Absolute geostrophic currents in global tropical oceans

• Main Authors: Yang Lina, Yuan Dongliang
• Format: Report
• Language: English
• Published: 2016
• Subjects: SVERDRUP BALANCE; NORTH-ATLANTIC; ARGO PROFILES; CIRCULATION; PACIFIC; FIELD; COUNTERCURRENT; 24-DEGREES-N; TRANSPORTS; VELOCITY; P-vector; absolute geostrophic currents; world tropical oceans; Indian; Pacific; North Atlantic
• Online Access: http://ir.qdio.ac.cn/handle/337002/171825

A set of absolute geostrophic current (AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profiles in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin (except the North Indian Ocean, where the circulation is dominated by monsoons). The identified non-Sverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom (JEBAR) and mesoscale eddy nonlinearity.