共查询到20条相似文献，搜索用时 156 毫秒
1.
Using reanalysis data, the role of initial signals in the tropical Pacific Ocean in predictions of negative Indian Ocean Dipole (IOD) events were analyzed. It was found that the summer predictability barrier (SPB) phenomenon exists in predictions, which is closely related to initial sea temperature errors in the tropical Pacific Ocean, with type-1 initial errors presenting a significant west-east dipole pattern in the tropical Pacific Ocean, and type-2 initial errors showing the opposite spatial pattern. In contrast, SPB-related initial sea temperature errors in the tropical Indian Ocean are relatively small. The initial errors in the tropical Pacific Ocean induce anomalous winds in the tropical Indian Ocean by modulating the Walker circulation in the tropical oceans. In the first half of the prediction year, the anomalous winds, combined with the climatological winds in the tropical Indian Ocean, induce a basin-wide mode of sea surface temperature (SST) errors in the tropical Indian Ocean. With the reversal of the climatological wind in the second half of the prediction year, a west-east dipole pattern of SST errors appears in the tropical Indian Ocean, which is further strengthened under the Bjerknes feedback, yielding a significant SPB. Moreover, two types of precursors were also identified: a significant west-east dipole pattern in the tropical Pacific Ocean and relatively small temperature anomalies in the tropical Indian Ocean. Under the combined effects of temperature anomalies in the tropical Indian and Pacific oceans, northwest wind anomalies appear in the tropical Indian Ocean, which induce a significant west-east dipole pattern of SST anomalies, and yield a negative IOD event. 相似文献
2.
南印度洋副热带偶极模（Subtropical Dipole Pattern,SDP）是印度洋存在的另一种很明显的偶极型海温差异现象,在年际和年代际尺度上均有十分明显的表现.而目前有关印度洋海气相互作用的研究主要集中在赤道印度洋地区,针对南印度洋地区的工作还比较少,特别是有关南印度洋海温与ENSO（El NiDo-Southern Oscillation）事件关系的研究.本文初步探讨了年际尺度上南印度洋副热带偶极型海温变化差异与ENSO事件的关系,发现SDP与ENSO事件有密切的联系,SDP事件就像连接正负ENSO位相转换的一个中间环节,SDP事件前后期ENSO的位相刚好完全相反.进一步,本文通过分析SDP事件前后期海温、高低层风、低层辐合辐散、高空云量和辐射等的变化特征研究了南印度洋偶极型海温异常在ENSO事件中的作用,结果表明：SDP在ENSO事件中的作用不仅涉及海气相互作用的正负反馈过程,还与热带和副热带大气环流之间的相互作用有关,特别是与东南印度洋海温变化所引起的异常纬向风由赤道印度洋向赤道太平洋传播的过程等有十分直接的关系;同时,SDP对ENSO事件的影响在很大程度上还依赖于大尺度平均气流随季节的变换. 相似文献
3.
北太平洋对北极的半封闭状态和南太平洋对南极的开放状态是厄尔尼诺事件发生的构造基础，它导致北太平洋海表热能的积累和周期性向南太平洋输送，强潮汐振荡和火山喷发是其激发因素。 相似文献
4.
Numerical modeling with application to tracking marine debris 总被引：1，自引：0，他引：1
Potemra JT 《Marine pollution bulletin》2012,65(1-3):42-50
This paper describes different numerical models of ocean circulation the output of which can be applied to study patterns and pathways of drifting marine debris. The paper focuses on model output that is readily available rather than on numerical models that could be configured and run locally. These include operational models from the US Navy (the Navy Layered Ocean Model (NLOM), Coastal Ocean Model (NCOM), and Hybrid Coordinate Ocean Model (HYCOM)), data assimilating reanalysis models (the Simple Ocean Data Assimilation (SODA), the Global Ocean Data Assimilation Experiment (GODAE) models), and the European Center for Medium-Range Weather Forecasts (ECMWF) ocean reanalysis (Ocean Reanalysis System, ECMWF/ORA-S3). The paper describes the underlying physics in each model system, limitations, and where to obtain the model output. 相似文献
5.
6.
Multi-scale variability of the tropical Indian Ocean circulation system revealed by recent observations 总被引：1，自引：0，他引：1
Ke HUANG Dongxiao WANG Weiqiang WANG Qiang XIE Ju CHEN Lingfang CHEN Gengxin CHEN 《中国科学:地球科学(英文版)》2018,(6)
The tropical Indian Ocean circulation system includes the equatorial and near-equatorial circulations, the marginal sea circulation, and eddies. The dynamic processes of these circulation systems show significant multi-scale variability associated with the Indian Monsoon and the Indian Ocean dipole. This paper summarizes the research progress over recent years on the tropical Indian Ocean circulation system based on the large-scale hydrological observations and numerical simulations by the South China Sea Institute of Oceanology(SCSIO), Chinese Academy of Sciences. Results show that:(1) the wind-driven Kelvin and Rossby waves and eastern boundary-reflected Rossby waves regulate the formation and evolution of the Equatorial Undercurrent and the Equatorial Intermediate Current;(2) the equatorial wind-driven dynamics are the main factor controlling the inter-annual variability of the thermocline in the eastern Indian Ocean upwelling;(3) the equatorial waves transport large amounts of energy into the Bay of Bengal in forms of coastal Kelvin and reflected free Rossby waves. Several unresolved issues within the tropical Indian Ocean are discussed:(i) the potential effects of the momentum balance and the basin resonance on the variability of the equatorial circulation system, and(ii) the potential contribution of wind-driven dynamics to the life cycle of the eastern Indian Ocean upwelling. This paper also briefly introduces the international Indian Ocean investigation project of the SCSIO, which will advance the study of the multi-scale variability of the tropical Indian Ocean circulation system, and provide a theoretical and data basis to support marine environmental security for the countries around the Maritime Silk Road. 相似文献
7.
Two modes of dipole events in tropical Indian Ocean 总被引：1，自引：0，他引：1
By analyzing the distributions of subsurface temperature and the surface wind stress anomalies in the tropical Pacific and
Indian Oceans during the Indian Ocean Dipole (IOD) events, two major modes of the IOD and their formation mechanisms are revealed.
(1) The subsurface temperature anomaly (STA) in the tropical Indian Ocean during the IOD events can be described as a “<”
-shaped and west-east-oriented dipole pattern; in the east side of the “<” pattern, a notable tongue-like STA extends westward
along the equator in the tropical eastern Indian Ocean; while in the west side of the “<” pattern, the STA has opposite sign
with two centers (the southern one is stronger than the northern one in intensity) being of rough symmetry about the equator
in the tropical mid-western Indian Ocean. (2) The IOD events are composed of two modes, which have similar spatial pattern
but different temporal variabilities due to the large scale air-sea interactions within two independent systems. The first
mode of the IOD event originates from the air-sea interaction on a scale of the tropical Pacific-Indian Ocean and coexists
with ENSO. The second mode originates from the air-sea interaction on a scale of the tropical Indian Ocean and is closely
associated with changes in the position and intensity of the Mascarene high pressure. The strong IOD event occurs when the
two modes are in phase, and the IOD event weakens or disappears when the two modes are out of phase. Besides, the IOD events
are normally strong when either of the two modes is strong. (3) The IOD event is caused by the abnormal wind stress forcing
over the tropical Indian Ocean, which results in vertical transports, leading to the upwelling and pileup of seawater. This
is the main dynamic processes resulting in the STA. When the anomalous easterly exists over the equatorial Indian Ocean, the
cold waters upwell in the tropical eastern Indian Ocean while the warm waters pileup in the tropical western Indian Ocean,
hence the thermocline in the tropical Indian Ocean is shallowed in the east and deepened in the west. The off-equator component
due to the Coriolis force in the equatorial area causes the upwelling of cold waters and the shallowing of the equatorial
India Ocean thermocline. On the other hand, the anomalous anticyclonic circulations and their curl fields located on both
sides of the equator, cause the pileup of warm waters in the central area of their curl fields and the deepening of the equatorial
Indian Ocean thermocline off the equator. The above three factors lead to the occurrence of positive phase IOD events. When
anomalous westerly dominates over the tropical Indian Ocean, the dynamic processes are reversed, and the negative-phase IOD
event occurs.
Supported by National Natural Science Foundation of China (Grant No. 40776013), National Basic Research Program of China (Grant
No. 2006CB403601) and the Knowledge Innovation Project of Chinese Academy of Sciences (Grant No. KZCX-SW-222) 相似文献
8.
本文对大西洋中北部两侧五个地震台站2015年记录到的地震数据进行处理,计算噪声功率谱密度和概率密度函数,并通过极化分析对双频微地动不同周期的主导源区方位角分布进行了分析。研究结果显示:大西洋中北部台站双频微地动发生显著分裂,各台站的峰值周期各不同,且来自相同方向和不同方向的双频微地动都有可能产生双频微地动分裂;大西洋中北部的噪声功率谱密度随季节变化复杂,部分台站冬季的功率谱密度振幅比夏季强,部分台站夏季的比冬季强;而大西洋中北部台站源区方位受季节影响不大,台站主要源区的方位不变,且两季的源区方位角在大范围内重合;大西洋东岸中北部台站,夏季受台站以南大西洋源区影响更多,冬季受台站以北大西洋源区影响更多;靠近加勒比海位于大西洋西岸的台站,其双频微地动源区方向在冬季和夏季都更多地指向加勒比海;大西洋西岸纬度最低的台站MPG,其双频微地动在冬季主要受台站以北大西洋源区的影响,而在夏季则同时受到台站以北大西洋源区和台站西南方位很可能源于太平洋源区的共同影响。 相似文献
9.
Although the Arctic methane reservoir is large,the emission of methane from the Arctic Ocean into the atmosphere remains poorly constrained.Continuous ship-borne measurements of atmospheric methane near the surface ocean were carried out during two cruises to investigate methane emission from the Arctic Ocean up to the latitude of 87°N.Three-day air mass back trajectories along the cruise tracks indicated that the surface Arctic Ocean could be a potentially important source of methane to the atmosphere.Rapid bursts in methane concentration occurred mainly along the ocean frontal area,suggesting that frontal upwelling in the upper layer of the Arctic Ocean might contribute to methane emissions into the atmosphere. 相似文献
10.
Zhang Jiali Zhang Anmin Zhang Xuefeng Zhang Liang Li Dong Shen Zheqi Sun Chaohui 《Ocean Dynamics》2020,70(10):1303-1313
Ocean Dynamics - Tidal characteristics in the well-known Coastal Marine Proving Ground near Chudao Island located in Shandong Province, China, are firstly investigated based on Princeton Ocean... 相似文献
11.
D. D. Singh 《Pure and Applied Geophysics》1997,150(1):53-73
—Rayleigh and Love waves generated by sixteen earthquakes which occurred in the Indian Ocean and were recorded at 13 WWSSN stations of Asia, Africa and Australia are used to determine the moment tensor solution of these earthquakes. A combination of thrust and strike-slip faulting is obtained for earthquakes occurring in the Bay of Bengal. Thrust, strike slip or normal faulting (or either of the combination) is obtained for earthquakes occurring in the Arabian Sea and the Indian Ocean. The resultant compressive and tensional stress directions are estimated from more than 300 centroid moment tensor (CMT) solution of earthquakes occurring in different parts of the Indian Ocean. The resultant compressive stress directions are changing from north-south to east-west and the resultant tensional stress directions from east-west to north-south in different parts of the Indian Ocean. The results infer the counterclockwise movement of the region (0°–33°S and 64°E–94°E), stretching from the Rodriguez triple junction to the intense deformation zone of the central Indian Ocean and the formation of a new subduction zone (island arc) beneath the intense deformation zone of the central Indian Ocean and another at the southern part of the central Indian basin. The compressive stress direction is along the ridge axis and the extensional stress manifests across the ridge axis. The north-south to northeast-south west compression and east-west to northwest-southeast extension in the Indian Ocean suggest the northward underthrusting of the Indian plate beneath the Eurasian plate and the subduction beneath the Sunda arc region in the eastern part. The focal depth of earthquakes is estimated to be shallow, varying from 4 to 20 km and increasing gradually in the age of the oceanic lithosphere with the focal depth of earthquakes in the Indian Ocean. 相似文献
12.
Ocean Dynamics - In the Indian Ocean regions under the influence of monsoons, two phytoplankton blooms characterize the seasonal cycle of surface chlorophyll, one during summer, and the other... 相似文献
13.
Ocean Dynamics - In this study, deep circulation in the South China Sea (SCS) is investigated using results from mesoscale-eddy-resolving, regional simulations using the Hybrid Coordinate Ocean... 相似文献
14.
Ocean Dynamics - Using the Estimating Circulation and Climate of the Ocean (ECCO) Phase II product, this study investigates the energetic characteristics during eddy shedding in the Gulf of Mexico.... 相似文献
15.
B. H. Vaid C. Gnanaseelan P. S. Polito P. S. Salvekar 《Pure and Applied Geophysics》2007,164(8-9):1765-1785
The sea-surface height anomalies derived from Simple Ocean Data Assimilation (SODA) during 1958–2001, Topex/Poseidon satellite
during 1993–2001 and the SODA heat content anomalies (125 m depth) during 1958–2001 are filtered into annual and biennial
Rossby wave components using a two-dimensional Finite Impulse Response filter. The filtered Rossby wave components (both annual
and biennial) in the southern Pacific and Indian Oceans have considerable strength and variability. The propagation of annual
and biennial Rossby waves in the Indonesian through-flow region [12.5°S–7.5°S] of the Indian Ocean is in phase with the southern
Pacific Ocean waves. So it is speculated that the Pacific Ocean influences the Indian Ocean, especially through the region
17.5°S to 7.5°S and thus the southern Pacific Rossby waves could be an unexplored contributor to the Indian Ocean Rossby waves.
We also carried out Fast Fourier Transform (FFT) and wavelet analysis on the tide gauge sea-level data along the Australian
coast to support our claim. Filtered annual and biennial components of SODA heat content anomalies (125 m depth) also support
these findings. 相似文献
16.
Ocean Dynamics - Since the 2004 Indian Ocean tsunami and particularly after the 2011 Tohuku tsunami, there has been a significant increase of computer simulation using real-time data; however,... 相似文献
17.
Wang Dingqi Fang Guohong Xu Tengfei Jiang Shumin Teng Fei Qiu Ting Wei Zexun Wang Yonggang 《Ocean Dynamics》2023,73(2):59-77
Ocean Dynamics - Mainly driven by wind stress, the upper ocean dynamic processes in the North Pacific Ocean serve as important pathways for mass and energy exchanges of the global ocean and thus... 相似文献
18.
Ocean Dynamics - Roles of atmospheric variabilities in the formation of Indian Ocean Dipole (IOD) were investigated using an ocean general circulation model and different atmospheric forcing... 相似文献
19.
Kaiser J&#;lia Nogueira Izabel C. M. Campos Ricardo M. Parente Carlos E. Martins Renato P. Belo Wellington C. 《Ocean Dynamics》2022,72(2):137-150
Ocean Dynamics - This paper evaluates the performance of the spectral wave model WAVEWATCH III for the South Atlantic Ocean forced by wind inputs from the most recent reanalyses, NCEP/CFSR and... 相似文献
20.
Ocean Dynamics - The performance of three different mixing schemes implemented in the HYbrid Coordinate Ocean Model (HYCOM), namely, K-Profile Parameterization (KPP), Goddard Institute of Space... 相似文献