### Overview

In order to forecast, students need to understand how advection influences the weather.  Since advection is a process, students need to view the phenomenon dynamically rather than through a static map.  Furthermore, students need to manipulate relevant variables (e.g. wind speed and direction) to investigate their effect on the advection process.

For undergraduate majors, advection is explained with equations.  However, for non-majors as well as high school students, using equations to explain advection often detracts from understanding the underlying physical phenomenon.  The purpose of this use case is to define a simulation which will allow students to investigate the process of advection prior to a discussion of the process.

### Description

Students are given a weather map of the U.S. with an initial temperature contour gradient.  Students will be able to specify the wind direction, speed and duration. When the simulation is run, the temperature gradient will move as a result of their input parameters.  An example is shown in  AdvectionSim . (We didn't have the manpower to develop a proper gradient display and so only used straight lines gradients.  Unidata to the rescue?)

Depending on the level of the student, students may be asked to:

• determine the value of the input parameters required to change the temperature in Boulder by 5 degrees
• describe what happens when the wind is parallel to the gradient
• derive the equation for temperature based on wind speed and direction

### Main Scenario

Steps:
1. Display U.S. map with temperature gradient
• Gradients could come from archives or current weather
• A particular situation would be chosen for each invocation of the simulation
• The instructor chooses which variables the student can adjust
• It may be useful to let the student choose certain advection events, provided by the instructor. This would be a list of names of archived datasets
• It might be helpful to have an "advection bean" which does the display and let us develop the GUI for the simulation.
3. Student clicks RUN and views animation
4. Student resets simulation and runs again, as needed