全球变暖背景下中国沿海地区海平面变化及预估

发布时间：2018-01-21 15:24

  本文关键词： 海平面高度 线性趋势 年最大值 模式模拟 模式预估　出处：《南京信息工程大学》2016年硕士论文　论文类型：学位论文

【摘要】：在全球变暖的背景下,热膨胀和冰盖融化等效应导致的全球海平面上升,直接影响到岛屿和沿海地区人类活动。因此,研究海平面变化具有重要意义。本文利用验潮站的验潮记录,AVISO观测的海平面异常,Church等(2011)验潮站和卫星资料的修正资料、CFSR再分析资料的海表风应力、OAFlux的海表面热通量资料,Ishii的SST资料以及太平洋十年涛动指数(PDO)和南方涛动指数(SOI)。发现中国海域无论是近40年(1970-2013)还是近20年(1993-2013)海平面均显著上升。各海区近20年的海平面上升有加速的趋势,且各时段上升速率大于全球平均海平面上升率。北部海域秋季最大,冬季最小；南海海域春季最大,秋季最小。AVISO资料在描述近20年海平面变化的线性趋势上与验潮站资料接近,较大的差异主要是由验潮站地表发生升降引起的。发现实际发生极端海表高度事件的机率比年平均海平面变化所体现出来的要大。年最大值的趋势与年际和年代际变化密切相关,造成年最大值的线性趋势大于年平均的线性趋势的直接原因是10月份净海表热通量的显著增加,而海表短波辐射的增加以及与海表风速减弱造成的潜热释放的减少是导致净热通量增加的主要因子。对模式分析发现在所选的16个模式中1950-2001年模拟结果不论在BYE海域还是SCS海域都比Church计算结果要弱的多而且空间上没有相似的分布。1993-2005年模拟结果要比前者好很多,在BYE海域MIROC-ESM模拟的空间特征和量值大小上都与观测相似。CMIP5模式对中国沿海海平面预估发现在不同场景不同模式下BYE、SCS海域海平面上升趋势模拟结果都不同,但大部分模式预估的结果在未来100年BYE、SCS海域呈上升趋势。MIROC-ESM模式预估的结果在RCP4.5、RCP8.5场景下均为海平面上升,上升趋势分别约为2. lmm/a、2.6mm/a。
[Abstract]:In the context of global warming, global sea level rise due to effects such as thermal expansion and ice sheet melting has a direct impact on human activities in islands and coastal areas. It is of great significance to study sea level change. In this paper, the corrected data of tide gauge and satellite data are obtained by means of AVISO observation of sea level anomaly Church and so on. Sea surface heat flux data of CFSR reanalysis data and OAFlux reanalysis data. The SST data of Ishii and the Pacific Oscillation Index (Ishii) and the Southern Oscillation Index (SOI). It is found that the sea area of China is no matter in the last 40 years (1970-2013). In the last 20 years (1993-2013), the sea level has risen significantly. The sea level rise in each sea area has a tendency to accelerate in the past 20 years. And the rising rate of sea level in each period is larger than the global average sea level rise rate. The northern sea area is the largest in autumn and the smallest in winter. The sea area in the South China Sea is the largest in spring and the smallest in autumn. AVISO data are close to the tide gauge data in describing the linear trend of sea level change in recent 20 years. The larger difference is mainly caused by the rise and fall of the surface of the tide gauge station. It is found that the probability of the actual extreme sea surface height event is greater than that of the annual mean sea level change. International change is closely related. The direct reason that the linear trend of annual maximum value is larger than the linear trend of annual average is the significant increase of net sea surface heat flux in October. The increase of sea surface shortwave radiation and the decrease of latent heat release due to the weakening of sea surface wind speed are the main factors leading to the increase of net heat flux. Analysis of the model shows that in the 16 selected models, 1950-2001 is the main factor leading to the increase of net heat flux. The annual simulation results are much weaker than the Church results in both BYE and SCS waters and there is no similar spatial distribution. 1993-2005 simulation results are much better than the former. . The spatial characteristics and magnitude of MIROC-ESM simulation in BYE sea area are similar to observations. CMIP5 model has been found in different scenarios and different models for the prediction of sea level in coastal China. The simulated results of sea level rise trend in SCS are different, but most of the predicted results of the model are BYE in the next 100 years. The results predicted by MIROC-ESM model in SCS are all sea level rise under RCP4.5 / RCP8.5 scenario, and the rising trend is about 2. Lmm/a respectively. 2.6mm/a.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P731.23
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本文编号：1451840