The top of the world is very different from most other places. There is a large area of water there, and during the darkest parts of the year,
this water area gets so cold that a layer of ice grows over its top.
Ice can be found any place where the water touches the air and land, so it is a key part of life for the people and animals that live on, under, and around the big ice-covered area.
As the world warms, the big ice-covered area at the top of the world is becoming much smaller.
This is causing other changes to the air, water, and land all over the world, but is especially important for those living where the ice is disappearing.
In order to know what the changing world will look like down the line, it's important that we learn more about what causes changes to the ice cover now.
I work on better understanding a small piece of this big story: I study how the top-of-the-world ice moves around from day to day.
Above and under the ice, winds and moving water push and pull on the ice.
These forces can move the ice to new places, drag it across land at the edges of the water area, and even cause it to crack open or push it together until it becomes thicker.
This strong and quick-moving ice can be a problem when it comes to staying safe in the water in this part of the world.
Since it can be hard to visit the ice-covered top of the world, in order to study it I often use computers in space that can take pictures of this part of the world.
With these pictures, we can see what's going on there with the ice every day, and figure out how wind, water, and land have caused the ice cover to move and crack in different ways.
By figuring out how this has happened so far, we can make better guesses how the ice will continue to move and change tomorrow.