The Arctic vortex is a persistent large-scale cyclonic circulation in the middle and upper troposphere and the stratosphere. Its activity and variation control the semi-permanent active centers of Pan-Arctic and the short-time cyclone activity in the subarctic areas. Its strength variation, which directly relates to the atmosphere, ocean, sea ice and ecosystem of the Arctic, can affect the lower atmospheric circulation, the weather of subarctic area and even the weather of middle latitude areas. The 2003 Chinese Second Arctic Research Expedition experienced the transition of the stratosphereic circulation from a warm anticyclone to a cold cyclone during the ending period of Arctic summertime, a typical establishing process of the polar vortex circulation. The impact of the polar vortex variation on the low-level circulation has been investigated by some scientists through studying the coupling mechanisms of the stratosphere and troposphere. The impact of the Stratospheric Sudden Warming (SFW) events on the polar vortex variation was drawing people’s great attention in the fifties of the last century. The Arctic Oscillation (AO), relating to the variation of the Arctic vortex, has been used to study the impact of the Arctic vortex on climate change. The recent Arctic vortex studies are simply reviewed and some discussions on the Arctic vertex are given in the paper. Some different views and questions are also discussed.
Evolution of the Arctic sea ice and its snow cover during the SHEBA year were simulated by applying a high-resolution thermodynamic snow/ice model (HIGHTSI).Attention was paid to the impact of albedo on snow and sea ice mass balance,effect of snow on total ice mass balance,and the model vertical resolution. The SHEBA annual simulation was made applying the best possible external forcing data set created by the Sea Ice Model Intercomparison Project.The HIGHTSI control run reasonably reproduced the observed snow and ice thickness.A number of albedo schemes were incorporated into HIGHTSI to study the feedback processes between the albedo and snow and ice thickness.The snow thickness turned out to be an essential variable in the albedo parameterization.Albedo schemes dependent on the surface temperature were liable to excessive positive feedback effects generated by errors in the modelled surface temperature.The superimposed ice formation should be taken into account for the annual Arctic sea ice mass balance.
