Spatio-Temporal Analysis of Gyres in Oriented Lakes on the Arctic Coastal Plain of Northern Alaska Based on Remotely Sensed Images

Shengan Zhan,Kenneth Hinkel,Benjamin Jones,Richard Beck,Hongxing Liu

doi:10.3390/rs6109170

Shengan Zhan, Kenneth Hinkel + Show 3 more

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https://doi.org/10.3390/rs6109170

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Abstract

The formation of oriented thermokarst lakes on the Arctic Coastal Plain of northern Alaska has been the subject of debate for more than half a century. The striking elongation of the lakes perpendicular to the prevailing wind direction has led to the development of a preferred wind-generated gyre hypothesis, while other hypotheses include a combination of sun angle, topographic aspect, and/or antecedent conditions. A spatio-temporal analysis of oriented thermokarst lake gyres with recent (Landsat 8) and historical (Landsat 4, 5, 7 and ASTER) satellite imagery of the Arctic Coastal Plain of northern Alaska indicates that wind-generated gyres are both frequent and regionally extensive. Gyres are most common in lakes located near the Arctic coast after several days of sustained winds from a single direction, typically the northeast, and decrease in number landward with decreasing wind energy. This analysis indicates that the conditions necessary for the Carson and Hussey (1962) wind-generated gyre for oriented thermokarst lake formation are common temporally and regionally and correspond spatially with the geographic distribution of oriented lakes on the Arctic Coastal Plain. Given an increase in the ice-free season for lakes as well as strengthening of the wind regime, the frequency and distribution of lake gyres may increase. This increase has implications for changes in northern high latitude aquatic ecosystems, particularly if wind-generated gyres promote permafrost degradation and thermokarst lake expansion.

Highlights

Thermokarst lakes were a significant source of carbon during the last deglaciation [1,2] and their release of carbon is influenced by a positive feedback to climate warming [3]
Earlier ice melt and later ice onset have been observed in lakes on the Arctic Coastal Plain (ACP) of northern Alaska [7,8]
This study investigates the spatial and temporal distribution of gyres in the oriented thermokarst lakes on the ACP of northern Alaska using satellite imagery and wind data

Summary

Introduction

Thermokarst (thaw) lakes were a significant source of carbon during the last deglaciation [1,2] and their release of carbon is influenced by a positive feedback to climate warming [3]. Earlier ice melt and later ice onset have been observed in lakes on the Arctic Coastal Plain (ACP) of northern Alaska [7,8]. Lakes with depths greater than the maximum ice thickness during winter (approximately 2 m) are important sources of liquid water for aquatic biota, inhabitants and the petroleum industry [9]. Lakes along the Arctic coast are influenced by coastal erosion and storm surge flooding that often result in lake drainage and their conversion to estuaries which affects the aquatic and terrestrial habitat [10]

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