热带海洋学报 ›› 2022, Vol. 41 ›› Issue (3): 29-37.doi: 10.11978/2021123

• 海洋调查与观测 • 上一篇    下一篇

琼东水体后向散射系数与浮游植物生物量的关系模型*

周雯1,2(), 魏盼盼1,3, 李彩1,2, 王桂芬4, 郑文迪1, 邓霖5, 赵红五一1,3, 余凌晖1, 曹文熙1,2()   

  1. 1.热带海洋环境国家重点实验室(中国科学院南海海洋研究所), 广东 广州 511458
    2.南方海洋科学与工程广东省实验室(广州), 广东 广州 511458
    3.中国科学院大学, 北京 100049
    4.河海大学海洋学院, 江苏 南京 210098
    5.中山大学海洋学院, 广东 珠海 510275
  • 收稿日期:2021-09-10 修回日期:2021-10-18 发布日期:2021-10-20
  • 通讯作者: 曹文熙
  • 作者简介:周雯 (1982—), 女, 湖南省邵东市人, 副研究员, 从事海洋光学和水色遥感应用研究。email: wenzhou@scsio.ac.cn
  • 基金资助:
    南方海洋科学与工程广东省实验室(广州)重大专项创新团队项目(GML2019ZD0602);南方海洋科学与工程广东省实验室(广州)重大专项创新团队项目(GML2019ZD0305);国家自然科学基金项目(41976172);国家自然科学基金项目(41976170);国家自然科学基金项目(41976181);国家自然科学基金项目(41576030);国家自然科学基金项目(41776044);国家自然科学基金项目(41776045);广州市科技计划项目(201707020023);. 中科院南海所热带海洋环境重点实验室自主项目(LTOZZ2003)

Particle backscattering as a function of chlorophyll a concentration off the eastern Hainan coast in the South China Sea*

ZHOU Wen1,2(), WEI Panpan1,3, LI Cai1,2, WANG Guifen4, ZHENG Wendi1, DENG Lin5, ZHAO Hongwuyi1,3, YU Linghui1, CAO Wenxi1,2()   

  1. 1. State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 511458, China
    2. Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
    3. University of Chinese Academy of Sciences, Beijing 100049, China
    4. College of Oceanography, Hohai University, Nanjing 210098, China
    5. School of Marine Sciences, Sun Yat-sen University, Guangzhou 510275, China
  • Received:2021-09-10 Revised:2021-10-18 Published:2021-10-20
  • Contact: CAO Wenxi
  • Supported by:
    Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering, Guangdong Laboratory (Guangzhou)(GML2019ZD0602);Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering, Guangdong Laboratory (Guangzhou)(GML2019ZD0305);National Natural Science Foundation of China(41976172);National Natural Science Foundation of China(41976170);National Natural Science Foundation of China(41976181);National Natural Science Foundation of China(41576030);National Natural Science Foundation of China(41776044);National Natural Science Foundation of China(41776045);Science and Technology Planning Project of Guangzhou(201707020023);State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences(LTOZZ2003)

摘要:

海洋中光后向散射系数的变化包含了浮游植物生物量的信息, 可应用于卫星遥感和光学剖面观测平台获取海洋中大时空尺度-高分辨率剖面的浮游植物生物量变化特征。本文选取了琼东上升流影响下生物—光学变异性较为显著的海域, 基于2013年航次实测数据, 建立了颗粒物后向散射系数(bbp)与叶绿素a浓度(Chl a)间的区域性关系模型。模型假定颗粒物后向散射系数由不随叶绿素浓度变化的固定背景值, 以及较大粒级(>2μm)和pico级(微微型, <2μm)两类浮游植物的后向散射贡献累加所得。采集的数据集进行了模型检验, 结果表明, 模型能很好地模拟琼东海域水体的bbp与Chl a间的变化趋势, 性能优于常用的幂函数关系模型, 尤其在低叶绿素浓度范围, 很好地解决幂函数显著低估的现象; 琼东海域的bbp和Chl a关系存在显著的水层变化, 底层后向散射固定背景值显著高于上层水体背景值, 表明底层受上升流的影响, 水体中不随Chl a共变的颗粒物浓度增大, 其后向散射相应增强; 叶绿素最大层的后向散射固定背景值显著低于上层其他水体的固定背景值, 后向散射固定背景值的贡献百分比约为21%~35%; 随着叶绿素浓度增大, 较大粒级的浮游植物对颗粒物后向散射系数的贡献也显著增大, 可达到50%以上, pico级浮游植物贡献稳定在40%附近。本研究的结果将为琼东海域浮游植物生物量的光学遥感、生物地球化学过程研究提供更为精确的区域性模型和基础支撑数据。

关键词: 颗粒物后向散射系数, 叶绿素a浓度, 浮游植物粒级结构, 琼东海域

Abstract:

Variability of light backscattering coefficient in the ocean can be used to quantify the biomass of phytoplankton, which can be applied in remote sensing and optical profile observation platforms to obtain the characteristics of phytoplankton biomass spanning various spatio-temporal scales and vertical profiles in the ocean. Significant variabilities of the bio-optical properties exist off the eastern Hainan coast, being influenced by upwelling. Based on the in-situ data collected off this area in 2013, we established a regional algorithm between the backscattering coefficient of particle [bbp] and chlorophyll a concentration [Chl a]. The algorithm is based on the assumption that the particle backscattering coefficient is determined by the constant background backscattering value independent of Chl a and two components by pico (< 2 μm) and large(>2 μm)phytoplankton. Results show that the modelled bbp values agree well with measurements, especially for low Chl a concentration. The relationships between bbp and Chl a vary in different water layers. For example, the constant background backscattering values at the bottom layer are significantly higher than those in the upper layer, indicating that driven by upwelling, the increasing concentration of submicron particles not covariant with Chl a might produce an increasing backscattering coefficient. At the chlorophyll maximum layer, the background backscattering values are significantly lower than those in the upper water, and the contribution percentage of background backscattering value is about 21%~35%. With the increase of Chl a concentration, the contribution of large phytoplankton to bbp increases significantly, accounting for 50% or higher, while the contribution of pico phytoplankton remains stable around 40%. Understanding the regional relationship of bbp and Chl a off the eastern Hainan coast can improve our understanding of marine biogeochemical processes in the region.

Key words: Backscattering coefficient of particulate, chlorophyll a concentration, phytoplankton size class, Qiongdong offshore water

中图分类号: 

  • Q948.8