On ocean and sea ice modes of variability in the Bering Sea

[1] Results from a 35 year hindcast of northeast Pacific Ocean conditions are confronted with observational data collected over the Bering Sea shelf within the integration time period. Rotary power spectra of the hindcast currents near NOAA mooring site M2 site fall within the 95% confidence bounds for the observational spectra, except for a high bias in the counter-clockwise rotating component at 10 m depth in the high frequencies (periods <24 h). The model exhibits the most skill in reproducing anomalies of the integrated annual sea ice concentration and monthly subsurface (60 m depth) temperature fields, accounting for 85% and 50% of their observed variability. Analysis of the integrated ice concentration time series reveals evolution in the mean duration of ice-free waters (40 year trend of +6.8 days/decade) and changes in this parameter's variance with time. Correlation and empirical orthogonal function (EOF) analyses reveal the primary temporal-spatial patterns of variability in the temperature and salinity fields over the Bering Sea and northern Gulf of Alaska for near-surface (0–20 m) and subsurface (40–100 m) depth layers. Correlation analysis between the EOF principal components and various climate index and observed time series shows that the Pacific Decadal Oscillation, the North Pacific Gyre Oscillation, and the Bering Sea annually integrated ice area anomalies are important indices of thermohaline variability; the spatial structures of these modes give insight to their potential impacts upon the ecosystem. We identify a number of ecologically and economically important species whose temporal variability is significantly correlated with the identified spatial patterns.

[1]  J. Overland,et al.  On exchange of water between the Gulf of Alaska and the Bering Sea through Unimak Pass , 1982 .

[2]  Jinlun Zhang,et al.  On the role of ocean circulation in seasonal and interannual ice-edge variations in the Bering Sea , 1991, Annals of Glaciology.

[3]  A. Trites,et al.  Ecological effects of regime shifts in the Bering Sea and eastern North Pacific Ocean , 2002 .

[4]  G. Johnson,et al.  Some controls on flow and salinity in Bering Strait , 2006 .

[5]  Pierre Brasseur,et al.  A variational inverse method for the reconstruction of general circulation fields in the northern Bering Sea , 1991 .

[6]  Z. Kowalik,et al.  Modeling of Storm Surges in the Bering Sea and Norton Sound , 1986 .

[7]  L. K. Coachman.  Flow convergence over a broad, flat continental shelf , 1982 .

[8]  Jinlun Zhang,et al.  Sea Ice Response to Atmospheric and Oceanic Forcing in the Bering Sea , 2010 .

[9]  H. J. Niebauer.  Variability in Bering Sea ice cover as affected by a regime shift in the North Pacific in the period 1947–1996 , 1998 .

[10]  Shoshiro Minobe,et al.  Resonance in bidecadal and pentadecadal climate oscillations over the North Pacific: Role in climatic regime shifts , 1999 .

[11]  J. Overland,et al.  A Numerical Study of the Circulation of the Bering Sea Basin and Exchange with the North Pacific Ocean , 1994 .

[12]  M. Spaulding,et al.  A Numerical Model of the M2 and K1 Tide in the Northwestern Gulf of Alaska , 1987 .

[13]  P. Stabeno,et al.  Distribution and transport patterns of northern rock sole, Lepidopsetta polyxystra, larvae in the southeastern Bering Sea , 2007 .

[14]  D. Douglas,et al.  At-sea distribution of spectacled eiders : A 120-year-old mystery resolved , 1999 .

[15]  Pollock Fishery.  ENVIRONMENTAL ASSESSMENT/REGULATORY IMPACT REVIEW/ INITIAL REGULATORY FLEXIBILITY ANALYSIS , 2008 .

[16]  Eric Deleersnijder,et al.  Three-dimensional General Circulation Model of the Northern Bering Sea’s Summer Ecohydrodynamics , 1993 .

[17]  G. Mellor,et al.  A two‐dimensional coupled ice‐ocean model of the Bering Sea marginal ice zone , 1989 .

[18]  J. Schumacher,et al.  Theoretical and observed profiles of tidal currents at two sites on the southeastern Bearing Sea shelf , 1984 .

[19]  J. Schumacher,et al.  Low-Frequency Current Regimes over the Bering Sea Shelf , 1983 .

[20]  R. Peterman,et al.  Comparison of methods to account for autocorrelation in correlation analyses of fish data , 1998 .

[21]  P. Stabeno,et al.  Characteristics and variability of the inner front of the southeastern Bering Sea , 2002 .

[22]  C. Pease.  Eastern Bering Sea Ice Processes , 1980 .

[23]  Acia.  Arctic Climate Impact Assessment - ACIA , 2005 .

[24]  C. Mooers.  A technique for the cross spectrum analysis of pairs of complex-valued time series, with emphasis on properties of polarized components and rotational invariants , 1973 .

[25]  J. Grebmeier,et al.  Late winter water column and sea ice conditions in the northern Bering Sea , 2004 .

[26]  B. Megrey,et al.  On relationships between cannibalism, climate variability, physical transport, and recruitment success of Bering Sea walleye pollock (Theragra chalcogramma) , 2000 .

[27]  Patricia A. Livingston,et al.  Ecosystem Change and the Decline of Marine Mammals in the Eastern Bering Sea : Testing the Ecosystem Shift and Commercial Whaling Hypotheses , 1999 .

[28]  Jia Wang,et al.  Modeling effects of tidal and wave mixing on circulation and thermohaline structures in the Bering Sea: Process studies , 2010 .

[29]  M. Steele,et al.  Role of the Molecular Sublayer in the Melting or Freezing of Sea Ice , 1989 .

[30]  P. Stabeno,et al.  Tidal energy in the Bering Sea , 2006 .

[31]  W. Maslowski,et al.  On the processes controlling shelf-basin exchange and outer shelf dynamics in the Bering Sea , 2009 .

[32]  W. Budgell,et al.  Numerical simulation of ice-ocean variability in the Barents Sea region , 2005 .

[33]  Donald J. Cavalieri,et al.  Passive microwave algorithms for sea ice concentration: A comparison of two techniques , 1997 .

[34]  L. K. Coachman.  Circulation, water masses, and fluxes on the southeastern Bering Sea shelf , 1986 .

[35]  N. Bond,et al.  Rise and fall of jellyfish in the eastern Bering Sea in relation to climate regime shifts , 2008 .

[36]  R. K. Reed,et al.  Characteristics of currents over the continental slope of the eastern Bering Sea , 1992 .

[37]  W. Large,et al.  Oceanic vertical mixing: a review and a model with a nonlocal boundary layer parameterization , 1994 .

[38]  L. Eisner,et al.  Thermal and haline variability over the central Bering Sea shelf: Seasonal and interannual perspectives , 2011 .

[39]  Haoguo Hu,et al.  Seasonal variations of sea ice and ocean circulation in the Bering Sea: A model‐data fusion study , 2009 .

[40]  H. Mofjeld.  Observed tides on the northeastern Bering Sea shelf , 1986 .

[41]  J. Napp,et al.  Transport through Unimak Pass, Alaska , 2002 .

[42]  P. Stabeno,et al.  Contraction of the geographic range of distribution of snow crab (Chionoecetes opilio) in the eastern Bering Sea: An environmental ratchet? , 2005 .

[43]  D. Prandle.  The vertical structure of tidal currents , 1982 .

[44]  R. S. Pritchard,et al.  Forecasting Bering Sea ice edge behavior , 1990 .

[45]  P. Stabeno,et al.  Evidence of episodic on-shelf flow in the southeastern Bering Sea , 1999 .

[46]  Steven R. Hare,et al.  Decadal-scale regime shifts in the large marine ecosystems of the North-east Pacific: a case for historical science , 1994 .

[47]  J. Napp,et al.  Zooplankton species composition, abundance and biomass on the eastern Bering Sea shelf during summer: The potential role of water-column stability and nutrients in structuring the zooplankton community , 2008 .

[48]  S. Levitus,et al.  On the Pacific Ocean regime shift , 2001 .

[49]  Robert F. Cahalan,et al.  Sampling Errors in the Estimation of Empirical Orthogonal Functions , 1982 .

[50]  J. Lovvorn,et al.  Diet and body condition of spectacled eiders wintering in pack ice of the Bering Sea , 2003, Polar Biology.

[51]  R. Mendelssohn,et al.  Spatial heterogeneity of sea surface temperature trends in the Gulf of Alaska , 2005 .

[52]  Y. Watanuki,et al.  Annual variation in the foraging behaviour of thick-billed murres in relation to upper-ocean thermal structure around St. George Island, Bering Sea , 2010 .

[53]  T. Royer.  Coastal fresh water discharge in the northeast Pacific , 1982 .

[54]  S. Danielson,et al.  Tidal currents in the St. Lawrence Island region , 2005 .

[55]  T. Weingartner,et al.  Freshwater variability and predictability in the Alaska Coastal Current , 2005 .

[56]  Walter H. F. Smith,et al.  Free software helps map and display data , 1991 .

[57]  James C. McWilliams,et al.  North Pacific Gyre Oscillation links ocean climate and ecosystem change , 2008 .

[58]  J. Napp,et al.  Factors influencing physical structure and lower trophic levels of the eastern Bering Sea shelf in 2005: Sea ice, tides and winds , 2010 .

[59]  C. Symon,et al.  Arctic climate impact assessment , 2005 .

[60]  James D. Schumacher,et al.  The Physical Oceanography of the Bering Sea , 1999 .

[61]  Albert J. Hermann,et al.  Modeled transport of freshwater from a line-source in the coastal Gulf of Alaska , 2009 .

[62]  G. Hunt,et al.  Increases in jellyfish biomass in the Bering Sea: implications for the ecosystem , 2002 .

[63]  J. Overland,et al.  Northward flow in the Bering and Chukchi seas , 1987 .

[64]  R. B. Tripp,et al.  Bering Strait the Regional Physical Oceanography , 1975 .

[65]  Thomas M. Powell,et al.  Modeling iron limitation of primary production in the coastal Gulf of Alaska , 2009 .

[66]  Malcolm L. Spaulding,et al.  Numerical Simulation of Wind-Driven Flow through the Bering Strait , 1987 .

[67]  K. Sherman,et al.  The Large Marine Ecosystem Concept: Research and Management Strategy for Living Marine Resources. , 1991, Ecological applications : a publication of the Ecological Society of America.

[68]  Judith A. Curry,et al.  Sea Ice-Albedo Climate Feedback Mechanism , 1995 .

[69]  Variability of physical and chemical characteristics along the 70-m isobath of the southeastern Bering Sea , 2002 .

[70]  J. Overland,et al.  Cyclone Climatology of the Bering Sea and Its Relation to Sea Ice Extent , 1982 .

[71]  Chuanmin Hu,et al.  Baroclinic tidal flows and inundation processes in Cook Inlet, Alaska: numerical modeling and satellite observations , 2007 .

[72]  N. Bond,et al.  The Aleutian Low, storm tracks, and winter climate variability in the Bering Sea , 2007 .

[73]  Michael Steele,et al.  PHC: A Global Ocean Hydrography with a High-Quality Arctic Ocean , 2001 .

[74]  P. Stabeno,et al.  Trapped motion around the Pribilof Islands in the Bering Sea , 1999 .

[75]  A. Hermann,et al.  A comparison of remote vs. local influence of El Niño on the coastal circulation of the northeast Pacific , 2009 .

[76]  J. Wallace,et al.  A Pacific Interdecadal Climate Oscillation with Impacts on Salmon Production , 1997 .

[77]  N. Bond,et al.  Decadal Variability of the Aleutian Low and Its Relation to High-Latitude Circulation* , 1999 .

[78]  Thomas M. Powell,et al.  Multi‐scale modeling of the North Pacific Ocean: Assessment and analysis of simulated basin‐scale variability (1996–2003) , 2005 .

[79]  Josef Y. Cherniawsky,et al.  A high‐resolution assimilating tidal model for the northeast Pacific Ocean , 2000 .

[80]  Glen Gawarkiewicz,et al.  The St. Lawrence polynya and the Bering shelf circulation : New observations and a model comparison , 2006 .

[81]  Elizabeth C. Hunke,et al.  Viscous–Plastic Sea Ice Dynamics with the EVP Model: Linearization Issues , 2001 .

[82]  George L. Mellor,et al.  An Ice-Ocean Coupled Model , 1989 .

[83]  Taotao Qian,et al.  Changes in Continental Freshwater Discharge from 1948 to 2004 , 2009 .

[84]  J. Overland,et al.  An Atmospherically Driven Sea-Ice Drift Model for the Bering Sea , 1984, Annals of Glaciology.

[85]  S. Lentz,et al.  Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE , 2002 .

[86]  Alexander F. Shchepetkin,et al.  Open boundary conditions for long-term integration of regional oceanic models , 2001 .

[87]  J. Carton,et al.  A Reanalysis of Ocean Climate Using Simple Ocean Data Assimilation (SODA) , 2008 .

[88]  Robert L. Haney,et al.  On the Pressure Gradient Force over Steep Topography in Sigma Coordinate Ocean Models , 1991 .

[89]  R. Heintz,et al.  Influence of size on the sources of energy consumed by overwintering walleye pollock (Theragra chalcogramma) , 2010 .

[90]  F. Mueter,et al.  Sea ice retreat alters the biogeography of the Bering Sea continental shelf. , 2008, Ecological applications : a publication of the Ecological Society of America.

[91]  H. Mofjeld.  Recent observations of tides and tidal currents from the northeastern Bering Sea shelf , 1984 .

[92]  Robert E. Davis,et al.  Statistics for the evaluation and comparison of models , 1985 .

[93]  James W. Hurrell,et al.  Decadal atmosphere-ocean variations in the Pacific , 1994 .

[94]  R. B. Tripp,et al.  Effects of a shelf polynya on flow and water properties in the northern Bering Sea , 1983 .

[95]  E. Hunke,et al.  An Elastic–Viscous–Plastic Model for Sea Ice Dynamics , 1996 .

[96]  Elizabeth H. Sinclair,et al.  Climate change and control of the southeastern Bering Sea pelagic ecosystem , 2002 .

[97]  Stephen G. Yeager,et al.  The global climatology of an interannually varying air–sea flux data set , 2009 .

[98]  S. Salo,et al.  Winter currents and hydrographic conditions on the northern central Bering Sea shelf , 1988 .

[99]  F. H. Fay.  Ecology and Biology of the Pacific Walrus, Odobenus Rosmarus Divergens Illiger , 1982 .

[100]  Lee W. Cooper,et al.  Ocean circulation and exchanges through the northern Bering Sea—1979–2001 model results , 2005 .

[101]  Kohei Mizobata,et al.  Eddy‐induced cross‐slope exchange maintaining summer high productivity of the Bering Sea shelf break , 2006 .

[102]  Allan J. Clarke,et al.  The effect of continental shelves on tides , 1981 .

[103]  Dale B. Haidvogel,et al.  Numerical Ocean Circulation Modeling , 1999 .

[104]  J. Napp,et al.  Anomalous conditions in the south-eastern Bering Sea, 1997: nutrients, phytoplankton and zooplankton , 2001 .

[105]  T. Weingartner,et al.  On the nature of winter cooling and the recent temperature shift on the northern Gulf of Alaska shelf , 2010 .

[106]  M. E. Sullivan,et al.  Observations from moorings in the Aleutian Passes: temperature, salinity and transport , 2005 .

[107]  K. Tadokoro,et al.  Interannual–interdecadal variations in zooplankton biomass, chlorophyll concentration and physical environment in the subarctic Pacific and Bering Sea , 1997 .

[108]  R. K. Reed,et al.  Circulation in the Bering Sea basin observed by satellite-tracked drifters: 1986-1993 , 1994 .

[109]  Thomas J. Weingartner,et al.  Direct measurements of transport and water properties through the Bering Strait , 1995 .

[110]  N. Bond,et al.  Quantifying cross-shelf and vertical nutrient flux in the Coastal Gulf of Alaska with a spatially nested, coupled biophysical model , 2009 .

[111]  Thomas J. Weingartner,et al.  Monthly temperature, salinity, and transport variability of the Bering Strait through flow , 2005 .

[112]  Dale B. Haidvogel,et al.  A regional tidal/subtidal circulation model of the southeastern Bering Sea: Development, sensitivity , 2002 .

[113]  K. Taylor.  Summarizing multiple aspects of model performance in a single diagram , 2001 .

[114]  J. Napp,et al.  Interannual and decadal variability in zooplankton communities of the southeast Bering Sea shelf , 2002 .

[115]  Y. Artukhin,et al.  Trends in populations of Red-legged Kittiwake Rissa brevirostris, a Bering Sea endemic , 1997, Bird Conservation International.

[116]  A. Hermann,et al.  A biophysical NPZ model with iron for the Gulf of Alaska: Reproducing the differences between an oceanic HNLC ecosystem and a classical northern temperate shelf ecosystem , 2009 .