Search found 669 matches

May 7th, 2021, 2:48 pm
Forum: Trajectory Model
Topic: Cloud height information
Replies: 1
Views: 389

Re: Cloud height information

It will depend on the meteorological dataset you want to use. Most of our datasets contain a precipitation field (e.g. 6 hour accumulated precipitation; TPP6 for GDAS) and a relative humidity field. For our deposition calculations using the dispersion model we use 80 % relative humidity as the thres...
March 18th, 2021, 11:50 am
Forum: Users
Topic: DEFGRID error
Replies: 8
Views: 4037

Re: DEFGRID error

If R has a function that is similar to the cat command in linux it should work.
March 5th, 2021, 1:28 pm
Forum: Trajectory Model
Topic: Inconsistent back trajectory using HRRR Met data
Replies: 1
Views: 309

Re: Inconsistent back trajectory using HRRR Met data

Please try setting the timestep (delt) to a fix value (e.g. 5 or 1). The model is using different time steps when calculating the trajectories at different heights and that causes the observed discrepancies.
February 26th, 2021, 3:47 pm
Forum: HYSPLIT for PCs
Topic: multiple trajectories in time
Replies: 2
Views: 366

Re: multiple trajectories in time

In the trajectory Display menu, click on Meters-agl (under the Vertical Coodinate:)
February 18th, 2021, 3:48 pm
Forum: Users
Topic: How is exactly is the vertical motion computed from the velocity divergence
Replies: 1
Views: 336

Re: How is exactly is the vertical motion computed from the velocity divergence

Wη = (-∂η/∂t - u ∂η/∂x - v ∂η/∂y) / (∂η/∂z)
January 26th, 2021, 5:26 pm
Forum: Dust
Topic: soil-dust density (K) and emission area (A) in alternate emission algorithm
Replies: 3
Views: 5795

Re: soil-dust density (K) and emission area (A) in alternate emission algorithm

Not exactly. The A parameter already includes the fraction of the area that is emitting. K and A are empirical parameters, they don't really have an absolute physical meaning.
November 30th, 2020, 10:50 am
Forum: Dust
Topic: Modify the AOD value used to calculate U*t
Replies: 1
Views: 1038

Re: Modify the AOD value used to calculate U*t

The tutorial contains a zip archive for the CONUS (https://ready.arl.noaa.gov/documents/Tutorial/dust/dust_conus.zip) and globally of monthly files of threshold friction velocity and soil dust density for each AOD grid cell over the domain that exceeds the threshold. You can modify these values to m...
October 5th, 2020, 8:25 am
Forum: Users
Replies: 1
Views: 1105

ASCDATA.CFG should be under the bdyfiles directory.
August 31st, 2020, 9:46 am
Forum: Users
Topic: Moving source of emission
Replies: 2
Views: 1386

Re: Moving source of emission

You are on to the correct approach to define a moving source by using the EMITIMES file. Although the help file S417.htm mentions that the file can be used to define a moving source, no specific instructions are provided. As an example, the EMITIMES file you provided has been modified to redefine th...
July 17th, 2020, 4:52 pm
Forum: Trajectory Model
Topic: How Do I get?
Replies: 1
Views: 1179

Re: How Do I get?

Please check chapter 13 of our workshop: