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Seasonal Variation, Distribution And Sources Of Particulate Organic Carbon In The Yellow Sea And East China Sea

Posted on:2012-01-29Degree:MasterType:Thesis
Country:ChinaCandidate:J ChengFull Text:PDF
GTID:2210330338964286Subject:Marine Chemistry
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Particulate Organic Carbon (POC) as one of the major forms of carbon in seawater, it plays an important role in carbon circulation in the sea. The continental margins have high productivity and it is susceptible to terrestrial inputs in the meantime, so it can easily get a high concentration of POC. For this reason, it is of great significance to do research on the distribution of POC in the continental margins and its impact on ocean. Based on the data from cruises that carried out in the Yellow Sea and East China Sea from 2006 to 2009, the seasonal variation, spatial and temporal distribution of the POC is analyzed in this paper. And also the sources of POC in typical sections of different zones in the Yellow Sea and East China Sea are further discussed by using C/N Mole ratio method and correlation analysis between POC and many other parameters such as chlorophyll a and turbidity. From what has been discussed above, the main conclusions are drawn as follows:(1) On the whole, distribution of POC in the Yellow Sea and East China Sea in four seasons have the same trend, the highest POC content in the western coastal zones and it tends to decrease toward the far eastern shore. In addition, POC concentration in the north area is much higher than the south both in summer and fall.(2) The high-value zones of POC concentration in the Yellow Sea and East China Sea in four seasons mainly set in the Yangze River estuary and its adjacent area, the North Jiangsu coastal waters and inshore in Zhejiang. What's more, the location of high-value area is moving from North to South as replacement of spring, summer, fall and winter.(3) Influencing factors of POC in the Yellow Sea and East China Sea vary in different seasons. In addition to phytoplankton production, the organic debris which derived from the Seaweed culture zone in the North Jiangsu coastal waters at the scene may be the main reason for the high-value areas in spring. However, in summer and fall, it is obviously that the distribution of POC closely related to the turning of the Yangze River diluted water. What's more, the effects of resuspension on distribution of POC at the bottom increase from summer to winter.(4) The seasonal changes of the concentration of POC in different zones in the Yellow Sea and East China Sea shows a certain degree of regularity, which is POC concentration highest in spring and lowest in fall. The seasonal changes of POC concentration follow the trend, Spring > Summer > Winter >Fall. All of these illustrate the phytoplankton production in spring maybe the biggest contributor of POC in the Yellow Sea and East China Sea.(5) The sources of POC in different typical sections of the Yellow Sea and East China Sea vary in different seasons. The nearshore POC in the 03 section of the South Yellow Sea in all seasons are mainly from terrestrial inputs and the far coast POC are mainly from phytoplankton. However, the POC of the 05 section in the Yangze River estuary and its adjacent area is mainly from phytoplankton production at the site in spring, while in summer it is mainly from the Yangze River diluted water. In fall and winter, POC are from the common contribution of terrestrial inputs and sediment resuspention. POC of the 10 section in South East China Sea are mainly from Ocean in spring and summer, and it nearshore comes from terrestrial inputs in fall, while in winter the main source of POC in upper coastal waters is phytoplankton production at the scene and at the bottom POC is mainly from sediment resuspention.(6) It is estimated that the POC in the Yangze River estuary and its adjacent area get the contribution of phytoplankton for around 57.33% in spring. However, in summer the average phytoplankton contribution to POC is around 41.71% in the South East China Sea.
Keywords/Search Tags:POC, seasonal variation, distribution, source
PDF Full Text Request
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