EGU Guest blogger

Image of The Week – When Glaciers Fertilize Oceans

Jon Hawkings March 25, 2016

Figure 1: Sediment rich meltwaters from Leverett Glacier pour over a waterfall in south west Greenland (credit: Jon Hawkings)

Today’s Image of the Week shows meltwaters originating from Leverett Glacier pouring over a waterfall in southwest Greenland. We have previously reported on how meItwater is of interest to Glaciologist (e.g. here) but today we are going to delve into how and why Biologists also study these meltwaters and how the cryosphere interacts with biogeochemical cycles in our oceans. Where? Leverett G ...[Read More]

Image of Week: Blue Ice in East Antarctica

Nanna B. Karlsson January 22, 2016

Blue ice area in front of the northernmost part of the Heimefrontfjella, East Antarctica. Credit: N. B. Karlsson

The blue ice areas of Antarctica are one of the most fascinating parts of the ice sheet. In these regions, snowfall is so low that the ice is laid bare by the wind and consequently sublimates. This exposes beautiful, blue ice surfaces, like an ocean frozen in time. This picture was taken at a site named “Windy Corner” by the Kottas Mountains, in the northernmost part of the Heimefrontf ...[Read More]

Image of the Week: Ice Sheets in the Climate

Nanna B. Karlsson December 11, 2015

The interaction of ice sheets with the atmosphere and the ocean. Excerpt from Figure 1 in Box 5.2, IPCC AR5.

Ice sheets play a central role in the climate system. They store significant amounts of fresh water and are the conveyor belts for transporting snow that accumulates on land back into the oceans. The figure above shows a few of the ice-climate interactions. In the figure below (click on the figure for full resolution) we see the complete picture of the processes taking place between ice sheets, so ...[Read More]

Image of the Week: Atmospheric CO2 from ice cores

Nanna B. Karlsson December 9, 2015

CO2 concentrations from EPICA and Vostok ice cores. The red bar at the side shows the Mauna Loa measurements. Credit: The IPCC AR 4 report Fig. 6.3

The measurements of atmospheric CO2 levels at Manu Loa, Hawaii read 401.01ppm on the 7th of December this year. To understand the significance of this number, you just need to look at the figure above from the 4th IPCC report. It shows the changes in CO2 concentrations during the past 800,000 years based on ice core measurements. Values have fluctuated between 190ppm and 280ppm. In other words, bo ...[Read More]

Image of the Week: Changes in Snow Cover

Nanna B. Karlsson December 4, 2015

Northern Hemisphere spring (March to April average) relative snow-covered area by dividing the simulated 5-year box smoothed spring snow-covered area by the simulated average spring snow-covered area of 1986–2005 reference period.

Who is dreaming of a white spring? In daily life we might be more interested in the chances of a white Christmas, but the amount of snow-covered ground in the spring is a very good indicator of climate change. The figure above shows the projected change in snow cover extent in the Northern hemisphere in March-April according to different future scenarios (i.e. Representative Concentration Pathways ...[Read More]

Sunshine, ice cores, buckets and ALE: Antarctic Fieldwork

Helen Millman November 12, 2015

The field site in the Patriot Hills. The katabatic winds scour the surface of the blue ice, making these ripples which look like the ocean. (Credit: H. Millman)

My Antarctic adventure started from Punta Arenas at the bottom of Chile, opposite Tierra del Fuego, on New Years Eve 2014 after a long journey from Heathrow via São Paulo and Santiago. Punta Arenas Punta Arenas is where Shackleton organised the rescue of his men from Elephant Island after his voyage to South Georgia in the James Caird. It is also where I met my PhD supervisors Chris Fogwill and Ch ...[Read More]

Image of the Week: Greenland Glacier Seen from a Drone

Nanna B. Karlsson November 5, 2015

UAV on its way back from a mission with Store Glacier, West Greenland, in the background. Credit: Johnny Ryan

The use of drones or Unmanned Aerial Vehicles (UAVs) is one of the most exciting development in glaciology in recent years. The picture was taken during fieldwork conducted in the summer of 2014 by Johnny Ryan and colleague Nick Toberg. The aim was to survey Store Glacier once a day using a fixed-wing UAV, that was equipped with a digital camera, which took photos every two seconds during its dang ...[Read More]

Filling the Gap between Science and Politics

Sammie Buzzard October 26, 2015

Have you ever wondered how results from scientific studies make their way into policy and influence government decisions? Read about the experiences of Sammie Buzzard, University of Reading, who spent her summer working for a government body in Westminster, London, UK. This summer I had the opportunity to take some time away from my usual Ph.D. work and spend 3 months working for the Government Of ...[Read More]

Image of Week: Inside the Greenland Ice Sheet

Nanna B. Karlsson October 23, 2015

Cross-section of the age of the Greenland Ice Sheet from radar data. Credit: NASA's Scientific Visualization Studio and MacGregor et al., 2015.

The image shows a cross section of the Greenland Ice Sheet, where a recent study by MacGregor et al. have mapped the layers imaged by radar. Thanks to ice core measurements the age of the layers have been determined, and in the image the layers from the Holocene period (the past 11.700 years) are shown in green. The ice formed during the last ice age, that spanned 11.700 to 115.000 years ago are c ...[Read More]

Image of the Week: Under a Glacier

Nanna B. Karlsson October 16, 2015

Under the Hochjochferner glacier. Credit: Ilkka Matero.

What is happening under a glacier? This is a difficult questions to answer as accessing the glacier bed is usually not that easy. Here, we are getting a rare glimpse of the different processes and materials that are often found at the ice-bed interface. The photograph shows both sediments and hard rock, clear ice and dirty ice, and of course flowing water. No wonder these processes are complicated ...[Read More]