1. Trainee Meteorologist, Meteorological Service of New Zealand Ltd, 30 Salamanca Rd., Kelburn, Wellington 6012, New Zealand.
2. Lecturer in Mathematics and Computational Geodynamics, School of Fundamental Sciences, Massey Univ., Colombo Rd., Palmerston North 4410, New Zealand (corresponding author). ORCID: .
3. Senior Lecturer in Mathematics, School of Fundamental Sciences, Massey Univ., Colombo Rd., Palmerston North 4410, New Zealand.