Part 5: Advanced Trajectories HANDS-ON EXERCISES Part 5: Advanced Trajectories PC-HYSPLIT WORKSHOP

Example Simulations Presented on the following slides are exercises for: (1) running trajectories for one season, (2) displaying them on a trajectory frequency plot, and (3) displaying them by trajectory clusters. The first slide of each example will present the problem to be answered, the next few slides will show the GUI inputs, and the last slide(s) will show the results. It is recommended to click on the Reset button of the main HYSPLIT menu before proceeding in order to clear out any old cases in the working directory. Also manually delete all files in \hysplit4\cluster\working or move them to another directory all ‘tdump’ files in \hysplit4\working. Note: These runs were produced using HYSPLIT version 4.9 (released January 2010). Slight differences are possible with older/newer versions of the model. PC-HYSPLIT WORKSHOP

Exercise 1: Automated trajectory calculations Assignment: Generate trajectories for one season Source Location: 39.0N, 77.0W (near Washington, DC) @ 500 meters AGL Date/Time: December 2, 2008 through February 28, 2009, once a day @ 18 UTC (Hint: do one month at a time) Duration: Backward, 24 hours Meteorology: EDAS archive extract (edas.dec08.001.extract, edas.dec08.002.extract, …) Comment: The EDAS extract is an extract in the horizontal and vertical. The “Trajectory Setup” Top of the model should be set accordingly (2000.0 m) or there will be a NOTICE comment about extrapolation in the vertical in the MESSAGE file. If trajectories would go above the noted level, you would need the full dataset. PC-HYSPLIT WORKSHOP

Exercise 1: Inputs Run one trajectory Set the start locations & meteorology: Display the results: PC-HYSPLIT WORKSHOP

Exercise 1: Inputs Run one month of trajectories Set the start/end date and time: Notes: Trajectory / Special Runs / Daily Defaults to entire month (days 1-31), and 4 times a day (00, 06, 12, 18 UTC) If year, month, day, of the previous step (one trajectory) were set to zeros, the trajectory would be fine, except the automated trajectories would not work. Year, month, day, MUST be non-zero. PC-HYSPLIT WORKSHOP

Exercise 1: Results One month of trajectories There should be one trajectory file for each day (tdumpYYYYMMDD) in the directory specified in Trajectory Setup. One way to view the trajectories is through the Trajectory Cluster Analysis section. We will come to this later. PC-HYSPLIT WORKSHOP

Exercise 1: Three-month set of trajectories As was done for December, 2008, calculate trajectories for January (days 1-31) and February (1-28), 2009. Remember the meteorology from the last day of the previous month is needed to calculate a 24-h back trajectory from the 1st of the month. Once the 3-month set of trajectories is complete, in /hysplit4/working, delete trajectory endpoints files with “tdump” in their name that are NOT part of the Dec-Jan-Feb exercise. PC-HYSPLIT WORKSHOP

Exercise 2: Trajectory frequency plot Assignment: Create a trajectory frequency plot Source Location: 39.0N, 77.0W (near Washington, DC) @ 500 meters AGL Date/Time: December 2, 2008 through February 28, 2009, trajectories once a day @ 18 UTC Duration: Backward, 24 hours Meteorology: EDAS archive extract PC-HYSPLIT WORKSHOP

Exercise 2: Inputs Trajectory frequency plot Notes: Trajectory / Display / Frequency All trajectory endpoint files with “tdump” in their name in the /hysplit4/working directory are used. First click Create file of trajectory filenames to make text file (INFILE) in the /hysplit4/working directory which lists the trajectory files to be used. Then click Execute Display. PC-HYSPLIT WORKSHOP

Exercise 2: Results Trajectory frequency plot PC-HYSPLIT WORKSHOP

Exercise 3: Trajectory cluster analysis Assignment: Run a trajectory cluster analysis program to view the predominant flow regimes for winter 2008-09. View two different possible outcomes (i.e. final number of clusters). Bonus: Display all the trajectories on one plot. Source Location: 39.0N, 77.0W (near Washington, DC) @ 500 meters AGL Date/Time: December 2, 2008 through February 28, 2009, trajectories once a day @ 18 UTC Duration: Backward, 24 hours Meteorology: EDAS archive extract Cluster Analysis Run_ID: Winter_2008-09 PC-HYSPLIT WORKSHOP

Exercise 3: Inputs Trajectory cluster analysis Step 1 inputs: Notes: Trajectory / Special Runs / Clustering / Standard If any ‘blanks’ are in the Run_ID, the Run_ID will be the characters up to the first blank Set endpoints folder accordingly, and delete unneeded ‘tdump’ files (above assumes you copied the files to /hysplit4/cluster/endpts) use HELP button at bottom as needed PC-HYSPLIT WORKSHOP

Exercise 3: Inputs Trajectory cluster analysis Cluster Step 2 … click Make INFILE. Verify filelist in the file INFILE in the cluster working folder specified in Step 1. click Run cluster. This is the master computation step and can take a while with a large numbers of trajectories. PC-HYSPLIT WORKSHOP

Exercise 3: Inputs Trajectory cluster analysis Cluster Step 2 (cont) … click Display plot to produce the TSV plot click Run. This makes a file CLUSEND. Both indicate possible solutions of 3 and 8 clusters. PC-HYSPLIT WORKSHOP

Exercise 3: Inputs Trajectory cluster analysis Cluster Step 3 … Enter the final Number of Clusters (8) Click Text. This makes a file CLUSLIST_N (N is the number of clusters), which is the text file that lists the trajectories that are in each cluster. If you do not need the graphics, CLUSLIST_N is your result. The first column is the cluster number, the second column is the number of trajectories in each cluster. If you want the graphics, see the next slides … PC-HYSPLIT WORKSHOP

Exercise 3: Inputs Trajectory cluster analysis Cluster Step 3, Display Means Notes: Check “View” for the postscript window to automatically open Select “None” for the Vertical Coordinate since it is not used This example forces a fixed map domain by setting the centerpoint (“Center”) and zero “Rings” of given radius. 5-16 PC-HYSPLIT WORKSHOP

Exercise 3: Inputs Trajectory cluster analysis Cluster Step 3, Display Clusters Notes: Inputs are the same as for Display Means 5-17 PC-HYSPLIT WORKSHOP

Exercise 3: Results 8-cluster solution 5-18 PC-HYSPLIT WORKSHOP

Exercise 3: Results 3-cluster solution PC-HYSPLIT WORKSHOP

Exercise 3: Results Comparison* Cluster 1 of 8 Cluster 4 of 8 Cluster 5 of 8 Cluster 1 of 3 + + = Cluster 2 of 8 Cluster 7 of 8 Cluster 2 of 3 + = Cluster 3 of 8 Cluster 6 of 8 Cluster 8 of 8 Cluster 3 of 3 + + = *Determined from inspection of the plots, or files CLUSLIST_8 and CLUSLIST_3. 5-20 PC-HYSPLIT WORKSHOP

Exercise 3: Bonus Trajectory cluster analysis How do you display all the trajectories in one plot ? 5-21 PC-HYSPLIT WORKSHOP

Exercise 3: Bonus Trajectory cluster analysis How do you display all the trajectories in one plot ? In Cluster Step 3 Set Number of Clusters to 1 Click Text Run Display Clusters 5-22 PC-HYSPLIT WORKSHOP