A significant increase in wave height in the North Atlantic Ocean over the 20th century

article i nfo A new 109 year numerical wind-wave hindcast is developed for the North Atlantic Ocean based on the 20th century atmospheric reanalysis (20CR). Wave results are validated directly against data originating from voluntary observing ships and satellite altimetry in the North-East Atlantic Ocean. The normalized error for yearly-mean significant wave height (Hs) is shown to be of the order of 5% for the second part of the 20th century. An indirect validation is also performed through 10 m wind speed and suggests that the accuracy of yearly-mean Hs only slightly decreases for the beginning of the 20th century. The comparison between Hs and the index of the North Atlantic Oscillation revealed that this phenomenon partly controls Hs inter-annual variability, with a positive (negative) correlation in the northeastern (southwestern) part of the study area. The analysis of model results shows an increase in Hs over the whole North Atlantic Ocean superimposed to the inter-annual variability, reaching 0.01 m.yr −1 (20 to 40% over the 20th century) north of 50°N. This increase is explained by a rise in wind speed exceeding 20% north of 50°N. The roughening in the wave climate demonstrated in this study is expected to have strong implications for the development of coastal zones and could explain the increase in erosion along the North Atlantic shorelines.

[1]  H. Tolman,et al.  Validation of a thirty year wave hindcast using the Climate Forecast System Reanalysis winds , 2013 .

[2]  G. Stelling,et al.  Development and validation of a three-dimensional morphological model , 2004 .

[3]  J. Bidlot,et al.  User manual and system documentation of WAVEWATCH III R version 4.18 , 2014 .

[4]  P. Bruun.  Sea-Level Rise as a Cause of Shore Erosion , 1962 .

[5]  J. Hurrell.  Decadal Trends in the North Atlantic Oscillation: Regional Temperatures and Precipitation , 1995, Science.

[6]  André B. Fortunato,et al.  Simulating morphodynamics with unstructured grids: Description and validation of a modeling system for coastal applications , 2009 .

[7]  R. Reynolds,et al.  The NCEP/NCAR 40-Year Reanalysis Project , 1996, Renewable Energy.

[8]  I. Losada,et al.  Variability of multivariate wave climate in Latin America and the Caribbean , 2013 .

[9]  Andrew T. Cox,et al.  A global wave hindcast over the period 1958–1997: Validation and climate assessment , 2001 .

[10]  Teleconnection Pattern Influence on Sea-Wave Climate in the Bay of Biscay , 2011 .

[11]  Lennart Bengtsson,et al.  Will Extratropical Storms Intensify in a Warmer Climate , 2009 .

[12]  G. Dodet,et al.  Wave climate variability in the North-East Atlantic Ocean over the last six decades , 2010 .

[13]  Yang Feng,et al.  North Atlantic wave height trends as reconstructed from the 20th century reanalysis , 2012 .

[14]  I. Young,et al.  Global Trends in Wind Speed and Wave Height , 2011, Science.

[15]  F. Zwiers,et al.  Trends and low frequency variability of extra-tropical cyclone activity in the ensemble of twentieth century reanalysis , 2013, Climate Dynamics.

[16]  Peter A. E. M. Janssen,et al.  Progress in ocean wave forecasting , 2008, J. Comput. Phys..

[17]  David K. Woolf,et al.  Assessment of the reliability of wave observations from voluntary observing ships: Insights from the validation of a global wind wave climatology based on voluntary observing ship data , 2003 .

[18]  Peter Ruggiero,et al.  Is the Intensifying Wave Climate of the U.S. Pacific Northwest Increasing Flooding and Erosion Risk Faster Than Sea-Level Rise? , 2013 .

[19]  S. Planton,et al.  Present Wave Climate in the Bay of Biscay: Spatiotemporal Variability and Trends from 1958 to 2001 , 2012 .

[20]  Hilde Haakenstad,et al.  A high‐resolution hindcast of wind and waves for the North Sea, the Norwegian Sea, and the Barents Sea , 2011 .

[21]  Thomas M. Smith,et al.  Daily High-Resolution-Blended Analyses for Sea Surface Temperature , 2007 .

[22]  J. Thepaut,et al.  The ERA‐Interim reanalysis: configuration and performance of the data assimilation system , 2011 .

[23]  Elizabeth C. Kent,et al.  ICOADS Release 2.5: extensions and enhancements to the surface marine meteorological archive , 2011 .

[24]  P. Ruggiero,et al.  Increasing wave heights and extreme value projections: The wave climate of the U.S. Pacific Northwest , 2010 .

[25]  L. Alexander,et al.  Reanalysis suggests long‐term upward trends in European storminess since 1871 , 2011 .

[26]  R. Preisendorfer,et al.  Principal Component Analysis in Meteorology and Oceanography , 1988 .

[27]  Tom H. Durrant,et al.  The effect of statistical wind corrections on global wave forecasts , 2013 .

[28]  P. Jones,et al.  The Twentieth Century Reanalysis Project , 2009 .

[29]  Interannual changes of the ocean wave variability in the North Atlantic and in the North Sea , 2001 .

[30]  U. Ulbrich,et al.  European storminess and associated circulation weather types: future changes deduced from a multi-model ensemble of GCM simulations , 2010 .

[31]  Sergey K. Gulev,et al.  Last century changes in ocean wind wave height from global visual wave data , 2004 .

[32]  Luigi Cavaleri,et al.  Comparison of wind and wave measurements and models in the Western Mediterranean Sea , 2007 .

[33]  U. Ulbrich,et al.  Changing Northern Hemisphere Storm Tracks in an Ensemble of IPCC Climate Change Simulations , 2008 .

[34]  Inigo J. Losada,et al.  A Global Ocean Wave (GOW) calibrated reanalysis from 1948 onwards , 2012 .

[35]  S. Brönnimann,et al.  Extreme winds at northern mid-latitudes since 1871 , 2012 .

[36]  A. Sterl,et al.  The ERA‐40 re‐analysis , 2005 .

[37]  Val R. Swail,et al.  Trends of Atlantic Wave Extremes as Simulated in a 40-Yr Wave Hindcast Using Kinematically Reanalyzed Wind Fields , 2002 .

[38]  S. Bacon,et al.  Wave climate changes in the North Atlantic and North Sea , 2007 .

[39]  P. D. Cotton,et al.  Variability and predictability of the North Atlantic wave climate , 2002 .