Details and instructions on the trajectory tool pagePage will plot trajectories that are calculated using various reanalysis datasets. A 3D calculation is used, using analyzed pressure level winds from 10000mb to 100mb.
If you have problems, please email with ALL the options you chose. You will get a plot as well as the data used to create the final plot (in netCDF), a post script image and information on the dataset.
Various global reanalyses are provided. Note that different reanalyses dataset have different levels. We use all the levels up to 100mb.
- Enter Dates
- Starting point
These values with be used as a starting point (or an ending point for backward trajectories). It is possible to enter a location that is below the surface. The reanalyses datasets used on this page are interpolated below the ground.
- Latitude range is -90 to 90.
- You can enter longitudes as degrees east (0 to 360) or degrees west which is entered as negative longitudes to -180 (e.g. -100 is 100W or 260E).
- Pressure level of initial point, in millibars. You can select multiple levels. If you choose a single level, the plot returned will show the level of the trajectory using colors. If you choose multiple levels, each level will have it's own color.
- Plot Options
- Markers drawn ever 6 hours
- Optionally, markers will be drawn every 6 hours to indicate where the trajectory is at each model time step.
- Select Region
- You can select from a set of regions to plot or you can choose a custom plot. For custom plots, choose S to N and use negative values for the first longitude if going over 0E.
- Select ProjectionYou can also select polar stereographic or cylindrical equidistant map projections. In some cases, choosing one over the other may not make sense or may make a 'bad' plot.
- Google Earth
- If you have the Google Earth module installed on your browser, you can view the trajectories in the Google Earth browser API. The level of the trajectory is in meters and not millibars. Pressure was converted to meters using a standard atmosphere. If you don't have the plug-in, you can download the kmz file as per below. Note in Google Earth and the KMZ files, single level trajectories are drawn as one color. This may be changed in the future.
- You will get a plot with the trajectories drawn on it (as per the level instructions above)
- Postscript Plot
- You can download a higher resolution postscript plot.
- KMZ file
- The data is stored in a kmz file which can be downloaded and used in an Google Earth desktop application.The level of the trajectory is in meters and not millibars. Pressure was converted to meters using a standard atmosphere. Note in Google Earth and the KMZ files, single level trajectories are drawn as one color. This may be changed in the future.
- How this page was created
The main interface for this page is an HTML form. The data that are input into this form are processed by a Perl script. The script reads the inputs, tests for bad inputs, runs the trajectory code and then is plotted using NCL. NetCDF, KML and postscript are also produced. The netCDF file, image and other files are kept in a directory in which the files are periodically deleted.
Please let me know if find the page useful. Likewise, let me know if you think any instructions are unclear, if you think there are bugs or if you have any suggestions for improvements of any type. I would particularly like to know if you use these pages for teaching purposes and if so, how. I can be reached by email at email@example.com or by phone at (303) 497-6263.
Enter a starting and ending date. If the 2nd date is greater than the first, you will get a backward trajectory calculation. All dates in the trajectory date range need to be in your selected dataset and they need to be proper dates. Hours are 0,6,12, and 18 (Z). Only enter numbers.
WRIT is supported in part by NOAA's Climate Goal and by the US Department of Energy's Office of Science (BER)