Tropical Highlights - October 2006

 

The pattern of tropical sea surface temperature (SST) anomalies during October 2006 featured warmer-than-average temperatures across the central and eastern Pacific (Fig. T18).  Accordingly, the SST anomalies in the Niño 4, Niño 3.4  and Niño 1+2  regions remained positive (latest values of 1.0, 0.9 and 1.2, respectively) (Table T2). Meanwhile, for the sixth month in a row, the Tahiti – Darwin SOI is negative (latest value: -1.7), primarily in response to higher than average pressure over Darwin (Table T1, Figs. T1, T19).

The oceanic thermocline, measured by the depth of the 20ºC isotherm along the equator, featured above average depth over most of the equatorial Pacific during October (Figs. T15, T16).  Consistent with these conditions, oceanic temperatures at thermocline depth were 1-2ºC above average throughout most of the equatorial Pacific (Fig. T17).

During October 2006, low-level westerly (easterly) anomalies (more than 3.0 m s-¹) were observed across the equatorial Pacific (eastern Indian Ocean ) (Fig. T20).  Suppressed convection (below-average rainfall amounts) was observed across the eastern Indian Ocean and Indonesia , while enhanced convection (above-average rainfall amounts) was seen over the equatorial Pacific, west of the Date Line (Figs. T25, T26 and E3).