Two EPICA ice cores revealing 800,000 years of climate ... · 23. Internationale Polartagung der...
Transcript of Two EPICA ice cores revealing 800,000 years of climate ... · 23. Internationale Polartagung der...
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008
Two EPICA ice cores revealing 800,000 years of climate history:
An overview.
Hans Oerter & EPICA team
Alfred-Wegener-Institut für Polar- und Meeresforschung in der Helmholtz-Gemeinschaft, Bremerhaven
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 2
Kohnen
Dome C
Vostok
Dome A
Dome F
Law Dome
Talos D.
Taylor D.
Siple D.
Byrd
Siple St.
Dyer Pl.B15 Berkner Is.
South Pole
layout: w. rack, h. oerter, AWI
EPICA-DML,2774m, >250 ka
JARE3029m, >700 ka
Russia, F, US3700m, 420 ka
China, planned
EPICA-DC,3270m, 800 ka
I, F, D, UK
Weddell Sea
Ross Sea
AntarcticPeninsula
Deep ice cores in
Antarctica
Neumayer
Mario Zuchelli
10° W 0° 10°E
10° W 0° 10°E20°W30°W
74°S
72°S
70°S
68°S
74°S
72°S
70°S
76°S
3000
2500
2000
1500 1000
500
500
1000
1
500
200
0
2500
3000
Neumayer
SANAE IV
Troll
WasaKottasCamp DML05
Amundsenisen
Wegenerisen
BruntIce Shelf
Riise
r-
Isen
Lars
en-
Heim
efron
tf.
Kirwa
nv.H.U.Sver
drupf.
Dronning-Maud-Land
Ritscherflya
Weddell Sea
Ekström-isen
Jutu
lstra
umen
km0 500
SANAE
Hall
III
ey
Novolazerevskaja
Sea Ice shelf Inland ice, grounded ice 2000 contour line grounding line
U.K.Traverse routes: Sweden Germany Norway
Kohnen
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 3
EPICA comprises two ice cores:Dome C (75 ° 06.10' S, 123° 23.71‘E, 3233 m;ice 3250 ±25m, -54.5 °C, 25 kg m-2 a-1)Dronning Maud Land (DML, Kohnen)(75 ° 0.10' S, 0° 4.07' E, 2892 m;ice 2782 ±10m, -44.6 °C, 64 kg m-2 a-1)
Dome C:21. Dec. 2004
3272mca. 800 ka
(~2x Vostok)
DML:17. Jan. 2006
2774 m> 250 ka
European Project for Ice Coring in Antarctica (EPICA)
10 European nations working together:
Belgium, Denmark, France, Germany, Italy, The Netherlands, Norway, Sweden, Switzerland, United Kingdom
Funding by the European Commission and by national contributions. For Germany AWI & DFG
Kohnen
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 4
typical forAntarctica
Summit
Equi
libriu
m li
ne
mea
n: 2
078
m
max
: 477
5 m
100 - 700 kmca. 2000 km500 - 1000 km
Icebergcalving
Ocean
Inland ice / Ice sheet
Ice shelf
subglacial melting
Accumulation
Ice
thic
knes
s
AblationMelting
Ablation Accumulation
Schematic Cross Section Through an Ice Sheetm
ean:
166
7 m
mea
n: 3
080
m
Gro
undi
ng li
ne
Greenland
Accumulation
Icebergcalving
Ice
thic
knes
s
graf
ic: A
WI /
han
s oe
rter,
200
4
Rock
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 5
The drill trench
foto
: han
s oe
rter
, 200
6
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 6
Cutting scheme for EPICA ice cores
33 x 33 mm
15 mm 24 mm
54 mm 44 mm55
mm
98mmfoto: hans oerter, 2006
10 m
m
Thin sectionsCFA
δ18O, δ2H10Be
Archive
Gases, dustCO2, CH4, N2O
& isotopes
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 7
The EPICA EDML-ice core
EPICA Community Members: nature 444, 9 November 2006. doi:10.038/nature06301
-63
-58
-53
-48
-43
-38
10
100
1000
0 50000 100000 150000
-530
-490
-450
-410
-370
-330-52-48-44-40-36
-48
-44
-40
-36
-32
EDML
δ18O
corr
[ °/°°
]
EDML age [yrs BP]
dust[ppb]
MIS1
EDC
EDML
δ Dcorr
[°/°° ]T
surf[°C
]
DO1
2345678
9101112
1314
1516
1718
1920 21
222324 25
Dome F
EDC
δ18O
[°/°°
]
NGRIP
MIS3MIS4
MIS5.5
LGM
25-50
synchronized by Methane
concentrations
Antarctic stable isotope records show synchronous millennial variations during the last glacial, whereas rapid variations areencountered in Greenland. a) EDML δ18O record (purple, 0.5-m resolution; grey, 15-m runningmean) after sea level and upstream correctionover the past150 kyr. The record shows features similar tothose of the EDC (blue) and the Dome F(pink) isotope records but with more fine structure during MIS3 and MIS4. We note thatEDML and EDC are plotted on the new commonEDC3 timescale while Dome F is plotted on its individual timescale. The temperature axis on the right side indicates approximate surfacetemperatures at EDML as derived from thespatial δ18O/temperature gradient.b) δ18O record ofthe NGRIP ice core (grey).c) Mineral dustrecords of the EDML (red) and EDC (pink) ice cores at 1,000-yr resolution; these dust recordswere used for synchronization of the cores.
a)
b)
c)
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 8
Age on new NGRIP time scale (kyrs BP)
Comparison Antarctica (EDML) - Greenland (NGRIP)
Each Antarctic Isotope Maximum (AIM) in the EDML-ice core corresponds to a D/O event in Greenland (NGRIP)
Warming in Antarctica starts in a cold phase (Stadial) of the North, Cooling in a warm phase (Interstadial)
AIM
D/O
Source: EPICA community members: Nature ,Vol. 444 , November 9, 2006)
Bipolar seesaw depending on AMOC
AMOC: Atlantic Meridional Overturning
Circulation
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 9
Dome C temperature anomaly over 810 ky
-10
-5
0
5
10050
-10
-5
0
450400350300250200150
-45
-40
-35
-10
-5
0
800750700650600550500
DO events
2 344.156 87
9
101112
131415
1617
1818.1
19 20 21 22 23 24 25North GRIP
ACR
TI
TII
TIII TIVTV
TVI
TVII TVIII TIX
d 18Oin ‰
°C°C
°C
Age (ky BP)
Age (ky BP)
Age (ky BP)
M IS 2
M IS 3
M IS 4
M IS 6
M IS 8
M IS 10
M IS 12.3
M IS 14.2
M IS 16.2 M IS
18.2
M IS19.3
M IS 5.5
M IS 5.4
M IS 5.1
M IS 5.2M IS 5.3
M IS 7.5M IS
7.3M IS 7.1
M IS 7.2
M IS 7.4
M IS 9.3
M IS 9.2
M IS 11.3M IS 11.1
M IS 11.2
M IS 12.2
M IS 12.4
M IS 13.1
M IS 13.2
M IS 13.3M IS 14.3
M IS 14.4
M IS15.1
M IS15.5
M IS 15.3
M IS 15.2
M IS 15.4 M IS
16.3
M IS 16.4
M IS 17.3
M IS 18.3
10
Age (ky B.P.)
Ant
arct
ic t
emp
erat
ure
chan
ge
(°C
)A
ntar
ctic
tem
per
atur
e ch
ang
e (°
C)
Ant
arct
ic t
emp
erat
ure
chan
ge
(°C
)N
ort
h G
RIP
δ18
O (‰
)
Jouzel, J. et al.:, Science 317, 793-796 (2007)
AIMs appear also in earlier glacials
Strength of interglacials depending on whether obliquity and precession peak in phase or not
Back to 140 ky B.P., 100-year mean values are shown, whereas for earlier periods (middle and lower traces), DTs is calculated from 0.55-m raw data; a smooth curve using a 700-year binomial filter is super-imposed on this detailed record.In the upper trace (which is plotted on a more highly resolved time axis), the correspondence is shown between the DO events as recorded in the North Greenland Ice Core Project isotopic record andAIM events recorded in the EDC tem-perature record during the last glacial period and the last deglaciation. We have indicated the successive MIS, and the transitions are labeled from TI to TIX.
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 10
Antarctic ice core records: Vostok and EPICA CO2, CH
4 and D
Petit et al., 1999 (Vostok), Siegenthaler et al., 2005 (Dome C - CO2),
Spahni et al., 2005 (Dome C - CH4), EPICA community members, 2004 ( D)
180
210
240
270
300C
O2 (
ppm
v)
-450
-420
-390
Cold
Warm
D ice (
‰)
300
400
500
600
700
0 200 400 600 800Age / kyr BP
CH
4 (
ppbv)
EPICA Dome C data
Vostok (black) and Dome C (blue) data
Vostok (black) and Dome C (blue) data
EPICA data are plotted on EDC2, Vostok data on GT4 timescale
100 300 500 700
today
vor 1850 AD
at present 375
EPICA has produced the definitive ice-core records of climate and evironmental change from Antarctica. EPICA extended the ice-core records back to 800,000 years BP.Greenhouse gases (CO2, CH4, N2O) are now at their highest concentrations of the past 650,000 years.CO2 and Antarctic climate have been tightly coupled over the entire period (providing great constraints on the role of the Southern Ocean).
Each of the rapid Dansgaard-Oeschger events, has an Antarctic counterpart (AIM), strongly supporting the idea that the mechanism was reorganisation of ocean heat transport.
23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 11
foto
: han
s oe
rter
, 200
8
Summary