We analyze detailed atmospheric gas/aerosol composition data acquired during the 2008 NASA ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) airborne campaign performed at high northern latitudes in spring (ARCTAS-A) and summer (ARCTAS-B) and in California in summer (ARCTAS-CARB). Biomass burning influences were widespread throughout the ARCTAS campaign. MODIS data from 2000 to 2009 indicated that 2008 had the second largest fire counts over Siberia and a more normal Canadian boreal forest fire season. Near surface arctic air in spring contained strong anthropogenic signatures indicated by high sulfate. In both spring and summer most of the pollution plumes transported to the Arctic region were from Europe and Asia and were present in the mid to upper troposphere and contained a mix of forest fire and urban influences. The gas/aerosol composition of the high latitude troposphere was strongly perturbed at all altitudes in both spring and summer. The reactive nitrogen budget was balanced with PAN as the dominant component. Mean ozone concentrations in the high latitude troposphere were only minimally perturbed (<5ppb), although many individual pollution plumes sampled in the mid to upper troposphere, and mixed with urban influences, contained elevated ozone (ΔO3/ΔCO=0.11±0.09v/v). Emission and optical characteristics of boreal and California wild fires were quantified and found to be broadly comparable. Greenhouse gas emission estimates derived from ARCTAS-CARB data for the South Coast Air Basin of California show good agreement with state inventories for CO2 and N2O but indicate substantially larger emissions of CH4. Simulations by multiple models of transport and chemistry were found to be broadly consistent with observations with a tendency towards under prediction at high latitudes.

Aluminum, one of most reactive metals, rapidly corrodes in strong acidic or alkaline solutions but passivates at pH of about 5–9. We have determined that the passivation of aluminum in this range of pH, and in particular in regular tap water, can be substantially prevented after milling of aluminum with water-soluble inorganic salts (referred to as “WIS”), such as KCl or NaCl. Ensuing corrosion of Al in tap water, with accompanying release of hydrogen and precipitation of aluminum hydroxide, at normal pressure and moderate temperatures (∼55°C) is rapid and substantial. For example, ∼92% of the Al in the Al–WIS system when milled for 1h and ∼81% when milled for 15min, corrodes in 1h, with the release of 1.5mol of hydrogen per each mole of Al consumed in the reaction. Besides gaseous hydrogen, only solid aluminum hydroxides were formed as the reaction byproducts, opening up the possibility of straightforward recycling of the system. The effects of WIS concentration, chemistry of other additives, powder particle size, temperature, and milling conditions on the reaction kinetics are reported.

Regional-scale measurements were made over the eastern United States (Intercontinental Chemical Transport Experiment - North America (INTEX-NA), summer 2004); Mexico (Megacity Initiative: Local and Global Research Observations (MILAGRO), March 2006); the eastern North Pacific and Alaska (INTEX-B May 2006); and the Canadian Arctic (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS), spring and summer 2008). For these field campaigns, instrumentation for the in situ measurement of CO2 was integrated on the NASA DC-8 research aircraft providing high-resolution (1 second) data traceable to the WMO CO2 mole fraction scale. These observations provide unique and definitive data sets via their intermediate-scale coverage and frequent vertical profiles (0.1 - 12 km) for examining the variability CO2 exhibits above the Earth s surface. A bottom-up anthropogenic CO2 emissions inventory (1deg 1deg) and processing methodology has also been developed for North America in support of these airborne science missions. In this presentation, the spatio-temporal distributions of CO2 and CO column values derived from the campaign measurements will be examined in conjunction with the emissions inventory and transport histories to aid in the interpretation of the CO2 observations.

A comprehensive group of reactive nitrogen species (NO, NO2, HNO3, HO2NO2, PANs, alkyl nitrates, and aerosol‐NO3−) were measured over North America during July/August 2004 from the NASA DC‐8 platform (0.1–12 km). Nitrogen containing tracers of biomass combustion (HCN and CH3CN) were also measured along with a host of other gaseous (CO, VOC, OVOC, halocarbon) and aerosol tracers. Clean background air as well as air with influences from biogenic emissions, anthropogenic pollution, biomass combustion, convection, lightning, and the stratosphere was sampled over the continental United States, the Atlantic, and the Pacific. The North American upper troposphere (UT) was found to be greatly influenced by both lightning NOx and surface pollution lofted via convection and contained elevated concentrations of PAN, ozone, hydrocarbons, and NOx. Observational data suggest that lightning was a far greater contributor to NOx in the UT than previously believed. PAN provided a dominant reservoir of reactive nitrogen in the UT while nitric acid dominated in the lower troposphere (LT). Peroxynitric acid (HO2NO2) was present in sizable concentrations peaking at around 8 km. Aerosol nitrate appeared to be mostly contained in large soil based particles in the LT. Plumes from Alaskan fires contained large amounts of PAN and aerosol nitrate but little enhancement in ozone. A comparison of observed data with simulations from four 3‐D models shows significant differences between observations and models as well as among models. We investigate the partitioning and interplay of the reactive nitrogen species within characteristic air masses and further examine their role in ozone formation.

In practice, the problem of vision discomfort appears at a number of different work-stands. Among others, it concerns people like drivers or people working with screen monitors. As a result of extensive research into appropriate illumination, a number of recommendations have been produced in order to ensure comfort of vision at work-stands. It is assumed that if the work-stand is provided with sufficiently high level of illuminance, and if the luminance distribution is uniform, and there is no glare, then we have comfort of vision and the eye fatigue is acceptable.Currently, to measure luminance distribution in order to assess the quality of illumination, it is necessary to carry out a large number of point measurements by using the luminance meter. Another way of determining the luminance distribution coming from the sources lying in a relatively small solid angle is the application of luminance meter built by using a CCD camera. Measurements of this type require, however, a great number of exposures to determine luminance distribution coming from light sources located in a large solid angle (e.g. a halfspace). This paper presents a design model of luminance distribution meter which makes it possible to obtain data about the distribution of luminance coming from light sources located in the whole halfspace only by a single measurement. Furthermore, the meter enables simultaneous determination of all the parameters on the work-stand illumination quality.

Airborne measurements of a large number of oxygenated volatile organic chemicals (OVOC) were carried out in the Pacific troposphere (0.1–12 km) in winter/spring of 2001 (24 February to 10 April). Specifically, these measurements included acetone (CH3COCH3), methylethyl ketone (CH3COC2H5, MEK), methanol (CH3OH), ethanol (C2H5OH), acetaldehyde (CH3CHO), propionaldehyde (C2H5CHO), peroxyacylnitrates (PANs) (CnH2n+1COO2NO2), and organic nitrates (CnH2n+1ONO2). Complementary measurements of formaldehyde (HCHO), methyl hydroperoxide (CH3OOH), and selected tracers were also available. OVOC were abundant in the clean troposphere and were greatly enhanced in the outflow regions from Asia. Background mixing ratios were typically highest in the lower troposphere and declined toward the upper troposphere and the lowermost stratosphere. Their total abundance (ΣOVOC) was nearly twice that of nonmethane hydrocarbons (ΣC2‐C8 NMHC). Throughout the troposphere, the OH reactivity of OVOC is comparable to that of methane and far exceeds that of NMHC. A comparison of these data with western Pacific observations collected some 7 years earlier (February–March 1994) did not reveal significant differences. Mixing ratios of OVOC were strongly correlated with each other as well as with tracers of fossil and biomass/biofuel combustion. Analysis of the relative enhancement of selected OVOC with respect to CH3Cl and CO in 12 plumes originating from fires and sampled in the free troposphere (3–11 km) is used to assess their primary and secondary emissions from biomass combustion. The composition of these plumes also indicates a large shift of reactive nitrogen into the PAN reservoir thereby limiting ozone formation. A three‐dimensional global model that uses state of the art chemistry and source information is used to compare measured and simulated mixing ratios of selected OVOC. While there is reasonable agreement in many cases, measured aldehyde concentrations are significantly larger than predicted. At their observed levels, acetaldehyde mixing ratios are shown to be an important source of HCHO (and HOx) and PAN in the troposphere. On the basis of presently known chemistry, measured mixing ratios of aldehydes and PANs are mutually incompatible. We provide rough estimates of the global sources of several OVOC and conclude that collectively these are extremely large (150–500 Tg C yr−1) but remain poorly quantified.

There is a large number of elements used for spatial correction of the luxmeter photometric head. However, none of them, as yet, ensures perfect correction. As a result, research work into this type of correction has been playing a crucial role in the measurement of photometric quantities. In this paper an original model of a luxmeter photometric head created on the basis of optical fibers has been presented. This photometric head operates on the principle of measurement of the spatial distribution of luminous flux.

In the paper a detailed theoretical analysis of the propagation of optical radiation and the energy losses of this radiation in short sections of optical fibers is presented. A laboratory stand for experimental verification of the theoretical results obtained is also described.

We report the first in situ measurements of hydrogen cyanide (HCN) and methyl cyanide (CH 3 CN, acetonitrile) from the Pacific troposphere (0-12 km) obtained during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) airborne mission (February-April 2001). Mean HCN and CH 3 CN mixing ratios of 243 ± 118 (median 218) ppt and 149 ± 56 (median 138) ppt, respectively, were measured. These in situ observations correspond to a mean tropospheric HCN column of 4.2 × 10 15 molecules cm -2 and a CH 3 CN column of 2.5 x 10 15 molecules cm -2 . This is in good agreement with the 0-12 km HCN column of 4.4 (±0.6) x 1015 molecules cm -2 derived from infrared solar spectroscopic observations over Japan. Mixing ratios of HCN and CH 3 CN were greatly enhanced in pollution outflow from Asia and were well correlated with each other as well as with known tracers of biomass combustion (e.g., CH 3 Cl, CO). Volumetric enhancement (or emission) ratios (ERs) relative to CO in free tropospheric plumes, likely originating from fires, were 0.34% for HCN and 0.17% for CH 3 CN. ERs with respect to CH 3 Cl and CO in selected biomass burning (BB) plumes in the free troposphere and in boundary layer pollution episodes are used to estimate a global BB source of 0.8 ± 0.4 Tg (N) yr -1 for HCN and 0.4 ± 0.1 Tg (N) yr -1 for CH 3 CN. In comparison, emissions from industry and fossil fuel combustion are quite small (<0.05 Tg (N) yr -1 ). The vertical structure of HCN and CH 3 CN indicated reduced mixing ratios in the marine boundary layer (MBL). Using a simple box model, the observed gradients across the top of the MBL are used to derive an oceanic loss rate of 8.8 × 10 -15 g (N) cm -2 s -1 for HCN and 3.4 x 10 -15 g (N) cm -2 s -1 for CH 3 CN. An air-sea exchange model is used to conclude that this flux can be maintained if the oceans are undersaturated in HCN and CH 3 CN by 27% and 6%, respectively. These observations also correspond to an open ocean mean deposition velocity (v d ) of 0.12 cm s -1 for HCN and 0.06 cm s -1 for CH 3 CN. It is inferred that oceanic loss is a dominant sink for these cyanides and that they deposit some 1.4 Tg (N) of nitrogen annually to the oceans. Assuming loss to the oceans and reaction with OH radicals as the major removal processes, a mean atmospheric residence time of 5.0 months for HCN and 6.6 months for CH 3 CN is calculated. A global budget analysis shows that the sources and sinks of HCN and CH 3 CN are roughly in balance but large uncertainties remain in part due to a lack of observational data from the atmosphere and the oceans. Pathways leading to the oceanic (and soil) degradation of these cyanides are poorly known but are expected to be biological in nature.

Airborne measurements of a large number of oxygenated organic chemicals (Oxorgs) were carried out in the Pacific troposphere (0.1-12 km) in the Spring of 2001 (Feb. 24-April 10). Specifically these measuremen ts included acetone, methylethyl ketone (MEK), methanol, ethanol, ace taldehyde, propionaldehyde, PANS, and organic nitrates. Complementary measurements of formaldehyde, organic peroxides, and tracers were al so available. Ox-orgs were abundant in the clean troposphere and were greatly enhanced in the outflow regions from Asia. Their mixing ratios were typically highest in the lower troposphere and declined toward s the upper troposphere and the lowermost stratosphere. Their total a bundance (Ox-orgs) significantly exceeded that of NMHC (C2-C8 NMHC). A comparison of these data with observations collected some seven yea rs earlier (Feb.-March, 1994), did not reveal any significant changes . Throughout the troposphere mixing ratios of Ox-orgs were strongly c orrelated with each other as well as with tracers of fossil and bioma sshiof'uel combustion. Analysis of the relative enhancement of selected Oxorgs with respect to CH3Cl and CO in twelve sampled plumes, origi nating from fires, is used to assess their primary and secondary sour ces from biomass combustion. The composition of these plumes also ind icates a large shift of reactive nitrogen into the PAN reservoir ther eby limiting ozone formation. The Harvard 3-D photochemical model, th at uses state of the art chemistry and source information, is used to compare simulated and observed mixing ratios of selected species. A 1 -D model is used to explore the chemistry of aldehydes. These results will be presented.

We report the first in situ measurements of hydrogen cyanide (HCN) and methyl cyanide (CH 3 CN, acetonitrile) from the Pacific troposphere (0–12 km) obtained during the NASA Transport and Chemical Evolution over the Pacific (TRACE‐P) airborne mission (February–April 2001). Mean HCN and CH 3 CN mixing ratios of 243 ± 118 (median 218) ppt and 149 ± 56 (median 138) ppt, respectively, were measured. These in situ observations correspond to a mean tropospheric HCN column of 4.2 × 10 15 molecules cm −2 and a CH 3 CN column of 2.5 × 10 15 molecules cm −2 . This is in good agreement with the 0–12 km HCN column of 4.4 (±0.6) × 10 15 molecules cm −2 derived from infrared solar spectroscopic observations over Japan. Mixing ratios of HCN and CH 3 CN were greatly enhanced in pollution outflow from Asia and were well correlated with each other as well as with known tracers of biomass combustion (e.g., CH 3 Cl, CO). Volumetric enhancement (or emission) ratios (ERs) relative to CO in free tropospheric plumes, likely originating from fires, were 0.34% for HCN and 0.17% for CH 3 CN. ERs with respect to CH 3 Cl and CO in selected biomass burning (BB) plumes in the free troposphere and in boundary layer pollution episodes are used to estimate a global BB source of 0.8 ± 0.4 Tg (N) yr −1 for HCN and 0.4 ± 0.1 Tg (N) yr −1 for CH 3 CN. In comparison, emissions from industry and fossil fuel combustion are quite small (<0.05 Tg (N) yr −1 ). The vertical structure of HCN and CH 3 CN indicated reduced mixing ratios in the marine boundary layer (MBL). Using a simple box model, the observed gradients across the top of the MBL are used to derive an oceanic loss rate of 8.8 × 10 −15 g (N) cm −2 s −1 for HCN and 3.4 × 10 −15 g (N) cm −2 s −1 for CH 3 CN. An air‐sea exchange model is used to conclude that this flux can be maintained if the oceans are undersaturated in HCN and CH 3 CN by 27% and 6%, respectively. These observations also correspond to an open ocean mean deposition velocity ( v d ) of 0.12 cm s −1 for HCN and 0.06 cm s −1 for CH 3 CN. It is inferred that oceanic loss is a dominant sink for these cyanides and that they deposit some 1.4 Tg (N) of nitrogen annually to the oceans. Assuming loss to the oceans and reaction with OH radicals as the major removal processes, a mean atmospheric residence time of 5.0 months for HCN and 6.6 months for CH 3 CN is calculated. A global budget analysis shows that the sources and sinks of HCN and CH 3 CN are roughly in balance but large uncertainties remain in part due to a lack of observational data from the atmosphere and the oceans. Pathways leading to the oceanic (and soil) degradation of these cyanides are poorly known but are expected to be biological in nature.

The paper presents a design model of a photometric head of luminance distribution meter. For the construction of this model optical fibres and CCD array were used. Such a photometric head makes it possible to obtain data about the distribution of optical radiation coming from the light sources located in a very large solid angle (even in the whole halfspace) only by a single measurement.

We find that the distribution of the spectral correction error on a spectrally corrected CCD array is dependent on the choice of both the correction filter and the lens angle of view. The distribution of the spectral correction error on the spectrally corrected CCD array is analyzed. We present a method of calculating of the spectral coefficient of the monochromatic transmission factor of the filter for CCD array spectral correction. A filter calculated in this manner ensures that the corrected CCD array has a known constant and high spectral accuracy throughout the whole surface of the array.