Identification

Title

On the seasonal cycle of the Tropical South Indian Ocean. Part I: Mixed layer heat and salt budgets

Abstract

Scale interactions in the coupled ocean and atmosphere of the tropics play a crucial role in shaping the climate state and its spatial and temporal variability. The mechanisms driving the seasonal cycles of mixed layer (ML) temperature and salinity in the tropical south Indian Ocean (TSIO) are revisited and quantified using model and observations to form a basis on which to assess the cycle's impact on shorter and longer time scale variability in the region. Budgets of ML heat for the western, central, and eastern TSIO in both model and observations indicate that seasonality in ML temperature is driven by surface heat fluxes in all regions; ocean processes, however, are essential to explain east-west differences in the cycle. In contrast, the salt budgets show that ML salinity in the west and central regions of the TSIO is driven by horizontal advection, with salinity increasing during austral winter mainly due to meridional advection, and freshening during spring-summer due to zonal advection; in the east, no single mechanism appears to dominate ML salinity seasonality. The ML seasonal cycle across the entire region is very much influenced by the basin-scale adjustment that occurs in response to monsoon winds in the eastern side of the basin. Zonal advection, as part of the adjustment process, is the key mechanism responsible for bringing fresher/colder waters from the east to the central and western TSIO during austral spring, leading to a lag in the coldestMLtemperatures in the east relative to the west/central TSIO, and effectively coupling the eastern and western TSIO beyond simply Rossby wave dynamics.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7988b36

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

2019-03-01T00:00:00Z

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

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