Spatio-temporal distribution of dissolved inorganic carbon and net community production in the Chukchi and Beaufort Seas

As part of the 2002 Western Arctic Shelf–Basin Interactions (SBI) project, spatio-temporal variability of dissolved inorganic carbon (DIC) was employed to determine rates of net community production (NCP) for the Chukchi and western Beaufort Sea shelf and slope, and Canada Basin of the Arctic Ocean. Seasonal and spatial distributions of DIC were characterized for all water masses (e.g., mixed layer, halocline waters, Atlantic layer, and deep Arctic Ocean) of the Chukchi Sea region during field investigations in spring (5 May–15 June 2002) and summer (15 July–25 August 2002). Between these periods, high rates of phytoplankton production resulted in large drawdown of inorganic nutrients and DIC in the Polar Mixed Layer (PML) and in the shallow depths of the Upper Halocline Layer (UHL). The highest rates of NCP (?1000–2850 mg C m?2 d?1) occurred on the shelf in the Barrow Canyon region of the Chukchi Sea and east of Barrow in the western Beaufort Sea. A total NCP rate of 8.9–17.8×1012 g for the growing season was estimated for the eastern Chukchi Sea shelf and slope region. Very low inorganic nutrient concentrations and low rates of NCP (?<15–25 mg C m?2 d?1) estimated for the mixed layer of the adjacent Arctic Ocean basin indicate that this area is perennially oligotrophic.

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

[2]  Glenn F. Cota,et al.  Spatial patterns of primary production on the shelf, slope and basin of the Western Arctic in 2002 , 2005 .

[3]  Scott M. Gallager,et al.  Transport of plankton and particles between the Chukchi and Beaufort Seas during summer 2002, described using a Video Plankton Recorder , 2005 .

[4]  Ann E. Gargett,et al.  Time and space scales of vertical mixing and advection of phytoplankton in the upper ocean , 1983 .

[5]  I. Semiletov,et al.  Carbonate chemistry dynamics in Bering Strait and the Chukchi Sea , 2002 .

[6]  Leif G. Anderson,et al.  Export production in the central Arctic Ocean evaluated from phosphate deficits , 2003 .

[7]  Dennis A. Hansell,et al.  Seasonal changes in POC export flux in the Chukchi Sea and implications for water column-benthic coupling in Arctic shelves , 2005 .

[8]  Kitack Lee Global net community production estimated from the annual cycle of surface water total dissolved inorganic carbon , 2001 .

[9]  Taro Takahashi,et al.  Primary production at 47°N and 20°W in the North Atlantic Ocean: a comparison between the 14C incubation method and the mixed layer carbon budget , 1993 .

[10]  D. Cavalieri,et al.  Circulation on the north central Chukchi Sea shelf , 2005 .

[11]  E. D’Asaro,et al.  Internal waves and mixing in the Arctic Ocean , 1992 .

[12]  Fridtjof Nansen,et al.  The polar oceans and their role in shaping the global environment : the Nansen centennial volume , 1994 .

[13]  A. Knap,et al.  Erratum to: Seasonal and interannual variability of oceanic carbon dioxide species at the U.S. JGOFS Bermuda Atlantic Time-series Study (BATS) site, Deep Sea Research Part II: Topical Studies in Oceanography, 43(2–3), 1996, 347-383. , 1996 .

[14]  L. Pomeroy Primary production in the Arctic Ocean estimated from dissolved oxygen , 1997 .

[15]  K. Aagaard,et al.  A year in the physical oceanography of the Chukchi Sea: Moored measurements from autumn 1990–1991 , 2005 .

[16]  D. Karl,et al.  Global estimates of net carbon production in the nitrate‐depleted tropical and subtropical oceans , 2002 .

[17]  L. Anderson,et al.  On the origin of the chemical properties of the Arctic Ocean halocline , 1986 .

[18]  J. Walsh,et al.  CO2 cycling in the coastal ocean. I – A numerical analysis of the southeastern Bering Sea with applications to the Chukchi Sea and the northern Gulf of Mexico , 1994 .

[19]  M. J. Hameedi Aspects of water column primary productivity in the Chukchi Sea during summer , 1978 .

[20]  W. Godwin Article in Press , 2000 .

[21]  W. K. Johnson,et al.  Coulometric total carbon dioxide analysis for marine studies: maximizing the performance of an automated gas extraction system and coulometric detector , 1993 .

[22]  C. Sabine,et al.  Ocean carbon cycling in the Indian Ocean: 2. Estimates of net community production , 2006 .

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

[24]  M. Gosselin,et al.  New measurements of phytoplankton and ice algal production in the Arctic Ocean , 1997 .

[25]  C. Mcroy,et al.  The paradox of pelagic food webs in the northern Bering Sea—III. Patterns of primary production , 1993 .

[26]  E. Carmack,et al.  Thermohaline circulation in the Arctic Mediterranean Seas , 1985 .

[27]  L. Codispoti,et al.  Hydrographic conditions during the 2002 SBI process experiments , 2005 .

[28]  R. Bidigare,et al.  Long-term changes in plankton community structure and productivity in the North Pacific Subtropical Gyre: The domain shift hypothesis , 2001 .

[29]  K. Aagaard,et al.  Revising the Bering Strait freshwater flux into the Arctic Ocean , 2005 .

[30]  N. Bates,et al.  A short-term sink for atmospheric CO2 in subtropical mode water of the North Atlantic Ocean , 2002, Nature.

[31]  C. Mcroy,et al.  The paradox of pelagic food webs in the northern Bering Sea—II. Zooplankton communities , 1989 .

[32]  Akihiko Murata,et al.  Summertime CO2 sinks in shelf and slope waters of the western Arctic Ocean , 2003 .

[33]  D. Wallace,et al.  Tracers of near-surface, halocline and deep waters in the Arctic Ocean: implications for circulation , 1991 .

[34]  N. Bates Interannual variability of oceanic CO2 and biogeochemical properties in the Western North Atlantic subtropical gyre , 2001 .

[35]  Chen Liqi,et al.  Investigations on distributions and fluxes of sea-air CO2 of the expedition areas in the Arctic Ocean , 2003 .

[36]  Dennis A. Hansell,et al.  Patterns of nitrate utilization and new production over the Bering-Chukchi shelf , 1993 .

[37]  Douglas W.R. Wallace,et al.  Ventilation of the Arctic Ocean cold halocline: rates of diapycnal and isopycnal transport, oxygen utilization and primary production inferred using chlorofluoromethane distributions , 1987 .

[38]  Laodong Guo,et al.  Biological productivity and carbon cycling in the Arctic Ocean , 2002 .

[39]  Alan M. Springer,et al.  The Bering Sea Green Belt: shelf-edge processes and ecosystem production , 1996 .

[40]  K. Koltermann,et al.  Water masses and circulation in the Eurasian Basin: Results from the Oden 91 expedition , 1994 .

[41]  B. Tilbrook,et al.  Seasonal coupling of organic matter production and particle flux in the western Bransfield Strait, Antartica , 1991 .

[42]  Pomeroy,et al.  Nutrients, primary production and microbial heterotrophy in the southeastern Chukchi Sea : Arctic summer nutrient depletion and heterotrophy , 1996 .

[43]  J. Swift,et al.  The role of the large-scale Arctic Ocean circulation in the transport of contaminants , 1995 .

[44]  E. Carmack,et al.  On the halocline of the Arctic Ocean , 1981 .

[45]  P. Minnett,et al.  The Northeast Water Polynya as an atmospheric CO2 sink: A seasonal rectification hypothesis , 1995 .

[46]  L. Anderson,et al.  Nutrient regeneration in cold, high salinity bottom water of the Arctic shelves , 1988 .

[47]  Dennis A. Hansell,et al.  Distribution of CO2 species, estimates of net community production, and air‐sea CO2 exchange in the Ross Sea polynya , 1998 .

[48]  S. Manabe,et al.  Study of abrupt climate change by a coupled ocean–atmosphere model , 2000 .

[49]  K. Aagaard,et al.  Arctic ocean‐shelf exchange: Measurements in Barrow Canyon , 1990 .

[50]  R. Sambrotto,et al.  Large Yearly Production of Phytoplankton in the Western Bering Strait , 1984, Science.

[51]  S. B. Moran,et al.  234Th/238U disequilibrium in the central Arctic Ocean: implications for particulate organic carbon export , 1997 .

[52]  R. Weiss,et al.  Geochemical studies of the Weddell sea , 1979 .

[53]  Leif G. Anderson,et al.  Formation and evolution of the surface mixed layer and halocline of the Arctic Ocean , 1996 .

[54]  D. C. Burrell,et al.  Chemical characteristics of water masses in the Amerasian Basin of the Arctic Ocean , 1970 .

[55]  G. Friederich,et al.  Variability in the inorganic carbon system over the southeastern Bering Sea shelf during spring 1980 and spring—summer 1981 , 1986 .

[56]  G. Friederich,et al.  Temporal changes in the inorganic carbon system of the southeastern Bering Sea during spring 1980 , 1982, Nature.

[57]  David L. Kirchman,et al.  Active cycling of organic carbon in the central Arctic Ocean , 1996, Nature.

[58]  Dennis A. Hansell,et al.  Seasonal and spatial distribution of particulate organic matter (POM) in the Chukchi and Beaufort Seas , 2005 .

[59]  A. Knap,et al.  Seasonal and interannual variability of oceanic carbon dioxide species at the U.S. JGOFS Bermuda Atlantic Time-series Study (BATS) site , 1996 .

[60]  Nicholas R. Bates,et al.  Overview of the US JGOFS Bermuda Atlantic Time-series Study (BATS): a decade-scale look at ocean biology and biogeochemistry , 2001 .