| 摘要: |
| 本文基于法国空间局AVISO提供的格点化绝对动力地形（MADT：maps of absolute dynamic topography）资料，分析了1993年1月—2013年12月班达海（Banda Sea）海平面的季节和年际变化特征。班达海海面高度的季节变化主要表现为12月到翌年4月西北季风盛行时较高，7月到10月东南季风盛行时较低，全年变化幅度为16.5cm；班达海东部近阿拉弗拉海（Arafuru Sea）与西南部近弗洛勒斯海（Flores Sea）海平面随季风转换表现出“跷跷板”形态。海平面的变化受比容海平面变化和海水质量变化共同调制，其中比容海面高度季节变化振幅为14cm左右，约占海平面变化的84%，并且班达海比容海平面的季节性空间分布与总体海平面具有明显的一致性，因此比容海平面的变化是造成班达海海平面季节变化的主要原因；而风生Ekman流引起的海水堆积会影响班达海东北部的海平面高度。年际尺度上，班达海海平面与ENSO事件密切相关，月平均海面高度异常EOF分解第一模态方差贡献率高达96%，第一模态时间序列（PC1）滞后Niño3.4指数1个月左右时相关系数达到-0.76，远超过95%置信度水平；相比之下，IOD事件对班达海海平面的影响较小，PC1与印度洋偶极子指数（DMI）之间的最大相关系数仅为-0.3，低于95%置信度水平。并且月平均比容海平面异常和动力地形异常之间的差异在ENSO事件期间显著增大，表明ENSO事件引起的平流输送在班达海海平面高度年际变化中起到重要作用。 |
| 关键词: 班达海 海面高度 季节及年际变化 比容海面高度 |
| DOI：10.11693/hyhz20160200031 |
| 分类号: |
| 基金项目:国家自然科学基金委员会-山东省人民政府联合资助海洋科学研究中心项目，U1406404号；国家自然科学基金项目，41476025号，41306031号；“全球变化与海气相互作用”专项项目，GASI-03-01-01-04号，GASI-IPOVAI-01-02号。 |
|
| SEASONAL AND INTERANNUAL VARIATION IN SEA LEVEL HEIGHT IN THE BANDA SEA BASED ON SATELLITE ALTIMETER DATA |
|
WANG Li-Wei1,2, WANG Yong-Gang1,2, XU Teng-Fei1,2, WEI Ze-Xun1,2
|
|
1.First Institute of Oceanography, SOA, Qingdao 266061, China;2.Laboratory for Regional Oceanography and Numerical Modeling, National Laboratory for Marine, Qingdao 266061, China
|
| Abstract: |
| Using the AVISO MADT (maps of absolute dynamic topography) data, seasonal and interannual variation in sea surface height anomaly (SSHA) in the Banda Sea from January 1993 to December 2013 (21 years) were analyzed. Results show that the SSHA is higher from December to April affected by northwest monsoon and lower in December to April by southeast monsoon. The seasonal variability is about 16.5 cm. The SSHA is higher (lower) in the eastern (western) part of the sea during northwest monsoon and opposite in the western (eastern) part during southeast monsoon. The sea level change could be explained by water density change, resulting in so-called steric height change; and the steric height anomalies (SHA) in Banda Sea show similar seasonal variation to that of SSHA, being lower in August-September but higher in March, with an annual range of 14 cm. In addition, the southwestward (northeastward) Ekman transport that induced by southeast (northwest) monsoon could be another reason for the SSHA. As Empirical Orthogonal Function (EOF) analysis shows, 96.1% of the variance accounts for the interannual variation in the SSHA, which agrees well with the ENSO, evidenced by a large correlation coefficient at -0.76 with a one-month lag, while that of the Dipole Mode Index (DMI) is only -0.3. Comparison between the monthly MADT anomaly and SHA shows larger differences in ENSO years than in normal years, suggesting that ENSO could induce the water transport in Banda Sea as an important contributor to the interannual variation of SSHA. |
| Key words: the Banda Sea sea level height seasonal and interannual variation steric height |
