HYSPLIT Forum: hysplitbbs.arl.noaa.gov

This "noise" function or dispersion/turbulent component is a function of time and ws stdev. The uncertainty, as you mentioned in your comment, increases as you go further back in time. In principle, the concentration mode is just a group of trajectories that have a turbulent component included in th...

How are you downloading the data? through a web browser?

Conceptually it makes sense. However, your 2-D Gaussian noise should reflect the state of the atmosphere. Ideally, you should use the standard deviation of the horizontal wind speed as a measure for the with of your Gaussian distribution. HYSPLIT explicitly calculates the standard deviations in the ...

Please make sure you have all the required meteorological variables in the ARL meteorological file that you created. Use the utility program such as chk_file located in the exec directory to see if the variables exist.

Here is the program. Please delete the .txt extension.

Unfortunately, the random number generator seed cannot be changed without recompiling the code.

The problem you are having is that your trajectories are hitting the ground.
Please take a look at the discussion about the that topic:
viewtopic.php?f=27&t=295&hilit=trajectory+hits+ground

Here you can find some information about the user entered meteorological data:
https://www.ready.noaa.gov/documents/Tu ... enter.html

Try replacing all the 0024 entries by 0001 and the 2400 by 0100. I assume you want to change your emissions hourly.

That will depend on the underlying meteorology. Evidently in your case there is a fair amount of vertical sheer at that location in the equator. HYSPLIT will only reflect what the meteorological data shows.