Particle sedimentation patterns in the eastern Fram Strait during 2000–2005: Results from the Arctic long-term observatory HAUSGARTEN     

Eduard Bauerfeind  Eva-Maria Nöthig  Agnieszka Beszczynska  Kirsten Fahl  Lars Kaleschke  Kathrin Kreker  Michael Klages  Thomas Soltwedel  Christiane Lorenzen  Jan Wegner 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(9):1471-1487

Since 2000 long-term measurements of vertical particle flux have been performed with moored sediment traps at the long-term observatory HAUSGARTEN in the eastern Fram Strait (79°N/4°E). The study area, which is seasonally covered with ice, is located in the confluence zone of the northward flowing warm saline Atlantic water with cold, low salinity water masses of Arctic origin. Current projections suggest that this area is particularly vulnerable to global warming. Total matter fluxes and components thereof (carbonate, particulate organic carbon and nitrogen, biogenic silica, biomarkers) revealed a bimodal seasonal pattern showing elevated sedimentation rates during May/June and August/September. Annual total matter flux (dry weight, DW) at ～300 m depth varied between 13 and 32 g m^?2 a^?1 during 2000 and 2005. Of this total flux 6–13% was due to CaCO₃, 4–21% to refractory particulate organic carbon (POC), and 3–8% to biogenic particulate silica (bPSi). The annual flux of all biogenic components together was almost constant during the period studied (8.5–8.8 g m^?2 a^?1), although this varied from 27% to 67% of the total annual flux. The fraction was lowest in a year characterized by the longest duration of ice coverage (91 and 70 days for the calendar year and summer season, May–September, respectively). Biomarker analyses revealed that organic matter originating from marine sources was present in excess of terrigenious material in the sedimented matter throughout most of the study period. Fluxes of recognizable phyto- and protozooplankton cells amounted up to 60×10⁶ m^?2 d^?1. Diatoms and coccolithophorids were the most abundant organisms. Diatoms, mainly pennate species, dominated during the first years of the investigation. A shift in the composition occurred during the last year when numbers of diatoms declined considerably, leading to a dominance of coccolithoporids. This was also reflected in a decrease in the sedimentation of bPSi. The sedimentation of biogenic matter, however, did not differ from the amount observed during the previous years. Among the larger organisms, pteropods at times contributed significantly to both the total matter and CaCO₃, fluxes.  相似文献   

Tidal dissipation from free drift sea ice in the Barents Sea assessed using GNSS beacon observations     

Vasulkar  Amey  Verlaan  Martin  Slobbe  Cornelis  Kaleschke  Lars 《Ocean Dynamics》2022,72(8):577-597

Ocean Dynamics - One of the major challenges facing global hydrodynamic tidal models is the modelling of the interaction between sea ice and tides in high-latitude waters. Recent studies have shown...  相似文献