Elizabeth Ritchie

Future Changes in Tropical Cyclone Exposure and Impacts in Southeast Asia From CMIP6 Pseudo‐Global Warming Simulations

Publisher: American Geophysical Union (AGU)

Date: 30-11-2022

DOI: 10.1029/2022EF003118

Hydrodynamic Drivers of the 2013 Marine Heatwave on the North West Shelf of Australia

Publisher: American Geophysical Union (AGU)

Date: 03-2021

DOI: 10.1029/2020JC016495

Abstract: The 2012/2013 Ningaloo Niño induced a strong marine heatwave (MHW) event on Australia's North West Shelf (NWS) during the austral summer, starting in December 2012 and peaking in January and February 2013. A high‐resolution regional numerical model based on the Regional Ocean Modeling System (ROMS) was implemented to simulate the variability of the upper ocean temperature and ocean circulation and understand the mechanisms that drive the evolution of the MHW. An upper ocean heat budget was used to quantify the roles of air‐sea heat flux and ocean circulation in the development of extreme temperature anomalies over the continental shelf. Results indicate that during December 2012 an increase of net air‐sea heat flux combined with positive horizontal advective heat flux anomaly led to development of the MHW. During the peak in January‐February 2013 high‐temperature anomalies were maintained by a combination of a decrease in negative heat advection and vertical mixing cooling and a decrease in net air‐sea flux warming. The delayed onset of the 2012–2013 Australian monsoon resulted in alongshore wind anomalies on the NWS which in turn caused the advection and mixing anomalies.

Evaluation of Extreme Temperatures Over Australia in the Historical Simulations of CMIP5 and CMIP6 Models

Publisher: American Geophysical Union (AGU)

Date: 07-2021

DOI: 10.1029/2020EF001902

Abstract: Historical simulations of models participating in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) are evaluated over 10 Australian regions for their performance in simulating extreme temperatures, among which three models with initial‐condition large ensembles (LEs) are used to estimate the effects of internal variability. Based on two observational data sets, the Australian Water Availability Project (AWAP) and the Berkeley Earth Surface Temperatures (BEST), we first analyze the models' abilities in simulating the probability distributions of daily maximum and minimum temperature (TX and TN), followed by the spatial patterns and temporal variations of the extreme indices, as defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). Overall, the CMIP6 models are comparable to CMIP5, with modest improvements shown in CMIP6. Compared to CMIP5, the CMIP6 ensemble tends to have narrower interquartile model ranges for some cold extremes, as well as narrower ensemble ranges in temporal trends for most indices. Over southeast, tropical, and southern regions, both CMIP ensembles generally exhibit relatively large deficiencies in simulating temperature extremes. We also confirm that internal variability can affect the trends of the extremes and there is uncertainty in representing the irreducible variability among different LEs in CMIP6. Furthermore, the evaluation based on Perkins' skill score (PSS) and root‐mean‐square error (RMSE) in the three LEs does not directly correlate with the ranges of the trends for extreme temperatures. The findings of this study are useful in informing and interpreting future projections of temperature‐related extremes over Australia.

Evaluation of Extreme Temperatures over Australia in the Historical Simulations of CMIP5 and CMIP6 Models

Publisher: Wiley

Date: 23-11-2020

DOI: 10.1002/ESSOAR.10504896.1

Influence of Seasonal River Discharge on Tidal Propagation in the Ganges‐Brahmaputra‐Meghna Delta, Bangladesh

Publisher: American Geophysical Union (AGU)

Date: 27-10-2020

DOI: 10.1029/2020JC016417

A 50‐Year Tropical Cyclone Exposure Climatology in Southeast Asia

Publisher: American Geophysical Union (AGU)

Date: 15-02-2022

DOI: 10.1029/2021JD036301

A Metric for Rainfall Asymmetry in Recurving Tropical Cyclones

Publisher: American Geophysical Union (AGU)

Date: 13-07-2018

DOI: 10.1029/2018GL078273

Influence of Wave–Current Interaction on a Cyclone-Induced Storm Surge Event in the Ganges–Brahmaputra–Meghna Delta: Part 1—Effects on Water Level

Publisher: MDPI AG

Date: 02-02-2023

DOI: 10.3390/JMSE11020328

Abstract: The Ganges–Brahmaputra–Meghna Delta (GBMD) located in the head of the Bay of Bengal is regularly affected by severe tropical cyclones frequently. The GBMD covers the Bangladesh coast, which is one of the most vulnerable areas in the world due to cyclone-induced storm surges. More than 30% of the total country’s population lives on the Bangladesh coast. Hence, it is crucial to understand the underlying processes that modulate the storm surge height in the GBMD. A barotropic numerical 3D model setup is established by using Delft3D and SWAN to investigate a cyclone-induced storm surge event. The model is calibrated and validated for Cyclone Sidr in 2007 and applied to six idealized cyclonic scenarios. Numerical experiments with different coupling configurations are performed to distinguish the contribution of wind, tides, waves, and wave–current interactions (WCI) on the storm surge height. Results show that the wind-driven setup is the dominant contributor to the storm surge height during cyclonic events. Based on the tidal phase and wind direction, the interaction between tide and wind can increase or decrease the magnitude of the storm surge height. Finally, considering the wind-driven wave may increase the surge height up to 0.3 m along the coastline through a strong wave setup.

Discovery Projects - Grant ID: DP210103203

Start Date: 2021

End Date: 12-2024

Amount: $373,000.00

Funder: Australian Research Council

ARC Centres Of Excellence - Grant ID: CE230100012

Start Date: 02-2024

End Date: 01-2030

Amount: $35,000,000.00

Funder: Australian Research Council