National Library of Energy BETA

Sample records for vulture cathartes aura

  1. Beasley Lab | Savannah River Ecology Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    vultures on transmission tower Black (Coragyps atratus) and turkey vultures (Cathartes aura) are scavengers commonly associated with areas of human development. Because vultures...

  2. Beasley Lab | Savannah River Ecology Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the response of black vultures (Coragyps atratus), turkey vultures (Cathartes aura), gulls (Laridae), blackbirds (Icteridae), and waterfowl (Anatidae) to treatment with...

  3. Aura Systems Inc | Open Energy Information

    Open Energy Info (EERE)

    Aura Systems Inc Jump to: navigation, search Name: Aura Systems Inc Place: El Segundo, California Zip: 90245 Product: El Segundo-head quartered developer of AuraGen, an axial flux...

  4. T-695: Avaya Aura Application Server Buffer Overflow in 'cstore.exe' Lets Remote Users Execute Arbitrary Code

    Broader source: Energy.gov [DOE]

    Avaya Aura Application Server Buffer Overflow in 'cstore.exe' Lets Remote Users Execute Arbitrary Code.

  5. Effects of heavy metals on biomarkers for oxidative stress in Griffon vulture (Gyps fulvus)

    SciTech Connect (OSTI)

    Espn, Silvia; Martnez-Lpez, Emma; Jimnez, Pedro; Mara-Mojica, Pedro; Garca-Fernndez, Antonio J.

    2014-02-01

    Metals are involved in the formation of reactive oxygen species (ROS) which may result in metal-related oxidative stress that can lead to oxidative damage to lipids, DNA and proteins. It is necessary to understand the mechanisms of metal toxicity in wild birds, and the concentrations that cause effects on oxidative stress biomarkers. The aim of this study is to assess the concentrations of lead (Pb), cadmium (Cd), mercury (Hg), copper (Cu) and zinc (Zn) with regards to oxidative stress in blood samples of 66 Griffon vultures (Gyps fulvus) from two areas of the Autonomous Community of Valencia (East of Spain). The two study areas (Alcoy n=36 and Cinctorres n=30) were selected as random locations of interest that had not yet been studied, and are feeding stations where supplementary food, mainly of pork origin, is provided for vultures. Given that the two study areas are not considered polluted sites, we expected to find low metal concentrations. However, there are no known threshold concentrations at which metals can affect antioxidant systems, and low metal levels may have an effect on antioxidant biomolecules. In this study, since sampling was done at the beginning of the hunting season, the low Pb levels found in most Griffon vultures from Alcoy and Cinctorres (median=12.37 and 16.26 ?g/dl, respectively) are suggestive of background levels usually found in vultures that feed on pork carcasses all year round. The ingestion of game meat with bullet fragments in carcasses or with Pb shots embedded in the flesh could be the cause of the high blood Pb concentrations found in three vultures from Cinctorres (83, 290 and 362 ?g/dl). Griffon vultures feeding in Cinctorres had enhanced CAT and GST activities and tGSH concentrations, which may be interpreted as protective response against the higher TBARS levels. This study provides threshold concentrations at which metals affect antioxidant system derived from 66 samples of Griffon vulture. Blood Cd concentrations greater

  6. XRD micro-XANES EMPA and SIMS investigation on phlogopite single crystals from Mt. Vulture (Italy)

    SciTech Connect (OSTI)

    F Scordari; M Dyar; E Schingaro; M Lacalamita; L Ottolini

    2011-12-31

    Selected phlogopite flakes from Mt. Vulture in southern Italy were studied using a combination of single-crystal techniques: electron microprobe analysis (EMPA), secondary ion mass spectrometry (SIMS), single-crystal X-ray diffraction (SCXRD), and micro-X-ray absorption near-edge spectroscopy (XANES). The latter technique was employed to analyze the structure of the Fe-K absorption edge over the region from 7080-8100 eV and to determine Fe{sup 3+}/{Sigma}Fe at a micrometer scale, albeit with large error bars due to known effects of orientation on pre-edge energy. The annite component, Fe/(Mg+Fe), of the samples studied ranged from 0.16 to 0.31, the Ti content from 0.11 to 0.27 atoms per formula unit (apfu) and the Ba content from 0.03 to 0.09 apfu. SIMS analysis showed H{sub 2}O (wt%) = 1.81-3.30, F (wt%) = 0.44-1.29, and Li{sub 2}O (wt%) = 0.001-0.027. The intra single-crystal chemical variability for major/minor elements (Mg, Fe, Al, Ba, Ti, and K) was found particularly significant for samples VUT191{_}11 and PG5{_}1, less significant for the other samples of the set. SIMS data relative to crystals VUT187{_}24, VUT191{_}10, VUT191{_}11, and VUT187{_}28 showed a noteworthy variation in the concentrations of some light elements (H, Li, and F) with coefficient of variation CV (as 1{sigma}%) up to {approx}18% for H{sub 2}O. The analyzed micas belong to the 1M polytype. Structure refinements using anisotropic displacement parameters were performed in space group C2/m and converged at 3.08 {<=} R {<=} 3.63, 3.32 {<=} R{sub w} {<=} 3.98%. Micro-XANES results yielded Fe{sup 3+}/{Sigma}Fe from 51-93%. Previous Moessbauer data from powdered samples suggested Fe{sup 3+}/{Sigma}Fe values ranging from 49-87%. However, the Fe{sup 3+} content determined by both techniques is sometimes remarkably different, in part because of the large errors ({+-}10-15%) presently associated with the micro-XANES technique and in part because the Fe{sup 3+} content of a single crystal may

  7. The probability of laser caused ocular injury to the aircrew of undetected aircraft violating the exclusion zone about the airborne aura LIDAR.

    SciTech Connect (OSTI)

    Augustoni, Arnold L.

    2006-12-01

    The probability of a laser caused ocular injury, to the aircrew of an undetected aircraft entering the exclusion zone about the AURA LIDAR airborne platform with the possible violation of the Laser Hazard Zone boundary, was investigated and quantified for risk analysis and management.

  8. Southern Great Plains

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    installed together at the SGP central facility (ARM photo). October 2004 3 Okmulgee Turkey Vultures Thwarted . . . Finally After years of trying to keep messy turkey vultures...

  9. Comparison of improved Aura Tropospheric Emission Spectrometer (TES) CO{sub 2} with HIPPO and SGP aircraft profile measurements

    SciTech Connect (OSTI)

    Kulawik, S. S.; Worden, J. R.; Wofsy, S. C.; Biraud, S. C.; Nassar, R.; Jones, D. B.A.; Olsen, E. T.; Osterman, G. B.

    2012-02-01

    Comparisons are made between mid-tropospheric Tropospheric Emission Spectrometer (TES) carbon dioxide (CO{sub 2}) satellite measurements and ocean profiles from three Hiaper Pole-to-Pole Observations (HIPPO) campaigns and land aircraft profiles from the United States Southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) site over a 4-yr period. These comparisons are used to characterize the bias in the TES CO{sub 2} estimates and to assess whether calculated and actual uncertainties and sensitivities are consistent. The HIPPO dataset is one of the few datasets spanning the altitude range where TES CO{sub 2} estimates are sensitive, which is especially important for characterization of biases. We find that TES CO{sub 2} estimates capture the seasonal and latitudinal gradients observed by HIPPO CO{sub 2} measurements; actual errors range from 0.8–1.2 ppm, depending on the campaign, and are approximately 1.4 times larger than the predicted errors. The bias of TES versus HIPPO is within 0.85 ppm for each of the 3 campaigns; however several of the sub-tropical TES CO{sub 2} estimates are lower than expected based on the calculated errors. Comparisons of aircraft flask profiles, which are measured from the surface to 5 km, to TES CO{sub 2} at the SGP ARM site show good agreement with an overall bias of 0.1 ppm and rms of 1.0 ppm. We also find that the predicted sensitivity of the TES CO{sub 2} estimates is too high, which results from using a multi-step retrieval for CO{sub 2} and temperature. We find that the averaging kernel in the TES product corrected by a pressure-dependent factor accurately reflects the sensitivity of the TES CO{sub 2} product.

  10. GRASSLAND BIRD DISTRIBUTION AND RAPTOR FLIGHT PATTERNS IN THE COMPETITIVE RENEWABLE ENERGY ZONES OF THE TEXAS PANHANDLE

    SciTech Connect (OSTI)

    Jansen, Erik

    2013-08-10

    fewer detections (MacKenzie and Nichols 2004). I used occupancy models that allow for the possibility of imperfect detection and species abundance to improve estimates of occurrence probability (Royal 2004). I focused species-specific analyses on grassland birds with few detections: Cassin’s sparrow (Peucaea cassinii), eastern meadowlark (Sturnella magna), and upland sandpiper (Bartramia longicauda). Chapter III uses a multi-season dynamic site occupancy model that incorporates bird abundance to better estimate occurrence probability. 3) When I considered the topographic relief of the study sites, the proposed design of the wind facility and its location within the central U.S. migratory corridor, I expanded the study to investigate raptor abundance and flight behavior (Hoover 2002, Miller 2008). I developed a new survey technique that improved the accuracy of raptor flight height estimates and compared seasonal counts and flight heights at the plateau rim and areas further inland. I used counts and flight behaviors to calculate species-specific collision risk indices for raptors based on topographic features. I focused species-specific analyses on raptors with the highest counts: American kestrel (Falco sparverius), northern harrier (Circus cyaneus), red-tailed hawk (Buteo jamaicensis), Swainson’s hawk (Buteo swainsoni), and turkey vulture (Cathartes aura). Chapter IV describes patterns of seasonal raptor abundance and flight behavior and how topography modulates collision risk with proposed wind energy turbines. 4) Finally, for completeness, in Chapter V I summarize morning point count data for all species and provide estimates of relative composition and species diversity with the Shannon-Wiener Diversity Index (Shannon and Weaver 1949).

  11. Beasley Lab | Savannah River Ecology Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aging an anesthetized bobcat Wildlife studies in the Chernobyl exclusion zone Chernobyl wolf Amanda attaching satellite transmitter to a vulture Anesthetizing a wild pig ...

  12. Status, Accomplishments, and Recent Developments at the ARM Climate...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    OK Installed revised version of rotating bird deterrent device to prevent roosting turkey vultures from damaging equipment. * LICOR-7500 IRGA calibrations Trained SGP...

  13. El Segundo, California: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    congressional district.12 Registered Energy Companies in El Segundo, California Aura Systems Inc Carbon Jungle International Rectifier Corporation International Rectifier...

  14. Inquiring Minds - Questions About Physics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aura You Wrote: I saw a TV show the other day that talked about a persons aura. I read in a book that a persons aura is made up of quarks. The book went on describe how the energy of your aura (quarks) may get stuck on the earth plane when you die and this is the energy that may represent a ghost running around your house. The book (Ghosthunter by Eddie Burks) indicated that quarks could pass through solid items as we understand solidity. It also went on to say that an aura is visible between

  15. Solar spectral irradiance changes during cycle 24 (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Title: Solar spectral irradiance changes during cycle 24 We use solar spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow ...

  16. SEARCHING FOR z {approx} 7.7 Ly{alpha} EMITTERS IN THE COSMOS...

    Office of Scientific and Technical Information (OSTI)

    Arizona State University, Tempe, AZ 85287 (United States) Gemini Observatory, co AURA, Casilla 603, La Serena (Chile) NOAO, Tucson, AZ 85719 (United States) Publication ...

  17. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... ; Maasakkers, J. D. ; Butz, A. ; Hasekamp, O. ; Biraud, S. C. March 2016 , Wiley Blackwell (John Wiley & Sons) Comparison of improved Aura Tropospheric Emission Spectrometer (TES) ...

  18. ARM - Publications: Science Team Meeting Documents

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    formation as part of a constellation of satellites including Aqua, CALIPSO, PARASOL and Aura. We develop an algorithm that will be implemented operationally to identify significant...

  19. Bench-Scale Cross Flow Filtration of

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from (a) the simulation ICE and (b) simulation REF and that measured by (c) the Aura MLS instrument... 5 iv X. Liu et al.,...

  20. New generation of the SORTI instruments

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    data of the atmospheric composition using SORTI instrument and integrated in the Aura validation campaign, a new instrument generation has been developed. SORTI is a Fourier...

  1. Validation of TES Temperature and Water Vapor Retrievals with...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The primary objective of the TES (Tropospheric Emission Spectrometer) instrument on the Aura spacecraft is the retrieval of trace gases, especially water vapor and ozone. The TES...

  2. Newsletter Southern Great Plains

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Technical Contact: Brad W. Orr Phone: 630-252-8665 Email: brad.orr@anl.gov Editor: Donna ... Scientists to Validate Satellite-Based Ozone Measurements Aura, the third and final ...

  3. Microsoft PowerPoint - McFarquhar_2007.ppt

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    , is a good test of whether shattering amplified CAS concentrations * During Costa-Rica Aura Validation Experiment (CR-AVE), coincident data with CAS, CIP and CDP also obtained in...

  4. BPA-2011-00504-FOIA Request

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atterbu ry , aura M - -7 . CEIVED BY BPA Oi: OFFICE THIS From: rchapman , < < is I * 2 Sent: Thursday, Janua ry 20, 2011 4:42 PM ,;t E DA1E: Subject: FOIA Request Z-" I e The...

  5. Prediction of Ice Crystal Number in Community Atmospheric Model...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    calculated in CAM is compared to the satellite and in situ measurements (e.g., HIRS, Aura-MLS, and MOZAIC datasets). The impacts of anthropogenic aerosols on climate through...

  6. Some key Y-12 General Foremen remembered

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in 1980 and continued in that role until around 1992. Herman, like Ray Guinn, had the 2 aura of being totally in charge of his operations. He had around-the-clock shift operations,...

  7. Camp Smith Microgrid Controls and Cyber Security

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ADVANCING THE POWER OF ENERGY Camp Smith Microgrid Controls and Cyber Security Darrell D. Massie, PhD, PE Aura Lee Keating, CISSP SPIDERS Industry Day - Camp Smith, HI 27 August ...

  8. Satellite observations of recent power plant construction in Inner Mongolia, China - article no. L15809

    SciTech Connect (OSTI)

    Zhang, Q.; Streets, D.G.; He, K.B.

    2009-08-15

    About 50% of the increase in China's NOx emissions since 2000 can be attributed to the construction of new power plants. We show that the newly added NOx emissions from new power plants in Inner Mongolia, China, were detected by the Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite. Increase rates of NO{sub 2} columns from OMI and NOx emissions from inventories are even in quantitative agreement in cases where new facilities are added to already-developed regions. This study confirms that the OMI products are quite capable of identifying the construction of large new emitting facilities through detection of their NOx emissions.

  9. L3-VUQ-SAUQ-P7-01-final

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    P7.01 Separate Effects V&V for Hydra-TH Brian Williams Lori Pritchett-Sheats Los Alamos National Laboratory Kevin Copps Laura Swiler Sandia National Laboratories Ernesto Prudencio University of Texas Austin September 30, 2013 CASL-U-2013-0213-000 2 Separate Effects V&V for H ydra---TH CASL M ilestone L 3:VUQ.SAUQ.P7.01 Brian Williams 1 , L ori P ritchett---Sheats 2 , K evin C opps 3 , L aura S wiler 4 , a nd E rnesto Prudencio 5 1 Statistical Sciences Group, Los Alamos National

  10. Satellite observations of the recent power plant construction in Inner Mongolia, China.

    SciTech Connect (OSTI)

    Zhang, Q.; Streets, D. G.; He, K.

    2009-08-05

    About 50% of the increase in China's NO{sub x} emissions since 2000 can be attributed to the construction of new power plants. We show that the newly added NO{sub x} emissions from new power plants in Inner Mongolia, China, were detected by the Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite. Increase rates of NO{sub 2} columns from OMI and NO{sub x} emissions from inventories are even in quantitative agreement in cases where new facilities are added to already-developed regions. This study confirms that the OMI products are quite capable of identifying the construction of large new emitting facilities through detection of their NO{sub x} emissions.

  11. Comparison of Satellite NO{sub 2} Observations with High Resolution Model Simulations over the Balkan Peninsula

    SciTech Connect (OSTI)

    Zyrichidou, I.; Koukouli, M. E.; Balis, D. S.; Katragkou, E.; Poupkou, A.; Kioutsioukis, I.; Markakis, K.; Melas, D.; van der A., R.; Boersma, F. K.; Roozendael, M. van

    2010-01-21

    High resolution model estimations of tropospheric NO{sub 2} column amounts from the Comprehensive Air Quality Model (CAMx) were simulated for the Balkan Peninsula and were compared with satellite data for a period of one year, in order to study the characteristics of the spatial and temporal variability of pollution in the area. The Balkan area is considered a crossroad of different pollution sources and therefore has been divided in urban, industrial and rural regions, aiming to investigate the consistency of satellite retrievals and model predictions at high spatial resolution. Satellite measurements of tropospheric NO{sub 2} are available daily at 13:30 LT since 2004 from OMI/Aura with a resolution of 13x24 km. The anthropogenic emissions used in CAMx for the domain under study, was compiled employing bottom-up approaches (road transport sector, off-road machinery) as well as other national registries and international databases. High resolution GIS maps (road network, landuses, population) were also used in order to achieve high spatial resolution. In most of the cases the model reveals similar spatial patterns with the satellite data, while over certain areas discrepancies were found and investigated.

  12. NOx Emission Reduction and its Effects on Ozone during the 2008 Olympic Games

    SciTech Connect (OSTI)

    Yang, Qing; Wang, Yuhang; Zhao, Chun; Liu, Zhen; Gustafson, William I.; Shao, Min

    2011-07-15

    We applied a daily-assimilated inversion method to estimate NOx (NO+NO2) emissions for June-September 2007 and 2008 on the basis of the Aura Ozone Monitoring Instrument (OMI) observations of nitrogen dioxide (NO2) and model simulations using the Regional chEmistry and trAnsport Model (REAM). Over urban Beijing, rural Beijing, and the Huabei Plain, OMI column NO2 reductions are approximately 45%, 33%, and 14%, respectively, while the corresponding anthropogenic NOx emission reductions are only 28%, 24%, and 6%, during the full emission control period (July 20 – Sep 20, 2008). The emission reduction began in early July and was in full force by July 20, corresponding to the scheduled implementation of emission controls over Beijing. The emissions did not appear to recover after the emission control period. Meteorological change from summer 2007 to 2008 is the main factor contributing to the column NO2 decreases not accounted for by the emission reduction. Model simulations suggest that the effect of emission reduction on ozone concentrations over Beijing is relatively minor using a standard VOC emission inventory in China. With an adjustment of the model emissions to reflect in situ observations of VOCs in Beijing, the model simulation suggests a larger effect of the emission reduction.

  13. Solar spectral irradiance changes during cycle 24

    SciTech Connect (OSTI)

    Marchenko, S. V.; DeLand, M. T.

    2014-07-10

    We use solar spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow long-term (years) and short-term (weeks) changes in the solar spectral irradiance (SSI) in the 265-500 nm spectral range. During solar Cycle 24, in the relatively line-free regions the SSI changed by ∼0.6% ± 0.2% around 265 nm. These changes gradually diminish to 0.15% ± 0.20% at 500 nm. All strong spectral lines and blends, with the notable exception of the upper Balmer lines, vary in unison with the solar 'continuum'. Besides the lines with strong chromospheric components, the most involved species include Fe I blends and all prominent CH, NH, and CN spectral bands. Following the general trend seen in the solar 'continuum', the variability of spectral lines also decreases toward longer wavelengths. The long-term solar cycle SSI changes are closely, to within the quoted 0.1%-0.2% uncertainties, matched by the appropriately adjusted short-term SSI variations derived from the 27 day rotational modulation cycles. This further strengthens and broadens the prevailing notion about the general scalability of the UV SSI variability to the emissivity changes in the Mg II 280 nm doublet on timescales from weeks to years. We also detect subtle deviations from this general rule: the prominent spectral lines and blends at λ ≳ 350 nm show slightly more pronounced 27 day SSI changes when compared to the long-term (years) trends. We merge the solar data from Cycle 21 with the current Cycle 24 OMI and GOME-2 observations and provide normalized SSI variations for the 170-795 nm spectral region.

  14. How consistent are top-down hydrocarbon emissions based on formaldehyde observations from GOME-2 and OMI?

    SciTech Connect (OSTI)

    Stavrakou, T.; Muller, J. F.; Bauwens, M.; De Smedt, I.; Van Roozendael, M.; De Maziere, M.; Vigouroux, C.; Hendrick, F.; George, M.; Clerbaux, C.; Coheur, P-F; Guenther, Alex B.

    2015-10-26

    The vertical columns of formaldehyde (HCHO) retrieved from two satellite instruments, the Global Ozone Monitoring Instrument-2 (GOME-2) on Metop-A and the Ozone Monitoring Instrument (OMI) on Aura, are used to constrain global emissions of HCHO precursors from open fires, vegetation and human activities in the year 2010. To this end, the emissions are varied and optimized using the ad-joint model technique in the IMAGESv2 global CTM (chem-ical transport model) on a monthly basis and at the model res-olution. Given the different local overpass times of GOME- 2 (09:30 LT) and OMI (13:30 LT), the simulated diurnal cy-cle of HCHO columns is investigated and evaluated against ground-based optical measurements at seven sites in Europe, China and Africa. The modeled diurnal cycle exhibits large variability, reflecting competition between photochemistry and emission variations, with noon or early afternoon max-ima at remote locations (oceans) and in regions dominated by anthropogenic emissions, late afternoon or evening max-ima over fire scenes, and midday minima in isoprene-rich re-gions. The agreement between simulated and ground-based columns is generally better in summer (with a clear after-noon maximum at mid-latitude sites) than in winter, and the annually averaged ratio of afternoon to morning columns is slightly higher in the model (1.126) than in the ground-based measurements (1.043).The anthropogenic VOC (volatile organic compound) sources are found to be weakly constrained by the inversions on the global scale, mainly owing to their generally minor contribution to the HCHO columns, except over strongly pol-luted regions, like China. The OMI-based inversion yields total flux estimates over China close to the bottom-up inven-tory (24.6 vs. 25.5 TgVOC yr-1 in the a priori) with, how-ever, pronounced increases in the northeast of China and re-ductions in the south. Lower fluxes are estimated based on GOME-2 HCHO columns (20.6 TgVOC yr-1), in

  15. U.S. NO₂ trends (2005–2013): EPA air quality system (AQS) data versus improved observations from the Ozone Monitoring Instrument (OMI)

    SciTech Connect (OSTI)

    Lamsal, Lok N.; Duncan, Bryan N.; Yoshida, Yasuko; Krotkov, Nickolay A.; Pickering, Kenneth E.; Streets, David G.; Lu, Zifeng

    2015-06-01

    Emissions of nitrogen oxides (NOx) and, subsequently, atmospheric levels of nitrogen dioxide (NO₂) have decreased over the U.S. due to a combination of environmental policies and technological change. Consequently, NO₂ levels have decreased by 30–40% in the last decade. We quantify NO₂ trends (2005–2013) over the U.S. using surface measurements from the U.S. Environmental Protection Agency (EPA) Air Quality System (AQS) and an improved tropospheric NO₂ vertical column density (VCD) data product from the Ozone Monitoring Instrument (OMI) on the Aura satellite.We demonstrate that the current OMI NO₂ algorithm is of sufficient maturity to allow a favorable correspondence of trends and variations in OMI and AQS data. Our trend model accounts for the non-linear dependence of NO₂ concentration on emissions associated with the seasonal variation of the chemical lifetime, including the change in the amplitude of the seasonal cycle associated with the significant change in NOx emissions that occurred over the last decade. The direct relationship between observations and emissions becomes more robust when one accounts for these non-linear dependencies. We improve the OMI NO₂ standard retrieval algorithm and, subsequently, the data product by using monthly vertical concentration profiles, a required algorithm input, from a high-resolution chemistry and transport model (CTM) simulation with varying emissions (2005-2013). The impact of neglecting the time-dependence of the profiles leads to errors in trend estimation, particularly in regions where emissions have changed substantially. For example, trends calculated from retrievals based on time-dependent profiles offer 18% more instances of significant trends and up to 15% larger total NO₂ reduction versus the results based on profiles for 2005. Using a CTM, we explore the theoretical relation of the trends estimated from NO₂ VCDs to those estimated from ground-level concentrations

  16. U.S. NO₂ trends (2005–2013): EPA air quality system (AQS) data versus improved observations from the Ozone Monitoring Instrument (OMI)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lamsal, Lok N.; Duncan, Bryan N.; Yoshida, Yasuko; Krotkov, Nickolay A.; Pickering, Kenneth E.; Streets, David G.; Lu, Zifeng

    2015-06-01

    Emissions of nitrogen oxides (NOx) and, subsequently, atmospheric levels of nitrogen dioxide (NO₂) have decreased over the U.S. due to a combination of environmental policies and technological change. Consequently, NO₂ levels have decreased by 30–40% in the last decade. We quantify NO₂ trends (2005–2013) over the U.S. using surface measurements from the U.S. Environmental Protection Agency (EPA) Air Quality System (AQS) and an improved tropospheric NO₂ vertical column density (VCD) data product from the Ozone Monitoring Instrument (OMI) on the Aura satellite.We demonstrate that the current OMI NO₂ algorithm is of sufficient maturity to allow a favorable correspondence of trendsmore » and variations in OMI and AQS data. Our trend model accounts for the non-linear dependence of NO₂ concentration on emissions associated with the seasonal variation of the chemical lifetime, including the change in the amplitude of the seasonal cycle associated with the significant change in NOx emissions that occurred over the last decade. The direct relationship between observations and emissions becomes more robust when one accounts for these non-linear dependencies. We improve the OMI NO₂ standard retrieval algorithm and, subsequently, the data product by using monthly vertical concentration profiles, a required algorithm input, from a high-resolution chemistry and transport model (CTM) simulation with varying emissions (2005-2013). The impact of neglecting the time-dependence of the profiles leads to errors in trend estimation, particularly in regions where emissions have changed substantially. For example, trends calculated from retrievals based on time-dependent profiles offer 18% more instances of significant trends and up to 15% larger total NO₂ reduction versus the results based on profiles for 2005. Using a CTM, we explore the theoretical relation of the trends estimated from NO₂ VCDs to those estimated from ground-level concentrations. The model