Environment

ESA's animation

40 years of melting Arctic ice in 1 minute

The decisive role of satellites in the study of Arctic amplification. The main factor of this climatic phenomenon is the disappearance of sea ice that in recent years has reached unprecedented minimum levels.

24/05/2023

ESA

Eyes once again focused on the Arctic, the area of the Earth most exposed to climate change.

Here the increase in temperatures is disproportionate to the rest of the planet. An anomaly that triggers a series of cascading effects that make up the so-called Arctic amplification.

The eyes, in this case, are those of satellites, the only ones able to document this phenomenon in an analytical way.

ESA's Science for Society Arktalas Hoavva project, which means Arctic Ocean in Northern Sami, is dedicated to studying Arctic amplification using satellite data.

A study led by Igor Esau of the Nansen Environmental and Remote Sensing Centre in Norway and recently published in the journal Remote Sensing explains how satellites are proving indispensable for monitoring the Arctic and helping to understand this climate phenomenon and its impact on the planet.

The animation shows in about a minute the average sea ice extent in the Arctic from 1979 to 2022.

The main factor of Arctic amplification is the disappearance of sea ice, which in recent years has reached unprecedented minimum levels of extent.

Sea ice forms when seawater freezes to form freshwater ice. The freezing process repels the salt water, which is cold and much denser than the surrounding seawater and then descends into the deep ocean, driving the global ocean circulation determined by the variation in the density of water masses due to the temperature/salinity binomial.

Without the formation of sea ice, this process is bound to stop leading to dramatic changes in global ocean circulation.

As the ice disappears, the exposed dark surface of the ocean absorbs more heat, leading to further warming and ice loss.

This rapid warming not only undermines the delicate balance of the Arctic ecosystem, but has profound implications for global climate patterns, human populations and wildlife.

ESA satellites such as Cryosat and Copernicus Sentinel-3 are able to accurately measure the thickness of Arctic sea ice, allowing researchers to assess ongoing changes.

The SMOS water mission and Copernicus Sentinel-1 complement the data by providing ocean salinity measurements and comprehensive sea ice mapping in all weather conditions.

ESA satellites have also facilitated the study of other fundamental parameters to understand Arctic amplification, such as surface temperature, atmospheric composition and albedo, i.e. the amount of light reflected from a surface.