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History of stratospheric volcanism over the last 2500 years
recorded in Dôme C - Antarctica
Based on sulfur isotopes in vo...
Reminder :
- 4 stable isotopes : 32S, 33S, 34S, 36S
- Proxy used in the study: ∆33S and ∆36S -> quantify an anomaly in the...
Reminder :
- 4 stable isotopes : 32S, 33S, 34S, 36S
- Proxy used in the study: ∆33S and ∆36S -> quantify an anomaly in the...
Reminder :
- 4 stable isotopes : 32S, 33S, 34S, 36S
- Proxy used in the study: ∆33S and ∆36S -> quantify an anomaly in the...
Troposphere
Stratosphere
SO2 -> H2SO4
AntarcticaGreenland
Elsa GAUTIER OCFCC 07 July 2015
Scientific issue sous parties
El...
Troposphere
Stratosphere
SO2 -> H2SO4
AntarcticaGreenland
ice record
Elsa GAUTIER OCFCC 07 July 2015
Scientific issue sous...
Sulfateconcentration
[ppb]
Time (year)
6Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate 1. Tropospheric...
D33S(‰)
Time (year)
7Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Strat...
Troposphere
Stratosphere
AntarcticaGreenland
8Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate 1. Tropos...
Troposphere
Stratosphere
AntarcticaGreenland
SO2 H2SO4
9Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate...
Troposphere
Stratosphere
AntarcticaGreenland
SO2 H2SO4
10Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfat...
Troposphere
Stratosphere
Antarctica
ice record
Greenland
SO2 H2SO4
11Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in vol...
Time (year)
12Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheri...
D33S(‰)
Time (year)
13Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stra...
D36S&D33S(‰)
Time (year)
14Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2....
How does the anomaly emerge?
15Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptio...
Troposphere
Stratosphere
UV
AntarcticaGreenland
SO2
H2SO4
ozone layer
16Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in ...
17Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions ...
No anomaly in initial SO2 reservoir
ΔxS(SO2)=0
T=0
18Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic sulfate 1....
No anomaly in initial SO2 reservoir
1st formed aerosols : enriched
in 33S
- > SO2 reservoir becomes
depleted in 33S
ΔxS(SO...
No anomaly in initial SO2 reservoir
1st formed aerosols : enriched in
33S
- > SO2 reservoir becomes
depleted in 33S
- Last...
Troposphere
Stratosphere UV
Antarctica
ice record
Greenland
21Elsa GAUTIER OCFCC 07 July 2015
Sulfur anomaly in volcanic s...
Troposphere
Stratosphere
∆33S ≠ 0
∆33S = 0
UV
SO2 H2SO4
Antarctica
ice record
Greenland
22Elsa GAUTIER OCFCC 07 July 2015
...
Troposphere
Stratosphere
∆33S ≠ 0
∆33S = 0
UV
SO2 H2SO4
Antarctica
ice record
Greenland
23Elsa GAUTIER OCFCC 07 July 2015
...
 5 100m - ice cores drilled in Dôme C – Antarctica (2010/2011)
24Elsa GAUTIER OCFCC 07 July 2015
Stratospheric index 1. D...
25Elsa GAUTIER OCFCC 07 July 2015
Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal
 5 100m - ice cor...
26Elsa GAUTIER OCFCC 07 July 2015
Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal
 5 100m - ice cor...
27Elsa GAUTIER OCFCC 07 July 2015
Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal
 5 100m - ice cor...
28Elsa GAUTIER OCFCC 07 July 2015
Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal
Time (year)
Dome C...
29Elsa GAUTIER OCFCC 07 July 2015
Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal
Time (year)
Dome C...
30Elsa GAUTIER OCFCC 07 July 2015
Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal
Time (year)
Dome C...
31Elsa GAUTIER OCFCC 07 July 2015
Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal
Time (year)
Dome C...
32Elsa GAUTIER OCFCC 07 July 2015
Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal
1. Validation of p...
33Elsa GAUTIER OCFCC 07 July 2015
Conclusion 1. Main points 2. Perspectives
 Isotopic characterization of stratospheric e...
34Elsa GAUTIER OCFCC 07 July 2015
Conclusion 1. Main points 2. Perspectives
 Isotopic characterization of stratospheric e...
35
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A reconstruction of terrestrial volcanism over the last 2500 years using sulfur isotopes in ice-cores, E. Gautier

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E. Gautier (CNRS/UJF, Saint Martin d'Hères, France), at the Our Common Future Under Climate Change conference, July 7-10 in Paris, France.

More at http://www.commonfuture-paris2015.org/

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A reconstruction of terrestrial volcanism over the last 2500 years using sulfur isotopes in ice-cores, E. Gautier

  1. 1. History of stratospheric volcanism over the last 2500 years recorded in Dôme C - Antarctica Based on sulfur isotopes in volcanic sulfate PhD supervisor : Joël Savarino1 Co-supervisor : James Farquhar2 1 UJF/CNRS, LGGE, Grenoble, France. 2 Department of Geology, University of Maryland, USA. Elsa Gautier – Our Common Futures - Paris 07 July 2015 0
  2. 2. Reminder : - 4 stable isotopes : 32S, 33S, 34S, 36S - Proxy used in the study: ∆33S and ∆36S -> quantify an anomaly in the isotopic composition Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin 1
  3. 3. Reminder : - 4 stable isotopes : 32S, 33S, 34S, 36S - Proxy used in the study: ∆33S and ∆36S -> quantify an anomaly in the isotopic composition Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin 2 Anomaly study in the first time in Archean rocks [Farquhar et al., 2000]: Johnston [2011] - Clear anomalies [0.2 < ∆33S < 12 ‰] before the great oxidation event (2.5 billion years ago) - Associated with photolysis in a low oxygen atmosphere allowing UV penetration Greatoxidationevent
  4. 4. Reminder : - 4 stable isotopes : 32S, 33S, 34S, 36S - Proxy used in the study: ∆33S and ∆36S -> quantify an anomaly in the isotopic composition Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin 3 Anomaly study in the first time in Archean rocks [Farquhar et al., 2000]: Johnston [2011] - Clear anomalies [0.2 < ∆33S < 12 ‰] before the great oxidation event (2.5 billion years ago) - Associated with photolysis in a low oxygen atmosphere allowing UV penetration Such sulfur anomalies can be found in stratospheric volcanic sulfate [Savarino et al., 2003] formed in current atmospheric conditions Greatoxidationevent
  5. 5. Troposphere Stratosphere SO2 -> H2SO4 AntarcticaGreenland Elsa GAUTIER OCFCC 07 July 2015 Scientific issue sous parties Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin 4
  6. 6. Troposphere Stratosphere SO2 -> H2SO4 AntarcticaGreenland ice record Elsa GAUTIER OCFCC 07 July 2015 Scientific issue sous parties Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin 5
  7. 7. Sulfateconcentration [ppb] Time (year) 6Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin Background level
  8. 8. D33S(‰) Time (year) 7Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin No anomaly in the tropospheric sulfate deposited in Antarctica Background level Sulfateconcentration [ppb]
  9. 9. Troposphere Stratosphere AntarcticaGreenland 8Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin
  10. 10. Troposphere Stratosphere AntarcticaGreenland SO2 H2SO4 9Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin 3 weeks
  11. 11. Troposphere Stratosphere AntarcticaGreenland SO2 H2SO4 10Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin
  12. 12. Troposphere Stratosphere Antarctica ice record Greenland SO2 H2SO4 11Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin
  13. 13. Time (year) 12Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin Rinjani eruption Sulfateconcentration [ppb]
  14. 14. D33S(‰) Time (year) 13Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin Rinjani Anomaly in the stratospheric sulfate deposited in Antarctica Time dependence of the signal Sulfateconcentration [ppb]
  15. 15. D36S&D33S(‰) Time (year) 14Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin Rinjani Anomaly in the stratospheric sulfate deposited in Antarctica Time dependence of the signal ∆33S and ∆36S display opposite variations during the deposition Sulfateconcentration [ppb]
  16. 16. How does the anomaly emerge? 15Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin
  17. 17. Troposphere Stratosphere UV AntarcticaGreenland SO2 H2SO4 ozone layer 16Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin altitude of injection : key factor in the photolysis process hν OH
  18. 18. 17Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin  Why such a temporal evolution?
  19. 19. No anomaly in initial SO2 reservoir ΔxS(SO2)=0 T=0 18Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin
  20. 20. No anomaly in initial SO2 reservoir 1st formed aerosols : enriched in 33S - > SO2 reservoir becomes depleted in 33S ΔxS(SO2)=0 Δ33S(SO2)< 0 Δ33S(H2SO4) >0 T=0 First aerosols hν 19Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin
  21. 21. No anomaly in initial SO2 reservoir 1st formed aerosols : enriched in 33S - > SO2 reservoir becomes depleted in 33S - Last formed aerosols are produced from a depleted reservoir : sign shift ΔxS(SO2)=0 Δ33S(SO2)< 0 Δ33S(H2SO4) >0 Δ33S(H2SO4) <0 T=0 First aerosols Last aerosols hν 20Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin
  22. 22. Troposphere Stratosphere UV Antarctica ice record Greenland 21Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin • Records based on bipolar signal [Crowley et al., 2012, Sigl et al., 2013 , Gao et al., 2008] : - Dating issue - Simultaneous tropospheric events - Representativity of the deposited flux + Fast analysis + Large number of records available
  23. 23. Troposphere Stratosphere ∆33S ≠ 0 ∆33S = 0 UV SO2 H2SO4 Antarctica ice record Greenland 22Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin 3 weeks • Records based on bipolar signal [Crowley et al., 2012, Sigl et al., 2013 , Gao et al., 2008] [Baroni et al., 2007, 2008 ; Cole Dai et al., 2009] - Dating issue - Simultaneous tropospheric events - Representativity of the deposited flux + Fast analysis + Large number of records available
  24. 24. Troposphere Stratosphere ∆33S ≠ 0 ∆33S = 0 UV SO2 H2SO4 Antarctica ice record Greenland 23Elsa GAUTIER OCFCC 07 July 2015 Sulfur anomaly in volcanic sulfate 1. Tropospheric eruptions 2. Stratospheric eruptions 3. Anomaly origin 3 weeks • Records based on bipolar signal [Crowley et al., 2012, Sigl et al., 2013 , Gao et al., 2008] [Baroni et al., 2007, 2008 ; Cole Dai et al., 2009] • First sytematic analysis of an entire volcanic record: - Experimental complexity + Use of a source proxy + Single drilling site - Dating issue - Simultaneous tropospheric events - Representativity of the deposited flux + Fast analysis + Large number of records available
  25. 25.  5 100m - ice cores drilled in Dôme C – Antarctica (2010/2011) 24Elsa GAUTIER OCFCC 07 July 2015 Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal
  26. 26. 25Elsa GAUTIER OCFCC 07 July 2015 Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal  5 100m - ice cores drilled in Dôme C – Antarctica  Sulfate concentration profile
  27. 27. 26Elsa GAUTIER OCFCC 07 July 2015 Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal  5 100m - ice cores drilled in Dôme C – Antarctica  Sulfate concentration profile  Peaks identified through automatic detection (concentrations above 2 times standard deviation)
  28. 28. 27Elsa GAUTIER OCFCC 07 July 2015 Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal  5 100m - ice cores drilled in Dôme C – Antarctica  Sulfate concentration profile  Peaks identified through automatic detection (concentrations above 2 times standard deviation)  Time resolved sampling of the volcanic events
  29. 29. 28Elsa GAUTIER OCFCC 07 July 2015 Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal Time (year) Dome C cores synchronized on WD age scale [Sigl et al., 2013, 2014] Volcanicsulfateflux(kg/km2)– DomeCcores
  30. 30. 29Elsa GAUTIER OCFCC 07 July 2015 Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal Time (year) Dome C cores synchronized on WD age scale [Sigl et al., 2013, 2014] Volcanicsulfateflux(kg/km2)– DomeCcores
  31. 31. 30Elsa GAUTIER OCFCC 07 July 2015 Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal Time (year) Dome C cores synchronized on WD age scale [Sigl et al., 2013, 2014] Volcanicsulfateflux(kg/km2)– DomeCcores
  32. 32. 31Elsa GAUTIER OCFCC 07 July 2015 Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal Time (year) Dome C cores synchronized on WD age scale [Sigl et al., 2013, 2014] Volcanicsulfateflux(kg/km2)– DomeCcores High latitude stratospheric eruptions? 1. Validation of previous bipolar reconstructions [Sigl et al., 2014]
  33. 33. 32Elsa GAUTIER OCFCC 07 July 2015 Stratospheric index 1. Dome C volcanic record 2. Stratospheric signal 1. Validation of previous bipolar reconstructions [Sigl et al., 2014] 2. Interpretation of the signal magnitude (link with volcanic eruption features) necessary to build a climatic reconstruction D33S(‰) Time (year) Dome C cores synchronized on WD age scale [Sigl et al., 2013, 2014] Volcanicsulfateflux(kg/km2)– DomeCcores
  34. 34. 33Elsa GAUTIER OCFCC 07 July 2015 Conclusion 1. Main points 2. Perspectives  Isotopic characterization of stratospheric eruptions  Most of the eruptions identified as stratospheric are listed as bipolar in Sigl et al., 2014, detection of two stratospheric unipolar eruptions  Necessity to link the isotopic signal amplitude with the volcanic features (strength, height, sulfate loading,...) to go further
  35. 35. 34Elsa GAUTIER OCFCC 07 July 2015 Conclusion 1. Main points 2. Perspectives  Isotopic characterization of stratospheric eruptions  Most of the eruptions identified as stratospheric are listed as bipolar in Sigl et al., 2014, detection of two stratospheric unipolar eruptions  Necessity to link the isotopic signal amplitude with the volcanic features (strength, height, sulfate loading,...) to go further Need accurate atmospheric models Need to constrain the stratospheric chemistry and isotopic mechanisms at stake : Validate lab experiments with constrains on natural samples Δ33S (‰) Δ36S(‰) Δ33S(‰) δ34S (‰)
  36. 36. 35 Thank you

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