1993-2011年北大西洋与北太平洋的波浪变化及其原因探究

摘要

基于1993-2011年的7套卫星高度计数据,分析北大西洋和北太平洋的波浪变化趋势;利用NCEP/NCAR提供的月平均风场及SLP(Surface Level Pressure)数据,分析风场和SLP的空间变化特征,并通过主成分分析进一步考察了波浪变化与SLP的相关关系.结果表明:北大西洋波浪变化趋势的空间分布呈偶极子形态,西南区域为增大趋势,东北区域为减小趋势;而北太平洋波浪变化的主要特征是在中纬度带呈明显的减小趋势;比较而言,波浪变化趋势的空间形态与SLP变化的空间分布特征更接近,波浪主要模态的空间分布及时间系数与SLP距平场的震荡特征十分吻合,大尺度背景场SLP的变化对波浪的长期变化趋势有重要的影响.%We studied the trends of significant wave height in 1993-2011 in the North Atlantic and North Pacific based on seven sets of satellite altimeter data,and analyzed the spatial variability of wind and SLP (surface level pressure),using monthly mean data provided by NCEP/NCAR.Furthermore,the link between wave and SLP is determined by PCA (principal component analysis).The results show that overall pattern of SWH (significant wave height) in North Atlantic is dipole-shaped.The increasing trend in SWH is in the southwestern North Atlantic and the decreasing trend in SWH in the northeastern Atlantic.In North Pacific,the wave variability features a significant decreasing trend in mid-latitudes.The spatial pattern of wave variability is very similar to the SLP's.The principal space and time modes of wave are consistent with the oscillation of the SLP anomaly filed.The changes of large-scale background field-SLP play an important role in long-term change of wave.