1. Centre for Environmental Mathematics, Faculty of Environment, Science and Economy, University of Exeter, Penryn Campus, Penryn TR10 9FE, UK
2. Mathematics Department, College of Science, Jouf University, Sakaka P.O. Box 2014, Saudi Arabia
3. Institute for Data Science and Artificial Intelligence, University of Exeter, North Park Road, Exeter EX4 4QE, UK