Perhaps the most enduring and important signal of a warming climate has been that the minimum Arctic sea ice extent, occurring each year in September, has declined precipitously. Over the last 40 years, most of the Arctic sea ice has thus been transformed to first-year ice that freezes in the winter and melts in the summer. Concern about sea ice extent and area is valid: since sea ice i ...[Read More]
Image of the Week – Stuck in the ice: could it have been predicted?
Figure 1: The RRS James Clark Ross stuck in the middle of Antarctic sea ice [Credit: British Antarctic Survey].
Expeditions in the Southern Ocean are invaluable opportunities to learn more about this fascinating but remote region of the world. However, sending vessels to navigate the hostile Antarctic waters is an expensive endeavor, not only financially but also from a human perspective. When vessels are forced to turn back due to hazardous conditions or, even worse, become stuck in the ice (as shown in ou ...[Read More]
Image of the Week – Icy expedition in the Far North
Fig.1: Mooring in the fjord next to Qaanaaq [Credit: Measurement campaign team].
Many polar scientists who have traveled to Svalbard have heard several times how most of the stuff there is the “northernmost” stuff, e.g. the northernmost university, the northernmost brewery, etc. Despite hosting the four northernmost cities and towns, Svalbard is however accessible easily by “usual-sized” planes at least once per day from Oslo and Tromsø. This is not the case for th ...[Read More]
Image of the week — Making pancakes
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 — Seasonal and regional considerations for Arctic sea ice changes
The Arctic sea ice is disappearing. There is no debate anymore. The problem is, we have so far been unable to model this disappearance correctly. And without correct simulations, we cannot project when the Arctic will become ice free. In this blog post, we explain why we want to know this in the first place, and present a fresh early-online release paper by Ingrid Onarheim and colleagues in Bergen ...[Read More]
Image of the Week – The colors of sea ice
Thin sections of sea ice photographed under polarized light. Individual ice crystals are shown by different colors. The color is random – it does not tell us anything specific about the crystals. Examples of granular ice, with smaller crystals in the top parts of the ice samples, are shown in the top rows. Columnar ice, with long layered ice crystals, can be seen in the bottom rows. Several pictures with columnar ice have air bubbles, for example all pictures in the left column and the center right picture [Credit: Polona Itkin and Anja Rösel, Norwegian Polar Institute].
The Oscars 2018 might be over, but we have something for you that is just as cool or even cooler (often cooler than -20°C)! Our Image of the Week shows thin sections of sea ice photographed under polarized light, highlighting individual ice crystals in different colors, and is taken from a short video that we made. Read more about what this picture shows and watch the movie about how we got these ...[Read More]
Image of the Week – A Hole-y Occurrence, the reappearance of the Weddell Polynya
Fig. 1: The Weddell polynya as seen in the 7th September 2017. The size is around 2500 km2. Black areas are sea-ice free (open water) [Credit: NASA].
REMARK: If you’ve enjoyed reading this post, please make sure you’ve voted for it in EGU blog competition (2nd choice in the list)! During both the austral winters of 2016 and 2017, a famous feature of the Antarctic sea-ice cover was observed once again, 40 years after its first observed occurrence: the Weddell Polynya! The sea-ice cover exhibited a huge hole (of around 2600 km2 up to ...[Read More]
Image of the Week – The Gap, the Bridge, and the Game-changer
The Gap, the Bridge, and the Game-changer are three series of satellites. They carry instruments that measure the microwave radiation emitted by the Earth (called passive microwave instruments), while flying 800 km above our heads at 7,5 km/s. Since the late 1970s, most sea ice properties (concentration, extent, area, velocity, age and more!) have been measured with such passive microwave instrume ...[Read More]
Image of the Week – Arctic changes in a warming climate
Fig. 1: Schematic representation of major changes in the Arctic regions caused by global warming [Credit: Fig. 1.2 of AMAP (2017), adapted from US National Center for Atmospheric Research (NCAR)].
The Arctic is changing rapidly and nothing indicates a slowdown of these changes in the current context. The Snow, Water, Ice and Permafrost in the Arctic (SWIPA) report published by the Arctic Monitoring and Assessment Program (AMAP) describes the present situation and the future evolution of the Arctic, the local and global implications, and mitigation and adaptation measures. The report is base ...[Read More]
Image of the Week – Understanding Antarctic Sea Ice Expansion
Sea ice is an extremely sensitive indicator of climate change. Arctic sea ice has been dubbed ‘the canary in the coal mine’, due to the observed steady decline in the summer sea ice extent in response to global warming over recent decades (see this and this previous posts). However, the story has not been mirrored at the other pole. As shown in our image of the week (blue line in Fig. 1), Antarcti ...[Read More]