ENSO and Sea Surface Temperatures
Pacific in a neutral ENSO state
Westerly surface wind anomalies
The Equatorial Pacific continues in a neutral state. Positive equatorial SSTs have eased
recently, but are still higher than normal, especially in the west. The mean SOI for December was +0.9, and 0.0 for October–December. The NINO3 SST anomaly for December was about +0.6°C and NINO4 is around +0.9°C (3-month means are +0.7°C and +1.0°C, respectively). The trade winds have been near-normal or somewhat stronger than normal in the eastern Equatorial Pacific during December, but a westerly wind burst occurred in the west in early January.
Subsurface ocean temperature anomalies show a positive anomaly above 100 m depth in the east, and a weak negative anomaly in the far west.
OLR anomalies show a region of suppressed equatorial convection from the Date Line eastwards. Enhanced convection and westerly surface wind anomalies are evident over Indonesia and northern Australia, associated with a Madden-Julian Oscillation (MJO) event that developed in early December. Almost all global climate models indicate neutral conditions (with positive SST anomalies) during early 2004.
Sea surface temperature anomalies (°C) for December 2003
Mean sea surface temperatures (°C) for December 2003
