GEOS-Chem model development priorities

On this page we list the current priorities for GEOS-Chem development. This list was compiled by the user Working Groups at the last International GEOS-Chem Meeting (IGC8) in May 2017 and will be continuously updated based on code readiness and input from the Working Groups and the Steering Committee.

We also invite you to view our GEOS-Chem Support Team project management board on Trello.com, which shows the current GCST workflow.

List of priorities from IGC8

The items listed below are in different stages of readiness and will be included in future versions of the model.

Slated for v11-03

The following updates are now slated for inclusion into GEOS-Chem v11-03:

Feature	Submitted by	Type	Status
Transport updates
Common set of tracers in GEOS-Chem and GEOS	Transport WG GCST	Benchmarking	Ready to be added
Chemistry updates
Extend UCX into the mesosphere	Sebastian Eastham (MIT)	Science	Ready to be added
Script for checking N, C, etc. balance in chemistry mechanism	Barron Henderson (EPA)	Software
Emissions updates
OMI-based volcanic emissions 2005-2012	Cui Ge (U. Iowa) Jun Wang (U. Iowa)	Science	Need to implement a fix to handle missing data for 2012/09 thru 2012/12. We can do one of 2 things: Create files with zero emissions for 2012/09 thru 2012/12. But because data for 2013- is copied from 2012, this will mean that the last 3 months of the year have no volcano emissions. Link to the existing volcano emsisions files for September thru December
Anthropogenic PM2.5 dust source	Sajeev Philip (Dalhousie)	Science	Need to fix an "under-the-hood" issue in HEMCO that causes 1200 Tg of dust to be emitted by this update.
FINN biomass burning emissions for 2014-2016	Barron Henderson (US EPA)	Science	Pending receipt of corrected data files
EPA NEI2011 Version EK	Zitely Tzompa-Sosa (CSU) Emily Fischer (CSU)	Science	Need extra time for validation
GFAS biomass burning emissions	Mat Evans (York)	Science
Aerosol updates
Sea salt aerosol alkalinity	Qianjie Chen (UW) Becky Alexander (UW) Xuan Wang (Harvard)	Science	UW version delivered to GCST (Nov 2017)
VBS SOA option	Rokjin Park (SNU)	Science
Specialty simulation updates
Oxidant fields from v10 for 2006-2012 3D chemical source for CO2, CO OH for tagged CO & CH4	Dylan Jones (UofT)	Science	Will make data files available on ftp site
Africa nested-grid for GEOS-FP and MERRA-2	Eloise Marais (U. Birmingham)	Science	Delivered to GCST (Dec 2017)
West Africa nested-grid for GEOS-FP	Mat Evans (York) Eleanor Morris (York)	Science
Tagged sulfate simulation	Becky Alexander (UW)	Science
Arsenic simulation	Shiliang Wu (MT)	Science
Structural updates
Updated flux diagnostics	Chris Holmes (Florida State) GCST	Structural/ Benchmarking	Work has not yet begun
Benchmark of stratospheric simulation	Dylan Jones (U. Toronto)	Benchmarking	1-yr benchmarks for GEOS-Chem v11-01d and later include comparisons with OSIRIS O3 Waiting on OSIRIS NO2 data Waiting on comparisons with ACE-FTS data
Add total column O3 to benchmarks	Chris Holmes (FSU) GCST	Benchmarking	Deferred until v11-03 Also note: GCST plans on migrating benchmark plotting code from IDL to Python in v11-03
ObsPack diagnostic as netCDF replacement for planeflight_mod.F	Andy Jacobson (NOAA/ESRL)	Structural	Delivered to GCST (May 2017)
Updates to eliminate differences between single and multi-segmented GEOS-Chem runs	GCST Christoph Keller	Bug fix Structural
Further structural updates to facilitate interfacing GEOS-Chem with external models (e.g. CAM, CESM)	GCST	Structural	Ongoing
Expansion of model capabilities
FlexGrid: Use HEMCO to read met fields and enable nested simulations over any custom domains	Jiawei Zhuang (Harvard) Jintai Lin (PKU)	Structural	Delivered to GCST (Oct 2016) Waiting for a stable v11-02 release before proceeding FlexGrid will facilitate adding new nested-grids
Update ISORROPIA from v2.0 to v2.2, in order to remove persistent noise in output	Seb Eastham (Harvard)	Science	Delivered to GCST (May 2017)
Archival of roughness length for temperature z0T	GCST	Met processing	Work has not yet begun

--Bob Yantosca (talk) 19:53, 23 May 2018 (UTC)

Almost there (< 6 months)

Item	Author(s)	Type	Status
Transport updates
GEOS resolution & subgrid convection	Karen Yu (Harvard)	Science	To be installed by Bob Yantosca (Harvard), tested by Tailong He (Toronto) Work to begin after v11-02 release
Chemistry updates
N2O5 hydrolysis updates	Viral Shah (UW)	Science	Defer until paper is submitted (Summer 2018) Code from v10 (SMVGEAR) needs to be translated to v11 (FlexChem); this may take some effort
H2 chemistry in UCX	Chris Holmes (FSU)	Science	Defer until paper is submitted Estimate Fall 2018 or sooner
Updated chlorine chemistry	Xuan Wang (Harvard)	Science	Defer until the paper is submitted
ND49 timeseries diagnostic for correcting ozone from the height of the lowest model level to 10m	Katie Travis (MIT)	Structural	Defer until the paper is submitted
OH + NO2 rate update	Barron Henderson (EPA)	Science
Aromatics and dicarbonyl chemistry	William Porter (MIT) Tzung-May Fu (PKU)	Science
Document chemical mechanism in KPP file	Mat Evans (York)	Structural
Diurnal variability for NH3	Henze group	Science
Uptake of HNO3 onto coarse-mode sea salt	Prasad Kasibhatla (Duke)	Science
Photolysis of NITs	Prasad Kasibhatla (Duke)	Science
Emissions updates
Grid-independent lightning NOx emissions (3-hourly)	Lee Murray (Rochester)	Science	Data has not yet been transferred to GCST
Grid-independent dust emissions (hourly)	David Ridley (MIT)	Science	Data has not yet been transferred to GCST
Grid-independent biogenic emissions (hourly)	Jintai Lin (PKU)	Science	Data has not yet been transferred to GCST
Grid-independent sea salt emissions (hourly)	Jintai Lin (PKU)	Science	Data has not yet been transferred to GCST
EPA-derived BC/OA emissions over US (1990-2012)	David Ridley (MIT) Chi Li (Dalhousie)	Science	Emissions are available but need to be formatted properly. Could be ready by Fall-Winter 2018, depending on D. Ridley's availability
MASAGE inventory in HEMCO as default	Fabien Paulot (NOAA/GFDL) Amos Tai (CUHK)	Science	MASAGE data is already available. GCST would need assistance from the user community to prepare HEMCO configuration files such that we do not double-count agricultural NH3 from MASAGE and other inventories. This has been the main delay. F. Paulot has left the GEOS-Chem community.
Non-agricultural NH3 for use with MASAGE	Amos Tai (CUHK)	Science	Waiting on data
Ocean ammonia emission inventory	Fabien Paulot (NOAA/GFDL)	Science	Data files delivered to GCST (Jan 2016) Needs to be implemented via HEMCO, which is the primary delay
Injection height for fire emissions	Juliet Zhu (CSU) Emily Fischer (CSU)	Science
Surface fluxes and land usage updates
Carbon bottom up fluxes: anthro, ocean, land	Kevin Bowman (JPL)	Science
Land cover module: Harmonized biosphere-atmosphere exchange and implementing CLM or manual land cover change experiments	Jeff Geddes (BU)	Science
Online O3-LAI coupling in GEOS-Chem	Amos Tai (CUHK)	Science
Wet deposition updates
Wet deposition parameterizations: pH dependency, Henry's law coefficients, etc.	Sarah Safieddine (MIT) GCST	Science
Wet scavenging in mixed-phase clouds	Bo Zhang (NIA/NASA Langley)	Science	Defer until paper is published Estimate Fall 2018
Specialty simulation updates
AMAP/UNEP 2035 for Hg simulation	Helene Angot (MIT)	Science	Data is available, but has not been transferred to GCST yet
Radon emission update	Bo Zhang (NIA/NASA Langley)	Science	Defer until paper is published Estimate Fall 2018
PCB simulation	Colin Thackray (Harvard) Carey Friedman (formerly MIT) Helen Amos (formerly Harvard)	Science
New EDGAR sectoral inventory for Hg (1970-2012)	Amanda Giang (MIT)	Science
Archive GISS met fields from RCP scenarios for community	Lee Murray (Rochester)	Science
Structural updates
Clean up SOA diagnostics	GCST	Structural	GCST has implemented many existing SOA diagnostics in netCDF GCST would need help from the community to streamline these diagnostics
Calculation consistency throughout code: surface area, HGF (via species database)	GCST	Structural
Harmonizing Henry's Law coefficients across wet and dry deposition	GCST	Science	Work not started yet. Will need input from the community.
Expansion of model capabilities
CESM-GC offline coupling in standard model + benchmark	Rokjin Park (SNU) Daniel Rothenberg (MIT)	Science	Dan Rothenberg is no longer working on GEOS-Chem Seb Eastham is already working on CESM-GCHP interface

--Bob Yantosca (talk) 19:16, 23 May 2018 (UTC)

Over the horizon (6-12 months)

Item	Author(s)	Type	Status
A snow NOx source from deep snowpack	Maria Zatko (UW) Becky Alexander (UW)	Science	Delivered to GCST (Nov 2017) Needs to be added as a HEMCO extension, but converting from ancient v9-01-01 code may take significant effort.
MEIC emissions over China (2000-2015)	Lu Shen (Harvard) Melissa Sulprizio (Harvard)	Science	Defer until MEIC paper is published
GISS-GC (ICECAP/GCAP2) in standard model + benchmark	Lee Murray (Rochester) Eric Leibensperger (SUNY Plattsburgh)	Science	Lee Murray replied: "I would say 6-12 months to be safe, but the goal is to have it done by the end of summer 2018. There will actually be very minimal updates to GEOS-Chem; most of the updates are to modify the GISS model to output MERRA2-like data, to facilitate integration with GCHP and future updates to the CTM."
GISS-GC GCHP	Lee Murray (Rochester) Pengfei Liu (Harvard) Yang Li (Harvard)	Science	Rochester and Harvard groups are coordinating, to avoid duplication of effort
CESM-GC GCHP	Seb Eastham (MIT)	Science	Seb Eastham is now the lead developer. Estimate late 2018 or early 2019; validation will take time
Additional modifications for FlexChem, including: Rebuild the pre-built chemistry mechanisms (Standard, Tropchem, SOA-SVPOA) with Kppa Add capability for custom chemistry mechanism by building KPP on-the-fly in GEOS-Chem	GCST	Structural	Mike Long, who was the principal proponent behind these updates, has since left the GC community. We are not sure who will take this over
Dynamic fire modeling/prediction	Shiliang Wu (MNT)	Science
Interannually varying ocean model BCs for Hg from ocean model	Colin Thackray (Harvard)	Science
PAH & PFCA simulations	Peter Ivatt (York) Mat Evans (York) Noelle Selin (MIT) Colin Thackray (Harvard)	Science
CH4 in full chemistry simulation	Seb Eastham (Harvard)	Science
Standard future land use maps (PFT, LAI) for RCP/CMIP6 simulations	Colette Heald (MIT) Loretta Mickley (Harvard)	Science
Archive GISS met fields from CMIP6 scenarios for community	Lee Murray (Rochester)	Science
Updates to cold-temperature deposition	Lyatt Jaegle (UW)	Science
Simple parameterization for CO2-O3 dependence of stomatal resistance	Amos Tai (CUHK)	Science
NH3 emissions over China	Lin Zhang (PKU)	Science
Using GEOS-Chem within GEOS-5	Loretta Mickley (Harvard)	Science
Carbon cycle outputs in xCO2, xCH4 as a diagnostic	Beata Bukosa (Wollongong) Dylan Jones (UofT)	Science
Seasonal EMEP emissions back to 1980	Mat Evans (York)	Science
Updates to NO2 dry deposition	Brian Boys (Dalhousie)	Science
APM update and integration with most recent GEOS-Chem version	Gan Luo (SUNY Albany)	Structural
Cosmogenic tracer production	Lee Murray (Rochester)	Science
Explore resolution-consistent dust emissions Make high-res concentrations or mass fluxes available offline, implement in met field processing	David Ridley (MIT) GCST Nested Model WG	Science
Dust emissions at nested-grid resolutions	Yuxuan Wang (U. Houston) Jun Wang (U. Iowa)	Science	Check for overlap with resolution-consistent dust emissions above
Update SO2 scavenging in convective updrafts for consistency	Duncan Fairlie (NASA/LARC)	Science

Longer term (12-24 months)

Item	Author(s)	Type	Status
GCHP stretched grid	Jiawei Zhuang (Harvard)	Science
1/8 degree nested-grid simulations with GEOS-FP	Nested Model WG	Science	Wait for more interest
Embedding GEOS-Chem into CESM	Jean-Francois Lamarque (NCAR)	Science	NOTE: Seb Eastham is already working on this
Adjoint of carbon cycle simulation in GCHP	Kevin Bowman (JPL)	Science
Isoprene chemistry v2 (new Caltech update)	Kelvin Bates (Caltech)	Science
Contemporary land cover: developing historical and updated GEOS-Chem land cover maps based on satellite remote sensing	Jeff Geddes (BU)	Science
Farquhar-Ball-Barry model to calculate stomatal resistance	Amos Tai (CUHK) Jeff Geddes (BU)	Science
Impacts of chemistry on ecosystem/carbon cycle	Kevin Bowman (JPL) Anthony Bloom (JPL)	Science
Improved lightning emission scheme	Lee Murray (Rochester)	Science
Resolution-independent lightning NOx	Lee Murray (Rochester)	Science
Bidirectional NH3 emissions	Juliet Zhu (CSU)	Science
Country-based weekday/weekend variability for EDGAR 4.2	Lee Murray (Rochester) Christoph Keller (Harvard)	Science
Update keytone photolysis	Jared Brewer (CSU) Emily Fischer (CSU)	Science
Small alkyl nitrates	Jenny Fisher (Wollongong)	Science
YIBS-GC chemistry-biosphere-fire coupling	Loretta Mickley (Harvard) Xu Yue (IAP)	Science
Nitrogen-LAI coupling	Lin Zhang (PKU) Amos Tai (CUHK)	Science
Implementing humidity/VPD dependence of dry deposition	Jennifer Murphy (U. Toronto)	Science
SO2 wet scavenging	Duncan Fairlie (NASA Langley)	Science
Heterogeneous sulfate production	Lin Zhang (PKU) Becky Alexander (UW) Yuxuan Wang (U. Houston)	Science
MOSAIC implementation	Sebastian Eastham (Harvard)	Science
Particle size climatology	Fangqun Yu (SUNY Albany)	Science
Sea salt/dust size distribution	David Ridley (MIT) Colette Heald (MIT)	Science
Updates to GTMM	Rebecca Stern (Harvard)	Science
Tracer transport ocean	Chris Holmes (FSU)	Science
Include Hg in full chemistry simulation	Noelle Selin (MIT)	Science
Goddard seasonal weather prediction in GCHP	Kevin Bowman (JPL)	Science
Climate index diagnostics (drought, etc.)	Chemistry-ecosystems-climate WG	Structural
Joint CO/CO2/CH4 simulation	Nicholas Deutscher (U. Wollongong)	Science
Carbon coupling: oceans and terrestrial models	Chris Holmes (FSU)	Science	Ocim-pure physical transport, ECCO-Darwin ocean biogeochemistry
DMS oxidation scheme updating	Qianjie Chen (UW) Chemistry WG	Science
Limiting NH3 uptake due to OA	Rachel Silvern (Harvard)	Science

--Bob Yantosca (talk) 15:32, 23 May 2018 (UTC)

Currently not prioritized

Item	Author(s)	Type	Status
Uniformity of units	GCST	Structural	Lizzie Lundgren wrote: We are not planning on resuming work to unify units in GEOS-Chem anytime soon. Any changes to units in the near future would be for better compatibility with other models, although none are currently planned. However, user consensus on preferred units would still be helpful to move the conversation forward.
Sea salt emission from sea ice	Jiayue Huang (UW)	Science
Re-evaluation of SST dependence of sea salt emissions	Jiayue Huang (UW)	Science
Update MODIS LAI fields through 2015	Barron Henderson (UF)	Science
Lightning NOx chemistry parameterization	Alicia Gressent (MIT)	Science

--Bob Yantosca (talk) 20:54, 23 May 2018 (UTC)