The GPM Ground Validation NCAR Cloud Microphysics Particle Probes MC3E dataset was collected during the Midlatitude Continental Convective Clouds Experiment (MC3E), which took place in central Oklahoma during the April-June 2011 period. The overarching goal was to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterization and space-based rainfall retrieval algorithms over land that had never before been available. The GPM Ground Validation NCAR Cloud Microphysics Particle Probes MC3E dataset was obtained from three instruments carried aboard the University of North Dakota (UND) Cessna Citation aircraft. These probes, the 2D-C, Cloud Imaging Probe (CIP) and High Volume Precipitation Spectrometer (HVPS-3), collected particle size distributions and particle images which were processed by the National Center for Atmospheric Research (NCAR). Data were collected April 22, 2011 through June 2, 2011.

The Particle Habit Imaging and Polar Scattering (PHIPS) Probes IMPACTS dataset consists of cloud particle imagery collected by the Particle Habit Imaging and Polar Scattering (PHIPS) probe onboard the NASA P-3 aircraft during the Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) field campaign. IMPACTS was a three-year sequence of winter season deployments conducted to study snowstorms over the U.S. Atlantic Coast (2020-2023). The campaign aimed to (1) Provide observations critical to understanding the mechanisms of snowband formation, organization, and evolution; (2) Examine how the microphysical characteristics and likely growth mechanisms of snow particles vary across snowbands; and (3) Improve snowfall remote sensing interpretation and modeling to significantly advance prediction capabilities. PHIPS allows for the measurement of particle shape, size, and habit. The browse files in this dataset contain the post-processed particle-by-particle stereo images (2 images from different angles) collected by PHIPS during the campaign. The files are available from January 18, 2020, through February 28, 2023, in PNG format.

The GPM Ground Validation NCAR Cloud Microphysics Particle Probes GCPEx data was collected during the GPM Cold-season Precipitation Experiment (GCPEx), which occurred in Ontario, Canada during the winter season of 2011 through 2012. GCPEx addressed shortcomings in the GPM snowfall retrieval algorithm by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow. The GPM Ground Validation NCAR Cloud Microphysics Particle Probes GCPEx dataset was obtained from three instruments carried aboard the University of North Dakota (UND) Cessna Citation aircraft. These probes, the 2D-C, Cloud Imaging Probe (CIP) and High Volume Precipitation Spectrometer (HVPS-3), collected particle size distributions and particle images which were processed by the National Center for Atmospheric Research (NCAR). Data were collected January 16, 2012 through February 25, 2012. A related cloud microphysics dataset, GPM Ground Validation UND Citation Cloud Microphysics GCPEx is also available.

The Particle Habit Imaging and Polar Scattering (PHIPS) Probes IMPACTS dataset consists of cloud particle imagery collected by the Particle Habit Imaging and Polar Scattering (PHIPS) probe onboard the NASA P-3 aircraft during the Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) field campaign. IMPACTS was a three-year sequence of winter season deployments conducted to study snowstorms over the U.S Atlantic Coast (2020-2023). The campaign aimed to (1) Provide observations critical to understanding the mechanisms of snowband formation, organization, and evolution; (2) Examine how the microphysical characteristics and likely growth mechanisms of snow particles vary across snowbands; and (3) Improve snowfall remote sensing interpretation and modeling to significantly advance prediction capabilities. PHIPS allows for the measurement of particle shape, size, and habit. The browse files included in this dataset contain the post-processed particle-by-particle stereo images (2 images from different angles) collected by PHIPS during the campaign. The files are available from January 18, 2020 through February 25, 2022 in PNG format.

DC3_Cloud_AircraftInSitu_NSF-GV-HIAPER_Data are in-situ cloud data collected onboard the NSF/NCAR GV-HIAPER aircraft during the Deep Convective Clouds and Chemistry (DC3) field campaign. Data collection for this product is complete.The Deep Convective Clouds and Chemistry (DC3) field campaign sought to understand the dynamical, physical, and lightning processes of deep, mid-latitude continental convective clouds and to define the impact of these clouds on upper tropospheric composition and chemistry. DC3 was conducted from May to June 2012 with a base location of Salina, Kansas. Observations were conducted in northeastern Colorado, west Texas to central Oklahoma, and northern Alabama in order to provide a wide geographic sample of storm types and boundary layer compositions, as well as to sample convection.DC3 had two primary science objectives. The first was to investigate storm dynamics and physics, lightning and its production of nitrogen oxides, cloud hydrometeor effects on wet deposition of species, surface emission variability, and chemistry in anvil clouds. Observations related to this objective focused on the early stages of active convection. The second objective was to investigate changes in upper tropospheric chemistry and composition after active convection. Observations related to this objective focused on the 12-48 hours following convection. This objective also served to explore seasonal change of upper tropospheric chemistry.In addition to using the NSF/NCAR Gulfstream-V (GV) aircraft, the NASA DC-8 was used during DC3 to provide in-situ measurements of the convective storm inflow and remotely-sensed measurements used for flight planning and column characterization. DC3 utilized ground-based radar networks spread across its observation area to measure the physical and kinematic characteristics of storms. Additional sampling strategies relied on lightning mapping arrays, radiosondes, and precipitation collection. Lastly, DC3 used data collected from various satellite instruments to achieve its goals, focusing on measurements from CALIOP onboard CALIPSO and CPL onboard CloudSat. In addition to providing an extensive set of data related to deep, mid-latitude continental convective clouds and analyzing their impacts on upper tropospheric composition and chemistry, DC3 improved models used to predict convective transport. DC3 improved knowledge of convection and chemistry, and provided information necessary to understanding the processes relating to ozone in the upper troposphere.

The NAMMA Two-Dimensional Stereo Probe and Cloud Particle Imager dataset consists of data from two probes used to measure the size, shape, and concentration of cloud particles; the two-dimensional stereo probe (2D-S), and the cloud particle imager (CPI). Both of these probes measure particle size distributions and derives extinction, particle concentration, ice water content and particle shape. Both probes provide hi-resolution black and white images of cloud particles. These data files were generated during support of the NASA African Monsoon Multidisciplinary Analyses (NAMMA) campaign, a field research investigation sponsored by the Science Mission Directorate of the National Aeronautics and Space Administration (NASA). This mission was based in the Cape Verde Islands, 350 miles off the coast of Senegal in west Africa. Commencing in August 2006, NASA scientists employed surface observation networks and aircraft to characterize the evolution and structure of African Easterly Waves (AEWs) and Mesoscale Convective Systems over continental western Africa, and their associated impacts on regional water and energy budgets.

The SBU Ceilometers IMPACTS dataset includes ceilometer cloud height measurements collected by the Vaisala CL51, Vaisala CT25K, and Lufft Ceilometer CHM 15k ceilometers operated by the State University of New York (SUNY) Stony Brook University. These data were collected during the Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) field campaign, a three-year sequence of winter season deployments conducted to study snowstorms over the U.S. Atlantic coast. IMPACTS aimed to (1) Provide observations critical to understanding the mechanisms of snowband formation, organization, and evolution; (2) Examine how the microphysical characteristics and likely growth mechanisms of snow particles vary across snowbands; and (3) Improve snowfall remote sensing interpretation and modeling to significantly advance prediction capabilities. The ceilometer dataset files are available from January 1, 2020, through March 2, 2023, in netCDF-3 and netCDF-4 formats.

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.

The UND Cloud Microphysics IMPACTS dataset consists of cloud particle measurements collected during the Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) field campaign. IMPACTS was a three-year sequence of winter season deployments conducted to study snowstorms over the U.S Atlantic Coast (2020-2023). The campaign aimed to (1) Provide observations critical to understanding the mechanisms of snowband formation, organization, and evolution; (2) Examine how the microphysical characteristics and likely growth mechanisms of snow particles vary across snowbands; and (3) Improve snowfall remote sensing interpretation and modeling to significantly advance prediction capabilities. The UND Cloud Microphysics IMPACTS dataset files are stored in ASCII format from January 25, 2020 through February 26, 2020, and from January 6, 2022 through February 25, 2022.

NARSTO_PAC2001_LANGLEY_GAS_PM_MET_DATA was obtained between August 8 and September 2, 2001 during the Pacific 2001 Air Quality Study (PAC2001).The Langley Ecole Lochiel (LEL) site was at 49.0289 N and -122.6025 W and at 90m above sea level (a.s.l). The site was surrounded by hobby farms and by relatively few country roads that are lined with both coniferous and deciduous trees, with little change in terrain heights within a radius of 15 km. Nontraditional agricultural practices, such as mushroom and chicken farming and small orchards, are common within this radius of the site. The nearest small urban center, Langley, is about 6 km north of the site. The site was approximately 10 km to the major expressways of Highway 1 in Canada and I-5 in the US and was approximately 6km to Highway 1A in Canada. Particle sampling was done in the center of an unobstructed field of approximately 30-50m2 about 2.5m from ground. On-site measurements were conducted from five temporary labs with inlets about 5m above ground. Measurements at this site, from August 13th to 31st, were intended to address the unknowns related to particles and ozone, with an emphasis on the transition from the urban mix to a suburban/rural setting, particularly the impact of agricultural sources on the particulate matter formation and evolution. Similar to the instrumentation package at Slocan Park site, the instrumentation package includes measurements in five categories.1) Measurements related to the precursors of fine PM and the oxidation environment in which the fine PM is formed. 2) Measurements related to the characterization of fine PM and the evolution process of PM.3) Measurements related to the emission of fine PM and its precursors in the valley.4) Measurements related to the mapping of fine PM horizontal and vertical distribution in the valley.5) Measurements of meteorological parameters in the valley. Measurements included detailed gas phase measurements of NOx=NOy (total and speciated), CO, O3, SO2, VOCs, OVOCs, carbonyls, NH3, HOx, and NH3 intended for a detailed understanding of the oxidation environment and chemical processes in which both O3 and secondary particulate matter are formed. Detailed measurements were made on size distributed inorganic ionic components, organic carbon, elemental carbon, and mass from 0.05 to 18 mm AD twice a day. High-time resolution measurements using a second AMS were made, measuring the size distribution of inorganic species and homologues of organic species from 0.06 to 0.7 mm. Detailed organic carbon speciation measurements, carbon isotope characterization, sulfur isotope characterization, and amorphous carbon were made for particles 2.5 mm on 10-h day samples collected twice daily. The gas-particle partitioning of semi-volatile organic compounds was studied using a Hi-cap denuder sampling system and detailed lab organic analyses. Continuous mass measurements for particles 2.5 mm were made using a tapered element oscillating microbalance (TEOM)with a diffusion dryer on the inlet. Particle number size distributions were measured from 0.01 to 3 mm using a DMA and an optical probe. Hygroscopic properties of particles were measured at two particle sizes using two DMAs in tandem. For NH3, HNO2, HNO3, HCHO, and PM 2.5 mm mass measurements and the particle chemical size distributions, more than one technique were deployed at this site. The multiple measurements of these species provided a test of the performance and validation of the different techniques and ensure that instrument biases were corrected. They also provide complementing data of different characteristics, such as better sensitivities versus time resolution. The diurnal evolution of the boundary layer height was studied using a scanning LIDAR that scanned the north, east and west quadrants. Radiation measurements, both UV and visible, were done using an Eppley and a CIMEL sun photometer. Vertical distribution of certain parameters, such as O3 and meteorological