International

Work package 1

The objective of this work package (WP) is to undertake collaborative research to improve our understanding of the relationship between large-scale atmospheric processes and Southeast Asian weather, and to improve their representation in models. 

This work package focusses on the impacts that large-scale processes have on the weather of Southeast Asia (SEA). Many elements of this work are regional in nature, but particular attention will be given to the monsoon systems that have a strong impact over the region, the Madden-Julian Oscillation (MJO) and the influence of large scale atmospheric patterns on tropical cyclones in the Philippines. This will be used to underpin improvements in the provision of advice around high impact weather in SEA.

Background:

In the tropics, severe weather events that bring strong impacts are often associated with small-scale convective processes. However, these can be modulated by the larger-scale (synoptic) atmospheric conditions. It is important to evaluate and improve the representation of large-scale atmosphere dynamics in the global model, so that their relationship to high impact weather (HIW) can be better understood. Clarifying the role of the global model in driving regional forecasts, as well as improving coupled modelling around the Maritime continent, will enable the development of tools and advice (<link>see WP3) to support forecasting of HIW in Southeast Asia.

Activities include:

  • Investigating large-scale atmospheric dynamics (large scale structure, synoptic events) and improving our understanding of their influence on High Impact Weather (HIW) events (cold surges, monsoon systems and tropical waves) and the MJO.

            Grant Award: University of Reading – The role of tropical waves on the weather of SEA. Understand and evaluate the relationship between tropical waves and high impact weather in SEA and the representation of these waves in forecast models. Develop tools and advice to support forecasting of high impact weather in SEA.

  • Improving our understanding and forecasting of tropical cyclones (TC), as well as producing metrics to measure our progress.

            Grant Award: University of Reading FASCINATE (Forecasting Air-Sea Coupled Interactions in NWP of Atmospheric Tropical Extremes). Evaluating how well the Met Office model predicts tropical cyclones in the West Pacific Investigating whether including air-sea coupled feedbacks improves forecast model performance for tropical cyclones.

            Grant Award: University of Leeds - Tropical cyclone (TC) Predictions in SEA using Numerical Weather Prediction) (NWP).Evaluation of storm structure and the vorticity aggregation during TC formation and rapid intensification (RI) phase; assess the model representation of vorticity aggregation at different horizontal resolutions; investigate the physical processes responsible for, and effects of, transitions in eyewall structure.

  • Investigating convection in global models and improving model skill (convective memory, convection scheme scale awareness and impact on SEA weather)

            Grant Award: University of Leeds – Vertical structures of weather over Southeast Asia.

  • Developing our understanding of low level influences on the atmosphere (update orographic/boundary layer schemes using drag partitioning, impact on SEA weather)

Benefits

This partnership is progressing knowledge of how large scale patterns influence high impact weather events in Southeast Asia (SEA), including high intensity rainfall and tropical cyclones. This is improving the global modelling and forecasting capability in the area, which underpins better, more accurate and timely warnings of HIW in SEA. This will reduce the socio-economic impacts of severe weather, protecting life and property, and encouraging prosperity.

This project will further strengthen the UK-SEA research community, linking WCSSP scientists to international monsoon research activities and model development. This will build collaborative work directed by shared goals, such as engagement with the Years of Maritime Continent work.