CryoSat: ESA s Ice Mission:

Transcription

1 CryoSat: ESA s Ice Mission: 6 years in operations: status and achievements T. Parrinello CryoSat Mission Manager M. Drinkwater Mission Scientist CryoSat March 2016 sea-ice thickness

2 CryoSat: A bit of history CryoSat-1 selected as the first Earth Explorer Opportunity mission in 1999 CryoSat-1 destroyed in a launch failure in 2005 Decision to rebuild the satellite in 2006 CryoSat-2 launch: 8 April 2010 Start of operational phase: 1st November 2010 First extension: Second extension: (TBC)

3 CryoSat: The Mission Requirements Primary Mission Objectives Determination of regional and basin-scale trends in perennial Arctic sea ice thickness and mass Determination of regional and total contributions to global sea-level of the Antarctic and Greenland ice sheets Secondary Mission Objectives To make observation of the seasonal cycle and variability of Arctic and Antarctic sea ice mass and thickness To make observation of the variation in thickness of the world s ice caps and glaciers Sea Ice Ice Sheets Regional scale 10 5 Km Km 2 Ice Sheets Km 2 Average thickness of Arctic sea [ ] Credits: CPOM Credits: Helm et al., 2014 Mode SAR LRM SARIn SARIn/LRM Mission Requirement 3.5 cm/yr 8.3 cm/yr 1.0 cm/yr (130 Gt/y) Measured < 3.0 cm/yr <4.8 cm/yr <0.2 cm/yr

4 CryoSat: SIRAL State-of-art radar altimetry Fine Spatial Resolution SAR mode improves along track resolution with tenfold improvement in capacity to detect floes and leads SARIn mode improves across track resolution, designed for rugged terrain

5 CryoSat: Unusual Drifting Orbit Orbit optimised for science mission 92 degree orbit inclination to survey Arctic Sea Ice and Antarctic and Greenland ice sheets. Increased coverage = 4.6 M km sq 369 day repeat with 30 day sub cycle provides dense across track sampling and captures temporal change

6 Polar sun-synchronous orbit Courtesy A. Shepherd

7 CryoSat: Space Segment Performance Platform is fully operational with a satellite availability of 99.78% Star Trackers (STR) are degrading according to specifications but we will have new software on board from June No technical limitations to continue mission exploitation until 2025 There have been 11 collision avoidance manoeuvres since launch Payload is very stable. Degradation is as expected. All specifications have been surpassed Satellite resources are exploited to maximize scientific return and preserve life-time of all subsystem

8 CryoSat: Ground Segment Performance 2010 Excellent reliability of the ground segment well fitted to continue exploitation until SARIN Swath data sets Global L2 GDR L Product Portfolio continuously evolving taking into consideration new demands and novel applications including NRT Sea ice maps Full FBR Ocean L2i L1 & FBR* NRT Meteo Ocean FDM nd reprocessing campaign to be completed Now with freeboard High data availability of science data. Overall performance of the mission is 98.3% well above mission expectation (i.e. 94.0%) Free-and-open data disseminated to users is around 50GB/d 2014 Product evolution since launch 2013 NRT & Operational use Fast generation products (NRT) for use of meteo, marine forecasting and operational agencies (ECMWF, CNES, NOAA, DUACS, WMO GTS) Sea-ice thickness interactive maps (i.e. every 2, 14 and 30 days) available to Polar operational agencies

9 CryoSat: Validation Campaigns (CryoVEx) Multi-year ice First-year ice 15 Apr-27 May Apr Apr Apr 29 Apr-4 May 26 Apr-16 May 30 April 3 weeks start 26 Apr 29 April 4 May Apr Freeboard(m) 20 Apr-24 May Credits: DTU/AWI Radar return as function of depth within snowpack Credits: CPOM/UCL

10 CryoSat: Scientific achievements Sea-ice Providing extensive sea-ice thickness measurements (up to 88 latitude) at unprecedented accuracy improving estimations of volume trends Extending the climate time record started in early nineties, revealing complete seasonal and annual distribution of signals Credits: R. Kwok. et al Phil. Trans. R. Soc. A Credits: R. L. Tilling et alt., Nature Geoscience, 2015 and courtesy of A. Ridout Total ice 1 st year ice Multi-year ice Courtesy: M. Nicolaus et alt. AWI

11 CryoSat: Near Real Time Ice Thickness 2 days 14 days 28 days Oct Mar Tilling et al. (2016)

12 CryoSat: Scientific achievements Land ice Envisat CryoSat Wouters et alt., 2015 Providing new assessment: compared to IMBIE, mass loss from Antarctica and Greenland has increased over recent years Able to retrieve on average 70% of coastline and in key areas of high ice flow and dynamic change, five time better than any previous mission Providing first assessment of mass balance of ice caps and mountain glaciers Credits: McMillan et al., 2014 Credits: Helm et al., 2014 Courtesy: B. Wouters

13 CryoSat: Science achievements Novel applications Developing new algorithm (SWATH) to deliver SARIN measurements of fine glacier and ice sheet margin derived through CryoSat-2 interferometric altimeter. Turning an altimeter into imaging sensor! Stimulating new scientific streams for innovative applications and avenues for future research and potential operational activities Identification of grounding lines, thickness and ice flux using SAR/SARIN, identifying changes around ice sheet periphery useful for accurate estimation of ice sheet mass balance Sea-ice products available from three groups (UCL, NASA, AWI). Others in preparations (e.g. FMI, CCI) Sub-glacial lakes, providing evidence of a dynamic hydrological system beneath the Antarctic Ice Sheet at high resolution using SARIN

14 SARIN: Swath processing Swath mode interferometric altimetry Courtesy N. Gourmelen

15 CryoSat: Mountain Glacier elevation Traditional (filtered) point of closest approach Interferometric swath processing (including phase unwrapping across track) CryoSat+ Mountain Glacier Study ESA Support to Science and Exploitation CryoSat+ Mountain Glacier Study

16 CryoSat: Ice Sheet Grounding lines CS2 GLL colour scaled by distance to DInSAR Courtesy ESA STSE CryoSat+ GLITter consortium Hogg et al. (2016) - Submitted

17 CryoSat: Ice Sheet Grounding lines Larsen Ice Shelf Ronne-Filchner Ice Shelf CS2 GLL colour scaled by distance to DInSAR Courtesy ESA STSE CryoSat+ GLITter consortium - Hogg et al. (2016) - Submitted

18 CryoSat: Ice shelf thickness Courtesy ENVEO, and ESA STSE CryoSat+ GLITter consortium

19 CryoSat: Scientific achievements Beyond ice CryoSat is providing high quality data for Oceanography, Coastal Zones, Gravity, Hydrology with valuable contributions to key climate change indicators and operational services Dynamic Topography Ocean Currents Bathymetry- Gravity Surges Tsunami Coastal Zones River & Lakes Wind Speed Maps Surface EM interaction

20 CryoSat: Along-track Sea-Surface Tilt (SAR mode) Courtesy Kwok and Morrison (2016)

21 CryoSat: Ocean Dynamic Topography (SAR mode) Hydrographic stations Comparison of DOT With Dynamic Height (DH) ( ) Courtesy: Kwok and Morrison (2016)

22 CryoSat (Ku)+AltiKa(Ka-band): Snow on Sea ice Guerreiro et al. (2016) Nov April 2014 *Black contour indicates MY ice extent Arrows indicate OSI-SAF Ice drift Comparison with IceBridge (OIB) Indicate ~5cm RMSE errors

23 CryoSat: Outlook to the scientific future Better characterisation of snow load and Antarctica sea-ice Improve assessment of volume changes and mass balance of ice caps and mountain glaciers in relation to their contribution to sea level change. Better integration of CryoSat measurements in climate assimilation model. New exploitation activities focusing of SARIn interferometric measurements both over land, ocean and coastal zones Maximise the use of NRT capabilities of CryoSat for forecast communities (meteo, marine, sea-ice) New releases of ice and marine products in NETCDF format in 2017 Collaboration in operations with ICESAT-2 after 2018 is a goal

24 CryoSat: Conclusions Space and Ground Segment are in very good status and well fitted to continue mission exploitation until The operations are reliable, stable and performing. The mission is well positioned to continue delivering in future front line science as well as valuable contributions to long data records, key climate change indicators, novel applications and operational services

25 CryoSat: Securing an operational successor Recent User Requirements Workshop convened by Commission Polar and Snow Cover Workshop identified CryoSat successor as a high priority requirement SAR Interferometric Polar altimeter identified as a High Priority Mission Candidate in Copernicus Space Component Evolution Plan currently under EC-ESA (see ESA presentation of P. Silvestrin) Current studies of benefits and technical evolution towards dual freq. Ku+Ka band capability (via combinations of CryoSat+SARAL/AltiKa) campaigns