosphere through infrared radiation.
Density
mass per unit volume or p=m/V
How does the Kelvin temperature scale differ from the Celsius scale? On a day when the outside air temperature is 273 K, would this air be considered warm or cold?
Kalvin Scale begins at absolute zero(273) and contains no negative numbers. Celsius Scale begins at absolute zero (Number 0 is on the scale) and it contains negative numbers for freezing points.
On a calm, sunny day, why is the air next to the ground normally much warmer than the air just above?
- As the sun rises higher in the sky, the air in contact with the ground becomes even warmer, and on a windless day, a substantial temperature different usually exists above the ground. - This is because air is such a poor heat conductor that this process only takes place within a few centimeters of the ground
Conservation law
- Total energy in the universe is constant - Can be transferred or transformed -Potential energy is constantly converted to kinetic energy in the atmosphere TE=KE+PE= Constant
2. Explain how incoming energy and outgoing energy regulate the daily variation in air temperature.
- the daily variation in temperature is controlled by incoming energy from the sun and outgoing energy from the earth's surface greatest temperature variations occur at SUNRISE and in the AFTERNOON
Relative humidity (RH)
- the ratio of the amount of water vapor actu- ally in the air to the maximum amount of water vapor required for saturation at that particular temperature (and pressure). It is the ratio of the air's water vapor content to its capacity; thus water vapor content RH = ---------------------- x 100 percent. water vapor capacity Relationship between air temperature (T) and wet bulb temperature (Tw); Lower temperature, higher humidity and vice versa - Wet Bulb temperature (Tw) - lowest temperature at which water will evaporate
Lapse rate
-Good indication of stability of the atmosphere - The rate at which air temperature decreases with height
1) Causes of death for various types of severe weather versus other causes of death
-Heat (43% of annual 500) and flood (15%) -Tobacco & obesity - Non Related Tobacco 1,450 Obesity 1,333
Shortwave (SW) radiation is converted to long wave (LW) radiation on Earth -Outgoing LW = Incoming SW twice a day
Energy in = Energy out (Radiative equilibrium) 255K
Energy : Kinetic & Potential
Energy in motion- Ability or capacity to do work - units of J, calorie (cal), or British Thermal Unit (btu) Kinetic - energy in motion A) KE= 1/2 (mv^2 ) Potential- Energy that is stored (difference between an object's ground state and some physical height) B) PE=mgh - Potential energy is constantly converted to kinetic energy in the atmosphere
Radiation
Energy transfer in the form of electromagnetic (EM) waves ○ Shorter wavelengths have more energy than longer wavelengths -Higher energy is associated with high frequency and short wavelength ○ Photons are discreet single visible packets of radiant energy • Ultraviolet (UV) > visible > infrared (IR)
What are some of the important roles that water vapor plays in our atmosphere?
Falls to the ground in the form of precipitation and releases latent heat
5. How does the amount of radiation emitted by the earth differ from that emitted by the sun?
The earth radiates less than the sun, causing the sun to warm the earth.
If the earth's surface continually radiates energy, why doesn't it become colder and colder?
The earth's atmosphere absorbs and emits infrared radiation; it is a selective absorber.
Composition of earth's atmosphere
The earth's atmosphere is a thin, gaseous envelope comprised mostly of nitrogen (N2) and oxygen (O2), with small amounts of other gases, such as water vapor (H2O) and carbon dioxide (CO2). Nestled in the atmosphere are clouds of liquid water and ice crystals. ○ nitrogen (about 78%), ○ oxygen (about 21%), ○ argon (about 0.9%) ○ with carbon dioxide and other gases in trace amounts. Permanent gases Nitrogen- 78% 28g/mol Oxygen - 21% 32g/mol & dry air 28.97 Argon - .93% Neon- .0018% Helium- .0005% Hydrogen .00006% Xenon. .000009%
9. What are the most abundant selectively absorbing greenhouse gases in the earth's atmosphere?
Nitrous Oxide, Methane, Oxygen, Ozone, Water Vapor, and Carbon Dioxide
trace gases
Noble gases of argon, neon,helium, and xenon Inert components ( radioactive decay)
How does weather differ from climate?
Weather is the condition of the atmosphere at any particular time and place. Climate is the average weather over many years.
Work
Work- CUMULATIVE W = F x D Work - moving a force over some distance
Explain two ways the relative humidity may be changed. change in vapor content:
add water vapor content to make it moist, increase RH or cool it to hold less RH; change saturation: do this by changing temp., water vapor molecules increase and gradually approach saturation
20. Why is cold polar air described as "dry" when the relative humidity of the air is very high?
as air temp. increases, relative humidity decreases, so low temps. mean higher RH; at high temps. molecules don't condense easily so RH is low
What is the average (standard) temperature lapse rate in the troposphere?
he average (or standard) lapse rate in this region of the lower atmosphere is about 6.5 degrees Celsius for every 1000 meters (m) or about 3.6°F for every 1000 ft rise in elevation.
Radiation inversion
measured increase in air temperature just above the ground is known as radiation inversion because it forms mainly through radiational cooling of the surface.
Albedo
the percent of radiation returning from a given surface compared to the amount of radiation initially striking that surface.
Energy transfer processes
the process by which energy is relocated from one system to another, for example, through the transfer of heat, work or mass transfer. - Energy cannot be created or destroyed but can be transformed or transferred
Importance of ozone
○ At the surface, ozone (O3) is the primary ingredient of photochemical smog,* ○. But the majority of atmospheric ozone (about 97 percent) is found in the upper atmosphere—in the stratosphere—where it is formed naturally, as oxygen atoms combine with oxygen molecules. where, the concentration of ozone averages less than 0.002 percent by volume. This small quantity is important, however, because it shields plants, animals, and humans from the sun's harmful ultraviolet rays provides a natural protective shield in the upper atmosphere so that plants on the surface may survive.
3 Gas laws
○ Boyle's Law- at CONSTANT TEMPERATURE the volume is inversely proportional to the pressure. (as the pressure increases, the volume decreases/ as the pressure decrease, the volume increases) PV= Constant ○ Charles's Law- at CONSTANT PRESSURES the volume is directly proportional to the temperature. (as the temperature increases the volume increase/ as the temperature decreases the volume decreases) V1/T1=V2/T2 ○ Gay-Lussac's Law- at CONSTANT VOLUME the pressure is directly proportional to the temperature. (as the temperature increase the pressure increase/ as the temperature decreases the pressure decreases) P1/T1=P2/T2 Ideal gas law pV = mRT
2. Explain how heat is transferred in our atmosphere by (a) conduction, (b) convection, (c) radiation.
○ Conduction- The transfer of heat from molecule to molecule within a substance is called conduction. It should be noted that air is an extremely poor conductor of heat. ○ Convection- The transfer of heat by the mass movement of a fluid; takes place in liquids and gases because they can move freely. ○ Radiation - The energy transferred from the sun to your face.
Power
○ P= Work/time; unit of J/s ; watts (W); horsepower (hp) 1 J/s = 1 W and 750 W = 1 hp ○ Solar constant- Amount of radiated sunlight per unit area hitting the earth : 1370 W/m^2 ○ Power- amount of work done over time
Sensible heat
○ Sensible heat is what you feel when a latent heat process releases or absorbs energy from the environment ○ Felt and measured Noticeable during release or gain of • evaporation - cooling • Condensation- heating
Radiation laws
○ Stefan-Boltzmann Law- E is the maximum rate of radiation emitted by each square meter of surface of an object, σ (the Greek letter sigma) is a constant, and T is the object's surface temperature in Kelvins (K) E = σT^4 -As temperature increases, the amount of radiation over a given spectrum increase
Tropopause
○ The boundary separating the troposphere from the stratosphere is the tropopause. (height varies but found at high elevations over equatorial regions, and it decrease in elevations as we travel poleward) ○ tropopause is higher in summer and lower in winter at all latitudes. In some regions, the tropopause "breaks" and is difficult to locate (breaks observe tropospheric air mixing with stratospheric air). - JET STREAMS" JET STREAMS" ○ Jet streams - high winds that meander in a narrow channel like an old river, often at speeds exceeding 115 miles per hour (mi/hr) which is the same speed as 100 knots.* - steady temperature ~ -60C (210K)
Temperature
○ The temperature of the air (or any substance) is a measure of the average speed of the atoms and molecules, where higher temperatures correspond to faster average speeds and lower temperatures to slower average speeds. C=5/9 (f-32) F=9/5 (C+32) K=C+273
On the basis of temperature, list the layers of the atmosphere from the lowest layer to the highest. Which layer is the coldest? The warmest? Which layer contains all of our weather?
○ Troposphere, ○ stratosphere, ○ mesosphere, ○ thermosphere. Coldest is at top of mesosphere and bottom of thermosphere, warmest is in thermosphere. All weather on earth occurs in the troposphere.
Thermosphere
○"hot layer" above the mesosphere ○Here, oxygen molecules (O2) absorb energetic solar rays, warming the air. -relatively few atoms and molecules. Consequently, the absorption of a small amount of energetic solar energy can cause a large increase in air temperature that may exceed 500°C, or 900°F
Mesosphere
○Same percentage of nitrogen and oxygen in the mesosphere but far fewer oxygen molecules than a breath of tropospheric air. ○ At this level, without proper oxygen-breathing equipment, the brain would soon become oxygen-starved—a condition known as hypoxia—and suffocation would result. ○ Avg. temperature 90°C, the top of the mesosphere represents the coldest part of our atmosphere.
Troposphere
(Greek tropein- to turn or change) - This region contains all of the weather we are familiar with on earth & is kept well stirred by rising and descending air currents. - This region of circulating air extending upward from the earth's surface to where the air stops becoming colder with height - Higher in summer, lower in winter due to Decrease in temperature due to less contact with heating from the ground (conduction)
Dew point temperature
(Td) - lowest temperature at which water vapor will condense to which air must be cooled (with no change in moisture content or air pressure) in order for saturation to occur. - sling psychrometer Rh= water vapor content/water vapor capacity lower temp = higher humidity -With ice there is no water vapor!!! Ice has much less water vapor close to none versus liquid water has water vapor (EXAM QUESTION!!!) Radiation inversions are more likely with a clear sky and dry air. Under these conditions, the ground is able to radiate its energy to outer space and thereby cool rapidly. However, with cloudy weather and moist air, much of the outgoing infrared energy is absorbed and radiated to the surface, retarding the rate of cooling. Also, on humid nights, condensation in the form of fog or dew will release latent heat, which warms the air. So, radiation inversions may occur on any night. But, during long winter nights, when the air is still, cloud-free, and relatively dry, these inversions can be- come strong and deep.
As of 2014 Co2 surpassed 400ppm
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Our climate is not "static" but does change over time.
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R+T+A=1
- Reflection + Absorption = Extinction or loss of light - Transmission - light always gets through
Role of water vapor and carbon dioxide (CO2) in the atmosphere
- water vapor (which is the most abundant greenhouse gas) - Not only does it form into both liquid and solid cloud particles that grow in size and fall to earth as precipitation, but it also releases large amounts of heat called latent heat when it changes from vapor into liquid water or ice. - Carbon dioxide enters the atmosphere mainly from the decay of vegetation, but it also comes from -volcanic eruptions, -the exhalations of animal life, - the burning of fossil fuels -deforestation. The removal of CO2 from the atmosphere takes place during photosynthesis, as plants consume CO2 to produce green matter. The CO2 is then stored in roots, branches, and leaves. The oceans act as a huge res- ervoir for CO2, as phytoplankton (tiny drifting plants) in surface water fix CO2 into organic tissues. Carbon dioxide that dissolves directly into surface water, mixes downward and circulates through greater depths. - CO2 is removed completely when it becomes fossilized (carbonate rock) - CO2 is removed partially when it is in organic form. (vegetation)
Radiation electromagnetic spectrum
-50% of Sun's energy in the visible range plank's law Distribution of radiation from a blackbody at a given temperature; continuum of wavelength emissions from SW to LW
Hoe does advection differ from convection
=Convection is heat transfer by the mass movement of a fluid in the vertical (up/down) direction. This type of heat transfer takes place in liquids and gases. This occurs naturally in our atmosphere. -Advection is the transfer of heat in the horizontal (north/east/south/west) direction. In meteorology, the wind transports heat by advection. This happens all the time on Earth, heat is transported in many ways.
(a) How does the risk of death from weather events compare with other risks in life? (Hint: See Table 1.1.) (b) On average, in the United States, which weather-related event takes the most lives annually? (Hint: See Fig. 1.3.)
A lot less than everything else, but still significant 2/100,000 heat 43%
1. Distinguish between temperature and heat.
A) Distinguish between temperature and heat. Temperature is a measure of molecular motion; B) Heat is energy in the process of being transferred from one object to another because of the temperature difference between them.
List the most abundant green- house gases in the earth's atmosphere. What makes them greenhouse gases?
CO2 and water vapor; absorbs a portion of the earth's outgoing radiant energy
What is the Winter (Northern) Tropic?
Capricorn
10. Explain how the earth's atmospheric greenhouse effect works.
Carbon dioxide (C02) , Water (H20), Methane (CH4), Nitrous oxide (N2O), and Chlorofluorocarbons (CFCs) And their absorption characteristics, inhibit to some degree the passage of outgoing infrared radiation from the earth by these elements is popularly called the greenhouse effect. (However, studies have shown that the warm air inside a greenhouse is probably caused more by the air's inability to circulate and mix with the cooler outside air, rather than by the entrapment of infrared energy.)
most important greenhouse gases; in order
Co2 is an import greenhouse gas, and like water vapor, it traps a portion of the earth's outgoing energy. Consequently, with everything else being equal, as the atmospheric concentration of CO2 increases, so should the average global surface air temperature. Variable gases Water 0-4% Co2 .039% methane (CH4) .00017% nitrous oxide (N2O) .000003% chlorofluorocarbons (CFCs) .00000002%
energy budget of the earth
Different latitudes maintain balance differently (different radiation amounts) - Wind and oceanic circulation patterns distribute heat - Tropics and poles are not in a 'runway' situation! Runway situation- weather is what balances this out between surplus and deficits - Ocean is in 1st, weather is in the 2nd for circulating heat
What causes seasons?
Due to Earth's tilt from the vertical (23.5 degrees) -If no tilt, then constant spring or autumn -Earth revolves in elliptical orbit Perihelion - 1.47 x 108 m; closest to Sun in January Aphelion - 1.52 x 108 m; furthest from Sun in July
. According to Fig. 1.4, p. 7, in the state where you presently live which weather event (flooding, lightning, or tornadoes) poses the greatest risk for a weather-related fatality?
Flooding and Tornadoes
times of peak heating (max temperature), min temperature, and max solar radiation
Hottest time- 2-4 PM Coldest time- Right before sunrise Sun @ highest - Local noon
What is the standard atmospheric pressure at sea level in (a) inches of mercury? (b) millibars? (c) hectopascals?
Mercury- 29.92 in. Hg. Millibars- 1013.25 mb hectopascal. 1013.25 hPa
List the two most abundant gases in today's atmosphere. What percentage does each one occupy in a volume of dry air near the earth's surface?
Nitrogen: 78% Oxygen: 21%
Radiation box diagram
Only change cloud reflectivity values (double, half, or no clouds); you will be given "A" and "R", solve for "T" at surface
Explain how ozone is a needed gas in the stratosphere, but an unwanted gas near the earth's surface.
Ozone at the surface is a photochemical smog that irritates eyes and plant life. Atmospheric ozone, however, is shields plants, animals, and humans from the sun's ultraviolet rays.
atmospheric window
Region where CO2 and H2O vapor do not absorb IR radiation (8-11 mm -When clouds are present they DO absorb at these wavelengths ◦ Cirrus clouds tend to trap LW (IR) radiation ◦ Cumulus clouds reflect SW (UV) radiation
Inversion layer
Temperature increases with height
How does the average speed of air molecules relate to the air temperature?
Temperature is the average speed of atoms and molecules. Higher temperatures correspond to faster average speeds
When a body reaches a radiative equilibrium temperature, what is taking place?
The earth behaves as a blackbody and absorbs solar radiation while emitting infrared radiation at equal rates.
5. Explain how radiational cooling at night produces a radiation temperature inversion.
The ground and air near the ground will cool quicker than the air above by radiating infrared radiation (radiation cooling). The warmer temperatures aloft do transfer some heat downward but the process is slow due to the air's poor thermal conductivity. Therefore, by late night or early morning, the coldest air is found next to the ground, with slightly warmer air above (radiational inversion).
4. How does the temperature of an object influence the radiation it emits?
The higher the object's temperature, the shorter the wavelengths of emitted radiation.
11. What gases are responsible for the enhancement of the earth's greenhouse effect?
The main cause of global warming appears to be an increase in carbon dioxide concentrations over the past 100 years primarily due to the burning of fossil fuels and to deforestation. Today, carbon dioxide concentrations continue to increase but other gases such as methane, nitrous oxide, and chlorofluorocarbons have collectively been shown to have an effect almost equal to that of carbon dioxide.
a) What does the relative humidity represent?
The relative humidity (RH) is the ratio of the amount of water vapor actual in the air to the maximum amount of water vapor required for saturation at that particular temperature (and pressure). Or in other words, it is the ratio of the air's water vapor current content to its possible full capacity.
Convection
The rising of hot air and the bubble of air that carries heat energy upward by convection. The development of a sinking of cool air sets up a convective circulation. Normally, the vertical part of the circulation is called convection, while the horizontal part is called wind. Near the surface the wind is advecting smoke from one region to another.
When the relative humidity is given, why is it also important to know the air temperature?
To know how much moisture is available for precipitation we need to know the temperature to know how much the air could hold.
(a) Explain the concept of air pressure in terms of mass of air above some level. (b) Why does air pressure always decrease with increasing height above the surface?
a) Pressure is a consequence of the weight of the atmosphere. A vertical column of atmosphere pushes down on whatever is beneath it with a force equal to its weight. That force divided by the cross-sectional area of the column is the force per unit area, or pressure, exerted at the base of the column. -higher barometric pressures are more associated with colder temperatures while lower barometric pressures are associated with warmer temperatures -sea level reference point b) As height above the surface increases, the amount of air above that level and therefore its weight and the resulting pressure all decrease.
ionosphere
an electrified region within the upper atmosphere extends from the mesosphere to the top of the atmosphere.
Reflectivity
backward scattering of light
Diurnal (day/night) temperature cycle
day/night; Solar SW radiation by day, Earth LW radiation by night
4. Explain why the warmest time of the day is usually in the afternoon,
even though the sun's rays are most direct at noon. even though the sun reaches its highest pint around noon and receives the most intense solar rays around this time, the air continues to be heated often reaching a maximum air temperature later in the afternoon; making an energy surplus for 2 to 4 hours after noon and substantially contributes to a lag between the time of maximum solar heating and the time of maximum air temperature several feet above the surface
Schaefer point
water instantly becomes ice
6. Explain why the daily range of temperature is normally greater (a) in dry regions than in humid regions and (b) on clear days than on cloudy days.
Dry regions have clearer skies and less water vapor in the atmosphere versus a humid region, therefore, where incoming solar radiation is greater during the day in dry regions because the sun's energy is not reflected by clouds (higher temps) and radiational cooling is greater during the overnight hours in a dry region because less water vapor is available to re-radiate outgoing infrared radiation back to the surface (lower temps). Clear days maximize daytime incoming solar radiation and nighttime radiational cooling (maximum daily temp range) while cloud cover will decrease daytime incoming solar radiation and hamper radiational cooling (minimal daily temp range).
Latent heat
Heat that is needed to change phases of a substance (L)- units of j/kg or cal/g - 3 types Vaporization (Lv) - Liquid to vapor or gas Fusion or melting (Lf)− liquid to solid Sublimation (Ls) - Solid to vapor or gas Q= mL Q=heat change (J or nm) M=mass (kg) L=specific latent heat (Jkg^(−1) ) ○ vaporization= liquid to vapor or gas 540 calories req. to evaporate 1 gram of water ○ Fusion/melting= liquid to solid 80 cal to freeze/melt ○ Sublimation= solid to vapor or gas (vis versa) 620 cal. To go from solid to vapor or vise versa
Climatograms
Images over time, what weather will be based off of. Need 10 years of data. Moderating effects of land and ocean on temperature - Moderating effects of land and ocean on air temperature
11. Why is the largest annual range of temperature normally observed over continents away from large bodies of water?
The upper layer of the ocean is nearly always in a mixing state, therefore heat losses and heat gains occurring at the surface are distributed throughout a large volume of water. The mixing process sharply reduces air temperature contrasts between day and night between winter and summer unlike land, where overland there is almost no redistribution of heat by land turbulence and the amount of conduction is quite limited