scholarly journals The response of glaciers to climatic persistence

2016 ◽  
Vol 62 (233) ◽  
pp. 440-450 ◽  
Author(s):  
GERARD H. ROE ◽  
MARCIA B. BAKER
Keyword(s):  
Mass Balance ◽  
Statistical Tests ◽  
Glacier Mass Balance ◽  
Climate Variables ◽  
Glacier Changes ◽  
Actual Degree ◽  
Glacier Length ◽  
Temporal Persistence ◽  
Random Fluctuations ◽  
The Impact

AbstractThe attribution of past glacier length fluctuations to changes in climate requires characterizing glacier mass-balance variability. Observational records, which are relatively short, are consistent with random fluctuations uncorrelated in time, plus an anthropogenic trend. However, longer records of other climate variables suggest that, in fact, there is a degree of temporal persistence associated with internal (i.e. unforced) climate variability, and that it varies with location and climate. Therefore, it is likely that persistence does exist for mass balance, but records are too short to confirm its presence, or establish its magnitude, with conventional statistical tests. Extending the previous work, we explore the impact of potential climatic persistence on glacier length fluctuations. We use a numerical model and a newly developed analytical model to establish that persistence, even of a degree so small as to be effectively undetectable in the longest mass-balance records, can significantly enhance the resulting glacier length fluctuations. This has a big impact on glacier-excursion probabilities: what was an extremely unlikely event (<1%) can become virtually certain (>99%), when persistence is incorporated. Since the actual degree of climatic persistence that applies to any given glacier is hard to establish, these results complicate the attribution of past glacier changes.

scholarly journals Longest time series of glacier mass changes in the Himalaya based on stereo imagery

2010 ◽  
Vol 4 (4) ◽  
pp. 2593-2613 ◽  
Author(s):  
T. Bolch ◽  
T. Pieczonka ◽  
D. I. Benn
Keyword(s):  
Time Series ◽  
Mass Loss ◽  
Mass Balance ◽  
Aerial Images ◽  
Glacier Mass Balance ◽  
Glacier Changes ◽  
Debris Cover ◽  
Stereo Imagery ◽  
Glacier Velocity ◽  
The Himalaya

Abstract. Mass loss of Himalayan glaciers has wide-ranging consequences such as declining water resources, sea level rise and an increasing risk of glacial lake outburst floods (GLOFs). The assessment of the regional and global impact of glacier changes in the Himalaya is, however, hampered by a lack of mass balance data for most of the range. Multi-temporal digital terrain models (DTMs) allow glacier mass balance to be calculated since the availability of stereo imagery. Here we present the longest time series of mass changes in the Himalaya and show the high value of early stereo spy imagery such as Corona (years 1962 and 1970) aerial images and recent high resolution satellite data (Cartosat-1) to calculate a time series of glacier changes south of Mt. Everest, Nepal. We reveal that the glaciers are significantly losing mass with an increasing rate since at least ~1970, despite thick debris cover. The specific mass loss is 0.32 ± 0.08 m w.e. a−1, however, not higher than the global average. The spatial patterns of surface lowering can be explained by variations in debris-cover thickness, glacier velocity, and ice melt due to exposed ice cliffs and ponds.

scholarly journals The impact of Saharan dust and black carbon on albedo and long-term glacier mass balance

2015 ◽  
Vol 9 (1) ◽  
pp. 1133-1175 ◽  
Author(s):  
J. Gabbi ◽  
M. Huss ◽  
A. Bauder ◽  
F. Cao ◽  
M. Schwikowski
Keyword(s):  
Mass Balance ◽  
Black Carbon ◽  
Mineral Dust ◽  
Ice Cores ◽  
Swiss Alps ◽  
Saharan Dust ◽  
Glacier Mass Balance ◽  
Mass Balances ◽  
The Impact

Abstract. Light-absorbing impurities in snow and ice control glacier melt as shortwave radiation represents the main component of the surface energy balance. Here, we investigate the long-term effect of snow impurities, i.e. Saharan dust and black carbon (BC), on albedo and glacier mass balance. The analysis was performed over the period 1914–2014 for two sites on Claridenfirn, Swiss Alps, where an outstanding 100 year record of seasonal mass balance measurements is available. Information on atmospheric deposition of mineral dust and BC over the last century was retrieved from two firn/ice cores of high-alpine sites. A combined mass balance and snow/firn layer model was employed to assess the dust/BC-albedo feedback. Compared to pure snow conditions, the presence of Saharan dust and BC lowered the mean annual albedo by 0.04–0.06 and increased melt by 15–19% on average depending on the location on the glacier. BC clearly dominated absorption which is about three times higher than that of mineral dust. The upper site has experienced mainly positive mass balances and impurity layers were continuously buried whereas at the lower site, surface albedo was more strongly influenced by re-exposure of dust-enriched layers due to frequent years with negative mass balances.

scholarly journals Characteristic mass-balance scaling with valley glacier size

1999 ◽  
Vol 45 (149) ◽  
pp. 17-21 ◽  
Author(s):  
David B. Bahr ◽  
Mark Dyurgerov
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Scaling Exponent ◽  
Scaling Relation ◽  
Glacier Recession ◽  
Glacier Terminus ◽  
Valley Glacier ◽  
Glacier Length ◽  
The Impact ◽  
Characteristic Mass

AbstractPrevious work on the relation between glacier volume and area and on accumulation area ratios suggests that balance rates measured at the glacier terminus are not constant or random from glacier to glacier but instead scale with glacier length. Using mass-balance data from a collection of 68 valley and cirque glaciers, we show that the terminus mass-balance rate scales roughly linearly with surface area and scales with length raised to an exponent constrained to fall roughly between 0.5 and 2 with 1.7 preferred if a glacier’s length is dependent on the mass-balance conditions (rather than balance being dependent on length). When these exponents are used to predict valley-glacier volume–area scaling, the results are very close to empirical volume–area observations. Although the data are noisy and the proposed fits could be modified by improved observations, the scaling trend for terminus balance vs length remains clear. Although the exact value of the scaling exponent is not well determined, establishing the existence of this scaling relation will be important for studies of climate change and the impact of glacier recession on sea level.

scholarly journals Sensitivity of mountain glacier mass balance to changes in bare-ice albedo

2017 ◽  
Vol 58 (75pt2) ◽  
pp. 119-129 ◽  
Author(s):  
Kathrin Naegeli ◽  
Matthias Huss
Keyword(s):  
Mass Balance ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Landsat 8 ◽  
Glacier Surface ◽  
Mountain Glacier ◽  
Albedo Feedback ◽  
In Situ Data ◽  
The Impact ◽  
Near Future

ABSTRACT Albedo is an important parameter in the energy balance of bare-ice surfaces and modulates glacier melt rates. The prolongation of the ablation period enforces the albedo feedback and highlights the need for profound knowledge on impacts of bare-ice albedo on glacier mass balance. In this study, we assess the mass balance sensitivity of 12 Swiss glaciers with abundant long-term in-situ data on changes in bare-ice albedo. We use pixel-based bare-ice albedo derived from Landsat 8. A distributed mass-balance model is applied to the period 1997–2016 and experiments are performed to assess the impact of albedo changes on glacier mass balance. Our results indicate that glacier-wide mass-balance sensitivities to changes in bare-ice albedo correlate strongly with mean annual mass balances (r 2 = 0.81). Large alpine glaciers react more sensitively to bare-ice albedo changes due to their ablation areas being situated at lower elevations. We find average sensitivities of glacier-wide mass balance of −0.14 m w.e. a−1 per 0.1 albedo decrease. Although this value is considerably smaller than sensitivity to air temperature change, we stress the importance of the enhanced albedo feedback that will be amplified due to atmospheric warming and a suspected darkening of glacier surface in the near future.

Forcings of mass-balance variability in Karakoram-Himalaya

2020 ◽  
Author(s):  
Pankaj Kumar ◽  
Vladimir A. Ryabchenko ◽  
Aaquib Javed ◽  
Dmitry V. Sein ◽  
Md. Farooq Azam
Keyword(s):  
Mass Balance ◽  
Large Scale ◽  
Climate Model ◽  
Model Simulation ◽  
Large Fraction ◽  
Water Security ◽  
Spatiotemporal Variability ◽  
Glacier Mass Balance ◽  
Russian Science ◽  
The Impact

&lt;p&gt;Glacier retreat is a key indicator of climate variability and change. Karakoram-Himalaya (KH) glaciers are the source of several perennial rivers protecting water security of a large fraction of the global population. The region is highly vulnerable to climate change impacts, hence the sensitivity of KH glaciers to regional microclimate, especially the impact of individual parameters forcing have been not quantified yet. The present study, using a coupled dynamical glacier-climate model simulation results, analyses the modelled interannual variability of mass-balance for the period 1989-2016. It is validated against available observations to quantify for the first time the sensitivity of the glaciers mass-balance to the individual forcing over KH. The snowfall variability emerges as the key factor, explaining ~60% of the variability of regional glacier mass balance. We provide insight into the recent divergent glacier response over the Karakoram Himalaya. The results underline the need for careful measurements and model representations of snowfall spatiotemporal variability, one of the HK's least-studied meteorological variables, to capture the large-scale, but region-specific, glacier changes at the third pole.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Acknowledgement:&lt;/p&gt;&lt;p&gt;The work was supported by Indian project no. DST/INT/RUS/RSF/P-33/G, and the Russian Science Foundation (Project 19-47-02015).&lt;/p&gt;

scholarly journals Preliminary results of mass-balance observations of Yala Glacier and analysis of temperature and precipitation gradients in Langtang Valley, Nepal

2014 ◽  
Vol 55 (66) ◽  
pp. 9-14 ◽  
Author(s):  
Prashant Baral ◽  
Rijan B. Kayastha ◽  
Walter W. Immerzeel ◽  
Niraj S. Pradhananga ◽  
Bikas C. Bhattarai ◽  
...  
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Lapse Rate ◽  
Convective Precipitation ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Temperature And Precipitation ◽  
Meteorological Observations ◽  
The Impact ◽  
Langtang Valley

AbstractMonitoring the glacier mass balance of summer-accumulation-type Himalayan glaciers is critical to not only assess the impact of climate change on the volume of such glaciers but also predict the downstream water availability and the global sea-level change in future. To better understand the change in meteorological parameters related to glacier mass balance and runoff in a glacierized basin and to assess the highly heterogeneous glacier responses to climate change in the Nepal Himalaya and nearby ranges, the Cryosphere Monitoring Project (CMP) carries out meteorological observations in Langtang Valley and mass-balance measurements on Yala Glacier, a debris-free glacier in the same valley. A negative annual mass balance of –0.89m w.e. and the rising equilibrium-line altitude of Yala Glacier indicate a continuation of a secular trend toward more negative mass balances. Lower temperature lapse rate during the monsoon, the effect of convective precipitation associated with mesoscale thermal circulation in the local precipitation and the occurrence of distinct diurnal cycles of temperature and precipitation at different stations in the valley are other conclusions of this comprehensive scientific study initiated by CMP which aims to yield multi-year glaciological, hydrological and meteorological observations in the glacierized Langtang River basin.

scholarly journals Local topography increasingly influences the mass balance of a retreating cirque glacier

2018 ◽  
Author(s):  
Caitlyn Florentine ◽  
Joel Harper ◽  
Daniel Fagre ◽  
Johnnie Moore ◽  
Erich Peitzsch
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Regional Climate ◽  
Glacier Mass Balance ◽  
Climate Variables ◽  
Climate Data ◽  
Local Effects ◽  
Surface Mass ◽  
Average Mass ◽  
Measured Mass

Abstract. Local topographically driven processes such as wind drifting, avalanching, and shading, are known to alter the relationship between the mass balance of small cirque glaciers and regional climate. Yet partitioning such local effects apart from regional climate influence has proven difficult, creating uncertainty in the climate representativeness of some glaciers. We address this problem for Sperry Glacier in Glacier National Park, USA using field-measured surface mass balance, geodetic constraints on mass balance, and regional climate data recorded at a network of meteorological stations. Geodetically derived mass changes between 1950–1960, 1960–2005, and 2005–2014 document average mass loss rates during each period at −0.22±0.12 m w.e. yr−1, −0.18±0.05 m w.e. yr−1, and −0.10±0.03 m w.e. yr−1. A correlation of field-measured mass balance and regional climate variables closely predicts the geodetically measured mass loss from 2005–2014. However, this correlation overestimates glacier mass balance for 1950–1960 by +1.18±0.92 m w.e. yr−1. This suggests that local effects, not represented in regional climate variables, have become a more dominant driver of the net mass balance as the glacier lost 0.50 km2 and retreated further into its cirque.

scholarly journals A Tri-Approach for Diagnosing Gridded Precipitation Datasets for Watershed Glacio-Hydrological Simulation in Mountain Regions

2020 ◽  
Author(s):  
Muhammad Shafeeque ◽  
Luo Yi
Keyword(s):  
Mass Balance ◽  
Indus Basin ◽  
Glacier Mass Balance ◽  
Multiple Perspectives ◽  
Mountain Regions ◽  
Hydrological Simulation ◽  
Physical Diagnosis ◽  
Annual Variations ◽  
Glacier Changes ◽  
Local Correction

Abstract. In mountain regions, validation and local correction of gridded precipitation datasets (GPDs) are pre-requisites for glacio-hydrological simulations. However, insufficient observed data and glacial involvement make it a complicated task in glacierized watersheds. To diagnose the potential problems in GPDs from multiple perspectives and provide directions for their correction, a Tri-approach framework, consisting of statistical analysis, physical diagnosis, and practical simulation, is proposed. Truc-Budyko theory is introduced into this framework, which can identify the actual under- or over-estimation of GPDs based on watershed water-energy balance, diagnose their possible causes, and provide directions for local correction. This framework was applied to the glacierized Upper Indus Basin (UIB) for evaluating GPDs, including APHRODITE, CFSR, PGMFD, TRMM, and HAR, against adjusted observed precipitation (OBS), specific runoff, and glacier mass balance over varying periods during 1951–2017. The Spatial Processes in HYdrology (SPHY) model was used to simulate the hydrology and glacier changes (2001–2007). The results suggest that (a) patterns of inter- and intra-annual variations of OBS precipitation were better captured by APHRODITE (CC > 0.6), but it was underestimated (−40 %), (b) UIB was characterized as Leaky catchment based on overestimated CFSR (106 %) and HAR (77 %), indicating positive glacier storage changes (0.37 and 0.21 m w.e. yr−1, respectively). In contrast, UIB was characterized as Gaining watershed for remaining underestimated datasets, indicating negative storage changes (−0.42 to −0.34 m w.e. yr−1). (c) For constant mass balance, the simulated runoff was overestimated in SPHY_CFSR (66 %) and SPHY_HAR (53 %), whereas it was underestimated for SPHY_APHRODITE (−41 %), SPHY_PGMFD (−26 %), and SPHY_TRMM (−33 %). It highlights that evaluated GPDs could not generally meet the requirements of the rational output of glacier mass balance and streamflow concurrently. The physical diagnosis directs local correction based on under- and over-estimation. The practical simulation explores the extent of expected uncertainties in intra/inter-annual characteristics of glacio-hydrology.

scholarly journals Measurements and modeling of snow albedo at Alerce Glacier, Argentina: effects of volcanic ash, snow grain size, and cloudiness

2020 ◽  
Vol 14 (12) ◽  
pp. 4581-4601
Author(s):  
Julián Gelman Constantin ◽  
Lucas Ruiz ◽  
Gustavo Villarosa ◽  
Valeria Outes ◽  
Facundo N. Bajano ◽  
...  
Keyword(s):  
Grain Size ◽  
Mass Balance ◽  
Volcanic Ash ◽  
Impurity Content ◽  
Field Measurements ◽  
Glacier Mass Balance ◽  
Surface Mass Balance ◽  
Surface Mass ◽  
Snow Albedo ◽  
The Impact

Abstract. The impact of volcanic ash on seasonal snow and glacier mass balance has been much less studied than that of carbonaceous particles and mineral dust. We present here the first field measurements on the Argentinian Andes, combined with snow albedo and glacier mass balance modeling. Measured impurity content (1.1 mg kg−1 to 30 000 mg kg−1) varied abruptly in snow pits and snow and firn cores, due to high surface enrichment during the ablation season and possibly local or regional wind-driven resuspension and redeposition of dust and volcanic ash. In addition, we observed high spatial heterogeneity, due to glacier topography and the prevailing wind direction. Microscopic characterization showed that the major component was ash from recent Calbuco (2015) and Cordón Caulle (2011) volcanic eruptions, with a minor presence of mineral dust and black carbon. We also found a wide range of measured snow albedo (0.26 to 0.81), which reflected mainly the impurity content and the snow and firn grain size (due to aging). We updated the SNow, ICe, and Aerosol Radiation (SNICAR) albedo model to account for the effect of cloudiness on incident radiation spectra, improving the match of modeled and measured values. We also ran sensitivity studies considering the uncertainty in the main measured parameters (impurity content and composition, snow grain size, layer thickness, etc.) to identify the field measurements that should be improved to facilitate the validation of the snow albedo model. Finally, we studied the impact of these albedo reductions on Alerce Glacier using a spatially distributed surface mass balance model. We found a large impact of albedo changes on glacier mass balance, and we estimated that the effect of observed ash concentrations can be as high as a 1.25 m water equivalent decrease in the annual surface mass balance (due to a 34 % increase in the melt during the ablation season).

scholarly journals Characteristic mass-balance scaling with valley glacier size

1999 ◽  
Vol 45 (149) ◽  
pp. 17-21
Author(s):  
David B. Bahr ◽  
Mark Dyurgerov
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Scaling Exponent ◽  
Scaling Relation ◽  
Glacier Recession ◽  
Glacier Terminus ◽  
Valley Glacier ◽  
Glacier Length ◽  
The Impact ◽  
Characteristic Mass

Abstract Previous work on the relation between glacier volume and area and on accumulation area ratios suggests that balance rates measured at the glacier terminus are not constant or random from glacier to glacier but instead scale with glacier length. Using mass-balance data from a collection of 68 valley and cirque glaciers, we show that the terminus mass-balance rate scales roughly linearly with surface area and scales with length raised to an exponent constrained to fall roughly between 0.5 and 2 with 1.7 preferred if a glacier’s length is dependent on the mass-balance conditions (rather than balance being dependent on length). When these exponents are used to predict valley-glacier volume–area scaling, the results are very close to empirical volume–area observations. Although the data are noisy and the proposed fits could be modified by improved observations, the scaling trend for terminus balance vs length remains clear. Although the exact value of the scaling exponent is not well determined, establishing the existence of this scaling relation will be important for studies of climate change and the impact of glacier recession on sea level.

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