1. a Institute for Geophysics, Jackson School of Geosciences , The University of Texas at Austin , Austin, Texas, USA
2. d Department of Oceanography and Center for Ocean‐Atmospheric Prediction Studies , Florida State University , Tallahassee, Florida, 32306, USA E-mail:
3. b Department of Mathematics and Statistics , Acadia University , Nova Scotia
4. c Department of Physics and Astronomy , University of Victoria , British Columbia