# Exercise #8

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• Problem #1 - The concentration utility section showed how to convert the binary concentration file to an ASCII text file. Use the hysplit2.bin.txt file you already created and import it into an existing program on your computer, not part of the HYSPLIT distribution, and see if you can display the results.

• Hint - There is no one answer as it depends upon the software you have already installed on your system.

• Solution - For this example, the file was imported into EXCEL, the latitude and longitude columns were reversed, and all the values starting on the 26th 1500 UTC were selected before creating a bubble plot for just that time period. Moving the cursor over the plot then shows the concentration value at the pointer location, in case, 1200 μg/m3at 79W 43.25N.

• Problem #2 - The concentration utility tutorial showed the concentration time series at Little Valley, NY (S510) for a relatively coarse concentration grid of 0.25 degrees. Would the results be similar if a finer grid resolution was used - perhaps 0.05 degrees?

• Hint - Retrieve captex_control.txt and captex_setup.txt and reconfigure. Remember to change the output file names so the previous simulation can be used for comparison.

• Solution - How does the fine grid time series compare with the coarse grid calculation? How do the coarse grid statistical results compare with the new fine grid simulation?
• 14 m 7 s

• Problem #3 - Continuing with problem #2, recompute the fine-grid concentrations using the 9 km WRF meteorological data.

• Hint - Follow the alternate approach by editing and running batch files: conc_cexp.bat, conc_util.bat, and conc_stat.bat

• Solution - In this example, the finer grid concentration and meteorology calculation shows a slightly better fit with the measurements at Little Valley because of the second peak. There is also an improvement in the statistical results compared with either of the previous calculations.
• 9 m 52 s