Ice in a changing climate

Transcription

1 Ice in a changing climate ESA$Ice$sheets$CCI$$ Phase$1$Results$&$Contribu8on$to$Climate$ Research$ $ $ R"Forsberg,"L"Sørensen,"R"Meister,"J"Levinsen,"" J"Dall,"A"Kusk"(DTU>Space,"Denmark)" T"Nagler"(ENVEO,"Austria)" D"Evansberget,"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)"

2 Outline 1. Phase 1 results 2. Contribution to climate research 3. Future work

3 CCI Products Overview ECV Product Spatial resolution Temporal resolution Period Spatial and temporal coverage, first 3-yr phase Surface Elevation Change (SEC) 5 km grid 4 per year present All ice sheet, year running means Ice Velocity (IV) 500 m grid 1 per year* present Coastal margin (winter 1995/96 and summer 2008) Timeseries on Jakobshavn and Upernavik isbræ; North Greenland interior drainage basin (winter 1991/92) Calving Front Location (CFL) 250 m shapefile 4 per year present 19 named major glaciers (some glaciers sampled yearly, depending on data availability) Grounding Line Location (GLL) 250 m shapefile 1 per year present Petermann, Hagen and 79- Fjord Glaciers

4 CCI Products Overview Example of first phase ECV data coverage: Ice Velocity from SAR interferometry: Coastal regions, northern basin, and time Series on Jakobshavn and Upernavik Glaciers Key regions for ECV validation from independent satellite, airborne and surface data (background image: Ice velocities from SAR, from I. Joughin)

5 Ice Velocity IV prototype results from winter 1995/1996 ERS-2 SAR imagery Ice speed (km/yr) 0 1.2

6 Calving Front Location CFL prototype results from 2003 to 2010 ENVISAT ASAR imagery

7 Grounding Line Location Seaward limit of flexure GLLprototype results from 1995 ERS-1/ ERS-2 tandem phase SAR imagery Landward limit

8 Surface Elevation Change SEC prototype results from EnviSat RT + XO RA and ICESat RT LA Elevation change (m yr -1 ) -4 +1

9 Surfave Elevation Change GRACE ICESat CCI EnviSat Mass change (mwe yr -1 ) Elevation change (m yr -1 )

10 Product validation (underway) CFL IV / GLL SEC LandSat GPS Airborne RA/LA

11 Contribution to climate research IMBIE Using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment there is good agreement between different satellite methods combining datasets leads to greater certainty

12 Contribution to climate research IMBIE ESA-NASA assessment of ice sheet mass balance using all available techniques Timed to provide CCI contribution to AR5 Major community effort (26 labs, 47 PI s) Common epochs, regions, ancillary datasets Inter-comparison & ensemble First paper among top 0.01% of all cited works Features prominently in AR5

13 Contribution to climate research IMBIE Since 1992, the polar ice sheets have contributed 0.59 ± 0.20 mm year -1 to the rate of global sea level rise IPCC AR5 The total ice loss from both ice sheets for the 20 years has been 0.60 ± 0.18 mm yr -1

14 Contribution to climate research IMBIE Ice loss from Greenland was 51 Gt yr -1 over the period 1992 to 2000, and 211 Gt yr -1 over the period 2000 to 2011 IPCC AR5 The average rate has very likely increased from 34 Gt yr -1 over the period to 215 Gt yr -1 over the period Cumulative sea level contribution (mm) imbie GrIS AR5 GrIS Year 2011

15 Contribution to climate research IMBIE Ice loss from Antarctica was 48 Gt yr -1 between 1992 to 2000, and 87 Gt yr -1 between 2000 to 2011 IPCC AR5 Cumulative sea level contribution (mm) ice loss from Antarctica likely increased from 30 Gt yr -1 2 over the period , to 147 Gt yr over the period imbie AIS AR5 AIS Year 2011 There is low confidence that the rate of Antarctic ice loss has increased over the last two decades

16 Contribution to climate research Study Greenland Antarctica Combined 1990 s 2000 s 1990 s 2000 s 1990 s 2000 s imbie 51 ± ± 37 AR5 34 ± ± ± ± ± ± ± ± ± ± 95

17 Contribution to climate research Technique Greenlan d Antarctic a GRACE 10 8 Laser Altimetry 5 1 Flux 2 1 Radar 1 0

18 Contribution to climate research Cumulative sea level contribution (mm) AR5 GrIS = 30 cm imbie GrIS = 28 cm AR5 AIS = 18 cm imbie AIS = 4 cm Year

19 Future work: Antarctica CCI Antarctic CCI Scoping Study now complete. Activities undertaken include Activities includes assessment of user requirements (URD), assessment of data availability (DARD), definition of product scenarios and specifications (PSD), and assessment of system requirements and scenario feasibility (SRD) Respondent$primary$ac8vity$ Remote"sensing" Volume/mass"balance" Outlet"glacier"changes"(e.g." Ice"sheet"Monitoring" Mapping" Ice"sheet"flow"models" Sea"ice"observa^ons" Surface"mass"balance" Weather"sta^on"and" Other"(please"specify)" Atmospheric"models" Coupled"climate"models" Oceanographic"models" Decision"maker"with" 61" 55" 46" 36" 34" 25" 21" 20" 17" 14" 12" 9" 6" 77" 0" 20" 40" 60" 80" 100" >160 respondents to user survey Additional product of GRACE ice sheet mass balance specified

20 Future work: CryoSat-2 CryoSat Option to CCI Greenland Elevation rate (m/yr) Objective is to supplement ERS/EV SEC with CS2 data CS2 dataset is now sufficiently mature Team includes MSSL as additional partners with CS2 expertise

21 Future work: Sentinel 1 Sentinel-1 Option to CCI Greenland S1 aims to provide complete coverage of GrIS at least once per year Objective is to supplement IV dataset with S1 data Aim is to develop system in advance of S1 data release Primary data product will be first complete IV map of GrIS

22 Phase 1 Status Greenland CCI project started Jan 1, 2012 First prototype products released ECV production ongoing in late : - ERS altimetry (awaits REAPER reprocessing) - SAR ice velocities (two epochs, coastal region + northern basin) - Grounding lines and calving from locations of all major glaciers Validation and usefulness for ice sheet and climate modelling New CCI project add-ons: - SAR software and methodology preparation Sentinel-1 - CryoSat-2 (fill-in between EnviSat and Sentinel-3) - Antarctica scoping exersize now complete Data web site: