A major consequence of the ongoing climate change is the swift reduction in the extent of the Arctic sea ice cover witnessed over the past few decades. The melting ice and disintegration of glaciers in regions with elevated latitudes have the potential to accelerate the increase in sea levels rapidly. However, scientists from the United States of America have developed an efficient and cost-effective method that could lead to the re-freezing of the Arctic ice.
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An Overview of Arctic Sea Ice Variations
The sea ice is pivotal in the Arctic climate system and its implications. It is essential in various significant climate feedback phenomena, influencing energy exchanges at the ocean's and atmosphere's interface, and engaging with atmospheric and oceanic circulation patterns.
The sea ice holds immense significance for the Arctic's biodiversity and economic and social advancement. Notably, the diminishing Arctic sea ice fosters the exploration of resources and the utilization of marine transportation routes.
Researchers have thoroughly assessed Arctic sea ice regional variations in the latest article published in Atmosphere. Since the inception of the satellite observation era in 1979, there has been an observable decline in the total September Arctic sea ice area (SIA).
On average, this decline amounts to approximately 11% per decade. Notably, while the decline in SIA during the summer months is over three times more rapid in relative percentage terms compared to the 3% decline during winter, the contrast in absolute trend values is not as pronounced due to the larger SIA during winter. Specifically, the absolute trend in summer SIA is only twice as swift as that observed during winter.
Effects of Ice Melting in the Arctic
The implications of sea ice loss exhibit regional variations, influenced by diverse driving factors and mechanisms operating in distinct geographical areas.
The transformations within the Arctic sea ice are evident through various significant attributes, encompassing distinct temporal and spatial patterns, the timing of ice formation and disappearance, the duration of melting seasons, the reduction in first-year sea ice thickness, and the contraction of multi-year ice expanse.
These alterations in sea ice area (SIA) impact atmospheric circulation, although this response is contingent upon the specific region and extent of sea ice loss. Conversely, atmospheric circulation reciprocally influences sea ice fluctuations across inter-annual and decadal time frames.
The accelerated melting of Arctic sea ice in the early 21st century can be attributed to the mounting influence of anthropogenic greenhouse forcing. This phenomenon might signify a shift toward a novel dynamic state characterized by heightened heat transportation from the ocean and atmosphere into the Arctic. Such a transition could potentially activate positive feedback mechanisms within the Arctic climate system, suggesting the likelihood of a tipping point scenario.
What is Sea Ice Modelling?
As per an article published in the Bulletin of the American Meteorological Society, Earth System Models (ESMs) encompass a component dedicated to sea ice, accurately portraying alterations in sea ice and their implementations on ocean circulation. The prevailing sea ice models commonly depict the sea ice pack as a continuous substance, a notion pioneered by the Arctic Ice Dynamics Joint Experiment (AIDJEX) consortium during the 1970s.
Initially conceived for climate investigations, the sea ice constituents integrated within ESMs are now harnessed across diverse resolutions, extending to very high resolutions exceeding their initial design specifications by over 100-fold. These models are being employed in an increasingly extensive array of applications.
By incorporating adjustments to account for grounded ridges and tensile strength, continuum models have been extended to replicate the arrangement of Arctic land-fast ice accurately. This type of ice comprises stationary sea ice patches affixed to the coastal areas or seabed.
Strategy for Refreezing the Arctic Ice
The Arctic region is confronted with a grave danger due to climate change, experiencing a rapid increase in temperature, approximately twice that of the global average. It is anticipated that by the middle of the century, if not sooner, the Arctic will likely witness the near-complete disappearance of summer sea ice, which could yield potentially catastrophic climatic repercussions for the Arctic locale and the entire planet.
The latest article published in Environmental Research Communications has presented a strategy for Arctic ice refreezing using stratospheric aerosol injection (SAI). Stratospheric aerosol injection (SAI) is a potential climate intervention strategy to mitigate global warming by modestly enhancing the Earth's upper atmosphere's reflectivity.
Subpolar geoengineering would include localized implementations at approximately 60°N/S latitudes compared to global solar geoengineering. Due to the lower tropopause altitude at these higher latitudes, the elevation requirement for aerosols or their precursors would be less, alleviating engineering complexities compared to worldwide deployment.
High-altitude aircraft are the proposed source to disperse aerosol particles into the atmosphere. When released at an elevation of 43,000 feet (approximately 13,000 meters) above the altitudes at which commercial airliners cruise, these aerosols would gradually drift toward the poles, resulting in a mild reduction of sunlight reaching the surface.
Currently, operational military air-to-air refueling tankers, such as the older KC-135 and the A330 MMRT, lack the payload capacity required at the specified altitudes. However, newly designed high-altitude tankers would offer considerably enhanced efficiency. A fleet comprising around 125 of these advanced tankers could effectively deliver the payload necessary for cooling the designated regions.
The expenses associated with this approach would be notably minimal compared to other climate-related strategies such as mitigation, adaptation, or carbon capture and sequestration.
It is improbable that a subpolar implementation would evade any SAI initiative’s governance complexities; this aspect could emerge as a pivotal subject for future social science investigation. Nonetheless, considering its apparent feasibility and economic nature, this scenario warrants more profound consideration.
The Future of Arctic Sea Ice
In the face of the imminent threat of losing summer sea ice in the Arctic, the SAI strategy represents a compelling avenue for further exploration and research.
As we continue to grapple with the challenges posed by climate change, innovative approaches like this may hold the key to preserving the Arctic environment and mitigating its cascading effects on our planet. It is a reminder that even in the face of challenges, human ingenuity and collaboration can offer solutions that could reshape our planet's future.
References and Further Reading
Matveeva, T. et. al. (2022). Regional Features of the Arctic Sea Ice Area Changes in 2000–2019 versus 1979–1999 Periods. Atmosphere. 2022; 13(9):1434. Available at: https://doi.org/10.3390/atmos13091434
Blockley, E. et. al. (2020). The Future of Sea Ice Modeling: Where Do We Go from Here? Bull. Amer. Meteor. Soc., 101, E1304–E1311. Available at: https://doi.org/10.1175/BAMS-D-20-0073.1
Smith et. al. (2022). A subpolar-focused stratospheric aerosol injection deployment scenario. Environmental Research Communications. 4. 095009. Available at: https://www.doi.org/10.1088/2515-7620/ac8cd3