Arctic lakes show strong decadal trend in earlier spring ice-out.

Tereza Šmejkalová,Mary E Edwards,Jadunandan Dash

doi:10.1038/srep38449

Tereza Šmejkalová, Mary E Edwards + Show 1 more

Open Access

https://doi.org/10.1038/srep38449

Copy DOI

Abstract

The timing of the seasonal freeze-thaw cycle of arctic lakes affects ecological processes and land-atmosphere energy fluxes. We carried out detailed ice-phenology mapping of arctic lakes, based on daily surface-reflectance time series for 2000–2013 from MODIS at 250 m spatial resolution. We used over 13,300 lakes, area >1 km2, in five study areas distributed evenly across the circumpolar Arctic — the first such phenological dataset. All areas showed significant trends towards an earlier break-up, stronger than previously reported. The mean shift in break-up start ranged from −0.10 days/year (Northern Europe) to −1.05 days/year (central Siberia); the shift in break-up end was between −0.14 and −0.72 days/year. Finally, we explored the effect of temperature on break-up timing and compared results among study areas. The 0 °C isotherm shows the strongest relationship (r = 0.56–0.81) in all study areas. If the trend in early break-up continues, rapidly changing ice phenology will likely generate significant, arctic-wide impacts.

Highlights

The timing of the seasonal freeze-thaw cycle of arctic lakes affects ecological processes and landatmosphere energy fluxes
We carried out detailed ice-phenology mapping of arctic lakes, based on daily surface-reflectance time series for 2000–2013 from MODIS at 250 m spatial resolution
Many processes occurring in and around arctic lakes are influenced by the phenology of lake ice

Summary

Introduction

The timing of the seasonal freeze-thaw cycle of arctic lakes affects ecological processes and landatmosphere energy fluxes. Changes in air temperature can explain up to 70% of the variance in freeze-up and break-up dates[1,4,5,6], and ice phenology should reflect both inter-annual trends and short-term variability in regional climate[7]. Due to the importance of ice cover to lake ecosystems and biogeochemistry, climate feedback, and the surface energy balance, there been numerous attempts to record (or quantify) recent spatial and temporal trends in lake ice phenology in the Northern Hemispere[11,12,13,14]. For the many lakes in remote arctic regions in-situ observations are sparse, and this limits our ability to quantify the impact of warming climate on lake ice at larger spatial scales. We examined over 13,300 lakes over a 14-year period, a www.nature.com/scientificreports/

Objectives

Methods

Results

Conclusion