scholarly journals Origins of Quasi-Biweekly and Intraseasonal Oscillations over the South China Sea and Bay of Bengal and Scale Selection of Unstable Equatorial and Off-Equatorial Modes

2020 ◽  
Vol 34 (1) ◽  
pp. 137-149 ◽  
Author(s):  
Ying Zhang ◽  
Tim Li ◽  
Jianyun Gao ◽  
Wei Wang
Keyword(s):  
South China Sea ◽  
South China ◽  
Bay Of Bengal ◽  
The South China Sea ◽  
Scale Selection ◽  
The South ◽  
China Sea ◽  
Intraseasonal Oscillations ◽  
Selection Of

An Analysis of the Characteristics of Monsoon Onset over the Bay of Bengal and the South China Sea in 2010

2012 ◽  
Vol 5 (4) ◽  
pp. 334-341
Author(s):  
Ding Xuan-Ru ◽  
Wang Dong-Xiao ◽  
Li Wei-Biao ◽  
Guan Zhao-Yong
Keyword(s):  
South China Sea ◽  
South China ◽  
Bay Of Bengal ◽  
Monsoon Onset ◽  
The South China Sea ◽  
The South ◽  
China Sea

Are the trends in the surface chlorophyll opposite between the South China Sea and the Bay of Bengal?

2014 ◽  
Author(s):  
Xiaoyan Chen ◽  
Delu Pan ◽  
Yan Bai ◽  
Xianqiang He ◽  
Tianyu Wang
Keyword(s):  
South China Sea ◽  
South China ◽  
Bay Of Bengal ◽  
The South China Sea ◽  
The South ◽  
China Sea

scholarly journals Evaluation of the ability of the Chinese stalagmite δ<sup>18</sup>O to record the variation in atmospheric circulation during the second half of the 20th century

2014 ◽  
Vol 10 (3) ◽  
pp. 975-985 ◽  
Author(s):  
S. Nan ◽  
M. Tan ◽  
P. Zhao
Keyword(s):  
Water Vapor ◽  
South China Sea ◽  
South China ◽  
Bay Of Bengal ◽  
North Pacific ◽  
Western North Pacific ◽  
Large Scale ◽  
The South China Sea ◽  
The South ◽  
China Sea

Abstract. The Chinese stalagmite δ18O (δ18Ocs) has provoked debate worldwide over the past few years due to its lack of quantitative calibration, leading us to questions of whether δ18Ocs records a local or large-scale signal and whether δ18Ocs records the signal of a single remote water vapor source or multiple water vapor sources. In this study, we observe all of the δ18Ocs trends within the instrumental period to verify whether they possess a common trend, which could be used as a basis to determine whether the trends reflect the large-scale signal together or whether each trend reflects the local signal. The results show that most of the δ18Ocs experienced a linear increase from 1960 to 1994, which may indicate that the δ18Ocs could record a trend occurring in large-scale atmosphere circulations. We then quantitatively describe the proportion of water vapor transport (WVT) from different source regions. Using the NCEP/NCAR (National Centers for Environmental Protection/National Center for Atmospheric Research) reanalysis data from 1960 to 1994, the ratios of the intensities of three WVTs from the Bay of Bengal, the South China Sea, and the western North Pacific during the summer are calculated. We define RSCS/BOB as the ratio of the WVT intensities from the South China Sea to those from the Bay of Bengal, RWNP/BOB as the ratio of the WVT intensities from the western North Pacific to those from the Bay of Bengal, and RWNP/SCS as the ratio of the WVT intensities from the western North Pacific to those from the South China Sea. The significant decadal increase occurs in the time series of RWNP/BOB and RWNP/SCS, most likely resulting from the strengthening of the WVT from the western North Pacific in the late 1970s due to the western Pacific subtropical high that extended westward. Further analysis indicates that when the equatorial central and eastern Pacific is in the El Niño phase, the sea surface temperature (SST) in the tropical Indian Ocean, the Bay of Bengal, and the South China Sea is high, and the SST at the middle latitudes in the North Pacific is low, then the RWNP/BOB and RWNP/SCS values tend to be high. After the late 1970s, the equatorial central and eastern Pacific have often been in the El Niño phase. Therefore, we confirm that the δ18Ocs primarily records the variation in atmospheric circulation during the second half of the 20th century.

scholarly journals Migratory Tropical Cyclones in the South China Sea Modulated by Intraseasonal Oscillations and Climatological Circulations

2019 ◽  
Vol 32 (19) ◽  
pp. 6445-6466
Author(s):  
Jau-Ming Chen ◽  
Ching-Hsuan Wu ◽  
Jianyun Gao ◽  
Pei-Hsuan Chung ◽  
Chung-Hsiung Sui
Keyword(s):  
South China Sea ◽  
Tropical Cyclones ◽  
South China ◽  
Western Pacific Subtropical High ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Anomalous Anticyclone ◽  
Intraseasonal Oscillations ◽  
Anomalous Cyclone

Abstract This study focuses on the migratory tropical cyclones (TCs) that form in the western North Pacific (WNP) and move into the South China Sea (SCS). Their movements are found to be modulated differently by intraseasonal oscillations (ISOs) and climatological circulations through the TC-active months. The modulating processes of climatological circulations vary from a westward intensifying western Pacific subtropical high (WPSH) in July and August to a southeastward extending monsoon trough (MT) in September, and a strengthening equatorial trough (ET) in October and November. In July and August, enhanced tropical ISO convections in the SCS are accompanied by a 30–60-day anomalous anticyclone to the northeast of the SCS. The migratory TCs move along the southern peripheries of this anomalous anticyclone and the WPSH into the SCS. In September, enhanced ISO convections in the SCS coincide with a meridional 30–60-day circulation pair with an anomalous anticyclone to the north of 20°N and an anomalous cyclone to the south. TCs move in between this meridional 30–60-day circulation pair and the northern periphery of the MT toward the SCS. In October and November, enhanced ISO convections in the SCS and WNP coexist with an overlying 30–60-day anomalous cyclone and an intensified ET. The migratory TCs move along the northern sections of this 30–60-day anomalous cyclone and the ET toward the SCS. With a different track, TCs recurving northward from the tropical WNP into the region east of Taiwan are modulated by completely different variability features of the 30–60-day ISO and climatological circulations.

scholarly journals Impact of Intraseasonal Oscillations on the Activity of Tropical Cyclones in Summer Over the South China Sea: Nonlocal Tropical Cyclones

2020 ◽  
Vol 8 ◽  
Author(s):  
Zheng Ling ◽  
Yuqing Wang ◽  
Guihua Wang ◽  
Hailun He
Keyword(s):  
South China Sea ◽  
Tropical Cyclones ◽  
South China ◽  
Western Pacific Subtropical High ◽  
The South China Sea ◽  
Northwest Pacific ◽  
The South ◽  
China Sea ◽  
Typhoon Intensity ◽  
Intraseasonal Oscillations

In addition to tropical cyclones (TCs) locally formed in the South China Sea (SCS), there are also TCs that initially form over the Northwest Pacific (NWP) and move westward to enter the SCS (often called nonlocal TCs). It is unclear how those nonlocal TCs are modulated by the intraseasonal climate variability. In this study, the impacts of two types of intraseasonal oscillations, namely the Madden–Julian Oscillation (MJO) and the quasi-biweekly oscillation (QBWO), on nonlocally formed TCs over the SCS in summer (May–September) are analyzed based on best-track TC data and global reanalysis during 1979–2018. Results show that in the convective phases of both MJO and QBWO, the western Pacific subtropical high shifted more eastward, and more TCs entered the SCS. This is mainly because more TCs formed in the NWP in the convective phases of intraseasonal oscillations and the genesis locations of the NWP TCs shifted westward and closer to the SCS. In addition to TC count, intraseasonal oscillations also affected the intensity of nonlocal TCs entered the SCS, with the influence of QBWO being more significant than MJO. In the convectively active phases of QBWO (phases 2–5), 34 nonlocal TCs reached typhoon intensity, while only two nonlocal TCs reached typhoon intensity in the convectively inactive phases (phases 1, 6, 7, 8). Further analysis indicates that nonlocal TCs often moved with the northwestward propagating convective signals of QBWO, resulting in more and stronger TCs that entered the SCS in the convective phases of QBWO. The mean location that the nonlocal TC entered the SCS also shifted northward with the northward propagation of intraseasonal oscillations.

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