GEOS-Chem model development priorities

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.

Merged and awaiting release

See the links below for items merged and awaiting release.

Mergeable at any time	Version in development
GEOS-Chem no-diff-to-benchmark	GEOS-Chem 14.5.0

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
ALK4 & R4N2 chemistry	Jared Brewer (UMN)	Chemistry	Simple	geos-chem PR #1625 Brewer, J.F. et al., J. Geophys. Res., 2023.
New soil NOx parameterization	Yi Wang (Iowa) Jun Wang (Iowa)	Emissions	Medium	geos-chem issue #1288 Incorporates new met field TSOIL1
Fix pressure handling in HEMCO standalone	Melissa Sulprizio (Harvard)	HEMCO	Simple	HEMCO issue #277
Fix obspack - not working in 14.4.0	Bob Yantosca (Harvard)	Diagnostics	Medium	geos-chem issue #2328
Horizontal flux regridding fix in MAPL	Tom Clune (GMAO)	GCHP	Medium	MAPL PR #36
Cloud-J 7.7.2 for greater flexibility in external models	Lizzie Lundgren (Harvard)	Photolysis	Medium	Cloud-J PR #17 geos-chem PR #2342 geos-chem PR #2553 Cloud-J PR #19
GCHP run directory improvements for mass flux, stretched grid, and GEOS-IT runs	Lizzie Lundgren (Harvard)	GCHP	Medium	geos-chem PR #2326
Fixes for GEOS-Chem 14.4 in CESM	Haipeng Lin (Harvard) Lizzie Lundgren (Harvard)	CESM	Medium	geos-chem PR #2348 geos-chem PR #2349 More PRs in progress

Prioritized and in the queue

Features listed in this table are prioritized for integration into GEOS-Chem in the near future.

Feature	Contributor(s)	Model scope	Ease of implementation	Delivery status	Notes and References
New version of CEDS at 0.1 deg	Dandan Zhang (WashU)	Emissions	Simple	Delivered June 2024	geos-chem issue #1745
Remove differences in GC-Classic due to HEMCO reading REAL8 restart as REAL4	Lizzie Lundgren (Harvard)	GC-Classic	Medium		HEMCO issue #18

Ready to go in

Features listed in this table are ready to go in but have either not been delivered or are not yet prioritized for integration into GEOS-Chem.

Feature	Contributor(s)	Model scope	Delivery status	Notes and Refereneces
Binary Activity Thermodynamic (BAT) model for non-ideal mixing of water and organics in organic aerosol	Camilo Serrano (McGill) Andreas Zuend (McGill)	Aerosols	Not delivered
Extend aerosol settling	Eloise Marais (UCL)	Aerosols	Not delivered
Comment back in Ca, Mg, and K cations in aerosol thermo (HETP)	Becky Alexander (UW)	Aerosols	Not delivered
Seasalt aerosol from sea ice leads (2002-2011)	Hannah Horrowitz (UIUC)	Aerosols	Not delivered	Offline and online, ready to go in HEMCO (optional in addition to existing seasalt emissions)
P/L species should not contribute to the error norm	Obin Sturm (USC)	Chemistry	Not delivered
Additional 6 peroxynitrates (many PANs like species); improve ALK4 & add ALK6	Katie Travis (NASA LARC)	Chemistry	Not delivered
Monoterpene oxidation more species & oxidation products	Kevin Bates (CU Boulder)	Chemistry	Not delivered
PPN photolysis	Eloise Marais (UCL)	Chemistry	Not delivered
Global organic N dep from various emissions; nitrate aromatics updates	May Fu (SUSTech)	Chemistry + Deposition	Not delivered
ALK4 from biogenic vs anthro	Jared Brewer (UMN)	Chemistry	Not delivered
Dry deposition to F90 to improve readability	Chris Holmes (FSU)	Dry Deposition	Not delivered
Ecophysiology module in GEOS-Chem for biosphere-atmosphere exchange	Joey Lam (CUHK) Amos Tai (CUHK)	Dry deposition	Delivered Feb 2021	geos-chem PR #629
FRP-based fire emissions for eastern US at 0.2 (2019-2020)	Chris Holmes (FSU)	Emissions	Not delivered
China agriculture NH3 emissions	Amos Tai (CUHK)	Emissions	Not delivered
T-dependent anthropogenic VOCs	May Fu (SUSTech)	Emissions	Not delivered	Option. Requires processing existing anthropogenic VOC emissions to generate offline emissions to read in. Parameterised for China.
New source functions for transport tracers beryllium-7 and beryllium-10	Minjie Zheng (ETH)	Emissions	Delivered June 2024	Available at https://zenodo.org/records/8372652
LPJ land cover (global), fire (W US), dust emissions (SW N America), 1700-2100	Yang Li (Baylor U) Loretta Mickley (Harvard)	Emissions	Delivered	Data involves many files- need to think about temporal frequency
Australian emissions	Stephen MacFarlane (Wollongong) Jenny Fisher (Wollongong)	Emissions	Not delivered
Hg geogenic emissions (volcanic, rock weathering)	Eric Roy (MIT)	Emissions	Not delivered	geos-chem #2361 cf. Dastoor et al. (2024)
Hg biomass burning - FINN2.5 & GFED4	Eric Roy (MIT)	Emissions	Not delivered	geos-chem #2361 cf. Dastoor et al. (2024)
BCC-GC online	Lin Zhang (PKU)	External Model	Not delivered
GC-YIBS with online fire emissions	Xu Yue (NUIST) Hong Liao (NUIST)	External Model	Not delivered
GISS-GC offline (GCAP)	Lee Murray (Rochester)	GCAP	Not delivered
Archived TCR-2 OH fields for carbon simulations	Kazu Miyazaki (JPL)	Input data	Not delivered	This will be the default OH, but users will have the option of selecting other OH fields

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
Capture all trop and PBL height changes in budget diagnostics	Chris Holmes (FSU) Lizzie Lundgren (Harvard)	Diagnostics	geos-chem PR 2103
Dust non-sphericity impacts on optical properties	Inderjeet Singh (WashU)	Aerosols
Fixes to stratospheric aerosol settling	Connor Barker (UCL) Eloise Marais (UCL)	Aerosols
DMS chemistry in v14	Linia Tashmim (UCR) Will Porter (UCR)	Chemistry
KPP standalone + 3D Interface	Obin Sturm (USC)	Chemistry
Load balancing in chemistry solver (GCHP)	Zhouran (Jordan) Sun (WashU)	Chemistry + Performance
UCX chemistry in mesosphere (GCHP/GCClassic)	Helena McDonald (MIT)	Chemistry
Updated aromatic oxidation	Stephen MacFarlane (Wollongong) Jenny Fisher (Wollongong)	Chemistry
MCO3 uptake by cloud forming MP; leading to lower PAN	Laura Yang (Harvard)	Chemistry
Implement isotope simulation for CH4 in the carbon simulation	Lee Murray (Rochester)	Chemistry	Will have to change negative emissions from soil to a first-order loss process
Active mesospheric chemistry	Helena McDonald (MIT) Seb Eastham (ICL)	Chemistry
Documentation for adding additional aerosol species	Connor Barker (UCL)	Documentation
Column diagnostics	Lizzie Lundgren (Harvard) Viral Shah (GMAO)	Diagnostics
TOMAS rate diagnostics -- improve performance	Betty Croft (WashU/Dal)	Diagnostics + Performance
Archive gamma values from heterogeneous chemistry	Bob Yantosca (Harvard)	Diagnostics
RRTMG Documentation	GCST	Documentation
Canopy Physics Model	Sam Silva (MIT)	Dry Deposition
Dry deposition diagnostics by land cover	Holly Nowell (FSU) Chris Holmes (FSU)	Dry Deposition
Dry deposition process diagnostics	Holly Nowell (FSU) Chris Holmes (FSU)	Dry Deposition
Biomass burning for TOMAS	Nicole June (CSU)	Emissions + Microphysics
Historic biomass burning (1750-2010)	Pengfei (Gtech)	Emissions
Rice methane emissions	Zichong Cheng (Harvard)	Emissions+ Carbon simulation
Fire and anthropogenic emissions not currently turned on (monoterpenes, 1-butadiene etc.)	Katie Travis (NASA) Kelvin Bates (CU Boulder)	Emissions
Updated bottom-up global CH4 oil, gas, and coal emissions (GFEI v3)	Tia Scarpelli (Carbon Mapper) Melissa Sulprizio (Harvard)	Emissions
New prior CO2 biospheric fluxes from CMS-FLUX and GMAO	Kevin Bowman (JPL) Lesley Ott (GMAO)	Emissions	GMAO can provide high-resolution fluxes (as high as 12 km)
Snowpack Br2 emission	Chris Holmes (FSU)	Emissions
EDGAR v8.1_toxHg emissions for 1970-2022	Eric Roy (MIT)	Emissions
Improve pressure handling in GCHP advection	Yuanjian Zhang (WashU) Seb Eastham (ICL)	GCHP
Add error trap for duplicate scale factors in HEMCO	Bob Yantosca (Harvard)	HEMCO
Integration testing: Add stretched grid	Lizzie Lundgren (Harvard)	Quality Assurance
Integration testing: Add GCAP2	GCST	Quality Assurance
Integration testing: Add GCHP mass flux run	Lizzie Lundgren (Harvard)	Quality Assurance
Integration testing: Add run with all diagnostics turned on	GCST	Quality Assurance
Integration testing: Reinstate TOMAS40	Betty Croft (Dalhousie/WashU)	Quality Assurance
Strat-adjusted RF in GCC and GCHP	Connor Barker (UCL) Eloise Marais (UCL)	Radiation
Continue cleanup of C-preprocessor switches	Lizzie Lundgren (Harvard)	Structural
Updates to Luo deposition scheme	Gan Luo (Albany)	Wet Deposition	New version, keep as switch (not default)
Testing the use of a new scavenging parameterization developed by Luo and Yu for cold cloud with Pb-210 aerosol tracer	Gan Luo (Albany) Fangqun Yu (Albany)	Wet Deposition

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
ML algorithms for bulk aerosol	Arshad Nair (Albany) Fangqun Yu (Albany)	Aerosols
Heterogeneous sulfate chemistry	Katie Travis (NASA)	Chemistry
H2 as an active species	Seb Eastham (ICL)	Chemistry
HCN, acetonitrile as fire tracers	Kevin Bates (CU Boulder)	Chemistry
Implement ethane in carbon simulation	Yuzhong Zhang (Westlake)	Chemistry
VCPs emissions	Kelvin Bates (CU Boulder)	Emissions
Mesospheric source of CO	Dylan Jones (UofT) Pam Wales (NASA GSFC)	Emissions
Drought-stress algorithm	Wei Li (Houston)	Emissions
Physically-based resolution correction for BVOC emissions using MEGAN	May Fu (SUSTech)	Emissions
Canadian forest fire prediction system (Canada government forecast model)	Robin Stevens (Montreal)	Emissions
Furan emission factors (updates existing emissions)	Lu Hu (Montana) Lixu Jin (Montana)	Emissions
Cooking emissions (not biofuel)	Kelvin Bates (CU Boulder)	Emissions
State-specific annual emissions scaling factors (US) (1990-2021)	Ishir Dutta (MIT)	Emissions
GISS-GC online	Lee Murray (Rochester)	External model
Hybrid MPI-OpenMP in GCHP	Seb Eastham (MIT) Killian Murphy (York) Lizzie Lundgren (Harvard)	GCHP
MAPL3: Update to MAPL3 in GCHP, including replacement of ExtData.rc and HISTORY.rc with YAML files	Lizzie Lundgren (Harvard)	GCHP
MAPL3: Comply with MAPL "positive" standard in GCHP diagnostic files	Lizzie Lundgren (Harvard)	GCHP
MAPL3: Wildcards in GCHP History	Lizzie Lundgren (Harvard)	GCHP
MAPL3: Output emissions with positive up convention in GCHP	Lizzie Lundgren (Harvard)	GCHP
Assessment/improvement of OpenMP performance in GC-Classic and HEMCO standalone	Bob Yantosca (Harvard)	Performance
Photophysical oxidation of aldehydes	Paulo Sebastianelli (Wollongong) Jenny Fisher (Wollongong)	Chemistry
DMS updates	Will Porter (UCR)	Chemistry
Furans emission and chemistry	Lixu Jin (Montana) Lu Hu (Montana)	Chemistry + Emissions
Cl2 prodcution from Fe aerosol	Qianjie Chen (HK Poly) Becky Alexander (UW)	Chemistry
VCP, cooking: tracers species added i.e., D5, ethanol affecting PAN	Kevin Bates (CU Boulder)	Emissions
bidirectional land-atmosphere exchange for Hg	Yuying Cui (MIT/Tsinghua)	Hg simulation
OH covariances for inversions	Elise Penn (Harvard)	Inversions
CESM2-GC offline	Seb Eastham (ICL) Lee Murray (Rochester)	Met fields
Re-binning of off-line sea salt and dust for TOMAS	Betty Croft (Dalhousie)	Microphysics
TOMAS nucleation updates	Sam O'Donnell (CSU)	Microphysics
Stratospheric aerosol APM	Fangqun Yu (SUNY Albany)	Microphysics
Transition from MERRA-2 to GEOS-IT for benchmarking	Yuanjian Zhang (WashU)	Quality Assurance
Automate integration testing on AWS	Yidan Tang (WashU)	Quality Assurance
Integration testing: Add across end of year run	GCST	Quality Assurance
Integration testing: Add GEOS-IT	Yuanjian Zhang (WashU)	Quality Assurance
Separate mixing, emissions, and drydep	Yuanjian Zhang (WashU)	Structural
Intel IFX compiler	Bob Yantosca (Harvard)	Structural
CMake option to only build libraries but not executable, also passing C-preprocessor statements to turn off code	Bob Yantosca (Harvard) Lee Murray (Rochester)	Structural
Remove differences introduced when breaking up GC-Classic runs in time; and flexible precision in HEMCO	Lizzie Lundgren (Harvard)	Structural
Limit allocation of State_Met to what is needed per simulation	Melissa Sulprizio (Harvard)	Structural

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
Modal aerosol model (MAM7) in GCHP	Shreya Sharma (MIT)	Aerosols
Online OCIM ocean biogeochemistry	Lee Murray (Rochester) Hannah Horowitz (UIUC) Chris Holmes (FSU)	Chemistry
Perchlorate chemistry	Yuk Chun Chan (UW)	Chemistry
Non-stomatal dry deposition (2-layer canopy model)	Michael Vermeuel (Purdue)	Dry Deposition
Continental chloride particle emissions (salty dust, road salt)	Jessica Haskins (Utah)	Emissions
Multivolatility emission inventory to address gaps in EDGAR/HTAP etc.	Ruochong (Tshingua)	Emissions
Lightning NOx production rates	Bex Horner (UCL)	Emissions
HFO and CF3CHO	Beth Killen (Wollongong) Jenny Fisher (Wollongong)	Chemistry
Glyoxal updates from isoprene	Tzung-May Fu (SUSTech)	Chemistry
Iodine chemistry	Becky Alexander (UW) Xuan Wang (CUHK)	Chemistry
Chlorine/Perchlorate	Yukchun Chan (UW)	Chemistry
Playa dust chemistry to improve Cl over land	Jessica Haskins (Utah)	Chemistry
GFED5 biomass burning	Eric Roy (MIT)	Emissions
Ocean Hg surface concentrations for 2010-2020 from multi-model ensemble	Eric Roy (MIT) Ari Feinberg (IQF-CSIC)	Hg simulation
Soil Hg emissions 2010-2020	Eric Roy (MIT) Ari Feinberg (IQF-CSIC)	Hg simulation
Air-sea exchange parameterization	Eric Roy (MIT)	Hg simulation
Soil Hg emissions parameterization	Ari Feinberg (IQF-CSIC)	Hg simulation
Sea salt uptake of GOM	Eric Roy (MIT)	Hg simulation
Photoreduction rate constant	Eric Roy (MIT)	Hg simulation
new observations (2010-2020) in standardized Hg benchmark for intercomparison	Eric Roy (MIT)/Ari Feinberg (IQF-CSIC)	Hg simulation
Hg simulation in GCHP	Eric Roy (MIT)	Hg simulation
OCIM - biogeochemical model - (C/P/N/Fe - no Hg yet) (MATLAB)	Hannah Horowitz (UIUC)	Hg simulation
possibly updating Hg oxidation chemistry based on Utah field campaigns	Jessica Haskins (Utah)	Hg simulation
New halogen/aerosol fields (surface area / AOD) from 10-year 14.4 benchmark simulation available online	Viral Shah (NASA GMAO); Eric Roy (MIT); Ari Feinberg (IQF-CSIC)	Input data
Extend IMI to CO2 (ICI)	Hannah Nesser (JPL)	Inversions
Global emission inventory of metals	Tzung-May Fu (SUSTech); He Zhong Tian (Peking Normal U)	Metals simulation
Investigate and improve performance of aerosol chemistry	Bob Yantosca (Harvard)	Performance
PAH - update from version 11	Lexia Cicone (MIT)	POPs simulation
Species database more accessible; doc updates; TOL discussion	Jessica Haskins (Utah)	Structural
Stretched-grid plotting in GCPy	Killian Murphy (York)	Tools
Model inter-comparison of transport (GEOS, GCHP, GCClassic)	Lizzie Lundgren (Harvard), Emma Knowland (NASA)	Transport
Comparing mass fluxes in GCHP vs. traditional lat/lon wind	Yuanjian Zhang (WashU), Seb Eastham (ICL)	Transport