Narwhals document continued warming of southern Baffin Bay
Article first published online: 23 OCT 2010
Copyright 2010 by the American Geophysical Union.
Journal of Geophysical Research: Oceans (1978–2012)
Volume 115, Issue C10, October 2010
How to Cite
2010), Narwhals document continued warming of southern Baffin Bay, J. Geophys. Res., 115, C10049, doi:10.1029/2009JC005820., , , and (
- Issue published online: 23 OCT 2010
- Article first published online: 23 OCT 2010
- Manuscript Accepted: 15 JUN 2010
- Manuscript Revised: 18 MAY 2010
- Manuscript Received: 18 SEP 2009
- Baffin Bay;
 We report on wintertime data collected from Baffin Bay and northern Davis Strait, a major gateway linking the Arctic with the subpolar North Atlantic, using narwhals (Monodon monoceros) as an oceanographic sampling platform. Fourteen narwhals were instrumented with satellite-linked time-depth-temperature recorders between 2005 and 2007. Transmitters collected and transmitted water column temperature profiles from each dive between December and April, where >90% of maximum daily dive depths reached the bottom. Temperature measurements were combined with 15 helicopter-based conductivity-temperature-depth (CTD) casts taken in April 2007 across central Baffin Bay and compared with hydrographic climatology values used for the region in Arctic climate models. Winter temperature maxima for whale and CTD data were in good agreement, ranging between 4.0°C and 4.6°C in inshore and offshore Baffin Bay and in Davis Strait. The warm Irminger Water was identified between 57°W and 59°W (at 68°N) between 200 and 400 m depths. Whale data correlated well with climatological temperature maxima; however, they were on average 0.9°C warmer ±0.6°C (P < 0.001). Furthermore, climatology data overestimated the winter surface isothermal layer thickness by 50–80 m. Our results suggest the previously documented warming in Baffin Bay has continued through 2007 and is associated with a warmer West Greenland Current in both of its constituent water masses. This research demonstrates the feasibility of using narwhals as ocean observation platforms in inaccessible Arctic areas where dense sea ice prevents regular oceanographic measurements and where innate site fidelity, affinity for winter pack ice, and multiple daily dives to >1700 m offer a useful opportunity to sample the area.