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

AUGUST 2023

During August 2023, 175 satellite-tracked surface drifting buoys were reporting from the tropical Pacific. As seen in July, a small number of drifters at 100W, Eq-5N measured eastward anomalies exceeding 40 cm/s; it is unclear if this is associated with the El Nino although it is consistent. Drifters at 9-10N across the central basin exhibited westward anomalies of 10-20 cm/s, continuing the pattern that appeared in May but significantly weaker than in May-June.

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.