Web-based Trajectory Tool

Plot a parcel trajectory using reanalysis pressure level winds. The code used to calculate the trajectories is kindly supplied by the University of Melbourne and details are on their Parcel Trajectory Software Home Page.
New! Extract air temperature and geopotential (height) "tracers" at interpolated locations

Trajectory Options

? Dataset:
? Start date to end date (YYYY MM DD HH format) e.g. 1989 2 1 0:
  • For backwards trajectory input in reverse order. You are currently limited to 60 time steps or about 15 days. HH should be 00,06,12, or 18
? Latitude/longitude and level for start/end grid: Lat (-90 to 90) Lon (-180 to 360)
Select Level(s):

? Optional: Add trajectories of box around selected point (single level only) No Yes Width:
? Optional: Calculate "tracer" values (returned in a NetCDF file) No Yes

Plot Options:

? Markers drawn for every 6 hours: No Yes
? Select region: ? Map type (non-default): Polar Stereographic Cylindical Equidistant
? US State Boundaries Drawn: No Yes
go to error submittal form (Report Bugs)

Trajectory model and caveats:

Levels used are from 1000mb to 100mb. Input winds are available 4 times daily(0,6,12 and 18z). The trajectory model does not know about the surface and calculations can result in air moving under the surface. Interpolated model output is used below the surface.

Referencing Trajectory Code:
The parcel trajectory software (traj3d) was obtained from the University of Melbourne Parcel Trajectory Software web page (http://www.cycstats.org/trajectories/trajhome.htm). A discussion of the algorithm is given by Noone and Simmonds (1999) and Barras and Simmonds (2009).
  • Noone, D., and I. Simmonds, 1999: A three-dimensional spherical trajectory algorithm. Research Activities in Atmospheric and Oceanic Modelling, Report No. 28, WMO/TD-No. 942. H. Ritchie, Ed., World Meteorological Organization, 3.26-3.27.
  • Barras, V., and I. Simmonds, 2009: Observation and modeling of stable water isotopes as diagnostics of rainfall dynamics over southeastern Australia Journal of Geophysical Research, 114, D23308, doi:10.1029/2009JD012132, 2009.

If you use plots or data from the page, we would also appreciate a mention: "Image provided by the NOAA Physical Sciences Laboratory, Boulder Colorado from their Web site at https://psl.noaa.gov/". Finally, you should reference the dataset that is used in the plot.

WRIT is supported in part by NOAA/ESRL Physical Sciences Laboratory, the NOAA Climate Program Office, and the US Department of Energy's Office of Science (BER). WRIT contributes to the Atmospheric Circulation Reconstructions over the Earth (ACRE) Initiative.

This is a Research and Development Application