A funny thing happens if you travel north in January.
Go far enough and it gets dark in the middle of the day.
This is what the brief winter daylight looks like in northern Norway.
That's where I meet up with a team of researchers bound for the Arctic Ocean.
I'm Eli Kintisch and I'm spending two weeks with scientists
exploring the Arctic during the polar night.
The time of year that brings 24-hour darkness.
We're here in the dark to study the Arctic ecosystem before
the ice that defines it disappears.
Seasons are supercharged in the Arctic.
As the Earth orbits the Sun,
the amount of light reaching the northern hemisphere changes.
You may have noticed your days shrinking in the winter,
but it's way more drastic near the North Pole.
Where for four months the Sun never rises above the horizon,
and then in the summer, the Sun never sets.
The sea ice floating on the Arctic Ocean
follows a similar pattern.
Growing in the fall and winter and melting in the spring
when the massive spring blooms of algae feed the ecosystem.
But alongside those drastic seasons,
scientists have also detected a long-term trend that's underway.
Back here on earth, new word that the Arctic sea ice
has melted to near record levels.
Global warming will leave the Arctic ice free
during the summer within two decades.
Look at where the sea ice was in the 1980s
compared to the first decade of the 2000s.
And this line shows the data from 2018 so far.
Twenty years ago, the part of the sea we explored on the Helmer Hanssen
would have been coated with ice three to six feet thick.
We visit 22 stations on our journey
collecting measurements and samples
to gauge the health of the ecosystem
before the light returns in the spring.
Scientists have mostly ignored the Arctic winter
assuming that life here is dormant during the dark months.
But when they looked closer, they found an ecosystem teeming with life.
The mission of this journey is to track the physical and biological
aspects of the ocean as the ice vanishes above it.
Water samples from the deep helped scientists
identify currents that may be changing.
Robotic gliders roam the sea for months
measuring the properties of water
and probing for signs of life.
You've probably heard that big arctic species like
polar bears are endangered by the melting ice,
but tiny creatures also rely on it.
Some types of algae cling to its surface
and when they die, they fall to the muddy sea floor
becoming food for mollusks, worms, and crustaceans
and those creatures are food for fish, seals, and ...
walruses.
Stir crazy scientists really like walruses.
Other scientists zap the water with light to
detect algae cells and measure their response.
Animals called zooplankton just a few millimeters long
come up in the nets.
And the scientists test how they behave
under different light and water conditions.
They also document which species are present
and how many. As do the team's studying fish.
Without this data we won't be able to measure
how less ice and more light will change the ecosystem.
Shrinking sea ice means more light reaches
the Arctic Ocean in the spring and fall.
And that light is fueling massive new
blooms of algae called phytoplankton.
That's already helping several species of whales
thrive in the Arctic.
But will the extra light benefit the entire ecosystem in the future?
It depends.
These nutrients like nitrogen and phosphate
are found naturally in the ocean.
They nourish the algae like fertilizer for a garden.
But we don't know whether their levels will rise
along with all the new sunlight.
As the light floods in a separate problem is disruptions in timing.
The blooms are coming earlier in the spring on average.
But if they appear too early baby zooplankton that
hatch later could go hungry. And fish populations in turn
would diminish as well.
The Arctic has undergone massive changes before.
But carbon pollution is causing Arctic
summer temperatures to rise faster than they have in 1,500 years.
It is too soon to know how severe these disruptions
will be on the ecosystem.
So scientists will return to the same stations in the spring and early summer
to monitor a rapidly changing landscape.
Thanks for watching Thaw.
The next episode in this three-part series
we'll look at how the Arctic could be affecting
weather across the world.