An official website of the United States government
The emergence of low-cost air quality sensors as viable tools for the monitoring of air quality at population and individual levels necessitates the evaluation of these instruments. The Flow air quality tracker, a product of Plume Labs, is one such sensor. To evaluate these sensors, we assessed 34 of them in a controlled laboratory setting by exposing them to PM10 and PM2.5 and compared the response with Plantower A003 measurements. The overall coefficient of determination (R2) of measured PM2.5 was 0.76 and of PM10 it was 0.73, but the Flows’ accuracy improved after each introduction of incense. Overall, these findings suggest that the Flow can be a useful air quality monitoring tool in air pollution areas with higher concentrations, when incorporated into other monitoring frameworks and when used in aggregate. The broader environmental implications of this work are that it is possible for individuals and groups to monitor their individual exposure to particulate matter pollution.
more »
« less
Source Tracing of PM2.5 in a Metropolitan Area Using a Low-Cost Air Quality Monitoring Network: Case Study of Denver, Colorado, USA
Air quality assessments often require source apportioning of the air pollutants observed at the receptor site. Conventional source apportionment models are subject to high uncertainties due to the lack of accurate emission profiles of all the contributing sources and a limited number of measurements at the receptor sites. Recent advances in the development and application of low-cost PM2.5 sensors have facilitated the formation of a more robust database with greater numbers of measurements per location and time. The main objective of this study is to combine a large database of PM2.5 concentration records to records from low-cost sensors in Denver, Colorado, during January 2021. Using wind speed and wind direction at the receptors, we developed a visualization tool for source tracing of PM2.5 with resulting statistical analyses and back-trajectory modeling. For this purpose, a combination of in-house and existing packages of R scripts along with National Oceanic and Atmospheric Administration (NOAA)’s trajectory model and climate and weather toolkits were used. In general, the results show that the PM2.5 measurements obtained from such a network of PM2.5 sensors incorporated with hourly wind field data, which are publicly available, can provide a powerful screening tool to discover the transport pathways of PM2.5 before requiring costly source apportionment approaches. The fraction of PM2.5 concentration detected by each sensor in regard to wind direction and speed bins were quantified using this method. The results of cluster analysis identified the area groups in respect to wind speed and wind direction bins, which shines a light on how far and in which direction polluting sources are. Finally, the back-trajectory modeling outputs illustrated the exact travel path of the PM2.5-laden air parcels of each day to each sensor.
more »
« less
- Award ID(s):
- 2022639
- PAR ID:
- 10654572
- Publisher / Repository:
- MDPI (Multidisciplinary Digital Publishing Institute)
- Date Published:
- Journal Name:
- Atmosphere
- Volume:
- 15
- Issue:
- 7
- ISSN:
- 2073-4433
- Page Range / eLocation ID:
- 797
- Subject(s) / Keyword(s):
- HYSPLIT source apportionment concentration mapping cluster analysis urban aerosol
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Rapid warming is likely increasing primary production and wildfire occurrence in the Arctic. Projected changes in the abundance and composition of carbonaceous aerosols during the summer are likely to impact atmospheric chemistry and climate, but our understanding of these processes is limited by sparse observations. Here, we characterize carbonaceous aerosol at two field sites, Toolik Field Station in the Interior and the Atmospheric Radiation Measurement facility at Utqiaġvik on the Arctic coast of Alaska, USA, through the summers of 2022 and 2023. We estimated particulate matter ≤2.5 micrometers (PM2.5) and particulate matter ≤10 micrometers (PM10) using laser light scattering (PurpleAir sensors) and examined total carbon (TC) and its organic carbon (OC) and elemental carbon (EC) fractions in total suspended particles (TSP). We also investigated the dominant sources of carbonaceous aerosol using air mass backward-trajectories from the National Oceanic and Atmospheric Administration (NOAA) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and radiocarbon source apportionment of TC. We found TC concentrations were about twice as high in the Interior than on the coast and that modern sources were the dominant sources of carbonaceous aerosol at both Toolik (95–99%) and Utqiaġvik (86–89%), with minor contributions from fossil sources. Periods of significantly elevated PM, TC, OC, and EC concentrations coincided with major boreal forest fire activity in North America that brought smoke to the region. The radiocarbon signature of EC measured at Toolik during these wildfire smoke events indicated that over 90% of the EC originated from modern sources. Our measurements demonstrate changing aerosol concentrations in the Arctic during the summer, and emphasize the need for continuous atmospheric monitoring to evaluate and advance our understanding of this rapidly changing atmospheric environment. (Manuscript in prep)more » « less
-
Rapid warming is likely increasing primary production and wildfire occurrence in the Arctic. Projected changes in the abundance and composition of carbonaceous aerosols during the summer are likely to impact atmospheric chemistry and climate, but our understanding of these processes is limited by sparse observations. Here, we characterize carbonaceous aerosol at two field sites, Toolik Field Station in the Interior and the Atmospheric Radiation Measurement facility at Utqiaġvik on the Arctic coast of Alaska, USA, through the summers of 2022 and 2023. We estimated particulate matter ≤2.5 micrometers (PM2.5) and particulate matter ≤10 micrometers (PM10) using laser light scattering (PurpleAir sensors) and examined total carbon (TC) and its organic carbon (OC) and elemental carbon (EC) fractions in total suspended particles (TSP). We also investigated the dominant sources of carbonaceous aerosol using air mass backward-trajectories from the National Oceanic and Atmospheric Administration (NOAA) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and radiocarbon source apportionment of TC. We found TC concentrations were about twice as high in the Interior than on the coast and that modern sources were the dominant sources of carbonaceous aerosol at both Toolik (95–99%) and Utqiaġvik (86–89%), with minor contributions from fossil sources. Periods of significantly elevated PM, TC, OC, and EC concentrations coincided with major boreal forest fire activity in North America that brought smoke to the region. The radiocarbon signature of EC measured at Toolik during these wildfire smoke events indicated that over 90% of the EC originated from modern sources. Our measurements demonstrate changing aerosol concentrations in the Arctic during the summer, and emphasize the need for continuous atmospheric monitoring to evaluate and advance our understanding of this rapidly changing atmospheric environment. (Manuscript in prep)more » « less
-
Demand is expected to accelerate for autonomous air vehicles that transport people and goods, making wind sensors on these vehicles and in the air space where they operate critical to ensure safe control of many simultaneous take-offs and landings. Conventional anemometers such as pitot tubes as well as rotating, heated-element, acoustic, and drag technologies have drawbacks for small and micro-aerial vehicles including high power consumption, high aerodynamic drag, complex signal processing, and high cost. This paper presents an airfoil-shaped anemometer that provides low drag while integrating sensors for measuring wind speed and direction on tethered kites, balloons, and drones. Wind speed is measured by an integrated dual-layer capacitive pressure sensor with a polyvinylidene fluoride (PVDF) diaphragm while wind direction is measured by a 3D digital magnetometer that senses the orientation of the airfoil relative to the earth’s magnetic field. A model is presented for a dual-layer capacitive sensor and validated through quasistatic pressure chamber testing. The capacitive sensor as well as a commercial digital magnetometer are integrated into a NACA 2412 profile airfoil and tested in a laboratory-scale wind tunnel. The capacitive sensor provides a sensitivity of 1.84 fF m 2 s −2 and the airfoil exhibits a unique stable angle-of-attack to within ±2° as measured by the magnetometer.more » « less
-
Small unmanned aircraft systems (sUAS) are rapidly transforming atmospheric research. With the advancement of the development and application of these systems, improving knowledge of best practices for accurate measurement is critical for achieving scientific goals. We present results from an intercomparison of atmospheric measurement data from the Lower Atmospheric Process Studies at Elevation—a Remotely piloted Aircraft Team Experiment (LAPSE-RATE) field campaign. We evaluate a total of 38 individual sUAS with 23 unique sensor and platform configurations using a meteorological tower for reference measurements. We assess precision, bias, and time response of sUAS measurements of temperature, humidity, pressure, wind speed, and wind direction. Most sUAS measurements show broad agreement with the reference, particularly temperature and wind speed, with mean value differences of 1.6 ± 2.6 ∘ C and 0.22 ± 0.59 m/s for all sUAS, respectively. sUAS platform and sensor configurations were found to contribute significantly to measurement accuracy. Sensor configurations, which included proper aspiration and radiation shielding of sensors, were found to provide the most accurate thermodynamic measurements (temperature and relative humidity), whereas sonic anemometers on multirotor platforms provided the most accurate wind measurements (horizontal speed and direction). We contribute both a characterization and assessment of sUAS for measuring atmospheric parameters, and identify important challenges and opportunities for improving scientific measurements with sUAS.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/atmos15070797
