How Hysplit treats emission rate and emission duration hour?
Posted: September 30th, 2020, 11:51 am
I am confused by the way that Hysplit treats the emission rate and the emission duration.
For example, I have two emission scenario. For the first emission scenario, I have a constant emission rate at 100 kg/hr and the emission duration is set to one hour. For the second emission scenario, I still have 100 kg/hr of emissions but the emission duration is only 10 min (the rest 50 min has zero emissions). My Hysplit simulation is one hour and in my SETUP.CFG, I set delt = 1.0. My output temporal resolution is set to 1 min so I have min-by-min concentrations. All other configurations are same except the emission duration (1 hour vs. 10 min).
Scenario 1 (1 hr emission):
TRACER
100
1
Scenario 2 (10 min emission):
TRACER
100
0.166667
What I expect from these two simulations is that for the first 10 min, the simulated min-by-min concentration should be the same between the two cases simply because for the first 10 min, both scenarios are emitting at 100 kg/hr. However, apparently this is not the case. The simulated concentrations from the two emission scenarios are totally different from each other. So I am very confused of how Hysplit treats the emission rate and the duration.
Thank you very much!
For example, I have two emission scenario. For the first emission scenario, I have a constant emission rate at 100 kg/hr and the emission duration is set to one hour. For the second emission scenario, I still have 100 kg/hr of emissions but the emission duration is only 10 min (the rest 50 min has zero emissions). My Hysplit simulation is one hour and in my SETUP.CFG, I set delt = 1.0. My output temporal resolution is set to 1 min so I have min-by-min concentrations. All other configurations are same except the emission duration (1 hour vs. 10 min).
Scenario 1 (1 hr emission):
TRACER
100
1
Scenario 2 (10 min emission):
TRACER
100
0.166667
What I expect from these two simulations is that for the first 10 min, the simulated min-by-min concentration should be the same between the two cases simply because for the first 10 min, both scenarios are emitting at 100 kg/hr. However, apparently this is not the case. The simulated concentrations from the two emission scenarios are totally different from each other. So I am very confused of how Hysplit treats the emission rate and the duration.
Thank you very much!