Embed Size (px)
Citation preview
Mass balance of the Greenland Ice sheet during 1900‐2012
Shfaqat Abbas Khan1, Anders A Bjørk2, Kristian K Kjeldsen2, John Wahr3, Mike Bevis3, Finn Bo Madsen1, Tonie van Dam5, Kurt Henrik Kjær2, and Niels Korsgaard2
1. Geodesy, Technical University of Denmark (DTU‐Space), Lyngby, Denmark.2. Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark.3. Department of Physics and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, United States.4. Geodetic Science, Ohio State University, Columbus, OH, United States. 5. Faculté des Sciences, de la Technologie et de la Communication, University of Luxembourg, Luxembourg, Luxembourg.
1
Outline
1. Data2. Method3. Results ‐Mass balance during 2003‐20124. Focus on Jakobshavn, Helheim and Kanger5. Mass balance during 1981 – 20126. Mass balance during 1900 – 20127. Conclusions
3
Airborne and satellite laser altimetry data(2003‐2012)
NASA´s The Airborne Topographic Mapper (ATM) 2003‐2012NASA's Land, Vegetation, and Ice Sensor (LVIS) 2007‐2012ICESat 2003‐2009
ENVISAT 2009‐2012
Annual termElv. Change rate
GrIS 2003‐2006 2006‐2009 2009‐2012Total volume loss 196.3±21.4 km3/yr 340.0±22.9 km3/yr 423.5±28.9 km3/yr
GrIS 2003‐2006 2006‐2009 2009‐2012Total volume loss 196.3 ± 21.4 km3/yr 340.0 ± 22.9 km3/yr 423.5 ± 28.9 km3/yrFirn correction 11.9 ± 3.4 Gt/yr 29.8 ± 3.4 Gt/yr ‐41.0± 3.4 Gt/yr
GrIS 2003‐2006 2006‐2009 2009‐2012Total volume loss 196.3 ± 21.4 km3/yr 339.9 ± 22.9 km3/yr 431.6 ± 28.9 km3/yrElastic correction 3.6±0.3 Gt/yr 8.2± 0.3 Gt/yr 9.9 ± 0.4 Gt/yr
GIA correction
‐0.1 km3 yr‐1 for the entire GrIS
+0.9 km3 yr‐1 For NEGIS
‐1.1 km3 yr‐1
Other GIA models like HUY2 gives similar results.
JI
GrIS 2003‐2006 2006‐2009 2009‐2012Total volume loss 196.3 ± 21.4 km3/yr 340.0 ± 22.9 km3/yr 423.6 ± 28.9 km3/yrTotal mass loss 172.4 ± 21.7 Gt/yr 292.0 ± 23.2 Gt/yr 359.8 ± 28.9 Gt/yr
Observed elevationChange rateSMB+Dynamic
SMB – RACMO2model
2003‐2006
2006‐2009
2009‐2012
Total ice loss dynamic SMB anomaly
2003‐2006
2006‐2009
2009‐2012
Total ice loss dynamic SMB anomaly
GrIS 2003‐2006 2006‐2009 2009‐2012 2003‐2012Total mass loss 172.4 ± 21.7 Gt/yr 292.0 ± 23.2 Gt/yr 359.8 ± 28.9 Gt/yr 274.7 Gt/yrSMB 41.7 Gt/yr 151.7 Gt/yr 203.5 Gt/yr 132.6 Gt/yrDynamic ice loss 129.7 Gt/yr 140.9 Gt/yr 156.3 Gt/yr 142.3 Gt/yr
GrIS 2003‐2006 2006‐2009 2009‐2012 2003‐2012Total mass loss 172.4 ± 21.7 Gt/yr 292.0 ± 23.2 Gt/yr 359.8 ± 28.9 Gt/yr 274.7 Gt/yrSMB 41.7 Gt/yr 151.7 Gt/yr 203.5 Gt/yr 132.6 Gt/yrDynamic ice loss 129.7 Gt/yr 140.9 Gt/yr 156.3 Gt/yr 142.3 Gt/yr
DTU Space - [email protected]
2010 and 2012melt anomaly
Mass loss 2003‐2012
GRACE: 262 ± 21 Gt/yrElv. data: 275 ± 26 Gt/yr
GRACE resultsfrom John Wahr
2011
GPS – land uplift
18
….after polar bear visit…
Photos provided byFinn Bo MadsenDTU, Denmark
DTU Space ‐ [email protected]
KAGA deployed by Thomas Nylen (UNAVCO) in 2006
Background shows Jakobshavn Isbræ
KAGA weekly solutions
2010, 2012 melt anomaly
GPS uplift at KAGA
Mass loss from GRACE
