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Sample records for aura tropospheric emission

  1. Estimate of carbonyl sulfide tropical oceanic surface fluxes using Aura Tropospheric Emission Spectrometer observations

    NASA Astrophysics Data System (ADS)

    Kuai, Le; Worden, John R.; Campbell, J. Elliott; Kulawik, Susan S.; Li, King-Fai; Lee, Meemong; Weidner, Richard J.; Montzka, Stephen A.; Moore, Fred L.; Berry, Joe A.; Baker, Ian; Denning, A. Scott; Bian, Huisheng; Bowman, Kevin W.; Liu, Junjie; Yung, Yuk L.

    2015-10-01

    Quantifying the carbonyl sulfide (OCS) land/ocean fluxes contributes to the understanding of both the sulfur and carbon cycles. The primary sources and sinks of OCS are very likely in a steady state because there is no significant observed trend or interannual variability in atmospheric OCS measurements. However, the magnitude and spatial distribution of the dominant ocean source are highly uncertain due to the lack of observations. In particular, estimates of the oceanic fluxes range from approximately 280 Gg S yr-1 to greater than 800 Gg S yr-1, with the larger flux needed to balance a similarly sized terrestrial sink that is inferred from NOAA continental sites. Here we estimate summer tropical oceanic fluxes of OCS in 2006 using a linear flux inversion algorithm and new OCS data acquired by the Aura Tropospheric Emissions Spectrometer (TES). Modeled OCS concentrations based on these updated fluxes are consistent with HIAPER Pole-to-Pole Observations during 4th airborne campaign and improve significantly over the a priori model concentrations. The TES tropical ocean estimate of 70 ± 16 Gg S in June, when extrapolated over the whole year (about 840 ± 192 Gg S yr-1 ), supports the hypothesis proposed by Berry et al. (2013) that the ocean flux is in the higher range of approximately 800 Gg S yr-1.

  2. Evidence of Convective Redistribution of Carbon Monoxide in Aura Tropospheric Emission Sounder (TES) and Microwave Limb Sounder (MLS) Observations

    NASA Technical Reports Server (NTRS)

    Manyin, Michael; Douglass, Anne; Schoeberl, Mark

    2010-01-01

    Vertical convective transport is a key element of the tropospheric circulation. Convection lofts air from the boundary layer into the free troposphere, allowing surface emissions to travel much further, and altering the rate of chemical processes such as ozone production. This study uses satellite observations to focus on the convective transport of CO from the boundary layer to the mid and upper troposphere. Our hypothesis is that strong convection associated with high rain rate regions leads to a correlation between mid level and upper level CO amounts. We first test this hypothesis using the Global Modeling Initiative (GMI) chemistry and transport model. We find the correlation is robust and increases as the precipitation rate (the strength of convection) increases. We next examine three years of CO profiles from the Tropospheric Emission Sounder (TES) and Microwave Limb Sounder (MLS) instruments aboard EOS Aura. Rain rates are taken from the Tropical Rainfall Measuring Mission (TRMM) 3B-42 multi-satellite product. Again we find a correlation between mid-level and upper tropospheric CO, which increases with rain rate. Our result shows the critical importance of tropical convection in coupling vertical levels of the troposphere in the transport of trace gases. The effect is seen most clearly in strong convective regions such as the Inter-tropical Convergence Zone.

  3. Satellite observations of ethylene (C2H4) from the Aura Tropospheric Emission Spectrometer: A scoping study

    NASA Astrophysics Data System (ADS)

    Dolan, Wayana; Payne, Vivienne H.; Kualwik, Susan S.; Bowman, Kevin W.

    2016-09-01

    We present a study focusing on detection and initial quantitative estimates of ethylene (C2H4) in observations from the Tropospheric Emission Spectrometer (TES), a Fourier transform spectrometer aboard the Aura satellite that measures thermal infrared radiances with high spectral resolution (0.1 cm-1). We analyze observations taken in support of the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission and demonstrate the feasibility of future development of C2H4 into a TES standard product. In the Northern Hemisphere, C2H4 is commonly associated with boreal fire plumes, motor vehicle exhaust and petrochemical emissions. It has a short lifetime (∼14-32 h) in the troposphere due to its reaction with OH and O3. Chemical destruction of C2H4 in the atmosphere leads to the production of ozone and other species such as carbon monoxide (CO) and formaldehyde. Results indicate a correlation between C2H4 and CO in boreal fire plumes. Quantitative C2H4 estimates are sensitive to assumptions about the plume height and width. We find that C2H4 greater than 2-3 ppbv can be detected in a single TES observation (for a fire plume at 3 km altitude and 1.5 km width). Spatial averaging will be needed for surface-peaking profiles where TES sensitivity is lower.

  4. The EOS AURA Tropospheric Emission Spectrometer (TES): Status of the Program

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard

    2005-01-01

    This slide presentation is a programmatic overview covering some of the highlights of the mission and serve as an introduction to the accompanying presentations at the workshop. It reviews the goals and the products of the TES experiment, a simplified chemistry of ozone in both the stratosphere and troposphere, a description of the instrument, and the TES operational modes. Included are graphs showing some of the results of TES analysis of the key constituents of the tropospheric chemistry and the inter-regional transport.

  5. Tropospheric and stratospheric ozone from assimilation of Aura data

    NASA Technical Reports Server (NTRS)

    Stajner, I.; Wargan, K.; Chang, L.-P.; Hayashi, H.; Pawwson, S.; Froidevaux, L.; Livesey, N.; Bhartia, P. K.

    2006-01-01

    Ozone is an atmospheric trace gas with multiple impacts on the environment. Global ozone fields are needed for air quality predictions, estimation of the ultraviolet radiation reaching the surface, climate-radiation studies, and may also have an impact on longer-term weather predictions. We estimate global ozone fields in the stratosphere and troposphere by combining the data from EOS Aura satellite with an ozone model using data assimilation. Ozone exhibits a large temporal variability in the lower stratosphere. Our previous work showed that assimilation of satellite data from limb-sounding geometry helps constrain ozone profiles in that region. We assimilated ozone data from the Aura Microwave Limb Sounder (MLS) and the Ozone Monitoring Instrument (OMI) into the ozone system at NASA's Global Modeling and Assimilation Office (GMAO). Ozone is transported within a general circulation model (GCM) which includes parameterizations for stratospheric photochemistry, tropospheric chemistry, and a simple scheme for heterogeneous ozone loss. The focus of this study is on the representation of ozone in the lower stratosphere and tropospheric ozone columns. We plan to extend studies of tropospheric ozone distribution through assimilation of ozone data from the Tropospheric Emission Spectrometer (TES). Comparisons with ozone sondes and occultation data show that assimilation of Aura data reproduces ozone gradients and variability in the lower stratosphere well. We proceed by separating the contributions to temporal changes in the ozone field into those that are due to the model and those that are due to the assimilation of Aura data. The impacts of Aura data are illustrated and their role in the representation of ozone variability in the lower stratosphere and troposphere is shown.

  6. Connecting Surface Emissions, Convective Uplifting, and Long-Range Transport of Carbon Monoxide in the Upper Troposphere: New Observations from the Aura Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Jiang, Jonathan H.; Livesey, Nathaniel J.; Su, Hui; Neary, Lori; McConnell, John C.; Richards, Nigel A. D.

    2007-01-01

    Two years of observations of upper tropospheric (UT) carbon monoxide (CO) from the Aura Microwave Limb Sounder are analyzed; in combination with the CO surface emission climatology and data from the NCEP analyses. It is shown that spatial distribution, temporal variation and long-range transport of UT CO are closely related to the surface emissions, deep-convection and horizontal winds. Over the Asian monsoon region, surface emission of CO peaks in boreal spring due to high biomass burning in addition to anthropogenic emission. However, the UT CO peaks in summer when convection is strongest and surface emission of CO is dominated by anthropogenic source. The long-range transport of CO from Southeast Asia across the Pacific to North America, which occurs most frequently during boreal summer, is thus a clear imprint of Asian anthropogenic pollution influencing global air quality.

  7. Nadir Measurements of Carbon Monoxide Distributions by the Tropospheric Emission Spectrometer Instrument Onboard the Aura Spacecraft: Overview of Analysis Approach and Examples of Initial Results

    NASA Technical Reports Server (NTRS)

    Rinsland, Curtis P.; Luo, Ming; Logan, Jennifer A.; Beer, Reinhard; Worden, Helen; Kulawik, Susan S.; Rider, David; Osterman, Greg; Gunson, Michael; Eldering, Annmarie; Goldman, Aaron; Shephard, Mark; Clough, Shepard A.; Rodgers, Clive; Lampel, Michael; Chiou, Linda

    2006-01-01

    We provide an overview of the nadir measurements of carbon monoxide (CO) obtained thus far by the Tropospheric Emission Spectrometer (TES). The instrument is a high resolution array Fourier transform spectrometer designed to measure infrared spectral radiances from low Earth orbit. It is one of four instruments successfully launched onboard the Aura platform into a sun synchronous orbit at an altitude of 705 km on July 15, 2004 from Vandenberg Air Force Base, California. Nadir spectra are recorded at 0.06/cm spectral resolution with a nadir footprint of 5 x 8 km. We describe the TES retrieval approach for the analysis of the nadir measurements, report averaging kernels for typical tropical and polar ocean locations, characterize random and systematic errors for those locations, and describe instrument performance changes in the CO spectral region as a function of time. Sample maps of retrieved CO for the middle and upper troposphere from global surveys during December 2005 and April 2006 highlight the potential of the results for measurement and tracking of global pollution and determining air quality from space.

  8. Nadir measurements of carbon monoxide distributions by the Tropospheric Emission Spectrometer instrument onboard the Aura Spacecraft: Overview of analysis approach and examples of initial results

    NASA Astrophysics Data System (ADS)

    Rinsland, Curtis P.; Luo, Ming; Logan, Jennifer A.; Beer, Reinhard; Worden, Helen; Kulawik, Susan S.; Rider, David; Osterman, Greg; Gunson, Michael; Eldering, Annmarie; Goldman, Aaron; Shephard, Mark; Clough, Shepard A.; Rodgers, Clive; Lampel, Michael; Chiou, Linda

    2006-11-01

    We provide an overview of the nadir measurements of carbon monoxide (CO) obtained thus far by the Tropospheric Emission Spectrometer (TES). The instrument is a high resolution array Fourier transform spectrometer designed to measure infrared spectral radiances from low Earth orbit. It is one of four instruments successfully launched onboard the Aura platform into a sun synchronous orbit at an altitude of 705 km on July 15, 2004 from Vandenberg Air Force Base, California. Nadir spectra are recorded at 0.06-cm-1 spectral resolution with a nadir footprint of 5 × 8 km. We describe the TES retrieval approach for the analysis of the nadir measurements, report averaging kernels for typical tropical and polar ocean locations, characterize random and systematic errors for those locations, and describe instrument performance changes in the CO spectral region as a function of time. Sample maps of retrieved CO for the middle and upper troposphere from global surveys during December 2005 and April 2006 highlight the potential of the results for measurement and tracking of global pollution and determining air quality from space.

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

    SciTech Connect

    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. A joint data record of tropospheric ozone from Aura-TES and MetOp-IASI

    NASA Astrophysics Data System (ADS)

    Oetjen, Hilke; Payne, Vivienne H.; Neu, Jessica L.; Kulawik, Susan S.; Edwards, David P.; Eldering, Annmarie; Worden, Helen M.; Worden, John R.

    2016-08-01

    The Tropospheric Emission Spectrometer (TES) on Aura and Infrared Atmospheric Sounding Interferometer (IASI) on MetOp-A together provide a time series of 10 years of free-tropospheric ozone with an overlap of 3 years. We characterise the differences between TES and IASI ozone measurements and find that IASI's coarser vertical sensitivity leads to a small (< 5 ppb) low bias relative to TES for the free troposphere. The TES-IASI differences are not dependent on season or any other factor and hence the measurements from the two instruments can be merged, after correcting for the offset, in order to study decadal-scale changes in tropospheric ozone. We calculate time series of regional monthly mean ozone in the free troposphere over eastern Asia, the western United States (US), and Europe, carefully accounting for differences in spatial sampling between the instruments. We show that free-tropospheric ozone over Europe and the western US has remained relatively constant over the past decade but that, contrary to expectations, ozone over Asia in recent years does not continue the rapid rate of increase observed from 2004 to 2010.

  11. Rapid increases in tropospheric ozone production and export from China: A view from AURA and TM5

    NASA Astrophysics Data System (ADS)

    Verstraeten, W. W.; Neu, J. L.; Williams, J. E.; Bowman, K. W.; Worden, J. R.; Boersma, K. F.

    2015-12-01

    Eastern Asia has the fastest growing anthropogenic emissions in the world, possibly affecting both the pollution in the local troposphere as well as in the trans-Pacific region. Local measurements over Asia show that tropospheric ozone (O3) has increased by 1 to 3% per year since the start of the millennium. This increase is often invoked to explain positive tropospheric O3 trends observed in western US, but to date there is no unambiguous evidence showing that enhanced Asian pollution is responsible for these trends. In this research we use observations of tropospheric O3 from TES (Tropospheric Emission Spectrometer, onboard AURA), tropospheric NO2 measurements from OMI (Ozone Monitoring Instrument, onboard AURA) and lower stratospheric observations of O3 from MLS (Microwave Limb Sounder, onboard AURA) in combination with the TM5 CTM. Satellite-based studies focusing on tropospheric O3 and NO2 have the potential to close the gap left by previous studies on air quality since spaceborne data provide large-scale observational evidence that both O3 precursor concentrations and tropospheric O3 levels are rapidly changing over source receptor areas. We show the increased ability of TM5 to reproduce the 2005-2010 observed rapid rise in free tropospheric O3 of 7% over China from TES, once OMI NO2 measurements were implemented in TM5 to update NOX emissions. MLS observations on lower stratospheric O3 have the potential to improve the stratosphere-troposphere exchange (STE) estimate in TM5 which is mainly driven by ECMWF meteorological fields. Constraining the TM5 modelled trend of the STE contribution to the 3-9 km partial O3 column using MLS observations of stratospheric O3 lead to a better explanation of the sources of the free tropospheric O3 trends over China. Based on the OMI inferred TM5 updates in NOX emissions, the impact of Asian O3 and its precursors on the free troposphere (3-9 km) over the western US could be quantified. Large import from China offsets the

  12. Study Pollution Impacts on Upper-Tropospheric Clouds with Aura, CloudSat, and CALIPSO Data

    NASA Technical Reports Server (NTRS)

    Wu, Dong

    2007-01-01

    This viewgraph presentation reviews the impact of pollution on clouds in the Upper Troposphere. Using the data from the Aura Microwave Limb Sounder (MLS), CloudSat, CALIPSO the presentation shows signatures of pollution impacts on clouds in the upper troposphere. The presentation demonstrates the complementary sensitivities of MLS , CloudSat and CALIPSO to upper tropospheric clouds. It also calls for careful analysis required to sort out microphysical changes from dynamical changes.

  13. Profiling Tropospheric CO2 using the Aura TES and TCCON instruments

    NASA Astrophysics Data System (ADS)

    Kuai, L.; Worden, J.; Kulawik, S. S.; Bowman, K. W.; Biraud, S. C.; Abshire, J. B.; Wofsy, S. C.; Natraj, V.; Frankenberg, C.; Wunch, D.; Connor, B. J.; Miller, C. E.; Roehl, C. M.; Shia, R.; Yung, Y. L.

    2012-12-01

    Characterizing the global carbon budget requires mapping the global distribution and variability of CO2 sources and sinks. Measurements of the total column of CO2 by ground or by satellite have the potential to estimate global sources and sinks (Rayner and O'Brien, GRL, 2001, Olsen and Randerson, JGR, 2004) but are less sensitive to regional scale and local sources and sinks because CO2 is a long-lived gas which makes it challenging to disentangle local sources from CO2 transported into the observed air parcel (Keppel-Aleks et al., BGD, 2011). We explore the use of total column measurements with estimates of the free tropospheric CO2 by TES to distinguish boundary layer CO2 and free tropospheric CO2 because quantify the vertical gradient between the free troposphere and boundary layer is critical for estimating CO2 fluxes (Stephens, Science, 2007) and near surface CO2 should be more sensitive to local fluxes than the total column CO2. In this study, CO2 profiles are estimated from the Total Carbon Column Observing Network (TCCON) measurements and integrated into a column-averaged concentration. These column averages agree with aircraft data within 0.67 ppm, consistent with the uncertainties due to measurement noise and temperature. There is a bias of about -5 ppm, consistent with Wunch et al. (Atmos. Meas. Tech. 2010). Free troposphere estimates of CO2 are obtained from the GEOS-Chem model that has assimilated CO2 measurements from Aura Tropospheric Emission Spectrometer. The boundary layer CO2 estimates are calculated by subtracting TES free tropospheric CO2 from TCCON column CO2. This estimate of boundary layer CO2 agrees well with aircraft data with RMS of 1.44 ppm for about the fifty PBL CO2 estimates. This work shows that total column from NIR measurements (GOSAT, TCCON and OCO-2) and free troposphere measurement from TIR (e.g. TES and AIRS) can be used to profile CO2 and obtain PBL CO2 with precision necessary to capture the atmospheric CO2 variability. It

  14. Science Accomplishments from a Decade of Aura OMI/MLS Tropospheric Ozone Measurements

    NASA Technical Reports Server (NTRS)

    Ziemke, Jerald R.; Douglass, Anne R.; Joiner, Joanna; Duncan, Bryan N.; Olsen, Mark A.; Oman, Luke D.; Witte, Jacquelyn C.; Liu, X.; Wargan, K.; Schoeberl, Mark R.; Strahan, Susan E.; Pawson, Steven; Bhartia, Pawan K.; Newman, Paul A.; Froidevaux, Lucien; Cooper, Owen R.; Haffner, David P.

    2014-01-01

    Measurements of tropospheric ozone from combined Aura OMI and MLS instruments have yielded a large number of new and important science discoveries over the last decade. These discoveries have generated a much greater understanding of biomass burning, lightning NO, and stratosphere-troposphere exchange sources of tropospheric ozone, ENSO dynamics and photochemistry, intra-seasonal variability-Madden-Julian Oscillation including convective transport, radiative forcing, measuring ozone pollution from space, improvements to ozone retrieval algorithms, and evaluation of chemical-transport and chemistry-climate models. The OMI-MLS measurements have been instrumental in giving us better understanding of the dynamics and chemistry involving tropospheric ozone and the many drivers affecting the troposphere in general. This discussion will provide an overview focusing on our main science results.

  15. The Aura Mission

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2008-01-01

    Aura was designed to probe the chemistry of the troposphere as well as the stratosphere. Two instruments, the Microwave Limb Sounder, the Tropospheric Emission Spectrometer (TES) and the Ozone Monitoring Instrument (OMI) have provided some remarkable information on pollution, long range pollution transport and strat-trop exchange. This talk will review some of the more startling observations and some new science that we are seeing in the Aura data.

  16. Tropospheric Ozone from Assimilation of Aura Data using Different Definitions of the Tropopause

    NASA Technical Reports Server (NTRS)

    Stajner, Ivanka; Wargan, K.; Chang, L.-P.; Hayashi, H.; Pawson, S.; Pawson, Steven; Livesey, N.; Bhartia, P. K.

    2006-01-01

    Ozone data from Aura OMI and MLS instruments were assimilated into the general circulation model (GCM) constrained by assimilated meteorological fields from the Global Modeling and Assimilation Office at NASA Goddard. Properties of tropospheric ozone and their sensitivity to the definition of the tropopause are investigated. Three definitions of the tropopause are considered: (1) dynamical (using potential vorticity and potential temperature), (2) using temperature lapse rate, and (3) using a fixed ozone value. Comparisons of the tropospheric ozone columns using these tropopause definitions will be presented and evaluated against coincident profiles from ozone sondes. Assimilated ozone profiles are used to identify possible tropopause folding events, which are important for stratosphere-troposphere exchange. Each profile is searched for multiple levels at which ozone attains the value typical of the troposphere-stratosphere transition in order to identify possible tropopause folds. Constrained by the dynamics from a global model and by assimilation of Aura ozone data every 3-hours, this data set provides an opportunity to study ozone evolution in the upper troposphere and lower stratosphere with high temporal resolution.

  17. Tropospheric and Airborne Emission Spectrometers

    NASA Technical Reports Server (NTRS)

    Glavich, Thomas; Beer, Reinhard

    1996-01-01

    X This paper describes the development of two related instruments, the Tropospheric Emission Spectrometer (TES) and the Airborne Emission Spectrometer (AES). Both instruments are infrared imaging Fourier Transform Spectrometers, used for measuring the state of the lower atmosphere, and in particular the measurement of ozone and ozone sources and sinks.

  18. Tropospheric Emission Spectrometer and Airborne Emission Spectrometer

    NASA Technical Reports Server (NTRS)

    Glavich, T.; Beer, R.

    1996-01-01

    The Tropospheric Emission Spectrometer (TES) is an instrument being developed for the NASA Earth Observing System Chemistry Platform. TES will measure the distribution of ozone and its precursors in the lower atmosphere. The Airborne Emission Spectrometer (AES) is an aircraft precursor to TES. Applicable descriptions are given of instrument design, technology challenges, implementation and operations for both.

  19. NO2 Total and Tropospheric Vertical Column Densities from OMI on EOS Aura: Update

    NASA Technical Reports Server (NTRS)

    Gleason, J.F.; Bucsela, E.J.; Celarier, E.A.; Veefkind, J.P.; Kim, S.W.; Frost, G.F.

    2009-01-01

    The Ozone Monitoring Instrument (OMI), which is on the EOS AURA satellite, retrieves vertical column densities (VCDs) of NO2, along with those of several other trace gases. The relatively high spatial resolution and daily global coverage of the instrument make it particularly well-suited to monitoring tropospheric pollution at scales on the order of 20 km. The OMI NO2 algorithm distinguishes polluted regions from background stratospheric NO2 using a separation algorithm that relies on the smoothly varying stratospheric NO2 and estimations of both stratospheric and tropospheric air mass factors (AMFs). Version 1 of OMI NO2 data has been released for public use. An overview of OMI NO2 data, some recent results and a description of the improvements for version 2 of the algorithm will be presented.

  20. A Global Climatology of Tropospheric and Stratospheric Ozone Derived from Aura OMI and MLS Measurements

    NASA Technical Reports Server (NTRS)

    Ziemke, J.R.; Chandra, S.; Labow, G.; Bhartia, P. K.; Froidevaux, L.; Witte, J. C.

    2011-01-01

    A global climatology of tropospheric and stratospheric column ozone is derived by combining six years of Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) ozone measurements for the period October 2004 through December 2010. The OMI/MLS tropospheric ozone climatology exhibits large temporal and spatial variability which includes ozone accumulation zones in the tropical south Atlantic year-round and in the subtropical Mediterranean! Asia region in summer months. High levels of tropospheric ozone in the northern hemisphere also persist in mid-latitudes over the eastern North American and Asian continents extending eastward over the Pacific Ocean. For stratospheric ozone climatology from MLS, largest ozone abundance lies in the northern hemisphere in the latitude range 70degN-80degN in February-April and in the southern hemisphere around 40degS-50degS during months August-October. The largest stratospheric ozone abundances in the northern hemisphere lie over North America and eastern Asia extending eastward across the Pacific Ocean and in the southern hemisphere south of Australia extending eastward across the dateline. With the advent of many newly developing 3D chemistry and transport models it is advantageous to have such a dataset for evaluating the performance of the models in relation to dynamical and photochemical processes controlling the ozone distributions in the troposphere and stratosphere.

  1. Global Free-tropospheric NO2 Abundances Derived Using a Cloud Slicing Technique from AURA OMI

    NASA Technical Reports Server (NTRS)

    Choi, S.; Joiner, J.; Choi, Y.; Duncan, B.N.; Vasilkov, A.; Krotkov, N.; Bucsela, E.J.

    2014-01-01

    We derive free-tropospheric NO2 volume mixing ratios (VMRs) by applying a cloud-slicing technique to data from the Ozone Monitoring Instrument (OMI) on the Aura satellite. In the cloud-slicing approach, the slope of the above-cloud NO2 column versus the cloud scene pressure is proportional to the NO2 VMR. In this work, we use a sample of nearby OMI pixel data from a single orbit for the linear fit. The OMI data include cloud scene pressures from the rotational-Raman algorithm and above-cloud NO2 vertical column density (VCD) (defined as the NO2 column from the cloud scene pressure to the top of the atmosphere) from a differential optical absorption spectroscopy (DOAS) algorithm. We compare OMI-derived NO2 VMRs with in situ aircraft profiles measured during the NASA Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign in 2006. The agreement is generally within the estimated uncertainties when appropriate data screening is applied. We then derive a global seasonal climatology of free-tropospheric NO2 VMR in cloudy conditions. Enhanced NO2 in the free troposphere commonly appears near polluted urban locations where NO2 produced in the boundary layer may be transported vertically out of the boundary layer and then horizontally away from the source. Signatures of lightning NO2 are also shown throughout low and middle latitude regions in summer months. A profile analysis of our cloud-slicing data indicates signatures of lightning-generated NO2 in the upper troposphere. Comparison of the climatology with simulations from the global modeling initiative (GMI) for cloudy conditions (cloud optical depth less than10) shows similarities in the spatial patterns of continental pollution outflow. However, there are also some differences in the seasonal variation of free-tropospheric NO2 VMRs near highly populated regions and in areas affected by lightning-generated NOx.

  2. A global climatology of tropospheric and stratospheric ozone derived from Aura OMI and MLS measurements

    NASA Astrophysics Data System (ADS)

    Ziemke, J. R.; Chandra, S.; Labow, G.; Bhartia, P. K.; Froidevaux, L.; Witte, J. C.

    2011-06-01

    A global climatology of tropospheric and stratospheric column ozone is derived by combining six years of Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) ozone measurements for the period October 2004 through December 2010. The OMI/MLS tropospheric ozone climatology exhibits large temporal and spatial variability which includes ozone accumulation zones in the tropical south Atlantic year-round and in the subtropical Mediterranean/Asia region in summer months. High levels of tropospheric ozone in the Northern Hemisphere also persist in mid-latitudes over the Eastern North American and Asian continents extending eastward over the Pacific Ocean. For stratospheric ozone climatology from MLS, largest ozone abundance lies in the Northern Hemisphere in the latitude range 70° N-80° N in February-April and in the Southern Hemisphere around 40° S-50° S during months August-October. The largest stratospheric ozone abundances in the Northern Hemisphere lie over North America and Eastern Asia extending eastward across the Pacific Ocean and in the Southern Hemisphere south of Australia extending eastward across the dateline. With the advent of many newly developing 3-D chemistry and transport models it is advantageous to have such a dataset for evaluating the performance of the models in relation to dynamical and photochemical processes controlling the ozone distributions in the troposphere and stratosphere. The OMI/MLS ozone gridded climatology data, both calculated mean values and RMS uncertainties are made available to the science community via the NASA total ozone mapping spectrometer (TOMS) website http://toms.gsfc.nasa.gov.

  3. A global climatology of tropospheric and stratospheric ozone derived from Aura OMI and MLS measurements

    NASA Astrophysics Data System (ADS)

    Ziemke, J. R.; Chandra, S.; Labow, G. J.; Bhartia, P. K.; Froidevaux, L.; Witte, J. C.

    2011-09-01

    A global climatology of tropospheric and stratospheric column ozone is derived by combining six years of Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) ozone measurements for the period October 2004 through December 2010. The OMI/MLS tropospheric ozone climatology exhibits large temporal and spatial variability which includes ozone accumulation zones in the tropical south Atlantic year-round and in the subtropical Mediterranean/Asia region in summer months. High levels of tropospheric ozone in the Northern Hemisphere also persist in mid-latitudes over the eastern part of the North American continent extending across the Atlantic Ocean and the eastern part of the Asian continent extending across the Pacific Ocean. For stratospheric ozone climatology from MLS, largest column abundance is in the Northern Hemisphere in the latitude range 70° N-80° N in February-April and in the Southern Hemisphere around 40° S-50° S during August-October. Largest stratospheric ozone lies in the Northern Hemisphere and extends from the eastern Asian continent eastward across the Pacific Ocean and North America. With the advent of many newly developing 3-D chemistry and transport models it is advantageous to have such a dataset for evaluating the performance of the models in relation to dynamical and photochemical processes controlling the ozone distributions in the troposphere and stratosphere. The OMI/MLS gridded ozone climatology data are made available to the science community via the NASA Goddard Space Flight Center ozone and air quality website http://ozoneaq.gsfc.nasa.gov/.

  4. Discoveries from EOS Aura

    NASA Technical Reports Server (NTRS)

    Douglass, Anne

    2006-01-01

    Aura, the third and final of three large observatories that are part of NASA s Earth Observing System, was launched July 15,2004. Aura carries four instruments - the Microwave Limb Sounder (MLS), the Tropospheric Emission Spectrometer (TES), the Ozone Monitoring Instrument (OMI) and the High Resolution Dynamics Limb Sounder (HIRDLS), all of which measure atmospheric constituents. Aura measurements provide information to address broad questions about the Earth atmosphere, particularly concerning the recovery of the stratospheric ozone layer, tropospheric air quality, and climate change. TES has made the simultaneous measurements of carbon monoxide and ozone in the lower and upper troposphere. OM1 continues to observe the total ozone column and measures columns of important pollutants like NO2 at unprecedented horizontal resolution and coverage. MLS measures profiles of stratospheric ozone and constituents that affect ozone from the mesosphere into the upper troposphere. This talk will highlight results from Aura s first years in orbit, and will emphasize the way information from Aura and other satellites has contributed to the development, evaluation, and application of global chemistry climate models.

  5. Sensitivity of Northern Hemispheric Tropospheric Ozone To Anthropogenic Emissions as Observed by Satellite Observations

    NASA Astrophysics Data System (ADS)

    Jiang, Z.; Worden, J. R.; Payne, V.; Bowman, K. W.; Kuai, L.; Jones, D. B. A.; Henze, D. K.

    2015-12-01

    Atmospheric composition is rapidly changing in response to changes in industrialization, land-use, and climate. Tropospheric ozone is at the nexus of atmospheric chemistry, air-quality, and climate as it is not only the third most important greenhouse gas and a primary air pollutant, but also affects carbon dioxide by damaging plants and the lifetime of atmospheric methane by influencing the oxidative capacity of the atmosphere. Observed trends in free-tropospheric ozone as observed by ozone-sondes and more recently by satellite measurements from the Aura TES and IASI instruments do not agree with models that are driven by observed changes in ozone pre-cursor emissions. As a consequence, estimates of ozone radiative forcing and the future trajectory of tropospheric ozone concentrations are highly uncertain. In this study, we explore the use of satellite observations of ozone and its pre-cursors for constraining the sensitivity of Northern hemispheric tropospheric ozone to anthropogenic emissions. New measurements of peroxyacetyl nitrate (PAN) from the Aura TES instrument suggest that one explanation for the model/data mismatch in trends is reduced ventilation of reactive nitrogen into the free-troposphere over Asia. Ultimately, continued well validated observation of ozone and its pre-cursors from IASI, AIRS, CRIS, and Trop-OMI will be needed to solve this critical scientific question.

  6. An Intercomparison of Tropospheric Ozone Retrievals Derived from Two Aura Instruments and Measurements in Western North America in 2006

    NASA Technical Reports Server (NTRS)

    Doughty, D. C.; Thompson, A. M.; Schoeberl, M. R.; Stajner, I.; Wargan, K.; Hui, W. C. J.

    2011-01-01

    Two recently developed methods for quantifying tropospheric ozone abundances based on Aura data, the Trajectory-enhanced Tropospheric Ozone Residual (TTOR) and an assimilation of Aura data into Goddard Earth Observing System Version 4 (ASM), are compared to ozone measurements from ozonesonde data collected in April-May 2006 during the INTEX Ozonesonde Network Study 2006 (IONS-06) campaign. Both techniques use Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) observations. Statistics on column ozone amounts for both products are presented. In general, the assimilation compares better to sonde integrated ozone to 200 hPa (28.6% difference for TTOR versus 2.7% difference for ASM), and both products are biased low. To better characterize the performance of ASM, ozone profiles based on the assimilation are compared to those from ozonesondes. We noted slight negative biases in the lower troposphere, and slight positive biases in the upper troposphere/lower stratosphere (UT/ LS), where we observed the greatest variability. Case studies were used to further understand ASM performance. We examine one case from 17 April 2006 at Bratt's Lake, Saskatchewan, where geopotential height gradients appear to be related to an underestimation in the ASM in the UT/LS region. A second case, from 21 April 2006 at Trinidad Head, California, is a situation where the overprediction of ozone in the UT/LS region does not appear to be due to current dynamic conditions but seems to be related to uncertainty in the flow pattern and large differences in MLS observations upstream.

  7. Global Assimilation of EOS-Aura Data as a Means of Mapping Ozone Distribution in the Lower Stratosphere and Troposphere

    NASA Technical Reports Server (NTRS)

    Wargan, Krzysztof; Olsen, M.; Douglass, A.; Witte, J.; Strahan, S.; Livesey, N.

    2012-01-01

    Ozone in the lower stratosphere and the troposphere plays an important role in forcing the climate. However, the global ozone distribution in this region is not well known because of the sparse distribution of in-situ data and the poor sensitivity of satellite based observations to the lowermost of the atmosphere. The Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) instruments on EOS-Aura provide information on the total ozone column and the stratospheric ozone profile. This data has been assimilated into NASA s Global Earth Observing System, Version 5 (GEOS-5) data assimilation system (DAS). We will discuss the results of assimilating three years of OMI and MLS data into GEOS-5. This data was assimilated alongside meteorological observations from both conventional sources and satellite instruments. Previous studies have shown that combining observations from these instruments through the Trajectory Tropospheric Ozone Residual methodology (TTOR) or using data assimilation can yield useful, yet low biased, estimates of the tropospheric ozone budget. We show that the assimilated ozone fields in this updated version of GEOS-5 exhibit an excellent agreement with ozone sonde and High Resolution Dynamics Limb Sounder (HIRDLS) data in the lower stratosphere in terms of spatial and temporal variability as well as integrated ozone abundances. Good representation of small-scale vertical features follows from combining the MLS data with the assimilated meteorological fields. We then demonstrate how this information can be used to calculate the Stratosphere - Troposphere Exchange of ozone and its contribution to the tropospheric ozone column in GEOS-5. Evaluations of tropospheric ozone distributions from the assimilation will be made by comparisons with sonde and other in-situ observations.

  8. Aura OMI observations of changes in SO2 and NO2 emissions at local, regional and global scales

    NASA Astrophysics Data System (ADS)

    Krotkov, N. A.; McLinden, C. A.; Li, C.; Lamsal, L. N.; Celarier, E. A.; Marchenko, S. V.; Swartz, W.; Bucsela, E. J.; Joiner, J.; Duncan, B. N.; Boersma, K. F.; Veefkind, P.; Levelt, P.; Fioletov, V.; Dickerson, R. R.; He, H.; Lu, Z.; Streets, D. G.

    2015-12-01

    Space-based pollution monitoring from current and planned satellite UV-Vis spectrometers play an increasingly important role in studies of tropospheric chemistry and also air quality applications to help mitigate anthropogenic and natural impacts on sensitive ecosystems, and human health. We present long-term changes in tropospheric SO2 and NO2 over some of the most polluted industrialized regions of the world observed by the Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite. Using OMI data, we identified about 400 SO2 "hot spots" and estimated emissions from them. In many regions emissions and their ambient pollution levels have decreased significantly, such as over eastern US, Europe and China. OMI observed about 50% reduction in SO2 and NO2 pollution over the North China plain in 2012-2014 that can be attributed to both government efforts to restrain emissions from the power and industrial sectors and the economic slowdown. While much smaller, India's SO2 and NO2 emissions from coal power plants and smelters are growing at a fast pace, increasing by about 200% and 50% from 2005 to 2014. Over Europe and the US OMI-observed trends agree well with those from available in situ measurements of surface concentrations, deposition and emissions data. However, for some regions (e.g., Mexico, Middle East) the emission inventories may be incomplete and OMI can provide emission estimates for missing sources, such as SO2 sources observed over the Persian Gulf. It is essential to continue long-term overlapping satellite data records of air quality with increased spatial and temporal resolution to resolve point pollution sources using oversampling technique. We discuss how Aura OMI pollution measurements and emission estimates will be continued with the US JPSS and European Sentinel series for the next 20 years and further enhanced by the addition of three geostationary UV-VIS instruments.

  9. Tropospheric emissions: monitoring of pollution (TEMPO)

    NASA Astrophysics Data System (ADS)

    Chance, Kelly; Liu, Xiong; Suleiman, Raid M.; Flittner, David E.; Al-Saadi, Jassim; Janz, Scott J.

    2013-09-01

    TEMPO was selected in 2012 by NASA as the first Earth Venture Instrument, for launch circa 2018. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO measures from Mexico City to the Canadian tar sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (~2 km N/S×4.5 km E/W at 36.5°N, 100°W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry. Measurements are from geostationary (GEO) orbit, to capture the inherent high variability in the diurnal cycle of emissions and chemistry. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a commercial GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve O3, NO2, SO2, H2CO, C2H2O2, H2O, aerosols, cloud parameters, and UVB radiation. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides near-real-time air quality products that will be made widely, publicly available. TEMPO will launch at a prime time to be the North American component of the global geostationary constellation of pollution monitoring together with European Sentinel-4 and Korean GEMS.

  10. Remote sensing of tropospheric constituents by OMI on the EOS Aura satellite

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.

    2006-01-01

    The Ozone Monitoring Instrument (OMI) was launched on NASA's EOS Aura satellite in July 2004. This instrument was built in the Netherlands with collaboration with Finland. The science data products are being developed jointly by scientists from the three countries. OMI is the first instrument to combine the high spatial resolution daily global mapping capability of TOMS with high spectral resolution measurements necessary for retrieving a number of trace gases of relevance to atmospheric chemistry, using techniques pioneered by GOME. In this talk I will show what our planet looks like at UV wavelengths and what these data can tell us about the effects of human activities on global air quality and climate.

  11. Tropospheric Emissions: Monitoring of Pollution (TEMPO)

    NASA Astrophysics Data System (ADS)

    Chance, Kelly; Liu, Xiong; Suleiman, Raid M.; Flittner, David E.; Al-Saadi, Jassim; Janz, Scott J.

    2014-06-01

    TEMPO, selected by NASA as the first Earth Venture Instrument, will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO measures from Mexico City to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution. TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry. Measurements are from geostationary (GEO) orbit, to capture the inherent high variability in the diurnal cycle of emissions and chemistry. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a GEO host spacecraft to provide a modest-cost mission that measures the spectra required to retrieve O3, NO2, SO2, H2CO, C2H2O2, H2O, aerosols, cloud parameters, and UVB radiation. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, reducing uncertainty in air quality predictions by 50 %. TEMPO quantifies and tracks the evolution of aerosol loading. It provides near-real-time air quality products that will be made widely, publicly available. TEMPO makes the first tropospheric trace gas measurements from GEO, by building on the heritage of five spectrometers flown in low-earth-orbit (LEO). These LEO instruments measure the needed spectra, although at coarse spatial and temporal resolutions, to the precisions required for TEMPO and use retrieval algorithms developed for them by TEMPO Science Team members and currently running in operational environments. This makes TEMPO an innovative use of a well-proven technique, able to produce a revolutionary data set. TEMPO provides much of the atmospheric measurement

  12. Tropospheric Emissions: Monitoring of Pollution (TEMPO)

    NASA Astrophysics Data System (ADS)

    Chance, K.; Liu, X.; Suleiman, R. M.; Flittner, D. E.; Al-Saadi, J. A.; Janz, S. J.; Tempo Science Team

    2013-05-01

    TEMPO has been selected by NASA as the first Earth Venture Instrument. It will measure atmospheric pollution for greater North America from space using ultraviolet/visible spectroscopy. TEMPO measures from Mexico City to the Canadian tar/oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (Mexico City is measured at 1.6 km N/S by 4.5 km E/W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry. Measurements are from geostationary (GEO) orbit, to capture the inherent high variability in the diurnal cycle of emissions and chemistry. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve O3, NO2, SO2, H2CO, C2H2O2, H2O, aerosols, cloud parameters, and UVB radiation. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, reducing uncertainty in air quality predictions by 50%. TEMPO quantifies and tracks the evolution of aerosol loading. It provides near-real-time air quality products that will be made widely, publicly available. TEMPO makes the first tropospheric trace gas measurements from GEO, by building on the heritage of five spectrometers flown in low-earth-orbit (LEO). These LEO instruments measure the needed spectra, although at coarse spatial and temporal resolutions, to the precisions required for TEMPO and use retrieval algorithms developed for them by TEMPO Science Team members and currently running in operational environments. This makes TEMPO an innovative use of a well proven technique, able to produce a revolutionary

  13. Tropospheric Emissions: Monitoring of Pollution (TEMPO)

    NASA Astrophysics Data System (ADS)

    Chance, K.; Liu, X.; Suleiman, R. M.; Flittner, D. E.; Janz, S. J.

    2012-12-01

    TEMPO is a proposed concept to measure pollution for greater North America using ultraviolet/visible spectroscopy. TEMPO measures from Mexico City to the Canadian tar/oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (9 km2). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry. Measurements are from geostationary (GEO) orbit, to capture the inherent high variability in the diurnal cycle of emissions and chemistry. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve O3, NO2, SO2, H2CO, C2H2O2, H2O, aerosols, cloud parameters, and UVB radiation. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, reducing uncertainty in air quality predictions by 50%. TEMPO quantifies and tracks the evolution of aerosol loading. It provides near-real-time air quality products that will be made widely, publicly available. TEMPO makes the first tropospheric trace gas measurements from GEO, by building on the heritage of five spectrometers flown in low-earth-orbit (LEO). These LEO instruments measure the needed spectra, although at coarse spatial and temporal resolutions, to the precisions required for TEMPO and use retrieval algorithms developed for them by TEMPO Science Team members and currently running in operational environments. This makes TEMPO an innovative use of a well proven technique, able to produce a revolutionary data set. TEMPO provides much of the atmospheric measurement capability recommended for GEO-CAPE in the 2007

  14. Methyl chloride from the Aura Microwave Limb Sounder: First global climatology and assessment of variability in the upper troposphere and stratosphere

    NASA Astrophysics Data System (ADS)

    Santee, M. L.; Livesey, N. J.; Manney, G. L.; Lambert, A.; Read, W. G.

    2013-12-01

    Methyl chloride (CH3Cl) is by far the largest natural carrier of chlorine to the stratosphere. Its importance in stratospheric ozone chemistry is expected to increase in the coming decades as emission controls alter the relative contributions from natural and anthropogenic halogen sources. The Microwave Limb Sounder (MLS) on NASA's Aura satellite provides the first daily global observations of CH3Cl. Here we quantify the quality of the MLS version 3 CH3Cl data (single-profile precision of ±100 pptv; accuracy of 30-45%; vertical and horizontal resolution of 4-5 km and 450-600 km, respectively) and demonstrate their utility for scientific studies over the vertical range from 147 to 4.6 hPa. We exploit the unmatched scope of the 8 year MLS data set to investigate the spatial, seasonal, and interannual variations in the distribution of CH3Cl in the upper troposphere/lower stratosphere (UTLS). Like carbon monoxide, CH3Cl is a marker of pollution from biomass burning that can be lofted to the UTLS very rapidly by deep convection. The climatological seasonal cycle in CH3Cl reflects variability in regional fire activity and other surface sources as well as convection, and anomalous CH3Cl enhancements in the tropical upper troposphere are linked to specific episodes of intense burning. Methyl chloride is shown to be very useful as a tracer of large-scale dynamical processes, such as diabatic descent inside the stratospheric winter polar vortices, quasi-isentropic cross-tropopause transport associated with the summer monsoon circulations, and effects related to the quasi-biennial oscillation and the tropical "tape recorder".

  15. Link Between Enhanced Arctic Tropospheric BrO Observed By Aura OMI and Meteorological Conditions

    NASA Astrophysics Data System (ADS)

    Choi, S.; Joiner, J.; Salawitch, R. J.; Canty, T. P.; Theys, N.; da Silva, A.; Chance, K.; Suleiman, R. M.; Kurosu, T. P.

    2014-12-01

    Bromine radicals (Br + BrO) are important species owing to the ability to destroy ozone catalytically. They may also impact oxidative pathways of many trace gases including dimethylsulfide (DMS) and mercury. Bromine monoxide (BrO) is the most commonly observed bromine radical species. Since it absorbs ultraviolet (UV) radiation, it can be observed using remote sensing technique including Differential Optical Absorption Spectroscopy (DOAS). Previous studies have reported rapid enhancements tropospheric BrO (so called "BrO explosion") connected to near-surface ozone depletion events during springtime in the Arctic. Space-based observation of BrO through Ozone Monitoring Instrument (OMI) is an excellent tool for studying bromine chemistry particularly for the Arctic due to its frequent observations at high latitudes. We derive tropospheric columns BrO by subtracting estimates of stratospheric column BrO from OMI total column BrO and air mass factor (AMF) correction, and analyze the tropospheric columns BrO in conjunction with Modern-Era Retrospective analysis for Research and Application (MERRA) meteorological fields provided by NASA Global Modeling and Assimilation Office (GMAO) in order to investigate a link between BrO explosion and near-surface meteorological factors.

  16. Link between Enhanced Arctic tropospheric BrO observed by Aura OMI and meteorological conditions

    NASA Astrophysics Data System (ADS)

    Choi, S.; Joiner, J.; Theys, N.; Salawitch, R. J.; Wales, P.; Canty, T. P.; Chance, K.; Suleiman, R. M.; Palm, S. P.; Cullather, R. I.; Darmenov, A.; da Silva, A.; Kurosu, T. P.

    2015-12-01

    Bromine radicals (Br + BrO) are important species owing to the ability to destroy ozone catalytically. They may also impact oxidative pathways of many trace gases including dimethylsulfide (DMS) and mercury. Bromine monoxide (BrO) is the most commonly observed bromine radical species. Since it absorbs ultraviolet (UV) radiation, it can be observed using remote sensing technique including Differential Optical Absorption Spectroscopy (DOAS). Previous studies have reported rapid enhancements tropospheric BrO (so called "bromine explosion") connected to near-surface ozone depletion events during springtime in the Arctic. Space-based observation of BrO through Ozone Monitoring Instrument (OMI) is an excellent tool for studying bromine chemistry particularly for the Arctic due to its frequent observations at high latitudes. We derive tropospheric columns BrO by subtracting estimates of stratospheric column BrO from OMI total column BrO and air mass factor (AMF) correction, and analyze the tropospheric columns BrO in conjunction with Modern-Era Retrospective analysis for Research and Application (MERRA) meteorological fields provided by NASA Global Modeling and Assimilation Office (GMAO) in order to investigate a link between bromine explosion and near-surface meteorological factors.

  17. Validation of Aura Microwave Limb Sounder O3 and CO Observations in the Upper Troposphere and Lower Stratosphere

    NASA Technical Reports Server (NTRS)

    Livesey, N. J.; Filipiak, M. J.; Froidevaux, L.; Read, W. G.; Lambert, A.; Santee, J. L.; Jiang, J. H.; Pumphrey, H. C.; Waters, J. W.; Cofield, R. E.; Cuddy, D. T.; Daffer, W. H.; Drouin, B. J.; Fuller, R. A.; Jarnot, R. F.; Jiang, Y. B.; Knosp, B. W.; Li, Q. B.; Perun, V. S.; Schwartz, M. J.; Snyder, W. V.; Stek, P. C.; Thurstans, R. P.; Wagner, P. A.; Avery, M.

    2008-01-01

    Global satellite observations of ozone and carbon monoxide from the Microwave Limb Sounder (MLS) on the EOS Aura spacecraft are discussed with emphasis on those observations in the 2 15 - 100 hPa region (the upper troposphere and lower stratosphere). The precision, resolution and accuracy of the data produced by the MLS "version 2.2" processing algorithms are discussed and quantified. O3 accuracy is estimated at approx.40 ppbv +5% (approx.20 ppbv +20% at 215 hPa) while the CO accuracy is estimated at approx.30 ppbv +30% for pressures of 147 hPa and less. Comparisons with expectations and other observations show good agreements for the O3 product, generally consistent with the systematic errors quoted above. In the case of COY a persistent factor of approx.2 high bias is seen at 215 hPa. However, the morphology is shown to be realistic, consistent with raw MLS radiance data, and useful for scientific study. The MLS CO data at higher altitudes are shown to be consistent with other observations.

  18. The Aura Mission and Its Application to Climate and Air Quality

    NASA Technical Reports Server (NTRS)

    Hilsenrath, Ernest; Schoeberl, Mark; Douglass, Anne

    2003-01-01

    NASA's Aura satellite is scheduled to launch in the second quarter of 2004 into a polar orbit. The Aura mission is designed to collect data to address three high priority environmental science questions: (1) Is the ozone layer recovering as expected? (2) What are the sources and processes that control tropospheric pollutants? And (3) what is the quantitative impact of constituents on climate change? Aura will answer these questions by globally measuring a comprehensive set of trace gases and aerosols in the troposphere and stratosphere. Aura data will also have applications for monitoring and predicting climate and air quality parameters. Aura s observations will continue the TOMS ozone trend record and provide an assessment as to whether the Montreal Protocol is achieving its objective. Aura will measure gases and aerosols in the upper troposphere and lower stratosphere that contribute to climate forcing. These data will be of sufficient coverage, vertical resolution, and accuracy to help constrain climate models. In addition, Aura observations of tropospheric ozone and its precursors will have regional as well as intercontinental coverage, which could improve emission inventories. Near real time data will tested for local air quality forecasts in collaboration with the US's Environmental Protection UV-B forecasts from Aura ozone and cloud cover data. An overview of Aura s instruments, data products, validation, and examples of data applications will be presented.

  19. Monitoring Air Quality from Space using AURA Data

    NASA Technical Reports Server (NTRS)

    Gleason, James F.; Chance, Kelly V.; Fishman, Jack; Torres, Omar; Veefkind, Pepijn

    2003-01-01

    Measurements from the Earth Observing System (EOS) AURA mission will provide a unique perspective on air quality monitoring. Ozone, nitrogen dioxide, formaldehyde and aerosols from the Ozone Monitoring Instrument (OMI) and carbon monoxide from the Tropospheric Emission Spectrometer (TES) will be simultaneously measured with the spatial resolution and coverage needed for improving our understanding of air quality. AURA data products useful for air quality monitoring will be given.

  20. Chemical discontinuity at the extratropical tropopause and isentropic stratosphere-troposphere exchange pathways diagnosed using Aura MLS data

    NASA Astrophysics Data System (ADS)

    Jin, J. J.; Livesey, N. J.; Manney, G. L.; Jiang, J. H.; Schwartz, M. J.; Daffer, W. H.

    2013-05-01

    The chemical discontinuity at the extratropical tropopause (ExTP) and stratosphere-troposphere exchange (STE) pathways are investigated using the long-lived chemical species carbon monoxide (CO) and ozone (O3) measured by the Aura Microwave Limb Sounder (MLS). A relative coordinate, tropopause latitude (TpLat), is developed based on potential vorticity (PV) from the Goddard Earth Observing System version 5 (GEOS-5) data assimilation system. TpLat is defined as the shortest geographic distance along an isentropic surface from the extratropical tropopause (ExTP) to an observation location. Our results show that this coordinate highlights the sharp chemical discontinuities at the ExTP more clearly than the widely-used equivalent latitude coordinate. Geographical distributions of STE pathways and barriers are investigated based on meridional gradients in O3 abundances in the new TpLat coordinate in conjunction with analysis of Rossby wave breaking between 330 K and 360 K. In northern hemispheric (NH) winter (Dec-Jan-Feb), NH STE pathways are seen mainly above the northeast Pacific. In NH summer (Jun-Jul-Aug), the NH pathway covers all longitudes at 330 K. However, it is mainly located above Asia at 340 K and above the Atlantic and the North Pacific at 350 K and 360 K. In the southern hemisphere (SH), there is a weaker STE region above the Eastern Indian Ocean and the southwestern Pacific, at and above 350 K in SH winter, and a stronger STE region over the Southeastern Pacific at these levels during SH summer. In addition, this study shows NH PV gradients are slightly stronger near the ExTP in summer than in winter even though the subtropical jet is weaker and Rossby wave breaking is stronger in summer than in winter.

  1. The EOS Aura Mission

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.; Douglass, A. R.; Hilsenrath, E.; Luce, M.; Barnett, J.; Beer, R.; Waters, J.; Gille, J.; Levelt, P. F.; DeCola, P.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The EOS Aura Mission is designed to make comprehensive chemical measurements of the troposphere and stratosphere. In addition the mission will make measurements of important climate variables such as aerosols, and upper tropospheric water vapor and ozone. Aura will launch in late 2003 and will fly 15 minutes behind EOS Aqua in a polar sun synchronous ascending node orbit with a 1:30 pm equator crossing time.

  2. Validation of Aura MLS retrievals of temperature, water vapour and ozone in the upper troposphere and lower-middle stratosphere over the Tibetan Plateau during boreal summer

    NASA Astrophysics Data System (ADS)

    Yan, Xiaolu; Wright, Jonathon S.; Zheng, Xiangdong; Livesey, Nathaniel J.; Vömel, Holger; Zhou, Xiuji

    2016-08-01

    We validate Aura Microwave Limb Sounder (MLS) version 3 (v3) and version 4 (v4) retrievals of summertime temperature, water vapour and ozone in the upper troposphere and lower-middle stratosphere (UTLS; 10-316 hPa) against balloon soundings collected during the Study of Ozone, Aerosols and Radiation over the Tibetan Plateau (SOAR-TP). Mean v3 and v4 profiles of temperature, water vapour and ozone in this region during the measurement campaigns are almost identical through most of the stratosphere (10-68 hPa), but differ in several respects in the upper troposphere and tropopause layer. Differences in v4 relative to v3 include slightly colder mean temperatures from 100 to 316 hPa, smaller mean water vapour mixing ratios in the upper troposphere (215-316 hPa) and a more vertically homogeneous profile of mean ozone mixing ratios below the climatological tropopause (100-316 hPa). These changes substantially improve agreement between ozonesondes and MLS ozone retrievals in the upper troposphere, but slightly worsen existing cold and dry biases at these levels. Aura MLS temperature profiles contain significant cold biases relative to collocated temperature measurements in several layers of the lower-middle stratosphere and in the upper troposphere. MLS retrievals of water vapour volume mixing ratio generally compare well with collocated measurements, excepting a substantial dry bias (-32 ± 11 % in v4) that extends through most of the upper troposphere (121-261 hPa). MLS retrievals of ozone volume mixing ratio are biased high relative to collocated ozonesondes in the stratosphere (18-83 hPa), but are biased low at 100 hPa. The largest relative biases in ozone retrievals (approximately +70 %) are located at 83 hPa. MLS v4 offers substantial benefits relative to v3, particularly with respect to water vapour and ozone. Key improvements include larger data yields, reduced noise in the upper troposphere and smaller fluctuations in the bias profile at pressures larger than 100

  3. The EOS Aura Mission

    NASA Technical Reports Server (NTRS)

    Schoebert, Mark R.; Douglass, A. R.; Hilsenrath, E.; Bhartia, P. K.; Barnett, J.; Gille, J.; Beer, R.; Gunson, M.; Waters, J.; Levelt, P. F.

    2004-01-01

    The Earth Observing System (EOS) Aura satellite is scheduled to launch in the second quarter of 2004. The Aura mission is designed to attack three science questions: (1) Is the ozone layer recovering as expected? (2) What are the sources and processes that control tropospheric pollutants? (3) What is the quantitative impact of constituents on climate change? Aura will answer these questions by globally measuring a comprehensive set of trace gases and aerosols at high vertical and horizontal resolution. Fig. 1 shows the Aura spacecraft and its four instruments.

  4. SVD analysis of Aura TES spectral residuals

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard; Kulawik, Susan S.; Rodgers, Clive D.; Bowman, Kevin W.

    2005-01-01

    Singular Value Decomposition (SVD) analysis is both a powerful diagnostic tool and an effective method of noise filtering. We present the results of an SVD analysis of an ensemble of spectral residuals acquired in September 2004 from a 16-orbit Aura Tropospheric Emission Spectrometer (TES) Global Survey and compare them to alternative methods such as zonal averages. In particular, the technique highlights issues such as the orbital variation of instrument response and incompletely modeled effects of surface emissivity and atmospheric composition.

  5. Tropospheric Ozone Determined from Aura OMI and MLS: Evaluation of Measurements and Comparison with the Global Modeling Initiative's Chemical Transport Model

    NASA Technical Reports Server (NTRS)

    Ziemke, J. R.; Chandra, S.; Duncan, B. N.; Froidevaux, L.; Bhartia, P. K.; Levelt, P. F.; Waters, J. W.

    2006-01-01

    Ozone measurements from the OMI and MLS instruments on board the Aura satellite are used for deriving global distributions of tropospheric column ozone (TCO). TCO is determined using the tropospheric ozone residual method which involves subtracting measurements of MLS stratospheric column ozone (SCO) from OMI total column ozone after adjusting for intercalibration differences of the two instruments using the convective-cloud differential method. The derived TCO field, which covers one complete year of mostly continuous daily measurements from late August 2004 through August 2005, is used for studying the regional and global pollution on a timescale of a few days to months. The seasonal and zonal characteristics of the observed TCO fields are also compared with TCO fields derived from the Global Modeling Initiative's Chemical Transport Model. The model and observations show interesting similarities with respect to zonal and seasonal variations. However, there are notable differences, particularly over the vast region of the Saharan desert.

  6. Influence of Chlorine Emissions on Ozone Levels in the Troposphere

    EPA Science Inventory

    Chlorine emissions from cooling towers are emitted mainly as hypochlous acid, not as molecular chlorine. Chlorine emissions from cooling towers in electric utilities in the U.S. are estimated to be 4,400 tons per year. Molecular chlorine increases more tropospheric ozone than hyp...

  7. Methane emissions to the troposphere from the Amazon floodplain

    NASA Technical Reports Server (NTRS)

    Devol, Allen H.; Richey, Jeffrey E.; Clark, Wayne A.; King, Stagg L.; Martinelli, Luiz A.

    1988-01-01

    The magnitudes of CH4 emissions to the troposphere from the Amazon River floodplain and the mechanism of these emissions were investigated using the data of 94 individual flux measurements made along a 1700-km stretch of the river during July/August 1985. The overall average rate of CH4 emission from wetlands was found to be 390 mg CH4/sq m per day, with the highest emissions (590 mg CH4/sq m per day) attributed to the water surfaces covered by aquatic macrophytes. Ebullition was the dominant mechanism of emission, accounting for 85 percent of the total. Surface-water CH4 concentrations were highly supersaturated, averaging 6.4 micromolar. The annual emission of CH4 from the Amazon Basin to the troposphere, estimated from the area and the known emission rate, is about 10 CH4 Tg/yr, indicating the importance of the area in the global atmospheric CH4 cycle.

  8. Tropospheric methanol observations from space: constraints on the seasonality of biogenic emissions

    NASA Astrophysics Data System (ADS)

    Wells, K. C.; Millet, D. B.; Cady-Pereira, K. E.; Shephard, M. W.; Xiao, Y.; Razavi, A.; Clerbaux, C.

    2011-12-01

    Methanol is the most abundant non-methane organic compound in the atmosphere, and is an important precursor of atmospheric pollutants such as CO and formaldehyde. The recent development of methanol retrievals from nadir-viewing satellite-based platforms offers powerful new information for quantifying methanol emissions on a global scale. This study uses methanol observations from the Tropospheric Emission Spectrometer (TES) on the Aura satellite and the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp-A satellite, in conjunction with aircraft data, to investigate methanol emissions from major plant functional types in the GEOS-Chem global chemical transport model (driven with MEGAN biogenic emissions). We first evaluate the TES methanol retrievals by comparing to simulation results and flight observations from several North American field campaigns. Results show that the retrieval performs well when the degrees of freedom for signal are above 0.5. We analyze one full year of TES and IASI observations and find a persistent model underestimate in springtime, and make recommendations for an improved seasonal distribution of biogenic methanol emissions over temperate regions of the globe.

  9. Remote sensing of the troposphere by infrared emission spectroscopy

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard; Glavich, Thomas A.

    1989-01-01

    This paper describes the concept of a cryogenic IR imaging Fourier transform spectrometer, called the Tropospheric Emission Spectrometer (TES), designed for observations of the troposphere and lower stratosphere from a near-earth orbit, using natural thermal emission and reflected sunlight. The principal molecular species to be measured by TES are O3, CO, CO2, N2O, H2O, H2O2, NO, NO2, HNO3, NH3, CH4, C2H6, C2H2, SO2, COS, CFCl3, and CF2Cl2. The TES is scheduled for a launch on the second polar platform of the Earth Observing System in 1998.

  10. The EOS-Aura Mission

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2004-01-01

    The EOS-Aura atmospheric chemistry mission is scheduled for launch in June 2004. Aura is the third of the large EOS observatories. The spacecraft carries an international instrument payload that has a planned six year lifetime. The Aura mission will collect data to help answer stratospheric and tropospheric atmospheric chemistry questions. The mission has the following four major objectives: 1) Track the ozone layer to determine if it is recovering as predicted. The four Aura instruments, HIRDLS, OMI, MLS, and TES will measure ozone, key source, radical, reservoir, tracer gases, and aerosols. Aura's unique design allows for major ozone controlling gases to be measured within the same air mass within a few minutes. The OMI instrument will continue the trends fiom NASA's TOMS series. 2) Track tropospheric pollutant sources and measure tropospheric ozone precursors. Major pollution sources include urban, industrial and biomass burning regions. Tropospheric trace gases will be measured, using TES and OMI, at an average spatial resolution of about approximately 15 km with near global coverage. 3) Measure key upper tropospheric atmospheric constituents that influence climate. The Aura instruments will monitor O3, H2O, CO, cirrus ice, and aerosols. EOS-Aura will fly in a sun-synchronous polar orbit about 15 minutes behind Aqua and make near coincident and synergistic measurements with the EOS- Aqua, Cloudsat, OCO, PARASOL and Calipso missions. Aura launched July 15,2004.

  11. The EOS-Aura Mission

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2005-01-01

    The EOS-Aura atmospheric chemistry mission is scheduled for launch in June 2004. Aura is the third of the large EOS observatories. The spacecraft carries an international instrument payload that has a planned six year lifetime. The Aura mission will collect data to help answer stratospheric and tropospheric atmospheric chemistry questions. The mission has the following four major objectives: 1) Track the ozone layer to determine if it is recovering as predicted. The four Aura instruments, HIRDLS, OMI, MLS, and TES will measure ozone, key source, radical, reservoir, tracer gases, and aerosols. Aura's unique design allows for major ozone controlling gases to be measured within the same air mass within a few minutes. The OMI instrument will continue the trends from NASA's TOMS series. 2) Track tropospheric pollutant sources and measure tropospheric ozone precursors. Major pollution sources include urban, industrial and biomass burning regions. Tropospheric trace gases will be measured, using TES and OMI, at an average spatial resolution of about approx. 15 km with near global coverage. 3) Measure key upper tropospheric atmospheric constituents that influence climate. The Aura instruments will monitor O3, H2O, CO, cirrus ice, and aerosols. EOS-Aura will fly in a sun-synchronous polar orbit about 15 minutes behind Aqua and make near coincident and synergistic measurements with the EOS-Aqua, Cloudsat, OCO, PARASOL and Calipso missions. Aura launched July 15,2004.

  12. Global Free Tropospheric NO2 Abundances Derived Using a Cloud Slicing Technique Applied to Satellite Observations from the Aura Ozone Monitoring Instrument (OMI)

    NASA Technical Reports Server (NTRS)

    Choi, S.; Joiner, J.; Choi, Y.; Duncan, B. N.; Bucsela, E.

    2014-01-01

    We derive free-tropospheric NO2 volume mixing ratios (VMRs) and stratospheric column amounts of NO2 by applying a cloud slicing technique to data from the Ozone Monitoring Instrument (OMI) on the Aura satellite. In the cloud-slicing approach, the slope of the above-cloud NO2 column versus the cloud scene pressure is proportional to the NO2 VMR. In this work, we use a sample of nearby OMI pixel data from a single orbit for the linear fit. The OMI data include cloud scene pressures from the rotational-Raman algorithm and above-cloud NO2 vertical column density (VCD) (defined as the NO2 column from the cloud scene pressure to the top-of-the-atmosphere) from a differential optical absorption spectroscopy (DOAS) algorithm. Estimates of stratospheric column NO2 are obtained by extrapolating the linear fits to the tropopause. We compare OMI-derived NO2 VMRs with in situ aircraft profiles measured during the NASA Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign in 2006. The agreement is generally within the estimated uncertainties when appropriate data screening is applied. We then derive a global seasonal climatology of free-tropospheric NO2 VMR in cloudy conditions. Enhanced NO2 in the free troposphere commonly appears near polluted urban locations where NO2 produced in the boundary layer may be transported vertically out of the boundary layer and then horizontally away from the source. Signatures of lightning NO2 are also shown throughout low and middle latitude regions in summer months. A profile analysis of our cloud slicing data indicates signatures of uplifted and transported anthropogenic NO2 in the middle troposphere as well as lightning-generated NO2 in the upper troposphere. Comparison of the climatology with simulations from the Global Modeling Initiative (GMI) for cloudy conditions (cloud optical thicknesses > 10) shows similarities in the spatial patterns of continental pollution outflow. However, there are also some differences in

  13. Tropospheric Emission Spectrometer for the Earth Observing System

    NASA Technical Reports Server (NTRS)

    Glavich, Thomas A.; Beer, Reinhard

    1991-01-01

    A Tropospheric Emission Spectrometer (TES) for the Earth Observing System (EOS) series of polar-orbiting platforms is described. TES is aimed at studying tropospheric chemistry, in particular, the exchange of gases between the surface and the atmosphere, urban and regional pollution, acid rain precursors, sources and sinks of greenhouse gases, and the interchange of gases between the troposphere and the stratosphere. TES is a high-resolution (0.025/cm) infrared Fourier transform spectrometer operating in the passive thermal-emission mode in a very wide spectral range (600 to 4350/cm; 2.3 to 16.7 microns). TES has 32 spatial pixels in each of four optically conjugated linear detector arrays, each optimized for a different spectral region.

  14. INTERCOMPARISON OF SCIAMACHY AND OMI TROPOSPHERIC NO2 COLUMNS: OBSERVING THE DIURNAL EVOLUTION OF CHEMISTRY AND EMISSIONS FROM SPACE

    EPA Science Inventory

    Concurrent (August 2006) satellite measurements of tropospheric NO2 columns from OMI aboard Aura (13:30 local overpass time) and SCIAMACHY aboard Envisat (10:00 overpass) offer an opportunity to examine the consistency between the two instruments under tropospheric ba...

  15. Sensitivity of simulated tropospheric CO to subgrid physics parameterization: A case study of Indonesian biomass burning emissions in 2006

    NASA Astrophysics Data System (ADS)

    Field, Robert D.; Luo, Ming; Kim, Daehyun; Del Genio, Anthony D.; Voulgarakis, Apostolos; Worden, John

    2015-11-01

    Recent cumulus and turbulence parameterization changes to the NASA GISS ModelE2 have improved representation of the Madden-Julian Oscillation and low cloud distribution, but their effect on composition-related quantities is not known. In this study, we simulate the vertical transport of carbon monoxide (CO) from uncontrolled biomass burning in Indonesia in late 2006, during which uniquely high CO was detected in the upper troposphere. Two configurations of ModelE2, one without the changes (AR5) and one with the changes (AR5'), are used for an ensemble simulation of the transport of CO from the biomass burning. The simulation results are evaluated against new CO profiles retrieved jointly from the Aura Tropospheric Emission Spectrometer and the Microwave Limb Sounder. Modeled upper tropospheric CO using the AR5 physics was unrealistically high. The AR5' physics suppress deep convection that reaches near the tropopause, reducing vertical transport of CO to the upper troposphere and bringing the model into better agreement with satellite CO. In this regard, the most important changes were related to the strength of entrainment of environmental air into the convective column, the strength of re-evaporation above cloud base, and a negative plume buoyancy threshold based on density temperature. This study illustrates how individual, noncomposition model changes can lead to significantly different modeled composition, which in this case improved agreement with satellite retrievals. This study also illuminates the potential usefulness of CO satellite observations in constraining unobservable processes in general circulation models.

  16. Implementation of Tropospheric Emissions: Monitoring of Pollution (TEMPO)

    NASA Astrophysics Data System (ADS)

    Chance, K.; Liu, X.; Suleiman, R. M.; Flittner, D. E.; Al-Saadi, J. A.; Janz, S. J.

    2014-12-01

    The updated status of TEMPO, as it proceeds from formulation phase into implementation phase is presented. TEMPO, the first NASA Earth Venture Instrument, will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO measures from Mexico City to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution. TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry. Measurements are from geostationary (GEO) orbit, to capture the inherent high variability in the diurnal cycle of emissions and chemistry. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve O3, NO2, SO2, H2CO, C2H2O2, H2O, aerosols, cloud parameters, and UVB radiation. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, reducing uncertainty in air quality predictions by 50%. TEMPO quantifies and tracks the evolution of aerosol loading. It provides near-real-time air quality products that will be made widely, publicly available. TEMPO provides much of the atmospheric measurement capability recommended for GEO-CAPE in the 2007 National Research Council Decadal Survey, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond. GEO-CAPE is not planned for implementation this decade. However, instruments from Europe (Sentinel 4) and Asia (GEMS) will form parts of a global GEO constellation for pollution monitoring later this decade, with a major focus on intercontinental

  17. A Tropospheric Emission Spectrometer HDO/H2O Retrieval Simulator for Climate Models

    NASA Technical Reports Server (NTRS)

    Field, R. D.; Risi, C.; Schmidt, G. A.; Worden, J.; Voulgarakis, A.; LeGrande, A. N.; Sobel, A. H.; Healy, R. J.

    2012-01-01

    Retrievals of the isotopic composition of water vapor from the Aura Tropospheric Emission Spectrometer (TES) have unique value in constraining moist processes in climate models. Accurate comparison between simulated and retrieved values requires that model profiles that would be poorly retrieved are excluded, and that an instrument operator be applied to the remaining profiles. Typically, this is done by sampling model output at satellite measurement points and using the quality flags and averaging kernels from individual retrievals at specific places and times. This approach is not reliable when the model meteorological conditions influencing retrieval sensitivity are different from those observed by the instrument at short time scales, which will be the case for free-running climate simulations. In this study, we describe an alternative, categorical approach to applying the instrument operator, implemented within the NASA GISS ModelE general circulation model. Retrieval quality and averaging kernel structure are predicted empirically from model conditions, rather than obtained from collocated satellite observations. This approach can be used for arbitrary model configurations, and requires no agreement between satellite-retrieved and model meteorology at short time scales. To test this approach, nudged simUlations were conducted using both the retrieval-based and categorical operators. Cloud cover, surface temperature and free-tropospheric moisture content were the most important predictors of retrieval quality and averaging kernel structure. There was good agreement between the D fields after applying the retrieval-based and more detailed categorical operators, with increases of up to 30 over the ocean and decreases of up to 40 over land relative to the raw model fields. The categorical operator performed better over the ocean than over land, and requires further refinement for use outside of the tropics. After applying the TES operator, ModelE had D biases of 8

  18. Status of Tropospheric Emissions: Monitoring of Pollution (TEMPO)

    NASA Astrophysics Data System (ADS)

    Suleiman, R. M.; Chance, K.; Liu, X.; Flittner, D. E.; Al-Saadi, J. A.; Janz, S. J.

    2015-12-01

    TEMPO is now well into its implementation phase, having passed both its Key Decision Point C and the Critical Design Review (CDR) for the instrument. The CDR for the ground systems will occur in March 2016 and the CDR for the Mission component at a later date, after the host spacecraft has been selected. TEMPO is on schedule to measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO measures from Mexico City to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution. TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry. Measurements are from geostationary (GEO) orbit, to capture the inherent high variability in the diurnal cycle of emissions and chemistry. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies.TEMPO takes advantage of a GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve O3, NO2, SO2, H2CO, C2H2O2, H2O, aerosols, cloud parameters, and UVB radiation. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, substantially reducing uncertainty in air quality predictions by 50%. TEMPO quantifies and tracks the evolution of aerosol loading. It provides near-real-time air quality products that will be made widely, publicly available.TEMPO provides much of the atmospheric measurement capability recommended for GEO-CAPE in the 2007 National Research Council Decadal Survey, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond. Instruments from Europe (Sentinel 4) and Asia (GEMS) will form

  19. Visualization, Analysis and Subsetting Tools for EOS Aura Data Products in HDF-EOS5

    NASA Technical Reports Server (NTRS)

    Johnson, J.; Ahmad, S.; Gopalan, A.; Smith, P.; Leptoukh, G.; Kempler, S.

    2004-01-01

    Aura data products are among the first to use the new version 5 of the Hierarchical Data Format for the Earth Observing System, or HDF-EOS5. This presentation discusses the common HDF-EOS5 file layout that is adopted for most of the EOS Aura standard data products. Details of the various tools that can be used to access, visualize and subset these data will also be provided. Aura, the NASA Earth Observing System's atmospheric chemistry mission, was successfully launched July 15, 2004. The Aura spacecraft includes four instruments: the High Resolution Dynamics Limb Sounder (HIRDLS), the Microwave Limb Sounder (MLS), the Ozone Monitoring Instrument (OMI), and the Tropospheric Emission Spectrometer (TES). Data from the HIRDLS, MLS and OMI will be archived at the NASA Goddard Earth Sciences (GES) Distributed Active Archive Center (DAAC), while TES data will be archived at the NASA Langley Research Center DAAC. For more information see http://daac.gsfc.nasa.gov/.

  20. SHADOZ in the Aura Era

    NASA Technical Reports Server (NTRS)

    Witte, J. C.; Thompson, A. M.; Oltmans, S. J.; Schoeberl, M. R.; Bhartia, P. K.; Froidevaux, L.; Schmidlin, F.; Calpini, B.; Shiotani, M.; Fujiwara, M.; Posny, F.; Vomel, H.; Chow, K. K.; Coetzee, G. R.; Kelder, H.

    2007-01-01

    We present comparisons of observed tropical and sub-tropical ozone from the Southern Hemisphere Additional Ozonesondes (SHADOZ) project with satellite measurements using Aura's Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) instruments. Satellite products of total and derived tropospheric column ozone from OMI and profiles of ozone in the UT/LS region from MLS are used.

  1. Tropospheric Emission Spectrometer (TES) for the Earth Observing System (EOS) CHEM Satellite

    NASA Technical Reports Server (NTRS)

    Beer, R.; Glavich, T.; Rider, D.

    2000-01-01

    The Tropospheric Emission Spectrometer (TES) is an imaging infrared Fourier transform spectrometer scheduled to be launched into polar sun-synchronous orbit on the Earth Observing System (EOS) CHEM satellite in December 2002.

  2. Monitoring of the Canadian Oil Sands from the Aura Satellite

    NASA Astrophysics Data System (ADS)

    McLinden, C. A.; Shephard, M. W.; Fioletov, V.; Cady-Pereira, K. E.; Krotkov, N. A.; Boersma, K. F.; Li, C.; Luo, M.; Joiner, J.; Bhartia, P. K.

    2014-12-01

    Two instruments on-board the NASA Aura satellite, the Ozone Monitoring Instrument (OMI) and Tropospheric Emission Spectrometer (TES), have been used to monitor air pollution over the Canadian oil sands region. Between them they provide a unique perspective on the distributions, evolution, and sources of several key pollutants. This presentation will detail some highlights from these Aura-based oil sands studies: (i) the evolution of OMI-measured nitrogen dioxide and sulfur dioxide enhancements over the past decade, including comparisons with other nearby sources, (ii) two years of ammonia, carbon monoxide, methanol, and formic acid observations from TES special-observation transects, and (iii) preliminary insights into emissions derived from these observations.

  3. New Results and Insight into Tropospheric Composition - (TES) Tropospheric Emission Spectrometer

    NASA Technical Reports Server (NTRS)

    Gunson, Michael R.; Eldering, Annmarie

    2006-01-01

    This viewgraph presentation describes the scientific challenges along with the chemical and dynamic processes that govern tropospheric ozone. The contents include: 1) The challenge and why; 2) The how to do 'it'; 3) Did 'it' work; 4) What we are trying to do with 'it'; 5) What else is happening; and 6) What next.

  4. Shifting emissions to low latitudes had a greater influence on global tropospheric ozone than changing emission magnitude, 1980-2010

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Cooper, O. R.; West, J. J.

    2015-12-01

    Global anthropogenic emissions of short-lived O3 precursors (NOx, NMVOCs and CO) have increased since 1980. These increases are greatest in developing countries (China and India), while emissions have generally decreased in North America and Europe. Consequently, emissions have shifted southwards. Modeling studies have shown that the tropospheric O3 burden and resulting radiative forcing are more sensitive to emission changes in the tropics and Southern Hemisphere than in other regions. Here we separate the influence of the change in the spatial distributions of short-lived global anthropogenic emissions from that of the change in the emission magnitude and the change in global CH4 between 1980 and 2010. We use the global CAM-chem model with 2008-2012 GEOS-5 meteorology for all simulations, neglecting possible effects of climate change. The global tropospheric O3 burden is estimated to have increased by 28.12 Tg from 1980 to 2010, with the largest increases over 30°S—30°N (17.93 Tg). Of the total O3 burden change, the influence of the change in the spatial distributions of emissions contributes 16.39 Tg, roughly double the effect of the change in emission magnitude (8.59 Tg) and of the global CH4 change (7.48 Tg). The three-month O3 season MDA8 surface O3 has decreased over the U.S. and Europe, and increased over East and South Asia from 1980 to 2010, mainly because of changes in the emission distributions. Significant increases in the zonal annual average O3 are modeled in the upper troposphere (500 to 150 hPa) between 15°N and 40°N. Upper tropospheric O3 also increases over the U.S. and Europe, despite peroxyacetyl nitrate (PAN) decreases in the middle to upper troposphere resulting from regional emission reductions. These upper tropospheric changes result from the change in the spatial distributions of emissions, with little from contributions from the changes in emissions magnitude or methane, and reflect the intercontinental transport of O3. We conclude

  5. The Impact of Emissions on Tropospheric Ozone over the Indian Subcontinent

    NASA Astrophysics Data System (ADS)

    David, L. M.; Ravishankara, A. R.; Brewer, J.

    2015-12-01

    Asia is a region of intense solar radiation, high water vapour abundance, and consequent high photochemical activity. The anthropogenic emissions from this region continue to grow. The abundance of tropospheric ozone-a product of this photochemical activity, an important climate gas, and an air pollutant-is examined using GEOS-Chem, a global three-dimensional chemical transport model (www.geos-chem.org). We have examined ozone abundances in the boundary layer, and mid and upper troposphere over the Indian subcontinent, a region with rapid growth in industrial, urbanization, transportation and agricultural activities. The work focuses on the export and import of tropospheric ozone and its precursors, out of and into the Indian subcontinent. The model simulations are compared against a comprehensive data set on ozone from soundings, MOZAIC aircraft data, and surface observations. Detailed modeling studies that enable an understanding of the impact of emission (particularly NOx) on tropospheric ozone are evaluated for the period of 15 years (2000-2014), when emissions were increasing rapidly. Modeling runs were conducted with emissions removed, emissions included, and emissions scaled by certain factors to study the sensitivity of ozone abundances to emissions from various regions of interest.

  6. The tropospheric emission spectrometer (TES) for the Earth Observing System (EOS)

    NASA Astrophysics Data System (ADS)

    Beer, R.

    In recent years, increasing concern has been expressed about Global Change - the natural and anthropogenic alteration of the Earth's environment involving global greenhouse warming and the associated climate change, urban and regional atmospheric pollution, acid deposition, regional increases in tropospheric zone, and the decrease in stratospheric ozone. A common theme among these problems is that they all involve those tropospheric trace gases which are fundamental to the biosphere-troposphere interaction, the chemistry of the free troposphere itself, and troposphere-stratosphere exchange. The chemical species involved all have spectral signatures within the near and mid infrared that can now be measured by advanced techniques of remote-sensing infrared spectroradiometry. Such a system is the Tropospheric Emission Spectrometer (TES), now in Phase B definition for the Earth Observing System (EOS) polar platforms. TES addresses these objectives by obtaining radiometrically calibrated, linewidth-limited spectral resolution, infrared spectra of the lower atmosphere using both natural thermal emission and reflected sunlight (where appropriate) in three different, but fully programmable, modes: a gobal mode, a pointed mode, and a limb-viewing mode. The goals of TES, its instrumentation, operational modes, sensitivity and data handling are discussed.

  7. The tropospheric emission spectrometer (TES) for the Earth Observing System (EOS)

    NASA Technical Reports Server (NTRS)

    Beer, R.

    1992-01-01

    In recent years, increasing concern has been expressed about Global Change - the natural and anthropogenic alteration of the Earth's environment involving global greenhouse warming and the associated climate change, urban and regional atmospheric pollution, acid deposition, regional increases in tropospheric zone, and the decrease in stratospheric ozone. A common theme among these problems is that they all involve those tropospheric trace gases which are fundamental to the biosphere-troposphere interaction, the chemistry of the free troposphere itself, and troposphere-stratosphere exchange. The chemical species involved all have spectral signatures within the near and mid infrared that can now be measured by advanced techniques of remote-sensing infrared spectroradiometry. Such a system is the Tropospheric Emission Spectrometer (TES), now in Phase B definition for the Earth Observing System (EOS) polar platforms. TES addresses these objectives by obtaining radiometrically calibrated, linewidth-limited spectral resolution, infrared spectra of the lower atmosphere using both natural thermal emission and reflected sunlight (where appropriate) in three different, but fully programmable, modes: a gobal mode, a pointed mode, and a limb-viewing mode. The goals of TES, its instrumentation, operational modes, sensitivity and data handling are discussed.

  8. The possible influences of the increasing anthropogenic emissions in India on tropospheric ozone and OH

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Li, Weiliang; Zhou, Xiuji; Isaksen, I. S. A.; Sundet, J. K.; He, Jinhai

    2003-11-01

    A 3-D chemical transport model (OSLO CTM2) is used to investigate the influences of the increasing anthropogenic emission in India. The model is capable of reproducing the observational results of the INDOEX experiment and the measurements in summer over India well. The model results show that when NO x and CO emissions in India are doubled, ozone concentration increases, and global average OH decreases a little. Under the effects of the Indian summer monsoon, NO x and CO in India are efficiently transported into the middle and upper troposphere by the upward current and the convective activities so that the NO x , CO, and ozone in the middle and upper troposphere significantly increase with the increasing NO x and CO emissions. These increases extensively influence a part of Asia, Africa, and Europe, and persist from June to September.

  9. Impact of road traffic emissions on tropospheric ozone in Europe for present day and future scenarios

    NASA Astrophysics Data System (ADS)

    Mertens, Mariano; Kerkweg, Astrid; Grewe, Volker; Jöckel, Patrick

    2016-04-01

    Road traffic is an important anthropogenic source of NOx, CO and non-methane hydrocarbons (NMHCs) which act as precursors for the formation of tropospheric ozone. The formation of ozone is highly non-linear. This means that the contribution of the road traffic sector cannot directly be derived from the amount of emitted species, because they are also determined by local emissions of other anthropogenic and natural sources. In addition, long range transport of precursors and ozone can play an important role in determining the local ozone budget. For a complete assessment of the impact of road traffic emissions it is therefore important to resolve both, local emissions and long range transport. This can be achieved by the use of the newly developed MECO(n) model system, which on-line couples the global chemistry-climate-model EMAC with the regional chemistry-climate-model COSMO-CLM/MESSy. Both models use the same chemical speciation. This allows a highly consistent model chain from the global to the local scale. To quantify the contribution of the road traffic emissions to tropospheric ozone we use an accounting system of the relevant reaction pathways of the different species from different sources (called tagging method). This tagging scheme is implemented consistently on all scales, allowing a direct comparison of the contributions. With this model configuration we investigate the impact of road traffic emissions to the tropospheric ozone budget in Europe. For the year 2008 we compare different emission scenarios and investigate the influence of both model and emission resolution. In addition, results of a mitigation scenario for the year 2030 are presented. They indicate that the contribution of the road traffic sector can be reduced by local reductions of emissions during summer. During winter the importance of long range transport increases. This can lead to increased contributions of the road traffic sector (e.g. by increased emissions in the US) even if local

  10. Seasonal dynamics in methane emissions from the Amazon River floodplain to the troposphere

    SciTech Connect

    Devol, A.H.; Richey, J.E. ); Forsberg, B.R. ); Martinelli, L.A. )

    1990-09-20

    Methane fluxes to the troposphere from the three principal habitats of the floodplain of the Amazon River main stem (open waters, emergent macrophyte beds, and flooded forests) were determined along a 1,700-km reach of the river during the low-water period of the annual flood cycle (November-December 1988). Overall, emissions averaged 68 ({plus minus} 20) mg CH{sub 4} m{sup {minus}2} d{sup {minus}1} and were significantly lower than similar emissions determined previously for the high-water period, 184 ({plus minus} 41) mg CH{sub 4} m{sup {minus}2} d{sup {minus}1} (July-August 1986). This difference was due to significantly lower emissions from floating macrophyte environments. Low-water emissions from open waters and flooded forest areas were not significantly different than at high water. A monthly time series of methane emissions from eight lakes located in the central Amazon basin showed similar results. Average annual emission from the lakes was 125 ({plus minus} 28) mg CH{sub 4} m{sup {minus}2} d{sup {minus}1}. Methane emissions from lakes were significantly higher during the high water period, again primarily due to an increase in emissions from macrophyte habitats. The data were used to calculate a seasonally weighted annual emission to the troposphere from the Amazon River main stem floodplain of 5.1 Tg yr{sup {minus}1}, which indicates the importance of the area in global atmospheric chemistry.

  11. The Aura mission, science, and validation

    NASA Astrophysics Data System (ADS)

    Hilsenrath, E.; Schoeberl, M. R.; Douglass, A. R.

    The EOS-Aura Mission is designed to answer three basic questions concerning the Earth's atmosphere: 1) Is stratospheric ozone recovering as predicted, 2) what are the processes that control air quality, and 3) how are changes in atmospheric chemistry effecting climate? Aura's four instruments work synergistically and observe from the ultraviolet to the microwave region and view in both the nadir and limb. The most important source, radical, and reservoir gases in the stratosphere will be observed globally on a daily basis. Aura will also continue the TOMS global ozone trend record. For the troposphere, key pollutants, including aerosols, gases, and their precursors will be observed with the best spatial resolution and coverage ever achieved from space. High vertical resolution measurements will be made in the vicinity of the tropopause to better define the interactions of the UT/LS and particularly determine the amount downward transport of ozone and upward transport of water vapor where both contribute to climate forcing. Aura will also measure aerosols in the stratosphere and troposphere where they play a role in ozone chemistry, air quality, and climate. Aura data will also be used by several environmental operational agencies for their decision support systems. Aura post launch validation program will augment the ground based measurement networks that measure atmospheric composition. Validation will be conducted under a range of geophysical conditions and throughout Aura's observing lifetime. Balloon campaigns will be conducted from a variety of latitudes and numerous aircraft missions are planned to cover an altitude range from the middle troposphere to the lower stratosphere and include in-situ and remote sensors. Long duration Un-inhabited aircraft are also being considered as part of the validation program. Substantial collaboration is planned with other chemistry satellite missions such as Envisat, SciSat, and Odin in order to make efficient use of

  12. Comparison between the first Odin-SMR, Aura MLS and CloudSat retrievals of cloud ice mass in the upper tropical troposphere

    NASA Astrophysics Data System (ADS)

    Eriksson, P.; Ekström, M.; Rydberg, B.; Wu, D. L.; Austin, R. T.; Murtagh, D. P.

    2007-08-01

    Emerging microwave satellite techniques are expected to provide improved global measurements of cloud ice mass. CloudSat, Aura MLS and Odin-SMR fall into this category and first cloud ice retrievals from these instruments are compared. The comparison is made for partial ice water columns above 12 km, following the SMR retrieval product. None of the instruments shows significant false cloud detections and a consistent view of the geographical distribution of cloud ice is obtained, but differences on the absolute levels exist. CloudSat gives the lowest values, with an overall mean of 2.12 g/m2. A comparable mean for MLS is 4.30 g/m2. This relatively high mean can be an indication of overestimation of the vertical altitude of cloud ice by the MLS retrievals. The vertical response of SMR has also some uncertainty, but this does not affect the comparison between MLS and CloudSat. SMR observations are sensitive to cloud inhomogeneities inside the footprint and some compensation is required. Results in good agreement with CloudSat, both in regard of the mean and probability density functions, are obtained for a weak compensation, while a simple characterisation of the effect indicates the need for stronger compensation. The SMR mean was found to be 1.89/2.62/4.10 g/m2 for no/selected/strongest compensation, respectively. Assumptions about the particle size distribution are a consideration for all three instruments, and constitute the dominating retrieval uncertainty for CloudSat. The comparison indicates a retrieval accuracy of about 40% (3.1±1.2 g/m2). This number is already very small compared to uncertainties of cloud ice parametrisation in atmospheric models, but can be decreased further through a better understanding of main retrieval error sources.

  13. Seasonal dynamics in methane emissions from the Amazon River floodplain to the troposphere

    NASA Technical Reports Server (NTRS)

    Devol, Allan H.; Richey, Jeffrey E.; Forsberg, Bruce R.; Martinelli, Luiz A.

    1990-01-01

    Methane fluxes to the troposphere from the three principal habitats of the floodplain of the Amazon River main stem (open waters, emergent macrophyte beds, and flooded forests) were determined along a 1700-km reach of the river during the low-water period of the annual flood cycle (November-December 1988). Overall, emissions averaged 68 mg CH4/sq m per day and were significantly lower than similar emissions determined previously for the high-water period, 184 mg CH4/sq m per day (July-August 1986). This difference was due to significantly lower emissions from floating macrophyte environments. Low-water emissions from open waters and flooded forest areas were not significantly different than at high water. A monthly time series of methane emission from eight lakes located in the central Amazon basis showed similar results. The data were used to calculate a seasonally weighted annual emission to the troposphere from the Amazon River main stem floodplain of 5.1 Tg/yr, which indicates the importance of the area in global atmospheric chemistry.

  14. The impact of global aviation NOx emissions on tropospheric composition changes from 2005 to 2011

    NASA Astrophysics Data System (ADS)

    Wasiuk, D. K.; Khan, M. A. H.; Shallcross, D. E.; Lowenberg, M. H.

    2016-09-01

    The impact of aviation NOx emissions from 2005 to 2011 on the chemical composition of the atmosphere has been investigated on the basis of integrations of the 3-D global chemical and transport model, STOCHEM-CRI with the novel CRIv2-R5 chemistry scheme. A base case simulation without aircraft NOx emissions and integrations with NOx emissions from aircraft are inter-compared. The sensitivity of the global atmosphere to varying the quantity and the geographical distribution of the global annual aviation NOx emissions is assessed by performing, for the first time, a series of integrations based on changing the total mass and distribution of aircraft NOx emissions derived from air traffic movements recorded between 2005 and 2011. The emissions of NOx from the global fleet based on actual records of air traffic movements between 2005 and 2011 increased the global tropospheric annual mean burden of O3 by 1.0 Tg and decreased the global tropospheric annual mean burden of CH4 by 2.5 Tg. The net NOy and O3 production increases by 0.5% and 1%, respectively between 2005 and 2011 in total. At cruise altitude, the absolute increase in the modelled O3 mixing ratios is found to be up to 0.7 ppb between 2005 and 2011 at 25°N-50°N.

  15. Aura Atmospheric Data Products and Their Availability from NASA Goddard Earth Sciences DAAC

    NASA Technical Reports Server (NTRS)

    Ahmad, S.; Johnson, J.; Gopalan, A.; Smith, P.; Leptoukh, G.; Kempler, S.

    2004-01-01

    NASA's EOS-Aura spacecraft was launched successfully on July 15, 2004. The four instruments onboard the spacecraft are the Microwave Limb Sounder (MLS), the Ozone Monitoring Instrument (OMI), the Tropospheric Emission Spectrometer (TES), and the High Resolution Dynamics Limb Sounder (HBDLS). The Aura instruments are designed to gather earth sciences measurements across the ultraviolet, visible, infra-red, thermal and microwave regions of the electromagnetic spectrum. Aura will provide over 70 distinct standard atmospheric data products for use in ozone layer and surface UV-B monitoring, air quality forecast, and atmospheric chemistry and climate change studies (http://eosaura.gsfc.nasa.gov/). These products include earth-atmosphere radiances and solar spectral irradiances; total column, tropospheric, and profiles of ozone and other trace gases, surface W-B flux; clouds and aerosol characteristics; and temperature, geopotential height, and water vapor profiles. The MLS, OMI, and HIRDLS data products will be archived at the NASA Goddard Earth Sciences (GES) Distributed Active Archive Center (DAAC), while data from TES will be archived at NASA Langley Research Center DAAC. Some of the standard products which have gone through quick preliminary checks are already archived at the GES DAAC (http://daac.nsfc.nasa.gov/) and are available to the Aura science team and data validation team members for data validation; and to the application and visualization software developers, for testing their application modules. Once data are corrected for obvious calibration problems and partially validated using in-situ observations, they would be made available to the broader user community. This presentation will provide details of the whole suite of Aura atmospheric data products, and the time line of the availability of the rest of the preliminary products and of the partially validated provisional products. Software and took available for data access, visualization, and data

  16. Analysis of the summertime buildup of tropospheric ozone abundances over the Middle East and North Africa as observed by the Tropospheric Emission Spectrometer instrument

    NASA Astrophysics Data System (ADS)

    Liu, Jane J.; Jones, Dylan B. A.; Worden, John R.; Noone, David; Parrington, Mark; Kar, Jay

    2009-03-01

    We use the GEOS-Chem chemical transport model to interpret observations of tropospheric ozone from the Tropospheric Emission Spectrometer (TES) satellite instrument in summer 2005. Observations from TES reveal elevated ozone in the middle troposphere (500-400 hPa) across North Africa and the Middle East. Observed ozone abundances in the middle troposphere are at a maximum in summer and a minimum in winter, consistent with the previously predicted summertime "Middle East ozone maximum." This summertime enhancement in ozone is associated with the Arabian and Sahara anticyclones, centered over the Zagros and Atlas Mountains, respectively. These anticyclones isolate the middle troposphere over northeast Africa and the Middle East, with westerlies to the north and easterlies to the south, facilitating the buildup of ozone. Over the Middle East, we find that in situ production and transport from Asia provides comparable contributions of 30-35% to the ozone buildup. Over North Africa, in situ production is dominant (at about 20%), with transport from Asia, North America, and equatorial Africa each contributing about 10-15% to the total ozone. We find that although the eastern Mediterranean is characterized by strong descent in the middle and upper troposphere in summer, transport from the boundary layer accounts for about 25% of the local Middle Eastern contribution to the ozone enhancement in the middle troposphere. This upward transport of boundary layer air is associated with orographic lifting along the Zagros Mountains in Iran and the Asir and Hijaz Mountain ranges in Saudi Arabia, and is consistent with TES observations of deuterated water.

  17. Pollution over Megacity Regions from the Tropospheric Emission Spectrometer (TES)

    NASA Astrophysics Data System (ADS)

    Cady-Pereira, K. E.; Payne, V.; Hegarty, J. D.; Luo, M.; Bowman, K. W.; Millet, D. B.

    2015-12-01

    The world's megacities, defined as urban areas with over 10 million people, are growing rapidly in population and increasing in number, as the migration from rural to urban areas continues. This rapid growth brings economic opportunities but also exacts costs, such as traffic congestion, inadequate sanitation and poor air quality. Monitoring air quality has become a priority for many regional governments, as they seek to understand the sources and distribution of the species contributing to the local pollution. Hyperspectral infrared instruments orbiting the Earth can measure many of these species simultaneously, and since they measure averages over their footprints, they are less sensitive to proximity to strong point sources than in situ measurements, and thus provide a more regional perspective. The JPL TES team has selected a number of megacities as Special Observation targets. These observations, or transects, are sets of 20 closely spaced (12 km apart) TES observations carried out every sixteen days. We will present the TES ozone (O3), peroxyacetyl nitrate (PAN), ammonia (NH3), formic acid (HCOOH) and methanol (CH3OH) data collected over Mexico City, Lagos (Nigeria) and Los Angeles from 2013 through 2015, and illustrate how the seasonality in the TES measurements is related to local emissions, biomass burning and regional circulation patterns, and we will reinforce our arguments with MODIS AOD and TES CO data. One of the transects over Mexico City in October demonstrates very nicely the synergy obtained from simultaneous measurements of multiple trace species. We will also discuss the spatial variability along the transects and how it is related to topography and land use.

  18. The Aura Mission, Science and Validation

    NASA Technical Reports Server (NTRS)

    Hilsenrath, Ernest; Schoeberl, Mark; Douglass, Anne

    2004-01-01

    The EOS-Aura Mission is designed to answer three basic questions concerning the Earth's atmosphere: 1) Is stratospheric ozone recovering as predicted, 2) what are the processes that control air quality, and 3) how is changes in atmospheric chemistry effecting climate? Aura's four instruments work synergistically and are dedicated to answering these questions. Aura's instruments observe from the ultraviolet to the microwave region and view in the nadir and limb. This capability allows measurements of all the critical source, radical, and reservoir gases in the stratosphere to be observed globally on a daily basis. Aura will also continue the TOMS global ozone trend record. Observations in the troposphere will be conducted with the best spatial resolution and coverage ever achieved from space. Key pollutants, including aerosols, gases, and their precursors are the primary targets for Aura. High vertical resolution measurements will be made in the vicinity of the tropopause to better define the interactions of the UT/LS and particularly determine the amount downward transport of ozone and upward transport.of water vapor where both contribute to climate forcing. Aura will also measure aerosols in the stratosphere and troposphere where they play a role in ozone chemistry, air quality and climate. Aura data will be used by several environmental agencies for their decision support systems. Aura post launch validation program includes an augmented ground based measurement program which include the operational networks which measure atmospheric composition. Validation will be conducted under a range of geophysical conditions and throughout most of Aura s observing range. Balloon campaigns will conducted from a variety of latitudes and numerous aircraft missions are planned to cover an altitude range from the middle troposphere to the lower stratosphere and include in-situ and remote sensors. Long duration Un-inhabited aircraft are also being considered as part of the

  19. Impacts of biogenic emissions of VOC and NOx on tropospheric ozone during summertime in eastern China.

    PubMed

    Wang, Qin'geng; Han, Zhiwei; Wang, Tijian; Zhang, Renjian

    2008-05-20

    This study is intended to understand and quantify the impacts of biogenic emissions of volatile organic compounds (VOC) and nitrogen oxides (NO(x)) on the formation of tropospheric ozone during summertime in eastern China. The model system consists of the non-hydrostatic mesoscale meteorological model (MM5) and a tropospheric chemical and transport model (TCTM) with the updated carbon-bond chemical reaction mechanism (CBM-IV). The spatial resolution of the system domain is 30 km x 30 km. The impacts of biogenic emissions are investigated by performing simulations (36 h) with and without biogenic emissions, while anthropogenic emissions are constant. The results indicate that biogenic emissions have remarkable impacts on surface ozone in eastern China. In big cities and their surrounding areas, surface ozone formation tends to be VOC-limited. The increase in ozone concentration by biogenic VOC is generally 5 ppbv or less, but could be more than 10 ppbv or even 30 ppbv in some local places. The impacts of biogenic NO(x) are different or even contrary in different regions, depending on the relative availability of NO(x) and VOC. The surface ozone concentrations reduced or increased by the biogenic NO(x) could be as much as 10 ppbv or 20 ppbv, respectively. The impacts of biogenic emissions on ozone aloft are generally restricted to the boundary layer and generally more obvious during the daytime than during the nighttime. This study is useful for understanding the role of biogenic emissions and for planning strategies for surface ozone abatement in eastern China. Due to limitations of the emission inventories used and the highly non-linear nature of zone formation, however, some uncertainties remain in the results.

  20. The Influence of Biogenic Emissions on Tropospheric Composition over Africa during 2006

    NASA Astrophysics Data System (ADS)

    Williams, J. E.; Scheele, R.; van Velthoven, P. F. J.; Cammas, J.-P.; Galy-Lacaux, C.; Thouret, V.

    2009-04-01

    Biogenic emissions of NO and Volatile Organic Compounds (BVOC's) play an important role in determining the oxidizing capacity of the troposphere near tropical regions which have sparse populations. Here we use a 3D global CTM (TM4) for the purpose of examining the effect of using a recent climatology of biogenic emissions from the ORCHIDEE model (Lathiére et al, 2006) on the distribution and concentrations of trace gas species over equatorial Africa during the AMMA measurement year of 2006. We compare the results against simulations which adopt an older biogenic inventory compiled during the POET project (Granier et al, 2005). Sensitivity studies are conducted to determine the effect of both NO emitted from soils and BVOC's emitted from vegetation (namely the cumulative effect of CO, HCHO, ethanol, acetic acid, acetone and CH3CHO) on tropospheric ozone, NOx and the nitrogen reservoir species PAN and HNO3. Comparisons with a host of measurements have been performed to assess the impact on model performance. Finally an analysis of the tropical O3 budget is performed to quantify differences introduced for the oxidizing capacity of the tropical troposphere. Granier, C., Guether, A., Lamarque, J. F., Mieville, A., Muller, J.F., Olivier, J., Orlando, J., Peters, J., Petron, G., Tyndall, G., amd Wallens, S., POET - a database of surface emissions of ozone precursors, available at: http://www.aero.jussieu.fr/project/ACCENT/POET.php, 2005. Lathiére, J., Hauglustaine, D. A., Friend, A. D., De Noblet-Ducoudré, N., Viovy, N., and Folberth, G. A., Impact of climate variability and land use changes on global biogenic volatile organic compound emissions, Atms. Chem. Phys., 6, 2129-2146, 2006.

  1. Tropospheric Ozone Changes, Radiative Forcing and Attribution to Emissions in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    NASA Technical Reports Server (NTRS)

    Stevenson, D.S.; Young, P.J.; Naik, V.; Lamarque, J.-F.; Shindell, D. T.; Voulgarakis, A.; Skeie, R. B.; Dalsoren, S. B.; Myhre, G.; Berntsen, T. K.; Folberth, G. A.; Rumbold, S. T.; Collins, W. J.; MacKenzie, I. A.; Doherty, R. M.; Zeng, G.; vanNoije, T. P. C.; Strunk, A.; Bergmann, D.; Cameron-Smith, P.; Plummer, D. A.; Strode, S. A.; Horowitz, L.; Lee, Y. H.; Szopa, S.; Sudo, K.; Nagashima, T.; Josse, B.; Cionni, I.; Righi, M.; Eyring, V.; Conley, A.; Bowman, K. W.; Wild, O.; Archibald, A.

    2013-01-01

    Ozone (O3) from 17 atmospheric chemistry models taking part in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) has been used to calculate tropospheric ozone radiative forcings (RFs). All models applied a common set of anthropogenic emissions, which are better constrained for the present-day than the past. Future anthropogenic emissions follow the four Representative Concentration Pathway (RCP) scenarios, which define a relatively narrow range of possible air pollution emissions. We calculate a value for the pre-industrial (1750) to present-day (2010) tropospheric ozone RF of 410 mW m-2. The model range of pre-industrial to present-day changes in O3 produces a spread (+/-1 standard deviation) in RFs of +/-17%. Three different radiation schemes were used - we find differences in RFs between schemes (for the same ozone fields) of +/-10 percent. Applying two different tropopause definitions gives differences in RFs of +/-3 percent. Given additional (unquantified) uncertainties associated with emissions, climate-chemistry interactions and land-use change, we estimate an overall uncertainty of +/-30 percent for the tropospheric ozone RF. Experiments carried out by a subset of six models attribute tropospheric ozone RF to increased emissions of methane (44+/-12 percent), nitrogen oxides (31 +/- 9 percent), carbon monoxide (15 +/- 3 percent) and non-methane volatile organic compounds (9 +/- 2 percent); earlier studies attributed more of the tropospheric ozone RF to methane and less to nitrogen oxides. Normalising RFs to changes in tropospheric column ozone, we find a global mean normalised RF of 42 mW m(-2) DU(-1), a value similar to previous work. Using normalised RFs and future tropospheric column ozone projections we calculate future tropospheric ozone RFs (mW m(-2); relative to 1750) for the four future scenarios (RCP2.6, RCP4.5, RCP6.0 and RCP8.5) of 350, 420, 370 and 460 (in 2030), and 200, 300, 280 and 600 (in 2100). Models show some

  2. Tropospheric ozone changes, radiative forcing and attribution to emissions in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    NASA Astrophysics Data System (ADS)

    Stevenson, D. S.; Young, P. J.; Naik, V.; Lamarque, J.-F.; Shindell, D. T.; Voulgarakis, A.; Skeie, R. B.; Dalsoren, S. B.; Myhre, G.; Berntsen, T. K.; Folberth, G. A.; Rumbold, S. T.; Collins, W. J.; MacKenzie, I. A.; Doherty, R. M.; Zeng, G.; van Noije, T. P. C.; Strunk, A.; Bergmann, D.; Cameron-Smith, P.; Plummer, D. A.; Strode, S. A.; Horowitz, L.; Lee, Y. H.; Szopa, S.; Sudo, K.; Nagashima, T.; Josse, B.; Cionni, I.; Righi, M.; Eyring, V.; Conley, A.; Bowman, K. W.; Wild, O.; Archibald, A.

    2013-03-01

    Ozone (O3) from 17 atmospheric chemistry models taking part in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) has been used to calculate tropospheric ozone radiative forcings (RFs). All models applied a common set of anthropogenic emissions, which are better constrained for the present-day than the past. Future anthropogenic emissions follow the four Representative Concentration Pathway (RCP) scenarios, which define a relatively narrow range of possible air pollution emissions. We calculate a value for the pre-industrial (1750) to present-day (2010) tropospheric ozone RF of 410 mW m-2. The model range of pre-industrial to present-day changes in O3 produces a spread (±1 standard deviation) in RFs of ±17%. Three different radiation schemes were used - we find differences in RFs between schemes (for the same ozone fields) of ±10%. Applying two different tropopause definitions gives differences in RFs of ±3%. Given additional (unquantified) uncertainties associated with emissions, climate-chemistry interactions and land-use change, we estimate an overall uncertainty of ±30% for the tropospheric ozone RF. Experiments carried out by a subset of six models attribute tropospheric ozone RF to increased emissions of methane (44±12%), nitrogen oxides (31 ± 9%), carbon monoxide (15 ± 3%) and non-methane volatile organic compounds (9 ± 2%); earlier studies attributed more of the tropospheric ozone RF to methane and less to nitrogen oxides. Normalising RFs to changes in tropospheric column ozone, we find a global mean normalised RF of 42 mW m-2 DU-1, a value similar to previous work. Using normalised RFs and future tropospheric column ozone projections we calculate future tropospheric ozone RFs (mW m-2; relative to 1750) for the four future scenarios (RCP2.6, RCP4.5, RCP6.0 and RCP8.5) of 350, 420, 370 and 460 (in 2030), and 200, 300, 280 and 600 (in 2100). Models show some coherent responses of ozone to climate change: decreases in the

  3. Influence of future climate and cropland expansion on isoprene emissions and tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Squire, O. J.; Archibald, A. T.; Abraham, N. L.; Beerling, D. J.; Hewitt, C. N.; Lathière, J.; Pike, R. C.; Telford, P. J.; Pyle, J. A.

    2014-01-01

    Over the 21st century, changes in CO2 levels, climate and land use are expected to alter the global distribution of vegetation, leading to changes in trace gas emissions from plants, including, importantly, the emissions of isoprene. This, combined with changes in anthropogenic emissions, has the potential to impact tropospheric ozone levels, which above a certain level are harmful to animals and vegetation. In this study we use a biogenic emissions model following the empirical parameterisation of the MEGAN model, with vegetation distributions calculated by the Sheffield Dynamic Global Vegetation Model (SDGVM) to explore a range of potential future (2095) changes in isoprene emissions caused by changes in climate (including natural land use changes), land use, and the inhibition of isoprene emissions by CO2. From the present-day (2000) value of 467 Tg C yr-1, we find that the combined impact of these factors could cause a net decrease in isoprene emissions of 259 Tg C yr-1 (55%) with individual contributions of +78 Tg C yr-1 (climate change), -190 Tg C yr-1 (land use) and -147 Tg C yr-1 (CO2 inhibition). Using these isoprene emissions and changes in anthropogenic emissions, a series of integrations is conducted with the UM-UKCA chemistry-climate model with the aim of examining changes in ozone over the 21st century. Globally, all combined future changes cause a decrease in the tropospheric ozone burden of 27 Tg (7%) from 379 Tg in the present-day. At the surface, decreases in ozone of 6-10 ppb are calculated over the oceans and developed northern hemispheric regions, due to reduced NOx transport by PAN and reductions in NOx emissions in these areas respectively. Increases of 4-6 ppb are calculated in the continental tropics due to cropland expansion in these regions, increased CO2 inhibition of isoprene emissions, and higher temperatures due to climate change. These effects outweigh the decreases in tropical ozone caused by increased tropical isoprene emissions

  4. Status of the first NASA EV-I Project, Tropospheric Emissions: Monitoring of Pollution (TEMPO)

    NASA Astrophysics Data System (ADS)

    Chance, K.; Liu, X.; Suleiman, R. M.; Flittner, D. E.; Al-Saadi, J. A.; Janz, S. J.

    2013-12-01

    TEMPO is the first NASA Earth Venture Instrument. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO measures from Mexico City to the Canadian tar sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (2 km N/S × 4.5 km E/W at the center of its field of regard). The status of TEMPO including progress in instrument definition and implementation of the ground system will be presented. TEMPO provides a minimally-redundant measurement suite that includes all key elements of tropospheric air pollution chemistry. Measurements are from geostationary (GEO) orbit, to capture the inherent high variability in the diurnal cycle of emissions and chemistry. The small spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO will be delivered in 2017 for integration onto a NASA-selected GEO host spacecraft for launch as early as 2018. It will provide the spectra required to retrieve O3, NO2, SO2, H2CO, C2H2O2, H2O, aerosols, cloud parameters, and UVB radiation. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides near-real-time air quality products that will be made widely, publicly available. Additional gases not central to air quality, including BrO, OClO, and IO will also be measured. TEMPO and its Asian (GEMS) and European (Sentinel-4) constellation partners make the first tropospheric trace gas measurements from GEO, building on the heritage of six spectrometers flown in low-earth-orbit (LEO). These LEO instruments measure the needed

  5. Carbon monoxide (CO) emissions and its tropospheric variability over Pakistan using satellite-sensed data

    NASA Astrophysics Data System (ADS)

    ul-Haq, Zia; Rana, Asim Daud; Ali, Muhammad; Mahmood, Khalid; Tariq, Salman; Qayyum, Zarmina

    2015-08-01

    This study presents major anthropogenic sources of carbon monoxide (CO) in Pakistan and discusses the spatio-temporal variability of tropospheric CO over Pakistan and neighboring regions of Afghanistan, India and Iran for a period from 2003 to 2012 using satellite-sensed (AIRS/AMSU) data. The results show a large spatio-temporal variability of CO over the study region mostly associated with anthropogenic activities such as crop residue burning, vehicular transport, and electricity and energy generation, and local meteorology. The annual mean value of tropospheric CO is observed to be 115 ± 2 ppbv that remains almost steady during the study period with decadal increase of only 2%. Due to more anthropogenic emissions of CO and its transport, the eastern zone shows a higher average value of 122 ± 2 ppbv with 2.7% decadal increase than the western zone (111 ± 3 ppbv with 1.4% decadal increase). Elevated concentrations of CO have been observed over the Indo-Gangetic Basin, Lahore, Karachi, and Delhi. During the study period large fluctuations in CO mean monthly values are found ranging from 99 ppbv to 131 ppbv. The fact that, in spite of a large increase in the CO emissions from 2003 to 2012, its average concentration remains almost stable indicates that a large scale regional transport contributes substantially to the tropospheric CO. Carbon monoxide concentrations exhibit a strong seasonal pattern with maximum amplitude in spring and minimum in autumn. July is found to have the highest decadal increasing trend of 13% followed by August at 8%, whereas May has the highest decreasing trend of -8% followed by November at -4.4%.

  6. Impact of Surface Emissions to the Zonal Variability of Tropical Tropospheric Ozone and Carbon Monoxide for November 2004

    NASA Technical Reports Server (NTRS)

    Bowman, K. W.; Jones, D.; Logan, J.; Worden, H.; Boersma, F.; Chang, R.; Kulawik, S.; Osterman, G.; Worden, J.

    2008-01-01

    The chemical and dynamical processes governing the zonal variability of tropical tropospheric ozone and carbon monoxide are investigated for November 2004 using satellite observations, in-situ measurements, and chemical transport models in conjunction with inverse-estimated surface emissions. Vertical ozone profile estimates from the Tropospheric Emission Spectrometer (TES) and ozone sonde measurements from the Southern Hemisphere Additional Ozonesondes (SHADOZ) network show the so called zonal 'wave-one' pattern, which is characterized by peak ozone concentrations (70-80 ppb) centered over the Atlantic, as well as elevated concentrations of ozone over Indonesia and Australia (60-70 ppb) in the lower troposphere. Observational evidence from TES CO vertical profiles and Ozone Monitoring Instrument (OMI) NO2 columns point to regional surface emissions as an important contributor to the elevated ozone over Indonesia. This contribution is investigated with the GEOS-Chem chemistry and transport model using surface emission estimates derived from an optimal inverse model, which was constrained by TES and Measurements Of Pollution In The Troposphere (MOPITT) CO profiles (Jones et al., 2007). These a posteriori estimates, which were over a factor of 2 greater than climatological emissions, reduced differences between GEOS-Chem and TES ozone observations by 30-40% and led to changes in GEOS-Chem upper tropospheric ozone of up to 40% over Indonesia. The remaining residual differences can be explained in part by upper tropospheric ozone produced from lightning NOx in the South Atlantic. Furthermore, model simulations from GEOS-Chem indicate that ozone over Indonesian/Australian is more sensitive to changes in surface emissions of NOx than ozone over the tropical Atlantic.

  7. A model investigation of the impact of increases in anthropogenic NOx emissions between 1967 and 1980 on tropospheric ozone

    NASA Technical Reports Server (NTRS)

    Dignon, J.; Hameed, S.

    1985-01-01

    The impact of anthropogenic NOx emission on tropospheric ozone has been investigated. Two statistical models were used for estimating annual global emissions of NOx and for driving the trend in the emission for the years 1966-1980. Both models show a steady increase in the NOx emission, except for two brief periods of leveling off: after 1973 and after 1978. The impact was estimated by calculating the rates of emissions as functions of latitude, longitude, and year, with a one-dimensional (latitudinal) model, which included coupled tropospheric photochemistry and diffusive meridional transport. Steady-state photochemical calculations with prescribed NOx emissions appropriate for 1966 and 1980 indicate an ozone increase of 8-11 percent in the Northern Hemisphere, a result compatible with the rise in ozone suggested by the observations.

  8. Potential Impacts of EOS-Aura Ozone Observations in Future Reanalyses

    NASA Astrophysics Data System (ADS)

    Wargan, K.; Pawson, S.; Olsen, M. A.; Witte, J. C.; Ziemke, J. R.; Douglass, A. R.

    2013-12-01

    As a crucial component of Earth's radiative budget, ozone is included in atmospheric reanalyses. Routine satellite observations of backscattered solar radiation (SBUV and TOMS datasets) provide long-term, cross-calibrated ozone records from a series of satellites, but do not have sufficient vertical resolution to resolve the sharp ozone gradients near the tropopause. Capturing this profile structure is essential for separating the stratospheric and tropospheric ozone distributions, which is important as we search for a full assessment of long-term changes in tropospheric ozone. As an important, chemically active pollutant, tropospheric ozone is known to be changing as emissions of its precursors (e.g., oxides of nitrogen) are controlled, but global impacts of such changes are complicated by the importance of the stratosphere as a source for ozone in the troposphere, as well as the roles of the lightning-produced nitrogen monoxide sources and of sinks due to chemical reactions and surface deposition. The EOS-Aura data record provides (to date) eight years of observations of total ozone column (from the Ozone Monitoring Instrument, OMI) and profiles (from the Microwave Limb Sounder, MLS). A low-resolution (2 by 2.5 degree), eight-year long assimilation experiment has been performed as a test for upcoming GMAO reanalyses, which will have higher (half-degree) spatial resolution. The analysis focuses on two aspects of the assimilated product: the degree to which this assimilation correctly separates the lower stratospheric and tropospheric air masses, and the quality of the assimilated tropospheric ozone column. There is a very good agreement between the assimilated product and independent data from ozonesondes and the High Resolution Dynamics Limb Sounder instrument. The analysis emphasizes the consistency of the assimilated ozone with temperature and dynamics, including estimates of the strength of the stratospheric ozone source for the troposphere. While these

  9. Calculation and measurement of terahertz radio emissions from a thin plasma filament in the tropospheric air

    NASA Astrophysics Data System (ADS)

    Isham, B.; Kunhardt, E.

    2012-12-01

    Recent advances in terawatt laser technology have made it possible to ionize the troposphere in long (centimeters to kilometers), narrow (less than 1 mm), wire-like plasma filaments. These filaments emit high-power stimulated electromagnetic emissions (SEE) in the terahertz (submillimeter) radio band, a frontier in the electromagnetic spectrum lying between the microwave and far infrared. Using an accepted model for the plasma oscillations in the filament, and a thin-wire approximation, we have calculated the current density and the resulting pattern of terahertz radiation emitted from the filament. The conical shape and opening angle match match those of recent measurements. Plans for future experiments and modeling include measurements of the radiation pattern and frequency spectrum for comparison with detailed calculations of filament plasma processes. Potential applications include safe high-resolution imaging and remote spectroscopic identification of chemical substances.

  10. Influence of Tropospheric SO2 Emissions on Particle Formation and the Stratospheric Humidity

    NASA Technical Reports Server (NTRS)

    Notholt, J.; Luo, B. P.; Fueglistaler, S.; Weisenstein, D.; Rex, M.; Lawrence, M. G.; Bingemer, H.; Wohltmann, I.; Corti, T.; Warneke, T.; vonKuhlmann, R.; Peters, T.

    2005-01-01

    Stratospheric water vapor plays an important role in the chemistry and radiation budget of the stratosphere. Throughout the last decades stratospheric water vapor levels have increased and several processes have been suggested to contribute to this trend. Here we present a mechanism that would link increasing anthropogenic SO2 emissions in southern and eastern Asia with an increase in stratospheric water. Trajectory studies and model simulations suggest that the SO2 increase results in the formation of more sulfuric acid aerosol particles in the upper tropical troposphere. As a consequence, more ice crystals of smaller size are formed in the tropical tropopause, which are lifted into the stratosphere more readily. Our model calculations suggest that such a mechanism could increase the amount of water that entered the stratosphere in the condensed phase by up to 0.5 ppmv from 1950-2000.

  11. Improved western U.S. background ozone estimates via constraining nonlocal and local source contributions using Aura TES and OMI observations

    NASA Astrophysics Data System (ADS)

    Huang, Min; Bowman, Kevin W.; Carmichael, Gregory R.; Lee, Meemong; Chai, Tianfeng; Spak, Scott N.; Henze, Daven K.; Darmenov, Anton S.; Silva, Arlindo M.

    2015-04-01

    Western U.S. near-surface ozone (O3) concentrations are sensitive to transported background O3 from the eastern Pacific free troposphere, as well as U.S. anthropogenic and natural emissions. The current 75 ppbv U.S. O3 primary standard may be lowered soon, hence accurately estimating O3 source contributions, especially background O3 in this region has growing policy-relevant significance. In this study, we improve the modeled total and background O3, via repartitioning and redistributing the contributions from nonlocal and local anthropogenic/wildfires sources in a multi-scale satellite data assimilation system containing global Goddard Earth Observing System-Chemistry model (GEOS-Chem) and regional Sulfur Transport and dEposition Model (STEM). Focusing on NASA's ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) field campaign period in June-July 2008, we first demonstrate that the negative biases in GEOS-Chem free simulation in the eastern Pacific at 400-900 hPa are reduced via assimilating Aura-Tropospheric Emission Spectrometer (TES) O3 profiles. Using the TES-constrained boundary conditions, we then assimilated into STEM the tropospheric nitrogen dioxide (NO2) columns from Aura-Ozone Monitoring Instrument to indicate U.S. nitrogen oxides (NOx = NO2 + NO) emissions at 12 × 12 km2 grid scale. Improved model skills are indicated from cross validation against independent ARCTAS measurements. Leveraging Aura observations, we show anomalously high wildfire NOx emissions in this summer in Northern California and the Central Valley while lower anthropogenic emissions in multiple urban areas than those representing the year of 2005. We found strong spatial variability of the daily maximum 8 h average background O3 and its contribution to the modeled total O3, with the mean value of ~48 ppbv (~77% of the total).

  12. The ozone response to ENSO in Aura satellite measurements and a chemistry-climate simulation

    NASA Astrophysics Data System (ADS)

    Oman, Luke D.; Douglass, Anne R.; Ziemke, Jerry R.; Rodriguez, Jose M.; Waugh, Darryn W.; Nielsen, J. Eric

    2013-01-01

    The El Niño-Southern Oscillation (ENSO) is the dominant mode of inter-annual variability in the tropical ocean and troposphere. Its impact on tropospheric circulation causes significant changes to the distribution of ozone. Here we derive the lower tropospheric to lower stratospheric ozone response to ENSO from observations by the Tropospheric Emission Spectrometer (TES) and the Microwave Limb Sounder (MLS) instruments, both on the Aura satellite, and compare to the simulated response from the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM). Measurement ozone sensitivity is derived using multiple linear regression to include variations from ENSO as well as from the first two empirical orthogonal functions of the quasi-biennial oscillation. Both measurements and simulation show features such as the negative ozone sensitivity to ENSO over the tropospheric tropical Pacific and positive ozone sensitivity over Indonesia and the Indian Ocean region. Ozone sensitivity to ENSO is generally positive over the midlatitude lower stratosphere, with greater sensitivity in the Northern Hemisphere. GEOSCCM reproduces both the overall pattern and magnitude of the ozone response to ENSO obtained from observations. We demonstrate the combined use of ozone measurements from MLS and TES to quantify the lower atmospheric ozone response to ENSO and suggest its possible usefulness in evaluating chemistry-climate models.

  13. Influence of future climate and cropland expansion on isoprene emissions and tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Squire, O. J.; Archibald, A. T.; Beerling, D.; Hewitt, C. N.; Lathiere, J.; Pike, R. C.; Telford, P.; Pyle, J. A.

    2013-12-01

    Over the 21st century, changes in CO2 levels, climate and land use are expected to alter the global distribution of vegetation, leading to changes in trace gas emissions from plants, including, importantly, the emissions of isoprene. This, combined with changes in anthropogenic emissions, has the potential to impact tropospheric ozone levels, which above a certain level are harmful to animals and vegetation. In this study we use a biogenic emissions model following the empirical parameterisation of the MEGAN model, with vegetation distributions calculated by the Sheffield Dynamic Global Vegetation Model (SDGVM) to calculate potential future (2095) changes in isoprene emissions caused by changes in climate, land use, and the inhibition of isoprene emissions by CO2. From the present day (2000) value of 467 Tg C yr-1, we find that the combined impact of these factors causes a net decrease in isoprene emissions of 259Tg C yr-1 (55%) with individual contributions of +78 Tg C yr-1 (climate change), -190 Tg C yr-1 (land use) and -147 Tg C yr-1 (CO2 inhibition). Using these isoprene emissions and changes in anthropogenic emissions, a series of integrations is conducted with the UM-UKCA chemistry-climate model with the aim of examining changes in ozone over the 21st century. Globally all combined future changes cause a decrease in the tropospheric ozone burden of 27 Tg (7%) from 379 Tg in the present day. At the surface, decreases in ozone of 6-10 ppb are calculated over the oceans and developed northern hemispheric regions due to reduced NOx transport by PAN and reductions in NOx emissions in these areas respectively. Increases of 4-6 ppb are calculated in the continental Tropics due to cropland expansion in these regions, increased CO2 inhibition of isoprene emissions, and higher temperatures due to climate change. These effects outweigh the decreases in tropical ozone caused by increased tropical isoprene emissions with climate change. Our land use change scenario

  14. Global modeling analysis of tropospheric ozone and its radiative forcing from biomass burning emissions in the twentieth century

    NASA Astrophysics Data System (ADS)

    Ito, Akinori; Sudo, Kengo; Akimoto, Hajime; Sillman, Sanford; Penner, Joyce E.

    2007-12-01

    This work evaluates the sensitivity of tropospheric ozone (O3) and its radiative forcing (RF) from 1890 to 1990 to different biomass burning (BB) emissions using a global tropospheric climate-chemistry model (CCM) with a modified chemical mechanism for anthropogenic volatile organic compounds (AVOC). The use of the most efficient simplified chemical scheme among three chemical mechanisms with different degrees of complexity is acceptable for global scale simulations of the radiative effects of tropospheric O3 changes in the CCM, since the differences in the results are small. The CCM model with simplified chemistry is implemented to study various aspects of the impact of BB emissions on tropospheric O3 and its RF. The backward emission model results are in good agreement with the present-day observations for regions downwind of BB sources, while the forward emission model may reasonably produce the distributions of regional emissions in the preindustrial period. The global mean RF due to tropospheric O3 increase from 1890 to 1990 is 0.41 W m-2 on a global average. When no anthropogenic emissions in the preindustrial period are considered, this forcing reaches 0.47 W m-2. We find that the global mean BB forcing due to tropospheric O3 changes from 1890 to 1990 is 0.15 W m-2 on a global average. The preindustrial BB emissions need to be represented realistically when evaluating controls on the emissions of trace gases and aerosols for a sustainable society, because there are significant open biomass burning emissions in the preindustrial period. The significant regional differences in the surface O3 concentrations among three different BB data sets are found in the United States for 1890 and in Brazil for 1990. In these regions during the periods, the most common land uses in the forests are logging and conversion of primary or secondary forests to cattle pasture or shifting cultivation. Improvement in the data sets of historical land use changes and accurate

  15. The empirical relationship between satellite-derived tropospheric NO2 and fire radiative power and possible implications for fire emission rates of NOx

    NASA Astrophysics Data System (ADS)

    Schreier, S. F.; Richter, A.; Kaiser, J. W.; Burrows, J. P.

    2014-03-01

    Nitrogen oxides (NOx) play key roles in atmospheric chemistry, air pollution, and climate. While the largest fraction of these reactive gases is released by anthropogenic emission sources, a significant amount can be attributed to vegetation fires. In this study, NO2 from GOME-2 on board EUMETSAT's MetOp-A and OMI on board NASA's Aura as well as fire radiative power (FRP) from the measurements of MODIS on board NASA's Terra and Aqua satellites are used to derive fire emission rates (FERs) of NOx for different types of vegetation using a simple statistical approach. Monthly means of tropospheric NO2 vertical columns (TVC NO2) have been analyzed for their temporal correlation with the monthly means of FRP for five consecutive years from 2007 to 2011 on a horizontal 1° × 1° grid. The strongest correlation is found to be largely confined to tropical and subtropical regions, which account for more than 80% of yearly burned area, on average, globally. In these regions, the seasonal variation of fire intensity, expressed by the FRP data, is similar to the pattern of TVC NO2. As chemical models typically require values for the amount of NOx being released as a function of time, we have converted the retrieved TVC NO2 into production rates of NOx from fire (Pf) by assuming a constant lifetime of NOx. The comparison between Pf and NOx emissions from the Global Fire Emissions Database (GFEDv3.1) over 5 characteristic biomass burning regions in the tropics and subtropics shows good agreement. By separating the monthly means of Pf and FRP according to land cover type, FERs of NOx could be derived for different biomes. The estimated FERs for the dominating types of vegetation burned are lowest for open shrublands and savannas (0.28-1.03 g NOx s-1 MW-1) and highest for croplands and woody savannas (0.82-1.56 g NOx s-1 MW-1). This analysis demonstrates that the strong empirical relationship between TVC NO2 and FRP and the following simplified assumptions are a useful tool for

  16. MeSMarT - Measurements of Shipping Emissions in the Marine Troposphere

    NASA Astrophysics Data System (ADS)

    Kattner, Lisa; Mathieu-Üffing, Barbara; Chirkov, Maksym; Burrows, John; Matthias, Volker; Richter, Andreas; Schmolke, Stefan; Theobald, Norbert; Weigelt-Krenz, Sieglinde; Wittrock, Folkard

    2013-04-01

    A new project called MeSMarT (Measurements of shipping emissions in the marine troposphere) to estimate the influence of ship emissions on the chemistry of the atmospheric boundary layer over the North Sea has been established in cooperation with the German Bundesamt für Seeschifffahrt und Hydrographie (Federal Maritime and Hydrographic Agency). Over the last years discussions about ship emissions have increased and grown in importance due to the increase of commercial shipping as well as studies about their dangerous health effects. While industrial and traffic air pollution from ashore is decreasing because of technological improvements and stronger political regulations the impact of ship emissions becomes more relevant, especially in coastal areas and harbor cities. The establishment of a Sulfur Emission Controlled Area (SECA) for the North Sea and the Baltic Sea has been a first step to control and reduce ship emissions by consecutively regulating the sulfur content of fuels. The project MeSMarT aims to monitor background concentration as well as elevated signals of gases and particles related to ship emissions with various physical and chemical methods to cover a wide range of relevant pollutants and their spatial and seasonal distribution. SO2, NO2, NO, CO2 and O3 are measured with in situ techniques, SO2 and NO2 as well by remote sensing applying the MAXDOAS-technique. The data will also be compared with satellite measurements and passive sampling in order to find a method to observe the long-term effect of regulations like SECA. High volume filter samples will be taken and analyzed especially for sulfate, nitrate, organics and elemental composition to investigate possible sources, sinks and conversion of ship emission derived compounds. Measurements and sampling take place during ship campaigns primarily in the North Sea and will be complemented with stationary measurements located on a coastal site close to the main shipping routes through the German

  17. Vertical transport of ozone and CO during super cyclones in the Bay of Bengal as detected by Tropospheric Emission Spectrometer.

    PubMed

    Fadnavis, S; Beig, G; Buchunde, P; Ghude, Sachin D; Krishnamurti, T N

    2011-02-01

    Vertical profiles of carbon monoxide (CO) and ozone retrieved from Tropospheric Emission Spectrometer have been analyzed during two super cyclone systems Mala and Sidr. Super cyclones Mala and Sidr traversed the Bay of Bengal (BOB) region on April 24-29, 2006 and November 12-16, 2007 respectively. The CO and ozone plume is observed as a strong enhancement of these pollutants in the upper troposphere over the BOB, indicating deep convective transport. Longitude-height cross-section of these pollutants shows vertical transport to the upper troposphere. CO mixing ratio ~90 ppb is observed near the 146-mb level during the cyclone Mala and near 316 mb during the cyclone Sidr. Ozone mixing ratio ~60-100 ppb is observed near the 316-mb level during both the cyclones. Analysis of National Centers for Environmental Prediction (NCEP) reanalysis vertical winds (omega) confirms vertical transport in the BOB.

  18. Tropospheric Ozone as a Short-lived Chemical Climate Forcer

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.

    2012-01-01

    Tropospheric ozone is the third most important greenhouse gas according to the most recent IPCC assessment. However, tropospheric ozone is highly variable in both space and time. Ozone that is located in the vicinity of the tropopause has the greatest effect on climate forcing. Nitrogen oxides (NOx) are the most important precursors for ozone In most of the troposphere. Therefore, pollution that is lofted upward in thunderstorm updrafts or NOx produced by lightning leads to efficient ozone production in the upper troposphere, where ozone is most important climatically. Global and regional model estimates of the impact of North American pollution and lightning on ozone radiative forcing will be presented. It will be shown that in the Northern Hemisphere summer, the lightning effect on ozone radiative forcing can dominate over that of pollution, and that the radiative forcing signal from North America extends well into Europe and North Africa. An algorithm for predicting lightning flash rates and estimating lightning NOx emissions is being incorporated into the NASA GEOS-5 Chemistry and Climate Model. Changes in flash rates and emissions over an ENSO cycle and in future climates will be assessed, along with the resulting changes in upper tropospheric ozone. Other research on the production of NOx per lightning flash and its distribution in the vertical based on cloud-resolving modeling and satellite observations will be presented. Distributions of NO2 and O3 over the Middle East from the OMI instrument on NASA's Aura satellite will also be shown.

  19. Interannual variability of tropospheric trace gases and aerosols: The role of biomass burning emissions

    NASA Astrophysics Data System (ADS)

    Voulgarakis, Apostolos; Marlier, Miriam E.; Faluvegi, Greg; Shindell, Drew T.; Tsigaridis, Kostas; Mangeon, Stéphane

    2015-07-01

    Fires are responsible for a range of gaseous and aerosol emissions. However, their influence on the interannual variability of atmospheric trace gases and aerosols has not been systematically investigated from a global perspective. We examine biomass burning emissions as a driver of interannual variability of large-scale abundances of short-lived constituents such as carbon monoxide (CO), hydroxyl radicals (OH), ozone, and aerosols using the Goddard Institute for Space Studies ModelE composition-climate model and a range of observations, with an emphasis on satellite information. Our model captures the observed variability of the constituents examined in most cases, but with substantial underestimates in boreal regions. The strongest interannual variability on a global scale is found for carbon monoxide (~10% for its global annual burden), while the lowest is found for tropospheric ozone (~1% for its global annual burden). Regionally, aerosol optical depth shows the largest variability which exceeds 50%. Areas of strong variability of both aerosols and CO include the tropical land regions (especially Equatorial Asia and South America) and northern high latitudes, while even regions in the northern midlatitudes experience substantial interannual variability of aerosols. Ozone variability peaks over equatorial Asia in boreal autumn, partly due to varying biomass burning emissions, and over the western and central Pacific in the rest of the year, mainly due to meteorological fluctuations. We find that biomass burning emissions are almost entirely responsible for global CO interannual variability, and similarly important for OH variability. The same is true for global and regional aerosol variability, especially when not taking into account dust and sea-salt particles. We show that important implications can arise from such interannual influences for regional climate and air quality.

  20. Infrared limb emission measurements of aerosol in the troposphere and stratosphere

    NASA Astrophysics Data System (ADS)

    Griessbach, Sabine; Hoffmann, Lars; Spang, Reinhold; von Hobe, Marc; Müller, Rolf; Riese, Martin

    2016-09-01

    Altitude-resolved aerosol detection in the upper troposphere and lower stratosphere (UTLS) is a challenging task for remote sensing instruments. Infrared limb emission measurements provide vertically resolved global measurements at day- and nighttime in the UTLS. For high-spectral-resolution infrared limb instruments we present here a new method to detect aerosol and separate between ice and non-ice particles. The method is based on an improved aerosol-cloud index that identifies infrared limb emission spectra affected by non-ice aerosol or ice clouds. For the discrimination between non-ice aerosol and ice clouds we employed brightness temperature difference correlations. The discrimination thresholds for this method were derived from radiative transfer simulations (including scattering) and Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)/Envisat measurements obtained in 2011. We demonstrate the value of this approach for observations of volcanic ash and sulfate aerosol originating from the Grímsvötn (Iceland, 64° N), Puyehue-Cordón Caulle (Chile, 40° S), and Nabro (Eritrea, 13° N) eruptions in May and June 2011 by comparing the MIPAS volcanic aerosol detections with Atmospheric Infrared Sounder (AIRS) volcanic ash and SO2 measurements.

  1. Impact of Asian Megacity Emissions on Regional and Global Tropospheric Chemistry

    NASA Astrophysics Data System (ADS)

    Guttikunda, S. K.; Tang, Y.; Yienger, J.; Carmichael, G. R.; Levy, H.; Dorwart, J.; Thongboonchoo, N.

    2001-12-01

    Air quality requires serious attention in the megacities. The current trend in urbanization and motorization in the developing countries of Asia are in many ways reproducing the patterns followed in developed countries. Air pollutants such as sulfur dioxide, nitrogen dioxide and ozone are known to cause damage to human health, crop production, and forest cover. Due to their longer lifetimes, these trace gas emissions play a vital role in the long-range transport. The GFDL/Global Chemistry Transport Model (GCTM) and regional chemical transport model STEM-III and RAMS were applied to better understand the chemical nature, transformation and transport of trace gases from the megacities of Asia. During the ACE-Asia and TRACE-P field experiments in the East Asia, some of the mission objectives were designed to understand the aging and transport features of pollutant plumes from East Asian megacities. We conducted GCTM simulations for the present emission levels compared to a reference run excluding Asian megacity air pollution and real-time simulations for the megacities using STEM-III during the campaign period of March-May'2001. The model simulation results included particulates, sulfur dioxide, nitrogen oxides and primary and secondary photochemical products. In this paper, we will present tropospheric chemistry and urban chemistry results from the GCTM and RCTM simulations respectively for the experiment period.

  2. The Response of Lower Atmospheric Ozone to ENSO in Aura Measurements and a Chemistry-Climate Simulation

    NASA Technical Reports Server (NTRS)

    Oman, L. D.; Douglass, A. R.; Ziemke, J. R.; Rodriquez, J. M.; Waugh, D. W.; Nielsen, J. E.

    2012-01-01

    The El Nino-Southern Oscillation (ENSO) is the dominant mode of tropical variability on interannual time scales. ENSO appears to extend its influence into the chemical composition of the tropical troposphere. Recent work has revealed an ENSO-induced wave-1 anomaly in observed tropical tropospheric column ozone. This results in a dipole over the western and eastern tropical Pacific, whereby differencing the two regions produces an ozone anomaly with an extremely high correlation to the Nino 3.4 Index. We have successfully reproduced this feature using the Goddard Earth Observing System Version 5 (GEOS-5) general circulation model coupled to a comprehensive stratospheric and tropospheric chemical mechanism forced with observed sea surface temperatures over the past 25 years. An examination of the modeled ozone field reveals the vertical contributions of tropospheric ozone to the column over the western and eastern Pacific region. We will show composition sensitivity in observations from NASA s Aura satellite Microwave Limb Sounder (MLS) and the Tropospheric Emissions Spectrometer (TES) and a simulation to provide insight into the vertical structure of these ENSO-induced ozone changes. The ozone changes due to the Quasi-Biennial Oscillation (QBO) in the extra-polar upper troposphere and lower stratosphere in MLS measurements will also be discussed.

  3. Fire emission rates of NOx based on the empirical relationship between satellite-derived tropospheric NO2 and fire radiative power

    NASA Astrophysics Data System (ADS)

    Schreier, S. F.; Richter, A.; Kaiser, J. W.; Burrows, J. P.

    2013-11-01

    Nitrogen oxides (NOx) play key roles in atmospheric chemistry, air pollution, and climate. While the largest fraction of these reactive gases is released by anthropogenic emission sources, a significant amount can be attributed to vegetation fires. In this study, NO2 from GOME-2 on board EUMETSAT's MetOp-A and OMI on board NASA's Aura as well as fire radiative power (FRP) from the measurements of MODIS on board NASA's Terra and Aqua are used to derive fire emission rates (FERs) of NOx for different types of vegetation using a simple statistical approach. Monthly means of tropospheric NO2 vertical columns (TVC NO2) have been analyzed for their temporal correlation with the monthly means of FRP for five consecutive years from 2007 to 2011 on a horizontal 1° × 1° grid. The strongest correlation is found to be largely confined to tropical and subtropical regions, which account for more than 80% of yearly burned area on average globally. In these regions, the seasonal variation of fire intensity, expressed by the FRP data, is similar to the pattern of TVC NO2. As chemical models typically require values for the amount of NOx being released as a function of time, we have converted the retrieved TVC NO2 into production rates of NOx from fire (Pf) by assuming a constant lifetime of NOx. The comparison between Pf and NOx emissions from GFEDv3.1 over 5 characteristic biomass burning regions in the tropics and subtropics indicated good agreement. By separating the monthly means of Pf and FRP according to land cover type, FERs of NOx could be derived for different biomes. The estimated FERs for the dominating types of vegetation burned are lowest for open shrublands and savannas (0.28-1.03 g NOx s-1 MW-1) and highest for croplands and woody savannas (0.82-1.56 g NOx s-1 MW-1). This analysis demonstrates clearly that there are biome-specific, diurnal, and regional differences in FERs for the dominating types of vegetation burned in the tropics and subtropics. Possible

  4. Summertime mid-to-upper tropospheric nitrous oxide over the Mediterranean as a footprint of Indian emissions

    NASA Astrophysics Data System (ADS)

    Kangah, Yannick; Ricaud, Philippe; Attié, Jean-Luc; Saitoh, Naoko; Hauglustaine, Didier; El Amraoui, Laaziz; Zbinden, Regina; Delon, Claire

    2016-04-01

    We used global scale thermal infrared measurements of mid-to-upper tropospheric nitrous oxide (N2O) from the Greenhouse gases Observing SATellite (GOSAT) and outputs from the 3D Chemical Transport Model LMDz-OR-INCA to assess the impact of the Indian subcontinent N2O emissions on the N2O field over the eastern Mediterranean Basin (MB) during summer. The use of nitrogen fertilizer coupled with high soil humidity during summer monsoon period produce high emissions of N2O in many south Asian countries and especially the Indian subcontinent. N2O is transported to the upper troposphere by updrafts associated to the monsoon and redistributed westward to the eastern Mediterranean via the Asian Monsoon Anticyclone. This summertime (June-July-August) enrichment in N2O in the eastern Mediterranean produces a maximum in the east-west difference of MB mid-to-upper tropospheric N2O anomaly representative for the period 2010-2013 with a maximum in July and a peak-to-peak amplitude of ~1.0 ± 0.3 ppbv observed by GOSAT consistently with LMDz-OR-INCA but less intense (~0.5 ppbv). This summertime enrichment of N2O over the eastern Mediterranean is consistent with the increase of the surface emissions and the convective precipitations over the Indian subcontinent during the summer monsoon period. N2O over the eastern Mediterranean can therefore be considered as a footprint of Indian summertime emissions.

  5. Aura of mystery.

    PubMed

    Dolgin, Elie

    2013-09-01

    It begins as a slowly expanding spot of light or similar visual disturbance, often accompanied by phantom noises and other sensory distortions. People who experience such 'auras' know all too well that these early warning signs will culminate in a head-splitting migraine, yet scientists have little idea what causes the debilitating deluge of symptoms. Elie Dolgin talks to neurologists hoping to change that - by triggering auras in the laboratory in order to study them.

  6. Composition of the Asian summer monsoon anticyclone: Climatology and variability from 10 years of Aura Microwave Limb Sounder measurements

    NASA Astrophysics Data System (ADS)

    Santee, Michelle; Manney, Gloria; Livesey, Nathaniel; Neu, Jessica; Schwartz, Michael; Read, William

    2016-04-01

    Satellite measurements are invaluable for investigating the composition of the upper troposphere / lower stratosphere (UTLS) in the region of the Asian summer monsoon anticyclone, which has been sparsely sampled by other means. The Microwave Limb Sounder (MLS), launched as part of NASA's Aura mission in July 2004, makes simultaneous co-located measurements of trace gases and cloud ice water content (IWC, a proxy for deep convection) in the UTLS on a daily basis. Here we exploit the dense spatial and temporal coverage, long-term data record, and extensive measurement suite of Aura MLS to characterize the climatological composition of the ASM anticyclone and quantify its considerable spatial, seasonal, and interannual variability. We relate the observed trace gas behavior to various meteorological quantities, such as the size and strength of the ASM anticyclone, the extent and intensity of deep convection, and variations in the tropopause and the upper tropospheric jets in that region. Multiple species of both tropospheric and stratospheric origin are examined to help assess whether the observed variability arises from variations in transport processes or changes in the strength or location of surface emissions.

  7. Vegetation fire emission coefficients derived from MODIS fire radiative power and GOME-2 tropospheric NO2 measurements

    NASA Astrophysics Data System (ADS)

    Schreier, Stefan; Richter, Andreas; Burrows, John

    2013-04-01

    In this study, we use satellite measurements of fire radiative power (FRP) from the MODerate resolution Imaging Spectroradiometer (MODIS) and nitrogen dioxide (NO2) from the Global Ozone Monitoring Experiment-2 (GOME-2) to derive fire emission coefficients for different types of vegetation. In a first step, monthly means of FRP have been analyzed for temporal correlation with monthly means of tropospheric NO2 for five consecutive years from 2007 to 2011 on a 1° x 1° grid. The strongest correlation is largely confined to tropical and subtropical regions which account for more than 80% of yearly burned area on average globally. In these regions, the seasonal variation of fire intensity explained by the FRP data is reflected by the tropospheric NO2 columns to a high degree. In a next step, spatially averaged regression coefficients were determined for four characteristic biomass burning regions. The obtained regression coefficients are used for the prediction of tropospheric NO2 columns by simply applying a linear regression model. The best agreement between estimated and observed tropospheric NO2 columns is found for the African regions north and south of equator with large fraction of the NO2 signal being explained by the seasonal variability of FRP. Indeed, the determination of regression coefficients on a 1° x 1° grid highlights a spatial heterogeneity of slope values (here referred to as fire emission coefficients) indicating changes of emission intensity over different biomes. Therefore, a global land cover map was included in the analysis for deriving fire emission coefficients for different types of vegetation. Retrieved fire emission coefficients for the dominating types of vegetation burned are 0.022, 0.02, 0.019, 0.0185, 0.0131, and 0.0101 1015 molecules 10-4 mW-1 cm-2 NO2 for wooded grassland, broadleaf evergreen forest, cultivated crops, broadleaf deciduous forest and woodland, grassland, and shrubs, respectively. However, the precedence of these

  8. Auras in generalized epilepsy

    PubMed Central

    Carlson, Chad; Bluvstein, Judith; Chong, Derek J.; Friedman, Daniel; Kirsch, Heidi E.

    2014-01-01

    Objective: We studied the frequency of auras in generalized epilepsy (GE) using a detailed semistructured diagnostic interview. Methods: In this cross-sectional study, participants with GE were drawn from the Epilepsy Phenome/Genome Project (EPGP). Responses to the standardized diagnostic interview regarding tonic-clonic (grand mal) seizures were then examined. This questionnaire initially required participants to provide their own description of any subjective phenomena before their “grand mal seizures.” Participants who provided answers to these questions were considered to have an aura. All participants were then systematically queried regarding a list of specific symptoms occurring before grand mal seizures, using structured (closed-ended) questions. Results: Seven hundred ninety-eight participants with GE were identified, of whom 530 reported grand mal seizures. Of these, 112 (21.3%) reported auras in response to the open-ended question. Analysis of responses to the closed-ended questions suggested that 341 participants (64.3%) experienced at least one form of aura. Conclusions: Auras typically associated with focal epilepsy were reported by a substantial proportion of EPGP subjects with GE. This finding may support existing theories of cortical and subcortical generators of GE with variable spread patterns. Differences between responses to the open-ended question and closed-ended questions may also reflect clinically relevant variation in patient responses to history-taking and surveys. Open-ended questions may underestimate the prevalence of specific types of auras and may be in part responsible for the underrecognition of auras in GE. In addition, structured questions may influence participants, possibly leading to a greater representation of symptoms. PMID:25230998

  9. Satellite Monitoring Over the Canadian Oil Sands: Highlights from Aura OMI and TES

    NASA Technical Reports Server (NTRS)

    Shephard, Mark W.; McLinden, Chris; Fioletov, Vitali; Cady-Pereira, Karen E.; Krotkov, Nick A.; Boersma, Folkert; Li, Can; Luo, Ming; Bhartia, P. K.; Joiner, Joanna

    2014-01-01

    Satellite remote sensing provides a unique perspective for air quality monitoring in and around the Canadian Oil Sands as a result of its spatial and temporal coverage. Presented are Aura satellite observations of key pollutants including nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), ammonia (NH3), methanol (CH3OH), and formic acid (HCOOH) over the Canadian Oil Sands. Some of the highlights include: (i) the evolution of NO2 and SO2 from the Ozone Monitoring Instrument (OMI), including comparisons with other nearby sources, (ii) two years of ammonia, carbon monoxide, methanol, and formic acid observations from 240 km North-South Tropospheric Emission Spectrometer (TES) transects through the oils sands, and (iii) preliminary insights into emissions derived from these observations.

  10. Climate versus emission drivers of methane lifetime against loss by tropospheric OH from 1860-2100

    NASA Astrophysics Data System (ADS)

    John, J. G.; Fiore, A. M.; Naik, V.; Horowitz, L. W.; Dunne, J. P.

    2012-12-01

    With a more-than-doubling in the atmospheric abundance of the potent greenhouse gas methane (CH4) since preindustrial times, and indications of renewed growth following a leveling off in recent years, questions arise as to future trends and resulting climate and public health impacts from continued growth without mitigation. Changes in atmospheric methane lifetime are determined by factors which regulate the abundance of OH, the primary methane removal mechanism, including changes in CH4 itself. We investigate the role of emissions of short-lived species and climate in determining the evolution of methane lifetime against loss by tropospheric OH, (τCH4_OH), in a suite of historical (1860-2005) and future Representative Concentration Pathway (RCP) simulations (2006-2100), conducted with the Geophysical Fluid Dynamics Laboratory (GFDL) fully coupled chemistry-climate model (CM3). From preindustrial to present, CM3 simulates an overall 5% increase in τCH4_OH due to a doubling of the methane burden which offsets coincident increases in nitrogen oxide (NOx emissions. Over the last two decades, however, the τCH4_OH declines steadily, coinciding with the most rapid climate warming and observed slow-down in CH4 growth rates, reflecting a possible negative feedback through the CH4 sink. Sensitivity simulations with CM3 suggest that the aerosol indirect effect (aerosol-cloud interactions) plays a significant role in cooling the CM3 climate. The projected decline in aerosols under all RCPs contributes to climate warming over the 21st century, which influences the future evolution of OH concentration and τCH4_OH. Projected changes in τCH4_OH from 2006 to 2100 range from -13% to +4%. The only projected increase occurs in the most extreme warming case (RCP8.5) due to the near-doubling of the CH4 abundance, reflecting a positive feedback on the climate system. The largest decrease occurs in the RCP4.5 scenario due to changes in short-lived climate forcing agents which

  11. Investigation of aviation emission impacts on global tropospheric chemistry and climate using a size-resolved aerosol-chemistry model

    NASA Astrophysics Data System (ADS)

    Kapadia, Zarashpe; Spracklen, Dominick; Arnold, Stephen; Borman, Duncan; Mann, Graham; Pringle, Kirsty; Monks, Sarah; Reddington, Carly; Rap, Alexandru; Scott, Catherine

    2014-05-01

    Aviation is responsible for 3% of global anthropogenic CO2 emissions, but 2-14% of anthropogenic induced climate warming due to contributions from short lived climate forcers. The global civil aviation fleet is projected to double by 2026 in relation to a 2006 baseline and so will play a substantial role in future climate change. Uncertainty in the net impact of aviation on climate is largely due to uncertainty in the impacts of aviation emissions on ozone and aerosol. To study the impact of aviation emissions we use the GLOMAP-mode global aerosol microphysics model coupled to the 3-D chemical transport model TOMCAT. GLOMAP-mode has been extended to include treatment of nitrate aerosol. We include a full suite of non-CO2 aviation emissions (including NOX, SO2, HCs, BC and OC) in the model. We combined the simulated changes in ozone and aerosol with a 3D radiative transfer model to quantify the radiative effect due to aviation non-CO2 emissions. We find that aviation emissions increase O3 concentrations by up to 5.3% in the upper troposphere (UT), broadly matching previous studies. Black carbon (BC) and organic carbon (OC) concentrations increase by 26.5% and 14.6% respectively in the UT, whereas nitrate aerosol is reduced in some regions due to co-emission of NOX and SO2 In the UT, aviation emissions increase both total aerosol number as well as the concentration of particles greater than 70 nm diameter (N70). Entrainment of these particles into the free troposphere results in aviation emissions also increasing N70 in the boundary layer, causing a cooling through the first aerosol indirect effect. We explore differences in these responses compared with those simulated when using the recommended aviation emissions from CMIP5 (5th Climate Model Intercomparison Project), which only include NOX and BC emissions. Our results suggest that aviation emissions of SO2 and HCs neglected by CMIP5 produce important effects on ozone, aerosol number, and N70. We suggest CMIP5

  12. EOS Aura Mission Status

    NASA Technical Reports Server (NTRS)

    Guit, William J.

    2015-01-01

    This PowerPoint presentation will discuss EOS Aura mission and spacecraft subsystem summary, recent and planned activities, inclination adjust maneuvers, propellant usage lifetime estimate. Eric Moyer, ESMO Deputy Project Manager-Technical (code 428) has reviewed and approved the slides on April 30, 2015.

  13. Temporal Evolution and Atmospheric Impacts of Tropospheric Volcanic Emissions from In-Situ Measurements and Modelling

    NASA Astrophysics Data System (ADS)

    Roberts, Tjarda

    2010-05-01

    Assessment of the impact of tropospheric volcanic gas and aerosol emissions requires integration of observation and modelling. Knowledge and understanding is rapidly advancing in both areas, particularly due to the development of kinetic plume models of reactive halogen chemistry, and due to recent advances in measurement techniques for collecting in situ measurements of plume physico-chemical properties (i.e. using meteorological balloon and aircraft platforms), as well as a proliferation of remote sensing DOAS measurements. Here, we demonstrate this synergic relationship through model-observation plume studies. Volcanoes are a large natural source of SO2 and sulphate to the atmosphere, as is well demonstrated from both observational and model studies. In a recent study that deployed quasi-Lagrangian balloons in emissions at Kilauea volcano, Hawaii, both H2O(g) and SO2(g) were measured in situ, in the downwind plume. The observations showed periods of both correlation and anti-correlation between SO2 and water-vapour, implying the occurrence of both source and sink processes. Co-emission of volcanic H2O with SO2 accounts for the correlation. We use a thermodynamic model along the plume transect to assess how H2O-sulphate interactions might account for H2O anti-correlation with SO2 within the plume to elucidate in-plume sulphate formation, both near-vent (as predicted by high-T thermodynamic models) and downwind (as predicted by kinetic models). Volcanoes are a source of halogens (HBr, HCl) to the atmosphere, and volcanic plumes are highly reactive zones, not only in the high-temperature region near the vent, but also in the downwind plume where autocatalytic chemistry cycles produce reactive halogens such as BrO, first discovered from DOAS observations. The rapid formation of BrO can be reproduced through modelling which predicts high concentrations (reaching ppbv) on short formation timescales (minutes). Simulations using the PlumeChem model (developed to analyse

  14. Improving Air Quality Forecasts with AURA Observations

    NASA Technical Reports Server (NTRS)

    Newchurch, M. J.; Biazer, A.; Khan, M.; Koshak, W. J.; Nair, U.; Fuller, K.; Wang, L.; Parker, Y.; Williams, R.; Liu, X.

    2008-01-01

    Past studies have identified model initial and boundary conditions as sources of reducible errors in air-quality simulations. In particular, improving the initial condition improves the accuracy of short-term forecasts as it allows for the impact of local emissions to be realized by the model and improving boundary conditions improves long range transport through the model domain, especially in recirculating anticyclones. During the August 2006 period, we use AURA/OMI ozone measurements along with MODIS and CALIPSO aerosol observations to improve the initial and boundary conditions of ozone and Particulate Matter. Assessment of the model by comparison of the control run and satellite assimilation run to the IONS06 network of ozonesonde observations, which comprise the densest ozone sounding campaign ever conducted in North America, to AURA/TES ozone profile measurements, and to the EPA ground network of ozone and PM measurements will show significant improvement in the CMAQ calculations that use AURA initial and boundary conditions. Further analyses of lightning occurrences from ground and satellite observations and AURA/OMI NO2 column abundances will identify the lightning NOx signal evident in OMI measurements and suggest pathways for incorporating the lightning and NO2 data into the CMAQ simulations.

  15. The Response of Tropospheric Ozone to ENSO in Observations and a Chemistry-Climate Simulation

    NASA Technical Reports Server (NTRS)

    Oman, L. D.; Douglass, A. R.; Ziemke, J. R.; Waugh, D. W.; Rodriguez, J. M.; Nielsen, J. E.

    2012-01-01

    The El Nino-Southern Oscillation (ENSO) is the dominant mode of tropical variability on interannual time scales. ENSO appears to extend its influence into the chemical composition of the tropical troposphere. Recent results have revealed an ENSO induced wave-l anomaly in observed tropical tropospheric column ozone. This results in a dipole over the western and eastern tropical Pacific, whereby differencing the two regions produces an ozone anomaly with an extremely high correlation to the Nino 3.4 Index. We have successfully reproduced this result using the Goddard Earth Observing System Version 5 (GEOS-5) general circulation model coupled to a comprehensive stratospheric and tropospheric chemical mechanism forced with observed sea surface temperatures over the past 25 years. An examination of the modeled ozone field reveals the vertical contributions of tropospheric ozone to the column over the western and eastern Pacific region. We will show targeted comparisons with observations from NASA's Aura satellite Microwave Limb Sounder (MLS), and the Tropospheric Emissions Spectrometer (TES) to provide insight into the vertical structure of ozone changes. The tropospheric ozone response to ENSO could be a useful chemistry-climate model evaluation tool and should be considered in future modeling assessments.

  16. Modeling and Observations of the Response of Tropical Tropospheric Ozone to ENSO

    NASA Astrophysics Data System (ADS)

    Oman, L.; Ziemke, J. R.; Douglass, A. R.; Waugh, D. W.; Lang, C.; Rodriguez, J. M.; Nielsen, J. E.

    2011-12-01

    The El Nino-Southern Oscillation (ENSO) is the dominant mode of tropical variability on interannual time scales. ENSO appears to extend its influence into the chemical composition of the tropical troposphere. Recent results have revealed an ENSO induced wave-1 anomaly in observed tropical tropospheric column ozone. This results in a dipole over the western and eastern tropical Pacific, whereby differencing the two regions produces an ozone anomaly with an extremely high correlation to the Nino 3.4 Index. We have successfully reproduced this result using the Goddard Earth Observing System Version 5 (GEOS-5) general circulation model coupled to a comprehensive stratospheric and tropospheric chemical mechanism forced with observed sea surface temperatures over the past 25 years. An examination of the modeled ozone field reveals the vertical contributions of tropospheric ozone to the column over the western and eastern Pacific region. We will show targeted comparisons with SHADOZ ozonesondes over these regions to provide insight into the vertical structure, along with comparisons of observations from NASA's Aura satellite Microwave Limb Sounder (MLS), the Tropospheric Emissions Spectrometer (TES), and other appropriate data sets. We are also investigating the water vapor response to ENSO to help illuminate its role relative to dynamics in impacting ozone concentrations. These results indicate that the tropospheric ozone response to ENSO is potentially a very useful chemistry-climate diagnostic and should be considered in future modeling assessments.

  17. Ozone, Tropospheric

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    1995-01-01

    In the early part of the 20th century, ground-based and balloon-borne measurements discovered that most of atmosphere's ozone is located in the stratosphere with highest concentrations located between 15 and 30 km (9,3 and 18.6 miles). For a long time, it was believed that tropospheric ozone originated from the stratosphere and that most of it was destroyed by contact with the earth's surface. Ozone, O3, was known to be produced by the photo-dissociation of molecular oxygen, O2, a process that can only occur at wavelengths shorter than 242 nm. Because such short-wave-length radiation is present only in the stratosphere, no tropospheric ozone production is possible by this mechanism. In the 1940s, however, it became obvious that production of ozone was also taking place in the troposphere. The overall reaction mechanism was eventually identified by Arie Haagen-Smit of the California Institute of Technology, in highly polluted southern California. The copious emissions from the numerous cars driven there as a result of the mass migration to Los Angeles after World War 2 created the new unpleasant phenomenon of photochemical smog, the primary component of which is ozone. These high levels of ozone were injuring vegetable crops, causing women's nylons to run, and generating increasing respiratory and eye-irritation problems for the populace. Our knowledge of tropospheric ozone increased dramatically in the early 1950s as monitoring stations and search centers were established throughout southern California to see what could be done to combat this threat to human health and the environment.

  18. Tropospheric ozone changes, radiative forcing and attribution to emissions in the Atmospheric Chemistry and Climate Model Inter-comparison Project (ACCMIP)

    NASA Astrophysics Data System (ADS)

    Stevenson, D. S.; Young, P. J.; Naik, V.; Lamarque, J.-F.; Shindell, D. T.; Voulgarakis, A.; Skeie, R. B.; Dalsoren, S. B.; Myhre, G.; Berntsen, T. K.; Folberth, G. A.; Rumbold, S. T.; Collins, W. J.; MacKenzie, I. A.; Doherty, R. M.; Zeng, G.; van Noije, T. P. C.; Strunk, A.; Bergmann, D.; Cameron-Smith, P.; Plummer, D. A.; Strode, S. A.; Horowitz, L.; Lee, Y. H.; Szopa, S.; Sudo, K.; Nagashima, T.; Josse, B.; Cionni, I.; Righi, M.; Eyring, V.; Conley, A.; Bowman, K. W.; Wild, O.

    2012-10-01

    Ozone (O3) from 17 atmospheric chemistry models taking part in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) has been used to calculate tropospheric ozone radiative forcings (RFs). We calculate a~value for the pre-industrial (1750) to present-day (2010) tropospheric ozone RF of 0.40 W m-2. The model range of pre-industrial to present-day changes in O3 produces a spread (±1 standard deviation) in RFs of ±17%. Three different radiation schemes were used - we find differences in RFs between schemes (for the same ozone fields) of ±10%. Applying two different tropopause definitions gives differences in RFs of ±3%. Given additional (unquantified) uncertainties associated with emissions, climate-chemistry interactions and land-use change, we estimate an overall uncertainty of ±30% for the tropospheric ozone RF. Experiments carried out by a subset of six models attribute tropospheric ozone RF to increased emissions of methane (47%), nitrogen oxides (29%), carbon monoxide (15%) and non-methane volatile organic compounds (9%); earlier studies attributed more of the tropospheric ozone RF to methane and less to nitrogen oxides. Normalising RFs to changes in tropospheric column ozone, we find a global mean normalised RF of 0.042 W m-2 DU-1, a value similar to previous work. Using normalised RFs and future tropospheric column ozone projections we calculate future tropospheric ozone RFs (W m-2; relative to 1850 - add 0.04 W m-2 to make relative to 1750) for the Representative Concentration Pathways in 2030 (2100) of: RCP2.6: 0.31 (0.16); RCP4.5: 0.38 (0.26); RCP6.0: 0.33 (0.24); and RCP8.5: 0.42 (0.56). Models show some coherent responses of ozone to climate change: decreases in the tropical lower troposphere, associated with increases in water vapour; and increases in the sub-tropical to mid-latitude upper troposphere, associated with increases in lightning and stratosphere-to-troposphere transport.

  19. Troposphere communications

    NASA Astrophysics Data System (ADS)

    Iakovlev, L. I.; Dediukin, G. V.; Kagramanov, E. S.; Redin, A. P.; Stuton, P. I.; Tsybulkin, L. D.

    The physical processes and features of troposphere radiowave propagation are reviewed, and fundamental principles for the construction of troposphere lines of communication are discussed. The technical characteristics of troposphere stations in the USA, England, France, FRG, and Japan are studied and compared. Attention is given to mobile and stationary military stations, and to stationary troposphere communication systems in the Americas, Greenland, the Caribbean islands, Asia, Africa, and Australia. Developments in troposphere communications, including the AN/TRC-170 station, are discussed.

  20. A USA Commercial Flight Track Database for Upper Tropospheric Aircraft Emission Studies

    NASA Technical Reports Server (NTRS)

    Garber, Donald P.; Minnis, Patrick; Costulis, Kay P.

    2003-01-01

    A new air traffic database over the contiguous United States of America (USA) has been developed from a commercially available real-time product for 2001-2003 for all non-military flights above 25,000 ft. Both individual flight tracks and gridded spatially integrated flight legs are available. On average, approximately 24,000 high-altitude flights were recorded each day. The diurnal cycle of air traffic over the USA is characterized by a broad daytime maximum with a 0130-LT minimum and a mean day-night air traffic ratio of 2.4. Each week, the air traffic typically peaks on Thursday and drops to a low Saturday with a range of 18%. Flight density is greatest during late summer and least during winter. The database records the disruption of air traffic after the air traffic shutdown during September 2001. The dataset should be valuable for realistically simulating the atmospheric effects of aircraft in the upper troposphere.

  1. Impact of lightning-NO emissions on the relationship between ENSO and tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Allen, D. J.; Oman, L. D.; Pickering, K. E.; Ott, L. E.; Pawson, S.

    2011-12-01

    NASA's Goddard Earth Observing System Chemistry-Climate Model (GEOS-CCM) is a tool that can be used to study the impact of various natural and anthropogenic perturbations on atmospheric chemistry and climate. In this study, the relationship between El Niño-Southern Oscillation (ENSO) and tropospheric ozone is examined for two different lightning-nitrogen oxide (NO) parameterizations; a default climatological scheme and a flash rate predictive scheme derived using a multiple regression between flash observations from the Optical Transient Detector/Lightning Imaging Sensor (OTD/LIS) and cloud and other meteorological parameters from the GEOS-CCM. The LIS observational record will be examined to see if there is an ENSO signal. The sensitivity of model flash rates and the subsequent effect on ozone to the phase of ENSO will be examined over a five year period.

  2. Grid-based versus big region approach for inverting CO emissions using Measurement of Pollution in the Troposphere (MOPITT) data

    NASA Astrophysics Data System (ADS)

    Stavrakou, T.; Müller, J.-F.

    2006-08-01

    The CO columns retrieved by the Measurement of Pollution in the Troposphere (MOPITT) satellite instrument between May 2000 and April 2001 are used together with the Intermediate Model for the Annual and Global Evolution of Species (IMAGES) global chemistry transport model and its adjoint to provide top-down estimates for anthropogenic, biomass burning, and biogenic CO emissions on the global scale, as well as for the biogenic volatile organic compounds (VOC) fluxes, whose oxidation constitutes a major indirect CO source. For this purpose, the big region and grid-based Bayesian inversion methods are presented and compared. In the former setup, the monthly emissions over large geographical regions are quantified. In the grid-based setup, the fluxes are optimized at the spatial resolution of the model and on a monthly basis. Source-specific spatiotemporal correlations among errors on the prior emissions are introduced in order to better constrain the inversion problem. Both inversion techniques bring the model columns much closer to the measurements at all latitudes, but the grid-based analysis achieves a higher reduction of the overall model/data bias. Further comparisons with observed mixing ratios at NOAA Climate Monitoring and Diagnostics Laboratory and Global Atmosphere Watch sites, as well as with airborne measurements are also presented. The inferred emission estimates are weakly dependent on the prior errors and correlations. Our best estimate for the global CO source amounts to 2900 Tg CO/yr in both inversion approaches, about 5% higher than the prior. The global anthropogenic emission estimate is 18% larger than the prior, with the biggest increase for east Asia and a substantial decrease in south Asia. The vegetation fire emission estimates decrease as well, from the prior 467 Tg CO/yr to 450 Tg CO/yr in the grid-based solution and 434 Tg CO/yr in the monthly big region setup, mainly due to a significant reduction of African savanna fire emissions. The

  3. Relationship between VOC and NOx emissions and chemical production of tropospheric ozone in the Aburrá Valley (Colombia).

    PubMed

    Toro, María Victoria; Cremades, Lázaro V; Calbó, Josep

    2006-10-01

    Relationship between volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions and the chemical production of tropospheric ozone is studied through mathematical simulation. The study is applied to the Aburrá Valley, in the Colombian Andes, which is a practically unknown area from the point of view of ozone formation. The model used for this application is the European modelling of atmospheric constituents (EUMAC) zooming model (EZM) which consists of a mesoscale prognostic model (MEMO, mesoscale meteorological model) and a chemical reaction model (MUSE, multiscale for the atmospheric dispersion of reactive species), coupled to the chemical mechanism EMEP (European monitoring and evaluation program). The analysis is performed for a real episode that was characterized by high ozone production and that happened during the 23rd and 24th December, 1999 in Medellín (Colombia). From this real scenario, a sensitivity analysis has been carried out in order to assess the influence of VOC and NOx amounts on ozone production and to extract some conclusions for future ozone abatement policies in Andean regions. As far as ozone air quality is concerned, it is shown that in order to keep current levels the emphasis must be put to avoid increasing NOx emissions, or alternatively, to augment VOC emissions in order to have a high VOC/NOx ratio. PMID:16631888

  4. A New Retrieval Algorithm for OMI NO2: Tropospheric Results and Comparisons with Measurements and Models

    NASA Technical Reports Server (NTRS)

    Swartz, W. H.; Bucesla, E. J.; Lamsal, L. N.; Celarier, E. A.; Krotkov, N. A.; Bhartia, P, K,; Strahan, S. E.; Gleason, J. F.; Herman, J.; Pickering, K.

    2012-01-01

    Nitrogen oxides (NOx =NO+NO2) are important atmospheric trace constituents that impact tropospheric air pollution chemistry and air quality. We have developed a new NASA algorithm for the retrieval of stratospheric and tropospheric NO2 vertical column densities using measurements from the nadir-viewing Ozone Monitoring Instrument (OMI) on NASA's Aura satellite. The new products rely on an improved approach to stratospheric NO2 column estimation and stratosphere-troposphere separation and a new monthly NO2 climatology based on the NASA Global Modeling Initiative chemistry-transport model. The retrieval does not rely on daily model profiles, minimizing the influence of a priori information. We evaluate the retrieved tropospheric NO2 columns using surface in situ (e.g., AQS/EPA), ground-based (e.g., DOAS), and airborne measurements (e.g., DISCOVER-AQ). The new, improved OMI tropospheric NO2 product is available at high spatial resolution for the years 200S-present. We believe that this product is valuable for the evaluation of chemistry-transport models, examining the spatial and temporal patterns of NOx emissions, constraining top-down NOx inventories, and for the estimation of NOx lifetimes.

  5. EOS-Aura's Ozone Monitoring Instrument (OMI): Validation Requirements

    NASA Technical Reports Server (NTRS)

    Brinksma, E. J.; McPeters, R.; deHaan, J. F.; Levelt, P. F.; Hilsenrath, E.; Bhartia, P. K.

    2003-01-01

    OMI is an advanced hyperspectral instrument that measures backscattered radiation in the UV and visible. It will be flown as part of the EOS Aura mission and provide data on atmospheric chemistry that is highly synergistic with other Aura instruments HIRDLS, MLS, and TES. OMI is designed to measure total ozone, aerosols, cloud information, and UV irradiances, continuing the TOMS series of global mapped products but with higher spatial resolution. In addition its hyperspectral capability enables measurements of trace gases such as SO2, NO2, HCHO, BrO, and OClO. A plan for validation of the various OM1 products is now being formulated. Validation of the total column and UVB products will rely heavily on existing networks of instruments, like NDSC. NASA and its European partners are planning aircraft missions for the validation of Aura instruments. New instruments and techniques (DOAS systems for example) will need to be developed, both ground and aircraft based. Lidar systems are needed for validation of the vertical distributions of ozone, aerosols, NO2 and possibly SO2. The validation emphasis will be on the retrieval of these products under polluted conditions. This is challenging because they often depend on the tropospheric profiles of the product in question, and because of large spatial variations in the troposphere. Most existing ground stations are located in, and equipped for, pristine environments. This is also true for almost all NDSC stations. OMI validation will need ground based sites in polluted environments and specially developed instruments, complementing the existing instrumentation.

  6. Accuracy of wet troposphere radio path delay estimated from infrared emission

    NASA Technical Reports Server (NTRS)

    Parker, J. W.

    1995-01-01

    Several radio science applications require determination of the excess radio-propagation path delay caused by the Earth's atmosphere. These include very long baseline interferometry, spacecraft tracking, and potentially, detection of gravitational waves utilizing a link to a distant interplanetary spacecraft. At Ka band, the major source of variability of path delay is the fluctuations in the moisture content of the troposphere. The path delay characterization requirements for a planned gravitational wave experiment are novel and challenging. the error contribution to the phase observations due to path delay variation must be reduced by nearly two orders of magnitude over that occurring naturally on time scales of 100 to 10,000 seconds. Current approaches relying on microwave water vapor radiometry with ancillary data can deliver one order of magnitude calibration of these fluctuations, and more advanced systems are under development within the 2001-2002 time frame of the Cassini Mission to Saturn. The current work evaluates the potential for an alternative observational approach, using a ground-based Fourier transform spectrometer.

  7. THE EFFECT OF CHLORINE EMISSIONS ON TROPOSPHERIC OZONE IN THE UNITED STATES

    EPA Science Inventory

    The effect of chlorine emissions on atmospheric ozone in the continental United States was evaluated. Atmospheric chlorine chemistry was combined with the carbon bond mechanism and incorporated into the Community Multiscale Air Quality model. Sources of chlorine included anthrop...

  8. Estimates of the changes in tropospheric chemistry which result from human activity and their dependence on NO(x) emissions and model resolution

    NASA Technical Reports Server (NTRS)

    Kanakidou, Maria; Crutzen, Paul J.; Zimmermann, Peter H.

    1994-01-01

    As a consequence of the non-linear behavior of the chemistry of the atmosphere and because of the short lifetime of nitrogen oxides (NO(x)), two-dimensional models do not give an adequate description of the production and destruction rates of NO(x) and their effects on the distributions of the concentration of ozone and hydroxyl radical. In this study, we use a three-dimensional model to evaluate the contribution of increasing NO(x) emissions from industrial activity and biomass burning to changes in the chemical composition of the troposphere. By comparing results obtained from longitudinally-uniform and longitudinally-varying emissions of NO(x), we demonstrate that the geographical representation of the NO(x) emissions is crucial in simulating tropospheric chemistry.

  9. Tropospheric Emissions: Monitoring of Pollution (TEMPO) - Status and Potential Science Studies

    NASA Astrophysics Data System (ADS)

    Chance, Kelly

    2016-05-01

    TEMPO is the first NASA Earth Venture Instrument, to launch between 2019 and 2021. It measures atmospheric pollution from Mexico City and Cuba to the Canadian oil sands, and from the Atlantic to the Pacific, hourly at high spatial resolution, ~ 10 km2. It measures the key elements of air pollution chemistry. Geostationary (GEO) measurements capture the variability in the diurnal cycle of emissions and chemistry at sub-urban scale to improve emission inventories, monitor population exposure, and enable emission-control strategies. TEMPO measures the UV/visible spectra to retrieve O3, NO2, SO2, H2 CO, C2 H2 O2, H2 O, aerosols, cloud parameters, and UVB radiation. It tracks aerosol loading. It provides near-real-time air quality products. TEMPO is the North American component of the global geostationary constellation for pollution monitoring, with the European Sentinel-4 and the Korean GEMS. TEMPO studies may include: Solar-induced fluorescence from chlorophyll over land and in the ocean to study tropical dynamics, primary productivity, carbon uptake, to detect red tides, and to study phytoplankton; Measurements of stratospheric intrusions that cause air quality exceedances; Measurements at peaks in vehicle travel to capture the variability in emissions from mobile sources; Measurements of thunderstorm activity, including outflow regions to better quantify lightning NOx and O3 production; Cropland measurements follow the temporal evolution of emissions after fertilizer application and from rain-induced emissions from semi-arid soils; Measurements investigate the chemical processing of primary fire emissions and the secondary formation of VOCs and ozone; Measurements examine ocean halogen emissions and their impact on the oxidizing capacity of coastal environments; Spectra of nighttime lights are markers for human activity, energy conservation, and compliance with outdoor lighting standards intended to reduce light pollution.

  10. Kudzu (Pueraria montana) Invasion Doubles Emissions of Nitric Oxide, a Precursor to Tropospheric Ozone.

    NASA Astrophysics Data System (ADS)

    Hickman, J. E.; Wu, S.; Mickley, L. J.; Lerdau, M. T.

    2008-12-01

    Nitrogen-fixing plants can increase rates of nitrogen (N) cycling in soils, fluxes of the greenhouse gas nitrous oxide (N2O), and fluxes of the ozone precursor nitric oxide (NO). Invasion by the nitrogen-fixing legume kudzu (Pueraria montana) across millions of hectares in the southeastern United States could be contributing to increased ozone concentrations. Ozone formation in the Southeast is broadly limited by atmospheric NO concentrations, so perturbations to the N cycle by kudzu have the potential to increase ozone concentrations in the region. At three sites in Madison County, Georgia, kudzu invasion increased rates of net N mineralization by up to an order of magnitude and rates of net nitrification and soil pools of NO3- and NO2- by up to 500%. Emissions of NO from soils invaded by kudzu averaged 2.81 ng NO-N cm-2 h-1, significantly higher than emissions from soil dominated by native vegetation, which averaged 1.24 ng NO-N cm-2 h-1. Emissions of N2O display a trend towards increasing under kudzu invasion, but N2O emissions at these sites were three orders of magnitude smaller than emissions of NO. Atmospheric chemical modeling suggests that these higher NO emissions could increase ozone concentrations in the region by up to 2 ppb. We propose that kudzu invasion in the southeastern United States represents a novel threat to air quality and could increase the frequency with which federal ozone standards are exceeded.

  11. Modeling uncertainties for tropospheric nitrogen dioxide columns affecting satellite-based inverse modeling of nitrogen oxides emissions

    NASA Astrophysics Data System (ADS)

    Lin, J.-T.; Liu, Z.; Zhang, Q.; Liu, H.; Mao, J.; Zhuang, G.

    2012-12-01

    Errors in chemical transport models (CTMs) interpreting the relation between space-retrieved tropospheric column densities of nitrogen dioxide (NO2) and emissions of nitrogen oxides (NOx) have important consequences on the inverse modeling. They are however difficult to quantify due to lack of adequate in situ measurements, particularly over China and other developing countries. This study proposes an alternate approach for model evaluation over East China, by analyzing the sensitivity of modeled NO2 columns to errors in meteorological and chemical parameters/processes important to the nitrogen abundance. As a demonstration, it evaluates the nested version of GEOS-Chem driven by the GEOS-5 meteorology and the INTEX-B anthropogenic emissions and used with retrievals from the Ozone Monitoring Instrument (OMI) to constrain emissions of NOx. The CTM has been used extensively for such applications. Errors are examined for a comprehensive set of meteorological and chemical parameters using measurements and/or uncertainty analysis based on current knowledge. Results are exploited then for sensitivity simulations perturbing the respective parameters, as the basis of the following post-model linearized and localized first-order modification. It is found that the model meteorology likely contains errors of various magnitudes in cloud optical depth, air temperature, water vapor, boundary layer height and many other parameters. Model errors also exist in gaseous and heterogeneous reactions, aerosol optical properties and emissions of non-nitrogen species affecting the nitrogen chemistry. Modifications accounting for quantified errors in 10 selected parameters increase the NO2 columns in most areas with an average positive impact of 18% in July and 8% in January, the most important factor being modified uptake of the hydroperoxyl radical (HO2) on aerosols. This suggests a possible systematic model bias such that the top-down emissions will be overestimated by the same magnitude

  12. How Tropospheric is Tropospheric Ozone?

    NASA Astrophysics Data System (ADS)

    Trickl, Thomas; Scheel, Hans-Eckhart; Sprenger, Michael; Vogelmann, Hannes

    2010-05-01

    There has been a long debate on the reasons of the increase in tropospheric ozone during the past century. Mostly the photochemical ozone formation combined with the growing level of air pollution has been stressed. However, with decreasing European precursor emissions in the 1990s and the ongoing positive trend of O3 at the high-lying Alpine station Zugspitze (2962 m a.s.l.) until about 2000 this view has started to change. Data filtering of the Zugspitze data based on relative humidity (RH), 7Be and CO measurements have revealed that the only positive ozone trend could be found for descending air masses of dominating stratospheric origin whereas the trend for polluted air masses is around zero. The 7Be data, recorded since 1970, showed a positive trend since the mid-seventies. Based on daily model forecasts by ETH of stratospheric air intrusions co-ordinated lidar measurements of ozone and, more recently, water vapour (Vogelmann and Trickl, 2008) have been carried out. It could be shown that there is an excellent agreement between the intrusion forecasts, the lidar measurements and low-RH events at the Zugspitze summit (Trickl et al., 2010). The forecasts also allowed us to define intrusion types as well as to review and to revise the data-filtering criteria used for the in-situ data. This study, carried out for the period 2001-2005, yields a significantly higher number of intrusions reaching 3000 m than obtained in previous investigations, with even about 20 per cent more cases (mostly overpasses) predicted by the forecasts. Seasonal cycles of the intrusion frequency were derived and, in all but one intrusion type, peaked during the cold season. Recent measurements with the water-vapour lidar (see parallel contribution) have revealed RH values of 0-2 per cent even in very thin layers of stratospheric origin reaching the lower troposphere. This indicates that significant mixing with tropospheric air can only occur during the early phase of an intrusion, if not

  13. Occipital seizures imitating migraine aura.

    PubMed Central

    Panayiotopoulos, C P; Sharoqi, I A; Agathonikou, A

    1997-01-01

    Three cases are reported in which symptoms of occipital seizures resembled the visual aura of migraine. Careful recording of the characteristics and timing of such visual effects will often resolve the diagnostic dilemma. PMID:9204019

  14. Field Observations of Increased Isoprene Emissions Under Ozone Fumigation: Implications for Tropospheric Chemistry?

    NASA Astrophysics Data System (ADS)

    Sparks, J. P.; Greenberg, J. P.; Harley, P. C.; Guenther, A. B.

    2003-12-01

    Isoprene is the most abundant biogenic hydrocarbon released from vegetation and plays a key role in the chemistry of the lower atmosphere. Isoprene is produced and emitted by many plant species, yet the reason plants produce this seemingly wasteful carbon compound is still in debate in the plant physiology community. It has been proposed that isoprene may protect plant leaves from thermal damage or damage from oxidant exposure by stabilizing cellular and chloroplast membranes or by direct reactions between exogenous isoprene and oxidative species. As part of the Chemical Emission, Loss, Transformation and Interactions within Canopies (CELTIC) study held at Duke Forest during the summer of 2003, we used dynamic cuvette systems to fumigate leaves of sweet gum (Liquidambar styraciflua) with ozone at partial pressures ranging from 0 to 300 ppbv. During fumigations, the effluent air was monitored using infrared gas analysis, on-line proton-transfer-reaction mass spectrometry (PTR-MS) and gas chromatography to quantify changes in partial pressure of CO2, water vapor, isoprene and other volatile organics. At fumigations above 100 ppbv ozone, leaf-isoprene emission increased 20-35% compared to pre-fumigation. To our knowledge, this is the first reported observation of increased isoprene emission under ozone fumigation. Over the timescale of our measurements (several hours), isoprene emissions, once elevated, did not decrease even after fumigation levels were reduced. The increase in isoprene emission could potentially be due to upregulation of the isoprene synthase gene or simply an increase in the production (or reallocation) of subcellular isoprene precursor species. However, our measurements did not elucidate or eliminate a particular mechanism. If increases in isoprene emission in response to ozone are common among isoprene emitting species, the feedback implications for the atmosphere could be large. Both a mechanistic understanding of the upregulation process and

  15. The use of IASI in the measurement of volcanic SO2: degassing and lower tropospheric emission.

    NASA Astrophysics Data System (ADS)

    Carboni, Elisa; Grainger, Roy G.; Hayer, Catherine; Mater, Tamsin A.; Preston, James; Theys, Nicolas; Hidalgo, Silvana

    2016-04-01

    Sulphur dioxide (SO2) is an important atmospheric constituent that plays a crucial role in many atmospheric processes. Volcanic eruptions are a significant source of atmospheric SO2 and its lifetime and impact depend on the SO2 injection altitude. Measurements of volcanic SO2 emissions can offer critical insight into the current and near-future activity of volcanoes, however, the majority of active volcanoes lack regular ground-based monitoring. We exploit the spectral range of IASI, from 1000 to 1200 cm‑1 and from 1300 to 1410 cm‑1 (the 7.3 and 8.7 μm SO2 absorption bands), to study volcanic SO2. The IASI-A dataset was analysed using a rapid linear retrieval algorithm as a global survey tool to show that IASI observations detect SO2 emissions from anthropogenic sources, volcanic eruptions and certain persistently degassing volcanoes over the IASI time series. Using this linear retrieval hundreds of potential degassing volcanoes are identified around the world. An iterative optimal estimation retrieval scheme was then employed to produce a more detailed analysis of the data, with a comprehensive error budget. This algorithm is significantly more computationally intensive but allows for the estimation of both the SO2 amount and altitude of volcanic plume from recent explosive and effusive eruptions. Thermal infrared spectrometers are particularly valuable in regions where shorter wavelength observations are limited, such as during polar winter. In particular here we present two case studies: 1) The vertical distribution of SO2 during the Bardabunga eruption from September 2014 to February 2015. 2) The monthly mean trends in SO2 emission over Ecuador and Northern Kamchatka. Over Ecuador, Tungurahua showed the most persistent signal, with a strong correlation between IASI, ground-based and OMI datasets. Over Kamchatka, IASI detected clear peaks in SO2 emissions coincident with reports of elevated volcanic activity.

  16. Tropospheric impact of methane emissions from clathrates in the Arctic Region

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, S.; Cameron-Smith, P. J.; Bergmann, D.; Reagan, M. T.; Elliott, S. M.; Moridis, G. J.

    2012-12-01

    A highly potent greenhouse gas, methane, is locked in the solid phase as ice-like deposits containing a mixture of water and gas (mostly methane) called clathrates in both ocean sediments and underneath permafrost regions. Clathrates are stable under high pressures and low temperatures. In a warming climate, increases in ocean temperatures could lead to dissociation of the clathrates and release of methane into the ocean and subsequently into the atmosphere. This is of particular importance in the shallow part of the Arctic Ocean, where clathrates are expected to start outgassing abruptly at depths of around 300m. Here we present a comparison of simulations from the Community Earth System Model (CESM1) for present-day conditions with and without additional methane emissions from a plausible clathrate release scenario based on a state-of-the-art ocean sediment model. The model includes a fully interactive physical ocean and a fast atmospheric chemistry mechanism that represents methane as a fully interactive tracer (with emissions rather than concentration boundary conditions), along with the main chemical reactions for methane, ozone, and nitrous oxide. The results show that such clathrate emissions increase methane concentrations spatially non-uniformly, and that increases in surface ozone concentrations are greatest in polluted regions. We also find that the interannual variability in surface methane and ozone increases. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-570979

  17. High resolution modeling of the upper troposphere and lower stratosphere region over the Arctic - GEM-AC simulations for the future climate with and without aviation emissions.

    NASA Astrophysics Data System (ADS)

    Porebska, Magdalena; Struzewska, Joanna; Kaminski, Jacek W.

    2016-04-01

    Upper troposphere and lower stratosphere (UTLS) region is a layer around the tropopause. Perturbation of the chemical composition in the UTLS region can impact physical and dynamical processes that can lead to changes in cloudiness, precipitation, radiative forcing, stratosphere-troposphere exchange and zonal flow. The objective of this study is to investigate the potential impacts of aviation emissions on the upper troposphere and lower stratosphere. In order to assess the impact of the aviation emissions we will focus on changes in atmospheric dynamic due to changes in chemical composition in the UTLS over the Arctic. Specifically, we will assess perturbations in the distribution of the wind, temperature and pressure fields in the UTLS region. Our study will be based on simulations using a high resolution chemical weather model for four scenarios of current (2006) and future (2050) climate: with and without aircraft emissions. The tool that we use is the GEM-AC (Global Environmental Multiscale with Atmospheric Chemistry) chemical weather model where air quality, free tropospheric and stratospheric chemistry processes are on-line and interactive in an operational weather forecast model of Environment Canada. In vertical, the model domain is defined on 70 hybrid levels with model top at 0.1 mb. The gas-phase chemistry includes detailed reactions of Ox, NOx, HOx, CO, CH4, ClOx and BrO. Also, the model can address aerosol microphysics and gas-aerosol partitioning. Aircraft emissions are from the AEDT 2006 database developed by the Federal Aviation Administration (USA) and the future climate simulations are based on RCP8.5 projection presented by the IPCC in the fifth Assessment Report AR5. Results from model simulations on a global variable grid with 0.5o x 0.5o uniform resolution over the Arctic will be presented.

  18. An analysis of the impacts of global climate and emissions changes on regional tropospheric ozone

    NASA Technical Reports Server (NTRS)

    John, Kuruvilla; Crist, Kevin C.; Carmichael, Gregory R.

    1994-01-01

    Many of the synergistic impacts resulting from future changes in emissions as well as changes in ambient temperature, moisture, and UV flux have not been quantified. A three-dimensional regional-scale photo-chemical model (STEM-2) is used in this study to evaluate these perturbations to trace gas cycles over the eastern half of the United States of America. The model was successfully used to simulate a regional-scale ozone episode (base case - June 1984) and four perturbations scenarios - viz., perturbed emissions, temperature, water vapor column, and incoming UV flux cases, and a future scenario (for the year 2034). The impact of these perturbation scenarios on the distribution of ozone and other major pollutants such as SO2 and sulfates were analyzed in detail. The spatial distribution and the concentration of ozone at the surface increased by about 5-15 percent for most cases except for the perturbed water vapor case. The regional scale surface ozone concentration distribution for the year 2034 (future scenario) showed an increase of non-attainment areas. The rural areas of Pennsylvania, West Virginia, and Georgia showed the largest change in the surface ozone field for the futuristic scenario when compared to the base case.

  19. Observational Diagnoses of Extratropical Ozone STE During the Aura Era

    NASA Technical Reports Server (NTRS)

    Olsen, Mark A.; Douglass, Anne R.; Witte, Jacquie C.; Kaplan, Trevor B.

    2011-01-01

    The transport of ozone from the stratosphere to the extratropical troposphere is an important boundary condition to tropospheric chemistry. However, previous direct estimates from models and indirect estimates from observations have poorly constrained the magnitude of ozone stratosphere-troposphere exchange (STE). In this study we provide a direct diagnosis of the extratropical ozone STE using data from the Microwave Limb Sounder on Aura and output of the MERRA reanalysis over the time period from 2005 to the present. We find that the mean annual STE is about 275 Tg/yr and 205 Tg/yr in the NH and SH, respectively. The interannual variability of the magnitude is about twice as great in the NH than the SH. We find that this variability is dominated by the seasonal variability during the late winter and spring. A comparison of the ozone flux to the mass flux reveals that there is not a simple relationship between the two quantities. This presentation will also examine the magnitude and distribution of ozone in the lower stratosphere relative to the years of maximum and minimum ozone STE. Finally, we will examine any possible signature of increased ozone STE in the troposphere using sonde and tropospheric ozone residual (TOR) data, and output from the Global Modeling Initiative Chemistry Transport Model (GMI CTM).

  20. The influence of ozone precursor emissions from four world regions on tropospheric composition and radiative climate forcing

    NASA Astrophysics Data System (ADS)

    Fry, Meridith M.; Naik, Vaishali; West, J. Jason; Schwarzkopf, M. Daniel; Fiore, Arlene M.; Collins, William J.; Dentener, Frank J.; Shindell, Drew T.; Atherton, Cyndi; Bergmann, Daniel; Duncan, Bryan N.; Hess, Peter; MacKenzie, Ian A.; Marmer, Elina; Schultz, Martin G.; Szopa, Sophie; Wild, Oliver; Zeng, Guang

    2012-04-01

    Ozone (O3) precursor emissions influence regional and global climate and air quality through changes in tropospheric O3 and oxidants, which also influence methane (CH4) and sulfate aerosols (SO42-). We examine changes in the tropospheric composition of O3, CH4, SO42- and global net radiative forcing (RF) for 20% reductions in global CH4 burden and in anthropogenic O3 precursor emissions (NOx, NMVOC, and CO) from four regions (East Asia, Europe and Northern Africa, North America, and South Asia) using the Task Force on Hemispheric Transport of Air Pollution Source-Receptor global chemical transport model (CTM) simulations, assessing uncertainty (mean ± 1 standard deviation) across multiple CTMs. We evaluate steady state O3responses, including long-term feedbacks via CH4. With a radiative transfer model that includes greenhouse gases and the aerosol direct effect, we find that regional NOx reductions produce global, annually averaged positive net RFs (0.2 ± 0.6 to 1.7 ± 2 mWm-2/Tg N yr-1), with some variation among models. Negative net RFs result from reductions in global CH4 (-162.6 ± 2 mWm-2 for a change from 1760 to 1408 ppbv CH4) and regional NMVOC (-0.4 ± 0.2 to -0.7 ± 0.2 mWm-2/Tg C yr-1) and CO emissions (-0.13 ± 0.02 to -0.15 ± 0.02 mWm-2/Tg CO yr-1). Including the effect of O3 on CO2 uptake by vegetation likely makes these net RFs more negative by -1.9 to -5.2 mWm-2/Tg N yr-1, -0.2 to -0.7 mWm-2/Tg C yr-1, and -0.02 to -0.05 mWm-2/Tg CO yr-1. Net RF impacts reflect the distribution of concentration changes, where RF is affected locally by changes in SO42-, regionally to hemispherically by O3, and globally by CH4. Global annual average SO42- responses to oxidant changes range from 0.4 ± 2.6 to -1.9 ± 1.3 Gg for NOxreductions, 0.1 ± 1.2 to -0.9 ± 0.8 Gg for NMVOC reductions, and -0.09 ± 0.5 to -0.9 ± 0.8 Gg for CO reductions, suggesting additional research is needed. The 100-year global warming potentials (GWP100) are calculated for the global CH

  1. Observation of ozone enhancement in the lower troposphere over East Asia from a space-borne ultraviolet spectrometer

    NASA Astrophysics Data System (ADS)

    Hayashida, S.; Liu, X.; Ono, A.; Yang, K.; Chance, K.

    2015-09-01

    We report observations from space using ultraviolet (UV) radiance for significant enhancement of ozone in the lower troposphere over central and eastern China (CEC). The recent retrieval products of the Ozone Monitoring Instrument (OMI) onboard the Earth Observing System (EOS) Aura satellite revealed the spatial and temporal variation of ozone distributions in multiple layers in the troposphere. We compared the OMI-derived ozone over Beijing with airborne measurements by the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) program. The correlation between OMI and MOZAIC ozone in the lower troposphere was reasonable, which assured the reliability of OMI ozone retrievals in the lower troposphere under enhanced ozone conditions. The ozone enhancement was clearly observed over CEC, with Shandong Province as its center, and was most notable in June in any given year. Similar seasonal variations were observed throughout the 9-year OMI measurement period of 2005 to 2013. A considerable part of this ozone enhancement could be attributed to the emissions of ozone precursors from industrial activities and automobiles, and possibly from open crop residue burning (OCRB) after the winter wheat harvest. The ozone distribution presented in this study is also consistent with some model studies. The lower tropospheric ozone distribution is first shown from OMI retrieval in this study, and the results will be useful in clarifying any unknown factors that influence ozone distribution by comparison with model simulations.

  2. Aura Satellite Mission: Oxford/RAL Spring School in Quantitative Earth Observation

    NASA Technical Reports Server (NTRS)

    Douglass, Anne

    2005-01-01

    The four instruments on Aura are providing new and exciting measurements of stratospheric and tropospheric ozone, species that contribute to ozone production and loss, and long-lived gases such as nitrous oxide and methane that provide information about atmospheric transport. These discussions of atmospheric chemistry will start with the basic principles of ozone production and loss. Aura data will be used where possible to illustrate the pertinent atmospheric processes. Three-dimensional model simulations will be used both to illustrate present capabilities in constituent modeling and to demonstrate how observations are used to evaluate and improve models and our ability to predict future ozone evolution.

  3. Cephalic aura after frontal lobe resection.

    PubMed

    Kakisaka, Yosuke; Jehi, Lara; Alkawadri, Rafeed; Wang, Zhong I; Enatsu, Rei; Mosher, John C; Dubarry, Anne-Sophie; Alexopoulos, Andreas V; Burgess, Richard C

    2014-08-01

    A cephalic aura is a common sensory aura typically seen in frontal lobe epilepsy. The generation mechanism of cephalic aura is not fully understood. It is hypothesized that to generate a cephalic aura extensive cortical areas need to be excited. We report a patient who started to have cephalic aura after right frontal lobe resection. Magnetoencephalography (MEG) showed interictal spike and ictal change during cephalic aura, both of which were distributed in the right frontal region, and the latter involved much more widespread areas than the former on MEG sensors. The peculiar seizure onset pattern may indicate that surgical modification of the epileptic network was related to the appearance of cephalic aura. We hypothesize that generation of cephalic aura may be associated with more extensive cortical involvement of epileptic activity than that of interictal activity, in at least a subset of cases.

  4. Aura MLS Cloud Measurements: First-Year Results

    NASA Technical Reports Server (NTRS)

    Jiang, Jonathan H.; Wu, Dong L.

    2005-01-01

    Aura MLS provides the first vertical upper tropospheric cloud profiling from space, enabling global survey of the vertical structure of cloud systems, with seasonal and geographical variations, needed to evaluate the way clouds are parameterized in global models, thereby contributing to the understanding of cloud-climate feedbacks, and improved weather and climate predictions. The vertical structure of cloud systems is fundamentally important for understanding how clouds affect both their regional and large-scale atmospheric and radiative environments. The regional cloud profiles provide a critical tests of important parameterizations that enable the calculation of radiative flux profiles and heating rates throughout the atmospheric column, which in turn also regulates the water and energy cycles in the upper troposphere

  5. Fingertip aura and interpersonal attraction.

    PubMed

    Murstein, B I; Hadjolian, S E

    1977-06-01

    Concluding from our survey of the literature that fingertip auras (Kirlian effect) might be associated with interpersonal attraction, four hypotheses were advanced to test this assertion. It was hypothesized that individuals would respond with bigger auras to (1) opposite-sex photographers as compared to same-sex photographers, (2) to seductive opposite-sex photographers as opposed to normally behaving opposite-sex photographers, (3) to opposite-sex unknown peers as opposed to same-sex unknown peers, and (4) to liked as opposed to disliked same-sex persons. All hypotheses except (2) were supported. The second hypothesis was significant in a direction contrary to hypothesis. Fingertip auras are seen as a promising measurement device in the study of interpersonal attraction. PMID:16367230

  6. Compilation of a Global Emission Inventory from 1980 to 2000 for Global Model Simulations of the Long-term Trend of Tropospheric Aerosols

    NASA Technical Reports Server (NTRS)

    Diehl, Thomas L.; Chin, Mian; Bond, Tami C.; Carn, SImon A.; Duncan, Bryan N.; Krotkov, Nickolay A.; Streets, David G.

    2006-01-01

    The approach to create a comprehensive emission inventory for the time period 1980 to 2000 is described in this paper. We have recently compiled an emission database, which we will use for a 21 year simulation of tropospheric aerosols with the GOCART model. Particular attention was paid to the time-dependent SO2, black carbon and organic carbon aerosol emissions. For the emission of SO2 from sporadically erupting volcanoes, we assembled emission data from the Global Volcanism Program of the Smithsonian Institution, using the VEI to derive the volcanic cloud height and the SO2 amount, and amended this dataset by the SO2 emission data from the TOMS instrument when available. 3-dimensional aircraft emission data was obtained for a number of years from the AEAP project, converted from burned fuel to SO2 and interpolated to each year, taking the sparsity of the flight patterns into account. Other anthropogenic SO2 emissions are based on gridded emissions from the EDGAR 2000 database (excluding sources from aircraft, biomass burning and international ship traffic), which were scaled to individual years with country/regional based emission inventories. Gridded SO2 emissions from international ship traffic for 2000 and the scaling factors for other years are from [Eyring et al., 2005]. We used gridded anthropogenic black and organic carbon emissions for 1996 [Bond et al., 2005], again excluding aircraft, biomass burning and ship sources. These emissions were scaled with regional based emission inventories from 1980 to 2000 to derive gridded emissions for each year. The biomass burning emissions are based on a climatology, which is scaled with regional scaling factors derived from the TOMS aerosol index and the AVHRR/ASTR fire counts to each year [Duncan et al., 2003]. Details on the integration of the information from the various sources will be provided and the distribution patterns and total emissions in the final product will be discussed.

  7. Compilation of a Global Emission Inventory from 1980 to 2000 for Global Model Simulations of the Long-term Trend of Tropospheric Aerosols

    NASA Technical Reports Server (NTRS)

    Diehl, T. L.; Mian, Chin; Bond, T. C.; Carn, S. A.; Duncan, B. N.; Krotkov, N. A.; Streets, D. G.

    2007-01-01

    The approach to create a comprehensive emission inventory for the time period 1980 to 2000 is described in this paper. We have recently compiled an emission database, which we will use for a 21 year simulation of tropospheric aerosols with the GOCART model. Particular attention was paid to the time-dependent SO2, black carbon and organic carbon aerosol emissions. For the emission of SO2 from sporadically erupting volcanoes, we assembled emission data from the Global Volcanism Program of the Smithsonian Institution, using the VEI to derive the volcanic cloud height and the SO2 amount, and amended this dataset by the SO2 emission data from the TOMS instrument when available. 3-dimensional aircraft emission data was obtained for a number of years from the AEAP project, converted from burned fuel to SO2 and interpolated to each year, taking the sparsity of the flight patterns into account. Other anthopogenic SO2 emissions are based on gridded emissions from the EDGAR 2000 database (excluding sources from aircraft, biomass burning and international ship traffic), which were scaled to individual years with country/regional based emission inventories. Gridded SO2 emissions from international ship traffic for 2000 and the scaling factors for other years are from [Eyring et al., 2005]. We used gridded anthropogenic black and organic carbon emissions for 1996 [Bond et al., 2005], again excluding aircraft, biomass burning and ship sources. These emissions were scaled with regional based emission inventories from 1980 to 2000 to derive gridded emissions for each year. The biomass burning emissions are based on a climatology, which is scaled with regional scaling factors derived from the TOMS aerosol index and the AVHRR/ATSR fire counts to each year [Duncan et al., 2003]. Details on the integration of the information from the various sources will be provided and the distribution patterns and total emissions in the final product will be discussed.

  8. Mission Status at Aura Science Team MOWG Meeting: EOS Aura

    NASA Technical Reports Server (NTRS)

    Fisher, Dominic

    2016-01-01

    Presentation at the 24797-16 Earth Observing System (EOS) Aura Science Team Meeting (Mission Operations Work Group (MOWG)) at Rotterdam, Netherlands August 29, 2016. Presentation topics include mission summary, spacecraft subsystems summary, recent and planned activities, spacecraft anomalies, data capture, propellant usage and lifetime estimates, spacecraft maneuvers and ground track history, mission highlights and past spacecraft anomalies and reliability estimates.

  9. Global satellite retrievals of Peroxy Acetyl Nitrate (PAN) in the troposphere

    NASA Astrophysics Data System (ADS)

    Payne, V.; Alvarado, M.; Cady-Pereira, K. E.; Worden, J.; Kulawik, S. S.; Fischer, E. V.

    2013-12-01

    Peroxyacetyl Nitrate (PAN) is a thermally unstable reservoir for NOx that allows NOx to be transported over large distances, enabling ozone formation far downwind from the original source. Satellite retrievals of PAN could potentially provide substantial information on the fate of NOx emissions from a range of sources including biomass burning and anthropogenic combustion. PAN has previously been retrieved in the upper troposphere and lower stratosphere on a global scale from limb-sounding satellite instruments. PAN signatures have also been detected in nadir-viewing satellite observations of smoke plumes from fires. However, to our knowledge, PAN has not yet been retrieved in the nadir view on a global scale. Here we present global observations of tropospheric PAN from the Tropospheric Emission Spectrometer (TES), a thermal infrared spectrometer flying on the Aura satellite since 2004. PAN can be detected in TES spectra for cases where the PAN signal is above the instrument noise. The detection limit for a single TES measurement is dependent on the atmospheric and surface conditions. For observations where the cloud optical depth is less than 0.5, we find that the TES detection limit for PAN is in the region of 200 to 300 pptv. We present example distributions of elevated PAN concentrations associated with (1) trans-Pacific transport of Asian pollution, (2) boreal biomass burning and (3) the Tropical South Atlantic in austral spring.

  10. Tropospheric processes: Observations and interpretation

    NASA Technical Reports Server (NTRS)

    Isaksen, Ivar S. A.; Fuglestvedt, J. A.; Lee, Yuan-Pern; Johnson, Colin; Atkinson, Roger; Lelieveld, Joseph; Sidebottom, Howard; Thompson, Anne; Brune, William H.; Oppenheimer, Michael

    1991-01-01

    Three aspects of tropospheric chemical processes imposed by manmade emission of source gases will be discussed. First, the implications for the OH distribution and thereby for the lifetime of source gases which are controlled by reactions with OH in the troposphere (e.g., CH4 and HCFC) are investigated. This is of importance for stratosphere ozone and climate. Second, we will study the impact of source gas emission on tropospheric ozone and discuss the possibility to estimate indirect climate effects from the changes in ozone and other climate gases. Finally, the degradation of HFC and HCFC's is discussed.

  11. The Influence of Ozone Precursor Emissions from Four World Regions on Tropospheric Composition and Radiative Climate Forcing

    NASA Technical Reports Server (NTRS)

    Fry, Meridith; Naik, Vaishali; West, J. Jason; Schwarzkopf, M. Daniel; Fiore, Arlene M.; Collins, William J.; Dentener, Frank J.; Shindell, Drew T.; Atherton, Cyndi; Bergmann, Daniel; Duncan, Bryan N.; Hess, Peter; MacKenzie, Ian A.; Marmer, Elina; Schultz, Martin G.; Szopa, Sophie; Wild, Oliver; Zeng, Guang

    2012-01-01

    Ozone (O3) precursor emissions influence regional and global climate and air quality through changes in tropospheric O3 and oxidants, which also influence methane (CH4) and sulfate aerosols (SO4 (sup 2-)). We examine changes in the tropospheric composition of O3, CH4, SO4 (sup 2-) and global net radiative forcing (RF) for 20% reductions in global CH4 burden and in anthropogenic O3 precursor emissions (NOx, NMVOC, and CO) from four regions (East Asia, Europe and Northern Africa, North America, and South Asia) using the Task Force on Hemispheric Transport of Air Pollution Source-Receptor global chemical transport model (CTM) simulations, assessing uncertainty (mean plus or minus 1 standard deviation) across multiple CTMs. We evaluate steady state O3 responses, including long-term feedbacks via CH4. With a radiative transfer model that includes greenhouse gases and the aerosol direct effect, we find that regional NOx reductions produce global, annually averaged positive net RFs (0.2 plus or minus 0.6 to 1.7 2 mWm(sup -2)/Tg N yr(sup -1), with some variation among models. Negative net RFs result from reductions in global CH4 (-162.6 plus or minus 2 mWm(sup -2) for a change from 1760 to 1408 ppbv CH4) and regional NMVOC (-0.4 plus or minus 0.2 to 0.7 plus or minus 0.2 mWm(sup -2)/Tg C yr(sup -1) and CO emissions (-0.13 plus or minus 0.02 to -0.15 plus or minus 0.02 mWm(sup-2)/Tg CO yr(sup-1). Including the effect of O3 on CO2 uptake by vegetation likely makes these net RFs more negative by -1.9 to- 5.2 mWm(sup -2)/Tg N yr(sup -1), -0.2 to -0.7 mWm(sup -2)/Tg C yr(sup -1), and -0.02 to -0.05 mWm(sup -2)/ Tg CO yr(sup -1). Net RF impacts reflect the distribution of concentration changes, where RF is affected locally by changes in SO4 (sup -2), regionally to hemispherically by O3, and globally by CH4. Global annual average SO4 2 responses to oxidant changes range from 0.4 plus or minus 2.6 to -1.9 plus or minus 1.3 Gg for NOx reductions, 0.1 plus or minus 1.2 to -0.9 plus

  12. Highlights from a Decade of OMI-TOMS Total Ozone Observations on EOS Aura

    NASA Technical Reports Server (NTRS)

    Haffner, David P.; Bhartia, Pawan K.; McPeters, Richard D.; Joiner, Joanna; Ziemke, Jerald R.; Vassilkov, Alexander; Labow, Gordon J.; Chiou, Er-Woon

    2014-01-01

    Total ozone measurements from OMI have been instrumental in meeting Aura science objectives. In the last decade, OMI has extended the length of the TOMS total ozone record to over 35 years to monitor stratospheric ozone recovery. OMI-TOMS total ozone measurements have also been combined synergistically with measurements from other Aura instruments and MLS in particular, which provides vertically resolved information that complements the total O3 mapping capability of OMI. With this combined approach, the EOS Aura platform has produced more accurate and detailed measurements of tropospheric ozone. This has led in turn to greater understanding of the sources and transport of tropospheric ozone as well as its radiative forcing effect. The combined use of OMI and MLS data was also vital to the analysis of the severe Arctic ozone depletion event of 2011. The quality of OMI-TOMS total O3 data used in these studies is the result of several factors: a mature and well-validated algorithm, the striking stability of the OMI instrument, and OMI's hyperspectral capabilities used to derive cloud pressures. The latter has changed how we think about the effects of clouds on total ozone retrievals. We will discuss the evolution of the operational V8.5 algorithm and provide an overview and motivation for V9. After reviewing results and developments of the past decade, we finally highlight how ozone observations from EOS Aura are playing an important role in new ozone mapping missions.

  13. Trends in emissions and concentrations of air pollutants in the lower troposphere in the Baltimore/Washington airshed from 1997 to 2011

    NASA Astrophysics Data System (ADS)

    He, H.; Stehr, J. W.; Hains, J. C.; Krask, D. J.; Doddridge, B. G.; Vinnikov, K. Y.; Canty, T. P.; Hosley, K. M.; Salawitch, R. J.; Worden, H. M.; Dickerson, R. R.

    2013-08-01

    Trends in the composition of the lower atmosphere (0-1500 m altitude) and surface air quality over the Baltimore/Washington area and surrounding states were investigated for the period from 1997 to 2011. We examined emissions of ozone precursors from monitors and inventories as well as ambient ground-level and aircraft measurements to characterize trends in air pollution. The US EPA Continuous Emissions Monitoring System (CEMS) program reported substantial decreases in emission of summertime nitrogen oxides (NOx) from power plants, up to ∼80% in the mid-Atlantic States. These large reductions in emission of NOx are reflected in a sharp decrease of ground-level concentrations of NOx starting around 2003. The decreasing trend of tropospheric column CO observed by aircraft is ∼0.8 Dobson unit (DU) per year, corresponding to ∼35 ppbv yr-1 in the lower troposphere (the surface to 1500 m above ground level). Satellite observations of long-term, near-surface CO show a ∼40% decrease over western Maryland between 2000 and 2011; the same magnitude is indicated by aircraft measurements above these regions upwind of the Baltimore/Washington airshed. With decreasing emissions of ozone precursors, the ground-level ozone in the Baltimore/Washington area shows a 0.6 ppbv yr-1 decrease in the past 15 yr. Since photochemical production of ozone is substantially influenced by ambient temperature, we introduce the climate penalty factor (CPF) into the trend analysis of long-term aircraft measurements. After compensating for inter-annual variations in temperature, historical aircraft measurements indicate that the daily net production of tropospheric ozone over the Baltimore/Washington area decreased from ∼20 ppbv day-1 in the late 1990s to ∼7 ppbv day-1 in the early 2010s during ozone season. A decrease in the long-term column ozone is observed as ∼0.2 DU yr-1 in the lowest 1500 m, corresponding to an improvement of ∼1.3 ppbv yr-1. Our aircraft

  14. The Earth Observing System Microwave Limb Sounder (EOS MLS) on the Aura Satellite

    NASA Technical Reports Server (NTRS)

    Waters, Joe W.; Froidevaux, Lucien; Harwood, Robert S.; Jarnot, Robert F.; Pickett, Herbert M.; Read, William G.; Siegel, Peter H.; Cofield, Richard E.; Filipiak, Mark J.; Flower, Dennis A.; Holden, James R.; Lau, Gary K.; Livesey, Nathaniel J.; Manney, Gloria L; Pumphrey, Hugh C.; Santee, Michelle L.; Wu, Dong L.; Cuddy, David T.; Lay, Richard R.; Loo, Mario S.; Perun, Vincent S.; Schwartz, Michael J.; Stek, Paul C.; Thurstans, Robert P.; Boyles, Mark A.

    2006-01-01

    The Earth Observing System Microwave Limb Sounder measures several atmospheric chemical species (OH, HO2, H2O, O3, HCl, ClO, HOCl, BrO, HNO3, N2O, CO, HCN, CH3CN, volcanic SO2), cloud ice, temperature, and geopotential height to improve our understanding of stratospheric ozone chemistry, the interaction of composition and climate, and pollution in the upper troposphere. All measurements are made simultaneously and continuously, during both day and night. The instrument uses heterodyne radiometers that observe thermal emission from the atmospheric limb in broad spectral regions centered near 118, 190, 240, and 640 GHz, and 2.5 THz. It was launched July 15, 2004 on the National Aeronautics and Space Administration's Aura satellite and started full-up science operations on August 13, 2004. An atmospheric limb scan and radiometric calibration for all bands are performed routinely every 25 s. Vertical profiles are retrieved every 165 km along the suborbital track, covering 82 S to 82 N latitudes on each orbit. Instrument performance to date has been excellent; data have been made publicly available; and initial science results have been obtained.

  15. Improvements and Validation of Sulfur Dioxide Retrievals from Aura/OMI Observations of Anthropogenic Pollution

    NASA Astrophysics Data System (ADS)

    Yang, K.; Krotkov, N. A.; He, H.; Dickerson, R. R.; Li, C.

    2011-12-01

    Both natural and anthropogenic sources can release the trace gas, sulfur dioxide (SO2), into the atmosphere, in which it is usually oxidized to form sulfate aerosols, affecting the environment and climate. The largest contributions to the total annual sulfur budget are anthropogenic emissions from combustions of fossil fuels and smelting of metal ores. While these sources emit SO2 into the atmospheric planetary boundary layer (PBL), leading to air quality degradation near the source regions, the pollutants are sometimes lifted into the free troposphere and subsequently transported over long distances, affecting remote regions. It is therefore important to monitor the spatial and temporal distribution of SO2 over the globe. This can be accomplished with satellite UV remote sensing, as exemplified by the SO2 data derived from the global daily observations made by the Dutch-Finnish Ozone Monitoring Instrument (OMI) on board NASA's Aura spacecraft launched in July 2004. In this presentation, we describe the recent progress in developing an advanced algorithm to improve detection and quantification of anthropogenic SO2, and compare the new retrievals with the operational OMI SO2 products to show significant reduction in noise and bias. We also present validation results obtained by the comparisons with co-located in-situ aircraft measurements in China in 2005 - 2008 and during DISCOVER-AQ field experiment in Maryland in July 2011, to illustrate improved accuracy achieved with the advanced algorithm.

  16. The 'Weekend Effect' in Tropospheric NO2 Seen from the Ozone Monitoring Instrument

    NASA Technical Reports Server (NTRS)

    Bucsela, E.; Wenig, M.; Celarier, E.; Gleason, J.

    2007-01-01

    The Ozone Monitoring Instrument has gathered daily global data on NO2 and other atmospheric trace gases since its launch on the EOS Aura satellite in 2004. The large accumulated data set makes it possible to monitor changes of both meteorological and anthropogenic origin in tropospheric NOz amounts. In particular, averages on time scales on the order of a year show a distinct 'weekend effect' in NO2 variation, with smaller NO2 amounts seen on Saturday and/or Sunday than on the remaining weekdays. Using the OMI NO2 Standard Product (SP), we examine this effect in relation to geopolitical boundaries and investigate implications for identifying sources. We also use the SP data to find evidence for other short-term anthropogenic changes in NO2 emissions over heavily polluted regions including the United States, Europe and China.

  17. Implementation of Cloud Retrievals for Tropospheric Emission Spectrometer (TES) Atmospheric Retrievals: Part 1. Description and Characterization of Errors on Trace Gas Retrievals

    NASA Technical Reports Server (NTRS)

    Kulawik, Susan S.; Worden, John; Eldering, Annmarie; Bowman, Kevin; Gunson, Michael; Osterman, Gregory B.; Zhang, Lin; Clough, Shepard A.; Shephard, Mark W.; Beer, Reinhard

    2006-01-01

    We develop an approach to estimate and characterize trace gas retrievals in the presence of clouds in high spectral measurements of upwelling radiance in the infrared spectral region (650-2260/cm). The radiance contribution of clouds is parameterized in terms of a set of frequency-dependent nonscattering optical depths and a cloud height. These cloud parameters are retrieved jointly with surface temperature, emissivity, atmospheric temperature, and trace gases such as ozone from spectral data. We demonstrate the application of this approach using data from the Tropospheric Emission Spectrometer (TES) and test data simulated with a scattering radiative transfer model. We show the value of this approach in that it results in accurate estimates of errors for trace gas retrievals, and the retrieved values improve over the initial guess for a wide range of cloud conditions. Comparisons are made between TES retrievals of ozone, temperature, and water to model fields from the Global Modeling and Assimilation Office (GMAO), temperature retrievals from the Atmospheric Infrared Sounder (AIRS), tropospheric ozone columns from the Goddard Earth Observing System (GEOS) GEOS-Chem, and ozone retrievals from the Total Ozone Mapping Spectrometer (TOMS). In each of these cases, this cloud retrieval approach does not introduce observable biases into TES retrievals.

  18. Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Buseck, P. R.; Schwartz, S. E.

    2003-12-01

    It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 μm, PM2.5=0.3 μg m-3; particulate matter of aerodynamic diameter less than 10

  19. Clinical image: MRI during migraine with aura

    SciTech Connect

    McNeal, A.C.

    1996-03-01

    Migraine refers to severe headaches that are usually unilateral, throbbing, and associated with nausea, vomiting, photophobia, and phonophobia. Migraine with aura (formerly called {open_quotes}classic migraine{close_quotes}) consists of the headache preceded or accompanied by neurological dysfunction. This dysfunction (aura) usually involves visual and sensory symptoms. The patient described herein experienced migraine with aura. MRI during and after the attack showed a reversible abnormality of the right posterior cerebral artery, with no parenchymal lesions. This appears to be the first report of abnormal MR vascular imaging during migraine with aura. 10 refs., 2 figs.

  20. Source attribution of tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Butler, T. M.

    2015-12-01

    Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this study we describe the implementation into a global chemistry-climate model of a scheme for tagging emissions of NOx and VOC with an arbitrary number of labels, which are followed through the chemical reactions of tropospheric ozone production in order to perform attribution of tropospehric ozone to its emitted precursors. Attribution is performed to both

  1. A new source of Southern Ocean and Antarctic aerosol from tropospheric polar cell chemistry of sea ice emissions

    NASA Astrophysics Data System (ADS)

    Humphries, R. S.; Klekociuk, A. R.; Schofield, R.; Robinson, A. D.; Harris, N. R. P.; Keywood, M.; Ward, J.; Galbally, I.; Molloy, S.; Thomas, A.; Wilson, S. R.

    2014-12-01

    The Antarctic region is a pristine environment with minimal anthropogenic influence. Aerosol measurements in this environment allow the study of natural aerosols and polar atmospheric dynamics. Measurements in this region have been limited primarily to continental and coastal locations where permanent stations exist, with a handful of measurements in the sea ice region. The MAPS campaign (Measurements of Aerosols and Precursors during SIPEXII) occurred as part of SIPEX II (Sea Ice Physics and Ecosystems eXperiment II) voyage in Spring, 2012, and produced the first Antarctic pack-ice focused aerosol dataset aimed at characterizing new particle formation processes off the coast of East Antarctica (~65°S, 120°E). Numerous atmospheric parameters and species were measured, including the number of aerosol particles in the 3-10 nm size range, the range associated with nucleating particle formation. A latitudinal transect through the sea ice identified the Polar Front from sudden changes in nucleating particle concentrations, averaging 51cm-3 north of the front in the Ferrel cell, and 766 cm-3 south of the front, in the Polar cell region. The Polar Front location was also confirmed by meteorological and back-trajectory data. Background aerosol populations in the Polar cell fluctuated significantly but displayed no growth indicators, suggesting transport. Back-trajectories revealed that air parcels often descended from the free-troposphere within the previous 24-48 hrs. It is proposed that particle formation occurs in the free troposphere from precursors uplifted at the polar front region which, being a sea-ice/ocean region, is a significant precursor source. After tropospheric formation, populations descending at the poles are transported northward and reach the sea ice surface, missing continental stations. Current measurements of Antarctic aerosol suggest very low loading which may be explained by these circulation patterns and may underestimate total regional loading

  2. Time-dependent inversion estimates of global biomass-burning CO emissions using Measurement of Pollution in the Troposphere (MOPITT) measurements

    NASA Astrophysics Data System (ADS)

    Arellano, Avelino F.; Kasibhatla, Prasad S.; Giglio, Louis; van der Werf, Guido R.; Randerson, James T.; Collatz, G. James

    2006-05-01

    We present an inverse-modeling analysis of CO emissions using column CO retrievals from the Measurement of Pollution in the Troposphere (MOPITT) instrument and a global chemical transport model (GEOS-CHEM). We first focus on the information content of MOPITT CO column retrievals in terms of constraining CO emissions associated with biomass burning and fossil fuel/biofuel use. Our analysis shows that seasonal variation of biomass-burning CO emissions in Africa, South America, and Southeast Asia can be characterized using monthly mean MOPITT CO columns. For the fossil fuel/biofuel source category the derived monthly mean emission estimates are noisy even when the error statistics are accurately known, precluding a characterization of seasonal variations of regional CO emissions for this source category. The derived estimate of CO emissions from biomass burning in southern Africa during the June-July 2000 period is significantly higher than the prior estimate (prior, 34 Tg; posterior, 13 Tg). We also estimate that emissions are higher relative to the prior estimate in northern Africa during December 2000 to January 2001 and lower relative to the prior estimate in Central America and Oceania/Indonesia during April-May and September-October 2000, respectively. While these adjustments provide better agreement of the model with MOPITT CO column fields and with independent measurements of surface CO from National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostics Laboratory at background sites in the Northern Hemisphere, some systematic differences between modeled and measured CO fields persist, including model overestimation of background surface CO in the Southern Hemisphere. Characterizing and accounting for underlying biases in the measurement model system are needed to improve the robustness of the top-down estimates.

  3. A Decade of Volcanic Observations from Aura and the A-Train

    NASA Technical Reports Server (NTRS)

    Carn, Simon A.; Krotkov, Nickolay Anatoly; Yang, Kai; Krueger, Arlin J.; Hughes, Eric J.; Wang, Jun; Flower, Verity; Telling, Jennifer

    2014-01-01

    Aura observations have made many seminal contributions to volcanology. Prior to the Aura launch, satellite observations of volcanic degassing (e.g., from TOMS) were mostly restricted to large eruptions. However, the vast majority of volcanic gases are released during quiescent 'passive' degassing between eruptions. The improved sensitivity of Aura OMI permitted the first daily, space-borne measurements of passive volcanic SO2 degassing, providing improved constraints on the source locations and magnitude of global SO2 emissions for input to atmospheric chemistry and climate models. As a result of this unique sensitivity to volcanic activity, OMI data were also the first satellite SO2 measurements to be routinely used for volcano monitoring at several volcano observatories worldwide. Furthermore, the Aura OMI SO2 data also offer unprecedented sensitivity to volcanic clouds in the UTLS, elucidating the transport, fate and lifetime of volcanic SO2 and providing critical input to aviation hazard mitigation efforts. Another major advance has been the improved vertical resolution of volcanic clouds made possible by synergy between Aura and other A-Train instruments (e.g., AIRS, CALIPSO, CloudSat), advanced UV SO2 altitude retrievals, and inverse trajectory modeling of detailed SO2 cloud maps. This altitude information is crucial for climate models and aviation hazards. We will review some of the highlights of a decade of Aura observations of volcanic activity and look ahead to the future of volcanic observations from space.

  4. Next-Generation Aura/OMI NO2 and SO2 Products

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay; Yang, Kai; Bucsela, Eric; Lamsal, Lok; Celarier, Edward; Swartz, William; Carn, Simon; Bhartia, Pawan; Gleason, James; Pickering, Ken; Dickerson, Russ

    2011-01-01

    The measurement of both SO2 and NO2 gases are recognized as an essential component of atmospheric composition missions. We describe current capabilities and limitations of the operational Aura/OMI NO2 and SO2 data that have been used by a large number of researchers. Analyses of the data and validation studies have brought to light a number of areas in which these products can be expanded and improved. Major improvements for new NASA standard (SP) NO2 product include more accurate tropospheric and stratospheric column amounts, along with much improved error estimates and diagnostics. Our approach uses a monthly NO2 climatology based on the NASA Global Modeling Initiative (GMI) chemistry-transport model and takes advantage of OMI data from cloudy scenes to find clean areas where the contribution from the trap NO2 column is relatively small. We then use a new filtering, interpolation and smoothing techniques for separating the stratospheric and tropospheric components of NO2, minimizing the influence of a priori information. The new algorithm greatly improves the structure of stratospheric features relative to the original SP. For the next-generation OMI SO2 product we plan to implement operationally the offline iterative spectral fitting (ISF) algorithm and re-process the OMI Level-2 SO2 dataset using a priori SO2 and aerosol profiles, clouds, and surface reflectivity appropriate for observation conditions. This will improve the ability to detect and quantify weak tropospheric SO2 loadings. The new algorithm is validated using aircraft in-situ data during field campaigns in China (2005 and 2008) and in Maryland (Frostburg, 2010 and DISCOVER-AQ in July 2011). The height of the SO2 plumes will also be estimated for high SO2 loading cases (e.g., volcanic eruptions). The same SO2 algorithm will be applied to the data from OMPS sensor to be launched on NPP satellite later this year. The next-generation NO2 and SO2 products will provide critical information (e

  5. The impact of air pollutant and methane emission controls on tropospheric ozone and radiative forcing: CTM calculations for the period 1990-2030

    NASA Astrophysics Data System (ADS)

    Dentener, F.; Stevenson, D.; Cofala, J.; Mechler, R.; Amann, M.; Bergamaschi, P.; Raes, F.; Derwent, R.

    2005-07-01

    To explore the relationship between tropospheric ozone and radiative forcing with changing emissions, we compiled two sets of global scenarios for the emissions of the ozone precursors methane (CH4), carbon monoxide (CO), non-methane volatile organic compounds (NMVOC) and nitrogen oxides (NOx) up to the year 2030 and implemented them in two global Chemistry Transport Models. The "Current Legislation" (CLE) scenario reflects the current perspectives of individual countries on future economic development and takes the anticipated effects of presently decided emission control legislation in the individual countries into account. In addition, we developed a "Maximum technically Feasible Reduction" (MFR) scenario that outlines the scope for emission reductions offered by full implementation of the presently available emission control technologies, while maintaining the projected levels of anthropogenic activities. Whereas the resulting projections of methane emissions lie within the range suggested by other greenhouse gas projections, the recent pollution control legislation of many Asian countries, requiring introduction of catalytic converters for vehicles, leads to significantly lower growth in emissions of the air pollutants NOx, NMVOC and CO than was suggested by the widely used and more pessimistic IPCC (Intergovernmental Panel on Climate Change) SRES (Special Report on Emission Scenarios) scenarios (Nakicenovic et al., 2000), which made Business-as-Usual assumptions regarding emission control technology. With the TM3 and STOCHEM models we performed several long-term integrations (1990-2030) to assess global, hemispheric and regional changes in CH4, CO, hydroxyl radicals, ozone and the radiative climate forcings resulting from these two emission scenarios. Both models reproduce broadly the observed trends in CO, and CH4 concentrations from 1990 to 2002.

    For the "current legislation" case, both models indicate an increase of the

  6. Exhaust emissions of volatile organic compounds of powered two-wheelers: effect of cold start and vehicle speed. Contribution to greenhouse effect and tropospheric ozone formation.

    PubMed

    Costagliola, M Antonietta; Murena, Fabio; Prati, M Vittoria

    2014-01-15

    Powered two-wheeler (PTW) vehicles complying with recent European type approval standards (stages Euro 2 and Euro 3) were tested on chassis dynamometer in order to measure exhaust emissions of about 25 volatile organic compounds (VOCs) in the range C1-C7, including carcinogenic compounds as benzene and 1,3-butadiene. The fleet consists of a moped (engine capacity ≤ 50 cm(3)) and three fuel injection motorcycles of different engine capacities (150, 300 and 400 cm(3)). Different driving conditions were tested (US FPT cycle, constant speed). Due to the poor control of the combustion and catalyst efficiency, moped is the highest pollutant emitter. In fact, fuel injection strategy and three way catalyst with lambda sensor are able to reduce VOC motorcycles' emission of about one order of magnitude with respect to moped. Cold start effect, that is crucial for the assessment of actual emission of PTWs in urban areas, was significant: 30-51% of extra emission for methane. In the investigated speed range, moped showed a significant maximum of VOC emission factor at minimum speed (10 km/h) and a slightly decreasing trend from 20 to 60 km/h; motorcycles showed on the average a less significant peak at 10 km/h, a minimum at 30-40 km/h and then an increasing trend with a maximum emission factor at 90 km/h. Carcinogenic VOCs show the same pattern of total VOCs. Ozone Formation Potential (OFP) was estimated by using Maximum Incremental Reactivity scale. The greatest contribution to tropospheric ozone formation comes from alkenes group which account for 50-80% to the total OFP. VOC contribution effect on greenhouse effect is negligible with respect to CO2 emitted.

  7. Exhaust emissions of volatile organic compounds of powered two-wheelers: effect of cold start and vehicle speed. Contribution to greenhouse effect and tropospheric ozone formation.

    PubMed

    Costagliola, M Antonietta; Murena, Fabio; Prati, M Vittoria

    2014-01-15

    Powered two-wheeler (PTW) vehicles complying with recent European type approval standards (stages Euro 2 and Euro 3) were tested on chassis dynamometer in order to measure exhaust emissions of about 25 volatile organic compounds (VOCs) in the range C1-C7, including carcinogenic compounds as benzene and 1,3-butadiene. The fleet consists of a moped (engine capacity ≤ 50 cm(3)) and three fuel injection motorcycles of different engine capacities (150, 300 and 400 cm(3)). Different driving conditions were tested (US FPT cycle, constant speed). Due to the poor control of the combustion and catalyst efficiency, moped is the highest pollutant emitter. In fact, fuel injection strategy and three way catalyst with lambda sensor are able to reduce VOC motorcycles' emission of about one order of magnitude with respect to moped. Cold start effect, that is crucial for the assessment of actual emission of PTWs in urban areas, was significant: 30-51% of extra emission for methane. In the investigated speed range, moped showed a significant maximum of VOC emission factor at minimum speed (10 km/h) and a slightly decreasing trend from 20 to 60 km/h; motorcycles showed on the average a less significant peak at 10 km/h, a minimum at 30-40 km/h and then an increasing trend with a maximum emission factor at 90 km/h. Carcinogenic VOCs show the same pattern of total VOCs. Ozone Formation Potential (OFP) was estimated by using Maximum Incremental Reactivity scale. The greatest contribution to tropospheric ozone formation comes from alkenes group which account for 50-80% to the total OFP. VOC contribution effect on greenhouse effect is negligible with respect to CO2 emitted. PMID:24095967

  8. Changes in SO2 and NO2 Pollution over the Past Decade Observed by Aura OMI

    NASA Astrophysics Data System (ADS)

    Krotkov, N. A.; Li, C.; Lamsal, L. N.; Celarier, E. A.; Marchenko, S. V.; Swartz, W.; Bucsela, E. J.; Fioletov, V.; McLinden, C. A.; Joiner, J.; Bhartia, P. K.; Duncan, B. N.; Dickerson, R. R.

    2014-12-01

    The Ozone Monitoring Instrument (OMI), a NASA partnership with the Netherlands and Finland, flies on the EOS Aura satellite and uses reflected sunlight to measure two critical atmospheric trace gases, nitrogen dioxide (NO2) and sulfur dioxide (SO2), characterizing daily air quality. Both gases and the secondary pollutants they produce (particulate matter, PM2.5, and tropospheric ozone) are among USEPA designated criteria pollutants, posing serious threats to human health and the environment (e.g., acid rain, plant damage, and reduced visibility). A new generation of the OMI standard SO2 and NO2 products (based on critically improved DOAS spectral fitting for NO2 and innovative Principal Component Analysis method for SO2) provides a valuable dataset for studying anthropogenic pollution on local to global scales. Here we highlight some of the OMI observed long-term changes in air quality over several regions. Over the US, average NO2 and SO2 pollution levels have decreased dramatically as a result of both technological improvements (e.g., catalytic converters on cars) and stricter regulations of emissions. We see continued decline in NO2 and SO2 pollution over Europe. Over China OMI observed a ~ 60% increase in NO2 pollution between 2005 and 2013, despite a temporary reversal of the growing trend due to both 2008 Olympic Games and the economic recession in 2009. Chinese SO2 pollution seems to have stabilized since peaking in 2007, probably due to government efforts to curb SO2 emissions from the power sector. We have also observed large increases in both SO2 and NO2 pollution particularly in Eastern India where a number of new large coal power plants have been built in recent years. We expect that further improvements in the OMI NO2 and SO2 products will allow more robust quantification of long-term trends in local to global air quality.

  9. Features of migraine aura in teenagers

    PubMed Central

    2014-01-01

    Background Complex migraine aura in teenagers can be complicated to diagnose. The aim of this study was to present detailed features of migraine aura in teenage migraineurs. Methods This cross-sectional study was conducted in the period from 2008 till 2013. A total number of 40 teenage migraineurs (20 females and 20 males) met criteria for this study. The patients were interviewed using a specially designed questionnaire for collecting data about migraine aura features. Main outcome measures were frequency of visual, somatosensory and higher cortical dysfunction (HCD) symptoms in teenage migraineurs population during the aura, and also within each individual. Results Visual aura was reported in every attack, followed by somatosensory (60%) and dysphasic (36.4%) aura. Scintillating scotoma and blurry vision were mostly reported and predominant visual symptoms. The most common somatosensory symptom was numbness in hand. HCD were reported by 22 (55%) patients. Slowed speech was mostly reported symptom of HCD, followed by dyslexia, déjà vu phenomenon, color dysgnosia, and dyspraxia. In patients with HCD, aura frequency per year (6.18 ± 3.17 vs. 3.33 ± 2.03, p = 0.003) and prevalence of somatosensory symptoms (77.3% vs. 38.9%, p = 0.014) were significantly higher than in patients without HCD. Conclusions Aura symptoms vary to a great extent in complexity in teenage migraineurs. Consequently, results obtained in this study provide useful information for clinicians when faced with unusual migraine aura. PMID:25496701

  10. Trace gas constraints on vertical transport in models: a case study of Indonesian biomass burning emissions in 2006

    NASA Astrophysics Data System (ADS)

    Field, R. D.; Luo, M.; Worden, J.; Kim, D.; Del Genio, A. D.; Voulgarakis, A.

    2014-12-01

    We investigate the use of joint Aura TES and MLS CO retrievals in constraining vertical transport in the NASA GISS ModelE2 composition-climate model. We examine September to November 2006 over the tropics. El Nino-induced dry conditions over western Indonesia led to extensive biomass burning and persistent CO greater than 200 ppb in the upper troposphere. This was one of the highest CO episodes over the MLS period since 2004. We show how improvements in the vertical resolution of trace gas retrievals can help to distinguish between errors in parameterized vertical transport and biases in bottom-up emissions estimates. We simulate the episode using the NASA GISS ModelE2 coupled composition-climate model with different subgrid physics for small ensembles of experiments with perturbed initial conditions. The starting point is the CMIP5 version of the model, in which there was a pronounced vertical CO dipole over the Maritime Continent, but with a CO peak 100 ppb higher than Aura CO in the upper troposphere. With modified cumulus and boundary layer parameterizations, but the same prescribed biomass burning emissions estimates, the upper tropospheric CO bias is significantly reduced. Concurrently, precipitation over the emissions source region is reduced relative to observational estimates, leading to better consistency with the dry conditions under which the burning occurred. We discuss the effects of the physics changes on the roles of convective frequency and depth in reducing the bias.

  11. First Satellite Observations of Lower Tropospheric Ammonia and Methanol

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard; Shephard, Mark W.; Kulawik, Susan S.; Clough, Shepard A.; Eldering, Annmarie; Bowman, Kevin W.; Sander, Stanley P.; Fisher, Brendan M.; Payne, Vivienne H.; Luo, Mingzhao; Osterman, Gregory B.; Worden, John R.

    2008-01-01

    The Tropospheric Emission Spectrometer (TES) on the EOS Aura satellite makes global measurements of infrared radiances which are used to derive profiles of species such as O3, CO, H2O, HDO and CH4 as routine standard products. In addition, TES has a variety of special modes that provide denser spatial mapping over a limited geographical area. A continuous-coverage mode (called ''transect'', about 460 km long) has now been used to detect additional molecules indicative of regional air pollution. On 10 July 2007 at about 05:37 UTC (13:24 LMST) TES conducted such a transect observation over the Beijing area in northeast China. Examination of the residual spectral radiances following the retrieval of the TES standard products revealed surprisingly strong features attributable to enhanced concentrations of ammonia (NH3) and methanol (CH3OH), well above the normal background levels. This is the first time that these molecules have been detected in space-based nadir viewing measurements that penetrate into the lower atmosphere.

  12. Estimation of NOx emissions from vegetation fires based on the empirical relationship between satellite-derived tropospheric NO2 and fire radiative power

    NASA Astrophysics Data System (ADS)

    Schreier, S. F.; Richter, A.; Kaiser, J. W.; Burrows, J. P.

    2013-12-01

    Vegetation fires release large quantities of nitrogen oxides (NOx) into the atmosphere. These relatively short-lived reactive gases play key roles in atmospheric chemistry, air pollution, and climate. The traditional estimation of global NOx emissions from vegetation fires is based on the bottom-up approach by aggregating various local statistics. These statistics are based on parameters such as burned area, available fuel load, combustion completeness, and emission factors, which are derived from satellite measurements, laboratory experiments, and biogeochemical models. However, despite the progress achieved in deriving these parameters, there still exist large uncertainties for each parameter. The top-down estimation of NOx emissions from satellite measurements has the advantage of having a much higher spatio-temporal resolution. On the other hand, the conversion of the column number density into production rates of NOx and the partitioning between different NOx sources still remains challenging. In this study, we present a simple statistical approach for the estimation of production rates of NOx from fire by using the empirical relationship between satellite-derived tropospheric NO2 columns (from the GOME-2 instrument on board MetOp-A) and fire radiative power (from the MODIS instrument on board Terra). We show that the conversion of the column number density into production rates of NOx from fire is in good agreement with existing emission inventories. Therefore, we argue that this method allows for the adequate partitioning between biomass burning and other sources of NOx. The computation of Fire Emission Rates (FERs) of NOx for different land cover types indicates considerable differences among both the selected biomes and regions. The obtained FERs of NOx in combination with quantitative information about the diurnal cycle of the fire intensity are then applied for the estimation of NOx emissions from vegetation fires. A comparison of the achieved results

  13. Understanding patterns of variability in tropospheric ozone over Europe and eastern Asia in 2005-2009 using TES observations and the TM5 chemistry transport model

    NASA Astrophysics Data System (ADS)

    Verstraeten, W. W.; van Geel, M. H. A.; Boersma, K. F.

    2012-04-01

    Tropospheric ozone is an important greenhouse gas and a global air pollutant. Because of its oxidizing power, it is harmful to the tissues of many living organisms. Ozone in the troposphere is produced by photo-chemical oxidation of precursors including volatile organic compounds (VOC's) and CO in the presence of NOx. These precursors may originate from anthropogenic emissions, but may also be naturally produced by vegetation, animals, bacteria and fungi. Intrusions of stratospheric ozone into the higher troposphere also contribute to the ozone abundance in the troposphere. The interpretation of tropospheric ozone observations remains a challenging task due to complex varying spatio-temporal emissions of ozone precursors with different lifetimes (from minutes to hours, days and weeks), stratospheric intrusion, and the effect of long-range transport of precursors and ozone driven by meteorological variables. In some areas the combination of favourable photochemical regimes and specific meteorological conditions may enhance the local tropospheric ozone productions. Thanks to their extensive spatial coverage and frequent overpasses, spaceborne sensors are excellent tools to map spatio-temporal patterns of tropospheric ozone. However, evaluating trends in tropospheric ozone concentrations over Europe (e.g. Mediterranean maxima) and China requires the use of advanced chemical transport models (CTM) for understanding and attributing the different sources to the observations. The objective of this study was to evaluate time series of tropospheric ozone observed from space by TES (Tropospheric Emission Spectrometer onboard NASA's EOS-Aura satellite) with the TM5 CTM using five years (2005-2009) of observations and simulations. From dedicated TM5 model runs, the spatio-temporal TES trends of tropospheric ozone are analysed aiming at understanding the different sources and mechanisms involved. First comparison of tropospheric ozone concentration from TES v4 observations and

  14. "Middle Class Aura" in Public Schools

    ERIC Educational Resources Information Center

    Payne, Charles; Bennett, Carson

    1977-01-01

    Selected perceptions of college educational psychology students toward middle class values evident during their secondary education experience, called by Charnovsky the "middle class aura", are presented, along with their own attitudes toward those values. (MJB)

  15. The Efficacy of Air Pollution Control Efforts: Evidence from AURA

    NASA Technical Reports Server (NTRS)

    Dickerson, Russell R.; Canty, Tim; Duncan, Bryan N.; Hao, He; Krotkov, Nickolay A.; Salawitch, Ross J.; Stehr, Jeffrey W.; Vinnikov, Konstatin

    2014-01-01

    Observations of NO2, SO2, and H2CO from OMI on AURA provide an excellent record of pollutant concentrations for the past decade. Abatement strategies to control criteria pollutants including ozone and fine particulate matter (PM2.5) have met with varying degrees of success. Sulfur controls had a profound impact on local SO2 concentrations and a measurable impact on PM2.5. Although substantial effort has gone into VOC control, ozone in the eastern US has responded dramatically to NOx emissions controls.

  16. Observing Tropospheric Ozone From Space

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    2000-01-01

    The importance of tropospheric ozone embraces a spectrum of relevant scientific issues ranging from local environmental concerns, such as damage to the biosphere and human health, to those that impact global change questions, Such is climate warming. From an observational perspective, the challenge is to determine the tropospheric ozone global distribution. Because its lifetime is short compared with other important greenhouse gases that have been monitored over the past several decades, the distribution of tropospheric ozone cannot be inferred from a relatively small set of monitoring stations. Therefore, the best way to obtain a true global picture is from the use of space-based instrumentation where important spatial gradients over vast ocean expanses and other uninhabited areas can be properly characterized. In this paper, the development of the capability to measure tropospheric ozone from space over the past 15 years is summarized. Research in the late 1980s successfully led to the determination of the climatology of tropospheric ozone as a function of season; more recently, the methodology has improved to the extent where regional air pollution episodes can be characterized. The most recent modifications now provide quasi-global (50 N) to 50 S) maps on a daily basis. Such a data set would allow for the study of long-range (intercontinental) transport of air pollution and the quantification of how regional emissions feed into the global tropospheric ozone budget. Future measurement capabilities within this decade promise to offer the ability to provide Concurrent maps of the precursors to the in situ formation of tropospheric ozone from which the scientific community will gain unprecedented insight into the processes that control global tropospheric chemistry

  17. Effects of the 2004 El Nino on Tropospheric Ozone and Water Vapor

    NASA Technical Reports Server (NTRS)

    Chandra, S.; Ziemke, J. R.; Schoeberl, M. R.; Froidevaux, L.; Read, W. G.; Levelt, P. F.; Bhartia, P. K.

    2007-01-01

    The global effects of the 2004 El Nino on tropospheric ozone and H2O based on Aura OM1 and MLS measurements are analyzed. Although it was a weak El Nino from a historical perspective, it produced significant changes in these parameters in tropical latitudes. Tropospheric ozone increased by 10-20% over most of the western Pacific region and decreased by about the same amount over the eastern Pacific region. H2O in the upper troposphere showed similar changes but with opposite sign. These zonal changes in tropospheric ozone and H2O are caused by the eastward shift in the Walker circulation in the tropical pacific region during El Nino. For the 2004 El Nino, biomass burning did not have a significant effect on the ozone budget in the troposphere unlike the 1997 El Nino. Zonally averaged tropospheric column ozone did not change significantly either globally or over the tropical and subtropical latitudes.

  18. The empirical relationship between satellite-derived tropospheric NO2 and fire radiative power and possible implications for fire emission rates of NOx

    NASA Astrophysics Data System (ADS)

    Schreier, Stefan F.; Richter, Andreas; Kaiser, Johannes W.; Schepaschenko, Dmitry; Shvidenko, Anatoly; Hilboll, Andreas; Burrows, John P.

    2014-05-01

    Vegetation fires across the globe have various impacts on Earth systems such as the atmosphere and biosphere. Every year, large quantities of biomass in different ecosystems are burned, either started by lightning strikes or caused by humans. Consequently, a considerable amount of trace gases (e.g. NOx) and aerosols is released into the atmosphere. As nitrogen oxides (NOx) affect atmospheric chemistry, air quality, and climate, a quantification of the total emissions is needed. Although several approaches have been developed for the estimation of NOx emissions from fires, they still suffer from large uncertainties. We present a simple statistical approach to estimate fire emission rates (FERs) of NOx based on the linear relationship between satellite-observed tropospheric NO2 vertical columns (TVC NO2) and fire radiative power (FRP). While the great advantage of the method is the spatial coverage of FERs and the application to various biomes and regions, the uncertainties in the two retrieved parameters can lead to uncertainties in the FERs. In general, the approach performs well for the tropical and subtropical regions where both the number and the spatial extent of vegetation fires are rather large throughout the fire season. However, due to the smaller number of fires and the patchy spatial occurrence, the estimation of FERs is more complicated in the boreal regions. Nevertheless, it is possible to derive FERs for some characteristic regions in the North American and Eurasian part of the boreal forest biome. The estimated FERs of NOx for the dominating types of vegetation burned are lowest for open shrublands, savannas, and boreal forest (0.28-1.03 g NOx s-1 MW-1) and highest for croplands and woody savannas (0.82-1.56 g NOx s-1 MW-1). Interestingly, there are large regional discrepancies of up to 40 % observed for evergreen broadleaf forest and boreal forest. Possible explanations for these regional discrepancies are discussed.

  19. What have we learned about global SO2 pollution with Aura/OMI data?

    NASA Astrophysics Data System (ADS)

    Krotkov, N.; Yang, K.; Bhartia, P. K.; Carn, S.; Krueger, A.; Dickerson, R.; Li, C.

    2008-05-01

    Sulfur Dioxide (SO2) is a short-lived gas produced by volcanoes, power plants, refineries, metal smelting and general burning of fossil fuels. It is one of five EPA criteria pollutants. Emitted SO2 is soon converted to sulfate aerosol, with climate effects that include direct radiative forcing and aerosol-induced changes in cloud microphysics and the hydrological cycle. The Ozone Monitoring Instrument (OMI) launched on NASA Aura satellite in July 2004 offers unprecedented spatial resolution, coupled with contiguous daily global coverage, for space- based UV measurements of volcanic and anthropogenic SO2 emissions. Anthropogenic SO2 emissions in the PBL present challenges, because these typically weak signals need to be separated from the noise in the radiances. Plumes from strong surface sources of SO2 (such as smelters and coal burning power plants) and from strong regional pollution can currently be detected in the operational pixel data. Operational data were evaluated with in-situ aircraft SO2 profiles measured in the lower troposphere over China during the East-AIRE campaign in April 2005. This comparison demonstrates that OMI can distinguish between background SO2 conditions and heavy pollutions on a daily basis, suggesting potential of using OMI SO2 data for the regional pollution monitoring. Chinese SO2 pollution lofting above the PBL and long-range transport over Pacific Ocean was first confirmed using OMI data. Quantification of anthropogenic SO2 emissions requires off-line corrections of the average photon path, characterized by the operational air-mass factor (AMF). The AMF corrections in turn require a-priori information about the altitude of the SO2 plume center of mass, the total ozone, and surface albedo. In addition, aerosols and subpixel clouds affect the AMF in different ways depending on their amounts and vertical distribution. Therefore, ancillary cloud, snow and aerosol information available from near simultaneous A-train sensors is valuable

  20. Ammonia Measurements by the NASA Tropospheric Emission Spectrometer (TES) and the NPP Suomi Cross-Track Infrared Sounder (CrIS)

    NASA Astrophysics Data System (ADS)

    Cady-Pereira, K. E.; Shephard, M. W.; Henze, D. K.; Zhu, J.; Pinder, R. W.; Bash, J. O.; Walker, J. T.; Luo, M.

    2013-12-01

    Ammonia is highly reactive, with concurrent high spatial and temporal variability; it can play a key role in determining air quality through its part in the formation of PM2.5 particles. Deposition of NH3 also impacts water quality. With increased fertilizer use and rising temperatures ammonia concentrations are expected to increase significantly over India and China. Nevertheless in situ measurements are sparse, especially in areas beyond North America and Europe. The air quality community has a pressing need for global information on the diurnal and seasonal cycles as well as the distribution and strength of the ammonia sources. Measurements from satellites can provide this information. An advanced optimal estimation algorithm has been developed to retrieve NH3 from the TES instrument flying on the AURA satellite and ammonia is currently a standard TES operational product, available at http://avdc.gsfc.nasa.gov/index.php?site=635564035&id=10&go=list&path=/NH3. A similar retrieval is at the prototyping stage for the CrIS instrument. We will first provide a short summary of the characteristics of TES retrieved ammonia, discuss the distinct characteristics of point and satellite measurements and illustrate how information from the latter is related to the former. We will then present results from comparisons with in situ measurements. Specifically, we will compare TES NH3 with surface measurements in North Carolina and China, and examine the trend in NH3 over China; we will also compare TES NH3 with surface and aircraft measurements in the San Joaquin Valley in California, during both the CalNex and DISCOVER-AQ campaigns. We will present results from the application of inverse methods using TES ammonia to constrain model emissions, an area of research that has showcased the value provided by satellite data. Finally, we will demonstrate the potential of a sensor with TES characteristics on a geostationary platform to provide data with quality sufficient to evaluate

  1. Global Monitoring of Atmospheric Pollutants from the Aura Satellite

    NASA Astrophysics Data System (ADS)

    Ahmad, S.; Leptoukh, G.; Johnson, J.; Farley, J.; Kempler, S.

    2007-12-01

    Atmospheric measurements of O3, CO, NO2, SO2, HCHO, Aerosol and other pollutants are routinely made by the OMI, MLS, HIRDLS and TES instruments flown on the EOS Aura satellite since its launch in July 2004. These measurements provide information on the vertical and horizontal distribution of atmospheric pollutants. High concentrations of these pollutants come principally from motor vehicle exhaust, coal and oil combustion, refineries, and biomass burning. These gases play a major role in the formation of unhealthy ground level ozone (or smog) and can trigger serious respiratory problems. The convective transport of these gases, smoke and dust also pollute the upper troposphere and lower stratosphere where the residence time of these pollutants is relatively long and atmospheric winds transport these pollutants to far distances across the oceans and continents. This presentation provides some examples of how Aura data can be used in monitoring air quality by identifying sources of air pollution and understanding the distribution of these pollutants as they get transported extensive distances from their source. In this study we have also used the Aerosol Index data from TOMS, CO data from MOPITT and AIRS, Aerosol data from MODIS, Aerosol layer height information from CALIPSO, and wind information from the NCEP/NCAR reanalysis. This study uses the web based data exploration and analysis tool Giovanni developed at the NASA Goddard Earth Sciences Data Services and Information Center (GES DSIC). Giovanni provides easy access to satellite data, eliminating the need to download large data sets and thus saving the user time. Giovanni capabilities include on- line animations of 2D maps, time-series plots (including statistics), several combinations of 2D cross-section maps (latitude/longitude/height/time), scatter plots, correlation maps, and collocated subsets of the data along CALIPSO tracks.

  2. CH4 and CO distributions over tropical fires during October 2006 as observed by the Aura TES satellite instrument and modeled by GEOS-Chem

    NASA Astrophysics Data System (ADS)

    Worden, J.; Wecht, K.; Frankenberg, C.; Alvarado, M.; Bowman, K.; Kort, E.; Kulawik, S.; Lee, M.; Payne, V.; Worden, H.

    2013-04-01

    Tropical fires represent a highly uncertain source of atmospheric methane (CH4) because of the variability of fire emissions and the dependency of the fire CH4 emission factors (g kg-1 dry matter burned) on fuel type and combustion phase. In this paper we use new observations of CH4 and CO in the free troposphere from the Aura Tropospheric Emission Sounder (TES) satellite instrument to place constraints on the role of tropical fire emissions versus microbial production (e.g. in wetlands and livestock) during the (October) 2006 El Niño, a time of significant fire emissions from Indonesia. We first compare the global CH4 distributions from TES using the GEOS-Chem model. We find a mean bias between the observations and model of 26.3 ppb CH4 that is independent of latitude between 50° S and 80° N, consistent with previous validation studies of TES CH4 retrievals using aircraft measurements. The slope of the distribution of CH4 versus CO as observed by TES and modeled by GEOS-Chem is consistent (within the TES observation error) for air parcels over the Indonesian peat fires, South America, and Africa. The CH4 and CO distributions are correlated between R = 0.42 and R = 0.46, with these correlations primarily limited by the TES random error. Over Indonesia, the observed slope of 0.13 (ppb ppb-1) ±0.01, as compared to a modeled slope of 0.153 (ppb ppb-1) ±0.005 and an emission ratio used within the GEOS-Chem model of approximately 0.11 (ppb ppb-1), indicates that most of the observed methane enhancement originated from the fire. Slopes of 0.47 (ppb ppb-1) ±0.04 and 0.44 (ppb ppb-1) ±0.03 over South America and Africa show that the methane in the observed air parcels primarily came from microbial-generated emissions. Sensitivity studies using GEOS-Chem show that part of the observed correlation for the Indonesian observations and most of the observed correlations over South America and Africa are a result of transport and mixing of the fire and nearby microbial

  3. CH4 and CO distributions over tropical fires as observed by the Aura TES satellite instrument and modeled by GEOS-Chem

    NASA Astrophysics Data System (ADS)

    Worden, J.; Wecht, K.; Frankenberg, C.; Alvarado, M.; Bowman, K.; Kort, E.; Kulawik, S.; Lee, M.; Payne, V.; Worden, H.

    2012-10-01

    Tropical fires represent a highly uncertain source of atmospheric methane (CH4) because of the variability of fire emissions and the dependency of the fire CH4 emission factors (g kg-1 dry matter burned) on fuel type and combustion phase. In this paper we use new observations of CH4 and CO in the free troposphere from the Aura Tropospheric Emission Sounder (TES) satellite instrument to place constraints on the role of tropical fire emissions versus microbial production (e.g. in wetlands and livestock) during the (October) 2006 El Nino, a time of significant peat fire emissions from Indonesia We first evaluate the global CH4 distributions from TES using the GEOS-Chem model. We find a mean bias between the observations and model of 26.3 ppb CH4 that is independent of latitude between 50° S and 80° N consistent with previous validation studies of TES CH4 retrievals using aircraft measurements. The slope of the distribution of CH4 versus CO as observed by TES and modeled by GEOS-Chem is consistent (within the TES observation error) for air parcels over the Indonesian peat fires, South America, and Africa. The CH4 and CO distributions are correlated between R = 0.42 and R = 0.46, with these correlations primarily limited by the TES random error. Over Indonesia, the observed slope of 0.13 (ppb ppb-1) ± 0.01, as compared to a modeled slop of 0.153 (ppb ppb-1) ± 0.005 and an emission ratio used within the GEOS-Chem model of approximately 0.11 (ppb ppb-1) indicates that most of the observed methane enhancement originated from the fire. Slopes of 0.47 (ppb ppb-1) ± 0.04 and 0.44 (ppb ppb-1) ± 0.03 over South America and Africa show that the methane in the observed air parcels primarily came from microbial generated emissions. Sensitivity studies using GEOS-Chem show that part of the observed correlation for the Indonesian observations and most of the observed correlations over South America and Africa are a result of transport and mixing of the fire and nearby

  4. Global Troposphere Experiment Project

    NASA Technical Reports Server (NTRS)

    Bandy, Alan R.; Thornton, Donald C.

    1997-01-01

    For the Global Troposphere Experiment project Pacific Exploratory Measurements West B (PEM West B), we made determinations of sulfur dioxide (SO2) and dimethyl sulfide (DMS) using gas chromatography-mass spectrometry with isotopically labelled internal standards. This technique provides measurements with precision of 1 part-per-trillion by volume below 20 pptv and 1% above 20 pptv. Measurement of DMS and SO2 were performed with a time cycle of 5-6 minutes with intermittent zero checks. The detection limits were about 1 pptv for SO2 and 2 pptv for DMS. Over 700 measurements of each compound were made in flight. Volcanic impacts on the upper troposphere were again found as a result of deep convection in the tropics. Extensive emission of SO2 from the Pacific Rim land masses were primarily observed in the lower well-mixed part of the boundary layer but also in the upper part of the boundary layer. Analyses of the SO2 data with aerosol sulfate, beryllium-7, and lead-210 indicated that SO2, contributed to half or more of the observed total oxidized sulfur (SO2 plus aerosol sulfate) in free tropospheric air. Cloud processing and rain appeared to be responsible for lower SO2 levels between 3 and 8.5 km than above or below this region. During both phases of PEM-West, dimethyl sulfide did not appear to be a major source of sulfur dioxide in the upper free troposphere over the western Pacific Ocean. In 1991 the sources Of SO2 at high altitude appeared to be both anthropogenic and volcanic with an estimated 1% being solely from DMS. The primary difference for the increase in the DMS source was the very low concentration of SO2 at high altitude. In the midlatitude region near the Asian land masses, DMS in the mixed layer was lower than in the tropical region of the western Pacific. Convective cloud systems near volcanoes in the tropical convergence in the western Pacific troposphere were a major source of SO2 at high altitudes during PEM-West B. High levels of SO2 were

  5. Prevalence and characteristics of visual aura in idiopathic generalized epilepsy.

    PubMed

    Gungor-Tuncer, Ozlem; Baykan, Betul; Altindag, Ebru; Bebek, Nerses; Gurses, Candan; Gokyigit, Aysen

    2012-12-01

    Some patients with idiopathic/genetic generalized epilepsy (IGE) experience visual aura, which can confuse the diagnosis. We sought to determine the frequency and characteristics of visual auras in IGE patients. Among the 176 IGE patients, 4 men and 7 women reported visual auras (mean age - 24 years). Syndromic diagnoses were juvenile myoclonic epilepsy in four, eyelid myoclonia with absences (EMA) in three, juvenile absence epilepsy in three, and other in one. Visual auras consisted of flashing lights, macropsia, illusional movements, and blindness. Eyelid myoclonia with absences was significantly more common in the group with visual aura (3 of 11 patients vs. 8 of 165 IGE patients; P=0.02). Furthermore, photosensitivity was found significantly more common in IGE patients with visual aura (90% vs 46% of the total IGE patients) (P=0.004). In conclusion, the visual auras do not exclude a diagnosis of IGE. The presence of visual aura in the EMA syndrome is also remarkable.

  6. Evaluation of UTLS Carbon Monoxide Simulations in GMI and GEOS-Chem Chemical Transport Models using Aura MLS Observations

    NASA Technical Reports Server (NTRS)

    Huang, Lei; Jiang, Jonathan H.; Murray, Lee T.; Damon, Megan R.; Su, Hui; Livesey, Nathaniel J.

    2016-01-01

    This study evaluates the distribution and variation of carbon monoxide (CO) in the upper troposphere and lower stratosphere (UTLS) during 2004-2012 as simulated by two chemical transport models, using the latest version of Aura Microwave Limb Sounder (MLS) observations. The simulated spatial distributions, temporal variations and vertical transport of CO in the UTLS region are compared with those observed by MLS. We also investigate the impact of surface emissions and deep convection on CO concentrations in the UTLS over different regions, using both model simulations and MLS observations. Global Modeling Initiative (GMI) and GEOS-Chem simulations of UTLS CO both show similar spatial distributions to observations. The global mean CO values simulated by both models agree with MLS observations at 215 and 147 hPa, but are significantly underestimated by more than 40% at 100 hPa. In addition, the models underestimate the peak CO values by up to 70% at 100 hPa, 60% at 147 hPa and 40% at 215 hPa, with GEOS-Chem generally simulating more CO at 100 hPa and less CO at 215 hPa than GMI. The seasonal distributions of CO simulated by both models are in better agreement with MLS in the Southern Hemisphere (SH) than in the Northern Hemisphere (NH), with disagreements between model and observations over enhanced CO regions such as southern Africa. The simulated vertical transport of CO shows better agreement with MLS in the tropics and the SH subtropics than the NH subtropics. We also examine regional variations in the relationships among surface CO emission, convection and UTLS CO concentrations. The two models exhibit emission-convection- CO relationships similar to those observed by MLS over the tropics and some regions with enhanced UTLS CO.

  7. Evaluation of UTLS carbon monoxide simulations in GMI and GEOS-Chem chemical transport models using Aura MLS observations

    NASA Astrophysics Data System (ADS)

    Huang, Lei; Jiang, Jonathan H.; Murray, Lee T.; Damon, Megan R.; Su, Hui; Livesey, Nathaniel J.

    2016-05-01

    This study evaluates the distribution and variation of carbon monoxide (CO) in the upper troposphere and lower stratosphere (UTLS) during 2004-2012 as simulated by two chemical transport models, using the latest version of Aura Microwave Limb Sounder (MLS) observations. The simulated spatial distributions, temporal variations and vertical transport of CO in the UTLS region are compared with those observed by MLS. We also investigate the impact of surface emissions and deep convection on CO concentrations in the UTLS over different regions, using both model simulations and MLS observations. Global Modeling Initiative (GMI) and GEOS-Chem simulations of UTLS CO both show similar spatial distributions to observations. The global mean CO values simulated by both models agree with MLS observations at 215 and 147 hPa, but are significantly underestimated by more than 40 % at 100 hPa. In addition, the models underestimate the peak CO values by up to 70 % at 100 hPa, 60 % at 147 hPa and 40 % at 215 hPa, with GEOS-Chem generally simulating more CO at 100 hPa and less CO at 215 hPa than GMI. The seasonal distributions of CO simulated by both models are in better agreement with MLS in the Southern Hemisphere (SH) than in the Northern Hemisphere (NH), with disagreements between model and observations over enhanced CO regions such as southern Africa. The simulated vertical transport of CO shows better agreement with MLS in the tropics and the SH subtropics than the NH subtropics. We also examine regional variations in the relationships among surface CO emission, convection and UTLS CO concentrations. The two models exhibit emission-convection-CO relationships similar to those observed by MLS over the tropics and some regions with enhanced UTLS CO.

  8. Enhanced Positive Water Vapor Feedback Associated with Tropical Deep Convection: New Evidence from Aura MLS

    NASA Technical Reports Server (NTRS)

    Su, Hui; Read, William G.; Jiang, Jonathan H.; Waters, Joe W.; Wu, Dong L.; Fetzer, Eric J.

    2006-01-01

    Recent simultaneous observations of upper tropospheric (UT) water vapor and cloud ice from the Microwave Limb Sounder (MLS) on the Aura satellite provide new evidence for tropical convective influence on UT water vapor and its associated greenhouse effect. The observations show that UT water vapor increases as cloud ice water content increases. They also show that, when sea surface temperature (SST) exceeds approx.300 K, UT cloud ice associated with tropical deep convection increases sharply with increasing SST. The moistening of the upper troposphere by deep convection leads to an enhanced positive water vapor feedback, about 3 times that implied solely by thermodynamics. Over tropical oceans when SST greater than approx.300 K, the 'convective UT water vapor feedback' inferred from the MLS observations contributes approximately 65% of the sensitivity of the clear-sky greenhouse parameter to SST.

  9. SO2 over Central China: Measurements, Numerical Simulations and the Tropospheric Sulfur Budget

    NASA Technical Reports Server (NTRS)

    He, Hao; Li, Can; Loughner, Christopher P.; Li, Zhangqing; Krotkov, Nickolay A.; Yang, Kai; Wang, Lei; Zheng, Youfei; Bao, Xiangdong; Zhao, Guoqiang; Dickerson, Russell R.

    2012-01-01

    SO2 in central China was measured in situ from an aircraft and remotely using the Ozone Monitoring Instrument (OMI) from the Aura satellite; results were used to develop a numerical tool for evaluating the tropospheric sulfur budget - sources, sinks, transformation and transport. In April 2008, measured ambient SO2 concentrations decreased from approx.7 ppbv near the surface to approx. 1 ppbv at 1800 m altitude (an effective scale height of approx.800 m), but distinct SO2 plumes were observed between 1800 and 4500 m, the aircraft's ceiling. These free tropospheric plumes play a major role in the export of SO2 and in the accuracy of OMI retrievals. The mean SO2 column contents from aircraft measurements (0.73 DU, Dobson Units) and operational OMI SO2 products (0.63+/-0.26 DU) were close. The OMI retrievals were well correlated with in situ measurements (r = 0.84), but showed low bias (slope = 0.54). A new OMI retrieval algorithm was tested and showed improved agreement and bias (r = 0.87, slope = 0.86). The Community Multiscale Air Quality (CMAQ) model was used to simulate sulfur chemistry, exhibiting reasonable agreement (r = 0.62, slope = 1.33) with in situ SO2 columns. The mean CMAQ SO2 loading over central and eastern China was 54 kT, approx.30% more than the estimate from OMI SO2 products, 42 kT. These numerical simulations, constrained by observations, indicate that ",50% (35 to 61 %) of the anthropogenic sulfur emissions were transported downwind, and the overall lifetime of tropospheric SO2 was 38+/-7 h.

  10. Increasing Anthropogenic Emissions in China Offset Air Quality Policy Efforts in Western United States: A Satellite and Modelling Perspective

    NASA Astrophysics Data System (ADS)

    Boersma, F. F.; Verstraeten, W. W.; Williams, J. E.; Neu, J. L.; Bowman, K. W.; Worden, J.

    2014-12-01

    Tropospheric ozone is an important greenhouse gas and a global air pollutant originating from photo-chemical oxidation of ozone precursors in the presence of NOX. Eastern Asia has the fastest growing anthropogenic emissions in the world, possibly affecting both the pollution in the local troposphere as well as in the trans-Pacific region. Local measurements over Asia show that tropospheric ozone has increased by 1 to 3% per year since the start of the millennium. This increase is often invoked to explain positive ozone trends observed in western United States, but to date there is no unambiguous evidence showing that enhanced Asian pollution is responsible for these trends. Here we interpret satellite measurements of tropospheric ozone and its precursor nitrate dioxide from the Aura Tropospheric Emission Spectrometer (TES) and Ozone Monitoring Instrument (OMI) using the TM5 global chemistry-transport model to directly show that tropospheric ozone over China has increased by ~10% from 2005-2010 in response to both a ~15% rise in Chinese emissions and an increased downward ozone transport from the stratosphere. What is more, we demonstrate that Chinese export of ozone and its precursors have offset one-third of the reduction in free tropospheric ozone over the western United States that should have occurred during 2005-2010 via emissions reductions associated with air quality policies in the United States. The issue of export and long-range transport of pollution from other countries indicates that global efforts may be required to address both the global as well as the regional air quality and climate change.

  11. EOS Aura and Future Satellite Studies of the Ozone Layer

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2007-01-01

    The EOS Aura mission, launched in 2004, provides a comprehensive assessment of the stratospheric dynamics and chemistry. This talk will focus on results from Aura including the chemistry of polar ozone depletion. The data from Aura can be directly linked to UARS data to produce long term trends in stratospheric trace gases.

  12. Assessment and Applications of NASA Ozone Data Products Derived from Aura OMI-MLS Satellite Measurements in Context of the GMI Chemical Transport Model

    NASA Technical Reports Server (NTRS)

    Ziemke, J. R.; Olsen, M. A.; Witte, J. C.; Douglass, A. R.; Strahan, S. E.; Wargan, K.; Liu, X.; Schoeberl, M. R.; Yang, K.; Kaplan, T. B.; Pawson, S.; Duncan, B. N.; Newman, P. A.; Bhartia, K.; Heney, M. K.

    2013-01-01

    Measurements from the Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS), both onboard the Aura spacecraft, have been used to produce daily global maps of column and profile ozone since August 2004. Here we compare and evaluate three strategies to obtain daily maps of tropospheric and stratospheric ozone from OMI and MLS measurements: trajectory mapping, direct profile retrieval, and data assimilation. Evaluation is based upon an assessment that includes validation using ozonesondes and comparisons with the Global Modeling Initiative (GMI) chemical transport model (CTM). We investigate applications of the three ozone data products from near-decadal and inter-annual timescales to day-to-day case studies. Zonally averaged inter-annual changes in tropospheric ozone from all of the products in any latitude range are of the order 1-2 Dobson Units while changes (increases) over the 8-year Aura record investigated http://eospso.gsfc.nasa.gov/atbd-category/49 vary approximately 2-4 Dobson Units. It is demonstrated that all of the ozone products can measure and monitor exceptional tropospheric ozone events including major forest fire and pollution transport events. Stratospheric ozone during the Aura record has several anomalous inter-annual events including stratospheric warming split events in the Northern Hemisphere extra-tropics that are well captured using the data assimilation ozone profile product. Data assimilation with continuous daily global coverage and vertical ozone profile information is the best of the three strategies at generating a global tropospheric and stratospheric ozone product for science applications.

  13. Science Objectives of EOS-Aura's Ozone Monitoring Instrument (OMI)

    NASA Technical Reports Server (NTRS)

    Levelt, P. F.; Veefkind, J. P.; Stammes, P.; Hilsenrath, E.; Bhartia, P. K.; Chance, K. V.; Leppelmeier, G. W.; Maelkki, A.; Bhartia, Pawan (Technical Monitor)

    2002-01-01

    OMI is a UV/VIS nadir solar backscatter spectrograph, which provides near global coverage in one day with a spatial resolution of 13 x 24 sq km. OMI is a new instrument, with a heritage from the European satellite instruments GOME, GOMOS and SCIAMACHY. OMI's unique capabilities for measuring important trace gases with a small footprint and daily global coverage, in conjunction with the other Aura instruments, will make a major contribution to our understanding of stratospheric and tropospheric chemistry and climate change. OMI will measure solar irradiance and Earth radiances in the wavelength range of 270 to 500 nm with spectral resolution of about 0.5 nm and a spectral sampling of about 2-3 per FWHM. From these observations, total columns of O3, NO2, BrO and SO2 will be derived from the back-scattered solar radiance using differential absorption spectroscopy (DOAS). The TOMS total ozone record will also be continued by employing the well established TOMS algorithm. Because of the high accuracy and spatial resolution of the measurements, a good estimate of tropospheric amounts of ozone and NO2 are expected. Ozone profiles will be derived using the optimal estimation method. The spectral aerosol optical depth will be determined from measurements between 340 and 500 nm. This will provide information on aerosol concentration, aerosol size distribution and aerosol type. This wavelength range makes it possible to retrieve aerosol information over both land and sea. OMI observations will also allow retrievals of cloud coverage and cloud heights. From these products, the UV-B flux at the surface can then be derived with high spatial resolution.

  14. Student Investigations of Tropospheric Ozone

    NASA Astrophysics Data System (ADS)

    Austin, S.; Johnson, L.; Merrill, J.; Johnson, R.; Renee, B.; Fortney, M.; Renee, D.

    2006-12-01

    Hands-on field work and data collection have been shown to be a major factor in motivating students in the study of geoscience and environmental science. An existing high-altitude balloon program at Medgar Evers College(MEC) has developed a new student research initiative focused on tropospheric ozone profile investigations. This effort was launched with involvement in the Ozonesonde Network Study (IONS) 2006 campaign of coordinated observations organized by the Goddard Space Flight Center (GSFC). The participation was stimulated by a collaboration between faculty at the University of Rhode Island (URI) and faculty at Medgar Evers College, a minority-serving institution. URI provided training, background material, access to lab facilities and continues to assist faculty at MEC in the engagement of minority students in this research experience. Undergraduate and graduate students are involved in all phases of the ozone study including ozonesonde preparation and calibration (URI), launch and communications (Paradox, NY), and data analysis (Medgar Evers College) which is being incorporated into selected courses in Environmental Science, Physical Science and Computer Science. A companion educational project involved high school students with a teacher-mentor in surface ozone measurements using the GLOBE protocol as well as linkages with the ozone profile study. This presentation describes the student-based participation, the URI-MEC collaboration, results from the ozone profiles as well as the details of ongoing curriculum integration and future work. The project is partially supported by the NASA Aura Education and Public Outreach program.

  15. Aura photography: mundane physics or diagnostic tool?

    PubMed

    Stanwick, M

    Kirlian photography is often associated with the paranormal. Many people believe it records the auras of living objects and that it can be used as a diagnostic tool. This paper argues against these beliefs and maintains that there is a simple, scientific explanation of the Kirlian effect. PMID:8718173

  16. Tropospheric Emission Spectrometer (TES) satellite observations of ammonia, methanol, formic acid, and carbon monoxide over the Canadian oil sands: validation and model evaluation

    NASA Astrophysics Data System (ADS)

    Shephard, M. W.; McLinden, C. A.; Cady-Pereira, K. E.; Luo, M.; Moussa, S. G.; Leithead, A.; Liggio, J.; Staebler, R. M.; Akingunola, A.; Makar, P.; Lehr, P.; Zhang, J.; Henze, D. K.; Millet, D. B.; Bash, J. O.; Zhu, L.; Wells, K. C.; Capps, S. L.; Chaliyakunnel, S.; Gordon, M.; Hayden, K.; Brook, J. R.; Wolde, M.; Li, S.-M.

    2015-12-01

    The wealth of air quality information provided by satellite infrared observations of ammonia (NH3), carbon monoxide (CO), formic acid (HCOOH), and methanol (CH3OH) is currently being explored and used for a number of applications, especially at regional or global scales. These applications include air quality monitoring, trend analysis, emissions, and model evaluation. This study provides one of the first direct validations of Tropospheric Emission Spectrometer (TES) satellite-retrieved profiles of NH3, CH3OH, and HCOOH through comparisons with coincident aircraft profiles. The comparisons are performed over the Canadian oil sands region during the intensive field campaign (August-September, 2013) in support of the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring (JOSM). The satellite/aircraft comparisons over this region during this period produced errors of (i) +0.08 ± 0.25 ppbv for NH3, (ii) +7.5 ± 23 ppbv for CO, (iii) +0.19 ± 0.46 ppbv for HCOOH, and (iv) -1.1 ± 0.39 ppbv for CH3OH. These values mostly agree with previously estimated retrieval errors; however, the relatively large negative bias in CH3OH and the significantly greater positive bias for larger HCOOH and CO values observed during this study warrant further investigation. Satellite and aircraft ammonia observations during the field campaign are also used in an initial effort to perform preliminary evaluations of Environment Canada's Global Environmental Multi-scale - Modelling Air quality and CHemistry (GEM-MACH) air quality modelling system at high resolution (2.5 × 2.5 km2). These initial results indicate a model underprediction of ~ 0.6 ppbv (~ 60 %) for NH3, during the field campaign period. The TES/model CO comparison differences are ~ +20 ppbv (~ +20 %), but given that under these conditions the TES/aircraft comparisons also show a small positive TES CO bias indicates that the overall model underprediction of CO is closer to ~ 10 % at 681 hPa (~ 3 km) during this period.

  17. Assimilation of Aura Ozone Data and Comparisons with In Situ Observations

    NASA Technical Reports Server (NTRS)

    Stajner, Ivanka; Wargan, Krzysztof; Pawson, Steven

    2008-01-01

    Ozone data from the Ozone Monitoring Instrument (OMI) and the Microwave Limb Sounder (MLS) onboard EOS Aura satellite were assimilated into the Goddard Earth Observing System Version 4 (GEOS-4) ozone assimilation system. Comparison of assimilated ozone with ozone sonde and MOZAIC data indicate an agreement within 10% in the lower stratosphere, where dynamical processes dominate. Assimilation of OMI and MLS data improves tropospheric column estimates in the Atlantic region, but leads to an overestimation in the tropical Pacific in comparison with SHADOZ sondes. Transport and data biases are considered in order to understand these discrepancies. Comparisons of assimilated tropospheric ozone columns with ozone sonde data reveal root-mean-square (RMS) differences of 2.9 to 7.2 DU, which are typically smaller than the model-sonde RMS differences. Four different definitions of the tropopause using temperature lapse rate, potential vorticity (PV) and isentropic surfaces or ozone isosurfaces are compared with respect to their global impact on the estimated tropospheric ozone column. The largest sensitivity in the tropospheric ozone column is found near the subtropical jet, where the ozone or PV determined tropopause typically lies below the lapse rate tropopause.

  18. Aura OMI Observations of Global SO2 and NO2 Pollution from 2005 to 2013

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay; Li, Can; Lamsal, Lok; Celarier, Edward; Marchenko, Sergey; Swartz, William H.; Bucsela, Eric; Fioletov, Vitali; McLinden, Chris; Joiner, Joanna; Bhartia, Pawan K.; Duncan, Bryan; Dickerson, Russ

    2014-01-01

    The Ozone Monitoring Instrument (OMI), a NASA partnership with the Netherlands and Finland, flies on the NASA Aura satellite and uses reflected sunlight to measure the two critical atmospheric trace gases: nitrogen dioxide (NO2) and sulfur dioxide (SO2) characterizing daily air quality. Both gases and the secondary pollutants they produce (particulate matter, PM2.5, and tropospheric ozone) are USEPA designated criteria pollutants, posing serious threats to human health and the environment (e.g., acid rain, plant damage and reduced visibility). Our group at NASA GSFC has developed and maintained OMI standard SO2 and NO2 data products. We have recently released an updated version of the standard NO2 L2 and L3 products (SP v2.1) and continue improving the algorithm. We are currently in the process of releasing next generation pollution SO2 product, based on an innovative Principal Component Analysis (PCA) algorithm, which greatly reduces the noise and biases. These new standard products provide valuable datasets for studying anthropogenic pollution on local to global scales. Here we highlight some of the OMI observed changes in air quality over several regions. Over the US average NO2 and SO2 pollution levels had decreased dramatically as a result of both technological improvements (e.g., catalytic converters on cars) and stricter regulations of emissions. We see continued decline in pollution over Europe. Over China OMI observed an increase of about 60 percent in NO2 pollution between 2005 and 2013, despite a temporal reversal of the growing trend due to both 2008 Olympic Games and the economic recession in 2009. Chinese SO2 pollution seems to have stabilized since peaking in 2007, probably due to government efforts to curb SO2 emissions from the power sector. We have also observed large increases in both SO2 and NO2 pollution particularly in Eastern India where a number of large new coal power plants had been built in recent years. We expect that further

  19. (abstract) Tropospheric Emission Spectrometer (TES)

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard

    1994-01-01

    A descope of the EOS program now requires that all EOS platforms after AM1 be launched on DELTA-class vehicles, which results in much smaller platforms (and payloads) than previously envisaged. A major part of the TES hardware design effort has therefore been redirected towards meeting this challenge. The development of the TES concept continues on a schedule to permit flight on the EOS CHEM platform in 2002, where it is planned to be accompanied by HIRDLS and MLS.

  20. [Clinical presentation and diagnosis of epileptic auras].

    PubMed

    Barletova, E I; Kremenchugskaia, M R; Mukhin, K Iu; Glukhova, L Iu; Mironov, M B

    2012-01-01

    To define clinical presentations of visual auras and to reveal their clinical, encephalographic and neuroimaging correlates, we examined 23 patients, aged from 5 to 25 years (mean 14±6 years), with focal forms of epilepsy. Patients had visual auras regardless of the etiology of epilepsy which developed immediately before epileptic seizures or were isolated. Patients had simple or complex visual hallucinations, the former occurring more frequently, visual illusions and ictal amaurosis. Positive visual phenomena were noted more frequently than negative ones. In most of the patients, visual hallucinations were associated with the pathological activity in cortical occipital regions of the brain and, in some cases, in temporal and parietal regions. The different pathologies (developmental defects, post-ischemic, atrophic and other disturbances) identified by MRI were found in a half of patients. PMID:23120768

  1. [Clinical presentation and diagnosis of epileptic auras].

    PubMed

    Barletova, E I; Kremenchugskaia, M R; Mukhin, K Iu; Glukhova, L Iu; Mironov, M B

    2012-01-01

    To define clinical presentations of visual auras and to reveal their clinical, encephalographic and neuroimaging correlates, we examined 23 patients, aged from 5 to 25 years (mean 14±6 years), with focal forms of epilepsy. Patients had visual auras regardless of the etiology of epilepsy which developed immediately before epileptic seizures or were isolated. Patients had simple or complex visual hallucinations, the former occurring more frequently, visual illusions and ictal amaurosis. Positive visual phenomena were noted more frequently than negative ones. In most of the patients, visual hallucinations were associated with the pathological activity in cortical occipital regions of the brain and, in some cases, in temporal and parietal regions. The different pathologies (developmental defects, post-ischemic, atrophic and other disturbances) identified by MRI were found in a half of patients.

  2. Recent Large Reduction in Sulfur Dioxide Emissions from Chinese Power Plants Observed by the Ozone Monitoring Instrument

    NASA Technical Reports Server (NTRS)

    Li, Can; Zhang, Qiang; Krotkov, Nickolay A.; Streets, David G.; He, Kebin; Tsay, Si-Chee; Gleason, James F.

    2010-01-01

    The Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite observed substantial increases in total column SO2 and tropospheric column NO2 from 2005 to 2007, over several areas in northern China where large coal-fired power plants were built during this period. The OMI-observed SO2/NO2 ratio is consistent with the SO2/ NO2, emissions estimated from a bottom-up approach. In 2008 over the same areas, OMI detected little change in NO2, suggesting steady electricity output from the power plants. However, dramatic reductions of S0 2 emissions were observed by OMI at the same time. These reductions confirm the effectiveness of the flue-gas desulfurization (FGD) devices in reducing S02 emissions, which likely became operational between 2007 and 2008. This study further demonstrates that the satellite sensors can monitor and characterize anthropogenic emissions from large point sources.

  3. Accurate Satellite-Derived Estimates of Tropospheric Ozone Radiative Forcing

    NASA Technical Reports Server (NTRS)

    Joiner, Joanna; Schoeberl, Mark R.; Vasilkov, Alexander P.; Oreopoulos, Lazaros; Platnick, Steven; Livesey, Nathaniel J.; Levelt, Pieternel F.

    2008-01-01

    Estimates of the radiative forcing due to anthropogenically-produced tropospheric O3 are derived primarily from models. Here, we use tropospheric ozone and cloud data from several instruments in the A-train constellation of satellites as well as information from the GEOS-5 Data Assimilation System to accurately estimate the instantaneous radiative forcing from tropospheric O3 for January and July 2005. We improve upon previous estimates of tropospheric ozone mixing ratios from a residual approach using the NASA Earth Observing System (EOS) Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) by incorporating cloud pressure information from OMI. Since we cannot distinguish between natural and anthropogenic sources with the satellite data, our estimates reflect the total forcing due to tropospheric O3. We focus specifically on the magnitude and spatial structure of the cloud effect on both the shortand long-wave radiative forcing. The estimates presented here can be used to validate present day O3 radiative forcing produced by models.

  4. The Satellite View of Extra-Tropical Stratosphere-Troposphere Exchange and the UT/LS

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2004-01-01

    This talk will review satellite studies which have helped define the UT/LS and stratosphere-troposphere exchange. Satellites have provided a global perspective but have had limited temporal and spatial measurements for stratosphere-troposphere exchange (STE) studies. Nonetheless, long lived tracer measurements from satellites can be used as proxies for age-of-air can thus provide estimates of mixing and transport processes in the UT/LS. These measurements can be compared to model estimates of the mean age-of-air and trace gas fluxes providing an important model diagnostic. With the launch of EOS Aura, the potential for satellite trace gas measurements of the lower-most stratosphere and STE is significantly improved, and Aura s mission will be briefly described.

  5. Ozone columns obtained by ground-based remote sensing in Kiev for Aura Ozone Measuring Instrument validation

    NASA Astrophysics Data System (ADS)

    Shavrina, A. V.; Pavlenko, Y. V.; Veles, A.; Syniavskyi, I.; Kroon, M.

    2007-12-01

    Ground-based observations with a Fourier transform spectrometer in the infrared region (FTIR) were performed in Kiev (Ukraine) during the time frames August-October 2005 and June-October 2006 within the Ozone Monitoring Instrument (OMI) validation project 2907 entitled "OMI validation by ground based remote sensing: ozone columns and profiles" in the frame of the international European Space Agency/Netherlands Agency for Aerospace Programmes/Royal Dutch Meteorological Institute OMI Announcement of Opportunity effort. Ozone column data for 2005 were obtained by modeling the ozone spectral band at 9.6 μm with the radiative transfer code MODTRAN3.5. Our total ozone column values were found to be lower than OMI Differential Optical Absorption Spectroscopy (DOAS) total ozone column data by 8-10 Dobson units (DU, 1 DU = 0.001 atm cm) on average, while our observations have a relatively small standard error of about 2 DU. Improved modeling of the ozone spectral band, now based on HITRAN-2004 spectral data as calculated by us, moves our results toward better agreement with the OMI DOAS total ozone column data. The observations made during 2006 with a modernized FTIR spectrometer and higher signal-to-noise ratio were simulated by the MODTRAN4 model computations. For ozone column estimates the Aqua Atmospheric Infrared Sounder satellite water vapor and temperature profiles were combined with the Aura Microwave Limb Sounder stratospheric ozone profiles and Tropospheric Emission Monitoring Internet Service-Koninklijk Nederlands Meteorologisch Instituut climatological profiles to create a priori input files for spectral modeling. The MODTRAN4 estimates of ozone columns from the 2006 observations compare rather well with the OMI total ozone column data: standard errors are of 1.11 DU and 0.68 DU, standard deviation are of 8.77 DU and 5.37 DU for OMI DOAS and OMI Total Ozone Mapping Spectrometer, respectively.

  6. Impact of Lightning-NO Emissions on Summertime U.S. Photochemistry as Determined Using the CMAQ Model with NLDN-Constrained Flash Rates

    NASA Technical Reports Server (NTRS)

    Allen, Dale; Pickering, Kenneth; Pinder, Robert; Koshak, William; Pierce, Thomas

    2011-01-01

    Lightning-NO emissions are responsible for 15-30 ppbv enhancements in upper tropospheric ozone over the eastern United States during the summer time. Enhancements vary from year to year but were particularly large during the summer of 2006, a period during which meteorological conditions were particularly conducive to ozone formation. A lightning-NO parameterization has been developed that can be used with the CMAQ model. Lightning-NO emissions in this scheme are assumed to be proportional to convective precipitation rate and scaled so that monthly average flash rates in each grid box match National Lightning Detection Network (NLDN) observed flash rates after adjusting for climatological intracloud to cloud-to-ground (IC/CG) ratios. The contribution of lightning-NO emissions to eastern United States NOx and ozone distributions during the summer of 2006 will be evaluated by comparing results of 12- km CMAQ simulations with and without lightning-NO emissions to measurements from the IONS field campaign and to satellite retrievals from the Tropospheric Emission Spectrometer (TES) and the Ozone Monitoring Instrument (OMI) aboard the Aura satellite. Special attention will be paid to the impact of the assumed vertical distribution of emissions on upper tropospheric NOx and ozone amounts.

  7. Simulating the Black Saturday 2009 smoke plume with an interactive composition-climate model: Sensitivity to emissions amount, timing, and injection height

    NASA Astrophysics Data System (ADS)

    Field, Robert D.; Luo, Ming; Fromm, Mike; Voulgarakis, Apostolos; Mangeon, Stéphane; Worden, John

    2016-04-01

    We simulated the high-altitude smoke plume from the early February 2009 Black Saturday bushfires in southeastern Australia using the NASA Goddard Institute for Space Studies ModelE2. To the best of our knowledge, this is the first single-plume analysis of biomass burning emissions injected directly into the upper troposphere/lower stratosphere (UTLS) using a full-complexity composition-climate model. We compared simulated carbon monoxide (CO) to a new Aura Tropospheric Emission Spectrometer/Microwave Limb Sounder joint CO retrieval, focusing on the plume's initial transport eastward, anticyclonic circulation to the north of New Zealand, westward transport in the lower stratospheric easterlies, and arrival over Africa at the end of February. Our goal was to determine the sensitivity of the simulated plume to prescribed injection height, emissions amount, and emissions timing from different sources for a full-complexity model when compared to Aura. The most realistic plumes were obtained using injection heights in the UTLS, including one drawn from ground-based radar data. A 6 h emissions pulse or emissions tied to independent estimates of hourly fire behavior produced a more realistic plume in the lower stratosphere compared to the same emissions amount being released evenly over 12 or 24 h. Simulated CO in the plume was highly sensitive to the differences between emissions amounts estimated from the Global Fire Emissions Database and from detailed, ground-based estimates of fire growth. The emissions amount determined not only the CO concentration of the plume but also the proportion of the plume that entered the stratosphere. We speculate that this is due to either or both nonlinear CO loss with a weakened OH sink or plume self-lofting driven by shortwave absorption of the coemitted aerosols.

  8. Infrared Solar Spectroscopic Measurements of Free Tropospheric CO, C2H6, and HCN above Mauna Loa, Hawaii: Seasonal Variations and Evidence for Enhanced Emissions from the Southeast Asian Tropical Fires of 1997-1998

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Goldman, A.; Murcray, F. J.; Stephen, T. M.; Pougatchev, N. S.; Fishman, J.; David, S. J.; Blatherwick, R. D.; Novelli, P. C.; Jones, N. B.

    1999-01-01

    High spectral resolution (0.003 per cm) infrared solar absorption measurements of CO, C2H6, and HCN have been recorded at the Network for the Detection of Stratospheric Change station on Mauna Loa, Hawaii, (19.5N, 155.6W, altitude 3.4 km). The observations were obtained on over 250 days between August 1995 and February 1998. Column measurements are reported for the 3.4-16 km altitude region, which corresponds approximately to the free troposphere above the station. Average CO mixing ratios computed for this layer have been compared with flask sampling CO measurements obtained in situ at the station during the same time period. Both show asymmetrical seasonal cycles superimposed on significant variability. The first 2 years of observations exhibit a broad January-April maximum and a sharper CO minimum during late summer. The C2H6 and CO 3.4-16 km columns were highly correlated throughout the observing period with the C2H6/CO slope intermediate between higher and lower values derived from similar infrared spectroscopic measurements at 32'N and 45'S latitude, respectively. Variable enhancements in CO, C2H6, and particularly HCN were observed beginning in about September 1997. The maximum HCN free tropospheric monthly mean column observed in November 1997 corresponds to an average 3.4-16 km mixing ratio of 0.7 ppbv (1 ppbv = 10(exp -9) per unit volume), more than a factor of 3 above the background level. The HCN enhancements continued through the end of the observational series. Back-trajectory calculations suggest that the emissions originated at low northern latitudes in southeast Asia. Surface CO mixing ratios and the C2H6 tropospheric columns measured during the same time also showed anomalous autumn 1997 maxima. The intense and widespread tropical wild fires that burned during the strong El Nino warm phase of 1997- 1998 are the likely source of the elevated emission products.

  9. Impact of climate variability on tropospheric ozone.

    PubMed

    Grewe, Volker

    2007-03-01

    A simulation with the climate-chemistry model (CCM) E39/C is presented, which covers both the troposphere and stratosphere dynamics and chemistry during the period 1960 to 1999. Although the CCM, by its nature, is not exactly representing observed day-by-day meteorology, there is an overall model's tendency to correctly reproduce the variability pattern due to an inclusion of realistic external forcings, like observed sea surface temperatures (e.g. El Niño), major volcanic eruption, solar cycle, concentrations of greenhouse gases, and Quasi-Biennial Oscillation. Additionally, climate-chemistry interactions are included, like the impact of ozone, methane, and other species on radiation and dynamics, and the impact of dynamics on emissions (lightning). However, a number of important feedbacks are not yet included (e.g. feedbacks related to biogenic emissions and emissions due to biomass burning). The results show a good representation of the evolution of the stratospheric ozone layer, including the ozone hole, which plays an important role for the simulation of natural variability of tropospheric ozone. Anthropogenic NO(x) emissions are included with a step-wise linear trend for each sector, but no interannual variability is included. The application of a number of diagnostics (e.g. marked ozone tracers) allows the separation of the impact of various processes/emissions on tropospheric ozone and shows that the simulated Northern Hemisphere tropospheric ozone budget is not only dominated by nitrogen oxide emissions and other ozone pre-cursors, but also by changes of the stratospheric ozone budget and its flux into the troposphere, which tends to reduce the simulated positive trend in tropospheric ozone due to emissions from industry and traffic during the late 80s and early 90s. For tropical regions the variability in ozone is dominated by variability in lightning (related to ENSO) and stratosphere-troposphere exchange (related to Northern Hemisphere Stratospheric

  10. Impact of climate variability on tropospheric ozone.

    PubMed

    Grewe, Volker

    2007-03-01

    A simulation with the climate-chemistry model (CCM) E39/C is presented, which covers both the troposphere and stratosphere dynamics and chemistry during the period 1960 to 1999. Although the CCM, by its nature, is not exactly representing observed day-by-day meteorology, there is an overall model's tendency to correctly reproduce the variability pattern due to an inclusion of realistic external forcings, like observed sea surface temperatures (e.g. El Niño), major volcanic eruption, solar cycle, concentrations of greenhouse gases, and Quasi-Biennial Oscillation. Additionally, climate-chemistry interactions are included, like the impact of ozone, methane, and other species on radiation and dynamics, and the impact of dynamics on emissions (lightning). However, a number of important feedbacks are not yet included (e.g. feedbacks related to biogenic emissions and emissions due to biomass burning). The results show a good representation of the evolution of the stratospheric ozone layer, including the ozone hole, which plays an important role for the simulation of natural variability of tropospheric ozone. Anthropogenic NO(x) emissions are included with a step-wise linear trend for each sector, but no interannual variability is included. The application of a number of diagnostics (e.g. marked ozone tracers) allows the separation of the impact of various processes/emissions on tropospheric ozone and shows that the simulated Northern Hemisphere tropospheric ozone budget is not only dominated by nitrogen oxide emissions and other ozone pre-cursors, but also by changes of the stratospheric ozone budget and its flux into the troposphere, which tends to reduce the simulated positive trend in tropospheric ozone due to emissions from industry and traffic during the late 80s and early 90s. For tropical regions the variability in ozone is dominated by variability in lightning (related to ENSO) and stratosphere-troposphere exchange (related to Northern Hemisphere Stratospheric

  11. Tropospheric Halogen Chemistry

    NASA Astrophysics Data System (ADS)

    von Glasow, R.; Crutzen, P. J.

    2003-12-01

    compilations of laboratory studies that were made to elucidate chemical reaction paths are given by, e.g., DeMore et al. (1997), Sander et al. (2000), and Atkinson et al. (1999, 2000). Emission inventories for chlorine were compiled by Graedel and Keene (1995) and Keene et al. (1999).In Section 4.02.2 of this overview we will first describe the main halogen reaction mechanisms and then discuss, in Section 4.02.3, the springtime surface ozone depletion events in high latitudes that were first observed in the Arctic. Another main part of this chapter is concerned with halogens in the marine boundary layer ( Section 4.02.4). In Section 4.02.5 we describe interactions of halogens with some other elements of atmospheric importance. A very recently discovered environment where halogen chemistry plays a large role are salt lakes ( Section 4.02.6). There the chemistry bears similarity to that of the high-latitude ozone depletion events. This is followed in Section 4.02.7 by a discussion of halogen chemistry in the free troposphere and in Section 4.02.8 by other sources of halogens such as industry and biomass burning.

  12. Improving of Aura Microwave Limb Sounder Data Products

    NASA Astrophysics Data System (ADS)

    Cuddy, D.; Wagner, P.; Read, W.; Livesey, N. J.; Martinez, E.

    2011-12-01

    The Microwave Limb Sounder (MLS) on NASA's Aura satellite began collecting atmospheric data in August of 2004, and the MLS Science Investigator-led Processing System (SIPS) processes the raw data to calibrated radiances and the 20 different geophysical parameters. Currently, SIPS provides two versions (V2 and V3) of these data products, and Goddard Earth Science Data and Information Service Centers (GES-DISC) archives and provides them to the user community. This paper will describe the current plans by the MLS Science Team (MST) to improve the V2 and V3 algorithms, and at the top of the list are how to ameliorate the issue with oscillations in the upper troposphere/lower stratosphere (UT/LS) ozone and improve behavior of UT/LS species in thick cloud. Other improvements include: removing adverse cloud interactions in some products (e.g. CO) that now occur in V3, ideally better still with the new cloud forward model; work to further reduce biases in 640 GHz species; extend species to lower altitude (including potentially those at 190 GHz); consider joint retrievals spanning multiple radiometers (e.g., joint 190/640 GHZ ClO to get methanol independently); better HCN lower down using a separate phase (q.v. 190 GHz goal above); and gain better understanding of hydrostatic / pressure inconsistency in Band 1. This paper will also discuss usability improvement such as TAI93 at 0Z of granule, day boundary discontinuities, and extending the data format to be compatible with NetCDF (network Common Data Form) that supports a machine-independent format for representing scientific data and is widely used in the community.

  13. Chemistry in the Troposphere.

    ERIC Educational Resources Information Center

    Chameides, William L.; Davis, Douglas D.

    1982-01-01

    Topics addressed in this review of chemistry in the troposphere (layer of atmosphere extending from earth's surface to altitude of 10-16km) include: solar radiation/winds; earth/atmosphere interface; kinetic studies of atmospheric reactions; tropospheric free-radical photochemistry; instruments for nitric oxide detection; sampling…

  14. The Observed Response of Ozone Monitoring Instrument (OMI) NO2 Columns to NOx Emission Controls on Power Plants in the United States: 2005-2011

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    We show that Aura Ozone Monitoring Instrument (OMI) nitrogen dioxide (NO2) tropospheric column data may be used to assess changes of the emissions of nitrogen oxides (NOx) from power plants in the United States, though careful interpretation of the data is necessary. There is a clear response for OMI NO2 data to NOx emission reductions from power plants associated with the implementation of mandated emission control devices (ECDs) over the OMI record (2005e2011). This response is scalar for all intents and purposes, whether the reduction is rapid or incremental over several years. However, it is variable among the power plants, even for those with the greatest absolute decrease in emissions. We document the primary causes of this variability, presenting case examples for specific power plants.

  15. Analysis of the Suitability of OMPS LP Ozone Profile Dataset for Extending the Aura MLS Record

    NASA Astrophysics Data System (ADS)

    Kramarova, N. A.; Bhartia, P. K.; Stolarski, R. S.; DeLand, M. T.

    2014-12-01

    The new Ozone Mapping and Profiler Suite (OMPS), launched on 28 October 2011 on the Suomi National Polar-orbiting Partnership satellite, represents the next generation of the US ozone monitoring system. The OMPS Limb Profiler (LP) sensor measures solar radiances scattered from the atmospheric limb in the UV and visible spectral ranges and reconstruct the vertical ozone profiles from the cloud top up to 60 km. The regular LP observations started in early 2012, and now the LP data record exceeds 2.5 years. In this presentation we will demonstrate capability of the new LP sensor to characterize the vertical ozone distribution in different atmospheric regions that are most sensitive to the changes in the stratospheric composition and dynamics. We will consider: a) the seasonal ozone patterns in the lower stratosphere - upper troposphere; b) the vertical ozone distribution inside the Antarctic ozone hole; c) the ozone patterns forced by the Quasi-Biennial Oscillations in the lower tropical stratosphere. The main focus of this study is to perform a comprehensive analysis of ozone patterns obtained from OMPS LP with those observed by Aura MLS to isolate similarities and differences between two sensors in characterizing these processes. We will examine how well LP reproduces the named above natural signals in comparison with MLS in terms of amplitude, phase and vertical structure. One of the key issues is that two instruments measure ozone in different coordinate systems: the LP measures ozone profiles as number density on a regular altitude scale, while Aura MLS retrieves ozone profiles as mixing ratios on pressure vertical grids. The comparison of two measurements requires unit conversion that in turn involves temperature profiles. Thus, the uncertainties related to the unit conversion should be accounted during the analysis. This scientific validation is critical for the further LP algorithm improvement and continuation of the Aura MLS ozone record in the future.

  16. Climate Impacts on Tropospheric Ozone and Hydroxyl

    NASA Technical Reports Server (NTRS)

    Shindell, Drew T.; Bell, N.; Faluvegi, G.

    2003-01-01

    Climate change may influence tropospheric ozone and OH via several main pathways: (1) altering chemistry via temperature and humidity changes, (2) changing ozone and precursor sources via surface emissions, stratosphere-troposphere exchange, and light- ning, and (3) affecting trace gas sinks via the hydrological cycle and dry deposition. We report results from a set of coupled chemistry-climate model simulations designed to systematically study these effects. We compare the various effects with one another and with past and projected future changes in anthropogenic and natural emissions of ozone precursors. We find that white the overall impact of climate on ozone is probably small compared to emission changes, some significant seasonal and regional effects are apparent. The global effect on hydroxyl is quite large, however, similar in size to the effect of emission changes. Additionally, we show that many of the chemistry-climate links that are not yet adequately modeled are potentially important.

  17. Tropospheric Ozone and Biomass Burning

    NASA Technical Reports Server (NTRS)

    Chandra, Sushil; Ziemke, J. R.; Bhartia, P. K.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    This paper studies the significance of pyrogenic (e.g., biomass burning) emissions in the production of tropospheric ozone in the tropics associated with the forest and savanna fires in the African, South American, and Indonesian regions. Using aerosol index (Al) and tropospheric column ozone (TCO) time series from 1979 to 2000 derived from the Nimbus-7 and Earth Probe TOMS measurements, our study shows significant differences in the seasonal and spatial characteristics of pyrogenic emissions north and south of the equator in the African region and Brazil in South America. In general, they are not related to the seasonal and spatial characteristics of tropospheric ozone in these regions. In the Indonesian region, the most significant increase in TCO occurred during September and October 1997, following large-scale forest and savanna fires associated with the El Nino-induced dry season. However, the increase in TCO extended over most of the western Pacific well outside the burning region and was accompanied by a decrease in the eastern Pacific resembling a west-to-east dipole about the date-line. The net increase in TCO integrated over the tropical region between 15 deg N and 15 deg S was about 6-8 Tg (1 Tg = 10(exp 12) gm) over the mean climatological value of about 72 Tg. This increase is well within the range of interannual variability of TCO in the tropical region and does not necessarily suggest a photochemical source related to biomass burning. The interannual variability in TCO appears to be out of phase with the interannual variability of stratospheric column ozone (SCO). These variabilities seem to be manifestations of solar cycle and quasibiennial oscillations.

  18. Laser Safety and Hazard Analysis for the Trailer (B70) Based AURA Laser System

    SciTech Connect

    AUGUSTONI, ARNOLD L.

    2003-01-01

    A laser safety and hazard analysis was performed for the AURA laser system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for ''Safe Use of Lasers'' and the 2000 version of the ANSI Standard Z136.6, for ''Safe Use of Lasers Outdoors''. The trailer based AURA laser system is a mobile platform, which is used to perform laser interaction experiments and tests at various national test sites. The trailer (B70) based AURA laser system is generally operated on the United State Air Force Starfire Optical Range (SOR) at Kirtland Air Force Base (KAFB), New Mexico. The laser is used to perform laser interaction testing inside the laser trailer as well as outside the trailer at target sites located at various distances from the exit telescope. In order to protect personnel, who work inside the Nominal Hazard Zone (NHZ), from hazardous laser emission exposures it was necessary to determine the Maximum Permissible Exposure (MPE) for each laser wavelength (wavelength bands) and calculate the appropriate minimum Optical Density (OD{sub min}) of the laser safety eyewear used by authorized personnel and the Nominal Ocular Hazard Distance (NOHD) to protect unauthorized personnel who may have violated the boundaries of the control area and enter into the laser's NHZ.

  19. Tropospheric Passive Remote Sensing

    NASA Technical Reports Server (NTRS)

    Keafer, L. S., Jr. (Editor)

    1982-01-01

    The long term role of airborne/spaceborne passive remote sensing systems for tropospheric air quality research and the identification of technology advances required to improve the performance of passive remote sensing systems were discussed.

  20. Pure menstrual migraine with sensory aura: a case report.

    PubMed

    Chen, Jiann-Jy; Hsu, Yung-Chu; Chen, Dem-Lion

    2012-07-01

    Hormonal changes related to the menstrual cycle have a great impact on migraines in women. Menstrual migraine attacks are almost invariably without aura. Categorizing migraines into menstrual or non-menstrual types is one way to stratify migraines without aura according to the appendix criteria of the International Classification of Headache Disorders. We report a peri-menopausal woman whose sensory aura exclusively heralded menstrual migraine. A 51-year-old woman had suffered from monthly episodic headaches since the age of 46. Before a headache, and within 1 h on the first day of her menstruation, she always experienced numbness in her entire left upper limb. After the sensory aura, migrainous headaches occurred with nausea and photophobia. In the postmenopausal period, she no longer had sensory aura, and her headache pattern changed and became less severe. Her physical and neurologic exams as well as electroencephalography, brain magnetic resonance imaging, and conventional angiography were all normal. She fulfilled the diagnosis of pure menstrual migraine with typical sensory aura. To our knowledge, this is the first formal case report of pure menstrual migraine with aura.

  1. Infrared Solar Spectroscopic Measurements of Free Tropospheric CO, C2H6, and HCN above Mauna Loa, Hawaii: Seasonal Variations and Evidence for Enhanced Emissions from the Southeast Asian Fires of 1997-1998. Revised

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Goldman, A.; Murcray, F. J.; Stephen, T. M.; Pougatchev, N. S.; Fishman, J.; David, S. J.; Blatherwick, R. D.; Novelli, P. C.; Jones, N. B.; Connor, B. J.

    1999-01-01

    High spectral resolution (0.003/ cm) infrared solar absorption measurements of CO, C2H6, and HCN have been recorded at the Network for the Detection of Stratospheric Change station on Mauna Loa, Hawaii, (19.5 deg N, 155.6 deg W, altitude 3.4 km). The observations were obtained on over 250 days between August 1995 and February 1998. Column measurements are reported for the 3.4 - 16 km altitude region, which corresponds approximately to the free troposphere above the station. Average CO mixing ratios computed for this layer have been compared with flask sampling CO measurements obtained in situ at the station during the same time period. Both show asymmetrical seasonal cycles superimposed on significant variability. The first two years of observations exhibit a broad January-April maximum and a sharper CO minimum during late summer. The C2H6 and CO 3.4 - 16 km columns were highly correlated throughout the observing period with the C2H6/CO slope intermediate between higher and lower values derived from similar infrared spectroscopic measurements at 32 deg N and 45 deg S latitude, respectively. Variable enhancements in CO, C2H6, and particularly HCN were observed beginning in about September 1997. The maximum HCN free tropospheric monthly mean column observed in November 1997 corresponds to an average 3.4 - 16 km mixing ratio of 0.7 ppbv (1 ppbv = 10(exp -9) per unit volume), more than a factor of 3 above the background level. The HCN enhancements continued through the end of the observational series. Back-trajectory calculations suggest that the emissions originated at low northern latitudes in southeast Asia. Surface CO mixing ratios and the C2H6 tropospheric columns measured during the same time also showed anomalous autumn 1997 maxima. The intense and widespread tropical wild fires that burned during 3 the strong El Nino warm phase of 1997-1998 are the likely source of the elevated emission products.

  2. The visual aura rating scale as an outcome predictor for persistent visual aura without infarction.

    PubMed

    Wang, Y-F; Fuh, J-L; Chen, W-T; Wang, S-J

    2008-12-01

    Persistent visual aura without infarction is rare. Its pathogenic mechanism is unknown, and the response to migraine prophylactic agents varies. A systematic analysis of 29 patients (23 from the literature and six in the present report; 6M/23F, mean age 37.6 years) was carried out in terms of demographics, headache and visual symptom profiles, treatment regimens and outcomes. Patterns of visual disturbances (VDs) were re-assessed with the Visual Aura Rating Scale (VARS, score 0-10). Even though the majority of patients had headache improvement, only eight (27.6%) had complete resolution of persistent VD, without definite relevance to any specific agent. Patients with complete resolution of VD tended to have scotoma (50.0% vs. 0%; P = 0.003), unilateral/homonymous involvement (62.5% vs. 9.5%; P = 0.008), higher VARS scores (1.88 +/- 1.73 vs. 0.10 +/- 0.30; P < 0.001) and shorter duration of illness (10.0 +/- 12.9 vs. 60.2 +/- 90.9 months, P = 0.008) compared with those without. These findings remained even when the six current patients were not included for analyses. In conclusion, the prognosis of persistent VD was poor, and higher VARS scores, i.e. more typical of migraine visual aura, predicted a better outcome. For those with a potential for complete resolution, improvement would occur early in the course.

  3. Auras in mysticism and synaesthesia: a comparison.

    PubMed

    Milán, E G; Iborra, O; Hochel, M; Rodríguez Artacho, M A; Delgado-Pastor, L C; Salazar, E; González-Hernández, A

    2012-03-01

    In a variety of synaesthesia, photisms result from affect-laden stimuli as emotional words, or faces of familiar people. For R, who participated in this study, the sight of a familiar person triggers a mental image of "a human silhouette filled with colour". Subjective descriptions of synaesthetic experiences induced by the visual perception of people's figures and faces show similarities with the reports of those who claim to possess the ability to see the aura. It has been proposed that the purported auric perception may be easily explained by the presence of a specific subtype of cross-modal perception. We analyse the subjective reports of four synaesthetes who experience colours in response to human faces and figures. These reports are compared with descriptions of alleged auric phenomena found in the literature and with claims made by experts in esoteric spheres. The discrepancies found suggest that both phenomena are phenomenologically and behaviourally dissimilar.

  4. Tracking the sources of tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Butler, T. M.; Churkina, G.; Coates, J.; Grote, R.; Mar, K.; von Schneidemesser, E.; Zhu, S.

    2013-12-01

    Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this set of studies we examine the attribution of tropospheric ozone to emissions of VOC using a tagging approach, whereby each VOC oxidation intermediate in model chemical mechanisms is tagged with the identity of its primary emitted compound, allowing modelled ozone production to be directly attributed to all emitted VOCs in the model. Using a global model we

  5. Auditory aura in frontal opercular epilepsy: sounds from afar.

    PubMed

    Thompson, Stephen A; Alexopoulos, Andreas; Bingaman, William; Gonzalez-Martinez, Jorge; Bulacio, Juan; Nair, Dileep; So, Norman K

    2015-06-01

    Auditory auras are typically considered to localize to the temporal neocortex. Herein, we present two cases of frontal operculum/perisylvian epilepsy with auditory auras. Following a non-invasive evaluation, including ictal SPECT and magnetoencephalography, implicating the frontal operculum, these cases were evaluated with invasive monitoring, using stereoelectroencephalography and subdural (plus depth) electrodes, respectively. Spontaneous and electrically-induced seizures showed an ictal onset involving the frontal operculum in both cases. A typical auditory aura was triggered by stimulation of the frontal operculum in one. Resection of the frontal operculum and subjacent insula rendered one case seizure- (and aura-) free. From a hodological (network) perspective, we discuss these findings with consideration of the perisylvian and insular network(s) interconnecting the frontal and temporal lobes, and revisit the non-invasive data, specifically that of ictal SPECT.

  6. Migraine aura and related phenomena: beyond scotomata and scintillations

    PubMed Central

    Vincent, MB; Hadjikhani, N

    2013-01-01

    Migraine affects the cortical physiology and may induce dysfunction both ictally and interictally. Although visual symptoms predominate during aura, other contiguous cortical areas related to less impressive symptoms are also impaired in migraine. Answers from 72.2% migraine with aura and 48.6% of migraine without aura patients on human faces and objects recognition, colour perception, proper names recalling and memory in general showed dysfunctions suggestive of prosopagnosia, dyschromatopsia, ideational apraxia, alien hand syndrome, proper name anomia or aphasia, varying in duration and severity. Symptoms frequently occurred in a successively building-up pattern fitting with the geographical distribution of the various cortical functions. When specifically inquired, migraineurs reveal less evident symptoms that are not usually considered during routine examination. Spreading depression most likely underlies the aura symptoms progression. Interictal involvement indicates that MWA and MWoA are not completely silent outside attacks, and that both subforms of migraine may share common mechanisms. PMID:17944958

  7. Rapid chemical evolution of tropospheric volcanic emissions from Redoubt Volcano, Alaska, based on observations of ozone and halogen-containing gases

    NASA Astrophysics Data System (ADS)

    Kelly, Peter J.; Kern, Christoph; Roberts, Tjarda J.; Lopez, Taryn; Werner, Cynthia; Aiuppa, Alessandro

    2013-06-01

    We report results from an observational and modeling study of reactive chemistry in the tropospheric plume emitted by Redoubt Volcano, Alaska. Our measurements include the first observations of Br and I degassing from an Alaskan volcano, the first study of O3 evolution in a volcanic plume, as well as the first detection of BrO in the plume of a passively degassing Alaskan volcano. This study also represents the first detailed spatially-resolved comparison of measured and modeled O3 depletion in a volcanic plume. The composition of the plume was measured on June 20, 2010 using base-treated filter packs (for F, Cl, Br, I, and S) at the crater rim and by an instrumented fixed-wing aircraft on June 21 and August 19, 2010. The aircraft was used to track the chemical evolution of the plume up to ~ 30 km downwind (2 h plume travel time) from the volcano and was equipped to make in situ observations of O3, water vapor, CO2, SO2, and H2S during both flights plus remote spectroscopic observations of SO2 and BrO on the August 19th flight. The airborne data from June 21 reveal rapid chemical O3 destruction in the plume as well as the strong influence chemical heterogeneity in background air had on plume composition. Spectroscopic retrievals from airborne traverses made under the plume on August 19 show that BrO was present ~ 6 km downwind (20 min plume travel time) and in situ measurements revealed several ppbv of O3 loss near the center of the plume at a similar location downwind. Simulations with the PlumeChem model reproduce the timing and magnitude of the observed O3 deficits and suggest that autocatalytic release of reactive bromine and in-plume formation of BrO were primarily responsible for the observed O3 destruction in the plume. The measurements are therefore in general agreement with recent model studies of reactive halogen formation in volcanic plumes, but also show that field studies must pay close attention to variations in the composition of ambient air

  8. Tropospheric Nitrogen Dioxide Column Density Trends Seen from the 10-year Record of OMI Measurements over East Asia

    NASA Astrophysics Data System (ADS)

    Irie, H.; Muto, T.; Itahashi, S.; Kurokawa, J. I.

    2015-12-01

    The Ozone Monitoring Instrument (OMI) aboard the Aura satellite recorded the 10-year (2005-2014) of tropospheric nitrogen dioxide (NO2) vertical column density (VCD) data. The data set taken over East Asia was analyzed to estimate linear trends on national and grid bases for two periods of 2005-2011 and 2011-2014. The most striking features are leveling-off or decreasing trends seen in NO2 VCDs over China for 2011-2014 after continuous increases for 2005-2011. In particular, a significant reduction by ~14% occurred from 2013 through 2014, attaining to the level of 2009. The grid-basis trend analysis implies that the turnaround seen in the trends occurred on a province or larger spatial scale and was likely due mainly to the technical improvement such as the widespread use of de-NOx units. Another prominent features are seen in Japan, where NO2 VCDs decreased at a rate of ~4% per year from 2005 to 2011. The rate was almost unchanged between the two periods 2005-2011 and 2011-2014, while the significant power substitution of thermal power generation for the nuclear power generation took place in Japan after 2011, when a massive earthquake occurred off the Pacific coast of northern Japan. This reflects a less contribution of NOx emissions from the power plant sector than that from the transport sector in the Pacific Belt Zone lying over metropolitan areas.

  9. Maintaining Aura's Orbit Requirements Under New Maneuver Operations

    NASA Technical Reports Server (NTRS)

    Johnson, Megan; Petersen, Jeremy D.

    2014-01-01

    The Earth Observing System (EOS) Afternoon Constellation consists of five member missions (GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura), each of which maintain a frozen, sun-synchronous orbit with a 16-day repeating ground track that follows the Worldwide Reference System-2 (WRS-2). Under nominal science operations for Aura, the propulsion system is oriented such that the resultant thrust vector is aligned 13.493 degrees away from the velocity vector along the yaw axis. When performing orbit maintenance maneuvers, the spacecraft performs a yaw slew to align the thrust vector in the appropriate direction. A new Drag Make Up (DMU) maneuver operations scheme has been implemented for Aura alleviating the need for the 13.493 degree yaw slew. The focus of this investigation is to assess the impact that no-slew DMU maneuver operations will have on Auras Mean Local Time (MLT) which drives the required along track separation between Aura and the constellation members, as well as Auras frozen orbit properties, eccentricity and argument of perigee. Seven maneuver strategies were analyzed to determine the best operational approach. A mirror pole strategy, with maneuvers alternating at the North and South poles, was implemented operationally to minimize impact to the MLT. Additional analysis determined that the mirror pole strategy could be further modified to include frozen orbit maneuvers and thus maintain both MLT and the frozen orbit properties under no-slew operations

  10. [Differential diagnosis of visual aura in migraine and epilepsy].

    PubMed

    Schulze-Bonhage, A

    2001-09-01

    Visual phenomena like lightnings, disturbed contours of objects, or skotoma, can be due to ophthalmological diseases, but can also occur as symptoms generated by the central nervous system ("aura") in migraine or epilepsy. A subsequent hemicrania is considered as a hallmark of migraine, but in many cases does not allow for a certain distinction from postictal headaches in patients with focal epilepsy. A detailed analysis of the aura does, however, provide sufficient information for classifying the disorder as an aura in migraine or as a simple partial epileptic seizure in most cases. The higher degree of differentiation of visual phenomena including colour, movement, and complex visual phenomena, is characteristic of the activation of neuronal circuits during an epileptic aura. The higher speed of transsynaptic propagation of epileptic discharges and postictal inactivation causes a more rapid time-course of the epileptic aura as compared to a migraine aura resulting from a depolarization spreading by diffusion. Clinically, the diagnosis of epilepsy is supported by additional positive motor phenomena or by a transition into a complex partial seizure, e. g. when epileptic activity spreads into a temporal lobe. Secondarily generalized seizures, however, may also occur in patients with migraine. Interictal and ictal EEG recordings can be important to prove an epileptic origin, but their sensitivity is low if ictal discharges remain limited to a small brain area. In rare cases, measurements of ictal cerebral perfusion can contribute to the differential diagnosis.

  11. Migraine with aura and patent foramen ovale: myth or reality?

    PubMed

    Finocchi, C; Del Sette, M

    2015-05-01

    Several observational studies report that subjects with migraine with aura have a higher prevalence of right-to left shunt, commonly due to patent foramen ovale, and that patent foramen ovale is more prevalent in subjects with migraine with aura. Although migraine without aura has been less extensively studied, it does not seem to be associated with an increased prevalence of right-to left shunt. The mechanism that underlies the possible relationship between patent foramen ovale and migraine with aura remains speculative. The proposed mechanisms are migraine-triggering vasoactive chemicals bypassing the pulmonary filter and reaching the cerebral circulation and paradoxical microembolization. However, it is unclear, at this time, if there is a causal or comorbid association between the two conditions. In some families atrial shunts show a dominant inheritance that seems to be linked to inheritance of migraine with aura. Migraine with aura is an independent risk factor for ischemic stroke, and patent foramen ovale is present more frequently in patients with cryptogenic stroke than in controls. At this moment, there is no convincing evidence that excess stroke risk of migraine is simply mediated by patent foramen ovale through paradoxical embolism. Several non-controlled studies suggest that closure of the foramen ovale significantly reduces attack frequency in migraine patient, but the only prospective placebo-controlled trial does not support these results. Patent foramen ovale closure, at present, is not indicated as a treatment for migraine in clinical practice.

  12. The TROPOspheric Monitoring Instrument (TROPOMI)

    NASA Astrophysics Data System (ADS)

    Veefkind, Pepijn; Kleipool, Quintus; Aben, Ilse; Levelt, Pieternel

    2015-04-01

    The Copernicus Sentinel 5 Precursor (S5P), scheduled for launch in 2016, is the first of the sentinels dedicated to monitoring of the atmospheric composition. The main application areas of the mission are air quality, climate and the ozone layer. The single payload of the S5P mission is TROPOspheric Monitoring Instrument (TROPOMI). TROPOMI is a nadir viewing shortwave spectrometer that will measure in the UV-visible wavelength range (270-500 nm), the near infrared (710-770 nm) and the shortwave infrared (2314-2382 nm). TROPOMI will have an unprecedented spatial resolution of about 7x7 km2 at nadir. The spatial resolution is combined with a wide swath to allow for daily global coverage. The high spatial resolution serves two goals: (1) emissions sources can be detected with more accuracy and (2) the number of cloud-free ground pixels will increase substantially. The TROPOMI/S5P geophysical (Level 2) data products include nitrogen dioxide, carbon monoxide, ozone (total column, tropospheric column & profile), methane, sulphur dioxide, formaldehyde and aerosol and cloud parameters. In this contribution we will present the TROPOMI instrument performance and the new science opportunities that it will enable.

  13. Impacts of long- and short-term climate variability on terrestrial biogenic emissions and their influence on the remote tropical troposphere

    NASA Astrophysics Data System (ADS)

    Monks, S. A.; Arnold, S.; Guenther, A. B.; Emmons, L. K.; Carpenter, L.; Read, K.

    2013-12-01

    Terrestrial vegetation emits a wide range of biogenic volatile organic compounds (BVOC) into the atmosphere (~1150 TgC/yr), which accounts for ~90% of total VOC surface emissions. Emissions of BVOC are largely dependent on environmental factors such as sunlight and temperature, which makes them sensitive to both long-term and short-term changes in the climate system. ENSO is well-known to have global impacts on temperature and precipitation, and therefore has the potential to impact regional BVOC emissions on inter-annual time-scales. In addition to this, increased global mean temperatures and atmospheric carbon dioxide (CO2) concentrations over the past few decades may also have affected BVOC emissions. Once in the atmosphere, these compounds have the ability to influence global and regional atmospheric chemistry and climate through impacts on the hydroxyl radical, ozone, particulate matter and methane lifetime. We use the NCAR Community Land Model (CLM) coupled to the Model of Emissions of Gases and Aerosols from Nature (MEGANv2) to investigate both long-term changes and inter-annual variability of BVOC emissions over a 50-year period at regional and global spatial-scales. This is done by considering the impacts of increasing temperatures and CO2 concentrations on long-term emissions of BVOC separately, in addition to using the Multivariate ENSO Index (MEI) to investigate the regional response in emissions due to natural ENSO variability. Global composites of ENSO-positive and ENSO-negative phase emissions are then used to drive global atmospheric chemistry simulations using the NCAR Community Earth System Model (CESM). Through comparisons with 6 years of measurements from the Cape Verde observatory in the tropical Atlantic Ocean, we explore the role of inter-annual variability in terrestrial biogenic emissions in controlling the observed variability in methanol, acetone and acetaldehyde in the remote tropical atmosphere. By accounting for inter-annual changes in

  14. Tropospheric Composition Change observed from Space (Invited)

    NASA Astrophysics Data System (ADS)

    Richter, A.; Hilboll, A.; Leitao, J.; Vrekoussis, M.; Wittrock, F.; Burrows, J. P.

    2010-12-01

    The composition of the troposphere is largely influenced by surface emissions of both natural and anthropogenic origins. These emissions change over time as result of human activities and natural variability, leading to varying atmospheric levels of primary and secondary pollutants. Satellite observations of sun light scattered back by the surface and the atmosphere can be used to retrieve information on atmospheric trace gases by application of optical absorption spectroscopy. In the UV and visible part of the spectrum, these measurements have good sensitivity to the lower troposphere providing information on relevant species such as O3, NO2, SO2, HCHO or glyoxal. Here, we report on recent results on tropospheric composition changes obtained from the GOME, SCIAMACHY and GOME-2 instruments which have a combined data record of nearly 15 years. The focus is on NO2 which shows an increasing trend over Asia and many large cities in countries with growing economies. At the same time, significant reductions are observed over the US and Europe, probably as result of changes in environmental legislation. SO2 signals have been decreasing over the US since 1996 while a strong upward trend was evident over China until recently when desulphurisation of power plant emissions came into effect. There also is evidence for increases in VOC levels over China which could be either of anthropogenic origin or from biogenic emissions.

  15. Global tropospheric ozone investigations

    NASA Technical Reports Server (NTRS)

    Browell, Edward V.

    1998-01-01

    Ozone (O3) is one of the most important trace gases in the troposphere, and it is responsible for influencing many critical chemical and radiative processes. Ozone contributes to the formation of the hydroxyl radical (OH), which is central to most chemical reactions in the lower atmosphere, and it absorbs UV, visible, and infrared radiation which affects the energy budget and atmospheric temperatures. In addition, O3 can be used as a tracer of atmospheric pollution and stratosphere troposphere exchange. At elevated concentrations, O3 can also produce detrimental biological and human health effects. The US National Research Council (NRC) Board on Sustainable Development reviewed the US Global Change Research Program (USGCRP) [NRC, 1995], and it identified tropospheric chemistry as one of the high priority areas for the USGCRP in the next decade. The NRC identified the following specific challenges in tropospheric chemistry. Although we understand the reason for the high levels of 03 over several regions of the world, we need to better establish the distribution of O3 in the troposphere in order to document and understand the changes in the abundance of global tropospheric O3. This information is needed to quantify the contribution of O3 to the Earth' s radiative balance and to understand potential impacts on the health of the biosphere. Having recognized the importance of particles in the chemistry of the stratosphere, we must determine how aerosols and clouds affect the chemical processes in the troposphere. This understanding is essential to predict the chemical composition of the atmosphere and to assess the resulting forcing effects in the climate system. We must determine if the self-cleansing chemistry of the atmosphere is changing as a result of human activities. This information is required to predict the rate at which pollutants are removed from the atmosphere. Over nearly two decades, airborne Differential Absorption Lidar (DIAL) systems have been used in

  16. TES/Aura L2 Summary Product (TL2SUMS)

    Atmospheric Science Data Center

    2015-01-30

    ... Title:  TES Discipline:  Tropospheric Chemistry Level:  L2 Spatial Coverage:  (-90, ... OPeNDAP Parameters:  Air Temperature Surface Air Temperature Carbon Monoxide Tropospheric Ozone Ozone ...

  17. TES/Aura L2 Supplemental Product (TL2SUPS)

    Atmospheric Science Data Center

    2015-01-30

    ... Title:  TES Discipline:  Tropospheric Chemistry Level:  L2 Spatial Coverage:  (-90, ... OPeNDAP Parameters:  Air Temperature Surface Air Temperature Carbon Monoxide Tropospheric Ozone Ozone ...

  18. Validation of the Aura Microwave Limb Sounder Temperature and Geopotential Height Measurements

    NASA Technical Reports Server (NTRS)

    Schwartz, M. J.; Lambert, A.; Manney, G. L.; Read, W. G.; Livesey, N. J.; Froidevaux, L.; Ao, C. O.; Bernath, P. F.; Boone, C. D.; Cofield, R. E.; Daffer, W. H.; Drouin, B. J.; Fetzer, E. J.; Fuller, R. A.; Jarnot, R. F.; Jiang, J. H.; Jiang, Y. B.; Knosp, B. W.; Krueger, K.; Li, J.-L. F.; Mlynczak, M. G.; Pawson, S.; Russell, J. M., III; Santee, M. L.; Snyder, W. V.

    2007-01-01

    This paper describes the retrievals algorithm used to determine temperature and height from radiance measurements by the Microwave Limb Sounder on EOS Aura. MLS is a "limbscanning" instrument, meaning that it views the atmosphere along paths that do not intersect the surface - it actually looks forwards from the Aura satellite. This means that the temperature retrievals are for a "profile" of the atmosphere somewhat ahead of the satellite. Because of the need to view a finite sample of the atmosphere, the sample spans a box about 1.5km deep and several tens of kilometers in width; the optical characteristics of the atmosphere mean that the sample is representative of a tube about 200-300km long in the direction of view. The retrievals use temperature analyses from NASA's Goddard Earth Observing System, Version 5 (GEOS-5) data assimilation system as a priori states. The temperature retrievals are somewhat deperrdezt on these a priori states, especially in the lower stratosphere. An important part of the validation of any new dataset involves comparison with other, independent datasets. A large part of this study is concerned with such comparisons, using a number of independent space-based measurements obtained using different techniques, and with meteorological analyses. The MLS temperature data are shown to have biases that vary with height, but also depend on the validation dataset. MLS data are apparently biased slightly cold relative to correlative data in the upper troposphere and slightly warm in the middle stratosphere. A warm MLS bias in the upper stratosphere may be due to a cold bias in GEOS-5 temperatures.

  19. Inter-Annual and Decadal Changes in Tropospheric and Stratospheric Ozone

    NASA Technical Reports Server (NTRS)

    Ziemke, Jr. R.; Chandra, S.

    2011-01-01

    Ozone data beginning October 2004 from the Aura Ozone Monitoring Instrument (OMI) and Aura Microwave Limb Sounder (MLS) are used to evaluate the accuracy of the Cloud slicing technique in effort to develop long data records of tropospheric and stratospheric ozone and studying their long-term changes. Using this technique, we have produced a 32-year (1979-2010) long record of tropospheric and stratospheric ozone from the combined Total Ozone Mapping Spectrometer (Toms) and OMI. The analyses of these time series suggest that the quasi-biennial oscillation (QBO) is the dominant source of inter-annual changes of 30-40 Dobson Units (DU). Tropospheric ozone also indicates a QBO signal in the peak to peak changes varying from 2 to 7 DU. Decadal changes in global stratospheric ozone indicate a turnaround in ozone loss around mid 1990's with most of these changes occurring in the Northern Hemisphere from the subtropics to high latitudes. The trend results are generally consistent with the prediction of chemistry climate models which include the reduction of ozone destroying substances beginning in the late 1980's mandated by the Montreal Protocol.

  20. An aura of confusion Part 2: the aided eye--"imaging the aura?".

    PubMed

    Duerden, Tim

    2004-05-01

    The second of three papers considers claims made for the perception or detection of vital energy. Many systems of complementary and alternative medicine assume the existence of a vital force that mediates therapeutic efficacy, for example chi or qi in Traditional Chinese Medicine. Vital energy directly perceived or imaged that surrounds living organisms is frequently termed the aura. A range of devices or techniques are claimed to image the aura. These include Kirlian photography, gas discharge visualisation (GDV) and polychromatic interference photography (PIP). This paper explores such claims and argues that the images produced can be explained using concepts from the physical sciences. It is suggested that techniques such as KP, GDV or PIP currently offer insufficient reliable research evidence concerning their use as diagnostic or imaging alternatives. Consequently their clinical use is debatable. Kirlian photography and its derivatives may however be useful as a research tool by providing visual records of complex bodily responses to experimental situations. For example, responses to physiological or psychological stressors. PMID:15135764

  1. Changes in tropospheric composition and air quality.

    PubMed

    Tang, X; Madronich, S; Wallington, T; Calamari, D

    1998-10-01

    Reductions in stratospheric ozone (O3) cause increased penetration of ultraviolet-B (UV-B) radiation to the troposphere, and therefore increases in the chemical activity in the lower atmosphere (the troposphere). Tropospheric ozone levels are sensitive to local concentrations of nitrogen oxides (NOx) and hydrocarbons. Model studies suggest that additional UV-B radiation reduces tropospheric ozone in clean environments (low NOx), and increases tropospheric ozone in polluted areas (high NOx). Assuming other factors remain constant, additional UV-B will increase the rate at which primary pollutants are removed from the troposphere. Increased UV-B is expected to increase the concentration of hydroxyl radicals (OH) and result in faster removal of pollutants such as carbon monoxide (CO), methane (CH4), non-methane hydrocarbons (NMHCs), sulfur and nitrogen oxides, hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs). Concentrations of peroxy radicals (both inorganic and organic) are expected to increase, leading to higher atmospheric levels of hydrogen peroxide (H2O2) and organic peroxides. The effects of UV-B increases on tropospheric O3, OH, methane, CO, and possibly other tropospheric constituents, while not negligible, will be difficult to detect because the concentrations of these species are also influenced by many other variable factors (e.g., emissions). Trifluoroacetic acid (TFA, CF3COOH) is produced in the atmosphere by the degradation of HCFC-123 (CF3CHCl2), HCFC-124 (CF3CHFCl), and HFC-134a (CF3CH2F), which are used as substitutes for ozone-depleting substances. The atmospheric oxidation mechanisms of these replacement compounds are well established. Reported measurements of TFA in rain, rivers, lakes, and oceans show it to be a ubiquitous component of the hydrosphere, present at levels much higher than can be explained by reported sources. The levels of TFA produced by the atmospheric degradation of HFCs and HCFCs emitted up to the year 2020 are

  2. Global Tropospheric OH

    NASA Astrophysics Data System (ADS)

    Nicely, J. M.; Canty, T. P.; Lang, C.; Duncan, B. N.; Liang, Q.; Oman, L.; Salawitch, R. J.; Stolarski, R. S.; Waugh, D. W.

    2012-12-01

    The oxidizing capacity of the troposphere is controlled, to a large extent, by the abundance of hydroxyl radical (OH). The global mean concentration of OH, inferred from measurements of methyl chloroform, has remained relatively constant during the past several decades, despite rising levels of CH4 that should have led to a steady decline. Here we examine other factors that may have affected global [OH], such as the overhead burden of stratospheric O3 and tropospheric H2O, using global OH fields from the GEOS Chemistry-Climate Model. Our analysis suggests these factors may have contributed a positive trend to global [OH] large enough to counter the decrease due to CH4.

  3. Alice in Wonderland syndrome as aura of migraine.

    PubMed

    Ilik, Faik; Ilik, Kemal

    2014-08-01

    Alice in Wonderland syndrome (AIWS), named for Lewis Carroll's titular character, is a disorder characterized by transient episodes of visual hallucinations and perceptual distortions, during which objects or body parts are perceived as altered in various ways (metamorphopsia), including enlargement (macropsia) or reduction (micropsia) in the perceived size of a form. Migraine aura is a transient neurological symptom that most commonly involves the visual fields and occurs before the headache phase. Aura symptoms include the perception of flashing lights that begin in the center of vision and expand in jagged patterns out into the periphery. Symptoms may be somatosensory, such as numbness and tingling in the lips or fingers. They may also involve a profound alteration of the perception of space and time (the "Alice in Wonderland" syndrome). In this article, we present a child had Alice in Wonderland syndrome as aura of migraine. PMID:23957288

  4. On Orbit Commissioning of the Earth Observing System Microwave Limb Sounder (EOS MLS) On the Aura Spacecraft

    NASA Technical Reports Server (NTRS)

    Lay, Richard R.; Lee, Karen A.; Holden, James R.; Oswald, John E.; Jarnot, Robert F.; Pickett, Herbert M.; Stek, Paul C.; Cofield, Richard E., III; Flower, Dennis A.; Schwartz, Michael J.; Shoemaker, Candace M.

    2005-01-01

    The Microwave Limb Sounder instrument was launched aboard NASA's EOS AURA satellite in July, 2004. The overall scientific objectives for MLS are to measure temperature, pressure, and several important chemical species in the upper troposphere and stratosphere relevant to ozone processes and climate change. MLS consists of a suite of radiometers designed to operate from 11 8 GHz to 2.5 THz, with two antennas (one for 2.5 THz, the other for the lower frequencies) that scan vertically through the atmospheric limb, and spectrometers with spectral resolution of 6 MHz at spectral line centers. This paper describes the on-orbit commissioning the MLS instrument which includes activation and engineering functional verifications and calibrations.

  5. Relationship between primary restless legs syndrome and migraine with aura.

    PubMed

    Acar, Bilgehan Atılgan; Acar, Türkan; Alagöz, Aybala Neslihan; Karacan, Alper; Varım, Ceyhun; Uyanık, Mehmet Şevki; Kaya, Tezcan; Akdemir, Ramazan

    2016-08-01

    In this study, the prevalence and characteristics of definite migraine in primary restless legs syndrome (pRLS) patients and matched control patients (CPs) were investigated. We evaluated 63 consecutive adult pRLS patients and 141 age- and sex-matched controls in this case-control study. The diagnosis of migraine and its subtypes were defined based on The International Classification of Headache Disorders-II. Only those with "definite" migraine were included in the study. The mean age of 63 adult pRLS patients (15 men and 48 women) who participated in the study was 49.4 years. A total of 27 patients (42.9%) had definite migraine. Of these migraineurs, seven (11.1%) were without aura and 20 (31.8%) were with aura. The mean age of the 141 matched CPs was 48.7 years. A total of 32 CPs (22.7%) experienced migraine. Among these 32 migraineurs, 28 (19.9%) were without aura and four (2.8%) were with aura. Migraine and migraine with aura were significantly more common in pRLS patients than in CPs. pRLS patients with migraine were more anxious and experienced a shorter duration of RLS symptoms than pRLS patients without migraine. Migraineurs in the pRLS group tended to have high scores for severity of migraine headache by Visual Analog Scale score and high levels of disability by Migraine Disability Assessment grading than those in the control group. pRLS patients showed a positive association with definite migraine headaches. In contrast to results highlighted in recent studies, we found a strong link between migraine with aura and pRLS.

  6. Relationship between primary restless legs syndrome and migraine with aura.

    PubMed

    Acar, Bilgehan Atılgan; Acar, Türkan; Alagöz, Aybala Neslihan; Karacan, Alper; Varım, Ceyhun; Uyanık, Mehmet Şevki; Kaya, Tezcan; Akdemir, Ramazan

    2016-08-01

    In this study, the prevalence and characteristics of definite migraine in primary restless legs syndrome (pRLS) patients and matched control patients (CPs) were investigated. We evaluated 63 consecutive adult pRLS patients and 141 age- and sex-matched controls in this case-control study. The diagnosis of migraine and its subtypes were defined based on The International Classification of Headache Disorders-II. Only those with "definite" migraine were included in the study. The mean age of 63 adult pRLS patients (15 men and 48 women) who participated in the study was 49.4 years. A total of 27 patients (42.9%) had definite migraine. Of these migraineurs, seven (11.1%) were without aura and 20 (31.8%) were with aura. The mean age of the 141 matched CPs was 48.7 years. A total of 32 CPs (22.7%) experienced migraine. Among these 32 migraineurs, 28 (19.9%) were without aura and four (2.8%) were with aura. Migraine and migraine with aura were significantly more common in pRLS patients than in CPs. pRLS patients with migraine were more anxious and experienced a shorter duration of RLS symptoms than pRLS patients without migraine. Migraineurs in the pRLS group tended to have high scores for severity of migraine headache by Visual Analog Scale score and high levels of disability by Migraine Disability Assessment grading than those in the control group. pRLS patients showed a positive association with definite migraine headaches. In contrast to results highlighted in recent studies, we found a strong link between migraine with aura and pRLS. PMID:27523456

  7. Estimation of the amount of tropospheric ozone in a cloudy sky by ground-based Fourier-transform infrared emission spectroscopy.

    PubMed

    Spänkuch, D; Döhler, W; Güldner, J; Schulz, E

    1998-05-20

    The problem of retrieving minor concentrations of constituents by ground-based Fourier-transform infrared emission spectroscopy is addressed by means of the concept of differential optical emission spectroscopy in analogy to the concept of differential optical absorption spectroscopy. Using the prominent nu3 ozone feature at 1043 cm(-1), we show that the strength of the spectral signature depends not only on the amount of ozone but also on the atmospheric thermal structure. This dependence can be described by a rather accurate approximation, which was used to construct a simple diagram to estimate the amount of column ozone between the instrument site and a cloud deck as well as to determine the detection limit. The detection limit is shown to depend on cloud base height. For a given thermal lapse rate it was found that the lower the detection limit, the higher the cloud base altitude. However, as shown in a case study with variable cloud base height, the concept fails for semitransparent clouds. Multiple scattering of the emitted radiation within the clouds yielded a path enhancement that simulated an enhanced amount of constituent. The path enhancement was estimated to be 2.4-4 km at 1000 cm(-1) for low-level clouds, equivalent to an enhancement factor of 6-21. The multiple scattering effect has considerable consequences for ground-based as well as for nadir satellite retrieval techniques in cloudy skies.

  8. Auras in patients with temporal lobe epilepsy and mesial temporal sclerosis.

    PubMed

    Asadi-Pooya, Ali A; Nei, Maromi; Sharan, Ashwini; Sperling, Michael R

    2016-05-15

    We investigated auras in patients with drug-resistant temporal lobe epilepsy (TLE) and mesial temporal sclerosis (MTS). We also investigated the clinical differences between patients with MTS and abdominal auras and those with MTS and non-mesial temporal auras. All patients with drug-resistant TLE and unilateral MTS who underwent epilepsy surgery at Jefferson Comprehensive Epilepsy Center from 1986 through 2014 were evaluated. Patients with good postoperative seizure outcome were investigated. One hundred forty-nine patients (71 males and 78 females) were studied. Thirty-one patients (20.8%) reported no auras, while 29 patients (19.5%) reported abdominal aura, and 30 patients (20.1%) reported non-mesial temporal auras; 16 patients (10.7%) had sensory auras, 11 patients (7.4%) had auditory auras, and five patients (3.4%) reported visual auras. A history of preoperative tonic-clonic seizures was strongly associated with non-mesial temporal auras (odds ratio 3.8; 95% CI: 1.15-12.98; p=0.02). About one-fifth of patients who had MTS in their MRI and responded well to surgery reported auras that are historically associated with non-mesial temporal structures. However, the presence of presumed non-mesial temporal auras in a patient with MTS may herald a more widespread epileptogenic zone. PMID:27084209

  9. Tropospheric ozone variability in the tropics from ENSO to MJO and shorter timescales

    NASA Astrophysics Data System (ADS)

    Ziemke, J. R.; Douglass, A. R.; Oman, L. D.; Strahan, S. E.; Duncan, B. N.

    2015-07-01

    Aura OMI and MLS measurements are combined to produce daily maps of tropospheric ozone beginning October 2004. We show that El Niño-Southern Oscillation (ENSO) related inter-annual change in tropospheric ozone in the tropics is small in relation to combined intra-seasonal/Madden-Julian Oscillation (MJO) and shorter timescale variability by a factor of ~ 3-10 (largest in the Atlantic). Outgoing longwave radiation (OLR), taken as a proxy for convection, suggests that convection is a dominant driver of large-scale variability of tropospheric ozone in the Pacific from inter-annual (e.g., ENSO) to weekly periods. We compare tropospheric ozone and OLR satellite observations with two simulations: (1) the Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) that uses observed sea surface temperatures and is otherwise free-running, and (2) the NASA Global Modeling Initiative (GMI) chemical transport model (CTM) that is driven by Modern Era Retrospective-Analysis for Research and Applications (MERRA) analyses. It is shown that the CTM-simulated ozone accurately matches measurements for timescales from ENSO to intra-seasonal/MJO and even 1-2-week periods. The CCM simulation reproduces ENSO variability but not shorter timescales. These analyses suggest that a model used to delineate temporal and/or spatial properties of tropospheric ozone and convection in the tropics must reproduce both ENSO and non-ENSO variability.

  10. Tropospheric ozone variability in the tropics from ENSO to MJO and shorter timescales

    NASA Astrophysics Data System (ADS)

    Ziemke, J. R.; Douglass, A. R.; Oman, L. D.; Strahan, S. E.; Duncan, B. N.

    2015-03-01

    Aura OMI and MLS measurements are combined to produce daily maps of tropospheric ozone beginning October 2004. We show that El Ni no Southern Oscillation (ENSO) related inter-annual change in tropospheric ozone in the tropics is small compared to combined intra-seasonal/Madden-Julian Oscillation (MJO) and shorter timescale variability by a factor ~ 3-10 (largest in the Atlantic). Outgoing Longwave Radiation (OLR) indicates further that deep convection is the primary driver of the observed tropospheric ozone variability from ENSO down to weekly timescales. We compare tropospheric ozone and OLR satellite observations with two simulations: (1) the Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) that uses observed sea surface temperatures and is otherwise free-running, and (2) the NASA Global Modeling Initiative (GMI) chemical transport model (CTM) that is driven by Modern-Era Retrospective Analysis for Research and Applications (MERRA) analyses. It is shown that the CTM-simulated ozone accurately matches measurements for timescales from ENSO to intra-seasonal/MJO and even 1-2 week periods; however (though not unexpected) the CCM simulation reproduces ENSO variability but not shorter timescales. These analyses suggest that using a model to delineate temporal/spatial properties of tropospheric ozone and convection in the tropics will require that the model reproduce the non-ENSO variability that dominates.

  11. Global tropospheric hydroxyl distribution, budget and reactivity

    NASA Astrophysics Data System (ADS)

    Lelieveld, Jos; Gromov, Sergey; Pozzer, Andrea; Taraborrelli, Domenico

    2016-10-01

    The self-cleaning or oxidation capacity of the atmosphere is principally controlled by hydroxyl (OH) radicals in the troposphere. Hydroxyl has primary (P) and secondary (S) sources, the former mainly through the photodissociation of ozone, the latter through OH recycling in radical reaction chains. We used the recent Mainz Organics Mechanism (MOM) to advance volatile organic carbon (VOC) chemistry in the general circulation model EMAC (ECHAM/MESSy Atmospheric Chemistry) and show that S is larger than previously assumed. By including emissions of a large number of primary VOC, and accounting for their complete breakdown and intermediate products, MOM is mass-conserving and calculates substantially higher OH reactivity from VOC oxidation compared to predecessor models. Whereas previously P and S were found to be of similar magnitude, the present work indicates that S may be twice as large, mostly due to OH recycling in the free troposphere. Further, we find that nighttime OH formation may be significant in the polluted subtropical boundary layer in summer. With a mean OH recycling probability of about 67 %, global OH is buffered and not sensitive to perturbations by natural or anthropogenic emission changes. Complementary primary and secondary OH formation mechanisms in pristine and polluted environments in the continental and marine troposphere, connected through long-range transport of O3, can maintain stable global OH levels.

  12. Man's impact on the troposphere: Lectures in tropospheric chemistry

    NASA Technical Reports Server (NTRS)

    Levine, J. S. (Editor); Schryer, D. R. (Editor)

    1978-01-01

    Lectures covering a broad spectrum of current research in tropospheric chemistry with particular emphasis on the interaction of measurements, modeling, and understanding of fundamental processes are presented.

  13. Total Column NO2 from the OMI Instrument on EOS Aura

    NASA Astrophysics Data System (ADS)

    Brinksma, E. J.; Boersma, K. F.; Gleason, J. F.; Bucsela, E. J.; Celarier, E.; de Haan, J. F.; Veefkind, J. P.

    2003-04-01

    OMI-EOS is a Dutch-Finnish nadir pointing spaceborne imaging spectrometer that will fly on NASA's Aura Mission, which is part of the Earth Observation System (EOS). OMI measures the reflected solar radiation in the ultraviolet and visible spectrum between 270 and 500 nm, using two channels with a spectral resolution of about 0.5 nm. OMI data products include ozone columns and profiles, aerosols, clouds, surface UV irradiance, and the trace gases NO_2, SO_2, HCHO, BrO, and OClO. Total column NO_2 will be measured using data from the visible channel, range, 365 - 500 nm; resolution, 0.63 nm; sampling, 0.21 nm/pixel. The NO_2 algorithm will compute vertical column densities (VCD) from spectrally fitted NO_2 slant column densities (SCD). The method to determine NO_2 slant column densities is Differential Optical Absorption Spectroscopy (DOAS), which uses a linear decomposition of a measured Earth reflectance spectrum into its component spectra, including NO_2, O_3, O_2-O_2, H_2O, Ring and a third order polynomial. Calculation of the air mass factor in regions of enhanced tropospheric NO_2 will be accomplished by designating two components of the column density: an unpolluted component, which includes stratospheric and free tropospheric NO_2, and a polluted component, containing boundary layer NO_2. The two parts will be separated through spatial filtering of the geographic NO_2 field. Polluted NO_2 is assumed to show the greatest small-scale variation and will be isolated and corrected for air mass factor and temperature.

  14. Trace gas evolution in the lowermost stratosphere from Aura Microwave Limb Sounder measurements

    NASA Astrophysics Data System (ADS)

    Santee, M. L.; Manney, G. L.; Livesey, N. J.; Froidevaux, L.; Schwartz, M. J.; Read, W. G.

    2011-09-01

    Daily global measurements from NASA's Aura Microwave Limb Sounder (MLS) allow comprehensive investigation of interhemispheric and interannual variations in chemical and transport processes throughout the lowermost stratosphere (LMS). We analyze nearly seven years of MLS O3, HNO3, HCl and ClO measurements along with meteorological analyses to place chemical processing in and dispersal of processed air from the winter polar lowermost vortex and subvortex in a global context. The MLS data, the first simultaneous observations of HCl and ClO covering much of the LMS, reveal that chlorine activation is widespread in the Antarctic subvortex and can occur to a significant degree in the Arctic subvortex. Unusually low temperatures and strong, prolonged chlorine activation in the lowermost vortex and subvortex promoted large ozone losses there in the 2006 (and 2008) Antarctic and 2004/2005 Arctic winters, consistent with reported record low column ozone. Processed air dispersing from the decaying vortex in spring induces rapid changes in extravortex trace gas abundances. After vortex breakdown, the subtropical jet/tropopause becomes the major transport barrier in the LMS. Quasi-isentropic transport of tropical tropospheric air into the LMS, associated with the summer monsoon circulations, leads to decreases in extratropical O3, HNO3, and HCl in both hemispheres. Strong mixing in the summertime LMS homogenizes extratropical trace gas fields. MLS measurements in the tropics show signatures of monsoon-related cross-equatorial stratosphere-to-troposphere transport. Observed seasonal and interannual variations in trace gas abundances in the LMS are consistent with variations in the strength of transport barriers diagnosed from meteorological analyses.

  15. New onset migraine with aura after treatment initiation with ivabradine

    PubMed Central

    2013-01-01

    Background Migraine with aura is a complex neurological disorder modeled in animals by cortical spreading depression. It is less usual to find complete animal models for the disease so any opportunity to test a human effect back at the bench is welcome. Findings We report the case of a 24 year old woman who developed new onset episodic migraine with visual aura shortly after treatment initiation with the If ion channel blocker ivabradine for frequency control in hypertrophic cardiomyopathy. We studied whether ivabradine could alter cortical spreading depression in a suitable animal model. Sixteen rats received either ivabradine or saline, and the number of depolarization shifts and blood flow changes induced by cortical spreading depression were measured in both groups. No significant differences between the ivabradine and saline group were detected. Conclusions Ivabradine is an interesting substance since it is known to produce migraine-like phosphenes frequently and the patient we report developed de novo migraine with aura. However, we were unable to demonstrate that the drug influences the susceptibility of the brain to cortical spreading depression with acute administration. The combined data show the relationship of migraine aura to cortical spreading depression may have some nuances yet to be identified. PMID:23718730

  16. Development of an Aura Chemical Reanalysis in support Air Quality Applications

    NASA Astrophysics Data System (ADS)

    Pierce, R. B.; Lenzen, A.; Schaack, T.

    2015-12-01

    We present results of chemical data assimilation experiments utilizing the NOAA National Environmental Satellite, Data, and Information Service (NESDIS), University of Wisconsin Space Science and Engineering (SSEC) Real-time Air Quality Modeling System (RAQMS) in conjunction with the NOAA National Centers for Environmental Prediction (NCEP) Operational Gridpoint Statistical Interpolation (GSI) 3-dimensional variational data assimilation system. The impact of assimilating NASA Ozone Monitoring Instrument (OMI) total column ozone, OMI tropospheric nitrogen dioxide columns, and Microwave Limb Sounder (MLS) stratospheric ozone profiles on background ozone is assessed using measurements from the 2010 NSF High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observation (HIPPO) and NOAA California Nexus (CalNex) campaigns. Results show that the RAQMS/GSI Chemical Reanalysis is able to provide very good estimates of background ozone and large-scale ozone variability and is suitable for use in constraining regional air quality modeling activities. These experiments are being used to guide the development of a multi-year global chemical and aerosol reanalysis using NASA Aura and A-Train measurements to support air quality applications.

  17. Migraine with persistent aura in a Mexican patient: case report and review of the literature.

    PubMed

    San-Juan, O D; Zermeño, P F

    2007-05-01

    Persistent aura symptoms in patients with migraine are rare but well documented. The International Headache Society defines persistent aura without infarction as when the aura symptoms persist for > 1 week without radiographic evidence of infarction. The visual aura of migraine attacks has been explained by cortical spreading depression. We describe a case of a 28-year-old Mexican woman, who presented with persistent aura symptoms, and a literature review. The patient had a 24-year history of migraine headache. In November 2005 the patient had an attack which started with scintillating scotomas bilaterally associated with photopsias and amaurosis followed by migraine headache. All imaging studies were negative. The episode lasted 35 days and probably resolved with nimodipine therapy. Persistent aura symptoms are rare entities. This is the first case documented of a Mexican patient with persistent aura without infarction and probably resolved with nimodipine therapy.

  18. Inducible nitric oxide synthase haplotype associated with migraine and aura.

    PubMed

    de O S Mansur, Thiago; Gonçalves, Flavia M; Martins-Oliveira, Alisson; Speciali, Jose G; Dach, Fabiola; Lacchini, Riccardo; Tanus-Santos, Jose E

    2012-05-01

    Migraine is a complex neurological disorder with a clear neurogenic inflammatory component apparently including enhanced nitric oxide (NO) formation. Excessive NO amounts possibly contributing to migraine are derived from increased expression and activity of inducible NO synthase (iNOS). We tested the hypothesis that two functional, clinically relevant iNOS genetic polymorphisms (C(-1026)A-rs2779249 and G2087A-rs2297518) are associated with migraine with or without aura. We studied 142 healthy women without migraine (control group) and 200 women with migraine divided into two groups: 148 with migraine without aura (MWA) and 52 with aura (MA). Genotypes were determined by real-time polymerase chain reaction using the Taqman(®) allele discrimination assays. The PHASE 2.1 software was used to estimate the haplotypes. The A allele for the G2087A polymorphism was more commonly found in the MA group than in the MWA group (28 vs. 18%; P < 0.05). No other significant differences in the alleles or genotypes distributions were found (P > 0.05). The haplotype combining both A alleles for the two polymorphisms was more commonly found in the MA group than in the control group or in the MWA group (19 vs. 10 or 8%; P = 0.0245 or 0.0027, respectively). Our findings indicate that the G2087A and the C(-1026)A polymorphism in the iNOS gene affect the susceptibility to migraine with aura when their effects are combined within haplotypes, whereas the G2087A affects the susceptibility to aura in migraine patients. These finding may have therapeutic implications when examining the effects of selective iNOS inhibitors.

  19. Tropospheric ozone column retrieval from OMI data by means of neural networks: a validation exercise with ozone soundings over Europe

    NASA Astrophysics Data System (ADS)

    Di Noia, Antonio; Sellitto, Pasquale; Del Frate, Fabio; Cervino, Marco; Iarlori, Marco; Rizi, Vincenzo

    2013-12-01

    The retrieval of the tropospheric ozone column from satellite data is very important for the characterization of tropospheric chemical and physical properties. However, the task of retrieving tropospheric ozone from space has to face with one fundamental difficulty: the contribution of the tropospheric ozone to the measured radiances is overwhelmed by a much stronger stratospheric signal, which has to be reliably filtered. The Tor Vergata University Earth Observation Laboratory has recently addressed this issue by developing a neural network (NN) algorithm for tropospheric ozone retrieval from NASA-Aura Ozone Monitoring Instrument (OMI) data. The performances of this algorithm were proven comparable to those of more consolidated algorithms, such as Tropospheric Ozone Residual and Optimal Estimation. In this article, the results of a validation of this algorithm with measurements performed at six European ozonesonde sites are shown and critically discussed. The results indicate that systematic errors, related to the tropopause pressure, are present in the current version of the algorithm, and that including the tropopause pressure in the NN input vector can compensate for these errors, enhancing the retrieval accuracy significantly.

  20. Tropospheric Ozone and Photochemical Smog

    NASA Astrophysics Data System (ADS)

    Sillman, S.

    2003-12-01

    global background ozone can make the effects of local pollution events everywhere more acute, and can also cause ecological damage in remote locations that are otherwise unaffected by urban pollution. Ozone at the global scale is also related to greenhouse warming.This chapter provides an overview of photochemical smog at the urban and regional scale, focused primarily on ozone and including a summary of information about particulates. It includes the following topics: dynamics and extent of pollution events; health and ecological impacts; relation between ozone and precursor emissions, including hydrocarbons and nitrogen oxides (NOx); sources, composition, and fundamental properties of particulates; chemistry of ozone and related species; methods of interpretation based on ambient measurements; and the connection between air pollution events and the chemistry of the global troposphere. Because there are many similarities between the photochemistry of ozone during pollution events and the chemistry of the troposphere in general, this chapter will include some information about global tropospheric chemistry and the links between urban-scale and global-scale events. Additional treatment of the global troposphere is found in Volume 4 of this work. The chemistry of ozone formation discussed here is also related to topics discussed in greater detail elsewhere in this volume (see Chapters 9.10 and 9.12) and in Volume 4.

  1. A multi-model intercomparison of halogenated very short-lived substances (TransCom-VSLS): linking oceanic emissions and tropospheric transport for a reconciled estimate of the stratospheric source gas injection of bromine

    NASA Astrophysics Data System (ADS)

    Hossaini, R.; Patra, P. K.; Leeson, A. A.; Krysztofiak, G.; Abraham, N. L.; Andrews, S. J.; Archibald, A. T.; Aschmann, J.; Atlas, E. L.; Belikov, D. A.; Bönisch, H.; Carpenter, L. J.; Dhomse, S.; Dorf, M.; Engel, A.; Feng, W.; Fuhlbrügge, S.; Griffiths, P. T.; Harris, N. R. P.; Hommel, R.; Keber, T.; Krüger, K.; Lennartz, S. T.; Maksyutov, S.; Mantle, H.; Mills, G. P.; Miller, B.; Montzka, S. A.; Moore, F.; Navarro, M. A.; Oram, D. E.; Pfeilsticker, K.; Pyle, J. A.; Quack, B.; Robinson, A. D.; Saikawa, E.; Saiz-Lopez, A.; Sala, S.; Sinnhuber, B.-M.; Taguchi, S.; Tegtmeier, S.; Lidster, R. T.; Wilson, C.; Ziska, F.

    2016-07-01

    The first concerted multi-model intercomparison of halogenated very short-lived substances (VSLS) has been performed, within the framework of the ongoing Atmospheric Tracer Transport Model Intercomparison Project (TransCom). Eleven global models or model variants participated (nine chemical transport models and two chemistry-climate models) by simulating the major natural bromine VSLS, bromoform (CHBr3) and dibromomethane (CH2Br2), over a 20-year period (1993-2012). Except for three model simulations, all others were driven offline by (or nudged to) reanalysed meteorology. The overarching goal of TransCom-VSLS was to provide a reconciled model estimate of the stratospheric source gas injection (SGI) of bromine from these gases, to constrain the current measurement-derived range, and to investigate inter-model differences due to emissions and transport processes. Models ran with standardised idealised chemistry, to isolate differences due to transport, and we investigated the sensitivity of results to a range of VSLS emission inventories. Models were tested in their ability to reproduce the observed seasonal and spatial distribution of VSLS at the surface, using measurements from NOAA's long-term global monitoring network, and in the tropical troposphere, using recent aircraft measurements - including high-altitude observations from the NASA Global Hawk platform. The models generally capture the observed seasonal cycle of surface CHBr3 and CH2Br2 well, with a strong model-measurement correlation (r ≥ 0.7) at most sites. In a given model, the absolute model-measurement agreement at the surface is highly sensitive to the choice of emissions. Large inter-model differences are apparent when using the same emission inventory, highlighting the challenges faced in evaluating such inventories at the global scale. Across the ensemble, most consistency is found within the tropics where most of the models (8 out of 11) achieve best agreement to surface CHBr3 observations

  2. Remote Sensing of Tropospheric Pollution from Space

    NASA Technical Reports Server (NTRS)

    Fishman, Jack; Bowman, Kevin W.; Burrows, John P.; Chance, Kelly V.; Edwards, David P.; Martin, Randall V.; Morris, Gary A.; Pierce, R. Bradley; Ziemke, Jerald R.; Al-Saadi, Jassim A.; Schaack, Todd K.; Thompson, Anne M.

    2008-01-01

    We review the progress of tropospheric trace gas observations and address the need for additional measurement capabilities as recommended by the National Academy of Science (NAS, 2007). Tropospheric measurements from current and earlier instruments show pollution in the Northern Hemisphere as a result of fossil fuel burning and a strong seasonal dependence with the largest amounts of photochemically-generated ozone in summer. At low latitudes, where photon flux is stronger throughout the year, trace gas concentrations are driven by the abundance of the emissions, where the largest source, biomass burning, is readily seen in carbon monoxide measurements, but lightning and biogenic trace gases may also contribute to trace gas variability. Although substantive progress has been achieved in seasonal and global mapping of a few tropospheric trace gases, satellite trace-gas observations with considerably better temporal and spatial resolution are essential to forecasting air quality at scales required by policy-makers. The concurrent use of atmospheric composition measurements for both scientific and operational purposes is a new paradigm for the atmospheric chemistry community. The examples presented illustrate both the promise and challenge of merging satellite information with in situ observations in state-of-the-art data assimilation models.

  3. Characterization of Water Vapor in the North American Monsoon with JLH Mark2 and Aura MLS

    NASA Astrophysics Data System (ADS)

    Herman, R. L.; Troy, R. F.; Rosenlof, K. H.; Ray, E. A.; Schwartz, M. J.; Read, W. G.; Bedka, K. M.; Fu, D.; Christensen, L. E.; Bui, T. V.

    2014-12-01

    Several NASA ER-2 aircraft flights during the recent NASA Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) field mission sampled the UTLS region heavily influenced by the North American Monsoon (NAM). Enhanced water vapor was measured in the lower stratosphere between 160 hPa and 80 hPa over the continental United States. Here we present in situ water vapor measurements from the newly improved JPL Laser Hygrometer (JLH Mark2) to characterize the NAM water vapor field during August and September 2013. Regional context is provided by water observations from the Aura Microwave Limb Sounder (MLS) and overshooting deep convective cloud tops from GOES imagery.

  4. Distinctive anatomical and physiological features of migraine aura revealed by 18 years of recording.

    PubMed

    Hansen, Jakob Møller; Baca, Serapio Michael; Vanvalkenburgh, Paul; Charles, Andrew

    2013-12-01

    The mechanisms underlying the initiation and propagation of the migraine aura, and the visual percept that is produces, remain uncertain. The objective of this study was to characterize and quantify a large number of visual auras recorded by a single individual over nearly two decades to gain insight into basic aura mechanisms. An individual made detailed drawings of his visual percept of migraine aura in real time during more than 1000 attacks of migraine aura without headache over 18 years. Drawings were made in a consistent fashion documenting the shape and location of the aura wavefront or scotoma in the visual field at one minute intervals. These drawings were digitized and the spatial and temporal features of auras were quantified and analysed. Consistent patterns of aura initiation, propagation and termination were observed in both right and left visual fields. Most aura attacks originated centrally (within 10° eccentricity), but there were also other distinct sites of initiation in the visual field. Auras beginning centrally preferentially propagated first through lower nasal field (69-77% of all auras) before travelling to upper and temporal fields, on both sides. Some auras propagated from peripheral to central regions of the visual field-these typically followed the reverse path of those travelling in the opposite direction. The mean velocity of the perceived visual phenomenon did not differ between attacks starting peripherally and centrally. The estimated speed of the underlying cortical event (2-3 mm/min) was in the same range as has been previously reported by others. Some auras had limited propagation and spontaneously 'aborted' after a few minutes, despite being initiated in similar locations to those that spread throughout the entire visual field. The visual percept of the aura changed corresponding with the presumed propagation from the V1 to the V2 region of the occipital cortex. In some cases the visual percept disappeared for several minutes

  5. Linkages between ozone-depleting substances, tropospheric oxidation and aerosols

    NASA Astrophysics Data System (ADS)

    Voulgarakis, A.; Shindell, D. T.; Faluvegi, G.

    2013-05-01

    Coupling between the stratosphere and the troposphere allows changes in stratospheric ozone abundances to affect tropospheric chemistry. Large-scale effects from such changes on chemically produced tropospheric aerosols have not been systematically examined in past studies. We use a composition-climate model to investigate potential past and future impacts of changes in stratospheric ozone depleting substances (ODS) on tropospheric oxidants and sulfate aerosols. In most experiments, we find significant responses in tropospheric photolysis and oxidants, with small but significant effects on methane radiative forcing. The response of sulfate aerosols is sizeable when examining the effect of increasing future nitrous oxide (N2O) emissions. We also find that without the regulation of chlorofluorocarbons (CFCs) through the Montreal Protocol, sulfate aerosols could have increased by 2050 by a comparable amount to the decreases predicted due to relatively stringent sulfur emissions controls. The individual historical radiative forcings of CFCs and N2O through their indirect effects on methane (-22.6 mW m-2 for CFCs and -6.7 mW m-2 for N2O) and sulfate aerosols (-3.0 mW m-2 for CFCs and +6.5 mW m-2 for N2O when considering the direct aerosol effect) discussed here are non-negligible when compared to known historical ODS forcing. Our results stress the importance of accounting for stratosphere-troposphere, gas-aerosol and composition-climate interactions when investigating the effects of changing emissions on atmospheric composition and climate.

  6. Linkages Between Ozone-depleting Substances, Tropospheric Oxidation and Aerosols

    NASA Technical Reports Server (NTRS)

    Voulgarakis, A.; Shindell, D. T.; Faluvegi, G.

    2013-01-01

    Coupling between the stratosphere and the troposphere allows changes in stratospheric ozone abundances to affect tropospheric chemistry. Large-scale effects from such changes on chemically produced tropospheric aerosols have not been systematically examined in past studies. We use a composition-climate model to investigate potential past and future impacts of changes in stratospheric ozone depleting substances (ODS) on tropospheric oxidants and sulfate aerosols. In most experiments, we find significant responses in tropospheric photolysis and oxidants, with small but significant effects on methane radiative forcing. The response of sulfate aerosols is sizeable when examining the effect of increasing future nitrous oxide (N2O) emissions. We also find that without the regulation of chlorofluorocarbons (CFCs) through the Montreal Protocol, sulfate aerosols could have increased by 2050 by a comparable amount to the decreases predicted due to relatively stringent sulfur emissions controls. The individual historical radiative forcings of CFCs and N2O through their indirect effects on methane (-22.6mW/sq. m for CFCs and -6.7mW/sq. m for N2O) and sulfate aerosols (-3.0mW/sq. m for CFCs and +6.5mW/sq. m for N2O when considering the direct aerosol effect) discussed here are non-negligible when compared to known historical ODS forcing. Our results stress the importance of accounting for stratosphere-troposphere, gas-aerosol and composition-climate interactions when investigating the effects of changing emissions on atmospheric composition and climate.

  7. The epileptic aura in literature: aesthetic and philosophical dimensions. An essay.

    PubMed

    Wolf, Peter

    2013-03-01

    In literary accounts of epilepsy the aura has a prominent place as the subjective aspect of the seizure experience. Descriptions by authors with their own aura experiences stand out by their precision and authenticity. Many different aura types are mentioned, but the ecstatic aura described by Dostoyevsky has received particular attention and is echoed in many later works. Some authors are interested primarily in the possibilities provided by auras to react, for example, by hiding, seeking help, counteracting the oncoming seizure, or taking measures to prevent damage. Others by their unique aura experiences are inspired to create specific literary flavors like oxymora, spectacular metaphors, or the depiction of complex perceptions and states of mind. Some authors, adding a philosophical dimension, proceed to analyze the consequences of patients' subjective seizure experiences for their identity and their self-perception as creative or religious persons. To sum up, the works discussed herein strongly support that literary texts provide valuable insights beyond those of medical texts.

  8. New Collections of Aura Atmospheric data Products at the GES DISC

    NASA Technical Reports Server (NTRS)

    Johnson, James; Ahmad, Suraiya; Gerasimov, Irina; Lepthoukh, Gregory

    2008-01-01

    The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) is the primary archive of atmospheric composition data from the Aura Ozone Monitoring Instrument (OMI), Microwave Limb sounder (MLS), and High-Resolution Dynamics Limb Sounder (HIRDLS) instruments. The most recent versions of Aura OMI, MLS and HIRDLS data are available free to the public (http://disc.gsfc.nasa.gov/Aura). TES data are at ASDC (http://eosweb.larc.nasa.gov).

  9. Migrainous Aura, Visual Snow, and "Alice in Wonderland" Syndrome in Childhood.

    PubMed

    Rastogi, Reena Gogia; VanderPluym, Juliana; Lewis, Kara Stuart

    2016-02-01

    Migraine is a condition that is common in the pediatric and adolescent population. Among children with migraine, visual aura can consist of either negative or positive features or both. Reports of sensory auras can also be elicited with a careful history. The understanding of the types of aura, as well as their relation to the more typical features of migraine, are discussed. The similar phenomena of visual snow and Alice in Wonderland syndrome in children are also described in detail. PMID:27017016

  10. 'Visual snow' - a disorder distinct from persistent migraine aura.

    PubMed

    Schankin, Christoph J; Maniyar, Farooq H; Digre, Kathleen B; Goadsby, Peter J

    2014-05-01

    Patients with 'visual snow' report continuous tiny dots in the entire visual field similar to the noise of an analogue television. As they frequently have migraine as a comorbidity with ophthalmological, neurological and radiological studies being normal, they are offered various diagnoses, including persistent migraine aura, post-hallucinogen flashback, or psychogenic disorder. Our aim was to study patients with 'visual snow' to characterize the phenotype. A three-step approach was followed: (i) a chart review of patients referred to us identified 22 patients with 'visual snow'. Fifteen had additional visual symptoms, and 20 patients had comorbid migraine, five with aura; (ii) to identify systematically additional visual symptoms, an internet survey (n = 275) of self-assessed 'visual snow' subjects done by Eye On Vision Foundation was analysed. In two random samples from 235 complete data sets, the same eight additional visual symptoms were present in >33% of patients: palinopsia (trailing and afterimages), entoptic phenomena (floaters, blue field entoptic phenomenon, spontaneous photopsia, self-light of the eye), photophobia, and nyctalopia (impaired night vision); and (iii) a prospective semi-structured telephone interview in a further 142 patients identified 78 (41 female) with confirmed 'visual snow' and normal ophthalmological exams. Of these, 72 had at least three of the additional visual symptoms from step (ii). One-quarter of patients had 'visual snow' as long as they could remember, whereas for the others the mean age of onset was 21 ± 9 years. Thirty-two patients had constant visual symptoms, whereas the remainder experienced either progressive or stepwise worsening. Headache was the most frequent symptom associated with the beginning or a worsening of the visual disturbance (36%), whereas migraine aura (seven patients) and consumption of illicit drugs (five, no hallucinogens) were rare. Migraine (59%), migraine with aura (27%), anxiety and depression

  11. The role of aura in psychopathology and dissociative experiences in epilepsy.

    PubMed

    Mula, Marco; Cavanna, Andrea; Collimedaglia, Laura; Barbagli, Davide; Magli, Elena; Monaco, Francesco

    2006-01-01

    Cognitive auras seem to be associated with depression and anxiety, especially in patients with temporal lobe epilepsy (TLE). Dissociative symptoms may occur as an aura or in the context of psychiatric disorders such as depression, anxiety or schizophrenia. This is a cross-sectional study of 62 patients with TLE, using personality and dissociation measures to investigate their relationship with the presence of aura and its different subtypes. Our findings show no difference in psychopathology in patients with different types of aura and reveal that dissociative symptoms correlate with specific measures of anxiety, suggesting a possible link between these experiences and anxiety disorders.

  12. Satellite Observations of Tropospheric Chemistry

    NASA Technical Reports Server (NTRS)

    Singh, Hanwant B.; Jacob, Daniel J.; Hipskind, R. Stephen (Technical Monitor)

    2001-01-01

    The troposphere is an essential component of the earth's life support system as well as the gateway for the exchange of chemicals between different geochemical reservoirs of the earth. The chemistry of the troposphere is sensitive to perturbation from a wide range of natural phenomena and human activities. The societal concern has been greatly enhanced in recent decades due to ever increasing pressures of population growth and industrialization. Chemical changes within the troposphere control a vast array of processes that impact human health, the biosphere, and climate. A main goal of tropospheric chemistry research is to measure and understand the response of atmospheric composition to natural and anthropogenic perturbations, and to develop the capability to predict future change. Atmospheric chemistry measurements are extremely challenging due to the low concentrations of critical species and the vast scales over which the observations must be made. Available tropospheric data are mainly from surface sites and aircraft missions. Because of the limited temporal extent of aircraft observations, we have very limited information on tropospheric composition above the surface. This situation can be contrasted to the stratosphere, where satellites have provided critical and detailed chemical data on the global distribution of key trace gases.

  13. Effects of the 2006 El Nino on Tropospheric Ozone and Carbon Monoxide: Implications for Dynamics and Biomass Burning

    NASA Technical Reports Server (NTRS)

    Chandra, S.; Ziemke, J. R.; Duncan, B. N.; Diehl, t. L.

    2008-01-01

    We have studied the effects of the 2006 El Nino on tropospheric O3 and CO at tropical and sub-tropical latitudes measured from the OMI and MLS instruments on the Aura satellite. The 2006 El Nino-induced drought allowed forest fires set to clear land to burn out of control during October and November in the Indonesian region. The effects of these fires are clearly seen in the enhancement of GO concentration measured from the MLS instrument. We have used a global model of atmospheric chemistry and transport (GMI CTM) to quantify the relative irrrportance of biomass burning and large scale transport: in producing observed changes in tropospheric O3 and CO . The model results show that during October and November both biomass burning and meteorological changes contributed almost equally to the observed increase in tropospheric O3 in the Indonesian region. The biomass component was 4-6 DU but it was limited to the Indonesian region where the fires were most intense, The dynamical component was 4-8 DU but it covered a much larger area in the Indian Ocean extending from South East Asia in the north to western Australia in the south. By December 2006, the effect of biomass taming was reduced to zero and the obsemed changes in tropospheric O3 were mostly due to dynamical effects. The model results show an increase of 2-3% in the global burden of tropospheric ozone. In comparison, the global burdean of CO increased by 8-12%.

  14. Elevated Tropospheric Ozone over the Atlantic

    NASA Technical Reports Server (NTRS)

    Chandra, S.; Ziemke, J. R.; Tie, X.

    2003-01-01

    Tropospheric column ozone (TCO) is derived from differential measurements of TOMS total column ozone and Microwave Limb Sounder stratospheric column ozone. It is shown that TCO during summer months over the Atlantic and Pacific Oceans in northern midlatitudes is about the same (50 to 60 Dobson Units) as over the continents of North America, Europe, and Asia, where surface emissions of nitrogen oxides from industrial sources, biomass and biofuel burning and biogenic emissions are significantly larger. This nearly uniform zonal variation in TCO is modulated by surface topography of the Rocky and Himalayan mountains, and Tibetan plateau where TCO is reduced by 20 to 30 Dobson Units. The zonal variation in TCO is well simulated by a global chemical transport model called MOZART-2 (Model of Ozone and Related Chemical Tracers, version 2). The model results are analyzed to delineate the relative importance of various processes contributing to observed zonal characteristics of TCO.

  15. Overview and sample applications of SMILES and Odin-SMR retrievals of upper tropospheric humidity and cloud ice mass

    NASA Astrophysics Data System (ADS)

    Eriksson, P.; Rydberg, B.; Sagawa, H.; Johnston, M. S.; Kasai, Y.

    2014-12-01

    Retrievals of cloud ice mass and humidity from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) and the Odin-SMR (Sub-Millimetre Radiometer) limb sounder are presented and example applications of the data are given. SMILES data give an unprecedented view of the diurnal variation of cloud ice mass. Mean regional diurnal cycles are reported and compared to some global climate models. Some improvements in the models regarding diurnal timing and relative amplitude were noted, but the models' mean ice mass around 250 hPa is still low compared to the observations. The influence of the ENSO (El Niño-Southern Oscillation) state on the upper troposphere is demonstrated using 12 years of Odin-SMR data. The same retrieval scheme is applied for both sensors, and gives low systematic differences between the two data sets. A special feature of this Bayesian retrieval scheme, of Monte Carlo integration type, is that values are produced for all measurements but for some atmospheric states retrieved values only reflect a priori assumptions. However, this "all-weather" capability allows a direct statistical comparison to model data, in contrast to many other satellite data sets. Another strength of the retrievals is the detailed treatment of "beam filling" that otherwise would cause large systematic biases for these passive cloud ice mass retrievals. The main retrieval inputs are spectra around 635/525 GHz from tangent altitudes below 8/9 km for SMILES/Odin-SMR, respectively. For both sensors, the data cover the upper troposphere between 30° S and 30° N. Humidity is reported as both relative humidity and volume mixing ratio. The vertical coverage of SMILES is restricted to a single layer, while Odin-SMR gives some profiling capability between 300 and 150 hPa. Ice mass is given as the partial ice water path above 260 hPa, but for Odin-SMR ice water content, estimates are also provided. Besides a smaller contrast between most dry and wet cases, the agreement

  16. New Insights in Tropospheric Ozone and its Variability

    NASA Technical Reports Server (NTRS)

    Oman, Luke D.; Douglass, Anne R.; Ziemke, Jerry R.; Rodriquez, Jose M.

    2011-01-01

    We have produced time-slice simulations using the Goddard Earth Observing System Version 5 (GEOS-5) coupled to a comprehensive stratospheric and tropospheric chemical mechanism. These simulations are forced with observed sea surface temperatures over the past 25 years and use constant specified surface emissions, thereby providing a measure of the dynamically controlled ozone response. We examine the model performance in simulating tropospheric ozone and its variability. Here we show targeted comparisons results from our simulations with a multi-decadal tropical tropospheric column ozone dataset obtained from satellite observations of total column ozone. We use SHADOZ ozonesondes to gain insight into the observed vertical response and compare with the simulated vertical structure. This work includes but is not limited to ENSO related variability.

  17. The Response of Tropical Tropospheric Ozone to ENSO

    NASA Technical Reports Server (NTRS)

    Oman, L. D.; Ziemke, J. R.; Douglass, A. R.; Waugh, D. W.; Lang, C.; Rodriguez, J. M.; Nielsen, J. E.

    2011-01-01

    We have successfully reproduced the Ozone ENSO Index (OEI) in the Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) forced by observed sea surface temperatures over a 25-year period. The vertical ozone response to ENSO is consistent with changes in the Walker circulation. We derive the sensitivity of simulated ozone to ENSO variations using linear regression analysis. The western Pacific and Indian Ocean region shows similar positive ozone sensitivities from the surface to the upper troposphere, in response to positive anomalies in the Nino 3.4 Index. The eastern and central Pacific region shows negative sensitivities with the largest sensitivity in the upper troposphere. This vertical response compares well with that derived from SHADOZ ozonesondes in each region. The OEI reveals a response of tropospheric ozone to circulation change that is nearly independent of changes in emissions and thus it is potentially useful in chemistry-climate model evaluation.

  18. The response of tropical tropospheric ozone to ENSO

    NASA Astrophysics Data System (ADS)

    Oman, L. D.; Ziemke, J. R.; Douglass, A. R.; Waugh, D. W.; Lang, C.; Rodriguez, J. M.; Nielsen, J. E.

    2011-07-01

    We have successfully reproduced the Ozone ENSO Index (OEI) in the Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) forced by observed sea surface temperatures over a 25-year period. The vertical ozone response to ENSO is consistent with changes in the Walker circulation. We derive the sensitivity of simulated ozone to ENSO variations using linear regression analysis. The western Pacific and Indian Ocean region shows similar positive ozone sensitivities from the surface to the upper troposphere, in response to positive anomalies in the Niño 3.4 Index. The eastern and central Pacific region shows negative sensitivities with the largest sensitivity in the upper troposphere. This vertical response compares well with that derived from SHADOZ ozonesondes in each region. The OEI reveals a response of tropospheric ozone to circulation change that is nearly independent of changes in emissions and thus it is potentially useful in chemistry-climate model evaluation.

  19. Sensory migraine aura is not associated with structural grey matter abnormalities.

    PubMed

    Hougaard, Anders; Amin, Faisal Mohammad; Arngrim, Nanna; Vlachou, Maria; Larsen, Vibeke Andrée; Larsson, Henrik B W; Ashina, Messoud

    2016-01-01

    Migraine with aura (MA) is characterized by cortical dysfunction. Frequent aura attacks may alter cerebral cortical structure in patients, or structural grey matter abnormalities may predispose MA patients to aura attacks. In the present study we aimed to investigate cerebral grey matter structure in a large group of MA patients with and without sensory aura (i.e. gradually developing, transient unilateral sensory disturbances). We included 60 patients suffering from migraine with typical visual aura and 60 individually age and sex-matched controls. Twenty-nine of the patients additionally experienced sensory aura regularly. We analysed high-resolution structural MR images using two complimentary approaches and compared patients with and without sensory aura. Patients were also compared to controls. We found no differences of grey matter density or cortical thickness between patients with and without sensory aura and no differences for the cortical visual areas between patients and controls. The somatosensory cortex was thinner in patients (1.92 mm vs. 1.96 mm, P = 0.043) and the anterior cingulate cortex of patients had a decreased grey matter density (P = 0.039) compared to controls. These differences were not correlated to the clinical characteristics. Our results suggest that sensory migraine aura is not associated with altered grey matter structure and that patients with visual aura have normal cortical structure of areas involved in visual processing. The observed decreased grey matter volume of the cingulate gyrus in patients compared to controls have previously been reported in migraine with and without aura, but also in a wide range of other neurologic and psychiatric disorders. Most likely, this finding reflects general bias between patients and healthy controls.

  20. Highlights from the 11-year record of tropospheric ozone from OMI/MLS and continuation of that long record using OMPS measurements

    NASA Astrophysics Data System (ADS)

    Ziemke, Jerry; Kramarova, Natalya; Bhartia, Pawan; Degenstein, Doug; Deland, Matthew

    2016-04-01

    Since October 2004 the Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) onboard the Aura satellite have provided over 11 years of continuous tropospheric ozone measurements. These OMI/MLS measurements have been used in many studies to evaluate dynamical and photochemical effects caused by ENSO, the Madden-Julian Oscillation (MJO) and shorter timescales, as well as long-term trends and the effects of deep convection on tropospheric ozone. Given that the OMI and MLS instruments have now extended well beyond their expected lifetimes, our goal is to continue their long record of tropospheric ozone using recent Ozone Mapping Profiler Suite (OMPS) measurements. The OMPS onboard the Suomi National Polar-orbiting Partnership NPP satellite was launched on October 28, 2011 and is comprised of three instruments: the nadir mapper, the nadir profiler, and the limb profiler. Our study combines total column ozone from the OMPS nadir mapper with stratospheric column ozone from the OMPS limb profiler to measure tropospheric ozone residual. The time period for the OMPS measurements is March 2012 - present. For the OMPS limb profiler retrievals, the OMPS v2 algorithm from Goddard is tested against the SASKatchewan radiative TRANsfer (SASKTRAN) algorithm. The retrieved ozone profiles from each of these algorithms are evaluated with ozone profiles from both ozonesondes and the Aura Microwave Limb Sounder (MLS). Effects on derived OMPS tropospheric ozone caused by the 2015-2016 El Nino event are highlighted. This recent El Nino produced anomalies in tropospheric ozone throughout the tropical Pacific involving increases of ~10 DU over Indonesia and decreases ~5-10 DU in the eastern Pacific. These changes in ozone due to El Nino were predominantly dynamically-induced, caused by the eastward shift in sea-surface temperature and convection from the western to the eastern Pacific.

  1. Highlights from the 11-Year Record of Tropospheric Ozone from OMI/MLS and Continuation of that Long Record Using OMPS Measurements

    NASA Technical Reports Server (NTRS)

    Ziemke, J. R.; Kramarova, N. A.; Bhartia, P. K.; Degenstein, D. A.; Deland, M. T.

    2016-01-01

    Since October 2004 the Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) onboard the Aura satellite have provided over 11 years of continuous tropospheric ozone measurements. These OMI/MLS measurements have been used in many studies to evaluate dynamical and photochemical effects caused by ENSO, the Madden-Julian Oscillation (MJO) and shorter timescales, as well as long-term trends and the effects of deep convection on tropospheric ozone. Given that the OMI and MLS instruments have now extended well beyond their expected lifetimes, our goal is to continue their long record of tropospheric ozone using recent Ozone Mapping Profiler Suite (OMPS) measurements. The OMPS onboard the Suomi National Polar-orbiting Partnership NPP satellite was launched on October 28, 2011 and is comprised of three instruments: the nadir mapper, the nadir profiler, and the limb profiler. Our study combines total column ozone from the OMPS nadir mapper with stratospheric column ozone from the OMPS limb profiler to measure tropospheric ozone residual. The time period for the OMPS measurements is March 2012 present. For the OMPS limb profiler retrievals, the OMPS v2 algorithm from Goddard is tested against the University of Saskatchewan (USask) Algorithm. The retrieved ozone profiles from each of these algorithms are evaluated with ozone profiles from both ozonesondes and the Aura Microwave Limb Sounder (MLS). Effects on derived OMPS tropospheric ozone caused by the 2015-2016 El Nino event are highlighted. This recent El Nino produced anomalies in tropospheric ozone throughout the tropical Pacific involving increases of approximately 10 DU over Indonesia and decreases approximately 5-10 DU in the eastern Pacific. These changes in ozone due to El Nino were predominantly dynamically-induced, caused by the eastward shift in sea-surface temperature and convection from the western to the eastern Pacific.

  2. The dynamics of Titan's troposphere.

    PubMed

    Tokano, Tetsuya

    2009-02-28

    While the Voyager mission could essentially not reveal the dynamics of Titan's troposphere, useful information was obtained by the Cassini spacecraft and, particularly, by the Huygens probe that landed on Titan's surface; this information can be interpreted by means of numerical models of atmospheric circulation. The meridional circulation is likely to consist of a large Hadley circulation asymmetric about the equator, but is susceptible to disruption by turbulence in clouds. The zonal wind in the troposphere is comparable to or even weaker than that in the terrestrial troposphere and contains zones of easterlies, much in contrast to the super-rotating stratosphere. Unique to Titan is the transition from a geostrophic to cyclostrophic wind balance in the upper troposphere. While Earth-like storm systems associated with baroclinic instability are absent, Saturn's gravitational tide introduces a planetary wave of wavenumber 2 and a periodical variation in the wind direction in the troposphere. Unlike on Earth, the wind over the equatorial surface is westerly. The seasonal reversal in the Hadley circulation sense and zonal wind direction is predicted to have a substantial influence on the formation of dunes as well as variation of Titan's rotation rate and length of day.

  3. Global Gravity Wave Variances from Aura MLS: Characteristics and Interpretation

    NASA Technical Reports Server (NTRS)

    Wu, Dong L.; Eckermann, Stephen D.

    2008-01-01

    The gravity wave (GW)-resolving capabilities of 118-GHz saturated thermal radiances acquired throughout the stratosphere by the Microwave Limb Sounder (MLS) on the Aura satellite are investigated and initial results presented. Because the saturated (optically thick) radiances resolve GW perturbations from a given altitude at different horizontal locations, variances are evaluated at 12 pressure altitudes between 21 and 51 km using the 40 saturated radiances found at the bottom of each limb scan. Forward modeling simulations show that these variances are controlled mostly by GWs with vertical wavelengths z 5 km and horizontal along-track wavelengths of y 100-200 km. The tilted cigar-shaped three-dimensional weighting functions yield highly selective responses to GWs of high intrinsic frequency that propagate toward the instrument. The latter property is used to infer the net meridional component of GW propagation by differencing the variances acquired from ascending (A) and descending (D) orbits. Because of improved vertical resolution and sensitivity, Aura MLS GW variances are 5?8 times larger than those from the Upper Atmosphere Research Satellite (UARS) MLS. Like UARS MLS variances, monthly-mean Aura MLS variances in January and July 2005 are enhanced when local background wind speeds are large, due largely to GW visibility effects. Zonal asymmetries in variance maps reveal enhanced GW activity at high latitudes due to forcing by flow over major mountain ranges and at tropical and subtropical latitudes due to enhanced deep convective generation as inferred from contemporaneous MLS cloud-ice data. At 21-28-km altitude (heights not measured by the UARS MLS), GW variance in the tropics is systematically enhanced and shows clear variations with the phase of the quasi-biennial oscillation, in general agreement with GW temperature variances derived from radiosonde, rocketsonde, and limb-scan vertical profiles.

  4. Using NASA's Aura Satellite Data for Inquiry Based Classroom Instruction

    NASA Astrophysics Data System (ADS)

    Carter, B. L.; Stockman, S.; Bojkov, B.

    2007-12-01

    NASA's Earth Observing Satellite Aura was launched in 2004, and since that time has been collecting a wealth of data that contributes to scientists' understanding of the complexity of air quality issues. The Aura spacecraft monitors five of the six EPA criteria pollutants (NO2, SO2, O3, aerosols, and CO). Data from one of the criteria pollutants, NO2, are now available in a format useful to educators and students. The data by itself is not enough for students to engage in the scientific reasoning process. Thus, inquiry-driven supporting material in the form of lessons, project based learning scenarios, and curricular support for online data have all been adapted as part of the scaffolding necessary to help students gain an understanding of issues pertaining to air quality. These materials are delivered online which makes them readily accessible to the education community. Currently, NO2 data are available for manipulation using tools such as GoogleEarth and MY NASA DATA (http://mynasadata.larc.nasa.gov). These tools are used to investigate common relationships between spatial distribution and variability of NO2 concentrations. Through guided investigations in the Earth Exploration Toolbook (http://serc.carleton.edu/eet/index.html) or MY NASA DATA, students gain an understanding of NO2 variability. Students are then asked to extrapolate their knowledge and understanding to investigate other air quality issues relating to NO2. Within the coming year, the lessons built around Aura data will be introduced in professional development workshops. Feedback from those attending the professional development workshops about how the data and lessons are used in the classroom will be used to help shape future lesson development on new data. Subsequent data on criteria pollutants of SO2, aerosols, and O3 will soon be made available in a similar format to the education community, helping to further student understanding of the complex nature of air quality issues.

  5. Future instrumentation and missions for measurements of tropospheric trace species from space: Workshop recommendations

    NASA Technical Reports Server (NTRS)

    1987-01-01

    It was recommended that gas filter correlation radiometry and high-resolution interferometry be exploited and expanded for measurements of the distribution of tropospheric trace gases. Instruments and missions were identified and discussed. Several instrument/measurement/mission feasibility studies were recommended, including: a three-layer measurement of carbon monoxide, using a nadir-viewing gas filter correlation radiometer; a lower or middle tropospheric measurement of methane, using a nadir-viewing gas filter correlation radiometer; and a survey of lower, middle, and upper tropospheric trace gases using a nadir-viewing high-resolution interferometer operating in the thermal emission mode. It was also concluded that lidar systems appear to have the potential of obtaining measurments of tropospheric trace gases and aerosols from space. In addition to the specific instrument/mission recommendations, the panels made several general recommendations that may lead to future spaceborne instruments, techniques, and missions for tropospheric research.

  6. 75 FR 13806 - Culturally Significant Objects Imported for Exhibition Determinations: “Loan From the Aura...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Loan From the Aura Collection of a... hereby determine that the object to be included in the exhibition ``Loan from the Aura Collection of...

  7. TES/Aura L2 Water Vapor (H2O) Limb (TL2H2OL)

    Atmospheric Science Data Center

    2015-02-06

    TES/Aura L2 Water Vapor (H2O) Limb (TL2H2OL) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Water Vapor Spatial Coverage:  27 x 23 km Limb ... Access: OPeNDAP Parameters:  H2O Water Volume Mixing Radio Precision Vertical Resolution Order ...

  8. TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N)

    Atmospheric Science Data Center

    2015-01-30

    TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N) News:  TES News ... L2 Platform:  TES/Aura L2 Carbon Dioxide Spatial Coverage:  5.2 x 8.5 km nadir ... Subset Data: TES Order Tool Parameters:  Carbon Dioxide Order Data:  Reverb:   Order Data ...

  9. TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2NS)

    Atmospheric Science Data Center

    2015-01-30

    TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2NS) News:  TES News ... L2 Platform:  TES/Aura L2 Carbon Dioxide Spatial Coverage:  5.3 x 8.5 km nadir ... Subset Data: TES Order Tool Parameters:  Carbon Dioxide Order Data:  Reverb:   Order Data ...

  10. TES/Aura L2 Ammonia (NH3) Nadir (TL2NH3N)

    Atmospheric Science Data Center

    2015-01-30

    TES/Aura L2 Ammonia (NH3) Nadir (TL2NH3N) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Ammonia Spatial Coverage:  5.3 x 8.5 km nadir ... Data: TES Order Tool Parameters:  Ammonia Order Data:  Reverb:   Order Data ...

  11. TES/Aura L3 Ammonia (NH3) Daily (TL3NH3D)

    Atmospheric Science Data Center

    2015-08-28

    TES/Aura L3 Ammonia (NH3) Daily (TL3NH3D) News:  TES News ... Level:  L3 Instrument:  TES/Aura L3 Ammonia Spatial Coverage:  5.3 x 8.5 km Spatial ... Data: TES Order Tool Parameters:  Ammonia Order Data:  Reverb:   Order Data ...

  12. TES/Aura L2 Ammonia (NH3) Nadir (TL2NH3NS)

    Atmospheric Science Data Center

    2015-01-30

    TES/Aura L2 Ammonia (NH3) Nadir (TL2NH3NS) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Ammonia Spatial Coverage:  5.3 x 8.5 km nadir ... Data: TES Order Tool Parameters:  Ammonia Order Data:  Reverb:   Order Data ...

  13. TES/Aura L2 Carbon Monoxide (CO) Lite Nadir (TL2COLN)

    Atmospheric Science Data Center

    2015-06-16

    TES/Aura L2 Carbon Monoxide (CO) Lite Nadir (TL2COLN) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Carbon Monoxide Spatial Coverage:  5.3 km nadir ... OPeNDAP Access:  OPeNDAP Parameters:  Carbon Monoxide Order Data:  Reverb:   Order Data ...

  14. TES/Aura L2 Formic Acid (FOR) Nadir (TL2FORN)

    Atmospheric Science Data Center

    2015-02-04

    TES/Aura L2 Formic Acid (FOR) Nadir (TL2FORN) News:  TES News Join ... L2 Platform:  TES/Aura L2 Formic Acid Spatial Coverage:  5.3 x 8.5 km nadir Spatial ... Access:  OPeNDAP Parameters:  Formic Acid Volume Mixing Ratio Precision Vertical Resolution Order ...

  15. TES/Aura L2 Formic Acid (FOR) Lite Nadir (TL2FORLN)

    Atmospheric Science Data Center

    2015-06-16

    TES/Aura L2 Formic Acid (FOR) Lite Nadir (TL2FORLN) News:  TES News ... L2 Instrument:  TES/Aura L2 Formic Acid Spatial Coverage:  5.3 km nadir Spatial ... Access:  OPeNDAP Parameters:  Formic Acid Volume Mixing Ratio Vertical Resolution Precision Order ...

  16. TES/Aura L2 Formic Acid (FOR) Nadir (TL2FORNS)

    Atmospheric Science Data Center

    2015-02-04

    TES/Aura L2 Formic Acid (FOR) Nadir (TL2FORNS) News:  TES News Join ... L2 Platform:  TES/Aura L2 Formic Acid Spatial Coverage:  5.3 x 8.5 km nadir Spatial ... Access:  OPeNDAP Parameters:  Formic Acid Volume Mixing Ratio Precision Vertical Resolution Order ...

  17. First detection of ammonia (NH3) in the upper troposphere

    NASA Astrophysics Data System (ADS)

    Höpfner, Michael; Volkamer, Rainer; Grabowski, Udo; Grutter de la Mora, Michel; Orphal, Johannes; Stiller, Gabriele; von Clarmann, Thomas

    2016-04-01

    Ammonia (NH3) is the major alkaline trace gas in the troposphere. Neutralization of atmospheric acids, like HNO3 and H2SO4, leads to formation of ammonium nitrate and ammonium sulfate aerosols. Further, there are indications that NH3 may enhance nucleation of sulfuric acid aerosols by stabilization of sulfuric acid clusters. By far the largest source of ammonia is agricultural food production. Major global emissions are located in S-E Asia as e.g. shown by satellite nadir observations. Besides its importance with respect to air quality issues, an increase of ammonia emissions in the 21st century might lead to a significant climate radiative impact through aerosol formation. In spite of its significance, there is a lack of observational information on the global distribution of NH3 in the mid- and upper troposphere. Observational evidence, however, would be important for testing e.g. model results on the fate of ammonia from its source regions on ground to altitudes up to the tropopause. In this contribution we will show, to our knowledge, the first unequivocal detection of ammonia in the upper troposphere. This result has been achieved through analysis of infrared limb-emission observations performed with the MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) instrument on board the Envisat satellite from 2002-2012. On a global scale, enhanced values of ammonia have been measured in the upper tropospheric region influenced by the Asian monsoon. We will present a quantitative analysis of the retrieved concentrations of NH3 including an error assessment and further retrieval diagnostics. The results will be discussed with respect to the variability of NH3 locally within the Asian monsoon region's upper troposphere and at different years. Further, we will show comparisons between global distributions of NH3 from published model simulations and our observational dataset from MIPAS.

  18. Impacts of anthropogenic and natural sources on free tropospheric ozone over the Middle East

    NASA Astrophysics Data System (ADS)

    Jiang, Zhe; Miyazaki, Kazuyuki; Worden, John R.; Liu, Jane J.; Jones, Dylan B. A.; Henze, Daven K.

    2016-05-01

    Significant progress has been made in identifying the influence of different processes and emissions on the summertime enhancements of free tropospheric ozone (O3) at northern midlatitude regions. However, the exact contribution of regional emissions, chemical and transport processes to these summertime enhancements is still not well quantified. Here we focus on quantifying the influence of regional emissions on the summertime O3 enhancements over the Middle East, using updated reactive nitrogen (NOx) emissions. We then use the adjoint of the GEOS-Chem model with these updated NOx emissions to show that the global total contribution of lightning NOx on middle free tropospheric O3 over the Middle East is about 2 times larger than that from global anthropogenic sources. The summertime middle free tropospheric O3 enhancement is primarily due to Asian NOx emissions, with approximately equivalent contributions from Asian anthropogenic activities and lightning. In the Middle Eastern lower free troposphere, lightning NOx from Europe and North America and anthropogenic NOx from Middle Eastern local emissions are the primary sources of O3. This work highlights the critical role of lightning NOx on northern midlatitude free tropospheric O3 and the important effect of the Asian summer monsoon on the export of Asian pollutants.

  19. The Alice in Wonderland Syndrome: A Case of Aura Accompanying Cluster Headache

    PubMed Central

    Uca, Ali Ulvi; Kozak, Hasan Hüseyin

    2015-01-01

    Background: Cluster headache (CH) is a primary headache which has highly specific and sensitive criteria, and notpresence of an aura. It has been recently reported that CH may not presence with aura more than ever and this condition will be identified by headache specialists as a new form of CH. Case Report: As there is no report to our knowledge on Alice in Wonderland syndrome (AIWS) manifested as CH aura in the literature, we present a case of a 35-year-old man having AIWS as CH aura. Conclusion: Clinically, AIWS is not uncommon and is likely to be underestimated as a diagnostic entity. Valproate may be preferred for treatment in CH patients with AIWS aura. PMID:26185724

  20. Long-term trend in tropospheric carbon monoxide over the globe

    NASA Astrophysics Data System (ADS)

    Girach, I. A.; Nair, Prabha R.

    2016-05-01

    Tropospheric carbon monoxide (CO) is an air pollutant and indirect greenhouse gas which plays a major role in atmospheric chemistry involving hydroxyl (OH) radical. We utilised the remote-sensing retrievals of lower-tropospheric CO (at 900 hPa) from Measurements of Pollution in the Troposphere (MOPITT) aboard Terra-satellite for the period of ~15 years. Using simple linear regression model, we estimated the decreasing trend of ~0-2 %year-1 in the lowertropospheric CO over the globe. Utilising the in-situ measurements of surface-CO over 83 locations carried out by the NOAA (National Oceanic and Atmospheric Administration) network, we confirmed the observed negative trend as surface-CO showed decreasing trend over most of the locations. To estimate the trend in columnar CO, we utilised multiple retrievals of from different satellites, MOPITT, AIRS (Atmospheric InfraRed Sounder), and TES (Tropospheric Emission Spectrometer). All data sets show the decreasing trend of 0.2-0.5 %year-1 in columnar CO when averaged over entire globe. However, the heterogeneity in the trend is observed on regional basis. The retrievals of upper-tropospheric CO (at 200 hPa) from MOPITT and AIRS show an increasing trend of 1-4 %year-1 over the globe. However, the retrievals of upper-tropospheric CO from MLS (Microwave Limb Sounder) show decreasing trend. Further investigations are needed to confirm the trend in the upper-tropospheric CO over the globe. The decreasing trend in lower-tropospheric CO and columnar CO could be due to moistening of troposphere and/or increase in tropospheric ozone, causing increase in OH radical (strengthening the depletion of lower-tropospheric CO).

  1. North American Tropospheric Ozone Profiles from IONS (INTEX Ozonesonde Network Study, 2004, 2006): Ozone Budgets, Polution Statistics, Satellite Retrievals

    NASA Astrophysics Data System (ADS)

    Dougherty, M.; Thompson, A. M.; Witte, J. C.; Miller, S. K.; Oltmans, S. J.; Cooper, O. R.; Tarasick, D. W.; Chatfield, R. B.; Taubman, B. F.; Joseph, E.; Baumgardner, D.; Merrill, J. T.; Morris, G. A.; Rappenglueck, B.; Lefer, B.; Forbes, G.; Newchurch, M. J.; Schmidlin, F. J.; Pierce, R. B.; Leblanc, T.; Dubey, M.; Minschwaner, K.

    2007-12-01

    During INTEX-B (both Milagro and IMPEX phases in Spring 2006) and during the summer TEXAQS- 2006/GOMACCS period, the INTEX Ozonesonde Network Study (IONS-06) coordinated ozonesonde launches over North America for Aura overpasses. IONS-06 supported aircraft operations and provided profiles for ozone budgets and pollution transport, satellite validation and evaluation of models. In contrast to IONS-04, IONS-06 had a greater range (all but one 2004 IONS site plus a dozen in California, New Mexico, Mexico City, Barbados and southwestern Canada), yielding more than 700 profiles. Tropospheric pollution statistics to guide Aura satellite retrievals and contrasts in UT-LS (upper tropospheric-lower stratospheric) ozone between 2004 and 2006 are presented. With IONS-04 dominated by low-pressure conditions over northeastern North America, UT ozone originated 25% from the stratosphere [Thompson et al., 2007a,b] with significant amounts from aged or relatively fresh pollution and lightning [Cooper et al., 2006; Morris et al., 2006]. Both IONS-04 and IONS-06 summer periods displayed a persistent UT ozone maximum [Cooper et al., 2007] over the south-central US. March 2006 IONS sondes over Mexico manifested persistent UT/LS gravity wave influence and more sporadic pollution. Regional and seasonal contrasts in IONS-06 ozone distributions are described. intexb/ions06.html

  2. Tropospheric gas at potentially toxic levels in air

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Atreyee

    2012-08-01

    Forest fires and emission of air pollutants, such as fumes from vehicles running on diesel and slow burning of coal and charcoal, release isocyanic acid in the troposphere. In 2011, scientists first detected isocyanic acid in the ambient atmosphere at levels toxic to human populations; at concentrations exceeding 1 part per billion by volume (ppbv), human beings could experience tissue decay when exposed to the toxin. For the first time, using a chemical transport model designed to estimate the distribution and budget of isocyanic acid in the troposphere, Young et al. showed that in several parts of the world, local emissions may increase the concentration of isocyanic acid in the ambient atmosphere, thereby exposing large populations to potentially toxic levels of the acid.

  3. Plant responses to tropospheric ozone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropospheric ozone is the second most abundant air pollutant and an important component of the global climate change. Over five decades of research on the phytotoxicity of ozone in model plants systems, crop plants and forest trees have provided some insight into the physiological, biochemical and m...

  4. Climate-chemistry interaction affecting tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Mao, Huiting

    1999-09-01

    Tropospheric ozone, an important radiative-chemical species, has been observed increasing especially at northern midlatitudes during the past few decades. This dissertation addresses climate-chemistry interaction associated with such increases in three aspects using observations as well as atmospheric chemistry and climate models. Ozone impact on climate is first evaluated by radiative forcing calculations due to observed ozone changes. It is found that a 10% increase in tropospheric ozone causes a radiative forcing of 0.17 Wm-2 using a fixed temperature (FT) method or 0.13 Wm-2 using a fixed dynamic heating (FDH) method, which is comparable to the radiative forcing 0.26 (FT) and -0.09 Wm-2 (FDH) caused by the stratospheric ozone depletion during the 1980s. Second, radiative forcing due to changes in ozone precursors is estimated. Ozone changes in response to a 20% reduction in surface NOx emission in six regions around the globe differ between regions. A maximum decrease in ozone column reaches 5% in southeast Asia and the central Atlantic Ocean, inducing a local radiative forcing of up to -0.1 Wm-2 in those regions. It indicates that surface NOx emission changes can potentially affect regional climate. Third, the effects of climate and climate changes on atmospheric chemistry are addressed with two studies. One study investigates the effects of global warming on methane and ozone, and another looks into cloud effects on photodissociation rate constants. Calculations based on the IPCC business-as-usual scenario indicate that by 2050, temperature and moisture increases can suppress methane and tropospheric ozone increases by 17% and 11%, respectively, in reference to the 1990 concentrations. The combined effects offset the global warming induced forcing 3.90 Wm -2 by -0.46 Wm-2. A one-dimensional study suggests that a typical cirrus cloud (τ = 2) can significantly increase J(O1D) and J(NO2) around the tropopause with a maximum of 21%. Geographical and seasonal

  5. Relationships of Upper Tropospheric Water Vapor, Clouds and SST: MLS Observations, ECMWF Analyses and GCM Simulations

    NASA Technical Reports Server (NTRS)

    Su, Hui; Waliser, Duane E.; Jiang, Jonathan H.; Li, Jui-lin; Read, William G.; Waters, Joe W.; Tompkins, Adrian M.

    2006-01-01

    The relationships of upper tropospheric water vapor (UTWV), cloud ice and sea surface temperature (SST) are examined in the annual cycles of ECMWF analyses and simulations from 15 atmosphere-ocean coupled models which were contributed to the IPCC AR4. The results are compared with the observed relationships based on UTWV and cloud ice measurements from MLS on Aura. It is shown that the ECMWF analyses produce positive correlations between UTWV, cloud ice and SST, similar to the MLS data. The rate of the increase of cloud ice and UTWV with SST is about 30% larger than that for MLS. For the IPCC simulations, the relationships between UTWV, cloud ice and SST are qualitatively captured. However, the magnitudes of the simulated cloud ice show a considerable disagreement between models, by nearly a factor of 10. The amplitudes of the approximate linear relations between UTWV, cloud ice and SST vary by a factor up to 4.

  6. Satellite-derived estimations of spatial and seasonal variation in tropospheric carbon dioxide mass over China

    PubMed Central

    Xu, Yuyue; Ke, Changqing; Wang, Juanle; Sun, Jiulin; Liu, Yang; Harris, Warwick; Kou, Cheng

    2013-01-01

    China has frequently been questioned about the data transparency and accuracy of its energy and emission statistics. Satellite-derived remote sensing data potentially provide a useful tool to study the variation in carbon dioxide (CO2) mass over areas of the earth's surface. In this study, Greenhouse gases Observing SATellite (GOSAT) tropospheric CO2 concentration data and NCEP/NCAR reanalysis tropopause data were integrated to obtain estimates of tropospheric CO2 mass variations over the surface of China. These variations were mapped to show seasonal and spatial patterns with reference to China's provincial areas. The estimates of provincial tropospheric CO2 were related to statistical estimates of CO2 emissions for the provinces and considered with reference to provincial populations and gross regional products (GRP). Tropospheric CO2 masses for the Chinese provinces ranged from 53 ± 1 to 14,470 ± 63 million tonnes were greater for western than for eastern provinces and were primarily a function of provincial land area. Adjusted for land area troposphere CO2 mass was higher for eastern and southern provinces than for western and northern provinces. Tropospheric CO2 mass over China varied with season being highest in July and August and lowest in January and February. The average annual emission from provincial energy statistics of CO2 by China was estimated as 10.3% of the average mass of CO2 in the troposphere over China. The relationship between statistical emissions relative to tropospheric CO2 mass was higher than 20% for developed coastal provinces of China, with Shanghai, Tianjin, and Beijing having exceptionally high percentages. The percentages were generally lower than 10% for western inland provinces. Provincial estimates of emissions of CO2 were significantly positively related to provincial populations and gross regional products (GRP) when the values for the provincial municipalities Shanghai, Tianjin, and Beijing were excluded from the linear

  7. Epileptic auras and their role in driving safety in people with epilepsy.

    PubMed

    Punia, Vineet; Farooque, Pue; Chen, William; Hirsch, Lawrence J; Berg, Anne T; Blumenfeld, Hal

    2015-11-01

    The aim of our study was to evaluate the role of auras in preventing motor vehicle accidents (MVAs) among patients with medically refractory epilepsy. The Multicenter Study of Epilepsy Surgery database was used to perform a case-control study by identifying patients who had seizures while driving that led to MVAs (cases) and those who had seizures while driving without MVAs (controls). We compared presence of reliable auras and other aura-related features between the two groups. Two hundred fifteen of 553 patients reported having seizure(s) while driving; 74 were identified as "controls" and 141 as "cases." The two groups had similar demographic and clinical features. The presence of reliable auras was not different between the two groups (67% in cases vs. 65% in controls; odds ratio [OR] 0.89, 95% confidence interval [CI] 0.49-1.61, p = 0.76). In addition, the groups did not differ in the proportion of patients who reported longer (>1 min) auras (OR 0.7, 95% CI 0.28-1.76, p = 0.47), or who thought that their auras were of sufficient duration to be protective (OR 1.19, 95% CI 0.62-2.00, p = 0.77). Our study questions the long-held belief of a protective role of reliable auras against MVAs in people with epilepsy.

  8. Analysis of 1970-1995 Trends in Tropospheric Ozone at Northern Hemisphere Midlatitudes with the GEOS-CHEM Model

    NASA Technical Reports Server (NTRS)

    Fusco, Andrew C.; Logan, Jennifer A.

    2004-01-01

    I ] The causes of trends in tropospheric ozone at Northern Hemisphere midlatitudes from 1970 to 1995 are investigated with the GEOS-CHEM model, a global three-dimensional model of the troposphere driven by assimilated meteorological observations from the Goddard Earth Observing System (GEOS). This model is used to investigate the sensitivity of tropospheric ozone with respect to (1) changes in the anthropogenic emission of nitrogen oxides and nonmethane hydrocarbons, (2) increases in methane concentrations, (3) variations in the stratospheric source of ozone, (4) changes in solar radiation resulting from stratospheric ozone depletion, and ( 5 ) increases in tropospheric temperatures. Model results indicate that local increases in NO, emissions have caused most of the increases seen in lower tropospheric ozone over Europe and Japan. Increases in methane are responsible for roughly one fifth of the anthropogenically induced increase in tropospheric ozone at northern midlatitudes. However, changes in ozone precursors do not adequately explain either the spatial differences in observed ozone trends across midlatitudes or the observed decreases in ozone over Canada throughout the troposphere. We argue that ozone depletion in the lowermost stratosphere is likely to have reduced the stratospheric source by as much as 30% from the early 1970s to the mid 1990s. Model simulations that account for such a reduction along with reported changes in anthropogenic emissions show steep declines of ozone in the upper troposphere and variable increases in the lower troposphere that are more consistent with observations. Differential temperature trends in summer between North America and Europe may account for at least some of the remaining spatial variation in tropospheric ozone trends. Increases in ultraviolet (UV) radiation due to stratospheric ozone depletion do not appear to significantly reduce tropospheric ozone, except at midlatitudes in the Southern Hemisphere following the

  9. Low to middle tropospheric profiles and biosphere/troposphere fluxes of acidic gases in the summertime Canadian taiga

    NASA Technical Reports Server (NTRS)

    Klemm, O.; Talbot, R. W.; Fitzgerald, D. R.; Klemm, K. I.; Lefer, B. L.

    1994-01-01

    We report features of acidic gases in the troposphere from 9 to 5000 m altitude above ground over the Canadian taiga in the summer of 1990. The measurements were conducted at a 30-m meteorological tower and from the NASA Wallops Electra aircraft as part of the joint U.S.-Canadian Arctic Boundary Layer Expedition (ABLE) 3B Northern Wetland Studies (NOWES). We sampled air for acidic gases using the mist chamber collector coupled with subsequent analysis using ion chromatography. At the tower we collected samples at two heights during a 13-day period, including diurnal studies. Using eddy flux and profile data, we estimated the biosphere/troposphere fluxes of nitric, formic, and acetic acids and sulfur dioxide. For the organic acids, emissions from the taiga in the afternoon hours and deposition during the predawn morning hours were observed. The flux intensities alone were however not high enough to explain the observed changes in mixing ratios. The measured deposition fluxes of nitric acid were high enough to have a significant influence on its mixing ratio in the boundary layer. On three days we measured vertical profiles of nitric, formic, and acetic acids through the lower to midtroposphere. We found that the chemical composition of the troposphere was extremely heterogenous. Pronounced layers of polluted air were readily apparent from our measurements. Local photochemical production and episodic long-range transport of trace components, originating from biomass burning and possibly industrial emissions, appear to have a strong influence on the composition of the troposphere and biosphere/troposphere fluxes of acidic gases at this site.

  10. Origin of tropospheric ozone: A global three-dimensional model analysis

    NASA Astrophysics Data System (ADS)

    Wang, Yuhang

    1997-12-01

    A three-dimensional global model is developed for simulations of tropospheric O3-NO x- hydrocarbon chemistry. The model is applied to examine the factors controlling concentrations of tropospheric O3 and to investigate the anthropogenic impact on tropospheric O3 and the oxidizing power of the atmosphere. The model includes state-of-the-art inventories of anthropogenic emissions, process-based formulations of natural emissions and deposition, and a detailed O3- NO x-hydrocarbon chemical mechanism. Model results of O3, NO, PAN, CO, ethane, acetone, and H2O2 are evaluated extensively with surface, ozonesonde, and aircraft measurements. The model reproduces well the observed seasonal variations of ozone in the troposphere, but underestimates the vertical gradient due to excessive vertical mixing in the extratropical upper troposphere and across the tropical trade wind inversion. Model results indicate that tropospheric O3 at present is controlled at all latitudes largely by a balance between chemical production and chemical loss in the tropospheric column. The contribution of transport from the stratosphere to O3 concentrations is 30% at mid latitudes in winter, 10% in summer, and 5-10% in the tropics. Sources of ozone in the upper, middle, and continental lower troposphere contribute in similar proportions (20-40%) to O3 levels at all altitudes throughout the troposphere. The springtime maximum of O3 observed in the remote northern extratropics can be explained by a phase overlap between O3 transported from the stratosphere which peaks in late winter to early spring, and O3 produced in the continental lower troposphere which peaks in late spring to summer. A new conceptual framework is introduced. The supply of CO and hydrocarbons dictates a lower limit of chemical production of O3 within the troposphere, which is evidently a larger source for tropospheric O3 than that from the stratosphere, thus bringing a long-standing debate to a closure. Model simulations for

  11. Southern Hemisphere Additional Ozonesondes (SHADOZ) Ozone Climatology (2005-2009): Tropospheric and Tropical Tropopause Layer (TTL) Profiles with Comparisons to Omi-based Ozone Products

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Miller, Sonya K.; Tilmes, Simone; Kollonige, Debra W.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Johnson, Brian J.; Fujiwara, Masatomo; Schmidlin, F. J.; Coetzee, G. J. R.; Komala, Ninong; Maata, Matakite; bt Mohammad, Maznorizan; Nguyo, J.; Mutai, C.; Ogino, S-Y; Da Silva, F. Raimundo; Paes Leme, N. M.; Posny, Francoise; Scheele, Rinus; Selkirk, Henry B.; Shiotani, Masato; Stubi, Rene; Levrat, Gilbert; Calpini, Bertrand; Thouret, Valerie; Tsuruta, Haruo; Canossa, Jessica Valverde; Voemel, Holger; Yonemura, S.; Andres Diaz, Jorge; Tan Thanh, Nguyen T.; Thuy Ha, Hoang T.

    2012-01-01

    We present a regional and seasonal climatology of SHADOZ ozone profiles in the troposphere and tropical tropopause layer (TTL) based on measurements taken during the first five years of Aura, 2005-2009, when new stations joined the network at Hanoi, Vietnam; Hilo, Hawaii; Alajuela Heredia, Costa Rica; Cotonou, Benin. In all, 15 stations operated during that period. A west-to-east progression of decreasing convective influence and increasing pollution leads to distinct tropospheric ozone profiles in three regions: (1) western Pacific eastern Indian Ocean; (2) equatorial Americas (San Cristobal, Alajuela, Paramaribo); (3) Atlantic and Africa. Comparisons in total ozone column from soundings, the Ozone Monitoring Instrument (OMI, on Aura, 2004-) satellite and ground-based instrumentation are presented. Most stations show better agreement with OMI than they did for EPTOMS comparisons (1998-2004; Earth-ProbeTotal Ozone Mapping Spectrometer), partly due to a revised above-burst ozone climatology. Possible station biases in the stratospheric segment of the ozone measurement noted in the first 7 years of SHADOZ ozone profiles are re-examined. High stratospheric bias observed during the TOMS period appears to persist at one station. Comparisons of SHADOZ tropospheric ozone and the daily Trajectory-enhanced Tropospheric Ozone Residual (TTOR) product (based on OMIMLS) show that the satellite-derived column amount averages 25 low. Correlations between TTOR and the SHADOZ sondes are quite good (typical r2 0.5-0.8), however, which may account for why some published residual-based OMI products capture tropospheric interannual variability fairly realistically. On the other hand, no clear explanations emerge for why TTOR-sonde discrepancies vary over a wide range at most SHADOZ sites.

  12. Tropospheric chemical models

    NASA Technical Reports Server (NTRS)

    Prinn, R. G.

    1992-01-01

    The differences in atmospheric composition over the globe and the short- and long-term variations in this composition are the net effect of several atmospheric and biospheric processes: biospheric emissions, atmospheric circulation, atmospheric chemical transformations and finally deposition back to the surface. Accurate and realistic atmospheric chemistry and circulation models are essential to interpret the observed global distributions and trends of atmospheric species in terms of these underlying processes. Comparisons between model predictions and observations test current understanding of these processes and models used in conjunction with inverse methods allow deductions of the rates of these processes from the observations. With the planned inclusion of at least CO and CH4 observations on the Earth Observing System (EOS) satellites, together with the large global data set expected from in situ observations under the International Global Atmospheric Chemistry (IGAC) Project, the further development of global three-dimensional high-resolution atmospheric chemistry and circulation models in order to interpret this new data is a high-priority endeavor.

  13. Development of a Climate Record of Tropospheric and Stratospheric Column Ozone from Satellite Remote Sensing: Evidence of an Early Recovery of Global Stratospheric Ozone

    NASA Technical Reports Server (NTRS)

    Ziemke, Jerald R.; Chandra, Sushil

    2012-01-01

    Ozone data beginning October 2004 from the Aura Ozone Monitoring Instrument (OMI) and Aura Microwave Limb Sounder (MLS) are used to evaluate the accuracy of the Cloud Slicing technique in effort to develop long data records of tropospheric and stratospheric ozone and for studying their long-term changes. Using this technique, we have produced a 32-yr (1979-2010) long record of tropospheric and stratospheric column ozone from the combined Total Ozone Mapping Spectrometer (TOMS) and OMI. Analyses of these time series suggest that the quasi-biennial oscillation (QBO) is the dominant source of inter-annual variability of stratospheric ozone and is clearest in the Southern Hemisphere during the Aura time record with related inter-annual changes of 30- 40 Dobson Units. Tropospheric ozone for the long record also indicates a QBO signal in the tropics with peak-to-peak changes varying from 2 to 7 DU. The most important result from our study is that global stratospheric ozone indicates signature of a recovery occurring with ozone abundance now approaching the levels of year 1980 and earlier. The negative trends in stratospheric ozone in both hemispheres during the first 15 yr of the record are now positive over the last 15 yr and with nearly equal magnitudes. This turnaround in stratospheric ozone loss is occurring about 20 yr earlier than predicted by many chemistry climate models. This suggests that the Montreal Protocol which was first signed in 1987 as an international agreement to reduce ozone destroying substances is working well and perhaps better than anticipated.

  14. Evaluation of Nitrogen Oxides Emissions over California in Spring 2010

    NASA Astrophysics Data System (ADS)

    Huang, M.; Bowman, K. W.; Carmichael, G. R.; Chai, T.; Pierce, R.; Pollack, I. B.; Ryerson, T. B.

    2013-12-01

    Nitrogen Dioxide (NO2) belongs to the regulated 'six common air pollutants' by the US Environmental Protection Agency (EPA), due to its adverse impacts on the human respiratory system. It is also often used as the indicator for the highly reactive group of gases nitrogen oxides (NOx), the important ozone precursors. We model California air quality during the NOAA CalNex field campaign period in May 2010 using the STEM chemical transport model on a 12 km horizontal resolution grid. Three different anthropogenic emission inventories were used in the simulations: 1) 2005 National Emission Inventory (NEI 2005); 2) daily-varying emissions recently developed by California Air Resources Board (CARB); and 3) NEI 2008. The model-simulated NO2 were compared with the measurements by aircraft and the Ozone Monitoring Instrument (OMI) on board of the Aura satellite. We further conduct NO2 emission inversion using the four-dimensional variational approach [Chai et al., 2009] and the OMI NO2 column data. The inversion generated grid-based emission scaling factors on the NEI 2005, and the resulting NOx fields were 'cross-validated' by comparing with aircraft NO2 measurements. The adjustment on original emissions was then compared with 1) the CARB-documented NOx emission trends, 2) other 'top-down' estimates of California NOx emissions using aircraft measurements [Brioude et al., 2013], and 3) the space-observed NO2 column trends [Russell et al., 2012]. References Chai, T., Carmichael, G., Tang, Y., and Sandu, A., Regional NO2 emission inversion through four-dimensional variational approach using Sciamachy tropospheric column observations, Atmos. Environ., 43, 5046-5055, 2009. Brioude, J., Angevine, W. M., Ahmadov, R., Kim, S.-W., Evan, S., McKeen, S. A., Hsie, E.-Y., Frost, G. J., Neuman, J. A., Pollack, I. B., Peischl, J., Ryerson, T. B., Holloway, J., Brown, S. S., Nowak, J. B., Roberts, J. M., Wofsy, S. C., Santoni, G. W., Oda, T., and Trainer, M.: Top-down estimate of surface

  15. Experimental lead poisoning in Turkey Vultures, Cathartes aura

    USGS Publications Warehouse

    Carpenter, J.W.; Pattee, O.H.; Fritts, S.H.; Rattner, B.A.; Wiemeyer, Stanley N.; Royle, J. Andrew; Smith, M.R.

    2003-01-01

    Lead-induced mortality appears to have been a major factor in the decline of the California condor, Gymnogyps californianus. We orally dosed turkey vultures (Cathartes aura) with BB-sized lead shot from January 1988 through July 1988 to determine physiological response (delta-aminolevulinic acid dehydratase inhibition, erythrocyte protoporphyrin levels, anemia), diagnostic tissue lead concentrations (blood, liver, and kidney), and comparative sensitivity of this species. Two turkey vultures died and two became so intoxicated they were euthanized. Overall, responses of measured parameters were comparable to other species exposed to lead although there was considerable individual variation. Survival time (143-211 days), even with the large number of shot and constant redosing, was much longer than reported for other species of birds, suggesting considerable tolerance by turkey vultures to the deleterious effects of lead ingestion. Based on these observations, turkey vultures appear to be poor models for assessing the risk of lead poisoning to California condors or predicting their physiological response.

  16. Direct Observations of PMC Local Time Variations by Aura OMI

    NASA Technical Reports Server (NTRS)

    DeLand, Matthew T.; Shettle, Eric P.; Thomas, Gary E.; Olivero, John J.

    2010-01-01

    The Ozone Monitoring Instrument (OMI) on the Aura satellite obtains unique measurements for polar mesospheric cloud (PMC) analysis. Its wide cross-track viewing swath and high along-track spatial resolution makes it possible to directly evaluate PMC occurrence frequency and brightness variations between 6S" and 8S' latitude as a function of local time over a 12-14 h continuous period. OMI PMC local time variations are closely coupled to concurrent variations in measurement scattering angle, so that ice phase function effects must be considered when interpreting the observations. Two different phase functions corresponding to bright and faint clouds are examined in this analysis. OMI observations show maximum frequency and albedo values at 8-10 h local time in the Northern Hemisphere, with decreasing amplitude at higher latitudes. Southern Hemisphere values reach a minimum at 18-20 h LT. Larger variations are seen in Northern Hemisphere data. No statistically significant longitudinal dependence was seen.

  17. Summary of Aqua, Aura, and Terra High Interest Events

    NASA Technical Reports Server (NTRS)

    Newman, Lauri

    2015-01-01

    Single-obs tracking Sparsely tracked objects are an unfortunate reality of CARA operations Terra vs. 32081: new track with bad data was included in OD solution for secondary object and risk became high CARA and JSpOC discussed tracking and OSAs threw out the bad data. Event no longer presented high risk based on new OD Improvement: CARA now sends JSpOC a flag indicating when a single obs is included, so OSAs can evaluate if manual update to OD is required. Missing ASW OCMsAura vs. 87178, TCA: 317 at 08:04 UTC. Post-maneuver risk (conjunction was identified in OO results)CARA confirmed with JSpOC that ASW OCMs should have been received in addition to OO OCMsJSpOC corrected the manual error in their script that prevented the data from being delivered to CARAJSpOC QAd their other scripts to ensure this error did not exist in other places.

  18. Experimental lead poisoning in turkey vultures (Cathartes aura).

    PubMed

    Carpenter, James W; Pattee, Oliver H; Fritts, Steven H; Rattner, Barnett A; Wiemeyer, Stanley N; Royle, J Andrew; Smith, Milton R

    2003-01-01

    Lead-induced mortality appears to have been a major factor in the decline of the California condor (Gymnogyps californianus). We orally dosed turkey vultures (Cathartes aura) with BB-sized lead shot from January 1988 through July 1988 to determine physiologic response (delta-aminolevulinic acid dehydratase inhibition, erythrocyte protoporphyrin levels, anemia), diagnostic tissue lead concentrations (blood, liver, and kidney), and comparative sensitivity of this species. Two turkey vultures died and two became so intoxicated they were euthanized. Overall, responses of measured parameters were comparable to other species exposed to lead although there was considerable individual variation. Survival time (143-211 days), even with the large numbers of shot and constant redosing, was much longer than reported for other species of birds, suggesting considerable tolerance by turkey vultures to the deleterious effects of lead ingestion. Based on these observations, turkey vultures appear to be poor models for assessing the risk of lead poisoning to California condors or predicting their physiologic response.

  19. Diagnosing changes in European tropospheric ozone: A model study of past and future changes

    NASA Astrophysics Data System (ADS)

    Tummon, Fiona; Revell, Laura; Stenke, Andrea; Staehelin, Johannes; Peter, Thomas

    2016-04-01

    In recent decades, the negative impacts of tropospheric ozone on human and ecosystem health have led to policy changes aimed at reducing emissions of ozone precursor gases such as nitrogen oxides (NOx) and carbon monoxide (CO). Although emissions of these species have significantly decreased in Europe and North America since the early 1990s, observational data indicate that free tropospheric ozone over Europe has not decreased as expected. Uncertainty remains as to how much of a role the transport of stratospheric ozone or tropospheric ozone from remote source regions has played in recent trends, as well as to how this will evolve in a changing climate. The global chemistry-climate model SOCOL (SOlar Chemistry Ozone Links) is used to investigate tropospheric ozone over Europe from 1960 to 2100. To fully disentangle the effects of both long-range transport and input from the stratosphere, simulations are run with ozone tracers from 21 different atmospheric regions. In addition to a standard reference run, several sensitivity simulations are run: one with emissions of NOx and CO held constant at 1960 levels, one with methane (CH4) held at constant 1960 levels (in addition to the NOx and CO), and a third with NOx and CO emissions from Asia fixed at 1960 levels. Results suggest that the largest contributions to European tropospheric ozone originate from the tropical and northern mid-latitude boundary layer and free troposphere. Contributions from these regions increase over the historical period (1960-2010), indicating that changes in source gas emissions have affected ozone concentrations in the European free troposphere most strongly. Contributions from these regions then decrease from 2010-2100, but remain considerably larger than input from the stratosphere, which is relatively small in all simulations throughout the entire simulated period (1960-2100). The stratospheric contribution does, however, increase slightly over the 21st century, in tandem with ozone

  20. Validation of Aura Microwave Limb Sounder HCl Measurements

    NASA Technical Reports Server (NTRS)

    Froidevaux, L.; Jiang, Y. B.; Lambert, A.; Livesey, N. J.; Read, W. G.; Waters, J. W.; Fuller, R. A.; Marcy, T. P.; Popp, P. J.; Gao, R. S.; Fahey, D. W.; Jucks, K. W.; Stachnik, R. A.; Toon, G. C.; Christensen, L. E.; Webster, C. R.; Bernath, P. F.; Boone, C. D.; Walker, K. A.; Pumphrey, H. C.; Harwood, R. S.; Manney, G. L.; Schwartz, M. J.; Daffer, W. H.; Drouin, B. J.

    2008-01-01

    The Earth Observing System (EOS) Microwave Limb Sounder (MLS) aboard the Aura satellite has provided daily global HCl profiles since August 2004. We provide a characterization of the resolution, random and systematic uncertainties, and known issues for the version 2.2 MLS HCl data. The MLS sampling allows for comparisons with many (1500 to more than 3000) closely matched profiles from the Halogen Occultation Experiment (HALOE) and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). These data sets provide HCl latitudinal distributions that are, overall, very similar to those from (coincident) MLS profiles, although there are some discrepancies in the upper stratosphere between the MLS and HALOE gradients. As found in previous work, MLS and ACE HCl profiles agree very well (within approximately 5%, on average), but the MLS HCl abundances are generally larger (by 10-20%) than HALOE HCl. The bias versus HALOE is unlikely to arise mostly from MLS, as a similar systematic bias (of order 15%) is not observed between average MLS and balloon-borne measurements of HCl, obtained over Fort Sumner, New Mexico, in 2004 and 2005. At the largest pressure (147 hPa) for MLS HCl, a high bias (approximately 0.2 ppbv) is apparent in analyses of low to midlatitude data versus in situ aircraft chemical ionization mass spectrometry (CIMS) HCl measurements from the Aura Validation Experiment (AVE) campaigns in 2004, 2005, and 2006; this bias is also observed in comparisons of MLS and aircraftHCl/O3 correlations. Good agreement between MLS and CIMS HCl is obtained at 100 to 68 hPa. The recommended pressure range for MLS HCl is from 100 to 0.15 hPa.

  1. An Improved Retrieval of Tropospheric Nitrogen Dioxide from GOME

    NASA Technical Reports Server (NTRS)

    Martin, Randall V.; Chance, Kelly; Jacob, Daniel J.; Kurosu, Thomas P.; Spurr, Robert J. D.; Bucsela, Eric; Gleason, James F.; Palmer, Paul I.; Bey, Isabelle; Fiore, Arlene M.

    2002-01-01

    We present a retrieval of tropospheric nitrogen dioxide (NO2) columns from the Global Ozone Monitoring Experiment (GOME) satellite instrument that improves in several ways over previous retrievals, especially in the accounting of Rayleigh and cloud scattering. Slant columns, which are directly fitted without low-pass filtering or spectral smoothing, are corrected for an artificial offset likely induced by spectral structure on the diffuser plate of the GOME instrument. The stratospheric column is determined from NO2 columns over the remote Pacific Ocean to minimize contamination from tropospheric NO2. The air mass factor (AMF) used to convert slant columns to vertical columns is calculated from the integral of the relative vertical NO2 distribution from a global 3-D model of tropospheric chemistry driven by assimilated meteorological data (Global Earth Observing System (GEOS)-CHEM), weighted by altitude dependent scattering weights computed with a radiative transfer model (Linearized Discrete Ordinate Radiative Transfer), using local surface albedos determined from GOME observations at NO2 wavelengths. The AMF calculation accounts for cloud scattering using cloud fraction, cloud top pressure, and cloud optical thickness from a cloud retrieval algorithm (GOME Cloud Retrieval Algorithm). Over continental regions with high surface emissions, clouds decrease the AMT by 20- 30% relative to clear sky. GOME is almost twice as sensitive to tropospheric NO2 columns over ocean than over land. Comparison of the retrieved tropospheric NO2 columns for July 1996 with GEOS-CHEM values tests both the retrieval and the nitrogen oxide radical (NOx) emissions inventories used in GEOS-CHEM. Retrieved tropospheric NO2 columns over the United States, where NOx emissions are particularly well known, are within 18% of GEOS-CHEM columns and are strongly spatially correlated (r = 0.78, n = 288, p less than 0.005). Retrieved columns show more NO2 than GEOS-CHEM columns over the Transvaal

  2. Observations and Modeling of Composition of Upper Troposphere/Lower Stratosphere (UTILS): Isentropic Mixing Events and Morphology of HNO3 as Observed by HIRDLS and Comparison with Results from Global Modeling Initiative

    NASA Technical Reports Server (NTRS)

    Rodriquez, J. M.; Douglass, A.R.; Yoshida, Y.; Strahan, S.; Duncan, B.; Olsen, M.; Gille, J.; Yudin, V.; Nardi, B.

    2008-01-01

    isentropic exchange of air masses between the tropical upper troposphere and mid-latitude lowermost stratosphere (the so-called "middle world") is an important pathway for stratospheric-tropospheric exchange. A seasonal, global view of this process has been difficult to obtain, in part due to the lack of the vertical resolution in satellite observations needed to capture the laminar character of these events. Ozone observations at a resolution of about 1 km from the High Resolution Dynamic Limb Sounder (HIRDLS) on NASA's Aura satellite show instances of these intrusions. Such intrusions should also be observable in HN03 observations; however, the abundances of nitric acid could be additionally controlled by chemical processes or incorporation and removal into ice clouds. We present a systematic examination of the HIRDLS data on O3 and HNO3 to determine the seasonal and spatial characteristics of the distribution of isentropic intrusions. At the same time, we compare the observed distributions with those calculated by the Global Modeling Initiative combined tropospheric-stratospheric model, which has a vertical resolution of about I km. This Chemical Transport Model (CTM) is driven by meteorological fields obtained from the GEOS-4 system of NASA/Goddard Global Modeling and Assimilation Office (GMAO), for the Aura time period, at a vertical resolution of about 1 km. Such comparison brings out the successes and limitations of the model in representing isentropic stratospheric-tropospheric exchange, and the different processes controlling HNO3 in the UTAS.

  3. Next Generation Aura-OMI SO2 Retrieval Algorithm: Introduction and Implementation Status

    NASA Technical Reports Server (NTRS)

    Li, Can; Joiner, Joanna; Krotkov, Nickolay A.; Bhartia, Pawan K.

    2014-01-01

    We introduce our next generation algorithm to retrieve SO2 using radiance measurements from the Aura Ozone Monitoring Instrument (OMI). We employ a principal component analysis technique to analyze OMI radiance spectral in 310.5-340 nm acquired over regions with no significant SO2. The resulting principal components (PCs) capture radiance variability caused by both physical processes (e.g., Rayleigh and Raman scattering, and ozone absorption) and measurement artifacts, enabling us to account for these various interferences in SO2 retrievals. By fitting these PCs along with SO2 Jacobians calculated with a radiative transfer model to OMI-measured radiance spectra, we directly estimate SO2 vertical column density in one step. As compared with the previous generation operational OMSO2 PBL (Planetary Boundary Layer) SO2 product, our new algorithm greatly reduces unphysical biases and decreases the noise by a factor of two, providing greater sensitivity to anthropogenic emissions. The new algorithm is fast, eliminates the need for instrument-specific radiance correction schemes, and can be easily adapted to other sensors. These attributes make it a promising technique for producing long-term, consistent SO2 records for air quality and climate research. We have operationally implemented this new algorithm on OMI SIPS for producing the new generation standard OMI SO2 products.

  4. Stratospheric and mesospheric HO2 observations from the Aura Microwave Limb Sounder

    NASA Astrophysics Data System (ADS)

    Millán, L.; Wang, S.; Livesey, N.; Kinnison, D.; Sagawa, H.; Kasai, Y.

    2015-03-01

    This study introduces stratospheric and mesospheric hydroperoxyl radical (HO2) estimates from the Aura Microwave Limb Sounder (MLS) using an offline retrieval (i.e. run separately from the standard MLS algorithm). This new data set provides two daily zonal averages, one during daytime from 10 to 0.0032 hPa (using day-minus-night differences between 10 and 1 hPa to ameliorate systematic biases) and one during nighttime from 1 to 0.0032 hPa. The vertical resolution of this new data set varies from about 4 km at 10 hPa to around 14 km at 0.0032 hPa. A description of the methodology and an error analysis are presented. Comparisons against the Whole Atmosphere Community Climate Model (WACCM), the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) and the Far Infrared Spectrometer (FIRS-2) measurements, as well as photochemical simulations, demonstrate the robustness of the retrieval and indicate that the retrieval is sensitive enough to detect mesospheric HO2 layers during both day and night. This new data set is the first long-term HO2 stratospheric and mesospheric satellite record and it provides needed constraints to help resolve the O3 deficit problem and the "HOx dilemma".

  5. Stratospheric and mesospheric HO2 observations from the Aura Microwave Limb Sounder

    NASA Astrophysics Data System (ADS)

    Millán, L.; Wang, S.; Livesey, N.; Kinnison, D.; Sagawa, H.; Kasai, Y.

    2014-09-01

    This study introduces stratospheric and mesospheric hydroperoxyl radical (HO2) estimates from the Aura Microwave Limb Sounder (MLS) using an offline retrieval (i.e. run separately from the standard MLS algorithm). This new dataset provides two daily zonal averages, one during daytime and one during nighttime, with a varying vertical resolution from about 4 km at 10 hPa to around 14 km at 0.0032 hPa. A description of the methodology and an error analysis are presented. Comparisons against the Whole Atmosphere Community Climate Model (WACCM), the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) and the Far Infrared Spectrometer (FIRS-2) measurements, as well as, photochemical simulations demonstrate the robustness of the retrieval and indicate that the retrieval is sensitive enough to detect mesospheric HO2 layers during both day and night. This new dataset is the first long-term HO2 stratospheric and mesospheric satellite record and it provides needed constraints to help resolve the O3 deficit problem and the "HOx dilemma".

  6. EOS Aura Mission Status at Earth Science Constellation MOWG Meeting @ LASP (Boulder, CO) April 13, 2016

    NASA Technical Reports Server (NTRS)

    Guit, William J.; Fisher, Dominic

    2016-01-01

    Presentation reflects EOS Aura mission status, spacecraft subsystems summary, recent and planned activities, inclination adjust maneuvers, propellant usage, orbit maintenance maneuvers, conjunction assessment events, orbital parameters trends and predictions.

  7. TES/Aura L2 Ozone (O3) Lite Nadir (TL2O3LN)

    Atmospheric Science Data Center

    2015-08-26

    TES/Aura L2 Ozone (O3) Lite Nadir (TL2O3LN) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Ozone Spatial Coverage:  5.3 km nadir Spatial ... OPeNDAP Access:  OPeNDAP Parameters:  Ozone Order Data:  Reverb:   Order Data Guide ...

  8. TES/Aura L2 Water Vapor (H2O) Limb (TL2H2OLS)

    Atmospheric Science Data Center

    2015-01-30

    TES/Aura L2 Water Vapor (H2O) Limb (TL2H2OLS) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Water Vapor Spatial Coverage:  27 x 23 km Limb ... Access:  OPeNDAP Parameters:  H2O Water Volume Mixing Radio Precision Vertical Resolution Order ...

  9. TES/Aura L2 Carbon Dioxide (CO2) Lite Nadir (TL2CO2LN)

    Atmospheric Science Data Center

    2015-06-24

    TES/Aura L2 Carbon Dioxide (CO2) Lite Nadir (TL2CO2LN) News:  TES News ... L2 Instrument:  TES/Aura L2 Carbon Dioxide Spatial Coverage:  5.3 km nadir Spatial ... OPeNDAP Access:  OPeNDAP Parameters:  Carbon Dioxide Order Data:  Reverb:   Order Data ...

  10. TES/Aura L2 Ammonia (NH3) Lite Nadir (TL2NH3LN)

    Atmospheric Science Data Center

    2015-08-26

    TES/Aura L2 Ammonia (NH3) Lite Nadir (TL2NH3LN) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Ammonia Spatial Coverage:  5.3 km nadir Spatial ... OPeNDAP Access:  OPeNDAP Parameters:  Ammonia Order Data:  Reverb:   Order Data ...

  11. TES/Aura L2 Methane (CH4) Lite Nadir (TL2CH4LN)

    Atmospheric Science Data Center

    2015-08-31

    TES/Aura L2 Methane (CH4) Lite Nadir (TL2CH4LN) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Methane Spatial Coverage:  5.3 km nadir Spatial ... OPeNDAP Access:  OPeNDAP Parameters:  Methane Order Data:  Reverb:   Order Data ...

  12. The epileptic aura in literature: aesthetic and philosophical dimensions. An essay.

    PubMed

    Wolf, Peter

    2013-03-01

    In literary accounts of epilepsy the aura has a prominent place as the subjective aspect of the seizure experience. Descriptions by authors with their own aura experiences stand out by their precision and authenticity. Many different aura types are mentioned, but the ecstatic aura described by Dostoyevsky has received particular attention and is echoed in many later works. Some authors are interested primarily in the possibilities provided by auras to react, for example, by hiding, seeking help, counteracting the oncoming seizure, or taking measures to prevent damage. Others by their unique aura experiences are inspired to create specific literary flavors like oxymora, spectacular metaphors, or the depiction of complex perceptions and states of mind. Some authors, adding a philosophical dimension, proceed to analyze the consequences of patients' subjective seizure experiences for their identity and their self-perception as creative or religious persons. To sum up, the works discussed herein strongly support that literary texts provide valuable insights beyond those of medical texts. PMID:23294431

  13. Cardiovascular risk factors and migraine without aura: A case-control study

    PubMed Central

    Harandi, Samaneh Aalami; Sadatnaseri, Azadeh; Hosseini, S. Hamed; Jahromi, Soodeh Razeghi

    2013-01-01

    Background Migraine with aura (MA) has been identified as a risk factor for cardiovascular disease. Previous observation has also found higher prevalence of cardiovascular risk factors in migraineurs without aura (MO), but the results have been conflicting. The present study was conducted to assess the association between cardiovascular risk factors and migraine without aura among Iranians. Methods In our study the prevalence of cardiovascular risk factors, including hypertension, hyperglycemia, dyslipidemia, obesity, cigarette smoking, and family history of early coronary artery disease, were studied in 347 migraineurs without aura and 267 non-migraineurs. The odds ratio (ORs) with 95% confidence interval (95% CI) was used to assess the strength of the association. Results Patients with migraine without aura were at an increased risk of developing hypertension (ORadj = 1.9; P = 0.029), but there was no difference in other cardiovascular risk profiles, including hyperglycemia, dyslipidemia, obesity, cigarette smoking, and family history of early coronary artery disease. Conclusion Our study revealed that the prevalence of hypertension was higher in migraineurs without aura in comparison with non-migraineurs. Therefore, physicians are supposed to be more vigilant in examining these patients and take care not to prescribe medications that may provoke hypertension. PMID:24250913

  14. Effect of tropospheric aerosols upon atmospheric infrared cooling rates

    NASA Technical Reports Server (NTRS)

    Harshvardhan, MR.; Cess, R. D.

    1978-01-01

    The effect of tropospheric aerosols on atmospheric infrared cooling rates is investigated by the use of recent models of infrared gaseous absorption. A radiative model of the atmosphere that incorporates dust as an absorber and scatterer of infrared radiation is constructed by employing the exponential kernel approximation to the radiative transfer equation. Scattering effects are represented in terms of a single scattering albedo and an asymmetry factor. The model is applied to estimate the effect of an aerosol layer made of spherical quartz particles on the infrared cooling rate. Calculations performed for a reference wavelength of 0.55 microns show an increased greenhouse effect, where the net upward flux at the surface is reduced by 10% owing to the strongly enhanced downward emission. There is a substantial increase in the cooling rate near the surface, but the mean cooling rate throughout the lower troposphere was only 10%.

  15. Integrating tropospheric oxidants - A measurement strategy

    NASA Astrophysics Data System (ADS)

    Prather, M. J.; Holmes, C. D.

    2013-12-01

    meant to simulate the near-term evolution of that parcel. Here we sample the CTM along a single pole-to-pole transect and use the chemical and other environmental conditions from each grid cell to initialize the box-model integration with the CTM's chemical package. We find extremely large variations across air parcels in the rates of methane loss, ozone production/loss, and other key sensitivities like the methane feedback factor. Comparing the average rates and sensitivities from the box model and CTM over latitude-height regions, we determine how well a single transect of observations can represent averages over the entire Pacific basin, or even the globe for that month. This measurement strategy will provide key information and even a quantitative basis for how future changes, such as industrial NOx emissions or climate-driven convection, could alter tropospheric ozone and the lifetime of methane.

  16. Balloon-borne cryogenic frost-point hygrometer observations of water vapour in the tropical upper troposphere and lower stratosphere over India: First results

    NASA Astrophysics Data System (ADS)

    Sunilkumar, S. V.; Muhsin, M.; Emmanuel, Maria; Ramkumar, Geetha; Rajeev, K.; Sijikumar, S.

    2016-03-01

    Balloon-borne cryogenic frost-point hygrometer (CFH) observations of water vapour in the upper troposphere and lower stratosphere (UTLS) region carried out over India, from Trivandrum [8.5°N, 76.9°E] and Hyderabad [17.5°N, 78.6°E], were compared with that obtained from quasi-collocated Aura-Microwave Limb Sounder (MLS) satellite observations. Comparisons show a small dry bias for MLS in the stratosphere. Saturated or super-saturation layers observed near the base of tropical tropopause layer (TTL) are consistent with the quasi-collocated space-based observations of tropical cirrus from KALPANA-1 and CALIPSO. Disturbance of large scale waves in the upper troposphere appears to modulate the water vapour and cirrus distribution.

  17. The Impact of ENSO on Trace Gas Composition in the Upper Troposphere to Lower Stratosphere

    NASA Astrophysics Data System (ADS)

    Oman, Luke; Douglass, Anne; Ziemke, Jerald; Waugh, Darryn

    2016-04-01

    The El Nino-Southern Oscillation (ENSO) is the dominant mode of interannual variability in the tropical troposphere and its effects extend well into the stratosphere. Its impact on atmospheric dynamics and chemistry cause important changes to trace gas constituent distributions. A comprehensive suite of satellite observations, reanalyses, and chemistry climate model simulations are illuminating our understanding of processes like ENSO. Analyses of more than a decade of observations from NASA's Aura and Aqua satellites, combined with simulations from the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM) and other Chemistry Climate Modeling Initiative (CCMI) models, and the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) reanalysis have provided key insights into the response of atmospheric composition to ENSO. While we will primarily focus on ozone and water vapor responses in the upper troposphere to lower stratosphere, the effects of ENSO ripple through many important trace gas species throughout the atmosphere. The very large 2015-2016 El Nino event provides an opportunity to closely examine these impacts with unprecedented observational breadth. An improved quantification of natural climate variations, like those from ENSO, is needed to detect and quantify anthropogenic climate changes.

  18. Trajectory model simulations of ozone and carbon monoxide in the Upper Troposphere and Lower Stratosphere (UTLS)

    NASA Astrophysics Data System (ADS)

    Wang, T.; Randel, W. J.; Dessler, A. E.; Schoeberl, M. R.; Kinnison, D. E.

    2014-03-01

    A domain-filling, forward trajectory model originally developed for simulating stratospheric water vapor is used to simulate ozone (O3) and carbon monoxide (CO) in the upper troposphere and lower stratosphere (UTLS). Trajectories are initialized in the upper troposphere, and the circulation is based on reanalysis wind fields. In addition, chemical production and loss rates along trajectories are included using calculations from the Whole Atmosphere Community Climate Model (WACCM). The trajectory model results show good overall agreement with satellite observations from the Aura Microwave Limb Sounder (MLS) and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) in terms of spatial structure and seasonal variability. The trajectory model results also agree well with the Eulerian WACCM simulations. Analysis of the simulated tracers shows that seasonal variations in tropical upwelling exerts strong influence on O3 and CO in the tropical lower stratosphere, and the coupled seasonal cycles provide a useful test of the transport simulations. Interannual variations in the tracers are also closely coupled to changes in upwelling, and the trajectory model can accurately capture and explain observed changes during 2005-2011. This demonstrates the importance of variability in tropical upwelling in forcing chemical changes in the tropical UTLS.

  19. First Global Maps of Stratospheric and Tropospheric NO2 from OMI

    NASA Technical Reports Server (NTRS)

    Bucsela, Eric J.; Celarier, Edward A.; Wenig, Mark O.; Gleason, James F.; Veefkind, J. Pepijn

    2004-01-01

    The Ozone Monitoring Instrument (OMI) was launched successfully in July 2004, as one of four instruments on the EOS Aura satellite. OMI makes hyperspectral measurements that are used to retrieve column densities of critical trace gases, including formaldehyde, BrO, SO2 and NO2 . We present the first results from the OM1 operational NO2 algorithm and demonstrate its ability to retrieve the tropospheric and stratospheric components of NO2. The DOAS method is used to determine slant column densities, and initial air mass factors (AMFs) are used. to give initial estimates of the vertical column densities (VCDs). VCDs from up to 15 consecutive orbits are collected, and a spatial filtering technique is applied to extract the synoptic-scale features characteristic of the stratospheric, field. features to be evidence of tropospheric excess NO2 , and apply an AMF appropriate to polluted conditions, to obtain an improved retrieval of the NO2 total VCD. We describe the assumptions underlying the algorithm in detail, and show global maps of NO2 VCDs, based on the first operational data from OMI.

  20. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay A.; McLinden, Chris A; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; Boersma, K. Folkert; Veefkind, J. Pepijn; Levelt, Pieternel F.; Fioletov, Vitali E.; Dickerson, Russell R.; He, Hao; Lu, Zifeng; Streets, David G.

    2016-01-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2/ and sulfur dioxide (SO2/, since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50% reduction in 2012- 2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air quality over different

  1. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015

    NASA Astrophysics Data System (ADS)

    Krotkov, Nickolay A.; McLinden, Chris A.; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; Folkert Boersma, K.; Pepijn Veefkind, J.; Levelt, Pieternel F.; Fioletov, Vitali E.; Dickerson, Russell R.; He, Hao; Lu, Zifeng; Streets, David G.

    2016-04-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 % reduction in 2012-2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air quality over different

  2. Aura OMI Observations of Regional SO2 and NO2 Pollution Changes from 2005 to 2015

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay A.; McLinden, Chris A.; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; Boersma, K. Folkert; Veefkind, J. Pepijn; Levelt, Pieternel F.; Fioletov, Vitali E.; Dickerson, Russell R.; He, Hao; Lu, Zifeng; Streets, David G.

    2016-01-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 percent, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 percent reduction in 2012-2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 percent, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air

  3. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2014

    NASA Astrophysics Data System (ADS)

    Krotkov, N. A.; McLinden, C. A.; Li, C.; Lamsal, L. N.; Celarier, E. A.; Marchenko, S. V.; Swartz, W. H.; Bucsela, E. J.; Joiner, J.; Duncan, B. N.; Boersma, K. F.; Veefkind, J. P.; Levelt, P. F.; Fioletov, V. E.; Dickerson, R. R.; He, H.; Lu, Z.; Streets, D. G.

    2015-10-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for the different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2014, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 % reduction in 2012-2014, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2014. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved to be very valuable in documenting rapid changes in air quality over

  4. [A case of focal epilepsy manifesting multiple psychiatric auras].

    PubMed

    Ezura, Michinori; Kakisaka, Yosuke; Jin, Kazutaka; Kato, Kazuhiro; Iwasaki, Masaki; Fujikawa, Mayu; Aoki, Masashi; Nakasato, Nobukazu

    2015-01-01

    We present a case of epilepsy with multiple types of focal seizures that were misdiagnosed as psychiatric disorders. A 20-year-old female patient presented with a variety of episodes, including loss of consciousness, deja vu, fear, delusion of possession, violent movements, and generalized convulsions. Each of these symptoms appeared in a stereotypic manner. She was initially diagnosed with a psychiatric disorder and treated with psychoactive medications, which had no effect. Long-term video electroencephalography revealed that her episodes of violent movement with impaired consciousness and secondarily generalized seizure were epileptic events originating in the right hemisphere. High-field brain magnetic resonance imaging for detecting subtle lesions revealed bilateral lesions from periventricular nodular heterotopia. Her final diagnosis was right hemispheric focal epilepsy. Carbamazepine administration was started, which successfully controlled all seizures. The present case demonstrates the pitfall of diagnosing focal epilepsy when it presents with multiple types of psychiatric aura. Epilepsy should thus be included in differential diagnoses, considering the stereotypic nature of symptoms, to avoid misdiagnosis.

  5. Multi-instrument gravity-wave measurements over Tierra del Fuego and the Drake Passage - Part 1: Potential energies and vertical wavelengths from AIRS, COSMIC, HIRDLS, MLS-Aura, SAAMER, SABER and radiosondes

    NASA Astrophysics Data System (ADS)

    Wright, Corwin J.; Hindley, Neil P.; Moss, Andrew C.; Mitchell, Nicholas J.

    2016-03-01

    Gravity waves in the terrestrial atmosphere are a vital geophysical process, acting to transport energy and momentum on a wide range of scales and to couple the various atmospheric layers. Despite the importance of these waves, the many studies to date have often exhibited very dissimilar results, and it remains unclear whether these differences are primarily instrumental or methodological. Here, we address this problem by comparing observations made by a diverse range of the most widely used gravity-wave-resolving instruments in a common geographic region around the southern Andes and Drake Passage, an area known to exhibit strong wave activity. Specifically, we use data from three limb-sounding radiometers (Microwave Limb Sounder, MLS-Aura; HIgh Resolution Dynamics Limb Sounder, HIRDLS; Sounding of the Atmosphere using Broadband Emission Radiometry, SABER), the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) GPS-RO constellation, a ground-based meteor radar, the Advanced Infrared Sounder (AIRS) infrared nadir sounder and radiosondes to examine the gravity wave potential energy (GWPE) and vertical wavelengths (λz) of individual gravity-wave packets from the lower troposphere to the edge of the lower thermosphere ( ˜ 100 km). Our results show important similarities and differences. Limb sounder measurements show high intercorrelation, typically > 0.80 between any instrument pair. Meteor radar observations agree in form with the limb sounders, despite vast technical differences. AIRS and radiosonde observations tend to be uncorrelated or anticorrelated with the other data sets, suggesting very different behaviour of the wave field in the different spectral regimes accessed by each instrument. Evidence of wave dissipation is seen, and varies strongly with season. Observed GWPE for individual wave packets exhibits a log-normal distribution, with short-timescale intermittency dominating over a well-repeated monthly-median seasonal

  6. Night-time tropospheric chemistry of the unsaturated alcohols ( Z)-pent-2-en-1-ol and pent-1-en-3-ol: Kinetic studies of reactions of NO 3 and N 2O 5 with stress-induced plant emissions

    NASA Astrophysics Data System (ADS)

    Pfrang, Christian; Baeza Romero, Maria T.; Cabanas, Beatriz; Canosa-Mas, Carlos E.; Villanueva, Florentina; Wayne, Richard P.

    The night-time tropospheric chemistry of two stress-induced volatile organic compounds (VOCs), ( Z)-pent-2-en-1-ol and pent-1-en-3-ol, has been studied at room temperature. Rate coefficients for reactions of the nitrate radical (NO 3) with these pentenols were measured using the discharge-flow technique. Because of the relatively low volatility of these compounds, we employed off-axis continuous-wave cavity-enhanced absorption spectroscopy for detection of NO 3 in order to be able to work in pseudo first-order conditions with the pentenols in large excess over NO 3. The rate coefficients were determined to be (1.53±0.23)×10 -13 and (1.39±0.19)×10 -14 cm 3 molecule -1 s -1 for reactions of NO 3 with ( Z)-pent-2-en-1-ol and pent-1-en-3-ol. An attempt to study the kinetics of these reactions with a relative-rate technique, using N 2O 5 as source of NO 3 resulted in significantly higher apparent rate coefficients. Performing relative-rate experiments in known excesses of NO 2 allowed us to determine the rate coefficients for the N 2O 5 reactions to be (5.0±2.8)×10 -19 cm 3 molecule -1 s -1 for ( Z)-pent-2-en-1-ol, and (9.1±5.8)×10 -19 cm 3 molecule -1 s -1 for pent-1-en-3-ol. We show that these relatively slow reactions can indeed interfere with rate determinations in conventional relative-rate experiments.

  7. Aerosol indirect effect on tropospheric ozone via lightning

    NASA Astrophysics Data System (ADS)

    Yuan, Tianle; Remer, Lorraine A.; Bian, Huisheng; Ziemke, Jerald R.; Albrecht, Rachel; Pickering, Kenneth E.; Oreopoulos, Lazaros; Goodman, Steven J.; Yu, Hongbin; Allen, Dale J.

    2012-09-01

    Tropospheric ozone (O3) is a pollutant and major greenhouse gas and its radiative forcing is still uncertain. Inadequate understanding of processes related to O3 production, in particular those natural ones such as lightning, contributes to this uncertainty. Here we demonstrate a new effect of aerosol particles on O3production by affecting lightning activity and lightning-generated NOx (LNOx). We find that lightning flash rate increases at a remarkable rate of 30 times or more per unit of aerosol optical depth. We provide observational evidence that indicates the observed increase in lightning activity is caused by the influx of aerosols from a volcano. Satellite data analyses show O3is increased as a result of aerosol-induced increase in lightning and LNOx, which is supported by modle simulations with prescribed lightning change. O3production increase from this aerosol-lightning-ozone link is concentrated in the upper troposphere, where O3 is most efficient as a greenhouse gas. In the face of anthropogenic aerosol increase our findings suggest that lightning activity, LNOx and O3, especially in the upper troposphere, have all increased substantially since preindustrial time due to the proposed aerosol-lightning-ozone link, which implies a stronger O3 historical radiative forcing. Aerosol forcing therefore has a warming component via its effect on O3 production and this component has mostly been ignored in previous studies of climate forcing related to O3and aerosols. Sensitivity simulations suggest that 4-8% increase of column tropospheric ozone, mainly in the tropics, is expected if aerosol-lighting-ozone link is parameterized, depending on the background emission scenario. We note, however, substantial uncertainties remain on the exact magnitude of aerosol effect on tropospheric O3 via lightning. The challenges for obtaining a quantitative global estimate of this effect are also discussed. Our results have significant implications for understanding past and

  8. Aerosol indirect effect on tropospheric ozone via lightning

    NASA Astrophysics Data System (ADS)

    Yuan, T.; Remer, L. A.; Bian, H.; Ziemke, J. R.; Albrecht, R. I.; Pickering, K. E.; Oreopoulos, L.; Goodman, S. J.; Yu, H.; Allen, D. J.

    2012-12-01

    Tropospheric ozone (O3) is a pollutant and major greenhouse gas and its radiative forcing is still uncertain. The unresolved difference between modeled and observed natural background O3 concentrations is a key source of the uncertainty. Here we demonstrate remarkable sensitivity of lightning activity to aerosol loading with lightning activity increasing more than 30 times per unit of aerosol optical depth over our study area. We provide observational evidence that indicates the observed increase in lightning activity is caused by the influx of aerosols from a volcano. Satellite data analyses suggest O3 is increased as a result of aerosol-induced increase in lightning and lightning produced NOx. Model simulations with prescribed lightning change corroborate the satellite data analysis. This aerosol-O3 connection is achieved via aerosol increasing lightning and thus lightning produced nitrogen oxides. This aerosol-lightning-ozone link provides a potential physical mechanism that may account for a part of the model-observation difference in background O3 concentration. More importantly, O3 production increase from this link is concentrated in the upper troposphere, where O3 is most efficient as a greenhouse gas. Both of these implications suggest a stronger O3 historical radiative forcing. This introduces a new pathway, through which increasing in aerosols from pre-industrial time to present day enhances tropospheric O3 production. Aerosol forcing thus has a warming component via its effect on O3 production. Sensitivity simulations suggest that 4-8% increase of tropospheric ozone, mainly in the tropics, is expected if aerosol-lighting-ozone link is parameterized, depending on the background emission scenario. We note, however, substantial uncertainties remain on the exact magnitude of aerosol effect on tropospheric O3 via lightning. The challenges for obtaining a quantitative global estimate of this effect are also discussed. Our results have significant implications

  9. Summertime tropospheric ozone distributions over central and eastern Canada

    NASA Technical Reports Server (NTRS)

    Anderson, B. E.; Gregory, G. L.; Barrick, J. D.; Collins, J. E., Jr.; Sachse, G. W.; Shipham, M. C.; Hudgins, C. H.

    1994-01-01

    Ozone measurements were obtained between the surface and the 6-km altitude on aircraft flights over central and eastern Canada during the summer 1990 NASA Global Tropospheric Experiment Arctic Boundary Layer Expedition (GTE/ABLE 3B). Tropospheric O3 budgets for these regions were observed to be highly variable and significantly impacted by long-range transport and regional scale air mass modification processes. For example, integrated O3 abundance below 5-km altitude averaged 40% and 30% greater in air masses influenced by anthropogenic sources and biomass burning, respectively, than in background (polar) air. Conversely, aged air transported from subtropical areas of the Pacific at times reduced O3 abundance in this height interval by up to 20%. Though intrusion of anthropogenic air was infrequent during the experiment period, the influence of biomass-burning emissions was particularly notable as two thirds of the flights sampled air influenced by plumes from fires burning in Alaska and western Canada. The impinging pollution, both natural and anthropogenic, not only elevated O3 levels directly but also was a source of reactive nitrogen (and nonmethane hydrocarbons) which generally increases the tropospheric lifetime of O3 via moderation of photochemical destruction rates.

  10. Recent Biomass Burning in the Tropics and Related Changes in Tropospheric Ozone

    NASA Technical Reports Server (NTRS)

    Ziemke; Chandra, J. R. S.; Duncan, B. N.; Schoeberl, M. R.; Torres, O.; Damon, M. R.; Bhartia, P. K.

    2009-01-01

    Biomass burning is an important source of chemical precursors of tropospheric ozone. In the tropics, biomass burning produces ozone enhancements over broad regions of Indonesia, Africa, and South America including Brazil. Fires are intentionally set in these regions during the dry season each year to clear cropland and to clear land for human/industrial expansion. In Indonesia enhanced burning occurs during dry El Nino conditions such as in 1997 and 2006. These burning activities cause enhancement in atmospheric particulates and trace gases which are harmful to human health. Measurements from the Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) from October 2004-November 2008 are used to evaluate the effects of biomass burning on tropical tropospheric ozone. These measurements show sizeable decreases approx.15-20% in ozone in Brazil during 2008 compared to 2007 which we attribute to the reduction in biomass burning. Three broad biomass burning regions in the tropics (South America including Brazil, western Africa, and Indonesia) were analyzed in the context of OMI/MLS measurements and the Global Modeling Initiative (GMI) chemical transport model developed at Goddard Space Flight Center. The results indicate that the impact of biomass burning on ozone is significant within and near the burning regions with increases of approx.10-25% in tropospheric column ozone relative to average background concentrations. The model suggests that about half of the increases in ozone from these burning events come from altitudes below 3 km. Globally the model indicates increases of approx.4-5% in ozone, approx.7-9% in NO, (NO+NO2), and approx.30-40% in CO.

  11. Sources of Ozone in the Free Troposphere in Houston During DISCOVER-AQ 2013

    NASA Astrophysics Data System (ADS)

    Kotsakis, A.; Lefer, B. L.; Morris, G. A.; Thompson, A. M.; Martins, D. K.; Weinheimer, A. J.; Orville, R. E.

    2014-12-01

    In September of 2013, NASA's DISCOVER-AQ (DAQ) air quality campaign took place in Houston, Texas. During the DAQ campaign, 58 ozonesondes were launched from the University of Houston-Main Campus and Smith Point, Texas combined. These launches were coordinated with the nine P-3B aircraft spirals and 4 TES (Tropospheric Emission Spectrometer) satellite overpasses. The combination of data sources provides useful insight into the composition and potential origins of free tropospheric ozone. Surface ozone production was not active during the 2013 DAQ Texas campaign with the Houston region only recording two eight-hour average ozone exceedance days during the campaign. The potential sources of free tropospheric ozone during DAQ include stratosphere-troposphere exchange, long-range transport of biomass burning, and lightning. High-resolution potential vorticity data from the NASA Goddard Trajectory Model is used to identify stratosphere-troposphere exchange. The HYSPLIT trajectory model is used to trace air parcels from areas of biomass burning. Lightning data provided by the Lightning Mapping Array will help determine ozone production from lightning. Through the use of these tools, this study will examine the origins of free tropospheric ozone over the Houston area during this campaign.

  12. Tropospheric chemistry in the integrated forecasting system of ECMWF

    NASA Astrophysics Data System (ADS)

    Flemming, J.; Huijnen, V.; Arteta, J.; Bechtold, P.; Beljaars, A.; Blechschmidt, A.-M.; Josse, B.; Diamantakis, M.; Engelen, R. J.; Gaudel, A.; Inness, A.; Jones, L.; Katragkou, E.; Marecal, V.; Peuch, V.-H.; Richter, A.; Schultz, M. G.; Stein, O.; Tsikerdekis, A.

    2014-11-01

    A representation of atmospheric chemistry has been included in the Integrated Forecasting System (IFS) of the European Centre for Medium-range Weather Forecasts (ECMWF). The new chemistry modules complement the aerosol modules of the IFS for atmospheric composition, which is named C-IFS. C-IFS for chemistry supersedes a coupled system, in which the Chemical Transport Model (CTM) Model for OZone and Related chemical Tracers 3 was two-way coupled to the IFS (IFS-MOZART). This paper contains a description of the new on-line implementation, an evaluation with observations and a comparison of the performance of C-IFS with MOZART and with a re-analysis of atmospheric composition produced by IFS-MOZART within the Monitoring Atmospheric Composition and Climate (MACC) project. The chemical mechanism of C-IFS is an extended version of the Carbon Bond 2005 (CB05) chemical mechanism as implemented in the CTM Transport Model 5 (TM5). CB05 describes tropospheric chemistry with 54 species and 126 reactions. Wet deposition and lightning nitrogen monoxide (NO) emissions are modelled in C-IFS using the detailed input of the IFS physics package. A one-year simulation by C-IFS, MOZART and the MACC re-analysis is evaluated against ozonesondes, carbon monoxide (CO) aircraft profiles, European surface observations of ozone (O3), CO, sulphur dioxide (SO2) and nitrogen dioxide (NO2) as well as satellite retrievals of CO, tropospheric NO2 and formaldehyde. Anthropogenic emissions from the MACC/CityZen (MACCity) inventory and biomass burning emissions from the Global Fire Assimilation System (GFAS) data set were used in the simulations by both C-IFS and MOZART. C-IFS (CB05) showed an improved performance with respect to MOZART for CO, upper tropospheric O3, winter time SO2 and was of a similar accuracy for other evaluated species. C-IFS (CB05) is about ten times more computationally efficient than IFS-MOZART.

  13. Tropospheric chemistry in the Integrated Forecasting System of ECMWF

    NASA Astrophysics Data System (ADS)

    Flemming, J.; Huijnen, V.; Arteta, J.; Bechtold, P.; Beljaars, A.; Blechschmidt, A.-M.; Diamantakis, M.; Engelen, R. J.; Gaudel, A.; Inness, A.; Jones, L.; Josse, B.; Katragkou, E.; Marecal, V.; Peuch, V.-H.; Richter, A.; Schultz, M. G.; Stein, O.; Tsikerdekis, A.

    2015-04-01

    A representation of atmospheric chemistry has been included in the Integrated Forecasting System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF). The new chemistry modules complement the aerosol modules of the IFS for atmospheric composition, which is named C-IFS. C-IFS for chemistry supersedes a coupled system in which chemical transport model (CTM) Model for OZone and Related chemical Tracers 3 was two-way coupled to the IFS (IFS-MOZART). This paper contains a description of the new on-line implementation, an evaluation with observations and a comparison of the performance of C-IFS with MOZART and with a re-analysis of atmospheric composition produced by IFS-MOZART within the Monitoring Atmospheric Composition and Climate (MACC) project. The chemical mechanism of C-IFS is an extended version of the Carbon Bond 2005 (CB05) chemical mechanism as implemented in CTM Transport Model 5 (TM5). CB05 describes tropospheric chemistry with 54 species and 126 reactions. Wet deposition and lightning nitrogen monoxide (NO) emissions are modelled in C-IFS using the detailed input of the IFS physics package. A 1 year simulation by C-IFS, MOZART and the MACC re-analysis is evaluated against ozonesondes, carbon monoxide (CO) aircraft profiles, European surface observations of ozone (O3), CO, sulfur dioxide (SO2) and nitrogen dioxide (NO2) as well as satellite retrievals of CO, tropospheric NO2 and formaldehyde. Anthropogenic emissions from the MACC/CityZen (MACCity) inventory and biomass burning emissions from the Global Fire Assimilation System (GFAS) data set were used in the simulations by both C-IFS and MOZART. C-IFS (CB05) showed an improved performance with respect to MOZART for CO, upper tropospheric O3, and wintertime SO2, and was of a similar accuracy for other evaluated species. C-IFS (CB05) is about 10 times more computationally efficient than IFS-MOZART.

  14. The Global Structure of UTLS Ozone in GEOS-5: A Multi-Year Assimilation of EOS Aura Data

    NASA Technical Reports Server (NTRS)

    Wargan, Krzysztof; Pawson, Steven; Olsen, Mark A.; Witte, Jacquelyn C.; Douglass, Anne R.; Ziemke, Jerald R.; Strahan, Susan E.; Nielsen, J. Eric

    2015-01-01

    Eight years of ozone measurements retrieved from the Ozone Monitoring Instrument (OMI) and the Microwave Limb Sounder, both on the EOS Aura satellite, have been assimilated into the Goddard Earth Observing System version 5 (GEOS-5) data assimilation system. This study thoroughly evaluates this assimilated product, highlighting its potential for science. The impact of observations on the GEOS-5 system is explored by examining the spatial distribution of the observation-minus-forecast statistics. Independent data are used for product validation. The correlation coefficient of the lower-stratospheric ozone column with ozonesondes is 0.99 and the bias is 0.5%, indicating the success of the assimilation in reproducing the ozone variability in that layer. The upper-tropospheric assimilated ozone column is about 10% lower than the ozonesonde column but the correlation is still high (0.87). The assimilation is shown to realistically capture the sharp cross-tropopause gradient in ozone mixing ratio. Occurrence of transport-driven low ozone laminae in the assimilation system is similar to that obtained from the High Resolution Dynamics Limb Sounder (HIRDLS) above the 400 K potential temperature surface but the assimilation produces fewer laminae than seen by HIRDLS below that surface. Although the assimilation produces 5 - 8 fewer occurrences per day (up to approximately 20%) during the three years of HIRDLS data, the interannual variability is captured correctly. This data-driven assimilated product is complementary to ozone fields generated from chemistry and transport models. Applications include study of the radiative forcing by ozone and tracer transport near the tropopause.

  15. Recent divergences in stratospheric water vapor measurements by frost point hygrometers and the Aura Microwave Limb Sounder

    NASA Astrophysics Data System (ADS)

    Hurst, Dale F.; Read, William G.; Vömel, Holger; Selkirk, Henry B.; Rosenlof, Karen H.; Davis, Sean M.; Hall, Emrys G.; Jordan, Allen F.; Oltmans, Samuel J.

    2016-09-01

    Balloon-borne frost point hygrometers (FPs) and the Aura Microwave Limb Sounder (MLS) provide high-quality vertical profile measurements of water vapor in the upper troposphere and lower stratosphere (UTLS). A previous comparison of stratospheric water vapor measurements by FPs and MLS over three sites - Boulder, Colorado (40.0° N); Hilo, Hawaii (19.7° N); and Lauder, New Zealand (45.0° S) - from August 2004 through December 2012 not only demonstrated agreement better than 1 % between 68 and 26 hPa but also exposed statistically significant biases of 2 to 10 % at 83 and 100 hPa (Hurst et al., 2014). A simple linear regression analysis of the FP-MLS differences revealed no significant long-term drifts between the two instruments. Here we extend the drift comparison to mid-2015 and add two FP sites - Lindenberg, Germany (52.2° N), and San José, Costa Rica (10.0° N) - that employ FPs of different manufacture and calibration for their water vapor soundings. The extended comparison period reveals that stratospheric FP and MLS measurements over four of the five sites have diverged at rates of 0.03 to 0.07 ppmv year-1 (0.6 to 1.5 % year-1) from ˜ 2010 to mid-2015. These rates are similar in magnitude to the 30-year (1980-2010) average growth rate of stratospheric water vapor ( ˜ 1 % year-1) measured by FPs over Boulder (Hurst et al., 2011). By mid-2015, the FP-MLS differences at some sites were large enough to exceed the combined accuracy estimates of the FP and MLS measurements.

  16. Spindle assembly checkpoint inactivation fails to suppress neuroblast tumour formation in aurA mutant Drosophila

    PubMed Central

    Caous, Renaud; Pascal, Aude; Romé, Pierre; Richard-Parpaillon, Laurent; Karess, Roger; Giet, Régis

    2015-01-01

    Tissue homeostasis requires accurate control of cell proliferation, differentiation and chromosome segregation. Drosophila sas-4 and aurA mutants present brain tumours with extra neuroblasts (NBs), defective mitotic spindle assembly and delayed mitosis due to activation of the spindle assembly checkpoint (SAC). Here we inactivate the SAC in aurA and sas-4 mutants to determine whether the generation of aneuploidy compromises NB proliferation. Inactivation of the SAC in the sas-4 mutant impairs NB proliferation and disrupts euploidy. By contrast, disrupting the SAC in the aurA mutant does not prevent NB amplification, tumour formation or chromosome segregation. The monitoring of Mad2 and cyclin B dynamics in live aurA NBs reveals that SAC satisfaction is not coupled to cyclin B degradation. Thus, the NBs of aurA mutants present delayed mitosis, with accurate chromosome segregation occurring in a SAC-independent manner. We report here the existence of an Aurora A-dependent mechanism promoting efficient, timed cyclin B degradation. PMID:26568519

  17. Migraine Aura: Retracting Particle-Like Waves in Weakly Susceptible Cortex

    PubMed Central

    Dahlem, Markus A.; Hadjikhani, Nouchine

    2009-01-01

    Cortical spreading depression (SD) has been suggested to underlie migraine aura. Despite a precise match in speed, the spatio-temporal patterns of SD observed in animal cortex and aura symptoms mapped to the cortical surface ordinarily differ in aspects of size and shape. We show that this mismatch is reconciled by utilizing that both pattern types bifurcate from an instability point of generic reaction-diffusion models. To classify these spatio-temporal pattern we suggest a susceptibility scale having the value σ = 1 at the instability point. We predict that human cortex is only weakly susceptible to SD (σ<1), and support this prediction by directly matching visual aura symptoms with anatomical landmarks using fMRI retinotopic mapping. Moreover, we use retinal SD to give a proof of concept of the existence of this instability point and describe how cortical susceptibility to SD must be adjusted for migraine drug testing. Close to the instability point at σ = 1 the dynamical repertoire of cortical tissue is increased. As a consequence, the picture of an engulfing SD that became paradigmatic for migraine with aura needs to be modified in most cases towards a more spatially confined pattern that remains within the originating major gyrus or sulcus. Furthermore, we discuss the resulting implications on migraine pharmacology that is hitherto tested in the regime (σ>1), and potentially silent aura occurring below a second bifurcation point at σ = 0 on the susceptible scale. PMID:19337363

  18. Overview of the Antarctic Tropospheric Chemistry Investigation (ANTCI)

    NASA Astrophysics Data System (ADS)

    Eisele, F. L.; Davis, D. D.

    2004-12-01

    The first ANTCI campaign took place during the austral spring/early summer from the second half of November through December of 2003. It consisted of ground based measurements at the South Pole and Twin Otter aircraft studies over portions of the polar plateau, glacial valleys, and the coast of the Ross Sea. The study makes use of previous findings of the Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT) and Sulfur Chemistry of the Antarctic Troposphere Experiment (SCATE) to define and address critical questions about what controls oxidation rates in the Antarctic troposphere and how these rates influence the evolution of reactive sulfur and nitrogen gases in the atmosphere prior to their incorporation into the ice core record. Ground based studies focused on vertical mixing and local photochemistry and sulfur chemistry. Boundary layer mixing heights were determined by several different methods including: acoustic sounder measurements up to 80 m, tethered balloon measurements of meteorological parameters and ozone to 500 m, and tethered balloon measurements of NO to 100m. These vertical measurements were designed to supplement a much larger suite of chemical measurements made from the South Pole ARO building in order to explore how chemical emissions from the snow mix into the lower troposphere and influence the photochemical oxidation process and its products. Aircraft measurements began the process of defining the horizontal extent of elevated NO concentrations over the plateau, which is presumed to result in enhanced photochemical oxidation rates. Flights also briefly investigated flow along large glacial valleys and the outflow of reactive nitrogen from the continent and the inflow of reactive sulfur gases like dimethyl sulfide.

  19. Effects of stratospheric ozone recovery on photochemistry and ozone air quality in the troposphere

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Wu, S.; Huang, Y.; Wang, Y.

    2014-04-01

    There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). With a full recovery of the stratospheric ozone, the projected increases in ozone column range from 1% over the low latitudes to more than 10% over the polar regions. The sensitivity factor of troposphere ozone photolysis rate, defined as the percentage changes in surface ozone photolysis rate for 1% increase in stratospheric ozone column, shows significant seasonal variation but is always negative with absolute value larger than one. The expected stratospheric ozone recovery is found to affect the tropospheric ozone destruction rates much more than the ozone production rates. Significant decreases in surface ozone photolysis rates due to stratospheric ozone recovery are simulated. The global average tropospheric OH decreases by 1.7%, and the global average lifetime of tropospheric ozone increases by 1.5%. The perturbations to tropospheric ozone and surface ozone show large seasonal and spatial variations. General increases in surface ozone are calculated for each season, with increases by up to 0.8 ppbv in the remote areas. Increases in ozone lifetime by up to 13% are found in the troposphere. The increased lifetimes of tropospheric ozone in response to stratospheric ozone recovery enhance the intercontinental transport of ozone and global pollution, in particular for the summertime. The global background ozone attributable to Asian emissions is calculated to increase by up to 15% or 0.3 ppbv in the Northern Hemisphere in response to the projected stratospheric ozone recovery.

  20. Role of tropospheric ozone increases in 20th-century climate change

    NASA Astrophysics Data System (ADS)

    Shindell, Drew; Faluvegi, Greg; Lacis, Andrew; Hansen, James; Ruedy, Reto; Aguilar, Elliot

    2006-04-01

    Human activities have increased tropospheric ozone, contributing to 20th-century warming. Using the spatial and temporal distribution of precursor emissions, we simulated tropospheric ozone from 1890 to 1990 using the NASA Goddard Institute for Space Studies (GISS) chemistry model. Archived three-dimensional ozone fields were then used in transient GISS climate model simulations. This enables more realistic evaluation of the impact of tropospheric ozone increases than prior simulations using an interpolation between preindustrial and present-day ozone. We find that tropospheric ozone contributed to the greater 20th-century warming in the Northern Hemisphere extratropics compared with the tropics and in the tropics compared with the Southern Hemisphere extratropics. Additionally, ozone increased more rapidly during the latter half of the century than the former, causing more rapid warming during that time. This is especially apparent in the tropics and is consistent with observations, which do not show similar behavior in the extratropics. Other climate forcings do not substantially accelerate warming rates in the tropics relative to other regions. This suggests that accelerated tropospheric ozone increases related to industrialization in the developing world have contributed to the accelerated tropical warming. During boreal summer, tropospheric ozone causes enhanced warming (>0.5°C) over polluted northern continental regions. Finally, the Arctic climate response to tropospheric ozone increases is large during fall, winter, and spring when ozone's lifetime is comparatively long and pollution transported from midlatitudes is abundant. The model indicates that tropospheric ozone could have contributed about 0.3°C annual average and about 0.4°C-0.5°C during winter and spring to the 20th-century Arctic warming. Pollution controls could thus substantially reduce the rapid rate of Arctic warming.

  1. Emissions of organic trace gases from savanna fires in southern Africa during the 1992 Southern African Fire Atmosphere Research Initiative and their impact on the formation of tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Koppmann, R.; Khedim, A.; Rudolph, J.; Poppe, D.; Andreae, M. O.; Helas, G.; Welling, M.; Zenker, T.

    1997-08-01

    CO, CH4, and organic trace gases were measured in air samples collected during several flights with a DC-3 aircraft through the plumes from savanna fires and agricultural fires during the SAFARI 92 campaign in southern Africa in September and October 1992. In all samples a variety of higher molecular weight organic compounds was found, most of which are very reactive. More than 70 of the roughly 140 major components present could be identified. Typically, mixing ratios of several hundred parts per billion carbon of organic compounds were measured inside the plumes, corresponding to an emission ratio of total organic carbon relative to CO2 of up to 1%. About 50% of these emissions were in the form of oxygenated and unsaturated compounds. The contributions of still unknown compounds to the total emission of organic compounds add up to another 20-30%. The observed emission ratios relative to CO2 show a considerable variation depending on the fuel type and the burning stages of the fire. The lowest value of the emission ratio of the sum of all identified organic compounds relative to CO2 was found for a sugar cane fire with (1.7±0.7)×10-3 (ppb C/ppb CO2). For a large savanna fire in Kruger National Park the ratio was (7.4±1.6)×10-3 (ppb C/ppb CO2). The highest value was (13.7±0.9)×10-3 (ppb C/ppb CO2) for an uncontrolled fire of mainly wood and shrub in the Drakensberg region. Results of model calculations show that in biomass-burning plumes, reactive organic compounds contribute significantly to the formation of ozone, especially during the initial phase of photochemical processing.

  2. Remote sounding of tropospheric minor constituents

    NASA Technical Reports Server (NTRS)

    Drayson, S. Roland; Hays, Paul B.; Wang, Jinxue

    1993-01-01

    The etalon interferometer, or Fabry-Perot interferometer (FPI), with its high throughput and high spectral resolution was widely used in the remote-sensing measurements of the earth's atmospheric composition, winds, and temperatures. The most recent satellite instruments include the Fabry-Perot interferometer flown on the Dynamics Explorer-2 (DE-2) and the High Resolution Doppler Imager (HRDI) to be flown on the Upper Atmosphere Research Satellite (UARS). These instruments measure the Doppler line profiles of the emission and absorption of certain atmospheric species (such as atomic oxygen) in the visible spectral region. The successful space flight of DE-FPI and the test and delivery of UARS-HRDI demonstrated the extremely high spectral resolution and ruggedness of the etalon system for the remote sensing of earth and planetary atmospheres. Recently, an innovative FPI focal plane detection technique called the Circle-to-Line Interferometer Optical (CLIO) system was invented at the Space Physics Research Laboratory (SPRL). The CLIO simplifies the FPI focal plane detection process by converting the circular rings or fringes into a linear pattern similar to that produced by a conventional spectrometer, while retaining the throughput advantage of the etalon interferometer. CLIO makes the use of linear array detectors more practical and efficient with FPI, the combination of FPI and CLIO represents a very promising new technique for the remote sensing of the lower atmospheres of Earth, Mars, Venus, Neptune, and other planets. The Multiorder Etalon Spectrometer (MOES), as a combination of the rugged etalon and the CLIO, compares very favorably to other spaceborne optical instruments in terms of performance versus complexity. The feasibility of an advanced etalon spectrometer for the remote sensing of tropospheric trace species, particularly carbon monoxide (CO), nitrous oxide (N2O), and methane (CH4) was discussed. The etalon atmospheric spectroscopy techniques are

  3. Drivers of the tropospheric ozone budget throughout the 21st century under the medium-high climate scenario RCP 6.0

    NASA Astrophysics Data System (ADS)

    Revell, L. E.; Tummon, F.; Stenke, A.; Sukhodolov, T.; Coulon, A.; Rozanov, E.; Garny, H.; Grewe, V.; Peter, T.

    2015-05-01

    Because tropospheric ozone is both a greenhouse gas and harmful air pollutant, it is important to understand how anthropogenic activities may influence its abundance and distribution through the 21st century. Here, we present model simulations performed with the chemistry-climate model SOCOL, in which spatially disaggregated chemistry and transport tracers have been implemented in order to better understand the distribution and projected changes in tropospheric ozone. We examine the influences of ozone precursor emissions (nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs)), climate change (including methane effects) and stratospheric ozone recovery on the tropospheric ozone budget, in a simulation following the climate scenario Representative Concentration Pathway (RCP) 6.0 (a medium-high, and reasonably realistic climate scenario). Changes in ozone precursor emissions have the largest effect, leading to a global-mean increase in tropospheric ozone which maximizes in the early 21st century at 23% compared to 1960. The increase is most pronounced at northern midlatitudes, due to regional emission patterns: between 1990 and 2060, northern midlatitude tropospheric ozone remains at constantly large abundances: 31% larger than in 1960. Over this 70-year period, attempts to reduce emissions in Europe and North America do not have an effect on zonally averaged northern midlatitude ozone because of increasing emissions from Asia, together with the long lifetime of ozone in the troposphere. A simulation with fixed anthropogenic ozone precursor emissions of NOx, CO and non-methane VOCs at 1960 conditions shows a 6% increase in global-mean tropospheric ozone by the end of the 21st century, with an 11 % increase at northern midlatitudes. This increase maximizes in the 2080s and is mostly caused by methane, which maximizes in the 2080s following RCP 6.0, and plays an important role in controlling ozone directly, and indirectly through its

  4. Drivers of the tropospheric ozone budget throughout the 21st century under the medium-high climate scenario RCP 6.0

    NASA Astrophysics Data System (ADS)

    Revell, L. E.; Tummon, F.; Stenke, A.; Sukhodolov, T.; Coulon, A.; Rozanov, E.; Garny, H.; Grewe, V.; Peter, T.

    2015-01-01

    Because tropospheric ozone is both a~greenhouse gas and harmful air pollutant, it is important to understand how anthropogenic activities may influence its abundance and distribution through the 21st century. Here, we present model simulations performed with the chemistry-climate model SOCOL, in which spatially disaggregated chemistry and transport tracers have been implemented in order to better understand the distribution and projected changes in tropospheric ozone. We examine the influences of ozone precursor emissions (nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs)), climate change and stratospheric ozone recovery on the tropospheric ozone budget, in a~simulation following the climate scenario Representative Concentration Pathway (RCP) 6.0. Changes in ozone precursor emissions have the largest effect, leading to a global-mean increase in tropospheric ozone which maximises in the early 21st century at 23%. The increase is most pronounced at northern midlatitudes, due to regional emission patterns: between 1990 and 2060, northern midlatitude tropospheric ozone remains at constantly large abundances: 31% larger than in 1960. Over this 70 year period, attempts to reduce emissions in Europe and North America do not have an effect on zonally-averaged northern midlatitude ozone because of increasing emissions from Asia, together with the longevity of ozone in the troposphere. A~simulation with fixed anthropogenic ozone precursor emissions of NOx, CO and non-methane VOCs at 1960 conditions shows a 6 % increase in global-mean tropospheric ozone, and an 11% increase at northern midlatitudes. This increase maximises in the 2080s, and is mostly caused by methane, which maximises in the 2080s following RCP 6.0, and plays an important role in controlling ozone directly, and indirectly through its influence on other VOCs and CO. Enhanced flux of ozone from the stratosphere to the troposphere as well as climate change-induced enhancements in

  5. Air Quality Research and Applications Using AURA OMi Data

    NASA Technical Reports Server (NTRS)

    Bhartia, P.K.; Gleason, J.F.; Torres, O.; Levelt, P.; Liu, X.; Ziemke, J.; Chandra, S.; Krotkov, N.

    2007-01-01

    The Ozone Monitoring Instrument (OMI) on EOS Aura is a new generation of satellite remote sensing instrument designed to measure trace gas and aerosol absorption at the UV and blue wavelengths. These measurements are made globally at urban scale resolution with no inter-orbital gaps that make them potentially very useful for air quality research, such as the determination of the sources and processes that affect global and regional air quality, and to develop applications such as air quality forecast. However, the use of satellite data for such applications is not as straight forward as satellite data have been for stratospheric research. There is a need for close interaction between the satellite product developers, in-situ measurement programs, and the air quality research community to overcome some of the inherent difficulties in interpreting data from satellite-based remote sensing instruments. In this talk we will discuss the challenges and opportunities in using OMI products for air quality research and applications. A key conclusion of this work is that to realize the full potential of OMI measurements it will be necessary to combine OMI data with data from instruments such as MLS, MODIS, AIRS, and CALIPSO that are currently flying in the "A-train" satellite constellation. In addition similar data taken by satellites crossing the earth at different local times than the A-train (e.g., the recently MetOp satellite) would need to be processed in a consistent manner to study diurnal variability, and to capture the effects on air quality of rapidly changing events such as wild fires.

  6. Abnormal sensorimotor plasticity in migraine without aura patients.

    PubMed

    Pierelli, Francesco; Iacovelli, Elisa; Bracaglia, Martina; Serrao, Mariano; Coppola, Gianluca

    2013-09-01

    The period between migraine attacks is characterized by paradoxical responses to repetitive sensory and transcranial magnetic stimulation (TMS). Abnormal long-term cortical functional plasticity may play a role and can be assessed experimentally by paired associative stimulation (PAS), in which somatosensory peripheral nerve stimuli are followed by TMS of the motor cortex. Changes in motor-evoked potential (MEP) amplitudes were recorded in 16 migraine without aura patients (MO) and 15 healthy volunteers (HV) before and after PAS, which consisted of 90 peripheral electrical right ulnar nerve stimulations and subsequent TMS pulses over the first dorsal interosseous (FDI) muscle activation site with a delay of 10 ms (excitability depressing) or 25 ms (excitability enhancing). As a control experiment of the 31 subjects studied, 8 (4 MO and 4 HV) also underwent PAS10 earlier, the recording of somatosensory high-frequency oscillations (HFOs) reflecting thalamocortical activation (early HFOs). Although PAS10 reduced MEP amplitudes in HV (-17.7%), it significantly increased amplitudes in MO (+35.9%). Although in HV MEP amplitudes were significantly potentiated (+55.1) after PAS25, only a slight, nonsignificant increase was observed in MO (+18.8%). In the control experiment, performed on 8 subjects pooled together, Pearson's correlation showed an inverse relationship between the percentage of MEP amplitude changes after PAS10 and early HFO amplitudes (r=-0.81; P=.01). Because we observed that the more deficient the long-term PAS-induced change, the more the thalamocortical activation decreased, we hypothesize that the abnormalities in long-term cortical plasticity observed in the interictal period between migraine episodes could be due to altered thalamic control.

  7. Exploiting Aura OMI Level 2 Data with High Resolution Visualization

    NASA Astrophysics Data System (ADS)

    Wei, J. C.; Yang, W.; Johnson, J. E.; Zhao, P.; Gerasimov, I. V.; Pham, L.; Vicente, G. A.; Shen, S.

    2014-12-01

    Satellite data products are important for a wide variety of applications that can bring far-reaching benefits to the science community and the broader society. These benefits can best be achieved if the satellite data are well utilized and interpreted, such as model inputs from satellite, or extreme event (such as volcano eruption, dust storm, …etc) interpretation from satellite. Unfortunately, this is not always the case, despite the abundance and relative maturity of numerous satellite data products provided by NASA and other organizations. One way to help users better understand the satellite data is to provide data along with 'Images', including accurate pixel-level (Level 2) information, pixel coverage area delineation, and science team recommended quality screening for individual geophysical parameters. Goddard Earth Sciences Data and Information Services Center (GES DISC) always strives to best support (i.e., Software-as-a-service, SaaS) the user-community for NASA Earth Science Data. In this case, we will present a new visualization tool that helps users exploiting Aura Ozone Monitoring Instrument (OMI) Level 2 data. This new visualization service utilizes Open Geospatial Consortium (OGC) standard-compliant Web Mapping Service (WMS) and Web Coverage Service (WCS) calls in the backend infrastructure. The functionality of the service allows users to select data sources (e.g., multiple parameters under the same measurement, like NO2 and SO2 from OMI Level 2 or same parameter with different methods of aggregation, like NO2 in OMNO2G and OMNO2D products), defining area-of-interest and temporal extents, zooming, panning, overlaying, sliding, and data subsetting and reformatting. The interface will also be able to connect to other OGC WMS and WCS servers, which will greatly enhance its expandability to integrate additional outside data/map sources (such as Global Imagery Browse Services (GIBS)).

  8. Estimating Western U.S. Oil & Gas Emissions with OMI NO2 Data

    NASA Astrophysics Data System (ADS)

    Clifton, O. E.; Holloway, T.; Oberman, J.

    2012-12-01

    In the last ten years, there has been a steep increase in the number natural gas and oil extraction facilities in the United States due to hydraulic fracturing ("fracking"). Each facility requires a large range of equipment, such as drilling rigs, compressor engines, heaters, and pneumatic devices. These activities can lead to elevated nitrogen dioxide (NO2) emissions in rural areas, often in regions without routine NO2 surface monitoring. Furthermore, permitting rules vary from state to state, and many new extraction facilities are unpermitted and exact emissions unknown. On April 18, 2012, the EPA announced air pollution standards for volatile organic compounds (VOCs) emissions from the oil and gas industry. Until 2015, when these standards must be in effect, NOx (NO2 + NO) will continue to react with VOCs to form unhealthy levels of tropospheric ozone in regions with heavy use of hydraulic fracturing. In order to identify areas of elevated NO2 emissions and constrain associated on-road and off-road sources in areas with prominent shale basins and known drilling, we employ remote sensing estimates of column NO2 from the Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite. OMI NO2 is sensitive to the planetary boundary layer and to surface air pollution and thus has high temporal and spatial variation. These Level-2 satellite data are processed with the Wisconsin Horizontal Interpolation Program for Satellites (WHIPS), developed at the University of Wisconsin-Madison. We interpolate the data to allow further ease in mapping change in NO2 associated with drilling, and the quantification of pollution trends attributable to hydraulic-fracturing in the Western U.S. from 2004 to the present.

  9. Changes in tropospheric composition and air quality due to stratospheric ozone depletion.

    PubMed

    Solomon, Keith R; Tang, Xiaoyan; Wilson, Stephen R; Zanis, Prodromos; Bais, Alkiviadis F

    2003-01-01

    Increased UV-B through stratospheric ozone depletion leads to an increased chemical activity in the lower atmosphere (the troposphere). The effect of stratospheric ozone depletion on tropospheric ozone is small (though significant) compared to the ozone generated anthropogenically in areas already experiencing air pollution. Modeling and experimental studies suggest that the impacts of stratospheric ozone depletion on tropospheric ozone are different at different altitudes and for different chemical regimes. As a result the increase in ozone due to stratospheric ozone depletion may be greater in polluted regions. Attributable effects on concentrations are expected only in regions where local emissions make minor contributions. The vertical distribution of NOx (NO + NO2), the emission of volatile organic compounds and the abundance of water vapor, are important influencing factors. The long-term nature of stratospheric ozone depletion means that even a small increase in tropospheric ozone concentration can have a significant impact on human health and the environment. Trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA) are produced by the atmospheric degradation of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). TFA has been measured in rain, rivers, lakes, and oceans, the ultimate sink for these and related compounds. Significant anthropogenic sources of TFA other than degradation HCFCs and HFCs have been identified. Toxicity tests under field conditions indicate that the concentrations of TFA and CDFA currently produced by the atmospheric degradation of HFCs and HCFCs do not present a risk to human health and the environment. The impact of the interaction between ozone depletion and future climate change is complex and a significant area of current research. For air quality and tropospheric composition, a range of physical parameters such as temperature, cloudiness and atmospheric transport will modify the impact of UV-B. Changes in the

  10. TES/Aura L2 Water Vapor (H2O) Lite Nadir (TL2H2OLN)

    Atmospheric Science Data Center

    2015-06-16

    TES/Aura L2 Water Vapor (H2O) Lite Nadir (TL2H2OLN) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Water Vapor Spatial Coverage:  5.3 km nadir ... HDFView Read Software Level 2 Google Earth Visualizations Related Data:  Level 2 Lite Survey ...

  11. Tools and Data Services from the GSFC Earth Sciences DAAC for Aura Science Data Users

    NASA Technical Reports Server (NTRS)

    Kempler, S.; Johnson, J.; Leptoukh, G.; Ahmad, S.; Pham, L.; Eng, E.; Berrick, S.; Teng, W.; Vollmer, B.

    2004-01-01

    In these times of rapidly increasing amounts of archived data, tools and data services that manipulate data and uncover nuggets of information that potentially lead to scientific discovery are becoming more and more essential. The Goddard Space Flight Center (GSFC) Earth Sciences (GES) Distributed Active Archive Center (DAAC) has made great strides in facilitating science and applications research by, in consultation with its users, developing innovative tools and data services. That is, as data users become more sophisticated in their research and more savvy with information extraction methodologies, the GES DAAC has been responsive to this evolution. This presentation addresses the tools and data services available and under study at the GES DAAC, applied to the Earth sciences atmospheric data. Now, with the data from NASA's latest Atmospheric Chemistry mission, Aura, being readied for public release, GES DAAC tools, proven successful for past atmospheric science missions such as MODIS, AIRS, TRMM, TOMS, and UARS, provide an excellent basis for similar tools updated for the data from the Aura instruments. GES DAAC resident Aura data sets are from the Microwave Limb Sounder (MLS), Ozone Monitoring Instrument (OMI), and High Resolution Dynamics Limb Sounder (HIRDLS). Data obtained by these instruments afford researchers the opportunity to acquire accurate and continuous visualization and analysis, customized for Aura data, will facilitate the use and increase the usefulness of the new data. The Aura data, together with other heritage data at the GES DAAC, can potentially provide a long time series of data. GES DAAC tools will be discussed, as well as the GES DAAC Near Archive Data Mining (NADM) environment, the GIOVANNI on-line analysis tool, and rich data search and order services. Information can be found at: http://daac.gsfc.nasa.gov/upperatm/aura/. Additional information is contained in the original extended abstract.

  12. Endothelial nitric oxide synthase haplotypes associated with aura in patients with migraine.

    PubMed

    Gonçalves, Flavia M; Martins-Oliveira, Alisson; Speciali, Jose G; Luizon, Marcelo R; Izidoro-Toledo, Tatiane C; Silva, Pamela S; Dach, Fabiola; Tanus-Santos, Jose E

    2011-06-01

    There is strong evidence implicating nitric oxide (NO) in the pathophysiology of migraine and aura. Therefore, genetic polymorphisms in the endothelial NO synthase (eNOS) gene have been studied as candidate markers for migraine susceptibility. We compared for the first time the distribution of eNOS haplotypes including the three clinically relevant eNOS polymorphisms (T(-786)C in the promoter, rs2070744; Glu298Asp in exon 7, rs1799983; and a 27 bp variable number of tandem repeats in intron 4) and two additional tagging single-nucleotide polymorphisms (rs3918226 and rs743506) in 178 women with migraine (134 without aura and 44 with aura) and 117 healthy controls (control group). Genotypes were determined by TaqMan allele discrimination assay, real-time polymerase chain reaction, and polymerase chain reaction followed by fragment separation by electrophoresis. The GA (rs743506) genotype was more common in the control group than in women with migraine (odds ratio = 0.47, 95% confidence interval [CI] = 0.29-0.78, p < 0.01). No significant differences were found in allele distributions for the five eNOS polymorphisms. However, the haplotypes including the variants "C C a Glu G" and the variants "C C b Glu G" were more common in women with migraine with aura than in women with migraine without aura (odds ratio = 30.71, 95% CI = 1.61-586.4 and odds ratio = 17.26, 95% CI = 1.94-153.4, respectively; both p < 0.0015625). These findings suggest that these two eNOS haplotypes affect the susceptibility to the presence of aura in patients with migraine.

  13. Novel Ground-Based Instrument For Day-And-Night Monitoring Of The Stratosphere And The Upper Troposphere Temperature Profile

    NASA Astrophysics Data System (ADS)

    Feigin, A.; Shvetsov, A.; Fedoseev, L.; Karashtin, D.; Bolshakov, O.; Mukhin, D.; Skalyga, N.

    2012-04-01

    The thermal structure of the stratosphere and the upper troposphere is one of the most important atmospheric characteristics determining the dynamic and photochemical processes in the atmosphere. At present, the data on the altitude distribution of the middle atmospheric temperature are almost entirely obtained by remote methods, mainly, radiometric sounding from the satellites within infrared and microwave frequency bands. Such measurements allow one to retrieve the temperature profile in a very wide altitude range from the surface layer to the mesosphere. However, they do not ensure obtaining of the data with time and space resolution that is required for studying the fast local atmospheric processes. A promising information resource about fast local temperature variations is atmospheric self-radiation in lines of different spin-rotational transitions of molecular oxygen. Among with better time and space resolution advantages of this measurement method are its usability for round-the-clock and almost all-weather (excluding heavy clouds, rainfalls, and snowstorms conditions) observations. The potential of the ground-based microwave remote sensing of the middle atmosphere has been discussed for a sufficiently long time [1]. Nevertheless up to date the ground-based microwave diagnostics of the middle atmosphere has not been realized for some hardware and software reasons. In this work, we describe the design and characteristics of the novel complex combining new method for retrieval of the altitude profile of the middle-atmosphere temperature on the basis of the results of the ground-based observation of emission in the lines at the slope of the 5-millimeter absorption band of molecular oxygen, and a high-sensitive spectroradiometer for such sensing. The spectroradiometer measures the spectrum of atmospheric self-radiation brightness temperature within (52.5-53.5) GHz frequency bands with the resolution of 61 kHz. The retrieval method is based first on the Bayesian

  14. The sulfur budget of the troposphere

    NASA Technical Reports Server (NTRS)

    Tiwari, S. N.; Augustsson, T. R.

    1981-01-01

    A one dimensional photochemical tropospheric model was used to calculate the vertical profiles of tropospheric species. Particular attention is focused on the recent inclusion of the chemistry of the sulfur group, which consists of 13 species involving a total of 45 chemical reactions. It is found that the chemistry of the sulfur species, because it is largely anthropogenic, plays an increasingly important role in the distribution of tropospheric gases. The calculated vertical profiles were compared to available measurements and generally found to be in good agreement.

  15. Sensitivity of tropospheric hydrogen peroxide to global chemical and climate change

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Stewart, Richard W.; Owens, Melody A.

    1989-01-01

    The sensitivities of tropospheric HO2 and hydrogen peroxide (H2O2) levels to increases in CH4, CO, and NO emissions and to changes in stratospheric O3 and tropospheric O3 and H2O have been evaluated with a one-dimensional photochemical model. Specific scenarios of CH4-CO-NO(x) emissions and global climate changes are used to predict HO2 and H2O2 changes between 1980 and 2030. Calculations are made for urban and nonurban continental conditions and for low latitudes. Generally, CO and CH4 emissions will enhance H2O2; NO emissions will suppress H2O2 except in very low NO(x) regions. A global warming or stratospheric O3 depletion will add to H2O2. Hydrogen peroxide increases from 1980 to 2030 could be 100 percent or more in the urban boundary layer.

  16. EOS Aura's Education and Public Outreach Program - A Lesson for a Scientist.

    NASA Astrophysics Data System (ADS)

    Hilsenrath, E.

    2002-12-01

    NASA's EOS Aura atmospheric chemistry mission is designed to answer three basic questions about the Earth's atmosphere: a) Is the Earth's ozone layer recovering? b) Is air quality changing? c) How is the Earth's climate changing? The Aura Project agreed to support an ambitious EPO program early in the mission to establish an Aura presence with the public prior to and after launch. The Aura EPO program's overarching objectives is to inform students, our peers, the general public, policy makers and industry. One of my roles as Aura Deputy Project Scientist was to develop a plan, cost, and schedule through launch with these objectives. Our goal was to have the maximum number of outreach contacts for the least cost. This meant taking advantage of well established and proven EPO enterprises. The selected Aura EPO partners include GLOBE, the American Chemical Society, the Smithsonian Institution, Environmental Defense, and NASA's Earth Observatory websites. Managing these tools to convey the Aura message through launch became an over arching task. A Project Scientist's role for a large NASA space mission has many facets and running an EPO program has several challenges. The first success came with bringing on-board experienced Outreach personnel familiar with NASA missions. This step was invaluable in launching Outreach projects since they did not necessarily conform to the NASA way of conducting research and flight missions. "Leveraging" is key element in Outreach programming and we found many avenues among our partners to put this to full use particularly since atmospheric chemistry is an important and sometimes controversial environmental issue. It was gratifying to see, as a scientist, our Outreach contacts get excited about the subject when explained in a personal way. Another important challenge for a scientist is the balance of time spent between research and Outreach. Each requires creativity and dedication of time and both have rewards that are very

  17. The impact of the stratosphere on tropospheric climate

    NASA Astrophysics Data System (ADS)

    Hinssen, Y. B. L.

    2010-12-01

    winters the influence can be substantial, on monthly as well as daily timescales. The stratospheric changes that accompanied the major sudden stratospheric warming in January 2009, for example, resulted in an easterly wind forcing of about 5 m/s on the tropospheric winds. Furthermore, the influence of the stratosphere on the tropospheric winds was felt until months after the warming event, indicating that inclusion of stratospheric processes in models might improve extended range weather forecasts. Due to CO2 increases, the SH stratospheric PV increases in winter, related to enhanced stratospheric emission of longwave radiation to space. In the NH, CO2 increases are associated with a decrease in the stratospheric polar PV in winter, related to an increased stratospheric wave forcing. The stratospheric changes that result from CO2 increases in a climate model also influence the tropospheric winds. Although the magnitude of the tropospheric response related to stratospheric changes is small, it is of the same order of magnitude as the total tropospheric response, indicating that changes in the stratosphere can certainly modify the tropospheric response to climate change.

  18. Applying modeling Results in designing a global tropospheric experiment

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A set of field experiments and advanced modeling studies which provide a strategy for a program of global tropospheric experiments was identified. An expanded effort to develop space applications for trospheric air quality monitoring and studies was recommended. The tropospheric ozone, carbon, nitrogen, and sulfur cycles are addressed. Stratospheric-tropospheric exchange is discussed. Fast photochemical processes in the free troposphere are considered.

  19. Ozonesonde Climatology and Satellite Product Evaluation: Tropospheric Ozone in the Mid-Atlantic from 2005-2010

    NASA Astrophysics Data System (ADS)

    Normile, C.; Thompson, A. M.; Schmidlin, F. J.; Schoeberl, M. R.

    2011-12-01

    Geostationary satellite missions are proposed to remotely assess regional air quality over large swaths, although the precise capability of the current set of satellite instruments to accurately resolve urban scale pollution remains unverified. We use the Trajectory Enhanced Tropospheric Ozone Residual product derived from Aura's Ozone Monitoring Instrument/Microwave Limb Sounder satellite data to examine the regional climatology of ozone pollution in the mid-Atlantic, focusing on the Washington, D.C. area and downwind Delmarva. We use the North American Regional Reanalysis to determine the synoptic scale flow patterns in the lower troposphere. In addition, a set of proxies (OMI NO2, surface ozone, cloud cover, and air mass classification) are employed to understand TTOR performance and interacting meteorological and chemical effects in the region. We find that the TTOR product accuracy varies substantially both temporally and spatially, improving during summer months (0.22% error in May compared to 11% error in October) for example, and over urban areas more than rural ones (12% error versus 16% error). TTOR product accuracy is influenced by air mass effects on advection and on planetary boundary layer ozone concentrations. Conditions conducive to ozone production yield a higher near-surface proportion of the tropospheric column as measured by Wallops Island ozonesondes. We identify synoptic-scale flow regimes that strengthen correlations between urban tropospheric ozone density and column density off the coast of the mid-Atlantic. These results indicate that remotely sensed measurements may indeed be able to discriminate urban influences on regional ozone and their effects in more remote areas and have implications for air quality assessment and model validation.

  20. Satellite remote sensing of tropospheric CO and CH4: forward model studies of the MOPITT instrument

    NASA Astrophysics Data System (ADS)

    Drummond, James R.; Pan, Liwen; Edwards, David P.; Gille, John C.; Smith, Mark W.

    1995-10-01

    The Measurements of Pollution in the Troposphere (MOPITT) instrument is designed to measure tropospheric CO and CH4 from a spaceborne platform by the use of infrared gas correlation radiometers. We describe the forward model that is used as the basis for the retrieval algorithm. We present the techniques used to model the instrument and describe the radiative transfer involved in the measurement process. Calculations have been performed to assess the sensitivity of the measured radiance to changes in the target-gas concentration profiles, changes in the concentration of contaminating constituents, and to variations in the parameters that describe reflection and emission of radiation at the Earth's surface.

  1. Space Opportunities for Tropospheric Chemistry Research

    NASA Technical Reports Server (NTRS)

    Levine, Joel S. (Editor)

    1987-01-01

    The objective of this workshop was to assess future technological and scientific directions for measurements of tropospheric trace gases and aerosols from space. Various instrument technologies were considered including spectrometry, gas correlation filter radiometry, spectral radiometry, and lidar.

  2. Global tropospheric chemistry: A plan for action

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Prompted by an increasing awareness of the influence of human activity on the chemistry of the global troposphere, a panel was formed to (1) assess the requirement for a global study of the chemistry of the troposphere; (2) develop a scientific strategy for a comprehensive plan taking into account the existing and projected programs of the government; (3) assess the requirements of a global study in terms of theoretical knowledge, numerical modeling, instrumentation, observing platforms, ground-level observational techniques, and other related needs; and (4) outline the appropriate sequence and coordination required to achieve the most effective utilization of available resources. Part 1 presents a coordinated national blueprint for scientific investigations of biogeochemical cycles in the global troposphere. part 2 presents much of the background information of the present knowledge and gaps in the understanding of tropospheric chemical cycles and processes from which the proposed program was developed.

  3. Space opportunities for tropospheric chemistry research

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Hoell, James M.; Mcneal, Robert J.

    1986-01-01

    The use of the Space Shuttle to measure tropospheric trace species is examined. Factors which affect the measurement of tropospheric trace species are discussed. The Academy of Sciences 1985 report categorized the trace species into levels: first-level gases include water vapor, O3, CO, and CH4, and the second-level gases are N2O, NO2, NH3, SO2, chlorofluoromethanes, and HCl. The effects of first-level gases on the earth's climate, the photochemistry/chemistry of the troposphere, and the photochemical/chemical production and destruction of the hydroxyl radical are studied; the distribution and magnitude of the hydroxyl radical in the troposphere are analyzed in terms of water vapor, O3, CO, and CH4.

  4. Tropospheric Delay Raytracing Applied in VLBI Analysis

    NASA Astrophysics Data System (ADS)

    MacMillan, D. S.; Eriksson, D.; Gipson, J. M.

    2013-12-01

    Tropospheric delay modeling error continues to be one of the largest sources of error in VLBI analysis. For standard operational solutions, we use the VMF1 elevation-dependent mapping functions derived from ECMWF data. These mapping functions assume that tropospheric delay at a site is azimuthally symmetric. As this assumption does not reflect reality, we have determined the raytrace delay along the signal path through the troposphere for each VLBI quasar observation. We determined the troposphere refractivity fields from the pressure, temperature, specific humidity and geopotential height fields of the NASA GSFC GEOS-5 numerical weather model. We discuss results from analysis of the CONT11 R&D and the weekly operational R1+R4 experiment sessions. When applied in VLBI analysis, baseline length repeatabilities were better for 66-72% of baselines with raytraced delays than with VMF1 mapping functions. Vertical repeatabilities were better for 65% of sites.

  5. Synthesis and Integration of Energy Related Tropospheric Chemistry Research

    SciTech Connect

    Hidy, George M.

    2007-01-15

    This is a final report of work done in support of DOE interests in air quality assessment or managemnt and tropospheric aerosol chemistry. A central focus for the activities was support for the North American cooperative, NARSTO. Leaderrship and oversight was provided for NARSTO products including two major state-of-science assessments on airborne particles (particulate matter) and the fundamentals of pollutant emissions characterization. In addition, review sof so-called 'policy related air quality science were prepared addressing multi-scale atmospheric phenomena, snowpack chemistry and pollution, and North American aerosol baseline or background conditions. The relationship between the identification of pollution sourcees and human exposure to outdoor particles was investigated, and results critiqued. This work led to a major review of the integration of atmospheric chemistry, epedimiology and toxicology in linking airborne particles with human health effects. The last topical area of work in the project related to the carbon component of tropospheric aerosols. Work was done in support of a project to obtain samples of power plant effluents to estimate the carbon present in palnt emissions. The results suggsted only a minor amount of ambient particles were carbon from coal-fired plants. Another studied provided a conceptual plan for using isotopic carbon data to provide a vapor and condensed phase carbon balance for particles, including fossil and biogenic sources.

  6. Climate change, tropospheric ozone and particulate matter, and health impacts.

    PubMed

    Ebi, Kristie; McGregor, Glenn

    2009-01-01

    We review how climate change could affect future concentrations of tropospheric ozone and particulate matter (PM), and what changing concentrations could mean for population health, as well as studies projecting the impacts of climate change on air quality and the impacts of these changes on morbidity/mortality. Climate change could affect local to regional air quality through changes in chemical reaction rates, boundary layer heights that affect vertical mixing of pollutants, and changes in synoptic airflow patterns that govern pollutant transport. Sources of uncertainty are the degree of future climate change, future emissions of air pollutants and their precursors, and how population vulnerability may change in the future. Given the uncertainties, projections suggest that climate change will increase concentrations of tropospheric ozone, at least in high-income countries when precursor emissions are held constant, increasing morbidity/mortality. There are few projections for low- and middle-income countries. The evidence is less robust for PM, because few studies have been conducted. More research is needed to better understand the possible impacts of climate change on air pollution-related health impacts.

  7. Tropospheric ozone variability over the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Kulkarni, Pavan S.; Bortoli, D.; Salgado, R.; Antón, M.; Costa, M. J.; Silva, A. M.

    2011-01-01

    To study tropospheric ozone variability over the Iberian Peninsula (IP), NASA Langley TOR data have been analyzed for the 1979-2005 period. The maximum tropospheric ozone concentration over the entire IP was found in June (˜41 DU) and a minimum in December (˜29 DU). However the maximum tropospheric ozone concentration was found over West Atlantic Coast (WAC) (˜44 DU), followed by Mediterranean Coast (MC) (˜42 DU), North Atlantic Coast (NAC) (˜41 DU), Central Iberian Peninsula (CIP) (˜40 DU) and Pyrenees Mountain Range (PMR) (˜39 DU) during June-July. The high concentration of tropospheric ozone in July over the Atlantic Ocean near IP is due to the presence of Azores anticyclone and related photochemistry and dynamics, and affects the observed higher tropospheric ozone concentration over WAC zone. Strong seasonal cycle in tropospheric ozone concentration has been observed with large variation over NAC (˜49%), followed by WAC (˜48%) and MC (˜41%) compared to CIP and PMR (˜38%) zones. When the data are compared over the IP for the two periods (1979-1993 and 1997-2005), a systematic increase in the number of months with higher tropospheric ozone concentration has been observed during the second period with respect to the first. These increases are almost 8% to 24% over NAC, 6% to 17% over WAC, 5% to 24% over CIP, 6% to 23% over MC and 13% to 18% over PMR, zones. It has been observed that topography, climatology and population density distribution plays a crucial role in the variability of tropospheric ozone concentration over the IP.

  8. SO2 Over China Detected With EOS Aura Ozone Monitoring Instrument

    NASA Astrophysics Data System (ADS)

    Krotkov, N. A.; Bhartia, P.; Yang, K.; Carn, S. A.; Krueger, A. J.; Dickerson, R. R.; Hains, J.; Li, C.; Li, Z.; Marufu, L.; Stehr, J.; Levelt, P. F.

    2006-12-01

    The Ozone Monitoring Instrument (OMI) on EOS/Aura offers unprecedented spatial and spectral resolution, coupled with global coverage, for space-based UV measurements of sulfur dioxide (SO2). Publicly released SO2 pollution data are processed with the Band Residual Difference (BRD) algorithm that uses calibrated residuals at SO2 absorption band centers produced by the NASA operational ozone algorithm (OMTO3). By using optimum wavelengths for retrieval of SO2, the retrieval sensitivity is improved over NASA predecessor Total Ozone Mapping Spectrometer (TOMS) by factors of 10 to 20, depending on location. The ground footprint of OMI is 8 times smaller than TOMS. These factors produce a two orders of magnitude improvement in the minimum detectable mass of SO2. The improved sensitivity now permits daily global measurement of heavy anthropogenic SO2 pollution. Anthropogenic SO2 emissions have been measured by OMI over known sources of air pollution, such as eastern China, Eastern Europe, and from individual copper smelters in South America and elsewhere. Here we present data from a case study conducted over Shenyang in NE China as part of EAST-AIRE in April 2005. SO2 observations from instrumented aircraft flights are compared with OMI SO2 maps. The OMI SO2 algorithm was improved to account for the known altitude profile of SO2, and the comparison demonstrates that this algorithm can distinguish between background SO2 conditions and heavy pollution on a daily basis. Between 5 and 7 April 2005 a cold front traveled from continental China, over Korea and on to the Sea of Japan. The satellite-derived measurements of SO2 confirm the in situ aircraft observations of high concentrations of SO2 (ca 4 DU) ahead of the front and lower concentrations behind it and provide evidence for a large-scale impact of pollutant emissions. The BRD algorithm sensitivity does not represent the maximum sensitivity theoretically achievable with OMI, and hence future improvements in instrument

  9. Aerosol in the Pacific troposphere

    NASA Technical Reports Server (NTRS)

    Clarke, Antony D.

    1989-01-01

    The use of near real-time optical techniques is emphasized for the measurement of mid-tropospheric aerosol over the Central Pacific. The primary focus is on measurement of the aerosol size distribution over the range of particle diameters from 0.15 to 5.0 microns that are essential for modeling CO2 backscatter values in support of the laser atmospheric wind sounder (LAWS) program. The measurement system employs a LAS-X (Laser Aerosol Spectrometer-PMS, Boulder, CO) with a custom 256 channel pulse height analyzer and software for detailed measurement and analysis of aerosol size distributions. A thermal preheater system (Thermo Optic Aerosol Descriminator (TOAD) conditions the aerosol in a manner that allows the discrimination of the size distribution of individual aerosol components such as sulfuric acid, sulfates and refractory species. This allows assessment of the relative contribution of each component to the BCO2 signal. This is necessary since the different components have different sources, exhibit independent variability and provide different BCO2 signals for a given mass and particle size. Field activities involve experiments designed to examine both temporal and spatial variability of these aerosol components from ground based and aircraft platforms.

  10. Rain-induced emission pulses of NOx and HCHO from soils in African regions after dry spells as viewed by satellite sensors

    NASA Astrophysics Data System (ADS)

    Zörner, Jan; Penning de Vries, Marloes; Beirle, Steffen; Veres, Patrick; Williams, Jonathan; Wagner, Thomas

    2014-05-01

    Outside industrial areas, soil emissions of NOx (stemming from bacterial emissions of NO) represent a considerable fraction of total NOx emissions, and may even dominate in remote tropical and agricultural areas. NOx fluxes from soils are controlled by abiotic and microbiological processes which depend on ambient environmental conditions. Rain-induced spikes in NOx have been observed by in-situ measurements and also satellite observations. However, the estimation of soil emissions over broad geographic regions remains uncertain using bottom-up approaches. Independent, global satellite measurements can help constrain emissions used in chemical models. Laboratory experiments on soil fluxes suggest that significant HCHO emissions from soil can occur. However, it has not been previously attempted to detect HCHO emissions from wetted soils by using satellite observations. This study investigates the evolution of tropospheric NO2 (as a proxy for NOx) and HCHO column densities before and after the first rain fall event following a prolonged dry period in semi-arid regions, deserts as well as tropical regions in Africa. Tropospheric NO2 and HCHO columns retrieved from OMI aboard the AURA satellite, GOME-2 aboard METOP and SCIAMACHY aboard ENVISAT are used to study and inter-compare the observed responses of the trace gases with multiple space-based instruments. The observed responses are prone to be affected by other sources like lightning, fire, influx from polluted air masses, as well measurement errors in the satellite retrieval caused by manifold reasons such as an increased cloud contamination. Thus, much care is taken verify that the observed spikes reflect enhancements in soil emissions. Total column measurements of H2O from GOME-2 give further insight into the atmospheric state and help to explain the increase in humidity before the first precipitation event. The analysis is not only conducted for averages of distinct geographic regions, i.e. the Sahel, but also

  11. OMI tropospheric NO2 air mass factors over South America: effects of biomass burning aerosols

    NASA Astrophysics Data System (ADS)

    Castellanos, P.; Boersma, K. F.; Torres, O.; de Haan, J. F.

    2015-03-01

    Biomass burning is an important and uncertain source of aerosols and NOx (NO + NO2) to the atmosphere. OMI observations of tropospheric NO2 are essential for characterizing this emissions source, but inaccuracies in the retrieval of NO2 tropospheric columns due to the radiative effects of aerosols, especially light-absorbing carbonaceous aerosols, are not well understood. It has been shown that the O2-O2 effective cloud fraction and pressure retrieval is sensitive to aerosol optical and physical properties, including aerosol optical depth (AOD). Aerosols implicitly influence the tropospheric air mass factor (AMF) calculations used in the NO2 retrieval through the effective cloud parameters used in the independent pixel approximation. In this work, we explicitly account for the effects of biomass burning aerosols in the tropospheric NO2 AMF calculation by including collocated aerosol extinction vertical profile observations from the CALIOP instrument, and aerosol optical depth (AOD) and single scattering albedo (SSA) retrieved by the OMI near-UV aerosol algorithm (OMAERUV) in the DISAMAR radiative transfer model for cloud-free scenes. Tropospheric AMFs calculated with DISAMAR were benchmarked against AMFs reported in the Dutch OMI NO2 (DOMINO) retrieval; the mean and standard deviation (SD) of the difference was 0.6 ± 8%. Averaged over three successive South American biomass burning seasons (2006-2008), the spatial correlation in the 500 nm AOD retrieved by OMI and the 532 nm AOD retrieved by CALIOP was 0.6, and 72% of the daily OMAERUV AOD observations were within 0.3 of the CALIOP observations. Overall, tropospheric AMFs calculated with observed aerosol parameters were on average 10% higher than AMFs calculated with effective cloud parameters. For effective cloud radiance fractions less than 30%, or effective cloud pressures greater than 800 hPa, the difference between tropospheric AMFs based on implicit and explicit aerosol parameters is on average 6 and 3

  12. Evaluation of ACCMIP Outgoing Longwave Radiation from Tropospheric Ozone Using TES Satellite Observations.

    NASA Technical Reports Server (NTRS)

    Bowman, Kevin W.; Shindell, Drew Todd; Worden, H. M.; Lamarque, J. F.; Young, P. J.; Stevenson, D. S.; Qu, Z.; delaTorre, M.; Bergmann, D.; Cameron-Smith, P. J.; Collins, W. J.; Doherty, R.; Dalsoren, S. B.; Faluvegi, G.; Folberth, G.; Horowitz, L. W.; Josse, B. M.; Lee, Y. H.; MacKenzie, I. A.; Myhre, G.; Nagashima, T.; Naik, V.; Strode, S. A.; Kulawik, S. S..; Worden, J. R.

    2013-01-01

    We use simultaneous observations of tropospheric ozone and outgoing longwave radiation (OLR) sensitivity to tropospheric ozone from the Tropospheric Emission Spectrometer (TES) to evaluate model tropospheric ozone and its effect on OLR simulated by a suite of chemistry-climate models that participated in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). The ensemble mean of ACCMIP models show a persistent but modest tropospheric ozone low bias (5-20 ppb) in the Southern Hemisphere (SH) and modest high bias (5-10 ppb) in the Northern Hemisphere (NH) relative to TES ozone for 2005-2010. These ozone biases have a significant impact on the OLR. Using TES instantaneous radiative kernels (IRK), we show that the ACCMIP ensemble mean tropospheric ozone low bias leads up to 120mW/ sq. m OLR high bias locally but zonally compensating errors reduce the global OLR high bias to 39+/- 41mW/ sq. m relative to TES data. We show that there is a correlation (Sq. R = 0.59) between the magnitude of the ACCMIP OLR bias and the deviation of the ACCMIP preindustrial to present day (1750-2010) ozone radiative forcing (RF) from the ensemble ozone RF mean. However, this correlation is driven primarily by models whose absolute OLR bias from tropospheric ozone exceeds 100mW/ sq. m. Removing these models leads to a mean ozone radiative forcing of 394+/- 42mW/ sq. m. The mean is about the same and the standard deviation is about 30% lower than an ensemble ozone RF of 384 +/- 60mW/ sq. m derived from 14 of the 16 ACCMIP models reported in a companion ACCMIP study. These results point towards a profitable direction of combining satellite observations and chemistry-climate model simulations to reduce uncertainty in ozone radiative forcing.

  13. Dynamic-Chemical Coupling of the Upper Troposphere and Lower Stratosphere Region

    NASA Technical Reports Server (NTRS)

    Grewe, Volker; Shindell, Drew T.; Reithmeier, Christian

    2000-01-01

    The importance of the interaction of chemistry and dynamics in the upper troposphere and lower stratosphere for chemical species like ozone is investigated using two chemistry-climate models. Species emitted in the upper troposphere, like NOx (=NO+NO2) by lightning or aircraft, have the chance to be transported into the lowermost stratosphere. Trajectory calculations suggest that the main transport pathway runs via the Inter Tropical Convergence Zone, across the tropical tropopause and then to higher latitudes, i.e. into the lowermost stratosphere. Longer lifetimes of NOx in the lower stratosphere yield an accumulation of NO. there, which feeds back on upper troposphere chemistry. This effect has been estimated for lightning NO. emissions and reveals a contribution of at least 25% to 40% to the total northern hemisphere mid-latitude lightning increase of either NOx and ozone.

  14. Aqua-Aura QuickDAM (QDAM) 2.0 Ops Concept

    NASA Technical Reports Server (NTRS)

    Nidhiry, John

    2015-01-01

    The presentation describes the Quick Debris Avoidance Maneuver (QDAM) 2.0 process used the Aqua and Aura flight teams to (a) reduce the work load and dependency on staff and systems; (b) reduce turn-around time and provide emergency last minute capabilities; and (c) increase burn parameter flexibility. The presentation also compares the QDAM 2.0 process to previous approaches.

  15. The Virtual Aura--Is There Space for Enchantment in a Technological World?

    ERIC Educational Resources Information Center

    Hazan, Susan

    As Walter Benjamin described in his famous essay, "The Work of Art in the Age of Mechanical Reproduction", the role of art in society and the notion that art has become modified through mechanical reproduction has engaged not only artists, but also curators and the museum public. Benjamin embraced the severing of the quasi-mystical "aura" from the…

  16. Vitamin supplementation as possible prophylactic treatment against migraine with aura and menstrual migraine.

    PubMed

    Shaik, Munvar Miya; Gan, Siew Hua

    2015-01-01

    Migraine is the most common form of headache disorder globally. The etiology of migraine is multifactorial, with genetic components and environmental interactions considered to be the main causal factors. Some researchers postulate that deficits in mitochondrial energy reserves can cause migraine or an increase in homocysteine levels can lead to migraine attacks; therefore, vitamins could play a vital role in migraine prevention. For instance, riboflavin influences mitochondrial dysfunction and prevents migraine. Genes such as flavoenzyme 5,10-methylenetetrahydrofolate reductase (MTHFR), especially the C677T variant, have been associated with elevated plasma levels of homocysteine and migraine with aura. Homocysteine catalyzation requires the presence of vitamins B6, B12, and folic acid, which can decrease the severity of migraine with aura, making these vitamins potentially useful prophylactic agents for treating migraine with aura. Menstrual migraine, on the other hand, is associated with increased prostaglandin (PG) levels in the endometrium, indicating a role for vitamin E, which is an anti-PG. Vitamin C can also be used as a scavenger of reactive oxygen species for treating neurogenic inflammation in migraine patients. This paper reviews possible therapies based on vitamin supplementation for migraine prophylaxis, focusing on migraine with aura and menstrual migraine.

  17. A case of strictly unilateral migraine without aura transformed in an episodic hemicrania continua.

    PubMed

    Terlizzi, Rossana; Cevoli, Sabina; Nicodemo, Marianna; Pierangeli, Giulia; Grimaldi, Daniela; Cortelli, Pietro

    2011-02-01

    According to the diagnostic criteria of International Headache Society classification, hemicrania continua is a strictly unilateral continuous headache of moderate intensity with painful exacerbations associated with ipsilateral autonomic signs without pain-free periods. We report a case of a 42-year-old woman suffered of a remitting form of hemicrania continua evolved from a strictly unilateral migraine without aura.

  18. Mechanisms of migraine aura revealed by functional MRI in human visual cortex

    PubMed Central

    Hadjikhani, Nouchine; Sanchez del Rio, Margarita; Wu, Ona; Schwartz, Denis; Bakker, Dick; Fischl, Bruce; Kwong, Kenneth K.; Cutrer, F. Michael; Rosen, Bruce R.; Tootell, Roger B. H.; Sorensen, A. Gregory; Moskowitz, Michael A.

    2001-01-01

    Cortical spreading depression (CSD) has been suggested to underlie migraine visual aura. However, it has been challenging to test this hypothesis in human cerebral cortex. Using high-field functional MRI with near-continuous recording during visual aura in three subjects, we observed blood oxygenation level-dependent (BOLD) signal changes that demonstrated at least eight characteristics of CSD, time-locked to percept/onset of the aura. Initially, a focal increase in BOLD signal (possibly reflecting vasodilation), developed within extrastriate cortex (area V3A). This BOLD change progressed contiguously and slowly (3.5 ± 1.1 mm/min) over occipital cortex, congruent with the retinotopy of the visual percept. Following the same retinotopic progression, the BOLD signal then diminished (possibly reflecting vasoconstriction after the initial vasodilation), as did the BOLD response to visual activation. During periods with no visual stimulation, but while the subject was experiencing scintillations, BOLD signal followed the retinotopic progression of the visual percept. These data strongly suggest that an electrophysiological event such as CSD generates the aura in human visual cortex. PMID:11287655

  19. Increasing Springtime Ozone Mixing Ratios in the Free Troposphere Over Western North America

    NASA Technical Reports Server (NTRS)

    Cooper, O. R.; Parrish, D. D.; Stohl, A.; Trainer, M.; Nedelec, P.; Thouret, V.; Cammas, J. P.; Oltmans, S. J.; Johnson, B. J.; Tarasick, D.; Leblanc, T.; McDermid, I. S.; Jaffe, D.; Gao, R.; Stith, J.; Ryerson, T.; Aikin, K.; Campos, T.; Weinheimer, A.; Avery, M. A.

    2010-01-01

    In the lowermost layer of the atmosphere - the troposphere - ozone is an important source of the hydroxyl radical, an oxidant that breaks down most pollutants and some greenhouse gases. High concentrations of tropospheric ozone are toxic, however, and have a detrimental effect on human health and ecosystem productivity1. Moreover, tropospheric ozone itself acts as an effective greenhouse gas. Much of the present tropospheric ozone burden is a consequence of anthropogenic emissions of ozone precursors resulting in widespread increases in ozone concentrations since the late 1800s. At present, east Asia has the fastest-growing ozone precursor emissions. Much of the springtime east Asian pollution is exported eastwards towards western North America. Despite evidence that the exported Asian pollution produces ozone, no previous study has found a significant increase in free tropospheric ozone concentrations above the western USA since measurements began in the late 1970s. Here we compile springtime ozone measurements from many different platforms across western North America. We show a strong increase in springtime ozone mixing ratios during 1995-2008 and we have some additional evidence that a similar rate of increase in ozone mixing ratio has occurred since 1984. We find that the rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. Our result agrees with previous modelling studies, which indicate that global ozone concentrations should be increasing during the early part of the twenty-first century as a result of increasing precursor emissions, especially at northern mid-latitudes, with western North America being particularly sensitive to rising Asian emissions. We suggest that the observed increase in springtime background ozone mixing ratio may hinder the USA s compliance with its ozone air quality standard.

  20. Increasing springtime ozone mixing ratios in the free troposphere over western North America.

    PubMed

    Cooper, O R; Parrish, D D; Stohl, A; Trainer, M; Nédélec, P; Thouret, V; Cammas, J P; Oltmans, S J; Johnson, B J; Tarasick, D; Leblanc, T; McDermid, I S; Jaffe, D; Gao, R; Stith, J; Ryerson, T; Aikin, K; Campos, T; Weinheimer, A; Avery, M A

    2010-01-21

    In the lowermost layer of the atmosphere-the troposphere-ozone is an important source of the hydroxyl radical, an oxidant that breaks down most pollutants and some greenhouse gases. High concentrations of tropospheric ozone are toxic, however, and have a detrimental effect on human health and ecosystem productivity. Moreover, tropospheric ozone itself acts as an effective greenhouse gas. Much of the present tropospheric ozone burden is a consequence of anthropogenic emissions of ozone precursors resulting in widespread increases in ozone concentrations since the late 1800s. At present, east Asia has the fastest-growing ozone precursor emissions. Much of the springtime east Asian pollution is exported eastwards towards western North America. Despite evidence that the exported Asian pollution produces ozone, no previous study has found a significant increase in free tropospheric ozone concentrations above the western USA since measurements began in the late 1970s. Here we compile springtime ozone measurements from many different platforms across western North America. We show a strong increase in springtime ozone mixing ratios during 1995-2008 and we have some additional evidence that a similar rate of increase in ozone mixing ratio has occurred since 1984. We find that the rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. Our result agrees with previous modelling studies, which indicate that global ozone concentrations should be increasing during the early part of the twenty-first century as a result of increasing precursor emissions, especially at northern mid-latitudes, with western North America being particularly sensitive to rising Asian emissions. We suggest that the observed increase in springtime background ozone mixing ratio may hinder the USA's compliance with its ozone air quality standard.

  1. On the role of climate variability on tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Lin, M.

    2014-12-01

    The response of tropospheric ozone to changing atmospheric circulation is poorly understood owing to a lack of reliable long-term observations. There is great current interest in quantifying the extent to which observed ozone trends over recent decades at northern mid-latitude sites are driven by changes in precursor emissions versus shifts in atmospheric circulation patterns. In this talk, I present a detailed analysis of the impact of interannual to decadal climate variability on tropospheric ozone, based on observations and a suite of chemistry-climate model hindcast simulations. Decadal shifts in circulation regimes modulate long-range transport of Asian pollution, leading to very different seasonal ozone trends at Mauna Loa Observatory in the subtropical Pacific Ocean. During autumn, the flow of ozone-rich air from Eurasia towards Hawaii strengthened in the mid-1990s onwards, as a result of the positive phase of the Pacific North American pattern, increasing ozone at Mauna Loa. During spring, weakening airflow from Asia in the 2000s, tied to La-Niña-like decadal cooling in the equatorial Pacific Ocean, offsets ozone increases at Mauna Loa that otherwise would have occurred due to rising Asian emissions. The circulation-driven variability in Asian pollution over the subtropical North Pacific regions manifests mainly as changes in the mean as opposed to in transport events. At high-elevation Western U.S. sites, intrusions of stratospheric ozone deep into the troposphere during spring exert a greater influence than Asian pollution, particularly on the high tail of observed surface ozone distribution. We show that year-to-year variability in springtime high-ozone episodes measured in Western U.S. surface air is tied to known modes of climate variability, which modulate meanders in the polar frontal jet conducive to deep stratospheric ozone intrusions. Specifically, the La Niña-related increase in the frequency of deep stratospheric intrusion events plays a

  2. An intercomparison study of tropospheric NO2 columns retrieved from MAX-DOAS and simulated by regional air quality models

    NASA Astrophysics Data System (ADS)

    Blechschmidt, Anne-Marlene

    2016-04-01

    Tropospheric NO2 is hazardous to human health and can lead to tropospheric ozone formation, eutrophication of ecosystems and acid rain production. It is therefore very important to accurately observe and simulate tropospheric NO2 on a regional and global scale. In the present study, MAX-DOAS tropospheric NO2 column retrievals from three European measurement stations are applied for validation of a regional model ensemble. In general, there is a good agreement between simulated and retrieved NO2 column values for individual MAX-DOAS measurements, indicating that the model ensemble does well represent the emission and tropospheric chemistry of NOx. However, the model ensemble tends to overestimate low and underestimate high tropospheric NO2 column values, respectively. Pollution transport towards the stations is on average well represented by the models. However, large differences can be found for individual pollution plumes. Seasonal cycles are overestimated by the model ensemble, which could point to problems in simulating photochemistry. While weekly cycles are reproduced well by the models, model performance is rather poor for diurnal cycles. In particular, simulated morning rush hour peaks are not confirmed by MAX-DOAS retrievals, which may result from inappropriate hourly scaling of NOx emissions, possibly combined with errors in chemistry. Our results demonstrate that a large number of validation points are available from MAX-DOAS data, which should therefore be used more extensively in future regional air quality modelling studies.

  3. Quantified estimates of total GWPs for greenhouse gases taking into account tropospheric chemistry

    SciTech Connect

    Wuebbles, D.J.; Tamaresis, J.S.; Patten, K.O.

    1993-11-01

    The purpose of this report is to give interim account of the progress being made at Lawrence Livermore National Laboratory (LLNL) in developing an improved capability for assessing the direct and indirect effects on Global Warming Potentials. Much of our current efforts are being devoted to improving the capability for modeling of global tropospheric processes in our state-of-the-art zonally-averaged chemical-radiative-transport model of the troposphere and stratosphere. These efforts are in preparation for an improved evaluation and better quantification of the indirect GWPs resulting from effects on tropospheric ozone from ethane and other gases with significant human-related emissions. There are three major findings that should result from this project that should have significant impacts on EPA and its programs. First, the current and ongoing studies of the direct and indirect GWPs should have a significant influence on the continuing national and international assessments of climate change. Second, the improved capability for modeling of chemical and physical processes should lead to enhanced understanding of the controlling factors influencing ozone, hydroxyl and other key tropospheric constituents. Third, the enhanced modeling capability should be important to future studies of human-related influences on tropospheric and stratospheric chemical processes.

  4. Sources of upper tropospheric HO X : A three-dimensional study

    NASA Astrophysics Data System (ADS)

    Müller, Jean-FrançOis; Brasseur, Guy

    1999-01-01

    The sources of odd hydrogen radicals (HOx = OH + HO2) in the upper troposphere are investigated and quantified using a three-dimensional model. While the reaction of O(1D) with water vapor constitutes the single major source of HOx in the lower and middle troposphere, the model calculations suggest that acetone photooxidation represents a large, almost ubiquitous source of HOx in the upper troposphere (around 20-40% of the total primary source in the main aircraft corridors, poleward of 40°N), while the convective injections of peroxides and aldehydes are the dominant sources in the tropics, above the oceans and the continents, respectively. The consequences for ozone photochemical production in the upper troposphere are discussed, in particular, in the perspective of the aircraft impact. The role of acetone on ozone photochemical production is estimated and discussed. It is calculated that the presence of acetone might enhance by about 20% the sensitivity of upper tropospheric ozone to the current aircraft emissions of NOx.

  5. Tropospheric Vertical Distribution of Tropical Atlantic Ozone Observed by TES during the Northern African Biomass Burning Season

    NASA Technical Reports Server (NTRS)

    Jourdain, L.; Worden, H. M.; Worden, J. R.; Bowman, K.; Li, Q.; Eldering, A.; Kulawik, S. S.; Osterman, G.; Boersma, K. F.; Fisher, B.; Rinsland, C. P.; Beer, R.; Gunson, M.

    2007-01-01

    We present vertical distributions of ozone from the Tropospheric Emission Spectrometer (TES) over the tropical Atlantic Ocean during January 2005. Between 10N and 20S, TES ozone retrievals have Degrees of Freedom for signal (DOF) around 0.7 - 0.8 each for tropospheric altitudes above and below 500 hPa. As a result, TES is able to capture for the first time from space a distribution characterized by two maxima: one in the lower troposphere north of the ITCZ and one in the middle and upper troposphere south of the ITCZ. We focus our analysis on the north tropical Atlantic Ocean, where most of previous satellite observations showed discrepancies with in-situ ozone observations and models. Trajectory analyses and a sensitivity study using the GEOS-Chem model confirm the influence of northern Africa biomass burning on the elevated ozone mixing ratios observed by TES over this region.

  6. The possible role of heterogeneous aerosol processes in the chemistry of CH4 and CO in the troposphere

    NASA Technical Reports Server (NTRS)

    Luther, C. J.; Peters, L. K.

    1982-01-01

    The effect of particle-gas interactions on the CH4 to CO oxidation sequence in the troposphere is investigated by developing rate expressions for the heterogeneous removal of gaseous species based on the absorption of the species by aerosol particles. The results of this analysis indicate that the homogeneous models describe the tropospheric chemistry of CO and CH4 more accurately than heterogeneous models, which suggests that heterogeneous processes may not be significant in this sequence of chemical reactions. Estimates of the CO and CH4 emission rates are not found to provide a conclusive basis on which to compare the significance of the homogeneous and heterogeneous processes. In addition, the time period during which an aerosol particle is effective in removing a trace gaseous species from the troposphere is determined to vary according to the tropospheric concentration and solubility of the particular gaseous species.

  7. Impacts of anthropogenic and natural NOx sources over the U.S. on tropospheric chemistry

    PubMed Central

    Zhang, Renyi; Tie, Xuexi; Bond, Donald W.

    2003-01-01

    We evaluate the impact of anthropogenic and natural NOx sources over the contiguous United States on tropospheric NOx and O3 levels by using a global 3D chemical transport model. The effects of major U.S. surface NOx emission sources (including anthropogenic, biomass burning, and soil emissions) are compared with that of lightning-produced NOx. Summer lightning is shown to play a dominant role in controlling NOx and O3 concentrations in the middle and upper troposphere, despite the fact that fossil-fuel burning represents the largest source of NOx over the U.S. Furthermore, the effect of regional U.S. lightning is propagated through large areas of the Northern Hemisphere by atmospheric circulation. The results reveal that a thorough assessment of atmospheric NOx emission sources and their impact is required to devise control strategies for regional and global air pollution. PMID:12552100

  8. Role of ozone precursors in tropospheric ozone formation and control: A report to Congress

    SciTech Connect

    Not Available

    1993-07-01

    Tropospheric ozone pollution, which occurs at ground level and is the major component of ground-level summertime smog, remains an important environmental and health concern despite nearly 20 years of regulatory efforts. Ozone is a secondary pollutant formed in the atmosphere by reactions of volatile organic compounds (VOCs) and oxides of nitrogen (NOx) in the presence of sunlight. Carbon monoxide (CO) also plays a role in the formation of ozone. Major sources of VOCs include exhaust and evaporative emissions from motor vehicles, emissions from solvent use and emissions from the chemical and petroleum industries. The following EPA perspectives identify two key components (strategy selection; modeling and data bases) which must be addressed in resolving the tropospheric ozone problem.

  9. Impacts of anthropogenic and natural NOx sources over the U.S. on tropospheric chemistry

    NASA Astrophysics Data System (ADS)

    Zhang, Renyi; Tie, Xuexi; Bond, Donald W.

    2003-02-01

    We evaluate the impact of anthropogenic and natural NOx sources over the contiguous United States on tropospheric NOx and O3 levels by using a global 3D chemical transport model. The effects of major U.S. surface NOx emission sources (including anthropogenic, biomass burning, and soil emissions) are compared with that of lightning-produced NOx. Summer lightning is shown to play a dominant role in controlling NOx and O3 concentrations in the middle and upper troposphere, despite the fact that fossil-fuel burning represents the largest source of NOx over the U.S. Furthermore, the effect of regional U.S. lightning is propagated through large areas of the Northern Hemisphere by atmospheric circulation. The results reveal that a thorough assessment of atmospheric NOx emission sources and their impact is required to devise control strategies for regional and global air pollution.

  10. Radiative Decay of Upper Tropospheric Anticyclones

    NASA Astrophysics Data System (ADS)

    Daniel, Vincent; Legras, Bernard

    We investigate the dynamics and the decay of upper tropospheric anticyclones. First, we focus on the nature, the frequency and the formation of these atmospheric patterns. Standard Isentropic Potential Vorticity maps (using analysed fields from ECMWF) show that these synoptic situations are common in the northern hemisphere with a higher frequency during autumn. Massive back-trajectory calculations (using the kinematic trajectory model FLEX- TRA) reveal that most of air parcels are coming from the tropical or the subtropical boundary layer following "warm conveyor belts". Advection of humid air into upper tropospheric anticyclones is in agreement with aircraft data from SONEX and POLI- NAT airborne campaigns and with MOZAIC humidity measurements. In anticyclonic vorticies, these data show frequent relative humidity sursaturation with respect to ice. Mesoscale simulations (using MesoNH model from Meteo-France) has been per- formed to investigate more precisely the advection of boundary layer air into an upper tropospheric anticyclone. Online lagrangian calculations have been performed and we plan to estimate the meridian humidity flux induced by this process. In a second stage, decay of upper tropospheric anticyclones is studied. The presence of thin cirrus clouds in these anticyclonic vortices is an open question. Nevertheless, airborne lidar measurements during the SONEX III campaign show that thin cirrus are present during the first stage of the anticyclone life. These clouds may play a ma- jor role concerning radiative decay. Idealized mesoscale simulations (using MesoNH model) have been performed. At the present time, realistic decay is obtained only in clear sky conditions. Radiative decay induces a net mass flux from the troposphere to the stratosphere. This flux is increased with the moistening of upper tropospheric cy- clones. Using realistic humidity fields, it is found to be of the same order of magnitude that net flux from the stratosphere to the

  11. Biogenic and biomass burning sources of acetone to the troposphere

    SciTech Connect

    Atherton, C.S.

    1997-04-01

    Acetone may be an important source of reactive odd hydrogen in the upper troposphere and lower stratosphere. This source of odd hydrogen may affect the concentration of a number of species, including ozone, nitrogen oxides, methane, and others. Traditional, acetone had been considered a by-product of the photochemical oxidation of other species, and had not entered models as a primary emission. However, recent work estimates a global source term of 40-60 Tg acetone/year. Of this, 25% is directly emitted during biomass burning, and 20% is directly emitted by evergreens and other plants. Only 3% is due to anthropogenic/industrial emissions. The bulk of the remainder, 51% of the acetone source, is a secondary product from the oxidation of propane, isobutane, and isobutene. Also, while it is speculated that the oxidation of pinene (a biogenic emission) may also contribute about 6 Tg/year, this term is highly uncertain. Thus, the two largest primary sources of acetone are biogenic emission and biomass burning, with industrial/anthropogenic emissions very small in comparison.

  12. Microwave limb sounding of the UT/LS: Stratosphere-Troposphere Exchange And Climate Monitor (STEAM) and related projects

    NASA Astrophysics Data System (ADS)

    Urban, Joachim

    The Stratosphere-Troposphere Exchange And climate Monitor (STEAM) radiometer is designed to provide vertically and horizontally well resolved profiles of key species in the climate relevant upper troposphere and lower stratosphere (UT/LS) altitude region such as H2O, O3, CO, HCN, CH3CN, CH3Cl, N2O, HNO3, and temperature. The instrument is a multi-beam limb sounder employing 12GHz wide sub-harmonically pumped double sideband mixers targeting the 324-336GHz (lower sideband) and 343.25-355.25GHz (upper sideband) spectral bands with a local oscillator set at 339.625GHz. Whilst the instrument configuration had been optimized during the recent years to fit the ESA Earth Explorer 7 candidate mission PREMIER, the instrument payload is now being studied in a smaller configuration for a different satellite mission in collaboration with international partners. The presentation provides an overview of the STEAM project and its science objectives and focuses on a description of the measurement capabilities of the newly configured STEAM radiometer, in comparison to related projects and existing sensors such as Odin/SMR and Aura/MLS.

  13. Tropospheric Trace Gas Interactions with Aerosols

    NASA Technical Reports Server (NTRS)

    Penner, Joyce E.; Maddrea, George L., Jr. (Technical Monitor)

    2002-01-01

    Tropospheric aerosols are of considerable environmental importance. They modify the radiative budget of Earth by scattering and absorbing radiation, and by providing nuclei for cloud formation. Additionally, they provide surfaces for heterogeneous and multiphase reactions that affect tropospheric chemistry. For example, Dentener and Crutzen (1993) showed that reactions of N2O5 and NO3 with sulfate aerosols may significantly alter the tropospheric concentrations of NO(x), O3, and OH by converting NOx to HNO3 which is rapidly removed by precipitation. Zhang et al. (1994) assumed these same reactions would occur on dust aerosols and showed that dust outbreaks may reduce NO(x) levels by up to 50%. Dentener et al. (1996) studied the possible effect of reactions on dust on sulfate, nitrate, and O3 concentration. Heterogeneous and multiphase reactions on aerosols may also perturb the sulfur cycle the chlorine cycle and the bromine cycle. Because these reactions can release free chlorine and free bromine they might lead to the destruction of ozone in the marine boundary layer that may be important to include in models of tropospheric chemistry. The goal of our proposed work is to examine the role of heterogeneous and multiphase reactions in the tropospheric cycles of reactive nitrogen and sulfur.

  14. Iodine - Its possible role in tropospheric photochemistry

    NASA Technical Reports Server (NTRS)

    Chameides, W. L.; Davis, D. D.

    1980-01-01

    A detailed study of the photochemistry of iodine and its oxides indicates that iodine species may play an important role in the tropospheric photochemical system. Methyl iodide, often observed in the marine troposphere with an average concentration of 5-10 ppt, is photolyzed and thereby produces I atoms. Chemical interactions with O3, HxOy, and NOx cause I to be converted to other inorganic compounds such as IO, HOI, IONO2, and I2. The production of these species and their subsequent recycling back to I can lead to the catalytic removal of tropospheric O3, the enhancement of the NO2/NO ratio, the destruction of HxOy free radicals, and the conversion of HO2 to OH. Ultimately, tropospheric inorganic iodine is removed by heterogeneous processes. Calculations using a numerical model to simulate tropospheric photochemistry indicate that iodine may have a strong impact upon the atmospheric O3-NOx-HxOy system. The magnitude of these effects is dependent upon the value of several uncertain rate constants and the primary source distributions of CH3I and other organic and inorganic iodine compounds.

  15. Discoveries about Tropical Tropospheric Ozone from Satellite and SHADOZ (Southern Hemisphere Additional Ozonesondes) and a Future Perspective on NASA's Ozone Sensors

    NASA Technical Reports Server (NTRS)

    Thompson, Anne

    2003-01-01

    We have been producing near-real tropical tropospheric ozone ('TTO') data from TOMS since 1997 with Prof. Hudson and students at the University of Maryland. Maps for 1996-2000 for the operational Earth-Probe instrument reside at: . We also have archived 'TTO' data from the Nimbus 7/TOMS satellite (1979-1992). The tropics is a region strongly influenced by natural variability and anthropogenic activity and the satellite data have been used to track biomass burning pollution and to detect interannual variability and climate signals in ozone. We look forward to future ozone sensors from NASA; four will be launched in 2004 as part of the EOS AURA Mission. The satellite view of chemical-dynamical interactions in tropospheric ozone is not adequate to capture vertical variability. Thus, in 1998, NASA's Goddard Space Flight Center, NOAA's Climate Monitoring and Diagnostics Laboratory (CMDL) and a team of international sponsors established the SHADOZ (Southern Hemisphere ADditional OZonesondes) project to address the gap in tropical ozone soundings. SHADOZ augments launches at selected sites and provides a public archive of ozonesonde data from twelve tropical and subtropical stations at http://croc.nsfc.nasa.gov/shadoz. The stations are: Ascension Island; Nairobi, Kenya; Irene, South Africa; R,union Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil, Malindi, Kenya; Paramaribo, Surinam. From the first 3-4 years of data (presently greater than 1700 sondes), the following features emerge: (a) highly variable tropospheric ozone; (b) a zonal wave-one pattern in tropospheric column ozone; (c) tropospheric ozone variability over the Indian and Pacific Ocean displays strong convective signatures.

  16. Influence of coal-based thermal power plants on the spatial-temporal variability of tropospheric NO2 column over India.

    PubMed

    Prasad, Anup K; Singh, Ramesh P; Kafatos, Menas

    2012-04-01

    The oxides of nitrogen--NO(x) (NO and NO(2))--are an important constituent of the troposphere. The availability of relatively higher spatial (0.25° grid) and temporal (daily) resolution data from ozone monitoring instrument (OMI) onboard Aura helps us to better differentiate between the point sources such as thermal power plants from large cities and rural areas compared to previous sensors. The annual and seasonal (summer and winter) distributions shows very high mean tropospheric NO(2) in specific pockets over India especially over the Indo-Gangetic plains (up to 14.2 × 10(15) molecules/cm(2)). These pockets correspond with the known locations of major thermal power plants. The tropospheric NO(2) over India show a large seasonal variability that is also observed in the ground NO(2) data. The multiple regression analysis show that the influence of a unit of power plant (in gigawatts) over tropospheric NO(2) (×10(15) molecules/cm(2)) is around ten times compared to a unit of population (in millions) over India. The OMI data show that the NO(2) increases by 0.794 ± 0.12 (×10(15) molecules/cm(2); annual) per GW compared to a previous estimate of 0.014 (×10(15) molecules/cm(2)) over India. The increase of tropospheric NO(2) per gigawatt is found to be 1.088 ± 0.18, 0.898 ± 0.14, and 0.395 ± 0.13 (×10(15) molecules/cm(2)) during winter, summer, and monsoon seasons, respectively. The strong seasonal variation is attributed to the enhancement or suppression of NO(2) due to various controlling factors which is discussed here. The recent increasing trend (2005-2007) over rural thermal power plants pockets like Agori and Korba is due to recent large capacity additions in these regions.

  17. TES Data and Information

    Atmospheric Science Data Center

    2016-09-07

    ... and Information The Tropospheric Emission Spectrometer ( TES ) launched into sun-synchronous orbit aboard Aura, the ... TES is a high-resolution imaging infrared Fourier-transform spectrometer that operates in both nadir and limb-sounding modes. TES global ...

  18. Climate Change, Tropospheric Ozone and Particulate Matter, and Health Impacts

    PubMed Central

    Ebi, Kristie L.; McGregor, Glenn

    2008-01-01

    Objective Because the state of the atmosphere determines the development, transport, dispersion, and deposition of air pollutants, there is concern that climate change could affect morbidity and mortality associated with elevated concentrations of these gases and fine particles. We review how climate change could affect future concentrations of tropospheric ozone and particulate matter (PM), and what changing concentrations could mean for population health. Data sources We review studies projecting the impacts of climate change on air quality and studies projecting the impacts of these changes on morbidity and mortality. Data synthesis Climate change could affect local to regional air quality through changes in chemical reaction rates, boundary layer heights that affect vertical mixing of pollutants, and changes in synoptic airflow patterns that govern pollutant transport. Sources of uncertainty include the degree of future climate change, future emissions of air pollutants and their precursors, and how population vulnerability may change in the future. Given these uncertainties, projections suggest that climate change will increase concentrations of tropospheric ozone, at least in high-income countries when precursor emissions are held constant, which would increase morbidity and mortality. Few projections are available for low- and middle-income countries. The evidence is less robust for PM, primarily because few studies have been conducted. Conclusions Additional research is needed to better understand the possible impacts of climate change on air pollution–related health impacts. If improved models continue to project higher ozone concentrations with climate change, then reducing greenhouse gas emissions would enhance the health of current and future generations. PMID:19057695

  19. Global Distribution and Trends of Tropospheric Ozone: An Observation-Based Review

    NASA Technical Reports Server (NTRS)

    Cooper, O. R.; Parrish, D. D.; Ziemke, J.; Cupeiro, M.; Galbally, I. E.; Gilge, S.; Horowitz, L.; Jensen, N. R.; Lamarque, J.-F.; Naik, V.; Oltmans, S. J.; Schwab, J.; Shindell, D. T.; Thompson, A. M.; Thouret, V.; Wang, Y.; Zbinden, R. M.

    2014-01-01

    Tropospheric ozone plays a major role in Earth's atmospheric chemistry processes and also acts as an air pollutant and greenhouse gas. Due to its short lifetime, and dependence on sunlight and precursor emissions from natural and anthropogenic sources, tropospheric ozone's abundance is highly variable in space and time on seasonal, interannual and decadal time-scales. Recent, and sometimes rapid, changes in observed ozone mixing ratios and ozone precursor emissions inspired us to produce this up-to-date overview of tropospheric ozone's global distribution and trends. Much of the text is a synthesis of in situ and remotely sensed ozone observations reported in the peer-reviewed literature, but we also include some new and extended analyses using well-known and referenced datasets to draw connections between ozone trends and distributions in different regions of the world. In addition, we provide a brief evaluation of the accuracy of rural or remote surface ozone trends calculated by three state-of-the-science chemistry-climate models, the tools used by scientists to fill the gaps in our knowledge of global tropospheric ozone distribution and trends.

  20. Contribution of isoprene-derived organosulfates to free tropospheric aerosol mass

    PubMed Central

    Froyd, K. D.; Murphy, S. M.; Murphy, D. M.; de Gouw, J. A.; Eddingsaas, N. C.; Wennberg, P. O.

    2010-01-01

    Recent laboratory studies have demonstrated that isoprene oxidation products can partition to atmospheric aerosols by reacting with condensed phase sulfuric acid, forming low-volatility organosulfate compounds. We have identified organosulfate compounds in free tropospheric aerosols by single particle mass spectrometry during several airborne field campaigns. One of these organosulfates is identified as the sulfate ester of IEPOX, a second generation oxidation product of isoprene. The patterns of IEPOX sulfate ester in ambient data generally followed the aerosol acidity and NOx dependence established by laboratory studies. Detection of the IEPOX sulfate ester was most sensitive using reduced ionization laser power, when it was observed in up to 80% of particles in the tropical free troposphere. Based on laboratory mass calibrations, IEPOX added > 0.4% to tropospheric aerosol mass in the remote tropics and up to 20% in regions downwind of isoprene sources. In the southeastern United States, when acidic aerosol was exposed to fresh isoprene emissions, accumulation of IEPOX increased aerosol mass by up to 3%. The IEPOX sulfate ester is therefore one of the most abundant single organic compounds measured in atmospheric aerosol. Our data show that acidity-dependent IEPOX uptake is a mechanism by which anthropogenic SO2 and marine dimethyl sulfide emissions generate secondary biogenic aerosol mass throughout the troposphere. PMID:21098310

  1. Source attribution of interannual variability of tropospheric ozone over the southern hemisphere

    NASA Astrophysics Data System (ADS)

    Liu, J.; Rodriguez, J. M.; Logan, J. A.; Steenrod, S. D.; Douglass, A. R.; Olsen, M. A.; Wargan, K.; Ziemke, J. R.

    2015-12-01

    Both model simulations and GMAO assimilated ozone product derived from OMI/MLS show a high tropospheric ozone column centered over the south Atlantic from the equator to 30S. This ozone maximum extends eastward to South America and the southeast Pacific; it extends southwestward to southern Africa, south Indian Ocean. In this study, we use hindcast simulations from the GMI model of tropospheric and stratospheric chemistry, driven by assimilated MERRA meteorological fields, to investigate the factors controlling the interannual variations (IAV) of this ozone maximum during the last two decades. We also use various GMI tracer diagnostics, including a stratospheric ozone tracer to tag the impact of stratospheric ozone, and a tagged CO tracer to track the emission sources, to ascertain the contribution of difference processes to IAV in ozone at different altitudes, as well as partial columns above different pressure level. Our initial model analysis suggests that the IAV of the stratospheric contribution plays a major role on in the IAV of the upper tropospheric ozone and explains a large portion of variance during its winter season. Over the south Atlantic region, the IAV of surface emissions from both South America and southern Africa also contribute significantly to the IAV of ozone, especially in the middle and lower troposphere

  2. OMI/Aura, SCIAMACHY/Envisat and GOME2/MetopA Sulphur Dioxide Estimate; The Case of Eastern Asia

    NASA Astrophysics Data System (ADS)

    Koukouli, M. E.; Balis, D. S.; Theys, N.; Brenot, H.; van Gent, J.; Hendrick, F.; Wang, T.; Valks, P.; Hedelt, P.; Lichtenberg, G.; Richter, A.; Krotkov, N.; Li, C.; van der A, R.

    2015-06-01

    The EU FP7 Monitoring and Assessment of Regional air quality in China using space Observations, Project Of Long-term sino-european co-Operation, MarcoPolo, project focuses on deriving emission estimates from space, http://www.marcopolo-panda.eu. Long term satellite observations of Sulphur Dioxide, SO2, over the greater China area from the SCIAMACHY/Envisat, GOME2/MetopA and OMI/Aura missions are compared and their relative strong points and limitations are discussed. For each satellite instrument, two different datasets are being analyzed in the same manner. Rigorous spatiotemporal statistical analysis based on novel analysis techniques is performed for each data set in order to reduce noise and biases and enhance pollution signals in satellite datasets. Furthermore, identification of point sources such as power plants, smelters and urban agglomerations, as well as definition of their relative contribution to the regional SO2 levels, form the main findings of this investigation. Trend analyses and their statistical representation help locate regions of interesting SO2 loading in China.

  3. Technique to produce daily estimates of the migrating diurnal tide using TIMED/SABER and EOS Aura/MLS

    NASA Astrophysics Data System (ADS)

    Nguyen, Vu; Palo, S. E.

    2013-12-01

    A technique to explicitly compute the day-to-day variability of the migrating diurnal tide (DW1) between 20 km and 80 km on a global scale is presented and analyzed. Our method employs temperature data from two satellite instruments: the MLS (Microwave Limb Sounder) instrument on the EOS (Earth Observing System) Aura spacecraft and the SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument on the TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) spacecraft. By taking advantage of the four daily solar local time measurements from the two instruments, a least squares fit representing the DW1 is constructed. Consequently, the daily zonal mean, DW1 amplitude and phase are all estimated on a daily basis. Before the implementation of our technique, a comparative analysis between the instrument data sets is conducted. The analysis reveals temperature biases of up to 10 K, which are removed to improve our estimates. To evaluate performance, our method is applied to a model atmosphere constructed from tidal fields obtained from the Global Scale Wave Model (GSWM). Performance results indicate that the DW1 is most effectively extracted from the background atmosphere and other tidal components when each latitude circle is well sampled and the local time sampling is evenly spaced. A comparison of our results to the GSWM and past observations support the conclusion that our method produces daily estimates of the DW1 that can be utilized for scientifically useful investigations of short term tidal variability.

  4. Mark 3 VLBI system: Tropospheric calibration subsystems

    NASA Technical Reports Server (NTRS)

    Resch, G. M.

    1980-01-01

    Tropospheric delay calibrations are implemented in the Mark 3 system with two subsystems. Estimates of the dry component of tropospheric delay are provided by accurate barometric data from a subsystem of surface meteorological sensors (SMS). An estimate of the wet component of tropospheric delay is provided by a water vapor radiometer (WVR). Both subsystems interface directly to the ASCII Transceiver bus of the Mark 3 system and are operated by the control computer. Seven WVR's under construction are designed to operate in proximity to a radio telescope and can be commanded to point along the line-of-sight to a radio source. They should provide a delay estimate that is accurate to the + or - 2 cm level.

  5. Consistent High-Quality Global SO2 and HCHO Datasets from EOS Aura/OMI and Suomi NPP/OMPS

    NASA Astrophysics Data System (ADS)

    Li, C.; Joiner, J.; Krotkov, N. A.; Fioletov, V.; McLinden, C. A.; Zhang, Y.

    2015-12-01

    We report on recent effort and progress at NASA Goddard Space Flight Center in developing consistent SO2 and HCHO retrieval products from Aura/Ozone Monitoring Instrument (OMI) and Suomi National Polar-orbiting Partnership (S-NPP)/Ozone Mapping and Profiler Suite (OMPS) nadir mapper. Given the substantial differences between OMI and OMPS in several key aspects, such as spatial and spectral resolution and signal-to-noise ratio, a major challenge in ensuring data continuity between the two instruments is to properly account for different instrument characteristics as well as instruments' degradation over time. To this end, we have developed an innovative approach based on principal component analysis (PCA) of measured Earthshine radiances. We utilize a PCA technique to extract a series of spectral features (principal components or PCs) explaining the variance of measured reflectance spectra, associated with both physical processes (e.g., ozone absorption, rotational Raman scattering) and measurement details (e.g., wavelength shift). By fitting these PCs along with pre-computed Jacobians for our target species (SO2 or HCHO) to the measured radiance spectra, we can estimate the atmospheric loading of SO2 or HCHO while minimizing the impacts of interfering processes and measurement imperfection on retrievals. Since no explicit instrument-specific radiance data correction scheme is required, the PCA method is easily implemented with both OMI and OMPS and maximizes data continuity. The PCA algorithm currently runs operationally in the production of the new generation NASA standard OMI planetary boundary layer (PBL) SO2 data that have been shown to improve the detection limit of anthropogenic SO2 emission sources by a factor of two, as compared with the previous generation product. In this presentation, we will demonstrate that the PCA algorithm can produce SO2 and HCHO retrievals from OMPS that have comparable data quality with our OMI retrievals. We will also demonstrate

  6. Impact of geoengineered aerosols on the troposphere and stratosphere

    SciTech Connect

    Tilmes, S.; Garcia, Rolando R.; Kinnison, Douglas E.; Gettelman, A.; Rasch, Philip J.

    2009-06-27

    A coupled chemistry climate model, the Whole Atmosphere Community Climate Model was used to perform a transient climate simulation to quantify the impact of geoengineered aerosols on atmospheric processes. In contrast to previous model studies, the impact on stratospheric chemistry, including heterogeneous chemistry in the polar regions, is considered in this simulation. In the geoengineering simulation, a constant stratospheric distribution of volcanic-sized, liquid sulfate aerosols is imposed in the period 2020–2050, corresponding to an injection of 2 Tg S/a. The aerosol cools the troposphere compared to a baseline simulation. Assuming an Intergovernmental Panel on Climate Change A1B emission scenario, global warming is delayed by about 40 years in the troposphere with respect to the baseline scenario. Large local changes of precipitation and temperatures may occur as a result of geoengineering. Comparison with simulations carried out with the Community Atmosphere Model indicates the importance of stratospheric processes for estimating the impact of stratospheric aerosols on the Earth’s climate. Changes in stratospheric dynamics and chemistry, especially faster heterogeneous reactions, reduce the recovery of the ozone layer in middle and high latitudes for the Southern Hemisphere. In the geoengineering case, the recovery of the Antarctic ozone hole is delayed by about 30 years on the basis of this model simulation. For the Northern Hemisphere, a onefold to twofold increase of the chemical ozone depletion occurs owing to a simulated stronger polar vortex and colder temperatures compared to the baseline simulation, in agreement with observational estimates.

  7. Upper tropospheric humidity changes under constant relative humidity

    NASA Astrophysics Data System (ADS)

    Gierens, Klaus; Eleftheratos, Kostas

    2016-03-01

    Theoretical derivations are given on the change of upper tropospheric humidity (UTH) in a warming climate. The considered view is that the atmosphere, which is getting moister with increasing temperatures, will retain a constant relative humidity. In the present study, we show that the upper tropospheric humidity, a weighted mean over a relative humidity profile, will change in spite of constant relative humidity. The simple reason for this is that the weighting function that defines UTH changes in a moister atmosphere. Through analytical calculations using observations and through radiative transfer calculations, we demonstrate that two quantities that define the weighting function of UTH can change: the water vapour scale height and the peak emission altitude. Applying these changes to real profiles of relative humidity shows that absolute UTH changes typically do not exceed 1 %. If larger changes would be observed they would be an indication of climatological changes of relative humidity. As such, an increase in UTH between 1980 and 2009 in the northern midlatitudes, as shown by earlier studies using the High-resolution Infrared Radiation Sounder (HIRS) data, may be an indication of an increase in relative humidity as well.

  8. Characterization of MJO-Related Upper Tropospheric Hydrological Processes using MLS

    NASA Technical Reports Server (NTRS)

    Schwartz, Michael J.; Waliser, Duane E.; Tian, Baijun; Wu, Dong L.; Jiang, Jonathan H.; Read, William G.

    2008-01-01

    This study quantifies Madden-Julian Oscillation (MJO)- related hydrological variability in the upper troposphere/ lower stratosphere (UT/LS) using Aura Microwave Limb Sounder (MLS) cloud ice water content (IWC) and water vapor (H2O). In a composite of six boreal-winter MJO events, the UT/LS IWC anomaly is strongly positively correlated with the convection (TRMM rainfall) anomaly. IWC anomalies range from +/-2 mg/cu m at 215 hPa to +/-0.08 mg/cu m at 100 hPa. The UT/LS H2O anomaly has an eastward-tilting structure similar to the previous-documented temperature structure, but the H2O maximum lags the temperature maximum by about a week. The H2O anomaly is positively correlated with the convection anomaly in the UT (261 hPa) and LS (68 hPa) but negatively correlated with the convection anomaly near the tropopause (100 hPa). This analysis provides a multi-parameter construct useful in validating and improving the parameterization of convection, clouds and cloud microphysics in MJO modeling.

  9. Signature of a tropical Pacific cyclone in the composition of the upper troposphere over Socorro, NM

    NASA Astrophysics Data System (ADS)

    Minschwaner, K.; Manney, G. L.; Petropavlovskikh, I.; Torres, L. A.; Lawrence, Z. D.; Sutherland, B.; Thompson, A. M.; Johnson, B. J.; Butterfield, Z.; Dubey, M. K.; Froidevaux, L.; Lambert, A.; Read, W. G.; Schwartz, M. J.

    2015-11-01

    We present a case study based on balloon-borne ozone measurements during the SouthEast American Consortium for Intensive Ozonesonde Network Study in August-September 2013. Data from Socorro, NM (34°N, 107°W) show a layer of anomalously low ozone in the upper troposphere (UT) during 8-14 August. Back trajectories, UT jet analyses, and data from the Microwave Limb Sounder (MLS) on the Aura satellite indicate that this feature originated from the marine boundary layer in the eastern/central tropical Pacific, where several disturbances and one hurricane (Henriette) formed within an active region of the Intertropical Convergence Zone in early August 2013. The hurricane and nearby convection pumped boundary layer air with low ozone (20-30 ppbv) into the UT. This outflow was advected to North America 3-5 days later by a strong subtropical jet, forming a tongue of low ozone observed in MLS fields and a corresponding layer of low ozone in Socorro vertical profiles.

  10. Interhemispheric differences of fMRI responses to visual stimuli in patients with side-fixed migraine aura.

    PubMed

    Hougaard, Anders; Amin, Faisal Mohammad; Hoffmann, Michael B; Rostrup, Egill; Larsson, Henrik B W; Asghar, Mohammad Sohail; Larsen, Vibeke Andrée; Olesen, Jes; Ashina, Messoud

    2014-06-01

    Migraine sufferers with aura often report photosensitivity and visual discomfort outside of attacks and many consider bright or flickering light an attack-precipitating factor. The nature of this visual hypersensitivity and its relation to the underlying pathophysiology of the migraine aura is unknown. Using fMRI measurements during visual stimulation we examined the visual cortical responsiveness of patients with migraine with aura. We applied a within-patient design by assessing functional interhemispheric differences in patients consistently experiencing visual aura in the same visual hemifield. We recruited 20 patients with frequent side-fixed visual aura attacks (≥90% of auras occurring in the same visual hemifield) and 20 age and sex matched healthy controls and compared the fMRI blood oxygenation level dependent (BOLD) responses to visual stimulation between symptomatic and asymptomatic hemispheres during the interictal phase and between migraine patients and controls. BOLD responses were selectively increased in the symptomatic hemispheres. This was found in the inferior parietal lobule (P = 0.002), the inferior frontal gyrus (P = 0.003), and the superior parietal lobule (P = 0.017). The affected cortical areas comprise a visually driven functional network involved in oculomotor control, guidance of movement, motion perception, visual attention, and visual spatial memory. The patients also had significantly increased response in the same cortical areas when compared to controls (P < 0.05). We discovered a lateralized alteration of a visually driven functional network in patients with side-fixed aura. These findings suggest a hyperexcitability of the visual system in the interictal phase of migraine with visual aura.

  11. Characteristics of atmospheric transport into the Antarctic troposphere

    NASA Astrophysics Data System (ADS)

    Stohl, A.; Sodemann, H.

    2010-01-01

    We have developed a 5.5 year climatology of atmospheric transport into the Antarctic troposphere, which uses the same data set and methods as described in a recent study for the Arctic. This allows direct comparisons of transport properties for the two polar regions. The climatology is based on a simulation with the Lagrangian particle dispersion model FLEXPART, where the model atmosphere was globally filled with particles. Transport characteristics as well as emission sensitivities were derived from 6 hourly particle positions. We found that the probability for near-surface air to originate from the stratosphere on a time scale of 10 days is an order of magnitude higher near the South Pole than near the North Pole, a result of higher topography and descent that partly compensates for the flow of air down the Antarctic Plateau with the katabatic winds. The stratospheric influence is largest in fall, which is opposite to the seasonality in the Arctic. Stratospheric influence is much smaller over the shelf ice regions and in a band around Antarctica. The average time for which air near the surface has been exposed to continuous darkness in July (continuous light in January) is longest over the Ronne Ice Shelf and Ross Ice Shelf at ˜11 days (20 days). We calculated how sensitive Antarctic air masses are to emission input up to 30 days before arriving in Antarctica if removal processes are ignored. The emission sensitivity shows strong meridional gradients and, as a result, is generally low over South America, Africa, and Australia. For a 10 day time scale, the largest emission sensitivities over these continents are 1-2 orders of magnitude smaller than over Eurasia for transport to the Arctic, showing that foreign continents have a much smaller potential to pollute the Antarctic than the Arctic troposphere. Emission sensitivities and derived black carbon (BC) source contributions over South America, Africa, and Australia are substantially (a factor 10 for Africa

  12. Investigations of functional and structural changes in migraine with aura by magnetic resonance imaging.

    PubMed

    Hougaard, Anders

    2015-08-01

    Migraine sufferers with aura often report visual discomfort outside of attacks and many consider bright or flickering light an attack-precipitating factor. The nature of this visual hypersensitivity and its relation to the underlying pathophysiology of the migraine aura is unknown. A useful technology to study these features of migraine with aura (MA) is functional magnetic resonance imaging (fMRI), which has the potential not only to detect, but also to localize hypersensitive cortex. The main objective of this thesis was to investigate the cortical responsivity of patients with MA during visual stimulation using fMRI. To optimize sensitivity, we applied a within-patient design by assessing functional interhemispheric differences in patients consistently experiencing visual aura in the same visual hemifield. To validate our data analysis methods, we initially studied healthy volunteers using single hemifield visual stimulation and compared the "stimulated" hemispheres (i.e. hemispheres contralateral to the visual stimulation) to the "non-stimulated" hemispheres. We then applied this validated method of interhemispheric comparison of fMRI-blood oxygenation level dependent (BOLD) activation to compare left versus right hemisphere responses to symmetric full-field visual stimulation in 54 healthy subjects (study I). This study concluded that, a) the applied visual stimulation is effective in activating large expanses of visual cortex, b) interhemispheric differences in fMRI-BOLD activation can be determined using the proposed method, and c) visual responses to symmetric full-field visual stimulation are asymmetrically distributed between the cerebral hemispheres. We investigated the effects of migraine aura, by including 20 patients with frequent side-fixed visual aura attacks, i.e. ≥= 90% of auras occurring in the same visual hemifield (study II). To circumvent bias relating to differences between right and left hemispheres (e.g. caused by physiological left

  13. Observation capability of Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) from International Space Station

    NASA Astrophysics Data System (ADS)

    Kasai, Yasuko; Tanaka, Takahiro; Dupuy, Eric; Kita, Kazuyuki; Baron, Philippe; Ochiai, Satoshi; Nishibori, Toshiyuki; Kikuchi, Kenichi; Mendrok, Jana; Murtagh, Donal P.; Urban, Joachim; Smiles Mission Team

    A new generation of sub-millimeter-wave receivers employing sensitive SIS (Superconductor-Insulator-Superconductor) detector technology will provide new opportunities for precise pas-sive remote sensing observation of minor constituents in atmosphere. Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) had been launched in September 11, 2009 and installed to the Japanese Experiment Module (JEM) on the International Space Station (ISS). SMILES is a collaboration project of National Institute of Information and Communications Technology (NICT) and Japan Aerospace Exploration Agency (JAXA). Mission objectives of SMILES are: 1. Space demonstration of super-sensitive SIS mixer and 4-K mechanical cooler technology 2. Super-sensitive global observation of atmospheric minor constituents with sub-millimeter-wave limb emission sounder JEM/SMILES will allow to observe the atmospheric species such as O3, H35Cl, H37Cl, ClO, HO2, BrO, HOCl, HOBr, HNO3, CH3CN, Ozone isotope species, H2O, and Ice Cloud with the precisions in a few to several tens percents. The altitude region of observation is from the upper troposphere to the mesopouse. We performed the early comparison/validation of ozone with 4 satellites measurements, AURA/MLS, Odin/SMR, ACE, and Odin/OSIRIS, and ozonesonde. SMILES ozone was in good agreement with these data. For example, difference between SMILES and MLS was less than 2 percent be-tween 20-50km. These results are consistent with the observation capabilities of JEM/SMILES with error analysis. This super technology may allow us to open new issues in atmospheric science.

  14. The impact of lightning on tropospheric ozone chemistry using a new global lightning parametrisation

    NASA Astrophysics Data System (ADS)

    Finney, D. L.; Doherty, R. M.; Wild, O.; Abraham, N. L.

    2016-06-01

    A lightning parametrisation based on upward cloud ice flux is implemented in a chemistry-climate model (CCM) for the first time. The UK Chemistry and Aerosols model is used to study the impact of these lightning nitric oxide (NO) emissions on ozone. Comparisons are then made between the new ice flux parametrisation and the commonly used, cloud-top height parametrisation. The ice flux approach improves the simulation of lightning and the temporal correlations with ozone sonde measurements in the middle and upper troposphere. Peak values of ozone in these regions are attributed to high lightning NO emissions. The ice flux approach reduces the overestimation of tropical lightning apparent in this CCM when using the cloud-top approach. This results in less NO emission in the tropical upper troposphere and more in the extratropics when using the ice flux scheme. In the tropical upper troposphere the reduction in ozone concentration is around 5-10 %. Surprisingly, there is only a small reduction in tropospheric ozone burden when using the ice flux approach. The greatest absolute change in ozone burden is found in the lower stratosphere, suggesting that much of the ozone produced in the upper troposphere is transported to higher altitudes. Major differences in the frequency distribution of flash rates for the two approaches are found. The cloud-top height scheme has lower maximum flash rates and more mid-range flash rates than the ice flux scheme. The initial Ox (odd oxygen species) production associated with the frequency distribution of continental lightning is analysed to show that higher flash rates are less efficient at producing Ox; low flash rates initially produce around 10 times more Ox per flash than high-end flash rates. We find that the newly implemented lightning scheme performs favourably compared to the cloud-top scheme with respect to simulation of lightning and tropospheric ozone. This alternative lightning scheme shows spatial and temporal differences in

  15. Report of the NASA working group on tropospheric program planning

    NASA Technical Reports Server (NTRS)

    Seinfeld, J. H.; Allario, F.; Bandeen, W. R.; Chameides, W. L.; Davis, D. D.; Hinkley, E. D.; Stewart, R. W.

    1981-01-01

    Increased understanding of the chemical phenomena occurring in the troposphere was the research goal. Emphasis was placed on tropospheric impact on environmental quality, including public health, agriculture, climate, and weather.

  16. Ozone density measurements in the troposphere and stratosphere of Natal

    NASA Technical Reports Server (NTRS)

    Kirchhoff, V. W. J. H.; Motta, A. G.

    1983-01-01

    Ozone densitities were measured in the troposphere and stratosphere of Natal using ECC sondes launches on balloons. The data analyzed so far show tropospheric densities and total ozone contents larger than expected.

  17. Tropospheric- Stratospheric Measurement Studies Summary

    NASA Technical Reports Server (NTRS)

    Browen, Stuart W.

    1998-01-01

    The two high altitude aircraft, ER-2 NASA #706 and 709 and the DC-8 NASA #717 are in active use in several programs of upper atmospheric research to study polar ozone changes, stratospheric-tropospheric exchange processes and atmospheric effects of aviation aircraft. The ER-2 has participated in seven major missions which mainly concentrated on vortex dynamics and the large losses of Ozone in the Polar regions (Ozone hole) observed in the spring. One mission verified the complex dynamical chemical and physical processes that occur during sunrise and sunset. Stratospheric Tracers of Atmospheric Transport (STRAT) obtained background measurements using the full ER-2 suite of instruments. Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) in 1997 assisted in understanding the mid-latitude and Arctic Ozone losses during the Northern Summer. The DC-8 with the Meteorological Measurement System (MMS) has participated in the Subsonic Aircraft: Cloud and Contrail Effects Special Study (SUCCESS), in 1996 and the Subsonic assessment Ozone and Nitrogen oxide experiment (SONEX) in 1997 missions. The MMS with its sophisticated software accurately measures ground speed and attitude, in-situ static and dynamic pressure total temperature, which are used to calculate the three dimensional wind fields, static pressure, temperature and turbulence values to meteorological accuracy. The meteorological data is not only of interest for its own sake in atmospheric dynamical processes such as mountain waves and flux measurements; but is also required by other ER-2 experiments that simultaneously measure water vapor, O3, aerosols, NO, HCl, CH4, N2O, ClO, BrO, CO2, NOy, HOx and temperature gradients. MMS products are extensively used to assist in the interpretation of their results in understanding the importance of convective effects relative to in-situ chemical changes, as may be noted by examining the list of references attached. The MMS consists of three subsystems: (a

  18. Maintaining Aura's Orbit Requirements While Performing Orbit Maintenance Maneuvers Containing an Orbit Normal Delta-V Component

    NASA Technical Reports Server (NTRS)

    Johnson, Megan R.; Petersen, Jeremy D.

    2014-01-01

    The Earth Observing System (EOS) Afternoon Constellation consists of five member missions (GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura), each of which maintain a frozen, sun-synchronous orbit with a 16-day repeating ground track that follows the Worldwide Reference System-2 (WRS-2). Under nominal science operations for Aura, the propulsion system is oriented such that the resultant thrust vector is aligned 13.493 degrees away from the velocity vector along the yaw axis. When performing orbit maintenance maneuvers, the spacecraft performs a yaw slew to align the thrust vector in the appropriate direction. A new Drag Make Up (DMU) maneuver operations scheme has been implemented for Aura alleviating the need for the 13.493 degree yaw slew. The focus of this investigation is to assess the impact that no-slew DMU maneuver operations will have on Aura's Mean Local Time (MLT) which drives the required along track separation between Aura and the constellation members, as well as Aura's frozen orbit properties, eccentricity and argument of perigee. Seven maneuver strategies were analyzed to determine the best operational approach. A mirror pole strategy, with maneuvers alternating at the North and South poles, was implemented operationally to minimize impact to the MLT. Additional analysis determined that the mirror pole strategy could be further modified to include frozen orbit maneuvers and thus maintain both MLT and the frozen orbit properties under noslew operations.

  19. Tropospheric Bromine Chemistry: Implications for Present and Pre-industrial Ozone and Mercury

    NASA Technical Reports Server (NTRS)

    Parella, J. P.; Jacob, D. J.; Liang, Q.; Zhang, Y.; Mickley, L. J.; Miller, B.; Evans, M. J.; Yang, X.; Pyle, J. A.; Theys, N.; VanRoozendael, M.

    2012-01-01

    We present a new model for the global tropospheric chemistry of inorganic bromine (Bry) coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM). Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone mixing ratios by <1-8 nmol/mol (6.5% globally), with the largest effects in the northern extratropics in spring. The global mean tropospheric OH concentration decreases by 4 %. Inclusion of bromine chemistry improves the ability of global models (GEOS-Chem and p-TOMCAT) to simulate observed 19th-century ozone and its seasonality. Bromine effects on tropospheric ozone are comparable in the present-day and pre-industrial atmospheres so that estimates of anthropogenic radiative forcing are minimally affected. Br atom concentrations are 40% higher in the pre-industrial atmosphere due to lower ozone, which would decrease by a factor of 2 the atmospheric lifetime of elemental mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  20. Injection of lightning-produced NOx, water vapor, wildfire emissions, and stratospheric air to the UT/LS as observed from DC3 measurements

    NASA Astrophysics Data System (ADS)

    Huntrieser, H.; Lichtenstern, M.; Scheibe, M.; Aufmhoff, H.; Schlager, H.; Pucik, T.; Minikin, A.; Weinzierl, B.; Heimerl, K.; Pollack, I. B.; Peischl, J.; Ryerson, T. B.; Weinheimer, A. J.; Honomichl, S.; Ridley, B. A.; Biggerstaff, M. I.; Betten, D. P.; Hair, J. W.; Butler, C. F.; Schwartz, M. J.; Barth, M. C.

    2016-06-01

    During the Deep Convective Clouds and Chemistry (DC3) experiment in summer 2012, airborne measurements were performed in the anvil inflow/outflow of thunderstorms over the Central U.S. by three research aircraft. A general overview of Deutsches Zentrum für Luft- und Raumfahrt (DLR)-Falcon in situ measurements (CO, O3, SO2, CH4, NO, NOx, and black carbon) is presented. In addition, a joint flight on 29 May 2012 in a convective line of isolated supercell storms over Oklahoma is described based on Falcon, National Science Foundation/National Center for Atmospheric Research Gulfstream-V (NSF/NCAR-GV), and NASA-DC8 trace species in situ and lidar measurements. During DC3 some of the largest and most destructive wildfires in New Mexico and Colorado state's history were burning, which strongly influenced air quality in the DC3 thunderstorm inflow and outflow region. Lofted biomass burning (BB) plumes were frequently observed in the mid- and upper troposphere (UT) in the vicinity of deep convection. The impact of lightning-produced NOx (LNOx) and BB emissions was analyzed on the basis of mean vertical profiles and tracer-tracer correlations (CO-NOx and O3-NO). On a regular basis DC3 thunderstorms penetrated the tropopause and injected large amounts of LNOx into the lower stratosphere (LS). Inside convection, low O3 air (~80 nmol mol-1) from the lower troposphere was rapidly transported to the UT/LS region. Simultaneously, O3-rich stratospheric air masses (~100-200 nmol mol-1) were present around and below the thunderstorm outflow and enhanced UT-O3 mixing ratios significantly. A 10 year global climatology of H2O data from the Aura Microwave Limb Sounder confirmed that the Central U.S. is a preferred region for convective injection into the LS.

  1. Tropospheric O3 over Indonesia during biomass burning events measured with GOME (Global Ozone Monitoring Experiment) and compared with backtrajectory calculation

    NASA Astrophysics Data System (ADS)

    Ladstaetter-Weissenmayer, A.; Meyer-Arnek, J.; Burrows, J. P.

    During the dry season, biomass burning is an important source of ozone precursors for the tropical troposphere, and ozone formation can occur in biomass burning plumes originating in Indonesia and northern Australia. Satellite based GOME (Global Ozone Measuring experiment) data are used to characterize the amount of tropospheric ozone production over this region during the El Niño event in September 1997 compared to a so called "normal" year 1998. Large scale biomass burning occurred over Kalimantan in 1997 caused by the absence of the northern monsoon rains, leading to significant increases in tropospheric ozone. Tropospheric ozone was determined from GOME data using the Tropospheric Excess Method (TEM). Backtrajectory calculations show that Indonesia is influenced every summer by the emissions of trace gases from biomass buring over northern Australia. But in 1997 over Indonesia an increasing of tropospheric ozone amounts can be observed caused by the fires over Indonesia itself as well as by northern Australia. The analysis of the measurements of BIBLE-A (Biomass Burning and Lightning Experiment) and using ATSR (Along the Track Scanning Radiometer) data show differences in the view to the intensity of fire counts and therefore in the amount of the emission of precursors of tropospheric ozone comparing September 1997 to September 1998.

  2. Validation of Aura OMI by Aircraft and Ground-Based Measurements

    NASA Astrophysics Data System (ADS)

    McPeters, R. D.; Petropavlovskikh, I.; Kroon, M.

    2006-12-01

    Both aircraft-based and ground-based measurements have been used to validate ozone measurements by the OMI instrument on Aura. Three Aura Validation Experiment (AVE) flights have been conducted, in November 2004 and June 2005 with the NASA WB57, and in January/February 2005 with the NASA DC-8. On these flights, validation of OMI was primarily done using data from the CAFS (CCD Actinic Flux Spectroradiometer) instrument, which is used to measure total column ozone above the aircraft. These measurements are used to differentiate changes in stratospheric ozone from changes in total column ozone. Also, changes in ozone over high clouds measured by OMI were checked in a flight over tropical storm Arlene on a flight on June 11th. Ground-based measurements were made during the SAUNA campaign in Sodankyla, Finland, in March and April 2006. Both total column ozone and the ozone vertical distribution were validated.

  3. A comparison study between model-predicted and OMI-retrieved tropospheric NO 2 columns over the Korean peninsula

    NASA Astrophysics Data System (ADS)

    Han, K. M.; Lee, C. K.; Lee, J.; Kim, J.; Song, C. H.

    2011-06-01

    In this study, Community Multi-scale Air Quality (CMAQ) model simulations, using the INTEX-B (Intercontinental Chemical Transport Experiment-Phase B) emission inventory for North Korea and China, CAPSS (Clean Air Policy Support System) emission inventory for South Korea, and REAS (Regional Emission Inventory in Asia) emission inventory for Japan, were carried out over four seasonal episodes from 2006, with a fine grid resolution of 30 km × 30 km, in order to evaluate the accuracy of the NO x emissions over the Korean peninsula. The tropospheric NO 2 columns from the CMAQ model simulations were then compared with those retrieved from a satellite sensor, Ozone Monitoring Instrument (OMI), over the Korean peninsula as well as briefly over East Asia. The results showed that the CMAQ modeling, using the NO x emissions from the CAPSS inventory over South Korea, produced tropospheric NO 2 columns that were over-predicted by factors between 1.38 and 1.87 compared to the OMI-retrieved tropospheric NO 2 columns. This appears to be in line with the findings from a previous study, i.e. when the ACE-ASIA emission inventory was used for the episodes from 2001 to 2003, the CMAQ modeling tended to produce NO 2 columns that were ˜1.46 times larger than the GOME-derived NO 2 columns over South Korea. On the other hand, over North Korea, the NO x emissions of the INTEX-B emission inventory appear to be overestimated by factors between 1.55 and 7.46 (3.18 over the four seasonal episodes), based on the comparison study between the CMAQ-simulated and OMI-retrieved tropospheric NO 2 columns. This may be caused by the large uncertainty in the NO x emission fluxes from North Korea due to insufficient information on the economic activity and energy consumption related to the political instability in North Korea.

  4. Global tropospheric distribution and calibration scale of HCFC-22

    SciTech Connect

    Montzka, S.A.; Myers, R.C.; Butler, J.H.; Elkins, J.W. ); Cummings, S.O.

    1993-02-01

    Measurements of atmospheric chlorodifluoromethane (HCFC-22), based upon a new calibration scale developed in this laboratory, suggest a global tropospheric mean that is [approx]28% lower than determined previously from surface-based measurements. A global mean of 101.8 ([+-]1.2, 1 s.d.) ppt and interhemispheric difference of 13 ([+-]1) ppt were determined for HCFC-22 in 1992 from air collected in flasks from seven remote sites located between 82[degree]N and 90[degree]S. These results are consistent with mixing ratios predicted from recent emission estimates and a lifetime for HCFC-22 of 13.6 (+1.9,-1.5) yr. Based upon the analysis of flasks and archived air samples from mid-1987 through 1992, a mean growth rate for HCFC-22 of 7.3 ([+-]0.3)% yr[sup [minus]1] was estimated for this period. 26 refs., 3 figs.

  5. Trends of Rural Tropospheric Ozone at the Northwest of the Iberian Peninsula

    PubMed Central

    Saavedra, S.; Rodríguez, A.; Souto, J. A.; Casares, J. J.; Bermúdez, J. L.; Soto, B.

    2012-01-01

    Tropospheric ozone levels around urban and suburban areas at Europe and North America had increased during 80's–90's, until the application of NOx reduction strategies. However, as it was expected, this ozone depletion was not proportional to the emissions reduction. On the other hand, rural ozone levels show different trends, with peaks reduction and average increments; this different evolution could be explained by either emission changes or climate variability in a region. In this work, trends of tropospheric ozone episodes at rural sites in the northwest of the Iberian Peninsula were analyzed and compared to others observed in different regions of the Atlantic European coast. Special interest was focused on the air quality sites characterization, in order to guarantee their rural character in terms of air quality. Both episodic local meteorological and air quality measurements along five years were considered, in order to study possible meteorological influences in ozone levels, different to other European Atlantic regions. PMID:22649298

  6. [Asomatognosia as a manifestation of migraine with aura. case report and review].

    PubMed

    Scribano Parada, María de la Paz; Buonanotte, Carlos Federico

    2015-01-01

    Introducción: Durante años el estudio de la migraña con aura ha sorprendido por la versatilidad de su forma de presentación. Las auras se manifiestan con el desarrollo gradual de síntomas neurológicos que van desde alteraciones visuales hasta trastornos de la percepción. Estos últimos son formas de presentación poco frecuentes siendo el motivo de este artículo. Caso Clínico: Se presenta el caso de una paciente de sexo femenino de 53 años con diagnóstico de migraña con aura la cual hace un relato autobiográfico de sus crisis, con especial énfasis en una variante de asomatognosia como forma de presentación. A continuación se discute sobre la asomatognosia como un fenómeno perteneciente a las alteraciones del esquema corporal y los diferentes conceptos y formas clínicas relacionados con estas y se hacer un breve repaso sobre las posibles localizaciones anatómicas de estas afecciones. Conclusión: La migraña con aura puede manifestarse con una variada sintomatología previa al dolor. La asomatognosia es una forma infrecuente de presentación. Un campo de interés en la investigación de esta área incluyen un esfuerzo por definir la especificidad y localización de la lesión como un método para la mejor comprensión de cómo las lesiones a áreas muy específicas del cerebro afectan la percepción y la memoria.

  7. Migraine with aura and risk of silent brain infarcts and white matter hyperintensities: an MRI study.

    PubMed

    Gaist, David; Garde, Ellen; Blaabjerg, Morten; Nielsen, Helle H; Krøigård, Thomas; Østergaard, Kamilla; Møller, Harald S; Hjelmborg, Jacob; Madsen, Camilla G; Iversen, Pernille; Kyvik, Kirsten O; Siebner, Hartwig R; Ashina, Messoud

    2016-07-01

    A small number of population-based studies reported an association between migraine with aura and risk of silent brain infarcts and white matter hyperintensities in females. We investigated these relations in a population-based sample of female twins. We contacted female twins ages 30-60 years identified through the population-based Danish Twin Registry. Based on questionnaire responses, twins were invited to participate in a telephone-based interview conducted by physicians. Headache diagnoses were established according to the International Headache Society criteria. Cases with migraine with aura, their co-twins, and unrelated migraine-free twins (controls) were invited to a brain magnetic resonance imaging scan performed at a single centre. Brain scans were assessed for the presence of infarcts, and white matter hyperintensities (visual rating scales and volumetric analyses) blinded to headache diagnoses. Comparisons were based on 172 cases, 34 co-twins, and 139 control subjects. Compared with control subjects, cases did not differ with regard to frequency of silent brain infarcts (four cases versus one control), periventricular white matter hyperintensity scores [adjusted mean difference (95% confidence interval): -0.1 (-0.5 to 0.2)] or deep white matter hyperintensity scores [adjusted mean difference (95% confidence interval): 0.1 (-0.8 to 1.1)] assessed by Scheltens' scale. Cases had a slightly higher total white matter hyperintensity volume compared with controls [adjusted mean difference (95% confidence interval): 0.17 (-0.08 to 0.41) cm(3)] and a similar difference was present in analyses restricted to twin pairs discordant for migraine with aura [adjusted mean difference 0.21 (-0.20 to 0.63)], but these differences did not reach statistical significance. We found no evidence of an association between silent brain infarcts, white matter hyperintensities, and migraine with aura. PMID:27190013

  8. Evaluation of water vapour assimilation in the tropical upper troposphere and lower stratosphere by a chemical transport model

    NASA Astrophysics Data System (ADS)

    Payra, Swagata; Ricaud, Philippe; Abida, Rachid; El Amraoui, Laaziz; Attié, Jean-Luc; Rivière, Emmanuel; Carminati, Fabien; von Clarmann, Thomas

    2016-09-01

    The present analysis deals with one of the most debated aspects of the studies on the upper troposphere/lower stratosphere (UTLS), namely the budget of water vapour (H2O) at the tropical tropopause. Within the French project "Multiscale water budget in the upper troposphere and lower stratosphere in the TROpics" (TRO-pico), a global-scale analysis has been set up based on space-borne observations, models and assimilation techniques. The MOCAGE-VALENTINA assimilation tool has been used to assimilate the Aura Microwave Limb Sounder (MLS) version 3.3 H2O measurements within the 316-5 hPa range from August 2011 to March 2013 with an assimilation window of 1 h. Diagnostics based on observations minus analysis and forecast are developed to assess the quality of the assimilated H2O fields. Comparison with an independent source of H2O measurements in the UTLS based on the space-borne Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) observations and with meteorological ARPEGE analyses is also shown. Sensitivity studies of the analysed fields have been performed by (1) considering periods when no MLS measurements are available and (2) using H2O data from another MLS version (4.2). The studies have been performed within three different spaces in time and space coincidences with MLS (hereafter referred to as MLS space) and MIPAS (MIPAS space) observations and with the model (model space) outputs and at three different levels: 121 hPa (upper troposphere), 100 hPa (tropopause) and 68 hPa (lower stratosphere) in January and February 2012. In the MLS space, the analyses behave consistently with the MLS observations from the upper troposphere to the lower stratosphere. In the model space, the analyses are wetter than the reference atmosphere as represented by ARPEGE and MLS in the upper troposphere (121 hPa) and around the tropopause (100 hPa), but are consistent with MLS and MIPAS in the lower stratosphere (68 hPa). In the MIPAS space, the sensitivity and the

  9. HALOE Algorithm Improvements for Upper Tropospheric Sounding

    NASA Technical Reports Server (NTRS)

    Thompson, Robert E.

    2001-01-01

    This report details the ongoing efforts by GATS, Inc., in conjunction with Hampton University and University of Wyoming, in NASA's Mission to Planet Earth UARS Science Investigator Program entitled "HALOE Algorithm Improvements for Upper Tropospheric Sounding." The goal of this effort is to develop and implement major inversion and processing improvements that will extend HALOE measurements further into the troposphere. In particular, O3, H2O, and CH4 retrievals may be extended into the middle troposphere, and NO, HCl and possibly HF into the upper troposphere. Key areas of research being carried out to accomplish this include: pointing/tracking analysis; cloud identification and modeling; simultaneous multichannel retrieval capability; forward model improvements; high vertical-resolution gas filter channel retrievals; a refined temperature retrieval; robust error analyses; long-term trend reliability studies; and data validation. The current (first year) effort concentrates on the pointer/tracker correction algorithms, cloud filtering and validation, and multichannel retrieval development. However, these areas are all highly coupled, so progress in one area benefits from and sometimes depends on work in others.

  10. TROPOSPHERIC AEROSOL PROGRAM, PROGRAM PLAN, MARCH 2001

    SciTech Connect

    SCHWARTZ,S.E.; LUNN,P.

    2001-03-01

    The goal of Tropospheric Aerosol Program (TAP) will be to develop the fundamental scientific understanding required to construct tools for simulating the life cycle of tropospheric aerosols--the processes controlling their mass loading, composition, and microphysical properties, all as a function of time, location, and altitude. The TAP approach to achieving this goal will be by conducting closely linked field, modeling, laboratory, and theoretical studies focused on the processes controlling formation, growth, transport, and deposition of tropospheric aerosols. This understanding will be represented in models suitable for describing these processes on a variety of geographical scales; evaluation of these models will be a key component of TAP field activities. In carrying out these tasks TAP will work closely with other programs in DOE and in other Federal and state agencies, and with the private sector. A forum to directly work with our counterparts in industry to ensure that the results of this research are translated into products that are useful to that community will be provided by NARSTO (formerly the North American Research Strategy on Tropospheric Ozone), a public/private partnership, whose membership spans government, the utilities, industry, and university researchers in Mexico, the US, and Canada.

  11. HALOE Algorithm Improvements for Upper Tropospheric Sounding

    NASA Technical Reports Server (NTRS)

    Thompson, Robert Earl; McHugh, Martin J.; Gordley, Larry L.; Hervig, Mark E.; Russell, James M., III; Douglass, Anne (Technical Monitor)

    2001-01-01

    This report details the ongoing efforts by GATS, Inc., in conjunction with Hampton University and University of Wyoming, in NASA's Mission to Planet Earth Upper Atmospheric Research Satellite (UARS) Science Investigator Program entitled 'HALOE Algorithm Improvements for Upper Tropospheric Sounding.' The goal of this effort is to develop and implement major inversion and processing improvements that will extend Halogen Occultation Experiment (HALOE) measurements further into the troposphere. In particular, O3, H2O, and CH4 retrievals may be extended into the middle troposphere, and NO, HCl and possibly HF into the upper troposphere. Key areas of research being carried out to accomplish this include: pointing/tracking analysis; cloud identification and modeling; simultaneous multichannel retrieval capability; forward model improvements; high vertical-resolution gas filter channel retrievals; a refined temperature retrieval; robust error analyses; long-term trend reliability studies; and data validation. The current (first year) effort concentrates on the pointer/tracker correction algorithms, cloud filtering and validation, and multichannel retrieval development. However, these areas are all highly coupled, so progress in one area benefits from and sometimes depends on work in others.

  12. HALOE Algorithm Improvements for Upper Tropospheric Sounding

    NASA Technical Reports Server (NTRS)

    McHugh, Martin J.; Gordley, Larry L.; Russell, James M., III; Hervig, Mark E.

    1999-01-01

    This report details the ongoing efforts by GATS, Inc., in conjunction with Hampton University and University of Wyoming, in NASA's Mission to Planet Earth UARS Science Investigator Program entitled "HALOE Algorithm Improvements for Upper Tropospheric Soundings." The goal of this effort is to develop and implement major inversion and processing improvements that will extend HALOE measurements further into the troposphere. In particular, O3, H2O, and CH4 retrievals may be extended into the middle troposphere, and NO, HCl and possibly HF into the upper troposphere. Key areas of research being carried out to accomplish this include: pointing/tracking analysis; cloud identification and modeling; simultaneous multichannel retrieval capability; forward model improvements; high vertical-resolution gas filter channel retrievals; a refined temperature retrieval; robust error analyses; long-term trend reliability studies; and data validation. The current (first-year) effort concentrates on the pointer/tracker correction algorithms, cloud filtering and validation, and multi-channel retrieval development. However, these areas are all highly coupled, so progress in one area benefits from and sometimes depends on work in others.

  13. The High Resolution Tropospheric Ozone Residual

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2006-01-01

    The co-flight of the MLS stratospheric limb sounder and the Ozone Monitoring Instrument (OMI) provides the capability of computing the Tropospheric Ozone Residual (TOR) in much greater detail [Ziemke et al., 2006]. Using forward trajectory calculations of MLS ozone measurements combined with OMI column ozone we have developed a high horizontal resolution tropospheric ozone residual (HTOR) which can provide even more detail than the standard TOR product. HTOR is especially useful for extra-tropical studies of tropospheric ozone transport. We find that both the Pacific pollution corridor (East Asia to Alaska) and the Atlantic pollution corridor (North America east coast to Europe) are also preferred locations for strat-trop folds leading to systematic overestimates of pollution amounts. In fact, fold events appear to dominate extra-tropical Northern Hemisphere day-to-day maps of HTOR. Model estimates of the tropospheric column are in reasonable agreement with the HTOR amounts when offsets due to different tropopause height calculations are taken into consideration.

  14. HALOE Algorithm Improvements for Upper Tropospheric Soundings

    NASA Technical Reports Server (NTRS)

    Thompson, Robert E.; Douglass, Anne (Technical Monitor)

    2000-01-01

    This report details the ongoing efforts by GATS, Inc., in conjunction with Hampton University and University of Wyoming, in NASA's Mission to Planet Earth UARS Science Investigator Program entitled "HALOE Algorithm Improvements for Upper Tropospheric Sounding." The goal of this effort is to develop and implement major inversion and processing improvements that will extend HALOE measurements further into the troposphere. In particular, O3, H2O, and CH4 retrievals may be extended into the middle troposphere, and NO, HCl and possibly HF into the upper troposphere. Key areas of research being carried out to accomplish this include: pointing/tracking analysis; cloud identification and modeling; simultaneous multichannel retrieval capability; forward model improvements; high vertical-resolution gas filter channel retrievals; a refined temperature retrieval; robust error analyses; long-term trend reliability studies; and data validation. The current (first year) effort concentrates on the pointer/tracker correction algorithms, cloud filtering and validation, and multichannel retrieval development. However, these areas are all highly coupled, so progress in one area benefits from and sometimes depends on work in others.

  15. The AURA Observatory in Chile - part of the IAU/UNESCO Extended Case Study.

    NASA Astrophysics Data System (ADS)

    Smith, Malcolm G.; Smith, R. Chris; Sanhueza, Pedro

    2015-08-01

    This talk discusses the Extended Case Study for AURA-O as a “Window to the Universe”http://www2.astronomicalheritage.net/index.php/show-entity=59&idsubentity=5That study was prepared in the context of supporting the desire to preserve humanity’s scientific/cultural heritage of outstanding, high-mountain, ground-based, observatory sites developed over the period 1870-2000. AURA-O includes the Cerro Tololo InterAmerican Observatory (CTIO), established in 1962 as the first of the major international observatories to be installed in Chile. The future of AURA-O now includes the Large Synoptic Survey Telescope (LSST).This Extended Case Study has provided the context for the development of possible initiatives to protect a variety of sites in Chile for their historical and scientific value to humanity. The dark skies and ideal weather patterns of northern Chile, along with its location in the southern hemisphere, have made this area of the world a major centre for astronomical facilities.While this talk will touch on the importance of dark skies as part of the Windows to the Universe concept, it is anticipated that others will be discussing (in FM2 and/or FM21) the current status and future plans (of the Chilean Government and the observatories) for protecting the dark skies of northern Chile.

  16. Laser hazard analysis for airborne AURA (Big Sky variant) Proteus platform.

    SciTech Connect

    Augustoni, Arnold L.

    2004-02-01

    A laser safety and hazard analysis was performed for the airborne AURA (Big Sky Laser Technology) lidar system based on the 2000 version of the American National Standard Institute's (ANSI) Standard Z136.1, for the Safe Use of Lasers and the 2000 version of the ANSI Standard Z136.6, for the Safe Use of Lasers Outdoors. The AURA lidar system is installed in the instrument pod of a Proteus airframe and is used to perform laser interaction experiments and tests at various national test sites. The targets are located at various distances or ranges from the airborne platform. In order to protect personnel, who may be in the target area and may be subjected to exposures, it was necessary to determine the Maximum Permissible Exposure (MPE) for each laser wavelength, calculate the Nominal Ocular Hazard Distance (NOHD), and determine the maximum 'eye-safe' dwell times for various operational altitudes and conditions. It was also necessary to calculate the appropriate minimum Optical Density (ODmin) of the laser safety eyewear used by authorized personnel who may receive hazardous exposures during ground base operations of the airborne AURA laser system (system alignment and calibration).

  17. Drivers of changes in stratospheric and tropospheric ozone between year 2000 and 2100

    NASA Astrophysics Data System (ADS)

    Banerjee, Antara; Maycock, Amanda C.; Archibald, Alexander T.; Abraham, N. Luke; Telford, Paul; Braesicke, Peter; Pyle, John A.

    2016-03-01

    A stratosphere-resolving configuration of the Met Office's Unified Model (UM) with the United Kingdom Chemistry and Aerosols (UKCA) scheme is used to investigate the atmospheric response to changes in (a) greenhouse gases and climate, (b) ozone-depleting substances (ODSs) and (c) non-methane ozone precursor emissions. A suite of time-slice experiments show the separate, as well as pairwise, impacts of these perturbations between the years 2000 and 2100. Sensitivity to uncertainties in future greenhouse gases and aerosols is explored through the use of the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. The results highlight an important role for the stratosphere in determining the annual mean tropospheric ozone response, primarily through stratosphere-troposphere exchange (STE) of ozone. Under both climate change and reductions in ODSs, increases in STE offset decreases in net chemical production and act to increase the tropospheric ozone burden. This opposes the effects of projected decreases in ozone precursors through measures to improve air quality, which act to reduce the ozone burden. The global tropospheric lifetime of ozone (τO3) does not change significantly under climate change at RCP4.5, but it decreases at RCP8.5. This opposes the increases in τO3 simulated under reductions in ODSs and ozone precursor emissions. The additivity of the changes in ozone is examined by comparing the sum of the responses in the single-forcing experiments to those from equivalent combined-forcing experiments. Whilst the ozone responses to most forcing combinations are found to be approximately additive, non-additive changes are found in both the stratosphere and troposphere when a large climate forcing (RCP8.5) is combined with the effects of ODSs.

  18. Midlatitude stratosphere - troposphere exchange as diagnosed by MLS O3 and MOPITT CO assimilated fields

    NASA Astrophysics Data System (ADS)

    El Amraoui, L.; Attié, J.-L.; Semane, N.; Claeyman, M.; Peuch, V.-H.; Warner, J.; Ricaud, P.; Cammas, J.-P.; Piacentini, A.; Cariolle, D.; Massart, S.; Bencherif, H.

    2009-10-01

    This paper presents a complete characterization of a very deep stratospheric intrusion which occurred over the British Isles on 15 August 2007. The signature of this event is diagnosed using ozonesonde measurements over Lerwick, UK (60.14° N, 1.19° W) and is also well characterized using meteorological analyses from the global operational weather prediction model of Météo-France, ARPEGE. Modelled as well as assimilated fields of both ozone (O3) and carbon monoxide (CO) have been used in order to better document this event. The paper also presents a demonstration of the capability of O3 and CO assimilated fields to better describe a stratosphere-troposphere exchange (STE) event in comparison with the free run modelled O3 and CO fields. O3 and CO from Aura/MLS and Terra/MOPITT instruments, respectively, are assimilated into the three-dimensional chemical transport model MOCAGE of Météo-France using a variational 3-D-FGAT (First Guess at Appropriate Time) method within the MOCAGE-PALM assimilation system. The usefulness of assimilated MOPITT CO data in a STE study is demonstrated in this novel result. The study shows that the use of the model MOCAGE gives consistent 3-D fields capable of describing the synoptic evolution of the event. However, modelled O3 and CO vertical distributions do not provide a quantitative evaluation of the intrusion. Although the assimilation of MLS data improves the distribution of O3 above the tropopause compared to the free model run, it is not sufficient to reproduce the stratospheric intrusion event well. Conversely, assimilated MOPITT CO allows a better description of the stratospheric intrusion event. Indeed, the horizontal distribution of the CO assimilated field is consistent with meteorological analyses. Moreover, the vertical distribution of the CO assimilated field is in accordance with the potential vorticity distribution and reveals a deeper intrusion from the lower stratosphere downward to the mid-troposphere compared to

  19. A reference GNSS tropospheric dataset over Europe.

    NASA Astrophysics Data System (ADS)

    Pacione, Rosa; Di Tomaso, Simona

    2016-04-01

    The present availability of 18 years of GNSS data belonging to the European Permanent Network (EPN, http://www.epncb.oma.be/) is a valuable database for the development of a climate data record of GNSS tropospheric products over Europe. This dataset has high potential for monitoring trend and variability in atmospheric water vapour, improving the knowledge of climatic trends of atmospheric water vapour and being useful for global and regional NWP reanalyses as well as climate model simulations. In the framework of the EPN-Repro2, a second reprocessing campaign of the EPN, five Analysis Centres have homogenously reprocessed the EPN network for the 1996-2013. Three Analysis Centres are providing homogenously reprocessed solutions for the entire network, which are analyzed by the three different software packages: Bernese, GAMIT and GIPSY-OASIS. Smaller subnetworks based on Bernese 5.2 are also provided. A huge effort is made for providing solutions that are the basis for deriving new coordinates, velocities and troposphere parameters, Zenith Tropospheric Delays and Horizontal Gradients, for the entire EPN. These individual contributions are combined in order to provide the official EPN reprocessed products. A preliminary tropospheric combined solution for the period 1996-2013 has been carried out. It is based on all the available homogenously reprocessed solutions and it offers the possibility to assess each of them prior to the ongoing final combination. We will present the results of the EPN Repro2 tropospheric combined products and how the climate community will benefit from them. Aknowledgment.The EPN Repro2 working group is acknowledged for providing the EPN solutions used in this work. E-GEOS activity is carried out in the framework of ASI contract 2015-050-R.0.

  20. Evaluation of the new UKCA climate-composition model - Part 2: The Troposphere

    NASA Astrophysics Data System (ADS)

    O'Connor, F. M.; Johnson, C. E.; Morgenstern, O.; Abraham, N. L.; Braesicke, P.; Dalvi, M.; Folberth, G. A.; Sanderson, M. G.; Telford, P. J.; Voulgarakis, A.; Young, P. J.; Zeng, G.; Collins, W. J.; Pyle, J. A.

    2014-01-01

    In this paper, we present a description of the tropospheric chemistry component of the UK Chemistry and Aerosols (UKCA) model which has been coupled to the Met Office Hadley Centre's HadGEM family of climate models. We assess the model's transport and scavenging processes, in particular focussing on convective transport, boundary layer mixing, wet scavenging and inter-hemispheric exchange. Simulations with UKCA of the short-lived radon tracer suggest that modelled distributions are comparable to those of other models and the comparison with observations indicate that apart from a few locations, boundary layer mixing and convective transport are effective in the model as a means of vertically redistributing surface emissions of radon. Comparisons of modelled lead tracer concentrations with observations suggest that UKCA captures surface concentrations in both hemispheres very well, although there is a tendency to underestimate the observed geographical and interannual variability in the Northern Hemisphere. In particular, UKCA replicates the shape and absolute concentrations of observed lead profiles, a key test in the evaluation of a model's wet scavenging scheme. The timescale for inter-hemispheric transport, calculated in the model using a simple krypton tracer experiment, does appear to be long relative to other models and could indicate deficiencies in tropical deep convection and/or insufficient boundary layer mixing. We also describe the main components of the tropospheric chemistry and evaluate it against observations and other tropospheric chemistry models. In particular, from a climate forcing perspective, present-day observed surface methane concentrations and tropospheric ozone concentrations are reproduced very well by the model, thereby making it suitable for long centennial integrations as well as studies of biogeochemical feedbacks. Results from both historical and future simulations with UKCA tropospheric chemistry are presented. Future projections

  1. Evaluation of the new UKCA climate-composition model - Part 2: The Troposphere

    NASA Astrophysics Data System (ADS)

    O'Connor, F. M.; Johnson, C. E.; Morgenstern, O.; Abraham, N. L.; Braesicke, P.; Dalvi, M.; Folberth, G. A.; Sanderson, M. G.; Telford, P. J.; Young, P. J.; Zeng, G.; Collins, W. J.; Pyle, J. A.

    2013-03-01

    In this paper, we present a description of the tropospheric chemistry component of the UK Chemistry and Aerosols (UKCA) model which has been coupled to the Met Office Hadley Centre's HadGEM family of climate models. We assess the model's transport and scavenging processes, in particular focussing on convective transport, boundary layer mixing, wet scavenging and inter-hemispheric exchange. Simulations with UKCA of the short-lived radon tracer suggest that modelled distributions are comparable to those of other models and the comparison with observations indicate that apart from a few locations, boundary layer mixing and convective transport are effective in the model as a means of vertically re-distributing surface emissions of radon. Comparisons of modelled lead tracer concentrations with observations suggest that UKCA captures surface concentrations in both hemispheres very well although there is a tendency to underestimate the observed geographical and interannual variability in the Northern Hemisphere. In particular, UKCA replicates the shape and absolute concentrations of observed lead profiles, a key test in the evaluation of a model's wet scavenging scheme. The timescale for inter-hemispheric transport, calculated in the model using a simple krypton tracer experiment, does appear to be long relative to other models and could indicate deficiencies in tropical deep convection and/or insufficient boundary layer mixing. We also describe the main components of the tropospheric chemistry and evaluate it against observations and other tropospheric chemistry models. In particular, from a climate forcing perspective, present-day observed surface methane concentrations and tropospheric ozone concentrations are reproduced very well by the model, thereby making it suitable for long centennial integrations as well as studies of biogeochemical feedbacks. Results from both historical and future simulations with UKCA tropospheric chemistry are presented. Future projections

  2. Methane Sensitivity to Perturbations in Tropospheric Oxidizing Capacity

    NASA Technical Reports Server (NTRS)

    Yegorova, Elena; Duncan, Bryan

    2011-01-01

    Methane is an important greenhouse gas and has a 25 times greater global warming potential than CO2 on a century timescale. Yet there are considerable uncertainties in the magnitude and variability of its sources and sinks. The response of the coupled non-linear methane-carbon monoxide-hydroxyl radical (OH) system is important in determining the tropospheric oxidizing capacity. Using the NASA Goddard Earth Observing System, Version 5 (GEOS-5) chemistry climate model, we study the response of methane to perturbations of OH and wetland emissions. We use a computationally-efficient option of the GEOS-5 CCM that includes an OH parameterization that accurately represents OH predicted by a full chemical mechanism. The OH parameterization allows for studying non-linear CH4-CO-OH feedbacks in computationally fast sensitivity experiments. We compare our results with surface observations (GMD) and discuss the range of uncertainty in OH and wetland emissions required to bring modeling results in better agreement with surface observations. Our results can be used to improve projections of methane emissions and methane growth.

  3. NO(x) Concentrations in the Upper Troposphere as a Result of Lightning

    NASA Technical Reports Server (NTRS)

    Penner, Joyce E.

    1998-01-01

    Upper tropospheric NO(x) controls, in part, the distribution of ozone in this greenhouse-sensitive region of the atmosphere. Many factors control NO(x) in this region. As a result it is difficult to assess uncertainties in anthropogenic perturbations to NO from aircraft, for example, without understanding the role of the other major NO(x) sources in the upper troposphere. These include in situ sources (lightning, aircraft), convection from the surface (biomass burning, fossil fuels, soils), stratospheric intrusions, and photochemical recycling from HNO3. This work examines the separate contribution to upper tropospheric "primary" NO(x) from each source category and uses two different chemical transport models (CTMS) to represent a range of possible atmospheric transport. Because aircraft emissions are tied to particular pressure altitudes, it is important to understand whether those emissions are placed in the model stratosphere or troposphere and to assess whether the models can adequately differentiate stratospheric air from tropospheric air. We examine these issues by defining a point-by-point "tracer tropopause" in order to differentiate stratosphere from troposphere in terms of NO(x) perturbations. Both models predict similar zonal average peak enhancements of primary NO(x) due to aircraft (approx. = 10-20 parts per trillion by volume (pptv) in both January and July); however, the placement of this peak is primarily in a region of large stratospheric influence in one model and centered near the level evaluated as the tracer tropopause in the second. Below the tracer tropopause, both models show negligible NO(x) derived directly from the stratospheric source. Also, they predict a typically low background of 1 - 20 pptv NO(x) when tropospheric HNO3 is constrained to be 100 pptv of HNO3. The two models calculate large differences in the total background NO(x) (defined as the source of NO(x) from lightning + stratosphere + surface + HNO3) when using identical loss

  4. Twenty years of balloon-borne tropospheric aerosol measurements at Laramie, Wyoming

    NASA Technical Reports Server (NTRS)

    Hofmann, David J.

    1993-01-01

    The paper examines the tropospheric aerosol record obtained over the period 1971 to 1990, during which high-altitude balloons with optical particle counters were launched at Laramie, Wyoming, in a long-term study of the stratospheric sulfate aerosol layer. All aerosol particle size ranges display pronounced seasonal variations, with the condensation nuclei concentration and the optically active component showing a summer maximum throughout the troposphere. Mass estimates, assuming spherical sulfate particles, indicate an average column mass between altitudes of 2.5 and 10 km of about 4 and 16 mg/sq m in winter and summer, respectively. Calculated optical depths vary between 0.01 and 0.04 from winter to summer; the estimated mass scattering cross section is about 3 sq m/g throughout the troposphere. There is evidence for a decreasing trend of 1.6-1.8 percent/yr in the optically active tropospheric aerosol over the past 20 yr, which may be related to a similar reduction in SO2 emission in the U.S. over this period.

  5. Sources of HOx and production of ozone in the upper troposphere over the United States