title: Variation of particulate organic carbon and its relationship with bio-optical properties during a phytoplankton bloom in the Pearl River estuary.
abstract: In this study, variations in the particulate organic carbon (POC) were monitored during a phytoplankton bloom event, and the corresponding changes in bio-optical properties were tracked at one station (114.29°E, 22.06°N) located in the Pearl River estuary. A greater than 10-fold increase in POC (112.29-1173.36 mg m⁻³) was observed during the bloom, with the chlorophyll a concentration (Chl-a) varying from 0.984 to 25.941 mg m⁻³. A power law function is used to describe the relationship between POC and Chl-a, and the POC:Chl-a ratio tends to change inversely with Chl-a. Phytoplankton carbon concentration is indirectly estimated using the conceptual model proposed by Sathyendranath et al. (2009), and this carbon is found to contribute 47.21% (±10.65%) to total POC. The estimated carbon-to-chlorophyll ratio of phytoplankton in diatom-dominated waters is found to be comparable with results reported in the literature. Empirical algorithms for determining the concentrations of Chl-a and POC were developed based on the relationships of these variables with the blue-to-green reflectance ratio. With these bio-optical models, the levels of particulate organic carbon and Chl-a could be predicted from the radiometric data measured by a marine optical buoy, which showed much more detailed information about the variability in biogeochemical parameters during this bloom event.
authors.affiliation: State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China. guifenwang@scsio.ac.cn
authors.forename: Guifen
authors.initials: G
authors.lastname: Wang
authors.forename: Wen
authors.initials: W
authors.lastname: Zhou
authors.forename: Wenxi
authors.initials: W
authors.lastname: Cao
authors.forename: Jianping
authors.initials: J
authors.lastname: Yin
authors.forename: Yuezhong
authors.initials: Y
authors.lastname: Yang
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Sun
authors.forename: Yuanzhi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
mesh_terms: D000465:Algorithms; D061006:Bays / Q000737:chemistry* / Q000382:microbiology; D002244:Carbon / Q000032:analysis* / Q000378:metabolism; D002681:China; D002734:Chlorophyll / Q000032:analysis / Q000378:metabolism; D000077194:Chlorophyll A; D003116:Color; D003124:Colorimetry / Q000379:methods*; D017377:Diatoms / Q000502:physiology; D004784:Environmental Monitoring / Q000379:methods*; D005068:Eutrophication; D052638:Particulate Matter / Q000032:analysis / Q000378:metabolism; D010839:Phytoplankton / Q000502:physiology; D012621:Seasons
chemical_list: D052638:Particulate Matter; D002734:Chlorophyll; D002244:Carbon; D000077194:Chlorophyll A