Search found 47 matches
- June 14th, 2019, 3:09 am
- Forum: Dispersion Model
- Topic: Time Step and Concentration Calculation
- Replies: 35
- Views: 16651
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 ...
- June 13th, 2019, 9:29 pm
- Forum: Dispersion Model
- Topic: Time Step and Concentration Calculation
- Replies: 35
- Views: 16651
Re: Time Step and Concentration Calculation
Dear alicec, Thanks for your reply. I am not clear about the formula for calculating the area. The area is calculated as (111198.323)^2 * lat * lon * cos(lat) The grid area in my simulation is 5000 m * 5000 m, because the grid spacing is 0.05. How is your formula related to the grid spacing (0.05)? ...
- June 13th, 2019, 2:47 am
- Forum: Dispersion Model
- Topic: Time Step and Concentration Calculation
- Replies: 35
- Views: 16651
Re: Time Step and Concentration Calculation
Dear alicec, Thank you very much for your reply and help. I ran some simple simulations with ichem=5 yesterday before seeing your rely, and the outputs are consistent with your explanation. But I sampled the deposition value using ‘time average’. As you suggested, ‘Maybe you just want to use a snaps...
- June 11th, 2019, 5:26 am
- Forum: Dispersion Model
- Topic: Time Step and Concentration Calculation
- Replies: 35
- Views: 16651
Re: Time Step and Concentration Calculation
Dear alicec, Thank you very much for your help. I am using HYSPLIT to model insect dispersal. The computational particles represent insects. Insects do not loss their mass during wind dispersal process, and will eventually land on the ground. That is why I am only interested in counting the number o...
- June 10th, 2019, 10:58 am
- Forum: Dispersion Model
- Topic: Time Step and Concentration Calculation
- Replies: 35
- Views: 16651
Re: Time Step and Concentration Calculation
Dear alicec, Thank you very much for your reply. I am very sorry that I did not make Question 3 clear. For Question 3, I would only like to calculate the number of particles via concentration/density (mass/area) on the deposition layer. As you suggested before, I would be able to work backward to ge...
- June 8th, 2019, 2:21 am
- Forum: Dispersion Model
- Topic: Time Step and Concentration Calculation
- Replies: 35
- Views: 16651
Re: Time Step and Concentration Calculation
Dear alicec, Thank you very much for your help. I really appreciate it. Now, I have a much better understanding of how HYSPLIT works. I would just like to confirm some of my final thoughts. Please see the example below and the attached MESSAGE file. Number particle released: 10,000 Emission rate: 33...
- June 7th, 2019, 11:19 am
- Forum: Dispersion Model
- Topic: Sampling Interval Type (snapshot)
- Replies: 2
- Views: 2660
Re: Sampling Interval Type (snapshot)
Thank you very much for your help, christopher.loughner.
- June 7th, 2019, 11:18 am
- Forum: Dispersion Model
- Topic: Time Step and Concentration Calculation
- Replies: 35
- Views: 16651
Re: Time Step and Concentration Calculation
Dear alicec, I actually would like to include dry deposition for my dispersal simulation, and will only sample concentration in a grid cell (m2) on the ground level (0 m). How do I ensure that the mass on the particles is not changing? According to the link that you sent, 'In the special case where ...
- June 6th, 2019, 4:19 am
- Forum: Dispersion Model
- Topic: Time Step and Concentration Calculation
- Replies: 35
- Views: 16651
Re: Time Step and Concentration Calculation
Dear alicec, Thank you very much for your reply. It is very helpful. I have a much better understanding of concentration calculation now, but I still have two questions. Question 1: Could you please see the example below? Would I be correct? For example, the sampling interval is every 2 hours (120 m...
- June 5th, 2019, 9:01 am
- Forum: Dispersion Model
- Topic: Sampling Interval Type (snapshot)
- Replies: 2
- Views: 2660
Sampling Interval Type (snapshot)
Dear all, According to the online tutorial, Sampling interval type: Snapshot (or now) will give the instantaneous output at the output interval. What does the output interval mean? Does it mean the last time step within the sampling interval? If so, the instantaneous output refers to a snapshot of w...