Rudolf Husar

Washington University in St. Louis | WUSTL , Wash U · Department of Energy, Environmental, and Chemical Engineering

The global continental haze pattern was evaluated based on daily average visibility data at 7000 surface weather stations over five years, 1994–98. The data processing consisted of three broad categories of filters: (1) validity of individual data points, (2) filters based on statistics for specific stations, and (3) filters based on spatial analys...

An algorithm has been developed to retrieve aerosol size distribution from the spectral extinction measurements by sun photometers. The algorithm considers the aerosol size distribution to be made up of fixed number of narrow log-normal distributions in the size range from 0.1um to 5 um. These sizes are equally spaced on a log-scale with a spacing...

With the recognition of air quality as a transboundary problem the need for harmonizing, harvesting and synthesizing air quality data on the continental and global scale has grown. Observational data from urban, rural and remote surface sites, from regular aircraft flights and from satellites are made available together with numerical analyses and...

Introduction Background on Satellite Remote Sensing Aerosol Physical and Optical Properties Principles of Satellite Aerosol Detection and Measurements Challenges of Satellite Aerosol Measuring Systems Satellite Data and Information Systems Applications Future Developments Acknowledgments List of Acronyms References

Stefan R. Falke received the Charles S. Falkenberg Award at the 2010 AGU Fall Meeting Honors Ceremony, held on 15 December 2010 in San Francisco, Calif. The award honors a ``scientist under 45 years of age who has contributed to the quality of life, economic opportunities, and stewardship of the planet through the use of Earth science information a...

This paper describes the air quality data products and services available through Giovanni, a web based tool for access, visualization, and analysis of satellite remote sensing products, and also model output and surface observations relevant to global air quality. Available datasets include total column aerosol measurements from numerous satellite...

To address a fuller understanding of intercontinental transport of air pollution in the Northern Hemisphere, the Task Force on Hemispheric Transport of Air Pollution (HTAP) is conducting a series of multi-model evaluation and intercomparison experiments to: produce estimates of intercontinental source-receptor relationships; improve our understandi...

This presentation explores the interaction between sensor webs and forecast models and data analysis processes within service oriented architectures (SOA). Earth observation data from surface monitors and satellite sensors and output from earth science models are increasingly available through open interfaces that adhere to web standards, such as t...

There are numerous, distributed Earth observations that are in principle available and useful for societal benefit applications such as analysis of air quality events or renewable energy. Currently, Earth observation providers face challenges efficiently disseminating data to users in needed formats. Data users also face hurdles in finding, accessi...

A current re-engineering of the United States routine ambient monitoring networks intended to improve the balance in addressing both regulatory and scientific objectives is addressed in this paper. Key attributes of these network modifications include the addition of collocated instruments to produce multiple pollutant characterizations across a ra...

Studies show that agricultural and animal feeding operations (AFOs) contribute a considerable amount of ammonia (NH 3) to the atmosphere. Agricultural NH 3 emissions are recognized as an important air quality issue. Biological decomposition of manure from dairy operations results in emissions of NH 3 and other gases. There is a need to determine NH...

The GEOSS Air Quality Community of Practice (CoP) is developing a community catalog and community portals that will facilitate the discovery, access and usage of distributed air quality data. The catalog records contain fields common for all datasets, additional fields using ISO 19115 and a link to DataSpaces for additional, community-contributed m...

Web portals are intended to provide consolidated discovery, filtering and aggregation of content from multiple, distributed web sources targeted at particular user communities. This paper presents a standards-based information architectural approach to developing portals aimed at air quality community collaboration in data access and analysis. An i...

Currently, metadata for air quality datasets is variable, distributed and normally created by the provider for the user. However, a single dataset can be used for many applications that the provider may or may not anticipate and the data may go through many value-adding processes before it reaches the "end user". Additional metadata can be created...

Recent developments in surface and satellite sensing along with new information technologies now allow real- time, 'just-in-time' data analysis for the characterization and partial explanation of the of major air pollution events. The data from surface-based air pollution monitoring networks now provides routinely high grade, spatio-temporal and ch...

Several independent types of information relating to the sources and effects of regional-scale air pollution are reviewed. Much of the information was obtained by in situ observations of plumes and field studies of individual pollution episodes. Attention is given to anthropogenic pollution sources in the U.S. (primarily fossil fuel combustion), ra...

DataFed is a distributed web-services-based computing environment for accessing, processing, and rendering environmental data in support of air quality management and science. The flexible, adaptive environment facilitates the access and flow of atmospheric data from provider to users by enabling the creation of user-driven data processing value ch...

This is a report on the federated data system,DataFed for distributed air quality data. Data sources are federated by applying a universal, multi-dimensional data model. The physical and semantic homogenization is accomplished by wrapper services. Data processing is performed through web services, which themselves can be distributed. Data processin...

The national air quality standards for PM2.5 and ozone provide for the exclusion of data for a given day when it is strongly influenced by "exceptional events" (EE), such as smoke from wildfires or windblown dust. In order to apply for EE exclusion, states must provide appropriate documentation to support the dominance of uncontrollable sources on...

Considerable effort is being devoted to the development, and testing of interoperability standards for data access, such as the OGC Web Services WMS/WCS/WFS. The federated data system, DataFed, developed as a broad partnership utilizes these data access standards to deliver a rich array of quantitative air quality and geospatial data to any client...

Data on atmospheric composition relevant to air quality are collected by numerous organizations through a variety of surface and based and remote sensors. The users of such data include managers, scientist and educators, also spread over the many organizations as they participate in broad programs and pursue specific projects. Emerging IS architect...

AB: The Open Geospatial Consortium (OGC) Web Coverage Service (WCS) revision 1.1 specification includes many modifications that are important to the communities working with existing services and clients based on netCDF (network Common Data Form), THREDDS THematic Real-time Environmental Distributed Data Services), OPeNDAP Open-source Project for N...

Interoperability among data sources and data applications is a fundamental principle in developing networked, reconfigurable environmental information systems, such as GEOSS. Air quality information systems provide a particularly good test environment for data interoperability standards because they involve observations from surface, air, and space...

DataFed is a distributed web-services-based computing environment for accessing, processing and rendering environmental data in support of air quality management and science. The flexible, adoptive environment facilitates the access and flow of atmospheric data from provider to users by enabling the creation of user-driven data processing value cha...

The main scientific challenge in the study of particulate matter (natural or man made) is to understand the immense structural and dynamic complexity of the aerosol system. Dynamic complexity arises from chemical and physical interactions of particles with the non-particle world. The structural complexity arises from the large dimensionality of the...

The scientific examination of the intercontinental dust transport has a long history, a vigorous present, and a promising future. Unlike the study of man-made pollution and biomass smoke, the fundamental causes of dust production, the long-range transport as well as the factors governing the removal processes of windblown dust were well established...

During early July 2002, dense smoke from a number of large forest fires in central Quebec Province was transported south by prevailing winds into the New England and Mid-Atlantic states. Given the high concentrations of smoke, strong flows from the north, and relative absence of other emissions in that direction, this event provides a unique opport...

Co-retrieval of aerosol and land surface reflectance recognizes the fact that land surface reflectance strongly influences the retrieval of aerosols and vice versa. This work utilizes the method of Raffuse to retrieve the aerosol-corrected surface reflectance of haze-free surfaces. The aerosol is retrieved from the excess reflectance (i.e. the diff...

Intercontinental transport of dust has been known for centuries. Recently, satellite observations of dust and smoke transport provide direct and compelling evidence that such global transport is taking place. Also, speciated aerosol chemical monitoring now allows a crude quantification of the magnitude of the intercontinental transport. The dust ov...

Satellite data have been used in air quality management at policy, regulatory and operational levels since the 1970s. The primary contribution of satellites is to provide a synoptic view of the aerosol pattern and transport. This subjective report summarizes the historical satellite data usage in several areas of PM air quality management, includin...

The management of fire, smoke, and air quality is tasked to multiple agencies at federal, state, and local levels. The diversity in data collection methods, data reporting requirements, data formatting schemes, data analysis methods, and data presentation create a daunting challenge for the integration of these data. However, integration of these h...

A synoptic scale transport climatology during days with high and low ozone concentrations was established for five summers from 1991 to 1995 over eastern North America. The airmass transport patterns were estimated from source impact regions derived from forward airmass histories. Daily maximum ozone concentrations were used to define locally and r...

Spaceborne sensors allow near-continuous aerosol monitoring throughout the world. This paper illustrates the fusion of Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) and TOMS satellite data with surface observations and topographic data during four extreme aerosol events: (1) the April 1998 Asian dust storm that impacted the west coast of North Am...

The patterns and trends of haze over the United States for the period of 1980–1995 are presented. Haze measurements are based on human visual range observations at 298 synoptic meteorological stations operated by the United States Weather Service. There was a significant (∼10%) decline in haziness over the 15-yr period. The reductions were evident...

On April 15 and 19, 1998, two intense dust storms were generated over the Gobi desert by springtime low-pressure systems descending from the northwest. The windblown dust was detected and its evolution followed by its yellow color on SeaWiFS satellite images, routine surface-based monitoring, and through serendipitous observations. The April 15 dus...

On April 15 and 19, 1998, two intense dust storms were generated over the Gobi desert by springtime low-pressure systems descending from the northwest. The windblown dust was detected and its evolution followed by its yellow color on SeaWiFS satellite images, routine surface-based monitoring, and through serendipitous observations. The April 15 dus...

This paper discusses statistical methods for mapping monitored air quality data. A key issue in mapping air pollutant concentrations is the proper accounting, or weighting, of high monitor station density urban areas and low station density rural areas. Improperly weighting of urban and rural monitors biases estimates in rural areas. The methods pr...

It is important to establish a reliable regional emission inventory of sulfur as a function of time when assessing the possible effects of global change and acid rain. This study developed a database of annual estimates of national sulfur emissions from 1850 to 1990. A common methodology was applied across all years and countries allowing for globa...

The National Oceanic and Atmospheric Administration (NOAA) advanced very high resolution radiometer (AVHRR) is an instrument on a polar orbiting satellite that provides information on global aerosol distributions. The remote sensing algorithm is based on measurements of backscattered solar radiation which yield a measure of the "radiatively equival...

Presented is a Monte Carlo model for the simulation of regional scale transport, transformation, and dry and wet removal. The model was newly re-designed in a modular framework, separating the emissions, transport, and kinetics calculations. The transport module employs a quantized Monte Carlo technique for the simulation of atmospheric boundary-la...

Anthropogenic sulfur dioxide emissions from energy-producing and metal production activities have become an important factor in better understanding the relationship between humans and the environment. Concerns about (1) acid rain effects on the environment and (2) anthropogenic aerosols affecting possible global change have prompted interest in th...

Center for Air Pollution Impact and Trend and Trend Analysis (CAPITA) Ecosystems consisting of producers, consumers and decomposers provide a metaphor for the flow of man-induced materials. Like the biosphere, humans are responsible for large-scale redistribution of chemicals on earth.

In this paper we present regional and seasonal trends of eastern United States haze and compare the haze trends to the corresponding SOx emission trends. Such a comparison may be of interest for both regulatory and scientific studies. The data show that trends in seasonal SOx emissions provide a plausible explanation for the observed seasonal trend...

This study describes the databases assembled for the project Climate and Properties of Atmospheric Aerosols. This database description (metadata) is provided to aid the data usage by other researchers. Applications of the database include atmospheric transmission models (e.g. LOWTRAN), global change studies, air pollution studies, and general contr...

This study examines and integrates two databases containing aerosol species for the fine mass from the NPS-NFPN and NESCAUM monitoring networks. The coarse mass for the NPS-NFPN network is also examined. These networks operated in different parts of the United States, and over different time periods. The final database is then partitioned into the...

This chapter presents historical sulfur emission and deposition trends for regions in the United States and describes methods for assessing changes in water chemistry based on current spatial patterns, ion ratios and empirical models, and paleolimnological approaches. Reconstruction of sulfur deposition trends shows that current deposition to case...

The purpose of the report is to present the methodology for filtering the European meteorological visibility data from undesirable and erroneous data. Seven data filters were devised and imposed on the European synoptic visibility data set. The data set consisted of fourteen years of meteorological data (1973- 1986) for about 1600 station in Europe...

Summarizes the flow of sulfur through the environment using a mass balance framework. Compares human-induced flows of sulfur to natural flows in the air, on land and in water. Presents information on sulfur reserves, emission density (world maps of the latter for atmosphere and rivers) and historical variation in flows. -C.J.Barrow

The overall objective of this project is to derive atmospheric aerosol climatology for the continental areas of the world. This is to be achieved by combining archived meteorological data observations, aerosol monitoring data, and general knowledge on the properties and behavior of aerosols. Exploration of meteorological data is a data intensive pr...

The reduction in visual range in the eastern U.S. is caused largely by sulfate particles. Therefore, it is expected that the spatial distribution and temporal trend of man-made haziness will, to some extent, correspond to the spatial-temporal pattern of sulfur emissions. The purpose of the study is to examine the sulfur emission-haze relationship u...

Epidemiological assessments of population exposures to airborne particles are often hampered by the scarcity of available fine particle mass measurements. In an attempt to overcome this serious problem, we analyze In this paper methods for predicting fine particle (M1) and Inhalable particle (IP) mass concentrations using relative humidity correcte...

A data base of tombstone thickness and depth of emblem inscription at Veterans Administration cemeteries has been compiled by New York University. A subset of measurements for two cemeteries in the vicinity of New York City was selected for analysis in this study. For comparable meteorological conditions, different weathering rates of fine grain ma...

The water and sulfur runoff data for 54 large river basins were assembled, covering 65% of the nondesert land area of the world. The sulfur concentration ranges from 0.5 mg S/L for the West African rivers Niger and Volta to 100 mg S/L in the Colorado River; the world average is 3.2 mg S/L. The concentrations in central and eastern Europe as well as...

During April and May 1980 scattering and extinction coefficients were measured at St. Louis, Mo. The instruments used were a MRI integrating nephelometer model 1550 belonging to the Center of Air Pollution Impact and Trend Analysis and a muhiwavelength telephotometer developed at the Institute for Experimental Physics of the University of Vienna, A...

Extinction coefficients and mass size distributions were measured at St. Louis, MO. and at Vienna, Austria with the same instrumentation (an 11-wavelength automated telephotometer and an 8-stage low pressure cascade impactor, both designed at the University of Vienna). A comparison between the sites gave lower extinction coefficients, mean aerodyna...

The ability of trajectory models and meteorological data bases to simulate long-distance transport of air pollutants is assessed by comparing trajectories of tetroons and tetroon grounding locations from several recent U.S. Environmental Protection Agency field studies with diagnostic trajectories computed from National Weather Service wind measure...

A study of major atmospheric particulate sulfate species was conducted during 30 July 1980–1983 September 1980 in Sterling Forest, a rural area in Tuxedo, NY, not affected by major local sources of pollution. In situ measurements of total sulfate, sulfuric acid and ammonium sulfate ammonium bisulfate were made using Thermal Analysis-Flame Photometr...

Both sulfur and nitrogen pollutants may contribute to acidification of the environment. Measurements indicate that nitric acid is an important contributor to the acidity of snowmelt but that sulfuric acid is the major contributor to rain acidity. In summer nitrate may be utilized by biological processes which effectively neutralize one hydrogen ion...

Continuous measurements of paniculate sulfur and sulfuric acid were taken in St. Louis over a one year period using the in-situ thermal analysis-flame photometric method. These measurements were used to calculate average diurnal patterns for each quarter of the year and also the seasonal pattern for one year. Enhanced formation of paniculate sulfur...

A one week intercomparison study was carried out to evaluate the ability of selected analytical instruments to measure fine paniculate sulfur concentrations. The instruments compared included five modified flame photometric detection systems and an automated dichotomous sampler that was coupled to an on-line, wavelength dispersive X-ray fluorescenc...

Light scattering coefficient and particulate sulfur concentrations were monitored continuously in St. Louis from July 1977 to June 1978. The measurements were made with an in situ aerosol thermal analysis system, which performed a thermal separation on each of the two aerosol parameters. Each parameter was divided into a number of components by vol...

One of the key features of the optical environment over the eastern U.S. is the frequent occurrence of regional haziness, particularly during the summer season. Four historical data bases were examined for estimation of the regional trend in haziness over the past 80 years: the surface visibility observations currently operated by the National Weat...

An airborne in-situ particulate sulfur monitor based on the FPD principle has been developed and tested. The lower detection limit for particulate sulfur is about 1 ppb(4 μg SO4 m−3). Time response to 90% of signal is about 5 s. The characteristic FPD zero drift caused by changes in pressure, humidity and other environmental factors has been compen...

The seasonal fate of pollutant emissions from eastern North America, Europe and East Asia during 1974 is examined via 850 mbar forward trajectories of 20 days duration. Simple pure-decay kinetic scenarios are presented for atmospheric residence times of 5 and 10 days to illustrate the spatial extent of the continental plumes. The 20-day cutoff scen...

The daily distribution of sulfate concentration over the eastern United States during August 1977 is simulated by a Monte Carlo model using quantized emissions, positioned in accordance with the 1973 EPA SOâ emission inventory. Horizontal advection within a single well-mixed vertical layer is driven by observed surface winds, speeded by a factor of...

During July 1977 and again in February 1978 in St. Louis, Missouri, episodes of about 3-day duration occurred in which sulfuric acid persisted as part of the regional haze aerosol. These sulfuric acid episodes were monitored with 15-min time resolution by a thermal analysis-flame photometric detection particulate sulfur monitor. The measurement tec...

In recent years the problems posed by air pollution have been tackled by people who previously had little in common… As research in air pollution proceeds, scientists become educated in related disciplines: the engineer and chemist learn some meteorology, the fluid dynamicist some medicine; all become aware of the associated economic and legislativ...

As part of the 1976 field program of Project MISTT, the plume of the coal-fired Labadie power plant near St Louis was positively identified and sampled from aircraft over a range exceeding 300 km and 10 h of transport during day and night on July 9 and July 18. Measurements were made of SO2, NOx, ozone, particulate sulfur and various other pollutan...

As part of the Midwest Interstate Sulfur Transformation and Transport (MISTT) study, the summer sulfur budget of the plume of the 2400 MW coal-fired Labadie power plant near St. Louis, Missouri is assessed via aircraft data, ground monitoring network data, and a two-box model. The particulate sulfur (Sp) formation rate is obtained from three-dimens...

The sulfur component of the St. Louis ambient aerosol has been continuously monitored using a flame photometric detector (FPD) to measure particulate sulfur concentration, and in situ thermal analysis to chemically analyze the aerosol for H2SO4 and its ammonium salts, NH4SO4, (NH4)3H(SO4)2, and (NH4)2SO4. During the sixteen day monitoring period, t...

A key question in the current energy debate concerns the economic and environmental costs of increased coal usage as a replacement for gas and oil. The environmental constraints are due to mining, transportation, and the release of combustion products (SOx, CO2, and fly ash). Sulfur oxide emissions and their effect on the environment were under int...

It is envisioned that the energy air pollution relationship is a closed loop system driven by the urge of man to increase his well-being, and eroding some of the quality of life through the environmental impact of his actions. For the sake of scientific rigor and depth, the symposium was confined to transport, transformation, and removal processes...

Each paper was abstracted and indexed separately for EDB. (JGB)

Eddy-correlation measurements of the vertical flux of particles in the size range of 0.05-0.1 μm indicate that the deposition velocity at 5 m above a moderately rough surface varies from 1.0-0.1 cm s−1 in light winds. These velocities are only slightly less than the corresponding estimates for momentum and a few gases that are highly reactive at th...

Data from a three-dimensional pollutant mapping program, conducted in the Los Angeles basin, were analyzed to obtain 'grand average' vertical profiles samples on 24 summer days in 1973. Morning and afternoon profiles at four locations show an erosion of the nighttime radiation inversion, increased temperatures, more intense mixing in the inland are...

Characteristics and applications of a detector for the sensing of rapidly changing concentrations of submicron aerosols are discussed. The fast-response device relies on the principle of diffusion charging and subsequent detection of charged aerosols. Field tests involving simultaneous automobile exhaust monitoring by a CO detector, a nephelometer...

An apparatus for monitoring the mass concentration of atmospheric pollutants above and below a predetermined size is described. A receptacle has an air inlet and outlet. Air is continuously drawn through the inlet and thence through the receptacle and the outlet. A first collector in the receptacle collects pollutants above the predetermined size....

In October 1975, General Motors sponsored a study of sulfate exposures utilizing a fleet of catalyst equipped motor vehicles in controlled, simulated, highway driving conditions. This paper reports some EPA sponsored measurements. Sulfuric acid aerosol, in the Aitken nuclei mode, geometric mean diameter (GMD) of about 0.02 µm, is emitted in the exh...

The development and long range transport of synoptic scale haziness affecting much of the eastern U.S. is studied using daily visibility contours, air parcel trajectories and air quality data. It is shown that sulphates and ozone are major ingredients of the associated air pollution over large exposed areas. (A)

Application of vaporization flame-photometric detector (FPD) method for analysis of submicrogram amounts (> 0.3 μg) of atmospheric particulate sulfur for samples collected in plumes is described. Aerosol is deposited on a portion (0.3 cm2) of a light weight, low pressure drop glass-fiber filter with a consistent, low sulfur blank of 0.36–0.5μg cm−2...

The origin of the yellow-brown coloration of the Los Angeles smog layer was investigated theoretically by solving the radiation transfer equation for an optically thin (in vertical direction) scattering and absorbing haze layer. Using the available data on NO2 absorption and smog aerosol size spectra, it was found that in addition to the NO2 absorp...

An SMS/GOES 1 n mi visible image taken an 30 June 1975 reveals a massive area of atmospheric turbidity over the central and eastern United States. This was during the midpoint of a two-week air stagnation episode engulfing the Plains to the East Coast. It is shown that image “haziness” is correlated to midday surface visibility reports, which are i...

Emissions from metropolitan St. Louis caused reduced visibilities and concentrations of ozone in excess of the federal ambient standard (0.08 part per million) 160 kilometers or more downwind of the city on 18 July 1975. Atmospheric production of ozone and visibility-reducing aerosols continues long after their primary precursors have been diluted...