The diurnal cycle of precipitation over the Maritime Continent: characterisation in observations and models

The meteorological diurnal cycle over the Maritime Continent is a major component of observed variability and features see-sawing of intense precipitation from over land through the afternoon and evening to over surrounding seas and oceans through the night into the morning. This high-frequency land-locked mode of variability interacts with lower-frequency propagating modes of tropical variability, such as the Madden-Julian Oscillation, therefore accurate forecasting of downstream impacts of these intraseasonal modes of variability depends on accurate understanding and model representation of the diurnal cycle.

In this presentation we compare the observed diurnal cycle of precipitation with the diurnal cycle generated by regional hindcast runs of the UK Met Office Unified Model with parameterised and with explicitly-resolved convection. A novel characterisation framework is used to quantify the cycle at each location in order to optimise the intuitive simplicity and the completeness of the characterisation.