The decadal variability of the North Atlantic thermohaline circulation(THC) is investigated within a three-dimensional ocean circulation model using the conditional nonlinear optimal perturbation method. The results s...The decadal variability of the North Atlantic thermohaline circulation(THC) is investigated within a three-dimensional ocean circulation model using the conditional nonlinear optimal perturbation method. The results show that the optimal initial perturbations of temperature and salinity exciting the strongest decadal THC variations have similar structures: the perturbations are mainly in the northwestern basin at a depth ranging from 1500 to 3000 m. These temperature and salinity perturbations act as the optimal precursors for future modifications of the THC, highlighting the importance of observations in the northwestern basin to monitor the variations of temperature and salinity at depth. The decadal THC variation in the nonlinear model initialized by the optimal salinity perturbations is much stronger than that caused by the optimal temperature perturbations, indicating that salinity variations might play a relatively important role in exciting the decadal THC variability. Moreover, the decadal THC variations in the tangent linear and nonlinear models show remarkably different characteristics, suggesting the importance of nonlinear processes in the decadal variability of the THC.展开更多
On the basis of the 2013 Chinese Social Survey(CSS)data,this paper makes an in-depth analysis of the influence of social,economic and cultural factors on the national identity of the population,with a focus on the dif...On the basis of the 2013 Chinese Social Survey(CSS)data,this paper makes an in-depth analysis of the influence of social,economic and cultural factors on the national identity of the population,with a focus on the differences between the younger and the older generation.Our findings show that the sense of national identity of the younger generation is weaker than that of the older generation,and this is even more marked among the tertiary-educated younger generation.The sense of national identity of the older generation is more influenced by social structural factors,especially by their position in the social hierarchy,while that of the younger generation is more affected by cultural and economic factors.In addition,we find that in China,the sense of national identity of the privileged stratum is stronger than that of the middle and base-level strata.These findings,which run counter to Huntington and Inglehart’s view of“the weakening of elite national identity,”may be due to the different roles of the state in globalization and economic growth.展开更多
基金supported by the National Basic Research Program of China(973 Program,Grant No.2012CB417404)
文摘The decadal variability of the North Atlantic thermohaline circulation(THC) is investigated within a three-dimensional ocean circulation model using the conditional nonlinear optimal perturbation method. The results show that the optimal initial perturbations of temperature and salinity exciting the strongest decadal THC variations have similar structures: the perturbations are mainly in the northwestern basin at a depth ranging from 1500 to 3000 m. These temperature and salinity perturbations act as the optimal precursors for future modifications of the THC, highlighting the importance of observations in the northwestern basin to monitor the variations of temperature and salinity at depth. The decadal THC variation in the nonlinear model initialized by the optimal salinity perturbations is much stronger than that caused by the optimal temperature perturbations, indicating that salinity variations might play a relatively important role in exciting the decadal THC variability. Moreover, the decadal THC variations in the tangent linear and nonlinear models show remarkably different characteristics, suggesting the importance of nonlinear processes in the decadal variability of the THC.
文摘On the basis of the 2013 Chinese Social Survey(CSS)data,this paper makes an in-depth analysis of the influence of social,economic and cultural factors on the national identity of the population,with a focus on the differences between the younger and the older generation.Our findings show that the sense of national identity of the younger generation is weaker than that of the older generation,and this is even more marked among the tertiary-educated younger generation.The sense of national identity of the older generation is more influenced by social structural factors,especially by their position in the social hierarchy,while that of the younger generation is more affected by cultural and economic factors.In addition,we find that in China,the sense of national identity of the privileged stratum is stronger than that of the middle and base-level strata.These findings,which run counter to Huntington and Inglehart’s view of“the weakening of elite national identity,”may be due to the different roles of the state in globalization and economic growth.
