The NARSTO_PAC2001_CESSNA_VOC_PM_OZONE_MET_DATA were obtained between August 14 and August 31, 2001 during the Pacific 2001 Air Quality Study (PAC2001).The missions of the Canadian Forest Service (CFS) Cessna 188 were to support the ground-based measurements at the Slocan Park (SL) site, the Langley Ecole Lochiel (LEL) site, and the Eagle Ridge site on Sumas Mountain (SER). Integration of the measurements on the Cessna with ground measurements was envisioned to provide the vertical chemical and thermal structure of the lowest part of the boundary layer at the sites, and how particle characteristics changes with altitude within the boundary layer. The Cessna flights included profiling and specialized flight patterns. The profiling was made over the sites and at the model boundaries. The profiling provided vertical profiles of O3, particle number size distribution from 0.12 to and total particle counts, VOCs, and meteorological parameters at these locations. During race-track flight patterns, filters were collected at 50, 100, and 300 m altitudes, for inorganic and OC/EC components. On August 20, based on forecast forward trajectories, the Cessna flew along the trajectories starting from the LEL site at the 500 m altitude in an attempt to understanding the time evolution of particles.The Pacific 2001 Air Quality Study (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.NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is 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 available.

NARSTO_PAC2001_CONVAIR_PM_OZONE_MET_DATA is the North American Research Strategy for Tropospheric Ozone (NARSTO) Pacific 2001 Air Quality Study (PAC2001) Convair Particulate Matter (PM) Ozone (O3) Meteorological Data product. Data was obtained between August 14 and August 30, 2001 during PAC2001. The main mission for the National Research Council (NRC) - Institute for Aerospace Research (IAR) Convair 580 was to map the particle spatial distribution in the valley through remote sensing as well as provide critical meteorological data, particle number size distribution, and O3 profiles. The flights followed mostly meridional and two approximately east-west tracks at 4800 m over the valley for remote sensing using two LIDARs (Strapp and Chevrier, 2001). Spirals from 150-6000 m, for vertical profiles of O3, particle number size distribution, and meteorological parameters, were conducted at the model western boundary at 49.20'N and 123.45' W, at the model southern boundary of 48.25' N and 123.W, as well as during takeoff and landing. A typical flight covered the valley in eight meridional legs, approximately equally spaced, with three of them directly over the ground sites Slocan Park (SP), Langley Ecole Lochiel (LEL), and Sumas Eagle Ridge (SER). East-west flight tracks were flown north and south of the Fraser River, covering most of the urban centers of the valley to probe the urban-suburban-rural gradient, with additional East-West tracks over the North shore lakes to help understand the valley flow situation. The remote sensing was based on aerosol backscattering using upward- and downward-looking LIDARs at the 1064 nm wavelength with a depolarization channel (Strawbridge and Snyder, 2004a). The profiles were obtained during aircraft spirals, specifically located at the western and southern boundaries of the domains of air quality models Urban Airshed Model Variable Grid (UAM-V ) and Model 3/Community Multiscale Air Quality (CMAQ) and were intended as the input as boundary conditions for further modeling. The Convair mission flights covered an area with boundaries roughly corresponding to the model domain of Model 3/CMAQ application to the region, with the eastern boundary at 121.52' 30 W and the western boundary at 123.50' 13 W and extended from 48.30' N to 49.30' N over the mountain tops. On August 26 and August 29, night missions were flown from approximately 9 p.m. to 2 a.m. the next morning, primarily to map the nighttime movement of the urban plume in the main and secondary valleys (Strawbridge and Snyder, 2004b). The ground site overflights provided an assessment of the vertical thermal structure and the extent of particle spatial distribution over the sites. The Pacific 2001 Air Quality Study (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 PM 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. Thre were five ground sampling sites during the study, which included: Cassiar Tunnel, Slocan Park, Langley Ecole Lochiel, Sumas Eagle Ridge, and 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

The NARSTO_EPA_SS_ST_LOUIS_AIR_CHEM_PM_MET_DATA were obtained between April 11, 2001 and July 21, 2003 during the St. Louis - Midwest Supersite program.The overall goal of the St. Louis - Midwest Supersite was to conduct aerosol physical and chemical measurements needed by the health effects community, the atmospheric science community and the regulatory community to properly assess the impact of particulate matter exposure on human health and to develop control strategies to mitigate these effects. Metropolitan St. Louis is a major population center well isolated from other urban centers of even moderate size, and is impacted by both distant and local sources. Local industry includes manufacturing,refining, and chemical plants. St. Louis is climatologically representative of the country's eastern interior, affected by a wide range of synoptic weather patterns and free of localized influences from the Great Lakes, Ocean, Gulf, and mountains. It accordingly provides an ideal environment for studying the sources, transport, and properties of ambient particles.The initial data types included:1) 5-minute PM 2.5 black carbon (880 nm) and uv-absorbing carbon (370 nm) measured by a Magee Scientific Aethalometer (Model AE-21).2) 1-hour PM 2.5 elemental carbon and blank-corrected organic carbon from semicontinuous thermo-optical analysis by the ACE-ASIA method.3) 24-hour PM 2.5 elemental carbon and organic carbon (both blank-corrected) from integrated filter with offline thermo-optical analysis by the ACE-ASIA method.4) 30-minute PM 2.5 metal composition from samples collected with a Semicontinuous Elements in Aerosol Sampler (SEAS) II.5) 5-minute meteorological data (wind, temperature, RH, solar radiation, atmospheric pressure, and precipitation) measured with a Climatronics anemometer, wind vane, thermocouple, lithium chloride sensor, pyranometer, barometer, and tipping bucket.6) 24-hour PM 1.0 filter mass concentration measured by sharp cut cyclone and gravimetric analysis.7) 1-hour PM 2.5 mass measured by an Andersen Continuous Ambient Mass Monitoring System (CAMMS).8) 24-hour PM 2.5 and PM 10 filter mass by Harvard Impactors and laboratory gravimetric analysis.The U.S. EPA Particulate Matter (PM) Supersites Program was an ambient air monitoring research program designed to provide information of value to the atmospheric sciences, and human health and exposure research communities. Eight geographically diverse projects were chosen to specifically address these EPA research priorities: (1) to characterize PM, its constituents, precursors, co-pollutants, atmospheric transport, and its source categories that affect the PM in any region; (2) to address the research questions and scientific uncertainties about PM source-receptor and exposure-health effects relationships; and (3) to compare and evaluate different methods of characterizing PM including testing new and emerging measurement methods. NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is 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 available.

PEM-West-A_Ground_Data is the ground site data collected during the Pacific Exploratory Mission (PEM) West A suborbital campaign. Data utilizing the Nondispersive Infrared Gas Analyzer (NDIR) and chemiluminescence technique are featured in this collection. Data collection for this product is complete.During 1983-2001, NASA conducted a collection of field campaigns as a part of the Global Tropospheric Experiment (GTE) for developing advanced instrumentation to quantify atmospheric trace gases’ sources, sinks, and distribution. Among those was PEM, which intended to improve the scientific understanding of human influence on tropospheric chemistry. Part of the PEM field campaigns (PEM-West) were conducted over the northwestern Pacific region, considered the only major region in the northern hemisphere that is “relatively” free from direct anthropogenic influences. PEM-West was a part of the East Asian/North Pacific Regional Study (APARE). The overarching objectives of PEM-West were 1) to investigate the atmospheric chemistry of ozone (O3) and its precursors over the northwestern Pacific, including the examination of their natural budgets as well as the impact of anthropogenic sources; and 2) to investigate the atmospheric sulfur cycle over the region with emphasis on the relative importance and influence of continental vs marine sulfur sources. The two phases of PEM-West were conducted during differing seasons due to contrasting tropospheric outflow from Asia. The first phase, PEM-West A, was conducted over the western Pacific region off the eastern coast of Asia from September-October 1991, a season characterized by the predominance of flow from mid-Pacific regions. The second phase, PEM-West B, was conducted from February-March 1994, a period characterized by maximum air mass outflow. To accomplish its objectives, the PEM-West campaign deployed the NASA DC-8 aircraft across the northwestern Pacific to gather latitudinal, longitudinal, and vertical profile sampling, as well as extensive sampling in both the marine boundary layer and free troposphere. The aircraft was equipped with a comprehensive suite of in-situ instrument packages for characterization of photochemical precursors, intermediate products, and airmass tracers, including O3, nitric oxide (NO), peroxyacetyl nitrate (PAN), nitrogen oxides (NOy), nonmethane hydrocarbons (NMHCs), hydrogen peroxide (H2O2), acetic acid (CH3OOH), carbon monoxide (CO), and formaldehyde (CH2O). Collectively, these measurements enabled the analyses of the photochemical production/destruction of O3 and the distribution of precursor species. In addition, the DC-8 was equipped with instruments for collecting sulfur measurements, including dimethyl sulfide (DMS), carbonyl sulfide (COS), sulfur dioxide (SO2), and carbon disulfide (CS2). Instruments that collected aerosol composition and microphysical properties were also aboard the DC-8. Both missions deployed a Differential Absorption Lidar (DIAL) system for measurements of O3 vertical profiles above and below the aircraft. One highlight of the project was that flight nine of PEM-West A flew over Typhoon Mireille while it made landfall on the coast of Japan. This allowed for a flight by the DC-8 to study the role of typhoons in the transport of trace gases. Detailed descriptions related to the motivation, implementation, and instrument payloads are available in the PEM-West A overview paper and the PEM-West B overview paper. A collection of the publications based on PEM-West A and B observation are available in the Journal of Geophysical Research special issues: Pacific Exploratory Mission-West Phase A and Pacific Exploratory Mission-West, Phase B (PEM-West B).

PEM-West-B_Aerosol_AircraftInSitu_DC8_Data is the in-situ aerosol data collected onboard the DC-8 aircraft during the Pacific Exploratory Mission (PEM) West B suborbital campaign. Data from the Forward Scattering Spectrometer Probe (FSSP) and the Passive-Cavity Aerosol Spectrometer Probe (PCASP) are featured in this collection. Data collection for this product is complete.During 1983-2001, NASA conducted a collection of field campaigns as a part of the Global Tropospheric Experiment (GTE) for developing advanced instrumentation to quantify atmospheric trace gases’ sources, sinks, and distribution. Among those was PEM, which intended to improve the scientific understanding of human influence on tropospheric chemistry. Part of the PEM field campaigns (PEM-West) were conducted over the northwestern Pacific region, considered the only major region in the northern hemisphere that is “relatively” free from direct anthropogenic influences. PEM-West was a part of the East Asian/North Pacific Regional Study (APARE). The overarching objectives of PEM-West were 1) to investigate the atmospheric chemistry of ozone (O3) and its precursors over the northwestern Pacific, including the examination of their natural budgets as well as the impact of anthropogenic sources; and 2) to investigate the atmospheric sulfur cycle over the region with emphasis on the relative importance and influence of continental vs marine sulfur sources. The two phases of PEM-West were conducted during differing seasons due to contrasting tropospheric outflow from Asia. The first phase, PEM-West A, was conducted over the western Pacific region off the eastern coast of Asia from September-October 1991, a season characterized by the predominance of flow from mid-Pacific regions. The second phase, PEM-West B, was conducted from February-March 1994, a period characterized by maximum air mass outflow. To accomplish its objectives, the PEM-West campaign deployed the NASA DC-8 aircraft across the northwestern Pacific to gather latitudinal, longitudinal, and vertical profile sampling, as well as extensive sampling in both the marine boundary layer and free troposphere. The aircraft was equipped with a comprehensive suite of in-situ instrument packages for characterization of photochemical precursors, intermediate products, and airmass tracers, including O3, nitric oxide (NO), peroxyacetyl nitrate (PAN), nitrogen oxides (NOy), nonmethane hydrocarbons (NMHCs), hydrogen peroxide (H2O2), acetic acid (CH3OOH), carbon monoxide (CO), and formaldehyde (CH2O). Collectively, these measurements enabled the analyses of the photochemical production/destruction of O3 and the distribution of precursor species. In addition, the DC-8 was equipped with instruments for collecting sulfur measurements, including dimethyl sulfide (DMS), carbonyl sulfide (COS), sulfur dioxide (SO2), and carbon disulfide (CS2). Instruments that collected aerosol composition and microphysical properties were also aboard the DC-8. Both missions deployed a Differential Absorption Lidar (DIAL) system for measurements of O3 vertical profiles above and below the aircraft. One highlight of the project was that flight nine of PEM-West A flew over Typhoon Mireille while it made landfall on the coast of Japan. This allowed for a flight by the DC-8 to study the role of typhoons in the transport of trace gases. Detailed descriptions related to the motivation, implementation, and instrument payloads are available in the PEM-West A overview paper and the PEM-West B overview paper. A collection of the publications based on PEM-West A and B observation are available in the Journal of Geophysical Research special issues: Pacific Exploratory Mission-West Phase A and Pacific Exploratory Mission-West, Phase B (PEM-West B).

The NARSTO_EPA_SS_HOUSTON_NO3_SO4_C_DATA files contain continuous measurements of PM2.5 nitrate, PM2.5 sulfate, and PM2.5 carbon collected during August 12, 2000 through November 5, 2001 at the Aldine, Deer Park, and LaPorte Houston Supersite monitoring locations. Nitrate measurements were collected using the R&P 8400N Method. Sulfate and carbon measurements were collected using the Prototype ADI Particulate Sulfate and Carbon Monitor Method.The Houston Supersite is one of several Supersites that was established in urban areas within the United States by the U.S. Environmental Protection Agency (EPA) to better understand the measurement, sources, and health effects of suspended particulate matter (PM). The overall goals were to characterize the composition and identify the sources of particulate matter in Southeastern Texas, to develop and test new methods for characterizing fine particulate matter, and to collect data on the physical and chemical characterization of fine particulate matter that can be used to support exposure and health effects studies.NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is 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 available.