Identification

Title

Rapid eddy-Induced modification of subtropical mode water during the Kuroshio Extension System study

Abstract

From 2004 to 2006 an observational array of current- and pressure-recording inverted echo sounders (CPIES) were deployed as part of the Kuroshio Extension (KEx) System Study (KESS). KESS observed a transition from a weakly meandering ("stable") to strongly meandering ("unstable") state (Qiu and Chen). As the KEx made this transition, potential vorticity (PV) observed within the southern recirculation gyre (SRG) rapidly increased from January to July 2005. In this study, the authors diagnose eddy PV fluxes (EPVFs) in isentropic coordinates within the subtropical mode water (STMW) layer from the CPIES data to determine the role of mesoscale eddies in this rapid increase of PV. The rapid increase in PV within the SRG coincided with enhanced cross-front EPVFs and eddy PV flux convergence upstream of a mean trough in the KEx path and adjacent to the SRG. The enhanced cross-front EPVFs were the result of the formation of a cold-core ring (CCR) and the interaction of the jet with a preexisting CCR. Eddy diffusivities are diagnosed for the unstable regime with values that range from 100 to 2000 m² s⁻¹. The high eddy diffusivities during the unstable regime reflect the nature of mesoscale CCR formation and CCR-jet interaction as efficient mechanisms for stirring and mixing high PV waters from the north side of the KEx into the low PV waters of the SRG where STMW resides. This mechanism for cross-frontal exchange can explain observed increases in the STMW PV in the SRG over the 16 months of KESS observations.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7rn38v5

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2014-07-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Copyright 2014 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work.

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact