Causes and consequences of decadal sea level changes in the Arctic Ocean in

Transcription

1 Causes and consequences of decadal sea level changes in the Arctic Ocean in Andrey Proshutinsky and Richard Krishfield Woods Hole Oceanographic Institution, USA Igor Ashik Arctic and Antarctic Research Institute, Russia Session 4 (c) : Contemporary sea level change Thursday, July 13, 2017

2 Three types of processes dominate in the observed changes: significant trends, decadal variability and interannual changes

3 Proshutinsky, A., D. Dukhovskoy, M. Timmermans, R. Krishfield, and J. L. Bamber (2015), Arctic circulation regimes, Philos. Trans. R. Soc. A, 373, doi: /rsta

4 Sea Level data sources Monthly mean sea levels are available for 71 stations ( ) located in the Barents and Siberian Seas but temporal coverage differs significantly from station to station.

5 Proshutinsky, A. Y. (1993), Arctic Ocean Sea Level Variability, 216 pp., Gidrometeoizdat, St. Petersburg. Proshutinsky, A., V. Pavlov, and R. Bourke (2001), Sea level rise in the Arctic Ocean, Geophys. Res. Lett., 28(11), Proshutinsky, A., I. M. Ashik, E. N. Dvorkin, S. Häkkinen, R. A. Krishfield, and W. R. Peltier (2004), Secular sea level change in the Russian sector of the Arctic Ocean, J. Geophys. Res., 109, C03042, doi: /2003jc Proshutinsky, A., I. Ashik, S. Häkkinen, E. Hunke, R. Krishfield, M. Maltrud, W. Maslowski, and J. Zhang (2007), Sea level variability in the Arctic Ocean from AOMIP models, J. Geophys. Res., 112, C04S08,

6 1. Andersen O.B. and G. Piccioni (2016), Recent Arctic Sea Level Variations from Satellites , Published 20 May, Armitage, T. W. K., S. Bacon, A. L. Ridout, S. F. Thomas, Y. Aksenov, and D. J. Wingham (2016), Arctic sea surface height variability and change from satellite radar altimetry and GRACE, , Published 24 June, Carret A., J. A. Johannessen, O. B. Andersen, M. Ablain, P. Prandi, A. Blazquez, A. Cazenave (2016), Arctic Sea Level During the Satellite Altimetry Era , Published 14 November 2016

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9 Based on the data from Siberian tide-gauges: In the average rate of relative sea level rise over the seas of the Siberian Arctic has been 2.41 ± 0.8 mm/year and with GIA corrections has been 2.82 ± 0.8 mm/year. This is higher than estimation of Proshutinsky et al. (2004) for (1.85 ± 0.75) and also higher than rates of sea level rise from satellite data ~2.2 ± 1.1 mm per year estimated by Andersen O.B. and Piccioni (2016) and Armitage et al. (2016). The contribution to the observed rate of sea level rise from: - steric effect was estimated as..~1.00 mm/year (35%). - inverse barometer effect.. ~0.25 mm year (8%); - wind forcing.~0.39 mm/year (14%). - global sea level rise..~1.18 mm/year which is in the range of global sea level rise estimates between 0.8 to 3.3 mm/year in different non-arctic regions. Updated: Proshutinsky, A., I. M. Ashik, E. N. Dvorkin, S. Häkkinen, R. A. Krishfield, and W. R. Peltier (2004), Secular sea level change in the Russian sector of the Arctic Ocean

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11 Proshutinsky, A., D. Dukhovskoy, M. Timmermans, R. Krishfield, and J. L. Bamber (2015), Arctic circulation regimes, Philos. Trans. R. Soc. A, 373

12 Correlation > 0.85

13 Correlation = 0.0

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15 Summary Decadal variability of sea level changes in the Arctic Ocean is strongly regulated by wind forcing associated with sense and duration of dominating atmospheric circulation regimes. Wind-driven ice and ocean disturbances initiate local sea level changes due to Ekman transport convergence or divergence accompanied by strong steric effects (Beaufort Gyre freshening or/and freshening and warming of waters along coasts) which differ from sea level variability in other regions. In the average rate of relative sea level rise over the seas of the Siberian Arctic has been 2.41 ± 0.8 mm/year and with GIA corrections has been 2.82 ± 0.8 mm/year.

16 Based on the data from Siberian tide-gauges: The contribution to the observed rate of sea level rise from: - steric effect was estimated as..~1.00 mm/year (35%). - inverse barometer effect.. ~0.25 mm year (8%); - wind forcing.~0.39 mm/year (14%). - global sea level rise..~1.18 mm/year which is in the range of global sea level rise estimates between 0.8 to 3.3 mm/year in different non-arctic regions. Updated: Proshutinsky, A., I. M. Ashik, E. N. Dvorkin, S. Häkkinen, R. A. Krishfield, and W. R. Peltier (2004), Secular sea level change in the Russian sector of the Arctic Ocean