This is the high frequency (10 Hz) eddy covariance (EC) measurements which mainly contain the wind data, ship motion data, gas concentration data and the underway measurements. These data were measured on summer 2019 during two Arctic cruises JR18006 (from and to Aberdeen, UK and visited the Barents Sea ) and JR18007 (from Harwich, UK to Svalbard and visited the Greenland Sea). These EC data can be used to directly calculate the air-sea CO2 and sensible heat fluxes. The EC system was deployed on RRS James Clark Ross by Thomas Bell and Mingxi Yang (Plymouth Marine Laboratory). Please see Dong et al., (2021) for details of these EC data. Eddy covariance air-sea CO2 flux measurements were made possible by funding from the NERC ORCHESTRA (NE/N018095/1) and European Space Agency AMT4oceanSatFluxCCN (4000125730/18/NL/FF /gp) projects.

This data product comprises 5 files, containing marine sediment pore water and solid phase leachate silicon (Si) isotopic and element concentration data, as well as benthic silica flux magnitudes derived from core incubation experiments and sediment biogenic silica contents. Samples were collected over three cruises of the Changing Arctic Ocean Seafloor (ChAOS) project summer sampling campaigns in the Barents Sea between 2017 and 2019 aboard the RRS James Clark Ross (cruises JR16006, JR17007 and JR18006). The aim of this study was to improve our mechanistic understanding of the cycling of Si within the Arctic Ocean seafloor through measurement of stable Si isotopes in the dissolved Si pool and the solid phase sources. This project was part of the Changing Arctic Ocean programme, funded by the Natural Environment Research Council (NERC) (grant no. NE/P005942/1).

Morphometric data were collected for 417 Calanus finmarchicus copepods (stage CV), swimming activity data were collected using locomotor activity monitors for 469 Calanus finmarchicus copepods (stage CV) and oxygen consumption activity data were collected using a Loligo microplate respirometry system for 40 Calanus finmarchicus copepods (stage CV). All data were collected in the Fram Strait, Arctic Ocean, from two stations (F7 and D6) in August 2019, coinciding with the timing of early diapause in this species. Photographs were taken and experiments were conducted onboard RRS James Clark Ross. The data are reported in detail in Grigor et al., Torpidity as an indicator of overwintering diapause in Calanus finmarchicus. Funding was provided by the CHASE project (NE/R012733/1), part of the Changing Arctic Ocean (CAO) programme, jointly funded by the UKRI Natural Environment Research Council (NERC) and the German Federal Ministry of Education and Research (BMBF). Sampling and experiments were performed on the DIAPOD cruise to the Fram Strait in August 2019.