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Atmospheric Circulation Reconstructions over the Earth

Atmospheric Circulation Reconstructions over the Earth

acre_ico.png Project type: European project
Period: April 2007
Status: In progress
Web: Atmospheric Circulation Reconstructions over the Earth

Twentieth Century Reanalysis (V1):

ACRE (Atmospheric Circulation Reconstructions over the Earth) is an international collaborative project led by a consortium of the Queensland Climate Change Centre of Excellence (QCCCE) in Australia, the Met Office Hadley Centre in the UK, and the National Oceanic and Atmospheric Administration (NOAA), Earth System Research Laboratory (ESRL) and Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado in the US.

ACRE is facilitating the recovery of historical instrumental surface terrestrial and marine global weather observations to create 3D weather reconstructions (reanalyses) over the last 200-250 years for climate applications and impacts needs worldwide.

The historical data component of the initiative builds on earlier undertakings, such as the EU-funded CLIWOC (CLImatological database for the World’s OCeans 1750-1850) project which looked primarily at non-instrumental weather observations in ship logbooks from the old European colonial powers. Ship logbooks are a vast and valuable source of data that has been scarcely examined - there are over 100,000 of them from before 1850 and even more post-1850. As a result of CLIWOC, ship logbooks from the late 17th Century have already been used to produce results, e.g. suggesting that the so called ‘Little Ice Age’ was stormier than today.

Linking with the international RECLAIM (RECovery of Logbooks And International Marine data) and ICOADS (International Comprehensive Ocean-Atmosphere Data Set) projects, ACRE, the CLIWOC participants, and various UK academics and archives, are expanding the recovery, imaging and digitisation of historical instrumental weather observations in marine logbooks held in various UK repositories (e.g. The British Library and the National Archives). However, these activities require considerable time and resources. Even working closely with US digitisers from the specialist NOAA CDMP (Climate Data Modernisation Program), a Met Office project to image and digitise records to fill the World War 2 dip in surface weather observations (shown in Figure 1) has taken 2 years.

Figure 1: Schematic diagram showing in the red trace the percentage of the globe from which historical marine and terrestrial weather observations have been digitised, overlain with the contemporary ERA-40 and NCEP reconstructions or reanalyses (using all data), plus the three historical surface weather input-only reanalyses that ACRE is facilitating, in shades of lighter blue.

The ACRE consortium is currently undertaking several major recovery, imaging, digitisation, archiving, and data inventory activities.

• 2007/2008: English East India Company (EEIC) ship logbooks (1780s-1830s) – held in the British Library (imaging by British Library, digitised by CDMP in the US) 900 logs have instrumental data [200K images]
• 2007/2008: Printed/published late 19th-early 20th Century Antarctic expeditions plus ships of exploration – online plus held in the Met Office Library & Archives (imaging & digitisation).
• 2008: With the Chinese Maritime Customs Project at Bristol University and hopefully the China Meteorological Agency (CMA), ACRE is undertaking an inventory to document old daily to sub-daily historical meteorological observations made at Chinese inland stations, and by ships travelling along its rivers, coastline and in the South China Sea.
• 2008: British hydrographic and survey vessel remarks books (1759-1909) – held at the UK Hydrographic Office (UKHO) (inventory of holdings in the archives of the UK Hydrographic Office) about 6,000 remarks books.
• 2008/2009: Extended World War 1 period (1914-1923) - held in the UK National Archives (imaging by the National Archives) at least 8,000 logs [300K+ images]. Aimed at filling the World War 1 dip in Figure 1.

ACRE and its collaborators are continuing to seek funding to complete the above activities (e.g. the digitisation of the extended World War 1 data, and the imaging and digitisation of the UKHO remarks books) and undertake new ones (e.g. Australian and Chilean historical weather observations). The imaging of all of this material is also creating a stunning resource for social, economic and political scientists (such as geographers and historians) to exploit.

A number of the above activities have already contributed important new marine historical weather observations for the 20th Century Reanalysis Project 1892-present (see Figure 1), which will be completed and released by our US partners early in 2009. In fact, all of the above will provide significant data for the three historical surface weather input-only reanalyses (reconstructions) that the US partners in ACRE are leading.

• the ongoing NOAA-CIRES 20th Century Reanalysis Project (1891-present)
• a NOAA-CIRES Surface Input Reanalysis for Climate Applications (SIRCA) (1840s-2011)
• a North Atlantic-European Region mid 18th-early 19th Century to present reanalysis

These reanalyses will produce the best dynamic reconstructions of historical global weather conditions throughout the depth of the atmosphere that are possible with current scientific capabilities. They will provide a unique long-term weather database which can be tailored or 'downscaled' to finer resolution in order to feed directly into various biophysical, ecological, environmental, production etc models that are used by the climate applications and impacts communities. This data base thus provides the full spectrum of users with a baseline with which they can assess, and reassess, the impacts of past climatic variability, putting them in a much stronger position to look into the future at possible implications and impacts of climate change.