A10/35绝对重力仪测试及性能分析

A10型绝对重力仪用于测量重力加速度(g),具有高精度、便携式和易操作等优点。介绍了A10的基本原理,并与FG5型重力仪进行了对比分析。基于A10/35绝对重力仪的室内和野外测量数据,分析了该仪器的稳定性和影响测量精度的主要因素。测试结果表明,不同环境下该仪器测量组间离散度均小于10×10-8ms-2,仪器性能稳定可靠。最后提出了实际使用的具体建议。     

新型绝对重力仪在海洋重力基点测量中的应用

利用自主研发的激光干涉绝对重力仪对广州海洋地质调查局海洋地质码头的三个重力基点进行绝对重力测量。通过对测量结果的分析处理和筛选,确定了各个基点的绝对重力值。测量结果表明,该方法具有快捷、高效和测量精度高的显著优势,是一次非常有意义的技术方法探索。可认为通过进一步的技术性能完善和方法改进,绝对重力测量技术将成为海洋重力测量中一种常规的基点测量手段。     

System Ⅱ型海洋重力仪静态观测结果与分析

根据青岛海洋地质研究所新购置System II型海洋重力仪的静态观测实验,分析了重力数据的变化情况,检测到该仪器单日记录数值较为稳定,但伴随有小于±0.1mGal左右的震荡。同时分析了该设备对固体潮的反映,静态观测重力值所展现的变化特征和周期性与固体潮相一致。鉴于其能明显反应固体潮对静态观测重力值的影响,可认为其静态观测精度优于0.2mGal。并测定了重力仪月漂值小于国家标准3mGal/月。同时比较讨论了与KSS31M型重力仪在中科院海洋研究所的静态观测数据的区别与联系。     

基于CMIP5模式与Argo观测数据的海洋有效重力势能分析

有效重力势能作为重力势能中活跃的部分,能够参与海洋能量循环。本文计算和评估了CMIP5中9个模式的全球大洋2 000 m以上积分的有效重力势能和200～500 m深度范围内的中尺度有效重力势能,并与由BOA_Argo观测数据计算的结果进行比较。分析表明,就全球大洋2 000 m以上积分的有效重力势能而言,多数模式的计算结果均大于由Argo观测数据计算的结果。通过比较有效重力势能的空间分布特征,发现在强动力活跃区（特别是黑潮、湾流、南极绕极流区）,模式与观测相差较大,其差别主要来源于观测与模式中扰动密度的差异。此外,在黑潮和南大洋区域,涡动能和有效重力势能具有较高的时间相关性,而在北大西洋湾流区域,两者的相关性较低;功率谱分析显示中尺度有效重力势能与涡动能都存在显著的半年和年变化周期。     

东南沿海前汛期与后汛期降水的比较分析

本文通过对东南沿海前汛期降水与后汛期降水的多年气候变化及500hPa环流场和北太平洋海温场对比分析发现:前汛期降水与后汛期降水在年代际变化上差异明显。前汛期降水逐年变化幅度小,大旱、大涝年少;后汛期降水逐年变化幅度大,大旱、大涝年多。前汛期降水与后汛期降水的大旱、大涝年环流形势场和海温场均存在明显差异。在与北半球500hPa高度场和北太平洋海温场的相关分布上,表现出基本相反的分布类型。计算分析还发现,前期8～9月和冬季1～2月北半球副高,尤其是太平洋副高与前汛期降水相关尚好。前期1月赤道洋流区中部海域的海温,对前汛期降水均有较好的预测指示意义。前期2月北大西洋涛动和黑潮区以东至太平洋中部海域的海温对后汛期降水具有较好的预测指示意义。     

Winds and Waves in the Yellow and East China Seas: A Comparison of Spaceborne Altimeter Measurements and Model Results

Wind speed and wave height measured by satellite altimeters represent a good data source to the study of global and regional wind and wave conditions. In this paper, the TOPEX altimeter wind and wave measurements in the Yellow and East China Seas are analyzed. The results provide a glimpse on the statistical properties and the spatial distributions of the regional wind and wave conditions. These data are excellent for use in the validation and verification of numerical simulations on global and regional scales. The altimeter measurements are compared with model output of temporal statistics and spatial distributions. The results show that the model simulations are in good agreement with TOPEX measurements in terms of the local mean and standard deviation of the variables (wave height and wind speed). For the comparison of spatial distributions, the quality of agreement between numerical simulations and altimeter measurements varies significantly from cycle to cycle of altimeter passes. In many cases, trends in the spatial distributions of wave heights and wind speeds between simulations and measurements are opposite. The statistics of biases, rms differences, linear regression coefficients and correlation coefficients are presented. A rather large percentage (∼50%) of cases show poor agreement based on a combination of low correlation, large rms difference or bias, and poor regression coefficient. There are indications that wave age is a factor affecting the performance of wave modeling skills. Generally speaking, the error statistics in the wave field is correlated to the corresponding error statistics in the wind field under the condition of active wind-wave generation. The error statistics between the wave field and the wind field become less correlated for large wave ages. This revised version was published online in August 2006 with corrections to the Cover Date.     

CMIP5模式对中国近海海表温度的模拟及预估

基于观测和再分析资料;利用多种指标和方法评估了国际耦合模式比较计划（CMIP5）中21个模式对中国近海海温的月、季节和年际变化模拟能力。多模式集合能够再现气候平均意义下近海海温的空间分布特征;但量值上存在一定的低估。在渤海和黄海;集合平均与观测差别比较明显。在年际尺度上;与观测数据对比;模式模拟海温与Niño3指数相关性较小。中国近海海表面温度在1960-2002年有明显的升高趋势;从2003年开始增温趋缓。评估结果表明;ACCESS1.0、BCC-CSM1.1、HadGEM2-ES、IPSL-CM5A-MR、CMCC-CM、FGOALS-g2、CNRM-CM5-2、INMCM4八个模式对中国近海海温的变化有较好的模拟能力。利用ACCESS1.0、INMCM4、BCC-CSM1.1、IPSL-CM5A-MR、CMCC-CM这5个模式结果对中国近海海温未来的变化进行了预估。在RCP4.5、RCP8.5情景下;未来近100年中国近海海温有明显升高趋势;最优模式多模式集合平均增温分别可达到1.5℃、3.3℃;净热通量变化和平流变化共同促进了东海升温。     

CMPI5多模式对南海上层海洋热含量的模拟比较

Seventeen models participating in the Coupled Model Intercomparison Project phase 5（CMIP5） activity are compared on their historical simulation of the South China Sea（SCS） ocean heat content（OHC） in the upper 300 m. Ishii＇s temperature data, based on the World Ocean Database 2005（WOD05） and World Ocean Atlas 2005（WOA05）, is used to assess the model performance by comparing the spatial patterns of seasonal OHC anomaly（OHCa） climatology, OHC climatology, monthly OHCa climatology, and interannual variability of OHCa. The spatial patterns in Ishii＇s data set show that the seasonal SCS OHCa climatology, both in winter and summer, is strongly affected by the wind stress and the current circulations in the SCS and its neighboring areas. However, the CMIP5 models present rather different spatial patterns and only a few models properly capture the dominant features in Ishii＇s pattern. Among them, GFDL-ESM2 G is of the best performance. The SCS OHC climatology in the upper 300 m varies greatly in different models. Most of them are much greater than those calculated from Ishii＇s data. However, the monthly OHCa climatology in each of the 17 CMIP5 models yields similar variation and magnitude as that in Ishii＇s. As for the interannual variability, the standard deviations of the OHCa time series in most of the models are somewhat larger than those in Ishii＇s. The correlation between the interannual time series of Ishii＇s OHCa and that from each of the 17 models is not satisfactory. Among them, BCC-CSM1.1 has the highest correlation to Ishii＇s, with a coefficient of about 0.6.     

南海东北部基于标准经验算法的遥感叶绿素a反演结果比较分析

比较了2000年夏季邻近珠江口的南海东北部海区海洋水色传感器SeaWiFS遥感与走航叶绿素a(Chla)的分布,着重对比在运用Ruddick的浑浊水体大气校正方法的条件下OC2,OC4和OCTSC的3种标准经验算法反演的SeaWiFS遥感Chla与实测Chla偏离的相对程度。结果表明,3种产品都能够反映Chla从近岸向远岸降低的空间分布特征,但从近岸到远岸划分3个子区域分别对遥感与走航Chla求均值比较的结果表明。OC4产品偏离实测Chla分布的程度明显小于其他2种产品。此外3种产品的Chla频率分布差异显著。这一结果可以为选择适用于该海域海洋环境变动研究的SeaWiFS Chla标准产品提供参考。     

CMIP5模式对南海SST的模拟和预估

分析了32个CMIP5模式对南海历史海表温度(SST)的模拟能力和不同排放情景下未来SST变化的预估。通过检验各气候模式对南海历史SST增温趋势和均方差的模拟,发现大部分模式都能较好地模拟出南海20世纪历史SST的基本特征和变化规律,但也有部分模式的模拟存在较大偏差。尽管这些模拟偏差较大的模式对SST多模式集合平均的影响不大,但会增加未来情景预估的不确定性。剔除15个模式后,分析了南海SST在RCP26、RCP45和RCP85三种排放情景下的变化趋势,发现在未来百年呈明显的增温趋势,多模式集合平均的增温趋势分别为0.42、1.50和3.30℃/(100a)。这些增温趋势在空间上变化不大,但随时间并不是均匀变化的。在前两种排放情景下,21世纪前期的增温趋势明显强于后期,而在RCP85情景下,21世纪后期的增温趋势强于前期。     

BCC_CSM对北极海冰的模拟:CMIP5和CMIP6历史试验比较

本文利用北京气候中心气候系统模式(BCC_CSM)在最近两个耦合模式比较计划(CMIP5和CMIP6)的历史试验模拟结果,对北极海冰范围和冰厚的模拟性能进行了比较,结果表明:(1) CMIP6改善了CMIP5模拟海冰范围季节变化过大的问题,总体上更接近观测结果;(2)两个CMIP试验阶段中BCC_CSM模拟的海冰厚度都偏小,但CMIP6试验对夏季海冰厚度过薄问题有所改进。通过对影响海冰生消过程的冰面和冰底热收支的分析,我们探讨了上述模拟偏差以及CMIP6模拟结果改善的成因。分析表明,8?9月海洋热通量、向下短波辐射和反照率对模拟结果的误差影响较大,CMIP6试验在这些方面有较大改善;而12月至翌年2月,CMIP5模拟的北极海冰范围偏大主要是海洋热通量偏低所导致,CMIP6模拟的海洋热通量较CMIP5大,但北大西洋表层海流的改善才是巴芬湾附近海冰外缘线位置改善的主要原因。CMIP试验模拟的夏季海冰厚度偏薄主要是因为6?8月海洋热通量和冰面热收支都偏大,而CMIP6试验模拟的夏季海冰厚度有所改善主要是由于海洋热通量和净短波辐射的改善。海冰模拟结果的改善与CMIP6海冰模块和大气模块参数化的改进有直接和间接的关系,通过改变短波辐射、冰面反照率和海洋热通量,使BCC_CSM模式对北极海冰的模拟性能也得到有效提高。     

南海北部陆缘OBS2018-H2测线地壳结构初步结果

南海北部陆缘洋陆转换带实施的OBS2018-H2测线的地壳速度结构, 将为探讨南海张裂-破裂机制提供重要证据。文章介绍了OBS2018-H2测线前期数据处理流程, 包括多道反射地震数据处理、海底地震仪OBS (Ocean Bottom Seismometer)数据格式转换、炮点和OBS位置校正, 以及OBS震相的初步识别, 并对地壳结构进行了初步分析。结果表明: 炮点和OBS位置校正效果良好; 多道反射地震数据为建立初始速度模型提供了良好约束; OBS综合地震剖面识别了多组清晰的P波震相, 包括Pw、Pg、PmP和Pn震相。根据测线西侧OBS36、OBS37两台站的震相分布特征初步估算台站下方地壳厚度约为6~7km, 与根据多道地震剖面LW3的双程走时估算的厚度6~9km大致相符。     

南海北部白云深水区东北部小型峡谷内的块体搬运

The process of mass movements and their consequent turbidity currents in large submarine canyons has been widely reported, however, little attention was paid to that in small canyons. In this paper, we document mass movements in small submarine canyons in the northeast of Baiyun deepwater area, north of the South China Sea(SCS), and their strong effects on the evolution of the canyons based on geophysical data. Submarine canyons in the study area arrange closely below the shelf break zone which was at the depth of –500 m. Within submarine canyons, seabed surface was covered with amounts of failure scars resulted from past small-sized landslides. A complex process of mass transportation in the canyons is indicated by three directions of mass movements.Recent mass movement deposits in the canyons exhibit translucent reflections or parallel reflections which represent the brittle deformation and the plastic deformation, respectively. The area of most landslides in the canyons is less than 3 km2. The trigger mechanisms for mass movements in the study area are gravitational overloading, slope angle and weak properties of soil. Geophysical data indicate that the genesis of submarine canyons is the erosion of mass movements and consequent turbidity currents. The significant effects of mass movements on canyon are incision and sediment transportation at the erosion phases and fillings supply at the fill phases. This research will be helpful for the geological risk assessments and understanding the sediment transportation in the northern margin of the SCS.     

禽流感病毒抗原表位分析及H5N1亚型基因工程疫苗设计

以亚洲地区H5N1亚型禽流感病毒(Avian Influenze Virus)流行株为研究对象,利用计算机软件,对同源性较高的HA1(Hemagglutnin,HA,血凝素)和NP(Nucleocapsid protein,核衣壳蛋白)进行全基因序列分析,优选出HA1蛋白的主要T细胞表位和B细胞表位,以及NP蛋白的主要CTL(Cytotoxicity T lymphocyte,细胞毒性T淋巴细胞)表位.依据这些优选表位,设计了禽流感病毒H5N1亚型基因工程疫苗.构建了基因工程疫苗表达载体pRSET-AIV,外源基因能够在大肠杆菌表达系统中得到良好表达.表达产物免疫小鼠后,血清中IgA和IgG抗体水平明显上升,在体外培养脾细胞可产生IL-2、IL-4和IFN-γ细胞因子.验证了该H5N1亚型基因工程疫苗的抗原性,证实该基因工程疫苗在免疫小鼠体内激发体液免疫的同时调动了细胞免疫.