Parallelization of the 3D Unified Curvilinear Coastal Ocean Model: Initial Results

The Unified Curvilinear Ocean Atmospheric Model (UCOAM) is a Large Eddie Simulation (LES) CFD model capable of running both ocean and atmospheric simulations. It is the only environmental model in existence today using a full, 3D curvilinear coordinate system, which results in increased accuracy and resolution. UCOAM is a petascale model: it is capable of resolving sub-km scale fluctuations requires large arrays (1010 elements, the curvilinear system requires large number of arrays (~100); communication occurs along all 3 axes, and full simulations will generate TBytes of data. Consequently, this model requires parallelization. To facilitate UCOAM computations and data management, we have developed a new parallel framework capable of distributing the computations across arbitrary 3D processor arrangements, manages the complexity of the staggered grid variables, and performs communications along all axes, including diagonal and tridiagonal neighbors. To facilitate computations, we have developed computational environment (CE) based on the Cyber infrastructure Web Application Framework (Cyber Web) which supports the development of web services and portals. In this paper we discuss the design and architecture of the parallel framework and supporting CE infrastructure, as well as challenges associated with parallelizing this novel model. We include the first initial parallel results for a small (10⁵ nodes) 1 meter resolution seamount test case that shows scaling of the parallel model.