Penetration of the 1990s warm temperature anomaly of Atlantic Water in the Canada Basin

Penetration of the 1990s warm temperature anomaly (WTA) of the Fram Strait branch of Atlantic Water (FSBW) in the Canada Basin is described using available temperature, salinity, and velocity data. The core temperatures of FSBW show distinct pathways. Over the Chukchi Borderland advective velocities of the FSBW are well‐correlated with bottom topography. The resulting multifarious pathways over the Chukchi Borderland act to modulate and substantially increase the time scale of WTA spreading and advancement. Further downstream two WTA tongues are observed. One tongue followed the Beaufort Slope and, along this pathway, the core temperatures of FSBW decreased rapidly. The depth integrated value of heat content remained near constant however, suggesting enhanced vertical mixing. The second tongue debouched from the northern tip of the Northwind Ridge and spread eastward into the deep Canada Basin, suggesting a complex recirculation structure within the Beaufort Gyre.

[1]  Frank Kauker,et al.  Arctic warming: Evolution and spreading of the 1990s warm event in the Nordic seas and the Arctic Ocean , 2003 .

[2]  E. Carmack,et al.  A note on evanescent behavior of Arctic thermohaline intrusions , 2002 .

[3]  V. Ivanov,et al.  Confluence and redistribution of Atlantic water in the Nansen, Amundsen and Makarov basins , 2002 .

[4]  J. Hurrell,et al.  The Arctic Ocean Response to the North Atlantic Oscillation , 2000 .

[5]  G. Bönisch,et al.  Renewal and circulation of intermediate waters in the Canadian Basin observed on the SCICEX 96 cruise , 2000 .

[6]  T. Boyd,et al.  Circulation features in the central Arctic Ocean revealed by nuclear fuel reprocessing tracers from Scientific Ice Expeditions 1995 and 1996 , 1999 .

[7]  U. Schauer,et al.  Double-diffusive layering in the Eurasian Basin of the Arctic Ocean , 1999 .

[8]  L. Nazarenko,et al.  Dynamics of transport of “Atlantic signature” in the Arctic Ocean , 1998 .

[9]  K. Logemann,et al.  Is the Arctic Ocean warming , 1998 .

[10]  R. Macdonald,et al.  Physical and geochemical properties across the Atlantic/Pacific water mass front in the southern Canadian Basin , 1996 .

[11]  R. Macdonald,et al.  Evidence for warming of Atlantic water in the Southern Canadian Basin of the Arctic Ocean: Results from the Larsen-93 Expedition , 1995 .

[12]  Greg Holloway,et al.  Representing topographic stress for large-scale ocean models , 1992 .

[13]  R. Macdonald,et al.  The joint roles of Pacific and Atlantic-origin waters in the Canada Basin, 1997–1998 , 2004 .

[14]  E. Carmack,et al.  The nested structure of Arctic thermohaline intrusions , 2003 .

[15]  H. Friedrich,et al.  The Transformations of Atlantic Water in the Arctic Ocean and Their Significance for the Freshwater Budget , 2000 .

[16]  J. Imberger.  Physical processes in lakes and oceans , 1998 .

[17]  J. Morison,et al.  Hydrography of the upper Arctic Ocean measured from the nuclear submarine U.S.S. Pargo , 1998 .