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At least 523 records · Page 29

Measurement of Particulate Pollutants in the Atmosphere

Representative measurements of the mass concentration of particulate matter in the atmosphere are presented, to demonstrate the application of a new type of instrument evolved from aerospace research to various types of particulate pollution and their dynamics. The instrument employs aerodynamic impaction of particles onto an adhesive-coated piezo-electric crystal whose resonant frequency decreases with mass accretion on its surface, with a resulting particulate mass resolution of 10(exp -11) gram. Applications include air basin with aerial measurement of particulate mass concentration, jet aircraft wake, stationary industrial sources, direct on-line measurement of automobile exhaust, and techniques for source detection.

Ckuan, Raymond L.↗

Infrared Laser System for Extended Area Monitoring of Air Pollution

An atmospheric pollution monitoring system using a spectrally scanning laser has been developed by the General Electric Company. This paper will report on an evaluation of a breadboard model, and will discuss applications of the concept to various ambient air monitoring situations. The system is adaptable to other tunable lasers. Operating in the middle infrared region, the system uses retroreflectors to measure average concentrations over long paths at low, safe power levels. The concept shows promise of meeting operational needs in ambient air monitoring and providing new data for atmospheric research.

Snowman, L. R.↗

The Role of Monitoring in Controlling Water Pollution

The purpose of this paper is to provide an overview of trends in the national water pollution control effort and to describe the role of monitoring in that effort, particularly in relation to the responsibilities of the Environmental Protection Agency (EPA). I hope the paper will serve as a useful framework for the more specific discussions of monitoring technology to follow.

Hirsch, Allan↗

National Emission Standards for Hazardous Air Pollutants (NESHAP) Memorandum of Agreement (MOA) Between NASA Headquarters and MSFC (Marshall Space Flight Center) for NASA Principal Center for Review of Clean Air Regulations

This paper presents a memorandum of agreement on Clean Air Regulations. NASA headquarters (code JE and code M) has asked MSFC to serve as principle center for review of Clean Air Act (CAA) regulations. The purpose of the principle center is to provide centralized support to NASA headquarters for the management and leadership of NASA's CAA regulation review process and to identify the potential impact of proposed CAA reguations on NASA program hardware and supporting facilities. The materials and processes utilized in the manufacture of NASA's programmatic hardware contain HAPs (Hazardous Air Pollutants), VOCs (Volatile Organic Compounds), and ODC (Ozone Depleting Chemicals). This paper is presented in viewgraph form.

Caruso, Salvadore V.↗

Joint Group on Pollution Prevention: Partnering for Progress

This viewgraph presentation outlines the Joint Group on Pollution Prevention (JG-PP) partnership. Details are given on what groups comprise JG-PP, the proven methodology for what JG-PP can accomplish, the common problems, joint solutions, and shared efforts, and some of the JG-PP projects.

Hill, R.↗

Desert Dust Layers Over Polluted Marine Boundary Layers: ACE-2 Measurements and ACE-Asia Plans

Aerosols in ACE-Asia are expected to have some commonalties with those in ACE-2, along with important differences. Among the commonalities are occurrences of desert dust layers over polluted marine boundary layers. Differences include the nature of the dust (yellowish in the East Asia desert outflow, vs. reddish-brown in the Sahara Outflow measured in ACE-2) and the composition of boundary-layer aerosols (e.g., more absorbing, soot and organic aerosol in-the Asian plume, caused by coal and biomass burning, with limited controls). In this paper we present ACE-2 measurements and analyses as a guide to our plans for ACE-2 Asia. The measurements include: (1) Vertical profiles of aerosol optical depth and extinction (380-1558 nm), and of water vapor column and concentration, from the surface through the elevated desert dust, measured by the 14-channel Ames Airborne Tracking Sunphotometer (AATS-14); (2) Comparisons of airborne and shipborne sunphotometer optical depths to satellite-retrieved values, with and without desert dust; (3) Comparisons between airborne Sunphotometer optical depth and extinction spectra and those derived from coincident airborne in situ measurements of aerosol size distribution, scattering and absorption; (4) Comparisons between size distributions measured in situ and retrieved from sunphotometer optical depth spectra; (5) Comparisons between aerosol single scattering albedo values obtained by several techniques, using various combinations of measurements of backscatter, extinction, size distribution, scattering, absorption, and radiative flux. We show how analyses of these data can be used to address questions important to ACE-Asia, such as: (1) How do dust and other absorbing aerosols affect the accuracy of satellite optical depth retrievals? How important are asphericity effects? (2) How important are supermicron dust and seasalt aerosols to overall aerosol optical depth and radiative forcing? How well are these aerosols sampled by aircraft inlets and instruments? (3) How consistent are suborbital in situ and remote measurements of aerosols, among themselves and with satellite retrievals? What are the main reasons for observed inconsistencies?

Russell, Philip B.↗

Simulating Local and Intercontinental Pollutant Effects of Biomass Burning: Integration of Several Remotely Sensed Datasets

Burning to clear land for crops and to destroy pests is an integral and largely unavoidable part of tropical agriculture. It is easy to note but difficult to quantify using remote sensing. This report describes our efforts to integrate remotely sensed data into our computer model of tropical chemical trace-gas emissions, weather, and reaction chemistry (using the MM5 mesoscale model and our own Global-Regional Atmospheric Chemistry Simulator). The effects of burning over the continents of Africa and South America have been noticed in observations from several satellites. Smoke plumes hundreds of kilometers long may be seen individually, or may merge into a large smoke pall over thousands of kilometers of these continents. These features are related to intense pollution in the much more confined regions with heavy burning. These emissions also translocate nitrogen thousands of kilometers in the tropical ecosystems, with large fixed-nitrogen losses balanced partially by locally intense fertilization downwind, where nitric acid is rained out. At a much larger scale, various satellite measurements have indicated the escape of carbon monoxide and ozone into large filaments which extend across the Tropical and Southern Atlantic Ocean. Our work relates the source emissions, estimated in part from remote sensing, in part from conventional surface reports, to the concentrations of these gases over these intercontinental regions. We will mention work in progress to use meteorological satellite data (AVHRR, GOES, and Meteosat) to estimate the surface temperature and extent and height of clouds, and explain why these uses are so important in our computer simulations of global biogeochemistry. We will compare our simulations and interpretation of remote observations to the international cooperation involving Brazil, South Africa, and the USA in the TRACE-A (Transport and Atmospheric Chemistry near the Equator - Atlantic) and SAFARI (Southern Africa Fire Atmosphere Research Initiative) and remote-sensing /aircraft/ecosystem observational campaigns.

Chatfield, Robert B.↗

Three-D Simulation of the Origin of the Pollutant Ozone Maxima in the Great African Plume: New Meteorology, New Chemistry for TRACE-A

Burning in South Central Africa is primarily responsible for the vast buildup of ozone in the mid-Atlantic noticeable in the Belem, Brazil, ozonesondes, and also visible in analyses using the Total Ozone Mapping Spectrometer (TOMS). We report on full-scale chemistry simulations for the SAFARI/TRACE-A field period of September-October, 1992. These observational programs provided a wealth of comparison data, including spectacular depictions of the vertical structure of ozone and particulate pollution over Africa, South America, and the Equatorial Atlantic [Browell JGR, 1996, submitted] above and below the NASA DC-8 airplane path. These depictions provide strict tests on the ability of a 3-d simulation and its controlling input parameters, most notably the biomass burning emissions strength. We use meteorology from MM5 used as a synoptic assimilation model and our own GRACES Global Regional Air Chemistry Event Simulator. This report will focus on the unique meteorology of the Equatorial Atmosphere around the Gulf of Guinea during the TRACE-A period, which we describe as "the opening of the gate," "the Great African Plume," and the "African Recirculatory System." We expect to assess whether the ozone observed is primarily "transported African smog," the standard view, or whether "re-$NO_[x)$-ification" of the Central Atlantic troposphere (reduction of nitric acid to active nitrogen oxides in clouds or aerosol) may be required for "extended intercontinental ozone production." A status report on a second nitrogen problem, "lower-tropospheric missing NO(y)," in which we find a serious imbalance in the $NO_ {x }$ and $NO_{y}$ budgets when compared with similar atmospheric tracers, will be given. An elaboration of the concepts set off by quotation marks in this abstract will be given in the talk.

Chatfeild, Robert↗

Innovation for Pollution Control

Kinetic Controls Inc.'s refuse-fired steam generating facility led to the development of an air pollution equipment control device. The device is currently marketed by two NASA/Langley Research Center employees. It automatically senses and compensates for the changes in smoke composition when refuse is used as a fuel by adjusting the precipitator's voltage and current to permit maximum collection of electrically charged dust particles. The control adapts to any electrostatic precipitator and should have extensive commercial applications.

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Pollution Detection Devices

Barringer Research, Inc.'s COSPEC IVB (correlation spectrometer) can sense from a considerable distance emissions from a volcanic eruption. Remote sensor is capable of measuring sulfur dioxide and nitrogen dioxide in the atmosphere. An associated product, GASPEC, a compression of Non-dispersive Gas Filter Spectrometer, is an infrared/ultraviolet gas analyzer which can be used as either a ground based detector or in aircraft/spacecraft applications. Extremely sensitive, it is useful in air pollution investigations for detecting a variety of trace elements, vapors, which exist in the atmosphere in small amounts.

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Pollution Measuring System

Research Ventures, Inc.'s visiplume is a portable, microprocessor-controlled air pollution monitor for measuring sulfur dioxide emissions from fossil fuel-fired power plants, and facilities that manufacture sulfuric acid. It observes smokestack plumes at a distance from the stack obviating the expense and difficulty of installing sample collectors in each stack and later analyzing the samples.

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Convective Lofting Links Indian Ocean Air Pollution to Paradoxical South Atlantic Ozone Maxima

We describe a broad resolution of the "Atlantic Paradox" concerning the seasonal and geographic distribution of tropical tropospheric ozone. We describe periods of significant maximum tropospheric O3 for Jan.-April, 1999, exploiting satellite estimates and SHADOZ (Southern Hemisphere Additional Ozonesondes). Trajectory analyses connecting sondes and Total Tropospheric Ozone (TTO)O3 maps suggest a complex influence from the Indian Ocean: beginning with mixed combustion sources, then low level transport, cumulonimbus venting, and finally high-level transport to the west, with possible mixing over Africa. For the Jan.- March highest column-O3 periods in the Atlantic, distinct sounding peaks trace to specific NO sources, especially lightning, while in the same episodes, recurring every 30 or 60 days, more diffuse buildups of Indian-to-Atlantic pollution make important contributions.

Chatfield, Robert B.↗

Development of a Real-Time Environmental Monitoring System, Life Cycle Assessment Systems, and Pollution Prevention Programs

Pollution prevention (P2) opportunities and Greening the Government (GtG) activities, including the development of the Real-Time Environmental Monitoring System (RTEMS), are currently under development at the NASA Glenn Research Center. The RTEMS project entails the ongoing development of a monitoring system which includes sensors, instruments, computer hardware and software, plus a data telemetry system.Professor Kocher has been directing the RTEMS project for more than 3 years, and the implementation of the prototype system at GRC will be a major portion of his summer effort. This prototype will provide mulitmedia environmental monitoring and control capabilities, although water quality and air emissions will be the immediate issues addressed this summer. Applications beyond those currently identified for environmental purposes will also be explored.

Kocher, Walter M.↗

Clean Air Slots Amid Dense Atmospheric Pollution in Southern Africa

During the flights of the University of Washington's Convair-580 in the Southern African Regional Science Initiative (SAFARI 2000) in southern Africa, a phenomenon was observed that has not been reported previously. This was the occurrence of thin layers of remarkably clean air, sandwiched between heavily polluted air, which persisted for many hours during the day. Photographs are shown of these clean air slots (CAS), and particle concentrations and light scattering coefficients in and around such slot are presented. An explanation is proposed for the propensity of CAS to form in southern Africa during the dry season.

Hobbs, Peter V.↗

Convective lofting links Indian Ocean air pollution to paradoxical South Atlantic ozone maxima

We describe a broad resolution of the Atlantic Parado concerning the seasonal and geographic distribution, of tropical tropospheric ozone. We highlight periods of significant maximum tropospheric O3 for Jan.- April, 1999, exploiting satellite estimates and SHADOZ (Southern Hemisphere Additional Ozonesondes). Trajectory analyses connecting sondes and Total Tropospheric Ozone (TTO) maps suggest a complex influence from the Indian Ocean: beginning with mixed combustion sources, then low level transport, cumulonimbus venting, possible stratospheric input, and finally high-level transport to the west, with possible mixing over Africa. For the Jan.-March highest column-O3 periods in the Atlantic, distinct sounding peaks trace to specific NO sources, especially lightning, while in the same episodes, recurring every 20-50 days, more diffuse buildups of Indian-to-Atlantic pollution make important contributions.

Chatfield, R. B.↗

"Weekend-effect" evidence for intensification of storms by pollution over U.S.

Aerosols change the way precipitating clouds evolve, due to their effect on condensation and ice formation. The net effect of aerosols on precipitation varies depending on the local environment and synoptic situation, the types of aerosols, and also on how far downstream one looks for effects. Repeated experiments with controlled release of aerosols would be helpful in unraveling how aerosols affect precipitation. The weekly variation in human activity may provide just such a set of experiments. Using the rainfall estimates from the passive microwave instrument on the Tropical Rainfall Measuring Mission (TRMM), which has been orbiting for over eight years and can view areas as far north as about 40 degs, we find that there is indeed a weekly variation in summer (JJA) rainfall over the southeastern U.S. land area, with the average rain rate peaking in the middle of the week (Tue-Thu). Rainfall over nearby oceanic areas, on the other hand, seems to peak on weekends. A bootstrap statistical test indicates that the variations are unlikely to be due to chance. Physically related weekly variations in the statistics of ground-based measurements and model reanalysis data are found. The midweek peak in rainfall over land coincides with the well documented midweek peak in pollution around much of the U.S., and is unlikely to be due to other weekly variations in human influence. The midweek increase is also unlikely to be a consequence of the radiative heating or cooling of the atmosphere by the aerosols.

Bell, T. L.↗

Linking Asthma Exacerbation and Air Pollution Data: A Step Toward Public Health and Environmental Data Integration

Studies have shown that reducing exposure to triggers such as air pollutants can reduce symptoms and the need for medication in asthma patients. However, systems that track asthma are generally not integrated with those that track environmental hazards related to asthma. Tlvs lack of integration hinders public health awareness and responsiveness to these environmental triggers. The current study is a collaboration between health and environmental professionals to utilize NASA-derived environmental data to develop a decision support system (DSS) for asthma prediction, surveillance, and intervention. The investigators link asthma morbidity data from the University of Mississippi Medical Center (UMMC) and Mississippi Department of Health (MDH) with air quality data from the Mississippi Department of Environmental Quality (MDEQ) and remote sensing data from NASA. Daily ambient environmental hazard data for PM2.5 and ozone are obtained from the MDEQ air quality monitoring locations and are combined with remotely sensed data from NASA to develop a state-wide spatial and time series profile of environmental air quality. These data are then used to study the correlation of these measures of air quality variation with the asthma exacerbation incidence throughout the state over time. The goal is to utilize these readily available measures to allow real-time risk assessment for asthma exacerbations. GeoMedStat, a DSS previously developed for biosurveillance, will integrate these measures to monitor, analyze and report the real-time risk assessment for asthma exacerbation throughout the state.

Faruque, Fazlay↗

Smoke and Pollution Aerosol Effect on Cloud Cover

Pollution and smoke aerosols can increase or decrease the cloud cover. This duality in the effects of aerosols forms one of the largest uncertainties in climate research. Using solar measurements from Aerosol Robotic Network sites around the globe, we show an increase in cloud cover with an increase in the aerosol column concentration and an inverse dependence on the aerosol absorption of sunlight. The emerging rule appears to be independent of geographical location or aerosol type, thus increasing our confidence in the understanding of these aerosol effects on the clouds and climate. Preliminary estimates suggest an increase of 5% in cloud cover.

Kaufman, Yoram J.↗