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We also maintain a list of current model development plans on the CCWG website: https://www.cesm.ucar.edu/working-groups/chemistry/development-plans
Awaiting merging/evaluation
These model updates are available in some development branches and are awaiting full merging in the trunk or evaluation after being merged.
| Feature Update | Component | Relevant model | Contibutor(s) | Notes |
|---|---|---|---|---|
| MEGAN-CLM5 | land and atmosphere: interactive emissions | CESM/CAM-Chem, WACCM and MUSICA | Danny Leung | An updated interactive dust scheme to emit dust into the atmopshere. Will be default in CESM3 | MAM5 aerosols | aerosol mechanism
Alex Guenther (UCI) | Implement updated interactive biogenic emissions with Model of Emissions of Gases and Aerosols from Nature (MEGAN) (CTSM Issue #1323) Already an update related to drought. CLM development is slightly different from offline MEGAN3. | |||
| HEMCO integration | emissions | CESM/CAM-Chem, WACCM and MUSICA | Haipeng Lin (Harvard, NCAR/CGD) | Online reading and re-gridding of emissions. Includes diurnal cycle options. (CAM Issue #560). Regrids to an intermediate grid. Needs testing with MPAS. |
| TUVx | Photolysis | CESM/CAM-Chem, WACCM and MUSICA | Doug Kinnison, Jun Zhang | New photolysis scheme. (https://github.com/NCAR/tuv-x) |
| CMIP7 Forcing | Emissions and external forcing (e.g. solar, volcano, fire) | CESM/CAM-Chem | Benjamin Gaubert, Simone Tilmes, Ilaria Quaglia, Louisa Emmons, | MAM5 (MAM4 + 1 mode for stratospheric sulfate) for all CESM configuration | Soil NOx | Updated Soil NOx emissions (CTSM Issue #1952) |
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| Rebecca Buchholz | https://github.com/NCAR/CMIP7_inputdata_processing | |||
| CARMA implementation | complex aerosols | CESM/CAM-Chem, WACCM and MUSICA | Simone Tilmes, Ilaria Quaglia, Francis Vitt, Charles Bardeen | Adding new compsets (T4S CARMA). Running with CAM6 Physics. Currently testing RRTMGP (CAM is Issue #1430) (CAM7 physics). |
| Short Lived Halogens (SLH) | chemistry mechanism | CESM/CAM-Chem, WACCM and MUSICA | Rafael Fenandez (ICB-CONICET), Carlos Cuevas (CSIC) | CESM3/CAM6 Physics has been implemented. CAM7 Physics still needed. |
| Oxidant saving for SO and stratospheric aerosol runs | Chemistry fields for other models without | Simone Tilmes | Oxidants, stratospheric O3 and aerosol. | |
| Aqueous phase chemistry bug fix | chemistry | CESM/CAM-Chem, WACCM and MUSICA | Kyle Shores, Francis Vitt, Simone Tilmes, Mary Barth |
Top priority for integration (6 months to 1 year)
The list below identifies model updates priorities, that are necessary to improve atmospheric chemistry modeling.
| Feature Update | Component | Relevant model | Contibutor(s) | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|
| Ozone and nitrogen deposition | Chemistry fields for other models without | WACCM output for other models | Doug Kinnison | Simulations performed with 2 degrees WACCM. Output from CMIP7 runs for non interactive chemistry runs. Updated EPP forcing. Possible connection with mid-top. Saving O3, N dep, OH? | |||||
| Soil NOx | online calculation of soil NO emissions | CESM/CAM-Chem, WACCM and MUSICA | Maria Val Martin (University of Sheffield) | Updated Soil NOx emissions (CTSM Issue #1952) | |||||
| Short Lived Halogens (SLH) | chemistry mechanism | CMIP7 Forcing | Emissions and external forcing | CESM/CAM-Chem | Benjamin Gaubert, Simone Tilmes, Louisa Emmons, Rebecca Buchholz | https://github.com/NCAR/CMIP7_inputdata_processing | , WACCM and MUSICA | Rafael Fenandez (ICB-CONICET), Carlos Cuevas (CSIC) | CAM7 Physics included. |
| Heterogeneous uptake on sea salt and dust | multi-phase chemistry | CESM/CAM-Chem, WACCM and MUSICA | Rafael Fenandez (ICB-CONICET), Carlos Cuevas (CSIC), Danny Leung | Heterogeneous reaction of N2O5 on sea salt and dust. Need ClNO2 (inc. in SLH mechanism). | |||||
| Marine Organic Aerosol Emissions | emissions | CESM/CAM | Simone Tilmes | Add emissions of marine aerosols (CAM Issue #531). Two more aerosol species added to the model. Impacts cloud condensation nuclei (CCN). | |||||
| Interactive methane | emissions | TUVx | Photolysis | CESM/CAM-Chem, WACCM and MUSICA | Doug Kinnison | New photolysis scheme. (https://github.com/NCAR/tuv-x) | Benjamin Gaubert | Carbon Tracker inversion. Wetland methane emissions are currently prescribed. | |
| Nitrate aerosols | aerosol mechanism | CESM/CAM-Chem, WACCM and MUSICA | Danny Leung, Yunqian Zhu (NOAA). | Implementation of MOSIAC and CARMA with nitrate aerosols. | |||||
| Chemistry on MPAS grid | chemistry | MUSICAv1 | Wenfu Tang, Behrooz Roozitalab, Ren Smith | Implementation and evaluation on MPAS dynamical core |
Long-term plans
These updates are on our radar, but either are low priority or do not have anyone assigned to work on them.
| Feature Update | Component | Relevant model | Notes |
|---|---|---|---|
| Saving 2m (height) ozone | diagnostic | CESM/CAM-Chem, WACCM and MUSICA | Some land component output is necessary for interpolating the surface layer to 2m. |
| Saving MDA8 ozone | diagnostic | CESM/CAM-Chem, WACCM and MUSICA | Important for comparing with air quality attainment standards. |
| Lightning NOx | atmosphere interactive emissions | CESM/CAM-Chem, WACCM and MUSICA | Scale aware production of lightning NOx. |
| Upper boundary conditions | External forcing | CESM/CAM-Chem, WACCM | Optional Upper boundary conditions for the low top L58 model created from a WACCM simulation (CAM Issue #533). NOy. |
| Marine Organic Aerosol Emissions | emissions | CESM/CAM-Chem, WACCM and MUSICA | Add emissions of marine aerosols (CAM Issue #531). |
| T3S | chemistry mechanism | CESM/CAM-Chem, WACCM and MUSICA | Urban chemistry relevant mechanism. Publication in prep. Duseong Jo (Seoul National University). |
Previous updates
Previous updates that have happened been implemented in the model.
| Feature Update | Component | Relevant model | Contibutor(s) | Notes | Date Finalized |
|---|---|---|---|---|---|
| New dust scheme | land and atmosphere: interactive emissions | CESM/CAM-Chem, WACCM and MUSICA | Danny Leung | An updated interactive dust scheme to emit dust into the atmosphere. Will be default in CESM3. (CAM Issue #651) | 2025 |
| MAM5 aerosols | aerosol mechanism | CESM/CAM-Chem, WACCM and MUSICA | Simone Tilmes, Louisa Emmons, Francis Vitt, Mike Mills | MAM5 (MAM4 + 1 mode for stratospheric sulfate) for all CESM configurations (CAM Issue #663, #664). Also added this functionality to specified oxidant simulations (CAM Issue #1187). | 2024/2025 |
| T4S Chemistry Mechanism | chemistry mechanism | CESM/CAM-Chem, WACCM and MUSICA | Louisa Emmons | Simplified tropospheric and stratospheric chemistry to be used for longer scale runs (e.g. CMIP7). | T3S | chemistry mechanism | HEMCO integration | emissions
| Online reading and re-gridding of emissions. | |||||
| Simple Chemistry | chemistry mechanism | CAM7 | Duseong Jo (Seoul National University), Louisa Emmons | Simple chemistry (for CAM7) with updated SOA parameterization to support tropospheric aerosol formation (MAM4) (CAM Issue #727) | |
| Feb 7, 2023 | |||||
| OASISS | interactive emissions | CESM/CAM-Chem, WACCM and MUSICA | Siyuan Wang | Online DMS emissions based on Online Air-Sea Interface for Soluble Species (OASISS) | 2019 |