GEOS-Chem model development priorities

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On this page we list the current priorities for GEOS-Chem development. This list is continuously updated based on code readiness and input from the Working Groups and the Steering Committee. For history of past releases see the GEOS-Chem Versions wiki page.

Release schedule

Please see the GEOS-Chem Release Proposal outlining the procedure and schedule for releasing GEOS-Chem versions.

Merged and awaiting release

See the links below for items merged and awaiting release.

Patch version in development	Minor version in development
-	GEOS-Chem 13.4.0

Feature integration in progress

Features listed in this table are actively being integrated into GEOS-Chem by the GEOS-Chem Support Team. In addition, we continuously implement structural updates in the model to maintain and develop coupling with other models including GEOS, CESM, and the model adjoint.

Feature	Contributor(s)	Model scope	Ease of implementation	Notes and References
Change State_Chm%Species from 4D to vector of 3D arrays	Lizzie Lundgren (GCST)	Structural	Medium	Done, slated for 14.0.0
Convert input.geos to YAML and rename	Bob Yantosca (GCST)	Run directories	Medium	See geoschem/geos-chem #1111 In testing, slated for 14.0.0
Upgrade GMAO libraries in GCHP	Liam Bindle (GCST) Lizzie Lundgren (GCST)	Structural	Easy	Done, slated for 14.0.0
Fixes to remove differences when restarting the model	Lizzie Lundgren (GCST)	Bug fixes	Medium	Done for GCHP, slated for 14.0.0
Provide climatologies for open fire emissions	Melissa Sulprizio (GCST)	Emissions	Easy
Climatologies for lightning NOx	Lee Murray (Rochester) Melissa Sulprizio (GCST)	Emissions	Easy
Updated offline biogenic emissions	Hongjian Weng (PKU)	Emissions	Easy	Delivered to GCST (Dec 2021)
Updated offline soil NOx emissions	Hongjian Weng (PKU)	Emissions	Easy	Delivered to GCST (Dec 2021)
Add new species concentration diagnostic in units of molec/cm3	GCST	Diagnostics	Easy	See geoschem/geos-chem #1022
Output satellite diagnostics as NetCDF	Eloise Marais (UCL)	Diagnostics	Easy	See geoschem/geos-chem #1134
Upgrade Fast-JX to Cloud-J	Lizzie Lundgren (GCST)	Structural	Difficult	geoschem/cloud-j Ongoing

Feature integration in the queue

Features listed in this table have been delivered to the GEOS-Chem Support Team and are prioritized to be integrated into GEOS-Chem in the near future.

Feature	Contributor(s)	Model scope	Ease of implementation	Notes and References
Adaptive chemical solver (as option)	Mike Long (Harvard) Haipeng Lin (Harvard) Bob Yantosca (GCST) Lu Shen (PKU)	Chemistry	Difficult	In testing, publication expected in mid-to-late 2022 Previous literature: Shen et al., 2022, Shen et al., 2020
MEGAN3	Sam Silva (MIT)	Emissions	Medium	DOI: 10.5281/zenodo.3614062 Sam Silva and GCST will work on updating this to a more recent GEOS-Chem version in the near future
Canopy Physics Model	Sam Silva (MIT)	Emissions & Science	Medium	DOI: 10.5281/zenodo.3614062 Sam Silva and GCST will work on updating this to a more recent GEOS-Chem version in the near future
Joint CO2-CO-CH4-OCS simulation	Beata Bukosa (NIWA) Kevin Bowman (JPL) Mike Long (GCST/Contractor)	Specialty simulation	Medium	geoschem/geos-chem #654 Ideally implemented as a chemical mechanism in KPP

Feature integration not yet prioritized

Features listed in this table have been delivered to the GEOS-Chem Support Team but are not yet prioritized for integrating into the model.

Feature	Contributor(s)	Model scope	Ease of implementation	Notes and References
Stratospheric adjustment with RRTMG in GEOS-Chem	Seb Eastham (MIT)	Science	Medium	geoschem/geos-chem #1094
Stratospheric HCN chemistry	Armin Kleinbohl (JPL) Debra Weisenstein (Harvard, retired)	Chemistry	Medium	Delivered to GCST (Jun 2020)
GC-YIBs biosphere-atmospheric chemistry coupled model	Xu Yue (NUIST)	Science	Easy	geoschem/geos-chem #425
Ecophysiology module in GEOS-Chem for biosphere-atmosphere exchange	Joey Lam(CUHK) Amos Tai (CUHK)	Science	Easy	Delivered to GCST (Feb 2021) geoschem/geos-chem #629
Extend UCX into the mesosphere	Sebastian Eastham (MIT) Eric Fleming (NASA GMAO)	Chemistry	Easy
Landcover/Fire Emissions Offline LPJlmfire	Loretta Mickley (Harvard) Yang Li (Harvard)	Emissions	Easy	Data files delivered to GCST (July 2021)

Almost there (< 6 months)

Features listed in this table are in development and will likely be delivered to the GEOS-Chem Support Team within the next 6 months.

Feature	Contributor(s)	Model scope	Notes and References
Implement H2 chemistry in UCX	Chris Holmes (FSU)	Chemistry	Identified as a priority for GC 13, but not yet delivered
New soil NOx parameterization	Yi Wang (U. Iowa) Jun Wang (U. Iowa)	Emissions
Updated offline sea salt emissions	Hongjian Weng (PKU)	Emissions	Identified as a priority for GC 13, but not yet delivered
Provide recommended rather than hard-coded scaling factors for online emissions	GCST	Emissions	Identified as a priority for GC 13, but not yet developed
Add stratospheric ozone species to full-chemistry simulations	Lee Murray (Rochester)	Chemistry
Diagnostic to archive XCO2, XCO, and XCH4	Dylan Jones (Toronto)	Diagnostic
Provide archived TCR-2 GEOS-Chem OH fields for carbon simulations	Kazu Miyazaki (JPL)	Input data
BrC aging	Xuan Wang (Harvard) Melanie Hammer(Dalhousie)	Chemistry
Shared Socioeconomic Pathways Emission Inventories	Hong Liao (NUIST)	Emissions
Rediagnosis of RAS convection in GEOS-Chem	Tailong He (Toronto) Dylan Jones (Toronto) Andrea Molod (NASA/GMAO)	Convection	Work is finished and a manuscript is in preparation.
HTAPv3 emissions (0.1 deg, 2002-2018)	Emissions & Deposition WG	Emissions
Migrating simple SOA formation from carbon_mod.F90 into the KPP "full-chemistry" mechanism	GCST	Chemistry
Updated parameterization of aerosol size distribution for bulk aerosol simulations	Haihui Zhu (WashU) Shixian Zhai (Harvard)	Aerosols

Over the horizon (6-12 months)

Features listed in this table are in development and will likely be delivered to the GEOS-Chem Support Team in the 6-12 months timeframe.

Feature	Contributor(s)	Model scope	Notes and References
Methylethylketone chemistry	Jared Brewer (CSU)	Chemistry
Add sulfate dependence to SOA yield from isoprene in simple SOA	Eloise Marais (UCL)	Chemistry
GTMM updates	Ben Geyman (Harvard)	Hg simulation
Integrating GMAO's tracer gridded component in GCHP	Christoph Keller (NASA GMAO)	Transport Tracer simulation
Streamlining of specialty simulations through HEMCO and KPP	GCST	Chemistry, Specialty simulations

Longer term (12-24 months)

Features listed in this table are in development and will likely be delivered to the GEOS-Chem Support Team in the 12-24 months timeframe.

Feature	Contributor(s)	Model scope	Notes and References
Implement isotope simulation for CO and CH4 in GCHP	Lee Murray (Rochester)	Specialty simulation
Migrate LETFK DA scheme to GCHP	Kazu Miyazaki (JPL)	Structural
Super fast chemistry scheme	Benjamin Brown-Steiner (AER) Makoto Kelp (Harvard)	Chemistry	SF mechanism has been implemented and benchmarked in GEOS-Chem 12.0.0. This mechanism is of interest for those groups wanting fast global simulation of oxidation fields in GEOS-Chem simulations focused on aerosol microphysics. The machine-learned chemical solver is still probably 12 months away from online implementation into GEOS-Chem.
Add non-volatile cations to ISORROPIA	Becky Alexander (UW)	Aerosols
DMS oxidation scheme updating	Becky Alexander (UW) Qianjie Chen (UW)	Chemistry	Delayed - implemented pre-KPP Currently bring implemented in KPP by UC Riverside group
Heterogeneous sulfate production	Lin Zhang (PKU) Becky Alexander (UW) Yuxuan Wang (U. Houston)	Chemistry	Delayed - implemented pre-KPP
Hg in WRF-GC	Yanxu Zhang (Nanjing)	Hg simulation
Hg with blowing snow	Yanxu Xhang (Nanjing)	Emissions, Hg simulation
Hg isotopes	Xiaotian Xu, Yanxu Xhang (Nanjing)	Hg simulation
Hg in CESM CAM-CHEM	Peng Zhang, Yanxu Xhang (Nanjing)	Hg simulation
Complex / multicomplex variables	Shannon Capps (Drexel)	Structural

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