scholarly journals Soot reference materials for instrument calibration and intercomparisons: a workshop summary with recommendations

2012 ◽  
Vol 5 (8) ◽  
pp. 1869-1887 ◽  
Author(s):  
D. Baumgardner ◽  
O. Popovicheva ◽  
J. Allan ◽  
V. Bernardoni ◽  
J. Cao ◽  
...  
Keyword(s):  
Reference Materials ◽  
Atmospheric Chemistry ◽  
Current Knowledge ◽  
Global Climate ◽  
Measurement Techniques ◽  
Measurement Methods ◽  
Standard Reference Materials ◽  
Many Instruments ◽  
Measurement Uncertainties ◽  
Soot Measurement

Abstract. Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure the properties of soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with solar radiation, influence on clouds, and health impacts. A major obstacle currently limiting progress is the absence of established standards or reference materials for calibrating the many instruments used to measure the various properties of soot. The current state of availability and practicability of soot standard reference materials (SRMs) was reviewed by a group of 50 international experts during a workshop in June of 2011. The workshop was convened to summarize the current knowledge on soot measurement techniques, identify the measurement uncertainties and limitations related to the lack of soot SRMs, and identify attributes of SRMs that, if developed, would reduce measurement uncertainties. The workshop established that suitable SRMs are available for calibrating some, but not all, measurement methods. The community of users of the single-particle soot-photometer (SP2), an instrument using laser-induced incandescence, identified a suitable SRM, fullerene soot, but users of instruments that measure light absorption by soot collected on filters did not. Similarly, those who use thermal optical analysis (TOA) to analyze the organic and elemental carbon components of soot were not satisfied with current SRMs. The workshop, and subsequent, interactive discussions, produced a number of recommendations for the development of new SRMs, and their implementation, that would be suitable for the different soot measurement methods.

scholarly journals Soot Reference Materials for instrument calibration and intercomparisons: a workshop summary with recommendations

2012 ◽  
Vol 5 (2) ◽  
pp. 2315-2362 ◽  
Author(s):  
D. Baumgardner ◽  
O. Popovicheva ◽  
J. Allan ◽  
V. Bernardoni ◽  
J. Cao ◽  
...  
Keyword(s):  
Reference Materials ◽  
Atmospheric Chemistry ◽  
Current Knowledge ◽  
Global Climate ◽  
Measurement Techniques ◽  
Measurement Methods ◽  
Standard Reference Materials ◽  
Many Instruments ◽  
Measurement Uncertainties ◽  
Soot Measurement

Abstract. Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with solar radiation, influence on clouds, and health impacts. A major obstacle currently limiting progress is the absence of established standards or reference materials for calibrating the many instruments used to measure the various properties of soot. The current state of availability and practicability of soot standard reference materials (SRMs) was reviewed by a group of 50 international experts during a workshop in June of 2011. The workshop was convened to summarize the current knowledge on soot measurement techniques, identify the measurement uncertainties and limitations related to the lack of SRMs, and identify attributes of SRMs that, if developed, would reduce measurement uncertainties. The workshop established that suitable SRMs are available for calibrating some, but not all, measurement methods. The community of single-particle sootphotometer (SP2) users identified a suitable SRM, fullerene soot, but users of instruments that measure light absorption by soot collected on filters did not. Similarly, those who use thermal optical analysis (TOA) to analyze the organic and elemental carbon components of soot were not satisfied with current SRMs. The workshop produced recommendations for the development of new SRMs that would be suitable for the different soot measurement methods.

scholarly journals Bacteria in the global atmosphere – Part 1: Review and synthesis of literature data for different ecosystems

2009 ◽  
Vol 9 (23) ◽  
pp. 9263-9280 ◽  
Author(s):  
S. M. Burrows ◽  
W. Elbert ◽  
M. G. Lawrence ◽  
U. Pöschl
Keyword(s):  
Atmospheric Chemistry ◽  
Current Knowledge ◽  
Measurement Techniques ◽  
Culturable Bacteria ◽  
Bacterial Cells ◽  
Natural Ecosystems ◽  
Near Surface ◽  
Cloud Development ◽  
Flux Measurements ◽  
Bacterial Concentrations

Abstract. Bacteria are ubiquitous in the atmosphere, with concentrations of bacterial cells typically exceeding 1×104 m−3 over land. Numerous studies have suggested that the presence of bacteria in the atmosphere may impact cloud development, atmospheric chemistry, and microbial biogeography. A sound knowledge of bacterial concentrations and distributions in the atmosphere is needed to evaluate these claims. This review focusses on published measurements of total and culturable bacteria concentrations in the atmospheric aerosol. We discuss emission mechanisms and the impacts of meteorological conditions and measurement techniques on measured bacteria concentrations. Based on the literature reviewed, we suggest representative values and ranges for the mean concentration in the near-surface air of nine natural ecosystems and three human-influenced land types. We discuss the gaps in current knowledge of bacterial concentrations in air, including the lack of reliable, long-term measurements of the total microbial concentrations in many regions and the scarcity of emission flux measurements.

scholarly journals Bacteria in the global atmosphere – Part 1: Review and synthesis of literature data for different ecosystems

2009 ◽  
Vol 9 (3) ◽  
pp. 10777-10827 ◽  
Author(s):  
S. M. Burrows ◽  
W. Elbert ◽  
M. G. Lawrence ◽  
U. Pöschl
Keyword(s):  
Atmospheric Chemistry ◽  
Current Knowledge ◽  
Measurement Techniques ◽  
Culturable Bacteria ◽  
Bacterial Cells ◽  
Natural Ecosystems ◽  
Near Surface ◽  
Cloud Development ◽  
Flux Measurements ◽  
Bacterial Concentrations

Abstract. Bacteria are ubiquitous in the atmosphere, with concentrations of bacterial cells typically exceeding 1×104 m−3 over land. Numerous studies have suggested that the presence of bacteria in the atmosphere may impact cloud development, atmospheric chemistry, and microbial biogeography. A sound knowledge of bacterial concentrations and distributions in the atmosphere is needed to evaluate these claims. This review focusses on published measurements of total and culturable bacteria concentrations in the atmospheric aerosol. We discuss emission mechanisms and the impacts of meteorological conditions and measurement techniques on measured bacteria concentrations. Based on the literature reviewed, we suggest representative values and ranges for the mean concentration in the near-surface air of nine natural ecosystems and three human-influenced land types. We discuss the gaps in current knowledge of bacterial concentrations in air, including the lack of reliable, long-term measurements of the total microbial concentrations in many regions and the scarcity of emission flux measurements.

scholarly journals Towards the development of standard reference materials for soot measurements – Part 1: Tailored graphitized soot

2010 ◽  
Vol 3 (2) ◽  
pp. 1743-1773
Author(s):  
O. Popovicheva ◽  
R. Subramanian ◽  
D. Baumgardner ◽  
G. Kok ◽  
R. Cary ◽  
...  
Keyword(s):  
Reference Material ◽  
Reference Materials ◽  
Elemental Carbon ◽  
Fossil Fuel ◽  
Measurement Techniques ◽  
Surface Coatings ◽  
Standard Reference Materials ◽  
Fossil Fuel Burning ◽  
Combustion Particles ◽  
Climate And Health

Abstract. The lack of standard reference materials for calibrating, troubleshooting and intercomparing instruments that measure the properties of black carbon, commonly referred to as soot, has been a major obstacle that hinders improved understanding of how climate and health is impacted by this ubiquitous component of the atmosphere. A different approach is offered here as a means of constructing precisely controlled material with fractions of organic carbon (OC) on the surface of elemental carbon (EC) whose structure reflects that of combustion particles found in the atmosphere. The proposed soot reference material (SRM) uses elemental carbon as a basis substrate for surface coatings of organic compounds that are representative of main classes of organics identified in the coverage of soot produced by fossil fuel burning. A number of methods are used to demonstrate the quality and stability of the reference EC and SRM. Comparison of the nominal fraction of OC deposited on the EC substrate with the fraction measured with thermal/optical analysis (TOA) shows excellent agreement. Application of this type of reference material for evaluating the different methods of carbon analysis may help resolve differences that currently exist between comparable measurement techniques when trying to separate OC and EC from ambient samples.

Effect of PM characterization on PM oxidative potential by acellular assays: a review

2020 ◽  
Vol 35 (4) ◽  
pp. 461-470
Author(s):  
Huibin Guo ◽  
Lei Jin ◽  
Sijing Huang
Keyword(s):  
Lung Cancer ◽  
Ascorbic Acid ◽  
Health Risks ◽  
Measurement Techniques ◽  
Measurement Methods ◽  
Redox Properties ◽  
Oxidative Potential ◽  
Cellular Assays ◽  
Copper Manganese ◽  
Risk Ratios

AbstractThe health risks brought by particles cannot be present via a sole parameter. Instead, the particulate matter oxidative potential (PM OP), which expresses combined redox properties of particles, is used as an integrated metric to assess associated hazards and particle-induced health effects. OP definition provides the capacity of PM toward target oxidation. The latest technologies of a cellular OP measurement has been growing in relevant studies. In this review, OP measurement techniques are focused on discussing along with PM characterization because of many related studies via OP measurements investigating relationship with human health. Many OP measurement methods, such as dithiothreitol (DTT), ascorbic acid (AA), glutathione (GSH) assay and other a cellular assays, are used to study the association between PM toxicity and PM characterization that make different responses, including PM components, size and sources. Briefly, AA and DTT assays are sensitive to metals (such as copper, manganese and iron etc.) and organics (quinones, VOCs and PAH). Measured OP have significant association with certain PM-related end points, for example, lung cancer, COPD and asthma. Literature has found that exposure to measured OP has higher risk ratios than sole PM mass, which may be containing the PM health-relevant fraction. PM characterization effect on health via OP measurement display a promising method.

scholarly journals Effects of the Marine Biotoxins Okadaic Acid and Dinophysistoxins on Fish

2021 ◽  
Vol 9 (3) ◽  
pp. 293
Author(s):  
Mauro Corriere ◽  
Lucía Soliño ◽  
Pedro Reis Costa
Keyword(s):  
Okadaic Acid ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Current Knowledge ◽  
Global Climate ◽  
Scientific Evidence ◽  
Shellfish Poisoning ◽  
Morphological Alterations ◽  
The Impact ◽  
Dsp Toxins

Natural high proliferations of toxin-producing microorganisms in marine and freshwater environments result in dreadful consequences at the socioeconomically and environmental level due to water and seafood contamination. Monitoring programs and scientific evidence point to harmful algal blooms (HABs) increasing in frequency and intensity as a result of global climate alterations. Among marine toxins, the okadaic acid (OA) and the related dinophysistoxins (DTX) are the most frequently reported in EU waters, mainly in shellfish species. These toxins are responsible for human syndrome diarrhetic shellfish poisoning (DSP). Fish, like other marine species, are also exposed to HABs and their toxins. However, reduced attention has been given to exposure, accumulation, and effects on fish of DSP toxins, such as OA. The present review intends to summarize the current knowledge of the impact of DSP toxins and to identify the main issues needing further research. From data reviewed in this work, it is clear that exposure of fish to DSP toxins causes a range of negative effects, from behavioral and morphological alterations to death. However, there is still much to be investigated about the ecological and food safety risks related to contamination of fish with DSP toxins.

scholarly journals Techniques for analyses of trends in GRUAN data

2015 ◽  
Vol 8 (4) ◽  
pp. 1673-1684 ◽  
Author(s):  
G. E. Bodeker ◽  
S. Kremser
Keyword(s):  
Measurement Uncertainty ◽  
Trend Analysis ◽  
Global Climate ◽  
Regional Climate ◽  
Added Value ◽  
Least Squares Regression ◽  
Target Uncertainty ◽  
Reference Quality ◽  
Measurement Uncertainties

Abstract. The Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) provides reference quality RS92 radiosonde measurements of temperature, pressure and humidity. A key attribute of reference quality measurements, and hence GRUAN data, is that each datum has a well characterized and traceable estimate of the measurement uncertainty. The long-term homogeneity of the measurement records, and their well characterized uncertainties, make these data suitable for reliably detecting changes in global and regional climate on decadal time scales. Considerable effort is invested in GRUAN operations to (i) describe and analyse all sources of measurement uncertainty to the extent possible, (ii) quantify and synthesize the contribution of each source of uncertainty to the total measurement uncertainty, and (iii) verify that the evaluated net uncertainty is within the required target uncertainty. However, if the climate science community is not sufficiently well informed on how to capitalize on this added value, the significant investment in estimating meaningful measurement uncertainties is largely wasted. This paper presents and discusses the techniques that will need to be employed to reliably quantify long-term trends in GRUAN data records. A pedagogical approach is taken whereby numerical recipes for key parts of the trend analysis process are explored. The paper discusses the construction of linear least squares regression models for trend analysis, boot-strapping approaches to determine uncertainties in trends, dealing with the combined effects of autocorrelation in the data and measurement uncertainties in calculating the uncertainty on trends, best practice for determining seasonality in trends, how to deal with co-linear basis functions, and interpreting derived trends. Synthetic data sets are used to demonstrate these concepts which are then applied to a first analysis of temperature trends in RS92 radiosonde upper air soundings at the GRUAN site at Lindenberg, Germany (52.21° N, 14.12° E).

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