Mt206 Instructor's Manual
Doug Yargerand Vicki Boysen
Iowa State University
Spring Semester 1999
Table of ContentsPage Number
Introduction2
Preliminary Activities3
"Ice breakers" for Small Group Activities3
Graph Interpretation problem sets3
Weather Map Symbols problem set3
Forecasting Exercise3
Purpose3
Structure4
Temperature Questions5
Precipitation Questions6
Wind Speed and Direction Questions7
Radiation Balance Simulation7
Description of Simulation7
Instructional Goals8
Assigning RadiationSim8
Post-Simulation Activity9
Suggested Thought Questions for Class or Group Discussion9
Lecture Outline10
Mountain Simulation11
Description of Simulation11
Instructional Goals11
Assigning MtnSim12
Post-Simulation Activity12
Suggested Thought Questions for Class or Group Discussion13
MtnSim Humidity13
MtnSim Advection13
MtnSim Adiabatic14
Lecture Outline14
Other course components14
AdvectionSim14
Clouds and Storms14
Severe weather contest14
Student Evaluation14
(Note: Underlined words will eventually be Web Links)
Introduction
The origins of this course involved the desire to convert a standard meteorology lecture course into one where constructivism was the main instructional model and students were expected to take a more active role in their own learning-all without reduction of class size! One of the major tools used to accomplish this undertaking was the use of World Wide Web server software (ClassNet, which manages Internet class activities. This allows every student to be an active participant in learning activities with easy access to course materials, enhanced communication with the instructor and other students, rapid feedback concerning assignment and exam scores, and ready access to their private records of course performance. Course assignments involve authentic activities (forecasting), simulated learning environments (Java-based simulations) and more standard evaluations of content understanding (short-answer responses).
The course goals have been expanded to include learning how to learn science as well as learning science content. The focus of the course is on the understanding of weather phenomena, and the primary vehicle for learning is an authentic activity where each student routinely predicts weather events and supports his or her prediction by identifying determining factors. This weather forecasting activity has been very successful in encouraging student participation and in promoting understanding in this course. The forecasts provide a continuing thread of meaningful discussion and motivation throughout the semester.
Course materials have been designed for introductory science courses at the secondary and college level. They are intended to be supplemental to the course, allowing the instructor to decide which materials to use and which to omit. Experience with these materials has shown that their effect, especially the effect of the simulations, is gradual and sufficient time must be allowed to observe a difference in student behavior and attitude. Students often find the simulations to be uncomfortable at first because they use them before they hear the corresponding lectures, but this approach is deliberate and is intended to create questions in students' minds so they will come to class seeking answers.
Part of class time should be allotted to the use of Small Group Activities. These allow students the opportunity to break away from the passive mode utilized in most large-scale classes and become more active learners. These activities have been well received by students. They often end up sitting in about the same place in the auditorium for every class meeting and usually look forward to interacting with the people who sit near them week after week. Various collaborative activities are used to draw each student into the construction of hypotheses for explaining observed scientific phenomena or processes. Lectures are then used to provide explanations when students have explored, tested and questioned various factors that relate to central course concepts.
Materials development for the new learning environment did not rely on traditional instructional development models. The new materials could not be designed to simply teach the course content when the goal was to encourage the learner to explore, conjecture and test ideas. The chosen solution was to develop problem-based simulations that pose scenarios and provide tools with which learners can explore, and that accurately reflect the results of specific learner's actions. The materials have served to set the stage for further learning by revealing misconceptions, raising questions, activating relevant existing knowledge, and alerting the learner to the structure and utility of the material to be learned.
Preliminary Activities
"Ice breakers" for Small Group Activities
Graph Interpretation problem sets
Weather Map Symbols problem set
Forecasting Exercise
Purpose
Prediction is a key goal of science and one which students eagerly embrace. They quickly realize that to improve their predictive skills they must develop additional skills of observation, hypothesis-generation and testing, and analysis. One particular activity that has proven to be highly motivating and very effective in creating authentic situations for scientific inquiry when used in a large introductory meteorology course is a Web-based Weather Forecasting exercise (Figure 1). This activity has become the common thread for the course and serves as an ever-present opportunity to apply course concepts in real-world contexts.
The forecasting exercise provides students repeated opportunities to test their understanding of various weather processes in a forum that is:
1. Goal-directed (students are asked to predict various weather parameters and select the appropriate physical reasons).
2. Failure-driven (situations are created that allow the student to make mistakes, followed up by opportunities to learn how to correct these mistakes).
3. Case-based (lecture discussions of difficult areas now become relevant to the student's goal of correcting mistakes).
4. Based on learning-by-doing (each student must do a minimum of 25 forecasts).
Figure 1. Forecasting Exercise
Structure
The forecasting exercise requires that participants use available weather products to predict weather parameters for 12Z and 18Z the next day. These times were selected to correspond to early morning (thus representing nighttime conditions) and mid-day periods for cities across the United States. There are several versions of this activity which have been tested in the Mt206 course at ISU:
1. The instructor can allow participants to select any available city they desire and forecast for current weather conditions. The codes for available cities can be found by accessing the "Find station code" option (see Figure 1).
2. The instructor can specify a city that is the forecast city. Figure 2 shows a case where Nashville, TN, was the forecast city for all students.
3. Because it is now very easy to find weather forecasts for many cities on the Internet (e.g., we have developed an archival version of the forecast exercise. Figure 2 is an example where the forecast city (Nashville, TN) and the forecast day have been pre-selected. The appearance of the forecast page is the same as before but now the weather data correspond to designated periods preceding the forecast times.
4. Any of the versions of the forecast exercise can be modified to add or delete forecast questions. It has been helpful to use a restricted set of questions at various times in the course to focus attention on specific physical processes.
Figure 2. Archival Forecast Page
Temperature Questions
The acceptable range for the 18Z daytime temperature forecast has been selected to be +/- 5 °F, although the range can be selected by the instructor. The scoring weights we have used give students 3 points for a correct answer, 1 point for an answer outside the bound and zero points for no submission. These can be changed at the discretion of the instructor as well. In addition to predicting weather parameters, participants in the forecast exercise are also asked to provide supporting rationales for their predictions. For the Mt206 course we identified several processes that could significantly influence temperature changes. These are addressed in the Temperature Influences questions and consist of:
1. Cloudiness
2. Advection
3. Fronts
4. Adiabatic processes
Daytime cloudiness is defined to have a significant influence on the 18Z temperature based on the following algorithm: The reporting site is evaluated for the times 15Z, 16Z, 17Z and 18Z to determine if two or more of these times report at least broken clouds (75% cloud cover). When this condition is met, clouds are said to have held down daytime temperature (since 18Z is near midday in the United States).
For this exercise, significant advection is defined as at least a 1 degree F. temperature change due to advection occurring in the two hour period preceding 18Z (i.e., the total change for two hours, 17Z and 18Z is 1 degree F or more). This corresponds to a 10 mph wind blowing directly across isotherms which have a spacing of about 10 degrees F. over a distance corresponding to the N-S dimension of Iowa (about 200 miles) for a two hour period.
Fronts can influence temperature in a variety of ways. These influences include cloud cover associated with specific frontal types, change of air mass as a result of frontal passage, and processes associated with precipitation. Because a fast cold front can move about 90 miles in a 3-hour period, the evaluation procedure checks for the appearance of a front in a 2-degree grid containing the selected site during a 3-hour period centered on 18Z (i.e. 17Z, 18Z, 19Z). This corresponds to determining whether a front is within 140 miles of the reporting site during the 3-hour period centered on 18Z. Warm, occluded and stationary fronts are all evaluated using this same criterion.
Adiabatic processes were explored by having students forecast in a mountain region (Reno, NV) to provide them with a practical application of this topic in a meteorological context. The Java-based simulation ( has been designed to engage students in exploring various factors which are associated with air motions on mountain slopes.
Factors that affect nighttime temperature changes are similar to those for daytime except that cloud influences are now different. Clouds restrict cooling at night because they absorb long-wave radiation emitted by the earth's surface and lower atmosphere and re-emit a significant portion back. The criterion selected for defining significant restriction of radiation cooling is whether there will be 3 or more hours of at least broken clouds (i.e., 75% cloud cover) in the 6 hours preceding 12Z (i.e., for 7Z to 12Z).
Precipitation Questions
If even a trace of precipitation is reported during the 24-hour period 12Z to 12Z, precipitation is defined to have occurred. Three factors that may influence the occurrence of precipitation are:
1. Moisture supply
2. Frontal position
3. Atmospheric instability
The algorithm that is used to evaluate whether the supply of moisture is adequate to favor precipitation is based on experience. A rule of thumb is that when the relative humidity is at least 70% at 850mb, overcast conditions are usually observed. At a relative humidity of 90%, there is probably precipitation occurring, so 80% is somewhere in between and is defined to be a "favorable" value. The criterion is whether the relative humidity is equal to or greater than 80% at 850mb at either 12Z, 00Z or the following 12Z time. Because the moisture supply is expected to change slowly, evaluation at these times is considered representative for the 24 hour period between 12Z and 12Z. 700mb relative humidity analyses can be found in the "Weather Products" link at the top of the forecast page (see Figure 1). Although 700mb humidities and 850mb humidities are different, 80% relative humidities at 700mb are also considered to be good estimates of moisture supply.
A grid area of 2 degrees by 2 degrees (about 140 miles by 140 miles) is associated with each reporting site for the purpose of evaluating the existence of fronts. If a front of any type is reported within this area during the 24-hour period between 12Z and 12Z, this will be defined to be a factor for favoring precipitation.
The algorithm that evaluates whether the atmosphere is sufficiently unstable so as to favor precipitation is based on the 850-500mb temperature difference for the forecast city. A temperature difference between 850mb and 500mb which is at least 25 degrees Celsius is representative of conditional instability and favors upward motion of cloudy air parcels and, thus, precipitation. 850mb and 500mb maps with temperature analyses are provided in the "Weather Products" section at the top of the forecast page (see Figure 1).
Wind Speed and Direction Questions
As with other aspects of the forecasting exercise, the instructor can also adjust the criteria for wind speed and direction predictions. For the Mt206 course at ISU, a value within + or - 5 knots of the reported wind speed is considered "correct." A wind direction forecast is considered "correct" if it is within + or - one octal of the reported value.
Radiation Balance Simulation
Description of Simulation
RadiationSim (Figure 3) is a simulation of radiation processes in the earth's atmosphere caused by solar, terrestrial, and atmospheric radiation transfer. Students analyze temperature data measured by a balloon (radiosonde) that they "launch" both in the morning and evening over four types of terrain (sand, plowed field, grass or fresh snow). As the balloon is dragged and dropped to various heights in the simulated atmosphere, the temperatures at these altitudes are automatically plotted on a graph. Several temperature profiles may be plotted concurrently to compare differences before clearing the graph.
Figure 3. RadiationSim
The students are asked to explore the various temperature profiles that can occur under different surface conditions and times of day. Then they answer questions designed to test their understanding of the concepts experienced in the simulation. Specifically, the questions address the effects of ground cover, time of day and altitude on temperature. Students may use the simulation in any manner they feel necessary in order to answer the questions.
Instructional Goals
The Radiation Balance Simulation has two instructional goals. First, it provides an environment in which beginning students can assume the role of scientist. Second, if students reason beyond the data collected, the simulation raises some interesting "why" questions that lead to a much deeper understanding of long and short wave radiation.
For these goals to be met, the instructor must support the simulation by creating the proper initial environment, emphasizing the process of scientific discovery, and building higher level discussions on the student's RadiationSim experience. Strategies for providing that support are discussed herein.
Assigning RadiationSim
This simulation is intended to be the initial simulated activity the students encounter in the meteorology course. It is also intended to be a pre-lecture experience rather than a post-lecture practice assignment. Experience has shown that this is a new type of learning endeavor for most students and much scaffolding needs to be provided. The mechanics of the simulation should be demonstrated and some global strategies should be discussed. It is most important, however, that the teacher's role not usurp the critical learning opportunities from the students. The teacher's role can be seen more clearly if the learning goals are understood.
During this initial simulation the students should begin to develop a strong Problem Solving Strategy. Most students are very weak in this area and need considerable encouragement in developing this skill. An example of a Problem Solving Strategy that is the desired result from the use of RadiationSim is as follows:
1. Explore the simulation, identifying the inputs, outputs and goals.
2. Estimate and note the expected outcomes.
3. Develop a plan to test these expectations.
4. Collect sufficient data and record results.
5. Analyze and summarize the data.
6. Compare and contrast the results with the expected results.
7. Question the reasonableness of the results and seek explanations for them.
8. Rethink the process, identifying additional data that needs to be collected and important questions that need to be resolved.
With these expectations in mind, it is recommended that the teacher demonstrate the simulation by showing how to activate it, set the parameters, move the balloon, plot the points and read the graph. Students should then be challenged to "become a meteorologist" and make predictions about the relationships among ground cover, time of day, altitude and temperature.
Students would be encouraged to develop a plan to test their expectations and, after using the simulation, reach a conclusion about the accuracy of their predictions. At this point in the learning process, it is important for students to develop their own strategy to test their theories; the teacher will present the "ideal" Problem Solving Strategy only after students have generated one of their own.
Post-Simulation Activity
Following students' use of the simulation, it is recommended that students be assigned a small group activity of sharing strategies used with the simulation exercise and agreeing on a good strategy. The teacher can solicit strategies from selected groups, outline one or two good approaches and discuss their merits. During this time the eight steps in the Problem Solving Strategy listed above can be presented and "methods" of meteorology can be described. Experience has shown that special attention also needs to be given to interpretation of graphs and their use to represent relationships of this type. The use of symbolic representation is a deficiency in many a student's knowledge base.
After the strategies have been covered, the results from the simulation can be shared. Questions of reasonableness of the conclusions and scientific basis for these phenomena can be raised. Suggested questions that may be helpful in initiating discussion are listed below. These questions should lead directly to a lecture on long and short wave radiation and their interaction with the earth's temperature.
Suggested Thought Questions for Class or Group Discussion
1. Of the four surfaces in RadiationSim (sand, plowed field, grass and snow), which one gets the hottest during the daytime? The coldest? Why?
2. How does temperature change with altitude? How do the daytime air temperatures above each surface compare with nighttime? How are they the same? How are they different? What causes the differences?
3. Focus on the temperature changes between 0 and 600 meters for all four surfaces. As altitude increases in the daytime, what happens to the temperature? What about nighttime? What causes nighttime temperatures to increase below 600 meters?