国内量大古碎碟贝壳化石落户青岛极地海洋世界

《中国海洋报》消息：近日，国家海洋局北海分局正式将由“大洋一号”科学考察船从中太平洋获取的、与新人类历史同龄的大型古砗碟贝壳化石赠送给青岛极地海洋世界。[第一段]     

国家自然科学基金委员会塔里木河流域科学考察专家组到塔中沙漠植物园视察工作

国家自然科学基金委员会塔里木河流域科学考察专家组于2007年10月12日在中国科学院新疆生态与地理研究所陈曦所长、雷加强副所长、以及巴州地区领导的陪同下访问了新疆生地所塔中沙漠植物园。     

NOAA参与国际极地年(IPY)科学活动

美国国家海洋和大气局(NOAA)在今后两年将参加第四届国际极地年(2007—2009年),这是由63个国家的50 000多人组成的迄今最大的国际合作极地科学研究计划。自2007年3月1日至2009年3月9日,来自全世界的科学家们将在科学考察和研究项目中进行合作,以监测极地状态并评估极地在全球气候系统中的角色和影响。世界上许多大学、实验室和观测站将进行228个以上的项目,他们不仅处在严酷的极地环境中,而且要研究从太阳辐射对极地大气的影响直到极冰下外来的海洋生命等每一件事物。     

难忘的南极考察

南极，熟悉而又陌生的名字，一个既神奇又神秘的地方，一块令人向往的冰雪世界，一块地球上没有受到人类破坏和污染的大陆。这一方净土，让许多人梦牵魂饶。作为第22次极地考察队的一员，我于2005年11月18日，从上海民生码头乘“雪龙”号极地考察船前往南极进行科学考察。经过1个月的长途航行，于2005年12月18日凌晨抵达南极。[第一段]     

海洋热点纵横

■中国第28次南极科学考察队从天津启程奔赴南极11月3日,伴着隆隆的汽笛声,中国第28次南极科学考察队乘坐"雪龙"号极地科考船缓缓驶离天津国际邮轮母港,启程奔赴遥远的南极执行科学考察任务。国家海洋局党组书记、局长刘赐贵在欢送仪式发表重要讲话,并向中国第28次南极科学考察队授旗。     

封面故事

编者按关于这一期封面故事的主题——我的极地之旅,组稿编辑有话要说。记者赵建东是我的极地之旅系列第一个发来稿件的作者。关于他文章当中提到的冰盖高原裸奔的话题,小编在第一时间的反应是在南极,顶多也就是脱了鞋子什么的‘奔’一下。是全脱了!赵记者在电话那头半是骄傲半是羞涩地说。在发来的近万字的文稿中,     

楼兰古城消失之谜引世人关注

延续了数千年的文明,湮没了数千年的记忆,慢慢揭开了神秘面纱,楼兰古城,在风沙和荒烟中渐渐显露出来。考古专家根据楼兰古城附近遗址出土的古墓干尸推论,在距今4000年左右,楼兰地区生活着一群以游牧为生的人。他们金发碧眼,与古欧罗巴人种同宗。或许是因为逐水草而居,他们仅留下几具干尸,就神秘地消失了。其后2000余年,这一地区的历史出现断层,考古发掘和文献中均找不到楼兰的一丝痕迹。从此,楼兰的这段历史成了不解之谜。随着科学考察的不断深入,人们提出了关于楼兰古城灭亡的六种假说。     

Variation of freshwater components in the Canada Basin during 1967–2010

As a conservative tracer, oxygen isotopes in seawater are widely used for water mass analysis, along with temperature and salinity. In this study, seawater oxygen-18 datasets in the Canada Basin during 1967–2010 were obtained from the four cruises of the Chinese National Arctic Research Expedition(1999, 2003, 2008, and 2010) and the NASA database. Fractions of sea ice meltwater and river runoff were determined from the salinity-18O system. Our results showed that the river runoff decreased from the south to the north in the Canada Basin. The enhanced amount of river runoff observed in the southern Canada Basin may originate from the Mackenzie River, transported by the Beaufort Gyre. The river runoff component showed maximum fractions during 1967–1969, 1978–1979, 1984–1985, 1993–1994, and 2008–2010, indicating the refresh time of the river runoff was 5.0–16.0 a in the Canada Basin. The temporal variation of the river runoff was related to the change of the Arctic Oscillation(AO) index, suggesting the freshwater stored in the Canada Basin was affected by surface sea ice drift and water mass movement driven by atmospheric circulation.     

Low 210Pb in the upper thermocline in the Canadian Basin: scavenge process over the Chukchi Sea

210Pb was measured during the 3rd Chinese National Arctic Research Expedition cruise to investigate its spatial pattern in the western Arctic Ocean, as well as its relation with the thermocline in the Canadian Basin. The specific activities varied from 0.04 to 2.72, 0.013 to 4.37, and 0.1 to 4.85 Bq/m3 for dissolved, particulate, and bulk 210Pb, respectively, corresponding to respective averages of 0.65, 0.43, and 1.08 Bq/m3. In the Canadian Basin, the minimum 210Pb activities occurred in the thermocline, which was characterized by low temperature of-1.52°C and salinity of 33.1. Combining the spatial distribution of 210Pb and hydrographical characteristics in the western Arctic Ocean, this scenario was ascribed to the effective scavenging of 210Pb when the Pacific water flowed across the Chukchi Shelf. Quantitatively, this interpretation was supported by both the shorter residence times and higher scavenging efficiencies(SE) of dissolved 210Pb over the Chukchi Shelf. The highest SE values were observed in the Herald Shoal and bottom waters over the slope.     

Distribution of dissolved oxygen and causes of maximum concentration in the Bering Sea in July 2010

According to data obtained in the Bering Sea during the 4th Chinese National Arctic Research Expedition, the distribution of dissolved oxygen(DO) was studied, causes of its maximum concentration were discussed, and the relationships between DO and other parameters, such as salinity, temperature, and chlorophyll a were analyzed. The results showed DO concentration ranged from 0.53 to 12.05 mg/L in the Bering Sea basin. The upper waters contained high concentrations and the maximum occurred at the depth range from 20 to 50 m. The DO concentration decreased rapidly when the depth was deeper than 200 m and reached the minimum at the depth range from 500 to 1 000 m, and then increased slowly with the depth increasing but still kept at a low level. On the shelf, the DO concentration ranged from 6.53 to 16.63 mg/L with a mean value of 10.75 mg/L, and showed a characteristic of decreasing from north to south. The DO concentration was higher in the area between the Bering Sea and Lawrence Island and was lower in the southeast and southwest of Lawrence Island at the latitude of 62°N. The formation of maximum DO concentration was concerned with phytoplankton photosynthesis and formation of the themocline. To the south of Sta. B07 in the Bering Sea basin, the oxygen produced by photosynthesis permeated to the deeper water and the themocline made it difficult to exchange vertically, and to the north of Sta. B07, the maximum DO concentration occurred above the themocline due to phytoplankton activities. On the shelf, the oxygen produced by phytoplankton photosynthesis gathered at the bottom of the thermocline and formed the DO maximum concentration. In the Bering Sea basin, the DO and salinity showed a weak negative correlation(r=0.40) when the salinity was lower than 33.1, a significant negative correlation(r=0.92) when the salinity ranged from 33.1 to 33.7, and an irregular reversed parabola(r=0.95) when the salinity was greater than 33.7.