Eddies in the Beaufort Sea its impact to

Eddies in the Beaufort Sea & its impact to ecosystem Watanabe (2011, JGR) & Nishino et al. (2011, GRL) Figure 13(a), Watanabe (2011) Figure 1, Nishino et al. (2011) 2) Preliminary results of XCTD measurement during UNCLOS 2011 cruise Kikuchi et al. (Abstract submitted to OSM 2012 in SLC in late Feb. )

Seminar at AWI November 11, 2011 Eddies in the Beaufort Sea & its impact to ecosystem Pacific Summer Water (PSW) One of the predominant sources of heat, fresh-water, and nutrients in the Arctic Ocean, especially for the Canada Basin (Beaufort Gyre). Advection into the Canada Basin as, • Sub-surface anti-cyclonic cold-core eddies • Sub-surface warm core eddies • Surface-intensified warm-core eddies R/V Mirai Canada Basin Shelf slope of the Chukchi Sea Topographiccontrolled current Buoyancy-driven (coastal) current Bering Strait Eastern Siberian Sea ? ? Chukchi Sea Bering Str. R/V Mirai Arctic Cruise in 2010 (MR 10 -05)

Eddies in the Beaufort Sea & its impact to ecosystem Seminar at AWI November 11, 2011 Very large warm-core eddy was found during MR 10 -05 !! (Nishino et al. , 2011 GRL; http: //www. jamstec. go. jp/e/about/press_release/20110826/) R/V Mirai Temperature at 50 m depth observed in MR 10 -05

Eddies in the Beaufort Sea & its impact to ecosystem Seminar at AWI November 11, 2011 Unusually large warm-core eddy Anti-cyclonic, ~100 km in diameter, Ammonium-rich shelf water Temperature at 50 m depth observed in MR 10 -05

Eddies in the Beaufort Sea & its impact to ecosystem Seminar at AWI November 11, 2011 Unusually large warm-core eddy Anti-cyclonic, ~100 km in diameter, Ammonium-rich shelf water 30 % higher biomass of picophytoplankton Large phytoplankton (e. g. , diatom) Picophyto plancton (e. g. , flagellate) Temperature at 50 m depth observed in MR 10 -05

Eddies in the Beaufort Sea & its impact to ecosystem Seminar at AWI November 11, 2011 How are such surface-intensified warm-core eddies generated in the western Arctic Ocean? (Watanabe, 2011 JGR. . . Published on the exact same day (Aug. 26 2011) as Nishino et al. (2011 GRL). ) Eddy-resolving coupled sea ice-ocean model with atmospheric forcing were used to examine meso-scale eddies and shelf-basin exchange of Pacific Summer Water. MODIS SST in September 2003 [Watanabe, 2011 JGR] Temperature at 50 m depth observed in MR 10 -05

Eddies in the Beaufort Sea & its impact to ecosystem Seminar at AWI November 11, 2011 How are such surface-intensified warm-core eddies generated in the western Arctic Ocean? (Watanabe, 2011 JGR. . . Published on the exact same day (Aug. 26 2011) as Nishino et al. (2011 GRL). ) Eddy-resolving coupled sea ice-ocean model with atmospheric forcing were used to examine meso-scale eddies and shelf-basin exchange of Pacific Summer Water. Pacific water content during May 1 - December 31 2003. [Courtesy from E. Watanabe]

Eddies in the Beaufort Sea & its impact to ecosystem Seminar at AWI November 11, 2011 How are such surface-intensified warm-core eddies generated in the western Arctic Ocean? (Watanabe, 2011 JGR. . . Published on the exact same day (Aug. 26 2011) as Nishino et al. (2011 GRL). ) Eddy-resolving coupled sea ice-ocean model with atmospheric forcing were used to examine meso-scale eddies and shelf-basin exchange of Pacific Summer Water. Type I is generated during Summer time in the vicinity of Barrow canyon by a combination of outflow of warm PSW with low potential vorticity and lateral shear of the canyon jet [Kubokawa (1991) theory].

Eddies in the Beaufort Sea & its impact to ecosystem Seminar at AWI November 11, 2011 How are such surface-intensified warm-core eddies generated in the western Arctic Ocean? (Watanabe, 2011 JGR. . . Published on the exact same day (Aug. 26 2011) as Nishino et al. (2011 GRL). ) Eddy-resolving coupled sea ice-ocean model with atmospheric forcing were used to examine meso-scale eddies and shelf-basin exchange of Pacific Summer Water. Type I is generated during Summer time in the vicinity of Barrow canyon by a combination of outflow of warm PSW with low potential vorticity and lateral shear of the canyon jet [Kubokawa (1991) theory]. Type II & III originate from an eastward current along the Beaufort shelf break. Type II is spawned from the shelf slope at mid-depth during early summer. Type III is generated from surface isopycnal front over the shelf break during late summer.

Eddies in the Beaufort Sea & its impact to ecosystem Seminar at AWI November 11, 2011 How are such surface-intensified warm-core eddies generated in the western Arctic Ocean? (Watanabe, 2011 JGR. . . Published on the exact same day (Aug. 26 2011) as Nishino et al. (2011 GRL). ) Eddy-resolving coupled sea ice-ocean model with atmospheric forcing were used to examine meso-scale eddies and shelf-basin exchange of Pacific Summer Water. Meso-scale eddies are primarily generated and induce the shelf-to-basin transport under weak or westerly wind conditions during summer, summer while wind-driven Ekman offshore-transport is a major driver in the easterly wind regime. Year 2003(2007) is the former (latter) case. NCEP/NCAR SLP averaged from June to August. (b) 2003, (c) 2007 [Figure 4, Watanabe (2011)]

Eddies in the Beaufort Sea & its impact to ecosystem Seminar at AWI November 11, 2011 Very large warm-core eddy was found during MR 10 -05 !! (Nishino et al. , 2011 GRL; http: //www. jamstec. go. jp/e/about/press_release/20110826/) H L H Wind-condition around the Beaufort shelf-slope was calm in July 2010, which suggests that very large warm-core eddy observed during MR 10 -05 cruise was generated near the Barrow canyon in July 2010. . Temperature at 50 m depth observed in MR 10 -05

Seminar at AWI November 11, 2011 Eddies in the Beaufort Sea & its impact to ecosystem 1) Eddies in the Beaufort Sea & its impact to ecosystem Watanabe (2011, JGR) & Nishino et al. (2011, GRL) Figure 13(a), Watanabe (2011) Figure 1, Nishino et al. (2011) Shelf slope and basin observation Eddies, upwelling (shelf basin exchange), acidification, impact to ecosystem and so on. . .