On 17/10/2013 TU Delft Climate Institute organised the symposium The Greenland and Antarctic ice sheets: present, future, and unknowns. This is one of the four presentations given there.
http://www.tudelft.nl/nl/actueel/agenda/event/detail/symposium-tu-delft-climate-institute-17th-october-2013/
Drinkwater ice sheet symposium - tu delft climate inst., 17 oct 2013(1)
1. “Progress and New Frontiers in
Ice Sheet Remote Sensing”
Mark R. Drinkwater
European Space Agency
ESA-ESTEC
Noordwijk, NL
2. Contents
Introduction
Recent Progress
New Frontiers
Summary
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 2
3. IPY 2007-2008: Satellite Remote Sensing
– The International Polar Year (IPY) provided an
international framework for understanding polar
processes and high-latitude climate
– IPY era spaceborne instrumentation represented a
technological leap beyond the capabilities of the IGY
– Spaceborne technology offered unique capabilities for
obtaining essential data for predictive models
– Unique opportunity to assess current state of art in
remote sensing of polar regions.
2000 Modified Antarctic Mapping Mission ice velocity model.
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 3
4. Collecting satellite polar snapshots
Aircraft and in-situ
Sounders and GPR
Systems
SSMI
MetOp
Aqua &
Terra
DMSP
AMSR-E
MODIS / ASTER
GRACE
ASCAT
AVHRR
Envisat
SMOS
ERS-2
SPOT-4
RADARSAT
HRVIR / VGT
IceSat
ASAR MERIS / A-ATSR
GOCE
ALOS
PALSAR
PRISM / AVNIR-2
wavelength (m)
Frequency (Hz)
M. Drinkwater (ESA)
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 4
6. Ice Sheet Mass Balance
Ma
Mc
Mm
Mg
Mb
δM / δa ≅ Ma − Mm − Mg
Mass change per year
Accumulation
Rate
Surface
Melt flux
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 6
Flux across
grounding
line
Where
Mc
Calving
Flux
7. Recent Progress:
Quantifying components of
the Mass budget
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 7
8. Assessing Continental Scale
Volume/Mass Changes:
δM / δa ≅ Ma − Mm − Mg
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 8
9. Greenland: Elevation (Volume)/
Mass Change
Envisat
m/yr
IceSat
m/yr
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 9
GRACE
mm/yr water eq.
Courtesy R. Forsberg et al. (ESA, CCI Project)
10. Antarctica: Elevation(Volume)/Mass Change
IceSAT (2003-08)
GRACE (2003-06)
m/yr
Envisat (2003-2012)
Courtesy T. Flament, LEGOS(2013)
•
•
•
Pritchard et al. (2009)
Velicogna (2009)
Envisat RA2 limited latitude (<82o) but all-weather; firn densification and isostatic
adjustment models needed to convert from elevation change (volume) to mass
change
IceSAT limited by cloud and discontinuous temporal sampling, and density of
cross-overs; firn densification model needed to convert to mass
GRACE – low res.; of limited use in Ant. Peninsula; Considerable residual
uncertainty due to Glacial Isostatic Adjustment (GIA)
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 10
11. ESA’s CryoSat Ice Mission: Basic Facts
– Instruments:
SIRAL (SAR/Interferometric Radar
Altimeter)
Star trackers
DORIS (Doppler Orbit and Radio
Positioning Integration by Satellite)
receiver
Laser retro-reflector
– High inclination orbit - 88°latitude
– Non sun-synchronous orbit
– SARIn mode improves across track resolution
designed for rugged ice-sheet terrain
– 369 day repeat (30 day sub cycle) gives dense
across track sampling and captures temporal
changes
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 11
Launched: April 8th 2010
http://earth.esa.int/cryosat
14. Continental Scale Melt Flux:
δM / δa ≅ Ma − Mm − Mg
& Key Surface Radiative Quantities
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 14
15. Passive Microwave: daily melt products
July 30, 2013
–
Extreme July 2012 melt, and extensive melting in 2013
–
Strong southeasterly winds across the western coast
–
Record warmest temperature of 25.9 degrees Celsius
in Maniitsoq
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 15
Weather map courtesy - DMI.
16. Ice Sheet Reflectivity (Albedo) & Melting
Before melt
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 16
After melt
17. Mass Flux across Grounding Line:
δM / δa ≅ Ma − Mm − Mg
& Ice shelf Calving Flux
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 17
18. SAR: IPY Pole-to-Coast Ice Velocity Mapping
Satellite InSAR data
Adapted from Rignot et al, Science
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 18
Courtesy: Schuechl, UCI
19. ERS-2: Kangerdlussuaq Tidewater Glacier
Calving and Retreat
Bevan et al. (2013)
• ERS-2 placed in 3d repeat orbit before deorbiting.
• Images focus on Greenland outlet glaciers (March-May 2011)
• Comparison of ERS-1, ERS-2, T-SAR-X indicate 20 year changes
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 19
20. Ice Sheet/Shelf Grounding Line
The Grounding Line is the
boundary
between
the
grounded ice and the
floating ice
It is important for:
a) the ice sheet and the ice shelves
mass budget calculation
b) numerical modelling of ice sheet
dynamics
c) Ice-ocean interactions
Grounding zone
d) oceanic tides
e) Sub-glacial environments
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 20
21. CryoSat: Ice shelf Grounding Line (GL)
Location & GL Ice Thickness
Courtesy, ENVEO
metres
University of Leeds (UK), of CryoSat+ GLITter consortium
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 21
27 metres ice shelf freeboard translates to ~220 m ice thickness.
22. Petermann Glacier: 1992 – 2011
Grounding Line Retreat & Thinning
2011
2911
Courtesy N. Gourmelen (Univ. Edinburgh)
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 22
23. Recent Progress:
Gravimetry –
**Covered by P. Ditmar
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 23
24. New Frontier:
Better resolution of timespace variability, and process
understanding
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 24
25. CryoSat: Basin-resolved rates of Ice
Sheet Elevation/Volume Change
2 years of CryoSat-2 data
m/yr
5½ years of ICESat data
ESA/University of Leeds
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 25
26. CryoSat: Sub-glacial Lakes & Basal
Hydrologic conditions
– CryoSat features a unique
capability to map changes in
Antarctica’s sub-glacial lakes in 3D.
– Sub-glacial lakes interesting in
terms of water transport and ice
dynamics beneath the surface.
– The crater shown was formed when
6 km3 of lake water drained
Malcolm McMillan et al – GRL (2013)
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 26
27. CryoSat: across-track swath elevations
• Standard CryoSat
level 2 SARIn height
product is from point
of closest approach
(POCA)
• Over sloping terrain,
SARIn echo maps a
wide swath across the
ground track, beyond
the POCA
• Swath SARIn mode
returns valid in range
0.5 to 2.0 degrees
• Elevations retrieved
where good coherence
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 27
28. Swath topographic mapping with CryoSat
Source: Noel Gourmelen and CryoSat+ CryoTop team (ESA STSE Study)
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 28
29. New Frontier:
Seeing beneath the surface
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 29
30. SMOS: Polar Ice Sheet Data
– Ice sheets used as natural, uniform
stable calibration reference site
(Dome C)
– But subtle variability observed in
signatures
– Absorption in ice is very low at Lband
– Thermal microwave emission could
originate from up to kilometres
depth.
– Potential for microwave
thermometry? (i.e. in-ice
temperature sounding)
– Lowest temperatures correspond
with subglacial lake basins
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 30
AMSR-E
C-band
v-pol
SMOS
L-band
v-pol
Courtesy L. Kaleschke
U. Hamburg
31. DomeCAir: L-band airborne Campaign Results
Tb Cold = Deep basins (counterintuitive)
Why? Normally warmer at
depth
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 31
33. Remaining Challenges
– Measure continental snow accumulation directly by remote
sensing
– Unify models for converting volume to mass (firn compaction)
in context of Surface Mass Balance efforts
– Direct, routine measurement of ice thickness at grounding
lines (P-band?)
– Tomography of in-ice layering properties using P-band (ESA
Biomass)
– Sub-surface sounding of ice profile properties (L-band and
UHF frequency range)
– Push temporal resolution of observations to sub-daily (i.e.
diurnal/tidally forced processes) at suitable spatial scales.
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 33
34. POLARIS: P-band coherent radar sounding in
Greenland
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 35
35. Summary
– IPY allow documenting state-of-art in satellite remote sensing of high
latitude regions and the cryosphere
– Satellites provide global perspective on the ice sheet processes on a range of
space and time scales (daily – decadal)
– Huge progress made in study of the mass balance (since early 1990s)
– Space observing system capabilities never better for investigating
cryosphere in a changing climate
– Legacy satellite datasets (ERS, Envisat) and the sustained met satellite
measurements support ice sheet climate research
– ESA’s new satellite missions (CryoSat, GOCE and SMOS) deliver new data
products with exciting potential
– Benefits of long satellite data time series self evident:
–
ESA’s Climate Change Initiative helping to construct fundamental
climate data records and Ice Sheet Essential Climate Variables
– ESA/EC Copernicus Sentinels coming in 2014 to sustain some capabilities
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 36
36.
37. Additional Spare Slides
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 38
38. Accessing ESA Data Products
http://earth.esa.int
Progress and Frontiers in Ice Sheet Remote Sensing | M. Drinkwater | TU Delft Climate Inst., 17 Oct 2013 | Pag. 39