Difference between revisions of "Talk:Sea level rise"
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==Review by Job Dronkers== | ==Review by Job Dronkers== | ||
| − | The sea level is highly variable over periods ranging from seconds to decades. Sea-level rise is the rising trend averaged over longer periods, which is observed at many coastal stations since a few centuries. Global warming due to human emissions of greenhouse gases is thought to be responsible for strengthening this trend over at least the last decades. Absolute sea-level rise is the rise of sea level independent from local vertical motion of the land surface. Relative sea-level rise is the locally observed rise of sea level with respect to the land level. It is equal to the sum of the local absolute sea-level rise and the local vertical motion of the land surface. | + | The sea level is highly variable over periods ranging from seconds to decades. Sea-level rise is the rising trend averaged over longer periods, which is observed at many coastal stations since a few centuries. Global warming due to human emissions of greenhouse gases is thought to be responsible for strengthening this trend over at least the last decades. Absolute sea-level rise is the rise of sea level independent from local vertical motion of the land surface. [[Relative sea level|Relative sea-level]] rise is the locally observed rise of sea level with respect to the land level. It is equal to the sum of the local absolute sea-level rise and the local vertical motion of the land surface. |
In a recent paper, Church and White (2011) have analysed trends in sea-level from world-wide available tide gauge records and from satellite measurements. The tide gauge data were corrected for vertical land surface motion, by using estimates for glacial isostatic adjustment (assuming that this is the major cause of vertical land surface motion). From these corrected tide gauge data, a linear trend of 1.7 ± 0.2 mm/year sea-level rise was found for the period 1900 to 1990 and a linear trend of 2.8 ± 0.8 mm/year for the period 1990 to 2009. From the satellite data a linear trend of 3.2 ± 0.4 mm/year was derived for the the same perod 1990 to 2009. From this analysis the authors conclude that there is a significant strengthening of sea-level rise during the last decades. | In a recent paper, Church and White (2011) have analysed trends in sea-level from world-wide available tide gauge records and from satellite measurements. The tide gauge data were corrected for vertical land surface motion, by using estimates for glacial isostatic adjustment (assuming that this is the major cause of vertical land surface motion). From these corrected tide gauge data, a linear trend of 1.7 ± 0.2 mm/year sea-level rise was found for the period 1900 to 1990 and a linear trend of 2.8 ± 0.8 mm/year for the period 1990 to 2009. From the satellite data a linear trend of 3.2 ± 0.4 mm/year was derived for the the same perod 1990 to 2009. From this analysis the authors conclude that there is a significant strengthening of sea-level rise during the last decades. | ||
Revision as of 16:38, 12 January 2013
Review by Job Dronkers
The sea level is highly variable over periods ranging from seconds to decades. Sea-level rise is the rising trend averaged over longer periods, which is observed at many coastal stations since a few centuries. Global warming due to human emissions of greenhouse gases is thought to be responsible for strengthening this trend over at least the last decades. Absolute sea-level rise is the rise of sea level independent from local vertical motion of the land surface. Relative sea-level rise is the locally observed rise of sea level with respect to the land level. It is equal to the sum of the local absolute sea-level rise and the local vertical motion of the land surface.
In a recent paper, Church and White (2011) have analysed trends in sea-level from world-wide available tide gauge records and from satellite measurements. The tide gauge data were corrected for vertical land surface motion, by using estimates for glacial isostatic adjustment (assuming that this is the major cause of vertical land surface motion). From these corrected tide gauge data, a linear trend of 1.7 ± 0.2 mm/year sea-level rise was found for the period 1900 to 1990 and a linear trend of 2.8 ± 0.8 mm/year for the period 1990 to 2009. From the satellite data a linear trend of 3.2 ± 0.4 mm/year was derived for the the same perod 1990 to 2009. From this analysis the authors conclude that there is a significant strengthening of sea-level rise during the last decades.
A recent model study (Slangen et al. 2012) shows that large regional differences in sea-level rise may occur, even after correcting for the effect of glacial isostatic adjustment. Major causes are:
- elastic solid Earth deformation and self-gravitation related to changes in land ice;
- changes in seawater density related to the influence of fresh water input, ocean currents and atmospheric temperature.
Each of these contributions to regional differences can dominate the local sea-level rise.
References
Church J.A. and White N.J. (2011) Sea-Level Rise from the Late 19th to the Early 21st Century. Surv.Geophys 32:585–602, DOI 10.1007/s10712-011-9119-1
Slangen A.B.A., Katsman C.A., van der Wal R.S.W., Vermeersen L.L.A. and Riva R.E.M. (2012) Towards regional projections of twenty-first century sea-level change using IPCC SRES scenarios. Clim. Dyn. 38 (5): 1191-1209, doi:10.1007/s00382-011-1057-6.
