I am a geophysicist, with expertise in the analysis of space gravity data and modelling solid Earth and surface processes. I create models of the Earth's time-varying gravity field using space gravity data from the Gravity Recovery And Climate Experiment (GRACE) mission and GRACE Follow-On (GRACE-FO) missions to study changes in Earth's mass distribution due to various geophysical and climatological processes. I have a particular interest in using space gravity data to measure changes in the mass of polar ice caps and glaciers and to monitor water availability in Australia.
My research is supported by the Australian Research Council ‘GRACE Follow-On: Validation of measurements and initial results’ project, the Australian Centre for Excellence in Antarctic Science and the Geoscience Australia ‘Processing and integration of new space gravity data (GRACE-FO) for groundwater storage changes in the Great Artesian Basin’ project. I am currently a member of the GRACE-FO space gravity Science Team.
Education and employment history
2022-present: Postdoctoral Research Associate, Research School of Earth Sciences, The Australian National University
2018-2022: Doctor of Philosophy (Geodesy), The Australian National University
Thesis title: "Estimating Earth’s temporal gravity field from GRACE observations: Mitigation of thermal errors, orbital characteristics, basis functions and spatial resolution"
2014-2017: Bachelor of Science (Advanced), First Class Honours (Geophyscis) and the University Medal, University of Sydney
Thesis title: "Kinematic and geodynamic evolution of the Panama Isthmus region: Implications for Central American Seaway closure"
McGirr, R., P. Tregoning, S. Allgeyer, H. McQueen & A.P. Purcell (2023), Interplay of altitude, ground track coverage, noise and regularisation in the spatial resolution of GRACE gravity field models, Journal of Geophysical Research: Solid Earth, 128(1), e2022JB024330, https://doi.org/10.1029/2022JB024330.
Allgeyer, S., Tregoning, P., McQueen, H., McClusky, S. C., Potter, E. K., Pfeffer, J., McGirr, R., Purcell, A. P., Herring, T. A., & Montillet, J. P. (2022). ANU GRACE data analysis: orbit modeling, regularization and inter-satellite range acceleration observations, Journal of Geophysical Research: Solid Earth, 127(2), e2021JB022489, https://doi.org/10.1029/2021JB022489.
Tregoning, P., McGirr, R., Pfeffer, J., Purcell, A., McQueen, H., Allgeyer, S., & McClusky, S. C. (2022). ANU GRACE data analysis: Characteristics and benefits of using irregularly shaped mascons, Journal of Geophysical Research: Solid Earth, 127(2), e2021JB022412, https://doi.org/10.1029/2021JB022412.
McGirr, R., Tregoning, P., Allgeyer, S., McQueen, H., & Purcell, A. (2022). Mitigation of thermal noise in GRACE accelerometer observations, Advances in Space Research, 69(1), 386-401, https://doi.org/10.1016/j.asr.2021.10.055.
McGirr, R., Seton, M., & Williams, S. (2021). Kinematic and geodynamic evolution of the Isthmus of Panama region: Implications for Central American Seaway closure. GSA Bulletin, 133(3-4), 867-884, https://doi.org/10.1130/B35595.1.
Seton, M., Müller, R. D., Zahirovic, S., Williams, S., Wright, N. M., Cannon, J., ... & McGirr, R. (2020). A global data set of present‐day oceanic crustal age and seafloor spreading parameters. Geochemistry, Geophysics, Geosystems, 21(10), e2020GC009214, https://doi.org/10.1029/2020GC009214.