Estimation of eddy heat transport in the global ocean from Argo data

Abstract

The Argo data are used to calculate eddy (turbulence) heat transport(EHT) in the global ocean and analyze its horizontal distribution and vertical structure. We calculate the EHT by averaging all the v0, T0profiles within each 2 � �2 � bin. The velocity and temperature anomalies are obtained by removing their climatological values from the Argo “instantaneous” values respectively. Through the Student’s t-test and an error evaluation, we obtained a total of 87% Argo bins with significant depth-integrated EHTs (D-EHTs). The results reveal a positive-and-negative alternating D-EHT pattern along the western boundary currents (WBC) and Antarctic Circumpolar Current (ACC). The zonally-integrated D-EHT (ZI-EHT) of the global ocean reaches 0.12 PW in the northern WBC band and –0.38 PW in the ACC band respectively. The strong ZI-EHT across the ACC in the global ocean is mainly caused by the southern Indian Ocean. The ZI-EHT in the above two bands accounts for a large portion of the total oceanic heat transport, which may play an important role in regulating the climate. The analysis of vertical structures of the EHT along the 35 � N and 45 � S section reveals that the oscillating EHT pattern can reach deep in the northern WBC regions and the Agulhas Return Current (ARC) region. It also shows that the strong EHT could reach 600 m in the WBC regions and 1 000 m in the ARC region, with the maximum mainly located between 100 and 400 m depth. The results would provide useful information for improving the parameterization scheme in models.