Holocene sea level and climate variability on the Great Barrier Reef, Australia

Weather and currents at eight sites were measured and drogue trajectories obtained in July 1979 at Britomart Reef, a middle reef located at 18�16'S.,146� 38'E. in the central region of the Great Barrier Reef province. The longest current records (3 weeks) were obtained at two sites in passes between the Coral Sea and the Great Barrier Reef Lagoon where westerly currents modulated by tides were observed. Analysis of residuals also showed the importance of wind-driven secondary circulation. Non-tidal sea-level oscillations were very small. Shorter current records (1-10 days) at six sites in the lagoon and on the reef flat showed a predominant northerly flow, also modulated by tides and wind. A residual anticlockwise water circulation existed in the lagoon where flushing was controlled more by winds than by tides. The rise in sea level over the reef flat as a result of waves breaking was negligible. Temperature differences between air and water accounted for the cooling of the water column during the expedition. Constant south-east trade winds were experienced at the reef, while on land the wind was weaker. more variable, and often dominated by land-sea breezes.

Download Full-text

Climate Variability and Change on the Great Barrier Reef

Oceanographic Processes of Coral Reefs ◽

10.1201/9781420041675.ch17 ◽

2000 ◽

pp. 269-300 ◽

Cited By ~ 5

Author(s):

Janice Lough

Keyword(s):

Climate Variability ◽

Great Barrier Reef ◽

Barrier Reef ◽

Climate Variability And Change

Download Full-text

Water circulation and shelf waves in the northern Great Barrier Reef lagoon

Marine and Freshwater Research ◽

10.1071/mf9810721 ◽

1981 ◽

Vol 32 (5) ◽

pp. 721 ◽

Cited By ~ 25

Author(s):

E Wolanski ◽

B Ruddick

Keyword(s):

Great Barrier Reef ◽

Sea Level ◽

Low Frequency ◽

Current Data ◽

Barrier Reef ◽

Sea Levels ◽

The North ◽

Level Data ◽

Shelf Wave ◽

Salinity Water

Currents and sea levels were measured at a number of locations in the Great Barrier Reef (GBR) lagoon from about 10 to 13� S., during the period October-December 1979. A strong non-tidal, low-frequency modulation of all sea-level and current data was found. The currents nearshore were driven northward by the wind, and then at least partially blocked by the dense network of reefs to the north of 10� s. The water then flowed southward in deeper water adjacent to the reef, driven by a longshore pressure gradient. The low- frequency sea-level data, though not the current records, showed northward phase propagation at speeds characteristic of a first-mode shelf wave trapped in the lagoon between the shore and the reef. Data are presented revealing the intrusion of low-salinity water, through Bligh Entrance, in the GBR lagoon, as a result of river discharges in the Gulf of Papua. It is suggested that low-frequency longshore currents may periodically flush these river plumes from the GBR lagoon and enhance interaction between reefs. In the Coral Sea in front of reef passages, the large horizontal velocities may result in forces upwelling by selective withdrawal and jet entrainment.

Download Full-text

Continental shelf waves and their influence on the circulation around the Great Barrier Reef

Marine and Freshwater Research ◽

10.1071/mf9830023 ◽

1983 ◽

Vol 34 (1) ◽

pp. 23 ◽

Cited By ~ 24

Author(s):

E Wolanski ◽

AF Bennett

Keyword(s):

Continental Shelf ◽

Great Barrier Reef ◽

Sea Level ◽

Atmospheric Pressure ◽

Low Frequency ◽

Internal Tides ◽

Wind Component ◽

Barrier Reef ◽

Longshore Current ◽

Shelf Waves

Winds and atmospheric pressure, sea level and water currents were measured at several locations over the continental shelf, both east and west of the Great Barrier Reef, between 14.5�s. and 20�S., from June to November 1980. The dominant wind direction changed from westward over the Coral Sea to north- westward (roughly parallel to the shore) over the shelf. A strong non-tidal low-frequency signal in all sea- level and longshore current data was found, highly coherent from site to site and strongly correlated with the longshore wind component over the shelf, though not with the atmospheric pressure. A model of wind- driven barotropic shelf waves is used to explain a number of observations, such as the invariance of temporal fluctuations of longshore current with distance from shore, and the northward longshore propagation of oceanic disturbances at a speed equal to twice that of the first-mode barotropic free shelf wave, a speed one order of magnitude smaller than that of the wind system. The low-frequency current fluctuations resulted in large water displacements, up and down the coast. Low-frequency cross-shelf currents were much weaker and less coherent. Two upwelling mechanisms are internal tides and internal Kelvin waves coupled to the barotropic shelf waves.

Download Full-text

Assessment of the Accuracy of Recent Empirical and Assimilated Tidal Models for the Great Barrier Reef, Australia, Using Satellite and Coastal Data

Remote Sensing ◽

10.3390/rs11101211 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1211 ◽

Cited By ~ 4

Author(s):

Fardin Seifi ◽

Xiaoli Deng ◽

Ole Baltazar Andersen

Keyword(s):

Great Barrier Reef ◽

Sea Level ◽

Root Mean Square ◽

Tide Gauge ◽

Bottom Topography ◽

Deep Ocean ◽

Mean Square ◽

Barrier Reef ◽

In Situ Data ◽

The Impact

The latest satellite and in situ data are a fundamental source for tidal model evaluations. In this work, the satellite missions TOPEX/Poseidon, Jason-1, Jason-2 and Sentinel-3A, together with tide gauge data, were used to investigate the performance of recent regional and global tidal models over the Great Barrier Reef, Australia. Ten models, namely, TPXO8, TPXO9, EOT11a, HAMTIDE, FES2012, FES2014, OSUNA, OSU12, GOT 4.10 and DTU10, were considered. The accuracy of eight major tidal constituents (i.e., K1, O1, P1, Q1, M2, S2, N2 and K2) and one shallow water constituent (M4) were assessed based on the analysis of sea-level observations from coastal tide gauges and altimetry data (TOPEX series). The outcome was compared for four different subregions, namely, the coastline, coastal, shelf and deep ocean zones. Sea-level anomaly data from the Sentinel-3A mission were corrected using the tidal heights predicted by each model. The root mean square values of the sea level anomalies were then compared. According to the results, FES2012 compares more favorably to other models with root mean square (RMS) values of 10.9 cm and 7.7 cm over the coastal and shelf zones, respectively. In the deeper sections, the FES2014 model compares favorably at 7.5 cm. In addition, the impact of sudden fluctuations in bottom topography on model performances suggest that a combination of bathymetric variations and proximity to the coast or islands contributes to tidal height prediction accuracies of the models.

Download Full-text

Climate variability of the Great Barrier Reef in relation to the tropical Pacific and El Niño-Southern Oscillation

Marine and Freshwater Research ◽

10.1071/mf11151 ◽

2012 ◽

Vol 63 (1) ◽

pp. 34 ◽

Cited By ~ 14

Author(s):

Ana Redondo-Rodriguez ◽

Scarla J. Weeks ◽

Ray Berkelmans ◽

Ove Hoegh-Guldberg ◽

Janice M. Lough

Keyword(s):

Climate Variability ◽

Great Barrier Reef ◽

El Niño ◽

El Nino ◽

Southern Oscillation ◽

Tropical Pacific ◽

Sea Surface ◽

El Nino Southern Oscillation ◽

Barrier Reef ◽

Enso Events

Understanding the nature and causes of recent climate variability on the Great Barrier Reef (GBR), Australia, is fundamental to assessing the impacts of future climate change on this complex ecosystem. New analytical tools, improved data quality and resolution, longer time-series and new variables provide an opportunity to re-assess existing paradigms. Here, we examined sea surface temperature (SST), sea level pressure, surface winds, sea surface height and ocean currents for the period from 1948 to 2009. We focussed on the relationship between GBR surface climate and the wider tropical Pacific, and the influence of El Niño-Southern Oscillation (ENSO) events. Also, for the first time, we investigated the impact of the El Niño/La Niña Modoki phenomenon. Although neither type of ENSO event is a primary driver of inter-annual climate variability on the GBR, their influence is conspicuous. Classical ENSO events have a strong signature in the atmospheric circulation in the northern GBR but no significant relationship with SSTs and the opposite applies for the southern GBR. Conversely, El Niño/La Niña Modoki is significantly related to summer SSTs on the northern GBR, but not for the southern GBR. This study enhances our understanding of tropical Pacific and GBR climate drivers and will improve future predictions of change in climate variables that are likely to impact on the complex GBR ecosystem.

Download Full-text