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
  
• Pacific Wind stress  A1.2
  
• Surface Currents (a)  A1.3
  
• Surface Currents (b)  A1.4
  
  

Tropical Pacific Drifting Buoys

Rick Lumpkin / Mayra Pazos, AOML, Miami

NOVEMBER 2011

During November 2011, 331 satellite-tracked surface drifting buoys, 56% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. Across the basin, drifters in the South Equatorial Current measured westward anomalies of O(20 cm/s) at 15-20S. Four drifters immediately north of the equator measured strong westward anomalies between 180-160W, but the robustness of this is difficult to determine from drifters alone due to the small sample size. Elsewhere, currents were near their climatological November values. Many drifters north of 10N and west of 160W measured SSTs warmer than normal by 0.5-3.0C, while drifters to the south and east measured SSTs at or slightly cooler (0-1.5C) than climatological November values.

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.