scholarly journals Changing Patterns in U.S. Air Quality

Eos ◽  
2015 ◽  
Vol 96 ◽  
Author(s):  
Colin Schultz

Over the northeast United States, ground-level ozone will peak in the winter rather than the summer thanks to continued reductions of regional nitrogen oxide emissions from smokestacks and tailpipes.

2012 ◽  
Vol 12 (1) ◽  
pp. 1585-1611
Author(s):  
Y. Choi ◽  
H. Kim ◽  
D. Tong ◽  
P. Lee

Abstract. Simulation results from the Community Multiscale Air Quality (CMAQ) model version 4.7.1 over the Conterminous United States (CONUS) for August 2009 are analyzed to evaluate how satellite-derived O3 sensitivity regimes capture weekly cycles of the U.S. EPA's Air Quality System (AQS) observed ground-level concentrations of ozone (O3). AQS stations are classified according to a geographically-based land use designation or an O3-NOx-VOC chemical sensitivity regime. Land use designations are derived from the Advanced Very High Resolution Radiometer (AVHRR) global land cover characteristic data representing three features: urban regions, forest regions, and other regions. The O3 chemical regimes (NOx-saturated, mixed, and NOx-sensitive) are inferred from low to high values of photochemical indicators based on the ratio of the HCHO to NO2 column density from the Global Ozone Monitoring Experiment 2 (GOME-2) and CMAQ. Both AQS-observed weekly cycles of NOx at measurement sites over AVHRR geographical regions and GOME-2 sensitivity regimes show high NOx on weekdays and low NOx on weekends. However, the AQS-observed O3 weekly cycle at sites over the GOME-2 NOx-saturated regime is noticeably different from that over the AVHRR urban region. Whereas the high weekend O3 anomaly is clearly shown at sites over the GOME-2 NOx-saturated regime in both AQS and CMAQ, the weekend effect is not captured at other sites over the AVHRR urban region. In addition, the weekend effect from AQS is more clearly discernible at sites above the GOME-2 NOx-saturated regime than at other sites above the CMAQ NOx-saturated regime. This study suggests that chemical classifications of GOME-2 chemical regime stations produces better results for weekly O3 cycles than either the CMAQ chemical or AVHRR geographical classifications.


Author(s):  
Teddy Surya Gunawan ◽  
Yasmin Mahira Saiful Munir ◽  
Mira Kartiwi ◽  
Hasmah Mansor

Recently, there is increasing public awareness of the real time air quality due to air pollution can cause severe effects to human health and environments. The Air Pollutant Index (API) in Malaysia is measured by Department of Environment (DOE) using stationary and expensive monitoring station called Continuous Air Quality Monitoring stations (CAQMs) that are only placed in areas that have high population densities and high industrial activities. Moreover, Malaysia did not include particulate matter with the size of less than 2.5μm (PM2.5) in the API measurement system. In this paper, we present a cost effective and portable air quality measurement system using Arduino Uno microcontroller and four low cost sensors. This device allows people to measure API in any place they want. It is capable to measure the concentration of carbon monoxide (CO), ground level ozone (O3) and particulate matters (PM10 & PM2.5) in the air and convert the readings to API value. This system has been tested by comparing the API measured from this device to the current API measured by DOE at several locations. Based on the results from the experiment, this air quality measurement system is proved to be reliable and efficient.


Author(s):  
L. Petry ◽  
H. Herold ◽  
G. Meinel ◽  
T. Meiers ◽  
I. Müller ◽  
...  

Abstract. This paper proposes a novel approach to facilitate air quality aware decision making and to support planning actors to take effective measures for improving the air quality in cities and regions. Despite many improvements over the past decades, air pollutants such as particulate matter (PM), nitrogen dioxide (NO2) and ground-level ozone (O3) pose still one of the major risks to human health and the environment. Based on both a general analysis of the air quality situation and regulations in the EU and Germany as well as an in-depth analysis of local management practices requirements for better decision making are identified. The requirements are used to outline a system architecture following a co-design approach, i.e., besides scientific and industry partners, local experts and administrative actors are actively involved in the system development. Additionally, the outlined system incorporates two novel methodological strands: (1) it employs a deep neural network (DNN) based data analytics approach and (2) makes use of a new generation of satellite data, namely Sentinel-5 Precursor (Sentinel-5P). Hence, the system allows for providing areal and high-resolution (e.g., street-level) real-time and forecast (up to 48 hours) data to inform decision makers for taking appropriate short-term measures, and secondly, to simulate air quality under different planning options and long-term actions such as modified traffic flows and various urban layouts.


2007 ◽  
Vol 39 (1) ◽  
pp. 103-119 ◽  
Author(s):  
Burton C. English ◽  
Kim Jensen ◽  
Jamey Menard ◽  
Marie E. Walsh ◽  
Craig Brandt ◽  
...  

The Southeastern United States depends on coal to supply 60% of its electricity needs. The region leads in CO2 emissions and ranks second in emissions of SO2 and NO2. Compared with coal, biomass feedstocks have lower emission levels of sulfur or sulfur compounds and can potentially reduce nitrogen oxide emissions. This study examines the economic impacts of cofiring biomass feedstocks with coal in coal-fired plants under three emission credit and two cofiring level scenarios. Economic impacts are estimated for producing, collecting, and transporting feedstock; retrofitting coal-fired utilities for burning feedstock; operating cofired utilities; and coal displaced from burning the feedstock.


2020 ◽  
pp. 81-119
Author(s):  
Paul F. Meier

Coal has two main energy applications, with about 90% used for electricity generation and 10% used for commercial and residential heating. In terms of electricity generation in the United States, coal is responsible for about 28%, a significant decrease from 53% twenty years earlier when it was the leading energy for producing electricity. There are two primary commercial methods for generating electricity from coal including pulverized coal combustion and fluidized bed coal combustion. To safely burn coal, sulfur, nitrogen, and heavy metals are removed at the electric plant. The sequestering of sulfur and nitrogen are important steps for limiting acid rain and ground level ozone. To generate electricity, the United States has about 360 coal plants with about 790 generators, of which greater than 90% use pulverized coal technology. Most coal is transported by rail.


Earth's atmosphere is made of two gases Nitrogen and Oxygen. Five major air pollutants are Ground level Ozone, Airborne particles or aerosols, Carbon monoxide, Sulfur dioxide, Nitrogen dioxide. Air pollutants risky to human health are Ground level Ozone and Aerosols. They are the main ingredients of Smog . The ground level ozone is formed when sunlight reacts with certain chemical emissions like nitrogen dioxide, carbon monoxide or methane These chemicals are emitted from industrial waste, car exhaust, gasoline vapors etc. Air quality is measured with the Air Quality Index. An AQI under 50 is considered as good air quality however as the AQI number increases , it becomes a concern for human health . Researcher measured the PM level (PM 2.5 and PM 10), temperature, Humidity and other related parameters continuously on different woods in different times in a fixed size room and constrained environment to establish that Yagya is a reliable source to reduce environment pollution .


2010 ◽  
Vol 10 (10) ◽  
pp. 4931-4952 ◽  
Author(s):  
S. N. Smith ◽  
S. F. Mueller

Abstract. A natural emissions inventory for the continental United States and surrounding territories is needed in order to use the US Environmental Protection Agency Community Multiscale Air Quality (CMAQ) Model for simulating natural air quality. The CMAQ air modeling system (including the Sparse Matrix Operator Kernel Emissions (SMOKE) emissions processing system) currently estimates non-methane volatile organic compound (NMVOC) emissions from biogenic sources, nitrogen oxide (NOx) emissions from soils, ammonia from animals, several types of particulate and reactive gas emissions from fires, as well as sea salt emissions. However, there are several emission categories that are not commonly treated by the standard CMAQ Model system. Most notable among these are nitrogen oxide emissions from lightning, reduced sulfur emissions from oceans, geothermal features and other continental sources, windblown dust particulate, and reactive chlorine gas emissions linked with sea salt chloride. A review of past emissions modeling work and existing global emissions data bases provides information and data necessary for preparing a more complete natural emissions data base for CMAQ applications. A model-ready natural emissions data base is developed to complement the anthropogenic emissions inventory used by the VISTAS Regional Planning Organization in its work analyzing regional haze based on the year 2002. This new data base covers a modeling domain that includes the continental United States plus large portions of Canada, Mexico and surrounding oceans. Comparing July 2002 source data reveals that natural emissions account for 16% of total gaseous sulfur (sulfur dioxide, dimethylsulfide and hydrogen sulfide), 44% of total NOx, 80% of reactive carbonaceous gases (NMVOCs and carbon monoxide), 28% of ammonia, 96% of total chlorine (hydrochloric acid, nitryl chloride and sea salt chloride), and 84% of fine particles (i.e., those smaller than 2.5 μm in size) released into the atmosphere. The seasonality and relative importance of the various natural emissions categories are described.


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