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Recent freshening of the East Australian Current and its eddies
Author(s) -
Rykova Tatiana,
Oke Peter R.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl066050
Subject(s) - argo , eddy , climatology , precipitation , context (archaeology) , geology , salinity , oceanography , temperature salinity diagrams , current (fluid) , ocean current , turbulence , geography , meteorology , paleontology
The East Australian Current (EAC) has a relatively weak mean flow and an energetic eddy field that dominates the circulation. The properties of the mean flow have been studied in detail, but the changes in the eddy field have received little attention. We analyze Argo temperature and salinity profiles for 2005–2012 to construct a picture of the time‐mean and time‐varying properties of EAC eddies. We find that eddies and the surrounding waters of the western Tasman Sea are freshening at a rate of 0.017–0.025 practical salinity unit/yr over the top 100 m, with no significant temperature change. Consistent with the observations, fields from an eddy‐resolving ocean model show freshening, with no temperature trend. Moreover, the model results indicate that observed changes are significant in the context of the variability over the last 20 years and may be part of a multiyear (perhaps decadal) cycle. We attribute the freshening of the region to increased precipitation off Eastern Australia.