Author Archives: Philip Kraaijenbrink

Future projections of glacier mass loss

In our new study published in Nature last week, we show that even if the planet only warms up by 1.5 degrees Celsius 36% of all Asian glacier ice will have melted by the end of the century. More extreme temperature scenarios, for example the ones projected by IPCC’s RCP8.5, will result in mass losses of up to 64%.

Glaciers in the high mountains of Asia play a substantial role in regional water resource and they have been losing mass over the last decades (e.g. Brun et al, 2017), a trend that is most likely to persist under future temperature rise. At the 2015 UN Climate Change Conference in Paris, 195 nations signed the “Paris Agreement” and agreed on efforts to limit the global temperature rise to 1.5 °C. It was unknown, however, how much of Asia’s ice mass would be lost under such a scenario, or under more extreme temperature scenarios.

To determine this, we have developed a glacier model for all individual Asian glaciers larger than 0.4 km2. We have forced the glacier model transiently up to 2100 by the full CMIP5 ensemble of 110 climate models, and have taken into account present-day climate, the imbalance of the glaciers, and the effect of debris cover.

Our results show that only a handful of the climate models project a global temperature rise of 1.5 °C and that the glaciers in the region warm consistently more than the global mean because of elevation dependent warming. By the end of the current century the 1.5 °C scenario results in a loss of over one third of the present-day ice mass in the region, while mass losses projected under more extreme temperature projections go up to almost two third.

We have also found that there are large regional differences in projected mass loss, which are caused primarily by regional differences in debris cover, ice mass, present-day glacier imbalance, and glacier sensitivity to climate perturbations.

 

Mass loss projections for the current century aggregated by sub-region of the Randolph Glacier Inventory v5.0. The bar charts indicate the regional prevalence of debris-covered glaciers.

 

To learn more about our study refer to the paper below, or have a look at our visual story line.

 

Impact of a global temperature rise of 1.5 degrees Celsius on Asia’s glaciers
Kraaijenbrink, P. D. A., Bierkens, M. F. P., Lutz, A. F., & Immerzeel, W. W. (2017)
Nature, 549(7671), 257-260. DOI: 10.1038/nature23878

 

New estimates of HMA glacier change

Fanny, Patrick, Etienne Berthier and colleagues from Oslo University (Andreas Kääb and Désirée Treichler) have just published the study “A spatially resolved estimate of High Mountain Asia glacier mass balances from 2000 to 2016” in Nature Geoscience. They used more than 50,000 ASTER satellite images to derive digital elevation models and to track glacier thickness changes over High Mountain Asia. They provide the first consistent estimate of volume change for ~90 000 km2 of glaciers.
 
Their study confirms the existence of the so called “Karakoram anomaly” and, following a 2015 study by Andreas Kääb et al. refines its location: glaciers located in the West Kunlun, Karakoram and Eastern Pamir have balanced or slightly positive mass changes. The most negative mass changes are found in the Eastern Himalaya, where glaciers loose mass at rates similar to the ones in the European Alps (up to 0.62 ± 0.23 m w.e. yr-1).
 

Rate of glacier elevation change (in m/yr) for the period 2000-2016. Red dots represent area where glaciers are thinning and blue dots area where glaciers are thickening.

Rate of glacier elevation change (in m/yr) for the period 2000-2016. Red dots represent area where glaciers are thinning and blue dots area where glaciers are thickening.

 

 
These data will help to constrain glacio-hydrological models and to better understand the contribution of glaciers to stream flow and sea level rise. Nevertheless, they provide only mass balance values averaged over 16 years and therefore do not give access to the processes responsible for these changes. More field data are needed to investigate these.

 

naturegeocmyk

Walter Immerzeel Boussinesq Awardee 2017

We are pleased to announce that on Friday June 2nd Walter Immerzeel received the Boussinesq Prize 2017, a tri-annual award given to a person for recognition of his/her outstanding scientific contributions to hydrological sciences. It was awarded by prof. Bob Su at the Boussinesq Spring Meeting 2017 in Enschede. At the meeting Walter gave a keynote presentation on “Recent advances in understanding climate, glacier and river dynamics in high mountain Asia”. A video of this presentation can be watched here.

 

 

Link to original news item

UAV surveys in Canadian Rockies

A report by Philip Kraaijenbrink

I am visiting Canmore in the Canadian Rocky Mountains to collaborate with Joe Shea on a new unmanned aerial vehicle study led by the Centre for Hydrology of the University of Saskatchewan. The objective is to monitor snow melt and redistribution throughout the melt season using UAV surveys and in situ measurements of the snow pack. The study site is near Fortress Mountain at about 2300 m elevation and is easily accessible by a combination of car and snowmobile.

Unfortunately, the site is often used by the film industry for winter forest scenes. Miscommunication has had us travel up there last week on snowmobiles to find out we could not fly because of a movie shoot. Additionally, the movie crew considerably disturbed the snow pack of interest…

Therefore, we went off to a new site just a bit further up the ridge today. Of course only after checking the weather and wind conditions using the various self-maintained weather stations at the site. Objective: redo the entire ground control survey that was carried out at the other site and perform some UAV flights.

Conditions on the ridge were a bit windy at first but we had faith it would settle down in the afternoon for the flights. Instead of settling down though, strong wind and heavy gusts came in at lunch time. Besides not being able to fly because of the wind, pounding in ground control poles and measuring them with the DGPS rover was not even possible since the gusts made walking around in the snow with all the gear next to impossible. Turned out to be the worst winds of the whole week. Let’s hope for better luck next time we’re in…

 

 ski-doo_and_toboggan
Getting up the ridge with snowmobiles and toboggans.

 

Pannable 360-panorama of the site on Fortress Ridge and the DGPS setup.

 

Onset of the winds while doing the final DGPS setup.

 

fortress_winds

Graph of wind speed measured at Fortress Mountain over the last week.

New ICIMOD video on our Himalayan research

We know very little about glaciers in the high mountains. We know they’re shrinking and temperatures are rising faster at higher altitudes than anywhere else on the planet. But, due to extreme conditions and inaccessibility, we have much to learn. Detailed field measurements are being made on just twelve out of some 54,000 glaciers in the Himalayas. More measurements are needed because these glaciers feed the rivers people living down below rely on.

 


Directed and produced by Susan Hale Thomas

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