North Atlantic wave climate variability and the North Atlantic oscillation index

The authors use an altimeter derived wave climate data set, covering the period 1985-1997, to investigate inter-annual wave climate variability in the North Atlantic. The data set has been generated following careful calibration of wind/wave data from four different altimeters against in situ buoy measurements. In this way a consistent altimeter wave climate data set has been created. Statistical techniques were then used to identify the most significant modes of variability in wave height climate, and the connections between these modes and major climate patterns are investigated. The first EOF mode of variability in North Atlantic wave climate represents over 40% of the non-seasonal variability, and has a strong resemblance to the sea level pressure pattern associated with the North Atlantic Oscillation (NAO). The significance of this, and higher order modes are described in terms of such connections with the atmospheric climate, and the implications in terms of the possibility of forecasting wave climate variability are discussed.