Proper way to control particle numbers released
Posted: September 3rd, 2021, 6:09 pm
I'm learning how to use the dispersion model and want to understand how to release an exact number of particles from a starting location. I am testing the starting location: (lat 31.0069, lon -88.0103, hgt 182.88). For a given day at hour 00, my goal is to follow n particles over the next 6 hours. For example, I'd like to release 2 particles at hour 00 then see where they are at hours 1, 2, 3, 4, 5, and 6. I tried two methods of accomplishing this, but got different results with each.
Could someone please explain how to properly control the number of particles released?
Method 1
Based on the tutorial (https://www.ready.noaa.gov/documents/Tu ... _base.html), I assumed that to release 2 particles, the emissions rate should be 100 and the hours of emission should be 0.02 in the CONTROL file. Then in the SETUP.CFG file, the numpar = 2 and maxpar = 10000 (the default). I was able to get 2 particles every 6 hours that I could track.
Method 2
Then, I tried changing the settings to emission rate = 1, hours of emission = 1, numpar = 2, maxpar = 2. I also was able to get 2 particles every 6 hours that I could track. (As a side note, when I set it to emission rate = 1, hours of emission = 1, numpar = 2, maxpar = 10000, I ended up with 60 particles every 6 hours instead. I'd like to also understand why this is the case).
Method 1 Results
particle_num lat lng height hour
0 00001 -88.0035 31.0446 179.0 001
1 00002 -88.0061 31.0442 166.0 001
2 00001 -88.0060 31.0968 167.0 002
3 00002 -88.0104 31.0959 160.0 002
4 00001 -88.0148 31.1638 162.0 003
5 00002 -88.0179 31.1631 166.0 003
6 00001 -88.0328 31.2448 144.0 004
7 00002 -88.0326 31.2448 174.0 004
8 00001 -88.0660 31.3371 116.0 005
9 00002 -88.0526 31.3410 171.0 005
10 00001 -88.1180 31.4403 83.0 006
11 00002 -88.0803 31.4513 166.0 006
Method 2 Results
particle_num lat lng height hour
0 00001 -88.0060 31.0443 166.0 001
1 00002 -88.0037 31.0441 179.0 001
2 00001 -88.0143 31.0953 133.0 002
3 00002 -88.0043 31.0965 169.0 002
4 00001 -88.0318 31.1607 145.0 003
5 00002 -88.0083 31.1639 179.0 003
6 00001 -88.0531 31.2410 153.0 004
7 00002 -88.0214 31.2452 167.0 004
8 00001 -88.0809 31.3368 124.0 005
9 00002 -88.0488 31.3387 130.0 005
10 00001 -88.1263 31.4440 107.0 006
11 00002 -88.0915 31.4440 117.0 006
I've attached my CONTROL and SETUP.CFG files to this post. The only difference between the control and setup files between the two methods are what I flagged above. Everything else is the same.
Could someone please explain how to properly control the number of particles released?
Method 1
Based on the tutorial (https://www.ready.noaa.gov/documents/Tu ... _base.html), I assumed that to release 2 particles, the emissions rate should be 100 and the hours of emission should be 0.02 in the CONTROL file. Then in the SETUP.CFG file, the numpar = 2 and maxpar = 10000 (the default). I was able to get 2 particles every 6 hours that I could track.
Method 2
Then, I tried changing the settings to emission rate = 1, hours of emission = 1, numpar = 2, maxpar = 2. I also was able to get 2 particles every 6 hours that I could track. (As a side note, when I set it to emission rate = 1, hours of emission = 1, numpar = 2, maxpar = 10000, I ended up with 60 particles every 6 hours instead. I'd like to also understand why this is the case).
Method 1 Results
particle_num lat lng height hour
0 00001 -88.0035 31.0446 179.0 001
1 00002 -88.0061 31.0442 166.0 001
2 00001 -88.0060 31.0968 167.0 002
3 00002 -88.0104 31.0959 160.0 002
4 00001 -88.0148 31.1638 162.0 003
5 00002 -88.0179 31.1631 166.0 003
6 00001 -88.0328 31.2448 144.0 004
7 00002 -88.0326 31.2448 174.0 004
8 00001 -88.0660 31.3371 116.0 005
9 00002 -88.0526 31.3410 171.0 005
10 00001 -88.1180 31.4403 83.0 006
11 00002 -88.0803 31.4513 166.0 006
Method 2 Results
particle_num lat lng height hour
0 00001 -88.0060 31.0443 166.0 001
1 00002 -88.0037 31.0441 179.0 001
2 00001 -88.0143 31.0953 133.0 002
3 00002 -88.0043 31.0965 169.0 002
4 00001 -88.0318 31.1607 145.0 003
5 00002 -88.0083 31.1639 179.0 003
6 00001 -88.0531 31.2410 153.0 004
7 00002 -88.0214 31.2452 167.0 004
8 00001 -88.0809 31.3368 124.0 005
9 00002 -88.0488 31.3387 130.0 005
10 00001 -88.1263 31.4440 107.0 006
11 00002 -88.0915 31.4440 117.0 006
I've attached my CONTROL and SETUP.CFG files to this post. The only difference between the control and setup files between the two methods are what I flagged above. Everything else is the same.