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近500年ENSO时间序列的建立与分析 被引量:10
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作者 王绍武 朱锦红 +1 位作者 蔡静宁 闻新宇 《自然科学进展》 北大核心 2004年第4期424-430,共7页
根据1861~2000年的年平均(3月至次年2月)Nino 3.4区SST及ENSO综合指数△I把ENSO分为7级.暖事件(E)分3级即3,2和1,大约相当SST距平1.5℃,1.0℃及0.5℃.冷事件(A)也分3级,-3,-2和-1,对应的SST距平大体如E,绝对值稍小.正常年为0级.然后利... 根据1861~2000年的年平均(3月至次年2月)Nino 3.4区SST及ENSO综合指数△I把ENSO分为7级.暖事件(E)分3级即3,2和1,大约相当SST距平1.5℃,1.0℃及0.5℃.冷事件(A)也分3级,-3,-2和-1,对应的SST距平大体如E,绝对值稍小.正常年为0级.然后利用与ENSO有密切关系的代用资料重建1501~2000年逐年的ENSO级.对1874~1973年100年根据观测的综合指数所划分的级与代用资料得到的结果比较.代用资料能反演出80%以上的E年及A年.这样建立的500年ENSO序列,显示出2年多、3年多及5年多左右以及10年的EN-SO变率,说明包括小冰期及现代暖期内的近500年中ENSO变率仍相对稳定.在小冰期冷期A年频率稍高,气候变暖的20世纪则E年频率较高. 展开更多
关键词 enso时间序列 变率 诊断 1501~2000年 南方涛动 “厄尔尼诺”现象 “拉尼娜”现象
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1951—2008年广西降水变化及对ENSO事件的响应初探 被引量:2
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作者 柳林秀 《科技资讯》 2011年第34期217-217,共1页
利用的1951年至2008年桂林、柳州、南宁、梧州、北海、百色的降水资料与南方涛动指数(SOI),应用统计相关分析等方法对ENSO事件与广西降水、干旱的关系进行探讨。研究表明,1951年至2008广西的降水呈现波动性变化特征:从1951年至1960年的1... 利用的1951年至2008年桂林、柳州、南宁、梧州、北海、百色的降水资料与南方涛动指数(SOI),应用统计相关分析等方法对ENSO事件与广西降水、干旱的关系进行探讨。研究表明,1951年至2008广西的降水呈现波动性变化特征:从1951年至1960年的10年多时间内,广西的降水经历了幅度较大的减少;从1961年至1981的近20年时间内,广西的降水量开始缓慢增加;从1981至世纪末的近20年时间内,广西省的年降水又开始逐渐减少。ENSO事件对广西的旱涝有显著影响。 展开更多
关键词 广西 降水 旱涝 enso时间
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Southern Ocean SST Variability and Its Relationship with ENSO on Inter-Decadal Time Scales 被引量:4
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作者 YAN Li DU Yan ZHANG Lan 《Journal of Ocean University of China》 SCIE CAS 2013年第2期287-294,共8页
Empirical orthogonal function (EOF) analysis reveals a co-variability of Sea surface temperatures (SSTs) in the Southern Hemisphere (0°-60°S). In the South Indian and Atlantic Oceans, there is a subtro... Empirical orthogonal function (EOF) analysis reveals a co-variability of Sea surface temperatures (SSTs) in the Southern Hemisphere (0°-60°S). In the South Indian and Atlantic Oceans, there is a subtropical dipole pattern slanted in the southwest-northeast direction. In the South Pacific Ocean, a meridional tripole structure emerges, whose middle pole co-varies with the dipoles in the South Indian and Atlantic Oceans and is used in this study to track subtropical Pacific variability. The South Indian and Atlantic Ocean dipoles and the subtropical Pacific variability are phase-locked in austral summer. On the inter-decadal time scales, the dipoles in the South Indian and Atlantic Oceans weaken in amplitude after 1979/1980. No such weakening is found in the subtropical South Pacific Ocean. Interestingly, despite the reduced amplitude, the correlation of the Indian Ocean and Atlantic dipoles with E1 Nino and Southern Oscillation (ENSO) are enhanced after 1979/1980. The same increase in correlation is found for subtropical South Pacific variability after 1979/1980. These inter-decadal modulations imply that the Southern Hemisphere participates in part of the climate shift in the late 1970s. The correlation between Southern Hemisphere SST and ENSO reduces after 2000. 展开更多
关键词 Southern Ocean SST enso subtropical dipole inter-decadal time scales
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Interannual variability in the North Pacific meridional overturning circulation 被引量:3
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作者 刘洪伟 张启龙 +1 位作者 侯一筠 段永亮 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第3期665-680,共16页
We analyzed the temporal and spatial variation, and interannual variability of the North Pacific meridional overturning circulation using an empirical orthogonal function method, and calculated mass transport using Si... We analyzed the temporal and spatial variation, and interannual variability of the North Pacific meridional overturning circulation using an empirical orthogonal function method, and calculated mass transport using Simple Ocean Data Assimilation Data from 1958-2008. The meridional streamfunction field in the North Pacific tilts N-S; the Tropical Cell (TC), Subtropical Cell (STC), and Deep Tropical Cell (DTC) may be in phase on an annual time scale; the TC and the STC are out of phase on an interannual time scale, but the interannual variability of the DTC is complex. The TC and STC interannual variability is associated with ENSO (El Nifio-Southem Oscillation). The TC northward, southward, upward, and downward transports all weaken in E1 Nifios and strengthen in La Nifias. The STC northward and southward transports are out of phase, while the STC northward and downward transports are in phase. Sea-surface water that reaches the middle latitude and is subducted may not completely return to the vopics. The zonal wind anomalies over the central North Pacific, which control Ekman transport, and the east-west slope of the sea level may be major factors causing the TC northward and southward transport interannual variability and the STC northward and southward transports on the interannual time scale. The DTC northward and southward transports decrease during strong E1 Nifios and increase during strong La Nifias. DTC upward and downward transports are not strongly correlated with the Nifio-3 index and may not be completely controlled by ENSO. 展开更多
关键词 North Pacific Ocean meridional overturning circulation interannual variation temporal andspatial variations
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Heat center of the western Pacific warm pool 被引量:4
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作者 HU Shijian Hu Dunxin 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第1期169-176,共8页
A heat center (HC) of the western Pacific warm pool (WPWP) is defined, its variability is examined, and a possible mechanism is discussed. Analysis and calculation of a temperature dataset from 1945-2006 show that... A heat center (HC) of the western Pacific warm pool (WPWP) is defined, its variability is examined, and a possible mechanism is discussed. Analysis and calculation of a temperature dataset from 1945-2006 show that the mean position of the HC during this period was near 0.4°S/169.0°E, at 38.0 m depth. From a time series of the HC, remarkable seasonal variability was found, mainly in the meridional and vertical directions. Interannual variabilities were dominant in the zonal and vertical directions. In addition, semiannual variation in the HC depth was discovered. The longitude of the HC varies with ENSO events, and its latitude is weakly related to ENSO on time scales shorter than a decade. The variation of the HC longitude leads the Nifio-3 index by about 3-4 months, and its depth lags the index for approximately 3 months. It is concluded that the HC depth results from a combination of its longitudinal and latitudinal variations. Low-pass-filtered time series reveal that the HC has moved eastward since the mid 1980s. 展开更多
关键词 western Pacific warm pool heat center VARIABILITY
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Interpretation of sea surface wind interannual vector EOFs over the China seas
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作者 赵喜喜 侯一筠 齐鹏 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第2期340-343,共4页
Using interpolation and averaging methods, we analyzed the sea surface wind data obtained from December 1992 to November 2008 by the scatterometers ERS-1, ERS-2, and QuikSCAT in the area of 2°N-39 °N, 105... Using interpolation and averaging methods, we analyzed the sea surface wind data obtained from December 1992 to November 2008 by the scatterometers ERS-1, ERS-2, and QuikSCAT in the area of 2°N-39 °N, 105°E-130°E, and we reported the monthly mean distributions of the sea surface wind field. A vector empirical orthogonal function (VEOF) method was employed to study the data and three temporal and spatial patterns were obtained. The first interannual VEOF accounts for 26% of the interannual variance and displays the interannual variability of the East Asian monsoon. The second interannual VEOF accounts for 21% of the variance and reflects the response of China sea winds to E1 Nifio events. The temporal mode of VEOF-2 is in good agreement with the curve of the Nifio 3.4 index with a four-month lag. The spatial mode of VEOF-2 indicates that four months after an E1 Nifio event, the southwesterly anomalous winds over the northern South China Sea, the East China Sea, the Yellow Sea, and the Bohai Sea can weaken the prevailing winds in winter, and can strengthen the prevailing winds in summer. The third interannual VEOF accounts for 10% of the variance and also reflects the influence of the ENSO events to China Sea winds. The temporal mode of VEOF-3 is similar to the curve of the Southern Oscillation Index. The spatial mode of VEOF-3 shows that the northeasterly anomalous winds over the South China Sea and the southern part of the East China Sea can weaken the prevailing winds, and southwesterly anomalous winds over the northern part of the East China Sea, the Yellow Sea, and the Bohai Sea can strengthen the prevailing winds when E1 Nifio occurs in winter. If E1 Nifio happens in summer, the reverse is true. 展开更多
关键词 scatterometer wind empirical orthogonal function
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Annual and interannual variations of the Western Pacific Warm Pool volume and sources of warm water revealed by Argo data 被引量:2
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作者 WU XiaoFen ZHANG QiLong LIU ZengHong 《Science China Earth Sciences》 SCIE EI CAS 2014年第9期2269-2280,共12页
Based on gridded Argo profile data from January 2004 to December 2010, together with the P-vector inverse method, the three-dimensional structure, annual and inter-annual variations in volume of the Western Pacific Wa... Based on gridded Argo profile data from January 2004 to December 2010, together with the P-vector inverse method, the three-dimensional structure, annual and inter-annual variations in volume of the Western Pacific Warm Pool (WPWP) are studied. The variations of latitudinal and longitudinal warm water flowing into and out of the WPWP and the probable mecha- nism of warm water maintenance are also discussed. From the surface to the bottom, climatic WPWP tilts southward and its area decreases. The maximum depth could extend to 120 m, such that its volume could attain 1.86x10^5 m3. Annual variation of the WPWP volume shows two obvious peaks that occur in June and October, whereas its inter-annual variations are related to ENSO events. Based on a climatic perspective, the warm water flowing latitudinally into the pool is about 52 Sv, which is mainly through upper layers and via the eastern boundary. Latitudinally, warm water flowing outward is about 49 Sv, and this is mainly through lower layers and via the western boundary. In contrast, along the latitude, warm water flowing into and out of the pool is about 28 Sv and 23 Sv, respectively. Annual and inter-annual variations of the net transportation of the warm water demonstrate that the WPWP mainly loses warm water in the west-east direction, whereas it receives warm water from the north-south direction. The annual variation of the volume of WPWP is highly related to the annual variation of the net warm water transportation, however, they are not closely related on inter-annual time scale. On the inter-annual time scale, in- fluences of ENSO events on the net warm water transportation in the north-south direction are much more than that in the west-east direction. Although there are some limitations and simplifications when using the P-vector method, it could still help improve our understanding of the WPWP, especially regarding the sources of the warm water. 展开更多
关键词 Western Pacific Warm Pool volume variability latitudinal flow longitudinal flow Argo data P-vector method
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Unified deep learning model for El Niño/Southern Oscillation forecasts by incorporating seasonality in climate data 被引量:6
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作者 Yoo-Geun Ham Jeong-Hwan Kim +1 位作者 Eun-Sol Kim Kyung-Yun On 《Science Bulletin》 SCIE EI CSCD 2021年第13期1358-1366,M0004,共10页
Although deep learning has achieved a milestone in forecasting the El Niño-Southern Oscillation(ENSO),the current models are insufficient to simulate diverse characteristics of the ENSO,which depends on the calen... Although deep learning has achieved a milestone in forecasting the El Niño-Southern Oscillation(ENSO),the current models are insufficient to simulate diverse characteristics of the ENSO,which depends on the calendar season.Consequently,a model was generated for specific seasons which indicates these models did not consider physical constraints between different target seasons and forecast lead times,thereby leading to arbitrary fluctuations in the predicted time series.To overcome this problem and account for ENSO seasonality,we developed an all-season convolutional neural network(A_CNN)model.The correlation skill of the ENSO index was particularly improved for forecasts of the boreal spring,which is the most challenging season to predict.Moreover,activation map values indicated a clear time evolution with increasing forecast lead time.The study findings reveal the comprehensive role of various climate precursors of ENSO events that act differently over time,thus indicating the potential of the A_CNN model as a diagnostic tool. 展开更多
关键词 Deep learning enso forecasts Seasonality of the enso
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