SUMMARYA numerical model is developed for the simulation of surges generated by a tropical cyclone in the Bay of Bengal. The analysis area extends from approximately 11"N to 22"N and, in the northeastern sector of the Bay, includes a representation of the Ganges-Brahmaputra-Meghna river system in Bangladesh. The extent of the analysis area allows three days of the surge-generating capacity of a cyclone originating in the southern Indian Ocean to be recorded before landfall at the Bangladesh coast. The incorporation of the river system permits a potentially deep inland penetration of surges originating in the Bay. The model is non-linear and this allows a determination of the interactive effect between surge and the astronomical tide. Numerical experiments are described that relate to the change in surge response resulting from a change in the cyclone track during the 24 hours preceding landfall. An account is given of the interaction between surge and tide in the Bay and the river system.

NOTES AND CORRESPONDENCEparameter values) C, C', D and D' remain non-zero. Therefore, it follows from Eq. (4) that 0 will diverge at the poles and pass outside the physical domain (0 to 1) at polar latitudes, a result that cannot be avoided by increasing the accuracy to which t is estimated. Paltridge's calculations did not extend beyond 64"N and 64"S, and so did not meet this limitation. Hence, the assumption of maximum vertical heat flux cannot be applied in the polar regions, for to retain it would require that (D'C-C'D) + 0 at the poles which would involve additional assumptions about high latitude atmospheric radiation processes. The assumption is also inapplicable if (g -d) is small.Paltridge, G. W. 1975 Global dynamics and climatea system of minimum entropy exchange, Quart. REFERENCE