Setting up EMITIMES for multiple time varying sources with different pollutants over long time periods

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claurel
Posts: 2
Joined: June 30th, 2021, 11:55 am
Registered HYSPLIT User: No

Setting up EMITIMES for multiple time varying sources with different pollutants over long time periods

Post by claurel »

I have 2 questions regarding EMITIMES file set up for multiple time varying emissions sources with multiple pollutants:

1. I am trying release emissions from multiple different fire sources over the course of a year. The start time, duration, emissions rate, and heat vary for each location (each fire releases for <1 day). Is it necessary to write a new header, and thus a new emissions cycle, for each source, redefining the start time and duration for each fire in the header? Or is it possible to use just one header for the year (one really long emissions cycle) and have the start time just be the date/time of the first fire of the year and the duration be the total number of hours spanning all fires (i.e. duration = numerous months)? Examples of these two options are below:

YYYY MM DD HH DURATION(hhhh) #RECORDS
YYYY MM DD HH MM DURATION(hhmm) LAT LON HGT(m) RATE(/h) AREA(m2) HEAT(w)
1981 05 09 00 2688 4
1981 05 09 00 00 0600 39.024 -120.365 0.0 2.120 40000 12409.83
1981 05 15 00 00 0600 38.772 -120.529 0.0 2.766 40000 14753.93
1981 06 07 00 00 1100 38.822 -119.997 0.0 2.532 40000 11580.51
1981 08 27 00 00 0600 39.058 -120.285 0.0 1.775 40000 13278.11

YYYY MM DD HH DURATION(hhhh) #RECORDS
YYYY MM DD HH MM DURATION(hhmm) LAT LON HGT(m) RATE(/h) AREA(m2) HEAT(w)
1981 05 09 00 0600 1
1981 05 09 00 00 0600 39.024 -120.365 0.0 2.120 40000 12409.83
1981 05 15 00 0600 1
1981 05 15 00 00 0600 38.772 -120.529 0.0 2.766 40000 14753.93
1981 05 07 00 1100 1
1981 06 07 00 00 1100 38.822 -119.997 0.0 2.532 40000 11580.51
1981 05 27 00 0600 1
1981 08 27 00 00 0600 39.058 -120.285 0.0 1.775 40000 13278.11

2. I am also looking to define two different pollutants in my simulation, but both pollutants are not release from each source. In other words, some sources release only pollutant A and some release only pollutant B. Is there a way to set this up in the EMITIMES/CONTROL files where different sources release different pollutants? Or will I have to set up two different runs, one for each pollutant?

Thank you in advance for your help!
alicec
Posts: 411
Joined: February 8th, 2016, 12:56 pm
Registered HYSPLIT User: Yes

Re: Setting up EMITIMES for multiple time varying sources with different pollutants over long time periods

Post by alicec »

Answer to question 1:
Either of the two options you mention would work.
When there are a lot of emissions, people usually pick a cycle time that is somewhere
between the two options that you mention. For instance they might choose to use a cycle time of 6,12, or 24 hours.
However, you only have 4 emission locations/times so the first option that you show works pretty well.

In the CONTROL file you have to add the same number of starting locations as there are records in the cycle (divided by the
number of species defined). So if one would use a year cycle time, then you might possibly have to write a really long CONTROL
file if you have a lot of emissions in that time period.

It looks like you only have 4 emissions during the year and are simulating four fires which take place on 5/9, 5/15, 6/7, and 8/27 and
emissions last between 6 and 11 hours. Is that correct?

Something to to think about:
You may want to split the four fires into different HYSPLIT runs rather than just doing one HYSPLIT run.
Then you could make the total duration of each run smaller.
For instance you probably don't need to model the emissions from your fire that occurs on 5/9 all
the way through August. You may want to at least set the particle age so that your particles are dropped from
the simulation after a certain amount of time.
See KHMAX: https://www.ready.noaa.gov/hysplitusersguide/S623.htm

Answer to question 2:

If you have two pollutants defined in your CONTROL file then in the EMITIMES file you need to have one line per
pollutant. If one of the pollutants has 0 emissions for that time period then you need to add a dummy line
with 0 emissions. See below. For this case you should have 4 start locations and two species defined in the CONTROL file.

The start locations and number of species in the CONTROL file are used to define how big some arrays should be. If
the array sizes defined when the CONTROL file is read don't match what is needed by the information in the EMITIMES file, you will end
up with segmentation faults.

Code: Select all

YYYY MM DD HH DURATION(hhhh) #RECORDS
YYYY MM DD HH MM DURATION(hhmm) LAT LON HGT(m) RATE(/h) AREA(m2) HEAT(w)
1981 05 09 00 2688 8
1981 05 09 00 00 0600 39.024 -120.365 0.0 2.120 40000 12409.83  # species one
1981 05 09 00 00 0600 39.024 -120.365 0.0 0 .000 40000 12409.83  # species two
1981 05 15 00 00 0600 38.772 -120.529 0.0 2.766 40000 14753.93  # species one
1981 05 15 00 00 0600 38.772 -120.529 0.0 5.000 40000 14753.93  # species two
1981 06 07 00 00 1100 38.822 -119.997 0.0 0.000 40000 11580.51  # species one
1981 06 07 00 00 1100 38.822 -119.997 0.0 2.532 40000 11580.51  # species two
1981 08 27 00 00 0600 39.058 -120.285 0.0 2.500 40000 13278.11  # species one
1981 08 27 00 00 0600 39.058 -120.285 0.0 1.775 40000 13278.11  # species two
claurel
Posts: 2
Joined: June 30th, 2021, 11:55 am
Registered HYSPLIT User: No

Re: Setting up EMITIMES for multiple time varying sources with different pollutants over long time periods

Post by claurel »

Thank you for your reply! It really cleared things up!
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