According to the authors, "we conclude on a balanced/positive mass balance in the Karakoram since the 1980s or 1990s, or even earlier, induced by changing climatic conditions since the 1960s.", "Out of 1219 glaciers in the inventory, the vast majority [79%] showed stable terminus positions (969)" and "Glacier recession is found for only 8% of the glaciers in the inventory, indicating decreasing numbers since the beginning of the 21st century, whereas the number of advancing glaciers has increased since then."
Conclusions and outlook
The present study utilizes different remote sensing-based methods to generate an updated glacier inventory for the entire Karakoram region. It provides a new comprehensive dataset on the state of advancing, stable, and retreating glaciers, including the temporal and spatial variations of frontal positions between 1976 and 2012. Out of 1219 glaciers in the inventory, the vast majority [79%] showed stable terminus positions (969). These findings support the assumption of the anomalous behavior of glaciers in the Karakoram in comparison to adjacent mountain ranges, which indicate glacier recession and thinning (Bolch et al., 2012; Hewitt, 2005; Gardelle et al., 2013; Kääb et al., 2012; Scherler et al., 2011). Glacier recession is found for only 8% of the glaciers in the inventory, indicating decreasing numbers since the beginning of the 21st century, whereas the number of advancing glaciers has increased since then. Considering the advance of small glaciers with assumed short response times of about 10–20 years, we conclude on a balanced/positive mass balance in the Karakoram since the 1980s or 1990s, or even earlier, induced by changing climatic conditions since the 1960s (Archer and Fowler, 2004; Bocchiola and Diolaiuti, 2013; Williams and Ferrigno, 2010; Yao et al., 2012).
The Cryosphere, 8, 977-989, 2014
1Institute of Geography, University of Erlangen-Nuremberg, Wetterkreuz 15, 91058 Erlangen, Germany
2Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775-7320, USA
Positive glacier-mass balances in the Karakoram region during the last decade have fostered stable and advancing glacier termini positions, while glaciers in the adjacent mountain ranges have been affected by glacier recession and thinning. In addition to fluctuations induced solely by climate, the Karakoram is known for a large number of surge-type glaciers. The present study provides an updated and extended inventory on advancing, stable, retreating, and surge-type glaciers using Landsat imagery from 1976 to 2012. Out of 1219 glaciers the vast majority showed a stable terminus (969) during the observation period. Sixty-five glaciers advanced, 93 glaciers retreated, and 101 surge-type glaciers were identified, of which 10 are new observations. The dimensional and topographic characteristics of each glacier class were calculated and analyzed. Ninety percent of nonsurge-type glaciers are shorter than 10 km, whereas surge-type glaciers are, in general, longer. We report short response times of glaciers in the Karakoram and suggest a shift from negative to balanced/positive mass budgets in the 1980s or 1990s. Additionally, we present glacier surface velocities derived from different SAR (synthetic aperture radar) sensors and different years for a Karakoram-wide coverage. High-resolution SAR data enables the investigation of small and relatively fast-flowing glaciers (e.g., up to 1.8 m day−1 during an active phase of a surge). The combination of multitemporal optical imagery and SAR-based surface velocities enables an improved, Karakoram-wide glacier inventory and hence, provides relevant new observational information on the current state of glaciers in the Karakoram.
"These findings support the assumption of the anomalous behavior of glaciers in the Karakoram in comparison to adjacent mountain ranges, which indicate glacier recession and thinning (Bolch et al., 2012; Hewitt, 2005; Gardelle et al., 2013; Kääb et al., 2012; Scherler et al., 2011)."ReplyDelete
so that means the glaciers around this region are behaving differently, thus are loosing mass.
Do you think growing glaciers in some regions contradicts AGW in any way?
Please read the second most recent paper I linked toDelete
which finds most Himalayan glaciers are stable & in steady state.
"Do you think growing glaciers in some regions contradicts AGW in any way?"
Yes, global warming is global and CO2 "radiative forcing" is essentially the same globally. The fact that there are large regional differences points to internal variability, not "radiative forcing" from GHGs as the drivers.
oh you seem to have a very simplistic view on the climate system then.Delete
we actually even expect ice mass increase in some regions.
and also the article the WUWTlers found. shows still a net loss. and the authors themself say the betterment in the number of stable glaciers, coinsides with the hiatus which could explain it, but more research is needed.
so no that is absolutely no argument against AGW.
it is grasping at straws.
You seem to have a very simplistic view on climate, such that you believe climate models can make regional projections of ice increase/decreaseDelete
Such as the pathetic prediction that Antarctica would lose more sea ice than the Arctic, while Antarctica is at record highs and global sea ice above normal.
Such as the claim from the models "wet gets wetter, dry gets drier" also recently falsified
Ice has been melting for the past 20,000 years since the last ice age and this won't stop until the next ice age begins. It is not "evidence" of AGW. Prior interglacials were much warmer, sea levels 31 feet higher during the Eemain. No evidence this interglacial is any different.
Norway and New Zealand glaciers are advancing....ReplyDelete
Norway and New Zealand both experienced recent glacial advances, commencing in the early 1980s and ceasing around 2000, which were more extensive than any other since the end of the Little Ice Age. Common to both countries, the positive glacier balances are associated with an increase in the strength of westerly atmospheric circulation which brought increased precipitation. In Norway, the changes are also associated with lower ablation season temperatures. In New Zealand, where the positive balances were distributed uniformly throughout the Southern Alps, the period of increased mass balance was coincident with a change in the Interdecadal Pacific Oscillation and an associated increase in El Niño/Southern Oscillation events
A comparison between these results and recent accumulation observations, together with the strong relationship between valley precipitation and snow accumulation, suggests that surface accumulation rates did not change significantly over the entire 20th century. Moreover, the small ice thickness changes, less than 3 m on the average, observed at Mont Blanc and Dôme du Goûter between 1905 and 2005 clearly reveal that these high-elevation glaciated areas have not been significantly affected by climate change over the last 100 years.