scholarly journals Interdecadal Difference of Interannual Variability Characteristics of South China Sea SSTs Associated with ENSO

2015 ◽  
Vol 28 (18) ◽  
pp. 7145-7160 ◽  
Author(s):  
Yali Yang ◽  
Shang-Ping Xie ◽  
Yan Du ◽  
Hiroki Tokinaga
Keyword(s):  
Indian Ocean ◽  
South China Sea ◽  
South China ◽  
El Niño ◽  
El Nino ◽  
Tropical Indian Ocean ◽  
Easterly Wind ◽  
China Sea ◽  
Sst Warming ◽  
The Indian Ocean

Abstract The correlation between sea surface temperature (SST) and El Niño–Southern Oscillation (ENSO) persists into post-ENSO September over the South China Sea (SCS), the longest correlation in the World Ocean. Slow modulations of this correlation are analyzed by using the International Comprehensive Ocean–Atmosphere Dataset (ICOADS). ENSO’s influence on SCS SST has experienced significant interdecadal changes over the past 138 years (1870–2007), with a double-peak structure correlation after the 1960s compared to a single-peak before the 1940s. According to the ENSO correlation character, the analysis period is divided into four epochs. In epoch 3, 1960–83, the SST warming and enhanced precipitation over the southeastern tropical Indian Ocean, rather than the Indian Ocean basinwide warming, induce easterly wind anomalies and warm up the SCS in the summer following El Niño. Besides the Indian Ocean effect, during epochs 2 (1930–40) and 4 (1984–2007), the Pacific–Japan (PJ) pattern of atmospheric circulation anomalies helps sustain the SCS SST warming through summer (June–August) with easterly wind anomalies. The associated increase in shortwave radiation and decrease in upward latent heat flux cause the SCS SST warming to persist into the summer. Meanwhile, the rainfall response around the SCS to ENSO shows interdecadal variability, with stronger variability after the 1980s. The results suggest that both the remote forcing from the tropical Indian Ocean and the PJ pattern are important for the ENSO teleconnection to the SCS and its interdecadal modulations.

scholarly journals Two Independent Triggers for the Indian Ocean Dipole/Zonal Mode in a Coupled GCM

2005 ◽  
Vol 18 (17) ◽  
pp. 3428-3449 ◽  
Author(s):  
Albert S. Fischer ◽  
Pascal Terray ◽  
Eric Guilyardi ◽  
Silvio Gualdi ◽  
Pascale Delecluse
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
Indian Ocean Dipole ◽  
El Nino ◽  
Tropical Indian Ocean ◽  
Sea Surface ◽  
Dynamical Response ◽  
Thermocline Depth ◽  
Second Phase ◽  
The Indian Ocean

Abstract The question of whether and how tropical Indian Ocean dipole or zonal mode (IOZM) interannual variability is independent of El Niño–Southern Oscillation (ENSO) variability in the Pacific is addressed in a comparison of twin 200-yr runs of a coupled climate model. The first is a reference simulation, and the second has ENSO-scale variability suppressed with a constraint on the tropical Pacific wind stress. The IOZM can exist in the model without ENSO, and the composite evolution of the main anomalies in the Indian Ocean in the two simulations is virtually identical. Its growth depends on a positive feedback between anomalous equatorial easterly winds, upwelling equatorial and coastal Kelvin waves reducing the thermocline depth and sea surface temperature off the coast of Sumatra, and the atmospheric dynamical response to the subsequently reduced convection. Two IOZM triggers in the boreal spring are found. The first is an anomalous Hadley circulation over the eastern tropical Indian Ocean and Maritime Continent, with an early northward penetration of the Southern Hemisphere southeasterly trades. This situation grows out of cooler sea surface temperatures in the southeastern tropical Indian Ocean left behind by a reinforcement of the late austral summer winds. The second trigger is a consequence of a zonal shift in the center of convection associated with a developing El Niño, a Walker cell anomaly. The first trigger is the only one present in the constrained simulation and is similar to the evolution of anomalies in 1994, when the IOZM occurred in the absence of a Pacific El Niño state. The presence of these two triggers—the first independent of ENSO and the second phase locking the IOZM to El Niño—allows an understanding of both the existence of IOZM events when Pacific conditions are neutral and the significant correlation between the IOZM and El Niño.

scholarly journals Linkage between Interannual Variation of the East Asian Intraseasonal Oscillation and Mei-Yu Onset

2018 ◽  
Vol 32 (1) ◽  
pp. 145-160 ◽  
Author(s):  
Yonghong Yao ◽  
Hai Lin ◽  
Qigang Wu
Keyword(s):  
Indian Ocean ◽  
South China Sea ◽  
South China ◽  
El Niño ◽  
El Nino ◽  
East Asian ◽  
Intraseasonal Oscillation ◽  
Eastern Indian Ocean ◽  
Ep El Niño ◽  
Sst Anomalies

AbstractThe mei-yu onset over the middle to lower reaches of the Yangtze River Valley (MLYRV) varies considerably from early June to mid-July, which leads to large interannual changes in rainy-season length, total summer rainfall, and flooding potential. Previous studies have investigated the impact of El Niño–Southern Oscillation (ENSO) on the mei-yu onset. This study shows that a strong (weak) East Asian and western North Pacific (EAWNP) intraseasonal oscillation (ISO) in spring leads to an early (late) onset of the mei-yu over the MLYRV, and this ISO–mei-yu relationship is attributed to different types of ENSO in the preceding winter. A strong EAWNP ISO in spring is related to an eastern Pacific El Niño (EP El Niño) in the previous winter, and negative sea surface temperature (SST) anomalies in the eastern Indian Ocean and the South China Sea (SCS) in May, which can cause an early onset of the South China Sea summer monsoon that also favors an early mei-yu onset. In contrast, a weak EAWNP ISO in spring is associated with a central Pacific El Niño (CP El Niño) before April, but with an EP El Niño after April, and positive SST anomalies in both the eastern Indian Ocean and the SCS in May. A statistical forecast model combining the intensity of spring EAWNP ISO, CP ENSO, and EP ENSO indices shows a high prediction skill of the observed mei-yu onset date.

TSUNAMI HAZARD AND CASUALTY ESTIMATION IN A COASTAL AREA THAT NEIGHBORS THE INDIAN OCEAN AND SOUTH CHINA SEA

2012 ◽  
Vol 06 (02) ◽  
pp. 1250010 ◽  
Author(s):  
ANAWAT SUPPASRI ◽  
FUMIHIKO IMAMURA ◽  
SHUNICHI KOSHIMURA
Keyword(s):  
Indian Ocean ◽  
South China Sea ◽  
South China ◽  
The South China Sea ◽  
The South ◽  
Worst Case ◽  
China Sea ◽  
Coastal Population ◽  
The Indian Ocean ◽  
Hazard Level

In the Indian Ocean and the South China Sea, many hundreds of thousands of lives have been lost due to tsunami events, and almost half of the lives lost occurred following the 2004 Indian Ocean event. Potential tsunami case scenarios have been simulated in these regions by a number of researchers to calculate the hazard level. The hazard level is based on a variety of conditions, such as the tsunami height, the inundation area, and the arrival time. However, the current assessments of the hazard levels do not focus on the tsunami risk to a coastal population. This study proposes a new method to quantify the risk to the coastal population in the region that includes the Indian Ocean and the South China Sea. The method is simple and combines the use of readily available tsunami data, far-field tsunami simulation models to determine the regional risk and global population data. An earthquake-generated tsunami was simulated, following an earthquake that had a magnitude larger than 8.5 Mw and occurred along a potential subduction zone. The 2004 Indian Ocean event seemed to be a "worst case scenario"; however, it has been estimated that a potential tsunami, occurring in a coastal region with a high population density, could cause significantly greater casualties.

scholarly journals Possible Impact of the Indian Ocean SST on the Northern Hemisphere Circulation during El Niño*

2007 ◽  
Vol 20 (13) ◽  
pp. 3164-3189 ◽  
Author(s):  
H. Annamalai ◽  
H. Okajima ◽  
M. Watanabe
Keyword(s):  
Indian Ocean ◽  
Northern Hemisphere ◽  
El Niño ◽  
El Nino ◽  
Tropical Indian Ocean ◽  
Tropical Pacific ◽  
The Indian Ocean ◽  
Precipitation Anomalies ◽  
Sst Anomalies ◽  
The Tropical Pacific

Abstract Two atmospheric general circulation models (AGCMs), differing in numerics and physical parameterizations, are employed to test the hypothesis that El Niño–induced sea surface temperature (SST) anomalies in the tropical Indian Ocean impact considerably the Northern Hemisphere extratropical circulation anomalies during boreal winter [January–March +1 (JFM +1)] of El Niño years. The hypothesis grew out of recent findings that ocean dynamics influence SST variations over the southwest Indian Ocean (SWIO), and these in turn impact local precipitation. A set of ensemble simulations with the AGCMs was carried out to assess the combined and individual effects of tropical Pacific and Indian Ocean SST anomalies on the extratropical circulation. To elucidate the dynamics responsible for the teleconnection, solutions were sought from a linear version of one of the AGCMs. Both AGCMs demonstrate that the observed precipitation anomalies over the SWIO are determined by local SST anomalies. Analysis of the circulation response shows that over the Pacific–North American (PNA) region, the 500-hPa height anomalies, forced by Indian Ocean SST anomalies, oppose and destructively interfere with those forced by tropical Pacific SST anomalies. The model results validated with reanalysis data show that compared to the runs where only the tropical Pacific SST anomalies are specified, the root-mean-square error of the height anomalies over the PNA region is significantly reduced in runs in which the SST anomalies in the Indian Ocean are prescribed in addition to those in the tropical Pacific. Among the ensemble members, both precipitation anomalies over the SWIO and the 500-hPa height over the PNA region show high potential predictability. The solutions from the linear model indicate that the Rossby wave packets involved in setting up the teleconnection between the SWIO and the PNA region have a propagation path that is quite different from the classical El Niño–PNA linkage. The results of idealized experiments indicate that the Northern Hemisphere extratropical response to Indian Ocean SST anomalies is significant and the effect of this response needs to be considered in understanding the PNA pattern during El Niño years. The results presented herein suggest that the tropical Indian Ocean plays an active role in climate variability and that accurate observation of SST there is of urgent need.

Super instrumental El Niño events recorded by a Porites coral from the South China Sea

Coral Reefs ◽  
2018 ◽  
Vol 37 (1) ◽  
pp. 295-308 ◽  
Author(s):  
Xijie Wang ◽  
Wenfeng Deng ◽  
Xi Liu ◽  
Gangjian Wei ◽  
Xuefei Chen ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
El Niño ◽  
El Nino ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Porites Coral ◽  
El Niño Events ◽  
El Nino Events

Interannual variability of South China Sea winter circulation: response to Luzon Strait transport and El Niño wind

2019 ◽  
Vol 54 (1-2) ◽  
pp. 1145-1159 ◽  
Author(s):  
Qiang Wang ◽  
Lili Zeng ◽  
Yeqiang Shu ◽  
Qinyan Liu ◽  
Tingting Zu ◽  
...  
Keyword(s):  
South China Sea ◽  
Interannual Variability ◽  
South China ◽  
El Niño ◽  
El Nino ◽  
Luzon Strait ◽  
China Sea ◽  
Luzon Strait Transport ◽  
Winter Circulation
Sign in / Sign up

Export Citation Format

Share Document