Ryan
September 28, 2019, 6:25am
1
Hi all,
Best,
1 Like
Ryan
September 29, 2019, 5:12am
2
Hi Ryan,
The tag ENX is defined in the sensinput.cmas.dat
The tag ESX is defined in the sensinput.cmas.dat as the sensitivity of ozone to SO2.
https://www.airqualitymodeling.org/index.php/CMAQ_version_5.2_DDM_Technical_Documentation
There was another issue in this forum that describes the setup for determining the sensitivity to NOX from the transportation sector that may be helpful.https://forum.cmascenter.org/t/cmaq-ddm-3d-sensinput-file-setting-about-ddm3d-es-emissions-split-into-categories-sensitivity/632
Liz
Ryan
September 29, 2019, 6:16pm
4
Hi Liz,
Best,
Hi Ryan,
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# 11. Integrated Source Apportionment Method (CMAQ-ISAM)
## 11.1 Introduction
The Integrated Source Apportionment Method (ISAM) calculates source attribution information for user specified ozone and particulate matter precursors within the CMAQ model. CMAQ-ISAM has been substantially updated in the CMAQv5.3 release.
The CMAQ model provides users the concentration and deposition fields of many pollutant species. These species are usually combinations of different types of primary emissions and secondary formation that have been physically and chemically transformed in the model. However, sometimes it is desirable to know specific source attribution information for the model outputs. For example, how much of the ozone in an urban area was formed due to nitrogen oxides emitted from motor vehicles in a neighboring state?
Answering this type of question often requires running an air quality model twice, once with the standard emissions scenario and once with the source of interest completely removed. The difference between the two runs is then assumed to be attributed to the removed source. While this approach is reasonably straightforward to implement, it has some drawbacks. For example, removing a large source from the system in a highly nonlinear chemical mixture can lead to some errors. Also, calculating source attribution of many sources can be logistically and computationally prohibitive.
Alternatively, running CMAQ with ISAM enabled allows the user the ability to calculate source attribution of a large number of sources directly by the model in one simulation.
Note: While full model species list apportionment is in development, currently ISAM is limited to the following species classes in CMAQ:
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Ryan
September 29, 2019, 7:12pm
6
Hi Liz,
Best,
Hi Ryan,
<!-- BEGIN COMMENT -->
[<< Previous Chapter](CMAQ_UG_ch10_HDDM-3D.md) - [Home](README.md) - [Next Chapter >>](CMAQ_UG_ch12_sulfur_tracking.md)
<!-- END COMMENT -->
# 11. Integrated Source Apportionment Method (CMAQ-ISAM)
## 11.1 Introduction
The Integrated Source Apportionment Method (ISAM) calculates source attribution information for user specified ozone and particulate matter precursors within the CMAQ model. CMAQ-ISAM has been substantially updated starting with the CMAQv5.3 release, and now differs significantly from previous releases. The major changes to the ISAM chemistry solver are detailed in the [ISAM Chemistry Supplement](Supplement/CMAQ_ISAM_Chemistry_Supplemental_Equations.pdf). In addition, signifcant updates and multiple minor fixes were included in the subsequent releases including substantial updates to the gas-phase chemistry apportionment algorithms that improve both physical and numerical aspects of the method. Users of CMAQ-ISAM are strongly encouraged to update to the latest available release of the model.
The base CMAQ model provides users the concentration and deposition fields of many pollutant species. These species are usually combinations of different types of primary emissions and secondary formation that have been physically and chemically transformed in the model. However, sometimes it is desirable to know specific source attribution information for the model outputs. For example, how much of the ozone in an urban area was formed due to nitrogen oxides emitted from motor vehicles in a neighboring state?
Answering this type of question often requires running an air quality model twice, once with the standard emissions scenario and once with the source of interest completely removed. The difference between the two runs is then assumed to be attributed to the removed source. While this approach is reasonably straightforward to implement, it has some drawbacks. For example, removing a large source from the system in a highly nonlinear chemical mixture can lead to some errors. Also, calculating source attribution of many sources can be logistically and computationally prohibitive.
Alternatively, running CMAQ with ISAM enabled allows the user the ability to calculate source attribution of a large number of sources directly by the model in one simulation.
Note: While full model species list apportionment is in development, currently ISAM is limited to the following species classes in CMAQ:
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How to specify the region that is adjusted for scaling:
## CMAQ Tutorial ##
### Prescribing Emissions Using DESID (Detailed Emissions Scaling, Isolation and Diagnostics) Module ###
Purpose: This tutorial will guide users to utilizing the DESID Control namelists to perform some basic manipulation
of their emission streams. For additional questions, contact Ben Murphy (murphy.ben@epa.gov) or visit the CMAS Forum.
------------
### Definitions of Terms
- Stream: An Online emission source or a group of sources processed offline and read into CMAQ from one file. Common
examples of streams include biogenic VOCs, mobile sources, wind-blown dust, prescribed fires, electric-generating units,
residential heating, etc.
- Species: A variable representing a chemical compound or group of compounds in CMAQ.
- Surrogate: A variable representing a chemical compound or group of compounds on an emission Stream.
### Important Notes to Remember
- Rules are applied in the order they are provided.
### Example Use Cases
- [1. Zero out emissions](#zero_out)
- [2. Add emissions for a new tracer species](#add_emissions)
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A cool example of calculating the Ozone due to wildfire emissions:https://ofmpub.epa.gov/rsig/rsigserver?cmaq_application/public/isam.html