North equatorial countercurrent
From Glossary of Meteorology
Revision as of 15:46, 20 February 2012 by
North Equatorial Countercurrent
(Abbreviated NECC.) A band of eastward flow between the westward flowing North and South Equatorial Currents.
The location and strength of the NECC is determined by the intertropical convergence zone (ITCZ) of the atmosphere. In the Pacific Ocean it is strongest in May–January when it flows between 5° and 10°N with 0.4–0.6 m s-1; in February–April it is restricted to 4°–6°N with speeds below 0.2 m s-1 and disappears east of 110°W. In the Atlantic Ocean the NECC is observed between 5° and 10°N with speeds of 0.1–0.3 m s-1; it is strongest during August when it flows from South America into the Gulf of Guinea and weakest in February when it is restricted to the region east of 20°W. In the Indian Ocean the NECC exists during the northeast monsoon season only and is then the only countercurrent; it is therefore mostly called the Equatorial Countercurrent. It is centered on 5°S, again the location of the ITCZ.