A 40-y record reveals gradual Antarctic sea ice increases followed by decreases at rates far exceeding the rates seen in the Arctic

Abstract

Following over 3 decades of gradual but uneven increases in sea ice coverage, the yearly average Antarctic sea ice extents reached a record high of 12.8 × 106 km2 in 2014, followed by a decline so precipitous that they reached their lowest value in the 40-y 1979–2018 satellite multichannel passive-microwave record, 10.7 × 106 km2, in 2017. In contrast, it took the Arctic sea ice cover a full 3 decades to register a loss that great in yearly average ice extents. Still, when considering the 40-y record as a whole, the Antarctic sea ice continues to have a positive overall trend in yearly average ice extents, although at 11,300 ± 5,300 km2⋅y−1, this trend is only 50% of the trend for 1979–2014, before the precipitous decline. Four of the 5 sectors into which the Antarctic sea ice cover is divided all also have 40-y positive trends that are well reduced from their 2014–2017 values. The one anomalous sector in this regard, the Bellingshausen/Amundsen Seas, has a 40-y negative trend, with the yearly average ice extents decreasing overall in the first 3 decades, reaching a minimum in 2007, and exhibiting an overall upward trend since 2007 (i.e., reflecting a reversal in the opposite direction from the other 4 sectors and the Antarctic sea ice cover as a whole).

Invasive non‐native species likely to threaten biodiversity and ecosystems in the Antarctic Peninsula region

“…Species allocated the highest score (A*B*C) are considered most likely to become invasive within the region Within the marine environment, there have been some major recent physical changes, mainly in reductions of marine ice over the continental shelf. In particular, in the past 50 years, seasonal sea ice cover has significantly declined at the west of the Antarctic Peninsula (Parkinson, 2019;Stammerjohn, Massom, Rind, & Martinson, 2012), with coincident considerable marine biodiversity changes (Barnes, 2015) due to marine terminating glacier retreat (Sahade et al, 2015) and ice shelf collapses (Ingels, Aronson, & Smith, 2018;Peck, Barnes, Cook, Fleming, & Clarke, 2010). These changes open up new areas and habitats (e.g.…”

Characterization of Moisture Sources for Austral Seas and Relationship with Sea Ice Concentration

“…Atmosphere 2019, 10, 627 2 of 21 covered by sea ice exceeds the area of continental ice [10]. Different from the Arctic, where a considerable decrease in sea ice extension has been observed in the last three decades, the global Southern Ocean showed a moderate increase until 2014 followed by a decline [11,12]. The long-term trend is not spatially homogeneous since it is positive over the western Ross Sea and negative on the Bellingshausen and Amundsen seas [13].…”

An On-Demand Service for Managing and Analyzing Arctic Sea Ice High Spatial Resolution Imagery

“…Public datasets are publicly available data usually collected by federal agencies, scientific communities, or non-governmental organizations, accessible to all visitors/ users, and can be discovered through the site-wide data catalog in a data portal. Public data has three characteristics: (1) the datasets are usually collected by large funded projects or missions, (2) the data volume is usually at TB (Terabyte) Data 2020, 5, 39 3 of 18 level, and (3) they are usually well-designed, managed and operated in a web server by professional data management teams.…”

“…Arctic sea ice has become increasingly important to climate change since it is not only a key driver of the Earth's climate, but also a sensitive climate indicator. The past 13 years (2007-2019) have marked the lowest Arctic summer sea ice extents in the modern era, with a record summer minimum (3.57 million km 2 ) set in 2012, followed by 2019 (4.15 million km 2 ), and 2007 (4.27 million km 2 ) [1]. Some climate models predict that the shrinking summer sea ice extent could lead to the Arctic being free of summer ice within the next 20 years [2].…”