A description of the seasonal cycle of the equatorial Atlantic from altimeter data

From 10 years of high-precision altimeter data, we examine the seasonal sea surface height (SSH) variability of the equatorial Atlantic Ocean. With the exception of the highly energetic North Brazil Current region, the seasonal cycle is the dominant source of variability in this region. As has been known from in situ observations and numerical model simulations, the seasonal adjustment to the wind stress forcing of the ocean leads to a cycle of consecutive Kelvin and Rossby waves. Now, we can also document these processes in their basinwide context by continuous high-quality observations from space. Interannual variations in the strength of the seasonal cycle seem to be connected to ENSO variability in the Pacific, but significant interannual signals unrelated to ENSO are also observed.