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Management and operation of the UK acid deposition network - New Contract - AQ0620



The Acid Deposition Monitoring Network was established in 1986 to monitor the composition of precipitation and hence to provide information on the deposition of acidifying compounds in the UK. The aims of the rainwater sampling programme are to provide (1) high quality data which can be used to identify trends with time and (2) information on the spatial distribution of acid deposition in the UK. In addition to the sampling of rainwater at the network sites, a range of other measurements are made which provide a more complete understanding of precipitation chemistry in the UK.

The measurements made in these networks have been, and continue to be, key inputs into the expert reviews of our understanding of acid deposition, provided formerly by the Review Group on Acid Rain and more recently by the National Expert Group on Transboundary Air Pollution (NEGTAP). In addition, wet deposition and particulate sulphate measurements have long been key inputs to the Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (EMEP). Rainfall composition, daily particulate sulphate and gas/particle ratio measurements made within the Acid Deposition Monitoring Network are submitted to EMEP as part of the UK’s Acidification and Eutrophication requirements under the new EMEP Monitoring Strategy.

Following the tendering of the monitoring contract in January 2006, significant changes were made to the measurement programme, most notably the expansion of the nitric acid denuder network from 12 to 30 sites. Filter-pack measurements of sulphur dioxide were terminated and effectively replaced by measurements made in the expanded denuder network. A small number of acid deposition sampling sites were re-located, where practical, to achieve greater co-location of sampling within this programme (i.e. with the nitric acid denuder measurements) and/or with other national monitoring programmes such as the National Ammonia Monitoring Network. Some diffusion tube monitoring sites not used in the nitrogen dioxide Pollution Climate Mapping work have been closed, allowing triplicate diffusion tubes to be established at sites co-located with automatic chemiluminescence analysers.
Project Documents
• Final Report : Acid Deposition Network 2006-2008_Contract AQ0620 Final Report   (1388k)
Time-Scale and Cost
From: 2006

To: 2008

Cost: £1,014,888
Contractor / Funded Organisations
Air Pollution              
Environmental Protection              
Fields of Study
Air Quality