The temperature and salinity data obtained by the Chinese national arctic research expedition （CHINARE2003） are used to study the water structure in the Bering Strait and ambient regions. Four water masses appeared ...The temperature and salinity data obtained by the Chinese national arctic research expedition （CHINARE2003） are used to study the water structure in the Bering Strait and ambient regions. Four water masses appeared in the research region： the intermediate Bering Sea water mass （IBWM）, the Alaska coastal water （ACW）, the Anadyr water （AW） and the Bering shelf water （BSW）. The AW originates from the IBWM, but the upper layer water has been greatly altered. In the cruise on 28/29 July 2003, there were only the BSW and ACW in a section across the Bering Strait （BS section）, but in the September 12/13 cruise, the AW, BSW and ACW flowed parallelly into the Bering Strait. The upper waters of these water masses were all altered due to ice melting, runoff, solar radiation, and wind mixing. The waters in the central and northern parts of Bering Strait stratified by two uniform layers,were expressed as the typical feature of the water masses originating from the pacific. A two-layer structure also dominated the vertical stratification in most part of the Chukchi Sea. An obvious subseasonal variation was observed in the BS section, which caused varying transportation of fresh water, heat, and substance, and produced a long-term and extensive impact on the Arctic Ocean.展开更多
There are awareness and concerns caused by the decreasing sea ice coverage around the Arctic and Antarctic due to effects of climate change. Emphasis in this study was on rapid changes in Arctic sea ice coverage and i...There are awareness and concerns caused by the decreasing sea ice coverage around the Arctic and Antarctic due to effects of climate change. Emphasis in this study was on rapid changes in Arctic sea ice coverage and its impacts on the marine ecology during the fourth Chinese National Arctic Research Expedition in 2010. Our purpose was to establish a baseline of Arctic fish compositions, and consequent effects of climate change on the fish community and biogeography. Fish specimens were col- lected using a multinet middle-water trawl, French-type beam trawl, otter trawl, and triangular bottom trawl. In total, 36 tows were carried out along the shelf of the Bering Sea, Bering Strait, and Chukchi Sea in the Arctic Ocean. in total, 41 fish species belonging to 14 families in 7 orders were collected during the expedition. Among them, the Scorpaeniformes, including 17 species, accounted for almost one third of the total number （34.8%）, followed by 14 species of the Perciformes （27.0%）, 5 species of the Pleuronecti- formes （22.3%）, and 2 species of the Gadiformes （15.4%）. The top 6 most abundant species were Hippoglossoides robustus, Bore- gadus saida, Myoxocephalus scorpius, Lumpenus fabricii, Artediellus scaber, and Gymnoeanthus trieuspis. Abundant species var- ied according to the different fishing methods; numbers of families and species recorded did not differ with the various fishing methods; species and abundances decreased with depth and latitude; and species extending over their known geographic ranges were observed during the expedition. Station information, species list, and color photographs of all fishes are provided.展开更多
The characteristics of current in the Bering Strait and the Chukchi Sea areanalyzed based on the two current data on the mooring stations during the Second National ArcticResearch Expedition of China in 2003. The tida...The characteristics of current in the Bering Strait and the Chukchi Sea areanalyzed based on the two current data on the mooring stations during the Second National ArcticResearch Expedition of China in 2003. The tidal currents of the principal diurnal and semidiurnalellipses rotate clockwise in the upper layer, except for N_2, S_2, and Q_1 at Sta. ST. In the BeringStrait (Sta. ST), the major semi-axis of tidal current constituent M_2 is 2.9 cm/s in the upperlayer, which is much smaller than that of semi-monthly oscillation (11.8 cm/s); and the mean currentflows northwestward at the amplitude of about 20 cm/s and varies a little with depth. During thecruise, the current has significant semi-monthly oscillation at the two mooring stations. Thespectra analyses of the air pressure gradient and the wind stress show that there are thesemi-monthly oscillations in these two data series. The near-inertial current, approximately 4 cm/s,presents almost the same magnitude of the principal tidal currents in the Bering Strait.展开更多
A high-resolution Arctic Ocean-Finite Volume Community Ocean Model(AO-FVCOM) and observational current data from 14 mooring stations in Bering Strait and surrounding regions between 1990 and 2015 were used to study th...A high-resolution Arctic Ocean-Finite Volume Community Ocean Model(AO-FVCOM) and observational current data from 14 mooring stations in Bering Strait and surrounding regions between 1990 and 2015 were used to study the seasonal and interannual variability of Bering Strait throughflow(BST). AO-FVCOM represented the BST with a climatological northward flux of 1.06 Sv, which was close to the observational mean of 0.94 ± 0.26 Sv. From the model results, the strongest volume flux was in summer, approximately 45% larger than that in winter. Interannual variability of BST was also indicated in the model results, and the maximum and minimum annual mean transports are in 2007 and 2012, respectively. AO-FVCOM showed larger differences from the observations in 2000, 2002, and 2015 than in other years, which may be related to the limitation of atmospheric forcing for the model. According to the driving mechanisms of BST, sea level difference(SLD) across the strait dominates the northward volume transport, and local wind is also important in forcing the seasonal variability of the BST and SLD patterns to change the BST indirectly.展开更多
Paleo reconstructions and model simulations have suggested the Bering Strait plays a pivotal role in climate change. However, the contribution of the Bering Strait throughflow to oceanic meridional heat transport (OMH...Paleo reconstructions and model simulations have suggested the Bering Strait plays a pivotal role in climate change. However, the contribution of the Bering Strait throughflow to oceanic meridional heat transport (OMHT) is about 100 times smaller than the OMHT at low latitudes in the modern climate and it is generally ignored. Based on model simulations under modern and Last Glacial Maximum (LGM,~21 ka;ka=thousand years ago) climate conditions, this study highlights the importance of the Bering Strait throughflow to OMHT. The interbasin OMHT induced by the Bering Strait throughflow is estimated by interbasin-intrabasin decomposition. Similar to barotropic-baroclinic-horizontal decomposition, we assume the nonzero net mass transport induced by interbasin throughflows is uniform across the entire section, and the interbasin term is separated to force zero net mass transport for the intrabasin term. Based on interbasinintrabasin decomposition, the contribution of the Bering Strait throughflow is determined as ~0.02 PW (1 PW=10 15 W) under the modern climate, and zero under the LGM climate because the closed Bering Strait blocked interbasin throughflows. The contribution of the Bering Strait throughflow to OMHT is rather small, consistent with previous studies. However, comparisons of OMHT under modern and LGM climate conditions indicate the mean absolute changes are typically 0.05 and 0.20 PWin the North Atlantic and North Pacific, respectively. Thus, the contribution of the Bering Strait throughflow should not be ignored when comparing OMHT under diff erent climate conditions.展开更多
基金supported by the National Natural Science Foundation of China under contract Nos 40376007 and 40306005.
文摘The temperature and salinity data obtained by the Chinese national arctic research expedition （CHINARE2003） are used to study the water structure in the Bering Strait and ambient regions. Four water masses appeared in the research region： the intermediate Bering Sea water mass （IBWM）, the Alaska coastal water （ACW）, the Anadyr water （AW） and the Bering shelf water （BSW）. The AW originates from the IBWM, but the upper layer water has been greatly altered. In the cruise on 28/29 July 2003, there were only the BSW and ACW in a section across the Bering Strait （BS section）, but in the September 12/13 cruise, the AW, BSW and ACW flowed parallelly into the Bering Strait. The upper waters of these water masses were all altered due to ice melting, runoff, solar radiation, and wind mixing. The waters in the central and northern parts of Bering Strait stratified by two uniform layers,were expressed as the typical feature of the water masses originating from the pacific. A two-layer structure also dominated the vertical stratification in most part of the Chukchi Sea. An obvious subseasonal variation was observed in the BS section, which caused varying transportation of fresh water, heat, and substance, and produced a long-term and extensive impact on the Arctic Ocean.
基金supported by the China Program for International Polar Year 2007-2011the Special Research Foundation for Public Welfare Marine Program (Grant no.201105022-2)
文摘There are awareness and concerns caused by the decreasing sea ice coverage around the Arctic and Antarctic due to effects of climate change. Emphasis in this study was on rapid changes in Arctic sea ice coverage and its impacts on the marine ecology during the fourth Chinese National Arctic Research Expedition in 2010. Our purpose was to establish a baseline of Arctic fish compositions, and consequent effects of climate change on the fish community and biogeography. Fish specimens were col- lected using a multinet middle-water trawl, French-type beam trawl, otter trawl, and triangular bottom trawl. In total, 36 tows were carried out along the shelf of the Bering Sea, Bering Strait, and Chukchi Sea in the Arctic Ocean. in total, 41 fish species belonging to 14 families in 7 orders were collected during the expedition. Among them, the Scorpaeniformes, including 17 species, accounted for almost one third of the total number （34.8%）, followed by 14 species of the Perciformes （27.0%）, 5 species of the Pleuronecti- formes （22.3%）, and 2 species of the Gadiformes （15.4%）. The top 6 most abundant species were Hippoglossoides robustus, Bore- gadus saida, Myoxocephalus scorpius, Lumpenus fabricii, Artediellus scaber, and Gymnoeanthus trieuspis. Abundant species var- ied according to the different fishing methods; numbers of families and species recorded did not differ with the various fishing methods; species and abundances decreased with depth and latitude; and species extending over their known geographic ranges were observed during the expedition. Station information, species list, and color photographs of all fishes are provided.
基金supported by the project of the National Nataral Science Foundation of China under contract Nos 40506006,40376007,40306005,40376005 and NCET-04-0646.
文摘The characteristics of current in the Bering Strait and the Chukchi Sea areanalyzed based on the two current data on the mooring stations during the Second National ArcticResearch Expedition of China in 2003. The tidal currents of the principal diurnal and semidiurnalellipses rotate clockwise in the upper layer, except for N_2, S_2, and Q_1 at Sta. ST. In the BeringStrait (Sta. ST), the major semi-axis of tidal current constituent M_2 is 2.9 cm/s in the upperlayer, which is much smaller than that of semi-monthly oscillation (11.8 cm/s); and the mean currentflows northwestward at the amplitude of about 20 cm/s and varies a little with depth. During thecruise, the current has significant semi-monthly oscillation at the two mooring stations. Thespectra analyses of the air pressure gradient and the wind stress show that there are thesemi-monthly oscillations in these two data series. The near-inertial current, approximately 4 cm/s,presents almost the same magnitude of the principal tidal currents in the Bering Strait.
基金supported by the National Program on Key Basic Research Project of China (No. 2015CB95 3902)the National Natural Science Foundation of China (Nos. 41276197 and 41706210)+1 种基金the National Key Research and Development Program of China (No. 2016 YFC1400903)support of various institutions with programs and grants to deploy mooring and achieve data
文摘A high-resolution Arctic Ocean-Finite Volume Community Ocean Model(AO-FVCOM) and observational current data from 14 mooring stations in Bering Strait and surrounding regions between 1990 and 2015 were used to study the seasonal and interannual variability of Bering Strait throughflow(BST). AO-FVCOM represented the BST with a climatological northward flux of 1.06 Sv, which was close to the observational mean of 0.94 ± 0.26 Sv. From the model results, the strongest volume flux was in summer, approximately 45% larger than that in winter. Interannual variability of BST was also indicated in the model results, and the maximum and minimum annual mean transports are in 2007 and 2012, respectively. AO-FVCOM showed larger differences from the observations in 2000, 2002, and 2015 than in other years, which may be related to the limitation of atmospheric forcing for the model. According to the driving mechanisms of BST, sea level difference(SLD) across the strait dominates the northward volume transport, and local wind is also important in forcing the seasonal variability of the BST and SLD patterns to change the BST indirectly.
基金Supported by the China’s National Key Research and Development Project(No.2016YFA0601803)the National Natural Science Foundation of China(Nos.41490641,41521091,U1606402)the Qingdao National Laboratory for Marine Science and Technology(No.2017ASKJ01)
文摘Paleo reconstructions and model simulations have suggested the Bering Strait plays a pivotal role in climate change. However, the contribution of the Bering Strait throughflow to oceanic meridional heat transport (OMHT) is about 100 times smaller than the OMHT at low latitudes in the modern climate and it is generally ignored. Based on model simulations under modern and Last Glacial Maximum (LGM,~21 ka;ka=thousand years ago) climate conditions, this study highlights the importance of the Bering Strait throughflow to OMHT. The interbasin OMHT induced by the Bering Strait throughflow is estimated by interbasin-intrabasin decomposition. Similar to barotropic-baroclinic-horizontal decomposition, we assume the nonzero net mass transport induced by interbasin throughflows is uniform across the entire section, and the interbasin term is separated to force zero net mass transport for the intrabasin term. Based on interbasinintrabasin decomposition, the contribution of the Bering Strait throughflow is determined as ~0.02 PW (1 PW=10 15 W) under the modern climate, and zero under the LGM climate because the closed Bering Strait blocked interbasin throughflows. The contribution of the Bering Strait throughflow to OMHT is rather small, consistent with previous studies. However, comparisons of OMHT under modern and LGM climate conditions indicate the mean absolute changes are typically 0.05 and 0.20 PWin the North Atlantic and North Pacific, respectively. Thus, the contribution of the Bering Strait throughflow should not be ignored when comparing OMHT under diff erent climate conditions.
