An external view of the Met Office building at night.

Rob Allan

Rob Allan leads the international ACRE (Atmospheric Circulation Reconstructions over the Earth) initiative, within the Climate Monitoring and Attribution Group.

Areas of expertise

  • Development of large regional to global historical weather and climate observational databases and their use for reanalyses and the wider global user community. 

  • Climatic variability and climate change, especially with regard to the El Niño Southern Oscillation (ENSO) phenomenon.

  • Forging linkages between climate science, climate applications, educators and students, the social sciences and humanities, libraries and archives, and with the general public.

My Publications - Allan, R

Current activities

In the course of the last 3.5 years, ACRE has progressed from a project into an international initiative that is providing new and unique historical weather reconstructions for users and climate applications needs for the entire global community.

With endorsement from organizations such as the World Meteorological Organisation (WMO), the Group on Earth Observations (GEO), the Global Climate Observing System (GCOS), wide international support and the aid of various working groups of GCOS and World Climate Research Program (WCRP), ACRE provides an umbrella that links together some 35+ projects, institutions, organisations, data rescue and climate applications activities around the globe.

ACRE is the only international initiative of its type, and consists of four interwoven elements which aim to:

  1. Undertake and facilitate the recovery of millions of historical instrumental surface terrestrial and marine global weather observations.
  2. To underpin a series of successive dynamical 4D global weather reanalyses or reconstructions with weather variables generated on a global grid every 6 hours at currently 2° latitude x 2° longitude resolution (with 56 realisations at each 6-hourly time step) by a numerical weather forecast model (used in hindcast mode) assimilating only surface synoptic pressure, monthly SST and sea-ice observations over the last 200+ years.
    • 20th Century Reanalysis Project: 1891-2008 [Released].
    • 20th Century Reanalysis Project: 1871-2008 [Autumn 2010].
    • Surface Input Reanalysis for Climate Applications (SIRCA): 1800-2016 [Autumn 2017].
  3. For climate research; climate applications, extremes, risks and impacts needs worldwide; educators and students and the general public.
  4. Via a web-based interface that will store, allow free access to, and enable free visualisations of the raw data, data images, meta data through to all of the variables generated by the 4D global weather reanalyses/reconstructions.

ACRE has also embraced the cross/interdisciplinary interest its activities have created. A series of recent collaborations between ACRE and citizen science, social science and humanities partners have made the above interactions an essential component of the initiative. Such projects are the OldWeather and Data Rescue at Home citizen science projects, the Sailsproject (Shipping Archives and Integrated Logbooks of Ships) and, with the Centre for e-Research, King's College London, looking at historic sources for weather in order to develop e-Research approaches to modelling, visualising and analysing such data. The latter network will build partnerships between scientists and humanities researchers around historic source materials that relate to weather, including ship log books.

Career background

Rob joined the Met Office Hadley Centre in mid-2000 after some 10 years working in the Climate Impact Group for CSIRO's Atmospheric Research Division in Melbourne, Australia. His research foci originally centred on the ENSO phenomenon, interannual to secular scale climatic variability and climate change. At the Met Office Hadley Centre, he was responsible for the development of historical gridded global monthly mean sea level pressure (MSLP) (HadSLP) and daily North Atlantic-European MSLP (EMSLP) data sets back to 1850. This has involved the rescue, recovery, quality control and archiving of historical global MSLP data from both terrestrial and marine sources.

In 2006-7, while working in his capacity as a co-convenor of the GCOS Atmosphere Observation Panel for Climate (AOPC)/Ocean Observation Panel for Climate (OOPC) Working Group on Surface Pressure, he developed a collaboration with the Queensland Climate Change Centre of Excellence (QCCCE) in Australia, in cooperation with the Cooperative Institute for Research in Environmental Sciences (CIRES)-a joint institute of the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado in Boulder, USA-this resulted in the international ACRE initiative which he now manages.

Funding for the ACRE Project Manager's position, which made ACRE possible, came about as the result of a Statement of Intent (SoI) signed in March 2007 between the Met Office Hadley Centre for Climate Change in the UK and the QCCCE in Australia to explore the potential to establish joint research and development projects that would advance scientific knowledge, academic opportunity and technology transfer. Under this SoI, the first project to be established was the ACRE initiative.

ACRE is acknowledged by the WMO Commission for Climatology, in the Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC (2010 Update), and endorsed by the Joint WMO-IOC Technical Commission on Oceanography and Marine Meteorology Expert Team on Marine Climatology and by the WCRP.

External recognition

  • Co-convenor of the GCOS AOPC/OOPC Working Group on Surface Pressure.
  • Member of Royal Meteorological Society's History of Meteorology and Physical Oceanography Special Interest Group.
  • Member of the International Commission on History of Meteorology.