CR
Cryospheric Sciences

Image of the Week

Image of the Week: Atmospheric CO2 from ice cores

December 9, 2015
Image of the Week: Atmospheric CO2 from ice cores
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

December 4, 2015
Image of the Week: Changes in Snow Cover
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)

December 1, 2015
Image of the Week — Future Decline of sea-ice extent in the Arctic (from IPCC)
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)

November 27, 2015
Image of the Week — Ice Sheets and Sea Level Rise (from IPCC)
(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

November 20, 2015
Image of the Week: Under the Sea
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?

November 13, 2015
Image of the Week — What’s up with the sea-ice leads?
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]

Image of the Week: Greenland Glacier Seen from a Drone

November 5, 2015
Image of the Week: Greenland Glacier Seen from a Drone
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]

Image of the Week : 63 years of the Muir Glacier’s retreat

October 30, 2015
Image of the Week : 63 years of the Muir Glacier’s retreat
Three repeat photos of the Muir Glacier, Alaska taken on 13 August 1941, 4 August 1950 and 31 August 2004 . Credit: U.S. Geological Survey

The Muir is a valley glacier (Alaska) that has significantly retreated over the last 2 centuries. The 3 pictures have the same field of view and record the changes that occurred during the 63 years separating 1941 and 2004. In the 1941, the terminus of the glacier is on the lower right corner of the photo. The Muir is then a tidewater glacier up to 700m thick and is well connected to its tributary ...[Read More]

Image of Week: Inside the Greenland Ice Sheet

October 23, 2015
Image of Week: Inside the Greenland Ice Sheet
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

October 16, 2015
Image of the Week: Under a Glacier
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]