Arctic lakes melting earlier each year

Thanks to the warming temperatures, Arctic lakes, covered with ice during the winter months, are melting earlier each spring, new research has warned.

The team, who monitored 13,300 lakes using satellite imagery, have shown that on average ice is breaking up one day earlier per year, based on a 14-year period between 2000 and 2013.

"Previous studies have looked into small numbers of lakes to show the impact of changes in temperature on the cyclic nature of lake-ice cover," said Jadu Dash, Professor at University of Southampton in Britain.

"However, ours is the first to use time-series of satellite data to monitor thousands of lakes in this way across the Arctic. It contributes to the growing range of observations showing the influence that warmer temperatures are having on the Arctic," Dash noted.

The researchers used information on how light is reflected off the lakes, as recorded by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, which collects a range of spectral and thermal data on a daily basis as it circles the globe on two satellites.

This study used the changes in reflectance to identify the freezing and thawing processes.

The researchers discovered that all five study areas in the Arctic (Alaska, Northeast Siberia, Central Siberia, Northeast Canada and Northern Europe) showed significant trends of early ice break-up in the spring, but to varying degrees.

Central Siberia demonstrated the strongest trend, with ice starting to break-up an average of 1.4 days earlier each year.

Northern Europe showed the lowest change of ice break-up at 0.84 days earlier per year. They found a strong relationship between decreasing ice cover and an increasingly early spring temperature rise.

Their findings were published in the journal Scientific Reports.

--IANS

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