Search found 145 matches

by alicec
July 19th, 2019, 3:57 pm
Forum: General questions on meteorological data needed for HYSPLIT
Topic: help needed using mixed resolutions meteo files
Replies: 2
Views: 18

Re: help needed using mixed resolutions meteo files

Please also see the following documentation for more detail on how meteorological grids should be specified. It can get quite complex! https://www.ready.noaa.gov/hysplitusersguide/S262.htm - Number of input data grids Default: 1 Number of simultaneous input meteorological files. The following two en...
by alicec
July 19th, 2019, 3:12 pm
Forum: General questions on meteorological data needed for HYSPLIT
Topic: help needed using mixed resolutions meteo files
Replies: 2
Views: 18

Re: help needed using mixed resolutions meteo files

Please use an additional gdas1 file so that there is an overlap in time between the two met datasets. See below for an example. HYSPLIT will automatically use the finer resolution (gdas0p5/ GHDA) during the overlap time. 2 03 01 00 00 1 42.768 -86.149 100.0 -24 0 10000.0 5 /tdir/gdas0p5/ 20120227_gd...
by alicec
July 19th, 2019, 10:39 am
Forum: Dispersion Model
Topic: even if the option of the pollutant is set to continuous release but is not continuously released.
Replies: 3
Views: 34

Re: even if the option of the pollutant is set to continuous release but is not continuously released.

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...
by alicec
July 15th, 2019, 10:39 am
Forum: Dispersion Model
Topic: even if the option of the pollutant is set to continuous release but is not continuously released.
Replies: 3
Views: 34

Re: even if the option of the pollutant is set to continuous release but is not continuously released.

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
by alicec
July 9th, 2019, 10:00 am
Forum: Dispersion Model
Topic: Diameter (µm) Density (g/cc) and Shape
Replies: 3
Views: 43

Re: Diameter (µm) Density (g/cc) and Shape

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. ...
by alicec
June 21st, 2019, 9:15 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 705

Re: Time Step and Concentration Calculation

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...
by alicec
June 19th, 2019, 9:19 am
Forum: Dispersion Model
Topic: the numbers of emitors
Replies: 5
Views: 132

Re: the numbers of emitors

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
by alicec
June 19th, 2019, 9:13 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 705

Re: Time Step and Concentration Calculation

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 ...
by alicec
June 18th, 2019, 5:30 pm
Forum: Dispersion Model
Topic: the numbers of emitors
Replies: 5
Views: 132

Re: the numbers of emitors

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 ...
by alicec
June 18th, 2019, 8:50 am
Forum: Dispersion Model
Topic: the numbers of emitors
Replies: 5
Views: 132

Re: the numbers of emitors

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...