 |
| Titel |
Extensive under-ice turbulence microstructure measurements in the central Arctic Ocean in 2015 |
| VerfasserIn |
Benjamin Rabe, Markus Janout, Rainer Graupner, Jens Hoelemann, Hendrik Hampe, Mario Hoppmann, Myriel Horn, Bennet Juhls, Meri Korhonen, Anna Nikolopoulos, Sergey Pisarev, Achim Randelhoff, John-Philippe Savy, Nicolas Villacieros |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250132712
|
| Publikation (Nr.) |
 EGU/EGU2016-13244.pdf |
|
|
|
|
|
| Zusammenfassung |
| The Arctic Ocean is a strongly stratified low-energy environment, where tides are weak and
the upper ocean is protected by an ice cover during much of the year. Interior mixing
processes are dominated by double diffusion. The upper Arctic Ocean features a cold
surface mixed layer, which, separated by a sharp halocline, protects the sea ice
from the warmer underlying Atlantic- and Pacific-derived water masses. These
water masses carry nutrients that are important for the Arctic ecosystem. Hence
vertical fluxes of heat, salt, and nutrients are crucial components in understanding the
Arctic ecosystem. Yet, direct flux measurements are difficult to obtain and hence
sparse.
In 2015, two multidisciplinary R/V Polarstern expeditions to the Arctic Ocean
resulted in a series of under-ice turbulence microstructure measurements. These cover
different locations across the Eurasian and Makarov Basins, during the melt season in
spring and early summer as well as during freeze-up in late summer. Sampling was
carried out from ice floes with repeated profiles resulting in 4-24 hour-long time
series.
2015 featured anomalously warm atmospheric conditions during summer followed by
unusually low temperatures in September. Our measurements show elevated dissipation rates
at the base of the mixed layer throughout all stations, with significantly higher levels above
the Eurasian continental slope when compared with the Arctic Basin. Additional peaks were
found between the mixed layer and the halocline, in particular at stations where Pacific
Summer water was present.
This contribution provides first flux estimates and presents first conclusions
regarding the impact of atmospheric and sea ice conditions on vertical mixing in 2015. |
|
|
|
|
|
|