An Integrated View of North
American Biosphere Carbon Flux
Inter-annual Variability:
from satellite CO2 to phenology
Junjie Liu1, Kevin Bowman1, Dave Schimel1, Nick Parazoo1, Anthony
Bloom1, Meemong Lee1, Kevin Gurney2, Dimitris Menemenlis1
1.
Jet Propulsion Lab, California Institute of Technology
2. Arizona State University
A-train Symposium
April, 2017
Global carbon cycle
Fossil fuel
photosynthesis
Atmospheric buildup
http://www.bigskyco2.org/
• About 50% of fossil fuel emissions remained in the atmosphere
• The land and ocean sink have large interannual variability
• The net biosphere sink is the difference between gross primary production (GPP)
and respiration
Focus of this study: North
American Temperate
North American temperate
Fossil fuel (FF)
2011
Atmospheric buildup
FF over North American Temperate
• FF over the region is about 20% of the global FF
 How much of this FF has been absorbed by biosphere over the region?
 What is the interannual variability of this net biosphere flux?
 What is the impact of drought events on net biosphere fluxes and carbon
exchange processes?
2012
A. W. King et al.: North America’s net terrestrial CO2 exchange with the atmos
Previous studies…
ean ± 1 standard deviation (σ) of annual net land–atmosphere exchange of CO2 -C (Tg C yr− 1 ) for North America by deca
0–2009 period.
Unit: TgC/year
Method
Atmospheric inversion a In-situ
Inventory: atmospheric flow approach b
Terrestrial biosphere modeling c
Inventory: production approach b
1990–1999
2000–2009
− 929 ± 477
-929±477
− 890 ± 400
-890±400
− 159
− 370 ± 138
− 83
− 348
− 359 ± 111
− 270
Best estimates
Mean ± σ
− 385 ± 382
− 467 ± 285
Median (interquartile range)
− 264 (− 510 to − 140) − 354 (− 492 to − 328)
Mode
> −in-situ
500 < 0 based
> − 400 < 0
• North American biosphere flux from
1990–2009
-890±409
− 890 ± 409
− 356
− 364 ± 120
− 280
King et al., 2015
− 472 ± 281
− 360 (− 496 to − 337)
> − 400 < 0
flux inversion has about 50% uncertainty;
The multi-model mean and standard deviation of the time-period means of the RECCAP-selected TransCom3 inversions of Peylin et al. (2013).
See Methods section. Note that there is single inventory estimate and thus no “multi-model” mean or standard deviation.
The multi-model mean and standard deviation of the time-period means of 10 RECCAP-Trendy models’ time-averaged annual NBP (see Methods
ction).
120 W
60 W
individual models are identified in Table 1 (p. 6703) of
et al. (2013). North America here is defined by the com
tion of TransCom3 (Baker et al., 2006) regions “North A
ican Boreal” and “North American Temperate” (Fig. 2
2.2
Terrestrial biosphere models (TBMs)
Methodology
A-train
OCO-2
Japanese GOSAT
2010
2011
2012
2013
2014
Column CO2
Carbon Cycle Data Assimilation
(CMS-Flux)
net biosphere
exchange
2015
Methodology
A-train
OCO-2
Japanese GOSAT
2010
2011
2012
Column CO2
2013
2014
2015
Solar Induced Chlorophyll
fluorescence (SIF)
MODIS
Carbon Cycle Data Assimilation
(CMS-Flux)
EVI
net biosphere
exchange
Gross Primary
Production (GPP)
Net biosphere carbon flux constrained by
satellite CO2 observations
North
America
North
American
Temperate
2
1.5
GtC/year
GtC/year
1
0.5
0
-0.5
-1
-1.5
-2
biosphere
fossil
air born ff
2010
2011
2012
2013
2014
2015
• Mean net biosphere sink is 1.2 ± 0.2 GtC with 0.2 GtC interannual variability
Biosphere, fossil fuel, and atmospheric buildup
North
America
North
American
Temperate
2
1.5
GtC/year GtC/year
1
0.5
0
-0.5
-1
-1.5
-2
?
2010
2010
2011
biosphere
fossil
air born ff
2012
2013
2014
2015
2015
• Mean (2010-2015) fossil fuel emission is 1.8 GtC; mean atmospheric build up is 0.6
GtC
• Mean FF air borne fraction is 33% (ranging from 17% to 54%)
2011 and 2012 drought impact
on biosphere carbon fluxes
2011 and 2012 precipitation anomaly
2011 precip anomaly
2012 precip anomaly
2011 drought impact
2011 drought impact
3
Precip
2.5
mm/day
2
1.5
1
0.5
0
2010
2011
2012
2013
2014
2015
2011 drought impact
3
2.8
Precip
2.5
2.6
mm/day
2
2.5
1.5
2.4
2.3
1
2.2
0.5
2.1
0
2
2010
2011
2012
2013
2014
2015
0.1
0
2010
2011
2012
2013
2014
GtC/year
-0.1
-0.2
-0.3
-0.4
-0.5
SIF-GPP
2.7
Net Biosphere Exchange
2015
2010
2011
0.3
0.28
0.26
0.24
0.22
0.2
0.18
0.16
0.14
0.12
0.1
2012
2013
2014
2015
MODIS-EVI
2010
2011
2012
2013
2014
2015
2011 drought impact
0.31
0.3
Fossil fuel
-0.01
Δ GPP (2011-2015)
Δ NBE (2011-2015)
-0.31
• Relative to 2015, the 2011 Texas-Mexican drought reduced biosphere sink by 0.3±0.1
GtC, which is comparable to regional FF.
2012 drought
2012 drought impact
3
Precip
mm/day
2.5
2
1.5
1
0.5
0
2010
2011
2012
2013
2014
2015
2012 drought impact
3
5.2
Precip
mm/day
2.5
4.8
2
4.6
1.5
4.4
1
4.2
0.5
4
0
3.8
2010
2011
2012
2013
2014
0
2010
2011
2012
2013
2014
-0.2
GtC/year
SIF-GPP
5
-0.4
-0.6
-0.8
-1
Net Biosphere Exchange
2015
2010
2011
0.3
0.28
2015 0.26
0.24
0.22
0.2
0.18
0.16
0.14
0.12
0.1
2012
2013
2014
2015
MODIS-EVI
2010
2011
•-1.2Lowes precipitation and smallest biosphere C sink in 2012;
• Annual GPP and EVI anomaly are not significant
2012
2013
2014
2015
2012 drought impact on seasonality
Precip anomaly
EVI
2010
2012
2015
2010
2012
2015
SIF-GPP
T anomaly
• Warmer and wetter at the beginning of the year=> higher EVI and GPP at the beginning
• Drought peaked in June and July
Impact of 2012 drought impact
0.9
0.22
Fossil fuel
0.1
-0.12
Δ GPP (2011-2015)
Δ NBE (2011-2015)
• The net biosphere sink was reduced by 0.22±0.17 GtC which is 24% of regional FF
emissions.
Impact of 2011 and 2012 drought
0.9
0.31
0.3
0.22
-0.01
-0.31
0.1
Fossil fuel
Δ GPP (2011-2015)
-0.12
Δ NBE (2011-2015)
• Both drought increased the FF air borne fraction; 2011 drought increased local FF
air borne fraction by 100%, while 2012 drought increased local FF air borne
fraction by 24%
• 2011 drought had larger impact on net biosphere carbon fluxes than 2012 drought
Conclusions
Synergistic use of A-train observations is critical to
quantify and understand biosphere carbon flux
interannual variability .
• Mean FF air borne fraction over North American
Temperate is 33%; with variability ranging from
17% to 54%
• Drought events have large impact on regional FF
air borne fraction.
Backup
Net biosphere exchange
Fossil fuel
Airborne Carbon
0.71
0.47
0.41
0.12
0.1
-0.13
-0.25
0.0
7
0.1
7
0.26
0.22
0
-0.19
-0.47
-0.45
Seasonality
Net biome exchange
2010
2011
2015
Precipitation anomaly
EVI
T anomaly
SIF-GPP
Net flux difference between
2011 and 2010
Black: FLUXCOM
Green: top-down
Net biosphere flux difference
between 2012 and 2010
Black: FLUXCOM
Red: top-down
• Increased uptake in April and reduced uptake in July, which are consistent with fluxnet
upscaled FLUXCOM product
Methodology
A-train
OCO-2
Japanese GOSAT
2010
2011
2012
A--Train
2013
2014
2015
500
Column CO2
Solar Induced Chlorophyll
fluorescence (SIF)
MODIS
Carbon Cycle Data Assimilation
(CMS-Flux)
EVI
net biosphere
exchange
Gross Primary
Production (GPP)
Independent Evaluation
FLUXCOM
Upscaled
FLUXNET fluxes