scholarly journals How sensitive are mountain glaciers to climate change? Insights from a block model

2018 ◽  
Vol 64 (244) ◽  
pp. 247-258 ◽  
Author(s):  
EVIATAR BACH ◽  
VALENTINA RADIĆ ◽  
CHRISTIAN SCHOOF
Keyword(s):  
Climate Change ◽  
Response Time ◽  
Response Times ◽  
Global Scale ◽  
Surface Slope ◽  
Block Model ◽  
Equilibrium Line Altitude ◽  
Mountain Glacier ◽  
Mountain Glaciers ◽  
Volume Sensitivity

ABSTRACTSimple models of glacier volume evolution are important in understanding features of glacier response to climate change, due to the scarcity of data adequate for running more complex models on a global scale. Two quantities of interest in a glacier's response to climate changes are its response time and its volume sensitivity to changes in the equilibrium line altitude (ELA). We derive a simplified, computationally inexpensive model of glacier volume evolution based on a block model with volume–area–length scaling. After analyzing its steady-state properties, we apply the model to each mountain glacier worldwide and estimate regionally differentiated response times and sensitivities to ELA changes. We use a statistical method from the family of global sensitivity analysis methods to determine the glacier quantities, geometric and climatic, that most influence the model output. The response time is dominated by the climatic setting reflected in the mass-balance gradient in the ablation zone, followed by the surface slope, while volume sensitivity is mainly affected by glacier size, followed by the surface slope.

scholarly journals Prediction of possible changes in glacio-hydrological characteristics under global warming: southeastern Alaska, U.S.A.

1996 ◽  
Vol 42 (142) ◽  
pp. 407-412 ◽  
Author(s):  
N.V. Davidovich ◽  
M.D. Ananicheva
Keyword(s):  
Global Warming ◽  
Air Temperature ◽  
Atmospheric Carbon Dioxide ◽  
Climate Model ◽  
Temperature Fields ◽  
Equilibrium Line Altitude ◽  
Mountain Glacier ◽  
Mountain Glaciers ◽  
Glacier Terminus ◽  
Statistical Relationships

Abstract We use the Wetherald and Manabe climate model to predict the response of mountain glaciers to a doubling of atmospheric carbon dioxide. The response is measured in terms of a change in the equilibrium-line altitude (ELA) and the glacier terminus altitude (GTA), net accumulation–ablation on these altitudes and the melt runoff for 12 mountain-glacier regions in southeastern Alaska, U.S.A. The methods we use involve extrapolating climate-model temperature fields to a glacier’s location, and empirical–statistical relationships between air temperature and percentage of solid precipitation, and between summer air temperature and ablation and melt runoff. Our study shows that, under global warming, glaciation in southeastern Alaska will not disappear, but mass exchange of glaciers will be more intensive and the ELA value will increase by 300–760 m, depending on the glacier’s distance from the ocean.

The response of Østre Svartisen Icefield, Norway, to 20th/21st century climate change

2020 ◽  
Author(s):  
Clare M. Boston ◽  
Harold Lovell ◽  
Paul Weber ◽  
Benjamin M. P. Chandler ◽  
Timothy T. Barrows ◽  
...  
Keyword(s):  
Climate Change ◽  
Response Times ◽  
Temporal Variations ◽  
Ice Age ◽  
Aerial Photographs ◽  
Outlet Glacier ◽  
Mountain Glaciers ◽  
The North ◽  
Warming Climate ◽  
Glacier Dynamics

<p>Recently deglaciated forelands contain a wealth of geomorphological and sedimentological data that can provide key information about glacier-climate relationships. Mountain glaciers are particularly important indicators of climate change due to their short response times, which means that their forelands provide a sub-decadal record of changes in glacier size and climate-related dynamics. In this contribution, we examine the glacial geomorphological and sedimentological record at Østre Svartisen, an Arctic plateau icefield in Norway, and discuss temporal variations in glacier dynamics and processes of sediment deposition in response to climate warming since the Little Ice Age (c.1750). We focus specifically on the northeastern sector of the icefield and include two separate cirque/valley glaciers immediately to the north. Differences in landform-sediment assemblages are apparent both within and between forelands relating to changes in topography as well as glacier dynamics. Satellite images and old aerial photographs are also used to investigate differences in the rates of glacier demise across the study area. This evidence enables links to be made between landform generation, bed morphology, glacier dynamics, and glacier response to climate change, which furthers understanding of plateau icefield and outlet glacier behaviour in a warming climate.</p>

Variation of glacial dynamics in Peru: from valley glaciers to mountain glaciers in a context of climate change

2020 ◽  
Author(s):  
Edwin Loarte ◽  
Katy Medina ◽  
Yadira Curo ◽  
Hairo Leon ◽  
Fiorella Quiñonez ◽  
...  
Keyword(s):  
Climate Change ◽  
Mountain Glacier ◽  
Morphometric Variation ◽  
Mountain Ranges ◽  
Mountain Glaciers ◽  
Tropical Glaciers ◽  
The Pacific ◽  
Short Period ◽  
Valley Glacier ◽  
Glacial Dynamics

<p>One of the effects of climate change on tropical glaciers is the accelerated reduction of their glacial tongue, reflected in a morphometric variation. Many glaciers that had pronounced tongues and that extended through a valley (Valley glacier) now have reduced their fronts located in the upper parts of the valleys (Mountain glacier).</p><p>This has been studied with glaciers of Peru located in 18 mountain ranges located from S 8°20'56" to 15°53'26" and W 77°56'10" to 69°05'14", which are an important solid water reserve that directly supplies the population of 11 departments.</p><p>The study focused on the "digit 1" (primary classification) of the Global Land Ice Measurement from Space (GLIMS), which classifies the glaciers mainly in: valley glaciers and mountain glaciers. The processing of raster and vector data through the use of geographic information system and remote sensing tools allowed to analyze the changes and variations affecting glaciers with respect to their morphometry. For this, a comparison was made between glacier coverage in 2016 (using images Sentinel 2), produced by INAIGEM, and the baseline of the glacier coverage of 1955 and 1970 (using aerial photography), from the first inventory of glaciers in Peru, produced by Hidrandina S.A.</p><p>The results show a significant morphometric variation of 83.7%, where valley glaciers (from Hidrandina inventory) became mainly mountain glaciers. Nowadays only four mountain ranges have mountain glaciers inside whereas in the past it were nine. When we analyze the results for watersheds, the most morphometric changes were 89% in the Atlantic watershed, followed by 57% in the Pacific watershed; in the Amazon watershed there was not any registration of any mountain glaciers since the first inventory in Peru. The surface changes do not show specific any predominant aspect, and average slopes are between 25° and 50°.</p><p>The glacial tongues that are considered valley glacier area located in ablation zones, where the mass balance is negative and there is more susceptibility to reducing their mass and, consequently, to variations in shape and size in a short period. This change has been accentuated in recent decades.</p>

scholarly journals The non-synchronous response of Rabots Glaciär and Storglaciären, northern Sweden, to recent climate change: a comparative study

2007 ◽  
Vol 46 ◽  
pp. 275-282 ◽  
Author(s):  
Keith A. Brugger
Keyword(s):  
Climate Change ◽  
Response Time ◽  
Response Times ◽  
Northern Sweden ◽  
Small Perturbations ◽  
Recent Climate Change ◽  
Recent Climate ◽  
Synchronous Behavior ◽  
The 19Th Century ◽  
Small Valley

AbstractRabots Glaciär and Storglaciären, two small valley glaciers in the Swedish Arctic, have not behaved synchronously in response to recent climate change. Both glaciers advanced late in the 19th century and then began to retreat in response to a ~1˚C warming that occurred around 1910. By the mid-1980s the terminus and volume of Storglaciären had essentially stabilized, so it may have completed its response to the earlier warming. In contrast, ongoing thinning and retreat of Rabots Glaciär are substantial and suggest its response time is considerably longer. A time-dependent numerical model was used to investigate each glacier’s response to perturbations in mass balance. This modeling suggests that, for small perturbations, volume timescales for Storglaciären and Rabots Glaciär are ~125 and ~215 years, respectively. Another measure of response time (i.e. length response time) yields somewhat lower values for each glacier; however, what is significant is that by either measure and accounting for uncertainties, the response time for Rabots Glaciär is consistently about 1.5 times longer than that for Storglaciären. This implies that their non-synchronous behavior is likely due to differences in response times. The latter ultimately result from markedly different longitudinal geometries (particularly near the termini), velocity profiles and specific net balance gradients.

scholarly journals Prediction of possible changes in glacio-hydrological characteristics under global warming: southeastern Alaska, U.S.A.

1996 ◽  
Vol 42 (142) ◽  
pp. 407-412 ◽  
Author(s):  
N.V. Davidovich ◽  
M.D. Ananicheva
Keyword(s):  
Global Warming ◽  
Air Temperature ◽  
Atmospheric Carbon Dioxide ◽  
Climate Model ◽  
Temperature Fields ◽  
Equilibrium Line Altitude ◽  
Mountain Glacier ◽  
Mountain Glaciers ◽  
Glacier Terminus ◽  
Statistical Relationships

AbstractWe use the Wetherald and Manabe climate model to predict the response of mountain glaciers to a doubling of atmospheric carbon dioxide. The response is measured in terms of a change in the equilibrium-line altitude (ELA) and the glacier terminus altitude (GTA), net accumulation–ablation on these altitudes and the melt runoff for 12 mountain-glacier regions in southeastern Alaska, U.S.A. The methods we use involve extrapolating climate-model temperature fields to a glacier’s location, and empirical–statistical relationships between air temperature and percentage of solid precipitation, and between summer air temperature and ablation and melt runoff. Our study shows that, under global warming, glaciation in southeastern Alaska will not disappear, but mass exchange of glaciers will be more intensive and the ELA value will increase by 300–760 m, depending on the glacier’s distance from the ocean.

Geomorphic feedbacks on the moraine record

2020 ◽  
Author(s):  
Leif Anderson ◽  
Dirk Scherler
Keyword(s):  
Climate Change ◽  
Numerical Modeling ◽  
Global Scale ◽  
Past Climate ◽  
Mountain Ranges ◽  
Mountain Glaciers ◽  
Term Evolution ◽  
Debris Cover ◽  
Mountain Landscapes

<p>Glacial moraines represent one of the most spatially diverse climate archives on earth. Moraine dating and numerical modeling are used to effectively reconstruct past climate from mountain ranges at the global scale. But because moraines are often located downvalley from steep mountain headwalls, it is possible that debris-covered glaciers emplaced many moraines preserved in the landscape today.</p><p>Before we can understand the effect of debris cover on the moraine recored we need to understand how debris modulates glacier response to climate change. To help address this need, we developed a numerical model that links feedbacks between mountain glaciers, climate change, hillslope erosion, and landscape evolution. Our model uses parameters meant to represent glaciers in the Khumbu region of Nepal, though the model physics are relevant for mountain glaciers elsewhere.</p><p>We compare simulated debris-covered and debris-free glaciers and their length evolution. We explore the effect of climate-dependent hillslope erosion. We also allow temperature change to control frost cracking and permafrost in the headwall above simulated glaciers. Including these effects holds special implications for glacial evolution during deglaciation and the long-term evolution of mountain landscapes.</p><p>Because debris cover suppresses melt, debris-covered glaciers can advance independent of climate change. When debris cover is present during cold periods, moraine emplacement can lag debris-free glacier moraine emplacement by hundreds of years. We develop a suite of tools to help determine whether individual moraines were formed by debris-covered glaciers. Our analyses also point to how we might interpret moraine ages and estimate past climate states from debris-perturbed settings.</p>

DEVELOPMENT AND EVALUATION OF EMULATORS FOR THE ASSESSMENT OF THE GLOBAL-SCALE ECONOMIC IMPACT OF CLIMATE CHANGE

2019 ◽  
Vol 75 (5) ◽  
pp. I_73-I_80
Author(s):  
Jun’ya TAKAKURA ◽  
Shinichiro FUJIMORI ◽  
Kiyoshi TAKAHASHI ◽  
Qian ZHOU ◽  
Naota HANASAKI ◽  
...  
Keyword(s):  
Climate Change ◽  
Economic Impact ◽  
Global Scale ◽  
Impact Of Climate Change

scholarly journals Shared socioeconomic pathways for climate change research in Finland: co-developing extended SSP narratives for agriculture

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Heikki S. Lehtonen ◽  
Jyrki Aakkula ◽  
Stefan Fronzek ◽  
Janne Helin ◽  
Mikael Hildén ◽  
...  
Keyword(s):  
Climate Change ◽  
National Level ◽  
Global Scale ◽  
Change Scenario ◽  
Policy Makers ◽  
Climate Change Research ◽  
Food And Agriculture ◽  
Agriculture And Food ◽  
Farm Subsidies

AbstractShared socioeconomic pathways (SSPs), developed at global scale, comprise narrative descriptions and quantifications of future world developments that are intended for climate change scenario analysis. However, their extension to national and regional scales can be challenging. Here, we present SSP narratives co-developed with stakeholders for the agriculture and food sector in Finland. These are derived from intensive discussions at a workshop attended by approximately 39 participants offering a range of sectoral perspectives. Using general background descriptions of the SSPs for Europe, facilitated discussions were held in parallel for each of four SSPs reflecting very different contexts for the development of the sector up to 2050 and beyond. Discussions focused on five themes from the perspectives of consumers, producers and policy-makers, included a joint final session and allowed for post-workshop feedback. Results reflect careful sector-based, national-level interpretations of the global SSPs from which we have constructed consensus narratives. Our results also show important critical remarks and minority viewpoints. Interesting features of the Finnish narratives compared to the global SSP narratives include greater emphasis on environmental quality; significant land abandonment in SSPs with reduced livestock production and increased plant-based diets; continued need for some farm subsidies across all SSPs and opportunities for diversifying domestic production under scenarios of restricted trade. Our results can contribute to the development of more detailed national long-term scenarios for food and agriculture that are both relevant for local stakeholders and researchers as well as being consistent with global scenarios being applied internationally.

scholarly journals Reduced resilience of terrestrial ecosystems locally is not reflected on a global scale

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Yuhao Feng ◽  
Haojie Su ◽  
Zhiyao Tang ◽  
Shaopeng Wang ◽  
Xia Zhao ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Vegetation Index ◽  
Global Climate ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Global Scale ◽  
Ecological Resilience ◽  
Terrestrial Vegetation ◽  
Ecosystem Resilience

AbstractGlobal climate change likely alters the structure and function of vegetation and the stability of terrestrial ecosystems. It is therefore important to assess the factors controlling ecosystem resilience from local to global scales. Here we assess terrestrial vegetation resilience over the past 35 years using early warning indicators calculated from normalized difference vegetation index data. On a local scale we find that climate change reduced the resilience of ecosystems in 64.5% of the global terrestrial vegetated area. Temperature had a greater influence on vegetation resilience than precipitation, while climate mean state had a greater influence than climate variability. However, there is no evidence for decreased ecological resilience on larger scales. Instead, climate warming increased spatial asynchrony of vegetation which buffered the global-scale impacts on resilience. We suggest that the response of terrestrial ecosystem resilience to global climate change is scale-dependent and influenced by spatial asynchrony on the global scale.

Contrasting wheat phenological responses to climate change in global scale

2019 ◽  
Vol 665 ◽  
pp. 620-631 ◽  
Author(s):  
Shilong Ren ◽  
Qiming Qin ◽  
Huazhong Ren
Keyword(s):  
Climate Change ◽  
Global Scale
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