Joint Seminar: Observational assessment of the early 21st century Atlantic water warm anomaly over the Eurasian Basin of the Arctic Ocean.

We document through the analysis of 2002-2005 observational
data the recent Atlantic water (AW) warming along the Siberian
continental margin due to several AW warm impulses that penetrated into
the Arctic Ocean through Fram Strait in 1999-2000. The AW temperature
record from our long-term monitoring site in the northern Laptev Sea
shows several events of rapid AW temperature increase totaling 0.8°C in
February-August 2004. We hypothesize the along-margin spreading of this
warmer anomaly has disrupted the downstream thermal equilibrium of the
late 1990s ? earlier 2000s. The anomaly mean velocity of 2.4-2.5±0.2
cm/s was obtained based on travel time required between the northern
Laptev Sea and two anomaly fronts delineated over the Eurasian flank of
the Lomonosov Ridge by comparing the 2005 snapshot along-margin data
with the AW pre-1990 mean. The magnitude of delineated anomalies exceeds
the level of pre-1990 mean along-margin cooling and rises above the
level of noise attributed to shifting of the AW jet across the basin
margins. The anomaly mean velocity estimation is confirmed by comparing
mooring-derived AW temperature time series from 2002-2005 with the
downstream along-margin AW temperature distribution from 2005. Our
mooring current-meter data corroborate these estimations.




15:15 Uhr


Bundesstr. 53, room 022/023
Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg


Igor Dmitrenko, IFM-GEOMAR, Kiel


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