scholarly journals Oxygenated volatile organic carbon in the western Pacific convective center: ocean cycling, air–sea gas exchange and atmospheric transport

2017 ◽  
Vol 17 (17) ◽  
pp. 10837-10854 ◽  
Author(s):  
Cathleen Schlundt ◽  
Susann Tegtmeier ◽  
Sinikka T. Lennartz ◽  
Astrid Bracher ◽  
Wee Cheah ◽  
...  
Keyword(s):  
South China ◽  
Atmospheric Transport ◽  
Coastal Region ◽  
Western Pacific ◽  
Northern Coast ◽  
The South ◽  
Model Calculations ◽  
Surface Ocean ◽  
Volatile Organic ◽  
The Western Pacific

Abstract. A suite of oxygenated volatile organic compounds (OVOCs – acetaldehyde, acetone, propanal, butanal and butanone) were measured concurrently in the surface water and atmosphere of the South China Sea and Sulu Sea in November 2011. A strong correlation was observed between all OVOC concentrations in the surface seawater along the entire cruise track, except for acetaldehyde, suggesting similar sources and sinks in the surface ocean. Additionally, several phytoplankton groups, such as haptophytes or pelagophytes, were also correlated to all OVOCs, indicating that phytoplankton may be an important source of marine OVOCs in the South China and Sulu seas. Humic- and protein-like fluorescent dissolved organic matter (FDOM) components seemed to be additional precursors for butanone and acetaldehyde. The measurement-inferred OVOC fluxes generally showed an uptake of atmospheric OVOCs by the ocean for all gases, except for butanal. A few important exceptions were found along the Borneo coast, where OVOC fluxes from the ocean to the atmosphere were inferred. The atmospheric OVOC mixing ratios over the northern coast of Borneo were relatively high compared with literature values, suggesting that this coastal region is a local hotspot for atmospheric OVOCs. The calculated amount of OVOCs entrained into the ocean seemed to be an important source of OVOCs to the surface ocean. When the fluxes were out of the ocean, marine OVOCs were found to be enough to control the locally measured OVOC distribution in the atmosphere. Based on our model calculations, at least 0.4 ppb of marine-derived acetone and butanone can reach the upper troposphere, where they may have an important influence on hydrogen oxide radical formation over the western Pacific Ocean.

scholarly journals Oxygenated volatile organic carbon in the western Pacific convective centre: ocean cycling, air–sea gas exchange and atmospheric transport

2017 ◽  
Author(s):  
Cathleen Schlundt ◽  
Christa A. Marandino ◽  
Susann Tegtmeier ◽  
Sinikka T. Lennartz ◽  
Astrid Bracher ◽  
...  
Keyword(s):  
South China ◽  
Hot Spot ◽  
Coastal Region ◽  
Western Pacific ◽  
The South ◽  
Model Calculations ◽  
Surface Ocean ◽  
North Borneo ◽  
Volatile Organic ◽  
The Western Pacific

Abstract. A suite of oxygenated volatile organic compounds (OVOCs – acetaldehyde, acetone, propanal, butanal and butanone) were measured concurrently in the surface water and atmosphere of the South China Sea and Sulu Sea in November 2011. A strong correlation was observed between all OVOC concentrations in the surface seawater along the entire cruise track, except for acetaldehyde, suggesting similar sources and sinks in the surface ocean. Additionally, several phytoplankton groups, such as haptophytes or pelagophytes, were also correlated to all OVOCs indicating that phytoplankton may be an important source for marine OVOCs in the South China and Sulu Seas. Humic and protein like fluorescent dissolved organic matter (FDOM) components seemed to be additional precursors for butanone and acetaldehyde. The atmospheric OVOC mixing ratios were relative high compared with literature values, suggesting the coastal region of North Borneo as a local hot spot for atmospheric OVOCs. The flux of atmospheric OVOCs was largely into the ocean for all 5 gases, with a few important exceptions near the coast of Borneo. The calculated amount of OVOCs entrained into the ocean seemed to be an important source of OVOCs to the surface ocean. When the fluxes were out of the ocean, marine OVOCs were found to be enough to control the local measured OVOC distribution in the atmosphere. Based on our model calculations, at least 0.4 ppb of marine derived acetone and butanone can reach the upper troposphere, where they may have an important influence on hydrogen oxide radical formation over the western Pacific Ocean.

scholarly journals Winter-to-Spring Transition in East Asia: A Planetary-Scale Perspective of the South China Spring Rain Onset

2008 ◽  
Vol 21 (13) ◽  
pp. 3081-3096 ◽  
Author(s):  
L. H. LinHo ◽  
Xianglei Huang ◽  
Ngar-Cheung Lau
Keyword(s):  
East Asia ◽  
South China ◽  
Stationary Wave ◽  
Rapid Expansion ◽  
Western Pacific ◽  
Monsoon Circulation ◽  
Jet Stream ◽  
The South ◽  
Central Pacific ◽  
The Western Pacific

Abstract Analysis of observations from 1979 to 2002 shows that the seasonal transition from winter to spring in East Asia is marked with a distinctive event—the onset of the south China spring rain (SCSR). In late February, the reduced thermal contrast between ocean and land leads to weakening of the Asian winter monsoon as well as the Siberian high and the Aleutian low. Meanwhile, convection over Australia and the western Pacific Maritime Continent is suppressed on the passage of the dry phase of a Madden–Julian oscillation (MJO). In conjunction with the seasonal march of monsoon circulation in the Indonesian–Australian sector, this MJO passage weakens the local thermally direct cell in the East Asia–Australia sector. This development is further accompanied by a series of adjustments in both the tropics and midlatitudes. These changes include attenuation of the planetary stationary wave, considerable weakening of the westerly jet stream over much of the central Pacific adjacent to Japan, and reduction of baroclinicity near the East Asian trough. The influence of concurrent local processes in midlatitudes on the SCSR onset is also important. The weakened jet stream is associated with confinement of frontal activities to the coastal regions of East Asia as well as with rapid expansion of the subtropical Pacific high from the eastern Pacific to the western Pacific. A parallel analysis using output from an experiment with a GFDL-coupled GCM shows that the above sequence of circulation changes is well simulated in that model.

scholarly journals The South China Sea: A Geopolitical Analysis

2016 ◽  
Vol 8 (3) ◽  
pp. 14
Author(s):  
Martin D Mitchell
Keyword(s):  
South China Sea ◽  
South China ◽  
The United States ◽  
The South China Sea ◽  
Western Pacific ◽  
The South ◽  
China Sea ◽  
Geographic Setting ◽  
Territorial Water ◽  
The Western Pacific

Since 1945 the South China Sea and the western Pacific has functioned as an uncontested global common patrolled by overwhelming U.S. naval and air power projected from a series of peripheral and over the horizon bases. The dramatic rise of China alters this situation and has transformed the South China Sea into a frontier of control as China seeks to morph this maritime theater into a landward extension of the Chinese coast where it can deploy land-based tactics into an arena previously dominated by maritime power and tactics to secure the South China Sea as a de facto territorial water that serves multiple Chinese strategic interests. Hence, the attempt by a land-based Eurasian power (China) to carve a permanent bridgehead into Spykman’s Eurasian maritime periphery. Against, this trend the United States has countered with President Obama’s Asian Pivot. However, the implementation of the Asian Pivot is limited by several post Cold War developments and certain constraints inherent in the geographic setting of the South China Sea. Beyond the South China Sea, the geographic setting favors the U.S. and its allies. Consequently, American options acting singly or in coalition with other nations, most notably Japan and Australia, remain more flexible and able to serve as a long term counterweight to Chinese force projection capabilities into the western Pacific proper. 

scholarly journals The South China Sea is not a mini-Atlantic: plate-edge rifting vs intra-plate rifting

2019 ◽  
Vol 6 (5) ◽  
pp. 902-913 ◽  
Author(s):  
Pinxian Wang ◽  
Chi-Yue Huang ◽  
Jian Lin ◽  
Zhimin Jian ◽  
Zhen Sun ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
The South China Sea ◽  
Passive Margin ◽  
Western Pacific ◽  
Small Scale ◽  
The South ◽  
Plate Edge ◽  
China Sea ◽  
The Western Pacific

Abstract The South China Sea, as ‘a non-volcanic passive margin basin’ in the Pacific, has often been considered as a small-scale analogue of the Atlantic. The recent ocean drilling in the northern South China Sea margin found, however, that the Iberian model of non-volcanic rifted margin from the Atlantic does not apply to the South China Sea. In this paper, we review a variety of rifted basins and propose to discriminate two types of rifting basins: plate-edge type such as the South China Sea and intra-plate type like the Atlantic. They not only differ from each other in structure, formation process, lifespan and geographic size, but also occur at different stages of the Wilson cycle. The intra-plate rifting occurred in the Mesozoic and gave rise to large oceans, whereas the plate-edge rifting took place mainly in the mid-Cenozoic, with three-quarters of the basins concentrated in the Western Pacific. As a member of the Western Pacific system of marginal seas, the South China Sea should be studied not in isolation on its origin and evolution, but in a systematic context to include also its neighboring counterparts.

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