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Maria-Elena Vorrath, Juliane Müller, Oliver Esper, Gesine Mollenhauer, Christian Haas, Jens Hefter, Frank Lamy
Alfred Wegener Institute , Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
References
Belt et al., 2011. Nature Communications, V. 7, p. 12655.
Müller et al., 2011. Earth and Planetary Science Letters, v. 306, no. 3-4, p. 137-148.
Schlitzer, R., Ocean Data View, https://odv.awi.de, 2018.
BREMERHAVEN
Am Handelshafen 12
27570 Bremerhaven
Telefon 0471 4831-0
www.awi.de
Evaluating the sea ice proxy IPSO25
at the Western Antarctic Peninsula
Poster: Thu_333_OS-3_53
Acknowledgments
Thank you to all the captains and crews at the cruises ANT-VI/2 and PS97. Further, we like to thank Lester
Lembke-Jene, Mandy Kiel, Liz Bonk, Hendrik Grotheer, and our student assistant Max Mues. Funding was
provided through the Helmholtz Research Grant VH-NG 1101.
The distribution plot was done with Ocean Data View 4.7.10 from 2017, all scatter plots with GrapherTM 13.
Fig.1:The distribution of the sea ice index PEIPSO25 at the
Western Antarctic Peninsula.The contour lines display satellite-
derived winter sea ice concentrations (•stations).
Fig. 2: The correlation of IPSO25 with HBI a) Z- and b) E-trienes.
A rough estimate of sea ice conditions is based on the calculated
PZIPSO25 and PEIPSO25.
Fig. 3: The correlation of PZIPSO25 (solid line ) and PEIPSO25 (dashed
line ) with a) satellite-derived winter sea ice cover and b) with diatom-
derived winter sea ice cover.
Introduction
Sea
ice proxies are important tools to reconstruct the climate
and
environmental
history in polar regions.The novel sea ice proxy for
the
Southern
Ocean is the biomarker IPSO25 (Ice Proxy Southern O
cean
with
25 carbon atoms), ahighly branched isoprenoid (HBI)
diene
produced
by sea ice diatoms [Belt et al., 2016]. To evaluate
the
advantages
and limitations of IPSO25 and to extend its
applicability
towards
quantitative sea ice reconstructions,surface sediments
from
the
Western Antarctic Peninsula (WAP) were used for
biomarker
analyses
and compared to recent sea ice observations.
PEIPSO25
Approach
Biomarkers
indicative of sea ice diatoms (IPSO25)and open
ocean
phytoplankton
(HBI Z- and E-trienes as plankton marker)are used
to
determine
PIPSO25, a concept modified after Müller et al., 2011.
algal remains
(incl. biomarkers)
permanent ice cover
(perennial)
stable ice-edge
(spring/summer)
dominantly ice-free
(year-round)
phytoplankton
bloom
IPSO25
Plankton marker
PIPSO25
indeterminable
IPSO25
Plankton marker
PIPSO25 moderate
IPSO25
Plankton marker
PIPSO25 0
ice algae
(inhabiting sea ice)
sea ice
-
-
++
++
-
++
lasting ice cover
(spring/summer)
IPSO25
Plankton marker
PIPSO25 high
++
+-
IPSO25 production
Phytoplankton production
Conclusions
Ø
IPSO25 is arobust and stable proxy for coastal sea ice in
the
Southern Ocean and Antarctica
Ø
The sea ice index PEIPSO25 permits to distinguish
between
dominantly ice-free (<0.3), stable ice-edge (0.3-0.8) and long-
lasting
ice cover (>0.9) conditions (Fig. 1 and 2)
Ø
PIPSO25 correlates very good with winter sea ice estimations
from
diatom species and satellite observations (Fig. 3)
Ø
Since our sediment samples at the WAP cover roughly the last
200
years we conclude that past spring sea ice distribution is similar
to
today´s winter sea ice
Method
Lipid Extraction Open Column
Chromatography
Measurement
with GC-MS
Radiocarbon Dating with MICADAS
Surface
Sediments
Long lasting
ice cover
Stable ice-edge Stable ice-edge
Dominantly ice-free Dominantly ice-free
Long lasting
ice cover
a
a
b
b