The impact of tropical - extratropical interactions on downstream predictability (TROP)

点击翻译按钮获取中文摘要

In this project we investigate the mechanisms by which organised tropical convective systems, and, in particular, tropical cyclones undergoing extratropical transition (ET), interact with the midlatitude upper-level wave guide. We consider how this interaction influences the dynamics and predictability of the ET system itself, the midlatitude flow, and sub tropical cyclones that may develop downstream. We will use a combined observational, COSMO modelling, and data denial approach applied to the ET cases of the THORPEX Pacific Asian Regional Campaign. Diagnostic techniques, including PV inversion and object-oriented diagnostics will be applied to investigate the interactions between the convective and synoptic-scale flow. We will investigate the impact of different regimes of tropical convection on midlatitude predictability through analysis of Year of Tropical Convection datasets and TIGGE data, conducting experiments with ensemble prediction systems (EPS), and diagnosing the results with ensemble sensitivity analysis and other techniques. Finally, we will investigate the predictability of the structural changes during ET and of sub-tropical cyclogenesis using the multiscale ensemble. The results of this study will be used to define observational strategies for a future THORPEX field campaign.