An Investigation Of Particulate Matter Air Pollution Using Caliop Observations

Particulate matter with aerodynamic diameters smaller than 2.5 µm (PM2.5) contributes greatly to air pollution and poses significant threats to human health. Space-borne passive aerosol measurements, with their large spatial coverage, have been applied for estimating surface-based PM2.5 concentrations. Specifically, column-integrated aerosol optical thickness (AOT) observations, like those from the National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR) instruments, have been leveraged for this task. In this doctoral research study, the issues and limitations with estimating PM2.5 from passively-retrieved MODIS and MISR AOT over the contiguous United States (CONUS) were first explored. Second, the potential of using active space-borne NASA Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) near-surface aerosol extinction retrievals for PM2.5 estimation is studied. This includes exploration of various factors that affect CALIOP aerosol data processing, including the retrieval fill value (RFV) issue that results from CALIOP minimum aerosol detection limits. Next, an innovative approach for deriving PM2.5 concentrations directly from CALIOP near-surface aerosol extinction data has been explored using a bulk-mass-modeling-based method, and were validated against in situ PM2.5 from U.S. Environmental Protection Agency (EPA) ground stations. Lastly, temporal variations of CALIOP-based aerosol vertical distribution, including trends of near-surface aerosol loading, were examined globally and regionally to infer possible changes in surface air quality

Long-Range Transport of Asian Dust and Air Pollutants to Taiwan

Dust storms and long-range transport of pollutants are major environ-mental concerns of Taiwan during the winter monsoon season when north-easterly winds prevail following passages of cold fronts. To quantify the impact on air quality, we develop an objective method to classify and study the long-range transport processes by examining the frontal passages in two representative years. We have found that there is about one frontal passage per week in winter and spring, consistent with the climatological average. The long-range transport events are classified into three types ac-cording to their degrees of impact on levels of dusts and air pollutants in Taiwan, namely dust storms (DS), long-range transport with pollutants (FP), and long-range transport of background air masses (BG). DS cases occurred 4.7 % of the time over 14 months and had a large average PM10 concentra-tion of 127.6 µg m 3 − at Wan-Li station. FP cases occurred 1.9 % of the time and the mean concentration of PM10 during the FP periods was about 85 µg m 3 −. BG cases happened 18.6 % of the time and the mean concentra-tion of PM10 was 32.8 µg m 3−. Dust storms and air pollutants tend to be transported in different air parcels as evidenced by a lack of correlation between dust aerosols and air pollutants. The frequency of local pollution (LP) cases was 71.7 % in winter and spring. The average PM10 concentra-tion of LP cases at the Wan-Li station was 47.4 µg m 3 −. However, about one to two-thirds of the PM10 during LP cases can be attributed to the long

Comparison of Satellite Observations of Nitrogen Dioxide to Surface Monitor Nitrogen Dioxide Concentration

Nitrogen dioxide is one of the U. S. EPA s criteria pollutants, and one of the main ingredients needed for the production of ground-level ozone. Both ozone and nitrogen dioxide cause severe public health problems. Existing satellites have begun to produce observational data sets for nitrogen dioxide. Under NASAs Earth Science Applications Program, we examined the relationship between satellite observations and surface monitor observations of this air pollutant to examine if the satellite data can be used to facilitate a more capable and integrated observing network. This report provides a comparison of satellite tropospheric column nitrogen dioxide to surface monitor nitrogen dioxide concentration for the period from September 1996 through August 1997 at more than 300 individual locations in the continental US. We found that the spatial resolution and observation time of the satellite did not capture the variability of this pollutant as measured at ground level. The tools and processes developed to conduct this study will be applied to the analysis of advanced satellite observations. One advanced instrument has significantly better spatial resolution than the measurements studied here and operates with an afternoon overpass time, providing a more representative distribution for once-per-day sampling of this photochemically active atmospheric constituent

The impact of three recent coal-fired power plant closings on Pittsburgh air quality: A natural experiment

<p>Relative to the rest of the United States, the region of southwestern Pennsylvania, including metropolitan Pittsburgh, experiences high ambient concentrations of fine particulate matter (PM_2.5), which is known to be associated with adverse respiratory and cardiovascular health impacts. This study evaluates whether the closing of three coal-fired power plants within the southwestern Pennsylvania region resulted in a significant decrease in PM_2.5 concentration. Both PM_2.5 data obtained from EPA ground stations in the study region and aerosol optical depth (AOD) data retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard the Terra and Aqua satellites were used to investigate regional air quality from January 2011 through December 2014. The impact of the plant closings on PM_2.5 concentration and AOD was evaluated using a series of generalized additive models. The model results show that monthly fuel consumption of the Elrama plant, which closed in October of 2012, and monthly fuel consumption of both the Mitchell and Hatfield’s Ferry plants, which closed in October of 2013, were significant predictors of both PM_2.5 concentration and AOD at EPA ground stations in the study region, after controlling for multiple meteorological factors and long-term, region-wide air quality improvements. The model’s power to predict PM_2.5 concentration increased from an adjusted <i>R</i>² of 0.61 to 0.68 after excluding data from ground stations with higher uncertainty due to recent increases in unconventional natural gas extraction activities. After preliminary analyses of mean PM_2.5 concentration and AOD showed a downward trend following each power plant shutdown, results from a series of generalized additive models confirmed that the activity of the three plants that closed, measured by monthly fuel consumption, was highly significant in predicting both AOD and PM_2.5 at 12 EPA ground stations; further research on PM_2.5 emissions from unconventional natural gas extraction is needed.</p> <p><i>Implications</i>: With many coal-fired power plants scheduled to close across the United States in the coming years, there is interest in the potential impact on regional PM_2.5 concentrations. In southwestern Pennsylvania, recent coal-fired power plant closings were coupled with a boom in unconventional natural gas extraction. Natural gas is currently seen as an economically viable bridge fuel between coal and renewable energy. This study provides policymakers with more information on the potential ambient concentration changes associated with coal-fired power plant closings as the nation’s energy reliance shifts toward natural gas.</p

Investigating Gradients in Ozone and Temperature with Respect to Lake Breeze Onsets During the 2017 Lake Michigan Ozone Study

Color poster with text, charts, maps, and graphs.The 2017 Lake Michigan Ozone Study (LMOS) was a collaborative, multi-agency field campaign that ran May 22, 2017, through June 22, 2017, in eastern Wisconsin and northeastern Illinois. The UW-Eau Claire mobile platform operated in between Sheboygan, WI, and Grafton WI. We drove an automobile and measured ozone via Personal Ozone Monitor, temperature, and relative humidity via Kestral sensor to investigate ozone gradients between ground monitoring stations at coastal and inland locations north of Milwaukee. The mobile platform deployed on targeted event days to coincide with other LMOS measurements on June 2, 3, 12, 13 and 17th. On June 2nd, a large lake breeze extended in land and ozone observations varied little across the study’s sites; however, on June 3rd there was a shallow lake breeze that formed and large temperature and ozone gradients were observed. The mobile data will be used to discern local ozone gradients in comparison to ground-based WI-DNR and Illinois EPA sites. Investigations using ozone, wind speed and direction, and temperature data collected from WI-DNR and Illinois EPA ground stations will construct an understanding into the onset of lake breezes at different sites will also be presented.University of Wisconsin--Eau Claire Office of Research and Sponsored Program

Estimating PM 2.5 concentration with MODIS for 2013 petrochemical industrial accident

[[abstract]]The concentration of PM 2.5 (Particulate Matter) is an important indicator of air condition. By 2014, there are 73 PM 2.5 monitoring stations established by the Environmental Protection Administration (EPA) in Taiwan. Based on the location and role in the further application, these stations could be classified into six types, namely, general stations, industrial stations, traffic stations, background stations, park stations and others. While the ground stations provide continuous and high precision in-situ observations, satellite borne remote sensing technique could provide a vast area coverage but with limited time epoch information. Among a number of satellite image sensors, MODIS provides a standard scientific product, MOD04, for AOD (Aerosol Optical Depth, AOD) measurement. With MOD04, PM 2.5 concentration could be estimated with correlation and regression to in-situ measurements. This study utilized the 73 EPA ground stations for an incidence occurred on Feb. 14, 2013 and Mar. 5, 2014 in the sixth naphtha cracker of Formosa Plastic Group. The result shows that the correlation index R2 between AOD and PM 2.5 is 0.50. While the AOD measurements derived from satellite images offer a way for estimating PM 2.5 concentration, further improvement in the modeling and data processing is required for reducing the uncertainty