ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. 17: 492–500 (2016) Published online 3 August 2016 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/asl.683 Characteristics of multiscale vortices in the simulated formation of Typhoon Durian (2001) , Yaping Wang,1,2 Xiaopeng Cui1,3 and Yongjie Huang1 2* 1Key Laboratory of Cloud-Precipitation Physics and Severe Storms (LACS), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China 2University of Chinese Academy of Sciences, Beijing, China 3Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing, China *Correspondence to: Abstract Y. Huang, Key Laboratory of The formation of Typhoon Durian (2001) was simulated well by the Weather Research and Cloud-Precipitation Physics and < Severe Storms (LACS), Forecasting model. The vorticity field was separated into three scales: small scale (L 30 km), < < > Institute of Atmospheric intermediate scale (30 km L 120 km), and system scale (L 120 km), where L is wavelength. Physics, Chinese Academy of During the formation, small-scale vorticity anomalies, associated with convection, aggregated Sciences, No. 40 Huayanli, radially inward and rotated anticlockwise. The system-scale vorticity field presented a distinct Chaoyang District, Beijing mid-level vortex before genesis, and then a well-organized low-level vortex. The spectral power 100029, China. of the low-level vorticity at the small scale barely changed, while that at the system scale E-mail:
[email protected] continued to grow steadily. The vorticity growth or spin-up of the near-surface tropical cyclone embryo was mainly due to the convergence of vertical vorticity flux at the planetary boundary layer.