## Search found 176 matches

June 10th, 2019, 11:44 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3466

### Re: Time Step and Concentration Calculation

I don't know what you mean by the number of particles on the deposition layer.
Maybe if you explain what you think this number is going to represent physically in the real world or what information
you hope to get from this number I can help you better.
June 10th, 2019, 10:28 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3466

### Re: Time Step and Concentration Calculation

I’m going to answer your questions slightly out of order. Question 2: The deposition calculation begins at the start of the simulation. During a three hour simulation with continuous emissions, some computational particles will be created at each time step. Once the particles are in the simulation, ...
June 7th, 2019, 1:02 pm
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3466

### Re: Time Step and Concentration Calculation

If you use the option to not have any deposition, then the particles will not change mass, but you also will not see any mass in the
deposition layer (0 m).

You could use ichem=5 if you want to calculate deposition without the particles losing mass.
June 6th, 2019, 10:17 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3466

### Re: Time Step and Concentration Calculation

Question 1 – Yes, this is correct. Question 2 – You can work backward to get the number of particles from the concentration as long as the mass on the particles is not changing. Mass on the computational particle may change if you have wet or dry deposition turned on. (see below for more on depositi...
June 5th, 2019, 11:42 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3466

### Re: Time Step and Concentration Calculation

The simplest case is the snapshot. At the output time, the total mass of all the particles in a grid box is summed and then divided by the volume of the grid box. To get a time average, Hysplit calculates the concentration at each time step as in the snapshot and then calculates the average concentr...
June 3rd, 2019, 6:36 pm
Forum: Conversion programs
Topic: Error using era52arl related to eccodes
Replies: 1
Views: 793

### Re: Error using era52arl related to eccodes

That sounds like the eccodes did not install properly.
You could try to re-install or see if if the libeccodes_f90.so is in another location.

In my system, libeccodes_f90.so is in that location.
May 30th, 2019, 12:58 pm
Forum: Bugs
Topic: PARDSP causing NaN particle trajectories in PARDUMPs
Replies: 1
Views: 839

### Re: PARDSP causing NaN particle trajectories in PARDUMPs

Could you share with us the setup you are using so we can reproduce this? In particular we would like know the value of KBLT in the SETUP.CFG file and the meteorological data you are using. Complete CONTROL and SETUP.CFG files would be helpful. The SIGW in the pardsp routine is the width of the turb...
May 23rd, 2019, 11:40 am
Forum: Users
Topic: GRIB2 to ARL with Eccodes
Replies: 6
Views: 1456

### Re: GRIB2 to ARL with Eccodes

One thing to check is that your eccodes compilation used the same fortran compiler as the HYSPLIT distribution.
It is difficult to trouble shoot compilation issues on other people's systems.
May 13th, 2019, 9:32 am
Forum: Dispersion Model
Topic: Configure the Turbulence Method
Replies: 2
Views: 632

### Re: Configure the Turbulence Method

HYSPLIT uses defaults which are based on what we find to be the best configuration for most simulations. The defaults also take into consideration what data is available in the meteorological input file you are using. For instance, the default is to use heat and momentum fluxes to compute velocity v...
May 13th, 2019, 9:16 am
Forum: Dispersion Model
Topic: Multiple Simulations for Dispersal
Replies: 2
Views: 636

### Re: Multiple Simulations for Dispersal

In the tutorial there are examples for creating scripts to run HYSPLIT.