HYSPLIT Forum: hysplitbbs.arl.noaa.gov

Please see the user guide on how to set the number of particles emitted and the maximum number of particles allowed by the simulation. https://ready.arl.noaa.gov/hysplitusersguide/S623.htm You can also check the MESSAGE file to see if there is a warning that the maximum number of particles allowed w...

It looks like you are only creating output at the deposition level.
So when you look at your contour plots, you are only seeing the deposition layer.

Num of vertical levels : 1
Height of levels(M agl) : 0


Try using at least two vertical levels, perhaps 0 and 100.


Alice

You may find this technical report by Richard Dare useful. It explains the calculation of the terminal fall velocity of the particles in detail. https://cawcr.gov.au/technical-reports/CTR_079.pdf Here is a relevant section of the HYSPLIT user manual. You may also wish to consult the reference here. ...

There will be differences because the random numbers generated on the two systems will not be the same. To see this on the same system, you can set the SEED parameter in the SETUP.CFG (at least if you have a more recent version). https://ready.arl.noaa.gov/hysplitusersguide/S410.htm Try running with...

The main output of a dispersion run is a binary file which we often refer to as a cdump file.
This file can be converted to ascii output as described here:
https://ready.arl.noaa.gov/hysplitusersguide/S341.htm

Try the following: 1. Repeat your runs with the deposition turned off. 2. Look and see how many particles HYSPLIT emitted. I think what you are running into is that HYSPLIT takes NUMPAR, number of particles to release, as a guide. When you go to the 24 hour emissions cycle, HYSPLIT wants to release ...

See the documentation below for an explanation of KRAND. Do you mean you do not have any cdump file output when setting KRAND? HYSPLIT will automatically use KRAND=1 if numpar > 5000 so you only have to set it if you want KRAND=2. https://www.ready.noaa.gov/hysplitusersguide/S640.htm KRAND (2) - if ...

HYSPLIT run time depends on several factors including - number of computational particles which are being simulated - model time step (which depends on grid size. Finer grids need smaller time steps). - system configuration One thing you can do is to break up your run into smaller runs. Instead of d...

Please check that your concentration grid is large enough so that the particles are not being deposited outside of your grid.
That would cause the number of particles that you are calculating from the output file to be lower than you expect.

1. Small particles reach a terminal fall velocity very quickly. So the gravitational settling velocity is a constant. There is extensive literature on how to estimate the terminal fall velocity of a particle given shape, size, and density. This is probably not relevant for insects though. 2. Yes - d...