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

SEPTEMBER 2008

During September 2008, 353 satellite-tracked surface drifting buoys, 85% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. Westward anomalies of 10-20 cm/s were measured by several drifters in the SEC at 140-180W, 2-8S. A few drifters in the eastern NECC revealed eastward anomalies of 20 cm/s, but the robustness of this is unclear. Elsewhere, currents were near their climatological September strength. Across most of the basin, SSTs were near or slightly cooler than their typical September values, with cold anomalies of -0.5 to -1.5C most common between 140W and the dateline. Warm anomalies of +0.5 to +3.0C were measured by many drifters in the northwest corner of the basin (west of 180, north of 10N) as seen last month.

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.