摘要: |
依据“科学一号”调查船1994年4月在东海10个断面上所进行的表层水连续走航观测资料(总航程3600km,47万个观测数据),研究东海表层水叶绿素a含量在不同空间尺度(0.01-100km)上的分布特征和变化规律、结果表明,叶绿素a含量在陆架区高,在外海低;测区南部海域的含量一般高于北部海域。叶绿素a含量的分布形态变化很大,在某些外海深水区,叶绿素a含量连续百余公里没有显著变化,变化幅度小于0.2 mg/m3;而在某些近海浅水区,叶绿素a含量在不到1公里范围内的变化幅度达1.5 mg/m3。叶绿素a含量大体存在着三种不同尺度的变化:普遍存在的0.01-0.1km量级的小尺度小幅度变化;1-10km量级的与斑块分市相关的脉冲式变化;更大尺度的与水团生产力水平相关的变化。功率谱随波数增加呈下降趋势,说明大幅度变化对应大空间尺度。 |
关键词: 叶绿素a 分布特征 东海 |
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基金项目:国家自然科学基金资助项目,49276265号 |
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DISTRIBUTION CHARACTERISTICS OF SURFACE LAYER CHLOROPHYLL-a CONCENTRATION ON DIFFERENT SPATIAL SCALES IN THE EAST CHINA SEA IN SPRING |
Lu Beiwei, Wang Rong
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Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071
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Abstract: |
Using surface layer chlorophyll-a concentration data obtained, by continuous flow measurement along ten transacts in the East China Sea (118 - 129° E, 24 - 32 ° N) in April, 1994, the authors analysed the distribution characteristics and the variation regularity of surface layer chlorophyll-a concentration on different spatial scales (0.01 – 100 km) in the East China Sea. The findings were as follows: chlorophyll-a concentration is comparatively high in the continental shelf and low in the open seas; the observed concentration in the south area is generally higher than that in the north. The variation of the distribution pattern of chlorophyll-a concentration is great, in some deep waters of the open seas, the variation of the concentration was not obvious within several hundreds of kilometers, the range of the variation was lower than 0.2 mg/m3, while in some shallow offshore waters, the range of the variation within one kilometer was high and up to 1.5 mg/m3. There were generally three kinds of variations of chlorophyll-a concentration: variation of 0.01 - 0.1 km in spatial scale, 0.1 - 0.2 mg/m3 range, influenced by short temporal scale and small spatial scale physical processes such as turbulence and waves pulse-shaped variation with 1 – 10 km spatial scale, 1.0 - 2.0 mg/m3 range, correlated to both biological oceanographic processes and physical oceanographic processes such as population growth of phytoplankton and sea front; variation of 100 km spatial scale, 1.0 - 2.0 mg/m3 range, reflecting the productivity level of large spatial scale physical processes such as water masses and current systems. The amplitude of power spectra tends to decrease when wave-number increases, showing that the bigger variation corresponds to larger spatial stretch. |
Key words: Chlorophyll-a, Distribution characteristics, East China Sea |