Identification

Title

Simulation and scaling of the turbulent vertical heat transport and deep-cycle turbulence across the equatorial Pacific cold tongue

Abstract

Microstructure observations in the Pacific cold tongue reveal that turbulence often penetrates into the thermocline, producing hundreds of watts per square meter of downward heat transport during nighttime and early morning. However, virtually all observations of this deep-cycle turbulence (DCT) are from 0 degrees, 140 degrees W. Here, a hierarchy of ocean process simulations, including submesoscale-permitting regional models and turbulence-permitting large-eddy simulations (LES) embedded in a regional model, provide insight into mixing and DCT at and beyond 0 degrees, 140 degrees W. A regional hindcast quantifies the spatiotemporal variability of subsurface turbulent heat fluxes throughout the cold tongue from 1999 to 2016. Mean subsurface turbulent fluxes are strongest (similar to 100 W m(-2)) within 2 degrees of the equator, slightly (similar to 10 W m(-2)) stronger in the northern than Southern Hemisphere throughout the cold tongue, and correlated with surface heat fluxes (r(2) = 0.7). The seasonal cycle of the subsurface heat flux, which does not covary with the surface heat flux, ranges from 150 W m(-2) near the equator to 30 and 10 W m(-2) at 4 degrees N and 4 degrees S, respectively. Aseasonal variability of the subsurface heat flux is logarithmically distributed, covaries spatially with the time-mean flux, and is highlighted in 34-day LES of boreal autumn at 0 degrees and 3 degrees N, 140 degrees W. Intense DCT occurs frequently above the undercurrent at 0 degrees and intermittently at 3 degrees N. Daily mean heat fluxes scale with the bulk vertical shear and the wind stress, which together explain similar to 90% of the daily variance across both LES. Observational validation of the scaling at 0 degrees, 140 degrees W is encouraging, but observations beyond 0 degrees, 140 degrees W are needed to facilitate refinement of mixing parameterization in ocean models.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d72r3wgh

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

2022-05-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

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name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

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