Status of CAM-chemChemistry-Climate Working Group

18 June 2019

Louisa EmmonsACOM, NCAR

Co-chairs: Louisa Emmons (NCAR)

Xiaohong Liu (U. Wyoming)

Liaison: Simone Tilmes (NCAR)

Software Engineer: Francis Vitt (NCAR)

Chemistry-Climate Working Group Status

CESM2 (CESM2.1.0 released)

• CAM6 with MAM4 aerosols, CLM5

• MOZART-T1 tropospheric chemistry in TS1 (CAM-chem) and TSMLT1

(WACCM), VBS-SOA

• CAM-chem and WACCM compsets

Description papers

• MOZART-TS1 chemistry (Emmons et al., in prep. for JAMES)

• VBS-SOA (Tilmes et al., in prep. for JAMES)

Simulations available

• CMIP6 (WACCM, CAM) – on /glade/

• CAM-chem-SD (2001-2016), QFED fire emissions – ACOM/CAM-chemwebsite

• WACCM forecasts: https://www.acom.ucar.edu/waccm/forecast/

Component Sets (“compsets”)

• 2-degree will be available in CESM2.2

Documentation

CAM-chem wiki page for new and experienced users: https://wiki.ucar.edu/display/camchem/Home

• Points to User’s Guide, Scientific Guide, Quick start guide

• Provides additional information for customizing simulations, modifying chemistry and code, etc.

• Identifies current users to promote collaboration

Send info, publications for

http://www.cesm.ucar.edu/working_groups/Chemistry/

and https://www2.acom.ucar.edu/gcm/cam-chem

We encourage users to share their current research and development activities

on the wiki page

CAM-chem with Regional Refinement

CAM6-chem with Spectral Element and Regional Refinement is running with ~14 km over U.S. (~1° elsewhere)

Current science goals:

• Studying air quality and health impacts in U.S.

• Evaluating importance of greater chemical complexity vs. higher horizontal resolution

On-going Development: Testing parameterizations for multiple

scales (e.g., Gravity waves, Dust emissions)

Gridding emissions to model variable resolution

Nudging to meteorological reanalyses

ne30

CONUS

ne30x8

R.Schwantes, F.Lacey, S.Tilmes

New Option In CAM-Chem For Nudging to Temperature and Winds

• New nudging method developed

for CAM was tested in CAM-Chem

• New method is more flexible

• Can nudge T, U, and V at

different levels

• Possibility of horizontal and/or

vertical window for nudging

• Similar to the old method, choice

of the relaxation time has a large

impact on clouds

• Sensitivity tests suggest

temperature is particularly

important

Aug 2013 Cloud Total (fraction)

• These regional

cloud differences

due to their

influence on

surface ozone are

important for air

quality studies

• Further evaluation

is needed

Cloud Total (fraction)Aug 2013: Surface Ozone (ppb)

New Option In CAM-Chem For Nudging to Temperature and Winds

On-line Ocean Emissions

• Online Air-Sea Interface for Soluble Species (OASISS) for CESM [Wang et al., GRL, 2019]

• Observationally trained machine-learning emulator for ocean biogeochemistry: fairly accurate & computationally efficient

• Example: DMS, short-lived ozone-depleting substance

Stratospheric

Ozone Hole

Atmospheric

Chemistry

Meteorology &

Ocean Physics

Aerosols &

Clouds

Ocean

Biogeochemistry

Air-Sea Exchange

Machine-

learning

Siyuan Wang (siyuan@ucar.edu)

CESM2/CMIP6 tropospheric composition

Tropospheric Ozone Assessment Report database of surface ozone contains gridded timeseries data from global monitors [Schultz et al., Elementa, 2017]

WACCM & CAM-chem consistently over-estimate surface O3 in US and Europe, especially in summer

CESM2/CMIP6 Tropospheric CO

NH CO much lower than MOPITT

CMIP6 emissions too low

SH CO largely from biomass burning, agrees well

CAMchem-SD

MOPITT

CAMchem-SD

WACCM-Hist

WACCM-AMIP

CESM2 / CMIP6 SOA

Primary Organic Aerosol Burden

WACCMext

WACCM

WACCM SOA Burden without minus with VBS scheme

More SOA production in source regions in WACCM with VBS results in a reduction of POM and BC mass -> Affects clouds and radiation

CAM6

WACCM-SC

WACCM SOAG

New VBS scheme• Formation of SOA slower due to

chemical processing -> reduced SOA near surface, more SOA in upper Tropics

• Removal processes included for SOAG (deposition) and SOA (photolysis) -> reduced values in high latitudes

-> Better agreement with observations

WACCM 10-day Forecasts

WACCM driven by GEOS5 meteorology run each day, with two biomass burning inventories (FINN, QFED)

Premade plots:

https://www.acom.ucar.edu/waccm/forecast/

In Worldview (with satellite products:

https://worldview.acom.ucar.edu/

Rainbow: WACCM CO from fires

Orange-Red: MODIS AOD

WACCM 10-day Forecasts

Supports NSF and other campaigns for both tropospheric and stratospheric research projects:

Ozone 50 hPa

ClOx 50 hPa

New features for CESM2.2 (or later)

• MOSAIC with nitrate aerosols

• Brown carbon

• Aerosol convective scavenging

• Online ocean emissions (OASISS)

• CAM-chem-SE-RR compset

Later (running, but need papers published first)

• MOZART-T2 (expanded isoprene & terpene oxidation)

• VBS-SOA for high and low NOx regimes, with MZ-T2, MOSAIC

• Expanded alkane chemistry

• VSLS Halogen Chemistry