Lisa Doner

Plymouth State University

Undergraduate Gen Ed lecture course on Weather, all non-science majors, max 45 students, co-requisite with Weather lab.

1. Prior understanding of causes for pressure and air density change (basically that air has mass and that results in pressure differences)
2. Ability to cut and paste text data off a web site and import it into word or excel
3. Ability to plot xy variables in excel, label axes, and print chart

I do this activity early in the term, to get the students interested in current weather events and catch under-prepared students early on (usually the computer tech aspects) so they learn techniques needed later on. It also sets the stage for later lectures on linkages between wind speed and pressure gradients.

Content - basic meteorological data on pressure and wind speed
Concept - weather is an active process, ongoing today, often significantly impacting human lives
Goals - focus student attention on weather news, weather impacts, and weather data resources; also engage students in the data itself so using the variables becomes a familiar and comfortable way of describing the environment

This task invokes relatively simple associations between data variables and observed weather, because it is introducing the concept of scientific data analysis to non-science majors. Students need to conceptualize inverse relationships and show this graphically. They also experience and need to resolve problems of scale in graphical representations, since wind speed values are much lower than pressure values. The intent is that students will be able to extrapolate their understanding of the wind-pressure relationship to more complex feedbacks related to hurricane behavior, such as with wind shear and SST variability.

Students must search for and distinguish relevant and irrelevant data on weather web sites, select appropriate variables to plot, and analyze the trends in the data with respect to other variables. They must synthesize these activities into a report that includes graphical representations and written summaries.

This homework assignment is given in the first two weeks of class. Students receive one or two lectures that cover the topics of atmospheric layers, temperature and pressure profiles, concepts of atmospheric mass and pressure and measuring (i.e. dropsonde) instrumentation. At the beginning of each lecture I briefly show them the tropical update from the NOAA National Hurricane Center web site; if there is an active storm, I show where I go to get more info, such as the projected storm track and storm history (for example, from Intellicast Hurricane Tracking). Then, for this assignment, I reintroduce them to these hurricane information web sites and demonstrate how to find the historical data on tropical storms (such as from the Unisys Hurricane Data Archive), and how to copy and paste text data into word and/or excel, as a tab- or space-delimited file. I point out some problem areas with this data-grabbing method, such as headers that get lost from their associated data column or date information that may not format as dates.
I then hand out the assignment, which asks them to:

1. Find data on a current or recent (this year) tropical system, provide the name and year of the storm and the reference web site, and plot the wind speed and pressure variables against time. Students should label the axes and give a descriptive title to the chart.
2. Describe what they notice in the graphed data and if it seems believable (this allows students to decide if they have done the task correctly by using their understanding of the data).
3. Predict what will happen if the storm a) intensifies or b) weakens.
4. I then provide another data set (of any long-duration tropical storm that formed, weakened and later re-intensified) and ask them to go through the same process of plotting and interpretation.
5. I tell them that some future climate predictions are for more storms with lower central pressures and ask which of the two charts best represents that future scenario, and why.

Assessments for this assignment use the student report for initial evaluation, with success met if at least 75% of the student reports include:

1. an accurate and labeled chart of the data;
2. written comments on the inverse relationship between wind speed and pressure;
3. extrapolation of this inverse relationship to hurricanes in general by identifying it in the second data set as well; and
4. predictions of future behavior and students choose the best representation for predicted change.

Follow-up assessments on learning retention and improved skills include quiz, homework and exam questions that require repeated success at graphing, web-based data downloads, and applied knowledge of the response of wind to pressure changes.

NOAA National Hurricane Center
Intellicast Hurricane Tracking
Unisys Hurricane Data Archive