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

MARCH 2012

During March 2012, 258 satellite-tracked surface drifting buoys, 48% with subsurface drogues attached for measuring mixed layer currents, were reporting from the tropical Pacific. Westward anomalies of O(10-20 cm/s) were observed across most of the basin. Warm anomalies seen in the northwest basin from December to February persisted through the first half of the month but were not apparent later in the month, when a number of drifters measured cold (-0.5 to -1.5C) anomalies in the region 10-30N, 120-170E. Cold anomalies were also measured east of the dateline between the equator and 20N.

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.