Issues

• Large and consistent tracer concentration difference between Intel ifx and GCC builds in GEOS-Chem 14.8.0

  category: Bug
  geoschem/geos-chem#3402 · Filter by author kenxedna opened on Oct 7, 2026

• Erroneous sulfate production from in-cloud Fe/Mn-catalysed SO2 oxidation when the in-cloud liquid water content is near zero

  category: Bug
  geoschem/geos-chem#3401 · Filter by author yuanjianz opened on Oct 6, 2026

• Floating-point exception in GET_F (wetscav_mod.F90) for TOMAS simulations built with -DLUO_WETDEP=y

  category: Bughelp needed: Request Input From Communitynever staletopic: Aerosolstopic: Build
  Bug

  geoschem/geos-chem#3396 · Filter by author yantosca opened on Sep 30, 2026 · 14.9.0
  4

  

• Instructions on modifying pre-14.8.0 GEOS-Chem versions to avoid dummy species in chemical mechanisms from affecting integration results

  category: Discussiontopic: Chemical Mechanisms
  geoschem/geos-chem#3388 · Filter by author yantosca opened on Sep 14, 2026
  

• Possible issue with the SO₂-based scaling of CMIP6 aircraft VOC emissions

  category: Debug Helpstaletopic: Configuration Filestopic: Emissionstopic: GCHP Only
  geoschem/geos-chem#3382 · Filter by author cora579 opened on Sep 2, 2026
  2

• Question about GFED4 data availability for 2024–2025

  category: Questionhelp needed: Request Input From Communitytopic: Emissions
  geoschem/geos-chem#3380 · Filter by author sithu-gc opened on Aug 31, 2026
  1

• Question Scaling Emissions by Species

  category: Questionstaletopic: Configuration Filestopic: Emissionstopic: HEMCO Submodule
  geoschem/geos-chem#3378 · Filter by author Biswajit-git-dot opened on Aug 28, 2026
  2

  

• Add !$OMP COLLAPSE to OpenMP-parallelized loops to improve performance (GC-Classic only)

  category: Feature Requestno-diff-to-benchmarktopic: Performancetopic: Structural Modifications
  Feature

  geoschem/geos-chem#3377 · Filter by author yantosca opened on Aug 27, 2026 · 14.9.0
  1

  

• GNU compiler minimum requirements for 15.0

  category: Feature Requestnever staleTODO: Documentationtopic: User Environment
  geoschem/geos-chem#3355 · Filter by author lizziel opened on Jul 16, 2026 · 15.0.0
  2

• Unexpected pressure observations when initializing KPP Standalone

  category: Bugnever staletopic: Chemical Mechanisms
  geoschem/geos-chem#3337 · Filter by author jcoley11 opened on Jun 24, 2026
  1

  

• Cloud-J in Hg simulation

  category: Feature Requesthelp needed: Request Input From Communitynever staleno-diff-to-benchmarktopic: Hg or POPs simulationstopic: Photolysis
  geoschem/geos-chem#3329 · Filter by author lizziel opened on Jun 12, 2026
  3

• Required valid_range in ExtData2G.yaml for collection needing extrapolation

  category: Bugnever staletopic: GCHP Only
  geoschem/geos-chem#3279 · Filter by author yuanjianz opened on Apr 17, 2026
  7

  

• Rosenbrock step-size failures and excessive fall velocity in GEOSCHEM-CESM coupled model

  category: Bugnever staletopic: CESMtopic: Runtime Error
  geoschem/geos-chem#3278 · Filter by author andrewyao16 opened on Apr 17, 2026
  1

• Reduce requested time, memory, and CPU allocation in benchmark and integration test scripts

  category: Feature Requestno-diff-to-benchmarktopic: Benchmarking and Testingtopic: Structural Modifications
  Feature

  geoschem/geos-chem#3275 · Filter by author yantosca opened on Apr 15, 2026
  

• GEOS-Chem ReadTheDocs documentation updates

  TODO: Documentation
  Task

  geoschem/geos-chem#3269 · Filter by author yantosca opened on Apr 10, 2026
  3

  

• J-values outside the chemistry grid are set to zero

  category: Bugnever staletopic: Photolysis
  geoschem/geos-chem#3268 · Filter by author yantosca opened on Apr 9, 2026
  3

• Question about GFED4.1s HDF5-to-NetCDF conversion consistency for NOx emissions

  category: Questionnever staletopic: Emissionstopic: Input Data
  geoschem/geos-chem#3265 · Filter by author RRRanxinyu opened on Apr 8, 2026
  17

  

• Brown carbon aerosols setting not applied if using Cloud-J photolysis

  category: Bugnever staletopic: Aerosolstopic: Photolysis
  geoschem/geos-chem#3245 · Filter by author lizziel opened on Mar 23, 2026 · 14.9.0
  1

• OFFLINE_LIGHTNING and VOLCANO data not yet available for 2025 — is there interest in updating?

  category: Questionhelp needed: Request Input From Communitytopic: Emissions
  geoschem/geos-chem#3243 · Filter by author lexierhodes opened on Mar 18, 2026
  3

  

• NEI 2022v2 Emissions Modeling Platform for GEOS-Chem (Available Within 6 Months)

  category: Feature Requesttopic: Emissionstopic: Input Data
  Feature

  geoschem/geos-chem#3221 · Filter by author laura-hyesung-yang opened on Mar 3, 2026
  29

• Guidance on Adding a Custom termolecular reaction in GEOS-Chem

  category: Questionhelp needed: Request Input From Communitytopic: Chemical Mechanisms
  geoschem/geos-chem#3215 · Filter by author vishva-atchem opened on Feb 26, 2026
  7

  

• source of instability in vdiff

  category: Bugnever staletopic: Aerosols
  geoschem/geos-chem#3165 · Filter by author fsolmon opened on Jan 16, 2026
  2

  

• Column diagnostics

  category: Feature Requesttopic: Diagnostics
  geoschem/geos-chem#3161 · Filter by author lizziel opened on Jan 13, 2026
  

• Possibly unused variables in planeflight_mod

  category: Questionhelp needed: Request Input From Communitytopic: Diagnostics
  geoschem/geos-chem#3156 · Filter by author IshirDutta opened on Jan 8, 2026
  6

  

• Discussion: Refactoring & optimizing GEOS-Chem aerosol code

  category: Discussiontopic: Aerosolstopic: Structural Modifications
  geoschem/geos-chem#3125 · Filter by author yantosca opened on Dec 1, 2025
  3