1. Estimation of mass balance from snowline monitoring in Central Asia
Martina Barandun (1), Matthias Huss (1, 2), Kathrin Naegeli (1, 3), Robert McNabb (4), Pete Bunting (3), Etienne Berthier (5), Martin Hoelzle (1)
(1) Department of Geoscience, University of Fribourg, Fribourg, Switzerland
(2) Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland,
(3) Centre for Glaciology, Department of Geography and Earth Sciences, Aberystwyth University, Wales, UK
(4) Department of Geoscience, University of Oslo, Norway,
(5) CNRS, LEGOS, University of Toulouse, Toulouse, France
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

2. region-wide estimate of annual glacier mass balance for Central Asia
Discussion
Introduction
Methods
Results
Conclusion
region-wide estimate of annual glacier mass balance for Central Asia
geodetic Method
+ good spatial resolution
restricted temporal resolution
glaciological Method
+ good temporal resolution
restricted spatial resolution
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
mass balance modelling constrained with transient snowline observations
+ good temporal resolution
+ applicable on extended, remote areas
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

3. combining different approaches
Discussion
Introduction
Methods
Results
Conclusion
combining different approaches
simple accumulation and temperature-index model  calibration with TSL observations
validation with glaciological measurements and high-resolution geodetic mass changes
region-wide geodetic mass balances (ASTER DEMs) to constrain snowline based, modelled mass balances
 annual surface mass balance time series for all glaciers > 2km2
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

4. study site BARKRAK BATYSH SOOK
Discussion
Introduction
Methods
Results
Conclusion
study site
BARKRAK
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
BATYSH SOOK
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

5. glaciological measurements
Discussion
Introduction
Methods
Results
Conclusion
glaciological measurements
geodetic method
+ good spatial resolution
restricted temporal resolution
glaciological method
+ good temporal resolution
restricted spatial resolution
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
mass balance modelling constrained with transient snowline observations
+ good temporal resolution
+ applicable on extended, remote areas
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

6. glaciological measurements
Discussion
Introduction
Methods
Results
Conclusion
glaciological measurements
Glacier No. 354 (6.4 km2)
Golubin
Glacier (5.5 km2)
Abramov Glacier (24 km2)
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
Barkrak
Glacier
(2.4 km2)
Batysh Sook Glacier /
Suyok Zapadniy (1.2 km2)
Hoelzle et al. (2017)
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

7. mass balance model constrained with TSL
Discussion
Introduction
Methods
Results
Conclusion
mass balance model constrained with TSL
geodetic method
+ good spatial resolution
restricted temporal resolution
glaciological method
+ good temporal resolution
restricted spatial resolution
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
mass balance modelling constrained with transient snowline observations
+ good temporal resolution
+ applicable on extended, remote areas
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

8. mass balance model constrained with TSL
Discussion
Introduction
Methods
Results
Conclusion
mass balance model constrained with TSL
accumulation and melt model calibration with transient snowline observations
step 1: a precipitation correction factor optimized by fitting the modelled winter snow accumulation to agree with the modelled cumulative melt
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
modified after Huss et al. (2013)
step 2: DDFs are optimized by comparing
modelled and observed SCAF   
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

9. automatic classification of TSL
Discussion
Introduction
Methods
Results
Conclusion
automatic classification of TSL
looking for abrupt albedo change within elevations band of all grid cells that are classified «unclear»
Secondary surface type evaluation
albedo < 0.25 = ice
albedo > 0.55
= snow
0.25 > albedo < 0.55 = unclear
Primary surface type evaluation
Albedo
Shortwave broadband albedo derived based on narrow-to-broadband formula by Liang 2000:
Final surface type classification
critical albedo = where rate of change in albedo is greatest
Albedo
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
albedo based classification
Naegeli et al., (2018)
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

10. gecadal geodetic mass balance
Discussion
Introduction
Methods
Results
Conclusion
gecadal geodetic mass balance
geodetic method
+ good spatial resolution
restricted temporal resolution
glaciological method
+ good temporal resolution
restricted spatial resolution
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
mass balance modelling constrained with transient snowline observations
+ good temporal resolution
+ applicable on extended, remote areas
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

11. ASTER derived geodetic mass balance
Discussion
Introduction
Methods
Results
Conclusion
ASTER derived geodetic mass balance
all available ASTER scenes with cloud cover lower than 50% are processed
elevation change is calculated for all scene-combinations with time difference higher than 5 years and overlap of 50%
range of geodetic mass balances summarized for reference period based on annual variability of regional glaciological measurements
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
using MicMAC ASTER (MMASTER)
(Girod et al., 2017)
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

12. combining the different approaches
Discussion
Introduction
Methods
Results
Conclusion
combining the different approaches
geodetic method
+ good spatial resolution
restricted temporal resolution
glaciological method
+ good temporal resolution
restricted spatial resolution
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
mass balance modelling constrained with transient snowline observations
+ good temporal resolution
+ applicable on extended, remote areas
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

13. snowline-constrained model - validation
Discussion
Introduction
Methods
Results
Conclusion
snowline-constrained model - validation
reconstructed mass balance for 3 Kyrgyz glaciers with snowline-constrained mass balance model for the past 1-2 decades
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
Barandun et al., in review
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

14. snowline-constrained model - validation
Discussion
Introduction
Methods
Results
Conclusion
snowline-constrained model - validation
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
model performance  evaluated with direct glaciological measurements / high-resolution geodetic mass balance
for three selected glaciers in Central Asia
Barandun et al., in review
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

15. ASTER based elevation changes - validation
Discussion
Introduction
Methods
Results
Conclusion
ASTER based elevation changes - validation
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
elevation change from high-resolution images from 2003 to 2012 (QuickBird – GeoEye)
elevation change from ASTER images from 2003 to 2012
difference
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

16. geodetic mass balance for a reference period 2004-2012
Discussion
Introduction
Methods
Results
Conclusion
geodetic mass balance for a reference period
comparison between Bgeod from high-resolution and ASTER images:
RMSE = 0.26 m w.e. yr-1
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
No. 354
all possible combinations of ASTER scenes (period > 5 years) summarized for reference period
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

17. mass balance comparison for selected glaciers in m w.e. yr-1
Discussion
Introduction
Methods
Results
Conclusion
comparison to other studies
mass balance comparison for selected glaciers in m w.e. yr-1
from 2004 to 2012
Glacier
Bsnl
Bglac/mod
Bgeod_aster
Bgeod_HR
Abramov
-0.28 ±0.35
-0.64 ±0.50
-0.36 ±0.32
-0.39 ±0.16 (Barandun et al., in review)
Golubin
-0.42 ±0.35
-0.40 ±0.36
-0.22 ±0.33
-0.30 ±0.37 (Barandun et al., in review)
No. 354
-0.25 ±0.31
-0.40 ±0.10
-0.61 ±0.30
-0.48 ±0.10 (Barandun et al., in review)
Urumqi
-0.72 (WGMS)
-0.39 ±0.13
-0.64 ± (Wang et al.2014)
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
Region
Bsnl
Baster
Bmod ( )
(Farinotti et al. 2015)
Bgeod ( )
(Brun et al. 2017)
North Tien Shan ?
-0.24±0.37
-0.33±0.16 to -0.49±0.22
West Tien Shan
-0.26±0.30
East Tien Shan
-0.40±0.41
-0.41±0.28
Central Tien Shan
-0.20±0.33
-0.31±0.32
Pamir Alay
-0.11±0.27
-0.04±0.07
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

18. comparison to other studies
Discussion
Introduction
Methods
Results
Conclusion
comparison to other studies
Comparison of mass balance constrained with transient snowline observations to other studies for three Benchmark glaciers and region-wide studies
Was kann man tun, wenn es zu wenige SL Beobachtungen gibt um gute rating curve herzuleiten? => idealized curve. Ausserdem musst Du betonen (vorne), dass die Kurve (im Normalfall) jährlich hergeleitet wird, kommt momentan nicht raus
Outlook: Region-wide estimate based on mass balance model constrained with transient snowline observations
SNL-model for individual glacier = this study
Barandun et al., in review
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

19. conclusions and outlook
Discussion
Introduction
Methods
Results
Conclusion
conclusions and outlook
first results of snowline-constrained model
region-wide decadal geodetic mass balance from ASTER data for a reference period
validation through in situ measurements and geodetic mass balance based on high-resolution DEMs
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

20. conclusions and outlook
Discussion
Introduction
Methods
Results
Conclusion
conclusions and outlook
Next step: region-wide application of snowline-constrained model to derive annual mass balances
automatically classified snowlines on a large amount of Landsat images
 reliable annual SMB time series coupled to decadal geodetic mass balance for remote regions
No. 354:
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
M.Barandun, WGMS Expert Workshop 2018 on Regional Mass Balance Estimates

21. Thank you for your attention
Photo: L. Sold
Thank you for your attention
Introd kyrgyzstan : old monitoring  aprupt breakdown  reestablishment in 2011
Motiviation: underrepresented in WGMS
Need of monitoring: glacier retreat patter/climate influence/hydorlogical porpose
Many Thanks to all people contributing to this work
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