Global Statistical Assessment and Cross-Calibration with Jason-2 for Reprocessed HY-2 A Altimeter Data     

Maofei Jiang  Ke Xu  Yalong Liu 《Marine Geodesy》2018,41(3):289-312

HY-2 A (Haiyang-2 A) satellite was launched on August 16, 2011 and radar altimeter is one of its main payloads. We reprocessed two years of HY-2 A altimeter sensor geophysical dataset records (SGDR) data. This paper presents the main results in terms of reprocessed HY-2 A altimeter data quality: verification of data availability and validity, monitoring several relevant altimeter parameters, and assessment of the HY-2 A altimeter system performances. A cross-calibration analysis of reprocessed HY-2 A altimeter data with Jason-2 was conducted. The reprocessed HY-2 A altimeter data show good quality and have a low level of noise with respect to Jason-2. The same geophysical correction methods were used to calculate the sea surface height (SSH) for the two missions. The mean standard deviations of the crossover differences for HY-2 A and Jason-2 are 5.24 cm and 5.34 cm, respectively. The mean standard deviation of the crossover differences between HY-2 A and Jason-2 is 5.37 cm. These show that HY-2 A can provide SSH measurements at almost the same level of accuracy as Jason-2. The relative SSH bias between HY-2 A and Jason-2 due to the Ultra Stable Oscillator (USO) drift is obviously observed, and it can affect the calculation of mean sea level and should be further studied and corrected.  相似文献   

Prediction of the South China Sea Dipole Using SSA-MEM     

Qiong Xia  Enbo Wei 《大气与海洋》2018,56(4):240-253

ABSTRACT

A dipole structure appears in the sea surface height off the central coast of Vietnam during boreal summer in the South China Sea. This dipole, which possesses a chlorophyll signature associated with higher phytoplankton concentrations arising from nutrient upwelling, is important for the productivity of local fisheries. Multi-satellite sea level anomalies are used to investigate the life cycle of the dipole structure. By applying empirical orthogonal function (EOF) analysis, the third EOF mode (EOF 3) is found to represent the major variations of the dipole structure. By removing the temporal noise of EOF 3, a South China Sea dipole index is defined. This index captures the life cycle of the dipole including its generation, mature strength, and final termination. Both one-dimensional and two-dimensional forecasts are generated using a statistical forecasting method that combines singular-spectrum analysis and the maximum entropy method. The appearance of the dipole structure can be predicted with an accuracy of 78% at one-month lead times and an accuracy of 61% at one-year lead times.  相似文献   

黔北正安地区五峰组—龙马溪组页岩气地质特征及有利区预测     

贺永忠  向坤鹏  安亚运  易成兴  杨忠琴  于宁 《中国地质调查》2020,7(3):21-29

为明确黔北正安地区上奥陶统五峰组至下志留统龙马溪组的页岩气地质特征,充分应用页岩气地质调查、重磁电、二维地震、地质调查井及测试分析等工作方法,开展黔北正安地区1:5万页岩气基础地质调查,对五峰组至龙马溪组富有机质页岩的分布、沉积环境、有机地球化学、岩石矿物、储集性能及含气性等特征进行分析研究,结果表明: 研究区五峰组—龙马溪组富有机质页岩为深水陆棚相沉积,主要分布有安场向斜、斑竹向斜和泥高向斜,厚度14.5~55 m,埋深0~3 200 m; 有机碳(TOC)含量1.0%~4.0%,有机质镜质体反射率(R_o)为1.82%~2.23%,有机质类型以Ⅰ型干酪根为主; 岩石主要由石英、长石和黏土矿物组成,脆性矿物含量高,一般大于50%; 孔隙度为2.03%~3.89%,渗透率为0.35×10^-5~1.86×10^-5μm²,表现为低孔、特低渗的特征; 最高含气量为2.88 m³/t,显示出较好的含气性特征。综合分析和评价圈出3个页岩气聚集有利区,分别为安场区块、斑竹区块和泥高区块,这为研究区页岩气进一步勘探开发指明了方向。  相似文献   

Coupling relationship between reservoir diagenesis and hydrocarbon accumulation in Lower Cretaceous Yingcheng Formation of Dongling,Changling fault depression,Songliao Basin,Northeast China     

《China Geology》2020,3(2):247-261

The Lower Cretaceous Yingcheng Formation in the southern Songliao Basin is the typical tight oil sandstone in China. In order to better predict the petrophysical properties of the tight sandstone reservoirs in the Lower Cretaceous Yingcheng Formation, Songliao Basin, Northeast China, the diagenesis and porosity evolution was investigated using a suite of petrographic and geochemical techniques including thin section analysis, scanning electron microscopy, mercury intrusion and fluid inclusion analysis, on a set of selected tight sandstone samples. Combined with the histories of burial evolution, organic matter thermal evolution and hydrocarbon charge, the matching relationship between reservoir porosity evolution and hydrocarbon accumulation history is analyzed. The result showed that the tight sandstone reservoirs characterized of being controlled by deposition, predominated by compaction, improved by dissolution and enhanced by cementation. The hydrocarbon accumulation period was investigated using a suite of hydrocarbon generation and expulsion history, microfluorescence determination and temperature measurement technology. According to the homogenization temperature of the inclusions and the history of burial evolution, Yingcheng Formation has mainly two phases hydrocarbon accumulation. The first phase of oil and gas is charged before the reservoir is tightened, the oil and gas generated by Shahezi source rocks enter the sand body of Yingcheng Formation, influenced by the carrying capability of sand conducting layer, oil and gas is mainly conducted by the better properties and higher connectivity sand body and enriched in the east, which belongs to the type of densification after hydrocarbon accumulation. The second phase of oil and gas charge after densification, which belongs to the type of densification before the hydrocarbon accumulation.  相似文献   

安徽黄梅尖地区基性岩脉K-Ar年代学、地球化学特征及地质意义          下载免费PDF全文

杨彪  王正其  肖金根  曹达旺 《华东地质》2020,(1):27-35

在野外地质调查和室内综合研究的基础上,通过对黄梅尖地区辉绿玢岩K-Ar年代学、地球化学和Sr-Nd同位素特征进行研究,探讨辉绿玢岩的形成时代、岩石成因及构造背景。K-Ar年代学研究表明,辉绿玢岩形成于~107 Ma,是早白垩世岩浆活动的产物,形成时代晚于该地区火山岩和侵入岩,与该地区铀成矿年龄基本一致;辉绿玢岩的侵入可能是该地区岩浆作用的最后一幕,铀成矿可能与辉绿玢岩具有成因联系。地球化学特征表明,辉绿玢岩富集大离子亲石元素K、Rb、U、Pb和轻稀土元素,亏损高场强元素Nb、Ta、P、Ti,具有较高的Isr值和负εNd(t)值,具有富集地幔源区特征;辉绿玢岩是在地壳伸展和岩石圈减薄的构造背景下,由俯冲交代作用形成的富集地幔部分熔融形成的,表明~107 Ma时该地区仍处于伸展构造环境下。  相似文献   

Evaluation of clayed silt properties on the behavior of hydrate production in South China Sea     

《China Geology》2020,3(3):362-368

Gas hydrate is one kind of potential energy resources that is buried under deep seafloor or frozen areas. The first trial offshore production from the silty reservoir was conducted in the South China Sea by the China Geological Survey (CGS). During this test, there were many unique characteristics different from the sand reservoir, which was believed to be related to the clayed silt physical properties. In this paper, simulation experiments, facilities analysis, and theoretical calculation were used to confirm the hydrate structure, reservoir thermo-physical property, and bond water movement rule. And the behavior of how they affected production efficiency was analyzed. The results showed that: It was reasonable to use the structure I rather than structure II methane hydrate phase equilibrium data to make the production plan; the dissociation heat absorbed by hydrate was large enough to cause hydrate self-protection or reformation depend on the reservoir thermal transfer and gas supply; clayed silt got better thermal conductivity compared to coarse grain, but poor thermal convection especially with hydrate; clayed silt sediment was easy to bond water, but the irreducible water can be exchanged to free water under high production pressure, and the most obvious pressure range of water increment was 1.9–4.9 MPa.  相似文献   

浮力装置触发深海管道水平向整体屈曲效果的数值模拟研究     

曹洋  张淑华  孙林 《海洋通报》2019,38(6):719-726

海洋油气资源的运输主要通过海底管道进行,管道在工作时受到较大的温度荷载,会产生整体屈曲变形。深海管道设计中常采用人为装置触发一定程度的水平向整体屈曲变形,来释放轴向的温度应力,浮力装置是常用的触发方式之一。本文通过数值模拟研究,分析了不同浮力大小和不同浮力施加范围下,管道水平向整体屈曲的临界屈曲力,得出临界屈曲力随浮力大小和施加范围变化的情况;并研究了不同土体阻力下,浮力装置触发整体屈曲的效果。研究表明,水平向土体阻力较大时,浮力装置触发水平向整体屈曲的效果较好。浮力装置的触发效果对轴向土体阻力不敏感。  相似文献   

近20年渤海叶绿素a浓度时空变化   总被引：3，自引：0，他引：3  

田洪阵  刘沁萍  Joaquim I. Goes  Helga do Rosario Gomes  杨萌萌 《海洋学报》2019,41(8):131-140

浮游植物作为食物链的基础，对海洋生态系统具有重要作用。渤海作为我国最大的内海和重要渔业生物的产卵场、育幼场和索饵场，该区浮游植物研究具有重要意义。叶绿素a浓度是反映浮游植物生物量的重要指标。利用Google Earth Engine平台，对1997–2010年的宽视场海洋观测传感器(SeaWiFS)叶绿素a浓度数据和2002–2018年的水色卫星中分辨率成像光谱仪传感器(MODIS Aqua)叶绿素a浓度数据进行合并，并研究其时空变化特征。研究表明，近20年来，渤海全年叶绿素a浓度增加了14.1%，且增加显著。叶绿素a浓度在所有季节都呈现增加趋势；除11月外，其他各月都呈现稳定或增加趋势。从滦河入河口沿岸至渤海海峡的渤海中部，叶绿素a浓度增加较明显。同时也分析了海洋表面温度、风速和降水量数据。夏季渤海周边区域降水量和风速增加以及秋季海表温度的降低都有助于同季叶绿素a浓度的升高。渤海浮游植物可能受陆源营养物质输入影响较大。  相似文献   

LED光色对欧洲舌齿鲈幼鱼抗氧化能力和消化能力的影响   总被引：1，自引：0，他引：1  

代明允  任纪龙  费凡  魏平平  马贺  高东奎  宋昌斌  喻胜  刘鹰 《海洋科学》2019,43(4):16-21

作者利用循环水养殖实验系统,研究了红、绿、白、黄、蓝5种光色对欧洲舌齿鲈(Dicentrarchus labrax)幼鱼抗氧化能力和消化能力的影响。结果表明,红光组的欧洲舌齿鲈幼鱼超氧化物歧化酶(SOD)活力显著高于其他光色组(P0.05),而绿、白、黄和蓝光色组的SOD活力没有显著性差异;红光组的还原型谷胱甘肽(GSH)含量显著高于其他光色组(P0.05),绿、白光组与黄、蓝光组的GSH含量之间有显著性差异(P0.05);红光组过氧化氢酶(CAT)活力显著高于其他光色组(P0.05),白光组的CAT活力显著低于其他光色组(P0.05)。黄光组的胃蛋白酶活力显著高于红、绿、白光组(P0.05),绿光组的胃蛋白酶活力显著低于其他光色组(P0.05);红、绿、蓝光组的淀粉酶活力要显著高于白、黄光组(P0.05),红、绿、蓝光组的淀粉酶活力没有显著性差异,黄、白光组的淀粉酶活力没有显著性差异;白光组纤维素酶活力显著高于其他光色组(P0.05),绿光组的纤维素酶活力显著高于红、蓝光组(P0.05),黄光组的纤维素酶活力和绿、红、蓝光组没有显著性差异。因此,欧洲舌齿鲈在红光下养殖,其体内的抗氧化能力强,能有效应对氧化应激,而在黄光或红光下养殖其消化能力更强。  相似文献   

多时相Landsat影像的平原河网区不透水面信息提取方法与应用     

周峰  廖钰冰  李娜 《测绘通报》2020,(1):94

不透水面是衡量城市生态环境的重要指标，针对平原河网区不透水面与水体、裸土等地物较难区分的问题，以苏北里下河平原快速城镇化区为研究对象，利用多时相Landsat影像为数据源，基于像元光谱特征及其季节性变化分析，构建了基于时序NDWI、NDVI和NDBI的决策树模型，并利用GIS空间分析技术对不透水面的时空变化特征进行了分析。结果表明：多时相光谱信息可有效改善水体、裸土和稀疏植被等像元与不透水面的混分，2005年和2016年的不透水面分类总体精度和Kappa系数均在0.85以上，合理反映了不透水面以向东和向南扩张为主的趋势特征，年均扩张速度约为6.7 km²。研究成果为该区城镇化下的生态环境效应研究提供数据基础，同时可为其他平原河网区不透水面信息提供借鉴和参考。  相似文献