Glaciers_cci

Glaciers_cci

Frank PaulUniversity of Zurich, Switzerland

The Target: Glaciers

Adequacy of the User requirements

• Is your URD adequate with GCOS/CMUG requirements?

-> Yes of course! (it is based on these documents)

• We analysed the following sources to determine the UR:• GCOS: 82, 92, 107; CEOS response, IGOS Cryosphere report

• feedback and advice from KSB (WGMS, GLIMS, CMUG)

• questionnaire among CRG and wider glaciological community

• scientific literature

• What did we learn from this analysis?• there is a strong demand to complete the global inventory (GCOS T2.1)

• strong support to also investigate elevation changes and velocity fields

• feedback from the community about ongoing work (to avoid overlap)

• created a new overview of key regions with completeness level

GCOS requirements (satellite specs.)

CMUG requirements (satellite specs.)

Some differences of Glaciers_cci

• Glaciers_cci (the area product) is based on a sensor that is in orbit since 27 years (Landsat TM)

• follow-up sensors have (ETM+) or will have the same spectral characteristics (LDCM, Sentinel 2)

• the main product depends on manual digitization by experts rather than an automated (button press) application

• key to product quality is thus communication and agreement on methodological standards and advice through tutorials

• we do produce in cooperation with the wider GLIMS community a one time snapshot of the global ice cover

• sometimes politically delicate (by location or person)

The Problem: Debris Cover

The Problem: Debris Cover

Selected key regions

Completeness Level (CL)

Did the PSD meet the needs of CRG?

• We are currently working on the PSD ...• it will provide an overview of the technical specifications, the error

characteristics and an error budget for all three products

• The short answer is: Yes, they will!• the specifications of the input data sets are largely given, whereas

the requirements for the output products (area / elev. ch. / velocity) differ

• individual CRG members or CMUG require different formats (shape files, GeoTiff, grid, netCDF, resolution, level of detail, completeness, etc.)

• depending on the needs (e.g. spatial resolution) the errors will differ

• CRG member Sven Kotlarski (IAC) will give a short overview on how the glacier area product can be used in RCMs

The integrated perspective

• How is the the integrated perspective on consistency between the ECVs addressed?

• we will follow the SoW and other CCIs as close as possible (e.g. website)

• our deliverables will have a similar structure than for all other CCIs

• we have a strong commitment to provide products that are relevant for IPCC AR5 and GTN-G

• KSB and climate/hydrological model experts are in our CRG

• we have a direct link to the Landcover_cci (validation data)

• However, the direct interaction with the other CCIs is weak

• We will be cooperative as best as possible!

Product uncertainties

• at first we will try to assess them (which is not easy)

• a number of round-robin experiments should help to provide improved guidelines for methodological data consistency

• multiple digitizings of the same glacier will give an internal accuracy measure

• comparison with independently created products (area)

• validation with higher accuracy products (LIDAR DEMs)

• application of different methods and ground truth data

• get feedback from the community, open for refinements

• we do not need ECMWF data

Using Glacier Inventory Datain Regional Climate Modelling

Sven KotlarskiInstitute for Atmospheric and Climate Science

ETH Zurich, Switzerland

A Case Study

BACKGROUND (1)

• Interactive role of glaciers in the climate system

• Direct and indirect feedback mechanisms

- Static glacier masks

- No changes in ice extent, no feedback to atmosphere

- No consideration of water volume stored

- No / simplified runoff generation

- Exception: Ice sheet models in ESM

• Poor representation in today's climate models:

BACKGROUND (2)

More sophisticated approach desirable for assessing regional climate change in

glacierized areas and for hydrological analyses in glacierized river basins

• Interactive glacierscheme for regionalclimate modelling(Kotlarski et al., Clim Dyn, 2010)

• Glacier mass balanceand area changes ona subgrid scale

TILE APPROACH

• two-layer ice body

• V-A-relation

MODEL SETUP

• 18 km x 18 km

• Forcing: ERA40 (model development and evaluation), ECHAM5-MPI-OM (scenario)

• Glacier inventory data needed for initialization of glacier areas(total area per grid cell, area-altitude distribution) and for model validation

CHANGE OF GLACIER AREA

Initialisation January 1958Initialisation January 1958

WGIWGI(collection of national (collection of national inventories, scaled to 1958)inventories, scaled to 1958)

End of simulation(December 2003)

- 23.6 %

So far: no Alpine-wide validation possible!

USING THE 2003 ALPINE GLACIER INVENTORY (1)

1.) Model validation

USING THE 2003 ALPINE GLACIER INVENTORY (2)

2.) Initializing glacier cover (here: regional climate change scenario)

- 47.4 %

- 74.2 %these scenarios are still initialized withthe simulated glacier cover in 2003!

Amplificationof warming

Te

mp

era

ture

ch

an

ge

an

om

aly

[K

]

ONGOING ...

Application of REMOGLACIER

in Himalayas / Karakorum(MPI-M Hamburg)

Implementation of glacier parameterization scheme into new Canadian RCM CRCM5(Environment Canada / UQAM Montréal)

glacier fraction derived fromGlobCover Land Cover product (on 0.05°)

To be updated bynew inventories

GLIMS inventoryto be completed

SUMMARY

• Interactive description of mountain glaciers in a state-of-the-artregional climate model

• Glacier inventory data important for both model development and model application (initialization and evaluation)

• Less important: - spatial accuracy and detail

- high temporal resolution

LOOKING FORWARD TO DATA FROM Glaciers_cci …

- completeness

- temporal consistency (snapshots)

- area-altitude distribution

• Main requirements:(URD)

GRID BOX CROSS SECTION