Cryospheric Sciences

Image of the Week — AGU Fall Meeting 2015

Sophie Berger December 18, 2015

Poster session at the AGU Fall Meeting 2015. (Credit: Emma Smith)

The American Geophysical Union (AGU) Fall Meeting, which takes place every December in San Francisco is ending today. With more than 24 000 attendees, 14 000 poster presentations and 7 000 talks, the AGU meeting is the largest conference on geophysical sciences in the World. The cryosphere is one the topics covered by the meeting and we hope that this year edition was a fruitful for every partici ...[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]

Image of the Week — Future Decline of sea-ice extent in the Arctic (from IPCC)

Sophie Berger December 1, 2015

Left: Projection of sea-ice extent in the Northern Hemisphere [NH], for the different scenarios of the IPCC ( RCPs). The dashed lines are the mean of all the models used in the CMIP5 experiment while the solid lines come from a subset of models that fit the observations the best. Right: maps of multi-model results in 2081-2100. The white and grey coloring result from the ensemble and the subset of models, respectively. (Credit: IPCC (2013), Assessment Report 5, Working Group I, Technical Summary , Figure TS.17, p92)

The Arctic sea-ice extent has declined in the past 20 years and its future is uncertain. In the end, greenhouse gas emissions will determine the impact on the sea-ice from man-made climate change through radiative forcing (i.e. Representative Concentration Pathways or RCPs). The COP21 can determine the path we will follow and which course we will take to reduce emissions. Reduction in sea-ice cove ...[Read More]

Image of the Week — Ice Sheets and Sea Level Rise (from IPCC)

Sophie Berger November 27, 2015

(Upper) Distribution of ice loss determined from Gravity Recovery and Climate Experiment (GRACE) time-variable gravity for (a) Antarctica and (b) Greenland, shown in centimetres of water per year (cm of water yr –1 ) for the period 2003–2012. (Lower) The assessment of the total loss of ice from glaciers and ice sheets in terms of mass (Gt) and sea level equivalent (mm). The contribution from glaciers excludes those on the periphery of the ice sheets. (Credit: IPCC (2013), Assessment Report 5, Working Group I, Technical Summary , Figure TS.3, p41)

Context On the eve of the COP21, it is of paramount importance to recall how strongly the cryosphere is affected by Climate Change. Today, we present the impact of melting ice on sea level rise, as it is presented in the latest assessment report of the Intergovernmental Panel on Climate Change. Quick facts -Since 1992, the Glaciers, Greenland and Antarctic Ice Sheets have risen the sea level by 14 ...[Read More]

Image of the Week: Under the Sea

Sophie Berger November 20, 2015

Sea ice from below. Credit: Marcus Arnold

Always wondered how it looks like under the sea ice? Getting an answer is simpler than you might think: Just go out to the front of McMurdo ice shelf in Antarctica and drill a tube into the sea ice. Then let people climb down and take pictures of the ice from below. More information: – Photo taken by Marcus Arnold, Gateway Antarctica, University of Canterbury during his November 2015, Antarc ...[Read More]

Image of the Week — What’s up with the sea-ice leads?

Sophie Berger November 13, 2015

Two polarimetric SAR images Artctic Sea Ice. The colours reflect the different polarimetric channels of the SAR (red = VV, green = HV and blue = HH). Credit: Jakob Grahn.

This illustration shows two Synthetic Aperture Radar (SAR) images taken over sea ice in the Arctic Ocean. Both images are polarimetric and the different colours reflect the different polarimetric channels of the SAR (red = VV, green = HV and blue = HH). The two images are from the two satellites “ALOS-2” and “RADARSAT-2”. These are equipped with radars that operate at wavel ...[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]