DOI: 10.5194/tc-14-2775-2020
论文题名: Seasonal and interannual variability of landfast sea ice in Atka Bay, Weddell Sea, Antarctica
作者: Arndt S. ; Hoppmann M. ; Schmithüsen H. ; Fraser A.D. ; Nicolaus M.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 9 起始页码: 2775
结束页码: 2793
语种: 英语
英文关键词: annual variation
; buoyancy
; coastal zone
; easterly wave
; satellite imagery
; sea ice
; seasonality
; snow accumulation
; thermodynamics
; time series analysis
; Antarctica
; Atka Bay
; Southern Ocean
; Weddell Sea
; West Antarctica
英文摘要: Landfast sea ice (fast ice) attached to Antarctic (near-)coastal elements is a critical component of the local physical and ecological systems. Through its direct coupling with the atmosphere and ocean, fast-ice properties are also a potential indicator of processes related to a changing climate. However, in situ fast-ice observations in Antarctica are extremely sparse because of logistical challenges and harsh environmental conditions. Since 2010, a monitoring program observing the seasonal evolution of fast ice in Atka Bay has been conducted as part of the Antarctic Fast Ice Network (AFIN). The bay is located on the northeastern edge of Ekström Ice Shelf in the eastern Weddell Sea, close to the German wintering station Neumayer III. A number of sampling sites have been regularly revisited each year between annual ice formation and breakup to obtain a continuous record of sea-ice and sub-ice platelet-layer thickness, as well as snow depth and freeboard across the bay. Here, we present the time series of these measurements over the last 9 years. Combining them with observations from the nearby Neumayer III meteorological observatory as well as auxiliary satellite images enables us to relate the seasonal and interannual fast-ice cycle to the factors that influence their evolution. On average, the annual consolidated fast-ice thickness at the end of the growth season is about 2 m, with a loose platelet layer of 4 m thickness beneath and 0.70 m thick snow on top. Results highlight the predominately seasonal character of the fast-ice regime in Atka Bay without a significant interannual trend in any of the observed variables over the 9-year observation period. Also, no changes are evident when comparing with sporadic measurements in the 1980s and 1990s. It is shown that strong easterly winds in the area govern the year-round snow distribution and also trigger the breakup of fast ice in the bay during summer months. Due to the substantial snow accumulation on the fast ice, a characteristic feature is frequent negative freeboard, associated flooding of the snow-ice interface, and a likely subsequent snow ice formation. The buoyant platelet layer beneath negates the snow weight to some extent, but snow thermodynamics is identified as the main driver of the energy and mass budgets for the fast-ice cover in Atka Bay. The new knowledge of the seasonal and interannual variability of fast-ice properties from the present study helps to improve our understanding of interactions between atmosphere, fast ice, ocean, and ice shelves in one of the key regions of Antarctica and calls for intensified multidisciplinary studies in this region. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164396
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; Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7001, Australia; Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, 7001, Australia
Recommended Citation:
Arndt S.,Hoppmann M.,Schmithüsen H.,et al. Seasonal and interannual variability of landfast sea ice in Atka Bay, Weddell Sea, Antarctica[J]. Cryosphere,2020-01-01,14(9)