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 2010

During April 2010, 459 satellite-tracked surface drifting buoys, 73% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. Dramatic 50 cm/s westward anomalies were measured by many near-equatorial drifters at longitudes 110-150W, somewhat east of the weaker anomalies seen last month. A narrower band of eastward anomalies was measured at 4-5N, centered on 120W. Warm anomalies of +0.5C to +1.5C were common south of 10N, while cold anomalies of -0.5C to -1.5C were measured by several drifters north of this and west of 140W.

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.