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 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 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.

A new working group on the Randolph Glacier Inventory (RGI) and its role in future glacier monitoring

2020 ◽  
Author(s):  
Fabien Maussion ◽  
Regine Hock ◽  
Frank Paul ◽  
Philipp Rastner ◽  
Bruce Raup ◽  
...  
Keyword(s):  
Mass Balance ◽  
Working Group ◽  
Ad Hoc ◽  
Current Status ◽  
Glacier Mass Balance ◽  
Complete Collection ◽  
Glacier Inventory ◽  
Glacier Changes ◽  
Polar Ice Sheets

&lt;p&gt;The Randolph Glacier Inventory (RGI) is a globally complete collection of digital glacier outlines, excluding the two polar ice sheets. It has become a pillar of glaciological research at global and regional scales, among others for estimates of recent and future glacier changes, glacier mass balance, and glacier contribution to sea-level rise. After its creation in 2012, the dataset&amp;#8217;s further development has been coordinated by an IACS Working Group (WG) until 2019. This new WG (2020 - 2023) expands the scope of the previous one with new and updated objectives.&lt;/p&gt;&lt;p&gt;The latest RGI version (V6) was released in July 2017, and several new glacier outline datasets have been generated by the community since then. In the past, the RGI was updated by an ad-hoc manual process, which was effective but labor-intensive. One of the main objectives of the WG is to automate this process as much as possible by incorporating RGI generation tools into the Global Land Ice Measurements from Space (GLIMS) glacier database. Furthermore, the RGI (as of version 6) needs further improvements&amp;#160; to remain useful to the wider scientific community. Examples include data quality (wrong/outdated outlines, ice divides) but also the quality and availability of glacier attributes (hypsometry, glacier type, ...). Additionally, there is a demand for consistent historic glacier outlines (e.g. from the mid-1980s or earlier) to facilitate validation of glacier evolution models or transient mass balance calculations. With this WG, we strive to continuously improve and update the RGI, as well as to lay out a long-term plan for sustainable continuation of the RGI beyond the end of this WG.&lt;/p&gt;&lt;p&gt;In this presentation, we will discuss the current status and future of the RGI, and will engage with the community to encourage participation and feedback.&lt;/p&gt;

scholarly journals Changes of the mass balance of the Garabashy Glacier, Mount Elbrus, at the turn of 20th and 21st centuries

2019 ◽  
Vol 59 (1) ◽  
pp. 5-22
Author(s):  
O. V. Rototaeva ◽  
G. A. Nosenko ◽  
A. M. Kerimov ◽  
S. S. Kutuzov ◽  
I. I. Lavrentiev ◽  
...  
Keyword(s):  
Mass Balance ◽  
Glacier Mass Balance ◽  
North Caucasus ◽  
Annual Variations ◽  
The North ◽  
Air Temperatures ◽  
European Part Of Russia ◽  
Summer Temperatures ◽  
Increasing Precipitation ◽  
Second Period

Long-term series of observations on the glacier of the southern slope of Elbrus manifest the change of two climatic periods in the highlands of the Caucasus. During the first one, relatively cold and snowy period of 1982–1997 with a small positive mass balance, the Garabashi Glacier accumulated a layer of 0.8 m.e. The second period (1998–2017) is characterized by rising summer air temperatures and increasing precipitation in the first decade, and catastrophic melting in 2010–2017. The mass balance of the glacier averaged −0.63 m w.e. yr−1, and in some years it reached −1.00 ÷ −1.50 m w.e. yr−1. In the last ten years, frequency of vast anticyclones covering the southern part of the European part of Russia and the North Caucasus increased. Summer temperatures in the Elbrus region rose to almost the level of the 1950s that was the hottest decade of the XX century. Duration of the summer season on the glaciers increased. Active melting resulted in elevation of the equilibrium line of the Garabashy Glacier by 200 m. In the main part of the glacier alimentation area, i.e. at heights of 3800–4000 m, the large parts of the firn area had disappeared, but open ice of the ablation zone had appeared. The former areas of the "warm" firn zone, where up to 35% of melt water retained within the 20‑meter firn thickness, were replaced by the firn-ice zone, and the ice discharge increased. The glacier alimentation is decreased, and its tongue retreats with increasing velocity. Rocks and entire lava ridges release from ice at different levels of the glacier. The inter-annual variations of the glacier mass balance are controlled by intensity of ablation. In the second period, the correlation coefficient of these values reached 0.97 compared to 0.82 in the first one. In total over 36 years of observations, reduction of the glacier mass during the second period resulted in loss of volume (0.05 km3 or 14%), area (0.51 km2 or 11.4%), and of ice layer (11.4 m).

Estimation of multi-period glacier mass balance in southeast Tibet using high-resolution remote sensing observations

2020 ◽  
Author(s):  
Yushan Zhou ◽  
Zhiwei Li ◽  
Xin Li ◽  
Donghai Zheng
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Tibet Plateau ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Southeastern Part ◽  
Glacier Changes ◽  
Southeast Tibet ◽  
Proglacial Lake ◽  
Basal Melting

&lt;p&gt;Glaciers in the southeastern part of the Tibet Plateau (TP) have experienced the most rapid mass loss over the High Mountain Asia. Hence, a multi-period investigation on the mass balance with focus on how glaciers evolve is imperative for better understanding of the glacier dynamics responding to climate change. Taking the Yanong glacier connected with a proglacial lake in the southeast TP as an example, we estimate the glacier mass budget at multiple-year and interannual timescales via reproducing a multiple-period DEM datasets, including KH-9 (1975), SRTM (2000), TanDEM-X (2011&lt;strong&gt;&amp;#8722;&lt;/strong&gt;2014) and SPOT-7 (2015) DEMs. We also estimate the penetration depths of both X- and C-band radar using Pl&amp;#233;iades stereo images and TanDEM-X data , which are found to be 3.2 m and 4.5 m on average in this area. The results show that the Yanong glacier has been subject to an accelerated mass loss over the past four decades (1975&lt;strong&gt;&amp;#8722;&lt;/strong&gt;2015), and the tendency of surface thinning spread from low altitudes to high altitudes. Specifically, the mass balance of the Yanong glacier changes from &lt;strong&gt;&amp;#8722;&lt;/strong&gt;0.50 &amp;#177; 0.13 m w.e./a (1974&lt;strong&gt;&amp;#8722;&lt;/strong&gt;2000) to &lt;strong&gt;&amp;#8722;&lt;/strong&gt;0.95 &amp;#177; 0.13 m w.e./a (2000&lt;strong&gt;&amp;#8722;&lt;/strong&gt;2012) and to &lt;strong&gt;&amp;#8722;&lt;/strong&gt;1.02 &amp;#177; 0.31 m w.e./a (2012&lt;strong&gt;&amp;#8722;&lt;/strong&gt;2015) at the multi-year timescale. A serious surface subsidence event is noted in areas that are about 2 km away from the glacier fronts after 2012, which are possibly caused by the internal/basal melting or collapsing. After further analyzing the evolution process of the proglacial lake, we found that the continuous disintegration of the glacier fronts may be the main reason for the accelerated mass deficit.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Climate and surface mass balance of Mocho Glacier, Chilean Lake District, 40°S

2016 ◽  
Vol 63 (238) ◽  
pp. 218-228 ◽  
Author(s):  
MARIUS SCHAEFER ◽  
JOSE LUIS RODRIGUEZ ◽  
MATTHIAS SCHEITER ◽  
GINO CASASSA
Keyword(s):  
Mass Balance ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Glacier Mass Balance ◽  
Surface Mass Balance ◽  
Climate Data ◽  
Lake District ◽  
Surface Mass ◽  
Annual Variations ◽  
Snow Drift

ABSTRACTWe present climate data, direct surface mass balance (SMB) observations and model results for Mocho Glacier in the Chilean Lake District. Mean annual temperature on a nunatak of Mocho Glacier at an elevation of ~2000 m was +2.6°C in 2006–15 and mean annual precipitation in Puerto Fuy (13 km from the glacier, at an elevation of 600 m) was 4000 mm for the same period. High interannual variations in the SMB of Mocho Glacier were observed. A simple SMB model is able to reproduce the observed annual variations in SMB, but fails to predict the steep observed mass-balance gradient. The average of the measured annual glacier mass balances in the four hydrological years 2009/10–2012/13 was −0.90 m w.e. a−1and the average modelled annual glacier mass balance 2006/07–2014/15 was −1.05 m w.e. a−1. The observed distributed ablation shows a clear altitudinal dependency, while accumulation is determined by patterns of snow drift as well. These patterns are only poorly represented in the model and have to be included in order to be able to reproduce a realistic SMB map of the glacier.

scholarly journals Trends in timing and magnitude of flow in the Upper Indus Basin

2013 ◽  
Vol 17 (4) ◽  
pp. 1503-1516 ◽  
Author(s):  
M. Sharif ◽  
D. R. Archer ◽  
H. J. Fowler ◽  
N. Forsythe
Keyword(s):  
Mass Balance ◽  
Trend Analysis ◽  
River Flow ◽  
Annual Runoff ◽  
Indus Basin ◽  
Onset Date ◽  
Trend Test ◽  
Glacier Mass Balance ◽  
Climate Trends ◽  
Upper Indus Basin

Abstract. River flow is a reflection of the input of moisture and its transformation in storage and transmission over the catchment. In the Upper Indus Basin (UIB), since high-altitude climate measurement and observations of glacier mass balance are weak or absent, analysis of trends in magnitude and timing in river flow provides a window on trends and fluctuations in climate and glacier outflow. Trend analysis is carried out using a Mann–Kendall nonparametric trend test on records extending from 1960 to 1998. High-level glacial catchments show a falling trend in runoff magnitude and a declining proportion of glacial contribution to the main stem of the Indus. Elsewhere annual flow has predominantly increased with several stations exhibiting statistically significant positive trends. Analysis of timing using spring onset date (SOT) and centre of volume date (CoV) indicated no clear trends – in direct contrast to what has been observed in western North America. There is, however, a consistent relationship between CoV and annual runoff volume. A consistently positive correlation was also found between SOT and CoV for all the stations, implying that initial snowpack conditions before the onset of runoff influence timing throughout the season. The results of the analysis presented here indicate that the magnitude and timing of streamflow hydrograph is influenced both by the initial snowpack and by seasonally varied trends in temperature. The study contributes to the understanding of the links between climate trends and variability and river runoff and glacier mass balance and runoff. The Upper Indus Basin is predominantly influenced by winter precipitation; similar trend analysis applied to summer-monsoon-dominated catchments of the central Himalaya is recommended.

scholarly journals Trends in timing and magnitude of flow in the Upper Indus Basin

2012 ◽  
Vol 9 (9) ◽  
pp. 9931-9966 ◽  
Author(s):  
M. Sharif ◽  
D. R. Archer ◽  
H. J. Fowler ◽  
N. Forsythe
Keyword(s):  
Mass Balance ◽  
Trend Analysis ◽  
River Flow ◽  
Annual Runoff ◽  
Indus Basin ◽  
Onset Date ◽  
Trend Test ◽  
Glacier Mass Balance ◽  
Climate Trends ◽  
Upper Indus Basin

Abstract. River flow is a reflection of the input of moisture and its transformation in storage and transmission over the catchment. In the Upper Indus Basin (UIB), since high altitude climate measurement and observations of glacier mass balance are weak or absent, analysis of trends in magnitude and timing in river flow provides a window on trends and fluctuations in climate and glacier outflow. Trend analysis is carried out using a Mann-Kendall nonparametric trend test on records extending from 1960 to 1998. High level glacial catchments show a falling trend in runoff magnitude and a declining proportion of glacial contribution to the main stem of the Indus. Elsewhere annual flow has predominantly increased with several stations exhibiting statistically significant positive trends. Analysis of timing using spring onset date (SOT) and centre of volume date (CoV) indicated no clear trends – in direct contrast to what has been observed in Western North America. There is, however, a consistent relationship between CoV and annual runoff volume. A consistently positive correlation was also found between SOT and CoV for all the stations implying that initial snowpack conditions before the onset of runoff influence timing throughout the season. The results of the analysis presented here indicate that the magnitude and timing of streamflow hydrograph is influenced both by the initial snowpack and by seasonally varied trends in temperature. The study contributes to the understanding of the links between climate trends and variability and river runoff and glacier mass balance and runoff. The Upper Indus Basin is predominantly influenced by winter precipitation; similar trend analysis applied to summer monsoon dominated catchments of the Central Himalaya is recommended.

scholarly journals Snowfall Variability Dictates Glacier Mass Balance Variability in Himalaya-Karakoram

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pankaj Kumar ◽  
Md. Saquib Saharwardi ◽  
Argha Banerjee ◽  
Mohd. Farooq Azam ◽  
Aditya Kumar Dubey ◽  
...  
Keyword(s):  
Mass Balance ◽  
Large Scale ◽  
Large Fraction ◽  
Water Security ◽  
High Sensitivity ◽  
Climate Impacts ◽  
Spatiotemporal Variability ◽  
Glacier Mass Balance ◽  
Meteorological Forcing ◽  
Glacier Changes

AbstractGlaciers in the Himalaya-Karakoram (HK) are critical for ensuring water-security of a large fraction of world’s population that is vulnerable to climate impacts. However, the sensitivity of HK glaciers to changes in meteorological forcing remains largely unknown. We analyzed modelled interannual variability of mass balance (MB) that is validated against available observations, to quantify the sensitivity of MB to meteorological factors over the HK. Within the model, snowfall variability (0.06 m/yr) explains ~60% of the MB variability (0.28 m/yr), implying a sensitivity of MB on snowfall to the tune of several hundreds of percent. This stunningly high sensitivity of MB to snowfall offers crucial insights into the mechanism of the recent divergent glacier response over the HK. Our findings underscore the need for sustained measurements and model representations of the spatiotemporal variability of snowfall, one of the least-studied factors over the glacierized HK, for capturing the large-scale and yet region-specific glacier changes taking place over the HK.

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