The Greenland Sea,Iceland Sea,and Norwegian Sea (GIN seas) form the main channel connecting the Arctic Ocean with other Oceans,where significant water and energy exchange take place,and play an important role in globa...The Greenland Sea,Iceland Sea,and Norwegian Sea (GIN seas) form the main channel connecting the Arctic Ocean with other Oceans,where significant water and energy exchange take place,and play an important role in global climate change.In this study steric sea level,associated with temperature and salinity,in the GIN seas is examined based on analysis of the monthly temperature and salinity fields from Polar science center Hydrographic Climatology (PHC3.0).A method proposed by Tabata et al.is used to calculate steric sea level,in which,steric sea level change due to thermal expansion and haline contraction is termed as the thermosteric component (TC) and the halosteric component (SC),recpectively.Total steric sea level (TSSL) change is the sum of TC and SC.The study shows that SC is making more contributions than TC to the seasonal change of TSSL in the Greenland Sea,whereas TC contributes more in the Norwegian and the Iceland Seas.Annual variation of TSSL is larger than 50 mm over most regions of the GIN Seas,and can be larger than 200 mm at some locations such as 308 mm at 76.5 N,12.5 E and 246 mm at 77.5 N,17.5 W.展开更多
The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DO...The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DOV) technique to assess the population structure and abundance of Sebastes schlegeli associated with two metallic,and three wooden,vessel reefs in Haizhou Bay during 2012 and2013.The study used video systems to obtain length measurements and estimates of abundance.The size composition of S.schlegeli differed among reefs and individuals around vessel reefs were all adults,with total lengths(TL) of >20 cm.Juvenile fish were encountered by divers in a rocky area near the island away from the vessel reefs.The largest individual S.schlegeli(with the highest TL) among five reefs were found around a metallic vessel reef in both 2012 and 2013.TL of S.schlegeli from all reefs increased by an average of 3.2 cm(P<0.05) from 2012 to 2013,with an estimated mean weight increase of 250.4 g(P<0.05).The video survey also indicated a decrease in the biomass of schools near two metallic vessels between the years.Stereo-video technology was found to be suitable for rockfish surveys around the reefs.展开更多
In this paper, we use the optimum interpolation sea surface temperature (OISST) provided by the National Center for Environmental Prediction (NCEP) to replace the temperature in the top three layers in the ISHII data,...In this paper, we use the optimum interpolation sea surface temperature (OISST) provided by the National Center for Environmental Prediction (NCEP) to replace the temperature in the top three layers in the ISHII data, and make use of the modified ISHII temperature data to calculate the thermosteric sea level (called modified steric sea level (SSL) hereafter). We subtract the modified SSL and the steric sea level (called ordinary SSL hereafter) derived from the ISHII temperature and salinity from the steric sea level (SSL) provided by the Gravity Recovery and Climate Experiment (GRACE), respectively, and find that the rms error of the difference of the former is obviously smaller than that of the latter. Therefore we reach the conclusion that under the assumption that the GRACE SSL is accurate, the modified SSL can reflect the true steric sea level more accurately. Making use of the modified SSL, we can find that the modified SSL in sea areas of different spatial scales shows an obvious rising trend in the upper 0-700 m layer for the period 1982-2006. The global mean SSL rises with a rate of 0.6 mm year-1 .The modified SSLs in sea areas of different spatial scales all show obvious oscillations with period of one year. There are oscillations with periods of 4-8 years in global oceans and with periods of 2-7 years in the Pacific. The Empirical Orthogonal Function method is applied to the sea areas of different spatial scales and we find that the first modes all have obvious 1-year period oscillations, the first mode of the global ocean has 4-8 year period oscillations, and that of the Pacific has 2-6 year period oscillations. The spatial distribution of the linear rising trend of the global modified SSL in the upper 0-700 m layer is inhomogeneous with intense regional characteristics. The modified SSL linear trend indicates a zonal dipole in the tropical Pacific, rising in the west and descending in the east. In the North Atlantic, the modified SSL indicates a meridional dipole, rising in the latitude band of 20°N-40°N and 45°N-65.5°N and descending obviously in the latitude band of 40°N-45°N.展开更多
The nonlinear propagation of dust acoustic waves is investigated in four-component plasmas consisting of positively charged dust grains, trapped ions, nonthermal electrons, and photoelectron due to ultraviolet irradia...The nonlinear propagation of dust acoustic waves is investigated in four-component plasmas consisting of positively charged dust grains, trapped ions, nonthermal electrons, and photoelectron due to ultraviolet irradiation.We use generalized viscoelastic hydrodynamic model for strongly coupled dust grain. In the weak nonlinearity limit, a modified Kadomstev–Petviashvili（KP） equation and a modified KP-Burger equation, which have a damping term coming from nonadiabatic charge variation, have been derived in the kinetic regime and hydrodynamic regime, respectively. With the increasing of UV photon flux, the hydrodynamic regime changes to kinetic regime. The approximate analytical line soliton and shock solutions are investigated in the kinetic regime and hydrodynamic regime, respectively.展开更多
基金funded by the National Natural Science Foundation of China (40806072)the National Science And Technology Supporting Plan (2007BAC03A0606)
文摘The Greenland Sea,Iceland Sea,and Norwegian Sea (GIN seas) form the main channel connecting the Arctic Ocean with other Oceans,where significant water and energy exchange take place,and play an important role in global climate change.In this study steric sea level,associated with temperature and salinity,in the GIN seas is examined based on analysis of the monthly temperature and salinity fields from Polar science center Hydrographic Climatology (PHC3.0).A method proposed by Tabata et al.is used to calculate steric sea level,in which,steric sea level change due to thermal expansion and haline contraction is termed as the thermosteric component (TC) and the halosteric component (SC),recpectively.Total steric sea level (TSSL) change is the sum of TC and SC.The study shows that SC is making more contributions than TC to the seasonal change of TSSL in the Greenland Sea,whereas TC contributes more in the Norwegian and the Iceland Seas.Annual variation of TSSL is larger than 50 mm over most regions of the GIN Seas,and can be larger than 200 mm at some locations such as 308 mm at 76.5 N,12.5 E and 246 mm at 77.5 N,17.5 W.
基金Supported by the National Natural Science Foundation of China(NSFC)-Shandong Joint Fund for Marine Science Research Centers(No.U1406403)the National Key Technology Research and Development Program of China(No.2011BAD13B02)+1 种基金the National Marine Public Welfare Research Project(No.201205023)the Key Laboratory of Marine Ecology and Environmental Science and Engineering,State Oceanic Administration(No.MESE-2013-05)
文摘The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DOV) technique to assess the population structure and abundance of Sebastes schlegeli associated with two metallic,and three wooden,vessel reefs in Haizhou Bay during 2012 and2013.The study used video systems to obtain length measurements and estimates of abundance.The size composition of S.schlegeli differed among reefs and individuals around vessel reefs were all adults,with total lengths(TL) of >20 cm.Juvenile fish were encountered by divers in a rocky area near the island away from the vessel reefs.The largest individual S.schlegeli(with the highest TL) among five reefs were found around a metallic vessel reef in both 2012 and 2013.TL of S.schlegeli from all reefs increased by an average of 3.2 cm(P<0.05) from 2012 to 2013,with an estimated mean weight increase of 250.4 g(P<0.05).The video survey also indicated a decrease in the biomass of schools near two metallic vessels between the years.Stereo-video technology was found to be suitable for rockfish surveys around the reefs.
基金supported by the National Natural Science Foundation of China (Grants 40806072, 40906002 and 41176009)Public Science and Technology Research Funds Projects of Ocean (201005019)
文摘In this paper, we use the optimum interpolation sea surface temperature (OISST) provided by the National Center for Environmental Prediction (NCEP) to replace the temperature in the top three layers in the ISHII data, and make use of the modified ISHII temperature data to calculate the thermosteric sea level (called modified steric sea level (SSL) hereafter). We subtract the modified SSL and the steric sea level (called ordinary SSL hereafter) derived from the ISHII temperature and salinity from the steric sea level (SSL) provided by the Gravity Recovery and Climate Experiment (GRACE), respectively, and find that the rms error of the difference of the former is obviously smaller than that of the latter. Therefore we reach the conclusion that under the assumption that the GRACE SSL is accurate, the modified SSL can reflect the true steric sea level more accurately. Making use of the modified SSL, we can find that the modified SSL in sea areas of different spatial scales shows an obvious rising trend in the upper 0-700 m layer for the period 1982-2006. The global mean SSL rises with a rate of 0.6 mm year-1 .The modified SSLs in sea areas of different spatial scales all show obvious oscillations with period of one year. There are oscillations with periods of 4-8 years in global oceans and with periods of 2-7 years in the Pacific. The Empirical Orthogonal Function method is applied to the sea areas of different spatial scales and we find that the first modes all have obvious 1-year period oscillations, the first mode of the global ocean has 4-8 year period oscillations, and that of the Pacific has 2-6 year period oscillations. The spatial distribution of the linear rising trend of the global modified SSL in the upper 0-700 m layer is inhomogeneous with intense regional characteristics. The modified SSL linear trend indicates a zonal dipole in the tropical Pacific, rising in the west and descending in the east. In the North Atlantic, the modified SSL indicates a meridional dipole, rising in the latitude band of 20°N-40°N and 45°N-65.5°N and descending obviously in the latitude band of 40°N-45°N.
基金Supported by National Natural Science Foundation of China under Grant No.11104012 the Fundamental Research Funds for the Central Universities under Grant Nos.FRF-TP-09-019A and FRF-BR-11-031B
文摘The nonlinear propagation of dust acoustic waves is investigated in four-component plasmas consisting of positively charged dust grains, trapped ions, nonthermal electrons, and photoelectron due to ultraviolet irradiation.We use generalized viscoelastic hydrodynamic model for strongly coupled dust grain. In the weak nonlinearity limit, a modified Kadomstev–Petviashvili（KP） equation and a modified KP-Burger equation, which have a damping term coming from nonadiabatic charge variation, have been derived in the kinetic regime and hydrodynamic regime, respectively. With the increasing of UV photon flux, the hydrodynamic regime changes to kinetic regime. The approximate analytical line soliton and shock solutions are investigated in the kinetic regime and hydrodynamic regime, respectively.
