CR
Cryospheric Sciences

sea ice floes

Did you know? – Storms can make Arctic sea ice disappear even faster

July 19, 2019
Did you know? – Storms can make Arctic sea ice disappear even faster
Fig. 1: The difficulties of in-situ observations on sea ice. Winter storm has broken up an ice floe that was only hours ago more than a kilometer wide into small pieces. Scientists are climbing over cracks and rescuing the equipment [Credit: Tor Ivan Karlsen, Norwegian Polar Institute].

The increase in air and water temperature due to climate change drives the retreat in the Arctic sea-ice cover. During summer, when sunlight reaches the Arctic, the absorption of heat by the dark ocean water enhances the sea-ice melt through the ice-albedo feedback. During winter, when sunlight does not reach the Arctic, another feedback is at work, as storms enhance the energy transfer between ai ...[Read More]

Image of the Week – The shape of (frozen sea) water

September 7, 2018

  Polar sea ice exists as isolated units of ice that we describe as floes. These floes do not have a constant shape (see here for instance); they can vary from almost circular to being jagged and rectangular. However, sea ice models currently assume that all floes have the same shape. Much focus has been paid to the size of floes recently, but do we also need to reconsider how floe shape is t ...[Read More]

Image of the week — Making pancakes

April 27, 2018

It’s pitch black and twenty degrees below zero; so cold that the hairs in your nose freeze. The Arctic Ocean in autumn and winter is inhospitable for both humans and most scientific equipment. This means there are very few close-up observations of sea ice made during these times. Recently, rapidly declining coverage of sea ice in the Arctic Ocean due to warming climate and the impending likelihood ...[Read More]

Image of the Week – Does size really matter? A story of ice floes and power laws

November 24, 2017

The retreating Arctic sea ice is one of the most well-known facets of Climate Change. Images of polar bears desperately swimming through polar seas searching for somewhere to rest and feed resonate strongly with the public. Beyond these headlines however, the Arctic Ocean is displaying a rapid transition from having mostly permanent ice cover to a more seasonal cover. The Marginal Ice Zone As both ...[Read More]

Image of the Week – Sea-ice dynamics for beginners

November 3, 2017
Image of the Week – Sea-ice dynamics for beginners
A block of ice in a pressure ridge. The scientist has to cross the ridge with equipment to continue measuring the sea-ice thickness on the other side. [Credit: Marius Bratrein, Norwegian Polar Institute]

When I ask school children or people who only know about sea ice from remote references in the newspapers: ‘How thick do you think is the Arctic sea ice?’, I often get surprising answers: ’10 meters? No, it must be thicker – 100 meters!’. It seems like sea ice, often depicted as a uniform white cover around the North Pole and as a key element in accelerated warming of the Polar Regions, imposes a ...[Read More]

Image of the Week – Sea Ice Floes!

December 2, 2016
Image of the Week – Sea Ice Floes!
Left: Floes in the Southern Ocean surrounding the Nathaniel Palmer, taken by a multi-rotor drone. The length of the Nathaniel Palmer, about 100 m, is shown for comparison [Credit: EOS]. Right: Floes in the Bering Strait in May, 2000 from the MODIS satellite. Arrow shows the width of the Bering Strait, 85 km, for comparison [Credit: NASA Earth Observatory].

The polar regions are covered by a thin sheet of sea ice – frozen water that forms out of the same ocean water it floats on. Often, portrayals of Earth’s sea ice cover show it as a great, white, sheet. Looking more closely, however reveals the sea ice cover to be a varied and jumbled collection of floating pieces of ice, known as floes. The distribution and size of these floes is vitally imp ...[Read More]