El Ni(n)o phenomenon in simple ocean data assimilation data     

CUI Maochang  WU Lingjuan 《海洋学报(英文版)》2005,24(4)

To study how the air and sea interact with each other during El Nino/La Nina onsets, extended associate pattern analysis (EAPA) is adopted with the simple ocean data assimilation (SODA) data. The results show that as El Nino/La Nina' s parents their behaviors are quite different, there does not exist a relatively independent tropical atmosphere but does exist a relatively independent tropical Pacific Ocean because the air is heated from the bottom surface instead of the top surface and of much stronger baroclinic instability than the sea and has a very large inter-tropical convergence zone covering the most tropical Pacific Ocean. The idea that it is the wester burst and wind convergence, coming from middle latitudes directly that produce the seawater eastward movement and meridional convergence in the upper levels and result in the typical El Nino sea surface temperature warm signal is confirmed again.  相似文献   

2004年厄尔尼诺事件的理论预测和实践检验   总被引：4，自引：1，他引：3  

林玎  杨学祥  杨冬红 《海洋预报》2005,22(3):5-10

地球自转速度减慢、赤道东太平洋表层海温升高、日食-厄尔尼诺系数增大与厄尔尼诺事件发生时间在一切细节上有惊人的对应关系。这个综合检验结果给出了地球自转减速和日食-厄尔尼诺系数预测厄尔尼诺事件的有效性和准确性。2004年的弱厄尔尼诺已得到初步证实,2005年的拉尼娜有待检验。  相似文献   

中国登陆热带气旋与太平洋海表温度的关系   总被引：16，自引：0，他引：16  

冯利华 《地理学报》2003,58(2):209-214

根据1951～2000年中国登陆热带气旋与厄尔尼诺年、拉尼娜年的关系分析,得到了一些重要认识：(1) 在厄尔尼诺年,中国登陆热带气旋数偏少;(2) 厄尔尼诺事件强度越大,中国登陆热带气旋数越少;(3) 厄尔尼诺事件的结束时间若超过5月1日,那么次年中国登陆热带气旋数偏少;(4) 中国登陆热带气旋数的特多年主要集中在拉尼娜年;(5) 在拉尼娜次年,中国登陆热带气旋数偏少;(6) 中国登陆热带气旋强度越大,在厄尔尼诺年出现机会越少;(7) 在厄尔尼诺年,中国初旋偏迟,终旋偏早。同时对其机理进行了探讨。  相似文献   

Singularly perturbed solution of coupled model in atmosphere-ocean for global climate   总被引：1，自引：1，他引：0  

Jiaqi Mo  Wantao Lin  Hui Wang 《中国地理科学(英文版)》2008,18(2):193-196

A box model of the interhemispheric thermohaline circulation （THC） in atmosphere-ocean for global climate is considered. By using the multi-scales method, the asymptotic solution of a simplified weakly nonlinear model is discussed. Firstly, by introducing first scale, the zeroth order approximate solution of the model is obtained. Secondly, by using the multi-scales, the first order approximate equation of the model is found. Finally, second order approximate equation is formed to eliminate the secular terms, and a uniformly valid asymptotic expansion of solution is decided. The multi-scales solving method is an analytic method which can be used to analyze operation sequentially. And then we can also study the diversified qualitative and quantitative behaviors for corresponding physical quantities. This paper aims at providing a valid method for solving a box model of the nonlinear equation.  相似文献   

Observations of the North Equatorial Current,Mindanao Current,and Kuroshio current system during the 2006/07 El Niño and 2007/08 La Niña   总被引：1，自引：0，他引：1  

Yuji Kashino  Norievill España  Fadli Syamsudin  Kelvin J. Richards  Tommy Jensen  Pierre Dutrieux  Akio Ishida 《Journal of Oceanography》2009,65(3):325-333

Two onboard observation campaigns were carried out in the western boundary region of the Philippine Sea in December 2006 and January 2008 during the 2006/07 El Niño and the 2007/08 La Niña to observe the North Equatorial Current (NEC), Mindanao Current (MC), and Kuroshio current system. The NEC and MC measured in late 2006 under El Niño conditions were stronger than those measured during early 2008 under La Niña conditions. The opposite was true for the current speed of the Kuroshio, which was stronger in early 2008 than in late 2006. The increase in dynamic height around 8°N, 130°E from December 2006 to January 2008 resulted in a weakening of the NEC and MC. Local wind variability in this region did not appear to contribute to changes in the current system.  相似文献   

海面温度异常时间序列的谱分析     

杜军  修延霞  罗爱军  晋海龙 《测绘信息与工程》2009,34(6):38-39

利用了傅里叶功率谱和小波功率谱分析方法,分析了太平洋中、东部地区海面温度异常时间序列的时频特征,发现了海面温度异常信号具有2~6年左右的周期特征。  相似文献   

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郭琳  刘玉光  刘雪源  吕学珠  李轶斐 《大地测量与地球动力学》2009,29(4):64-69

????1992??11???2007??5?μ???????????????????????????仯???????????????1???????24~42???μ???????Я???????????ENSO?????2??SLA_2442?????????????????????????????????????????????????????????????????3?????????У????????????SLA_2442?????????·??????O???Σ??????????????,??γ????????λ??????9.86??N??8??S??????  相似文献   

Perturbed solution of sea-air oscillator for the E1 Ni(n)o/La Ni(n)a-Southern Oscillation mechanism     

ZHOU Xianchun  LIN Yihua  WANG Hui  MO Jiaqi 《海洋学报(英文版)》2009,28(3)

A class of coupled system of the E1 Ni(n)o/La Ni(n)a-Southern Oscillation (ENSO) mechanism is studied. Using the perturbed theory, the asymptotic expansions of the solution for ENSO model are obtained and the asymptotic behavior of solution for corresponding problem is considered.  相似文献   

Emplacement of the La Peña alkaline igneous complex,Mendoza, Argentina (33° S): Implications for the early Miocene tectonic regime in the retroarc of the Andes     

《Journal of South American Earth Sciences》2014

The La Peña alkaline complex (LPC) of Miocene age (18–19 Ma) lies on the eastern front of the Precordillera (32°41ʹ34ʺS, 68°59ʹ48″W, 1400–2900 m a.s.l.), 30 km northwest of Mendoza city, Argentina. It is a subcircular massif of 19 km² and 5 km in diameter, intruded in the metasedimentary sequence of the Villavicencio Formation of Silurian-Devonian age. It is the result of integration of multiple pulses derived from one or more deep magma chambers, which form a suite of silicate rocks grouped into: a clinopyroxenite body, a central syenite facies with a large breccia zone at the contact with the clinopyroxenite, bodies of malignite, trachyte and syenite porphyry necks, and a system of radial and annular dikes of different compositions. Its subcircular geometry and dike system distribution are frequent features of intraplate plutons or plutons emplaced in post-orogenic settings. These morphostructural features characterize numerous alkaline complexes worldwide and denote the importance of magmatic pressures that cause doming with radial and annular fracturing, in a brittle country rock. However, in the LPC, the attitude of the internal fabric of plutonic and subvolcanic units and the preferential layout of dikes match the NW–SE extensional fractures widely distributed in the host rock. This feature indicates a strong tectonic control linked to the structure that facilitate space for emplacement, corresponding to the brittle shear zone parallel to the N–S stratigraphy of the country rock. Shearing produced a system of discontinuities, with a K fractal fracture pattern, given by the combination of Riedel (R), anti-Riedel (R′), (P) and extensional (T) fracture systems, responsible for the control of melt migration by the opening of various fracture branches, but particularly through the NW–SE (T) fractures. Five different pulses would have ascent, (1) an initial one from which cumulate clinopyroxenite was formed, (2) a phase of mafic composition represented by dikes cross-cutting the clinopyroxenite, (3) a malignite facies that causes a small breccia in the clinopyroxenite, (4) a central syenite facies that develops breccias at the contact with the clinopyroxenite and, finally, (5) porphyry necks and a system of radial dikes intruding all units. At the moment of the emplacement different mechanisms would have acted, they summarized in: 1) opening of discontinuities synchronous to the magma circulation as the principal mechanism for formation of dikes and conduits; 2) stoping processes, that play an important role in the development of the breccia zone and enabling an efficient transference of material during the emplacement of the syenitic magma and 3) shear-related deformation (regional stress), affected the internal fabric of the facies, causing intracrystalline deformation and submagmatic flow, which is very evident in the central syenite intrusive. The kinematic analysis of shear planes allows proposing that emplacement of the LPC took place in a transtensive regime, which would have occurred in the back-arc of the Andes orogen, during a long period spanning from Miocene to the present, of the compressive deformation responsible, westward and at the same latitude, for the development of the Aconcagua fold and thrust belt.  相似文献   

西秦岭印支期高Sr/Y花岗岩类的成因及动力学背景——以同仁地区舍哈力吉岩体为例   总被引：5，自引：4，他引：1  

黄雄飞  莫宣学  喻学惠  李小伟  杨梦楚  罗明非  和文言  于峻川 《岩石学报》2014,30(11):3255-3270

西秦岭印支期花岗岩类分布十分广泛,形成时代集中于248~234Ma和224~211Ma两个阶段.其中,夏河岩体(248~238Ma)和温泉岩体(223~216Ma)的部分样品被厘定为埃达克岩(Sr>400×10^-6,Yb<2×10^-6),指示陆壳厚度大于50km.本文对西秦岭同仁地区舍哈力吉岩体进行了锆石U-Pb定年、岩石学、地球化学和Sr-Nd同位素研究.舍哈力吉岩体主要由石英二长岩组成,同时含有许多暗色镁铁质微粒包体(MME).寄主岩中发育少量的钾长石巨晶,并且部分巨晶具有环斑结构.舍哈力吉石英二长岩化学成分比较均一,而且也显示出类似埃达克岩的一些地球化学特点,如富SiO₂(66.07%~67.52%)和Al₂O₃(14.85%~15.95%),高Sr(560×10^-6~692×10^-6),低Y(11.4×10^-6~12.9×10^-6)和Yb(0.99×10^-6~1.09×10^-6),并具有较高的(La/Yb)_N比值(27.8~34.3)和微弱的负Eu异常(δEu=0.77~0.95).锆石U-Pb测年结果为234.1±0.5Ma,表明其形成于印支早期.岩石为偏铝质、高钾钙碱性系列且K₂O/Na₂O>1,高Mg^#(59~60)、Cr(69.1×10^-6~81.2×10^-6)和Ni(31.6×10^-6~36.1×10^-6),以富集大离子亲石元素(Rb、Ba、Th、U)而相对亏损高场强元素(Nb、Ti、P)为特征,(⁸⁷Sr/⁸⁶Sr)_i=0.7075~0.7077,ε_Nd(t)=-6.3~-6.1,亏损地幔模式年龄为1.25~1.33Ga.舍哈力吉石英二长岩起源于石榴角闪岩相古老下地壳的部分熔融,之后经历了壳幔岩浆混合作用和以斜长石为主的分离结晶作用.寄主岩的环斑结构和相对一致的地球化学特征,很可能是高温幔源熔体对壳源富钾高黏度岩浆改造所导致的晶粥快速再活化的结果.西秦岭在印支早期可能并未经历显著的地壳加厚过程.西秦岭印支早期花岗岩类形成于活动大陆边缘局部伸展环境,可能与古特提斯洋壳俯冲极性的改变有关.  相似文献