Thursday, February 14 we did a spreadsheet introduction lesson (Excel) where he entered his barometric pressure log data, and made a graph of the result. He continues to log the barometric pressure and update his spreadsheet and graph. Here's his spreadsheet: Barometric Pressure (Excel Spreadsheet)

Later, we made our own barometer, out of an old graduated cylinder we picked up for $2 at State Surplus. Filled with water and inverted into a pan of water, the graduated cylinder is easy to read. Joe invented his own "unit" of pressure to describe this scale, which he calls the "prebar" and denotes with the symbol of empty parentheses (). We started logging prebars along with inches of mercury and millibars, and then plotted them on the spreadsheet. He observed prebars had an inverted pattern and correctly inferred that was because our scale (the graduated cylinder) was upside down. We made the conversion by inverting the axis, plotting on same graph with different y-axis. I think he got it OK.

Another day, we visited the USWX website where there is hourly barometric pressure data for Juneau in an convenient form. We downloaded the data and put it in Joe's spreadsheet and superimposed this on his graph. He was tracking this very closely, and correctly observed that the phase shift was because the airport data were measured in zulu time! The topic of measurement error arises again....

Barometric Pressure Project Concepts and Skills

• Spreadsheet skills
  • data entry and editing
  • graphing data, formatting graphs
  • inserting new data in graphs
  • fill down
  • spreadsheet formulas
• Aviation: basis for altimeter setting/corrected pressures
• Laboratory data recording skills
• Principles of barometric pressure
• Unit Conversions, incl algebraic formulas
• Meteorology - weather maps