The aim of this programme is to improve the representation of convection in the UK’s weather, climate and Earth system modelling systems. This will enable better understanding of convective processes and enable more accurate predictions of hazardous weather conditions.
This programme aims to deliver a better understanding of convective processes and their interactions with atmospheric flows, and to translate this into new convection parameterisation schemes.
Weather and climate models are critical to society’s ability to reduce the impacts of hazardous weather. This is because these models inform decisions on mitigating and adapting to climate change. Representing convection is still the key error in weather and climate models. This limits our confidence in predictions and in turn their value when it comes to making decisions on timescales, which can range from days to decades.
The main issue in representing convection in global models is that the resolutions of these models are too coarse to represent individual convective systems. Instead, models rely on physically based parameterisations of convection. However, these parameterisations are based on paradigms developed 30 to 40 years ago, where convection was represented as a one-dimensional, balanced problem between atmospheric instability and the convection needed to remove that instability. Much more is now known about convection, how it relates to the local dynamics and how it is organised on a range of space and timescales from the diurnal cycle of precipitation to synoptic scales such as tropical storms or the Madden-Julian Oscillation. These outdated paradigms have been identified as a major blocker to more reliable weather forecasts and climate predictions, where it is critical to realistically simulate convection and the regional water cycle.
The goal of this programme is to significantly improve the representation of convection across a range of scales (primarily 1km to 100km grid lengths) in the UK’s weather, climate and Earth system modelling systems. The programme aims to deliver a better understanding of convective processes and their interactions with atmospheric flows, and to translate this understanding into new convection parameterisation schemes.
The new approaches are likely to include an improved representation of:
- the fluid dynamics of convection itself, including entrainment, downdraughts, cold pools, and gravity waves
- the temporal and spatial scales of convection
- the role of additional processes in controlling the organisation and location of convection
- the interaction of convection with the larger-scale atmospheric flow
- the way in which new convection parameterisations interact with the model dynamics, in particular within the Met Office Unified Model.
This programme brings together expertise from NERC and the Met Office community to deliver strategic, world-leading research to create a step change in our ability to predict weather and climate impacts.