Key Laboratory of Meteorological Disaster of Ministry of Education, and College of Atmospheric Sciences, Nanjing University of Information Science and Technology, 219 Ningliu Road, Nanjing 210044, China

Rossby Centre, Swedish Meteorological and Hydrological Institute (SMHI), 601 76 Norrköping, Sweden

Department of Earth Sciences, University of Gothenburg, P.O. Box 460, 405 30 Gothenburg, Sweden

Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4J1, Canada

Meteorological Research Division, Environment Canada, 45 Alderney Drive, Dartmouth, NS B2Y 2N6, Canada