Observed temperature advection by tropical instability waves

For the years 2002 to 2005 it is found that this process heats the equatorial mixed layer at an annual mean rate of +0.8°C/month at 0°N, 140°W; and +2.8°C/month at 0°N, 110°W. At 0°N, 110°W, approximately 25% of the heating is contributed by zonal temperature advection, a process that has often been assumed to be negligible.

From a nine month segment of data (May 2004-February 2005), the zonal temperature advection at 2°N, 140°W has been estimated to be approximately 0.7°C/month, much larger than the equatorial value for the same time period. Thus, the data supports a recent hypothesis that tropical instability waves contribute a significant mean zonal temperature advection with off-equatorial maxima to the equatorial mixed-layer heat budget.