John Calder and Jia Wang Follow-up of PAG Model-Data Fusion Workshop and Recent Update of Work in Progress John Calder and Jia Wang NOAA, Silver Spring, MD USA NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, Michigan, USA PAG Model-Data Fusion Workshop, Sanya, China, February 18-20, 2008

I. Follow up PAG Model-Data Fusion Workshop: Outline I. Follow up PAG Model-Data Fusion Workshop: Proceedings--Special Volume on Chinese Journal for Polar Science: “Pacific Arctic Group (PAG) Model-Data Fusion Studies in the Arctic Ocean and Subpolar Seas” II. Work in Progress in Modeling III. Summary

PAG Special Volume in CJPS 0. Preface to the Special Volume Climate Impacts on the Ocean, Sea ice, and Ecosystems in the Pacific Arctic: Contribution to IPY by the PAG Model-Data Fusion Workshop Jia Wang, John Calder, and Huigen Yang (Guest editors) Arctic Ocean: 1. Outflow of Pacific Water from the Chukchi Sea into the Arctic Ocean Robert Pickart 2. Contribution of a pathway through the Arctic Ocean to the recent reduction in the ice cover Motoyoshi Ikeda 3. The role of Pacific water in the dramatic retreat of arctic sea ice during summer 2007 Zhang Jinlun, Mike Steele and Rebecca Woodgate 4. Snow and sea ice thermodynamics in the Arctic: Model validation and sensitivity study against SHEBA data Cheng Bin，Timo Vihma，Zhang Zhanhai，Li Zhijun and Wu Huiding 5. Modeling Arctic Ocean heat transport and warming episodes in the 20th century caused by the intruding Atlantic Water Wang Jia, Jin Meibing, Jun Takahashi, Tatsuo Suzuki, Igor V Polyakov, Kohei Mizobata, Moto Ikeda, Fancois J. Saucier and Markus Meier 6. A coupled multi category sea ice model and POM for Baffin Bay and the Labrador Sea Tang Charles L

PAG Special Volume in CJPS (continued) Chukchi, Beaufort, Bering Seas: 7. Results of recent Pacific Arctic ice-ocean modeling studies at the Naval Postgraduate School Jaclyn Clement Kinney and Wieslaw Maslowski 8. Modeling seasonal variations of Ocean and Sea Ice circulation in the Beaufort and Chukchi Seas: A model data fusion study Wang Jia, Kohei Mizobata, Hu Haoguo, Jin Meibing, Zhang Sheng, Walter Johnson, Koji Shimada, Moto Ikeda, and Yu Yanling 9. Toward development of the 4Dvar data assimilation system in the Bering Sea: reconstruction of the Mean Dynamic Ocean Topography Gleb Panteleev, Dmitri Nechaev, Vladimir Luchin, Phyllis Stabeno, Nikolai Maximenko and Motoyoshi Ikeda 10. Modeling the ocean circulation in the Bering Sea Hu Haoguo and Wang Jia 11 Mechanical and numerical models for sea ice dynamics on small- meso scale Ji Shunying（季顺迎）, Wang Anliang (王安良), Li Hai（李海）and Yue Qianjin（岳前进） 12. The significance of water column nitrification in the southeastern Bering Sea Clara J Deal, Jin Meibing and Wang Jia 13. A coupled ice-ocean ecosystem model for 1D and 3D applications in the Bering and Chukchi Seas Jin Meibing, Clara Deal and Wang Jia

A schematic diagram for coastal circulation in the northern Bering, Chukchi-Beaufort Seas and part of the Arctic Ocean (Courtesy of Weingartner).

II. Models Models being applied/developed at NOAA GLERL and IARC/UAF (Arctic Modeling Group: Wang, Hu, Mizobata, Deal, Jin) Regional Coupled Ice-Ocean Model (CIOM, Wang et al. 2002, 2005, 2009) in the Bering Sea (POM-based) (local computers, ARSC) (tides and wind-wave mixing) 2) 1-D and 3-D NPZD (9-compartment) coupled Physical-Ecosystem (biogeochemical) Models (PhEcoM, Wang et al. 2003; Jin et al. 2006, 2007, 2009) (tides and wind-wave mixing)

II. Models (CIOM, cont.) 1 . Problems It is well known that the circulation can be simulated with the POM . But the simulated vertical temperature structure is quite different from observations: that is, the simulated upper mixed layer is too shallow and the thermocline is too weak. There are two reasons: (1) Wave mixing effect is not considered ; (2) Tidal current is not included simultaneously . Since the tidal current is strong in the Bering Sea shelf, the tidal energy is more than 90% of the total energy (Kinder and Schumacher 1981). If the tidal current is not considered , the simulated current is too weak to compare with observations, and the important mixing effect of tidal current is underestimated.

Work in Progress Bering-Chukchi (-Beaufort) seas model

Simulation of surface ocean current

Simulation of SIC + ice velocity

Simulation of SIT + ice velocity

Comparison of Bering Strait transport (Data: Woodgate, climatology; Model year: 1996)

IV. Conclusions (Ocean) A robust, state-of-the-art ocean circulation model (CIOM) has been established with improvements by wind wave mixing and tidal mixing Bering Sea ocean circulation results from the combination of --barotropic Pacific-Arctic Pressure Head (basin-wide circulation driven by large-scale wind and the remote Pacific Ocean circulation inflows/outflow): southern KC, northeastward Western Current, AS --baroclinic (density-driven): BSC, ANSC --wind-driven: Shelf Current, Northern KC --tidal residual currents: Shelf Current, Aleutian Is. and passes, KC, BSC (~1-2 cm/s)  PAPH+Wind+Baroclinic+Tidal Residuals (shelves+islands) Both wind-wave mixing and tidal mixing are key for the formulation of thermocline, in which the former mixes the upper layer uniformly and the latter mixes the bottom layer, respectively, which are important to ecosystem modeling.

IV. Conclusions (Sea ice, continue) Sea ice seasonal cycle was reproduced: concentration, thickness, polynyas, etc. Upwelling occurs in summer along the Siberian coast and the Gulf of Anadyr, resulting in a narrow, high productivity belt. Downwelling occurs in winter, enhancing dense water formation during sea ice formation Cold Pool formation and maintenance are resulted from seasonal cycle of ice formation, dense formation in the Gulf of Anadyr, shelves, and summer upper thermocline insulation (not shown here)

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