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.
| Feature Update | Component | Relevant model | Contibutor(s) | Notes |
|---|---|---|---|---|
| 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) |
| 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 configuration (CAM Issue #663, #664) |
| MEGAN-CLM5 | land and atmosphere: interactive emissions | CESM/CAM-Chem, WACCM and MUSICA | 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) | Online reading and re-gridding of emissions. Includes diurnal cycle options. (CAM Issue #560). Regrids to an intermediate grid. Needs testing with MPAS. |
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 |
|---|---|---|---|---|
| CMIP7 Forcing | Emissions and external forcing (e.g. solar, volcano, fire) | CESM/CAM-Chem | Benjamin Gaubert, Simone Tilmes, Louisa Emmons, Rebecca Buchholz | https://github.com/NCAR/CMIP7_inputdata_processing |
| 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? |
| MAM5 code for Mid Top CMIP7 simulations | Reading 5th mode forcing in simple chemistry | CAM | Simone Tilmes, Francis Vitt | add pull request link? |
| TUVx | Photolysis | CESM/CAM-Chem, WACCM and MUSICA | Doug Kinnison | New photolysis scheme. (https://github.com/NCAR/tuv-x) |
| 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 | CESM/CAM-Chem, WACCM and MUSICA | Rafael Fenandez (ICB-CONICET), Carlos Cuevas (CSIC) | |
| 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). |
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). |
| Nitrate aerosols | aerosol mechanism | CESM/CAM-Chem, WACCM and MUSICA | Implementation of MOSIAC and CARMA with nitrate aerosols. Danny Leung, Yunqian Zhu (NOAA). |
| T3S | chemistry mechanism | CESM/CAM-Chem, WACCM and MUSICA | Urban chemistry relevant mechanism. Publication in prep. Duseong Jo |
| CARMA implementation | complex aerosols | CESM/CAM-Chem, WACCM and MUSICA |
|
Previous updates
Previous updates that have happened in the model.
| Feature Update | Component | Relevant model | Contibutor(s) | Notes | Date Finalized |
|---|---|---|---|---|---|
| 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). | |
| Simple Chemistry | chemistry mechanism | CAM7 | Duseong Jo, Louisa Emmons | Simple chemistry (for CAM7) with updated SOA parameterization to support tropospheric aerosol formation (MAM4) (CAM Issue #727) | |
| OASISS | interactive emissions | CESM/CAM-Chem, WACCM and MUSICA | Siyuan Wang | Online DMS emissions based on Online Air-Sea Interface for Soluble Species (OASISS) |