The Role of the NECC in a Strong El Niño.
<p>An analysis of archived data from the NEMO 1/12th degree global ocean model shows the importance of the North Equatorial Counter Current (NECC) in the development of the strong 1982&#8211;1983 and 1997&#8211;1998 El Ni&#241;os.&#160; The model results indicate that in a normal year the coreof warm water in the NECC is diluted by the surface Ekman transport, by geostrophic inflow and by tropical instability waves. During the development of the 1982&#8211;1983 and 1997&#8211;1998 El Ni&#241;os, these processes had reduced effect at the longitudes of warmest equatorial temperatures. During the autumns of 1982 and 1997, the speed of the NECC was also increased by a stronger-than-normal annual Rossby wave and other changes in sea level in the western Pacific.&#160; The resulting increased transport of warm water by the NECC resulted in water with temperatures above 28C reaching the eastern Pacific.&#160; This appears to have been a major factor in moving the centre of deep atmospheric convection eastwards across the Pacific.</p><p>Note:&#160; This is based on the paper published in Ocean Science.&#160; An oral presentation is possible.</p>