Version 3 MM5 Modeling System At A Glance

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1. Introduction

Version 3 of the MM5 modeling system is being released in the summer of 1999. This version has come about as the result of several large changes that affect the modeling system. (I) The addition of a land-surface model that requires several more input datasets than standard model applications. (II) The use of a new, more efficient, file format for all the modeling system files. (III) The change of representation of date in the modeling system in order to be Y2K compliant as well as enabling date manipulation down to seconds on 32-bit machines. (IV) The removal of the hydrostatic option, and consequent streamlining of the code. (V) The re-writing of the solver routine for better efficiency. (VI) The need to move to a new set of pre-processing programs that make use of generalized data input formats, and many of which now use Fortran 90.