Applications of the Mean Recentering Scheme to Improve Typhoon Track Prediction: A Case Study of Typhoon Nanmadol (2011)

摘要

Under strong nonlinear dynamics, the assumption of a Gaussian distribution for an ensemble may be strongly violated, and thus the mean of the ensemble cannot be the best estimate for the atmosphere. A mean recentering (MRC) scheme is proposed to handle a track ensemble that has a strong non-Gaussian distribution when the track prediction is conducted under a highly uncertain condition. The validity of the MRC scheme is confirmed using a case study of Typhoon Nanmadol in 2011, which moves northward initially but turns westward sharply at 0000UTC 24 August. Factors contributing to Nanmadol's movement prediction include the saddle field between typhoons Nanmadol and Talas, the development of the subtropical high on the north side of both typhoons, and Nanmadol's own circulation.