## Search found 36 matches

June 18th, 2019, 4:23 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

Please see the attached MESSAGE files. Thanks.
June 18th, 2019, 4:21 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

Dear alicec, Thank you very much for your reply. I have run two simulations today again, and I set the sampling domain: Span (80.0, 100.00) and Spacing (0.25*0.25). It should be large enough to sample the deposited particles. Simulation 1: one source location. Simulation 2: six source locations (the...
June 17th, 2019, 10:19 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

Dear alicec, Thank you very much for your help. ' HYSPLIT takes a small shortcut and uses the location of the computational particle to calculate the grid area rather than the center of the concentration grid square. So the larger grid sizes may be off by a few particles if the particles are concent...
June 17th, 2019, 8:27 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

Thanks for your help, alicec. So deposition velocity is actually not gravitational velocity? From what I understand, the deposition velocity is a kind of velocity that is used to calculate the deposition flux. The value of deposition velocity depends on the types of particles or gases. That is why i...
June 16th, 2019, 2:09 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

HYSPLIT takes a small shortcut and uses the location of the computational particle to calculate the grid area rather than the center of the concentration grid square. So the larger grid sizes may be off by a few particles if the particles are concentrated near an edge. Please double check your numbe...
June 15th, 2019, 2:09 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

Dear alicec, Thank you very much for your help. I really appreciate it. I figured it out. The formula should be Area = (111198.323)^2 * Latspan * Lonspan * COS(Lat*π/180). In my case, the formula in Excel is Area = (111198.323)^2 * 0.05 * 0.05 * COS(RADIANS(E2)), where 0.05 (Latspan) * 0.05 (Lonspan...
June 14th, 2019, 11:51 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

Do you mean something like 0.05Deg × π/180 = 0.0008727Rad? Thanks.
June 14th, 2019, 11:49 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

No, I do not think so. I am sorry that I do not have much knowledge on that. Could you please give me an example? Thanks.
June 14th, 2019, 10:30 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

Thank you very much, alicec.

I still could not get the correct numbers using your formula [e.g. (111198.323)^2 * 0.05 * 0.05 * COS(E2)]. I got negative values. Please see the attached file. Thanks.
June 14th, 2019, 3:09 am
Forum: Dispersion Model
Topic: Time Step and Concentration Calculation
Replies: 35
Views: 3465

### Re: Time Step and Concentration Calculation

Dear alicec, Thank you very much for your reply and help. I really appreciate your help. I used your area calculation formula to calculate the area. I did the calculation in an Excel file. Please see the attached output file. It seems not right. That would be great if you could explain your formula ...