3D.7 An Overview of the 2016 Indian Monsoon Progression from INCOMPASS Field Observations and Modelling

Monday, 16 April 2018: 3:00 PM
Heritage Ballroom (Sawgrass Marriott)
Arathy Menon, Univ. of Reading, Reading, UK; and A. G. Turner, S. Webster, and G. Martin

The onset timing and progression of the Indian monsoon have strong socio-economic implications as a significant percentage of the country’s GDP depends on rain-fed agriculture. Hence a skilful prediction of the timing and strength of the monsoon ahead of the season is vital. However, modelling and forecasting the monsoon is limited by inadequate representation of sub-grid scale processes and lack of adequate observations to understand such processes. The INCOMPASS (Interaction of Convective Organization and Monsoon Precipitation, Atmosphere, Surface and Sea) project seeks to improve understanding of the detailed physics and dynamics associated with the Indian monsoon through an intensive field campaign and high resolution modelling. During the 2016 monsoon, 21 research flights were conducted, measuring dynamic and thermodynamic properties of the atmosphere, including vertical profiles. These observations showed that the mid-level dry air incursions from northwest India can play a significant role in the north-westward progression of the monsoon. These results were corroborated by concurrent high-frequency radiosonde launches.
We compare these in-situ data from aircraft sorties, radiosonde launches and flux towers with a high resolution (4 km) nested version of the UK Met Office Unified Model. This high resolution model captures the dynamics and thermodynamics associated with the 2016 monsoon progression well compared to observations. Mid-level dry air incursions are also quite well captured by the model, in addition to passage of a monsoon depression during July 2016. The model is also tested with two different land ancillaries to explore its sensitivity to land surface processes.
- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner