UK Earth System Modelling News

January 2020

The UK Earth system modelling project is a joint venture between the Met Office and the Natural Environmental Research Council (NERC) to develop and apply a world-leading Earth System Model.

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First results from UKESM1 CH4 emission-driven simulations

by Robert Parker, Gerd Folberth, Chris Jones, Nicola Gedney, Fiona O’Connor, Alistair Sellar and Andy Wiltshire 

Methane (CH4) is the second most important greenhouse gas after carbon dioxide (CO2), with potential for both climate mitigation and air pollution abatement due to its relatively short lifetime. ESMs participating in CMIP6 were driven by prescribed CH4 concentrations rather than through internally generating their own emissions, which are interactively coupled to the model atmosphere. Here we describe first results from a configuration of UKESM1 where CH4 emissions are calculated by the model and the evolution of atmospheric CH4 is allowed to freely evolve. Read more…

Improving the simulation of historical surface temperatures in UKESM1

by Steven Rumbold and Colin Jones.

UKESM1 CMIP6 historical simulations exhibit a cold bias in 20th century global mean surface temperatures. This bias appears to be associated with excessive SO2 concentrations in the model atmosphere, resulting in strong aerosol driven cooling. We have extended the parameterization of SO2 deposition in UKESM1, which strongly reduces SO2 amounts in the model atmosphere and reduces aerosol driven cooling over the historical period. These changes have a major impact on the historical cold bias in repeat CMIP6 historical simulations with an updated version of UKESM1. Read more…

Bringing fire into UKESM

by Douglas I. Kelley, Chantelle Burton, João Teixeira

Wildfires have been making global headlines over the last few years, highlighting the importance of fire and it’s feedbacks within the Earth System. Unravelling the complex interplay between climate controls, human manipulation and land use has made modelling fire extremely difficult, and many global fire models struggle to reproduce even basic fire properties when driven by observed climate variables. We describe ongoing work to interactively couple a wildfire model into UKESM1, with a range of promising results. Read more…

Earth System Music 

by Lee de Mora.

Have you ever wondered how a simulation of the climate system would sound?  
As part of the UKESM project, I converted some CMIP6 simulations time series data into musical notes, then played them through a digital keyboard. Using this method, I produced six musical pieces..
Read more…


Save the Date: 20-21 April 2020 – CMIP6 Analysis Workshop and Poster Session, Met Office, Exeter

Following the successful 2019 UK CMIP6 workshop, a 2020 CMIP6 Analysis workshop will take place at the Met Office in Exeter. The aim of this 2-day meeting is to bring together UK scientists working on the analysis of CMIP6 simulations to present and discuss their work. The format will be poster presentations with short (2 minute) oral presentations of each poster. A few keynote presentations will frame each poster session.

The meeting will be organized around the 3 CMIP6 overarching science objectives, with a 4th session targeting the use of CMIP6 simulations in climate impact assessment work and for informing policy. We particularly encourage Early Career Scientists to present at the workshop.

Further information will be circulated soon, including details on registration and abstract submission. For now, please save the date and ensure other interested researchers and students at your respective institutes are aware of this workshop

On behalf of the UK CMIP6 Analysis Team.

Save the Date: 16-17 June 2020 – UKESM – LTSM Annual Meeting, Leicester

Please save the date for the next annual meeting for the UKESM-LTSM will take place in June at the University of Leicester, Leicester. Further details about this meeting will be communicated soon.


7-8 January 2020 – UK Volcano-Climate Modelling meeting – Queens’ College, Cambridge: 

by Thomas J. Aubry, Anja Schmidt, Sue Loughlin 

The first UK volcano-climate modelling community meeting took place at Queens’ College in Cambridge in January 2020. The meeting was attended by 23 researchers from universities across the UK, the UK Met Office, the British Geological Survey, and the National Centre for Atmospheric Science. 

Group picture

The meeting built on the strong momentum carried forward by the UKESM project, the ability of the model to interactively simulate volcanic sulfate aerosol, and the world-leading climate science and volcanology communities in the UK. The meeting focused on presentations and discussions related to scientific challenges and opportunities as well as model capabilities and the UK contributions to international research initiatives such as VolMIP. Several PhD students and early career researchers also presented their work in the form of keynotes and lightning talks. Discussion topics included the role of observations of recent eruptions (e.g., Holuhraun 2014-2015 and Raikoke 2019) in evaluating UKESM and constraining aerosol effects on climate and atmospheric chemistry, the impacts of volcanic forcing on climate variability, geoengineering, and to enhance our capability to inform decision-makers about the climatic impacts of a future large-magnitude volcanic eruption. 

Outcomes from the meeting include the establishment of key research questions, opportunities and actions that will guide the community in the coming years. Attendees identified opportunities for collaboration and joint analysis of existing or planned model experiments with UKESM or UM-UKCA. Furthermore, a handful of new experiments were proposed, including a historical run in which interactive volcanic sulfur dioxide emissions will be used instead of prescribed aerosol forcing fields, as was done in the standard UKESM1 CMIP6 simulations. Attendees unanimously agreed to reconvene a second meeting in 2021. 


Papers related to UKESM:

UKESM1 in the research literature 

by Jeremy Walton 

Following the release of UKESM1 in 2019, a number of technical publications have been produced for the peer-reviewed research literature which describe the model and present some of its results from several experiments.  The paper which documents the model in detail, and which is intended as its standard reference, is: 

This appears in a special issue (The UK Earth System Models for CMIP6) of the Journal of Advances in Modeling Earth Systems that is devoted to the scientific characterisation and evaluation of the physical and Earth System models developed in the UK.  Other papers of interest in that issue which describe aspects of UKESM1 and HadGEM3-GC3.1 (the model which forms the physical core of UKESM1) include: 

Other papers have been submitted for appearance in that issue, including: 

  • Implementation of UK Earth system models for CMIP6 by Sellar et al. (2019).   
  • Spin-up of UK Earth System Model 1 (UKESM1) for CMIP6 by Yool et al. (2019).   
  • UK Community Earth System Modelling for CMIP6 by Senior et al. (2019).   

In addition, this paper is currently under review in Geoscientific Model Development: 

  • Description and evaluation of the UKCA stratosphere-troposphere chemistry scheme (StratTrop vn 1.0) implemented in UKESM1 by Archibald et al. (2019).  

and this paper has been submitted to the same journal: 

  • Description and evaluation of aerosol in UKESM1 and HadGEM3-GC3.1 CMIP6 historical simulations by Mulcahy et al. (2019).   

Other papers are also in preparation – including one on the evaluations of oceans in UKESM1 simulations.  We will update the status of the publications in the next issue of the Newsletter. 


Update on UKESM1 CMIP6 data 

by Jeremy Walton 

As mentioned in earlier articles (e.g. we have used UKESM1 to run the experiments prescribed by CMIP6.  In particular, we have completed the DECK – consisting of the pre-industrial control, the abrupt 4xCO2, the 1pctCO2 and AMIP runs – and historical runs, together with the future projection experiments.  The latter consist of seven pathways that explore a range of uncertainty in climate projections; we have produced a five-member ensemble of results for each pathway (and – currently – fifteen members of an ensemble for the historical experiment).   

Following the completion of the simulations, the model output is archived at the Met Office before selected variables are extracted, converted into the standard format required by CMIP6 and made available on the Earth System Grid Federation (ESGF) for use by climate scientists and analysts.  The ESGF data store can be interrogated at  At the moment, it contains 53,911 datasets from the UK (that is, which have been produced by either the Met Office or NERC).  Here, a dataset can be viewed as a variable (e.g. near-surface air temperature) at a frequency (e.g. monthly) from an experiment (e.g. historical) run using a model (e.g. UKESM1).  Currently, 70% of those datasets come from UKESM1, whilst the remainder have been produced by (five) different resolutions of HadGEM3-GC3.1.   

The conversion of output is now largely complete for variables of interest at monthly and daily frequencies.  We are just about to start work on the selection and conversion of variables at subdaily frequencies, which will appear on ESGF in due course.   

For further information about UKESM1 data for CMIP6, or to be kept informed about progress with subsequent datasets, please contact Jeremy Walton ( 


Recent additions to the UKESM Core Group:

Phil Harris, UK Centre for Ecology & Hydrology (UKCEH), Wallingford:  Phil joined the UKESM core group in October 2019, prior to which he was a UKCEH National Centre for Earth Observation staff member working on land-atmosphere interactions and climate model evaluation.  He is a long-time JULES user and will be working on the development of land surface processes in UKESM.  Phil has a Ph.D. in Meteorology from the University of Reading where he investigated the effect of future climate change on the Amazon forest.  In recent years he has been using satellite observations to research the role of soil moisture on land surface energy fluxes and storm initiation, and using this to develop diagnostics for evaluating global climate models.

Hazel Jeffery, NCAS, Met Office Hadley Centre, Exeter: Hazel joined the UKESM core group in December 2019. She is the Project Manager for UKESM and CRESCENDO. Prior to joining the Met Office Hazel has worked at NERC as Head of Strategic Management, in Brussels at the UK Research Office and in a European Commission funded research programme and had a research career in environmental chemistry at CEH and Harwell.