Quiz #2 Study Guide

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 rising air is important. Sinking air. Strong and weak pressure gradients and their effects.

Fronts (20 pts). Cross-sectional structure of cold and warm fronts (such as shown below). Symbols used on surface maps, where is the warm & cold air, what direction are the fronts moving. Weather changes (temperature, moisture/dew points, winds) 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.

Upper level charts (10-15 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 (from the online quiz packet)
Practice Quiz: 2, 10, 11, 14 Quiz #1: 7, 8, 9, 10, 11 Final Exam: 7, 10a&d, 34, 47, 52

Energy, temperature and heat (15 pts). Kinetic energy - energy of motion. Temperature (which scale?) provides a measure of the average kinetic energy of the atoms or molecules in a substance. Heat energy is the total kinetic energy of all the atoms or molecules in a material. Energy units: calories. What is the relationship between energy added to (or removed from) an object, ΔE, and the temperature change, ΔT, that results? Specific heat (aka thermal mass or thermal capacity). Water has a relatively high specific heat (4 or 5 times higher than soil). A city on a coastline will have a more moderate climate (what does that mean?) than a city located further inland. Other than a change in temperature what else can happen when energy is added to or removed from a material?

Temperature scales (10-15 pts). Fahrenheit, Celsius, and Kelvin (absolute) scales. You should know the temperatures of the boiling point of water at sea level and the melting point of ice/freezing point of water on the F and C scales. The global average surface temperature of the earth is about what temperature on the Kelvin scale?

Energy transport (40 pts).
(1) Conduction. Energy is transported from hot to cold by random atomic or molecular motions at a rate that depends on the material (thermal conductivity) and the temperature gradient. Examples of good and poor conductors. An object with high thermal conductivity will often feel cold to the touch because it rapidly conducts energy away from your body (our perception of temperature is not a good measurement of temperature).

(2) Convection. Energy transport by organized motion of atoms or molecules (works in gases and liquids but not solids). Free (rising and sinking air) and forced convection. Free convection is a third way of causing rising air motions in the atmosphere. Wind chill temperature.

(3) Latent heat energy transport. 2nd most important energy transport process. Six phase change names. For each phase change you should know whether energy is added to a material (absorbed from or taken from the surroundings) or taken from the material (released into the surroundings).

Sample Questions
Quiz #1: 5, 12, EC3 Final Exam: 12, 43, 53 See also this new set of Sample Questions

Static electricity and electric fields (5 pts). Like charges repel, opposite charges attract. An electric field arrow shows the direction and strength of the force that would be exerted on a positive charge placed at that location. Would the electric field at Point X below, halfway between a + and a - charge, point toward the right, the left, or would the electric field be zero?

+ X -

Electromagnetic radiation (15 pts). The most important of the 4 energy transport processes (why?). Oscillating electric and magnetic fields that can propagate (at the speed of light) through empty space (and also transparent materials like glass & air). Radiation can be produced by moving charges. You add energy to cause the charges to oscillate and produce the radiation. Energy reappears when the resulting radiation causes electrical charges somewhere else to move. Wavelength is one way of distinguishing between different types of radiation (frequency is another). Would a slowly-oscillating charge produce long- or short-wavelength radiation? Would this be a relatively high- or low-energy form of radiation? Electromagnetic spectrum. We will mostly be concerned with ultraviolet (UV), visible (VIS), infrared (IR) light. What is the wavelength interval for visible light? What is white light? Does red light have longer, shorter, or the same wavelength as blue light? Wavelength units.

Rules governing the emission of radiation (10 pts). What determines how much and what type of radiation an object will emit (the same variable is found in both the Stefan-Boltzmann law and Wien's law)? A light bulb connected to a dimmer switch was used to demonstrate. Radiant energy emitted by the earth (300 K) and sun (6000 K).

Radiative equilibrium (0 pts). Energy balance. Incoming radiant energy (sunlight) is balanced by an equal amount of (but not necessarily the same kind of) outgoing radiant energy, temperature remains constant.

Filtering effect of the atmosphere (0 pts). Does the atmosphere mostly absorb, selectively absorb, or mostly transmit UV, VIS, and IR radiation? What gases are important in each case? What does the term window mean? What property makes water vapor, carbon dioxide, methane, etc. greenhouse gases?

Sample Questions
Quiz #2: 11, 12, 13, 14, 15, EC3 Final Exam: 15, 36 Questions 1-3, 5-8, 9?, 10, 12, 13, 15 from this 2nd set of Sample Questions

Reviews

Tue., Oct. 15	2 - 3:15 pm	Saguaro 225
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