Search found 155 matches

by alicec
August 19th, 2019, 8:56 am
Forum: Trajectory Model
Topic: "Flooring effect" on mixing layer depth data generated from GDAS files
Replies: 3
Views: 110

Re: "Flooring effect" on mixing layer depth data generated from GDAS files

By default HYSPLIT does set a minimum mixing depth (150m or 250m depending on the version of HYSPLIT you are using). Please see the documentation on why HYSPLIT uses this default. https://www.ready.noaa.gov/hysplitusersguide/S625.htm Mixed Layer Depth Computation KMIXD is used to control how the bou...
by alicec
August 9th, 2019, 4:34 pm
Forum: Dispersion Model
Topic: Deposition Velocity
Replies: 4
Views: 376

Re: Deposition Velocity

If I understand what you are saying correctly, then yes, you are correct. If you define a constant settling velocity for the particle (by specifying the deposition velocity for a 'particulate' computational particle), then you over-ride the calculation and the settling velocity is the value that you...
by alicec
August 9th, 2019, 10:12 am
Forum: Dispersion Model
Topic: PARINIT vs. EMITIMES
Replies: 7
Views: 1591

Re: PARINIT vs. EMITIMES

The PARINIT file basically contains a list of computational particles with their relevant characteristics. (Time, location, mass, etc.) With NINIT=1, HYSPLIT opens the file at the beginning of the simulation and looks for particles with the same time as the run start. If it finds some, then it reads...
by alicec
August 8th, 2019, 3:20 pm
Forum: Dispersion Model
Topic: even if the option of the pollutant is set to continuous release but is not continuously released.
Replies: 13
Views: 732

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

Please review the tutorial to understand how changing the particle number affects results.

Section 7 is particularly relevant.
https://ready.arl.noaa.gov/documents/Tu ... _test.html
by alicec
July 31st, 2019, 6:45 pm
Forum: Dispersion Model
Topic: Deposition Velocity
Replies: 4
Views: 376

Re: Deposition Velocity

This section of the tutorial may help you. https://www.ready.noaa.gov/documents/Tutorial/html/chem_linear.html If particle diameter, density, and shape are all 0, then the computational particle is treated as a gas and no gravitational settling is applied, but dry deposition may occur when the compu...
by alicec
July 29th, 2019, 1:33 pm
Forum: Dispersion Model
Topic: Diameter (µm) Density (g/cc) and Shape
Replies: 6
Views: 507

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

The lat lon coordinate for the HYSPLIT concentration grid is generally the center of the cell (for computational particles on a square concentration grid). Met data output is valid for the point at which it is output. For computational particles which are between met grid points, the met data is int...
by alicec
July 29th, 2019, 7:43 am
Forum: Dispersion Model
Topic: even if the option of the pollutant is set to continuous release but is not continuously released.
Replies: 13
Views: 732

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

Yes - you are exceeding the number of particles / puffs allowed. That is what this warning in the MESSAGE file means. WARNING emspnt: exceeding puff limit WARNING depsus: exceeding puff limit NOTICE main: 168 58515839 10000 2.6298373E+14 WARNING emspnt: exceeding puff limit HYSPLIT will not emit mor...
by alicec
July 26th, 2019, 8:29 am
Forum: Dispersion Model
Topic: even if the option of the pollutant is set to continuous release but is not continuously released.
Replies: 13
Views: 732

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

Thank you for explaining more.
Could you please attach your CONTROL, SETUP.CFG and MESSAGE file.
by alicec
July 25th, 2019, 9:45 am
Forum: Dispersion Model
Topic: even if the option of the pollutant is set to continuous release but is not continuously released.
Replies: 13
Views: 732

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

Are you concerned by the concentration contours not being smooth? Please review the tutorial, in particular this portion. https://www.ready.noaa.gov/documents/Tutorial/html/conc_part.html Increasing the number of particles or making the concentration grid size larger will help. If you still have pro...