202
Keywords: Fram Strait, East Greenland Current, Atlantic
Water, Recirculation, Transport
In Fram Strait (FS), between Greenland and Svalbard,
heat is transported to, and sea-ice is exported from the Arctic
Ocean. The oceanography in the area plays an important role
in the stability of two of the Greenland ice-sheet’s largest
outlet glaciers and thus mass loss of the Greenland ice-sheet
to the ocean. In Fram Strait, a source of North Atlantic Deep
Water is in contact with the atmosphere last before contributing to the Atlantic Meridional Overturning Circulation. The
East Greenland Current (EGC) in western FS flows southward. The West Spitsbergen Current (WSC) in eastern FS
transports relatively warm Atlantic Water (AW), originating
at lower latitudes, northward. However, not all AW entering
FS from the south is transported to the Arctic Ocean. Rather
a part of it “recirculates” in FS, it flows westward to join the
EGC. Here, we use hydrographical and velocity data (yielding absolute geostrophic velocity) collected by RV Polarstern
in FS in summer 2016 to investigate the meridional extent
and spatial structure of this recirculation to determine at
what latitudes AW joins the EGC and how that changes the
structure of the EGC. Further, we investigate possible AW
pathways in two troughs on the Greenland shelf, leading to
the large outlet glaciers. Four sections cross the EGC between
77.8°N and 80.8°N; two are located at the mouths of the
troughs, while one continues across the central FS and the
WSC. Additionally, a meridional section at 0°EW spans the
recirculation in the central FS. We use these sections to show
the first estimate of absolute geostrophic transports of different water masses in the recirculation and the EGC north of
79°N and their spatial structure at an appropriate spatial resolution. Based on these results we update the circulation
scheme in FS and to the outlet glaciers and elucidate transport mechanisms.
2.2.4 Measuring Temperature Variability of Deep
Atlantic Water in the Arctic
Sara E. Sahlin
1*
1
Department of Marine Sciences, University of
Gothenburg, Box 115, 405 30 Gothenburg, Sweden
*corresponding author: gussahlisa@student.gu.se
Keywords:
Physical
Oceanography,
Greenland,
Temperature, Variability, Arctic, NADW
Warm waters melt the polar ice shelves from below. For
the marine terminating glaciers of Greenland and Antarctica,
melting not only adds freshwater to a rising sea level, but
these ice tongues may also act as buffers between the ocean
and the large land-based glaciers. However, very little is
known of the variability of the temperature of these warm
water masses. In August 2015, ten prototype autonomous
expendable bottom temperature sensors were deployed in
Petermann Fjord and adjacent Nares Strait in the northwest
of Greenland. The instrument measures bottom temperature
over a relatively long time (up to 10 years) and at high frequency (every half hour). After several months measuring
temperature, the sensors floated to the surface, sent the
recorded data by satellite, and then acted as drifters. Part of
this project is to analyze the temperature data from these
Lotus buoys and relate it to other measurements in the area,
primarily CTD casts. Using historical observations from
CTD casts and moorings, the depth and location of deployment of a second batch of sensors was defined for the Barents
Sea shelf break during expedition PS106.2 of the icebreaking research vessel Polarstern in July 2017. The warm core
of the Atlantic Water can be identified just as it enters the
Arctic, and its temperature variability can be monitored with
an accuracy of at least 0.05 °C using these sensors on the sea
bed. The aim of the project is to determine the utility and
advantages of these buoys, and to come up with a strategy of
how to put them to best use in future deployments. Their
potential as a cost-effective monitoring device is of great
importance to the increasing demand of temporally high
resolution large-range hydrographic data in the field of climate change related research effort.
2.2.5 Characteristic of the Arctic Climate
as a Response to Air-Sea Interaction
Iwona Wrobel
1,2*
, J. Piskozub
1
, P. Makuch
1
, V. Drozdowska
1
,
P. Markuszewski
1
, T. Petelski
1
, T. Zielinski
1
1
Institute of Oceanology Polish Academy of Sciences
Sopot, Poland
2
IOPAS – Centre for Polar Studies KNOW (Leading
National Research Centre), Sopot, Poland
*corresponding author: iwrobel@iopan.gda.pl
Keywords: Arctic Ocean, Air-sea interaction, Carbon
cycle, Climate change
There are three active reservoirs for carbon dioxide (CO 2 ):
the atmosphere, the oceans, and the terrestrial system. The
atmosphere is the link with the other reservoirs, and the
ocean plays a major part in determining the atmosphere’s
concentration of CO 2 through physical, chemical, and biological processes. It is well known that the Arctic Ocean
(AO) is an overall sink for CO 2 throughout the year even
though continental shelves can either be regional or seasonal
sinks or sources of atmospheric CO 2 . Relevant knowledge of
air-sea CO 2 fluxes and their spatial and temporal variability
is essential to gain the necessary understanding of the global
carbon cycle and to fully resolve the ocean’s role in climate
variability. At present, the net air-sea CO 2 fluxes in the AO
have been estimated at −0.12 ± 0.06 Pg C year
−1
with net
global ocean CO 2 uptake at −2.2 ± 0.5 Pg C year
−1
. The
direction and rates of net air-sea CO 2 exchange are determined by the product of the difference in values between
pCO 2 in seawater and the atmosphere, and also by the rate of
k. Net air-sea CO 2 fluxes were calculated using the
FluxEngine toolset, which was created as a part of the
Appendices
Keywords: Fram Strait, East Greenland Current, Atlantic
Water, Recirculation, Transport
In Fram Strait (FS), between Greenland and Svalbard,
heat is transported to, and sea-ice is exported from the Arctic
Ocean. The oceanography in the area plays an important role
in the stability of two of the Greenland ice-sheet’s largest
outlet glaciers and thus mass loss of the Greenland ice-sheet
to the ocean. In Fram Strait, a source of North Atlantic Deep
Water is in contact with the atmosphere last before contributing to the Atlantic Meridional Overturning Circulation. The
East Greenland Current (EGC) in western FS flows southward. The West Spitsbergen Current (WSC) in eastern FS
transports relatively warm Atlantic Water (AW), originating
at lower latitudes, northward. However, not all AW entering
FS from the south is transported to the Arctic Ocean. Rather
a part of it “recirculates” in FS, it flows westward to join the
EGC. Here, we use hydrographical and velocity data (yielding absolute geostrophic velocity) collected by RV Polarstern
in FS in summer 2016 to investigate the meridional extent
and spatial structure of this recirculation to determine at
what latitudes AW joins the EGC and how that changes the
structure of the EGC. Further, we investigate possible AW
pathways in two troughs on the Greenland shelf, leading to
the large outlet glaciers. Four sections cross the EGC between
77.8°N and 80.8°N; two are located at the mouths of the
troughs, while one continues across the central FS and the
WSC. Additionally, a meridional section at 0°EW spans the
recirculation in the central FS. We use these sections to show
the first estimate of absolute geostrophic transports of different water masses in the recirculation and the EGC north of
79°N and their spatial structure at an appropriate spatial resolution. Based on these results we update the circulation
scheme in FS and to the outlet glaciers and elucidate transport mechanisms.
2.2.4 Measuring Temperature Variability of Deep
Atlantic Water in the Arctic
Sara E. Sahlin
1*
1
Department of Marine Sciences, University of
Gothenburg, Box 115, 405 30 Gothenburg, Sweden
*corresponding author: gussahlisa@student.gu.se
Keywords:
Physical
Oceanography,
Greenland,
Temperature, Variability, Arctic, NADW
Warm waters melt the polar ice shelves from below. For
the marine terminating glaciers of Greenland and Antarctica,
melting not only adds freshwater to a rising sea level, but
these ice tongues may also act as buffers between the ocean
and the large land-based glaciers. However, very little is
known of the variability of the temperature of these warm
water masses. In August 2015, ten prototype autonomous
expendable bottom temperature sensors were deployed in
Petermann Fjord and adjacent Nares Strait in the northwest
of Greenland. The instrument measures bottom temperature
over a relatively long time (up to 10 years) and at high frequency (every half hour). After several months measuring
temperature, the sensors floated to the surface, sent the
recorded data by satellite, and then acted as drifters. Part of
this project is to analyze the temperature data from these
Lotus buoys and relate it to other measurements in the area,
primarily CTD casts. Using historical observations from
CTD casts and moorings, the depth and location of deployment of a second batch of sensors was defined for the Barents
Sea shelf break during expedition PS106.2 of the icebreaking research vessel Polarstern in July 2017. The warm core
of the Atlantic Water can be identified just as it enters the
Arctic, and its temperature variability can be monitored with
an accuracy of at least 0.05 °C using these sensors on the sea
bed. The aim of the project is to determine the utility and
advantages of these buoys, and to come up with a strategy of
how to put them to best use in future deployments. Their
potential as a cost-effective monitoring device is of great
importance to the increasing demand of temporally high
resolution large-range hydrographic data in the field of climate change related research effort.
2.2.5 Characteristic of the Arctic Climate
as a Response to Air-Sea Interaction
Iwona Wrobel
1,2*
, J. Piskozub
1
, P. Makuch
1
, V. Drozdowska
1
,
P. Markuszewski
1
, T. Petelski
1
, T. Zielinski
1
1
Institute of Oceanology Polish Academy of Sciences
Sopot, Poland
2
IOPAS – Centre for Polar Studies KNOW (Leading
National Research Centre), Sopot, Poland
*corresponding author: iwrobel@iopan.gda.pl
Keywords: Arctic Ocean, Air-sea interaction, Carbon
cycle, Climate change
There are three active reservoirs for carbon dioxide (CO 2 ):
the atmosphere, the oceans, and the terrestrial system. The
atmosphere is the link with the other reservoirs, and the
ocean plays a major part in determining the atmosphere’s
concentration of CO 2 through physical, chemical, and biological processes. It is well known that the Arctic Ocean
(AO) is an overall sink for CO 2 throughout the year even
though continental shelves can either be regional or seasonal
sinks or sources of atmospheric CO 2 . Relevant knowledge of
air-sea CO 2 fluxes and their spatial and temporal variability
is essential to gain the necessary understanding of the global
carbon cycle and to fully resolve the ocean’s role in climate
variability. At present, the net air-sea CO 2 fluxes in the AO
have been estimated at −0.12 ± 0.06 Pg C year
−1
with net
global ocean CO 2 uptake at −2.2 ± 0.5 Pg C year
−1
. The
direction and rates of net air-sea CO 2 exchange are determined by the product of the difference in values between
pCO 2 in seawater and the atmosphere, and also by the rate of
k. Net air-sea CO 2 fluxes were calculated using the
FluxEngine toolset, which was created as a part of the
Appendices