Note: Intro -- Contents -- Contributors -- Chapter 1: The Pacific Arctic Region: An Introduction -- 1.1 Introduction -- 1.2 The Pacific Arctic Region -- 1.3 Physical Processes, Hydrography and Sea Ice: Field and Modeling -- 1.4 Atmospheric Forcing and Sea Ice -- 1.5 Physical Processes and Modeling -- 1.6 Carbon Transformations and Cycling -- 1.7 Lower and Upper Trophic Levels and Ecosystem Modeling -- 1.8 Summary -- References -- Chapter 2: Recent and Future Changes in the Meteorology of the Pacific Arctic -- 2.1 Introduction -- 2.2 Climatological Fields -- 2.3 Storms and Temporal Variability -- 2.4 The Differences of the Pacific Sector Relative to the Larger Arctic System -- 2.5 The Future Climate of the Pacific Arctic -- 2.6 Summary -- References -- Chapter 3: Recent Variability in Sea Ice Cover, Age, and Thickness in the Pacific Arctic Region -- 3.1 Introduction -- 3.2 Sea Ice Cover -- 3.2.1 Trends in Sea Ice Cover -- 3.2.2 Interannual Variability in Sea Ice Cover -- 3.3 Sea Ice Age -- 3.3.1 Sea Ice Age Data and Analysis -- 3.3.2 Recent Variability in Sea Ice Age -- 3.4 Sea Ice Thickness -- 3.4.1 Sea Ice Thickness Data and Background -- 3.4.2 Sea Ice Thickness Model Description -- 3.4.3 Sea Ice Thickness Model Validation -- 3.4.4 Recent Variability in Modeled Sea Ice Thickness -- 3.4.5 Potential Mechanisms of Sea Ice Thinning -- 3.5 Implications and Possible Future States -- 3.6 Summary -- References -- Chapter 4: Abrupt Climate Changes and Emerging Ice- Ocean Processes in the Pacific Arctic Region and the Bering Sea -- 4.1 Introduction -- 4.2 Data and Methods -- 4.3 Leading Climate Forcing: Arctic Dipole (DA) Pattern -- 4.4 Investigating Mechanisms Responsible for Arctic Sea Ice Minima Using PIOMAS -- 4.5 Bering Strait Heat Transport and the DA -- 4.6 Modeling the Bering Sea Cold Pool Using CIOM. , 4.7 Modeling Landfast Ice in the Beaufort-Chukchi Seas Using CIOM -- 4.8 Possible Air-Ice-Sea Feedback Loops in the Western Arctic -- 4.9 Summary -- References -- Chapter 5: The Large Scale Ocean Circulation and Physical Processes Controlling Pacific-Arctic Interactions -- 5.1 Introduction -- 5.2 The Northern North Pacific, Gulf of Alaska, and Alaskan Stream -- 5.3 Western Subarctic Gyre -- 5.4 Bering Sea -- 5.5 Chukchi Sea -- 5.6 Beaufort Sea -- 5.7 Heat/Freshwater Content and Sea Ice -- 5.8 Summary -- References -- Chapter 6: Shelf-Break Exchange in the Bering, Chukchi and Beaufort Seas -- 6.1 Introduction -- 6.2 The Bering Shelf-Break -- 6.3 The Chukchi and Beaufort Shelf-Break -- 6.3.1 Shelf-Basin Connections -- 6.3.2 Instabilities of the Shelf-Break Jet -- 6.3.3 Wind-Driven Exchange -- 6.4 Undersea Canyons of the Chukchi and Beaufort Shelves -- 6.4.1 Herald Canyon -- 6.4.2 Barrow Canyon -- 6.4.3 Mackenzie Trough -- 6.5 Polynya-Formed Dense Shelf Water -- 6.6 Summary -- 6.6.1 Bering Shelf-Break -- 6.6.2 Chukchi/Beaufort Shelf-Break -- References -- Chapter 7: On the Flow Through Bering Strait: A Synthesis of Model Results and Observations -- 7.1 Introduction -- 7.2 Model Descriptions -- 7.2.1 Bering Ecosystem Study Ice-Ocean Modeling and Assimilation System (BESTMAS) -- 7.2.2 Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2) -- 7.2.3 Naval Postgraduate School Arctic Modeling Effort (NAME) -- 7.2.4 Nucleus for European Modelling of the Ocean (NEMO) with ORCA Configuration -- 7.2.5 Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS) -- 7.3 Bering Strait Observational Mooring Data -- 7.4 Results -- 7.5 Discussion -- 7.6 Summary -- References -- Chapter 8: Carbon Fluxes Across Boundaries in the Pacific Arctic Region in a Changing Environment -- 8.1 Introduction -- 8.2 Geographic and Water Mass Features. , 8.2.1 Geographic Definition and Description -- 8.2.2 Water-Mass Characterizations -- 8.3 Pacific Ocean Inflow -- 8.4 Fluxes Across the Arctic Land-Sea Interface -- 8.5 CO 2 Flux Across the Air-Sea Boundary -- 8.5.1 Sea Surface p CO 2 Distribution -- 8.5.2 Air-Sea CO 2 Flux -- 8.6 Impact of Seasonal Sea-Ice Cycle -- 8.7 Overall DIC Budget -- 8.8 Summary -- References -- Chapter 9: Carbon Biogeochemistry of the Western Arctic: Primary Production, Carbon Export and the Controls on Ocean Acidification -- 9.1 Introduction -- 9.2 Primary Production -- 9.2.1 Northern Bering Sea -- 9.2.2 Chukchi Sea -- 9.2.3 Deep Canada Basin -- 9.3 DOC Production -- 9.3.1 Spatial Variability -- 9.3.2 The Use of DOC/Salinity Relationships -- 9.3.3 Dynamical Characterization of tDOC-Inputs & -- Sinks -- 9.4 Export Flux of Particulate Organic Carbon -- 9.4.1 Regional Case Studies -- 9.4.1.1 Chukchi Sea: The Shelf Basin Interaction Study (SBI-II) -- 9.4.1.2 Mackenzie Shelf: Canadian Arctic Shelf Exchange Study (CASES) -- 9.4.1.3 Laptev Sea, Northern Baffin Bay and the Beaufort Sea Shelves -- 9.4.1.4 Eastern and Central Arctic Ocean: Polarstern ARK-XXII/2 Expedition -- 9.4.2 Conclusions -- 9.5 Grazing -- 9.6 Benthic Carbon Cycling -- 9.6.1 Sediment Nutrient Efflux -- 9.7 Contribution of Heterotrophic Bacteria to Carbon Cycling -- 9.7.1 Respiration by Heterotrophic Bacteria -- 9.7.2 Biomass Production by Heterotrophic Bacteria and Phytoplankton -- 9.7.3 Growth Efficiency in the Arctic Ocean -- 9.7.4 Implications for Shelf-Basin Exchange -- 9.8 Ocean Acidification -- 9.8.1 The Bering Sea -- 9.8.2 The Western Arctic Ocean -- 9.9 Summary -- References -- Chapter 10: Biodiversity and Biogeography of the Lower Trophic Taxa of the Pacific Arctic Region: Sensitivities to Climate Change -- 10.1 General Introduction -- 10.2 Phytoplankton in the PAR -- 10.2.1 Introduction. , 10.2.2 Phytoplankton and Sea Ice Algae: An Overview -- 10.2.3 Latitudinal Variation of Phytoplankton Biodiversity and Community Composition in the Western Arctic Ocean -- 10.2.4 Synechococcus -- 10.2.5 Sensitivities to Habitat Changes -- 10.3 Heterotrophic Microbes in the PAR -- 10.3.1 Introduction -- 10.3.2 Viruses -- 10.3.3 Bacterial Diversity -- 10.3.4 Bacterial and Archaeal Diversity Levels in the Arctic Ocean Versus Lower-Latitude Oceans -- 10.3.5 Diversity and Distribution of Heterotrophic Protists -- 10.3.5.1 Diversity of Heterotrophic Protists Assessed by Microscopy -- 10.3.5.2 Diversity of Heterotrophic Protists Assessed by Molecular Genetics -- 10.3.5.3 Biogeographical and Depth Distribution of Heterotrophic Protists -- 10.3.5.4 Heterotrophic Microbes: Future Research -- 10.4 Benthic Fauna of the PAR -- 10.4.1 Introduction -- 10.4.2 Benthic Fauna of the Northern Bering, Chukchi, and Western Beaufort Seas -- 10.4.2.1 Environmental Setting -- 10.4.2.2 General Biogeography -- 10.4.3 Benthic Invertebrate Patterns in the Canadian Beaufort Sea Shelf -- 10.4.3.1 Environmental Setting -- 10.4.3.2 General Biogeography and Biodiversity -- 10.4.4 Deep-Sea Benthos -- 10.4.5 Effect of Climate Change on Benthic Fauna of the PAR -- 10.5 Sea Ice Associated Diversity and Production in the PAR -- 10.5.1 Introduction -- 10.5.2 Primary Producers: Diversity, Abundance and Activity -- 10.5.3 Sea Ice Meiofauna Abundance and Diversity -- 10.5.4 Effects of Climate Change -- 10.6 Biodiversity and Biogeography of Metazoan Zooplankton of the PAR -- 10.6.1 Introduction -- 10.6.2 Species Diversity -- 10.6.3 Zooplankton Advection: Expatriate Analysis -- 10.6.4 Horizontal Zooplankton Community Structure -- 10.6.5 Vertical Distribution of Zooplankton in the Deep Waters of the PAR -- 10.6.6 Long-Term Change -- 10.7 Summary -- References. , Chapter 11: Marine Fishes, Birds and Mammals as Sentinels of Ecosystem Variability and Reorganization in the Pacific Arctic Region -- 11.1 Introduction -- 11.1.1 Ecological Scale -- 11.2 Overview: Ecology of Upper Trophic Level (UTL) Species -- 11.2.1 Fishes and Crabs -- 11.2.1.1 Northern Bering and Chukchi Seas -- 11.2.1.2 Beaufort Sea -- 11.2.2 Marine Birds -- 11.2.2.1 At-Sea Distribution -- 11.2.2.2 Breeding Colonies -- 11.2.2.3 Seasonal Dynamics -- 11.2.3 Marine Mammals -- 11.2.3.1 Core Arctic Species -- 11.2.3.2 Seasonally Migrant Species -- 11.3 Case Studies: Responses of UTL Species to Environmental Variability -- 11.3.1 Fishes and Crabs -- 11.3.1.1 Salmon and Forage Fish in the Northern Bering Sea -- 11.3.1.2 Snow Crab in the Chukchi Sea -- 11.3.1.3 Demersal Fish and Crab in the Beaufort Sea -- 11.3.2 Marine Birds -- 11.3.2.1 Nesting Auklets and the Anadyr Current -- 11.3.3 Eiders During Winter and Migration -- 11.3.4 Marine Mammals -- 11.3.4.1 Timing and Relative Abundance of Bowhead Whales Feeding in the Canadian Beaufort Sea -- 11.3.4.2 Body Condition of Ringed Seals in the Western Canadian Arctic -- 11.3.4.3 Changes in Life-History and Diet of Walruses and Seals in the Northern Bering and Chukchi Seas -- 11.4 UTL Species as Ecosystem Sentinels -- 11.4.1 UTL-Focused Research Framework -- 11.4.1.1 Trophic Interactions -- 11.4.1.2 Foraging Dynamics -- 11.4.1.3 Species Composition -- 11.5 Summary -- 11.5.1 Tracking Biological Responses in an Era of Rapid Change and Extreme Events -- 11.5.2 Integration of Science and Local Knowledge -- 11.6 Personal Communications -- References -- Chapter 12: Progress and Challenges in Biogeochemical Modeling of the Pacific Arctic Region -- 12.1 Introduction -- 12.2 PAR Characteristics Particularly Relevant for Biogeochemical Modeling -- 12.3 A Brief History of PAR Biogeochemical Models. , 12.4 Modeling PAR in 1-D: Introduction and Locations.