Tropical Highlights

  Table of Atmospheric Indices  (Table 1)

  Table of Oceanic Indices  (Table 2)

  Time Series

  Time-Longitude Sections

  Mean & Anomaly Fields

  Appendix 1: Outside Contributions

• Tropical Drifting Buoys  A1.1
  
• Thermistor Chain Data  A1.2
  
• TAO/TRITON Array (a)  A1.3
  
• TAO/TRITON Array (b)  A1.4
  
• East Pac. SST & Sea Level  A1.5
  
• Pacific Wind stress  A1.6
  
• Surface Currents (a)  A1.7
  
• Surface Currents (b)  A1.8
  
  

Tropical Pacific Drifting Buoys

Rick Lumpkin / Mayra Pazos, AOML, Miami

DECEMBER 2008

During December 2008, 380 satellite-tracked surface drifting buoys, 91% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. Strong westward anomalies persisted from last month, indicating an acceleration of the equatorial SEC (5S-5N) of 20-40 cm/s. Further north, the NECC and NEC were close to their climatological December strengths. SSTs were close to climatological December values in the center of the basin, with warm anomalies of +0.5 to +1.5C common west of the dateline and north of 10N, a persistent pattern over the last several months of 2008. Very warm anomalies (+1.5 to +3.0C) were measured by many drifters north of 20N and west of the dateline, a pattern established in November. In the southeastern tropical Pacific, many drifters measured cold anomalies of -0.5 to -1.5C, also persisting since November.

FIGURE A1.1 a) Top: Movements of drifting buoys in the tropical Pacific Ocean. The linear segments of each trajectory represent a one week displacement. Trajectories of buoys which have lost their subsurface drogues are gray; those with drogues are blue. b) Middle: Monthly mean currents calculated from all buoys 1993-2002 (gray), and currents measured by the drogued buoys this month (black) smoothed by an optimal filter. c) Bottom: Anomalies from the climatological monthly mean currents for this month.