Seasonal variability in the continental shelf waters off southeastern Australia: Fact or fiction?

Wood, J. E.; Schaeffer, Amandine; Roughan, Moninya; Tate, Peter M.

doi:10.1016/j.csr.2015.11.006

Cited by 27 publications

(29 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Seasonal vertical temperature stratification is due to local wind forcing driving upwelling during the summer months and mixing during the winter months (Wood et al, 2016). This also influenced the seasonal in situ daily temperature ranges (averaged across each month) observed in this study (Figure 3).…”

Section: Seasonal Temperature Cyclementioning

confidence: 73%

“…This also influenced the seasonal in situ daily temperature ranges (averaged across each month) observed in this study (Figure 3). In situ daily temperature ranges were greatest (up to 4.20 • C) in the austral summer and early autumn months (January to March-months 1-3 on Figure 3), which corresponded with the strongest vertical temperature stratification (Wood et al, 2016). These larger daily temperature fluctuations in the summer and early autumn in turn correlated with greater differences between the in situ and satellite temperatures (Figures 8-10).…”

Section: Seasonal Temperature Cyclementioning

confidence: 78%

See 1 more Smart Citation

Assessing the Use of Area- and Time-Averaging Based on Known De-correlation Scales to Provide Satellite Derived Sea Surface Temperatures in Coastal Areas

et al. 2018

View full text Add to dashboard Cite

Satellite derived sea surface temperatures (SSTs) are often used as a proxy for in situ water temperatures, as they are readily available over large spatial and temporal scales. However, contamination of satellite images can prohibit their use in coastal areas. We compared in situ temperatures to SST foundation (∼10 m depth) at 31 sites inshore of the East Australian Current (EAC), the dynamic western boundary current of the south Pacific gyre, using an area averaging approach to overcome coastal contamination. Varying across-and along-shelf distances were used to area average SST measurements and de-correlation time scales were used to gap fill data. As the EAC is typically anisotropic (dominant along-shore flow) the choice of across-shelf distances influenced the correlation with in situ temperatures more than along-shelf distances. However, the "optimal" distances for both measurements were within known de-correlation length scales. Incorporating both SST area and time averaging (based on de-correlation time scales) produced data for an average of 96% of days that in situ loggers were deployed, compared to 27% (52%) without (with) area averaging. Temperature differences between the in situ data and SSTs varied depending on time of year, with higher differences in the austral summer when daily in situ temperatures can range by up to 4.20 • C. The differences between the in situ and SST measurements were, however, significant with or without area averaging (t-test: p-values < 0.05). Nevertheless, when using the area averaging approaches SSTs were only an average of ∼1.05 • C different from in situ temperatures and less than in situ temperature fluctuations. Linear mixed models revealed that latitude, distance to the coast and nearest estuary did not influence the difference between the in situ and satellite data as much as the water depth. This study shows that using de-correlation length and time scales to inform how to process satellite data can overcome contamination and missing data thereby greatly increasing the coverage and utility of SST data, particularly in coastal areas.

show abstract

Section: Seasonal Temperature Cyclementioning

confidence: 73%

Section: Seasonal Temperature Cyclementioning

confidence: 78%

Assessing the Use of Area- and Time-Averaging Based on Known De-correlation Scales to Provide Satellite Derived Sea Surface Temperatures in Coastal Areas

et al. 2018

View full text Add to dashboard Cite

show abstract

“…At a mid-shelf mooring (CH070) at 308S, Wood et al (2016) observed a seasonal cycle with a maximum in March in the upper waters, but the phase changed with depth so that near the bottom the minimum was in November. Wood et al (2016) ascribed this to wind-driven upwelling and the EAC in summer driving slope water onto the shelf and causing stratification.…”

Section: Discussionmentioning

confidence: 99%

“…Wood et al (2016) ascribed this to wind-driven upwelling and the EAC in summer driving slope water onto the shelf and causing stratification. In winter, the winds were downwelling favourable and, with vertical mixing, broke down the stratification to give relatively warm bottom waters (Wood et al 2016).…”

Section: Discussionmentioning

confidence: 99%

“…Again near 308S, Wood et al (2016) used 3 years of moored in situ temperature and velocity observations and wind measurements to show that from spring through autumn the winds were usually either north-eastward or south-westward, favourable for downwelling and upwelling respectively. The wind-driven upwelling, combined with EAC encroachments driving continental slope water onto the shelf, resulted in cool bottom waters and strong stratification during summer.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The East Australian Current, upwellings and downwellings off eastern-most Australia in summer

Cresswell

Peterson

Pender³

2017

Mar. Freshwater Res.

View full text Add to dashboard Cite

Abstract. The complex influences of the East Australian Current (EAC) and winds on the waters of the continental shelf were addressed with a ship survey, moored and drifting instruments, satellite images and wind and sea level measurements. The study revealed intrusions of continental slope water reaching the inner continental shelf when the EAC was near the shelf edge and wind stress was near zero or upwelling favourable (northerly). The process was the onshore movement of a southward flowing stream of water originally from the continental slope. One event was captured near Cape Byron and Evans Head when these waters upwelled to the surface. When the wind stress turned northward, it reversed the inner shelf current and drove downwelling. Variations in the wind stress also modulated the strength of the EAC out across the shelf to the upper slope. The strength of the EAC per se varied with a time scale of 2-3 months; these variations decreased in amplitude westward until they were undetectable at the inner shelf. The EAC had a subsurface speed maximum of up to 1.6 m s À1 at 100-150-m depth above the continental slope and was seen to accelerate with both time and distance southward along the 190-km length surveyed by the ship.

show abstract

Summertime coastal current reversal opposing offshore forcing and local wind near the middle east coast of Korea: Observation and dynamics

Park

Chang

Nam

2016

Geophysical Research Letters

View full text Add to dashboard Cite

A 6 year long current measurement at a buoy station off the middle east coast of Korea reveals an equatorward reversal of coastal current in summer opposing poleward local wind stress and offshore boundary current. The current reversal extends about 40 km offshore from the coast and is concurrent with warming and freshening of water column. Estimates of the depth‐averaged alongshore momentum balance suggest a major balance between the alongshore pressure gradient and the lateral friction. Sources of the pressure gradient for the summertime current reversal are identified as the alongshore buoyancy gradient driven by the wind curl gradient and the prevalence of warmer and lower salinity water in the north. Alongshore pressure gradient and velocity induced by the wind curl gradient are quantified, which yields the observed seasonal current reversal.

show abstract

Seasonal variability in the continental shelf waters off southeastern Australia: Fact or fiction?

Cited by 27 publications

References 42 publications

Assessing the Use of Area- and Time-Averaging Based on Known De-correlation Scales to Provide Satellite Derived Sea Surface Temperatures in Coastal Areas

Assessing the Use of Area- and Time-Averaging Based on Known De-correlation Scales to Provide Satellite Derived Sea Surface Temperatures in Coastal Areas

The East Australian Current, upwellings and downwellings off eastern-most Australia in summer

Summertime coastal current reversal opposing offshore forcing and local wind near the middle east coast of Korea: Observation and dynamics

Contact Info

Product

Resources

About