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[Music]

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Narrator: On September 18th 2019, satellites observed that

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Arctic sea ice had reached its annual low.

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This year's sea ice minimum is effectively tied for the second lowest on record. 

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And while sea ice grows and shrinks with the seasons,

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2019 continues the downward trend of the extent. 

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Nathan Kurtz: The trends we’ve been seeing 

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with the sea ice minimum have just been a decrease.

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So, in the 70’s since the modern record began tracking to today,

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there is variation from year to year, but it’s really just a 

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a downward trend. Narrator: Satellite observations show that Arctic sea ice

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is not only shrinking in extent, it is also becoming younger 

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and thiner. That means less and less ice survives 

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the annual melt. Kurtz: The Artic has actually warmed a lot more than

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the globe at a whole. There is something called Artic amplification, which means 

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that the temperatures in the Arctic have warmed about 2 – 3 times 

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the global average. 

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Narrator: A major cause of this warming is due to the loss of the reflectivity - or albedo – of the sea ice. 

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Snow-covered sea ice has a high albedo. This helps keep the 

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sun’s energy from being absorbed by a dark ocean.  

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But when sea ice melts, it loses some of that reflectivity.

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And without the sea ice cover, the ocean will absorb most 

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of the sun’s energy. 

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This creates a feedback loop that leads to more melting and warming in the Arctic.

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Kurtz: We care about sea ice for a variety of reasons. 

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One being is because it does have an impact on things like our weather and our climate.

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Because of the albedo effect if you decrease the amount of sea ice

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you start warming up the Arctic, and when you start warming up the Arctic

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you start changing the circulating of the jet stream which brings 

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weather to us here in the mid latitudes. 

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Other reasons why we care about sea ice, Arctic sea ice in particular,

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Because we’ve such big changes due to warming

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melting ice, it is a good visual to show that, yes, the climate

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Is changing and it is because of warming. 

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Narrator: NASA continues to monitor these changes to the Arctic so that we may get a better 

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understanding of what we can expect in the future. 

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[Music]