1. Houghton, J. T., and Seeley, J. S., Quart. J. Roy. Met. Soc., 86, 358 (1960).
2. Houghton, J. T., Quart. J. Roy. Met. Soc., 89, 332 (1963).
3. Neporent, D. S., Kiselva, M. S., Makogonenko, A. G., and Shlyakhov, V. I., Atmos. Ocean. Phys., 4, 473 (1968).
4. Murcray, D. G., Murcray, F. H., Williams, W. J., and Leslie, F. E., J. Geophys. Res., 65, 3461 (1960).
5. Zander, R., J. Geophys. Res., 71, 3775 (1966).