DOI: 10.5194/tc-14-1795-2020
论文题名: New observations of the distribution, morphology and dissolution dynamics of cryogenic gypsum in the Arctic Ocean
作者: Wollenburg J.E. ; Iversen M. ; Katlein C. ; Krumpen T. ; Nicolaus M. ; Castellani G. ; Peeken I. ; Flores H.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 6 起始页码: 1795
结束页码: 1808
语种: 英语
英文关键词: biological pump
; cryogenic fluid
; crystal structure
; dissolution
; gypsum
; melting
; remotely operated vehicle
; sea ice
; spatial distribution
; surface water
; Arctic
; Arctic Ocean
; Atlantic Ocean
; Eurasian Basin
; Nansen Basin
; Svalbard
; Svalbard and Jan Mayen
英文摘要: To date, observations on a single location indicate that cryogenic gypsum (Ca[SO4]ĝ « 2H2O ) may constitute an efficient but hitherto overlooked ballasting mineral enhancing the efficiency of the biological carbon pump in the Arctic Ocean. In June-July 2017 we sampled cryogenic gypsum under pack ice in the Nansen Basin north of Svalbard using a plankton net mounted on a remotely operated vehicle (ROVnet). Cryogenic gypsum crystals were present at all sampled stations, which suggested a persisting cryogenic gypsum release from melting sea ice throughout the investigated area. This was supported by a sea ice backtracking model, indicating that gypsum release was not related to a specific region of sea ice formation. The observed cryogenic gypsum crystals exhibited a large variability in morphology and size, with the largest crystals exceeding a length of 1 cm. Preservation, temperature and pressure laboratory studies revealed that gypsum dissolution rates accelerated with increasing temperature and pressure, ranging from 6 % d-1 by mass in polar surface water (-0.5 ĝˆ C) to 81 % d-1 by mass in Atlantic Water (2.5 ĝˆ C at 65 bar). When testing the preservation of gypsum in formaldehyde-fixed samples, we observed immediate dissolution. Dissolution at warmer temperatures and through inappropriate preservation media may thus explain why cryogenic gypsum was not observed in scientific samples previously. Direct measurements of gypsum crystal sinking velocities ranged between 200 and 7000 m d-1 , suggesting that gypsum-loaded marine aggregates could rapidly sink from the surface to abyssal depths, supporting the hypothesized potential of gypsum as a ballasting mineral in the Arctic Ocean. © 2020 Copernicus GmbH. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164628
Appears in Collections: 气候变化与战略
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作者单位: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, 27570, Germany; MARUM - Zentrum für Marine Umweltwissenschaften der Universität Bremen, University of Bremen, Bremen, 27359, Germany
Recommended Citation:
Wollenburg J.E.,Iversen M.,Katlein C.,et al. New observations of the distribution, morphology and dissolution dynamics of cryogenic gypsum in the Arctic Ocean[J]. Cryosphere,2020-01-01,14(6)