[ ahy-on-uh-pawz ]
/ aɪˈɒn əˌpɔz /
the transitional zone between the ionosphere and the mesosphere.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for ionopause
/ (aɪˈɒnəˌpɔːz) /
the transitional zone in the atmosphere between the ionosphere and the exosphere, about 644 km (400 miles) from the earth's surface
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012