中国第四次北极科学考察期间北极点附近海冰和融池的航空遥感观测

An aerial photography has been used to provide validation data on sea ice near the North Pole where most polar orbiting satellites cannot cover. This kind of data can also be used as a supplement for missing data and for reducing the uncertainty of data interpolation. The aerial photos are analyzed near the North Pole collected during the Chinese national arctic research expedition in the summer of 2010(CHINARE2010). The result shows that the average fraction of open water increases from the ice camp at approximately 87°N to the North Pole, resulting in the decrease in the sea ice. The average sea ice concentration is only 62.0% for the two flights(16 and 19 August 2010). The average albedo(0.42) estimated from the area ratios among snow-covered ice,melt pond and water is slightly lower than the 0.49 of HOTRAX 2005. The data on 19 August 2010 shows that the albedo decreases from the ice camp at approximately 87°N to the North Pole, primarily due to the decrease in the fraction of snow-covered ice and the increase in fractions of melt-pond and open-water. The ice concentration from the aerial photos and AMSR-E(The Advanced Microwave Scanning Radiometer-Earth Observing System) images at 87.0°–87.5°N exhibits similar spatial patterns, although the AMSR-E concentration is approximately 18.0%(on average) higher than aerial photos. This can be attributed to the 6.25 km resolution of AMSR-E, which cannot separate melt ponds/submerged ice from ice and cannot detect the small leads between floes. Thus, the aerial photos would play an important role in providing high-resolution independent estimates of the ice concentration and the fraction of melt pond cover to validate and/or supplement space-borne remote sensing products near the North Pole.     

磁性构造学研究方法述评

本文分析了磁性构造学的各种基本研究方法，继而讨论了近年来古地磁视极移曲线分析方法的研究进展，然后讨论了真极移问题，最后对当前磁性构造学的研究动向作了简要的概括。     

南极点和罗斯海滨壳幔结构

本文根据美国极地台（南极点）和新西兰斯科特台罗斯海滨的ＷＷＳＳＮ台所接收的长周期深源远震图Ｐ波波形的理论地震图拟合，探讨南极洲壳幔构造特征。结果表明，南极点下方地壳厚约４５ｋｍ，双层结构；罗斯海滨地层厚约２４ｋｍ，３５０～４５０ｋｍ深度有明显低速带存在，它们反映了南极横贯山脉两侧不同的构造特征     

一种利用哨兵1号数据提取南极接地线方法

针对因IW工作模式数据在南极地区覆盖不全面导致对南极接地线的全面提取造成影响的问题,提出利用双差干涉测量提取接地线的基本原理,分别利用工作模式为IW和EW的Sentinel-1雷达卫星数据,对东南极毛德皇后地沿岸冰川接地线进行提取,将提取结果分别与MEa-SUREs接地线产品进行对比,同时再将这两种模式下的提取结果进行对比分析。结果表明,双差干涉测量可以去除冰流相位的影响,使用EW工作模式的Sentinel-1数据进行南极接地线提取可以忽略其地面分辨率较低这一缺陷,同时,这一模式的Sentinel-1数据在幅宽、南极覆盖范围等方面更具优势。因此,综合利用IW和EW工作模式的Sentinel-1数据,对南极接地线的全面、高效、长期动态监测具有重要意义。     

北极王湾表层沉积物中的粘土矿物及其对物源与古环境变化的指示意义

Kongsfjorden is a typical fjord on the edge of the ice cap of the Arctic Svalbard-Barents Sea. Its inner bay is connected with a modern glacier front along the direction of the fjord axis with a significant gradient change in the parameters of hydrology, sedimentation, and biology. In summer, ice and snow melt-water and floating ice collapse continuously and thus transport the weathering products on the surrounding land into the sea. Thus Kongsfjorden is regards as a natural laboratory for the study of unique sedimentation in polar fjords under modern glacial-sea water conditions. In this study, fifty-two surface sediments were collected in Kongsfjorden for clay mineral analysis to study the sediment source and sediment-transport process. Our results indicate that clay minerals in the surface sediments from Kongsfjorden are mainly composed of illite, chlorite, and kaolinite, and no smectite is found. Rocks from different periods exposed extensively in the surrounding areas of Kongsfjorden provide an important material basis for clay minerals in the Kongsfjorden. Kaolinite may be mainly derived from the fluvial deposits, weathered from reddish sandstones and conglomerates during the Carboniferous Period.Illite is mainly derived from Proterozoic low-grade and medium-grade metamorphic phyllite, mica schist, and gneiss. While chlorite is mainly from Proterozoic low-grade metamorphic phyllite and mica schist. In the direction from the fluvio-glacial estuary to the sea of the glacier front of Kongsfjorden, illite increase gradually,and the content of kaolinite declines gradually. However, the change pattern of chlorite is insignificant, which may be related to the provenance. Kongsfjorden detritus is mainly transported by the fluvio-glacial streams and icebergs into the sea and deposited in the inner bay. Coarse sediments are rapidly deposited in the glacier front,estuary, and near-shore areas. Clay fraction begins to deposit significantly by 200–400 m after flowing into the sea,which due to the crystal behavior of clay minerals, hydrodynamic condition and flocculation. Kaolinite and chlorite on the south of the bay near the Blomstrandhalv?ya Island is mainly affected by ice-rafted detritus and thus can reveal the trajectory of transportation by the floating ice while entering the sea.     

利用FY-1D全球数据监测北极冰雪覆盖

利用FY-1D极轨气象卫星全球数据(GDPT)4个通道资料选取了北极冰雪样本2 366个、云2 024个,陆地1 602个,水体1 648个,分析各类别的光谱特征和纹理特征,利用光谱特征从图像上识别出陆地、水体和部分云,根据冰雪和云纹理特征不同用贝叶斯判别方法建立类别判别函数进一步对北极冰雪与云进行分类,然后通过5 d合成,得到北极地区完整的冰雪覆盖范围.所得结果与NOAA/NESDIS的IMS提供的北半球日积雪产品检验分类结果相比较,一致率达到70 %以上.     

第三极地区冰川径流研究进展北大核心CSCD

青藏高原是地球上除南北极之外冰川面积最大的区域,被称为地球“第三极”。全球变暖导致该地区冰川普遍退缩,融水释放成为冰川径流,使得下游河川径流发生重大变化,给下游流域水资源利用与管理带来挑战。然而由于第三极地区特殊的地形和复杂的气候,加上冰川水文过程内在的复杂性,使得冰川径流的研究十分困难。本文总结了目前关于冰川径流研究的几类主要方法:直接观测法、遥感观测法、水量平衡法、水化学示踪法和冰川水文模型法,其中冰川水文模型法使用最为广泛。在第三极地区,前人利用这些方法对于冰川径流的研究结果表明,自20世纪90年代以来,冰川径流普遍呈现上升趋势,但是其对于总径流的贡献同时受气候条件和流域内冰储量的影响,存在显著的空间差异;总体来看,位于西风控制区的流域的冰川径流贡献普遍大于季风控制区的流域。未来变化方面,除部分冰储量较大的西风区流域(塔里木河、印度河)外,第三极地区大多数流域冰川径流将在本世纪中叶前达到峰值。但是目前由于观测不足、模型物理机制简化等制约,对于第三极地区冰川径流的研究存在很大的不确定性,未来需要开展更多观测、开发更先进的冰川水文模型以提高第三极地区冰川径流研究的准确性,进而为该地区水资源利用与管理和防洪减灾工作提供科学依据。     

NUTRIENTS NEAR THE ARCTIC POLE REGION

The distributions of SiO_3-Si, PO_4-P, NO_3-N and NO_2-N concentrations in the seawater, iceand snow from 82°45′21″W, 88°01′20″N to the North Pole are reported and the exchange of thenutrients among the seawater, ice and snow are discussed. The average concentrations of the nutrients inthe seawater near the North Pole were 4.9±2.4μmol/L for SiO_3-Si; 0.60±0.10μmol/L for PO_4-P,3.4±1.7μmol/L for NO_3-N and 0.13±0.04μmol/L for NO_2-N. The nutrient concentrations inthe ice and snow in the North Pole were 0.20 and 0.65μmol/L for SiO_3-Si; 0.22 and 0.25μmol/L forPO_4-P; 1.6 and 5.8μmol/L for NO_3-N, 0.19 and 0.15μmol/L for NO_2-N.     

德日进"亚洲干极"理论的现实意义

"亚洲干极"是德日进总结中国北方中生代以来不断干旱化得出的观点.构造运动驱动气候变干是其主导思想.德日进关于中国新生代古地理演化的基本框架至今仍然适用,当代研究补充和深化了"亚洲干极"的理论,老第三纪行星风系的干热气候逐渐在新第三纪被季风气候取代,代表干旱气候的粉尘沉积逐步扩大空间范围,湖相沉积则逐渐收缩.22MaB.P.,8.5MaB.P.,3.6MaB.P.和1.2MaB.P.是"亚洲于极"逐步加强的关键时段.     

南极乔治王岛地区太阳光照气候特征及影响分析

利用南极长城站 1988—2017 年连续的日照、云量、天气现象、气温和湿度等观测资料,研究 了南极西部乔治王岛 30 a的日照变化特征及其与气象要素的关系。 结果显示,南极地区的日照时 间远少于中低纬度地区,这主要因为该地区常年以阴云天气为主,云层对太阳光的遮挡降低了日 照时间的总量值。2000 年以来,随着总云量和相对湿度的增加,日照时间呈减少趋势。 根据统计分析月平均相对湿度以及每月出现雨、雪、雾、轻雾、吹雪等天气现象和最低气温三0 ℃的天数,发 现液态（ 固态） 现象的发生频率与日照百分率的变化趋势一致（相反） ,即日照百分率低（高） 时,液态现象少（多） ,固态现象多（少） 。