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Report on CCSM Biogeochemistry Working Group Meeting

Co-Chairs: Inez Fung and Scott Doney

26 March 2002

The CCSM Biogeochemistry Working Group (BGC-WG) met for a two-day meeting at NCAR in Boulder. The morning and first part of the afternoon of the first day were devoted to updates on the CCSM 1.0 Carbon-Climate Experiment, the development of the biogeochemical components for CCSM 2.0, and stand-up presentations on new topics. The remainder of the afternoon involved plenary and sub-group discussions on the future directions of the BGC-WG. On the second day, the BGC-WG met jointly with the CCSM Land-WG to discuss coordination issues across the two groups.

March 26, 2002 - BGC WG

CCSM 1.0 Carbon-Climate Experiment ("Flying Leap-0") (I. Fung and S. Doney)

Significant progress has been made on the CCSM 1.0 Carbon-Climate model. In particular, multi-century ocean-atmosphere and land-atmosphere coupled carbon spin-up runs have been completed. These solutions have remained stable, with no significant drift in either the physics or biogeochemistry. The underlying philosophy of Flying Leap-0 was to use existing biogeochemical model components. For land, the CASA model has been coupled with the Land Surface Model (LSM). Simulated net primary production is computed as the difference between gross primary production, provided by LSM thus linking carbon uptake and stomatal water loss, and autotrophic respiration; NPP is allocated to three biomass pools (leaf, wood, root), and heterotrophic respiration and detrital material are incorporated through nine soil carbon pools. Developments underway are prognostic leaf phenology and dynamic allocation.

The ocean biogeochemical model is derived from the international Ocean Carbon Model Inter-comparison Project (OCMIP-II) model, which includes the main processes for the solubility carbon pump, organic and inorganic biological carbon pumps, and air-sea CO2 flux. The original model has a single limiting nutrient (phosphorus), and new/export production is computed diagnostically by restoring surface PO4 concentrations to a monthly climatology. A new baseline model version with prognostic production (limited by light, temperature, phosphate and iron) and a dynamical iron cycle has a significantly reduced bias in the seasonal particle export. Work is still underway to improve the predicted iron field via the iron scavenging and organic ligand parameterization; minor changes in the ocean physics parameterizations (vertical mixing, horizontal viscosity) are also planned.

The modified land and ocean models should be ready by mid-spring, and a new set of spin-up integrations started before the June workshop. The Flying Leap-0 control, and fossil fuel emission experiments are slated to begin over the summer.

Terrestrial Biogeochemistry (P. Thornton)
Starting from the CCSM 2.0 Land Model (CLM2.0), Thornton has created a new code structure to facilitate the hierarchical incorporation of (level 1) different landscape elements (e.g., glaciers, lakes, natural vegetation, urban, etc.), (level 2) age-classes, and multiple competing plant functional types (PFT). The new structure has been tested against the original CLM 2.0 code, with "bit for bit" correspondence found. Peter has also started to include into the new code the main biogeochemical elements identified by the BGC-WG at the Spring 2001 meeting (prognostic phenology, carbon-nitrogen coupling, disturbance) based on the Biome-BGC model. Promising preliminary results were presented for a site near Missoula, Montana, and a complete global model is being prepared for the June meeting.

Ocean Biogeochemistry (S. Doney, K. Lindsay, and J.K. Moore)
The OCMIP-II biogeochemistry model has been ported to the POP-based CCSM 2.0 ocean physical model. A multi-nutrient (N, P, Si, Fe) and multi-phytoplankton functional group (picoplankton, diatoms, calcifiers) ecosystem model has been implemented, and tuning experiments for the upper ocean seasonal cycle are underway using the subsurface nutrient fields approximately fixed at climatological values. A parameterization of nitrogen fixation and diazotrophs, with elevated iron requirements, is being developed. For June, a fully coupled, full depth coupled eco-biogeochemistry solution is being prepared.

DOE SCIDAC Project (D. Erickson)
A five-year DOE project has been initiated with a significant carbon cycle component. Elements include: carbon tracers (Erickson, Taylor, Duffy, Caldeira, Hernadez); biomass burning (Taylor, Erickson); coupled carbon-climate (Thompson); atmospheric chemistry; ocean biogeochemistry and tracers (Duffy, Caldeira, Elliot, Maltrud); mixed layer trace gases (Elliot, Chu, Erickson); land biogeochemistry (King, Post); and code evaluation (Hoffman, Branstetter, Drake). The SCIDAC project includes a significant software engineering component, and first priority is to document the requirement specifications for carbon cycle modeling.

Land Biogeochemistry-Atmosphere Chemistry (E. Holland)
A number of biogeochemical thrusts are underway related to land biogeochemistry-atmosphere chemistry coupling using the CCSM Land Model 2.0 framework. These include biogenic VOC emissions (Wiedenmeyer and Guenther); wet and dry nitrogen deposition (Hess and Holland); dust deposition (Levis and Bonan), nitrogen biogeochemistry (Thornton, Holland, et al.). Efforts are also underway within the Atmospheric Chemistry Division (ACD) at NCAR over the next year to include reactive chemistry (with a stratospheric focus) by combining MOZART and WACCM. Active research is also underway to explore the interactions of models with atmospheric data (e.g., MOPPITT CO and CH4, BVOC emission and flux measurement data.)

Pop-Up Presentations (~5 minute updates on new/ongoing research)

Infrastructure issues (S. Doney)

Future model formulations and experiments (Plenary Session)

Elements required for CCSM production experiments/simulation (Plenary Discussion)

Issues/Ideas Raised for Future Modeling (Plenary Discussion)

The working group divided up into a number of subgroups on particular topics, and the subgroups reported back in a final plenary session for the day.

Disturbance Modeling (Steve Running)

Atmospheric Chemistry (Natalie Mahowald)

Ocean Biogeochemistry (Keith Moore)

Land processes - Peter Thornton

March 27, 2002 - Joint BGC and Land WG

General issues/action items for the two working groups:

CCSM-2 and the Community Land Model 2.0 (Gordon Bonan)
A new version of the Community Climate System Model (CCSM-2) has been frozen and a 350 year spin-up and 40 year control run completed with an atmosphere resolution of T42 and ocean at x1 (~1 deg.). The model code and control integration will be released to the community in May 2002. The land model in CCSM-2, called the Community Land Model (CLM) is a recoding of the biogeophysics from the Common Land Model produced by the CCSM Land WG. There is now a suite of land carbon models:

The CLM model runs on a 20-minute time step with two detrital carbon pools (litter and soil). For the version incorporating dynamic biogeography, the phenology runs on a daily time step using 10-day mean temperature, photosynthesis, growing degree-day accumulation and comes in three types (evergreen, raingreen, and summergreen). Also for the biogeography version, the carbon pools are updated once a year so the BGC works off same pool every 20 minutes through the year. The prognostic PFT (Dynamic Vegetation Model) framework has also been studied in the LSM, and a 200-year land only (3x3) has been completed (see S. Levis talk below).

Analysis of the CLM2 spin-up experiment is underway. Significant errors have been found in the coupled solution and the SSC has directed the working groups that the solution of these errors is a major focus for the working groups. Problems include:

A comparison of the CLM2 and CCM3+LSM1 solutions suggests that the CLM2 has less precipitation (e.g., tropical America) because of excessive canopy interception resulting in less water reaching ground, more canopy evaporation, and less runoff. CLM2 has essentially no transpiration in Amazon. Need to revisit interception routine in CLM2. Maximum canopy water storage in CLM2 is 0.1 mm per unit leaf and stem area while LSM1 restricts interception to 20% of precipitation.

As discussed on Tuesday a new code framework for CLM (to be CLM2.1 upon SSC approval) is under development. CLM2.1 will have the following properties:

A review committee was appointed (Thornton, Hoffman, Vertenstein, Houser, King, Zeng, Fung, Holland, Yang, Dai, Noone, Doney) to report back by June CCSM meeting. The ground rules are:

How can the working group implement small changes in code? - e.g. an IF test to prevent negative water. Cannot easily repeat the coupled 350yr spin up. Another window is when we fix the interception; then we can sneak in other small changes. Working group plan to recommend a package of changes to SSC.


Dynamic Vegetation Model (Sam Levis-entrepreneurial research)
A twin experiment was conducted with the DVGM forced in uncoupled mode by NCEP reanalysis with either CLM or LSM biogeophysics. The results show that:

River Routing Scheme (Jay Famigletti)
The U. Texas group developed the river routing scheme currently implemented in CSM and PCM, but it does not yet include lakes and wetlands and thus cannot have climate-flooding interactions (e.g., 1990's Mississippi flooding). Some results to date include:

Developments underway by Randy Koster include a catchment-based land surface model with complementing river routing, high resolution topography, source-to-sink (instead of cell-to-cell) routing within watershed and cell-to-cell routing from catchment to catchment. Could incorporate lakes, reservoirs, dams, etc. Discussion touched on a number of issues: ground water, water table coupling with river routing scheme, irrigation, subsurface flow to ocean, river evaporation, erosion, thermal balance of streamflow and ocean inputs, flooding and BGC, and urbanization's impact on surface properties.

Methane (Steve Frolking)
Estimating natural/agricultural methane emissions requires more detailed treatment of wetland hydrology and wetland ecology. Outstanding questions include how many types of wetland plants required and whether partitioning of emission into ebullition, diffusion and transport through plants is needed. Also need to consider uptake by upland soils?



Gordon Bonan
P.O. Box 3000
Boulder, CO 80307
Phone: 303-497-1613 Fax: 303-497-1324
Email: bonan@ucar.edu

Celine Bonfils

Michael G. Bosilovich
Data Assimilation Office
NASA GSFC Code 910.3
Greenbelt, MD 20771
Phone: 301-614-6147 Fax: 301-614-6297
Email: mikeb@dao.gsfc.nasa.gov
URL: http://dao.gsfc.nasa.gov/

Marcia Branstetter

Lori M. Bruhwiler
NOAA Climate Monitoring and Diagnostics Laboratory
Carbon Cycle Group
325 Broadway R-CG1
Boulder, CO 80303
Phone: 303-497-6921 Fax: 303-497-6290
Email: lbruhwiler@cmdl.noaa.gov

Wolfgang Buermann

Shapiong Chiu

Yong-Jiu Dai
Georgia Institute of Technology
School of Earth and Atmospheric Sciences
221 Bobby Dodd Way
Atlanta, GA 30332-0340
Phone: 404-385-1665 Fax: 404-894-1779
Email: dai@eas.gatech.edu
URL: http://climate.eas.gatech.edu/dai/dai.htm

Robert E. Dickinson
Georgia Institute of Technology
Earth and Atmospheric Sciences Dept
221 Bobby Dodd Way
Atlanta, GA 30332-0340
Phone: 404-385-1509 Fax: 404-385-1510
Email: robted@eas.gatech.edu

Scott Doney

Scott Elliott

David J. Erickson
Oak Ridge National Laboratory
Computer Science and Mathematics Division
P. O. Box 2008
Oak Ridge, TN 37831
Phone: 865-574-3136 Fax: 865-574-0680
Email: ericksondj@ornl.gov

Jay Famiglietti

Inez Fung
U.C. - Berkeley
Center for Atmospheric Sciences
307 McCone Hall, MC 4767
Berkeley, CA 94720-4767
Phone: 510-643-9367 Fax: 510-643-9377
Email: inez@atmos.berkeley.edu
URL: http://www.atmos.berkeley.edu

Forrest M. Hoffman
Oak Ridge National Laboratory
Environmental Sciences Division
Building 1505, Room 216
Mail Stop 6036
P.O. Box 2008
Oak Ridge, Tennessee 37831-6036
Phone: 865-576-7680 Fax: 865-576-3989
Email: forrest@esd.ornl.gov
URL: http://research.esd.ornl.gov/~forrest

Paul R. Houser
NASA Goddard Space Flight Center
Hydrological Sci.
Code 974
Greenbelt, MD 20771
Phone: 301-614-5772 Fax: 301-614-5808
Email: Paul.Houser@gsfc.nasa.gov

Menglin Jin

Jasmin G. John
U.C. - Berkeley
Earth and Planetary Science
Center for Atmospheric Sciences
307 McCone Hall, #4767 Berkeley, CA 94720-4767
Phone: 510-643-8336 Fax: 510-643-9377
Email: jjohn@uclink4.berkeley.edu

Anthony W. King
Oak Ridge National Laboratory
Environmental Sciences Division
Bldg 1509, MS 6335
PO Box 2008 Oak Ridge, TN 37831-6335
Phone: 865-576-3436 Fax: 865-574-2232
Email: kingaw@ornl.gov

Tim Kittel

Axel Kleidon

Randa Koster

Samuel Levis
P.O. Box 3000
Boulder, CO 80307
Phone: 303-497-1627 Fax: 303-497-1324
Email: slevis@ucar.edu

Keith T. Lindsay
P.O. Box 3000
Boulder, CO 80307-3000
Phone: 303-497-1722 Fax: 303-497-1700
Email: klindsay@cgd.ucar.edu
URL: http://www.cgd.ucar.edu/oce/klindsay/klindsay.html

Qing Liu
Georgia Institute of Technology
Earth and Atmospheric Sciences
221 Bobby Dodd Way
Atlanta, GA 30332
Phone: 404-894-1512 Fax:
Email: gte710s@prism.gatech.edu

Natalie M. Mahowald
U.C. - Santa Barbara
Bren School Santa Barbara, CA 93106
Phone: 805-893-7234 Fax: 805-893-7612
Email: natalie@bren.ucsb.edu

Matthew Maltrud

Rebecca McKeown
Colorado State University
Natural Resource Ecology Laboratory Fort Collins, CO 80523
Phone: 970-491-1623 Fax: 970-491-1965
Email: beckym@nrel.colostate.edu

Jefferson K. Moore
P.O. Box 3000
Boulder, CO 80307-3000
Phone: 303-497-1692 Fax: 303-497-1646
Email: jkmoore@ucar.edu
URL: http://www.cgd.ucar.edu/oce/jkmoore

Ranga Myneni

David C. Noone
California Institute of Technology
Geological and Planetary Sciences
Mail Stop 170-25
1200 E. California Blvd. Pasadena, CA 91125
Phone: 626-395-6496 Fax: 626-568-0935
Email: dcn@caltech.edu

Dennis Ojima

Keith W. Oleson
P.O. Box 3000
Boulder, CO 80307
Phone: 303-497-1332 Fax: 303-497-1324
Email: oleson@ucar.edu

Bette L. Otto-Bliesner
P.O. Box 3000
Boulder, CO 80307
Phone: 303-497-1723 Fax: 303-497-1348
Email: ottobli@ucar.edu

Christa Peters-Lidard

Philip Rasch
P.O. Box 3000
Boulder, CO 80307
Phone: 303-497-1368 Fax: 303-497-1324
Email: pjr@ucar.edu

Steve Running

Crystal Schaff

Britton B. Stephens
325 Broadway Boulder, CO 80305
Phone: 303-497-6999 Fax: 303-497-5590
Email: bstephens@cmdl.noaa.gov

John Taylor

Peter E. Thornton
P.O. Box 3000
Boulder, CO 80307-3000
Phone:303-497-1727 Fax: 303-497-1348
Email: peter@ucar.edu

Yuhong Tian

Elena Tsvetsinskaya

Guiling Wang

Christine Wiedinmyer

Zong-Liang Yang
University of Arizona
Hydrology and Water Resources
1133 E. North Campus Dr.
P.O. Box 210011 Tucson, AZ 85721-0011
Phone: 520-621-8922 Fax: 520-621-1422
Email: liang@hwr.arizona.edu
URL: http://www.hwr.arizona.edu/~liang

Charlie Zender

Xubin Zeng
University of Arizona
Atmospheric Sciences
P.O. Box 210081
Tucson, AZ 85721
Phone: 520-621-4782 Fax: 520-621-6833
Email: xubin@atmo.arizona.edu

Liming Zhou