the sea level rise story bruno tremblay mcgill university [email protected] slide from steven...
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The Sea Level Rise The Sea Level Rise StoryStory
Bruno TremblayBruno Tremblay
McGill UniversityMcGill University
Slide from Steven Nerem – University of Colorado
Annual Global Mean Surface Temperatures
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1880 1900 1920 1940 1960 1980 2000
°C
Year [Hansen et al., 2005]
Cause of Sea Level Rise Eustatic:
Water mass added. Steric:
Salinity or temperature change Isostatic:
Change in the level of land (e.g. thermal effect, plate tectonic, compaction effect)
Withdrawal of ground water land subsidence.
Cooling of volcanic island land subsidence.
Short Term Changes in Sea Level
Diurnal-semidiurnal tides Atmospheric pressure – Winds - Evaporation-
precipitations Water density and currents El Niño/southern oscillation Water mass exchange between Arctic, Atlantic,
Pacific, Indian Oceans River runoff/floods Seiches Tsunamis Abrupt change in land level
Potential Sea Level Change Contributions
Thermal Expansion: ~1 meter
Mountain Glaciers: 0.5 meters
Greenland Ice Melt: 7 meters
Antarctic Ice Melt: 60 meters
Land Water Storage: < 0.5 meters
Greenland Ice Mass Loss from GRACE
Credit: Roger Braithwaite
362 Gt = 1 mm GMSL
-210 Gt/year = 0.6 mm/year GMSL
Antarctic Ice Mass Flux from InSAR
SLR 0.4 to 0.6 mm/yr
-114 km3/yr
-37±20 km3/yr
+33 km3/yr
-38 km3/yr+48 km3/yr
-2 km3/yr
+5 km3/yr
-22 km3/yr
-3 km3/yr
+5 km3/yr
-2 km3/yr
-56 km3/yr
-2 km3/yr
+21 km3/yr
-4 km3/yr
-33 km3/yr
-4 km3/yr
-49±20 km3/yr
[Rignot, 2005]GRACE
Sea Level Observations versus Predictions
[Rahmstorf et al., 2007]
Tide Gauge Observations
Satellite Observations
Climate Model Predictions(IPCC 3rd Assessment, 2001)
What to Expect in the Future
The IPCC 4th Assessment: 0.28 - 0.59 m by 2100
Recent study suggests higher rates (0.5 - 1.4 m by 2100).
[Rahmstorf, 2007]
1.4°
5.8°
Greenland Ice Mass Loss Estimates
Luthcke et al. [2006]Krabill et al. [2004]Zwally et al. [2005]Rignot et al. [2006]Velicogna and Wahr [2005]Ramillien et al. [2006]Chen et al. [2006]Velicogna and Wahr [2006]
[Cazenave, 2006]
362 Gt = 1 mm GMSL
Antarctic Ice Mass Loss Estimates
Rignot and Thomas [2002]Zwally et al. [2005]Davis et al. [2005]Velicogna and Wahr [2006]Chen et al. [2006]Ramillien et al. [2006]
[Cazenave, 2006]
362 Gt = 1 mm GMSL