Tropical Highlights - January 2007

 

The pattern of tropical sea surface temperature (SST) anomalies during January 2007 featured warmer-than-average temperatures across the central and eastern Pacific (Fig. T18). Accordingly, the SST anomalies in the Niño 4 and Niño 3.4 regions remained positive (latest values of 0.8 and 0.7, respectively) (Table T2). Meanwhile, the Tahiti – Darwin SOI is negative (latest value: -1.1), primarily in response to lower-than-average pressure over Tahiti (Table T1, Figs. T1 and T19).

The oceanic thermocline, measured by the depth of the 20ºC isotherm along the equator, featured above average depth over the eastern equatorial Pacific and below average depth across the central equatorial Pacific during January (Figs. T15, T16).  Consistent with these conditions, oceanic temperatures at thermocline depth were 1-2ºC above average over the eastern equatorial Pacific and 2-3ºC below average across the central equatorial Pacific (Fig. T17).

During January 2007, low-level easterly anomalies (more than 3.0 m s-¹) were observed over the central equatorial Pacific (Fig. T20). Enhanced convection (above-average rainfall amounts) was observed across the western and central equatorial Pacific, while suppressed convection (below-average rainfall amounts) was seen over the eastern Indian Ocean , northeast Brazil and eastern central Africa (Figs. T25 and E3).

For the latest status of the ENSO cycle see the ENSO Diagnostic Discussion at: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/index.html