Simulation And Analysis Of DMS Changes In The Yellow Sea And East China Sea Under Future Climate Change Scenarios

Dimethylsulfide(DMS)is a volatile sulfide produced mainly by marine organisms,and DMS is capable of regulating global climate change.Future climate change will also indirectly affect marine DMS by changing the physical ecology of the Yellow Sea and East China Sea.Studying the future changes of DMS concentration and its sea-air flux in the Yellow Sea and East China Sea is important to understand the response of DMS in the Yellow Sea and East China Sea to future climate change and to provide scientific support for addressing climate change.In this paper,we use the mean climate state results of CORDEX-EA for the current(2000-2009)and future(2041-2050)in the RCP4.5 scenarios to drive the coupled physical-ecological DMS model of the Yellow Sea and East China Sea.The differences between future and current sea surface DMS concentration and sea-air flux are discussed quantitatively,and the links between the differences and climate factors are also explored.The results show that:Compared to the current,the mean sea surface DMS concentration in the Yellow Sea and East China Sea increases by 4.16%in the future,among which the South Yellow Sea and East China Sea increase by 6.73%and 12.54%,respectively.The strength of the high value area of sea surface DMS concentration also changed.The high value area strengthened in the following areas:The Shandong Peninsula in April,the west side of South Yellow Sea in May,the shallow shore of northern Jiangsu Province in June,the shallow shore of northern Jiangsu Province,the central South Yellow Sea and the East China Sea shelf area in August,the inland shelf of the East China Sea in September,near the West Korea Bay and the eastern South Yellow Sea in October,and the central South Yellow Sea in November.The high value area weakened in the northern Shandong Peninsula in May and June,and near the Shandong Peninsula in July.The seasonal characteristics of sea surface DMS concentration in the Yellow Sea changed:the peak in the North Yellow Sea occurred one month earlier in spring and one month later in autumn,while the peak in the South Yellow Sea was one month earlier in autumn,and no significant change occurred in the East China Sea.The dominant factors for differences(between future and present)in sea surface DMS concentration differ in different regions,with the heat flux and wind stress having a dominant influence on differences in sea surface DMS concentration near the Shandong Peninsula and the east-central part of the South Yellow Sea,and the total cloud cover and precipitation being relatively important climate influencing factors for differences in sea surface DMS concentration near the West Korea Bay.The differences of sea surface DMS concentration in the shallow waters of the North Jiangsu Province and the East China Sea are influenced by all climate factors.Compared to the present,the future DMS sea-air flux in the Yellow Sea and East China Sea will increase by 0.93μmol/m~2/d on average,and the DMS sea-air flux in the South Yellow Sea and the East China Sea can increase by 11.01%and 10.42%;the total annual DMS release in the future will increase by 0.01 Tg S/a,among which the contribution of the South Yellow Sea and the East China Sea to the DMS release in the Yellow East Sea will increase.The difference between DMS sea-air flux and sea surface DMS concentration is basically consistent except for the significant decrease of DMS sea-air flux on the middle and outer shelf in the East China Sea in September.The differences in seasonal variation characteristics of future and current DMS sea-air flux are highly similar to the differences in sea surface DMS concentration,i.e.,the peak of DMS sea-air flux in the North Yellow Sea occurs one month earlier in spring and one month later in autumn,while the South Yellow Sea is one month earlier in autumn.The differences between future and current DMS sea-air flux in the Yellow Sea and East China Sea are mainly caused by sea surface DMS concentration,while the effect of sea-air exchange coefficient exists only in the North Yellow Sea,South Yellow Sea nearshore,and middle and outer shelf of the East China Sea.Where the sea-air exchange coefficient in the east side of the Yellow Sea and East China Sea is largely controlled by the10m wind speed,while the sea-air exchange coefficient in the west side of the sea may be influenced by the sea surface temperature in addition to the 10m wind speed.