HYSPLIT Forum: hysplitbbs.arl.noaa.gov

Hi,

I am currently utilizing the trajectory source geolocation script with my own sampling data. The estimate for the source location (red grid cell) seems to be at the location of the sampling site and does not converge to the source location. The contours are also very trajectory like, they are narrow and long and are not at all similar to the output given in the Trajectory Source Geolocation tutorial 5.4. Is there an option of changing the integration period to cover a longer period?


Thanks

How many samples do you have and what is the sampling time of the samples? You probably don't have very many samples and that is what would cause the "trajectory-like" contour patterns you mentioned. There is no option to create trajectories more frequently than the beginning, middle and end of the sampling period (see the program dat2cntl for details).

The CONTROL file that is used for the dat2cntl is for a forward location but if the source location is not known, which I guess is why you would use this in the first place, then what should you use for the lat/long in the base CONTROL file that is needed by dat2cntl?

You need to guess at a source location. Section 6.4 of the Tutorial, Source Geolocation, says the "forward trajectory ... encompasses the time period of the sampling." This is probably because the meteorology file(s) in the output CONTROL files will be the same as in this forward trajectory.