科研之友
微信
新浪微博
Facebook
分享链接
摘要
The Bering Sea is a marginal sea of the North Pacific located in middle and high latitudes. It can be divided into almost two equal part. The northern one called the Bering Sea Shelf whose depth less than 200 m, meanwhile, the other southwest part is the Bering Basin which is deeper than 3000 m. There is a cyclonic circulation in the basin, which consists of the Kamchatka Current in the west, the Aleutian North Slope Current in the south and the Bering Slope Current in the east. As a transitional area connecting the Pacific Ocean and the Arctic Ocean, the variations of hydrological environment directly affect the properties of Pacific inflow, which not only is the key factor of the Shelf-Slope-Basin system in the west of the Arctic Ocean, but also can expand its impact to the north of Atlantic through the Arctic. What's more, the broad Bering Sea is a productive ecosystem that has great economic and cultural value, the changes in the physical environment are capable of reorganizing the ecosystem. In the summers of 1999, 2003, 2008, 2010, 2012 and 2014, a total of six Chinese National Arctic Research Expeditions were carried out. In these researches, the Arctic-Pacific sector has always been the focus, so that many years of hydrographic data were obtained in the Bering Sea basin. Based on the valuable CTD data from the repeated section, which is along the common border shared by the Russia and the America and intersects the whole basin, the distribution and interannual variation of water masses in the Bering Sea basin are analyzed. The results indicate that the water in this area can be divided into three types of water masses based on the differences in temperature and salinity: Bering Sea Basin Upper Water, Bering Sea Basin Intermediate Water, Bering Sea Basin Deep Water. In summer, Bering Sea Basin Upper Water is the warmest water mass in the basin and located at depths <40 m with the highest temperature of 10.9°C in 2008. Its thickness decreases from south to north. Furthermore, there is a marked thermocline between the upper and intermediate waters, with a noticeable interannual variation. The Bering Sea Basin Intermediate Water occurs at depths <500 m. Affected by the Bering Slope Current, its thickness increases in the north, which can up to 470 m. Including the residual cold water from winter is the most obvious characteristic of the intermediate water. The core of cold water is located between 54.6°N and 59.4°N with depth of 110-200 m, whose lowest temperature is 0.5°C in 1999. It varies simultaneously with cold water on the Bering Sea shelf. Based on annual temperature and cold-water ranges, it can be divided into two types: cold event and warm event. In recent years, the warm event has alternated with cold event in cycles of approximately 6 years. The 2003 and 2014 are the warm years and the 1999, 2008, 2010 and 2012 are the cold years. In 2014, the intermediate cold water displays the greatest temperature and minimum range, which may point to a new warm event requiring further study. As the largest and most stable water mass, Bering Sea Basin Deep Water makes up more than 80% of the Bering Sea Basin water mass. The Bering Slope Current can affect waters at depths of up to 1000 m, but the effect intensity is decrease with the increase of depth. In the future, more observed data and long term mooring are expected. The cause and effect of warm and cold events, especially its relationship with the surface pressure and polar warming and the impact on the ecosystem, need to be further analyzed.
- 出版日期2016-5-1
- 单位山东科技大学
