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

APRIL 2009

During April 2009, 363 satellite-tracked surface drifting buoys, 66% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. A tendency for eastward anomalies, compared to April climatology, was exhibited by some drifters in the NEC and SEC, but these anomalies were small compared to the anomalies seen in February. Most drifters away from the northwest part of the basin measured SST at or above normal March values, with anomalies of 0 to +1.5C. Warm anomalies were especially prevalent in the southeast tropical Pacific. Cold anomalies (-0.5C to -3.0C) were measured by many drifters in the northwest, north of 20N and west of 170W, a pattern persisting from earlier in 2009.

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.