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

DECEMBER 2015

During December 2015, 398 satellite-tracked surface drifting buoys, 69% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. As seen since August, across the basin a number of drifters measured very strong eastward anomalies between 5S and 5N. These anomalies were ~20 cm/s in December, weaker than in previous months. In the eastern Pacific, a number of drifters indicated a narrower than normal NECC. This current normally spans 4-10N, but was not present at 8.5-10N in December.

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.