ACSOE/OXICOA - Testing Atmospheric Chemistry In Anticyclones (TACIA) C-130 data

The Atmospheric Chemistry Studies in the Oceanic Environment (ACSOE) programme was a 5-year NERC Community Research programme to investigate the physico-chemical processes in the layer of the atmosphere immediately above the oceans. The programme comprised a wide range of measurements coupled with modelling studies. Measurements were made at remote field sites (Mace Head, Ireland; Weybourne, Norfolk; Tenerife), from the NERC research vessels Challenger and Discovery and aboard the Meteorological Research Flight C-130 and the Cranfield Jetstream aircrafts.

The aims of the programme were to understand the processes occuring in the remote marine atmosphere and to discover how these are modified by anthropogenic emissions. The ACSOE study area extends from the cold water regions south of Iceland, through the temperate eastern Atlantic and North Sea, to the Canary Islands in the sub-tropical Atlantic. The project had three consortia of UK institutes and universities, each of which focused on a different scientific topic:

• OXICOA (OXIdising Capacity of the Ocean Atmosphere) - a study of oxidant, radical and related gas-phase chemistry in the clean and moderately polluted marine atmosphere.
• MAGE (Marine Aerosol and Gas Exchange) - a study of aspects of air-sea exchange relevant to atmospheric chemistry and aerosol production.
• (ACE) Aerosol Characterisation Experiment - a study of the processing of gases and aerosols through hill-cap clouds on Tenerife and sub-tropical marine subtropical stratocumuli.

Known affectionately as Snoopy, the C-130 research aircraft is a former transport aircraft operated by the Meteorological Research Flight (MRF), with a Royal Air Force crew. It has a range of 5,000 km and an endurance of up to 12 hours. It can reach a ceiling of 10 km, or can skim the wave-tops at fifty feet. During ACSOE it flew missions over the North Sea and North Atlantic from its home base at Boscombe Down, Wiltshire, and was also detached to the Azores, mainland Portugal, and Tenerife for experiments further afield. It was instrumented in a number of different configurations, depending on the experiment in progress, including a new fit of fast in situ trace gas photochemistry instruments developed specifically for ACSOE. The aircraft has a central data acquisition system that logs data from all of the instruments and an on-board computer system called HORACE. The latter was configured to run various algorithms based on the real-time measurements.

ACSOE data are public. However,

The data provider's name can be found on line 2 of each data file. An electronic contact is also given in the data file header. If the provided address appears out of date, please refer to the List of Data Providers, that includes links to ACSOE participants' addresses. In case a data provider could not be reached, please contact Dr Claire E. Reeves.

N.B. After a restricted access phase intended to protect the rights of ACSOE scientists, data have been progressively released to the public domain from January 2000 to July 2001, following a time chart specified in the ACSOE Implementation Plan. During the restricted access phase, data were only available to users subject to the terms and conditions of the ACSOE Data Protocol which aimed at encouraging rapid dissemination of scientific results while simultaneously protecting the rights of individual scientists.

Access to the archive

• ACSOE Data Directory containing all atmospheric data files (to access a subdirectory, click on its name)
• IDL software to plot NASA-Ames files
• IDL software to plot trajectory files
• Gateway to ACSOE oceanographic data sets held at BODC.

If you need help in downloading the data via the Web or by anonymous FTP, please refer to our Help Desk.

Data file format

• The aims and objectives of the ACSOE programme are defined in the Atmospheric Chemistry Studies in the Oceanic Environment (ACSOE) Science Plan, issued December 1994.
• The BADC ACSOE documentation directory contains a mixture of PostScript and plain-text documents on file naming and formatting, trajectory data etc.
• Information on NASA-Ames format: primarily intended for ACSOE data providers intending to submit data to the BADC, this may also provide a useful introduction for potential users of the data. A newer and more complete documentation on NASA-Ames format is available from the BADC's Formats page.
• The ACSOE final report is available in the BADC ACSOE documentation directory.

• Further details of the ACSOE programme are available from the ACSOE www pages at UEA.
• Routine 5-day back trajectories calculated from ECMWF dynamical data were also made available for an arrival pressure of 900 mb based on three regular latitude / longitude grids centred over the UK., the mid-Atlantic storm track region and the eastern U.S.A. Both ACSOE-specific and routine trajectories are archived at BADC.
• If you are a registered BADC user with access to data distributed by the Met Office, the BADC Trajectory Web Service also allows you to run and plot your own trajectories.
• The ACSOE Web page at BODC is the gateway to the oceanographic data from ACSOE cruises, stored at BODC.
• A list of references is also available.

Natural Environment Research Council, [Allan, B.; Allen, A.; Bandy, B.; Bassford, M.; Bauguitte, S.; Beswick, K.; Bradbury, C.; Brassington, D.; Broadgate, W.; Burgess, R.; Cape, J.N.; Cardenas, L.; Carpenter, L.; Carrick, A.; Choularton, T.W.; Coe, H.; Consterdine, I.E.;Creasey,D.J.; Davison, B.; Edwards, G.D.; Evans, M.; Gerbig, C.; Green, T.; Grenfell, L.; Heard, D.E.; James, J.; Jickells, T.; Law, K.; Lee, J.D.; Lewis, A.C.; Lightman, P.; Liss, P.S.; McArdle, N.; McFadyen, G.; McIntyre H.; McQuaid, J.B.; Mills, G.; Monks, P.S.; Nickless, G.; O'Doherty, S.; Oram, D.; Pilling, M.J.; Plane, J.; Pyle, J.; Reeves, C.; Richer, H.; Robertson, L.; Salisbury, G.; Schmitgen, S.; Shallcross, D.; Simmonds, P.;Smith, M.H.; Spain, G.; Spokes, L.; Sturges, W.; Thompson, A.;Tiddeman, D.; Vaughan, G.; Wild, O.; Wilson, K.; Yeatman, S.; Yoshiteru, I.; Zanis, P.] . Atmospheric Chemistry Studies in the Oceanic Environment (ACSOE/OXICOA) - Testing Atmospheric Chemistry In Anticyclones (TACIA) C-130 data, [Internet]. NCAS British Atmospheric Data Centre, 2007, Date of citation. Available from http://badc.nerc.ac.uk/view/badc.nerc.ac.uk__ATOM__dataent_11746748795418933 .

• If you have queries about these pages or difficulties accessing ACSOE data at the BADC, you should contact the BADC Support.
• Before using a specific data set, you should contact its provider (see Data status above).
• The principal scientific contacts for the ACSOE programme are:
  • Prof Stuart A. Penkett - ACSOE programme leader & OXICOA consortium leader (UEA)
  • Dr William (Bill) T. Sturges - ACSOE programme manager (UEA)
  • Dr Claire E. Reeves - ACSOE database manager (UEA)
  • Prof Peter S. Liss - MAGE consortium leader (UEA)
  • Prof Tom W. Choularton - ACE consortium leader (UMIST)