Water mass transformation in the Barents Sea inferred from radiogenic neodymium 
isotopes, rare earth elements and stable oxygen isotopes

Laukert, Georgi; Makhotin, Mikhail; Petrova, Mariia V.; Frank, Martin; Hathorne, Ed C.; Bauch, Dorothea; Böning, Philipp; Kassens, Heidemarie

アイテム詳細

登録内容を編集ファイル形式で保存

一時保存へ追加

タグ情報を表示リリース履歴を表示詳細要約

公開

学術論文

Water mass transformation in the Barents Sea inferred from radiogenic neodymium isotopes, rare earth elements and stable oxygen isotopes

MPS-Authors

/persons/resource/persons210278

Böning, Philipp
Max Planck Research Group Marine Isotope Geochemistry, Max Planck Institute for Marine Microbiology, Max Planck Society;

External Resource

There are no locators available

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

フルテキスト (公開)

公開されているフルテキストはありません

付随資料 (公開)

There is no public supplementary material available

引用

Laukert, G., Makhotin, M., Petrova, M. V., Frank, M., Hathorne, E. C., Bauch, D., Böning, P., & Kassens, H. (2018). Water mass transformation in the Barents Sea inferred from radiogenic neodymium isotopes, rare earth elements and stable oxygen isotopes. Chemical Geology.

引用: https://hdl.handle.net/21.11116/0000-0003-B753-1

要旨

Nearly half the inflow of warm and saline Atlantic Water (AW) to the Arctic Ocean is substantially cooled and freshened in the Barents Sea, which is therefore considered a key region for water mass transformation in the Arctic Mediterranean (AM). Numerous studies have focused on this transformation and the increasing influence of AW on Arctic climate and biodiversity, yet geochemical investigations of these processes have been scarce. Using the first comprehensive data set of the distributions of dissolved radiogenic neodymium (Nd) isotopes (expressed as ɛNd), rare earth elements (REE) and stable oxygen isotope (δ18O) compositions from this region we are able to constrain the transport and transformation of AW in the Barents Sea and to investigate which processes change the chemical composition of the water masses beyond what is expected from circulation and mixing.

Inflowing AW and Norwegian Coastal Water (NCW) both exhibit distinctly unradiogenic ɛNd signatures of −12.4 and −14.5, respectively, whereas cold and dense Polar Water (PW) has considerably more radiogenic ɛNd signatures reaching up to −8.1. Locally formed Barents Sea Atlantic Water (BSAW) and Barents Sea Arctic Atlantic Water (BSAAW) are encountered in the northeastern Barents Sea and have intermediate ɛNd values resulting from admixture of PW containing small amounts of riverine freshwater from the Ob (<~1.1%) to AW and NCW. Similar to the Laptev Sea, the dissolved Nd isotope composition in the Barents Sea seems to be mainly controlled by water mass advection and mixing despite its shallow water depth. Strikingly, the BSAW and BSAAW are marked by the lowest dissolved REE concentrations reported to date for the AM reaching 11 pmol/kg for Nd ([Nd]), which in contrast to the Nd isotopes, cannot be attributed to the admixture of REE-rich Ob freshwater to AW or NCW ([Nd] = 16.7, and 22 pmol/kg, respectively) and instead reflects REE removal from the dissolved phase with preferential removal of the light over the heavy REEs. The REE removal is, however, not explainable by estuarine REE behavior alone, suggesting that scavenging by (re)suspended (biogenic) particles occurs locally in the Barents Sea. Regardless of the exact cause of REE depletion, we show that AW transformation is accompanied by geochemical changes beyond those expected from water mass mixing.