Transport artifact at poles
Posted: June 29th, 2017, 5:05 pm
I have encountered transport artifacts near the geographic poles when using meteorological fields on a lat-lon grid. This could be a bug or a weakness in the transport method. I would appreciate knowing if there is a fix or if this is just a known weakness.
I've attached figures to demonstrate the effects. I started a matrix of trajectories northward of 89.2 °N (spaced every 0.2° latitude and every 30° longitude), then run 3 hour forward trajectories. Some trajectories converge on the pole in order to pass over it then diverge on the other side, which is unrealistic. Trajectories that start further from the pole tend to move tangent to latitude lines, which is suspicious but possibly realistic. The attached figures reproduce these features with 4 different meteorological fields (GFS 1°, GFS 0.5°, GDAS 0.5° NCDC) for selected times in the last 6 months. All figures were generated through the HYSPLIT website. I've reproduced similar patterns with other meteorology on my own computer.
I would appreciate any help understanding and correcting this issue. Thanks.
I've attached figures to demonstrate the effects. I started a matrix of trajectories northward of 89.2 °N (spaced every 0.2° latitude and every 30° longitude), then run 3 hour forward trajectories. Some trajectories converge on the pole in order to pass over it then diverge on the other side, which is unrealistic. Trajectories that start further from the pole tend to move tangent to latitude lines, which is suspicious but possibly realistic. The attached figures reproduce these features with 4 different meteorological fields (GFS 1°, GFS 0.5°, GDAS 0.5° NCDC) for selected times in the last 6 months. All figures were generated through the HYSPLIT website. I've reproduced similar patterns with other meteorology on my own computer.
I would appreciate any help understanding and correcting this issue. Thanks.