Quiz #1 Study Guide
Composition of the atmosphere (15 - 10 pts). The five most abundant gases in the atmosphere (listed here in alphabetical order): argon (Ar), carbon dioxide (CO2), nitrogen (N2), oxygen (O2), and water vapor (H2O) (you should know approximate concentrations of all but CO2).  Water vapor (H2O) and carbon dioxide (CO2) are greenhouse gases. What do they (what does the greenhouse effect) do?  What weather variable is commonly used to measure atmospheric water vapor content?   Typical values of that variable in Tucson during the year.

Atmospheric evolution (5 pts). About how old is the earth? What was the earth's first atmosphere composed of?  Where is our present atmosphere thought to have come from? What are the three most abundant gases emitted by volcanoes? What important atmospheric constituent in our present atmosphere did not come from volcanoes? What is the principal source of that gas?  Why were stromatolites, cyanobacteria, and the banded iron formation mentioned in class?

Air pollution (0 pts).   Air Quality Index (AQI). A pollutant is considered unhealthy when the AQI exceeds what value?

Carbon monoxide (CO) (15 pts). Toxic, colorless, odorless.  Incomplete combustion (what would complete combustion produce). Oxygenated fuels and catalytic converters.  Early morning wintertime pollutant. What is a surface inversion layer, when do they form? Stable and unstable atmospheric conditions.  Would a surface inversion layer act to concentrate or disperse CO?  CO is a serious indoor hazard.

Scattering of Light (0 pts).   Microscopic water droplets and ice crystals in clouds, particles, and air molecules all scatter ("splatter") light.  Are we able to see sunlight being scattered by air?

Tropospheric ozone and Stratospheric Ozone (O3) (10 - 15 pts). Ozone aggravates existing respiratory diseases, is harmful to plant life, and damages materials such as rubber. Ozone is a secondary pollutant and is a key component of photochemical smog (also known as Los Angeles-type smog). To produce smog, ozone reacts with hydrocarbons. The gaseous product of that reaction condenses and forms a smog cloud that we can see.  Peak ozone and photochemical smog concentrations occur on summer afternoons.

Ozone layer.  What beneficial role does it play?  Natural formation of stratospheric ozone.  Chlorofluorocarbons (CFCs) destroy stratospheric ozone.

Sulfur dioxide (SO2) (10 pts). Toxic and aggravates existing respiratory diseases. The first pollutant that people were aware of.  Natural and manmade sources. Involved in some of the world's worst air pollution disasters: Great London Smog of 1952, Donora (Pennsylvania) 1948. The word smog was first used to describe the combination of sulfurous smoke + fog; the term London-type smog is now used.  SO2 reacts in clouds to form acid rain.  The pH scale.  What gas was used in the acid rain demonstration in class?

Particulate Matter (PM) (5 pts).  Small particles (generally less than 10 micrometers) that are inhaled into the lungs and sometimes even enter the bloodstream.  Sources of PM.  PM is a year round pollutant, a health concern, and also affects visibility.  How are PM and gaseous pollutants most effectively removed  from the atmosphere?

Sample questions ( from the online example quizzes )
Practice Quiz: 1, 3, 4-7, 9, 13, 16a, 20?, EC1        Quiz #1: 1, 2, 4a       Final Exam: 2, 20(2nd part)
 
Mass, weight, density, and pressure (20 pts).  Mass is the amount of a particular substance. On the earth gravity pulls downward on a mass producing weight. Pressure at any level in the atmosphere is a measure of the weight of the air above (this is a large scale of thinking about and understanding pressure).   Pressure is defined as force (weight) divided by area and acts like a force (a force that pushes upward, downward, and sideways). Common pressure units and typical sea level pressure values.   What is the name of the instrument used to measure air pressure?  About when (what century) was it invented?  Pressure and density decrease with increasing altitude (you should be able to explain why).  How does the rate at which pressure decreases with increasing altitude depend on air density?

Sample questions
 Practice Quiz: 15, EC2, EC3     Quiz #1:  3, 17a&b          Final Exam: 6, 11

This semester's Practice Quiz covered material up to this point

Ideal Gas Law (20 pts).  This is a microscopic explanation of air pressure.  Two equations

P = N k T / V     &     P = ρ R T

N is the number of air molecules in a volume V, T is temperature and ρ is density.  R and k are both constants.  You should be able to determine what will happen to the pressure in a rigid container or something flexible like a balloon if you change one or more of the variables in the equations above.  What variables could you change together in such a way that the pressure would stay constant?  Charles' Law.  In the atmosphere why is warm air normally low density air and cold air normally high density air?

Sample questions
Quiz #1: 16     Final Exam: 22     

Vertical forces acting on air parcels (the strength of one of the forces depends on the air inside the parcel, the other on the air outside the parcel). These two forces are usually in balance. What happens to the balance when you warm or cool a parcel of air?  Basically you should be able to explain why a balloon of hot low density air rises and a balloon of cold high density air sinks.

Archimedes principle states than an object immersed in a fluid (this can be a liquid like water or a gas like air) experiences an upward buoyant force that is equal to the weight of the fluid displaced by the object.  Basically objects that are less dense than the fluid around them float, objects that are denser sink.  What causes the upward buoyant force (see Quiz #1 Question #13 in the list of sample questions below).

Sample questions
Quiz #1: 13, 14     

Layers of the atmosphere (20 pts).  Troposphere: lowest layer in the atmosphere, decreasing temperature with increasing altitude (why is the warmest air found near the ground), contains most of the water vapor, clouds and weather, can be stable or unstable (strong up & down air motions possible).  Stratosphere: there's an isothermal layer and then a layer where temperature increases with increasing altitude (a temperature inversion), what causes air to warm in the stratosphere, stable layer, contains the ozone layer.  Approximate altitudes of these layers.  Units: meters, kilometers, feet, miles.

Sample questions
Practice Quiz: #8, 16b     Quiz #1: 4, 17

Station model notation (20 pts).  How and where are the following weather variables plotted on a surface map: cloud cover, temperature, dew point temperature (typical values for Tucson), wind direction and speed, common weather symbols (rain, snow, fog, rain shower, thunderstorm, tropical storm and hurricane), pressure.  Units.   After pressure is measured, what important adjustment is made before the pressure is plotted on the surface map? Why is that necessary? Average and typical range of sea-level pressure values.

Sample questions
Practice Quiz: 14, 19?     Quiz #1: 6?, 10       Final Exam: 52
 
Surface weather maps (30 pts).  Isobars and isotherms (one of each is shown in the figure below). Small horizontal differences in pressure cause the wind to blow. Air motions around high and low pressure centers (northern hemisphere).  Does the figure below show a center of  high or low pressure?  Would you expect the air at Pt. A to be warmer or colder than at Pt. B?

Convergence and divergence.  Rising air motions, what can cause air to rise and why is rising air.  Sinking air.  Strong and weak pressure gradients and their effects.

Sample questions
Practice Quiz: 2, 10, 11     Quiz #1: 7, 8, 9     Quiz #2: 3?       Final Exam: 7, 10a&d, 34?

Fronts (35 pts).  Cross-sectional structure of cold and warm fronts (such as shown below).  You should be able to identify the warm and cold air and be able to determine which direction the cold air mass is moving.  Symbols used on surface maps, where is the warm & cold air, what direction are the fronts moving.  Weather changes (temperature, moisture/dew point, wind) that precede and follow passage of warm and cold fronts.  You will not have to locate a front on a surface map like was done in class, though I might draw a front and ask you what type it is.

We may well get started on the next section but it won't be covered on Quiz #1
Upper level charts (0 pts).  What is an upper level chart, how do they differ from surface maps?  You should be able to identify ridges and troughs, know where the warmest and coldest air would be found and should know something about how the winds blow on upper level charts.

Sample Questions
Quiz #1: 11     Final Exam: 17, 21 (cP means a cold,dry air mass), 47

Reviews
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 4 - 5 pm
 Modern Languages 311
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 Haury(Anthropology) 129