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

FEBRUARY 2008

During February 2008, 288 satellite-tracked surface drifting buoys, 77% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. Westward anomalies were observed throughout most of the tropical Pacific basin, except in the latitude band 0-5N. Anomalies were 20-30 cm/s westward between 9 and 10N, a persistent feature in the last several months; they averaged 5-10 cm/s westward south of the equator. Eastward anomalies of 20 cm/s were measured by several drifters between 0-5N, 140-160W. Cold SST anomalies (-0.5 to -3.0C) persisted across the basin between 10S and 15N, while most drifters south of 10S and west of 140E measured SST near normal February values. Warm anomalies of +0.5 to +3.0C were common in the region 120E-160W, 20-30N, and spanned the Pacific basin south of 20S.

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.