Exercise #14




  • Problem #1 - All the previous dust simulations were done assuming no gravitational settling. Rerun the last dust simulation, the one with the corrected emission factors, with deposition and evaluate changes.

  • Hint - Assume a particle density of 4.0 g/cc with a diameter of 2.5 µm and a shape factor of 1.0

  • Solution - The scatter diagram and statistical results with deposition should be compared with the previous no deposition scatter and statistical results.

  • Problem #2 - Using the output from problem #1, display the concentration contours with the sampling data and county boundaries.

  • Hint - From the concentration display menu optimize the map scale by forcing the map center and radius, define a map background with county boundaries, adjust the contour intervals to clarify the graphic, and select the measured data file.

  • Solution - These options result in this graphic, although many other combinations will also produce satisfactory results.

  • Problem #3 - On 21 June 2020 around 1200 UTC, the GOES satellite captured an image of Saharan dust crossing the Atlantic Ocean. Configure and run HYSPLIT to create the model equivalent of this image.

  • Hint - Start the simulation about a week before. The 15th of June would be a good starting point if using the weekly GDAS meteorological data files. Create a global concentration grid with snapshot output with sufficient vertical extent to capture the satellite view.

  • Solution - There should be quite good correspondence between the satellite image and the model graphic.