T3 evolution
Level 1:
Annual mean control inversion (Nature paper)
Annual mean flux sensitivity and model-to-model (Tellus)
Annual mean data sensitivity (Tellus)
Level 2:
Cyclostationary control (in preparation – GBC)
Cyclo sensitivity, model-to-model?
IAV in progress (Baker, Law, Gurney)
Level 3 in progress (Houweling)
Offshoots
Isotope
networks
Satellite
etc
Kevin Gurney, Scott Denning, Rachel Law*, Peter Rayner*, Bernard Pak†
Colorado State University, *CSIRO Australia, †UC Irvine
Philippe Bousquet, Lori Bruhwiler, Yu-Han Chen, Philippe Ciais, Songmiao Fan, Inez Y. Fung, Emanuel Gloor, Martin Heimann, Kaz Higuchi, Jasmin John,
Shamil Maksyutov, Philippe Peylin, Michael Prather, Jorge Sarmiento, Shoichi Taguchi, Taro Takahashi, Takashi Maki, Ken Yuen
May 2003
TransCom control results for the estimation of seasonal carbon sources and sinks
Inversion set-up
Flux Priors
Land: CASA NEP (presub) +
Ocean: Takahashi (presub)
composite inventory from Level 1 (distributed over particular months)
Prior Flux Uncertainties
Land: Level 1 (annual GSNF) + +
Ocean: 2.0 * Level 1
30% of CASA |resp|
30% of CASA |NPP|
Set-up continued
CO2 Observations
• Monthly mean for 1992-1996 period (filled data) from GV2000
• 75 stations (dropped DAA) meeting 70% criteria
“Data Uncertainties”
Setting the floor:
If then
1992 19961979 1996
1979 1996
3.6
am m
a
RSDRSD
RSDP
122
1 0.25m
m
appm
A
min
0.25m
A
Presub results: surface maps
Strong northern seasonality for MATCH variants, NIES, NIRE,
and TM3
• MATCH:NCEP and NIES show widespread Winter max
Weak northern seasonality for CSU, JMA, UCI, and TM2
GCTM has average Winter max but strong Summer minimum
Aggregated model mean results
Uncertainties
Greatest uncertainty reduction in the northern extratropics and Southern Ocean
Model spread is greatest in the tropics but varies in the north – greatest at height of growing season
Model spread goes up where there is data and vice-versa
Fluxes
Northern Land: less emission during March, April, and September and greater uptake in July relative to prior
Oceans: greater seasonality……may be ‘contamination’ from land
Disaggregated model mean results
Land
Boreal NA: deviations in April, June, and August….uptake occurring later in the growing season
Europe: greater net uptake - June through September
Boreal Asia: Reduction in early Spring emissions. Less net uptake in June, more in July
Temperate NA: lessened seasonal amplitude. Significant deviations in Spring and late Fall
Temperate Asia: Large phase disagreement. CASA error or real advance?
Disaggregated continued
Ocean
Heightened seasonality in northern and tropical ocean regions
North Pacific and North Atlantic: out of phase with prior
Southern Ocean winter uptake lessened compared to prior
Tropical Oceans: net uptake as an annual mean and large negative fluxes centered on July to September months
Sensitivity to prior flux uncertainty
Observationally constrained regions show little change
Boreal NA, Temperate NA, Boreal Asia, Temperate Asia, Europe, Northern Ocean, Southern Ocean, South Indian
Tropics (land mainly) are generally sensitive to the prior flux uncertainty
Lower uncertainty (4x lower) on Northern Ocean, N Atlantic, and N. Pacific
Northern Land:
Combined flux difference (Gt C/year)
X2 per station
Two or more months with a 2 exceeding 4:
CRI, GMI, IZO, UTA, CARR (5000m), PRS, HUN
Driven by Feb value (14.7)
which results from small
Station sensitivity
Most pronounced changes in tropical regions – primarily the removal of GMI and CRI
Some stations in the southern high latitudes (SPO, SYO, MAA, PSA, HBA, Bass Strait) had 2 of < 0.25 implying uncertainties that may be 2x too loose
Tightening uncertainty on these 6 stations (factor of 2) imparts small changes in the South Indian Ocean
Comparison to annual mean inversion
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
Annual Inversion
Cyclostionary Inversion
-3.5
-2.5
-1.5
-0.5
0.5
1.5
NorthernLand
TropicalLand
SouthernLand
NorthernOcean
TropicalOcean
SouthernOcean
Total Land TotalOcean
GlobalTotal
Wild speculation on Biogeochemistry
Greater net uptake in Boreal Asia and Europe at the height of the growing season……..
greater NPP or lessened respiration?
The use of air temperature versus soil to drive respiration in CASA? Would explain some of the Winter flux differences
NPP could be wrong in CASA
Phase difference in Temperate Asia
Aggregation error (big region spanning large latitudinal gradient)
Real Springward shift in growing season?
Delay in the onset of the growing season in Boreal regions
Earlier Spring thaw causing respiration to precede photosynthesis
Could heightened ocean seasonality be real?
Conclusions Amplitude of N background flux response is inversely related to N
posterior flux amplitude. This is directly related to N land mean uptake and strength of rectifier
Land posterior flux: deviations from the prior occur in Summer and Winter
Europe: greater uptake in growing season
Temperate Asia: ~2 month uptake timing discrepency
Spring timing in Coreal land
Ocean posterior flux
Heightened seasonality in Northern oceans
Southern Ocean discrepency with prior is primarily during Austral Winter
Northern extratropics are insensitive to prior flux information
Northern extratropics are insensitive to high 2 per station instances
Good agreement with annual mean inversion
Phase and amplitude differences from CASA may be biogeochemically interpretable