Sebastien Moreau

Hanna Kauko

Thomas Ryan-Keogh

Asmita Singh

Ilka Peeken

Gunnar Bratbak

Chlorophyll (Chl) a samples were collected from multiple depths, filtered (500-1000 ml, typically 1000 ml) with a gentle vacuum pressure on 0.7 um GF/F filters, and extracted in 100 % methanol in darkness, 5° C and for 24 h. Pigment concentration was measured with a calibrated Turner 10-AU Fluorometer (Turner Designs, San Jose, USA).

Flow cytometry samples (FCM) were filled in 4.5 ml cryovials, fixed with glutaraldehyde (final concentration 0.5 %), and stored in -80° C until analysis. The samples were analysed with a Attune™ NxT Acoustic Focusing Cytometer (Invitrogen™, Thermo Fisher Scientific Inc. USA) at the University of Bergen, Norway 6 months after the campaign (September 2019). Before the analysis, the bacteria samples were diluted (10x) with filtered TE buffer, stained with SYBR Green I and incubated at room temperature in darkness for 10 minutes. Bacteria concentration estimates were based on side scatter and green fluorescence. Pico- and nanophytoplankton concentration estimates (included in version 2) were based on side scatter and red fluorescence.

[To be included in version 2 in 2022:]

Samples for HPLC analysis were collected in the same way and stored in -80° C until analysis at the Alfred Wegener Institute (Bremen, Germany) with a Waters Alliance 2695 HPLC Separation Module, Waters photodiode array detector (2,996), Agilent Technologies Microsorb-MV3 C8 column (4.6 × 100 mm), and 1 molar ammonium acetate solution. For more details see the below mentioned articles. Header explanations: Chla - chlorophyll a; Chlb - chlorophyll b; Chlc1_Chlc2 - chlorophyll c1 + chlorophyll c2; Chlc3 - chlorophyll c3; Fucox - fucoxanthin; 19But - 19’butanoyloxyfucoxanthin; 19Hex - 19’hexanoyloxyfucoxanthin; Perid - peridinin; Lutein - lutein; Allox – alloxanthin; Zeax - zeaxanthin; DD - diadinoxanthin; DT – diatoxanthin; Beta_car - beta carotene.

Also included here Chl a concentrations from an underway fluorometer (WETStar, Sea-Bird Scientific; scientific seawater intake at 4 m depth) calibrated with Chl a samples (taken every 4 hours during longer transits; y=0.09x + 0.06; R2=0.85) processed with the above mentioned method.

Unpublished data to be included in future versions (v3): biogenic silica, particulate organic carbon and nitrogen (POC and PON), dissolved organic carbon (DOC) and total dissolved nitrogen (TDN).

For more details see [Kauko et al. (2021)]( https://doi.org/10.3389/fmars.2021.623856) and Kauko et al. (in prep). See also [Chl a vertical profiles]( https://data.npolar.no/dataset/5e510f85-29e1-42c3-89a5-8766f5c5948c) from an in situ fluorometer, [taxonomy and abundance data]( https://data.npolar.no/dataset/283e500c-732b-4f9b-a48a-3bc4990e3f55) and [nutrients data]( https://doi.org/10.21335/NMDC-1503664923). The microscopy sample IDs (taxonomy and abundance) are included in this dataset (v2) for easier combination.

Regarding the underway data, see also [Ogundare et al. (2021)]( https://doi.org/10.3389/fmars.2020.614263) and [this dataset]( https://doi.org/10.21334/npolar.2020.cc4bfb5f).

CEOS IDN DIF

9.8.4