Adaptive observation guidance applied to Typhoon Rusa: Implications for THORPEX-PARC 2008

In this study, total energy (TE) singular vectors (SVs) based on the fifth generation Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Mesoscale Model (MM5) and its tangent linear and adjoint models with a Lanczos algorithm are applied to Typhoon Rusa. The structures of SVs are evaluated to understand the sensitivity of forecasts with respect to the initial conditions, and thence to suggest the sensitive regions in terms of adaptive observations. In addition, the implications of applying this adaptive observation strategy for the THORPEX- Pacific Asian Regional Campaign (T-PARC) are discussed. Sensitive regions identified by TESVs are located horizontally in inflow regions along the edge of the subtropical high and the mid-latitude trough. Sensitive regions are located vertically in the mid-troposphere with several secondary peaks throughout the troposphere. In contrast to the upward energy propagation mechanism of SV development in extratropical cyclones, this does not occur for Typhoon Rusa. Vertically-confined, upshear-tilted SV structures under the mid-latitude trough are noticed for the temperature component of SV. The results of this study are quite consistent with recent studies on targeted observation strategies of tropical cyclones, and demonstrate that the TESVs can capture the signal of the environmental features affecting the evolution of Typhoon Rusa. The TESV guidance shown in this study will be calculated and provided for real-time field experiments during the T-PARC.