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Phytoplankton pigment and phytoplankton group chlorophyll-a concentrations during POLARSTERN cruise PS126 from North Sea to Fram Strait in May to June 2021 from HPLC analysis of water samples

Phytoplankton pigments were determined in the water surface (from 0 to 11 m depth) of a transect from the North Sea to Fram Strait and back during RV Polarstern expedition PS126 from 24 Jun to 25 Jun 2021. Water samples were collected from CTD Niskin bottles at five to six different depths from the upper 100 m at CTD stations and from underway sampling. Between 0.4 to 3.5 L of each seawater sample was filtered through Whatman GF/F filters. The sample filters were then shock‐frozen in liquid N2 and kept at−80 °C until analysis. High Pressure Liquid Chromatography (HPLC) was performed to quantify various phytoplankton pigments (see Table 1 in Taylor et al. 2011) following the method of Barlow et al. (1997) that was adjusted to our temperature‐controlled instruments as detailed in Alvarez et al. (2022).

Phytoplankton pigment concentrations during POLARSTERN cruise PS121 from North Sea to Fram in August to September 2019

Phytoplankton pigments were determined in the water column of a transect from the North Sea to Fram Strait during RV Polarstern expedition PS121 from 11 Aug to 10 Sep 2019. Water samples were collected from CTD Niskin bottles at five to six different depths from the upper 100 m at CTD stations and from underway sampling. This were the same water samples as in Bracher et al. (https://doi.pangaea.de/10.1594/PANGAEA.938260). Between 0.2 to 3.5 L of each seawater sample was filtered through Whatman GF/Ffilters. The sample filters were then shock‐frozen in liquid N2 and kept at−80 °C until analysis. High Pressure Liquid Chromatography (HPLC) was performed to quantify various phytoplankton pigments (see Table 1 in Taylor et al. 2011) following the method of Barlow et al. (1997) that was adjusted to our temperature‐controlled instruments as detailed in Alvarez et al. (2022).

Phytoplankton pigment concentrations in the North Sea and Sogne Fjord from 29 April to 7 May 2016 during RV HEINCKE cruise HE462

We present a data set on the concentration of various phytoplankton pigments using High Pressure Liquid Chromatography (HPLC) during the spring (29 April to 7 May 2016) cruise HE462 with RV Heincke in the North Sea and Sogne Fjord.

Vertical profiles of settling particles in the water column.

During 16 months of deployment, 239 g m−2 dry matter settled in the 40-m trap, with an average flux of 14.9 g m−2 month−1 (Table 2 and Fig. 2). The content of organic carbon was 21.9% at that depth and that of total nitrogen 1.6% (Table 2 and Fig. 2). The resulting atomic C/N ratio of 15 indicated that the sedimented material resulted from the autochthonous production by suspended phytoplankton and that terrigenous input is likely to be negligible at that site. The amount of pigments gathered during the 16 months deployment in the 40-m trap was 193.1 μmol m−2 for chlorophyll a and 797 μmol m−2 for chlorophyllide a+pheopigment a. The average flux was hence 61.8 μmol m−2 month−1 settled chlorophyll a+chlorophyllide a+pheopigment a (Table 1). It is worth noting that the replicate samples of the 40-m trap deviated strongly (coefficient of variation: 60.5%), whereas the coefficients of variation for the replicate samples in the traps

The relationship between concentrations of chl-a calculated from SeaWiFS OC2 and chl-a calculated determined from ground truth measurements during field expeditions in Lake Baikal during 2001 and 2002

Values of measured chlorophyll (HPLC=High Pressure Liquid Chromatography) are the mean concentrations of each sampling point from 5 to 30 m depth. For the OC2 chl-a calculations, the least clouded acquisitions in 2001 (2001/07/19) and 2002 (2002/07/20) were chosen. Note the considerable chl-a overestimation caused by the influences of terrigenous input in case 2 waters.

Depth profiles of marker pigments from Bacillariophyceae plus Chrysophyceae (A), Chlorophyta (B), cyanobacterial picoplankton (C), Eustigmatophyceae, and Cryptophyta (D).

The traps were deployed for about 16 months. The respective regression equations and its coefficients of determination (r2) are reported in Table 5.In the 40-m trap, fucoxanthin was the dominant carotenoid (Table 1 and Fig. 3). Other pigments of Bacillariophyceae plus Chrysophyceae (chlorophyll c, diadinoxanthin, and diatoxanthin) as well as the cyanobacterial zeaxanthin also showed high sedimentation rates, whereas the chlorophyte chlorophyll b and lutein, as well as the cryptophyte alloxanthin, sedimented only in low amounts (Table 1 and Fig. 3). Abbreviations: Chl—chlorophyll, Fuco—fucoxanthin, Zea—zeaxanthin, β-car—β-carotene, Allo—alloxan

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