Influence of the South China Sea Biweekly Sea Surface Temperature on the South China Sea Summer Monsoon Especially during the Indian Ocean Dipole

This paper investigates the impact of the South China Sea summer monsoon (SCSSM) on the Indian Ocean dipole (IOD). The results show that the SCSSM has a significant positive relationship with the IOD over the boreal summer [June–August (JJA)] and fall [September–November (SON)]. When the SCSSM is strong, the enhanced southwesterly winds that bring more water vapor to the western North Pacific (WNP) lead to surplus precipitation in the WNP, inducing anomalous ascending there. Consequently, the anomalous descending branch of the SCSSM Hadley circulation (SCSSMHC) develops over the Maritime Continent (MC), favoring deficit precipitation in situ. The precipitation dipole over the WNP and MC as well as the enhanced SCSSMHC leads to intensification of the southeasterly anomalies off Sumatra and Java, which then contributes to the negative sea surface temperature (SST) anomalies through the positive wind–evaporation–SST and wind–thermocline–SST (Bjerknes) feedbacks. Consequently, a positive IOD develops because of the increased zonal gradient of the tropical Indian Ocean SST anomalies and vice versa. The SCSSM has a peak correlation with the IOD when the former leads the latter by three months. This implies that a positive IOD can persist from JJA to SON and reach its mature phase within the frame of the positive Bjerknes feedback in SON. In addition, the local and remote SST anomalies in the tropical Indian and Pacific Oceans have a slight influence on the relationship between the SCSSM and precipitation dipole over the WNP and MC.

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The relative roles of the South China Sea summer monsoon and ENSO in the Indian Ocean dipole development

Climate Dynamics ◽

10.1007/s00382-019-04953-4 ◽

2019 ◽

Vol 53 (11) ◽

pp. 6665-6680 ◽

Cited By ~ 1

Author(s):

Yazhou Zhang ◽

Jianping Li ◽

Jiaqing Xue ◽

Fei Zheng ◽

Renguang Wu ◽

...

Keyword(s):

Indian Ocean ◽

South China Sea ◽

Summer Monsoon ◽

South China ◽

Indian Ocean Dipole ◽

The South China Sea ◽

The South ◽

China Sea ◽

The Indian Ocean

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The relative roles of the South China Sea summer monsoon and ENSO in the Indian Ocean dipole development

10.5194/egusphere-egu2020-1819 ◽

2020 ◽

Author(s):

Jianping Li ◽

Yazhou Zhang ◽

Jiaqing Xue ◽

Fei Zheng ◽

Renguang Wu ◽

...

Keyword(s):

Indian Ocean ◽

South China Sea ◽

Summer Monsoon ◽

South China ◽

Indian Ocean Dipole ◽

The South China Sea ◽

Boreal Summer ◽

The South ◽

China Sea ◽

The Indian Ocean

<p>The influence of El Ni&#241;o-Southern Oscillation (ENSO) on the Indian Ocean Dipole (IOD), a coupled ocean&#8211;atmosphere mode of interannual climate variability, has been widely investigated over recent decades. However, a latest study indicates that the South China Sea summer monsoon (SCSSM) might also be responsible for IOD formation. Furthermore, an abnormal SCSSM does not always coincide with ENSO during boreal summer (June&#8211;August, JJA); consequently, the individual and combined effects of the SCSSM and ENSO on the IOD remain elusive. This study shows that the amplitude of the IOD tends to be much stronger under the coexistence of SCSSM and ENSO than that under individual SCSSM or ENSO events during JJA and autumn. The findings also indicate that the SCSSM and ENSO play the dominant role around the eastern and western poles of the IOD, respectively. An anomalous local Hadley circulation closely related to the stronger SCSSM favors anomalous southeasterly of Sumatra and Java during JJA, which enhance oceanic upwelling and subsequently result in cooling of the sea surface temperature (SST) over this area. Similarly, it can be envisaged that the contemporaneous ENSO could influence JJA SST anomalies over the western Indian Ocean via the Walker circulation coupled with oceanic variations.</p>

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

Journal of Earthquake and Tsunami ◽

10.1142/s1793431112500108 ◽

2012 ◽

Vol 06 (02) ◽

pp. 1250010 ◽

Cited By ~ 20

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.

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