Progress towards interactive Ice Sheets in UKESM1

There is currently an intense focus in the UKESM development group on finalising the 1st version of UKESM that will be used for the majority of CMIP6 runs that start early next year. But there will be more than one configuration of UKESM, each with different strengths, designed to explore different science questions. One of […]

Final steps to UKESM1

INTRODUCTION As discussed in the 5th UKESM Newsletter (Sellar et al.2017, Parameter tuning for UKESM1, newsletter no. 5), over the past 12 months we have been working intensively on the scientific calibration of UKESM1, an important and necessary final step when a set of complex component models are coupled together into a fully coupled Earth […]

Parameter tuning for UKESM1

We are nearing the completion of UKESM1 development, with the planned science capabilities now included and all components coupled together. What remains before finalising the model is to calibrate the fully coupled system to achieve good performance across a range of observed climate indicators, such as radiative fluxes, temperature and rainfall. This calibration step is […]

Atmospheric Chemistry in UKESM1

Atmospheric trace gas constituents and aerosols exert important influences on global-scale and regional-scale climate. Atmospheric chemistry determines the abundance and lifetime of many greenhouse gases. In the stratosphere, heterogeneous chemistry involving reactive chlorine causes ozone (O3) depletion while, in the troposphere, reactive gases such as carbon monoxide, nitrogen oxides, and volatile organic compounds (VOCs) perturb […]

Land-use in UKESM1

Improving aerosol processes and radiative forcing in preparation for UKESM1

UKESM1 is developed on top of the coupled physical model, HadGEM3-GC3 (hereafter GC3). GC3 consists of the Unified Model (UM) atmosphere, JULES land surface scheme, NEMO ocean model and the CICE sea ice model. The UM atmosphere in GC3 is Global Atmosphere version 7 (GA7). Inclusion in GA7 of both a new cloud microphysics parameterization […]

Spinning up marine biogeochemistry in UKESM1

To a first approximation, much of what happens in the Earth system depends on the dynamics and interactions of the two key geophysical fluids that make it up: the atmosphere and the ocean. As anyone familiar with the UK’s weather will attest, the atmosphere is flighty and dynamic, with perturbations in temperature, humidity or chemical […]