Aiming to produce an engineering-quality, homogeneous, long-term wind and data base for assessment of the climate, trends and variability of ocean waves in the North Atlantic, the Climate Research Branch of the Meteorological Service of Canada has recently finished an intensive reanalysis of surface winds over the North Atlantic basin. The reanalyzed wind fields were then used to drive a third generation ocean wave model (OWI 3G) to produce a 40-year numerical hindcast of ocean waves in the North Atlantic for 1958-1997 (Swail and Cox, 2000; Cox et al., 2001). This wave hindcast was analyzed by Wang and Swail (2001) for trends in the seasonal extremes of Significant Wave Height (SWH). Their analysis reveals that there have been statistically highly significant increases in SWH extremes in the northeast North Atlantic in winter (JFM), and in the region off the North American coast in summer (JAS) and fall (OND).

Just like the wind and wave reanalysis, ocean wave climate change scenarios are useful information for the operation, design/planing of coastal and off-shore industries. In this study we construct wave climate change scenarios for the North Atlantic ocean, using the possible future climates projected by the CGCM2 simulations of the Canadian Centre for Climate Modelling and Analysis. We first use statistical approaches to relate the observed sea level pressure to ocean wave statistics (e.g., means, extremes, distribution parameters of wave time series) derived from the 40-year wave hindcast. Then, we use the statistical relationship to project possible future changes in the wave statistics given the GCM simulated possible future atmospheric conditions under different anthropogenic forcing scenarios.

References

1. Swail, V.R. and A. T. Cox, 2000: On the use of NCEP/NCAR reanalysis surface marine wind fields for a long term North Atlantic wave hindcast. J. Atmos. Ocean. Technol., 17, 532-545.

2. Cox, A.T., V.J. Cardone and V.R. Swail, 2001: On the use of in situ and satellite wave measurements for evaluation of wave hindcasts. In : Guide to the Applications of Marine Climatology, Part II. World Meteorological Organization, Geneva, Switzerland. (In press).

3. Wang, X. L. and V. R. Swail, 2001: Trends of Atlantic wave extremes as simulated in a 40-year wave hindcast using kinematically reanalyzed wind fields. (Submitted to J. Clim. )