The Characteristics And Influencing Factors Of SST Variation Along The South China Coast During The Period 1960～2013

It is no doubt that global warming has become a serious problem in the world. According to the sequence of surface temperature of HadCRUT4, IPCC-AR5 figured out that the super-heating rate is 0.85±0.20℃/100a from the year of 1880 to 2012. We can forecast that the result from 2046 to 2065 will rise 1.0-2.0℃ in compare with the year from 1986 to 2005. As we all know, about 70% of the earth is covered by oceans, so the research of Sea Temperature is a conventional subject of ocean research. And sea surface temperature (Sea Surface Temperature, SST) research is the focus in the study of ocean temperature, which is the most valuable ocean hydrological element in the research of oceanographic physics and global climate change. And it is also one of the important element to report the past, estimate the future climate changes. The STT is often be regarded as the determining factor of other discipline researches. Studies on the changes of SST play an important role in marine fishery production, in offshore oil and gas development, transportation, military activities, and long-term weather forecast is also important. Nowadays, the abnormal changes in the regional climate has increasingly become the focus of people, and the sea surface temperature is an important index which reflects the climate change, the change is always a hot topic at home and abroad. This paper focuses on the analysis of the changing trend, mutation situation and periodic characteristics on SST of Southern China coast from 1960m to 2013 and its relationship with the change of ENSO and global warming, in order to provide reference for the Southern China climate change assessment. This paper is divided into four aspects:1.The basic characteristics of Southern China coast average SST changeThis article is mainly based on the observational data of monthly average sea surface temperature (SST) from seven ocean stations of Southern China coast from 1960 to 2013, using linear trend analysis, computing trend coefficient, mutation test and wavelet analysis, analysis of the basic characteristics of the annual average change in SST.2. Analysis of Extreme Weather CausesThis section analyzes the lowest and highest difference in Guangdong, Guangxi provinces annual average SST seasonal changes in the past 54 years and its causes. We can work out average minimum and maximum SST in nearly 54 years were 1984 (SST anomalies of -0.95 ℃) and 2002 (anomaly of +0.91 ℃). And we also found that SST differences occurred mainly in the winter and spring months. Its causes is closely related to global warming, high-pressure changes in the strength Nanhai seasonal variation, solar radiation intensity, and the change of winter wind strength.3. the statistical relationship of several affected factors.Previous studies have drawn that South China Sea SST interannual, decadal scale SST change have relationship with global warming, atmospheric circulation anomalies, air-sea interaction, changes of wind. This article discussed from global warming, the South China Sea high pressure changes in the strength and the decrease of wind of surface layer offshore. These three factors are discussed in order to deepen the Analytic Hierarchy.4. Estimation of 2050 southern mainland coast SST rising.This section is an innovation of this paper. The main reference is IPCC-AR5 literature which estimated the base year average increase in magnitude of global temperature in 2046-2065. By analyzing the relationship between Sea surface temperature data of the southern coastal ocean observing stations and HadCRUT4 global temperature anomaly (△tGB).We can figure out the 2050 forecast rise of southern mainland coast SST.After analysis, the main conclusions of this article are:1) the average annual SST southern mainland coast in past 54 years showed a quasi-synchronous changes and significant warming trend, the climate tends to yield 0.08-0.22 ℃/10a, an average of 0.12 ℃/10a, with the most significant warming in winter;2) SST changes occur mutation phenomenon in 1993.3) SST changes has spatial and temporal scales of variation. The most significant change is the annual variation cycle 2-4 years;4) SST changes influenced by ENSO events, and will lags with MEI index about 2 to 4 months.5) The main factor affecting SST warming have global warming, the increase of South China Sea high pressure, the weak of wind of surface layer off shore and so on.