基于船载走航观测高光谱颗粒物吸收系数反演浮游植物粒级结构
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摘要
利用高光谱监测数据反演浮游植物种群组成是当前海洋光学和水色遥感的研究热点。文章采用大西洋经向断面航次中走航式观测系统测量的海水总颗粒物吸收光谱数据,尝试建立了两种模型对浮游植物粒级结构(Phytoplankton size class,简称PSC)进行反演和比较讨论。一类模型是基于总颗粒物吸收光谱高斯分解获得的典型波段高斯带强度与色素浓度之间的关系,建立了偏最小二乘回归模型(Partial Least Squares regression model,简称PLS回归模型);另一类模型是采用长波波段吸收基线高度推算海水总叶绿素a浓度,进而根据Brewin等(2010)生物量算法推算PSC的三组分模型(简称三组分模型)。模型比较验证结果显示,两类模型对海水总叶绿素浓度的反演都有较高的精度,相对偏差ME在15%左右;对于三个粒级浮游植物对应的叶绿素浓度(Pico级C_p, Nano级C_n, Micro级C_m)的反演效果也相当, PLS回归模型反演的ME分别为28.4%、31.9%和41%,三组分模型反演的ME分别为31%、35.9%、37.7%。研究结果初步表明了采用高光谱吸收系数反演浮游植物种群结构的潜在优势,可为不同海域走航式高光谱观测系统的推广应用提供思路。
Retrieving of phytoplankton groups from hyperspectral optical data has been a hot topic in recent years for studies of marine optics and ocean color remote sensing.In this paper,based on the hyperspectral particulate absorption data(a_p(λ))measured by the ship’s flow-through system during the Atlantic Meridional Transect(AMT)cruise,two models were proposed and compared for estimating phytoplankton size class(PSC)from the a_p(λ)spectra.An algorithm that defines phytoplankton pigment absorption as a sum of Gaussian functions was used for decomposing the total particulate absorption,and a partial least squares model(PLS_model)was developed for estimating PSC using the Gaussian magnitudes at specific wavelengths.Another model(3component_model)is a modified abundance-based model proposed by Brewin et al(2010),in which the total chlorophyll-a concentration(C,mg·m~(-3))was estimated from the absorption line height at 676 nm.Results showed that both models give good results for retrieving PSC from the particulate absorption spectra,with the mean relative errors(ME)for estimating total C in the range of 15%.ME values for estimating the size-specific chlorophyll a concentration(C_p for pico-,C_n for nano-and C_m for micro-plankton)are 28.4%,31.9%and 41%for the PLS_model,and are 31%,35.9%and 37.7%for the 3component_model.Our results confirmed the potential advantages of hyperspectral optical measurements for retrieving phytoplankton groups,which also provided much insights for the application of ship-based underway flow-through system in different sea areas.
Retrieving of phytoplankton groups from hyperspectral optical data has been a hot topic in recent years for studies of marine optics and ocean color remote sensing.In this paper,based on the hyperspectral particulate absorption data(a_p(λ))measured by the ship’s flow-through system during the Atlantic Meridional Transect(AMT)cruise,two models were proposed and compared for estimating phytoplankton size class(PSC)from the a_p(λ)spectra.An algorithm that defines phytoplankton pigment absorption as a sum of Gaussian functions was used for decomposing the total particulate absorption,and a partial least squares model(PLS_model)was developed for estimating PSC using the Gaussian magnitudes at specific wavelengths.Another model(3component_model)is a modified abundance-based model proposed by Brewin et al(2010),in which the total chlorophyll-a concentration(C,mg·m~(-3))was estimated from the absorption line height at 676 nm.Results showed that both models give good results for retrieving PSC from the particulate absorption spectra,with the mean relative errors(ME)for estimating total C in the range of 15%.ME values for estimating the size-specific chlorophyll a concentration(C_p for pico-,C_n for nano-and C_m for micro-plankton)are 28.4%,31.9%and 41%for the PLS_model,and are 31%,35.9%and 37.7%for the 3component_model.Our results confirmed the potential advantages of hyperspectral optical measurements for retrieving phytoplankton groups,which also provided much insights for the application of ship-based underway flow-through system in different sea areas.
引文
黄邦钦,刘媛,陈纪新,等,2006.东海、黄海浮游植物生物量的粒级结构及时空分布[J].海洋学报,28(2):156-164.HUANG BANQIN,LIU YUAN,CHEN JIXIN,et al,2006.Temporal and spatial distribution of size-fractionized phytoplankton biomass in East China Sea and Huanghai Sea[J].Acta Oceanologica Sinica,28(2):156-164(in Chinese with English abstract).
丘仲锋,孙德勇,王胜强,等,2016.海洋浮游植物粒径等级遥感研究现状与展望[J].广西科学,23(6):492-498.QIU ZHONGFENG,SUN DEYONG,WANGSHENGQIANG,et al,2016.Research status and prospect of remote sensing of phytoplankton size classes in marine waters[J].Guangxi Sciences,23(6):492-498(in Chinese with English abstract).
孙军,刘东艳,钟华,等,2003.浮游植物粒级研究方法的比较[J].青岛海洋大学学报,33(6):917-924.SUN JUN,LIU DONGYAN,ZHONG HUA,et al,2003.Acomparison of three methods for studying phytoplankton size fraction[J].Journal of Ocean University of Qingdao,33(6):917-924(in Chinese with English abstract).
王桂芬,曹文熙,周雯,等,2010.基于南海北部海区浮游植物吸收光谱斜率变化的粒级结构反演[J].热带海洋学报,29(2):25-32.WANG GUIFEN,CAO WENXI,ZHOU WEN,et al,2010.Retrieval of phytoplankton size structure based on the spectral slope of phytoplankton absorption in the northern South China Sea[J].Journal of Tropical Oceanography,29(2):25-32(in Chinese with English abstract).
王桂芬,周雯,林俊芳,等,2014.南海北部海区浮游植物粒级结构生物光学反演模型的验证与评价[J].激光生物学报,23(6):502-515.WANG GUIFEN,ZHOU WEN,LIN JUNFANG,et al,2014.Validation and assessment on the bio-optical models for retrieving phytoplankton size structure in the northern South China Sea[J].Acta Laser Biology Sinica,23(6):502-515(in Chinese with English abstract).
BABIN M,STRAMSKI D,FERRARI G M,et al,2003.Variations in the light absorption coefficients of phytoplankton,nonalgal particles,and dissolved organic matter in coastal waters around Europe[J].Journal of Geophysical Research:Oceans,108(C7):3211.
BOSS E,PICHERAL M,LEEUW T,et al,2013.The characteristics of particulate absorption,scattering and attenuation coefficients in the surface ocean;Contribution of the Tara Oceans expedition[J].Methods in Oceanography,7:52-62.
BRACHER A,TAYLOR M H,TAYLOR B,et al,2015.Using empirical orthogonal functions derived from remote-sensing reflectance for the prediction of phytoplankton pigment concentrations[J].Ocean Science,11(1):139-158.
BREWIN R J W,DALL'OLMO G,PARDO S,et al,2016.Underway spectrophotometry along the Atlantic Meridional Transect reveals high performance in satellite chlorophyll retrievals[J].Remote Sensing of Environment,183:82-97.
BREWIN R J W,SATHYENDRANATH S,HIRATA T,et al,2010.A three-component model of phytoplankton size class for the Atlantic Ocean[J].Ecological Modelling,221(11):1472-1483.
BREWIN R J W,DEVRED E,SATHYENDRANATH S,et al,2011.Model of phytoplankton absorption based on three size classes[J].Applied Optics,50(22):4535-4549.
BREWIN R J W,SATHYENDRANATH S,MüLLER D,et al,2015.The ocean colour climate change initiative:III.Around-robin comparison on in-water bio-optical algorithms[J].Remote Sensing of Environment,162:271-294.
BRICAUD A,STRAMSKI D,1990.Spectral absorption coefficients of living phytoplankton and nonalgal biogenous matter:a comparison between the Peru upwelling area and the Sargasso Sea[J].Limnology and Oceanography,35(3):562-582.
CATLETT D,SIEGEL D A,2018.Phytoplankton pigment communities can be modeled using unique relationships with spectral absorption signatures in a dynamic coastal environment[J].Journal of Geophysical Research:Oceans,123(1):246-264.
CHASE A,BOSS E,ZANEVELD R,et al,2013.Decomposition of in situ particulate absorption spectra[J].Methods in Oceanography,7:110-124.
CHASE A P,BOSS E,CETINI?I,et al,2017.Estimation of phytoplankton accessory pigments from hyperspectral reflectance spectra:toward a global algorithm[J].Journal of Geophysical Research:Oceans,122(12):9725-9743.
DALL'OLMO G,WESTBERRY T K,BEHRENFELD M J,et al,2009.Significant contribution of large particles to optical backscattering in the open ocean[J].Biogeosciences,6(6):947-967.
GIBB S W,BARLOW R G,CUMMINGS D G,et al,2000.Surface phytoplankton pigment distributions in the Atlantic Ocean:an assessment of basin scale variability between 50?N and 50?S[J].Progress in Oceanography,45(3-4):339-368.
HOEPFFNER N,SATHYENDRANATH S,1991.Effect of pigment composition on absorption properties of phytoplankton[J].Marine Ecology Progress Series,73:11-23.
HOEPFFNER N,SATHYENDRANATH S,1993.Determination of the major groups of phytoplankton pigments from the absorption spectra of total particulate matter[J].Journal of Geophysical Research:Oceans,98(C12):22789-22803.
IOCCG,2014.Phytoplankton functional types from space[R]//SATHYENDRANATH S.Reports of the International Ocean-Colour Coordinating Group,No.15.Dartmouth,Canada:IOCCG.
LIN JUNFANG,CAO WENXI,WANG GUIFEN,et al,2014.Inversion of bio-optical properties in the coastal upwelling waters of the northern South China Sea[J].Continental Shelf Research,2014,85:73-84.
MOUW C B,CIOCHETTO A B,GRUNERT B,et al,2017.Expanding understanding of optical variability in Lake Superior with a 4-year dataset[J].Earth System Science Data,9(2):497-509.
ORGANELLI E,BRICAUD A,ANTOINE D,et al,2013.Multivariate approach for the retrieval of phytoplankton size structure from measured light absorption spectra in the Mediterranean Sea(BOUSSOLE site)[J].Applied Optics,52(11):2257-2273.
ROESLER C S,BARNARD A H,2013.Optical proxy for phytoplankton biomass in the absence of photophysiology:rethinking the absorption line height[J].Methods in Oceanography,7:79-94.
SIEBURTH J M,SMETACEKV,LENZ J,1978.Pelagic ecosystem structure:heterotrophic compartments of the plankton and their relationship to plankton size fractions[J].Limnology and oceanography,23:1256-1263.
SLADE W H,BOSS E,DALL’OLMO G,et al,2010.Underway and moored methods for improving accuracy in measurement of spectral particulate absorption and attenuation[J].Journal of Atmospheric and Oceanic Technology,27(10):1733-1746.
SULLIVAN J M,TWARDOWSKI M S,ZANEVELD J R V,et al,2006.Hyperspectral temperature and salt dependencies of absorption by water and heavy water in the 400-750 nm spectral range[J].Applied Optics,45(21):5294-5309.
SUN XUERONG,SHEN FANG,LIU DONGYAN,et al,2018.In situ and satellite observations of phytoplankton size classes in the entire continental shelf sea,China[J].Journal of Geophysical Research:Oceans,123:3523-3544.
UITZ J,CLAUSTRE H,MOREL A,et al,2006.Vertical distribution of phytoplankton communities in open ocean:An assessment based on surface chlorophyll[J].Journal of Geophysical Research:Oceans,111(C8):C08005.
VIDUSSI F,CLAUSTRE H,MANCA B B,et al,2001.Phytoplankton pigment distribution in relation to upper thermocline circulation in the eastern Mediterranean Sea during winter[J].Journal of Geophysical Research:Oceans,106(C9):19939-19956.
WANG GUIFEN,CAO WENXI,YANG DINGTIAN,et al,2008.Partitioning particulate absorption coefficient into contributions of phytoplankton and nonalgal particles:Acase study in the northern South China Sea[J].Estuarine,Coastal and Shelf Science,78(3):513-520.
WANG GUOQING,LEE Z,MISHRA D R,et al,2016.Retrieving absorption coefficients of multiple phytoplankton pigments from hyperspectral remote sensing reflectance measured over cyanobacteria bloom waters[J].Limnology and Oceanography:Methods,14(7):432-447.
WOLANIN A,SOPPA M,BRACHER A,2016.Investigation of spectral band requirements for improving retrievals of phytoplankton functional types[J].Remote Sensing,8(10):871.
ZHENG GUANGMING,STRAMSKI M,2013.A model based on stacked-constraints approach for partitioning the light absorption coefficient of seawater into phytoplankton and non-phytoplankton components[J].Journal of Geophysical Research:Oceans,118(4):2155-2174,doi:10.1002/jgrc.20115.
丘仲锋,孙德勇,王胜强,等,2016.海洋浮游植物粒径等级遥感研究现状与展望[J].广西科学,23(6):492-498.QIU ZHONGFENG,SUN DEYONG,WANGSHENGQIANG,et al,2016.Research status and prospect of remote sensing of phytoplankton size classes in marine waters[J].Guangxi Sciences,23(6):492-498(in Chinese with English abstract).
孙军,刘东艳,钟华,等,2003.浮游植物粒级研究方法的比较[J].青岛海洋大学学报,33(6):917-924.SUN JUN,LIU DONGYAN,ZHONG HUA,et al,2003.Acomparison of three methods for studying phytoplankton size fraction[J].Journal of Ocean University of Qingdao,33(6):917-924(in Chinese with English abstract).
王桂芬,曹文熙,周雯,等,2010.基于南海北部海区浮游植物吸收光谱斜率变化的粒级结构反演[J].热带海洋学报,29(2):25-32.WANG GUIFEN,CAO WENXI,ZHOU WEN,et al,2010.Retrieval of phytoplankton size structure based on the spectral slope of phytoplankton absorption in the northern South China Sea[J].Journal of Tropical Oceanography,29(2):25-32(in Chinese with English abstract).
王桂芬,周雯,林俊芳,等,2014.南海北部海区浮游植物粒级结构生物光学反演模型的验证与评价[J].激光生物学报,23(6):502-515.WANG GUIFEN,ZHOU WEN,LIN JUNFANG,et al,2014.Validation and assessment on the bio-optical models for retrieving phytoplankton size structure in the northern South China Sea[J].Acta Laser Biology Sinica,23(6):502-515(in Chinese with English abstract).
BABIN M,STRAMSKI D,FERRARI G M,et al,2003.Variations in the light absorption coefficients of phytoplankton,nonalgal particles,and dissolved organic matter in coastal waters around Europe[J].Journal of Geophysical Research:Oceans,108(C7):3211.
BOSS E,PICHERAL M,LEEUW T,et al,2013.The characteristics of particulate absorption,scattering and attenuation coefficients in the surface ocean;Contribution of the Tara Oceans expedition[J].Methods in Oceanography,7:52-62.
BRACHER A,TAYLOR M H,TAYLOR B,et al,2015.Using empirical orthogonal functions derived from remote-sensing reflectance for the prediction of phytoplankton pigment concentrations[J].Ocean Science,11(1):139-158.
BREWIN R J W,DALL'OLMO G,PARDO S,et al,2016.Underway spectrophotometry along the Atlantic Meridional Transect reveals high performance in satellite chlorophyll retrievals[J].Remote Sensing of Environment,183:82-97.
BREWIN R J W,SATHYENDRANATH S,HIRATA T,et al,2010.A three-component model of phytoplankton size class for the Atlantic Ocean[J].Ecological Modelling,221(11):1472-1483.
BREWIN R J W,DEVRED E,SATHYENDRANATH S,et al,2011.Model of phytoplankton absorption based on three size classes[J].Applied Optics,50(22):4535-4549.
BREWIN R J W,SATHYENDRANATH S,MüLLER D,et al,2015.The ocean colour climate change initiative:III.Around-robin comparison on in-water bio-optical algorithms[J].Remote Sensing of Environment,162:271-294.
BRICAUD A,STRAMSKI D,1990.Spectral absorption coefficients of living phytoplankton and nonalgal biogenous matter:a comparison between the Peru upwelling area and the Sargasso Sea[J].Limnology and Oceanography,35(3):562-582.
CATLETT D,SIEGEL D A,2018.Phytoplankton pigment communities can be modeled using unique relationships with spectral absorption signatures in a dynamic coastal environment[J].Journal of Geophysical Research:Oceans,123(1):246-264.
CHASE A,BOSS E,ZANEVELD R,et al,2013.Decomposition of in situ particulate absorption spectra[J].Methods in Oceanography,7:110-124.
CHASE A P,BOSS E,CETINI?I,et al,2017.Estimation of phytoplankton accessory pigments from hyperspectral reflectance spectra:toward a global algorithm[J].Journal of Geophysical Research:Oceans,122(12):9725-9743.
DALL'OLMO G,WESTBERRY T K,BEHRENFELD M J,et al,2009.Significant contribution of large particles to optical backscattering in the open ocean[J].Biogeosciences,6(6):947-967.
GIBB S W,BARLOW R G,CUMMINGS D G,et al,2000.Surface phytoplankton pigment distributions in the Atlantic Ocean:an assessment of basin scale variability between 50?N and 50?S[J].Progress in Oceanography,45(3-4):339-368.
HOEPFFNER N,SATHYENDRANATH S,1991.Effect of pigment composition on absorption properties of phytoplankton[J].Marine Ecology Progress Series,73:11-23.
HOEPFFNER N,SATHYENDRANATH S,1993.Determination of the major groups of phytoplankton pigments from the absorption spectra of total particulate matter[J].Journal of Geophysical Research:Oceans,98(C12):22789-22803.
IOCCG,2014.Phytoplankton functional types from space[R]//SATHYENDRANATH S.Reports of the International Ocean-Colour Coordinating Group,No.15.Dartmouth,Canada:IOCCG.
LIN JUNFANG,CAO WENXI,WANG GUIFEN,et al,2014.Inversion of bio-optical properties in the coastal upwelling waters of the northern South China Sea[J].Continental Shelf Research,2014,85:73-84.
MOUW C B,CIOCHETTO A B,GRUNERT B,et al,2017.Expanding understanding of optical variability in Lake Superior with a 4-year dataset[J].Earth System Science Data,9(2):497-509.
ORGANELLI E,BRICAUD A,ANTOINE D,et al,2013.Multivariate approach for the retrieval of phytoplankton size structure from measured light absorption spectra in the Mediterranean Sea(BOUSSOLE site)[J].Applied Optics,52(11):2257-2273.
ROESLER C S,BARNARD A H,2013.Optical proxy for phytoplankton biomass in the absence of photophysiology:rethinking the absorption line height[J].Methods in Oceanography,7:79-94.
SIEBURTH J M,SMETACEKV,LENZ J,1978.Pelagic ecosystem structure:heterotrophic compartments of the plankton and their relationship to plankton size fractions[J].Limnology and oceanography,23:1256-1263.
SLADE W H,BOSS E,DALL’OLMO G,et al,2010.Underway and moored methods for improving accuracy in measurement of spectral particulate absorption and attenuation[J].Journal of Atmospheric and Oceanic Technology,27(10):1733-1746.
SULLIVAN J M,TWARDOWSKI M S,ZANEVELD J R V,et al,2006.Hyperspectral temperature and salt dependencies of absorption by water and heavy water in the 400-750 nm spectral range[J].Applied Optics,45(21):5294-5309.
SUN XUERONG,SHEN FANG,LIU DONGYAN,et al,2018.In situ and satellite observations of phytoplankton size classes in the entire continental shelf sea,China[J].Journal of Geophysical Research:Oceans,123:3523-3544.
UITZ J,CLAUSTRE H,MOREL A,et al,2006.Vertical distribution of phytoplankton communities in open ocean:An assessment based on surface chlorophyll[J].Journal of Geophysical Research:Oceans,111(C8):C08005.
VIDUSSI F,CLAUSTRE H,MANCA B B,et al,2001.Phytoplankton pigment distribution in relation to upper thermocline circulation in the eastern Mediterranean Sea during winter[J].Journal of Geophysical Research:Oceans,106(C9):19939-19956.
WANG GUIFEN,CAO WENXI,YANG DINGTIAN,et al,2008.Partitioning particulate absorption coefficient into contributions of phytoplankton and nonalgal particles:Acase study in the northern South China Sea[J].Estuarine,Coastal and Shelf Science,78(3):513-520.
WANG GUOQING,LEE Z,MISHRA D R,et al,2016.Retrieving absorption coefficients of multiple phytoplankton pigments from hyperspectral remote sensing reflectance measured over cyanobacteria bloom waters[J].Limnology and Oceanography:Methods,14(7):432-447.
WOLANIN A,SOPPA M,BRACHER A,2016.Investigation of spectral band requirements for improving retrievals of phytoplankton functional types[J].Remote Sensing,8(10):871.
ZHENG GUANGMING,STRAMSKI M,2013.A model based on stacked-constraints approach for partitioning the light absorption coefficient of seawater into phytoplankton and non-phytoplankton components[J].Journal of Geophysical Research:Oceans,118(4):2155-2174,doi:10.1002/jgrc.20115.