scholarly journals Identifying Dynamically Induced Variability in Glacier Mass-Balance Records

2016 ◽  
Vol 29 (24) ◽  
pp. 8915-8929 ◽  
Author(s):  
John Erich Christian ◽  
Nicholas Siler ◽  
Michelle Koutnik ◽  
Gerard Roe
Keyword(s):  
Time Series ◽  
Mass Balance ◽  
North Pacific ◽  
Large Scale ◽  
Significant Degree ◽  
Temperature Fields ◽  
Dynamical Response ◽  
Glacier Mass Balance ◽  
Local Climate ◽  
Pacific Climate Variability

Abstract Glacier mass balance provides a direct indicator of a glacier’s relationship with local climate, but internally generated variability in atmospheric circulation adds a significant degree of noise to mass-balance time series, making it difficult to correctly identify and interpret trends. This study applies “dynamical adjustment” to seasonal mass-balance records to identify and remove the component of variance in these time series that is associated with large-scale circulation fluctuations (dynamical adjustment refers here to a statistical method and not a glacier’s dynamical response to climate). Mass-balance records are investigated for three glaciers: Wolverine and Gulkana in Alaska and South Cascade in Washington. North Pacific sea level pressure and sea surface temperature fields perform comparably as predictors, each explaining 50%–60% of variance in winter balance and 25%–35% in summer balance for South Cascade and Wolverine Glaciers. Gulkana Glacier, located farther inland, is less closely linked to North Pacific climate variability, with the predictors explaining roughly 30% of variance in winter and summer balance. To investigate the degree to which this variability affects trends, adjusted mass-balance time series are compared to those in the raw data, with common results for all three glaciers; winter balance trends are not significant initially and do not gain robust significance after adjustment despite the large amount of circulation-related variability. However, the raw summer balance data have statistically significant negative trends that remain after dynamical adjustment. This indicates that these trends of increasing ablation in recent decades are not due to circulation anomalies and are consistent with anthropogenic warming.

scholarly journals Influence of atmospheric circulation on glacier mass balance in western Tibet: an analysis based on observations and modeling

2021 ◽  
pp. 1-55
Author(s):  
Meilin Zhu ◽  
Lonnie G. Thompson ◽  
Huabiao Zhao ◽  
Tandong Yao ◽  
Wei Yang ◽  
...  
Keyword(s):  
Mass Balance ◽  
Atmospheric Circulation ◽  
Air Temperature ◽  
Large Scale ◽  
Snow Accumulation ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
The Tibetan Plateau ◽  
Local Climate ◽  
Average Mass

AbstractGlacier changes on the Tibetan Plateau (TP) have been spatially heterogeneous in recent decades. The understanding of glacier mass changes in western Tibet, a transitional area between the monsoon-dominated region and the westerlies-dominated region, is still incomplete. For this study, we used an energy-mass balance model to reconstruct annual mass balances from October 1967 to September 2019 to explore the effects of local climate and large-scale atmospheric circulation on glacier mass changes in western Tibet. The results showed Xiao Anglong Glacier is close to a balanced condition, with an average value of -53±185 mm w.e. a-1 for 1968-2019. The interannual mass balance variability during 1968-2019 was primary driven by ablation-season precipitation, which determined changes in the snow accumulation and strongly influenced melt processes. The interannual mass balance variability during 1968-2019 was less affected by ablation-season air temperature, which only weakly affected snowfall and melt energy. Further analysis suggests that the southward (or northward) shift of the westerlies caused low (or high) ablation-season precipitation, and therefore low (or high) annual mass balance for glaciers in western Tibet. In addition, the average mass balance for Xiao Anglong Glacier was 83±185, -210±185, and -10±185 mm w.e. a-1 for 1968-1990, 1991-2012, and 2013-2019, respectively. These mass changes were associated with the variations in precipitation and air temperature during the ablation season on interdecadal time scales.

Extending the Place Glacier mass-balance record to AD 1585, using tree rings and wood density

2011 ◽  
Vol 76 (3) ◽  
pp. 305-313 ◽  
Author(s):  
Lisa J. Wood ◽  
Dan J. Smith ◽  
Michael N. Demuth
Keyword(s):  
British Columbia ◽  
Mass Balance ◽  
Large Scale ◽  
Ring Width ◽  
Climate Forcing ◽  
Glacier Mass Balance ◽  
Increment Core ◽  
Engelmann Spruce ◽  
Circulation Indices ◽  
Forcing Mechanisms

AbstractRecognizing that climate influences both annual tree-ring growth and glacier mass balance, changes in the mass balance of Place Glacier, British Columbia, were documented from increment core records. Annually resolved ring-width (RW), maximum (MXD), and mean density (MD) chronologies were developed from Engelmann spruce and Douglas-fir trees sampled at sites within the surrounding region. A snowpack record dating to AD 1730 was reconstructed using a multivariate regression of spruce MD and fir RW chronologies. Spruce MXD and RW chronologies were used to reconstruct winter mass balance (Bw) for Place Glacier to AD 1585. Summer mass balance (Bs) was reconstructed using the RW chronology from spruce, and net balance was calculated from Bw and Bs. The reconstructions provide insight into the changes that snowpack and mass balance have undergone in the last 400 years, as well as identifying relationships to air temperature and circulation indices in southern British Columbia. These changes are consistent with other regional mass-balance reconstructions and indicate that the persistent weather systems characterizing large scale climate-forcing mechanisms play a significant glaciological role in this region. A comparison to dated moraine surfaces in the surrounding region substantiates that the mass-balance shifts recorded in the proxy data are evident in the response of glaciers throughout the region.

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 Multi-decadal mass loss of glaciers in the Everest area (Nepal Himalaya) derived from stereo imagery

2011 ◽  
Vol 5 (2) ◽  
pp. 349-358 ◽  
Author(s):  
T. Bolch ◽  
T. Pieczonka ◽  
D. I. Benn
Keyword(s):  
Time Series ◽  
Mass Loss ◽  
Mass Balance ◽  
Aerial Images ◽  
Glacier Mass Balance ◽  
Ice Melt ◽  
Debris Cover ◽  
Stereo Imagery ◽  
Glacier Velocity ◽  
The Himalaya

Abstract. Mass loss of Himalayan glaciers has wide-ranging consequences such as changing runoff distribution, 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. Here, we present a time series of mass changes for ten glaciers covering an area of about 50 km2 south and west of Mt. Everest, Nepal, using stereo Corona spy imagery (years 1962 and 1970), aerial images and recent high resolution satellite data (Cartosat-1). This is the longest time series of mass changes in the Himalaya. We reveal that the glaciers have been significantly losing mass since at least 1970, despite thick debris cover. The specific mass loss for 1970–2007 is 0.32 ± 0.08 m w.e. a−1, however, not higher than the global average. Comparisons of the recent DTMs with earlier time periods indicate an accelerated mass loss. This is, however, hardly statistically significant due to high uncertainty, especially of the lower resolution ASTER DTM. The characteristics of surface lowering can be explained by spatial variations of glacier velocity, the thickness of the debris-cover, and ice melt due to exposed ice cliffs and ponds.

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

<p>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.</p><p> </p><p> </p><p> </p><p>Acknowledgement:</p><p>The work was supported by Indian project no. DST/INT/RUS/RSF/P-33/G, and the Russian Science Foundation (Project 19-47-02015).</p>

scholarly journals A re-analysis of the 58 year mass-balance record of Storglaciären, Sweden

2005 ◽  
Vol 42 ◽  
pp. 389-394 ◽  
Author(s):  
Per Holmlund ◽  
Peter Jansson ◽  
Rickard Pettersson
Keyword(s):  
Time Series ◽  
Mass Balance ◽  
Measurement Methods ◽  
Summer Temperature ◽  
Quality Data ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
High Quality Data ◽  
Time Periods

AbstractThe use of glacier mass-balance records to assess the effects of glacier volume change from climate change requires high-quality data. The methods for measuring glacier mass balance have been developed in tandem with the measurements themselves, which implies that the quality of the data may change with time. We have investigated such effects on the mass-balance record of Storglaciären, Sweden, by re-analyzing the records using a better map base and applying successive maps over appropriate time periods. Our results show that errors <0.8 m occur during the first decades of the time series. Errors decrease with time, which is consistent with improvements in measurement methods. Comparison between the old and new datasets also shows improvements in the relationships between net balance, equilibrium-line altitude and summer temperature. A time-series analysis also indicates that the record does not contain longer-term (>10 year) oscillations. The pseudo-cyclic signal must thus be explained by factors other than cyclically occurring phenomena, although the record may still be too short to establish significant signals. We strongly recommend re-analysis of long mass-balance records in order to improve the mass-balance records used for other analyses.

scholarly journals Local- and Regional-Scale Forcing of Glacier Mass Balance Changes in the Swiss Alps

2021 ◽  
Vol 13 (10) ◽  
pp. 1949
Author(s):  
Saeideh Gharehchahi ◽  
Thomas J. Ballinger ◽  
Jennifer L. R. Jensen ◽  
Anshuman Bhardwaj ◽  
Lydia Sam ◽  
...  
Keyword(s):  
Mass Balance ◽  
Large Scale ◽  
Regional Scale ◽  
Atlantic Multidecadal Oscillation ◽  
Swiss Alps ◽  
Glacier Mass Balance ◽  
Landsat Images ◽  
Air Temperatures ◽  
Lake Formation ◽  
The Impact

Glacier mass variations are climate indicators. Therefore, it is essential to examine both winter and summer mass balance variability over a long period of time to address climate-related ice mass fluctuations. In this study we analyze glacier mass balance components and hypsometric characteristics with respect to their interactions with local meteorological variables and remote large-scale atmospheric and oceanic patterns. The results show that all selected glaciers have lost their equilibrium condition in recent decades, with persistent negative annual mass balance trends and decreasing accumulation area ratios (AARs), accompanied by increasing air temperatures of ≥+0.45 °C decade−1. The controlling factor of annual mass balance is mainly attributed to summer mass losses, which are correlated with (warming) June to September air temperatures. In addition, the interannual variability of summer and winter mass balances is primarily associated to the Atlantic Multidecadal Oscillation (AMO), Greenland Blocking Index (GBI), and East Atlantic (EA) teleconnections. Although climate parameters are playing a significant role in determining the glacier mass balance in the region, the observed correlations and mass balance trends are in agreement with the hypsometric distribution and morphology of the glaciers. The analysis of decadal frontal retreat using Landsat images from 1984 to 2014 also supports the findings of this research, highlighting the impact of lake formation at terminus areas on rapid glacier retreat and mass loss in the Swiss Alps.

scholarly journals Relationships Between Synoptic-Scale Atmospheric Circulation and Glacier Mass Balance in South-Western Canada During the International Hydrological Decade, 1965–74

1984 ◽  
Vol 30 (105) ◽  
pp. 188-198 ◽  
Author(s):  
Brent Yarnal
Keyword(s):  
Mass Balance ◽  
Atmospheric Circulation ◽  
Large Scale ◽  
Small Scale ◽  
Glacier Mass Balance ◽  
Western Canada ◽  
Synoptic Scale ◽  
Wave Disturbances ◽  
Synoptic Weather ◽  
The Relationship

AbstractThe relationship between synoptic-scale atmospheric circulation and glacier mass balance in the Cordillera of south-western Canada is investigated. Objective synoptic typing techniques are applied to glaciometeorological data from Peyto Glacier, Alberta, and Sentinel Glacier, British Columbia, and to climatological data from nearby weather stations. Two scales of 500 mbar synoptic weather maps are analyzed and compared. One is smaller with high-wavenumber patterns, the other is larger with more general patterns.The results demonstrate that the mass balance of Peyto and Sentinel Glaciers are related to the 500 mbar patterns. Synoptic types with cyclonic curvature favor glacier accumulation, while anticyclonic types inhibit build-up of the regional snow-pack. Ablation is suppressed by synoptic types associated with cloudy days and/or low temperatures, and is enhanced by types associated with warm, sunny days. Furthermore, findings suggest that both the accumulation and ablation of Sentinel Glacier are controlled by small-scale, high-wavenumber synoptic patterns. Conversely, Peyto Glacier accumulation is more closely associated with large-scale patterns, suggesting that high-frequency mid-tropospheric oscillations embedded within the slow-moving baroclinic zones associated with long-wave disturbances may be dampened by the rough topography of the Canadian Cordillera. Ablation is predicted poorly by both scales at Peyto.

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