Argo observes physical variability of the global oceans

• Argo observes physical variability of the global ocean’s upper 2 km. • US Argo partners: AOML, FNMOC, PMEL, SIO, UW, and WHOI. • UW and PMEL work together on Argo through JISAO. • UW leads on ship chartering for US Argo and deploys about 120 floats/year. • PMEL leads delayed mode salinity QC for Argo and deploys about 80 floats/year. The Argo Project Gregory C. Johnson PMEL (http: //floats. pmel. noaa. gov) Stephen Riser UW Oceanography (http: //runt. ocean. washington. edu/argo)

Black – Active, non-NIWA deployed Blue – Active, NIWA deployed Green – Planned Red - Hypothetical • UW, with JISAO assistance for NZ ship chartering, has led in South Pacific Float deployments • PMEL, with JISAO assistance (both scientific and in data management), has led in delayedmode salinity quality control. • UW and PMEL each deploy significant numbers of Argo floats (combined 25% of total effort) • UW has provided PMEL assistance with starting up a float lab. • UW and PMEL have shared staffing and pooled floats for deployment cruises. • UW and PMEL have cooperated on scientific analysis and delayed mode QC of float data.

Argo (~2003) vs. WOCE (1985 -1995) Comparisons (courtesy of Li Ren and Stephen Riser) • Argo (2003) - WOCE P 1 (47 N, 1985) salt differences on isopycnals (left) reveal sub polar -S freshening • What are the time-scales for such variations? • An isopycnal slice for the basin (26. 7 kg m-3, left) is limited by WOCE, but should be complete in the future. • This analysis gives a hint at Argo data value • Argo coverage will be basinwide and seasonal

(1) The South Pacific Eastern Subtropical Mode Water is renewed in 2004 (20 S, 110 W) (2) A salinity anomaly is injected, likely by strong evaporation (with latent cooling). (3) The salinity anomaly destabilizes the water column for double diffusion (4) Salt and temperature are diffused into the pycnocline on longer time-scales.