176 results on '"Arnold SR"'
Search Results
2. The POLARCAT Model Intercomparison Project (POLMIP): Overview and evaluation with observations
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Emmons, LK, Arnold, SR, Monks, SA, Huijnen, V, Tilmes, S, Law, KS, Thomas, JL, Raut, JC, Bouarar, I, Turquety, S, Long, Y, Duncan, B, Steenrod, S, Strode, S, Flemming, J, Mao, J, Langner, J, Thompson, AM, Tarasick, D, Apel, EC, Blake, DR, Cohen, RC, Dibb, J, Diskin, GS, Fried, A, Hall, SR, Huey, LG, Weinheimer, AJ, Wisthaler, A, Mikoviny, T, Nowak, J, Peischl, J, Roberts, JM, Ryerson, T, Warneke, C, and Helmig, D
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Meteorology & Atmospheric Sciences ,Atmospheric Sciences ,Astronomical and Space Sciences - Abstract
A model intercomparison activity was inspired by the large suite of observations of atmospheric composition made during the International Polar Year (2008) in the Arctic. Nine global and two regional chemical transport models participated in this intercomparison and performed simulations for 2008 using a common emissions inventory to assess the differences in model chemistry and transport schemes. This paper summarizes the models and compares their simulations of ozone and its precursors and presents an evaluation of the simulations using a variety of surface, balloon, aircraft and satellite observations. Each type of measurement has some limitations in spatial or temporal coverage or in composition, but together they assist in quantifying the limitations of the models in the Arctic and surrounding regions. Despite using the same emissions, large differences are seen among the models. The cloud fields and photolysis rates are shown to vary greatly among the models, indicating one source of the differences in the simulated chemical species. The largest differences among models, and between models and observations, are in NOy partitioning (PAN vs. HNO3) and in oxygenated volatile organic compounds (VOCs) such as acetaldehyde and acetone. Comparisons to surface site measurements of ethane and propane indicate that the emissions of these species are significantly underestimated. Satellite observations of NO2 from the OMI (Ozone Monitoring Instrument) have been used to evaluate the models over source regions, indicating anthropogenic emissions are underestimated in East Asia, but fire emissions are generally overestimated. The emission factors for wildfires in Canada are evaluated using the correlations of VOCs to CO in the model output in comparison to enhancement factors derived from aircraft observations, showing reasonable agreement for methanol and acetaldehyde but underestimate ethanol, propane and acetone, while overestimating ethane emission factors.
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- 2015
3. Statistical inference of OH concentrations and air mass dilution rates from successive observations of nonmethane hydrocarbons in single air masses
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Arnold, SR, Methven, J, Evans, MJ, Chipperfield, MP, Lewis, AC, Hopkins, JR, McQuaid, JB, Watson, N, Purvis, RM, Lee, JD, Atlas, EL, Blake, DR, and Rappenglück, B
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Meteorology & Atmospheric Sciences - Abstract
Bayesian inference has been used to determine rigorous estimates of hydroxyl radical concentrations ([OH]) and air mass dilution rates (K) averaged following air masses between linked observations of nonmethane hydrocarbons (NMHCs) spanning the North Atlantic during the Intercontinental Transport and Chemical Transformation (ITCT)-Lagrangian-2K4 experiment. The Bayesian technique obtains a refined (posterior) distribution of a parameter given data related to the parameter through a model and prior beliefs about the parameter distribution. Here, the model describes hydrocarbon loss through OH reaction and mixing with a background concentration at rate K. The Lagrangian experiment provides direct observations of hydrocarbons at two time points, removing assumptions regarding composition or sources upstream of a single observation. The estimates are sharpened by using many hydrocarbons with different reactivities and accounting for their variability and measurement uncertainty. A novel technique is used to construct prior background distributions of many species, described by variation of a single parameter α. This exploits the high correlation of species, related by the first principal component of many NMHC samples. The Bayesian method obtains posterior estimates of [OH], K and α following each air mass. Median [OH] values are typically between 0.5 and 2.0 × 106 molecules cm-3, but are elevated to between 2.5 and 3.5 × 106 molecules cm-3, in low-level pollution. A comparison of [OH] estimates from absolute NMHC concentrations and NMHC ratios assuming zero background (the "photochemical clock" method) shows similar distributions but reveals systematic high bias in the estimates from ratios. Estimates of K are ∼0.1 day-1 but show more sensitivity to the prior distribution assumed. Copyright 2007 by the American Geophysical Union.
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- 2007
4. Establishing Lagrangian connections between observations within air masses crossing the Atlantic during the International Consortium for Atmospheric Research on Transport and Transformation experiment
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Methven, J, Arnold, SR, Stohl, A, Evans, MJ, Avery, M, Law, K, Lewis, AC, Monks, PS, Parrish, DD, Reeves, CE, Schlager, H, Atlas, E, Blake, DR, Coe, H, Crosier, J, Flocke, FM, Holloway, JS, Hopkins, JR, McQuaid, J, Purvis, R, Rappenglück, B, Singh, HB, Watson, NM, Whalley, LK, and Williams, PI
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Meteorology & Atmospheric Sciences - Abstract
The ITCT-Lagrangian-2K4 (Intercontinental Transport and Chemical Transformation) experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of air masses in the free troposphere away from emissions. To this end, attempts were made to intercept and sample air masses several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts from two Lagrangian models that were used to direct the aircraft into target air masses. A novel technique then identifies Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole air samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these "coincident matches" is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown, and the downwind minus upwind differences in tracers are discussed. Copyright 2006 by the American Geophysical Union.
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- 2006
5. The effect of adverse childhood experiences and social determinants of health on child flourishing
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Conner, A, primary, Wideman, L, additional, Yaun, J, additional, and Arnold, SR, additional
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- 2023
- Full Text
- View/download PDF
6. Exploiting satellite measurements to explore uncertainties in UK bottom-up NOx emission estimates
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Pope, RJ, Kelly, R, Marais, EA, Graham, AM, Wilson, C, Harrison, JJ, Moniz, SJA, Ghalaieny, M, Arnold, SR, and Chipperfield, MP
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Nitrogen oxides (NOx, NO + NO2) are potent air pollutants which directly impact on human health and which aid the formation of other hazardous pollutants such as ozone (O3) and particulate matter. In this study, we use satellite tropospheric column nitrogen dioxide (TCNO2) data to evaluate the spatiotemporal variability and magnitude of the United Kingdom (UK) bottom-up National Atmospheric Emissions Inventory (NAEI) NOx emissions. Although emissions and TCNO2 represent different quantities, for UK city sources we find a spatial correlation of ∼0.5 between the NAEI NOx emissions and TCNO2 from the high-spatial-resolution TROPOspheric Monitoring Instrument (TROPOMI), suggesting a good spatial distribution of emission sources in the inventory. Between 2005 and 2015, the NAEI total UK NOx emissions and long-term TCNO2 record from the Ozone Monitoring Instrument (OMI), averaged over England, show annually decreasing trends of 4.4 % and 2.2 %, respectively. Top-down NOx emissions were derived in this study by applying a simple mass balance approach to TROPOMI-observed downwind NO2 plumes from city sources. Overall, these top-down estimates were consistent with the NAEI, but for larger cities such as London and Birmingham the inventory is significantly (>25 %) less than the top-down emissions.
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- 2022
7. 732 - The role of the tracheal aspirate in antibiotic usage in a level IV neonatal intensive care unit
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Petersen, R, Russell, AR, Shapiro, K, Arnold, SR, and Talati, AJ
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- 2024
- Full Text
- View/download PDF
8. Late-spring and summertime tropospheric ozone and NO2 in western Siberia and the Russian Arctic: regional model evaluation and sensitivities
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Thorp, T, Arnold, SR, Pope, RJ, Spracklen, DV, Conibear, L, Knote, C, Arshinov, M, Belan, B, Asmi, E, Laurila, T, Skorokhod, AI, Nieminen, T, Petäjä, T, Global Atmosphere-Earth surface feedbacks, Institute for Atmospheric and Earth System Research (INAR), and Department of Physics
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ddc:550 ,115 Astronomy, Space science ,1172 Environmental sciences - Abstract
We use a regional chemistry transport model (Weather Research and Forecasting model coupled with chemistry, WRF-Chem) in conjunction with surface observations of tropospheric ozone and Ozone Monitoring Instrument (OMI) satellite retrievals of tropospheric column NO2 to evaluate processes controlling the regional distribution of tropospheric ozone over western Siberia for late spring and summer in 2011. This region hosts a range of anthropogenic and natural ozone precursor sources, and it serves as a gateway for near-surface transport of Eurasian pollution to the Arctic. However, there is a severe lack of in situ observations to constrain tropospheric ozone sources and sinks in the region. We show widespread negative bias in WRF-Chem tropospheric column NO2 when compared to OMI satellite observations from May–August, which is reduced when using ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants) v5a emissions (fractional mean bias (FMB) = −0.82 to −0.73) compared with the EDGAR (Emissions Database for Global Atmospheric Research)-HTAP (Hemispheric Transport of Air Pollution) v2.2 emissions data (FMB = −0.80 to −0.70). Despite the large negative bias, the spatial correlations between model and observed NO2 columns suggest that the spatial pattern of NOx sources in the region is well represented. Scaling transport and energy emissions in the ECLIPSE v5a inventory by a factor of 2 reduces column NO2 bias (FMB = −0.66 to −0.35), but with overestimates in some urban regions and little change to a persistent underestimate in background regions. Based on the scaled ECLIPSE v5a emissions, we assess the influence of the two dominant anthropogenic emission sectors (transport and energy) and vegetation fires on surface NOx and ozone over Siberia and the Russian Arctic. Our results suggest regional ozone is more sensitive to anthropogenic emissions, particularly from the transport sector, and the contribution from fire emissions maximises in June and is largely confined to latitudes south of 60∘ N. Ozone dry deposition fluxes from the model simulations show that the dominant ozone dry deposition sink in the region is to forest vegetation, averaging 8.0 Tg of ozone per month, peaking at 10.3 Tg of ozone deposition during June. The impact of fires on ozone dry deposition within the domain is small compared to anthropogenic emissions and is negligible north of 60∘ N. Overall, our results suggest that surface ozone in the region is controlled by an interplay between seasonality in atmospheric transport patterns, vegetation dry deposition, and a dominance of transport and energy sector emissions.
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- 2021
9. Production of HONO from heterogeneous uptake of NO₂ on illuminated TiO₂ aerosols measured by Photo-Fragmentation Laser Induced Fluorescence
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Dyson, JE, Boustead, GA, Fleming, LT, Blitz, M, Stone, D, Arnold, SR, Whalley, LK, and Heard, DE
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The rate of production of HONO from illuminated TiO2 aerosols in the presence of NO2 was measured using an aerosol flow tube coupled to a photo-fragmentation laser induced fluorescence detection apparatus. The reactive uptake coefficient of NO2 to form HONO, γNO2→HONO, was determined for NO2 mixing ratios in the range 34–400 ppb, with γNO2→HONO spanning the range (9.97 ± 3.52) × 10−6 to (1.26 ± 0.17) × 10−4 at a relative humidity of 15 ± 1 % and for a lamp photon flux of (1.63 ± 0.09) × 1016 photons cm−2 s −1 (integrated between 290 and 400 nm), which is similar to values of ambient actinic flux at midday. γNO2→HONO increased as a function of NO2 mixing ratio at low NO2 before peaking at (1.26 ± 0.17) × 10−4 at 51 ppb NO2 and then sharply decreasing at higher NO2 mixing ratios, rather than levelling off which would be indicative of surface saturation. The dependence of HONO production on relative humidity was also investigated, with a peak in production of HONO from TiO2 aerosol surfaces found at ~25 % RH. Possible mechanisms consistent with the observed trends in both the HONO production and reactive uptake coefficient were investigated using a zero-dimensional kinetic box model. The modelling studies supported a mechanism for HONO production on the aerosol surface involving two molecules of NO2, as well as a surface HONO loss mechanism which is dependent upon NO2. In a separate experiment, significant production of HONO was observed from illumination of mixed nitrate/TiO2 aerosols in the absence of NO2. However, no statistically significant production of HONO was seen from the illumination of pure nitrate aerosols. The rate of production of HONO observed from mixed nitrate/TiO2 aerosols was scaled to ambient conditions found at the Cape Verde Atmospheric Observatory (CVAO) in the remote tropical marine boundary layer. The rate of HONO production from aerosol particulate nitrate photolysis containing a photocatalyst was found to be similar to the missing HONO production rate necessary to reproduce observed concentrations of HONO at CVAO. These results provide evidence that particulate nitrate photolysis may have a significant impact on the production of HONO and hence NOx in the marine boundary layer where mixed aerosols containing nitrate and a photocatalytic species such as TiO2, as found in dust, are present.
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- 2020
10. Pollutant emission reductions deliver decreased PM2.5-caused mortality across China during 2015–2017
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Silver, B, Conibear, L, Reddington, CL, Knote, C, Arnold, SR, and Spracklen, DV
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ddc:550 - Abstract
Air pollution is a serious environmental issue and leading contributor to disease burden in China. Rapid reductions in fine particulate matter (PM2.5) concentrations and increased ozone concentrations occurred across China during 2015 to 2017. We used measurements of particulate matter with a diameter µm (PM2.5) and ozone (O3) from more than 1000 stations across China along with Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) regional air quality simulations, to explore the drivers and impacts of observed trends. The measured nationwide median PM2.5 trend of -3.4µgm-3yr-1 was well simulated by the model (-3.5µgm-3yr-1). With anthropogenic emissions fixed at 2015 levels, the simulated trend was much weaker (-0.6µgm-3yr-1), demonstrating that interannual variability in meteorology played a minor role in the observed PM2.5 trend. The model simulated increased ozone concentrations in line with the measurements but underestimated the magnitude of the observed absolute trend by a factor of 2. We combined simulated trends in PM2.5 concentrations with an exposure–response function to estimate that reductions in PM2.5 concentrations over this period have reduced PM2.5-attributable premature mortality across China by 150 000 deaths yr−1.
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- 2020
11. The impact of COVID-19 control measures on air quality in China
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Silver, B, He, X, Arnold, SR, and Spracklen, DV
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The outbreak of Coronavirus Disease 2019 (COVID-19) in China in January 2020 prompted substantial control measures including social distancing measures, suspension of public transport and industry, and widespread cordon sanitaires ('lockdowns'), that have led to a decrease in industrial activity and air pollution emissions over a prolonged period. We use a 5 year dataset from China's air quality monitoring network to assess the impact of control measures on air pollution. Pollutant concentration time series are decomposed to account for the inter-annual trend, seasonal cycles and the effect of Lunar New Year, which coincided with the COVID-19 outbreak. Over 2015–2019, there were significant negative trends in particulate matter (PM2.5, −6% yr−1) and sulphur dioxide (SO2, −12% yr−1) and nitrogen dioxide (NO2, −2.2% yr−1) whereas there were positive trends in ozone (O3, + 2.8% yr−1). We quantify the change in air quality during the LNY holiday week, during which pollutant concentrations increase on LNY's day, followed by reduced concentrations in the rest of the week. After accounting for interannual trends and LNY we find NO2 and PM concentrations were significantly lower during the lockdown period than would be expected, but there were no significant impacts on O3. Largest reductions occurred in NO2, with concentrations 27.0% lower on average across China, during the lockdown. Average concentrations of PM2.5 and PM10 across China were respectively 10.5% and 21.4% lower during the lockdown period. The largest reductions were in Hubei province, where NO2 concentrations were 50.5% lower than expected during the lockdown. Concentrations of affected pollutants returned to expected levels during April, after control measures were relaxed.
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- 2020
12. Impact on short-lived climate forcers increases projected warming due to deforestation
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Scott, CE, Monks, SA, Spracklen, DV, Arnold, SR, Forster, PM, Rap, A, Aijala, M, Artaxo, P, Carslaw, KS, Chipperfield, MP, Ehn, M, Gilardoni, S, Heikkinen, L, Kulmala, M, Petaja, T, Reddington, CLS, Rizzo, LV, Swietlicki, E, Vignati, E, Wilson, C, and Department of Physics
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LAND-COVER CHANGE ,TROPOSPHERIC OZONE ,Science ,MODEL SIMULATIONS ,GLOBAL CLIMATE ,HISTORICAL CHANGES ,114 Physical sciences ,CLOUD CONDENSATION NUCLEI ,SECONDARY ORGANIC AEROSOL ,ISOPRENE OXIDATION ,SCALE DEFORESTATION ,lcsh:Q ,lcsh:Science ,GREENHOUSE GASES - Abstract
The climate impact of deforestation depends on the relative strength of several biogeochemical and biogeophysical effects. In addition to affecting the exchange of carbon dioxide (CO2) and moisture with the atmosphere and surface albedo, vegetation emits biogenic volatile organic compounds (BVOCs) that alter the formation of short-lived climate forcers (SLCFs), which include aerosol, ozone and methane. Here we show that a scenario of complete global deforestation results in a net positive radiative forcing (RF; 0.12Wm-2) from SLCFs, with the negative RF from decreases in ozone and methane concentrations partially offsetting the positive aerosol RF. Combining RFs due to CO2, surface albedo and SLCFs suggests that global deforestation could cause 0.8 K warming after 100 years, with SLCFs contributing 8% of the effect. However, deforestation as projected by the RCP8.5 scenario leads to zero net RF from SLCF, primarily due to nonlinearities in the aerosol indirect effect.
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- 2018
13. 512 - The effect of adverse childhood experiences and social determinants of health on child flourishing
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Conner, A, Wideman, L, Yaun, J, and Arnold, SR
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- 2023
- Full Text
- View/download PDF
14. Exploring the impacts of anthropogenic emission sectors on PM2.5 and human health in South and East Asia
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Reddington, CL, Conibear, L, Knote, C, Silver, BJ, Li, YJ, Chan, CK, Arnold, SR, and Spracklen, DV
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ddc:550 - Abstract
To improve poor air quality in Asia and inform effective emission-reduction strategies, it is vital to understand the contributions of different pollution sources and their associated human health burdens. In this study, we use the WRF-Chem regional atmospheric model to explore the air quality and human health benefits of eliminating emissions from six different anthropogenic sectors (transport, industry, shipping, electricity generation, residential combustion, and open biomass burning) over South and East Asia in 2014. We evaluate WRF-Chem against measurements from air quality monitoring stations across the region and find the model captures the spatial distribution and magnitude of PM2.5 (particulate matter with an aerodynamic diameter of no greater than 2.5 µm). We find that eliminating emissions from residential energy use, industry, or open biomass burning yields the largest reductions in population-weighted PM2.5 concentrations across the region. The largest human health benefit is achieved by eliminating either residential or industrial emissions, averting 467 000 (95 % uncertainty interval (95UI): 409 000–542 000) or 283 000 (95UI: 226 000–358 000) annual premature mortalities, respectively, in India, China, and South-east Asia, with fire prevention averting 28 000 (95UI: 24 000–32 000) annual premature mortalities across the region. We compare our results to previous sector-specific emission studies. Across these studies, residential emissions are the dominant cause of particulate pollution in India, with a multi-model mean contribution of 42 % to population-weighted annual mean PM2.5. Residential and industrial emissions cause the dominant contributions in China, with multi-model mean contributions of 29 % for both sectors to population-weighted annual mean PM2.5. Future work should focus on identifying the most effective options within the residential, industrial, and open biomass-burning emission sectors to improve air quality across South and East Asia.
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- 2019
15. Simulated global climate response to tropospheric ozone-induced changes in plant transpiration
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Arnold, SR, Lombardozzi, D, Lamarque, J-F, Richardson, T, Emmons, LK, Tilmes, S, Sitch, SA, Folberth, G, Hollaway, MJ, and Val Martin, M
- Abstract
Tropospheric ozone (O 3 ) pollution is known to damage vegetation, reducing photosynthesis and stomatal conductance, resulting in modified plant transpiration to the atmosphere. We use an Earth system model to show that global transpiration response to near-present-day surface tropospheric ozone results in large-scale global perturbations to net outgoing long-wave and incoming shortwave radiation. Our results suggest that the radiative effect is dominated by a reduction in shortwave cloud forcing in polluted regions, in response to ozone-induced reduction in land-atmosphere moisture flux and atmospheric humidity. We simulate a statistically significant response of annual surface air temperature of up to ~ +1.5 K due to this ozone effect in vegetated regions subjected to ozone pollution. This mechanism is expected to further increase the net warming resulting from historic and future increases in tropospheric ozone.
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- 2018
16. Residential energy use emissions dominate health impacts from exposure to ambient particulate matter in India
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Conibear, L, Butt, EW, Knote, C, Arnold, SR, and Spracklen, DV
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Science ,lcsh:Q ,ddc:610 ,lcsh:Science ,complex mixtures - Abstract
Exposure to ambient fine particulate matter (PM2.5) is a leading contributor to diseases in India. Previous studies analysing emission source attributions were restricted by coarse model resolution and limited PM2.5 observations. We use a regional model informed by new observations to make the first high-resolution study of the sector-specific disease burden from ambient PM2.5 exposure in India. Observed annual mean PM2.5 concentrations exceed 100 μg m−3 and are well simulated by the model. We calculate that the emissions from residential energy use dominate (52%) population-weighted annual mean PM2.5 concentrations, and are attributed to 511,000 (95UI: 340,000–697,000) premature mortalities annually. However, removing residential energy use emissions would avert only 256,000 (95UI: 162,000–340,000), due to the non-linear exposure–response relationship causing health effects to saturate at high PM2.5 concentrations. Consequently, large reductions in emissions will be required to reduce the health burden from ambient PM2.5 exposure in India.
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- 2018
17. Photochemical box modelling of volcanic SO2 oxidation: isotopic constraints
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Galeazzo, T, Bekki, S, Martin, E, Savarino, J, Arnold, SR, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre de Paris (iSTeP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institute for Climate and Atmospheric Science [Leeds] (ICAS), School of Earth and Environment [Leeds] (SEE), University of Leeds-University of Leeds, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS), and Université Grenoble Alpes (UGA)
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[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere - Abstract
The photochemical box model CiTTyCAT is used to analyse the absence of oxygen mass-independent anomalies (O-MIF) in volcanic sulfates produced in the troposphere. An aqueous sulfur oxidation module is implemented in the model and coupled to an oxygen isotopic scheme describing the transfer of O-MIF during the oxidation of SO2 by OH in the gas-phase, and by H2O2, O3 and O2 catalysed by TMI in the liquid phase. Multiple model simulations are performed in order to explore the relative importance of the various oxidation pathways for a range of plausible conditions in volcanic plumes. Note that the chemical conditions prevailing in dense volcanic plumes are radically different from those prevailing in the surrounding background air. The first salient finding is that, according to model calculations, OH is expected to carry a very significant O-MIF in sulfur-rich volcanic plumes and, hence, that the volcanic sulfate produced in the gas phase would have a very significant positive isotopic enrichment. The second finding is that, although H2O2 is a major oxidant of SO2 throughout the troposphere, it is very rapidly consumed in sulfur-rich volcanic plumes. As a result, H2O2 is found to be a minor oxidant for volcanic SO2. According to the simulations, oxidation of SO2 by O3 is negligible because volcanic aqueous phases are too acidic. The model predictions of minor or negligible sulfur oxidation by H2O2 and O3, two oxidants carrying large O-MIF, are consistent with the absence of O-MIF seen in most isotopic measurements of volcanic tropospheric sulfate. The third finding is that oxidation by O2∕TMI in volcanic plumes could be very substantial and, in some cases, dominant, notably because the rates of SO2 oxidation by OH, H2O2 and O3 are vastly reduced in a volcanic plume compared to the background air. Only cases where sulfur oxidation by O2∕TMI is very dominant can explain the isotopic composition of volcanic tropospheric sulfate.
- Published
- 2018
18. The TOMCAT global chemical transport model v1.6: description of chemical mechanism and model evaluation
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Monks, SA, Arnold, SR, Hollaway, MJ, Pope, RJ, Wilson, C, Feng, W, Emmerson, KM, Kerridge, BJ, Latter, BL, Miles, GM, Siddans, R, and Chipperfield, MP
- Abstract
This paper documents the tropospheric chemical mechanism scheme used in the TOMCAT 3-D chemical transport model. The current scheme includes a more detailed representation of hydrocarbon chemistry than previously included in the model, with the inclusion of the emission and oxidation of ethene, propene, butane, toluene and monoterpenes. The model is evaluated against a range of surface, balloon, aircraft and satellite measurements. The model is generally able to capture the main spatial and seasonal features of high and low concentrations of carbon monoxide (CO), ozone (O3), volatile organic compounds (VOCs) and reactive nitrogen. However, model biases are found in some species, some of which are common to chemistry models and some that are specific to TOMCAT and warrant further investigation. The most notable of these biases are (1) a negative bias in Northern Hemisphere (NH) winter and spring CO and a positive bias in Southern Hemisphere (SH) CO throughout the year, (2) a positive bias in NH O3 in summer and a negative bias at high latitudes during SH winter and (3) a negative bias in NH winter C2 and C3 alkanes and alkenes. TOMCAT global mean tropospheric hydroxyl radical (OH) concentrations are higher than estimates inferred from observations of methyl chloroform but similar to, or lower than, multi-model mean concentrations reported in recent model intercomparison studies. TOMCAT shows peak OH concentrations in the tropical lower troposphere, unlike other models which show peak concentrations in the tropical upper troposphere. This is likely to affect the lifetime and transport of important trace gases and warrants further investigation.
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- 2017
19. Sensitivity of tropospheric ozone to chemical kinetic uncertainties in air masses influenced by anthropogenic and biomass burning emissions
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Ridley, DA, Cain, M, Methven, J, Arnold, SR, Cain, Michelle [0000-0003-2062-6556], and Apollo - University of Cambridge Repository
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4105 Pollution and Contamination ,13 Climate Action ,3701 Atmospheric Sciences ,37 Earth Sciences ,Climate-Related Exposures and Conditions ,41 Environmental Sciences - Abstract
We use a Lagrangian chemical transport model with a Monte Carlo approach to determine impacts of kinetic rate uncertainties on simulated concentrations of ozone, NOy and OH in a high‐altitude biomass burning plume and a low‐level industrial pollution plume undergoing long‐range transport. Uncertainties in kinetic rate constants yield 10–12 ppbv (5th to 95th percentile) uncertainty in the ozone concentration, dominated by reactions that cycle NO and NO2, control NOx conversion to NOy reservoir species, and key reactions contributing to O3 loss (O(1D) + H2O, HO2 + O3). Our results imply that better understanding of the peroxyacetylnitrate (PAN) thermal decomposition constant is key to predicting large‐scale O3 production from fire emissions and uncertainty in the reaction of NO + O3 at low temperatures is particularly important for both the anthropogenic and biomass burning plumes. The highlighted reactions serve as a useful template for targeting new laboratory experiments aimed at reducing uncertainties in our understanding of tropospheric O3 photochemistry.
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- 2017
20. Potential controls of isoprene in the surface ocean
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Hackenberg, SC, Andrews, SJ, Airs, R, Arnold, SR, Bouman, HA, Brewin, RJW, Chance, RJ, Cummings, D, Dall'Olmo, G, Lewis, AC, Minaeian, JK, Reifel, KM, Small, A, Tarran, GA, Tilstone, GH, and Carpenter, LJ
- Abstract
Isoprene surface ocean concentrations and vertical distribution, atmospheric mixing ratios, and calculated sea-to-air fluxes spanning approximately 125° of latitude (80°N–45°S) over the Arctic and Atlantic Oceans are reported. Oceanic isoprene concentrations were associated with a number of concurrently monitored biological variables including chlorophyll a (Chl a), photoprotective pigments, integrated primary production (intPP), and cyanobacterial cell counts, with higher isoprene concentrations relative to all respective variables found at sea surface temperatures greater than 20°C. The correlation between isoprene and the sum of photoprotective carotenoids, which is reported here for the first time, was the most consistent across all cruises. Parameterizations based on linear regression analyses of these relationships perform well for Arctic and Atlantic data, producing a better fit to observations than an existing Chl a-based parameterization. Global extrapolation of isoprene surface water concentrations using satellite-derived Chl a and intPP reproduced general trends in the in situ data and absolute values within a factor of 2 between 60% and 85%, depending on the data set and algorithm used.
- Published
- 2017
21. Sensitivity of mid-19th century tropospheric ozone to atmospheric chemistry-vegetation interactions
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Hollaway, MJ, Arnold, SR, Collins, WJ, Folberth, G, and Rap, A
- Abstract
We use an Earth-System model (HadGEM2-ES) to investigate the sensitivity of mid-19th century tropospheric ozone to vegetation distribution and atmospheric chemistry-vegetation interaction processes. We conduct model experiments to isolate the response of mid-19th century tropospheric ozone to vegetation cover changes between the 1860s and present-day and to CO2 induced changes in isoprene emissions and dry deposition over the same period. Changes in vegetation distribution and CO2 suppression of isoprene emissions between mid-19th century and present-day, lead to decreases in global isoprene emissions of 19% and 21% respectively. This results in increases in surface ozone over the continents of up to 2ppbv and of 2-6ppbv in the tropical upper troposphere. The effects of CO2 increases on suppression of isoprene emissions and suppression of dry deposition to vegetation are small compared with the effects of vegetation cover change. Assuming present-day climate in addition to present-day vegetation cover and atmospheric CO2 concentrations, leads to increases in surface ozone concentrations of up to 5ppbv over the entire northern hemisphere (NH), and of up to 8ppbv in the NH free troposphere, compared with a mid-19th century simulation. Ozone changes are dominated by: 1) the role of isoprene as an ozone sink in the low NOx mid-19th century atmosphere, and 2) the redistribution of NOx to remote regions and the free troposphere via PAN (peroxyacetyl nitrate) formed from isoprene oxidation. We estimate a tropospheric ozone radiative forcing of 0.264W m-2 and a sensitivity in ozone radiative forcing to mid-19th century to present-day vegetation cover change of -0.012W m-2.
- Published
- 2017
22. Testing the "Inverted-U" Phenomenon in Moral Development on Recently Promoted Senior Managers and Partners.
- Author
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BERNARDI, RICHARD A. and ARNOLD SR., DONALD F.
- Subjects
MORAL development ,BUSINESS enterprises ,EXPERIMENTAL design ,INDUSTRIAL research ,ACCOUNTING firms ,PROFESSIONAL ethics - Abstract
This paper examines the change in the average level of moral development over a 7.5-year period of promotion, attrition, and survival in five Big 6 firms. The study improves upon previous cross-sectional studies that found decreases in the average level of moral development at the senior manager and partner levels, which has been referred to as the "inverted-U" phenomenon. Problems with these studies that limit the generalizability of their findings include their cross-sectional nature and samples that usually come from one or two firms. Over a 7.5-year period, we found that the participating Big 6 firms retained auditors with higher average levels of moral development (measured using the defining issues test), while those with lower average levels left the firms. The average level of moral development for new partners was at least as high as the group from which they came. This research suggests that the concern about Big 6 firms retaining a higher proportion of auditors with lower moral development may be an artifact of research design. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
23. Pan-Eurasian Experiment (PEEX): Towards a holistic understanding of the feedbacks and interactions in the land-Atmosphere-ocean-society continuum in the northern Eurasian region
- Author
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Lappalainen, HK, Kerminen, V-M, Petäjä, T, Kurten, T, Baklanov, A, Shvidenko, A, Bäck, J, Vihma, T, Alekseychik, P, Andreae, MO, Arnold, SR, Arshinov, M, Asmi, E, Belan, B, Bobylev, L, Chalov, S, Cheng, Y, Chubarova, N, De Leeuw, G, Ding, A, Dobrolyubov, S, Dubtsov, S, Dyukarev, E, Elansky, N, Eleftheriadis, K, Esau, I, Filatov, N, Flint, M, Fu, C, Glezer, O, Gliko, A, Heimann, M, Holtslag, AAM, Hõrrak, U, Janhunen, J, Juhola, S, Järvi, L, Järvinen, H, Kanukhina, A, Konstantinov, P, Kotlyakov, V, Kieloaho, A-J, Komarov, AS, Kujansuu, J, Kukkonen, I, Duplissy, E-M, Laaksonen, A, Laurila, T, Lihavainen, H, Lisitzin, A, Mahura, A, Makshtas, A, Mareev, E, Mazon, S, Matishov, D, Melnikov, V, Mikhailov, E, Moisseev, D, Nigmatulin, R, Noe, SM, Ojala, A, Pihlatie, M, Popovicheva, O, Pumpanen, J, Regerand, T, Repina, I, Shcherbinin, A, Shevchenko, V, Sipilä, M, Skorokhod, A, Spracklen, DV, Su, H, Subetto, DA, Sun, J, Terzhevik, AY, Timofeyev, Y, Troitskaya, Y, Tynkkynen, V-P, Kharuk, VI, Zaytseva, N, Zhang, J, Viisanen, Y, Vesala, T, Hari, P, Hansson, HC, Matvienko, GG, Kasimov, NS, Guo, H, Bondur, V, Zilitinkevich, S, and Kulmala, M
- Abstract
The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic-boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land-Atmosphere-Aquatic-society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context.
- Published
- 2016
24. Intercomparison and evaluation of satellite peroxyacetyl nitrate observations in the upper troposphere-lower stratosphere
- Author
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Pope, RJ, Richards, NAD, Chipperfield, MP, Moore, DP, Monks, SA, Arnold, SR, Glatthor, N, Kiefer, M, Breider, TJ, Harrison, JJ, Remedios, JJ, Warneke, C, Roberts, JM, Diskin, GS, Huey, LG, Wisthaler, A, Apel, EC, Bernath, PF, and Feng, W
- Abstract
Peroxyacetyl nitrate (PAN) is an important chemical species in the troposphere as it aids the long-range transport of NOx and subsequent formation of O3 in relatively clean remote regions. Over the past few decades observations from aircraft campaigns and surface sites have been used to better understand the regional distribution of PAN. However, recent measurements made by satellites allow for a global assessment of PAN in the upper troposphere-lower stratosphere (UTLS). In this study, we investigate global PAN distributions from two independent retrieval methodologies, based on measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument, on board Envisat from the Institute of Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology, and the Department of Physics and Astronomy, University of Leicester (UoL). Retrieving PAN from MIPAS is challenging due to the weak signal in the measurements and contamination from other species. Therefore, we compare the two MIPAS datasets with observations from the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS), in situ aircraft data and the 3-D chemical transport model TOMCAT. MIPAS shows peak UTLS PAN concentrations over the biomass burning regions (e.g. ranging from 150 to > 200 pptv at 150 hPa) and during the summertime Asian monsoon as enhanced convection aids the vertical transport of PAN from the lower atmosphere. At 150 hPa, we find significant differences between the two MIPAS datasets in the tropics, where IMK PAN concentrations are larger by 50-100 pptv. Comparisons between MIPAS and ACE-FTS show better agreement with the UoL MIPAS PAN concentrations at 200 hPa, but with mixed results above this altitude. TOMCAT generally captures the magnitude and structure of climatological aircraft PAN profiles within the observational variability allowing it to be used to investigate the MIPAS PAN differences. TOMCAT-MIPAS comparisons show that the model is both positively (UoL) and negatively (IMK) biased against the satellite products. These results indicate that satellite PAN observations are able to detect realistic spatial variations in PAN in the UTLS, but further work is needed to resolve differences in existing retrievals to allow quantitative use of the products.
- Published
- 2016
25. Satellite constraint on the tropospheric ozone radiative effect
- Author
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Rap, A, Richards, NAD, Forster, PM, Monks, S, Arnold, SR, and Chipperfield, M
- Abstract
Tropospheric ozone directly affects the radiative balance of the Earth through interaction with shortwave and longwave radiation. Here we use measurements of tropospheric ozone from the Tropospheric Emission Spectrometer satellite instrument, together with chemical transport and radiative transfer models, to produce a first estimate of the stratospherically adjusted annual radiative effect (RE) of tropospheric ozone. We show that differences between modeled and observed ozone concentrations have little impact on the RE, indicating that our present-day tropospheric ozone RE estimate of 1.17 ± 0.03 W m−2 is robust. The RE normalized by column ozone decreased between the preindustrial and the present-day. Using a simulation with historical biomass burning and no anthropogenic emissions, we calculate a radiative forcing of 0.32 W m−2 for tropospheric ozone, within the current best estimate range. We propose a radiative kernel approach as an efficient and accurate tool for calculating ozone REs in simulations with similar ozone abundances.
- Published
- 2015
26. Impacts of aviation fuel sulfur content on climate and human health
- Author
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Kapadia, ZZ, Spracklen, DV, Arnold, SR, Borman, DJ, Mann, GW, Pringle, KJ, Monks, SA, Reddington, CL, Benduhn, F, Rap, A, Scott, CE, Butt, EW, and Yoshioka, M
- Abstract
Aviation emissions impact both air quality and climate. Using a coupled tropospheric chemistry-aerosol microphysics model we investigate the effects of varying aviation fuel sulfur content (FSC) on premature mortality from long-term exposure to aviation-sourced PM2.5 (particulate matter with a dry diameter of < 2.5 μm) and on the global radiation budget due to changes in aerosol and tropospheric ozone. We estimate that present-day non-CO2 aviation emissions with a typical FSC of 600 ppm result in 3597 (95 % CI: 1307–5888) annual mortalities globally due to increases in cases of cardiopulmonary disease and lung cancer, resulting from increased surface PM2.5 concentrations. We quantify the global annual mean combined radiative effect (REcomb) of non-CO2 aviation emissions as −13.3 mW m−2; from increases in aerosols (direct radiative effect and cloud albedo effect) and tropospheric ozone. Ultra-low sulfur jet fuel (ULSJ; FSC =15 ppm) has been proposed as an option to reduce the adverse health impacts of aviation-induced PM2.5. We calculate that swapping the global aviation fleet to ULSJ fuel would reduce the global aviation-induced mortality rate by 624 (95 % CI: 227–1021) mortalities a−1 and increase REcomb by +7.0 mW m−2. We explore the impact of varying aviation FSC between 0–6000 ppm. Increasing FSC increases annual mortality, while enhancing climate cooling through increasing the aerosol cloud albedo effect (aCAE). We explore the relationship between the injection altitude of aviation emissions and the resulting climate and air quality impacts. Compared to the standard aviation emissions distribution, releasing aviation emissions at the ground increases global aviation-induced mortality and produces a net warming effect, primarily through a reduced aCAE. Aviation emissions injected at the surface are 5 times less effective at forming cloud condensation nuclei, reducing the aviation-induced aCAE by a factor of 10. Applying high FSCs at aviation cruise altitudes combined with ULSJ fuel at lower altitudes result in reduced aviation-induced mortality and increased negative RE compared to the baseline aviation scenario.
- Published
- 2015
27. An Examination of Moral Development within Public Accounting by Gender, Staff Level, and Firm.
- Author
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BERNARDI, RICHARD A. and ARNOLD SR., DONALD F.
- Subjects
GOVERNMENT accounting ,MORAL development ,ACCOUNTING departments ,AUDITORS ,ACCOUNTING firms ,PROFESSIONAL ethics - Abstract
Copyright of Contemporary Accounting Research is the property of Canadian Academic Accounting Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1997
- Full Text
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28. Design trade Study for a 4-meter off-axis primary mirror substrate and mount for the Habitable-zone Exoplanet Direct Imaging Mission.
- Author
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Arnold Sr., William R. and Stahl, H. Philip
- Published
- 2017
- Full Text
- View/download PDF
29. Auditor Perspectives on Confidentiality: A Qualitative Investigation Examining the Differences in European Auditor’s Opinions
- Author
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Donald F. Arnold Sr., Richard A. Bernadi, and Presha E. Neidermeyer
- Abstract
This exploratory research examines the existence of variations in the application of the principle of auditor confidentiality within a western European setting. A case study method was used employing a series of open ended questions to isolate participants’ views on the importance of and factors influencing the practice of keeping client information confidential. The interviews yielded substantially different views on the application of the principle of confidentiality when placed in the context of a dilemma situation. Participants were partners and managers from four large international accounting firms located in eight western European countries (Denmark, France, Ireland, Italy, Spain, Sweden, the Netherlands and the United Kingdom). The findings imply that, although similar codes regarding confidentially exist, in practice there may be substantial variations in western European auditors’ interpretations of the codes, resulting in potential audit opinion variations despite similar factual situations. Understanding this type of variation is critical to stakeholders in the international financial communities who rely on auditors to attest to the accuracy of the financial statements for decision making purposes.
- Published
- 2005
30. ATLAST-8 Mission concept study for 8-meter monolithic UV/optical space telescope
- Author
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Stahl, H. Philip, primary, Postman, Marc, additional, Arnold, Sr., William R., additional, Hopkins, Randall C., additional, Hornsby, Linda, additional, Mosier, Gary E., additional, and Pasquale, Bert A., additional
- Published
- 2010
- Full Text
- View/download PDF
31. Design for an 8-meter monolithic UV/OIR space telescope
- Author
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Stahl, H. Philip, primary, Postman, Marc, additional, Arnold, Sr., William R., additional, Hopkins, Randall, additional, Hornsby, Linda, additional, Mosier, Gary E., additional, and Pasquale, Bert A., additional
- Published
- 2009
- Full Text
- View/download PDF
32. Structural design considerations for an 8-m space telescope
- Author
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Arnold, Sr., William r., primary and Stahl, H. Philip, additional
- Published
- 2009
- Full Text
- View/download PDF
33. Flux-pinning mechanisms for improving cryogenic segmented mirror performance.
- Author
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Gersh-Range, Jessica, Arnold Sr., William R., Lehner, David, and Stahl, H. Philip
- Published
- 2015
- Full Text
- View/download PDF
34. Edgewise connectivity: an approach to improving segmented primary mirror performance.
- Author
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Gersh-Range, Jessica, Arnold Sr., William R., and Stahl, H. Philip
- Published
- 2015
- Full Text
- View/download PDF
35. Interventions to improve antibiotic prescribing practices in ambulatory care
- Author
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Arnold, SR, primary and Straus, SE, additional
- Published
- 2006
- Full Text
- View/download PDF
36. Auditor Perspectives on Confidentiality: A Qualitative Investigation Examining the Differences in European Auditor’s Opinions
- Author
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Arnold Sr., Donald F., primary, Bernadi, Richard A., additional, and Neidermeyer, Presha E., additional
- Published
- 2005
- Full Text
- View/download PDF
37. Structural design considerations for an 8-m space telescope.
- Author
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Arnold Sr., William r. and Stahl, H. Philip
- Published
- 2009
- Full Text
- View/download PDF
38. Design for an 8-meter monolithic UV/OIR space telescope.
- Author
-
Stahl, H. Philip, Postman, Marc, Arnold Sr., William R., Hopkins, Randall, Hornsby, Linda, Mosier, Gary E., and Pasquale, Bert A.
- Published
- 2009
- Full Text
- View/download PDF
39. Interventions to improve antibiotic prescribing practices in ambulatory care
- Author
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Arnold, SR, primary, Evans, M, additional, and Straus, SE, additional
- Published
- 2002
- Full Text
- View/download PDF
40. Internal and external auditor ethical decision-making.
- Author
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Arnold Sr, Donald F., Dorminey, Jack W., Neidermeyer, A.A., and Neidermeyer, Presha E.
- Subjects
AUDITING ,INTERNAL auditing ,ETHICAL decision making ,ACCOUNTING ethics ,AUDITORS ,ETHICS research ,ETHICS - Abstract
Purpose – The aim of this exploratory research is to compare three sectors of the auditing profession – internal auditors, external auditors from larger international firms, and external auditors from smaller/regional firms – in regard to the influence of situational context on their ethically-related decision-making and judgment evaluations. Design/methodology/approach – Against the backdrop of five vignettes applied with a survey, the paper examines the potential influence of social consensus and magnitude of consequence on the ethical decision path of these three auditor groups. Findings – The paper finds that, in all cases, social consensus and magnitude of consequences exert influence on the ethical decision path. In the case of social consensus, however the paper finds that the ethical decision path is fully mediated for large firm auditors but is only partial mediated for the other two groups of auditors. Originality/value – This research examines responses from both internal and external auditors. Comparison between such groups is unique because these groups have not been well researched in the past literature. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
41. DISCUSSION. CONCRETE CUBE STRENGTHS - WHAT USE ARE STATISTICS?
- Author
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MANNERS, W, SWEETMAN, NB, SYM, R, ARNOLD, SR, BROCK, G, SPINDEL, JE, KEENE, PW, BEAL, AN, BAKER, MJ, and BLAND, JA
- Published
- 1982
- Full Text
- View/download PDF
42. Personal versus professional ethics in confidentiality decisions: an exploratory study in Western Europe.
- Author
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Arnold Sr., Donald F., Bernardi, Richard A., Neidermeyer, Presha E., and Schmee, Josef
- Subjects
PROFESSIONAL ethics ,CONFIDENTIAL communications ,AUDITORS ,AUDITOR-client relationships ,ACCOUNTING firms - Abstract
This article examines the importance to auditors of the principle of confidentiality regarding information obtained from one client on the audit opinion expressed on a second client. The empirical research sample includes 195 managers and partners from four international auditing firms with offices located in Denmark, Ireland, Italy, Spain, Sweden, the Netherlands and the United Kingdom. The analysis indicates that, while the average estimate for not signing off on a clean audit opinion did not vary among countries, the considerations involved in the decision process varied among the seven countries. The research raises questions as to whether strict adherence to confidentiality is in the best interest of all financial statement users. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
43. EFFECT OF SELECTED PSYCHOLOGICAL CHARACTERISTICS UPON CHOICE-SHIFT PATTERNS FOUND WITHIN HIERARCHICAL GROUPS OF PUBLIC ACCOUNTANTS.
- Author
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Kent Jr., D. Donald, Arnold Sr., Donald F., and Nydegger, Rudy V.
- Subjects
- *
PSYCHOLOGY , *ACCOUNTANTS , *RISK management in business - Abstract
Investigates the effects of several psychological characteristics on choice-shift patterns found within hierarchal groups of public accountants in the U.S. Relationship of choice shift with social desirability, control and moral reasoning; Role of risk management in audit functions; Change in the practice of professional public accounting.
- Published
- 2002
- Full Text
- View/download PDF
44. REPLY: The Effect of Independence on Decisions concerning Additional Audit Work: A European Perspective.
- Author
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Arnold Sr., Donald F., Bernardi, Richard A., and Neidermeyer, Presha E.
- Subjects
AUDITING ,MANAGEMENT controls ,ACCOUNTING ,INDIVIDUALISM - Abstract
In this article, the author replies to articles by L. Thorne and B. Jenkins that were about the effect of independence on decisions concerning additional audit work. Thorne's concerns can be broken down into four categories: justifying the use of the individualism construct; interpretation of the data. Jenkins' comments are made up of an evaluation of the case studies that were used in this research and the applicability of the research findings to the international accounting environment. The first case describes an audit client with the potential of substantial consulting revenues, to evoke independence in appearance. The second case 2 describes an audit client where the controller was a former member of the audit team, to evoke independence in fact. In both cases, the auditors' estimations of the need to do additional audit work are used as surrogates for independence. The plan was to include information in the second case study that would evoke a strong individualism response.
- Published
- 1999
- Full Text
- View/download PDF
45. The Effect of Independence on Decisions concerning Additional Audit Work: A European Perspective.
- Author
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Arnold Sr., Donald F., Bernardi, Richard A., and Neidermeyer, Presha E.
- Subjects
AUDITORS ,PROFITABILITY ,FINANCIAL performance ,ECONOMIC development ,FINANCIAL statements - Abstract
This research examines the importance of previously identified factors (i.e., investor needs, client retention, professional values and obligations, and time budget pressures) on independence in two scenarios. The sample includes 198 auditors from Big 6 auditing firms located in Denmark, Ireland, Italy, Spain, Sweden, The Netherlands, and the United Kingdom. In Case 1 (2), auditor judgment (stockholders' reliance on the thoroughness of the audit) was the primary factor for doing more work prior to signing off on the audit. The second most important factor was fear of losing the client (time-budget problems). Hofstede's (1980) individualism was associated with auditor judgment, fear of losing the client, and stockholders' reliance on the audit in Case 1 and relying on auditing rules in Case 2. Wingate's (1997) litigation index was higher for countries with reduced perceptions of the importance of auditing rules and the obligation to be an independent representative in Case 2. [ABSTRACT FROM AUTHOR]
- Published
- 1999
- Full Text
- View/download PDF
46. PRACTICE SUMMARY.
- Author
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Lowe, D. Jordan, Geiger, Marshall A., Pany, Kurt, Arnold Sr., Donald F., Bernardi, Richard A., Neidermeyer, Presha E., Shafer, William E., Morris, Roselyn E., Ketchand, Alice A., Gramling, Audrey A., Boritz, J. Efrim, and Zhang, Ping
- Subjects
INTERNAL auditing ,CONTRACTING out ,MANAGEMENT controls ,FINANCIAL statements ,ACCOUNTING ,CORPORATION reports - Abstract
This article focuses on the effects of internal audit outsourcing on perceived external auditor independence. This article also addresses financial statement users' perceptions related to public accounting firms performing internal auditing outsourcing activities--an area in which CPAs are becoming increasingly involved. Loan officers were provided with a realistic loan application for a medium-sized retail grocery company and asked to evaluate auditor independence, assess the reliability of financial statements, and make a loan decision. Loan officers receive the case where the internal audit was outsourced to their external audit firm using different personnel not only had significantly higher ratings than when using the same personnel, but also had uniformly the highest perceptions of auditor independence, financial statement reliability, and loan approval rate. However, the results also indicate that the image of auditor independence and the resultant perception of financial statement reliability could be enhanced by requiring CPA firms that perform internal audit services for audit clients to perform those services with different personnel.
- Published
- 1999
47. The Effect of Independence On Additional Audit Work: A European Perspective.
- Author
-
Arnold Sr., Donald F., Bernardi, Richard A., and Neidermeyer, Presha E.
- Subjects
AUDITORS ,AUDITOR-client relationships ,CORPORATE finance ,JUDGMENT (Logic) ,EXECUTIVES - Abstract
The article deals with the study which examined the judgments of a sample of managers and partners from corporations in the Western European countries regarding auditor independence. In the first case, the client wanted to release earnings information before all the audit work was complete. The second case addressed the potential influence of a former audit manager who had subsequently become the clients controller. The study also incorporated time budget pressures. The audit was behind schedule and there was a history of running over time budgets. The results showed a link between the reason for failing to do additional audit work and both selected cultural characteristics and an index indicating the level of litigation within each of the seven countries. The findings also demonstrated that prior time-budget problems significantly influenced the independence of the audit senior in the second case. Finally, the data showed that relying on personal relationships and not on auditing rules might lead to a higher litigation risk. The research had three major implications for audit practice.
- Published
- 2001
48. Case report of a young child with disseminated histoplasmosis and review of hyper immunoglobulin e syndrome (HIES).
- Author
-
Robinson WS, Arnold SR, Michael CF, Vickery JD, Schoumacher RA, Pivnick EK, Ward JC, Nagabhushanam V, and Lew DB.
- Published
- 2011
49. Financial Accounting, An Introduction to Concepts, Methods, and Uses (Book).
- Author
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Arnold Sr., Donald F. and Meyer, Philip E.
- Subjects
ACCOUNTING ,NONFICTION - Abstract
Reviews the book "Financial Accounting: An Introduction to Concepts, Methods, and Uses," 3rd ed., by Sidney Davidson, Clyde P. Sticney and Roman Weil.
- Published
- 1983
50. Transcriptomic Biomarkers Associated with Microbiological Etiology and Disease Severity in Childhood Pneumonia.
- Author
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Williams DJ, Gautam S, Creech CB, Jimenez N, Anderson EJ, Bosinger S, Grimes T, Arnold SR, McCullers JA, Goll J, Edwards KM, and Ramilo O
- Abstract
Background: Challenges remain in discerning microbiologic etiology and disease severity in childhood pneumonia. Defining host transcriptomic profiles during illness may facilitate improved diagnostic and prognostic approaches., Methods: Using whole blood ribonucleic acid sequencing from 222 hospitalized children with radiographic pneumonia and 45 age-matched controls, we identified differentially expressed genes that best identified children according to detected microbial pathogens (viral-only vs. bacterial-only and typical vs. atypical bacterial [+/- viral co-detection]) and an ordinal measure of phenotypic severity (moderate, severe, very severe)., Results: Overall, 135 (61%) children had viral-only detections, 15 (7%) had typical bacterial (+/- viral co-detections), and 26 (12%) had atypical bacterial (+/- viral co-detections). Eleven DE genes distinguished between viral-only and bacterial-only detections. Sixteen DE genes distinguished between atypical and typical bacterial detections (+/- viral co-detections). Nineteen DE genes distinguished between levels of pneumonia severity, including four genes also identified in the viral-only vs. bacterial-only model (IGHGP, PI3, CD177, RAP1GAP1) and four genes from the typical vs atypical bacterial model (PRSS23, IFI27, OLFM4, and ABO)., Conclusions: We identified transcriptomic biomarkers associated with microbial detections and phenotypic severity in children hospitalized with pneumonia. These DE genes are promising candidates for validation and translation into diagnostic and prognostic tools., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)
- Published
- 2024
- Full Text
- View/download PDF
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