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

NOVEMBER 2009

During November 2009, 405 satellite-tracked surface drifting buoys, 75% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. Across the eastern part of the basin, a number of drifters in the latitude band of the NECC were transported northward by TIWs, rather than westward in the countercurrent. In addition, a few drifters in the equatorial cold tongue traveled eastward, opposite the climatological drift which is westward. As a result, very large (peaking at ~40 cm/s) eastward anomalies appear on the November map from 4S to 6N in the eastern Pacific. This El Nino pattern of eastward anomalies was associated with hot SST anomalies, measured by the drifters at +0.5C to +3.0C across much of the basin. Slightly cold SST anomalies (-0.5 to -1.5C) were observed in the southeasternmost corner of the domain.

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.