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
  
• 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

JANUARY 2011

During January 2011, 461 satellite-tracked surface drifting buoys, 66% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. As seen since September 2010, the westward SEC was stronger than normal, although the anomalies were not as dramatic as in the previous month. Westward anomalies of O(10 cm/s) were present in a broad latitude range from 5-25S. Cold SST anomalies of -0.5 to -1.5C were measured by most drifters east of the dateline from 25S to 10N, with very cold anomalies of -1.5 to -3.0C common in the region 90-125W, 12-24S. In contrast, warm anomalies of +0.5 to +1.5C were measured by many drifters in the Kuroshio system.

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 1993-2010 (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.