## Search found 328 matches

June 22nd, 2021, 10:26 am
Forum: 2021 HYSPLIT Workshop Questions
Topic: CAMEO vs Hysplit
Replies: 1
Views: 18

### Re: CAMEO vs Hysplit

CAMEO is a Gaussian plume model while HYSPLIT is a Lagrangian transport and dispersion model. The Gaussian plume models are quite fast and accurate in the region where the plume retains a nice Gaussian shape. This is generally when meteorological conditions/ winds are steady. The Lagrangian transpor...
June 22nd, 2021, 8:49 am
Forum: Users
Topic: Multiple bins for varying particle diameters
Replies: 1
Views: 1563

### Re: Multiple bins for varying particle diameters

You can define multiple species within the same HYSPLIT run. So for instance suppose you have total emission of 1 kg/hr. You want 3 particle sizes with 10%, 50% and 40% of mass respectively. Emission rates for the 3 particle sizes would then be defined as 0.10 0.50 0.40 https://www.ready.noaa.gov/hy...
June 22nd, 2021, 8:39 am
Forum: 7. Air concentration calculations
Topic: Particle velocity and Stokes number assumptions
Replies: 4
Views: 119

### Re: Particle velocity and Stokes number assumptions

tvf_curves.png HYSPLIT uses equations for passive tracers - non-inertial particles. It only uses Langevin equations for a single phase flow. For inertial particles, a gravitational settling velocity is added but that is the only correction made. I think what you are asking is when using equations f...
June 22nd, 2021, 7:48 am
Forum: 7. Air concentration calculations
Topic: daily concentration contours over 12 months
Replies: 1
Views: 16

### Re: daily concentration contours over 12 months

I'm glad you found the workshop useful. The workshop mostly focused on using the GUI, but it did touch on scripting. For your application, you probably want to use scripting. The tutorial comes with scripts for windows and linux for every exercise. You can also use another programming language. The ...
June 21st, 2021, 7:04 am
Forum: HYSPLIT Workshop
Topic: How to understand the trajectory endpoints file format?
Replies: 1
Views: 24

### Re: How to understand the trajectory endpoints file format?

The diagnostic variables that can be output in the trajectory endpoints file are the following: https://www.ready.noaa.gov/hysplitusersguide/S410.htm https://www.ready.noaa.gov/hysplitusersguide/S614.htm TM_PRES=0 trajectory diagnostic output pressure variable marker flag TM_TPOT=0 trajectory diagno...
June 21st, 2021, 6:59 am
Forum: 16. Volcanic eruptions with gravitational settling
Topic: Time-dependent emissions
Replies: 5
Views: 76

### Re: Time-dependent emissions

Could you clarify your question. The original question was about creating an emit-times file (see https://www.ready.noaa.gov/hysplitusersguide/S417.htm) from a netcdf file which has emissions inventory information. What do you mean by a "2D raster with the same layout of the meteorology to HYSPLIT a...
June 18th, 2021, 1:10 pm
Forum: 16. Volcanic eruptions with gravitational settling
Topic: Time-dependent emissions
Replies: 5
Views: 76

### Re: Time-dependent emissions

Various people have developed their own scripts for converting emission information into an emit-times file. For instance this has been done for fire-smoke, emissions from power plants, dust, volcanic emissions and more. No general utility for doing this is supplied with the HYSPLIT distribution as ...
June 18th, 2021, 12:57 pm
Forum: 5. Trajectory options
Topic: Convection
Replies: 2
Views: 106

### Re: Convection

If CAPE (convective available potential energy) is available in the MET data set then HYSPLIT can utilize that.

This is discussed in the advanced tutorial a bit a well.
June 18th, 2021, 12:05 pm
Forum: 16. Volcanic eruptions with gravitational settling
Topic: Shape value = -1
Replies: 1
Views: 42

### Re: Shape value = -1

June 18th, 2021, 11:55 am
Forum: 16. Volcanic eruptions with gravitational settling
Topic: Extracting Particles
Replies: 3
Views: 76

### Re: Extracting Particles

There is a utility called par2asc which will convert PARDUMP output to ascii files. You can find it in the exec directory. Description of the pardump/parinit file is here. https://www.ready.noaa.gov/hysplitusersguide/S442.htm There is python code with a class that can read/write pardump files here i...