Hydrographic conditions during the 2002 SBI process experiments
Hydrographic conditions during the 2002 SBI process experiments
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DOI：
10.1016/j.dsr2.2005.10.007
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发表时间：
2005-01-01
影响因子：
3
通讯作者：
Swift, JH
中科院分区：
文献类型：
--
作者：
Codispoti, LA;Flagg, C;Swift, JH
对2002年北极西部陆架-盆地相互作用（SBI）过程巡航的水文数据的回顾可以得出以下结论。(1)温度-盐度关系与规范描述相似，但在外大陆架/斜坡区5个站点，大西洋暖水/高盐度水出现上升，取代下盐跃层，并与大陆架/上盐跃层水混合。(2) SBI研究区初级生产受白令海峡进入的溶解无机氮（DIN）平流的强烈影响。这种DIN（铵+硝酸盐+亚硝酸盐）的进口通过当地工艺进行了修改，但如果没有白令海峡的流入，SBI地区的生物生产力将会低得多。(3)与大西洋入流水域相比，在150 m水柱上部占主导地位的太平洋水域，DIN+尿素/磷酸盐和DIN+尿素/硅酸盐比例较低。相对于浮游植物的红田吸收比率，它们也很低。(4)随着太平洋水域经过SBI地区，微生物过程继续大量破坏DIN。(5)硝态氮和铵态氮是DIN的主要贡献者。亚硝酸盐浓度均< 0.4 μ m，尿素浓度< 0.5 μ m为少数例外。(6)春季陆架表层DIN浓度适中，但邻近盆地表层浓度较低，表明盆地生产力较低。(7)夏季，表层DIN耗竭普遍存在，但15m以下的营养线叶绿素和溶解氧含量最高。这一层的生产。(8)加拿大盆地净初级深海水体中营养物和溶解氧浓度与Fram海峡条件的比较表明，SBI区域的深层代谢值与典型的深海值相比非常低。(9)深海低代谢和磷酸盐-硅酸盐关系表明，生物源溶质（铵、硅酸盐等）的最大值似乎起源于陆架，并在盐斜深度穿透内部，而不伴有可挥发有机质的类似浓度。因此。由白令海峡进口DIN支撑的陆架和斜坡上的中高初级生产大部分在陆架上再生。（10）我们的最东段（巴罗岛以东）在大约100米的深度显示出营养最大值，就像我们在西部的三个部分一样，但在这一段，这些信号与陆架没有联系，很可能是由向东的陆架断裂射流平流而来。(c) 2005 Elsevier Ltd版权所有。
A review of the hydrographic data from the 2002 Western Arctic Shelf-Basin Interactions (SBI) Process Cruises permits the following conclusions. (1) Temperature-salinity relationships were similar to canonical descriptions, but at five stations in the outer shelf/slope region, warm/high-salinity Atlantic Layer Water appeared to have risen, displaced the lower halocline, and mixed with shelf/upper halocline water. (2) Primary production in the SBI study region was strongly influenced by the advection of dissolved inorganic nitrogen (DIN) entering via Bering Strait. This import of DIN (ammonium + nitrate + nitrite) is modified by local processes, but without the Bering Strait inflow, biological productivity in the SBI region would be much lower. (3) In comparison to the inflowing Atlantic waters, DIN+ urea/phosphate and DIN + urea/silicate ratios in the Pacific waters that dominated the upper similar to 150 m of the water column were low. They were also low relative to Redfield uptake ratios for phytoplankton. (4) Microbial processes continue to destroy DIN in significant quantities as the Pacific waters transit the SBI region. (5) Nitrate and ammonium were the principal contributors to DIN. Nitrite concentrations were always < 0.4 mu M. With a few exceptions urea concentrations were < 0.5 mu M. (6) Moderate concentrations of DIN occurred in surface layers over the shelf in spring, but surface concentrations in the adjacent basin were low, suggesting that basin productivity is low. (7) In summer, DIN depletion in the surface layers was widespread, but a nutricline below similar to 15m contained chlorophyll and dissolved oxygen maxima. production in this layer. (8) A comparison of nutrient and dissolved oxygen concentrations in Suggesting net primary abyssal waters of the Canada Basin with conditions in Fram Strait suggests that the deep metabolism in the SBI region is exceedingly low compared to typical deep-ocean values. (9) The low abyssal metabolism and phosphate-silicate relationships suggest that the maxima in biogenic solutes (ammonium, silicate, etc.) that appear to originate on the shelf and penetrate the interior at halocline depths are not accompanied by comparable concentrations of labile organic matter. Thus. the moderate to high primary production over the shelf and slope supported by the import of DIN from Bering Strait is largelv regenerated over the shelf. (10) Our easternmost section (east of Pt. Barrow) displayed nutrient maxima at depths of similar to 100m as did our three sections to the west, but in this section these signals were not connected to the shelf, and were most likely advected by an eastward shelf-break jet. (c) 2005 Elsevier Ltd. All rights reserved.