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Statistical-dynamical Downscaling. Asuka Suzuki-Parker. NCAR Earth System Laboratory National Center for Atmospheric Research. NCAR is Sponsored by NSF and this work is partially supported by the Willis Research Network and the Research Program to Secure Energy for America. Approach.
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Statistical-dynamical Downscaling Asuka Suzuki-Parker NCAR Earth System Laboratory National Center for Atmospheric Research NCAR is Sponsored by NSF and this work is partially supported by the Willis Research Network and the Research Program to Secure Energy for America
Approach 1. Randomly place a weak storm 3. Calculate intensity based on large-scale info along the trajectory 4. Majority of storms don’t reach TC intensity, but some do 2. Determine trajectory based on large-scale info and probabilistic perturbation Large-scale info from bias corrected CCSM Current: 1950-1999 (20C3M) Future: 2000-2099 (A2)
Genesis Distribution Pretty good agreement with current observation except for tropical Atlantic
North AtlanticTC frequency projection No trend in annual frequency
Intensity projection No change in intensity either
Why no trends? Projected large-scale trends Stat-dyn downscale genesis location Less favorable More favorable Compared to observation, stat-dyn downscale technique is producing more storms in high latitutdes, and less in tropics As North Atlantic as a whole, trend gets canceled out
TC duration projection Increasing average TC duration PDI increases
TC size projection Reduction in TC size is projected
Summary Stat-dyn downscaling is successful in reproducing general global TC formation Little TC formation in tropical Atlantic Fails to capture large-scale trend No trend in frequency or intensity as whole North Atlantic Storm size and duration trends in agreement with NRCM