MCI Inversion Comparisons

CarbonTracker vs MCI Inventory

MAX CROP SIGNAL

MAX CROP SIGNAL

• In general, looks pretty reasonable• However, max crop signal might be reversed?• CarbonTracker has little flexibility to adjust sub-ecoregion scale fluxes, even if fine

spatial scale data is available.

-350gCm-2yr-1

100gCm-2yr-1

SiB-CROP Prior NEE (TgC/deg2)(June 1 – Dec 31, 2007)

Posterior NEE (TgC/deg2)(June 1 – Dec 31, 2007)

Lauvaux et al. 2011 (in prep)

• Notice the max C drawdown in prior is somewhat similarly placed (NW Iowa/SW MN) to CarbonTracker (CASA).

• The posterior appears to ‘spread’ out the crop signal as well as relocate the max C drawdown location to central/northern Illinois.

• My inversion appears to capture the location of the maximum sink but can’t obtain the overall source/sink total for area

• Max sink less than 50% of max sink of inventory

• Strong efflux in SE

GgC/0.5°

Post

erio

rs

P

riors

UMich 2008 CSU 2008

annual nee estimates for 2008 (GgC/gridcell) gC/m2?

Post

erio

rs

P

riors

UMich 2008 CSU 2008

annual nee estimates for 2008 (GgC/gridcell)• Has corn belt been re-located? … probably not• Something in CO2 records seem to point to anomalous fluxes to north of Iowa• LAI anomaly in MODIS?• Notes: inversions acting on long spatial scales, correction occurs OUTSIDE of Ring2, inventory more uncertain outside of corn belt,

Transport: Comparing infl functions

• Comparison of integration of passive flux tracer between inversions, as function of distance from tower.

• This is sensitivity of afternoon observations to “daytime” fluxes (GPP>0)

• This is sensitivity of afternoon observations to “daytime” fluxes (GPP>0)

• A bit stronger signal coming in for SiBRAMS and implying possibly a stronger far-field signal

• Nighttime obs, nighttime fluxes

• Nighttime obs, daytime fluxes

Night time trapping

Integrating up to time series at towers

General point is that my signal (blue) is somewhat stronger than Thomas’s signal (green) my far field effect (grey-blue), which is over 500 km from tower, comprises of a significant

portion of the overall signal.

Spatially…

Interior Nudging effect?u,v winds

Interior Nudging effect? w winds

No smoking gun, where to go?

• Investigate sensitivity of LPDM to biases in vertical velocity (long distance effects)

• Best results so far are with short backwards integration time (a couple days) and CarbonTracker inflow. However, there are likely non-trivial far field flux contributions to towers and we know CT has positive bias.

• Reinvestigating SiB / RAMS surf energy interface (and co2 exchange) and trying to make more consistent