Hironori Fudeyasu et al., Global cloud-system-resolving model NICAM successfully simulated the lifecycles of two real tropical cyclones

Global cloud-system-resolving model NICAM successfully simulated the lifecycles of two real tropical cyclones

Global cloud-system-resolving model NICAM successfully simulated the lifecycles of two real tropical cyclones

Hironori Fudeyasu and Yuqing Wang (International Pacific Research Center, School of Ocean and Earth Science and Technology, University of Hawai'i at Manoa, Honolulu, Hawaii, U.S.A.), Masaki Satoh (Center for Climate System Research, University of Tokyo, Kashiwa, JapanFrontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan), Tomoe Nasuno and Hiroaki Miura (Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan), and Wataru Yanase (Center for Climate System Research, University of Tokyo, Kashiwa, Japan)

The increasing capability of high-end computers allows numerical simulations with horizontal resolutions high enough to resolve cloud systems in a global model. In this paper, initial results from the global Nonhydrostatic ICosahedral Atmospheric Model (NICAM) are highlighted to demonstrate the beginning of a potentially new era for weather and climate predictions with global cloud-system-resolving models. The NICAM simulation with a horizontal resolution of about 7 km successfully reproduced the lifecycles of two real tropical cyclones that formed in Indian Ocean in the austral summer 2006. Initialized with the atmospheric conditions 1-2 weeks before the cyclones genesis, the model captured reasonably not only the timing of the observed cyclone geneses but also their motions and mesoscale structures. The model provides a high temporal/spatial resolution dataset for detailed studies of mesoscale aspects of tropical cyclone genesis. These promising results suggest the predictability of tropical cyclones by high-resolution global cloud-system-resolving models.

(Received 12 September 2008; accepted 17 October 2008; published 25 November 2008.)

Citation: Fudeyasu, H., Y. Wang, M. Satoh, T. Nasuno, H. Miura, & W. Yanase (2008), Global cloud-system-resolving model NICAM successfully simulated the lifecycles of two real tropical cyclones, Geophys. Res. Lett., 35, L22808; doi:10.1029/2008GL036003.

Link to abstract: http://www.agu.org/pubs/crossref/2008/2008GL036003.shtml

Global model reproduces behavior of two real cyclones

Atmospheric models that resolve clouds have greatly contributed to understanding local and regional climate; excessive computational needs have in the past allowed these models to be run only over limited areas. The increasing capability of high-end computers now allows numerical simulations with horizontal resolutions high enough to resolve cloud systems in a global model. Fudeyasu et al. analyze initial results from the global Nonhydrostatic Icosahedral Atmospheric Model (NICAM), developed by Japanese scientists. In their study, NICAM simulation successfully reproduces the life cycles of two real tropical cyclones that formed in the Indian Ocean in 2006's austral summer. Initialized with atmospheric conditions that were present a few weeks before the cyclones formed, the model captures the timing of formation, motions, and overall evolution of the observed cyclones. The successful simulation is attributed to the realistic representation of the large-scale circulation and the embedded convective vortices. Thus, NICAM provides high temporal and spatial resolution data sets for detailed studies of tropical cyclone genesis and evolution, potentially ushering in a new era for weather and climate predictions.