downscaling the noaa carbontracker inversion for north america gabrielle petron 1,2, arlyn e....
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Downscaling the NOAA CarbonTracker Inversion for North AmericaGabrielle Petron1,2, Arlyn E. Andrews1, Michael E. Trudeau1,2,3, Janusz Eluszkiewicz4, Thomas Nehrkorn4, John Henderson4, Roland Draxler5, Ariel Stein5, Colm Sweeney1,2, Anna Karion1,2, Andy Jacobson1,2, Ken Masarie1, Lori Bruhwiler1, John B. Miller1,2, Benjamin R. Miller1,2, Wouter Peters6, Sharon M. Gourdji7, Kimberly L. Mueller8, Anna M. Michalak7, Pieter P. Tans1
1NOAA Global Monitoring Division, Boulder, CO2University of Colorado, CIRES, Boulder, CO3Colorado State University, CIRA, Fort Collins, CO
4Atmospheric and Environmental Research, Lexington, MA5NOAA Air Resources Laboratory, Silver Spring, MA6Wageningen University, Wagenigen, USA7CIW, Department of Global Ecology, Stanford, CA8Congressional Science Fellow, USA
A31B-0074
CarbonTracker 19 ecosystem types for two large regions, Boreal North America and Temperate North America (left), and the US corn belt (below). Weekly mean NEE is optimized for each regional ecosystem based on atmospheric observations collected over a 5 week period.
Boreal North America Temperate North America
Crops: one single ecoregion NEE for conterminous USA adjusted weekly
156 Weekly scaling factors are optimized-> 11 TRANSCOM land regions with at most 19 land cover types-> 30 ocean basins-> short-term biospheric flux variability based on: local
temperature & radiationhttp://www.esrl.noaa.gov/gmd/ccgg/carbontracker/
F(x, y, t) = λb • Fbio(x, y, t) + λo • Foce(x, y, t) + Fff(x, y, t) + Ffire(x, y, t)
NOAA CarbonTracker (CT) is a global data assimilation system which adjusts weekly prior natural fluxes over large regions (NEE and net oceanic fluxes) to improve the match with observed atmospheric CO2 mixing ratios.
The North American Carbon Program MidContinent Intensive experiment around the state of Iowa (2007-2009) revealed some strong spatial gradients in the cornbelt and dramatic summertime CO2 minimum. The goal of the study was to try to oversample a relatively homogenous region with a strong natural flux (driven by crops) and evaluate inversion results against reported detailed crop yield estimates.
Assimilated observations include data from the NOAA long term collaborative sampling networks: surface weekly flasks, daily flasks at towers, and middle of the day or middle of the night averages calculated from in-situ tall tower records. Long-term observations from other labs (CSIRO, Australia; EC, Canada; IPEN, Brazil) involved in on-going intercomparison studies with the NOAA Global Monitoring Division are also used (Masarie et al., JGR, 2011).
In the global CT, CO2 vertical profiles from aircraft measurements over North America are not assimilated and are only used as an independent data set to evaluate the performance of the inversion (figure on left). Some of the largest biases in the free troposphere or at the surface occur in the summer time, when the surface sink may be too weak.
Why downscaling global CT?
High resolution inputs• Surface vegetation• Emissions models
or inventories
Quality controlled well calibrated
CO2 dry air mixing ratios with objective uncertainty estimates
Boundary conditions• Based on global CT
optimized CO2 mole fractions OR
• Based on the extrapolation of NOAA surface and aircraft measurements
High resolution transport model• WRF-ARW• 40 km outer
domain• 10 km inner
domain• STILT/HYSPLIT
Lagrangian model
RKW
RRL
RMMRCE
RGV
WBI
LEF
Regional Inversion for North America
Regional inversion components
Differences between 3 estimates of the “background” contribution to CO2 at two NOAA tall towers (LEF, Wisconsin and WKT, Texas)CT: Boundary values sampled from CT2010GV: First empirical boundary condition constructed using the GLOBALVIEW methodology applied to aircraft data and the marine boundary layer reference product. GV was used in Gourdji et al., BGD, 2011.NANEW: Second empirical boundary condition constructed using statistical fit to aircraft data and Pacific ocean only marine boundary layer reference product.
The new empirical boundary condition NANEW and the values derived from global CT 2010 show larger differences at LEF and WKT in the summer and almost no differences in the fall and winter.
Based on 10 day back-trajectories
LEF
WBI
RRL
RMM
RCE RKW
RGV
Data from the NOAA ESRL Tall Tower Network and from Penn State's "Ring 2: High-precision, high-accuracy CO2 mixing ratio measurements in support of the North American Carbon Program Mid Continent Intensive" Experiment (Ken Davis, Tasha Miles, Scott Richardson)
Two inversions were conducted using global CT2009. One inversion did not use the RING2 data (release run, blue) and the other one used afternoon averages of the RING2 CO2 data (branched run, red). The detrended smoothed seasonal cycles derived from the observations (black line) and the two CT inversions are shown for various sites in the MidContinent. Global CT was not able to use the additional information provided by the RING2 data to reduce its summer positive bias.
Boundary layer evaluation: CT vs empirical
Lagrangian models intercomparison: WKT Fall 2010
Comparison of the fossil fuel (left) and biogenic (right) CO2 total contributions to WKT midday mixing ratios based on 10 day back-trajectories and the convolution of surface influences with the same fluxes (CT 2010).
Breakdown of the hourly contributions of fossil fuel (left) and biogenic (right) fluxes to CO2 at WKT on 8/28/2010 for the entire 10 day period simulated with the Lagrangian models.Results from an on-going Lagrangian model intercomparison exercise.
Contact Arlyn Andrews ([email protected]) if you are interested in participating.
Lauvaux et al., ACPD, 2011
Based on 56m resolution IRS satellite datahttp://www.nass.usda.gov/research/Cropland/SARS1a.htm