Trajectories of NASA's super pressure balloons @35km over Antarctica

[Waveguyde]

I really enjoy playing with the HYSPLIT Trajectory model. Recently I wanted to compute the trajectories of NASA's super pressure balloons that they have been launching since the 90s from McMurdo, Antarctica. However, it seems like the model I've chosen, the GFS, does not reach the balloons "cruise altitudes", which is about 35km. I know that the GFS provides meteorological data at these high altitudes. Hence my question: Is it possible to extend the trajectory model towards let's say 1hPa?

[sonny.zinn]

The original GFS may have more data for higher altitudes. For the ARL-formatted files for HYSPLIT, the lowest pressure for the GFS Model (1 degree, pressure), the GFS (Long Range) Model, and the GFS (0.25 degree, sigma-pressure hybrid) Model are 100 hPa, 100 hPa, and 13 hPa, respectively: please refer to https://www.ready.noaa.gov/READYmetdata.php.

[alicec]

You may also want to look at using MERRA2 data but you would have to download it from NASA and convert it yourself.
See this thread.
viewtopic.php?t=1353