热带太平洋上层热力状况季节变化的正压特征——海表至深400m热储量的季节变化

SEASONAL CYCLE OF HEAT STORAGE FROM SURFACE TO 400m DEPTH IN THE TROPICAL PACIFIC OCEAN

使用斯克里普斯海洋研究所 (SIO)整编的海洋上层 (海表至 4 0 0m)热储量资料 ,研究了热带太平洋上层热力状况季节变化的正压特征 ,指出与SST的分布不同 ,热储量在北纬 5°N～ 10°N之间有一东西贯穿整个太平洋的带状热储量低值区 ,其季节变化率的分布特征分为两种 ,一是 11月至 2月为代表的“北半球冬季型”和 5～ 8月的“北半球夏季型” ,3月、4月和 9月、10月为过渡阶段 .北半球 10°N和 2°N的季节变率的时间变化反位相 ,南半球的10°S、2°S其季节变率随时间变化的位相则比较一致且与沿 10°N位相大致相反 .东太平洋季节变化明显早于中、西太平洋 ,具有明显自东向西传播的特征 .10°S与 10°N之间东、西太平洋的季节变率随时间的演变也基本上呈现反位相特征 .

We use the upper layer data of sea (from sea surface to 400m depth, downloaded from the website of Scripps Institution of Oceanography) to investigate the seasonal cycle of heat storage in the tropical Pacific Ocean. It shows the different features from that of sea surface temperature. Two low value areas occur through the Pacific Ocean between 5°N～10°N, and there are two rather clear patterns—one is ‘boreal winter pattern (November, December, January and February)’, another is ‘boreal summer pattern (May, June, July and August)’. The other months (March, April, September, and October) are relatively short as the transition period. The seasonalities on 2°N and 10°N vary out of phase. On the contrary, they vary in-phase on 2°N and 10°S. The variation in the east Pacific Ocean is earlier than that of the central Pacific Ocean, clearly propagating from east to west. The evolution of the seasonality presents out of phase between 10°N and 10°S.