Connections between the Eurasian teleconnection and concurrent variation of upper-level jets over East Asia

The variation of the East Asian jet stream(EAJS) associated with the Eurasian(EU) teleconnection pattern is investigated using 60-yr NCEP–NCAR daily reanalysis data over the period 1951–2010. The EAJS consists of three components: the polar front jet(PFJ); the plateau subtropical jet(PSJ); and the ocean subtropical jet(OSJ). Of these three jets over East Asia,the EU pattern exhibits a significant influence on the PFJ and OSJ. There is a simultaneous negative correlation between the EU pattern and the PFJ. A significant positive correlation is found between the EU pattern and the OSJ when the EU pattern leads the OSJ by about 5 days. There is no obvious correlation between the EU pattern and the PSJ. The positive EU phase is accompanied by a weakened and poleward-shifted PFJ, which coincides with an intensified OSJ. A possible mechanism for the variation of the EAJS during different EU phases is explored via analyzing the effects of 10-day high-and low-frequency eddy forcing. The zonal wind tendency due to high-frequency eddy forcing contributes to the simultaneous negative correlation between the EU pattern and the PFJ, as well as the northward/southward shift of the PFJ. High- and low-frequency eddy forcing are both responsible for the positive correlation between the EU pattern and the OSJ, but only high-frequency eddy forcing contributes to the lagged variation of the OSJ relative to the EU pattern. The negative correlation between the EU pattern and winter temperature and precipitation anomalies in China is maintained only when the PFJ and OSJ are out of phase with each other. Thus, the EAJS plays an important role in transmitting the EU signal to winter temperature and precipitation anomalies in China.     

Evaluation of CMIP5 Climate Models in Simulating 1979–2005 Oceanic Latent Heat Flux over the Pacific

The climatological mean state,seasonal variation and long-term upward trend of 1979–2005 latent heat flux(LHF) in historical runs of 14 coupled general circulation models from CMIP5(Coupled Model Intercomparison Project Phase 5) are evaluated against OAFlux(Objectively Analyzed air–sea Fluxes) data. Inter-model diversity of these models in simulating the annual mean climatological LHF is discussed. Results show that the models can capture the climatological LHF fairly well,but the amplitudes are generally overestimated. Model-simulated seasonal variations of LHF match well with observations with overestimated amplitudes. The possible origins of these biases are wind speed biases in the CMIP5 models. Inter-model diversity analysis shows that the overall stronger or weaker LHF over the tropical and subtropical Pacific region,and the meridional variability of LHF,are the two most notable diversities of the CMIP5 models. Regression analysis indicates that the inter-model diversity may come from the diversity of simulated SST and near-surface atmospheric specific humidity.Comparing the observed long-term upward trend,the trends of LHF and wind speed are largely underestimated,while trends of SST and air specific humidity are grossly overestimated,which may be the origins of the model biases in reproducing the trend of LHF.     

基于检查算子地形图内业质量检查系统的实现

随着数字地形图产品内容和数据日益多样化,如何严格把控地形图产品的质量成为质检部门不断深入探讨的问题.本系统以内业质检为目标,设计与研发了地形图内业质量检查系统.该系统采用自动检查算子库与可定制化检查方案相结合的手段进行自动化检查,通过实际应用推广发现,利用该系统可大幅提高数字化地形图的质检效率及可靠性,在地形图质量检查方面具有较高的研究价值.     

南北两极北斗二号三频数据质量对比分析

南北两极地区是人类最后的资源宝库,加强对两极地区的考察是非常重要的.针对南北两极地区北斗二号三频数据质量评估问题,本文以两极地区IGS连续跟踪站北斗二号三频数据为基础,对比分析了两极地区北斗二号卫星可见数、DOP值、数据完整率、信噪比以及多路径.经研究发现,低纬度地区卫星可见数多于南极地区,南极地区多于北极地区,低纬度地区的DOP值小于南极地区,南极地区小于北极;在数据完整率方面,3个频率对应相同类型卫星相当,低纬度高于南极,南极高于北极,GEO最优,其次为IGSO、MEO最低;在信噪比方面,低纬度高于南极,南极高于北极;在多路径方面,南极整体低于低纬度,低纬度低于北极.     

河北承德甲山正长岩成因的Sr-Nd-Pb-Hf同位素制约

报道了华北克拉通北缘承德地区甲山正长岩的锆石U-Pb年龄及Hf同位素、主微量元素、Sr-Nd-Pb同位素组成。甲山岩体的LA-ICP-MS锆石U-Pb年龄为111~108 Ma,代表岩体的结晶年龄,表明其侵位于早白垩世晚期。岩体高Si O2、K2O+Na2O、Al2O3、LILEs(Rb、K)和LREE,低Fe2O3T、Ca O、Ti O2、Mg O和HFSE,具有板内裂谷岩浆岩的特征,属A型花岗岩。甲山岩体εNd(t)=-5.0~-0.9,tDM2(Nd)=0.98~1.31 Ga;εHf(t)=-2.7~+4.3,tDM2(Hf)=0.90~1.33 Ga;Δ8/4=84.9~91.3,Δ7/4=-6.4~-4.0,(206Pb/204Pb)i=16.63~17.10,(207Pb/204Pb)i=15.24~15.30,(208Pb/204Pb)i=36.54~37.20。根据野外地质观察、实验岩石学以及元素地球化学和Sr-Nd-PbHf同位素示踪的综合分析,认为甲山岩体可能起源于下地壳与亏损地幔的混合源区,是华北克拉通北缘岩石圈强烈减薄、地壳伸展作用的结果。早白垩世甲山岩体形成过程中亏损地幔物质的参与指示了华北克拉通北缘岩石圈减薄和软流圈地幔上涌,记录了陆内伸展环境下与软流圈底侵作用相关的岩浆事件。     

新疆哈密市红海铜金矿地质特征及成矿预测

红海铜金矿位于卡拉塔格铜金成矿带,是最近发现的VMS矿床,本文主要介绍了该矿的区域地质、矿区地质、构造及矿脉特征。通过对成矿地质特征进行分析研究,认为该区具有良好的成矿条件和找矿前景。     

Formation of the Jurassic Changboshan‐Xieniqishan highly fractionated I‐type granites,northeastern China: implication for the partial melting of juvenile crust induced by asthenospheric mantle upwelling

Zircon U–Pb ages, major and trace elements, and Sr, Nd and Hf isotope compositions of the Changboshan‐Xieniqishan (CX) intrusion from the Great Xing'an Range (GXAR), northeastern China, were studied to investigate its derivation, evolution and geodynamic significance. Laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) zircon U–Pb dating yields an emplacement age of 161 ± 2 Ma for the CX intrusion. Bulk‐rock analyses show that this intrusion is characterized by high SiO₂, Na₂O and K₂O, but low MgO, CaO and P₂O₅. They are enriched in large‐ion lithophile elements and light rare earth elements, with marked Eu anomalies (mostly from 0.36 to 0.65), and depleted in heavy rare earth elements and high field strength elements. Most samples have relatively low (⁸⁷Sr/⁸⁶Sr)_i values (0.70423–0.70457), with ε_Nd(t) fluctuating between −0.4 and 2.3. The ε_Hf(t) for zircons varies from 5.4 to 8.7. Sr–Nd isotope modelling results, in combination with young Nd and Hf model ages (760–986 and 549–728 Ma, respectively) and the presence of relict zircons, indicate that the CX intrusion may originate from the partial melting of juvenile crust, with minor contamination of recycled crustal components, and then underwent extensive fractional crystallization of K‐feldspar, plagioclase, biotite, sphene, apatite, zircon and allanite. Considering the widespread presence of granitoids with coeval volcanic rocks, we contend that the CX intrusion formed in an extensional environment related to the upwelling of asthenospheric mantle induced by the subduction of the Palaeo‐Pacific plate, rather than a lithospheric delamination model. Copyright © 2013 John Wiley & Sons, Ltd.     

Erratum to: Analysis of differences in nutrients chemistry in seamount seawaters in the Kocebu and M5 seamounts in Western Pacific Ocean

Journal of Oceanology and Limnology - Comprehensive surveys were conducted in the Kocebu deep seamount and the M4 shallow seamount in the Western Pacific Ocean in March 2018 and May 2019,...     

Identification and evaluation of desertification reversal in China: indicators and methods review

With gradual emergence of desertification reversal after inception of combative attempts in China, its evaluation which is based on solid identification is imperative. However, either identification or evaluation lacks consensus and are limited in earlier studies. This paper endeavors to fill this gap by relying on a systematic review of recent studies. After a clarification of causal relation of identification and evaluation, an argument of indicators and models selection is presented taking sustainability, cost and benefits, public interest and individual behavior into account. At first, we emphasize the logical and sequential importance of identification as prerequisite of evaluation, and demonstrate that fundamental identification could be operated by both direct and indirect implementations, though direct implementation usually seems to be a favorite al- tel＇native. Here, we emphasize a consideration of sustainable development, cost and benefits, public interest and individual behaviors together, due to the hiatus of incorporating economic and ecological segments together, and the innate theoretical deficiencies on environmental products of traditional economic and ecological methods of evaluation. Thus, we conceptually merge the economic and ecological segments into one theoretical framework. However, no matter how elaborate the models is, there is an apparent gap of both identification and evaluation due to failure of dynamic interpretations, thereby, it may be future trend and urgency on models＇ elaboration.     

基于水下光纤应变监测的导管架结构总冰力测量方法

基于测量结构水下光纤应变获取冰力的方法首次应用于渤海JZ20-2NW加锥导管架平台,该方法方便进行零点标定,可获取结构总冰力的绝对信息(包括均值和波动值)。首先介绍了JZ20-2NW平台的现场监测系统,主要包括结构水下应变响应记录冰力信息,甲板上部视频记录同步冰情(冰厚、冰速和来冰方向)信息和拾振器记录结构冰振响应;重点分析了由测点应变向结构总冰力的转化方法,并对总冰力进行了初步分析。将无量纲化实测冰力与5种典型冰力计算模型进行了比较,分析结果表明,锥体宽度与海冰厚度比值(简称"宽厚比")对冰力大小及变化起决定作用。