Impact of the Scandinavian pattern on long-lived cold surges over the South China Sea

2021 ◽  
pp. 1-44
Keyword(s):  
South China Sea ◽  
East Asia ◽  
South China ◽  
Weather Forecast ◽  
The South China Sea ◽  
The South ◽  
Sea Level Pressure ◽  
Central Siberia ◽  
China Sea ◽  
Cold Surges

Abstract This study investigates the influence of the Scandinavian (SCA) pattern on long-lived cold surges over the South China Sea (SCS). The results show that, different from the short-lived ones, the majority of long-lived cold surges over the SCS are preceded by a negative phase of quasi-stationary SCA pattern in the extratropics, which is characterized as a primary cyclonic center over the Scandinavian Peninsula and two anticyclonic ones over North Atlantic and central Siberia. This connection is mainly conducted through a continuous amplification of the high pressure anomalies over East Asia. On the other hand, the SCA-related anomalies also reveal identical responses as an increase in sea level pressure over East Asia and northerly flows over the SCS. Besides, the SCA pattern may influence the long-lived cold surges over the SCS by facilitating blocking occurrence through the extensive and quasi-stationary anticyclone over central Siberia. The present results have an implication for the extended weather forecast: The long-lasting circulation anomalies, such as the SCA pattern, can affect long-lasting weather phenomena in the regions which are located remotely in both the zonal and meridional directions, such as long-lived cold surges over the SCS.

Influence of Siberian Blocking on Long-Lived Cold Surges over the South China Sea

2020 ◽  
Vol 33 (16) ◽  
pp. 6945-6956
Author(s):  
Bo Pang ◽  
Riyu Lu ◽  
Rongcai Ren
Keyword(s):  
South China Sea ◽  
East Asia ◽  
South China ◽  
The South China Sea ◽  
The South ◽  
Sea Level Pressure ◽  
Cold Surge ◽  
China Sea ◽  
Cold Surges ◽  
Extratropical Circulation

AbstractCold surges occur frequently over the South China Sea (SCS) in winter, and most of them last only a few days. However, some cold surge events can persist longer, for instance, more than 5 days. This study focuses on these long-lived cold surge events and investigates the associated extratropical circulation anomalies. The results indicate that long-lived cold surges, characterized as strong northerlies over the SCS, can be triggered by a successive high anomaly center over East Asia. Accompanying this is an anomalously extensive and quasi-stationary anticyclone over Siberia in the midtroposphere, hinting at a more frequent occurrence of Siberian blocking. Further analyses reveal that the blocking frequency is indeed significantly high over 90°–150°E from day −4 to day +2 relative to the onset of long-lived cold surge events. Furthermore, there exist significant correlations between the leading occurrence of Siberian blocking and the sea level pressure (SLP) anomalies over East Asia, which are directly related to long-lived cold surges. The intensification of the high SLP anomaly over East Asia is found to mainly result from cold advection induced by the anomalous northerly winds along the southeastern edge of the Siberian blocking.

scholarly journals Monopole Mode of Precipitation in East Asia Modulated by the South China Sea Over the Last Four Centuries

2019 ◽  
Vol 46 (24) ◽  
pp. 14713-14722 ◽  
Author(s):  
Feng Shi ◽  
Hugues Goosse ◽  
François Klein ◽  
Sen Zhao ◽  
Ting Liu ◽  
...  
Keyword(s):  
South China Sea ◽  
East Asia ◽  
South China ◽  
The South China Sea ◽  
The South ◽  
China Sea

REGIONAL SECURITY COMPLEX IN ASEAN: Neutrality and Centrality at Brink in the South China Sea Issue

2017 ◽  
Vol 7 (1) ◽  
pp. 43-54
Author(s):  
Arfin Sudirman
Keyword(s):  
South China Sea ◽  
East Asia ◽  
South China ◽  
International System ◽  
The South China Sea ◽  
Regional Security ◽  
South East Asia ◽  
The South ◽  
China Sea ◽  
East Asia Region

The South China Sea conflict has been a highly sensitive issue for the last 5 years in ASEAN. China and the US have been using the South China Sea as the New Cold War Arena of power and military hegemonic competition in the South East Asia region. This has been a major challenge for ASEAN as the only regional organization in the South East Asia region that has direct in the area must take major role in managing and resolving the dispute peacefully even though ASEAN has no defense pact like NATO. This paper argues that ASEAN, at this moment, must maintain its role as a mediator and independent-negotiator in the region but at the same time apply its principle of gradually adapting with the new international system. This article also suggests that in the future, ASEAN can take a major role in the governance of the South China Sea and the South East Asia region.

scholarly journals On the high resolution regional weather forecast model (HRM) and forecasting tropical cyclone motion over the south china sea

2005 ◽  
Vol 27 (4) ◽  
pp. 193-203
Author(s):  
Le Duc ◽  
Le Cong Thang ◽  
Kieu Thi Xin
Keyword(s):  
High Resolution ◽  
South China Sea ◽  
South China ◽  
Weather Forecast ◽  
Forecast Model ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Weather Forecast Model ◽  
Slow Moving

Chan (1995) [2] has found that, only 70% in 60 cases of the tropical cyclone (TC) movement test (TMT-90) developed from steering flows. The 30% remain of cases have to be explained by nonbarotropic processes. We are of the opinion that all weak, slow-moving and unexpected changing TCs over the South China Sea are in this 30% set. The nonlinear interaction between barotropic and nonbarotropic processes has affected on motion and structure of such TCs. In this paper, we use the high resolution weather forecast model (HRM), which is able to simulate meso-scale phenomena in limited regions, to predict motion of TCs in the South China Sea in 2002-2004, including two typical weak, slow-moving and unexpected changing TCs Mekhala and Nepartak. We have chosen two forecast domains with different areas and resolutions. The results show that with the smaller domain, appropriate buffer and higher resolution HRM can predict better motion of TCs operating in the South China Sea.

scholarly journals Two Distinct Types of Extratropical Circulation Anomalies Associated with Cold Surges over the South China Sea

2019 ◽  
Vol 32 (16) ◽  
pp. 5069-5084 ◽  
Author(s):  
Bo Pang ◽  
Riyu Lu
Keyword(s):  
South China Sea ◽  
Rossby Wave ◽  
South China ◽  
The South China Sea ◽  
The South ◽  
Cold Surge ◽  
Siberian High ◽  
China Sea ◽  
Wave Trains ◽  
Cold Surges

Abstract This study investigated the extratropical circulation anomalies responsible for cold surges over the South China Sea in winter. The surge events were identified by the intensity of northerly winds over 110°–117.5°E along 15°N at 925 hPa. Two distinct patterns of sea level pressure (SLP) anomalies in East Asia were found to have a crucial role in inducing cold surges over the South China Sea. Accordingly, the cold surge events were classified into two types. The first type of cold surge is characterized by a pair of SLP anomalies with positive and negative ones centered over China and Japan, respectively, whereas the second type of cold surge is characterized by widespread and persistent positive SLP anomalies over East Asia. Furthermore, the first type of cold surge is accompanied by a deepened East Asian trough and precursory Rossby wave trains across the Eurasian continent in the mid- and upper troposphere, but the latter is not. Prior to both types of the cold surges, the Siberian high is significantly intensified. However, diagnosis of the SLP tendency indicates that the intensification is related to different physical processes. In the first type of cold surge, the Rossby wave trains favor negative vorticity advection and cold advection, inducing intensification of the Siberian high. By contrast, in the second type of cold surge, vorticity advection can be ignored due to the lack of Rossby wave trains, and only the lower-tropospheric cold advection induced by anomalous northerly winds, resulting from the anomalous Siberian high, contributes to the further intensification of the Siberian high.

scholarly journals EAST ASIA: THE SYSTEMIC DISORDER AND THE SOUTH CHINA SEA DISPUTE. AN INTERNATIONAL LAW PROSPECT

2021 ◽  
pp. 66-83
Author(s):  
Victor Alexandre TEIXEIRA ◽  
Jose Francisco Lynce Zagallo PAVIA
Keyword(s):  
South China Sea ◽  
East Asia ◽  
International Law ◽  
South China ◽  
International System ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Systemic Disorder ◽  
Regional Order

"Abstract: This paper analyzes the South China Sea dispute when the international system lacks orientation and respect for the norms, values, and institutions. The conflict is conceptualized to encompass the States, International Law, and the East Asia order. The evidence demonstrates that ASEAN’s regional order is more efficient than the US-Led Liberal order through UNCLOS. Additionally, it is necessary to overhaul and strengthen the institutional mechanisms from international law regarding the United Nations. A change in the order and an international recognition are recommended to legitimize regional institutions to arbitrate territorial disputes. Keywords: ASEAN, regional order, conflict resolution, South China Sea Dispute."

Water, heat and salt budgets over South East Asia seas : a high resolution modeling approach

2021 ◽  
Author(s):  
Marine Herrmann ◽  
Ngoc Trinh Bich ◽  
Caroline Ulses ◽  
Patrick Marsaleix ◽  
Thomas Duhaut ◽  
...  
Keyword(s):  
High Resolution ◽  
South China Sea ◽  
East Asia ◽  
Ocean Circulation ◽  
South China ◽  
The South China Sea ◽  
South East Asia ◽  
The South ◽  
China Sea ◽  
Numerical Studies

<p>South East Asia seas, that include the South China Sea and the Indonesian Seas, transfer the warm and light waters of the surface branch of the global thermohaline circulation between the Pacific and Indian Oceans. To better understand the key contribution of South East Asia seas in the regional and global climate and ocean circulation, it is therefore essential to improve our knowledge of the functioning and variability at different scales of water, heat and salt budgets over this region. The complex topography of this region makes it difficult to study those budgets based on in-situ measurements only. Numerical studies are necessary and relevant to complement and interpret those measurements, however until now, most of numerical studies were performed at low resolution and/or on short periods.</p><p> </p><p>To better quantify and understand the contributions of ocean, rivers and atmosphere to the variability at different scales of the water, heat and salt budgets over South East Asia seas, high resolution configurations (< 5 km) of the SYMPHONIE ocean model are developed over the area. State of the art datasets available from COPERNICUS and ECMWF are used to prescribe boundary conditions. Each term of the budgets is computed online in order to obtain rigorously closed budgets.</p><p> </p><p>This methodology applied on the 2009-2018 period, that includes strong El Niño and La Niña years as well as neutral years, allows us to better characterize the seasonal to interannual variability of water, salt and heat budgets over the South East Asia seas, by quantifying and explaining the contribution of each factor (lateral fluxes, surface fluxes, rivers, internal variations, ENSO). We examine in particular the surface salinification of the South China Sea that was observed by previous authors between 2012 and 2016 (Zeng et al. 2018, doi:10.1002/2017GL076574) : our simulations suggest that it is mostly related to an increase of net lateral water influx at Luzon strait, itself induced by a deficit of precipitation over the region, rather than to an increase of the salinity of the inflowing water. We finally also explore the role of tides and mesoscale processes. This methodology, our key results and the future steps of this work, that include the on-going development of an ocean-atmosphere regional coupled model, will be synthetically summarized.</p>

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