Soil carbon and nitrogen stocks in Arctic river deltas: New data for three Northwest Alaskan deltas

Arctic river deltas are dynamic and rapidly changing permafrost environments in a warming Arctic. Our study presents new data on permafrost carbon and nitrogen stocks from 26 soil permafrost cores collected from the Noatak, Kobuk and Selawik river deltas in Western Alaska. We analyzed 318 samples for total carbon (TC) and total nitrogen (TN). Average landscape-scale carbon storage is 50.1 ± 7.8 kg C (both organic and inorganic) and 2.4 ± 0.3 kg N m-2 (0-200 cm). This totals 67 ± 11 Mt C and 3.3 ± 0.6 Mt N in the first two meters of soil in the Noatak, Kobuk and Selawik deltas combined. Our findings demonstrate that Arctic river deltas are important regions of permafrost soil carbon storage and need to be considered in panarctic permafrost carbon estimations.