近30年南海海平面高度的时空变化

Temporal and spatial variation characteristics of sea level in the South China Sea in recent 30 years

基于AVISO卫星高度计、验潮站数据,利用最小二乘、集合经验模态分解(EEMD)、差分自回归移动平均模型(ARIMA)等方法,在研究1993—2019年南海海平面时空变化特征的基础上,对沿岸海域SLA的变化周期和趋势及El Nino和La Nina时期南海SLA时空变化进行了研究.结果表明:1)27年间海平面变化空间分布存在不均匀性;2)沿海海平面有半年、年际周期信号,其中年际周期与整个南海的规律略有不同;中国香港、越南、菲律宾沿海的SLA上升速率分别是3.41,2.71,3.17 mm/a;未来5年内,越南、中国香港沿岸海平面将分别上升2.56,2.11 cm,菲律宾沿岸海平面将下降3.47 cm;3)受El Nino和La Nina事件的影响,南海SLA呈现多次上升、下降的变化趋势;4)南海海平面对于El Nino和La Nina事件的响应存在空间上的差异,民都洛海峡以南海域对这些事件最为敏感,该海域在El Nino期间负异常显著,低于多年平均12.00 cm左右,在La Nina期间,正异常显著,高于多年平均8.00 cm左右.

Based on AVISO satellite altimeter and tide gauges,using the least squares method,empirical mode decomposition(EEMD),difference autoregressive moving average model(ARIMA),and other methods,it was surveyed the temporal and spatial variation characteristics of sea level in the South China Sea from 1993 to 2019,the variation cycle and trend of SLA in coastal waters and the temporal and spatial variation of SLA in the South China Sea during El Nino and La Nina periods were studied.The results showed that:1)The spatial distribution of sea level change in 27 years was uneven;2)Coastal sea level had semi-annual and interannual periodic signals,in which the interannual cycle was slightly different from that of the whole South China Sea;The rising rates of SLA in Hong Kong of China,Vietnam and the Philippines were 3.41,2.71 and 3.17 mm/a,respectively.In the next five years,the sea level along the coast of Vietnam and Hong Kong of China was predicted to rise by 2.56 and 2.11 cm respectively,and the sea level along the coast of Philippines was predicted to drop by 3.47 cm;3)Affected by El Nino and La Nina events,SLA in the South China Sea showed a trend of increasing and decreasing for many times;4)The response of sea level in South China Sea to El Nino and La Nina events was spatially different,the sea area south of Mindoro Strait was the most sensitive to these events.The negative anomaly in this sea area was significant during El Nino,which was about 12.00 cm lower than the annual average,and the positive anomaly was significant during La Nina,which was about 8.00 cm higher than the annual average.