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 14.4.0

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
Global continental chlorine (pCl and HCl) emissions	Bingqing Zhang (Georgia Tech) Pengfei Liu (Georgia Tech)	Emissions	Simple
Parameterization of SNA and OM dry size	Haihui Zhu (WashU)	Aerosols	Medium	Zhu et al., EGUsphere, submitted 2023. geos-chem PR #1902
New soil NOx parameterization	Yi Wang (U. Iowa) Jun Wang (U. Iowa)	Emissions	Medium	geos-chem issue #1288 Incorporates new met field TSOIL1
Remove differences in GC-Classic due to HEMCO reading REAL8 restart as REAL4	Lizzie Lundgren (Harvard)	GC-Classic	Medium	hemco issue #18
Replace ISORROPIA with HETPv1.0	Lizzie Lundgren (Harvard) Seb Eastham (ICL)	Aerosol thermodynamics	Medium	geos-chem issue #2235
Only convert units for species that need it	Bob Yantosca (Harvard)	Unit conversions	Medium	geos-chem PR #2072
Capture all trop and PBL height changes in budget diagnostics	Chris Holmes (FSU) Lizzie Lundgren (Harvard)	Diagnostics	Medium	geos-chem PR 2103

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
ALK4 & R4N2 chemistry	Jared Brewer (UMN)	Chemistry	TBD	Not delivered	geos-chem issue #1625 Brewer, J.F. et al., J. Geophys. Res., 2023.
Mass flux regridding fix in MAPL	Tom Clune (GMAO) Seb Eastham (MIT)	GCHP input regridding	Medium		GCHP Issue #377 Currently on hold, as the submitted update results in zero diff
New version of CEDS at 0.1 deg	Dandan Zhang (WashU)	Emissions	Simple	Delivered	geos-chem issue #1745 Currently on hold while an issue with seasonality in the new CEDS data is being investigated by the authors.

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 References
KORUS-AQ emissions for East Asia (as an option)	Katie Travis (NASA)	Emissions	Simple
Geologic emission of ethane and propane	Matthew Rowlinson and Mat Evans(York)	Emissions	Delivered Jan 2023	Global source from https://doi.org/10.1038/s41561-018-0073-0 with spatial distribution from https://doi.org/10.5194/essd-11-1-2019
Ecophysiology module in GEOS-Chem for biosphere-atmosphere exchange	Joey Lam(CUHK) Amos Tai (CUHK)	Science	Delivered Feb 2021	geos-chem PR #629
LPJ land cover (global), fire (W US), dust emissions (SW N America), 1700-2100	Yang Li (Baylor University) Loretta Mickley (Harvard)	Emissions	Delivered Jul 2021	Data involves many files- need to think about temporal frequency
Online H2 chemistry	Maria Paula Pérez-Peña (UNSW) Jenny Fisher (UOW) Dylan Millet (UMN)	Chemistry	Delivered June 2023	Pérez-Peña, M.P. et al., ACP, 2022. Implemented in v12.5, needs to be brought up to current version
DMS Chemistry	Linia Tashmim (UC Riverside) William Porter (UC Riverside)	Chemistry	Not delivered
Organic acids (RCOOH)	Katie Travis (NASA)	Chemistry	Not delivered
Improve carbon & nitrogen conservation in reactions	Kelvin Bates (Harvard)	Chemistry	Not delivered
Blowing snow sea salt in TOMAS	Betty Croft (Dalhousie)	Aerosols	Not delivered
Australian anthropogenic Hg emissions	Stephen MacFarlane (UOW) Jenny Fisher (UOW) Hannah Horowitz (U. Illinois) Viral Shah (Harvard)	Hg simulation	Not delivered
WRF-GC Hg simulation	Xiaotian Xu (Nanjing U.) Yanxu Zhang (Nanjing U.)	Hg simulation WRF-GC	Not delivered
Updated HgII gas-partical partitioning	Kaiyun Liu (Tsinghua U.) Qingru Wu (Tsinghua U.) Shuxiao Wang (Tsinghua U.)	Hg simulation	Not delivered	Should be option, not default
Dry deposition to F90 (readability)	Chris Holmes (FSU)	Dry deposition	Not delivered

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
PPN+hv, PPN+OH	Robert Ryan (UCL)	Chemistry
MBO	Michael Vermeuel (UMN)	Chemistry
Initial conditions for CH4 correcting background and stratospheric biases	Todd Mooring (Harvard)	Methane simulation
Migrating simple SOA formation from carbon_mod.F90 into the KPP "full-chemistry" mechanism	Bob Yantosca (Harvard)	Aerosols Structural	Ongoing
Re-binning of off-line sea salt and dust for use in TOMAS	Betty Croft (Dalhousie)	Aerosols
Adaption of TOMAS' in-cloud aqueous sulfate production for KPP versus sulfate_mod.F90	Betty Croft (Dalhousie)	Aerosols
ML algorithms for bulk aerosols	Arshad Nair (SUNY Albany) Fangqun Yu (SUNY Albany)	Aerosols
PM2.5 and PM10 calculations: aerodynamic vs geometric diameters	Shixian Zhai (Harvard)	Aerosols
Updates to Hodzic SOA scheme	Jared Brewer (Harvard)	Aerosols
Automated reduction in isoprene scheme	Dan Westervelt (Lamont-Doherty)	Aerosols
Brown carbon chemsitry	Jingqiu Mao (U. Alaska) Xuan Wang (CUHK)	Aerosols
GEOS resolution and subgrid convection - Part 2 RAS parameter tuning	Tailong He (Toronto) Dylan Jones (Toronto) Andrea Molod (NASA GMAO)	Convection
High-res top-down TROPOMI-derived seasonal mean NOx emissions for China	Jintai Lin (PKU)	Emissions	Horizontal resolution: 5km, temporal resolution: JJA mean monthly data will be available at a later stage; please contact us
Updated biomass burning emission factors and species	Tess Carter (MIT)	Emissions
Updated offline sea salt emissions	Hongjian Weng (PKU) Jintai Lin (PKU)	Emissions
Canopy Physics Model	Sam Silva (MIT)	Emissions & Science	DOI: 10.5281/zenodo.3614062 Needs to be updated to a more recent GEOS-Chem version
Assessment/improvement of OpenMP performance in GC-Classic and HEMCO standalone	Bob Yantosca (Harvard)	Model performance	Ongoing (will be done as time allows)
Retire all BPCH diagnostics	Bob Yantosca (Harvard)	Diagnostics	Can be done following the TOMAS update for GCHP
Assess memory leak in GCHP	Killian Murphy (York)	Model performance	NOTE: Most memory leaks in GCHP have been fixed by geoschem/geos-chem PR #1353. Need to assess if any memory leaks still remain.
Hybrid MPI-OpenMP in GCHP	Seb Eastham (MIT) Killian Murphy (York)	Model performance
Improve run directory templating and creation with init_rd.sh and shared directories	Jourdan He (WashU)	Run directories
Table of CTM and online GCM properties: GCHP, GCC, GEOS-CTM, GC-Nested, online GEOS, GEOS-replay, etc	GCST?	Documentation

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
Snow / Icy Bromine	Becky Alexander (UW) William Swanson (U. Alaska) Shuting Zhai (UW)	Chemistry
Monoterpene oxidation scheme	Jessica Haskins (MIT)	Chemistry
Fire related VOCs including furans	Lu Hu (UMT) Lixu Jin (UMT)	Chemistry
Extension of UCX into the mesosphere	Seb Eastham (MIT) Eric Fleming (NASA)	Chemistry
Methane flux ingestion	Eloise Marais (UCL)	Chemistry
Dust non-sphericity impacts on surface chem and optical properties	Inderjeet Singh (WashU)	Aerosols
Size-resolved stratospheric aerosol	Seb Eastham (MIT)	Aerosols
Extend aerosol settling	Eloise Marais (UCL)	Aerosols
Stratospheric aerosol APM	Fangqun Yu (SUNY)	Aerosols
Plume-in-grid model	Hongwei Sun (Harvard)	Chemistry
Updated lightning NOx: Prescribe from ground and geostationary lightning flashes	Lee Murray (Rochester)	Emissions
Seb aircraft emissions beyond recent 2019 update	Seb Eastham (MIT)	Emissions
FRP-based fire emsisions for eastern US at 0.2 deg	Charlie Fite (FSU)	Emissions
Hg iodine chemistry	Yiming Fu Yanxu Zhang (Nanjing U.)	Hg simulation
Hg simulation in GCHP	Ari Feinberg (MIT) Lyssa Freese (MIT)	Hg simulation
Update Hg ocean and soil boundary conditions for consistency with new chemistry	Yanxu Zhang (Nanjing U.)	Hg simulation
Dry deposition diagnostics by land cover	Holly Nowell (FSU)	Diagnostics
Dry deposition process diagnostics	Holly Nowell (FSU)	Diagnostics
Isotope simulation for CO and CH4 in GCHP	Lee Murray (Rochester)	Carbon simulation
Updated bottom-up global CH4 oil, gas, and coal emissions (GFEI v3)	Melissa Sulprizio (Harvard) Tia Scarpelli (U. Edinburgh) Zichong Chen (Harvard)	Emissions CH4 simulation
Modularization of aerosols code for interface with GOCART in GEOS	Christoph Keller (GMAO)	Structural
Improve load balancing in GCHP	Seb Eastham (MIT)	Model performance
Testing the use of monthly mean MERRA-2 CWC with Pb-210 aerosol tracer	Bo Zhang (NIA) Hongyu Liu (NIA / NASA Langley)	Transport
Testing the use of a new scavenging parameterization developed by Luo and Yu for cold cloud with Pb-210 aerosol tracer	Gan Luo (SUNY Albany) Fangqun Yu (SUNY-Albany)	Transport
Evaluate vertical mixing in GEOS-Chem with model-model and model-observation comparisons	Seb Eastham (MIT) Clara Orbe (NASA GISS) Andrew Schuh (CSU)	Transport

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
Updates to Aromatic chemistry	Stephen MacFarlane (UOW) Jenny Fisher (UOW)	Chemistry
Nitrate photolysis	Mat Evans (York) Thomas Sherwen (York) Matthew Rowlinson (York)	Chemistry
In aerosol chemistry Halogens	Mat Evans (York) Hansen Cao (CU Boulder)	Chemistry
Benchmark box model of GC Chemistry	Katie Travis (NASA)	Chemistry
Alkyl nitrates Alk7, PHAN	Katie Travis (NASA)	Chemistry
Add stratospheric ozone species to full-chemistry simulations	Lee Murray (Rochester)	Chemistry
Perchlorate chemistry	Yuk Chun Chan (UWAB)	Chemistry
Explicit heterogeneous sulfate chemistry	Katie Travis (NASA) Becky Alexander (UT)	Chemistry
HOx and ozone "emissions" from lightning as option in model to play with	Jingqiu (Alaska) Lee Murray (Rochester)	Emissions
Sea salt aerosol from sea ice leads	Hannah Horowitz (U. Illinois)	Emissions
Drought-stress algorithm	Wei Li (U. Houston)
Biomass burning injection height profiles	Inderjeet Singh (WashU)	Emissions
OCIM integration	Chris Holmes (FSU) Lee Murray (Rochester)
Updating landcover products in GEOS-Chem	Chris Holmes (FSU) Jeff Geddes (BU)	Input data
Dry deposition physical improvement	Chris Holmes (FSU)	Dry deposition
TOMAS WRF-GC in regional Thailand simulation	Win Trivitayanurak (Chulalongkorn U)	Aerosols