1. Center for Climate Physics, Institute for Basic Science, Busan 46241, South Korea
2. Pusan National University, Busan 46241, South Korea
3. Centre for the Mathematics of Planet Earth, University of Reading, Reading RG6 6AX, United Kingdom
4. Department of Mathematics and Statistics, University of Reading, Reading RG6 6AX, United Kingdom
5. CEN, Meteorological Institute, University of Hamburg, Hamburg 20144, Germany