Title: Recent Development of the NASA CAMVis for Tropical Cyclone Studies
Author: Bo-Wen Shen
Organization: UMCP/ESSIC and NASA Goddard Space Flight Center
Co-Authors: Wei-Kuo Tao, Bron Nelson

One of the current challenges in tropical cyclone (TC) research is how to improve our understanding of TC inter-annual variability and the impact of climate change on TCs. Paired with the substantial computing power of the NASA Columbia and Pleiades supercomputers, the newly-developed Coupled Global Multiscale Modeling and Concurrent Visualization System (CAMVis; Shen et al., 2011) shows potential for such studies. The CAMVis consists of the NASA state-of-the-art multi-scale modeling framework (MMF; Tao et al., 2008, 2009), a high-resolution general circulation model (fvGCM; Shen et al., 2006), the Goddard Cumulus Ensemble model (GCE; Tao et al., 1993) and concurrent visualization (CV) systems (Ellsworth et al., 2006; Green et al., 2010). With the goal of improving hurricane climate simulations, a recent development within CAMVis is discussed that improves the scalability of the MMF making it feasible to perform long-term simulations and hence improve scientific visualizations of simulated hurricanes (e.g., Katrina) and consequently yield more insight into the understanding of hurricane transient dynamics. A meta grid system is introduced wherein thousands of copies of the GCE are integrated into a meta-global GCE. A revised parallelism is also implemented with a 2D domain decomposition in this grid-point space. The mgGCE and fvGCM are then coupled into the new version 2 of the MMF. A revised parallel implementation in MMF v2 shows very promising scalability, giving a nearly linear speedup as the number of CPUs is increased from 30 to 364. In addition, a 3D streamline package is developed to provide insight into the multiscale interactions between a (mesoscale) hurricane and the large-scale environmental flow. 3D visualizations of hurricane Katrina show that the interaction of Katrinaís outflow with an approaching upper-level jet stream may have been an important process that led to Katrinaís intensification before it made landfall. The visualizations of Katrina and other TCs illustrate how CAMVis can help address the scenarios of ìextreme event warningî to achieve the goal of ìdiscovering predictive relationships between meteorological and climatological events and less obvious precursor conditions from massive data sets.î The improved CAMVis makes it more feasible to study TC climate and has the potential to support the Decadal Survey Missions (NRC, 2007). Future work on model improvement will be discussed at the end.