The Stepwise Reduction of Multiyear Sea Ice Area in the Arctic Ocean Since 1980

The loss of multiyear sea ice (MYI) in the Arctic Ocean is a significant change that affects all facets of the Arctic environment. Using a Lagrangian ice age product, we examine MYI loss and quantify the annual MYI area budget from 1980 to 2021 as the balance of export, melt, and replenishment. Overall, MYI area declined at 72,500 km2 /yr; however, a majority of the loss occurred during two stepwise reductions that interrupt an otherwise balanced budget and resulted in the northward contraction of the MYI pack. First, in 1989, a change in atmospheric forcing led to a +56% anomaly in MYI export through Fram Strait. The second occurred from 2006 to 2008 with anomalously high melt (+25%) and export (+23%) coupled with low replenishment (−8%). In terms of trends, melt has increased since 1989, particularly in the Beaufort Sea, export has decreased since 2008 due to reduced MYI coverage north of Fram Strait, and replenishment has increased over the full time series due to a negative feedback that promotes seasonal ice survival at higher latitudes exposed by MYI loss. However, retention of older MYI has significantly declined, transitioning the MYI pack toward younger MYI that is less resilient than previously anticipated and could soon elicit another stepwise reduction. We speculate that future MYI loss will be driven by increased melt and reduced replenishment, both of which are enhanced with continued warming and will one day render the Arctic Ocean free of MYI, a change that will coincide with a seasonally ice-free Arctic Ocean

Landscapes of Heathrow : the aircraft landing gear compartment and the politics of global transfer

This paper, an output of an art research project, explores the agency of the aircraft landing gear compartment in global transfer. Through the prism of historical events involving aircraft preparing to land at London Heathrow, it reflects on the part played by the compartment in ecological and humanitarian struggle. Its theoretical frameworks include John Ruskin’s writing on geology, new materialism, and the planetary garden. These are brought into proximity with methodologies and collaborations developed through practice-based elements of the research, such as architectural modelling, geoforensic science and exhibition making. It incorporates an account of the process of reconstructing a compartment, as well as extracts from a microstratigraphic survey commissioned as part of the project. It examines the landing gear compartment’s capacity as a vessel in which dust, seeds, insects, pollen and even people are transported around the globe. It explores, too, its role as expository instrument, as far as it makes available for inspection the politics inscribed into its formal, spatial and temporal configuration. The paper argues that the wheel bay gives shape to a set of otherwise intangible aeromobilities, knowledge of which is integral to a nuanced understanding of the political geography of London Heathrow

Cognitive processing models in performance appraisal: evidence from the Malaysian education system.

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