The Initial Errors in the Tropical Indian Ocean that Can Induce a Significant “Spring Predictability Barrier” for La Ni?a Events and Their Implication for Targeted Observations

Initial errors in the tropical Indian Ocean (IO-related initial errors) that are most likely to yield the Spring Prediction Barrier (SPB) for La Ni?a forecasts are explored by using the CESM model. These initial errors can be classified into two types. Type-1 initial error consists of positive sea temperature errors in the western Indian Ocean and negative sea temperature errors in the eastern Indian Ocean, while the spatial structure of Type-2 initial error is nearly opposite. Both kinds of IO-related initial errors induce positive prediction errors of sea temperature in the Pacific Ocean, leading to under-prediction of La Ni?a events. Type-1 initial error in the tropical Indian Ocean mainly influences the SSTA in the tropical Pacific Ocean via atmospheric bridge, leading to the development of localized sea temperature errors in the eastern Pacific Ocean. However, for Type-2 initial error, its positive sea temperature errors in the eastern Indian Ocean can induce downwelling error and influence La Ni?a predictions through an oceanic channel called Indonesian Throughflow. Based on the location of largest SPB-related initial errors, the sensitive area in the tropical Indian Ocean for La Ni?a predictions is identified. Furthermore, sensitivity experiments show that applying targeted observations in this sensitive area is very useful in decreasing prediction errors of La Ni?a. Therefore, adopting a targeted observation strategy in the tropical Indian Ocean is a promising approach toward increasing ENSO prediction skill.     

东南极夏季中山站邻近固定冰DMS、DMSP分布初探

中国第30次南极科学考察期间,在中山站邻近固定冰区采集了两支海冰冰芯并首次分析其中的DMS、DMSP含量。结果表明,两支冰芯上层均含有较高浓度的DMSP+DMS,分别高达114.93及134.41 nmol·L-1。冰芯中DMS、DMSP+DMS浓度随深度的增加而递减。两支冰芯顶部DMSP+DMS高值的成因不同,冰芯1主要受藻类活动影响而产生DMSP+DMS高值,冰芯2主要是由于雪层及薄冰层阻碍,致使DMS在冰芯顶部聚集产生DMS高值。因为海冰底部较高生物量的海冰融化进入水体,所观测的剩余海冰底部Chl a、DMSP+DMS值均较低。在海冰的融化过程中,卤道内的卤水可发生垂向运输,致使冰芯中Chl a、DMSP+DMS的垂直分布有所不同。冰芯的Chl a、DMSP+DMS总量分别为6.79和10.20、51.83和88.41μmol·m-2,与前人研究结果比较,在海冰融化过程中,海冰中Chl a、DMSP+DMS总量变化的总趋势是递减的。     

“北斗二号”导航定位系统与GPS伪距单点定位性能对比研究

对GPS系统、北斗二号系统以及GPS/北斗组合系统伪距单点定位的关键技术进行研究,分析了3种导航系统的DOP值。单一系统随卫星高度角的增加,DOP值增大,定位精度下降。GPS伪距单点定位的精度达到2 m,北斗伪距单点定位的精度在5 m以内,GPS/北斗联合定位的精度和GPS相差不大。     

煤层气钻井中煤储层的保护措施

煤层作为煤层气的生成层和储集层,在储层特征和储存方式等方面与常规油气储层具有不同的特点,决定了煤层气钻井、完井、储层保护及压裂等技术的特殊性。在钻井中,选用欠平衡钻井技术、空气潜孔锤钻井技术;使用低密度、低粘度、低失水量、中性pH值及低（无）固相含量的钻井液;采用低密度、低上返的固井技术。这不仅对煤储层具有一定的适应性,也保护了煤储层的渗透性。     

CHZ-Ⅱ海空重力仪格值标定

详细介绍了倾斜法标定格值,并利用自主研发的CHZ-Ⅱ海空重力仪进行格值标定实验,得到格值最终的加权平均值。     

长白山天池火山热(温)泉观测与研究

火山热 (温 )泉的观测与研究 ,对掌握休眠火山的活动状态、评估其潜在喷发危险性及火山喷发预测预报具有重要意义。延边朝鲜族自治州地震局于 1985年开始对长白山天池火山热 (温 )泉进行勘查、观测与分析研究。观测与研究结果表明长白山天池火山热 (温 )泉的温度和气体有较明显的变化 ,该区深部岩浆源目前可能处在不稳定时期 ;长白山火山热 (温 )泉水受较大断裂带的控制 ,与热 (温 )泉有关的断裂有EW向断裂带和近SN向断裂带     

四川大槽地区铂、钯地球化学异常源的示踪与镍矿体的发现

通过对四川大槽地区水系沉积物铂、钯异常源的示踪和查证,发现镍矿体中伴生的铂钯是水系沉积物中的铂钯源,通过土壤测量和岩石剖面测量,发现一镍矿体,平均镍含量为0.23%,铂 钯矿的最高品位0.4g/t,地表矿体已控制规模为130m宽,325m长,显示该地区具有较大的找矿远景。     

黄河口及其附近海域沉积物中可提取的铅和镍

讨论了黄河口及其附近海域沉积物中１ｍｏｌ盐酸可提取铅与镍的含量范围为铅７．９２～２８．８６ｍｇ／ｋｇ，镍４．５１～１４．７１ｍｇ／ｋｇ，与典型性的五步形态提取地前四部分之和具有可比性。同时Ｉｍｏｌ盐酸提取的铅、镍与可提取锰、铁及沉积物的外比表面积具有很好的正相关。通过进一步的多元回归分析可以发现黄河口及其附近海域沉积物可提取铅主要结合在氧化锰及粘土矿的外表面上，而和铁的关系不明显，可提取镍与铁，锰     

地球赤道上空地月距离的4.425a周期与厄尔尼诺、地球自转、海面变化及地裂缝的关系

文中论述了在地球赤道上空,地月距离存在4.425a 的变化周期,是由于月近地点在8.85a的周期性运移中,每到黄径0°和180°(赤道线上)在地球自转的背景下使地月距效果相同所致。而每年的地近日点(1月3日或4日)正置圣诞节过后几天,因此,日、月、地相对运动每隔4.425a 在圣诞节前后三者距离总会达到最近。本文计算了1910～1991年圣诞节前后赤道上空地月距离的变化,发现日、月、地最近时与厄尔尼诺、地球自转、海平面变化,地裂缝等自然现象的发生存在着统计上可以认可的相关性。     

Distribution of Trace Bioelements in the Subarctic North Pacific Ocean and the Bering Sea (the R/V Hakuho Maru Cruise KH-97-2)

A column concentration-high resolution inductively coupled plasma mass spectrometry (ICP-MS) determination was applied to measure the total dissolved concentrations of Fe, Co, Ni, Cu and Zn in seawater collected from the subarctic North Pacific (~45°N) and the Bering Sea in July–September 1997. Total adsorbable Mn was determined on board by column electrolysis preconcentration and chemiluminescence detection. The vertical profiles for Fe, Ni and Zn were nutrient-like. The deep water concentration of Fe was ~0.5 nM in the northeast Pacific (18°-140°W) and increased to ~1 nM in the northwest Pacific (161°E) and ~2 nM in the Bering Sea (57°N, 180°E). The deep water concentrations for Ni and Zn in the Bering Sea were also 1.3–2 times higher than in the North Pacific. The profiles for Co and Cu were examined in the subarctic North Pacific, and results obtained were consistent with previous reports. There was a significant correlation between the concentrations of Co and Mn except for surface mixed layer. The profiles for total adsorbable Mn were similar to the reported profiles for total dissolvable Mn. The deep water concentration of Mn in the Bering Sea was also 4 times higher than in the North Pacific. Iron and zinc were depleted in surface water of the subarctic North Pacific. The relationship between these trace elements and nutrients suggests that these elements could be a limiting factor of phytoplankton productivity. In the Bering Sea, surface water contained ~0.3 nM of Fe. The Zn concentration, which was less than the detection limit in surface water, increased at shallower depths (~30 m) compared with the subarctic North Pacific. These results imply a higher flux of Fe and Zn to surface water in the Bering Sea. This in turn may cause the ecosystem in the Bering Sea characterized by a dominance of diatoms and high regenerated production.