The ESA Greenland CCI project

R. Forsberg, L Sørensen, R Meister, S Simonsen, J Dall, A Kusk

(DTU-Space, Denmark) T Nagler, M Hetzenegger (ENVEO, Austria)

D Evensberget, K Hauglund, C Ås (S&T, Norway), K Khvorostovsky (NERSC, Norway) A Shepherd, A Hogg (U Leeds, UK)

S Andersen, M Langer (GEUS, Denmark) C Hvidberg (NBI, Denmark), S Svendsen (DMI, Denmark)

Ice sheet changes – satellites

Elevation measurements: •! Radar altimetry (ERS-1, ERS-2, EnviSat, CryoSat ..) •! Laser altimetry (NASA IceSat..) Measures height of the surface from space – few cm accuracy ! Measurements of gravity field changes: •! Satellite-to-satellite ranging (NASA/DLR GRACE 2002- ..) Direct measurement of mass loss ! Measurements of ice flow velocity: •! Radar interferometri (ERS, EnviSat ++ .. ) Velocity and knowledge of ice thickness Can also give mass balance, when combined with radar thickness and accumulation data

ESA Cryosat-2 (2010- ..)

NASA IceSat (2003-9)

NASA/DLR GRACE

ESA Sentinel-1 SAR

•! IV: Ice velocity – costal regions + select areas (phase 1), all ice sheet (ph. 2) •! SEC: Surface elevation changes, ERS/Envisat/CryoSat, 1991-present •! GLL: Grounding lines from SAR, main northern floating glaciers 1991-present •! CFL: Calving front locations - 20+ main outlet glaciers 1991-present •! GMB: Gravimetric mass balance from GRACE (phase 2, starting 2015)

ECV grid/line data SEC IV GLL CFL GMB - Horizontal resolution 5 km 500 m 200 m 200 m 50 km

- Temporal resolution 1 yr 1 yr (S1) 5 yr 1 yr 1 month

-! Accuracy 0.1 m/yr 20 m/yr 1 km 200 m ?

(Greenland) Ice Sheets CCI

Jakobshavn Glacier front

Coastal margin – automated processing (CIOP)

Time series of velocities - Upernavik

2007 1992

2002

2014

Sentinel-1 (ENVEO)

Greenland-wide IV coverage – first S-1 results (Enveo) (Phase 1 S-1 CCN)

28 tracks with 3 repeat acquisitions ~800 slices ~25000 bursts

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-! 29 Outlet Glaciers for CFL Analysis -! Time series of SAR data processed

(Overall 4000 ERS/ENVISAT SAR data processed)

Time series: Calving Front Locations

79 Fjord

@CCAD@?(>??ED?E(

Grounding line locations from SARin

Petermann

Ryder Hagen

79 glacier / Zachariae

Ryder Glacier – April 2014 (ESA CryoVex campaign)

Ryder Glacier – Calving front

GLL – Petermann Glacier

F/=G)((H)=(I"/;%<(>EJ>CD@?D@CCA(

K/%(L&4/#%(M(>BE(0<(;49N$"0%<%/-(4/(OK=(;4&%07*/((P"/3"$(;%$4/%"7*/(*L((Q$%R3&%(.*/%S((T*+%;(U(=%"V"&;9($4<4-(*L(WO((T"9:%;(U($"/;V"&;($4<4-(*L(WO(((((

Trends in Greenland ice sheet

5-year running means of ERS-2/Envisat height changes (composite repeat-track and cross-over algorithm, L.Sørensen, K. Khovostovsky, R. Meister)

Trends – associated errors

IV SEC

Google earth data

CryoSat 2010-14 dh/dt

zoom

in

Storstrømmen

79 Glacier Zacahariae

[m/yr]

GMB – GRACE (new ECV – CCI phase 2)

GRACE inversion: Solving for Greenland mass changes by inverting to masscons, including Canada, Svalbard, Iceland .. assuming no signal from ocean

Ice mask grid with Greenland, Canada, Svalbard and Iceland ice caps

Mass loss unit: mm water equivalent/year

GMB - Greenland mass loss (GT/yr)

-174 GT/yr (to 2010)

-279 GT/yr (from 2010)

-41 GT/yr

-24 GT/yr

Results (still) depends on algorithms/methods ! Round-Robin ongoing, joint with AIS-CCI

Joint mass loss estimation CryoSat, Envisat, GRACE

25 km resolution grid in UTM zone 23 – firn compaction model from HIRHAM A new ECV .. GRACE-FO 2017- ?

GRACE/ENVISAT solution (-224 GT/yr) GRACE/CryoSat (-240 GT/yr) GRACE solution 2010-14 (-255 GT/yr)

mm water equivalent/yr

•! NASA IceBridge 2009-19: 50 mio USD+

•! DTU-Space airborne surveys ESA CryoVEx 2003-14 National monitoring programs (PROMICE)

DTU

NASA

Validation of ECV’s: airborne data

ESA CryoVex 2012 (CryoSat validation)

-! Scanning lidar, GPS, INS -! 13 GHz Ku-band radar

SE-Greenland calving front, Køge Bugt

Greenland ice sheet CCI: •! First European SAR mapping of ice velocity at margins / basins •! Demonstrated the potential of Envisat and ERS for height changes •! Grounding lines of floating glaciers •! Time series of calving fronts – 20+ major outlet glaciers Overall mass loss from GRACE and altimetry: -175 -> -275 GT/yr Upcoming: •! Seamless SEC 1991-2017 (ERS, Envisat, CS-2, AltiKa, Sentinel-3) •! Icesheet-wide velocity mapping, Sentinel-1 mission •! Continuation of velocity time series on major outlet glaciers •! GRACE-derived mass balance

Users: •! Glaciologists, ice sheet modellers (coupled ice /climate modellers) •! National authorities and stakeholders – global sea level rise .. •! General public

Public outreach: www.polarportal.dk DMI-DTU-GEUS

Monthly mass loss (GMB) Daily ice sheet melt (met model)