Tropical cyclogenesis associated with four types of summer monsoon circulation over the South China Sea

2017 ◽  
Vol 37 (11) ◽  
pp. 4229-4236 ◽  
Author(s):  
Lei Wang
Keyword(s):  
South China Sea ◽  
Summer Monsoon ◽  
South China ◽  
The South China Sea ◽  
Tropical Cyclogenesis ◽  
Monsoon Circulation ◽  
The South ◽  
China Sea

A Climatological Monsoon Break in Rainfall over Indochina—A Singularity in the Seasonal March of the Asian Summer Monsoon

2006 ◽  
Vol 19 (8) ◽  
pp. 1545-1556 ◽  
Author(s):  
Hiroshi G. Takahashi ◽  
Tetsuzo Yasunari
Keyword(s):  
South China Sea ◽  
Summer Monsoon ◽  
South China ◽  
Cyclonic Circulation ◽  
The South China Sea ◽  
Monsoon Circulation ◽  
Mountain Range ◽  
The South ◽  
China Sea ◽  
Seasonal March

Abstract This study investigated the climatological pentad mean annual cycle of rainfall in Thailand and the associated atmospheric circulation fields. The data used included two different data of rainfall: rain gauge data for Thailand from the Thai Meteorological Department and satellite-derived rainfall data from the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP). Climatological mean pentad values of rainfall taken over 50 yr clearly show a distinct climatological monsoon break (CMB) occurring over Thailand in late June. The occurrence of the CMB coincides with a drastic change of large-scale monsoon circulation in the seasonal march. The CMB is a significant singularity in the seasonal march of the Southeast Asia monsoon, which divides the rainy season into the early monsoon and the later monsoon over the Indochina Peninsula. A quasi-stationary ridge dynamically induced by the north–south-oriented mountain range in Indochina is likely to cause the CMB. The formation of the strong ridge over the mountain ranges of Indochina is preceded by a sudden enhancement (northward expansion) of the upstream monsoon westerlies along a latitudinal band between 15° and 20°N in late June. The CMB also has an impact downstream. The orographically induced stationary Rossby waves enhance the cyclonic circulation to the lee of Indochina, and over the South China Sea. The enhancement of cyclonic circulation may be responsible for the summer monsoon rains peaking in late June over the South China Sea and the western North Pacific, and in the baiu front.

April-June rainfall features in South China in relation to the establishment of summer monsoon in the South-China Sea

2006 ◽  
Author(s):  
Yanzhen Chi ◽  
Zhaoyong Guan ◽  
Jinhai He ◽  
Li Qi ◽  
Xuefen Zhang
Keyword(s):  
South China Sea ◽  
Summer Monsoon ◽  
South China ◽  
The South China Sea ◽  
The South ◽  
China Sea

scholarly journals The role of synoptic-scale waves in the onset of the South China Sea summer monsoon

2018 ◽  
Vol 19 (11) ◽  
pp. e858 ◽  
Author(s):  
Jingliang Huangfu ◽  
Wen Chen ◽  
Xu Wang ◽  
Ronghui Huang
Keyword(s):  
South China Sea ◽  
Summer Monsoon ◽  
South China ◽  
The South China Sea ◽  
Synoptic Scale ◽  
The South ◽  
China Sea

scholarly journals Role of Air-sea Coupling in the Interannual Variability of the South China Sea Summer Monsoon

2011 ◽  
Vol 89A ◽  
pp. 283-290 ◽  
Author(s):  
Rosbintarti Kartika LESTARI ◽  
Masahiro WATANABE ◽  
Masahide KIMOTO
Keyword(s):  
South China Sea ◽  
Interannual Variability ◽  
Summer Monsoon ◽  
South China ◽  
The South China Sea ◽  
The South ◽  
China Sea

scholarly journals Intraseasonal Variability of the South China Sea Summer Monsoon

2005 ◽  
Vol 18 (13) ◽  
pp. 2388-2402 ◽  
Author(s):  
Jiangyu Mao ◽  
Johnny C. L. Chan
Keyword(s):  
South China Sea ◽  
Summer Monsoon ◽  
South China ◽  
Intraseasonal Variability ◽  
Lower Troposphere ◽  
Monsoon Trough ◽  
The South China Sea ◽  
The South ◽  
Central Pacific ◽  
China Sea

Abstract The objective of this study is to explore, based on the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis data, the intraseasonal variability of the South China Sea (SCS) summer monsoon (SM) in terms of its structure and propagation, as well as interannual variations. A possible mechanism that is responsible for the origin of the 10–20-day oscillation of the SCS SM is also proposed. The 30–60-day (hereafter the 3/6 mode) and 10–20-day (hereafter the 1/2 mode) oscillations are found to be the two intraseasonal modes that control the behavior of the SCSSM activities for most of the years. Both the 3/6 and 1/2 modes are distinct, but may not always exist simultaneously in a particular year, and their contributions to the overall variations differ among different years. Thus, the interannual variability in the intraseasonal oscillation activity of the SCS SM may be categorized as follows: the 3/6 category, in which the 3/6 mode is more significant (in terms of the percentage of variance explained) than the 1/2 mode; the 1/2 category, in which the 1/2 mode is dominant; and the dual category, in which both the 3/6 and 1/2 modes are pronounced. Composite analyses of the 3/6 category cases indicate that the 30–60-day oscillation of the SCS SM exhibits a trough–ridge seesaw in which the monsoon trough and subtropical ridge exist alternatively over the SCS, with anomalous cyclones (anticyclones), along with enhanced (suppressed) convection, migrating northward from the equator to the midlatitudes. The northward-migrating 3/6-mode monsoon trough–ridge in the lower troposphere is coupled with the eastward-propagating 3/6-mode divergence–convergence in the upper troposphere. It is also found that, for the years in the dual category, the SCS SM activities are basically controlled by the 3/6 mode, but modified by the 1/2 mode. Composite results of the 1/2-mode category cases show that the 10–20-day oscillation is manifest as an anticyclone–cyclone system over the western tropical Pacific, propagating northwestward into the SCS. A close coupling also exists between the upper-level convergence (divergence) and the low-level anticyclone (cyclone). It is found that the 1/2 mode of the SCS SM mainly originates from the equatorial central Pacific, although a disturbance from the northeast of the SCS also contributes to this mode. The flow patterns from an inactive to an active period resemble those associated with a mixed Rossby–gravity wave observed in previous studies.

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