Description
- Abstract:
- The Great Barrier Reef, the world’s largest coral reef ecosystem, is subjected to a number of global and local stressors, including tropical cyclones. Although tropical cyclones are natural, localized disturbances to reef ecosystems, their characteristics are sensitive to global, anthropogenic climate change. This thesis uniquely explores both the relationship between tropical cyclone characteristics and the Great Barrier Reef environment, and addresses the dynamical response of cyclones to climate change and the implications for the reef ecosystem. Using remotely sensed data, this work finds that tropical cyclones significantly reduce water quality over the Great Barrier Reef 1-2 weeks after cyclone activity. This time lag demonstrates that reduced water quality is dominated by cyclone-induced runoff and river discharge and not wind mixing. Importantly, this work finds that cyclone size (and thus the coastal catchment where nutrients can be extracted from) is the strongest predictor of resultant water quality change. To understand the effects of climate change on tropical cyclone behavior, this thesis developed and tested novel regional numerical weather modeling techniques for simulating tropical cyclones in northeastern Australia. Using both this modeling framework and downscaled predictions of the future climate, it is demonstrated that cyclones in this region are likely to increase in intensity in response to climate change forcing by the year 2070-2100, with decreasing central pressure and increasing maximum wind speeds on average of 5-10%. Cyclone-associated precipitation will also increase by 15-45% in the future scenario. Smaller and weaker systems may increase in size up to 40%. The study highlights that the responses of cyclone trajectories and translation speed to climate change are more complex, as these properties are highly sensitive to the environmental steering flow. These future changes to cyclone characteristics will compound increasing local and global stressors with serious implications for the future of the ecosystem. The findings suggest that local policy and mitigation efforts should work to improve water quality to strengthen natural reef resilience to disturbances, such as tropical cyclones, that cannot be controlled. The results of this thesis can be applied to the future of other reef environments that face a similar combination of stressors.
- Notes:
- Thesis (Ph. D.)--Brown University, 2017
Access Conditions
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- Restrictions on Use
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Citation
Parker, Chelsea Lauren,
"Australian Tropical Cyclones: The Response to Climate Change and the Effects on Water Quality in the Great Barrier Reef"
(2017).
Earth, Environmental and Planetary Sciences Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.7301/Z0H993N0
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Earth, Environmental and Planetary Sciences Theses and Dissertations
Theses and Dissertations for the Earth, Environmental and Planetary Sciences department....