NEW TOOLS FOR INVESTIGATING THE CARBON CYCLE: THE BACKGROUND

Transcription

1 NEW TOOLS FOR INVESTIGATING THE CARBON CYCLE: THE BACKGROUND Chlorophyll Fluorescence Carbonyl Sulfide Next-Generation Approach for Detecting Climate-Carbon Feedbacks: Space-Based Integration of Carbonyl Sulfide (OCS), CO2, and Solar Induced Fluorescence (SIF). Sept. 18, 2017

2 Early steps: Remote Sensing AVHRR and NDVI 146 Jim Tucker Cover of Nature ca. 1986

3 Inez Fung Models of Atmospheric CO2

4 Integration Remote Sensing, Atmospheric Measurements and Models The Flying Carpet Plots

5 Including Biology in the Models Piers Sellers Canopy Conductance

6 Climate-Carbon Feedbacks 6 Friedlingstein, P. et al. Uncertainties in CMIP5 climate projections due to carbon cycle feedbacks J. Clim. 27, (2014).

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8 We don t do global photosynthesis very well Grayson Badgley Lea Anderegg Joe Berry many others Beer, C., Reichstein, M., Tomelleri, E., Ciais, P., Jung, M., Carvalhais, N., et al. (2010). Terrestrial Gross Carbon Dioxide Uptake: Global Distribution and Covariation with Climate. Science,, 329(5993),

9 Chlorophyll Fluorescence is a new remote sensing product Plascyk, J. A. (1975). The MK II Fraunhofer Line Discriminator (FLD-II) for Airborne and Orbital Remote Sensing of Solar- Stimulated Luminescence. Optical Engineering, 14(4), Guanter, L., Alonso, L., Gómez-Chova, L., Amorós-López, J., Vila, J., & Moreno, J. (2007). Estimation of solar-induced vegetation fluorescence from space measurements. Geophysical Research Letters, 34(8), L /2007GL Frankenberg, C., Butz, A., & Toon, G. C. (2011). Disentangling chlorophyll fluorescence from atmospheric scattering effects in O 2A-band spectra of reflected sun-light. GEOPHYSICAL RESEARCH LETTERS, 38(3), L doi: /2010GL Joiner, J., Yoshida, Y., Vasilkov, A. P., Yoshida, Y., Corp, L. A., & Middleton, E. M. (2011). First observations of global and seasonal terrestrial chlorophyll fluorescence from space. Biogeosciences, 8(3), doi: /bg Retrievals now from: GOSAT, GOME-2 & OCO-2 FLEX is selected and scheduled for launch in 2020 s!

10 SIF is correlated with GPP Monthly MPI-GPP at o 0.5 vs SIF (GOME-2)

11 SIF Results from the Decay of an Excited Chlorophyll Molecule Chlorophyll Fluorescence Fleming, G. R., Schlau-Cohen, G. S., Amarnath, K., & Zaks, J. (2012). Design principles of photosynthetic light-harvesting. Faraday Discussions, 155, 27.

12 Solar induced Fluorescence (SIF) is Specific to Light Absorbed by Chlorophyll

13 SIF can be Detected from Space GOME-2 40 x 60 km pixel daily update global coverage 9:30 AM crossing time

14 SIF is specific to vegetation Reflectance sees the whole scene SIF is less sensitive to atmospheric scattering SIF radiance is correlated with GPP HyPlant (aircraft) Image of SIF and Greeness (Uwe Rascher)

15 The correlation between SiF and GPP is based on: Physiological control of the yield of fluorescence ( ) Structural properties of the canopy that effect leaf display F physiology structure

16 Physiology - PSII decides what to do with an absorbed photon Fluorescence photon Antenna Complex Solar photon PS-II Reaction Center O 2 2 photo-damage Non-photochemical Quenching Fleming, G. R., Schlau-Cohen, G. S., Amarnath, K., & Zaks, J. (2012). Design principles of photosynthetic light-harvesting. Faraday Discussions, 155, 27.

17 Interactions between the light and dark reactions: PAR CO2 light dark A reactions [R] reactions Sugars feedback light reactions (WJ) dark reactions (WC)

18 Modeled Leaf Physiology

19 Summary: Physiology and SIF We have linked a fluorescence parameterization to a conventional photosynthesis model by inverting the Genty equation. This requires knowledge of one more adjustable leaf property, KN o. Requires PAM measurements. The Vcm RUBISCO (or effects of stress on it) have a large control on SIF. This parameterization has been added to SCOPE and the land surface models, SiB and CLM.

20 The Effect of Canopy Structure on SIF Modeling studies with SCOPE indicate that near infrared reflectance (NIR) from vegetation is strongly correlated with SIF and is sensitive to differences in fluorescence yield. The probability that a fluorescence photon escapes is similar to that of a reflected NIR photon.

21 NDVI x NIR Radiance = NIRV (vegetation)? NIRT * NDVI

22 CAN WE USE NIRV TO ESTIMATE GPP? Monthly MPI-GPP at o 0.5 vs SIF (GOME-2) or NIRV (MODIS) Badgley, G., Field, C. B., & Berry, J. A. (2017). Canopy near-infrared reflectance and terrestrial photosynthesis. Science Advances, 3(3), e

23 Making the canopy integration factor (π) in the SiB 3 proportional to SIF or NIR V improves the match to observation at AmeriFlux sites.

24 Final Thoughts on SIF: SIF is turning out to be surprisingly useful: Seems to be proportional to GPP; Indicates drought; Indicates beginning and end of growing season. Seems to be related to Vcm Rubisco It is also a hot topic in fundamental research on photosynthesis - connection to another community. NIR V is a good proxy for SIF, but the latter would probably be more reliable if we had an appropriate satellite. OCS exchange may provide another way to check on GPP

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26 Atmospheric CO2 and OCS concentration Carbonyl sulfide (COS or OCS) A new tracer for terrestrial photosynthesis 26

27 There is strong covariation of CO 2 and OCS in the global atmosphere Montzka, S. A., Calvert, P., Hall, B. D., Elkins, J. W., Conway, T. J., Tans, P. P., & Sweeney, C. (2007). On the global distribution, seasonality, and budget of atmospheric carbonyl sulfide (COS) and some similarities to CO2. Journal of Geophysical Research, 112(D9),

28 Properties CO2 OCS or COS atmospheric concentration 400 ppm 500 ppt turnover time ~7 years ~2 years net biosphere exchange (terrestrial) key enzymes weak uptake Rubisco + respiration strong uptake Carbonicanhydrase

29 Leaf Uptake OCS follows the same path as CO ppt boundary stomatal mesophyll biochemical activity [COS] layer diffusion diffusion [H 2 S] (1.04) (0.060) (0.30) (0.56) c a c s c i c c (1.17) (0.073) (0.30) (.0076 [CO 2 ] [CH 2 O] n ppm

30 Keren Stimler and Dan Yakir of the Weizmann Inst. have conducted gas exchange studies on single leaves with a QCL spectrometer.

31 Uptake of both CO2 and COS is stimulated by light. In the case of CO2 this is expected because synthesis of the CO2 acceptor, RuBP requires light. No energy is required for hydrolysis of COS. Uptake of OCS is largely controlled by stomatal conductance (gsw) which is linked to photosynthesis (JCO2). gsw = m J CO2 [H 2O] v [CO 2 ] + b The intercept term (b) becomes important at low light.

32 Coding it into a model J COS =[COS] ( 1.55 gbw gsw + 1 g cell ) 1 COS$flux,$pmol$m-2$s-1$ 50.0# 45.0# 40.0# 35.0# 30.0# 25.0# 20.0# 15.0# 10.0# 5.0# 0.0# R²#=# # 0# 100# 200# 300# 400# [COS],$intercellular,$pmol/mol$ Uptake of COS is linear on [COS] g cell(cos) = f(di usion, biochemistry) g cell (COS) = v m (gi3 C 3 + gi4 C 4 ) logical scaling factors Rubisco activity, f(t,stress)

33 C4 Light Response 3.00E&05" 2.50E&05" 2.00E&05" CO2&uptake& y"="1e&06x"+"8e&07" R²"="0.9806" 7.00E&11" 6.00E&11" 5.00E&11" COS&uptake& y"="8e&13x"+"7e&12" R²"=" " Modeled& 1.50E&05" Modeled& 4.00E&11" 3.00E&11" 1.00E&05" 2.00E&11" 5.00E&06" 1.00E&11" 0.00E+00" 0" 5" 10" 15" 20" 25" 30" Observed,&umol&m/2&s/1& 0.00E+00" 0" 10" 20" 30" 40" 50" 60" 70" Observed,&pmol&m/2&s/1& C3 Light Response 1.40E&05" 1.20E&05" CO2&Uptake& y"="1e&06x"+"4e&07" R²"=" " 3.00E&11" 2.50E&11" COS&Uptake& y"="9e&13x" R²"=" " 1.00E&05" 2.00E&11" Modeled& 8.00E&06" 6.00E&06" Modeled& 1.50E&11" 1.00E&11" 4.00E&06" 5.00E&12" 2.00E&06" 0.00E+00" 0" 2" 4" 6" 8" 10" 12" 14" Observed,&umol&m/2&s/1& 0.00E+00" &5" 0" 5" 10" 15" 20" 25" 30" &5.00E&12" Observed,&pmol&m/2&s/1&

34 C3 Temperature Response CO2&Uptake& COS&Uptake& 1.20E&05" 1.00E&05" y"="8e&07x"+"8e&07" R²"=" " 7.00E&11" 6.00E&11" y"="1e&12x" R²"="&0.0933" 8.00E&06" 5.00E&11" Modeled& 6.00E&06" Modeled& 4.00E&11" 3.00E&11" 4.00E&06" 2.00E&11" 2.00E&06" 1.00E&11" 0.00E+00" 0" 2" 4" 6" 8" 10" 12" Observed,&umol&m/2&s/1& 0.00E+00" 0" 5" 10" 15" 20" 25" 30" 35" 40" 45" Observed,&pmol&m/2&s/1& Summary: CO2 uptake was modeled with a fitted Vmax for each leaf - no other adjustments. COS uptake was modeled using that Vmax with additional adjustments to the scaling factors, gi3 or gi4. These differed from species to species by at least a factor of 3 - presumably due to differences in the ratio of carbonic anhydrase to Rubisco. Much of the noise is due to inaccuracy in modeling gsw.

35 Diurnal Patterns of CO2 and OCS Exchange CO2 Fluxes 10 5 mol m-2s GPP RESP NEE hour, local time COS Fluxes Night air is different than day air. OCS day night pmol m-2s-1 CO Total COS Ground Uptake Leaf Uptake hour local time

36 Exchange processes pull the atmosphere in different directions in CO2 - OCS space soil production [CO2] photosynthesis net respiration [OCS] I have only discussed OCS exchange in photosynthesis, respiration and soil production of OCS will be topics of later discussion.

37 The atmosphere integrates the impact of all exchanges (global) ocean anthropogenic [CO2] photosynthesis photochem. respiration [OCS]

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39 [OCS] vertical slice at Equator Jim Stinecipher and Elliott Campbell (unpublished)

40 Conclusions: COS has potential to help estimate GPP and by difference Respiration at site-, regional-, and global-scales. COS should be highly correlated with solar induced fluorescence. Our work has led to a substantial revisions of the global budget of COS. We posit the existence of a large source in the tropical oceans. There is satellite evidence to support this. No in situ studies of mechanism. Models of soil uptake, soil production, anthropogenic production and ocean production (at least) are needed to complete the cycle. Inclusion of COS in data assimilation systems may help to understand the basis of inferred changes in net CO2 exchange over the continents.

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