1. C3S_312a Lot8: Glaciers
Frank Paul, Michael Zemp
Dept. of Geography, University of Zurich

2. Glaciers around the world

3. GLACIER DISTRIBUTION & INVENTORY

4. Main purpose of glacier monitoring
The key questions
How much glacier ice is out there?
How (fast) do glaciers change?
Glacier extent and distribution
from satellite: semi-automated mapping
one point in time, decadal repeat
Ice thickness distribution
field-based: interpolated points / models
only once for bedrock topography
Digital Elevation Model (DEM)
orthorectifcation of satellite images
drainage divides, topogr. parameters
Changes in glacier extent
area from satellite: decadal repeat
length in the field: annual repeat
Changes in thickness / volume
field-based: stakes & pits (indiv. gl.)
RS: DEM differencing (entire regions)
RS: altimetry (along repeat tracks)
Spatial inter- & extrapolation
to entire glaciers (DEM), density (field)
to entire regions (voids, hypsometry, upscaling, representativeness)
What do we need?

5. Current situat ion for area & elev. change
C3S Lot8 (glaciers) has a focus on area & elevation change
should be a complimentary & useful service based on existing approaches
lots of work is going on by other scientists, so how to add on this?
largely different approaches used for monitoring area / elev. change
Glacier area (GLIMS database)
based on classification of (optical) satellite data and digitized maps
region and approach is driven by research projects, not coordinated
results are not submitted to GLIMS/RGI after publication as scientists leave or national incentives prevent sharing (Greenland, Chile)
quality is sometimes not sufficient (debris, snow, water), in particular RGI
Elevation change (WGMS database)
field data (direct glaciological method) are regularly requested & compiled
efforts are globally coordinated, standards exist, regular publication by WGMS
geodetic methods (volume change) from two DEMs (rare) are increasingly applied but results are not forwarded (dh/dt grids or glacier specific changes)
computational methods (voids, cell size) proposed, but not standardized

6. Data processing glacier outlines
TM3
TM5
Ratio
=> Challenges
(Patagonia)
manual
work!
Mask
Outlines

7. The main bot tleneck: Debris cover
=> Coherence
=> Sentinel 2
Landsat data: USGS
Paul et al. (2015)

8. Measuring mass balance in the field
Hot steam drilling for
ablation stakes
Excavating a snow pit
Density measurement
Extra-
polated
values
Observational
Network on
Vernagtferner

9. Elevat ion changes from DEM dif ferencing
Alaska
Canada
Karakoram
Larsen et al. (2007)
Alps
Paul and Haeberli (2008)
Gardelle et al. (2013)
Berthier et al. (2010)
=> geodetic mass balance

10. The three pillars of our C3S approach
Data production within C3S
based on established methods and community needs (RGI coordination)
focus on new regions and multi-temporal outlines, reprocessing
wait for TanDEM-X DEM and new datasets (Arctic DEM, Greenland DEM)
Improve and enrich existing datasets (GLIMS/RGI/WGMS)
RGI has partly severe quality issues (snow), meta-data not consistent
GLIMS database has missing attributes (topography, length, thickness)
WGMS MB data difficult to extrapolate to regional scale (representative?)
use of RS to extend time series Abramov, delta l since LIA)
Communication and data acquisition
Reach out to scientists (conferences) & ask for their data after publication
Analyse publications and try to get them, standardization?
Use WGMS call for data and GLIMS executive board mailing lists

11. The glacier distribut ion & change service
STEP 1

12. The glacier distribut ion & change service
STEP 2
STEP 1
STEP 3

13. Step 1: Adaptors to integrate exist ing databases
WGMS database
GLIMS database
RGI

14. Step 2:Community outreach &improvements
Required
corrections
in the RGI
1985
2000
2011

15. Step 3:Integrat ion of both data streams

16. Work Breakdown Structure

17. TIMELINE Test Phase First update Second update
Continuous Data Production in WP4 from M5 to M22

18. THE TEAM

19. Where everything is based on
GCOS107
Requirements from Tender

20. The three main steps in detail