Observations of water masses and circulation with focus on the Eurasian Basin of the Arctic Ocean from the 1990s to the late 2000s 1Department of Physics, University of Helsinki, P.O. Box 64, 00014, Helsinki, Finland
19 Feb 2013
2Finnish Meteorological Institute, Erik Palmenin aukio 1, P.O. Box 503, 00101 Helsinki, Finland
3Alfred Wegener Institute for Polar and Marine Research, P.O. Box 120161, 27515 Bremerhaven, Germany
4Department of Earth Sciences, University of Gothenburg, Box 460, 40530 Gothenburg, Sweden
5Shirshov Institute of Oceanology, 36 Nakhimovsky Prospect, Moscow 117997, Russia
Received: 05 Jul 2012 – Published in Ocean Sci. Discuss.: 08 Aug 2012Abstract. The circulation and water mass properties in the Eurasian Basin are
discussed based on a review of previous research and an examination of
observations made in recent years within, or parallel to, DAMOCLES
(Developing Arctic Modeling and Observational Capabilities for Long-term
Environmental Studies). The discussion is strongly biased towards
observations made from icebreakers and particularly from the cruise with R/V
Polarstern 2007 during the International Polar Year (IPY). Focus is on the
Barents Sea inflow branch and its mixing with the Fram Strait inflow branch.
It is proposed that the Barents Sea branch contributes not just intermediate
water but also most of the water to the Atlantic layer in the Amundsen Basin
and also in the Makarov and Canada basins. Only occasionally would high
temperature pulses originating from the Fram Strait branch penetrate along
the Laptev Sea slope across the Gakkel Ridge into the Amundsen Basin.
Interactions between the Barents Sea and the Fram Strait branches lead to
formation of intrusive layers, in the Atlantic layer and in the intermediate
waters. The intrusion characteristics found downstream, north of the Laptev
Sea are similar to those observed in the northern Nansen Basin and over the
Gakkel Ridge, suggesting a flow from the Laptev Sea towards Fram Strait. The
formation mechanisms for the intrusions at the continental slope, or in the
interior of the basins if they are reformed there, have not been identified.
The temperature of the deep water of the Eurasian Basin has increased in the
last 10 yr rather more than expected from geothermal heating. That
geothermal heating does influence the deep water column was obvious from
2007 Polarstern observations made close to a hydrothermal vent in the Gakkel
Ridge, where the temperature minimum usually found above the 600–800 m
thick homogenous bottom layer was absent. However, heat entrained from the
Atlantic water into descending, saline boundary plumes may also contribute
to the warming of the deeper layers.
Revised: 15 Jan 2013 – Accepted: 28 Jan 2013 – Published: 19 Feb 2013
Citation: Rudels, B., Schauer, U., Björk, G., Korhonen, M., Pisarev, S., Rabe, B., and Wisotzki, A.: Observations of water masses and circulation with focus on the Eurasian Basin of the Arctic Ocean from the 1990s to the late 2000s, Ocean Sci., 9, 147-169, doi:10.5194/os-9-147-2013, 2013.