Brainstorming on next generation Atm Model

Steve Ghan (Unlicensed) will lead this activity while Shaocheng Xie and Phil Rasch (pnl.gov) are attending council session

Charge to attendees:

are there opportunities on our current science problems there are being neglected?
- water cycle
  - absorbing aerosol effects on global ET
  - Asia monsoon at high resolution
  - N Australia rainfall stratified by forcing regime, mesoscale organization, land coupling
  - Great Plains propagation of MCS
- biogeochemistry
  - iron and phosphorus deposition effects on carbon cycle.
  - anthropogenic effects on deposition
  - interactive fire emission
  - coupling DMS and primary emissions, between components
- ocean-cryosphere
  - more energetic storms effects on sea ice
  - brown carbon in snow/ice
what science problems exist that we should be looking at that we are not looking at?
- tropical cyclones
- stagnation
- electrification. lightning response to warming.
- tornados!
- strat processes (QBO, SSW, overturning, ozone recovery)
- volcanic aerosol
- geoengineering
- human interactions
where are we subcritical?
feel free to flesh out things that Phil brought up during the main atm session

What model features need to be fixed?
- pressure gradient term
- sub-column treatment for radiation (convective/stratiform partitioning)
What physics is missing/deficient? (Ideas relevant to ACME science, but not vetted/definitive)
- elevation classes
  - deep dive for v2 data structures and will intersect w the CMDV software project (Ghan, Goldhaber, Salinger, Taylor, Atm GLs)
  - Surface coupling
- Intersection with parallel/sequential splitting of physics processes?
- deep convection that can propagate
- Q3D MMF
- water tracers requirement for physics
- cloud overlap (correlation length scales)
- See Talking points on Radiative Transfer + Prather Fast-J → generalized shortwave code
- consistent treatment of cloud precipitation and aerosol scavenging
- coupling biogeochemistry between components
- Improvements to aerosols
  - Prognostic aerosol surface area
  - Modify MAM aerosols to allow stratospheric aerosols
  - Gas/Particle partitioning (MOSAIC) & Nitrate
  - SOA
  - Brown Carbon
  - Speciated Dust (iron & phosphorus) and dust chemistry
- lightning parameterization
- What software capabilities are missing?
  - in-situ diagnostics (diurnal cycles, PDFs, etc, c.f. Katherine Calvin (Unlicensed), Po-Lun Ma, Steve Goldhaber (Unlicensed) conversations, high time res depending on conditions, regional output by namelist, vortex tracking, blocking diagnostic, tornado ingredients diagnostic)
  - easy to create and use data models
  - consistent BGC coupling mechanism. which component?
- More Atm Chemistry? (from conversation with Ruby Leung)
  - For biogeochemistry, the v2/v3 focus is on the impacts of different carbon reduction pathways (e.g., high fossil fuel vs. high renewable energy penetration) on the carbon sink and associated impacts on water availability. We’ve identified a particular need for improving modeling of the nitrogen cycle as relate to the terrestrial C-N cycle, land use (e.g., land management/fertilizers), and related atmospheric chemistry. This topic fits in well with the biogeochemistry question for v2/v3 and we also recognized the opportunities to collaborate with university teams on topic.
  - We will continue this discussion and include others to further define key atmospheric chemistry modeling needs that are consistent with the v2/v3 science drivers. For example, one topic that still needs to be explored is the methane cycle