A global assessment of precipitation chemistry and deposition has been carried out under the direction of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) Scientific Advisory Group for Precipitation Chemistry (SAG-PC). The assessment addressed three questions: (1) what do measurements and model estimates of precipitation chemistry and wet, dry and total deposition of sulfu...

Acid deposition is not just a domestic concern; it is also a regional environmental problem that transcends national boundaries. As emphasized in Chapter 9 of Agenda 21 (on transboundary atmospheric pollution), adopted at the 1992 United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro, acid deposition is a problem that requires international cooperative efforts for its ...

Surface-level ozone (O3) is a secondary air pollutant that has adverse effects on human health. In the troposphere, O3 is produced in complex cycles of photochemical reactions involving nitrogen oxides (NOx)and volatile organic compounds (VOCs). Determining if O3 levels will be decreased by lowering NOx emissions (“NOx -sensitive”), VOC emissions (“VOC-sensitive”), or both (“the transition zone”) ...

This report describes a pilot study on aldehyde monitoring in ambient air at a number of locations in the UK. The pilot study was carried out by the National Physical Laboratory (NPL) on behalf of the Department of the Environment, Transport and the Regions (DETR) during the period January - March 2000.Aldehydes form an homologous series of oxygenated organic compounds found in both the natural an...

Urban boundary layers (UBLs) can be highly complex due to the heterogeneous roughness and heating of the surface, particularly at night. Due to a general lack of observations, it is not clear whether canonical models of boundary layer mixing are appropriate in modelling air quality in urban areas. This paper reports Doppler lidar observations of turbulence profiles in the centre of London, UK, as ...

This document is connected to the Directive of the European Parliament and of the Council on ambient air quality and cleaner air for Europe (recast). This document was prepared as part of the "Research Infrastructures Services Reinforcing Air Quality Monitoring Capacities in European Urban & IndustrialAreaS” (RI-URBANS) EU-project that connects the atmospheric observation expertise from the Ae...

The UK Black Carbon research monitoring programme began operation on 1st September 2006. Black carbon concentrations are measured using the Magee Aethalometer, model AE33. The Aethalometer measures the light absorption of carbon particles at seven wavelengths from the near-infrared (950 nm) to the near-ultraviolet (370 nm). Results from channel 880 nm (IR), give the quantitative concentration of '...

This report pictures the methodology established to produce equivalent black carbon mass concentration (eBC) in near real-time (NRT) from absorption coefficients measured by online monitors, such as the Multi-Angle Absorption Photometer (MAAP) or the various Aethalometer models (e.g., AE33) installed at fixed observatory platforms. These instruments are referred here as Filter Absorption Photomete...

These guidelines cover manual Quality Control (QC) of MAAP (Multiangle Absorption Photometer) data.The manual data QC is performed on the level 0 data, i.e. the raw data output, augmented with essential discovery and use metadata, and brought to a standardised data format. For the purpose of manual QC, temporary level 1 and 2 data versions are produced from the initial level 0 version. When perfor...

These guidelines cover manual Quality Control (QC) of AE33 absorption photometer data.The manual data QC is performed on the level 0 data, i.e. the raw data output, augmented with essential discovery and use metadata, and brought to a standardised data format. For the purpose of manual QC, temporary level 1 and 2 data versions are produced from the initial level 0 version. When performing manual Q...