Global warming leading to alarming recession of the Arctic sea-ice cover: Insights from remote sensing observations and model reanalysis

Abstract

The present study quantifies the magnitude of Arctic sea-ice loss in the boreal summer (July–September), especially in September at different timescales (daily, monthly, annual and decadal). The investigation on the accelerated decline in the Arctic sea-ice was performed using different datasets of passive microwave satellite imagery and model reanalysis. Arctic sea-ice declined rapidly in the boreal summer (-10.2 ± 0.8 %decade −1 ) during 1979–2018, while, the highest decline in sea-ice extent (SIE) (i.e., 82,300 km 2 yr −1 /-12.8 ± 1.1 %decade −1 ) is reported in the month of September. Since late 1979, the SIE recorded the sixth-lowest decline during September 2018 (4.71 million km 2 ). Incidentally, the records of twelve lowest extents in the satellite era occurred in the last twelve years. The loss of SIE and sea-ice concentration (SIC) are attributed to the impacts of land-ocean warming and the northward heat advection into the Arctic Ocean. This has resulted in considerable thinning of sea-ice thickness (SIT) and reduction in the multiyear ice (MYI) for summer 2018. Global and Arctic land-ocean temperatures have increased by ~0.78 °C and ~3.1 °C, respectively, over the past 40 years (1979–2018) while substantial warming rates have been identified in the Arctic Ocean (~3.5 °C in the last 40-year) relative to the Arctic land (~2.8 °C in the last 40-year). The prevailing ocean-atmospheric warming in the Arctic, the SIE, SIC and SIT have reduced, resulting in the decline of the sea-ice volume (SIV) at the rate of -3.0 ± 0.2 (1000 km 3 decade −1 ). Further, it observed that the SIV in September 2018 was three times lower than September 1979. The present study demonstrates the linkages of sea-ice dynamics to ice drifting and accelerated melting due to persistent low pressure, high air-ocean temperatures, supplemented by the coupled ocean-atmospheric forcing.

Survival and abundance of polar bears in Alaska’s Beaufort Sea, 2001–2016

“…The high survival and long life of adult polar bears throughout the Arctic since the curtailment of overharvest are consistent with expectations for an apex predator in a stable environment with adequate resources. However, Arctic sea ice habitat can no longer be considered stable; sea ice loss is accelerating (Serreze & Strove, 2015 ) and new record lows are occurring more frequently (Kumar et al, 2020 ). Increasing environmental degradation and variability can be expected to periodically result in extreme conditions that some individuals or certain segments of a population may be unable to survive.…”

The Roles of Sea Ice Export, Atmospheric and Oceanic Factors in the Seasonal and Regional Variability of Arctic Sea Ice during 1979–2020

“…The positive feedback of summer sea ice albedo is active due to maximum solar radiation and heat absorption into the ocean. Therefore, sea ice loss in summer has been generally larger [15]. The feedback of sea ice albedo is inhibited in winter; heat transportation from the ocean is the major mechanism for the decrease in sea ice.…”

Seasonal Trends in Clouds and Radiation over the Arctic Seas from Satellite Observations during 1982 to 2019

“…According to the Sea Ice Index derived from the National Snow and Ice Data Center (NSIDC), a persistent negative trend in Arctic sea ice is exhibited ever since November 1978, the initial time of satellite record. In recent decades, the rapid decline of sea ice [3][4][5][6][7] has come into notice, which indicates the Arctic climate has undergone significant changes.…”