Monthly measurements of particulate organic carbon and nitrogen concentrations in a sub-Arctic fjord, Ramfjord in Tromsø, Norway between September 2020 and August 2021

Fjord water was collected on a monthly basis between September 2020 and August 2021 from 5m and 30m depth in a sub-Arctic fjord (Ramfjorden, Tromso, Norway) with a GoFlo (General Oceanics). Water for particulate organic carbon (POC) and particulate nitrogen (PN) analyses (~300-1500ml) was filtered in triplicates through a precombusted GFF filter (0.7mum, Whatman). The filters were wrapped in aluminium foil and stored at -20C unde further processing. Before sample analysis, the filters were thawed and dried at 60C in a drying oven for 24h. Subsequently they were acid-fumed in a desiccator for 24h, and dried again for 24h in a drying oven. The filters were packed in tin capsules, and POC and PN concentrations were measured with a CHN analyzer (CE440, Exeter Analytical).