Pathways of intraseasonal variability in the Indonesian Throughflow region

Schiller, A.; Wijffels, Susan E.; Sprintall, Janet; Molcard, Robert; Oke, Peter R.

doi:10.1016/j.dynatmoce.2010.02.003

Cited by 59 publications

(61 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Using the same model, Schiller et al (2010) showed that the deep-reaching sub-surface intraseasonal variability in the eastern Indian Ocean and the ITF is closely linked with equatorial wind stress anomalies in the central Indian Ocean. Other applications of previous versions of OFAM include an investigation of a series of coral bleaching events in the Great Barrier Reef (Schiller et al, 2009), an analysis of eddy dynamics in the Tasman Sea (Oke and Griffin, 2011), an analysis of fronts in the Southern Ocean (Langlais et al, 2010), an investigation of the seasonality of chlorophyll a in anti-cyclonic eddies off Western Australia (Dietze et al, 2009), and a climate downscaling (Sun et al, 2012).…”

Section: P R Oke Et Al: Evaluation Of a Near-global Eddy-resolvingmentioning

confidence: 99%

Evaluation of a near-global eddy-resolving ocean model

et al. 2013

Self Cite

View full text Add to dashboard Cite

Abstract. Analysis of the variability of the last 18 yr (1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012) of a 32 yr run of a new near-global, eddy-resolving ocean general circulation model coupled with biogeochemistry is presented. Comparisons between modelled and observed mean sea level (MSL), mixed layer depth (MLD), sea level anomaly (SLA), sea surface temperature (SST), and chlorophyll a indicate that the model variability is realistic. We find some systematic errors in the modelled MLD, with the model generally deeper than observations, which results in errors in the chlorophyll a, owing to the strong biophysical coupling. We evaluate several other metrics in the model, including the zonally averaged seasonal cycle of SST, meridional overturning, volume transports through key straits and passages, zonally averaged temperature and salinity, and El Niño-related SST indices. We find that the modelled seasonal cycle in SST is 0.5-1.5 • C weaker than observed; volume transports of the Antarctic Circumpolar Current, the East Australian Current, and Indonesian Throughflow are in good agreement with observational estimates; and the correlation between the modelled and observed NINO SST indices exceeds 0.91. Most aspects of the model circulation are realistic. We conclude that the model output is suitable for broader analysis to better understand upper ocean dynamics and ocean variability at mid-and low latitudes. The new model is intended to underpin a future version of Australia's operational short-range ocean forecasting system.

show abstract

Section: P R Oke Et Al: Evaluation Of a Near-global Eddy-resolvingmentioning

confidence: 99%

Evaluation of a near-global eddy-resolving ocean model

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…5c,d) are highly energetic throughout the water column. In both passages, there is strong variability in the mixed layer to ;100-m depth, likely because of local fluctuations in wind (Schiller et al 2010). Deeper, there are episodic positive and negative anomalies in the flow through both straits, distinctive events that persist for a few days or longer.…”

mentioning

confidence: 98%

“…The variability in the intraseasonal band (30-90 days) is particularly striking. Although some intraseasonal energy in the ITF exit passages originates from local and remote Pacific Ocean winds (Qiu et al 1999;Schiller et al 2010), the majority of the energy is forced remotely by wind anomalies over the Indian Ocean, which excite Kelvin waves that propagate eastward along the equator to the Indonesian coast and then on into the ITF region as coastally trapped Kelvin waves (Potemra et al 2002;Wijffels and Meyers 2004).…”

Section: Introductionmentioning

confidence: 99%

Vertical Structure of Kelvin Waves in the Indonesian Throughflow Exit Passages

Drushka

Sprintall

Gille

et al. 2010

Journal of Physical Oceanography

View full text Add to dashboard Cite

The subsurface structure of intraseasonal Kelvin waves in two Indonesian Throughflow (ITF) exit passages is observed and characterized using velocity and temperature data from the 2004-06 International Nusantara Stratification and Transport (INSTANT) project. Scatterometer winds are used to characterize forcing, and altimetric sea level anomaly (SLA) data are used to trace the pathways of Kelvin waves east from their generation region in the equatorial Indian Ocean to Sumatra, south along the Indonesian coast, and into the ITF region.During the 3-yr INSTANT period, 40 intraseasonal Kelvin waves forced by winds over the central equatorial Indian Ocean caused strong transport anomalies in the ITF outflow passages. Of these events, 21 are classed as ''downwelling'' Kelvin waves, forced by westerly winds and linked to depressions in the thermocline and warm temperature anomalies in the ITF outflow passages; 19 were ''upwelling'' Kelvin waves, generated by easterly wind events and linked to shoaling of the thermocline and cool temperature anomalies in the ITF. Both downwelling and upwelling Kelvin waves have similar vertical structures in the ITF outflow passages, with strong transport anomalies over all depths and a distinctive upward tilt to the phase that indicates downward energy propagation. A linear wind-forced model shows that the first two baroclinic modes account for most of the intraseasonal variance in the ITF outflow passages associated with Kelvin waves and highlights the importance of winds both in the eastern equatorial Indian Ocean and along the coast of Sumatra and Java for exciting Kelvin waves.Using SLA as a proxy for Kelvin wave energy shows that 37% 6 9% of the incoming Kelvin wave energy from the Indian Ocean bypasses the gap in the coastal waveguide at Lombok Strait and continues eastward. Of the energy that continues eastward downstream of Lombok Strait, the Kelvin waves are split by Sumba Island, with roughly equal energy going north and south to enter the Savu Sea.

show abstract

“…Yuan et al, 2011;Sprintall and Revelard, 2014). Ocean waves such as equatorial/coastal Kelvin and Rossby waves drive interannual variation of the ITF with an amplitude of roughly ±3 Sv (Schiller et al, 2010). The variations of South China Sea Throughflow (SCST) can also affect the ITF transport, since SCST returns the Pacific via the Makassar Strait and then partly block the Makassar Strait Throughflow which accounts for 80% of total ITF volume transport (Qu et al, 2005).…”

Section: Mechanism Of Multi-decadal Variations Of the Tropical Sio Sumentioning

confidence: 99%

Multi-decadal variations of the South Indian Ocean subsurface temperature influenced by Pacific Decadal Oscillation

Zhou

Alves

Marsland

et al. 2017

Tellus A: Dynamic Meteorology and Oceanography

View full text Add to dashboard Cite

Over recent decades, a strong subsurface cooling trend in the South Indian Ocean (SIO) occurred, despite a continuous sea surface warming. Previous studies suggest this long-term (around 1960-2000) cooling trend is mainly driven by remote Pacific atmospheric forcing or local Indian Ocean (IO) forcing. This study reveals that the dominant driver of the SIO subsurface cooling trend in different periods is closely related to the phase of Pacific Decadal Oscillation (PDO). Our results suggest that the local IO wind forcing is responsible for the majority of the subsurface cooling trend and overwhelms a weak warming trend induced by the remote tropical Pacific wind forcing during the negativephase period of PDO during 1960-76. However, this situation reverses during the PDO positive-phase period during 1977-98. Our analysis suggests that the PDO strengthens/weakens the tropical Pacific trade winds during negative/ positive phase periods. Furthermore, the multi-decadal variations in the western Pacific induced by PDO impact the SIO subsurface temperature via baroclinic Rossby waves.

show abstract

Pathways of intraseasonal variability in the Indonesian Throughflow region

Cited by 59 publications

References 29 publications

Evaluation of a near-global eddy-resolving ocean model

Evaluation of a near-global eddy-resolving ocean model

Vertical Structure of Kelvin Waves in the Indonesian Throughflow Exit Passages

Multi-decadal variations of the South Indian Ocean subsurface temperature influenced by Pacific Decadal Oscillation

Contact Info

Product

Resources

About