| Climate change has become the most important environmental issue in today's society.The East China Sea and the adjacent Northwest Pacific not only has great impact on China's climate,but also is hot topic the international hot spots in recent years.Since sea water temperature of each layer influences each other,ocean is able to transfer heat to the atmosphere through the air-sea heat exchange,drive atmospheric movement through thermal variations,affect the atmospheric circulation and thus affect the climate change.Therefore,it is important to discuss the temperature change in the sea around China.The monthly average temperature data of 30 years from 1981 to 2010 in the data set were collected by SODA--2.2.4.The temperature data of the surface layer of the sea area studied during 1981-2010 and each year for 12 months and 360 months were extracted through programming through MATLAB.The distribution characteristics of surface temperature changes in the new 30-year climate baseline period,the east China sea and the adjacent northwest Pacific Ocean were analyzed,and the following results were obtained:(1)The average surface temperature in the study area is mainly affected by solar radiation,and generally decreases from south to north.Affected by the east China sea kuroshio,this region mainly contains three obvious temperature characteristic fields: the estuary area of the Yangtze river,where the lowest temperature of the whole research area is located;the east China sea kuroshio sea area,where the strong warm current running from southwest to northeast;and the northwest Pacific Ocean,where the overall temperature is the highest;the isotherm is sparse and parallel to the parallel.The annual temperature amplitude is larger in the north of Yangtze estuary.(2)In the inter-monthly variation,January and June are the months with the largest temperature drop amplitude and the largest temperature rise amplitude respectively.Cooling rate in January 5.69?-0.632?,increase in June 0.37?-5.17?,the biggest change is in the north of the Yangtze river estuary north jiangsu coastal region;(3)In the inter-monthly variation,the surface SST heating and cooling areas in March and August were significantly affected by the sea current.The warming area in March was consistent with the trend of the east China sea kuroshio,and the regions where the temperature first changed were all in low latitudes.(4)In the annual amplitude,as a whole,the higher the latitude is,the higher the annual temperature amplitude is.Due to the influence of the kuroshio in the east China sea,the coastal water in northern jiangsu province and the diluent water in the Yangtze river,there are high value centers and low value centers.A maximum of 19.9? is located in the northern end of the Yangtze river estuary,the minimum value of 3.8? is located in the southeast of the island,at the entrance of the kuroshio;(5)On the whole,the intermonthly variation is the lowest temperature in February and march,and the highest temperature in July and August.The temperature difference is the biggest in February and march,July and August.The monthly mean temperature of most feature points is distributed according to the rule that the lower the latitude is,the higher the temperature is.In some months,the temperature in places with higher latitude is higher than that in places with lower latitude.This is mainly due to the dominant influence of ocean currents or runoff into the sea;(6)The overall surface SST in 140 years was lower than that in 30 years.Areas with greater warming were along the continental coast.The east of 124 ° E warming is smaller.Heating up the most obvious areas in the Taiwan strait area,rose 1.52?.Heat up the smallest in the east of north jiangsu coastal region,rose 0.016?.And in the eastern coast of north jiangsu 124.25 ° E? 33.25 °E N area appeared to cool.In the east China sea kuroshio area,most of the temperature difference value displayed as 0.7 ~ 0.6?,that is to say,nearly 30 years the kuroshio area high the annual average temperature of 0.7?,the kuroshio marginal sea temperature increase of 0.5?,the kuroshio with the surrounding sea temperature difference.In the Pacific northwest region,the center of the region temperature difference value is 0.6?,the surrounding temperature difference value of 0.5?,that is to say,nearly 30 years annual average temperature rise of the central region of the Pacific northwest with the surrounding temperature;(7)using the sliding t test to detect 140 years of mutations: 1883,1903,1929,1949,1997,these mutations are closely related to the time of ENSO.According to the mutation year,it is divided into six stages.The first five stages of the linear trend of the six stages are all upward,and the last five stages are downward from 1997 to 2010.And through the wavelet power spectrum analysis,we can see that the 140-year cycle is 18 years.(8)Through the analysis of the intermonthly changes in the research area in 140 years,it is found that the increase of temperature in April,may,June,July and August is greater than the annual average increase.The increase of temperature in 1,2,3,9,10,11 and 12 months was less than the average annual increase.May rise,the largest is 0.019 ° / a.Rise in the minimum,in October of 0.0047 ° / a.That is to say,the warming rate in summer is higher than that in winter,which is contrary to what has been stated in the IPCC report in the past 30 years;(9)through the analysis of different climatic zones within the 140-year study area,it was found that the temperature in the estuary area of the Yangtze river and the Taiwan strait area increased faster than that in the whole study area.The Taiwan strait saw the fastest temperature rise.The temperature rise in the kuroshio region of the east China sea has been rapid or slow.The fast-changing area is close to the continental shelf of the east China sea.The slow-changing region is close to the Pacific northwest.In the northwest Pacific Ocean,the rising speed of temperature is lower than that of the whole research area,and the higher the latitude of the feature points,the faster the rising speed;(10)(31.75 ° N,124.25 ° E)D1 and D2(30.25 ° N,123.25 ° E)in negative temperature difference value of the annual average temperature is 1946-1986.This is consistent with the cold period of bohai sea discovered by predecessors(zou honglin et al.,1988).In the D12(31.25 ° N,128.75 ° E)with D11(29.25 ° N,126.75 ° E)annual average temperature of the temperature difference value.The year in which the annual mean temperature of the two points is the closest is only one year later than the year when li liyun(1986)carried out the cooling and heating subsection in the offshore of China. |
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