共查询到10条相似文献，搜索用时 93 毫秒
1.
Junqiao Feng Dunxin Hu Fei-fei Jin Fan Jia Qingye Wang Shoude Guan 《Journal of Oceanography》2018,74(5):523-539
The Pacific interior subtropical?tropical cells (STCs) and their relation to the two types of El Niño-Southern Oscillation (ENSO) are investigated by using GODAS reanalysis ocean data for the period of 1980–2017. The results show that the interior STC transport into the equatorial region across 9°S and 9°N has a close relationship with the eastern Pacific (EP) ENSO, while it is much weaker with the central Pacific (CP) ENSO. It is suggested that the effect of interior STCs on the tropical Pacific climate is reflected in its relation with the western Pacific thermocline depth or SSHA. During the EP El Niño, the anomalous interior STCs at 9°S and 9°N converge to the equatorial region from the lag months of ? 25 to ? 8, leading to an accumulation of heat content in the equatorial Pacific; from the lag months of ? 8 to 10, they diverge poleward, inducing a discharge of equatorial heat content. The peak poleward interior STC anomaly first appears at 9°N at a zero-lag time, while that at 9°S is observed 4–5 months later. But there is also no appearance of a time lag between the interior STCs at 9°N and 9°S in recharging the period during the EP La Niña mature phase. However, during CP El Niño, only the conspicuous anomalous interior STC divergence appears during the mature and decay phases for the lag months of ? 2 to 10, with being symmetric at 9°N and 9°S. 相似文献
2.
Positive SST anomalies usually appear in remote ocean such as the China seas during an ENSO event.By analyzing the monthly data of HadISST from 1950 to 2007,it shows that the interannual component of SST anomalies peak approximately 10 months after SST anomalies peak in the eastern equatorial Pacific.As the ENSO event progresses,the positive SST anomalies spread throughout the China seas and eastward along the Kuroshio extension.Atmospheric reanalysis data demonstrate that changes in the net surface heat flux entering into the China seas are responsible for the SST variability.During El Ni o,the western north Pacific anticyclone is generated,with anomalous southwester lies prevailing along the East Asian coast.This anticyclone reduces the mean surface wind speed which decreases the surface heat flux and then increases the SST.The delays between the developing of this anticyclone and the south Indian Ocean anticyclone with approximately 3–6 months cause the 2–3 months lag of the surface heat flux between the China seas and the Indian Ocean.The northwestern Pacific anticyclone is the key process bridging the warming in the eastern equatorial Pacific and that in the China seas. 相似文献
3.
Analysis of the first 26 months of data from the Aquarius satellite confirms the existence of a sharp sea surface salinity (SSS) front along the equator in the western equatorial Pacific. Following several earlier studies, we use the longitudinal location of the 34.8-psu isohaline as an index, termed Niño-S34.8, to measure the zonal displacement of the SSS front and consequently the eastern edge of the western Pacific warm pool. The on-going collection of the Array for Real-time Geostrophic Oceanography (ARGO) program data shows high correlations between Niño-S34.8 and the existing indices of El Niño, suggesting its potential important role in ENSO evolution. Further analysis of the ARGO data reveals that SSS variability in the southeastern tropical Pacific is crucial to identify the type of El Niño. A new SSS index, termed the southeastern Pacific SSS index (SEPSI), is defined based on the SSS variability in the region (0°–10°S, 150°–90°W). The SEPSI is highly correlated with the El Niño Modoki index, as well as the Trans-Niño index, introduced by previous studies. It has large positive anomalies during central Pacific El Niño or El Niño Modoki events, as a result of enhanced zonal sea surface temperature gradients between the central and eastern tropical Pacific, and can be used to characterize the type of El Niño. The processes that possibly control these SSS indices are also discussed. 相似文献
4.
Mingqiang Fang 《Journal of Oceanography》2006,62(5):759-766
This study reveals the physical backgrounds of the geometric centroid and the thermal centroid of the Western Pacific Warm Pool (WPWP) and points out their differences. The geometric centroid (actually a very close approximation to the mass centroid) anomaly of the surface WPWP correlates more closely with the Niño-3 region sea surface temperature anomaly (Niño-3 SSTA, an important indicator of El Niño/La Niña events) than the surface thermal centroid. Taking the WPWP depth (or heat storage) into account, the “real” mass or thermal centroid of the WPWP might correlate better with the El Niño/Southern Oscillation (ENSO) signals. 相似文献
5.
Four year-long time-series sediment trap experiments were conducted along the equatorial Pacific Ocean in order to understand the biogeochemistry of particulate organic matter (POM) on the basis of amino acid (AA) and hexosamine (HA) compositions of the settling particles. Total mass flux in the study area varied over 4 orders of magnitude without a common seasonality among all trap sites. Planktonic blooms were apparent in terms of total mass and AA fluxes at the easternmost end of the Niño-4 region. AA fluxes closely followed the total mass flux profiles, suggesting that increased particle flux delivered a greater amount of labile OM to the deep ocean. A labile OM index (LI)-based classification showed that during the El Niño conditions in 2002, the eastern side of the equatorial Pacific transported relatively more labile OM than the western equatorial Pacific. An overall change in AA and HA composition of settling particles could be revealed with the help of discriminant analysis, suggesting that settling particles during El Niño were compositionally different from those settling during La Niña condition in the equatorial Pacific. 相似文献
6.
Analysis of the cause and effect relationships between El Niño in the Pacific and its analog in the equatorial Atlantic 总被引：1，自引：0，他引：1
S. S. Kozlenko I. I. Mokhov D. A. Smirnov 《Izvestiya Atmospheric and Oceanic Physics》2009,45(6):704-713
The relations between the processes occurring in the equatorial latitudes of the Pacific and Atlantic oceans were studied on the basis of the Granger causality analysis and a simulation of phase dynamics using the indices of the El Niño-Southern Oscillation (ENSO) and the equatorial Atlantic mode (EAM). Data on the monthly means of the sea-surface temperature over the period 1870–2006 for the Niño 3 (5° S-5° N, 150° W-90° W) and Niño 3.4 (5° S-5° N, 170° W-120° W) regions in the Pacific and the Atlantic 3 region (20° W-0, 3° S-3° N) in the Atlantic Ocean were used as the ENSO and EAM indices. The statistically significant influence of the EAM on the ENSO is noted. The lag time of this influence is estimated at two months. No significant reverse effect is revealed. An increase in the EAM’s influence on the ENSO was observed in the second half of the 20th century. 相似文献
7.
Thirty La Niña events have been selected from monthly mean sea surface temperature (SST) data of the Hadley Centre Global Sea Ice and Sea Surface Temperature (HadISST) and Centennial Observation-Based Estimates (COBE SST2) datasets from 1870 to 2013 based on a criterion of –0.5°С for a cold anomaly in the Niño 3.4 region (5° N–5° S, 170°–120° W) and its minimum duration of 5 months. The selected events are classified by hierarchical clustering analysis according to two characteristics: geographic coordinates and SST anomalies during the mature phase of La Niña. The objective classification method identifies two types of La Niña differing by the evolution of negative SST anomalies in the equatorial Pacific and by the Southern Oscillation Index. 相似文献
8.
赤道太平洋次表层海温异常年际和年代际变率特征与ENSO循环 总被引：6，自引：0，他引：6
用美国马里兰大学提供的海洋同化(SODA)月平均资料,分析了赤道太平洋次表层海温异常年际和年代际变率的演化特征,讨论了它们对ENSO循环的影响.结果指出,赤道太平洋次表层海温异常年际和年代际变率具相似的ENSO模分布和演变过程,二者均以赤道西太平洋暖池次表层海温显著的异常中心与赤道东太平洋表层海温异常中心显著反号为主要分布特征,其演变过程通过赤道西太平洋暖池次表层海温异常中心沿海洋气候温跃层向东向上传播来完成.赤道西太平洋暖池次表层海温异常年际变率决定了ENSO循环,年代际变率对ENSO循环也有重要影响,其影响主要在中太平洋, 造成ENSO模的年代际变化.当年代际变率处于正常状态时,ENSO循环基本上是东部型冷暖事件之间的转换;当年际和年代际变率位相相同时,ENSO事件强度将会加强和持续,并出现中部型ENSO事件;当二者位相相反时, ENSO事件强度将会减弱. 相似文献
9.
In this study, El Niño Southern Oscillation (ENSO)-induced interannual variability in the South China Sea (SCS) is documented using outputs from an eddy-resolving data-assimilating model. It is suggested that during an El Niño (La Niña) event, off-equatorial upwelling (downwelling) Rossby waves induced by Pacific equatorial wind anomalies impinge on the Philippine Islands and excite upwelling (downwelling) coastal Kelvin waves that propagate northward along the west coast of the Philippines after entering the SCS through the Mindoro Strait. The coastal Kelvin waves may then induce negative (positive) sea level anomalies in the southeastern SCS and larger (smaller) volume transport through the Mindoro and Luzon Straits during an El Niño (La Niña) event. 相似文献
10.
Upper ocean heat content and atmospheric anomaly fields in the off-equatorial North Pacific related to ENSO 总被引：1，自引：1，他引：1
We have investigated interannual-scale variations of oceanic and atmospheric anomaly fields, such as upper ocean heat content (OHC), sea surface temperature (SST), latent heat flux (LHF) through the sea surface, sea level pressure (SLP) and wind stress curl (WSC) in the tropical Pacific and their relationships to El Niño/Southern Oscillation (ENSO) events. The results reported here show that the OHC and SST anomalies are almost in phase and lead LHF anomalies in the western tropical Pacific (WTP) region, which are preferable to the generation of subsequent atmospheric anomalies in the WTP. We also describe linear relationships between the amplitudes of these variables in the WTP. In addition, the results show that the both WSC and LHF anomalies are in phase with the temporal trend of OHC anomalies in the WTP, and suggest a combined effect of the local WSC and LHF anomaly in the WTP and ENSO-related, off-equatorial, westward propagating OHC anomaly to generate a large OHC anomaly in the WTP. In contrast to the WTP, OHC and SST anomalies are not in phase to the east of the WTP. The results also indicate that OHC anomalies in the WTP have a potential effect on the generation of an equatorial OHC anomaly via both a reflection of waves at the western boundary and atmospheric variations, which force the enhancement of western equatorial OHC anomaly. Therefore, the WTP is a key region where ENSO events are significantly modulated, and OHC anomalies in the WTP play an important role in the subsequent ENSO event. 相似文献