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The Arctic amplification–as it has been termed, is resulting in a perceptible shift of this region to a new environment which is warmer, wetter and more variable than ever before.
The dramatic changes in the Arctic environment over the past couple of decades, caused by rising surface temperatures, loss of sea ice and diminishing habitat for its wild life have forced policy makers to find science-based answers to the problem. The surface air temperatures over the Arctic have been rising twice as fast as the global average. The Arctic amplification-as it has been termed- is resulting in a perceptible shift of this region to a new environment which is warmer, wetter and more variable than ever before.
The Second assessment report of the Arctic Monitoring and Assessment Programme’s Snow, Water, Ice and Permafrost in the Arctic (SWIPA) provides findings related to the observed changes in the Arctic during 2010 to early 2017 (SEIPA, 2017) some of the significant observations of this assessment are:
- Arctic Ocean could be largely free of sea ice in summer as early as the 2030s.
- Recent data on additional melting processes affecting the Polar Regions seem to suggest that the low-end projections of global sea-level rise made by the Intergovernmental Panel on Climate Change (IPCC) are underestimated.
- Changes in the Arctic may be affecting weather in mid-latitudes, even influencing the Southeast Asian monsoon,
The extent and thickness of Arctic sea ice has been declining over the past few decades with an annual-mean aerial reduction of ~20 per cent since 1980. Despite the prominent year-to-year variablities, this long-term decline appears to be largely, but not wholly, due to greenhouse gas forcing (IPCC, 2007). The Observatory for atmospheric research and monitoring located on the Zeppelin Mountain at Ny-Ålesund, in an untouched Arctic environment, has recorded an increase in the concentration of atmospheric CO
2 form 355 ppm in 1988 to 400 ppm in 2015 (aces.su.se). Black carbon and tropospheric ozone have also been suggested to have contributed ~0.5-1.4
o C and ~0.2-0.4
o C, respectively, to Arctic warming since 1890.
Since our understanding of the Arctic is mostly based on data when the Arctic had a thick sea ice cover, a paradigm shift in thinking and developing a strategy to predict the future of the Arctic sea ice, its effects on the climate, ocean and ecosystems, is called for. Knowledge of the state of the system operating today under the changed scenario is essential. To fill this knowledge gap, the Norwegian Polar Institute initiated a project in 2015–Norewegian Young Sea Ice Cruise (N-ICE 2015)–aimed at understanding ‘….how the rapid shift to a younger and thinner seaice regime in the Arctic affects energy fluxes, sea ice dynamics and the ice-associated ecosystem, as well as well as local and global climate. The multidisciplinary observational study on drifting Arctic sea ice from winter to summer in early 2015 had components of climate, ecology, oceanography, sea ice, biology, chemistry, acidification, atmosphere, biodiversity, eco-toxicology, marine ecosystems, remote sensing, etc as core subjects. The preliminary results of this multinational cruise have been made feely available to the research community to appreciate the actual situation in the Arctic, and ultimately improve our capacity to model the future”.
The highlights of the preliminary findings of N-ICE 2015 as published on the NPI website are:
- The ice pack had already accumulated nearly 0.5 m of snow in January. This is much more than we expected based on climatology.
- The thick snow cover slowed sea ice growth. Ice formed mainly in leads (fractures in sea ice). The thick heavy snow also contributed positively to the ice mass balance through snow-ice formation.
- Many storms took place, especially in winter. These brought with them warm and moist air, even in the middle of the polar night, also slowing ice growth.
- The storms also affected ocean mixing. Heat, nutrients, and CO2 were mixed throughout the upper water column during storms. We saw the ocean heat flux increased twofold during storms.
- The thinner sea ice was more easily broken up and we saw more ridging and lead formation than previously.
- Leads caused by storms allowed enough light to reach the water, sufficient to initiate and maintain an algae bloom under thick snow-covered ice that otherwise would have kept the algae community in the dark and unable to grow.
- The heavy snow load resulted in seawater infiltration at the snow-ice interface. This provided a habitat that supported ample algae growth resembling conditions in the Antarctic sea ice zone.
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