ECInvestigation of NO2 Pollutions on Board of Research Aircraft (Some Results of QUANTIFY and POLARCAT Field Campaigns) (original) (raw)
Related papers
2009
The results of investigation of NO2 pollutions on board of research aircraft Falcon (DLR, Germany) are presented. The measurements have been carried out by chemiluminescent ni- trogen dioxide analyzer developed in Central Aerological Observatory (Russia). The data of NO2 distribution have been obtained during QUANTIFY (West Europe, July 2007) and POLARCAT (Greenland, July 2008) field campaigns. NO2 measurements over Greenland during POLARCAT field campaign have been carried out using ACCENT support. Different sources of nitrogen oxides are investigated. Some aspects of nitrogen dioxide distribution and transport are considered. Chemi- cal transformation of nitrogen oxides inside ship plumes is observed and analyzed.
Atmospheric Environment, 1997
The AERONOX project investigated the emissions of nitrogen oxides (NOx) from aircraft engines and global air traffic at cruising altitudes, the resultant increase in NOx concentrations, and the effects on the composition of the atmosphere, in particular with respect to ozone formation in the upper troposphere and lower stratosphere. The project was structured into three subprojects: Engine exhaust emissions, physics and chemistry in the aircraft wake, and global atmospheric model simulations. A complementary program of work by aviation experts has provided detailed information on air traffic data which was combined with data on aircraft performance and emissions to produce a global emissions inventory. This summary gives an overview of the results of this project. Further details are given in the following papers of this issue and the final project report of 1995. The work resulted in improved predictive equations to determine NOx emissions at cruise conditions based on available data for aircraft/engine combinations, and NOx emission measurements on two engines in cruise conditions. This information was combined with a traffic database to provide a new global NOx emissions inventory. It was found that only minor chemical changes occur during the vortex regime of the emission plume; however, this result does not exclude the possibility of further changes in the dispersion phase. A variety of global models was set up to investigate the changes in NOx concentrations and photochemistry. Although aviation contributes only a small proportion (about 3%) of the total global NOx from all anthropogenic sources, the models show that aviation contributes a large fraction to the concentrations of NOX in the upper troposphere, in particular north of 30°N. ~
An intercomparison of airborne nitrogen dioxide instruments
Journal of Geophysical Research: Atmospheres, 1990
Results from an airborne intercomparison of techniques to measure tropospheric levels of nitrogen dioxide (NO2) are discussed. The intercomparison was part of the National Aeronautics and Space Administration's Global Tropospheric Experiment and was conducted during the summer of 1986. Instruments intercompared included a two-photon nitric oxide (NO) laser-induced fluorescence system with laser photolysis of NO2 to NO, an NO/O3 chemiluminescence detector using FeSO4 for conversion of NO2 to NO, an NO/O3 chemiluminescence detector with arc lamp photolysis of NO2 to NO, and a tunable diode laser multipath absorption system. All intercomparisons were for NO2 mixing ratios of <200 pptv with most at mixing ratios of <tOO pptv. The FeSO 4 converter was found to convert peroxyacetyl nitrate (PAN) to NO, resulting in NO2 values a factor of 2-3 higher than reported by the other techniques. Thus the FeSO 4 converter data are excluded from the analyses. Intercomparison data were analyzed in various mixing ratio ranges. Good correlation was observed between the remaining three instruments for those data sets which included mixing ratios to tOO or 200 pptv, showing on the average a 30-40% level of agreement among the techniques. However, when the data were restricted to mixing ratios of <50 pptv, little correlation among the measurements was observed. Even though correlations were poor at mixing ratios of <50 pptv, the tunable diode laser system tended to be high compared to data reported by the two-photon laser and arc lamp chemiluminescence systems, and agreement between the latter two instruments was generally better than 20 pptv with an equal tendency for one to be high relative to the other. objectives of CITE 2 were (1) to evaluate instrumentation for measuring NO2, HNO3, and PAN in remote environments and (2) to determine the relative abundances of these major odd-nitrogen species for various tropospheric environments. CITE 1, an intercomparison of carbon monoxide, nitric oxide, and hydroxyl radical instrumentation, demonstrated the existing capability for aircraft measurements of NO in remote environments . Results from CITE Chem), and (4) a tunable diode laser multipath absorption system operated by York University (York/TDLAS). It was acknowledged that the York/TDLAS instrument with a detection limit of about 25 pptv would not be able to make measurements in some tropospheric environments. It was desirable to include the tunable laser instrument in CITE 2, since it spectroscopically measures NO2 directly.
Environmental Science & Technology, 2008
Nitrogen oxides (NO x ) concentrations were measured in individual plumes from aircraft departing on the northern runway at Heathrow Airport in west London. Over a period of four weeks 5618 individual plumes were sampled by a chemiluminescence monitor located 180 m from the runway. Results were processed and matched with detailed aircraft movement and aircraft engine data using chromatographic techniques. Peak concentrations associated with 29 commonly used engines were calculated and found to have a good relationship with NOx emissions taken from the International Civil Aviation Organization (ICAO) databank. However, it is found that engines with higher reported NO x emissions result in proportionately lower NO x concentrations than engines with lower emissions. We show that it is likely that aircraft operational factors such as takeoff weight and aircraft thrust setting have a measurable and important effect on concentrations of NO x . For example, NO x concentrations can differ by up to 41% for aircraft using the same airframe and engine type, while those due to the same engine type in different airframes can differ by 28%. These differences are as great as, if not greater than, the reported differences in NO x emissions between different engine manufacturers for engines used on the same airframe.
Journal of Geophysical Research, 1985
Whole air samples were obtained in the stratosphere using a liquid helium-cooled cryosampler mounted on a balloon platform. Approximately 1 g mol of sample was obtained at each of three altitudes per balloon flight and was maintained at 4 K until desorption just prior to analysis. Samples were obtained at six altitudes ranging from 12 to 30 km and at five latitudes from 9 ø to 64øN. Nitric oxide and the sum of nitric oxide and nitrogen dioxide content of the samples were determined using two chemiluminescence analyzers. Results from flights conducted between 1977 and 1981 are correlated with atmospheric motions and other significant variables and evaluated in terms of both one-and two-dimensional models of the stratosphere. 1. INTRODUCTION Concern arose in the early 1970's that anthropogenic influences might lead to catalytic destruction of the ozone layer. Oxides of nitrogen from the exhausts of supersonic transports [Johnston, 1971] and photodissociation of fluorocarbons as they diffuse upward [Molina and Rowland, 1974] were postulated to be the principal agents. Subsequent studies have diminished the level of concern over aircraft emissions [e.g., Oliver et al., 1977]. Nevertheless, sufficient uncertainty exists regarding the fate of the ozone layer [Federal Aviation Administration, 1981; National Research Council, 1983] to warrant continued investigation. A research program was initiated at Air Force Geophysics Laboratory (AFGL) (then Air Force Cambridge Research Laboratories) to obtain whole air samples in the stratosphere using a balloon platform. The air was to be sampled cryogenically, maintained as a cryofrost near 4 K until just prior to analysis, and subsequently analyzed for NO,, and fluorocarbon content. A major advantage of this approach is that it affords the opportunity to obtain values for both NO and NO,, simultaneously, a situation not possible with most of the alternate experimental techniques reported. A series of 24 balloon flights was conducted between 1975 and 1981. NO and NO,, results from flights conducted between 1977 and 1981 are reported herein and compared with the predictions of several stratospheric models. Also, individual measurements are correlated with specific air masses, tropopause height differences, and diurnal variations. At the lower altitudes, possible hyrocarbon influences and local anthropogenic sources are also considered. The fluorocarbon results have been reported separately [Gallagher et al., 1983]. 2. EXPERIMENTAL
Development, enhancement, and evaluation of aircraft measurement techniques for criteria pollutants
2014
The atmospheric contaminants most harmful to human health are designated Criteria Pollutants. To help Maryland attain the national ambient air quality standards (NAAQS) for Criteria Pollutants, and to improve our fundamental understanding of atmospheric chemistry, I conducted aircraft measurements in the Regional Atmospheric Measurement Modeling Prediction Program (RAMMPP). These data are used to evaluate model simulations and satellite observations. I developed techniques for improving airborne observation of two NAAQS pollutants, particulate matter (PM) and nitrogen dioxide (NO 2). While structure and composition of organic aerosol are important for understanding PM formation, the molecular speciation of organic ambient aerosol remains largely unknown. The spatial distribution of reactive nitrogen is likewise poorly constrained. To examine water-soluble organic aerosol (WSOA) during an air pollution episode, I designed and implemented a shrouded aerosol inlet system to collect PM onto quartz fiber filters from a Cessna 402 research aircraft. Inlet evaluation conducted during a side-by-side flight with the NASA P3 demonstrated agreement to within 30%. An ion chromatographic mass spectrometric method developed using the NIST Standard Reference Material (SRM) 1649b Urban Dust, as a surrogate material resulted in acidic class separation and resolution of at least 34 organic acids; detection limits approach pg/g concentrations. Analysis of aircraft filter samples resulted in detection of 8 inorganic species and 16 organic acids of which 12 were quantified. Aged, re-circulated metropolitan air showed a greater number of dicarboxylic acids compared to air recently transported from the west. While the NAAQS for NO 2 is rarely exceeded, it is a precursor molecule for ozone, America's most recalcitrant pollutant. Using cavity ringdown spectroscopy employing a light emitting diode (LED), I measured vertical profiles of NO 2 (surface to 2.5 km) west (upwind) of the Baltimore/Washington, area in the morning, and east (downwind) in the afternoon. Column contents (altitude integrals of concentration) were remarkably similar (≈3x10 molecules cm −2). These measurements indicate that NO 2 is widely distributed over the eastern US and help quantify the regional nature of smog events and prove extensive interstate transport of pollutants. These results were used to help shape air pollution control policy based on solid science.
Satellite measurements of NO2 from international shipping emissions
Geophysical Research Letters, 2004
1] Measurements from the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) instrument on board the ENVISAT satellite have been analyzed for tropospheric NO 2 signatures of shipping emissions. Clear indication for NO 2 produced from ship emissions has been found over the Red Sea and along the main shipping lane to the southern tip of India, to Indonesia and north towards China and Japan where the signal is lost. Using simple assumptions for the NO x loss, emission strengths were estimated and compared to an updated ship emission inventory. Good agreement was found in the spatial distribution and the absolute values for the Red Sea agree within a factor of 2, but larger discrepancies exist in other areas. Although the fluxes calculated still have large uncertainties, the results highlight the importance of ship emissions for the marine boundary layer and at the same time demonstrate the potential of satellite observations.
Analytical Methods, 2014
Dinitrogen pentoxide (N2O5) plays a central role in nighttime tropospheric chemistry as its formation and subsequent loss in sink processes limits the potential for tropospheric photochemistry to generate ozone the next day. Since accurate observational data for N2O5 are critical to examine our understanding of this chemistry, it is vital also to evaluate the capabilities of N2O5 measurement techniques through the co-deployment of the available instrumentation. This work compares measurements of N2O5 from two aircraft instruments onboard the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 aircraft during the Role of Nighttime Chemistry in Controlling the Oxidising Capacity of the Atmosphere (RONOCO) measurement campaigns over the United Kingdom in 2010 and 2011. A chemical ionisation mass spectrometer (CIMS), deployed for the first time for ambient N2O5 detection during RONOCO, measured N2O5 directly using Iionisation chemistry and an aircraft-based broadband cavity enhanced absorption spectrometer (BBCEAS), developed specifically for RONOCO, measured N2O5 by thermally dissociating N2O5 and quantifying the resultant NO3 spectroscopically within a high finesse optical cavity. N2O5 mixing ratios were simultaneously measured at 1 second time resolution (1 Hz) by the two instruments for 8 flights during RONOCO. The sensitivity for the CIMS instrument was 52 ion counts pptv-1 with a limit of detection of 7.4 pptv for 1 Hz measurements. BBCEAS, a proven technique for N2O5 measurement, had a limit of detection of 2 pptv. Comparison of the observed N2O5 mixing ratios show excellent agreement between the CIMS and BBCEAS methods for the whole dataset, as indicated by the square of the linear correlation coefficient, R 2 = 0.89. Even stronger correlations (R 2 values up to 0.98) were found for individual flights. Altitudinal profiles of N2O5 obtained by CIMS and BBCEAS also showed close agreement (R 2 = 0.93). Similarly, N2O5 mixing ratios from both instruments were greatest within pollution plumes and were strongly positively correlated with the NO2 concentrations. The transition from day to night time chemistry was observed during a dusk-to-dawn flight during the summer 2011 RONOCO campaign: the CIMS and BBCEAS instruments simultaneously detected the increasing N2O5 concentrations after sunset. The performance of the CIMS and BBCEAS techniques demonstrated in the RONOCO dataset illustrate the benefits that accurate, high-frequency, aircraft-based measurements have for improving understanding the nighttime chemistry of N2O5.
Journal of Geophysical Research, 2007
1] The nocturnal nitrogen oxides, NO 3 and N 2 O 5 , are important to the chemical transformation and transport of NO x , O 3 and VOC. Their concentrations, sources and sinks are known to be vertically stratified in the nighttime atmosphere. In this paper, we report vertical profiles for NO 3 and N 2 O 5 measured from an aircraft (the NOAA P-3) as part of the New England Air Quality Study in July and August 2004. The aircraft data are compared to surface measurements made in situ from a ship and by long-path DOAS. Consistent with previous, vertically resolved studies of NO 3 and N 2 O 5 , the aircraft measurements show that these species occur at larger concentrations and are longer lived aloft than they are at the surface. The array of in situ measurements available on the P-3 allows for investigation of the mechanisms that give rise to the observed vertical gradients. Selected vertical profiles from this campaign illustrate the role of biogenic VOC, particularly isoprene and dimethyl sulfide, both within and above the nocturnal and/or marine boundary layer. Gradients in relative humidity and aerosol surface may also create a vertical gradient in the rate of N 2 O 5 hydrolysis. Low-altitude intercepts of power plant plumes showed strong vertical stratification, with plume depths of 80 m. The efficiency of N 2 O 5 hydrolysis within these plumes was an important factor determining the low-level NO x and O 3 transport or loss at night. Averages of nocturnal O 3 , NO 2 , NO 3 and N 2 O 5 binned according to altitude were consistent with the trends from individual profiles. While production rates of NO 3 peaked near the surface, lifetimes of NO 3 and N 2 O 5 were maximum aloft, particularly in the free troposphere. Variability in NO 3 and N 2 O 5 was large and exceeded that of NO 2 or O 3 because of inhomogeneous distribution of NO x emissions and NO 3 and N 2 O 5 sinks. Citation: Brown, S. S., et al. (2007), Vertical profiles in NO 3 and N 2 O 5 measured from an aircraft: Results from the NOAA P-3 and surface platforms during the New England Air Quality Study 2004,
Intercontinental transport of nitrogen oxide pollution plumes
Atmospheric Chemistry and Physics, 2003
We describe the first satellite observation of intercontinental transport of nitrogen oxides emitted by power plants, verified by simulations with a particle tracer model. The analysis of such episodes shows that anthropogenic NO x plumes may influence the atmospheric chemistry thousands of kilometers away from its origin, as well as the ocean they traverse due to nitrogen fertilization. This kind of monitoring became possible by applying an improved algorithm to extract the tropospheric fraction of NO 2 from the spectral data coming from the GOME instrument (see Appendix A).