The UKC2 regional coupled environmental prediction system

Abstract

Abstract. It is hypothesized that more accurate prediction and warning of natural hazards, such as of the impacts of severe weather mediated through various components of the environment, require a more integrated Earth System approach to forecasting. This hypothesis can be explored using regional coupled prediction systems, in which the known interactions and feedbacks between different physical and biogeochemical components of the environment across sky, sea and land can be simulated. Such systems are becoming increasingly common research tools. This paper describes the development of the UKC2 regional coupled research system, which has been delivered under the UK Environmental Prediction Prototype project. This provides the first implementation of an atmosphere-land-ocean-wave modelling system focussed on the United Kingdom and surrounding seas at km-scale resolution. The UKC2 coupled system incorporates models of the atmosphere (Met Office Unified Model), land surface with river routing (JULES), shelf-sea ocean (NEMO) and ocean waves (WAVEWATCH III). These components are coupled, via OASIS3-MCT libraries, at unprecedentedly high resolution across the UK within a north-western European regional domain. A research framework has been established to explore the representation of feedback processes in coupled and uncoupled modes, providing a new research tool for UK environmental science. This paper documents the technical design and implementation of UKC2, along with the associated evaluation framework. An analysis of new results comparing the output of the coupled UKC2 system with relevant forced control simulations for six contrasting case studies of 5-day duration is presented. Results demonstrate that performance can be achieved with the UKC2 system that is at least comparable to its component control simulations. For some cases, improvements in air temperature, sea surface temperature, wind speed, significant wave height and mean wave period highlight the potential benefits of coupling between environmental model components. Results also illustrate that the coupling itself is not sufficient to address all known model issues. Priorities for future development of the UK Environmental Prediction framework and component systems are discussed.

AMM15: a new high-resolution NEMO configuration for operational simulation of the European north-west shelf

“…Umlauf and Burchard, 2005); however, they still struggle through a lack of specific physical process representation (Luneva et al, 2017). Bringing together recent developments in direct observations of turbulent properties and LES modelling, for example in research projects such as PycnMix (Pycnocline Mixing in shelf seas) and OSMOSIS (Ocean Surface Mixing, Ocean Sub-mesoscale Interaction Study; Belcher et al, 2012), has the potential to lead to substantial improvements in vertical mixing schemes for the shelf seas.…”

“…However, this configuration has already been implemented as the ocean component of the UK Environmental Prediction (UKEP) system (Lewis et al, 2018), in which it has been coupled with atmospheric and wave models. Initial results are very promising and demonstrate the value of increased ocean resolution for simulating the wider climate system.…”

“…However, given that there are spatially varying anomalies across the shelf, the response to altering available parameters will vary. Improving the choice of vertical mixing schemes is still an active topic of research (Luneva et al, 2017), and the aim would be to improve those used in future operational systems.…”

“…considering location of mountain ranges and the Mediterranean within the domain used for ocean-atmosphere coupling; Lewis et al, 2018). This chosen common domain is now also in use at the Met Office for uncoupled operational UK weather forecasts (extending the existing operational domain; e.g.…”

Toward an Operational Water Cycle Prediction System for the Great Lakes and St. Lawrence River

“…Consequently, the water cycle represented is incomplete. Similarly, the recently introduced UCK2 regional coupled environmental prediction system (Lewis et al 2018) predicts the water cycle over the United Kingdom. UCK2, developed by the Joint Weather and Climate Research Programme and the Met Office, couples models for the atmosphere (Met Office Unified Model; Brown et al 2012), land surface [Joint UK Land Environment Simulator (JULES); Best et al 2011;Clark et al 2011], ocean [Nucleus for European Modelling of the Ocean (NEMO); Madec et al 1998Madec et al , 2008, and ocean waves (WAVEWATCH III;Tolman 2009).…”