NARSTO_PAC2001_GVRD_CAPMON_AIR_QUAL_DATA is the North American Research Strategy for Tropospheric Ozone (NARSTO) Pacific 2001 Air Quality Study (PAC2001) Greater Vancouver Regional District (GVRD) and and Canadian Air and Precipitation Monitoring Network (CAPMoN) Supplemental Air Quality Data product. Data was obtained from January 1, 2001 to January 1, 2002. Air quality monitoring data routinely collect by the GVRD CAPMoN during the sampling period of PAC2001, are included as supplemental data for PAC2001.The GVRD monitoring network of 20 sites continued operation during the PAC2001 field study period, with enhanced quality assurance (QA) and quality control (QC) activities. At all sites, meteorological measurements were carried out at a 5-min time resolution. At a few specially equipped sites, particle mass PM10 were measured using tapered element oscillating microbalances (TEOMs). The network data complements the special study sites and form a spatial distribution of the pollutants. CAPMoN is a non-urban air quality monitoring network with siting criteria designed to ensure that the measurement locations are regionally representative (not affected by local sources of air pollution).The objectives were to determine the spatial patterns and establish the temporal trends of pollutants related to acid rain; provide for long-range transport model evaluations and effects research (aquatic, terrestrial, building materials and health); ensure the compatibility of federal, provincial and U.S. measurements; and study atmospheric processes. Scientists involved with the measurement of atmospheric pollution in urban centers would consider most CAPMoN sites to be remote and pristine. There are currently 19 measurement sites in Canada and 1 in the U.S. The Saturna Island site is located in the PAC2001 area of interest. PAC2001 was conducted from 1 August to 31 September 2001 in the Lower Fraser Valley (LFV), British Columbia, Canada. The study consisted of individual research projects organized to address several issues on ambient particulate matter and ozone that are important to policy makers. A special issue of Atmospheric Environment [Vol. 38(34), Nov 2004] described specific study objectives (Li, 2004) and presented a series of results papers from the field study. The ground sampling sites during the study were (1) Cassiar Tunnel, (2) Slocan Park, (3) Langley Ecole Lochiel, (4) Sumas Eagle Ridge, and (5) Golden Ears Provincial Park. Aloft measurements were taken from a Convair 580 and a Cessna 188. Selected measurement data were compiled for each site and aircraft and are archived as site-specific data sets.North American Research Strategy for Tropospheric Ozone (NARSTO), which has since disbanded, was a public/private partnership, whose membership spanned across government, utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission was to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are still available.