1. Climate regime and Sensitivity of Asian
Glaciers Revealed by GAMDAM Glacier
Inventory
ClimDev 14 Jan. 2015
Akiko Sakai and Koji Fujita
Nagoya University
GAMDAM:
Glacier Area Mapping for Discharge in Asian Mountains
2. 1st Motivation <glacier inventory>
GlacierSea level change Water resource
Glacier
volume change
Glacier
Inventory
Kääb et al., 2012
Gardner et al., 2013
Discharge
from glacier
Karser et al., 2010
Immerzeel et al., 2010
Mass balance profile
Area-altitude
distribution of glaciers
Altitude
Positive
Equilibrium
Negative
- +
3. Important parameter to
estimate river runoff
BUT Gridded data observed data
2nd Motivation <precipitation in mountain>
at Karabat kak Glacier
Observation
Sakai et al. (in prep.)
4. Purpose
Glacier
1. Create quality controlled glacier inventory
2. Estimate precipitation over glaciers
using an ELA concept
to reveal climate regime
Target region:
High Mountain Asia
Glacier Area Mapping for Discharge in Asian Mountains
5. Coverage & Data source
Manual delineation
• Data source
– LANDSAT (USGS)
(1999-2003)
226 path-row
356 scenes
– Thermal band
– Contour line
– Slope
– Basin polygon
– Google Earth
• Delineation tests
• Two years, total 10 persons
• 82,776 glaciers in total
no glacier
Nuimura et al. (2014TCD, in 2nd review)
6. GAMDAM vs. ICIMOD
HKH region Area
(×103 km2)
GAMDAM 40.3
ICIMOD 40.6
Each 0.5×0.5 degree grid cell
Consistent each other
Nuimura et al. (2014TCD, in 2nd review)
7. Median elevation of GAMDAM
GAMDAM Glacier Inventory
& ASTER-GDEM2
Glacier Inventory of China
(Shi, 2008)
Nuimura et al. (2014TCD, in 2nd review)
8. Median Altitude vs. Observed ELA
Mass balance at median elevation = 0 (in the past few decades)
Braithwaite & Raper (2009)
ELA observation at 10 glaciers
Dyurgerov (2002); Fujita & Nuimura (2011)
Balanced budget ELA = Median glacier elevation ELA: equilibrium line altitude
mass balance =0
rmse = 71
bias = + 2.8
GAMDAM glacier inventory + GDEM2
Observation
Sakai et al. (2014TCD, in revision)
9. Calculating Optimized Precipitation at ELA
GAMDAM Glacier Inventory
Input data
<ERA-Interim >
Air temperature (level)
Solar radiation(surface flux )
Wind speed (surface flux 10m)
Relative humidity (surface)
precipitation=APHRODHITE ×Ap
Mass balance model
Fujita & Ageta (2000) (energy balance model)
Yatagai et al. (2009, 2012)
Sakai et al. (2014TCD, in revision)
12. Validation –Winter Balance-
Observed data at 12 glacier
Dyurgerov (2002)
1979-2004
Validated by observed winter balance
rmse to observation
Aphrodite snow = 503 mm
Optimized snow = 292 mm
Sakai et al. (2014TCD, in revision)
14. Summary & Perspectives
A novel GAMDAM glacier inventory
Optimized precipitation at ELA
Spatially heterogeneous glacier response
over the High Mountain Asia
• The GAMDAM will be provided/merged to
Randolph v5 within this year
Contact: Akiko Sakai <shakai@nagoya-u.jp>
• Contributions of Sensitivity, dAT and dPR to
changes in glaciers
