Chemistry-Climate Working Group (CCWG or CHWG) Current Status

Co-chairs: Louisa Emmons (NCAR), Steve Ghan (PNNL), Peter Hess (Cornell)

Liaisons: Simone Tilmes (NCAR), Po-Lun Ma (PNNL) Software Engineer: Francis Vitt (NCAR)

• General CAM-chem and gas-phase chemistry updates • Aerosol updates • Short discussion

CESM Workshop Breckenridge June 2014

CESM2 and CMIP6 and CSL

• CESM2 – release June 2016 - development complete by June 2015

• For CMIP6

– 1-degree CAM5.5 (for BGC/Chem/WACCM) – CAM5.5 released by June 2015 – with MAM4, MG2 – CLM updates

• CSL

– CESM2 development – Our inputs to CSL proposal due mid-August (proposal due

mid-September)

CESM2 CCWG Development Plan

MAM4

FAST-J photolysis

Volcanic aerosols in MAM4

Nitrate aerosol

Fire emissions from CLM

Nitrogen deposition

Coupling with BGC (CH4)

SOA – VBS?

2014 2015 2016 June 2014

June 2015

June 2016

Marine aerosols, DMS

Dust speciation

Compsets CESM1.2. for res: 1.9x2.5

Model (phys)/ radiation

Chemistry Components / Meteorology

B_2000_TROP_MOZART (BMOZ) B_2000_MOZSOA_CN B_2000_MOZMAM_CN (BMOZMAM) F_2000_MOZMAM_CN (FMOZMAM) F_SD_BAM_CN B_2000_CN_CHEM (B2000CNCHM) B_1850_CN_CHEM (B1850CNCHM) B_1850-2000_CN_CHEM (B20TRCNCHM) F_1850_CN_CHEM (F1850CNCHM) F_2000_C4SSOA_L40 (FSOA) FGEOS_C4SSOA_L40 F2000_STRATMAM3_CN FGEOS_STRATMAM3_CN F_2000_STRATMAM7_CN

CAM4, active CAM4, passive CAM4, active CAM4, passive CAM4, passive CAM5, passive CAM5, passive

trop_mozart +soa chemistry trop_mozart +mam trop_mozart trop_bam super_fast_llnl trop_strat +soa chemistry trop_strat +mam+soa chem. trop_strat mam+soa chemistry

All active + CLM/CN All active, CLM/CN Prescr. ocn/ice, CLM/CN MEGAN VOC emis, all active CLM/CN Prescr. ocn/ice, CLM/CN Prescr. ocn/ice, MEGAN GEOS5 met. Prescr. ocn/ice,CLM/CN GEOS5 met. Prescr. ocn/ice, CLM/CN

SOA chemistry = 2-step SOA [Heald et al., 2008]

Discussion: Plans for Compsets for CESM 1.3

Currently available: Only 1.9x2.5 compset, CAM4 (MEGAN no CN coupling) and CAM5 (no MEGAN) B2000 and F2000, 1 transient GEOS5 CESM 1.3: CAM4: • Maintain existing compsets • RCP compsets (CCMI) • No additions in resolution CAM5: • Update to coupling of CN and MEGAN • Keep both trop and trop/strat mechanism? • MAM3/MAM4/MAM7? • 1deg res. ? • 1850 control? • RCP compsets ?

SO2 Neu wet deposition fix Replacing Henry’s Law coefficient for SO2 (from H2O2 to SO2)

Aircraft 2-7km

Significant change in SO4 burden and cloud forcings

CCMI Branch – to be released in CESM1.3 CAM-chem and WACCM versions provided to CCMI (CESM1-CAM4-

chem, CESM1-WACCM) and presented at Lancaster meeting last month

Being used for HTAP2: Tim Butler (IASS Potsdam), Steve Arnold (U.Leeds) and Louisa will provide simulations

CESM1-CAM4-chem CESM1-WACCM

Resolution 1.9°x2.5°, SD: 56L, FR: 28L (0-40km) 1.9°x2.5°, FR: 66L, SD: 88L (0-140km)

Chemistry Troposphere-Stratosphere 157 species; 373 reactions, JPL-2010

Troposphere through Lower Thermosphere 164 spc, 459 reactions; JPL-2010

Trop. Aerosols Bulk Aerosols (BAM) with 2-step SOA [Heald et al., 2008]

Bulk Aerosols (BAM)

Dry Deposition New DV scheme [val Martin, 2014] Original scheme

Wet Deposition Neu scheme

Specified Dynamics MERRA, 1% nudging, 50-hr relaxation time constant MERRA, 1% nudging, 50-hr relaxation time constant up to 50km, free-running above 60km

Volcanic Heating Observed sulfate mass and radius with CAMRT

Emissions Biogenic: online MEGAN; Anthro, BB, etc: CCMI MACCity; Lightning NOx ~ 5Tg N per year

Lower boundary CCMI-specified mixing ratios for halogens, CO2, CH4, N2O

SAD CCMI Stratospheric sulfate SAD

CCMI Results

Ozo

ne [p

pb]

Ozo

ne [p

pb]

Ozo

ne [p

pb]

Ozo

ne [p

pb]

1960 2010

SON

JJA

DJF

MAM

Western Europe – 500 hPa

WACCM REFC1 WACCM SDREFC1

CAM-Chem REFC1 CAM-Chem SDREFC1

Methane Lifetime WACCM REFC1 WACCM SDREFC1 CAM-Chem REFC1 CAM-Chem SDREFC1

CH4 lifetime due to OH loss decreases in all simulations from 1950 to 2010

CH4 lifetime is a bit lower than that derived from observations, consistent with an over-prediction of ozone in the NH

Working on understanding differences between WACCM & CAM-chem, Free-running & SD

sondes

Comparisons to OMI O3

are consistent with sonde comparisons – models over-estimate ozone in Northern Hemisphere. SD simulations have greater mid-latitude peaks, both NH & SH.

Model CO is lower than

MOPITT climatology in all simulations at all latitudes, greatest in NH spring. Likely due to an underestimate of emissions, but also too high OH.

WACCM FR WACCM SD CAM-Chem FR CAM-Chem SD

Jan

Jul

Latitude

Trop

O3 [

DU

]

WACCM FR WACCM SD CAM-Chem FR CAM-Chem SD

Jul

Jan

Latitude

CO

[101

7 mol

ec/c

m2 ]

CCMI: Zonal average tropospheric O3 and CO columns

MOPITT

OMI

• Global model intercomparison study – AeroCom II (Tsigaridis et al. 2014, ACPD) - SOA burden: 0.3 - 1.7 Tg

- SOA lifetime: 5 - 15 days

⇒ Need to better constrain SOA production and removals in 3D models

Predicted global burden of SOA

Predicted SOA burden and lifetime are highly uncertain

Predicted SOA lifetime

Perform a more focused SOA comparison within CESM

Study period: 2006 or 2008

Unified meteorological and emissions forcing

- CAM5 (1.9× 2.5°), nudged to GEOS5 meteorology

- FINN fire emissions

- Anthropogenic emissions

Simulations based on MOZART gas-phase chemistry coupled with aerosols:

- MAM3 (updated by Manish Shrivastava, PNNL)

- MAM7 (updated by Yang Zhang, NCSU) (also NCSU CB05-MAM7)

- MAM7 (NCAR, updated SOA from GECKO-A)

Source-resolved SOA predictions from 3 precursor classes: anthropogenic, biomass burning and biogenic

Model evaluation using

- Surface measurements of PM and precursors

- Aircraft field campaign data

- Satellite Data: aerosol optical depth (AOD) from MODIS

CONTACT Alma Hodzic (NCAR/ACD) if you are interested in participating: alma@ucar.edu

Box Model

BOXMOX: Wrapper for KPP created by Christoph Knote (NCAR/ACD)

Reads KPP format mechanism files Allows for specification of time-varying or

constant emissions, photolysis rates, temperature, PBLH, BL entrainment/detrainment, turbulent mixing, deposition

Used for intercomparison of AQMEII regional model mechanisms (Knote et al., submitted to Atmos. Env.)

Available from Christoph: knote@ucar.edu

CESM Chemical Mechanisms Goal: Create a Master List of reactions to replace multiple versions of “MOZART” and “WACCM” mechanisms

• Single list for updating rates, etc.

• Standard (supported) subsets could be extracted from Master List: – T: Tropospheric mechanism (more complex than TS, TMA)

– TS: Troposphere-Stratosphere

– TMA: TSMLT (Trop-Strat-Meso-Lower Thermosphere)

– MA: Middle Atmosphere (SMLT) These would replace “trop_mozart”, “trop_strat”, “waccm” and have version numbers (e.g., T1)

Work in progress …

Other chemistry is also available in CESM: Superfast (LLNL), Reduced (Houweling), CB05 (NCSU), etc…

Supersaturation bug in CAM5

• Most apparent for droplet number in polluted conditions for updrafts weaker than 0.2 m s-1

• CAM5 minimum w=0.2 m s-1

• Impact on global mean – SWCF: 0.2 W m-2

– ΔSWCF: 0.05 W m-2 (indirect effect)

0

100

200

300

400

500

600

700

800

900

0 500 1000 1500 2000

Nd

(/cm

3)

Accumlation Mode Number (/cm3)

Three Modes Bug w=10

No Bug w=10

Bug w=20

No Bug w=20

Bug w=50

No Bug w=50

MAM4: MAM3 with a

separate primary carbon mode

• Increases BC and primary OM up to 10-fold in remote regions

• Insignificant changes most places for other species

• Agrees well with MAM7 • 10% additional cost

Aitken number sulfate secondary OM sea salt

Accumulation number sulfate secondary OM primary OM BC soil dust sea salt

Primary Carbon number primary OM BC

Coarse number soil dust sea salt sulfate

coagulation condensation

VBS-MAM SOA treatment: Effects of fragmentation and semi-solid SOA

Ratio: Non-volatile/Semi-volatile

Functionalization: 7.5 Tg SOA

Fragmentation: 1.8 Tg SOA

Standard CAM : 1.1 Tg SOA

MOSAIC Processes

Reversible Gas-Particle Reactions

Zaveri et al., Model for Simulating Aerosol Interactions and Chemistry (MOSAIC), JGR, 2008

• Gas-phase chemistry treated by MOZART photochemical mechanism • Fully dynamic partitioning of sulfate, nitrate, chloride, and ammonium amongst different

modes via reversible and irreversible reactions • Equilibrium water content calculated using the ZSR mixing rule

– Polynomial fits for water due to inorganic salts – Kappa-Kohler theory for water due to organics – Kelvin effect taken into account at high RH

• Particles assumed to be completely deliquesced at RH > 35% (water hysteresis will be activated after implementing organic-inorganic interactions)

Variables and Species in CAM5-MAM7-MOSAIC No. Variables

or Species Gas-Phase

Accum. Aitken Primary Carbon

Fine Seasalt

Coarse Seasalt

Fine Dust

Coarse Dust

1. Number X X X X X X X

1. BC X X

2. POM X X

3. SOA X X X

4. SO4 X X X X X X X

5. NH4 X X X X X X X

6. NO3 X X X X X X X

7. Cl X X X X X X X

8. Na X X X X

9. Dust X X

10. Ca X X

11. CO3 X X

12. MOZART Trace Gases

114

119 9 7 3 6 6 8 8

Total Number of Species = 166 X = Standard CAM5-MAM7 X = CAM5-MAM7-MOSAIC

Total Number of Species = 147 X = Standard CAM5-MAM4 X = CAM5-MAM4-MOSAIC

No. Variables or Species

Gas-Phase

Accum. Aitken Primary Carbon

Coarse

1. Number X X X X

1. BC X X

2. POM X X

3. SOA X X X

4. SO4 X X X X

5. NH4 X X X X

6. NO3 X X X X

7. Cl X X X X

8. Na X X X

9. Dust X X

10. Ca X X

11. CO3 X X

12. MOZART Trace Gases

114

119 9 7 3 9

Variables and Species in CAM5-MAM4-MOSAIC

Other (aerosol) developments in progress

Coupling to wildfire model Coupled DMS emissions Aiken mode dust Dust speciation Aerosol scavenging Stratospheric aerosol Organic intercomparison Nucleation Coupling to SNICAR Marine organic

If time …

Methane emissions simulated by CLM4 and CLM4.5 – same emission module

Lei Meng, Rajendra Paudel

Meng, Paudel, Mahowald, Hess, in preparation, 2014

• Average CH4 concentrations in the atmosphere estimated by box model for three lifetimes(7.5, 8.5, and 10 years). Anthropogenic, fire and termite emissions are based on Olivier and Berdowski (2001), GFED v3, and Fung et al. (1991), respectively.

• CH4 emissions from natural wetlands and rice paddies are calculated from CLM4me’ and CLM4.5me

• CLM driven by analyzed meteorology (NCEP/NCAR reanalysis data) • Satellite inundation specified

METHANE EMISSIONS: CLM4 & CLM4.5

Climate Dependent Ammonia Emissions from Manure/Fertilizer

Riddick, Hess, Mahowald, Holland and Ward, in review

% Nr in Manure (left) and Fertilizer (right) lost as NH3

Riddick, Hess, Mahowald, Holland and Ward, in review

National Center for Atmospheric Research (NCAR) Colorado Department for Health and Environment (CDPHE)

NASA Airborne Science Program, Colorado State University (CSU), University of Colorado Boulder, Environmental Protection Agency (EPA) Region 8, National Oceanic and Atmospheric Administration (NOAA), National Park Service (NPS), Regional Air Quality Council (RAQC), UC Berkeley, UC Irvine, UC Riverside, US Naval Academy, U of Wisconsin, U of Rhode Island, U of Cincinnati, Georgia Tech, GO3 Project, Aerodyne Inc., and many others!

High summertime ozone - non-attainment Complex topography and meteorology

active photochemistry Diverse set of emission sources (urban,

oil/gas, industrial, agriculture, biogenic, fires) Impact on downwind regions (central plains) Inflow from UT, WY, CA, and Asia

https://www2.acd.ucar.edu/frappe

Objective: Characterize the factors driving summertime pollution