ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Quantifying atmospheric methane emissions from oil and natural gas production in the Bakken shale region of North Dakota (2016)
    Wiley
    Details
    Publication Date: 2016-05-12
    Description: We present in situ airborne measurements of methane (CH 4 ) and ethane (C 2 H 6 ) taken aboard a NOAA DHC-6 Twin Otter research aircraft in May 2014 over the Williston Basin in northwestern North Dakota, a region of rapidly growing oil and natural gas production. The Williston Basin is best known for the Bakken shale formation, from which a significant increase in oil and gas extraction has occurred since 2009. We derive a CH 4 emission rate from this region using airborne data by calculating the CH 4 enhancement flux through the planetary boundary layer downwind of the region. We calculate CH 4 emissions of (36 ± 13), (27 ± 13), (27 ± 12), (27 ± 12), and (25 ± 10) × 10 3  kg/hr from five transects on three days in May 2014 downwind of the Bakken shale region of North Dakota. The average emission, (28 ± 5) × 10 3  kg/hr, extrapolates to 0.25 ± 0.05 Tg/yr, which is significantly lower than a previous estimate of CH 4 emissions from northwestern North Dakota and southeastern Saskatchewan using satellite remote sensing data. We attribute the majority of CH 4 emissions in the region to oil and gas operations in the Bakken based on the similarity between atmospheric C 2 H 6 to CH 4 enhancement ratios and the composition of raw natural gas withdrawn from the region.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    HONO emission and production determined from airborne measurements over the Southeast U. S. (2016)
    Wiley
    Details
    Publication Date: 2016-07-28
    Description: The sources and distribution of tropospheric nitrous acid (HONO) were examined using airborne measurements over the Southeast U.S. during the SENEX experiment in June and July 2013. HONO was measured once per second using a chemical ionization mass spectrometer on the NOAA WP-3D aircraft to assess sources that affect HONO abundance throughout the planetary boundary layer (PBL). The aircraft flew at altitudes between 0.12 and 6.4 km above ground level on 18 research flights that were conducted both day and night, sampling emissions from urban and power plant sources that were transported in the PBL. At night, HONO mixing ratios were greatest in plumes from agricultural burning, where they exceeded 4 ppbv and accounted for 2 − 14% of the reactive nitrogen emitted by the fires. The HONO to carbon monoxide ratio in these plumes from flaming stage fires ranged from 0.13 − 0.52%. Direct HONO emissions from coal-fired power plants were quantified using measurements at night, when HONO loss by photolysis was absent. These direct emissions were often correlated with total reactive nitrogen with enhancement ratios that ranged from 0 − 0.4%. HONO enhancements in power plant plumes measured during the day were compared with a Lagrangian plume dispersion model, showing that HONO produced solely from the gas phase reaction of OH with NO explained the observations. Outside of recently emitted plumes from known combustion sources, HONO mixing ratios measured several hundred m above ground level were indistinguishable from zero within the 15 pptv measurement uncertainty. The results reported here do not support the existence of a ubiquitous unknown HONO source that produces significant HONO concentrations in the lower troposphere.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Airborne Measurements of the Atmospheric Emissions from a Fuel Ethanol Refinery (2015)
    Wiley
    Details
    Publication Date: 2015-04-10
    Description: Ethanol made from corn now constitutes approximately 10% of the fuel used in gasoline vehicles in the U.S. The ethanol is produced in over 200 fuel ethanol refineries across the nation. We report airborne measurements downwind from Decatur, Illinois, where the third largest fuel ethanol refinery in the U.S. is located. Estimated emissions are compared with the total point source emissions in Decatur according to the 2011 National Emissions Inventory (NEI-2011), in which the fuel ethanol refinery represents 68.0% of sulfur dioxide (SO 2 ), 50.5% of nitrogen oxides (NOx=NO+NO 2 ), 67.2% of volatile organic compounds (VOCs) and 95.9% of ethanol emissions. Emissions of SO 2 and NOx from Decatur agreed with NEI-2011, but emissions of several VOCs were underestimated by factors of 5 (total VOCs) to 30 (ethanol). By combining the NEI-2011 with fuel ethanol production numbers from the Renewable Fuels Association, we calculate emission intensities, defined as the emissions per ethanol mass produced. Emission intensities of SO 2 and NOx are higher for plants that use coal as an energy source, including the refinery in Decatur. By comparing with fuel-based emission factors, we find that fuel ethanol refineries have lower NOx, similar VOC and higher SO 2 emissions than from the use of this fuel in vehicles. The VOC emissions from refining could be higher than from vehicles, if the underestimated emissions in NEI-2011 downwind from Decatur extend to other fuel ethanol refineries. Finally, chemical transformations of the emissions from Decatur were observed, including formation of new particles, nitric acid, peroxyacyl nitrates, aldehydes, ozone and sulfate aerosol.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Modeling the weekly cycle of NOx and CO emissions and their impacts on O3 in the Los Angeles-South Coast Air Basin during the CalNex 2010 field campaign (2016)
    Wiley
    Details
    Publication Date: 2016-01-11
    Description: We developed a new nitrogen oxides (NO x ) and carbon monoxide (CO) emission inventory for the Los Angeles-South Coast Air Basin (SoCAB) expanding the Fuel-based Inventory for motor-Vehicle Emissions (FIVE) and applied it in regional chemical transport modeling focused on the California Nexus of Air Quality and Climate Change (CalNex) 2010 field campaign. The weekday NO x emission over the SoCAB in 2010 is 620 metric tons day −1 while the weekend emission is 410 metric tons day −1 . The NO x emission decrease on weekends is caused by reduced diesel truck activities. Weekday and weekend CO emissions over this region are similar: 2340 and 2180 metric tons day −1 , respectively. Previous studies reported large discrepancies between the airborne observations of NO x and CO mixing ratios and the model simulations for CalNex based on the available bottom-up emission inventories. Utilizing the newly developed emission inventory in this study, the simulated NO x and CO mixing ratios agree with the observations from the airborne and the ground-based in-situ and remote-sensing instruments during the field study. The simulations also reproduce the weekly cycles of these chemical species. Both the observations and the model simulations indicate that decreased NO x on weekends leads to enhanced photochemistry and increase of O 3 and O x (=O 3  + NO 2 ) in the basin. The emission inventory developed in this study can be extended to different years and other urban regions in the US to study the long-term trends in O 3 and its precursors with regional chemical transport models.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Impact of Turbulent Mixing on Isoprene Chemistry (2016)
    Wiley
    Details
    Publication Date: 2016-07-05
    Description: Isoprene, a volatile organic compound that is mainly emitted from trees, rapidly reacts with hydroxyl radical (OH) during daytime and subsequently forms ozone and aerosols in the troposphere. The isoprene-OH reaction can be affected by the interplay between chemistry and mixing because the two processes occur at a similar time scale. We investigate the impact of turbulent mixing on isoprene-OH reactivity with large-eddy simulations (LES) coupled with comprehensive chemistry. Our results show that the covariance of isoprene and OH causes ~20% decrease to ~10% increase of the horizontal average reaction rate, depending on nitrogen oxides (NO x  = NO + NO 2 ) abundances, compared to the rate that neglects the covariance. This wide range of effects on reaction rates is caused by the primary production and loss reactions of OH in each NO x regime. Our research promotes the use of LES for better understanding the role of turbulence in isoprene-OH reaction and parameterizations in large-scale models.
    Print ISSN: 0094-8276
    Electronic ISSN: 1944-8007
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Weakening of the Weekend Ozone Effect over California's South Coast Air Basin (2015)
    Wiley
    Details
    Publication Date: 2015-10-14
    Description: We have observed lower nitrogen dioxide (NO 2 ) and ozone (O 3 ) during a hot weekend (summer 2010) from aircraft over the entire South Coast Air Basin (SoCAB). Surface concentrations of NO 2 , O 3 and temperature from 1996-2014 corroborate that this lower O 3 on weekends is increasingly likely in recent years. While higher surface O 3 on the weekends (weekend ozone effect, WO3E) remains widespread, the spatial extent and the trend in the probability of WO3E occurrences (P WO3E ) has decreased significantly compared to a decade ago. This decrease is mostly the result of lower O 3 on hot weekends in recent years. P WO3E is lowest in the eastern SoCAB. The major decrease happened during the 2008 economic recession, after which P WO3E has stabilized at a 15-25% lower level throughout most of the basin. Future NO x reductions are likely to be increasingly effective at reducing O 3 pollution initially under hot conditions in the coming decade.
    Print ISSN: 0094-8276
    Electronic ISSN: 1944-8007
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Quantifying atmospheric methane emissions from the Haynesville, Fayetteville, and northeastern Marcellus shale gas production regions (2015)
    Wiley
    Details
    Publication Date: 2015-02-19
    Description: We present measurements of methane (CH 4 ) taken aboard a NOAA WP-3D research aircraft in 2013 over the Haynesville shale region in eastern Texas/northwestern Louisiana, the Fayetteville shale region in Arkansas, and the northeastern Pennsylvania portion of the Marcellus shale region, which accounted for the majority of Marcellus shale gas production that year. We calculate emission rates from the horizontal CH 4 flux in the planetary boundary layer downwind of each region after subtracting the CH 4 flux entering the region upwind. We find one-day CH 4 emissions of (8.0 ± 2.7) × 10 7 g/hr from the Haynesville region, (3.9 ± 1.8) × 10 7 g/hr from the Fayetteville region, and (1.5 ± 0.6) × 10 7 g/hr from the Marcellus region in northeastern Pennsylvania. Finally, we compare the CH 4 emissions to the total volume of natural gas extracted from each region to derive a loss rate from production operations of 1.0–2.1% from the Haynesville region, 1.0–2.8% from the Fayetteville region, and 0.18–0.41% from the Marcellus region in northeastern Pennsylvania. The climate impact of CH 4 loss from shale gas production depends upon the total leakage from all production regions. The regions investigated in this work represented over half of the U.S. shale gas production in 2013, and we find generally lower loss rates than those reported in earlier studies of regions that made smaller contributions to total production. Hence, the national average CH 4 loss rate from shale gas production may be lower than values extrapolated from the earlier studies.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    A volatility basis set model for summertime secondary organic aerosols over the eastern United States in 2006 (2012)
    Wiley
    Details
    Publication Date: 2012-03-16
    Description: A new secondary organic aerosol (SOA) parameterization based on the volatility basis set is implemented in a regional air quality model WRF-CHEM. Full meteorological and chemistry simulations are carried out for the United States for August–September 2006. Predicted organic aerosol (OA) concentrations are compared against surface measurements made by several networks and aircraft data from the TexAQS-2006 field campaign. Elemental carbon simulations are also evaluated in order to evaluate the model's ability to capture their emissions, transport, and removal. Certain measurement limitations, such as daily averaged OA concentrations, impose some difficulties on the model evaluation, and hourly averaged OA measurements provide more informative constraints compared to daily concentrations. The updated model demonstrates a significant improvement in simulating the OA concentrations compared to the standard WRF-CHEM, which predicts very little SOA. The improvement in organic carbon (OC) predictions is noticeable in correlations and model bias. The correlations of OC exceed that of the persistence forecasts for hourly concentrations in the southeast United States during daytime. The updated traditional SOA yields still lead to an underestimation of observed OA, while addition of the multigenerational volatile organic compound (VOC) oxidation drastically improves model performance. However, several key uncertainties remain in SOA formation and loss mechanisms, which are characterized through several perturbation simulations. Dry deposition of VOC oxidation products is an important factor in the atmospheric SOA budget. The combination of the biogenic VOC emissions, updated SOA yields, and aging mechanism result in biogenic SOA being the dominant OA component for much of the nonurban United States.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Ammonia sources in the California South Coast Air Basin and their impact on ammonium nitrate formation (2012)
    Wiley
    Details
    Publication Date: 2012-04-12
    Description: Observations from the NOAA WP-3D aircraft during CalNex in May and June 2010 are used to quantify ammonia (NH3) emissions from automobiles and dairy facilities in the California South Coast Air Basin (SoCAB) and assess their impact on particulate ammonium nitrate (NH4NO3) formation. These airborne measurements in the SoCAB are used to estimate automobile NH3 emissions, 62 ± 24 metric tons day−1, and dairy facility NH3 emissions, 33 ± 16 to 176 ± 88 metric tons day−1. Emission inventories agree with the observed automobile NH3:CO emission ratio, but substantially underpredict dairy facility NH3 emissions. Conditions observed downwind of the dairy facilities were always thermodynamically favorable for NH4NO3 formation due to high NH3 mixing ratios from the concentrated sources. Although automobile emissions generated lower NH3 mixing ratios, they also can thermodynamically favor NH4NO3 formation. As an aerosol control strategy, addressing the dairy NH3 source would have the larger impact on reducing SoCAB NH4NO3 formation.
    Print ISSN: 0094-8276
    Electronic ISSN: 1944-8007
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Ozone and alkyl nitrate formation from the Deepwater Horizon oil spill atmospheric emissions (2012)
    Wiley
    Details
    Publication Date: 2012-05-11
    Description: Ozone (O3), alkyl nitrates (RONO2), and other photochemical products were formed in the atmosphere downwind from the Deepwater Horizon (DWH) oil spill by photochemical reactions of evaporating hydrocarbons with NOx (=NO + NO2) emissions from spill response activities. Reactive nitrogen species and volatile organic compounds (VOCs) were measured from an instrumented aircraft during daytime flights in the marine boundary layer downwind from the area of surfacing oil. A unique VOC mixture, where alkanes dominated the hydroxyl radical (OH) loss rate, was emitted into a clean marine environment, enabling a focused examination of O3 and RONO2 formation processes. In the atmospheric plume from DWH, the OH loss rate, an indicator of potential O3 formation, was large and dominated by alkanes with between 5 and 10 carbons per molecule (C5–C10). Observations showed that NOx was oxidized very rapidly with a 0.8 h lifetime, producing primarily C6–C10 RONO2 that accounted for 78% of the reactive nitrogen enhancements in the atmospheric plume 2.5 h downwind from DWH. Both observations and calculations of RONO2 and O3 production rates show that alkane oxidation dominated O3 formation chemistry in the plume. Rapid and nearly complete oxidation of NOx to RONO2 effectively terminated O3 production, with O3 formation yields of 6.0 ± 0.5 ppbv O3 per ppbv of NOx oxidized. VOC mixing ratios were in large excess of NOx, and additional NOx would have formed additional O3 in this plume. Analysis of measurements of VOCs, O3, and reactive nitrogen species and calculations of O3 and RONO2 production rates demonstrate that NOx-VOC chemistry in the DWH plume is explained by known mechanisms.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...