We are used to think of algae as marine or lacustrine organisms, but they are actually able to thrive also on the cryosphere. In a previous post, we learnt how snow algae live and reproduce on snow. Now we will explore how and why scientists study snow algae, and how social media can be used …[Read More]
albedo
Questions from space: what is snow and what is ice on the Greenland ice sheet?
We usually think of a glacier as a white, clean surface. Well, this is only an idealized vision because in reality glaciers are far from immaculate, they can be colored! And this is extremely important since colored (dirty) ice absorbs more solar radiation than clean ice, accelerating melt. One of the places on Earth where …[Read More]
Time To Reflect
Albedo or albedon’t? One possible solution to global warming is to turn everything white to increase the planet’s albedo, i.e. how reflective it is (see, for example, this website). A higher albedo would be one way to reduce global warming, by reducing the amount of incoming shortwave solar radiation absorbed by the planet’s surface, which …[Read More]
Image of the Week – What darkens snow and ice?
“Be thou as chaste as ice, as pure as snow”. Hamlet, Act 3 Scene 1 (W. Shakespeare) Snow and ice are not always as pristine as one may think. If you have ever walked on a glacier or on a snowfield during summer, you might have already noticed that. In fact, both snow and ice …[Read More]
Climate Change & Cryosphere – Summer 2019: The year that the Arctic was sunburned
June, July and August 2019 saw extensive heat waves across Europe, with air temperatures reaching above 40°C in many countries. In response, record breaking ice melt was observed in Greenland and wildfires in Siberia, Alaska, Arctic Canada and Greenland occurred. A particularly dry and warm summer was responsible for hemisphere-wide changes to the cryosphere. In …[Read More]
Image of the Week – On thin [Arctic sea] ice
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 …[Read More]
Image of the Week — Climate change and disappearing ice
The first week of the Climate Change summit in Bonn (COP 23 for those in the know) has been marked by Syria’s decision to sign the Paris Accord, the international agreement that aims at tackling climate change. This decision means that the United States would become the only country outside the agreement if it were to …[Read More]
Image of the Week – Bioalbedo: algae darken the Greenland Ice Sheet
Most of the energy that drives glacier melting comes directly from sunlight, with the amount of melting critically dependent on the amount of solar energy absorbed compared to that reflected back into the atmosphere. The amount of solar energy that is reflected by a surface without being absorbed is called the albedo. A low albedo …[Read More]
Image of the Week – Fifty shades of snow
When I think of snow, I tend to either think about the bright white ski slopes in the mountains or the large white areas in the Arctic. However, natural phenomena can lead to colorful snow. Our Image of the Week shows snow can be green! Snow can also turn orange, pinkish, grey and even yellow… …[Read More]
Black Carbon: the dark side of warming in the Arctic
When it comes to global warming, greenhouse gases – and more specifically CO2 – are the most often pointed out. Fewer people know however that tiny atmospheric particles called ‘black carbon’ also contribute to the current warming. This post presents a paper my colleague and I recently published in nature communications. Our study sheds more …[Read More]