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1.
In this paper, by using ocean surface temperature data (COADS), the study is made of the characteristics of the monthly and annual changes of the SST in the tropical western Pacific and Indian Oceans, which have important influences on the climate change of the whole globe and the relation between ENSO(E1 Nino-Southern Oscillation) and the Antarctic ice area is also discussed. The result indicates that in the tropical western Pacific and the Indian Oceans the change of Sea Surface Temperture (SST) is conspicuous both monthly and armaully, and shows different change tendency between them. This result may be due to different relation in the vibration period of SST between the two Oceans. The better corresponding relationship is obvious in the annual change of SST in the tropical Indian Ocean with the occurrence El Nino and LaNlra. The change of the SST in the tropical western Pacific and the tropical Indian Oceans has a close relation to the Antarctic ice area, especially to the ice areas in the eastern-south Pole and Ross Sea, and its notable correlative relationship appears in 16 months when the SST of the tropical western Pacific and the Indian Oceans lag back the Antarctic ice area. 相似文献
2.
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 Niño-Southern Oscillation). The TC northward, southward, upward, and downward transports all weaken in El Niños and strengthen in La Niñas. 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 tropics. 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 El Niños and increase during strong La Niñas. DTC upward and downward transports are not strongly correlated with the Niño-3 index and may not be completely controlled by ENSO. 相似文献
3.
This paper attempts to analyze in detail the remote influence of the Indian Ocean Basin warming on the Northwest Pacific (NWP) during the year of decaying El Niño. Observation data and the Fast Ocean-Atmosphere coupled Model 1.5 were used to investigate the triggering conditions under which the remote influence is formed between the positive sea surface temperature (SST) anomaly in the North Indian Ocean and the Anomalous Northwest Pacific anticyclone (ANWPA). Our research show that it is only when there is a contributory background wind field over the Indian Ocean, i.e., when the Indian Summer Monsoon (ISM) reaches its peak, that the warmer SST anomaly in the North Indian Ocean incites significant easterly wind anomalies in the lower atmosphere of the Indo-West tropical Pacific. This then produces the remote influence on the ANWPA. Therefore, the SST anomaly in the North Indian Ocean might interfere with the prediction of the East Asia Summer Monsoon in the year of decaying El Niño. Both the sustaining effect of local negative SST anomalies in the NWP, and the remote effect of positive SST anomalies in the North Indian Ocean on the ANWPA, should be considered in further research. 相似文献
4.
Southern ocean SST variability and its relationship with ENSO on inter-decadal time scales 总被引：1，自引：0，他引：1
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- north-east 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 El Nio 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. 相似文献
5.
The Simple Ocean Data Assimilation (SODA) package is used to better understand the variabilities of surface current transport in the Tropical Pacific Ocean from 1950 to 1999. Seasonal variation, internnual and decadal variability analyses are conducted on the three major surface currents of the Tropical Pacific Ocean: the North Equatorial Current (NEC), the North Equatorial Countecurrent (NECC), and the South Equatorial Current (SEC). The transport of SEC is quite larger than those of NEC and NECC. The SEC has two maximums in February and August. The NEC has a small annual variation. The NECC has a maximum in October and is very weak in March and April. All currents have remarkable interannual and decadal variabilities. The variabilities of the NEC and the SEC related to the winds over them well, but the relationship between the NECC and the wind over it is not close. Analysis related to El Niño-Southern Oscillation (ENSO) suggests that before El Niño (La Niña) the SEC is weaker (stronger) and the NECC is stronger (weaker), after El Niño (La Niña) the SEC is stronger (weaker) and the SEC is weaker (stronger). There is no notable relationship between the NEC and ENSO. 相似文献
6.
The Sea Level Anomaly-Torque （SLAT, relative to a reference location in the Pacific Ocean）, which means the total torque of the gravity forces of sea waters with depths equal to the Sea Level Anomaly （S/A） in the tropical Pacific Ocean, is defined in this study. The time series of the SLAT from merged altimeter data （1993-2003） had a great meridional variation during the 1997-1998 E1 Nifio event. By using historical upper layer temperature data （1955-2003） for the tropical Pacific Ocean, the temperature-based SLAT is also calculated and the meridional variation can be found in the historical E1 Nifio events （1955-2003）, which suggests that the meridional shifts of the sea level anomaly are also intrinsic oscillating modes of the E1 Nifio cycles like the zonal shifts. 相似文献
7.
The standard deviation of the central Pacific sea surface temperature anomaly (SSTA) during the period from October to February shows that the central Pacific SSTA variation is primarily due to the occurrence of the Central Pacific El Nio (CP-El Nio) and has a connection with the subtropical air-sea interaction in the northeastern Pacific. After removing the influence of the Eastern Pacific El Nio, an S-EOF analysis is conducted and the leading mode shows a clear seasonal SSTA evolving from the subtropical northeastern Pacific to the tropical central Pacific with a quasi-biennial period. The initial subtropical SSTA is generated by the wind speed decrease and surface heat flux increase due to a north Pacific anomalous cyclone. Such subtropical SSTA can further influence the establishment of the SSTA in the tropical central Pacific via the wind-evaporation-SST (WES) feedback. After established, the central equatorial Pacific SSTA can be strengthened by the zonal advective feedback and thermocline feedback, and develop into CP-El Nio. However, as the thermocline feedback increases the SSTA cooling after the mature phase, the heat flux loss and the re-versed zonal advective feedback can cause the phase transition of CP-El Nio. Along with the wind stress variability, the recharge (discharge) process occurs in the central (eastern) equatorial Pacific and such a process causes the phase consistency between the thermocline depth and SST anomalies, which presents a contrast to the original recharge/discharge theory. 相似文献
8.
Based on the monthly average SST and 850 hPa monthly average wind data,the seasonal,interannual and long-term variations in the eastern Indian Ocean warm pool(EIWP) and its relationship to the Indian Ocean Dipole(IOD),and its response to the wind over the Indian Ocean are analyzed in this study.The results show that the distribution range,boundary and area of the EIWP exhibited obviously seasonal and interannual variations associated with the ENSO cycles.Further analysis suggests that the EIWP had obvious l... 相似文献
9.
An experiment using the Community Climate System Model (CCSM4), a participant of the Coupled Model Intercomparison Project phase-5 (CMIP5), is analyzed to assess the skills of this model in simulating and predicting the climate variabilities associated with the oceanic channel dynamics across the Indo-Pacific Oceans. The results of these analyses suggest that the model is able to reproduce the observed lag correlation between the oceanic anomalies in the southeastern tropical Indian Ocean and those in the cold tongue in the eastern equatorial Pacific Ocean at a time lag of 1 year. This success may be largely attributed to the successful simulation of the interannual variations of the Indonesian Throughflow, which carries the anomalies of the Indian Ocean Dipole (IOD) into the western equatorial Pacific Ocean to produce subsurface temperature anomalies, which in turn propagate to the eastern equatorial Pacific to generate ENSO. This connection is termed the “oceanic channel dynamics” and is shown to be consistent with the observational analyses. However, the model simulates a weaker connection between the IOD and the interannual variability of the Indonesian Throughflow transport than found in the observations. In addition, the model overestimates the westerly wind anomalies in the western-central equatorial Pacific in the year following the IOD, which forces unrealistic upwelling Rossby waves in the western equatorial Pacific and downwelling Kelvin waves in the east. This assessment suggests that the CCSM4 coupled climate system has underestimated the oceanic channel dynamics and overestimated the atmospheric bridge processes. 相似文献
10.
SST variations of the Kuroshio from AVHRR observation 总被引：1，自引：0，他引：1
1 INTRODUCTION The Kuroshio Current (KC), being the western boundary current in the North Pacific subtropical gyre, is the second strongest current in the world af- ter the Gulf Stream and is famous as a strong and fast flow. KC plays an important role in… 相似文献
11.
El Niño and Southern Oscillation (ENSO) is an interannual phenomenon involved in the tropical Pacific sea-air interactions. An asymptotic method of solving equations for the ENSO model is proposed. Based on a class of oscillator of ENSO model and by employing a simple and valid method of the variational iteration, the coupled system for a sea-air oscillator model of interdecadal climate fluctuations is studied. Firstly, by introducing a set of functionals and computing the variationals, the Lagrange multipliers are obtained. And then, the generalized variational iteration expressions are constructed. Finally, by selecting appropriate initial iteration, and from the iterations expressions, the approximations of solution for the sea-air oscillator ENSO model are solved successively. The approximate dissipative travelling wave solution of equations for corresponding ENSO model is studied. It is proved from the results that the method of the variational iteration can be used for analyzing the sea surface temperature anomaly in the equatorial Pacific of the sea-air oscillator for ENSO model. 相似文献
12.
Jun Zhao Hans-Ulrich Peter Haisheng Zhang Zhengbing Han Chuanyu Hu Peisong Yu Bing Lu Thomas S. Bianchi 《中国海洋大学学报(英文版)》2014,13(3):437-444
The study provides one of the first lines of evidence showing linkages between Antarctic phytoplankton abundance and composition in response to ENSO, based on historical reconstruction of sediment biomarkers. In addition to sediment biomarkers, field measured and remote sensing data of phytoplankton abundance were also recorded from Prydz Bay, Eastern Antarctica. Com-munity structure of field measured phytoplankton showed significant El Ni？o/La Ni？a-related succession during 1990 to 2002. In general, the number of algae species decreased during El Ni？o and La Ni？a years compared to normal years. Austral summer monthly variation of remotely sensed chlorophyll-a （Chl-a）, particulate organic carbon （POC）, and sea surface temperature （SST） indicated that ENSO impacted the timing of phytoplankton blooms during 2007 to 2011. Phytoplankton blooms （indicated by Chl-a and POC） preceded the increases in SST during El Ni？o years, and lagged behind the SST increases during La Ni？a years. Stratigraphic record of marine sedimentary lipid （brassicasterol, dinosterol and alkenones） biomarkers inferred that the proportions of different algae （diatoms, dinoflagellates and haptophytes） changed significantly between El Ni？o and La Ni？a events. The relative proportion of diatoms increased, with that of dinoflagellates being decreased during El Ni？o years, while it was reversed during La Ni？a years. 相似文献
13.
Based on the Had ISST1 and NCEP datasets,we investigated the influences of the central Pacific El Ni?o event(CP-EL)and eastern Pacific El Ni?o event(EP-EL)on the Sea Surface Temperature(SST)anomalies of the Tropical Indian Ocean.Considering the remote ef fect of Indian Ocean warming,we also discussed the anticyclone anomalies over the Northwest Pacific,which is very important for the South China precipitation and East Asian climate.Results show that during the El Ni?o developing year of EP-EL,cold SST anomalies appear and intensify in the east of tropical Indian Ocean.At the end of that autumn,all the cold SST anomaly events lead to the Indian Ocean Dipole(IOD)events.Basin uniform warm SST anomalies exist in the Indian Ocean in the whole summer of EL decaying year for both CP-and EP-ELs.However,considering the statistical significance,more significant warm SST anomalies only appear in the North Indian Ocean among the June and August of EP-EL decaying year.For further research,EP-EL accompany with Indian Ocean Basin Warming(EPI-EL)and CP El Ni?o accompany with Indian Ocean Basin Warming(CPI-EL)events are classified.With the remote ef fects of Indian Ocean SST anomalies,the EPI-and CPI-ELs contribute quite differently to the Northwest Pacific.For the EPI-EL developing year,large-scale warm SST anomalies arise in the North Indian Ocean in May,and persist to the autumn of the El Ni?o decaying year.However,for the CPI-EL,weak warm SST anomalies in the North Indian Ocean maintain to the El Ni?o decaying spring.Because of these different SST anomalies in the North Indian Ocean,distinct zonal SST gradient,atmospheric anticyclone and precipitation anomalies emerge over the Northwest Pacific in the El Ni?o decaying years.Specifically,the large-scale North Indian Ocean warm SST anomalies during the EPI-EL decaying years,can persist to summer and force anomalous updrafts and rainfall over the North Indian Ocean.The atmospheric heating caused by this precipitation anomaly emulates atmospheric Kelvin waves accompanied by low level easterly anomalies over the Northwest Pacific.As a result,a zonal SST gradient with a warm anomaly in the west and a cold anomaly in the east of Northwest Pacific is generated locally.Furthermore,the atmospheric anticyclone and precipitation anomalies over the Northwest Pacific are strengthened again in the decaying summer of EPI-EL.Af fected by the local WindEvaporation-SST(WES)positive feedback,the suppressed East Asian summer rainfall then persists to the late autumn during EPI-EL decaying year,which is much longer than that of CPI-EL. 相似文献
14.
The South China Sea (SCS) is significantly influenced by El Niño and the Southern Oscillation (ENSO) through ENSO-driven atmospheric and oceanic changes. We analyzed measurements made from 1960 to 2004 to investigate the interannual variability of the latent and sensible heat fluxes over the SCS. Both the interannual variations of latent and sensible heat fluxes are closely related to ENSO events. The low-pass mean heat flux anomalies vary in a coherent manner with the low-pass mean Southern Oscillation Index (SOI). Time lags between the heat flux anomalies and the SST anomalies were also studied. We found that latent heat flux anomalies have a minimum value around January of the year following El Niño events. During and after the mature phase of El Niño, a change of atmospheric circulation alters the local SCS near-surface humidity and the monsoon winds. During the mature phase of El Niño, the wind speed decreases over the entire sea, and the air-sea specific humidity difference anomalies decreases in the northern SCS and increases in the southern SCS. Thus, a combined effect of wind speed anomalies and air-sea specific humidity difference anomalies results in the latent heat flux anomalies attaining minimum levels around January of the year following an El Niño year. 相似文献
15.
Interannual variations of Pacific North Equatorial Current (NEC) transport during eastern-Pacific El Niños (EP-El Niños) and central-Pacific El Niños (CP-El Niños) are investigated by composite analysis with European Centre for Medium-Range Weather Forecast Ocean Analysis/Reanalysis System 3. During EP-El Niño, NEC transport shows significant positive anomalies from the developing to decay phases, with the largest anomalies around the mature phase. During CP-El Niño, however, the NEC transport only shows positive anomalies before the mature phase, with much weaker anomalies than those during EP-El Niño. The NEC transport variations are strongly associated with variations of the tropical gyre and wind forcing in the tropical North Pacific. During EP-El Niño, strong westerly wind anomalies and positive wind stress curl anomalies in the tropical North Pacific induce local upward Ekman pumping and westward-propagating upwelling Rossby waves in the ocean, lowering the sea surface height and generating a cyclonic gyre anomaly in the western tropical Pacific. During CP-El Niño, however, strength of the wind and associated Ekman pumping velocity are very weak. Negative sea surface height and cyclonic flow anomalies are slightly north of those during EP El Niño. 相似文献
16.
Interannual variations in the surface and subsurface tropical Indian Ocean were studied using HadISST and SODA datasets.Wind and heat flux datasets were used to discuss the mechanisms for these variations.Our results indicate that the surface and subsurface variations of the tropical Indian Ocean during Indian Ocean Dipole(IOD)events are significantly different.A prominent characteristic of the eastern pole is the SSTA rebound after a cooling process,which does not take place at the subsurface layer.In the western pole,the surface anomalies last longer than the subsurface anomalies.The subsurface anomalies are strongly correlated with ENSO,while the relationship between the surface anomalies and ENSO is much weaker.And the subsurface anomalies of the two poles are negatively correlated while they are positively correlated at the surface layer.The wind and surface heat flux analysis suggests that the thermocline depth variations are mainly determined by wind stress fields,while the heat flux effect is important on SST. 相似文献
17.
ENSO cycle and climate anomaly in China 总被引：2，自引：0，他引：2
The inter-annual variability of the tropical Pacific Subsurface Ocean Temperature Anomaly (SOTA) and the associated anomalous atmospheric circulation over the Asian North Pacific during the El Ni o-Southern Oscillation (ENSO) were investigated using National Centers for Environmental Prediction/ National Center for Atmospheric Research (NCEP/NCAR) atmospheric reanalysis data and simple ocean data simulation (SODA). The relationship between the ENSO and the climate of China was revealed. The main results indicated the following: 1) there are two ENSO modes acting on the subsurface tropical Pacific. The first mode is related to the mature phase of ENSO, which mainly appears during winter. The second mode is associated with a transition stage of the ENSO developing or decaying, which mainly occurs during summer; 2) during the mature phase of El Ni o, the meridionality of the atmosphere in the mid-high latitude increases, the Aleutian low and high pressure ridge over Lake Baikal strengthens, northerly winds prevail in northern China, and precipitation in northern China decreases significantly. The ridge of the Ural High strengthens during the decaying phase of El Ni o, as atmospheric circulation is sustained during winter, and the northerly wind anomaly appears in northern China during summer. Due to the ascending branch of the Walker circulation over the western Pacific, the western Pacific Subtropical High becomes weaker, and south-southeasterly winds prevail over southern China. As a result, less rainfall occurs over northern China and more rainfall over the Changjiang River basin and the southwestern and eastern region of Inner Mongolia. The flood disaster that occurred south of Changjiang River can be attributed to this. The La Ni a event causes an opposite, but weaker effect; 3) the ENSO cycle can influence climate anomalies within China via zonal and meridional heat transport. This is known as the "atmospheric-bridge", where the energy anomaly within the tropical Pacific transfers to the mid-high latitude in the northern Pacific through Hadley cells and Rossby waves, and to the western Pacific-eastern Indian Ocean through Walker circulation. This research also discusses the special air-sea boundary processes during the ENSO events in the tropical Pacific, and indicates that the influence of the subsurface water of the tropical Pacific on the atmospheric circulation may be realized through the sea surface temperature anomalies of the mixed water, which contact the atmosphere and transfer the anomalous heat and moisture to the atmosphere directly. Moreover, the reason for the heavy flood within the Changjiang River during the summer of 1998 is reviewed in this paper. 相似文献
18.
By using monthly historical sea surface temperature (SST) data for the years from 1950 to 2000, the Western Pacific Warm Pool (WPWP) climatology and anomalies are studied in this paper. The analysis of WPWP centroid (WPWPC) movement anomalies and the Niño-3 region SST anomalies(SSTA) seems to reveal a close, linear relation between the zonal WPWPC and Niño-3 region SSTA, which suggests that a 9° anomaly of the zonal displacement from the climatological position of the WPWPC corresponds to about a l°C anomaly in the Niño-3 region area-mean SST. This study connects the WPWPC zonal displacement with the Niño-3 SSTA, and it may be helpful in better understanding the fact that the WPWP eastward extension is conducive to the Niño-3 region SST increase during an El Niño-Southern Oscillation (ENSO) event. 相似文献
19.
Zonal heat advection （ZHA） plays an important role in the variability of the thermal structure in the tropical Pacific Ocean, especially in the western Pacific warm pool （WPWP）. Using the Simple Ocean Data Assimilation （SODA） Version 2.02/4 for the period 1958-2007, this paper presents a detailed analysis of the climatological and seasonal ZHA in the tropical Pacific Ocean. Climatologically, ZHA shows a zonal- band spatial pattern associated with equatorial currents and contributes to forming the irregular eastern boundary of the WPWP （EBWP）. Seasonal variation of ZHA with a positive peak from February to July is most prominent in the Nifio3.4 region, where the EBWP is located. The physical mechanism of the seasonal cycle in this region is examined. The mean advection of anomalous temperature, anomalous advection of mean temperature and eddy advection account for 31%, 51%, and 18% of the total seasonal variations, respectively. This suggests that seasonal changes of the South Equatorial Current induced by variability of the trade winds are the dominant contributor to the anomalous advection of mean temperature and hence, the seasonality of ZHA. Heat budget analysis shows that ZHA and surface heat flux make comparable contributions to the seasonal heat variation in the Nifio3.4 region, and that ZHA cools the upper ocean throughout the calendar year except in late boreal spring. The connection between ZHA and EBWP is further explored and a statistical relationship between EBWP, ZHA and surface heat flux is established based on least squares fitting. 相似文献
20.
Satellite measurements of global sea surface temperatures (SST) have been made since 1982 using the multi-channel radiometers (AVHRR) on NOAA polar orbiting satellites. A four year data set was accumulated at daily intervals and a spatial resolution of about 100 kilometers on an interactive computer system. The time lapse evaluation of the data revealed variations of the SST which were related to coastal and equatorial upwelling events as well as to the pronounced equatorial warming associated with the 1982–1983 El Niño. In the present study, satellite time series are used to describe the annual variability of the SST at selected locations along the coast of China, the Yellow Sea, the Sea of Japan and the Equatorial Indian and Pacific Oceans. Further study of the SST off China using higher resolution satellite data are also described.
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