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Sample records for aura tropospheric emission

  1. Free tropospheric observations of Carbonyl Sulfide from Aura Tropospheric Emission Spectrometer over ocean

    NASA Astrophysics Data System (ADS)

    Kuai, Le; Worden, John; Campbell, Ellitt; Kulawik, Susan; Montzka, Stephen; Liu, Jiabin

    2014-05-01

    Carbonyl sulfide (OCS) is the most abundant sulfur gas in the troposphere with a global averaging mixing ratio of about 500 part per trillion (ppt). The ocean is the primary source of OCS, emitting OCS directly or its precursors, carbon disulfide and dimethyl sulfide. The most important atmospheric sink of OCS is uptake by terrestrial plants via photosynthesis. Although the global budget of atmospheric OCS has been studied, the global integrated OCS fluxes have large uncertainties, e.g. the uncertainties of the ocean fluxes are as large as 100% or more and how the ocean sources are distributed is not well known. We developed a retrieval algorithm for free tropospheric carbonyl sulfide (OCS) observations above the ocean using radiance measurements from the Tropospheric Emission Spectrometer (TES). These first observations of the free tropospheric OCS provide global maps with information of OCS seasonal and spatial variability in the mid troposphere. These data will help to characterize ocean OCS fluxes. Evaluation of the biases and uncertainties in the TES OCS estimates against aircraft profiles from the HIPPO campaign and ground data from the NOAA Mauna Loa site suggests that the OCS retrievals (1) have less than 1.0 degree of freedom for signals (DOFs), (2) are sensitive in the mid-troposphere with a peak sensitivity typically between 300 to 500 hPa, (3) and have much smaller systematic errors from temperature, CO2 and H2O calibrations relative to random errors from measurement noise. Here we estimate the monthly means from TES measurements averaged over multiple years so that random errors are reduced and useful information about OCS seasonal and latitudinal variability can be derived. With this averaging, TES OCS data are found to be consistent (within the calculated uncertainties) with NOAA ground observations and HIPPO aircraft measurements and captures the seasonal and latitudinal variations observed by these in situ data within the estimated uncertainties

  2. Aircraft validation of Aura Tropospheric Emission Spectrometer retrievals of HDO / H2O

    NASA Astrophysics Data System (ADS)

    Herman, R. L.; Cherry, J. E.; Young, J.; Welker, J. M.; Noone, D.; Kulawik, S. S.; Worden, J.

    2014-09-01

    The EOS (Earth Observing System) Aura Tropospheric Emission Spectrometer (TES) retrieves the atmospheric HDO / H2O ratio in the mid-to-lower troposphere as well as the planetary boundary layer. TES observations of water vapor and the HDO isotopologue have been compared with nearly coincident in situ airborne measurements for direct validation of the TES products. The field measurements were made with a commercially available Picarro L1115-i isotopic water analyzer on aircraft over the Alaskan interior boreal forest during the three summers of 2011 to 2013. TES special observations were utilized in these comparisons. The TES averaging kernels and a priori constraints have been applied to the in situ data, using version 5 (V005) of the TES data. TES calculated errors are compared with the standard deviation (1σ) of scan-to-scan variability to check consistency with the TES observation error. Spatial and temporal variations are assessed from the in situ aircraft measurements. It is found that the standard deviation of scan-to-scan variability of TES δD is ±34.1‰ in the boundary layer and ± 26.5‰ in the free troposphere. This scan-to-scan variability is consistent with the TES estimated error (observation error) of 10-18‰ after accounting for the atmospheric variations along the TES track of ±16‰ in the boundary layer, increasing to ±30‰ in the free troposphere observed by the aircraft in situ measurements. We estimate that TES V005 δD is biased high by an amount that decreases with pressure: approximately +123‰ at 1000 hPa, +98‰ in the boundary layer and +37‰ in the free troposphere. The uncertainty in this bias estimate is ±20‰. A correction for this bias has been applied to the TES HDO Lite Product data set. After bias correction, we show that TES has accurate sensitivity to water vapor isotopologues in the boundary layer.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  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. 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.

  16. 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.

  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. 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.

  19. 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.

  20. 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.

  1. The study of tropospheric ozone column enhancements over North America using a regional model and the current versions of the Aura satelite data

    NASA Astrophysics Data System (ADS)

    Yang, Q.; Cunnold, D.; Choi, Y.; Wang, Y.

    2008-05-01

    A new set of tropospheric ozone columns (TCOs) is being computed from the difference between the Aura Ozone Monitoring Instrument (OMI) total ozone retrieved using Differential Optical Absorption Spectroscopy (DOAS) algorithm (level 2 collection 3) and the Aura Microwave Limb Sounding (MLS) measurements of stratospheric ozone (version 2.2). Previous comparisons of earlier version of OMI/MLS against ozonesonde measurements showed considerable variability in the differences (Yang et al., 2007). Similar comparisons have been made using the newer version of OMI/MLS TCOs and ozonesonde measurements from the Intercontinental Chemical Transport Experiment (Intex) Ozonesonde Network Study (IONS) campaign in spring and summer, 2006. These ozonesonde measurements possess the advantage that they are closer in times and locations to the MLS measurements. A spring time ozone enhancement event over North America in spring, 2005 has been revisited using the updated versions of OMI/MLS TCOs, a 3-D Regional chEmical trAnsport Model (REAM), and the Tropospheric Emission Spectrometer (TES) measurements. The high ozone concentration in mid- and lower- troposphere over the west coast of California was concluded to have been under the influence of cross-Pacific transport in spring, 2005 while the high ozone concentration in the upper troposphere over the west coast of California and the high TCOs over the Baja peninsula (Mexico) were associated with a stratospheric intrusion through a deep Rossby wave breaking event. The correlation between REAM TCOs and the surface ozone from Environmental Protection Agency ground network measurements suggest that the TCO enhancement over the west coast was associated with an increase of surface ozone. Correlations with geopotential height, wind fields, and tropopause height suggest that TCO enhancement was best characterized during the studied spring period by geopotential height decreases on the 500 mb surface. Comparisons are being made against TCO

  2. 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.

  3. 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.

  4. 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.

  5. Evaluation of Aura/OMI Total Column Ozone and Tropospheric Ozone Residual Products using Ozonesonde Profiles from the ARCIONS Campaign

    NASA Astrophysics Data System (ADS)

    Witte, J.; Schoeberl, M.; Thompson, A. M.; Tarasick, D.; Oltmans, S.; Johnson, B.; Davies, J.

    2009-05-01

    During the Arctic Intensive Ozonesonde Network Study (ARCIONS), a large number of sites located over the middle to high latitudes of North America launched daily ozonesondes in the spring (April) and summer (June/July) of 2008. We take advantage of the large number of launches at high northern latitudes to examine the retrieval accuracy of Aura's Ozone Monitoring Instrument (OMI) Total Column Ozone (TCO) and derived Tropospheric Ozone Residual (TOR) products with the equivalent integrated column amounts from ozonesondes with the SBUV/SAGE climatology add-on that estimates the ozone column amounts from the top of the sonde profile to the top of the atmosphere. We find that the OMI TCO and TOR tend to underestimate the sondes for all sites and both seasons. TCO differences between OMI and the sondes are found to be within 10%, while TOR-Sonde differences are observed to be as high as 50% at a number of sites, regardless of latitude and season. TCO amounts from OMI compared to those sonde sites located above 50N are found to be typically over 375 DU in April 2008 while June/July values are clustered around 300-350 DU. Below 50N, OMI-Sonde comparisons show less seasonal separation in total column ozone amounts. Comparisons between the TOR product and sonde integrated tropospheric column (ITC) show no apparent difference between spring and summer. Large differences in troposphere amounts occur even though tropopause heights compare to within just a few percent. Evaluation of the stratospheric column amounts between the ARCIONS sondes and Aura's Microwave Limb Sounder instrument may also be presented. Further investigation into a preliminary method of improving the TOR product using sondes as a validation source shows promise, particularly at high latitudes.

  6. Tropospheric Emission Spectrometer Product File Readers

    NASA Technical Reports Server (NTRS)

    Fisher, Brendan M.

    2010-01-01

    TES Product File Reader software extracts data from publicly available Tropospheric Emission Spectrometer (TES) HDF (Hierarchical Data Format) product data files using publicly available format specifications for scientific analysis in IDL (interactive data language). In this innovation, the software returns data fields as simple arrays for a given file. A file name is provided, and the contents are returned as simple IDL variables.

  7. 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.

  8. 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".

  9. Ozone and Nitric Acid Variability in the Upper Troposphere and Lower Stratosphere Measured during the Polar Aura Validation Experiment

    NASA Astrophysics Data System (ADS)

    Avery, M.; Plant, J.; Dibb, J.; Scheuer, E.; Browell, E.; Hair, J.; Pfister, L.; Shoeberl, M.; Lait, L.

    2005-05-01

    Understanding the response of stratospheric and tropospheric constituents to climate and chemical change requires synthesizing a complex combination of physical and chemical processes that operate simultaneously on a wide range of spatial and temporal scales to produce the large-scale global distributions observed by satellites. However, retrieval algorithms are difficult to develop in the critical upper tropospheric, tropopause and lower stratospheric regions, where the radiative properties of trace gases most affect the global climate. This is because most retrieval algorithms depend on an initial a priori profile assumption based on a geographical measurement climatology, but the actual vertical mixing ratio gradients are large across the tropopause, which varies in height based on the location of geophysical features. In this presentation we show high-resolution, accurate in situ correlative ozone and nitric acid measurements from the NASA DC-8 during the Polar Aura Validation Experiment (PAVE) in January-February of 2005. In addition to providing calibrated correlative measurements, these high-resolution measurements help to characterize the variability of ozone and nitric acid in the near-tropopause region. We use our measurements to illustrate both vertical and horizontal variability under various synoptic conditions encountered during the mission. During late winter ozone acts as a conserved dynamical tracer in the lower stratosphere, and we examine correlations of ozone with measured nitric acid and modeled potential vorticity, as well as calculate the observed ozone variance power spectrum and structure functions to better quantify mixing and eddy dissipation rates at scales that are too fine for the satellite instruments and ozone lidars to resolve, but that span the subrange between the inertial (isotropic) and buoyant (anisotropic) turbulent mixing scales. Accurate characterization of mixing of chemical species and energy dissipation in this subrange

  10. 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.

  11. 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.

  12. 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

  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. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. First estimates of global free-tropospheric NO2 abundances derived using a cloud-slicing technique applied to satellite observations from the Aura Ozone Monitoring Instrument (OMI)

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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 > 10) 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. 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

  3. Aura Science and Validation

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.; Schoeberl, M.; Douglass, A.; Anderson, J.; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    The EOS-Aura Mission is designed to answer three basic questions concerning the Earth's atmosphere: 1) Is ozone recovering as predicted, 2) is air quality getting worse, and 3) how is climate changing? Aura's four instruments work synergistically and are dedicated to answering these questions. These questions relate to NASA Earth Science Enterprise's overall strategic questions, which seek to understand the consequences of climate change for human civilization and determine if these changes can be predicted. NASA supports an ongoing research and analysis program, which is conducted independently and in support of satellite missions. The research program conducts several on-going field campaigns employing aircraft, balloons, and ground based systems. These campaigns have focused on exploring processes in the tropics, high latitudes, and continental outflow to explain the chemistry and transport in the troposphere and stratosphere and how these regions interact. NASA is now studying how the Aura mission and requirements of the research and analysis program might be merged to achieve its strategic goals related to global atmospheric chemistry changes. In addition, NASA field campaign resources will be folded into Aura's validation requirements. Aura validation requires correlative measurements throughout the troposphere and stratosphere under a range of observing and geophysical conditions. Because of the recent launches of Envisat and other smaller international chemistry satellites, the NASA program plans to collaborate with European space agencies in developing a series of campaigns that will provide continuity between those satellites missions and Aura.

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. Intercomparison of SCIAMACHY and OMI Tropospheric NO2 Columns: Observing the Diurnal Evolution of Chemistry and Emissions from Space

    NASA Technical Reports Server (NTRS)

    Boersma, K. Folkert; Jacob, Daniel J.; Eskes, Henk J.; Pinder, Robert W.; Wang, Jun; vanderA, Ronald J.

    2008-01-01

    Concurrent (August 2006) measurements of tropospheric NO2 columns from OMI aboard Aura (1330 local overpass time) and SCIAMACHY aboard Envisat (1000 local overpass time) offer an opportunity to examine the consistency between the two instruments under tropospheric background conditions and the effect of different observing times. For scenes with tropospheric NO 2 columns <5.0 x 10(exp 15) molecules cm 2, SCIAMACHY and OMI agree within 1.0-2.0 x 10(exp 15) molecules cm 2, consistent with the detection limits of both instruments. We find evidence for a low bias of 0.2 x 10(exp 15) molecules cm 2 in OMI observations over remote oceans. Over the fossil fuel source regions at northern midlatitudes, we find that SCIAMACHY observes up to 40% higher NO2 at 1000 local time (LT) than OMI at 1330 LT. Over biomass burning regions in the tropics, SCIAMACHY observes up to 40% lower NO 2 columns than OMI. These differences are present in the spectral fitting of the data (slant column) and are augmented in the fossil fuel regions and dampened in the tropical biomass burning regions by the expected increase in air mass factor as the mixing depth rises from 1000 to 1330 LT. Using a global 3-D chemical transport model (GEOS-Chem), we show that the 1000-1330 LT decrease in tropospheric NO2 column over fossil fuel source regions can be explained by photochemical loss, dampened by the diurnal cycle of anthropogenic emissions that has a broad daytime maximum. The observed 1000-1330 LT NO2 column increase over tropical biomass burning regions points to a sharp midday peak in emissions and is consistent with a diurnal cycle of emissions derived from geostationary satellite fire counts.

  10. 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

  11. 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

  12. 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/.

  13. 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

  14. AURA 2

    PubMed Central

    Dassi, Erik; Re, Angela; Leo, Sara; Tebaldi, Toma; Pasini, Luigi; Peroni, Daniele; Quattrone, Alessandro

    2014-01-01

    Post-transcriptional regulation (PTR) of gene expression is now recognized as a major determinant of cell phenotypes. The recent availability of methods to map protein-RNA interactions in entire transcriptomes such as RIP, CLIP and their variants, together with global polysomal and ribosome profiling techniques, are driving the exponential accumulation of vast amounts of data on mRNA contacts in cells, and of corresponding predictions of PTR events. However, this exceptional quantity of information cannot be exploited at its best to reconstruct potential PTR networks, as it still lies scattered throughout several databases and in isolated reports of single interactions. To address this issue, we developed the second and vastly enhanced version of the Atlas of UTR Regulatory Activity (AURA 2), a meta-database centered on mapping interaction of trans-factors with human and mouse UTRs. AURA 2 includes experimentally demonstrated binding sites for RBPs, ncRNAs, thousands of cis-elements, variations, RNA epigenetics data and more. Its user-friendly interface offers various data-mining features including co-regulation search, network generation and regulatory enrichment testing. Gene expression profiles for many tissues and cell lines can be also combined with these analyses to display only the interactions possible in the system under study. AURA 2 aims at becoming a valuable toolbox for PTR studies and at tracing the road for how PTR network-building tools should be designed. AURA 2 is available at http://aura.science.unitn.it. PMID:26779400

  15. 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.

  16. An Assessment of Upper Tropospheric and Lower Stratospheric Moisture Simulations in Analysis and Reanalysis Models Using 10-Year Aura MLS Observations

    NASA Astrophysics Data System (ADS)

    Jiang, J. H.; Su, H.

    2014-12-01

    We use 10-year global water vapor maxing ratio (H2O) measurements from Microwave LimeSounder (MLS) on Aura satellite to evaluate the performance of three analysis/reanalysis models: Goddard Earth Observation System data assimilation system, version 5 (GEOS5); Modern-Era Retrospective Analysis for research and Applications (MERRA); and European Centre for Medium-Range Weather Forecasts (ECMWF). We focus on H2O variations on both seasonal and decadal time scales. Vertical and horizontal speeds of H2O transport are estimated from the pressure-time and latitude-time series analyses. The differences between the MLS observations and analysis/reanalysis models are quantified.

  17. Present and future impact of aircraft, road traffic and shipping emissions on global tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Koffi, B.; Szopa, S.; Cozic, A.; Hauglustaine, D.; van Velthoven, P.

    2010-06-01

    In this study, the LMDz-INCA climate-chemistry model and up-to-date global emission inventories are used to investigate the "present" (2000) and future (2050) impacts of transport emissions (road traffic, shipping and aircraft) on global tropospheric ozone. For the first time, both impacts of emissions and climate changes on transport-induced ozone are investigated. The 2000 transport emissions are shown to mainly affect ozone in the Northern Hemisphere, with a maximum increase of the tropospheric column of up to 5 DU, from the South-Eastern US to Central Europe. The impact is dominated by road traffic in the middle and upper troposphere, north of 40° S, and by shipping in the northern lower troposphere, over oceanic regions. A strong reduction of road emissions and amoderate (B1 scenario) to high (A1B scenario) increase of the ship and aircraft emissions are expected by the year 2050. As a consequence, LMDz-INCA simulations predict a drastic decrease in the impact of road emissions, whereas aviation would become the major transport perturbation on tropospheric ozone, even in the case of avery optimistic aircraft mitigation scenario. The A1B emission scenario leads to an increase of the impact of transport on zonal mean ozone concentrations in 2050 by up to +30% and +50%, in the Northern and Southern Hemispheres, respectively. Despite asimilar total amount of global NOx emissions by the various transport sectors compared to 2000, the overall impact on the tropospheric ozone column is increased everywhere in 2050, due to a sectoral shift in the emissions of the respective transport modes. On the opposite, the B1 mitigation scenario leads to asignificant reduction (by roughly 50%) of the ozone perturbation throughout the troposphere compared to 2000. Considering climate change, and according to scenario A1B, a decrease of the O3 tropospheric burden is simulated by 2050 due to climate change (-1.2%), whereas an increase of ozone of up to 2% is calculated in the upper

  18. Present and future impact of aircraft, road traffic and shipping emissions on global tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Koffi, B.; Szopa, S.; Cozic, A.; Hauglustaine, D.; van Velthoven, P.

    2010-12-01

    In this study, the LMDz-INCA climate-chemistry model and up-to-date global emission inventories are used to investigate the "present" (2000) and future (2050) impacts of transport emissions (road traffic, shipping and aircraft) on global tropospheric ozone. For the first time, both impacts of emissions and climate changes on transport-induced ozone are investigated. The 2000 transport emissions are shown to mainly affect ozone in the Northern Hemisphere, with a maximum increase of the tropospheric column of up to 5 DU, from the South-eastern US to Central Europe. The impact is dominated by road traffic in the middle and upper troposphere, North of 40° S, and by shipping in the northern lower troposphere, over oceanic regions. A strong reduction of road emissions and a moderate (B1 scenario) to high (A1B scenario) increase of the ship and aircraft emissions are projected by the year 2050. As a consequence, LMDz-INCA simulations predict a drastic decrease in the impact of road emissions, whereas aviation would become the major transport perturbation on tropospheric ozone, even in the case of a very optimistic aircraft mitigation scenario. The A1B emission scenario leads to an increase of the impact of transport on zonal mean ozone concentrations in 2050 by up to +30% and +50%, in the Northern and Southern Hemispheres, respectively. Despite a similar total amount of global NOx emissions by the various transport sectors compared to 2000, the overall impact on the tropospheric ozone column is increased everywhere in 2050, due to a sectoral shift in the emissions of the respective transport modes. On the opposite, the B1 mitigation scenario leads to a significant reduction (by roughly 50%) of the ozone perturbation throughout the troposphere compared to 2000. Considering climate change, and according to scenario A1B, a decrease of the O3 tropospheric burden is simulated by 2050 due to climate change (-1.2%), whereas an increase of ozone of up to 2% is calculated in the

  19. 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

  20. The Aqua-Aura Train

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark; Einaudi, Franco (Technical Monitor)

    2001-01-01

    This talk will focus on the afternoon constellation of EOS platforms and the scientific benefits that arise from this formation. The afternoon EOS constellation or the "A-train" will provide unprecedented information on clouds and aerosols. At 1:30 PM crossing time EOS-Aqua begins the train with the MODIS, CERES and AIRS instruments making aerosol, cloud, radiation budget , temperature and water vapor measurements. AMSR-E will also make total column water measurements. Following Aqua by one minute, Cloudsat will make active radar precipitation measurements as and PICASSOCENA will make lidar measurements of clouds and aerosols. Fourteen minutes later, EOS-Aura will pass through the same space making upper troposphere water vapor and ice profiles as well as some key trace gases associated with convective processes (MLS and HIRDLS). Additional measurements of aerosols will be made by Aura's OMI instrument.

  1. 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.

  2. 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.

  3. The satellite and chemical transport model tandem: constraining TM5 with AURA observations

    NASA Astrophysics Data System (ADS)

    Verstraeten, Willem W.; Neu, Jessica L.; Williams, Jason E.; Bowman, Kevin W.; Worden, John R.; (K. F.) Boersma, Folkert

    2015-04-01

    Satellite-based studies focusing on tropospheric ozone (O3) and nitrogen dioxide (NO2) have the potential to close the gap left by previous studies on air quality. After all, satellites can provide large-scale robust observational evidence that both O3 precursor concentrations and tropospheric O3 levels are rapidly changing over source receptor areas. Chemical transport models (CTM) significantly contribute to our understanding on transport patterns, production and destruction of tropospheric air constituents, but the infrequently update of emission inventories and the slow implementation of updates on chemical reactions and reaction rates slow down the widespread use. Satellite observations of tropospheric NO2 have the potential to improve and update anthropogenic NOx emissions in a near-continuous way and may provide information on the life time of NOx, impacting the production and destruction of many air constituents including O3. Here we show the increased ability of the CTM TM5 to reproduce the 2005-2010 observed strong and rapid rise in free tropospheric ozone of 0.8% per year over China from TES (Tropospheric Emission Spectrometer, onboard AURA), once OMI (Ozone Monitoring Instrument, onboard AURA) NO2 measurements were implemented in TM5 to update NOx emissions. What is more, MLS observations (Microwave Limb Sounder, onboard AURA) on stratospheric ozone demonstrate its potential to constrain the stratosphere-troposphere exchange (STE) in TM5 which is mainly driven by ECMWF meteorological fields. The use of MLS observations of stratospheric O3 improved the TM5 modelled trends in tropospheric O3 significantly. Thanks to the TM5 input updates from satellite observations, the impact of Asian O3 and its precursors on the western United States could be quantified showing a large import from China to the West. Here we also show that deriving NOx life times from OMI NO2 observations to evaluate new rate constants of the reaction NO2 + OH => HNO3 in TM5 is a

  4. Uncertainty in biogenic isoprene emissions and its impacts on tropospheric chemistry in East Asia.

    PubMed

    Han, K M; Park, R S; Kim, H K; Woo, J H; Kim, J; Song, C H

    2013-10-01

    In this study, the accuracy of biogenic isoprene emission fluxes over East Asia during two summer months (July and August) was examined by comparing two tropospheric HCHO columns (ΩHCHO) obtained from the SCIAMACHY sensor and the Community Multi-scale Air Quality (CMAQ v4.7.1) model simulations, using three available biogenic isoprene emission inventories over East Asia: i) GEIA, ii) MEGAN and iii) MOHYCAN. From this comparative analysis, the tropospheric HCHO columns from the CMAQ model simulations, using the MEGAN and MOHYCAN emission inventories (Ω(CMAQ, MEGAN) and Ω(CMAQ, MOHYCAN)), were found to agree well with the tropospheric HCHO columns from the SCIAMACHY observations (Ω(SCIA)). Secondly, the propagation of such uncertainties in the biogenic isoprene emission fluxes to the levels of atmospheric oxidants (e.g., OH and HO2) and other atmospheric gaseous/particulate species over East Asia during the two summer months was also investigated. As the biogenic isoprene emission fluxes decreased from the GEIA to the MEGAN emission inventories, the levels of OH radicals increased by factors of 1.39 and 1.75 over Central East China (CEC) and South China, respectively. Such increases in the OH radical mixing ratios subsequently influence the partitioning of HO(y) species. For example, the HO2/OH ratios from the CMAQ model simulations with GEIA isoprene emissions were 2.7 times larger than those from the CMAQ model simulations based on MEGAN isoprene emissions. The large HO2/OH ratios from the CMAQ model simulations with the GEIA biogenic emission were possibly due to the overestimation of GEIA biogenic isoprene emissions over East Asia. It was also shown that such large changes in HO(x) radicals created large differences on other tropospheric compounds (e.g., NO(y) chemistry) over East Asia during the summer months. PMID:23867846

  5. 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

  6. Weekly and Decadal Changes in NOx Emissions and Tropospheric Ozone

    NASA Astrophysics Data System (ADS)

    Marr, L. C.; Harley, R. A.

    2004-12-01

    Variations in air pollutant emissions and ambient concentrations on both weekly and decadal time scales can be used to test our understanding of atmospheric responses to changes in anthropogenic forcing. Combining records of fuel sales and on-road measurements of vehicle activity and emissions, we have estimated motor vehicle emissions by hour and day of week, separately for gasoline and diesel-powered vehicles. Between 1990 and 2000, emissions of nitrogen oxides (NOx) from motor vehicles in California decreased by more than 30%. However, NOx emissions from heavy-duty diesel trucks actually increased by over 40%, offsetting some of the reductions in light-duty vehicle emissions. During the past two decades, the occurrence of higher ozone levels on weekends, a phenomenon known as the weekend effect, has become more widespread in California. The effect impacted 11% of surface observation sites in 1980-84 and 38% in 1995-1999. Results of chemical transport modeling show that the primary cause of the weekend ozone effect is the large decrease in NOx emissions due to a ~75% reduction in diesel truck traffic on weekends. Areas where ozone formation is VOC-sensitive therefore can experience higher ozone concentrations on weekends. Long-term (decadal) changes in anthropogenic emissions have produced a shift towards greater VOC-sensitivity, and the weekend ozone effect has grown more prevalent because diesel trucks now account for over 50% of total motor vehicle NOx emissions.

  7. An assessment of upper troposphere and lower stratosphere water vapor in MERRA, MERRA2, and ECMWF reanalyses using Aura MLS observations

    NASA Astrophysics Data System (ADS)

    Jiang, Jonathan H.; Su, Hui; Zhai, Chengxing; Wu, Longtao; Minschwaner, Kenneth; Molod, Andrea M.; Tompkins, Adrian M.

    2015-11-01

    Global water vapor (H2O) measurements from Microwave Limb Sounder (MLS) are used to evaluate upper tropospheric (UT) and lower stratospheric (LS) H2O products produced by NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA), its newest release MERRA2, and European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Reanalyses. Focusing on the H2O amount and transport from UT to LS, we show that all reanalyses overestimate annual global mean UT H2O by up to ~150% compared to MLS observations. Substantial differences in H2O transport are also found between the observations and reanalyses. Vertically, H2O transport across the tropical tropopause (16-20 km) in the reanalyses is faster by up to ~86% compared to MLS observations. In the tropical LS (21-25 km), the mean vertical transport from ECMWF is 168% faster than the MLS estimate, while MERRA and MERRA2 have vertical transport velocities within 10% of MLS values. Horizontally at 100 hPa, both observation and reanalyses show faster poleward transport in the Northern Hemisphere (NH) than in the Southern Hemisphere (SH). Compared to MLS observations, the H2O horizontal transport for both MERRA and MERRA2 is 106% faster in the NH but about 42-45% slower in the SH. ECMWF horizontal transport is 16% faster than MLS observations in both hemispheres. The ratio of northward to southward transport velocities for ECMWF is 1.4, which agrees with MLS observation, while the corresponding ratios for MERRA and MERRA2 are about 3.5 times larger.

  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. Have tropospheric aerosol emissions contributed to the recent climate hiatus?

    NASA Astrophysics Data System (ADS)

    Kühn, Thomas; Partanen, Antti-Ilari; Laakso, Anton; Lu, Zifeng; Bergman, Tommi; Mikkonen, Santtu; Kokkola, Harri; Korhonen, Hannele; Räisänen, Petri; Streets, David G.; Romakkaniemi, Sami; Laaksonen, Ari

    2014-05-01

    During the last 15 years global warming has slowed considerably, with the resulting plateau in global temperature records being dubbed the climate hiatus. Apart from variations in solar irradiance and ocean temperature, increased anthropogenic aerosol emissions in South and East Asia have been suggested as possible causes for this hiatus. While European and and North American aerosol emissions have constantly decreased since the 1980's, emissions in China and India have started increasing at the same time and, although total global aerosol emissions have decreased, aerosol effects on the global energy budget are expected to enhance towards the equator due to stronger irradiance there. In this study we used the aerosol-climate model ECHAM5-HAM2 to assess the effect that this re-distribution of anthropogenic aerosol emissions towards the equator may have on climate. To this end, we computed radiative forcing and equilibrium temperature response due to the change in global aerosol emissions (black carbon (BC), organic carbon and sulphur dioxide) between 1996 and 2010, keeping all other anthropogenic influences fixed. Surprisingly we found that the cooling due the increased aerosol emissions in China and India is almost negligible compared to the warming caused by the decreasing aerosol emissions in Europe and North America. The radiative flux perturbation (RFP; includes aerosol indirect effects) was 0.42 W/m2 and the change in global equilibrium 2 m temperature increased by 0.25 °C. The lack of cooling in China and India stems from a cancellation of sulfate cooling and BC warming, especially over China. There, the strong cloud cover leads to both attenuation of sulphate aerosol light scattering and saturation tendency of indirect aerosol effects on clouds. BC levels on the other hand increase also above the clouds (relative increase of BC levels is almost uniform with height), leading to warming through light absorption.

  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. Impacts of Boreal wildfire emissions on Arctic tropospheric ozone: a multi-model analysis

    NASA Astrophysics Data System (ADS)

    Arnold, Steve; Emmons, Louisa; Monks, Sarah; Law, Kathy; Tilmes, Simone; Turquety, Solene; Thomas, Jennie; Bouarar, Idir; Raut, Jean-Christophe; Flemming, Johannes; Huijnen, Vincent; Mao, Jingqiu; Duncan, Bryan; Steenrod, Steve; Strode, Sarah; Yoshida, Yasuko

    2013-04-01

    Observations suggest that the Arctic has warmed rapidly in the past few decades compared with observed global-mean temperature increases. Model calculations suggest that changes in short-lived pollutants such as ozone and aerosol may have contributed significantly to this warming. Arctic tropospheric budgets of short-lived pollutants are impacted by long-range transport of gases and aerosols from Europe, Asia and N. America, but also by Boreal wildfires in summer. Our understanding of how Boreal fires impact Arctic budgets of climate-relevant atmospheric constituents is limited, and is reliant on sparse observations and models of tropospheric chemistry. In particular, the role of Boreal fires in the Arctic tropospheric ozone budget is poorly constrained, and has been the subject of some controversy, with different studies suggesting both minor and major roles for fires as a source of Arctic ozone. A better understanding of Boreal fire influence on Arctic ozone and aerosol is essential for improving the reliability of our projections of future Arctic and Northern Hemisphere climate change, especially in light of proposed climate-fire feedbacks which may enhance the intensity and extent of high latitude wildfire under a warming climate. Here we use results from the POLARCAT Model Intercomparison Project (POLMIP) and observations collected in the Arctic troposphere as part of International Polar Year in 2008, to evaluate simulated Arctic tropospheric ozone and how it is influenced by Boreal fire emissions in a series of state-of-the-art global atmospheric chemical transport models. By following large plumes exported from Siberian and North American Boreal fire regions in both the models and observations, we show that different models produce a wide range of influence on Arctic tropospheric ozone from fires, despite using identical emissions and having broadly consistent transport patterns. We demonstrate that the different models display highly varied NOy partitioning

  12. Time and Spatially Dependent Estimates of Pollutant Trace Gas Emissions and Their Effect on Tropospheric Ozone

    NASA Astrophysics Data System (ADS)

    Dignon, Jane Elizabeth

    Statistical models have been developed to relate the rate of pollutant emissions from fossil fuel combustion to the rate of fuel consumption. These models have been used to estimate global emissions of nitrogen and sulfur oxides in fossil fuel combustion since the year 1860. When averaged over the 1860 to 1980 period, global sulfur emissions increased at a rate of 2.9 percent per year, and the nitrogen emissions increased a rate of 3.4 percent per year. Using these statistical models along with population distribution estimates, high resolution geographical maps of emissions can be produced for each year which fuel consumption data are available. Global emissions of NO_ {x} and SO_{x} emissions for 1966 and 1980 are illustrated on a latitude-longitude grid appropriate for general circulation models of the atmosphere. Emissions of carbon monoxide from fossil fuel, wood and biomass fuel, and open burning of vegetation, as well as emissions of nitrogen and sulfur oxides from wood and biomass fuel burning, are estimated for 1980 using emission factor methods. These trace gas sources are also mapped globally. The impact of increasing emissions of NO _{x} on tropospheric ozone abundance is estimated by calculations with a one-dimensional (latitudinal) model which includes coupled tropospheric photo-chemistry and diffusive meridional transport. Steady-state photochemical calculations with the prescribed NO_{x } emissions appropriate for 1966 and 1980 indicate an ozone increase of 8 to 11 percent in the Northern Hemisphere, a result which is compatible with the rise of about 12 percent between 1970 and 1981 suggested by recent observations.

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

    NASA Astrophysics Data System (ADS)

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

    1990-09-01

    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.

  16. 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.

  17. TES/Aura L2 Water Vapor (H2O) Nadir (TL2H2ON)

    Atmospheric Science Data Center

    2015-01-30

    TES/Aura L2 Water Vapor (H2O) Nadir (TL2H2ON) News:  TES News ... Title:  TES Discipline:  Tropospheric Chemistry Level:  L2 Instrument:  TES/Aura L2 Water Vapor Spatial Coverage:  5.3 x 8.5 km nadir ...

  18. TES/Aura L2 Water Vapor (H2O) Nadir (TL2H2ONS)

    Atmospheric Science Data Center

    2015-01-30

    TES/Aura L2 Water Vapor (H2O) Nadir (TL2H2ONS) News:  TES News ... Title:  TES Discipline:  Tropospheric Chemistry Level:  L2 Platform:  TES/Aura L2 Water Vapor Spatial Coverage:  5.3 8.5 km nadir ...

  19. 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.

  20. 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

  1. 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

  2. Observational constraints on upper tropospheric NOx emissions, lifetime, and oxidative products

    NASA Astrophysics Data System (ADS)

    Nault, Benjamin Albert

    Nitrogen oxides (NOx ≡ NO + NO2) regulate tropospheric ozone (O3) production rates. In the upper troposphere (~8 -- 15 km above ground level), where O3 is an important greenhouse gas, there are few detailed measurements of NOx and its oxidation products. As a result, the chemical reactions that involve NO x are poorly characterized under the low temperature conditions in this region of the atmosphere. For the reactions that have been studied under these conditions (e.g., daytime nitric acid, or HNO3, and pernitric acid, or HO2NO2, production), the results from various experiments indicate a 20 -- 50% disagreement for the rate constants, and the other important NOx oxidation reactions (production of acyl peroxy nitrate, like PAN and PPN, and alkyl and multifunctional nitrates) have not been well characterized for the conditions characteristic of the upper troposphere. Besides the poorly understood NOx oxidation rates, recent calculations have indicated there is an important upper tropospheric NOx oxidation product (methyl peroxy nitrate, or CH3O2NO2) that has not been measured in the atmosphere. These uncertainties in the products and oxidation rate constants affect the characterization of the input of NO x from lightning. In this dissertation, I report observations obtained during two airborne field campaigns, the Deep Convective Clouds and Chemistry (DC3, May -- June, 2012) and the Studies of Emissions and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys (SEAC4RS, August -- September, 2013) experiments, and use these observations to investigate the reaction products and rate constants for the oxidation of NOx to less reactive reservoirs. The observations focused on fresh lightning emissions in deep convective outflow, and the subsequent chemical aging of the outflow downwind. First, I present the first ambient observations of CH3O 2NO2, and recommendations on how to measure upper tropospheric in situ NO2 with minimal interferences from

  3. Estimates of 4.7 μm surface emissivity and their impact on the retrieval of tropospheric carbon monoxide by Measurements of Pollution in the Troposphere (MOPITT)

    NASA Astrophysics Data System (ADS)

    Ho, Shu-Peng; Edwards, David P.; Gille, John C.; Chen, Jarmei; Ziskin, Daniel; Francis, Gene L.; Deeter, Merritt N.; Drummond, James R.

    2005-11-01

    Carbon monoxide (CO) is an important tropospheric trace species. The Measurements of Pollution in the Troposphere (MOPITT) instrument uses the 4.7 μm CO band to measure the global CO profile and total column amount in the troposphere from space. In the operational MOPITT CO retrieval algorithm, surface skin temperature (Ts) and emissivity (E) are retrieved simultaneously with the CO profile. However, because both Ts and E are retrieved from the same piece of information from the MOPITT measurements, the accuracy of both variables may be limited, which leads to an increase of uncertainty in the CO retrievals. An accurate specification of the surface skin temperature is required to determine surface emissivity and vice versa. In this study, a method is developed which uses Ts from the Moderate Resolution Imaging Spectroradiometer (MODIS) and MOPITT radiances to derive an improved 4.7 μm surface emissivity estimate (E) for use in retrievals by the MOPITT instrument. Monthly mean 4.7 μm surface emissivity maps for 1 year are generated and used as the a priori E in the MOPITT Ts and CO retrieval algorithm. We show that the geographical distribution of the 4.7 μm emissivity is very consistent with MODIS normalized difference vegetation index distribution, which is strongly tied to the surface emissivity. This a priori E has a much smaller standard deviation than values currently used in the MOPITT retrieval. As a result, more radiance information tends to be used in the MOPITT Ts and CO retrievals. By using the improved a priori E over the land, the information content of MOPITT radiances increases 15% at night and 5% during the day relative to the current version MOPITT data products. The difference between day and night information content (or diurnal difference) decreases from 0.3 (current version) to 0.21, showing that nighttime retrievals are improved. Over the global ocean the diurnal difference of the MOPITT information content decreases from 0.15 (current

  4. 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).

  5. 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

  6. 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%.

  7. Satellite Observations of Tropospheric Ammonia

    NASA Astrophysics Data System (ADS)

    Shephard, M. W.; Luo, M.; Rinsland, C. P.; Cady-Pereira, K. E.; Beer, R.; Pinder, R. W.; Henze, D.; Payne, V. H.; Clough, S.; Rodgers, C. D.; Osterman, G. B.; Bowman, K. W.; Worden, H. M.

    2008-12-01

    Global high-spectral resolution (0.06 cm-1) nadir measurements from TES-Aura enable the simultaneous retrieval of a number of tropospheric pollutants and trace gases in addition to the TES standard operationally retrieved products (e.g. carbon monoxide, ozone). Ammonia (NH3) is one of the additional species that can be retrieved in conjunction with the TES standard products, and is important for local, regional, and global tropospheric chemistry studies. Ammonia emissions contribute significantly to several well-known environmental problems, yet the magnitude and seasonal/spatial variability of the emissions are poorly constrained. In the atmosphere, an important fraction of fine particulate matter is composed of ammonium nitrate and ammonium sulfate. These particles are statistically associated with health impacts. When deposited to ecosystems in excess, nitrogen, including ammonia can cause nutrient imbalances, change in ecosystem species composition, eutrophication, algal blooms and hypoxia. Ammonia is also challenging to measure in-situ. Observations of surface concentrations are rare and are particularly sparse in North America. Satellite observations of ammonia are therefore highly desirable. We recently demonstrated that tropospheric ammonia is detectable in the TES spectra and presented some corresponding preliminary retrievals over a very limited range of conditions (Beer et al., 2008). Presented here are results that expand upon these initial TES ammonia retrievals in order to evaluate/validate the retrieval results utilizing in-situ surface observations (e.g. LADCO, CASTNet, EPA /NC State) and chemical models (e.g. GEOS-Chem and CMAQ). We also present retrievals over regions of interest that have the potential to help further understand air quality and the active nitrogen cycle. Beer, R., M. W. Shephard, S. S. Kulawik, S. A. Clough, A. Eldering, K. W. Bowman, S. P. Sander, B. M. Fisher, V. H. Payne, M. Luo, G. B. Osterman, and J. R. Worden, First

  8. 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.

  9. Characterization of Aura TES carbonyl sulfide retrievals over ocean

    NASA Astrophysics Data System (ADS)

    Kuai, L.; Worden, J.; Kulawik, S. S.; Montzka, S. A.; Liu, J.

    2014-01-01

    We present a description of the NASA Aura Tropospheric Emission Spectrometer (TES) carbonyl sulfide (OCS) retrieval algorithm for oceanic observations, along with evaluation of the biases and uncertainties using aircraft profiles from the HIPPO (HIAPER Pole-to-Pole Observations) campaign and data from the NOAA Mauna Loa site. In general, the OCS retrievals (1) have less than 1.0 degree of freedom for signals (DOFs), (2) are sensitive in the mid-troposphere with a peak sensitivity typically between 300 and 500 hPa, (3) but have much smaller systematic errors from temperature, CO2 and H2O calibrations relative to random errors from measurement noise. We estimate the monthly means from TES measurements averaged over multiple years so that random errors are reduced and useful information about OCS seasonal and latitudinal variability can be derived. With this averaging, TES OCS data are found to be consistent (within the calculated uncertainties) with NOAA ground observations and HIPPO aircraft measurements. TES OCS data also captures the seasonal and latitudinal variations observed by these in situ data.

  10. 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.

  11. 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.

  12. Rapid increases in tropospheric ozone production and export from China

    NASA Astrophysics Data System (ADS)

    Verstraeten, Willem W.; Neu, Jessica L.; Williams, Jason E.; Bowman, Kevin W.; Worden, John R.; Boersma, K. Folkert

    2015-09-01

    Rapid population growth and industrialization have driven substantial increases in Asian ozone precursor emissions over the past decade, with highly uncertain impacts on regional and global tropospheric ozone levels. According to ozonesonde measurements, tropospheric ozone concentrations at two Asian sites have increased by 1 to 3% per year since 2000, an increase thought to contribute to positive trends in the ozone levels observed at North America’s West Coast. However, model estimates of the Asian contribution to North American ozone levels are not well-constrained by observations. Here we interpret Aura satellite measurements of tropospheric concentrations of ozone and its precursor NO2, along with its largest natural source, stratospheric ozone, using the TM5 global chemistry-transport model. We show that tropospheric ozone concentrations over China have increased by about 7% between 2005 and 2010 in response to two factors: a rise in Chinese emissions by about 21% and increased downward transport of stratospheric ozone. Furthermore, we find that transport from China of ozone and its precursors has offset about 43% of the 0.42 DU reduction in free-tropospheric ozone over the western United States that was expected between 2005 and 2010 as a result of emissions reductions associated with federal, state and local air quality policies. We conclude that global efforts may be required to address regional air quality and climate change.

  13. 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

  14. Dependence of Simulated Tropospheric Ozone Trends on Uncertainties in U.S. Mobile Fleet Emissions.

    NASA Astrophysics Data System (ADS)

    Monks, S. A.; Ryerson, T. B.; Emmons, L. K.; Tilmes, S.; Hassler, B.; Lamarque, J. F.

    2015-12-01

    Long-term surface observations show a rapid increase in background concentrations of ozone since the 1960s. Global chemistry-climate models have difficulties in reproducing this trend, overestimating the mid-century observed concentrations. This suggests that the impacts of ozone on climate and air quality throughout the second half of the 20th century may be misrepresented in current models. We use the MACCity emissions inventory constrained by ambient observations to examine the dependence of simulated long-term ozone trends on U.S. land transportation (mobile fleet) emissions of nitrogen oxides (NOX), carbon monoxide (CO) and volatile organic compounds (VOCs). Two sensitivity simulations are performed using the CAM-Chem chemical transport model, where the U.S. MACCity land transportation sector emissions of either NO or CO and co-emitted VOCs are constrained to the observed NO:CO ratio between 1960-2010. We present results from these sensitivity simulations to quantify the dependence of simulated background tropospheric ozone concentrations on these emissions.

  15. Comprehensive study of emission source contributions for tropospheric ozone formation over East Asia

    NASA Astrophysics Data System (ADS)

    Itahashi, Syuichi; Hayami, Hiroshi; Uno, Itsushi

    2015-01-01

    Emission source contributions of tropospheric ozone (O3) were comprehensively investigated by using the higher-order decoupled direct method (HDDM) for sensitivity analysis and the ozone source apportionment technology (OSAT) for mass balance analysis in the comprehensive air-quality model with extensions (CAMx). The response of O3 to emissions reductions at various levels in mainland China, Korea, and Japan were estimated and compared with results calculated by the brute force method (BFM) where one model parameter is varied at a time. Emissions were assessed at three receptor sites in Japan that experienced severe pollution events in May 2009. For emissions from China, HDDM assessed O3 response with a bias of only up to 3 ppbv (a relative error of 4.5%) even for a 50% reduction but failed to assess a more extreme reduction. OSAT was reasonably accurate at 100% reduction, with a -4 ppbv (-7%) bias, but was less accurate at moderate ranges of reduction (˜50-70%). For emissions from Korea and Japan, HDDM captured the nonlinear response at all receptor sites and at all reduction levels to within 1% in all but one case; however, the bias of OSAT increased with the increasing reduction of emissions. One possible reason for this is that OSAT does not account for NO titration. To address this, a term for potential ozone (PO; O3 and NO2 together) was introduced. Using of PO instead of O3 improved the performance of OSAT, especially for emissions reductions from Korea and Japan. The proposed approach with PO refined the OSAT results and did not degrade HDDM performance.

  16. 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.

  17. The SPARC Data Initiative: Comparison of upper troposphere/lower stratosphere ozone climatologies from limb-viewing instruments and the nadir-viewing Tropospheric Emission Spectrometer

    NASA Astrophysics Data System (ADS)

    Neu, J. L.; Hegglin, M. I.; Tegtmeier, S.; Bourassa, A.; Degenstein, D.; Froidevaux, L.; Fuller, R.; Funke, B.; Gille, J.; Jones, A.; Rozanov, A.; Toohey, M.; Clarmann, T.; Walker, K. A.; Worden, J. R.

    2014-06-01

    We present the first comprehensive intercomparison of currently available satellite ozone climatologies in the upper troposphere/lower stratosphere (UTLS) (300-70 hPa) as part of the Stratosphere-troposphere Processes and their Role in Climate (SPARC) Data Initiative. The Tropospheric Emission Spectrometer (TES) instrument is the only nadir-viewing instrument in this initiative, as well as the only instrument with a focus on tropospheric composition. We apply the TES observational operator to ozone climatologies from the more highly vertically resolved limb-viewing instruments. This minimizes the impact of differences in vertical resolution among the instruments and allows identification of systematic differences in the large-scale structure and variability of UTLS ozone. We find that the climatologies from most of the limb-viewing instruments show positive differences (ranging from 5 to 75%) with respect to TES in the tropical UTLS, and comparison to a "zonal mean" ozonesonde climatology indicates that these differences likely represent a positive bias for p ≤ 100 hPa. In the extratropics, there is good agreement among the climatologies regarding the timing and magnitude of the ozone seasonal cycle (differences in the peak-to-peak amplitude of <15%) when the TES observational operator is applied, as well as very consistent midlatitude interannual variability. The discrepancies in ozone temporal variability are larger in the tropics, with differences between the data sets of up to 55% in the seasonal cycle amplitude. However, the differences among the climatologies are everywhere much smaller than the range produced by current chemistry-climate models, indicating that the multiple-instrument ensemble is useful for quantitatively evaluating these models.

  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, 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

  19. 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.

  20. 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

  1. Evaluation of NOx emission fluxes over East Asia using model-predicted and OMI-retrieved tropospheric NO2 columns

    NASA Astrophysics Data System (ADS)

    Han, Kyung M.; Lee, Sojin; Song, Chul H.

    2015-04-01

    To evaluate bottom-up NOx emission fluxes of INTEX-B, CAPSS, and REAS v1.11 inventories, CMAQ-simulated tropospheric NO2 columns were compared with OMI-retrieved tropospheric NO2 columns. For the direct comparison between the two columns, the averaging kernels retrieved from the KNMI algorithm were applied to the CMAQ model results. In the study, the two tropospheric NO2 columns showed good spatial and seasonal correlation with correlation coefficients ranging from 0.71 to 0.96. In terms of the normalized mean error, the CMAQ-simulated NO2 columns were, on annual average, ~28% smaller than the OMI-retrieved NO2 columns, indicating the NOx emission fluxes were possibly underestimated in East Asia. In addition, large absolute differences between the two tropospheric NO2 columns found over Central East China during winter were investigated and analyzed with several sensitivity runs (monthly variations in NOx emissions; different NOx emission fluxes; and reaction probability of N2O5 onto aerosols).

  2. 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 ... Title:  TES Discipline:  Tropospheric Chemistry Version:  V6 Level:  L2 Instrument:  TES/Aura L2 Water Vapor Spatial Coverage:  5.3 km nadir ...

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Improvement of the global surface emissivity from MOPITT measurements and its impacts on the retrievals of tropospheric carbon monoxide profiles

    NASA Astrophysics Data System (ADS)

    Ho, Shu-peng; Edwards, David P.; Gille, John C.; Chen, Jarmei; Ziskin, Daniel

    2004-12-01

    Carbon monoxide (CO) is an important tropospheric trace species and can serve as a useful tracer of atmospheric transport. The Measurements of Pollution In The Troposphere (MOPITT) instrument uses the 4.7 μm CO band to measure the spatial and temporal variation of the CO profile and total column amount in the troposphere from space. Launched in 1999 on board the NASA Terra satellite, the MOPITT views the earth with a pixel size 22 km by 22 km and a cross-track swath that measures a near-global distribution of CO every 3 days. In the operational MOPITT CO retrieval algorithm (V3; Version 3), surface skin temperature (Ts) and emissivity (E) are retrieved simultaneously with the CO profile. The accuracy of E and Ts is crucial for obtaining the CO retrieval within the 10% accuracy from the MOPITT measurements. However, because both Ts and E are retrieved from the same piece of information from the MOPITT measurements, the accuracy of both valuables may be limited. Extra surface skin temperature information is needed to determine surface emissivity, and vice versa. In this study, we use MODIS Ts within the MOPITT FOVs, in conjunction with those MOPITT signals most sensitive to the background scene, to compute the surface emissivity through an iterative retrieval algorithm. A monthly 1degree grid averaged 4.7 μm surface emissivity map is generated. The evaluation of the accuracy of this monthly 1 degree grid averaged 4.7 μm surface emissivity map is presented and its impacts on the retrievals of tropospheric CO profiles from the MOPITT measurements are also discussed.

  10. 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.

  11. [Migraine with visual aura].

    PubMed

    Bidot, S; Biotti, D

    2016-06-01

    Migraine with visual aura is marked by recurrent episodes of transient visual disturbance, often followed by headaches. Its pathophysiology has not been fully understood, but visual auras might be related to a self-propagating wave of cortical depolarization called "cortical spreading depression", triggering a trigemino-vascular "storm" ultimately leading to headaches. The most specific visual symptom is the "fortification spectrum" consisting of glimmering jagged lines spreading from the center to the periphery, and leaving a transient scotoma in its wake. Other visual symptoms are numerous, ranging from elementary positive or negative visual phenomena to complex and elaborate hallucinations. The diagnosis can be made according to the International Classification of Headache Disorders revised in 2013. The main goal of the treatment is to relieve the patient's pain quickly and to decrease the frequency of the episodes. PMID:27324232

  12. Effects of additional nonmethane volatile organic compounds, organic nitrates, and direct emissions of oxygenated organic species on global tropospheric chemistry

    NASA Astrophysics Data System (ADS)

    Ito, Akinori; Sillman, Sanford; Penner, Joyce E.

    2007-03-01

    This work evaluates the sensitivity of tropospheric ozone and its precursors to the representation of nonmethane volatile organic compounds (NMVOCs) and organic nitrates. A global 3-D tropospheric chemistry/transport model (IMPACT) has been exercised initially using the GEOS-Chem chemical reaction mechanism. The model was then extended by adding emissions and photochemical reactions for aromatic and terpenoid hydrocarbons, and by adding explicit representation of hydroxy alkyl nitrates produced from isoprene. Emissions of methanol, phenol, acetic acid and formic acid associated with biomass burning were also added. Results show that O3 increases by 20% in most of the troposphere, peroxyacetyl nitrate (PAN) increases by 30% over much of the troposphere and OH increases by 10%. NOx (NO + NO2) decreases near source regions and increases in remote locations, reflecting increased transport of NOx away from source regions by organic nitrates. The increase in O3 was driven largely by the increased role of PAN as a transporter of NOx and by the rerelease of NOx from isoprene nitrates. The increased PAN production was associated with increases in methyl glyoxal and hydroxyacetone. Comparison with measured values show reasonable agreement for O3 and PAN, but model measurement agreement does not either improve or degrade in the extended model. The extended model shows improved agreement with measurements for methanol, acetic acid and peroxypropional nitrate (PPN). Results from the extended model were consistent with measured alkyl nitrates and glycolaldehyde, but hydroxyacetone and methyl glyoxal were overestimated. The latter suggests that the effect of the isoprene nitrates is somewhat smaller than estimated here. Although the model measurement comparison does not show specific improvements with the extended model, it provides a more complete description of tropospheric chemistry that we believe is important to include.

  13. Validation of the retrieval of surface skin temperature and surface emissivity from MOPITT measurements and their impacts on the retrieval of tropospheric carbon monoxide profiles

    NASA Astrophysics Data System (ADS)

    Ho, Shu-Peng; Gille, John C.; Edwards, David P.; Warner, Juying; Deeter, Merritt N.; Francis, Gene L.; Ziskin, Daniel C.

    2003-04-01

    The Measurements of Pollution In The Troposphere (MOPITT) instrument is designed to measure the spatial and temporal variation of the carbon monoxide (CO) profile and total column amount in the troposphere from the space. MOPITT channels are sensitive to both thermal emission from the surface and target gas absorption and emission. Surface temperature and emissivity are retrieved simultaneously with the CO profile. To obtain the desired 10% precision for the retrieved CO from MOPITT measurements, it is important to understand MOPITT CO channel sensitivity to surface temperature and emissivity and the impacts of the effects of any errors in retrieved skin temperature and emissivity on retrieved CO for various underlying surfaces. To demonstrate the impacts of the surface temperature and emissivity on the retrieval of the tropospheric CO profile, simulation studies are performed. The collocated Moderate Resolution Imaging Spectroradiometer (MODIS) surface products are used to assess the accuracy of the retrieved MOPITT surface temperature and emissivity.

  14. OMI tropospheric NO2 profiles from cloud slicing: constraints on surface emissions, convective transport and lightning NOx

    NASA Astrophysics Data System (ADS)

    Belmonte Rivas, M.; Veefkind, P.; Eskes, H.; Levelt, P.

    2015-12-01

    We derive annual and seasonal global climatologies of tropospheric NO2 profiles from OMI cloudy observations for the year 2006 using the cloud-slicing method on six pressure levels centered at about 280, 380, 500, 620, 720 and 820 hPa. A comparison between OMI and the TM4 model tropospheric NO2 profiles reveals striking overall similarities, which confer great confidence to the cloud-slicing approach to provide details that pertain to annual as well as seasonal means, along with localized discrepancies that seem to probe into particular model processes. Anomalies detected at the lowest levels can be traced to deficiencies in the model surface emission inventory, at mid-tropospheric levels to convective transport and horizontal advective diffusion, and at the upper tropospheric levels to model lightning NOx production and the placement of deeply transported NO2 plumes such as from the Asian summer monsoon. The vertical information contained in the OMI cloud-sliced NO2 profiles provides a global observational constraint that can be used to evaluate chemistry transport models (CTMs) and guide the development of key parameterization schemes.

  15. 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

  16. 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.

  17. 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.

  18. Water vapour variability in the high-latitude upper troposphere - Part 2: Impact of volcanic emissions

    NASA Astrophysics Data System (ADS)

    Sioris, C. E.; Zou, J.; McElroy, C. T.; Boone, C. D.; Sheese, P. E.; Bernath, P. F.

    2015-09-01

    The impact of volcanic eruptions on water vapour in the region of the high latitude tropopause is studied using deseasonalized time series based on observations by the Atmospheric Chemistry Experiment (ACE) water vapour sensors, namely MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) and the Fourier Transform Spectrometer (ACE-FTS). The three eruptions with the greatest impact on the high latitude upper troposphere during the time frame of this satellite-based remote sensing mission are chosen. The Puyehue-Cordón Caulle volcanic eruption in June 2011 was the most explosive eruption in the past 24 years and resulted in an observed (50 ± 12) % increase in water vapour in the southern high-latitude upper troposphere in July 2011 that persisted into September 2011. A pair of Northern Hemisphere volcanoes, namely Eyjafjallajökull and Nabro, erupted in 2010 and 2011 respectively, increasing water vapour in the upper troposphere at northern high latitudes significantly for a period of ~ 3 months following each eruption. Both had a volcanic explosivity index of 4. Nabro led to a statistically significant increase of ~ 1 ppm in lower stratospheric (13.5-15.5 km) water vapour at northern high-latitudes (60-90° N) in September 2011, when the brunt of its plume arrived in the Arctic. These findings imply that steam emitted into the high-latitude, upper troposphere during volcanic eruptions must be taken into account to properly determine the magnitude of the trend in water vapour over the last decade.

  19. Quantifying lower tropospheric methane concentrations using GOSAT near-IR and TES thermal IR measurements

    NASA Astrophysics Data System (ADS)

    Worden, J. R.; Turner, A. J.; Bloom, A.; Kulawik, S. S.; Liu, J.; Lee, M.; Weidner, R.; Bowman, K.; Frankenberg, C.; Parker, R.; Payne, V. H.

    2015-08-01

    Evaluating surface fluxes of CH4 using total column data requires models to accurately account for the transport and chemistry of methane in the free troposphere and stratosphere, thus reducing sensitivity to the underlying fluxes. Vertical profiles of methane have increased sensitivity to surface fluxes because lower tropospheric methane is more sensitive to surface fluxes than a total column, and quantifying free-tropospheric CH4 concentrations helps to evaluate the impact of transport and chemistry uncertainties on estimated surface fluxes. Here we demonstrate the potential for estimating lower tropospheric CH4 concentrations through the combination of free-tropospheric methane measurements from the Aura Tropospheric Emission Spectrometer (TES) and XCH4 (dry-mole air fraction of methane) from the Greenhouse gases Observing SATellite - Thermal And Near-infrared for carbon Observation (GOSAT TANSO, herein GOSAT for brevity). The calculated precision of these estimates ranges from 10 to 30 ppb for a monthly average on a 4° × 5° latitude/longitude grid making these data suitable for evaluating lower-tropospheric methane concentrations. Smoothing error is approximately 10 ppb or less. Comparisons between these data and the GEOS-Chem model demonstrate that these lower-tropospheric CH4 estimates can resolve enhanced concentrations over flux regions that are challenging to resolve with total column measurements. We also use the GEOS-Chem model and surface measurements in background regions across a range of latitudes to determine that these lower-tropospheric estimates are biased low by approximately 65 ppb, with an accuracy of approximately 6 ppb (after removal of the bias) and an actual precision of approximately 30 ppb. This 6 ppb accuracy is consistent with the accuracy of TES and GOSAT methane retrievals.

  20. Understanding the Tropospheric Ozone Response to Changes in the Stratospheric Circulation

    NASA Astrophysics Data System (ADS)

    Neu, J. L.; Kinnison, D. E.; Glanville, A. S.; Lee, M.; Walker, T. W.

    2015-12-01

    Chemistry-climate models robustly predict increases in the large-scale stratospheric circulation and stratosphere-troposphere exchange (STE) in response to increasing greenhouse gases. Our previous work has shown that current variability in the stratospheric circulation and stratosphere-to-troposphere ozone flux driven by a combination of El Niño /Southern Oscillation (ENSO) and the stratospheric Quasi-Biennial Oscillation (QBO) provides a "natural experiment" that may reduce uncertainties in predictions of the tropospheric ozone response to future changes in stratospheric transport. Using six years of measurements from the Tropospheric Emission Spectrometer (TES) and Microwave Limb Sounder (MLS) onboard NASA's Aura satellite, we found that interannual variability in the stratospheric circulation of ~±40% leads to changes of ~±2% in northern midlatitude tropospheric ozone (equaling ~1/2 the total observed interannual variability). Here, we further explore the relationship between the stratospheric circulation and tropospheric ozone variability using two models: the Whole Atmosphere Chemistry-Climate Model (WACCM) and the GEOS-Chem chemistry-transport model (CTM). With the WACCM model, we further explore and untangle the roles of ENSO and the QBO in driving circulation changes and examine small but important differences in the response of the residual vertical velocity and the transport velocity (as measured by the water vapor tape recorder) to these cycles. We also diagnose large differences in the relationship between stratospheric and tropospheric ozone in the specified dynamics and free-running versions of WACCM. With the GEOS-Chem CTM, we use a 30-year simulation to examine the stability of our satellite-derived diagnostics over longer time periods and their sensitivity to changes in meteorology and emissions. We also apply our diagnostics to a 6-year joint 3Dvar assimilation of TES and MLS observations in GEOS-Chem and examine whether the assimilation

  1. 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.

  2. 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.

  3. Attribution of free tropospheric ozone over eastern China using TES ozone observations, NO2 OMI retrievals and the TM5 chemistry transport model

    NASA Astrophysics Data System (ADS)

    Verstraeten, Willem W.; (K. F.) Boersma, Folkert; Williams, Jason; Bowman, Kevin W.; Worden, John R.

    2014-05-01

    Tropospheric ozone is an important greenhouse gas and a global air pollutant originating from photo-chemical oxidation of precursors such as volatile organic compounds (VOCs) and CO in the presence of NOX in favouring meteorological conditions, long range transport and stratosphere-troposphere ozone exchange (STE). Assessing ozone trends in the troposphere remain difficult due to scarcity of long-term measurement sites, but spaceborne sensors can cope much better with that thanks to their spatio-temporal abilities. Today, eastern Asia has the fastest growing anthropogenic emissions. It has been suggested that much of this pollution is exported eastwards towards western North America affecting the local ozone concentrations in the troposphere. We analysis time series of free tropospheric ozone observed from space by TES (Tropospheric Emission Spectrometer onboard NASA's EOS-Aura satellite) over eastern China. Based on the TM5 chemical transport models (CTM) using six years (2005-2010) of model simulations we attribute the observations to the different sources of ozone using model runs with different anthropogenic emissions of NOX. Here we show a strong and rapid increase (~7 ppbv, or 10% per year) in free tropospheric ozone over China retrieved with the TES satellite instrument from 2005 to 2010. We attribute this increase to a larger inflow of stratospheric ozone and particularly to enhanced ozone production following highly significant increases in Chinese NOX emissions as observed with the OMI satellite instrument. Despite the emission reduction in the western United States, the observed ozone concentrations in the free troposphere raise, which is attributed to the increase of Chinese emissions.

  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. 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. PMID:24613491

  6. 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

  7. 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).

  8. Observational diagnoses of extratropical ozone STE during the Aura era

    NASA Astrophysics Data System (ADS)

    Olsen, M. A.; Douglass, A. R.; Witte, J. C.; Kaplan, T.

    2011-12-01

    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).

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Disaggregating global commercial aviation emissions by background static-stability in the upper-troposphere and lower-stratosphere

    NASA Astrophysics Data System (ADS)

    Whitt, D. B.; Wilkerson, J. T.; Jacobson, M. Z.; Naiman, A. D.; Lele, S. K.

    2010-12-01

    In 2006 commercial aircraft burned 188 Tg of jet fuel which resulted in the emission of 162 Tg of carbon dioxide among other combustion products. Many of the constituents of burned jet fuel are thought to have significant effects on climate, particularly because they are released in the upper-troposphere and lower-stratosphere (UTLS) where the vertical mixing is slow. The exact radiative effect, however, is difficult to quantify because the UTLS is a complicated dynamical zone where chemical transport time-scales can range from years (e.g. global scale stratosphere-troposphere exchange) to hours (e.g. tropopause folding processes) and horizontal scales can range from thousands of kilometers (e.g. eddy mixing along isentropic surfaces) to a single kilometer (e.g. the width of a tropopause fold). Furthermore, there are steep vertical gradients in the dynamical and chemical properties of the atmosphere near the tropopause which are only visible in tropopause relative coordinates because the tropopause height varies significantly from month to month and day to day. Therefore, since a third of global commercial aviation emissions occur near the tropopause, within a chemically defined transition layer, disaggregating aviation emissions by background atmospheric properties represents a step toward a more complete understanding of the potential impact aviation emissions have on climate and surface air quality. This study disaggregates global commercial aviation emissions in tropopause relative coordinates with respect to background static-stability and chemical composition. Furthermore, the data are regionally and temporally disaggregated and statistics are derived. The static-stability is derived from high resolution temperature profiles obtained from the Challenging Minisatellite Payload (CHAMP) and the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites. The daily thermal tropopause height is also obtained from the Atmospheric

  14. The influence of boreal biomass burning emissions on the distribution of tropospheric ozone over North America and the North Atlantic during 2010

    NASA Astrophysics Data System (ADS)

    Parrington, M.; Palmer, P. I.; Henze, D. K.; Tarasick, D. W.; Hyer, E. J.; Owen, R. C.; Helmig, D.; Clerbaux, C.; Bowman, K. W.; Deeter, M. N.; Barratt, E. M.; Coheur, P.-F.; Hurtmans, D.; George, M.; Worden, J. R.

    2011-09-01

    We analyse the tropospheric ozone distribution over North America and the North Atlantic to boreal biomass burning emissions during the summer of 2010 using the GEOS-Chem 3-D global tropospheric chemical transport model, and observations from in situ and satellite instruments. In comparison to observations from the PICO-NARE observatory in the Azores, ozonesondes across Canada, and the Tropospheric Emission Spectrometer (TES) and Infrared Atmospheric Sounding Instrument (IASI) satellite instruments, the model ozone distribution is shown to be in reasonable agreement with mean biases less than 10 ppbv. We use the adjoint of GEOS-Chem to show the model ozone distribution in the free troposphere over Maritime Canada is largely sensitive to NOx emissions from biomass burning sources in Central Canada, lightning sources in the central US, and anthropogenic sources in eastern US and south-eastern Canada. We also use the adjoint of GEOS-Chem to evaluate the Fire Locating And Monitoring of Burning Emissions (FLAMBE) inventory through assimilation of CO observations from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. The CO inversion showed that, on average the FLAMBE emissions needed to be reduced to 89 % of their original values, with scaling factors ranging from 12 % to 102 %, to fit the MOPITT observations in the boreal regions. Applying the CO scaling factors to all species emitted from boreal biomass burning sources led to a decrease of the model tropospheric distributions of CO, PAN, and NOx by as much as -20 ppbv, -50 ppbv, and -20 ppbv respectively. The impact of optimizing the biomass burning emissions was to reduce the model ozone distribution by approximately -3 ppbv (-8 %) and on average improved the agreement of the model ozone distribution compared to the observations throughout the free troposphere reducing the mean model bias from 5.5 to 4.0 ppbv for the PICO-NARE observatory, 3.0 to 0.9 ppbv for ozonesondes, 2.0 to 0.9 ppbv

  15. The Aura Mission and the "A-Train"

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2002-01-01

    By the end of 2004 the A-Train will have been assembled in orbit. The A-Train consists of five low earth orbit satellites flying within 15 minutes of each other. The first in the train is Aqua, launched early this year, in an ascending node orbit with 1 :30 PM crossing time. In January 2004, Aura will be launched, following 15 minutes behind Aqua. Aura's focus is atmospheric chemistry, with both forward looking, and backward looking instruments along with nadir sounders. Aura's limb microwave instrument will also be able to make temperature and humidity measurements into the troposphere. By mid-2004, CALIPSO, a cloud lidar mission and CloudSat, a cloud radar mission will be co-manifested. These two spacecraft will follow, and maneuver about 1 minute behind Aqua. The lidar on CALIPSO will provide aerosol and cloud height information which can enhance the aerosol information from Aqua s MODIS instrument. CloudSat s radar will enhance the information from AMSR-E, AIRS and HSB on Aqua. The fifth satellite to be launched in 2004 is PARASOL which will use the POLDER instrument to provide polarization information which can be used to determine aerosol composition and size distribution.

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Simulation of the interannual variations of tropospheric ozone over China: Roles of variations in meteorological parameters and anthropogenic emissions

    NASA Astrophysics Data System (ADS)

    Lou, Sijia; Liao, Hong; Yang, Yang; Mu, Qing

    2015-12-01

    We quantify the interannual variations (IAVs) of tropospheric O3 over China for the years 2004-2012 by using the one-way nested-grid version of the global three-dimensional Goddard Earth Observing System chemical transport model (GEOS-Chem). The roles of variations in meteorological fields and anthropogenic emissions of O3 precursors are examined separately and together through sensitivity simulations. With variations in both meteorological parameters and emissions, simulated seasonal mean surface-layer O3 concentrations over North China (NC, 110-120°E, 32-42°N) exhibit the largest IAVs in June-July-August (JJA). The regionally averaged absolute percent departure from the mean (APDM) values over NC are 0.7%, 3.2%, 3.9%, and 2.1% in December-January-February (DJF), March-April-May (MAM), and September-October-November (SON), respectively. Over South China (SC, 110-120°E, 22-32°N), the IAVs of O3 are found maximum in MAM, and minimum in JJA; the APDM values are 2.7%, 3.7%, 1.4%, and 2.6% in DJF, MAM, JJA, and SON, respectively. With respect to the IAVs of O3 over the Sichuan Basin (SCB, 102-110°E, 27-33°N), the APDM values are simulated to be 2.7-3.8% throughout the year. The IAVs in surface-layer O3 by variations in meteorological fields are simulated to be larger than those by variations in anthropogenic emissions throughout the year in NC and SC except for JJA in SC. The relatively more important role of variations in anthropogenic emissions is simulated in SCB in all seasons. Process analyses are performed to identify key meteorological parameters that influence the IAVs of O3 over NC, SC, and SCB. Over all of these regions, variations in winds are found to have the largest impact on the IAVs of O3, followed by those in temperature and specific humidity. Considering that the APDM values represent the IAVs averaged over 2004-2012, the magnitudes of IAVs of O3 for specific years can be more significant than the numbers reported here. Our results have

  9. Tropospheric Chemistry

    NASA Technical Reports Server (NTRS)

    Mohnen, V.

    1984-01-01

    The fundamental processes that control the chemical composition and cycles of the global troposphere and how these processes and properties affect the physical behavior of the atmosphere are examined. The long-term information needs for tropospheric chemistry are: to be able to predict tropospheric responses to perturbations, both natural and anthropogenic, of these cycles, and to provide the information required for the maintenance and effective future management of the atmospheric component of our global life support system. The processes controlling global tropospheric biogeochemical cycles include: the input of trace species into the troposphere, their long-range transport and distribution as affected by the mean wind and vertical venting, their chemical transformations, including gas to particle conversion, leading to the appearance of aerosols or aqueous phase reactions inside cloud droplets, and their removal from the troposphere via wet (precipitation) and dry deposition.

  10. Persistent migraine aura in an adolescent girl.

    PubMed

    Bruen, Robin; Peng, Si Liang; Perreault, Sebastien; Major, Philippe; Ospina, Luis H

    2013-08-01

    A 14-year-old girl presented with a prolonged migraine visual aura of several weeks' duration. Symptoms gradually resolved over a 6-week period, with no recurrence of visual aura over a 20-month follow-up period. Although there is significant overlap between the features of stereotypical and persistent migraine auras, or "visual snow," the latter tend to be unformed and can occupy the entire visual field of both eyes. To our knowledge, this phenomenon has been reported only twice before in children. Recognition of its features will allow the pediatric ophthalmologist to differentiate persistent visual aura from visual hallucinations. PMID:23871134

  11. 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.

  12. Evaluating the Information from Minor Trace Gas Measurements by the Tropospheric Emission Spectrometer (TES)

    NASA Astrophysics Data System (ADS)

    Cady-Pereira, K. E.; Shephard, M. W.; Henze, D. K.; Zhu, L.; Pinder, R. W.; Bash, J. O.; Walker, J. T.; Millet, D. B.; Wells, K. C.; Jeong, G.; Luo, M.; Chaliyakunnel, S.

    2012-12-01

    The high spectral resolution and good SNR provided by the TES instrument allow for the detection and retrieval of numerous trace species. Advanced optimal estimation algorithms have been developed to retrieve three of these, ammonia, methanol and formic acid, from TES radiances. Ammonia is currently a standard TES operational product, while methanol and formic acid will be standard products in the next TES software update (V006). Given the highly reactive nature of ammonia, with its concurrent high spatial and temporal variability, the large uncertainty in global emissions of methanol, and the large biases between measured and modeled formic acid, the air quality community has a pressing need for global information on these species; there is great interest in using these new satellite derived products, but there is often no clear idea on the information they provide. Here we will provide a short summary of the characteristics of the retrieved products, then present results from comparisons with in situ measurements. We will discuss the distinct characteristics of point and satellite measurements and illustrate how information from the latter is related to the former. We will compare global TES ammonia and methanol measurements with outcome from the GEOS-CHEM model. These comparisons have led us to examine a potential sampling bias driven by TES insensitivity in regions with low concentrations (less than 1 ppbv) or with low thermal contrast or thick clouds. We will present results from the application of inverse methods using TES ammonia and methanol 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 high quality data sufficient to evaluate models of the ammonia bi-directional exchange at the surface.

  13. 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.

  14. 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.

  15. 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.

  16. Bromine, chlorine and sulfur emission into the free troposphere from a Rift volcano

    NASA Astrophysics Data System (ADS)

    Bobrowski, N.; Giuffrida, G. B.; Tedeso, D.; Yalire, M. M.; Galle, B.

    2007-12-01

    In June 2007 spectroscopic measurements were carried out at the crater rim of the Niyragongo volcano located 15 km north of the city Goma, North Kivu region (DRC). Niyragongo volcano belongs to the Virunga volcanic chain and it is associated with the Western branch of the Great Rift Valley. The volcanism at Niyragongo is caused by the rifting of the Earth's crust where two parts of the African plates are breaking apart. Niyragongo is a 3470 m high stratovolcano, which a large summit crater usually containing a lava lake inside and it is considered one of the most active volcanoes in Africa. Satellite measurements show an extremely large sulphur dioxide plume since May 2002, and it is considered one of the biggest sulphur dioxide sources on Earth. The ground - based remote sensing technique - MAX-DOAS (Multi Axis Differential Optical Absorption Spectroscopy) using scattered sunlight has been applied during a one week field trip on top of the crater rim of Niyragongo volcano to measure nitrogen oxide, halogen oxides and sulphur dioxide. The used Mini-MAX-DOAS is a lightweight, compact, robust instrument and has very low power consumption which allows to be deployed over several days with some small lead batteries. The measurements provide valuable information of the chemical composition as well its variability within the volcanic plume of the lava lake and allowed also studying chemical transformation processes of the halogens inside the plume. Bromine-sulphur and chlorine-sulphur ratios were investigated and a minimal bromine and chlorine emission flux estimation will be presented.

  17. 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.

  18. 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.

  19. WAVES (Water Vapor Variability Satellite/Sondes) - An Aura Satellite Validation Field Campaign Hosted at the Howard University Research Campus in Beltsville, MD

    NASA Astrophysics Data System (ADS)

    Whiteman, D. N.; Adam, M.; Barnet, C.; Bojkov, B.; Demoz, B.; Fitzgibbon, J.; Forno, R.; Herman, R.; Hoff, R.; Joseph, E.; Landulfo, E.; McCann, K.; McGee, T.; Miloshevich, L.; Restrepo, I.; Schmidlin, F.; Taubman, B.; Thompson, A.; Venable, D.; Voemel, H.; Walthall, C.

    2006-12-01

    The NASA Aura satellite was launched on July 15, 2004 and is the trailing member of the A-train series of satellites. A field campaign called WAVES2006 (Water Vapor Variability Satellite-Sondes) was hosted at the Howard University Research Campus in Beltsville, MD from July 7 - August 10, 2006 to provide research quality measurements of ozone, temperature, pressure and water vapor for comparison with Aura satellite retrievals and for instrument accuracy assessment studies. Because of the small difference in overpass time, WAVES2006 measurements are also being used for Aqua satellite retrieval studies. The operations plan for WAVES included intensive observations by multiple radiosonde/ozonesonde sensors and several lidar systems during thirty-seven overpasses of the Aura satellite. Special staring-mode observations of the Beltsville region were performed by the TES (Tropospheric Emission Spectrometer) instrument during WAVES, which increased the amount of coincident data for evaluating an updated TES ozone retrieval algorithm. NOAA-NESDIS provided AIRS water vapor and ozone retrievals using both the near real-time system running the AIRS science team version 4 algorithm and a research algorithm incorporating the latest algorithm improvements planned for version 5. Coordinated measurements from 4 different lidar systems were acquired during WAVES. The Penn State University NATIVE trailer containing extensive gas sampling and radiation measurement instrumentation was also deployed to the Beltsville site for WAVES. The measurements from this system are being compared with comparable measurements from the MDE instrumentation adding to the confidence level of the trace gas validation data. The U.S. Department of Agriculture deployed a sun-photometer member of the AERONET network for use during WAVES. A member of the SuomiNet network of GPS systems was deployed by NASA-GSFC for total column water measurements. An overview of the WAVES campaign and preliminary comparison

  20. Tropospheric ozone and El Niño-Southern Oscillation: Influence of atmospheric dynamics, biomass burning emissions, and future climate change

    NASA Astrophysics Data System (ADS)

    Doherty, R. M.; Stevenson, D. S.; Johnson, C. E.; Collins, W. J.; Sanderson, M. G.

    2006-10-01

    We investigate how El Niño Southern Oscillation (ENSO) influences tropospheric ozone and its precursors in a coupled climate-chemistry model. As shown in similar studies, tropospheric column ozone (TCO) decreases in the central and east Pacific and increases in the west Pacific/Indonesia in response to circulation and convective changes during El Niño conditions. Simulated changes in TCO for "peak" El Niño events in the central and east Pacific are in good agreement but are underestimated in the west Pacific compared to previous observational and modeling studies for October 1997. Tropospheric column-average NOx decreases over Indonesia and generally over South America as a result of suppressed convection and lightning over these land regions. NOx and HOx changes during El Niño modify ozone chemical production and destruction. When we include annually varying biomass burning emissions in our model simulations we find that these emissions peak over Indonesia 1-2 months in advance of the peak elevated sea-surface temperatures (SSTs) and hence the "meteorological" El Niño. We underestimate the strength of the TCO increase due to El Niño-related dry conditions over Indonesia in October 1997 compared to observations. We also examine how future mean and variability changes in ENSO, as simulated in the HadCM3 climate model, impacts tropospheric ozone. A mean future El Niño-like state is simulated in the tropical Pacific in HadCM3, but this has no discernable impact on the future TCO trend in this region. However, we do simulate increased variability in precipitation and TCO related to ENSO in the future.

  1. Tropospheric Emission Spectrometer (TES) satellite validations of ammonia, methanol, formic acid, and carbon monoxide over the Canadian oil sands

    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.

    2015-09-01

    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 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 the 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 km × 2.5 km). These initial results indicate model under-prediction 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 under-prediction of CO is closer to ~ 10 % at 681 hPa (~ 3 km) during this

  2. Tropospheric chemistry

    NASA Technical Reports Server (NTRS)

    Mohnen, V. A.; Chameides, W.; Demerjian, K. L.; Lenschow, D. H.; Logan, J. A.; Mcneal, R. J.; Penkett, S. A.; Platt, U.; Schurath, U.; Dias, P. D.

    1985-01-01

    The chemistry of the background troposphere, the source region, and the transition regions are discussed. The troposphere is governed by heterogeneous chemistry far more so than the stratosphere. Heterogeneous processes of interest involve scavenging of trace gases by aerosols, cloud and precipitation elements leading to aqueous phase chemical reactions and to temporary and permanent removal of material from the gas phase. Dry deposition is a major removal process for ozone, as well as for other gases of importance in tropospheric photochemistry. These processes are also discussed.

  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. 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.

  5. 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

  6. 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.

  7. Quantifying lower tropospheric methane concentrations using near-IR and thermal IR satellite measurements: comparison to the GEOS-Chem model

    NASA Astrophysics Data System (ADS)

    Worden, J. R.; Turner, A. J.; Bloom, A. A.; Kulawik, S. S.; Liu, J.; Lee, M.; Weidner, R.; Bowman, K.; Frankenberg, C.; Parker, R.; Payne, V. H.

    2015-04-01

    Evaluating surface fluxes of CH4 using total column data requires models to accurately account for the transport and chemistry of methane in the free-troposphere and stratosphere, thus reducing sensitivity to the underlying fluxes. Vertical profiles of methane have increased sensitivity to surface fluxes because lower tropospheric methane is more sensitive to surface fluxes than a total column. Resolving the free troposphere from the lower-troposphere also helps to evaluate the impact of transport and chemistry uncertainties on estimated surface fluxes. Here we demonstrate the potential for estimating lower tropospheric CH4 concentrations through the combination of free-tropospheric methane measurements from the Aura Tropospheric Emission Spectrometer (TES) and XCH4 (dry-mole air fraction of methane) from the Greenhouse Gases Observing Satellite Thermal And Near Infrared for Carbon Observations (GOSAT TANSO, herein GOSAT for brevity). The mean precision of these estimates are calculated to be ~ 23 ppb for a monthly average on a 4 × 5 latitude/longitude degree grid making these data suitable for evaluating lower-tropospheric methane concentrations. Smoothing error is approximately 10 ppb or less. The accuracy is primarily determined by knowledge error of XCO2, used to estimate XCH4 from the GOSAT CH4/CO2 "proxy" retrieval. For example, we use different XCO2 fields to quantify XCH4 from the GOSAT CH4/CO2 retrieval, one from Carbontracker and another from the NASA Carbon Monitoring System, and find that differences of up to approximately 60 ppb are possible with a mean value of approximately 35 ppb or less for any given latitude for these lower-tropospheric methane estimates using these two different XCO2 distributions. We show that these lower-tropospheric concentrations are more directly sensitive to the underlying fluxes than a total column using the GEOS-Chem model. In particular, we compare these lower-tropospheric methane estimates with those from the GEOS

  8. 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

  9. 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

  10. 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.

    2015-01-01

    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 most notable in June in any given year. Similar seasonal variations were observed throughout the nine-year OMI measurement period of 2005 to 2013. The ozone enhancement in June was associated with the enhancement of carbon monoxide (CO) and hotspots, which is consistent with previous studies of in-situ measurements such those made by the MTX2006 campaign. A considerable part of this ozone enhancement could be attributed to the emissions of ozone precursors from open crop residue burning (OCRB) after the winter wheat harvest, in addition to emissions from industrial activities and automobiles. The ozone distribution presented in this study is also consistent with some model studies that apply emissions from OCRB. 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.

  11. 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.

    2004-12-01

    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 IPCC (Intergovernmental Panel on Climate Change) SRES (Special Report on Emission Scenarios) scenarios (Nakicenovic et al., 2000). 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 realistically the observed trends in background ozone, CO, and CH4 concentrations from 1990 to 2002. For the "current legislation" case, both models indicate an increase of the annual average ozone levels in the Northern hemisphere by 5 ppbv, and up to 15 ppbv over the Indian sub

  12. 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.

  13. 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

  14. [Recurrent dreams as migraine aura symptoms].

    PubMed

    Podoll, K; Töpper, R; Robinson, D; Sass, H

    2000-04-01

    Elementary geometric imagery seen in the visual aura of migraine can be experienced as incorporated into the content of a dream which precedes the awakening with a migraine headache. Furthermore, recurrent dreams featuring complex visual imagery, often terrifying nightmares, can occur as migraine aura symptoms. The said phenomena are illustrated by two original case reports and discussed against the background of a review of the literature. PMID:10803382

  15. 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.

  16. Regional and hemispheric impacts of anthropogenic and biomass burning emissions on summertime CO and O3 in the North Atlantic lower free troposphere

    NASA Astrophysics Data System (ADS)

    Honrath, R. E.; Owen, R. C.; Val MartíN, M.; Reid, J. S.; Lapina, K.; Fialho, P.; Dziobak, M. P.; Kleissl, J.; Westphal, D. L.

    2004-12-01

    We report summertime measurements of CO and O3 obtained during 2001-2003 at the PICO-NARE mountaintop station in the Azores. Frequent events of elevated CO mixing ratios were observed. On the basis of backward trajectories arriving in the free troposphere and global simulations of biomass burning plumes, we attribute nearly all these events to North American pollution outflow and long-range transport of biomass burning emissions. There was a high degree of interannual variability in CO levels: median [CO] ranged from 65 ppbv in 2001 to 104 ppbv in 2003. The highest concentrations were associated with transport of Siberian fire emissions during summer 2003, when Siberian fire activity was unusually high. Ozone mixing ratios also increased (by up to ˜30 ppbv) during the fire events. These findings demonstrate the significant hemispheric scale impact that biomass burning events have on background CO and O3 levels. O3 enhancements of similar magnitude were also observed in North American pollution outflow. O3 and CO were correlated during North American outflow events, with a slope averaging 1.0 (d[O3]/d[CO], ppbv/ppbv) when no fire impact was present. This slope is more than 80% larger than early 1990s observations made in the eastern United States and nearshore outflow region, even after accounting for declining U.S. CO emissions and for CO loss during transport to the Azores, and is not consistent with simple dilution of U.S. outflow with marine background air. We conclude that a significantly larger amount of O3 production occurred in the air sampled during this study, and we suggest several potential reasons for this, each of which could imply potentially significant shortcomings in current estimates of the hemispheric impact of North American emissions on tropospheric ozone and should be evaluated in future studies.

  17. 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.

    2013-02-01

    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, ground-level observations and long-term aircraft measurements to characterize trends in air pollution. The USEPA Continuous Emissions Monitoring System (CEMS) program reported substantial decreases in point sources resulting from national and regional control measures; these decreases are definitely reflected in the ground-level observations. The decreasing trend of CO column contents is ~8.0 Dobson Unit (DU) decade-1, corresponding to ~350 ppbv decade-1 in the lower troposphere. Satellite observations of long-term, near-surface CO show ~40% decrease over western Maryland between 2000 and 2011, the same magnitude as indicated by aircraft measurements over upwind regions of Baltimore/Washington aished. After compensating for inter-annual temperature variations, historical aircraft measurements suggest the daily net production of tropospheric ozone over Baltimore/Washington area decreases from ~20 ppbv in the late 1990s to ~7 ppbv in the early 2010s during the ozone season. A decrease in the long-term ozone column content is observed as ~2.0 DU decade-1 in the lowest 1500 m, corresponding to ~13 ppbv decade-1 decrease. Back trajectory cluster analysis demonstrates that emissions of air pollutants from Ohio and Pennsylvania through Maryland influence column contents of downwind ozone in the lower atmosphere. The trends of air pollutants reveal the success of regulations implemented over the last decade and the importance of region wide emission controls over the eastern United States.

  18. 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.

  19. 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

  20. 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

  1. Global Retrieval of BrO, HCHO, and OClO for the EOS--Aura Ozone Monitoring Instrument

    NASA Astrophysics Data System (ADS)

    Kurosu, T. P.; Chance, K.

    2003-12-01

    The Ozone Monitoring Instrument (OMI) is scheduled for launch on the EOS--Aura platform in March 2004. OMI is a nadir viewing UV/Vis instrument observing continuously from 270 to 500 nm, and thus similar to the European Space Agency's Global Ozone Monitoring Experiment (GOME), from which it derives much of its heritage. Compared to GOME, OMI has about 3--5 times coarser spectral resolution but a more than 40 times smaller ground footprint of 13x24 km2, and it achieves global coverage within one day. Stratospheric bromine oxide (BrO) and chlorine dioxide (OClO) are key elements in the destruction of stratospheric ozone and the formation of the Antarctic ozone hole; in the troposphere, BrO is released from the snow and ice-pack during high-latitude Spring. Tropospheric formaldehyde (HCHO), a volatile organic compound (VOC), is an indicator of isoprene emissions and a byproduct of forest fires; it is a key measure for air quality determination from space. We present results from the operational algorithms for BrO, HCHO, and OClO, as well as auxiliary retrievals of ozone, which we are currently developing for OMI. Global retrievals of BrO and HCHO, and OClO within the polar vortex, have been performed by applying the OMI algorithms to existing GOME data. The trace gas algorithms developed for OMI are scientifically mature since they are able to fully exploit their heritage from GOME. Key elements in the retrieval are the non-linear least squares minimization procedure to derive trace gas slant columns and the conversion from slant to vertical columns using cloud information and a shape factor analysis. This poster demonstrates the capabilities of atmospheric chemistry monitoring with the OMI instrument.

  2. The derivation of tropospheric column ozone using the TOR approach and mapping technique

    NASA Astrophysics Data System (ADS)

    Yang, Qing

    2007-12-01

    Tropospheric ozone columns (TCOs) derived from differences between the Dutch-Finnish Aura Ozone Monitoring Instrument (OMI) measurements of the total atmospheric ozone column and the Aura Microwave Limb Sounder (MLS) measurements of stratospheric ozone columns are discussed. Because the measurements by these two instruments are not spatially coincident, interpolation techniques, with emphasis on mapping the stratospheric columns in space and time using the relationships between lower stratospheric ozone and potential vorticity (PV) and geopotential heights (Z), are evaluated at mid-latitudes. It is shown that this PV mapping procedure produces somewhat better agreement in comparisons with ozonesonde measurements, particularly in winter, than does simple linear interpolation of the MLS stratospheric columns or the use of typical coincidence criteria at mid-latitudes. The OMI/MLS derived tropospheric columns are calculated to be 4 Dobson units (DU) smaller than the sonde measured columns at mid-latitudes. This mean difference is consistent with the MLS (version 1.5) stratospheric ozone columns being high relative to Stratospheric Aerosol and Gas Experiment (SAGE II) columns by 3 DU. Standard deviations between the derived tropospheric columns and those measured by ozonesondes are 9 DU (30%) annually but they are just 6 DU (15%) in summer. Uncertainties in the interpolated MLS stratospheric columns are likely to be the primary cause of these standard deviations. An important advantage of the PV mapping approach is that it works well when MLS data are missing (e.g., when an orbit of measurements is missing). In the comparisons against ozonesonde measurements, it provides up to twice as many comparisons compared to the other techniques. The OMI/MLS derived tropospheric ozone columns have been compared with corresponding columns based on the Tropospheric Emission Spectrometer (TES) measurements, and Regional chEmical trAnsport Model (REAM) simulations. The variability of

  3. 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

  4. 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

  5. AURA and its US National Observatories

    NASA Astrophysics Data System (ADS)

    Edmondson, Frank K.

    1997-04-01

    The subject of this history is the science and politics of the establishment, funding, construction and operation of two important American observatories, the Kitt Peak National Observatory (KPNO) and the Cerro Tololo Inter-American Observatory (CTIO) by the Association of Universities for Research in Astronomy (AURA). The book is written from the unique perspective of Frank K. Edmondson, a former member of the AURA board of directors. Drawing on oral histories, archival material, as well as the author's personal participation from 1956 to the present, this is a personal account of a period of major innovation in American optical astronomy. Will be of interest to historians and astronomers alike.

  6. 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.

  7. 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.

  8. Assessing global radiative forcing due to regional emissions of tropospheric ozone precursors: a step towards climate credit for ozone reductions

    NASA Astrophysics Data System (ADS)

    Mauzerall, D. L.; Naik, V.; Horowitz, L. W.; Schwarzkopf, D.; Ramaswamy, V.; Oppenheimer, M.

    2005-05-01

    Carbon dioxide emissions from fossil-fuel consumption are presented for the five Asian countries that are among the global leaders in anthropogenic carbon emissions: China (13% of global total), Japan (5% of global total), India (5% of global total), South Korea (2% of global total), and Indonesia (1% of global total). Together, these five countries represent over a quarter of the world's fossil-fuel based carbon emissions. Moreover, these countries are rapidly developing and energy demand has grown dramatically in the last two decades. A method is developed to estimate the spatial and seasonal flux of fossil-fuel consumption, thereby greatly improving the temporal and spatial resolution of anthropogenic carbon dioxide emissions. Currently, only national annual data for anthropogenic carbon emissions are available, and as such, no understanding of seasonal or sub-national patterns of emissions are possible. This methodology employs fuel distribution data from representative sectors of the fossil-fuel market to determine the temporal and spatial patterns of fuel consumption. These patterns of fuel consumption are then converted to patterns of carbon emissions. The annual total emissions estimates produced by this method are consistent to those maintained by the United Nations. Improved estimates of temporal and spatial resolution of the human based carbon emissions allows for better projections about future energy demands, carbon emissions, and ultimately the global carbon cycle.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Effect of petrochemical industrial emissions of reactive alkenes and NOx on tropospheric ozone formation in Houston, Texas

    NASA Astrophysics Data System (ADS)

    Ryerson, T. B.; Trainer, M.; Angevine, W. M.; Brock, C. A.; Dissly, R. W.; Fehsenfeld, F. C.; Frost, G. J.; Goldan, P. D.; Holloway, J. S.; Hübler, G.; Jakoubek, R. O.; Kuster, W. C.; Neuman, J. A.; Nicks, D. K.; Parrish, D. D.; Roberts, J. M.; Sueper, D. T.; Atlas, E. L.; Donnelly, S. G.; Flocke, F.; Fried, A.; Potter, W. T.; Schauffler, S.; Stroud, V.; Weinheimer, A. J.; Wert, B. P.; Wiedinmyer, C.; Alvarez, R. J.; Banta, R. M.; Darby, L. S.; Senff, C. J.

    2003-04-01

    Petrochemical industrial facilities can emit large amounts of highly reactive hydrocarbons and NOx to the atmosphere; in the summertime, such colocated emissions are shown to consistently result in rapid and efficient ozone (O3) formation downwind. Airborne measurements show initial hydrocarbon reactivity in petrochemical source plumes in the Houston, TX, metropolitan area is primarily due to routine emissions of the alkenes propene and ethene. Reported emissions of these highly reactive compounds are substantially lower than emissions inferred from measurements in the plumes from these sources. Net O3 formation rates and yields per NOx molecule oxidized in these petrochemical industrial source plumes are substantially higher than rates and yields observed in urban or rural power plant plumes. These observations suggest that reductions in reactive alkene emissions from petrochemical industrial sources are required to effectively address the most extreme O3 exceedences in the Houston metropolitan area.

  14. 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.

  15. Variability of tropospheric methane above the Mediterranean Basin inferred from satellite and model data

    NASA Astrophysics Data System (ADS)

    Ricaud, P.; Sič, B.; El Amraoui, L.; Attié, J.-L.; Huszar, P.; Szopa, S.; Parmentier, J.; Jaidan, N.; Michou, M.; Abida, R.; Zbinden, R.; Carminati, F.; Hauglustaine, D.; August, T.; Warner, J.; Imasu, R.; Saitoh, N.; Peuch, V.-H.

    2014-04-01

    The space and time variabilities of methane (CH4) total column and upper tropospheric mixing ratios are analyzed above the Mediterranean Basin (MB) as part of the Chemical and Aerosol Mediterranean Experiment (ChArMEx) programme. Spaceborne measurements from the Thermal And Near infrared Sensor for carbon Observations-Fourier Transform Spectrometer (TANSO-FTS) instrument on the Greenhouse gases Observing SATellite (GOSAT) satellite, the Atmospheric InfraRed Spectrometer (AIRS) on the AURA platform and the Infrared Atmospheric Sounder Interferometer (IASI) instrument aboard the MetOp-A platform are used in conjunction with model results from the Chemical Transport Model (CTM) MOCAGE, and the Chemical Climate Models (CCMs) CNRM-AOCCM and LMDz-OR-INCA (according to different emission scenarios). In order to minimize systematic errors in the spaceborne measurements, we have only considered maritime pixels over the MB. The period under interest spans from 2008 to 2011 considering satellite and MOCAGE data and, regarding the CCMs, from 2001 to 2010. An East-West gradient in CH4 is observed and modelled whatever the season considered. In winter, air masses mainly originating from Atlantic Ocean and Europe tend to favour an elevated amount of mid-to-upper tropospheric CH4 in the West vs. the East of the MB, with a general upward transport above the MB. In summer, the meteorological state of the MB is changed, favouring air from Northern Africa and Middle East together with Atlantic Ocean and Europe, with a general downward motion above the MB. The Asian Monsoon traps and uplifts high amounts of CH4 that are transported towards North Africa and Middle East by the Asian Monsoon Anticyclone to finally reach and descent in the East of the MB. Consequently, the mid-to-upper tropospheric CH4 is much greater in the East than in the West of the MB. The seasonal variation of the difference in CH4 between the East and the West MB does show a maximum in summer for pressures from 500

  16. Migraine headache is present in the aura phase

    PubMed Central

    Hansen, Jakob M.; Lipton, Richard B.; Dodick, David W.; Silberstein, Stephen D.; Saper, Joel R.; Aurora, Sheena K.; Goadsby, Peter J.

    2012-01-01

    ABSTRACT Objectives: Migraine aura is commonly considered to be a distinct phase of a migraine attack that precedes headache. The objective of the study was to examine a large number of prospectively recorded attacks of migraine with aura and determine the timing of headache and other migraine symptoms relative to aura. Methods: As part of a clinical trial we collected prospective data on the time course of headache and other symptoms relative to the aura. Patients (n = 267) were enrolled from 16 centers, and asked to keep a headache diary for 1 month (phase I). They were asked to record headache symptoms as soon as possible after aura began and always within 1 hour of aura onset. A total of 456 attacks were reported during phase I by 201 patients. These patients were then randomized and included in phase II, during which a total of 405 attacks were reported in 164 patients. In total, we present data from 861 attacks of migraine with aura from 201 patients. Results: During the aura phase, the majority of attacks (73%) were associated with headache. Other migraine symptoms were also frequently reported during the aura: nausea (51%), photophobia (88%), and photophobia (73%). During the first 15 minutes within the onset of aura, 54% of patients reported headache fulfilling the criteria for migraine. Conclusion: Our results indicate that headaches as well as associated migraine symptoms are present early, during the aura phase of the migraine attack in the majority of patients. PMID:23115208

  17. 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

  18. 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.

  19. 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.

  20. Ozone-CO relationships in plumes carrying North American pollution and boreal biomass burning emissions through the central North Atlantic lower free troposphere

    NASA Astrophysics Data System (ADS)

    Honrath, R. E.; Owen, R. C.; Val Martín, M.; Reid, J. S.; Lapina, K.; Kleissl, J. P.; Fialho, P.

    2004-12-01

    North American anthropogenic activities and biomass burning are both significant sources of nitrogen oxides emissions. Recent studies have indicated changes in the NOx\\ to CO emission ratio in U.S. urban regions, and amplified response to global climate change in boreal regions is expected to result (and may already have resulted) in increased frequency of large boreal fires. The PICO-NARE mountaintop (2.2~km altitude) station in the Azores Islands is well situated to probe the overall impact of both processes on lower tropospheric O3\\ levels. Measurements made there during the summers of 2001--2003 have been analyzed to assess these impacts. The relationship between CO and O3\\ in North American pollution outflow was found to be significantly steeper than expected, with a slope (d[O3]/d[ CO]) averaging 1.0 ppbv/ppbv, implying significantly more ozone formation per unit CO emissions than observed in prior measurements over eastern North America and in the nearby downwind region. Potential reasons for this difference, including changes in eastern North American emissions of ozone precursors, airmass history, and NOx,y\\ export, will be discussed. In contrast to the moderate CO enhancements in North American outflow, we find that boreal fires in Siberia and North America result in the highest CO levels observed, produce ozone enhancements comparable to those in North American pollution outflow, and play a major role in interannual variability of CO. It has been suggested that the magnitude of boreal fires may be increasing as a result of changing boreal climate; these findings imply that such an increase could significantly impact hemispheric scale ozone, CO, and nitrogen oxides levels.

  1. Impact of the Asian monsoon anticyclone on the variability of mid-to-upper tropospheric methane above the Mediterranean Basin

    NASA Astrophysics Data System (ADS)

    Ricaud, P.; Sič, B.; El Amraoui, L.; Attié, J.-L.; Zbinden, R.; Huszar, P.; Szopa, S.; Parmentier, J.; Jaidan, N.; Michou, M.; Abida, R.; Carminati, F.; Hauglustaine, D.; August, T.; Warner, J.; Imasu, R.; Saitoh, N.; Peuch, V.-H.

    2014-10-01

    The space and time variabilities of methane (CH4) total column and upper tropospheric mixing ratios are analysed above the Mediterranean Basin (MB) as part of the Chemical and Aerosol Mediterranean Experiment (ChArMEx) programme. Since the analysis of the mid-to-upper tropospheric CH4 distribution from spaceborne sensors and model outputs is challenging, we have adopted a climatological approach and have used a wide variety of data sets. We have combined spaceborne measurements from the Thermal And Near infrared Sensor for carbon Observations - Fourier Transform Spectrometer (TANSO-FTS) instrument on the Greenhouse gases Observing SATellite (GOSAT) satellite, the Atmospheric InfraRed Spectrometer (AIRS) on the AURA platform and the Infrared Atmospheric Sounder Interferometer (IASI) instrument aboard the MetOp-A platform with model results from the Chemical Transport Model (CTM) MOCAGE, and the Chemical Climate Models (CCMs) CNRM-AOCCM and LMDz-OR-INCA (according to different emission scenarios). In order to minimize systematic errors in the spaceborne measurements, we have only considered maritime pixels over the MB. The period of interest spans from 2008 to 2011 considering satellite and MOCAGE data and, regarding the CCMs, from 2001 to 2010. Although CH4 is a long-lived tracer with lifetime of ~12 years and is supposed to be well mixed in the troposphere, an east-west gradient in CH4 is observed and modelled in the mid-to-upper troposphere with a maximum in the Western MB in all seasons except in summer when CH4 accumulates above the Eastern MB. The peak-to-peak amplitude of the east-west seasonal variation in CH4 above the MB in the upper troposphere (300 hPa) is weak but almost twice as great in the satellite measurements (~25 ppbv) as in the model data (~15 ppbv). The maximum of CH4 in summer above the eastern MB can be explained by a series of dynamical processes only occurring in summer. The Asian monsoon traps and uplifts high amounts of CH4 to the upper

  2. 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

  3. 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.

  4. Tropospheric Ozone Over North America

    NASA Astrophysics Data System (ADS)

    Oltmans, S. J.; Thompson, A. M.; Cooper, O. R.; Merrill, J. T.; Tarasick, D. W.; Newchurch, M. J.

    2007-05-01

    Ozone in the troposphere plays a significant role as an absorber of infrared radiation (greenhouse gas), in the cleansing capacity of the atmosphere as a precursor of hydroxol radical formation, and a regulated air pollutant capable of deleterious health and ecosystem effects. Knowledge of the ozone budget in the troposphere over North America (NA) is required to properly understand the various mechanisms that contribute to the measured distribution and to develop and test models capable of simulating and predicting this key player in atmospheric chemical and physical processes. Recent field campaigns including the 2004 and 2006 INTEX Ozone Network Studies (IONS) http:croc.gsfc.nasa.gov/intexb/ions06.html that have included intensive ozone profile measurements from ozonesondes provide a unique data set for describing tropospheric ozone over a significant portion of the North American continent. These campaigns have focused on the spring and summer seasons when tropospheric ozone over NA is particularly influenced by long-range transport processes, significant photochemical ozone production resulting from both anthropogenic and natural (lightning) precursor emissions, and exchange with the stratosphere. This study uses ozone profiles measured over NA in the latitude band from approximately 12-60N, extending from the tropics to the high mid latitudes, to describe the seasonal behavior of tropospheric ozone over NA with an emphasis on the spring and summer. This includes the variability within seasons at a particular site as well as the contrasts between the seasons. Emphasis is placed on the variations among the sites including latitudinal and longitudinal gradients and how these differ through the seasons and with altitude in the troposphere. Regional differences are most pronounced during the summer season likely reflecting the influence of a wider variation in processes influencing the tropospheric ozone distribution including lightning NOX production in the upper

  5. 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

  6. 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.

  7. [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

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. Methane emission from Western Siberia derived from the integral methane balance in the troposphere for 2001 -2011

    NASA Astrophysics Data System (ADS)

    Bogomolov, Vasiliy; Stepanenko, Victor; Okladnikov, Igor; Titov, Alexander

    2014-05-01

    Although a number of estimates of methane emissions from large Earth regions have been proposed, based on either empirical or inverse transport modeling approaches, these emissions still remain highly uncertain motivating the development of new methods of surface flux assessment. In this study a new mathematical formulation for calculation of surface flux of methane, or any other gaseous component of the atmosphere, is developed. In it, the surface flux is retrieved from the integral balance of methane in bounded atmospheric domain. This balance includes the surface flux, the net advective flux through lateral boundaries of the atmospheric domain, methane sink due to oxidation by hydroxyl radical, and the rate of change of total methane amount in the domain. Western Siberia, being on of the most prominent surface methane sources in Northern hemisphere, is used as a test region for the method. The components of methane balance are calculated using methane concentrations and wind speeds from MACC reanalysis at 1.125 deg. grid (http://www.ecmwf.int/research/EU_projects/MACC), and hydroxyl concentrations provided by (Spivakovsky, 2000). The total methane flux from Western Siberia is thus assessed at 6 h resolution for 2001-2011. The time averaged total flux corresponds well to empirical estimates at diurnal and annual timescales. It may be anticipated that the method will be useful in close future when the satellite-retrieved methane concentration profiles will achieve high accuracy.

  13. Simulating the effects of mid- to upper-tropospheric clouds on microwave emissions in EC-Earth using COSP

    NASA Astrophysics Data System (ADS)

    Johnston, M. S.; Holl, G.; Hocking, J.; Cooper, S. J.; Chen, D.

    2015-11-01

    In this work, the Cloud Feedback Model Intercomparison (CFMIP) Observation Simulation Package (COSP) is expanded to include scattering and emission effects of clouds and precipitation at passive microwave frequencies. This represents an advancement over the official version of COSP (version 1.4.0) in which only clear-sky brightness temperatures are simulated. To highlight the potential utility of this new microwave simulator, COSP results generated using the climate model EC-Earth's version 3 atmosphere as input are compared with Microwave Humidity Sounder (MHS) channel (190.311 GHz) observations. Specifically, simulated seasonal brightness temperatures (TB) are contrasted with MHS observations for the period December 2005 to November 2006 to identify possible biases in EC-Earth's cloud and atmosphere fields. The EC-Earth's atmosphere closely reproduces the microwave signature of many of the major large-scale and regional scale features of the atmosphere and surface. Moreover, greater than 60 % of the simulated TB are within 3 K of the NOAA-18 observations. However, COSP is unable to simulate sufficiently low TB in areas of frequent deep convection. Within the Tropics, the model's atmosphere can yield an underestimation of TB by nearly 30 K for cloudy areas in the ITCZ. Possible reasons for this discrepancy include both incorrect amount of cloud ice water in the model simulations and incorrect ice particle scattering assumptions used in the COSP microwave forward model. These multiple sources of error highlight the non-unique nature of the simulated satellite measurements, a problem exacerbated by the fact that EC-Earth lacks detailed micro-physical parameters necessary for accurate forward model calculations. Such issues limit the robustness of our evaluation and suggest a general note of caution when making COSP-satellite observation evaluations.

  14. Lower tropospheric aerosol loadings over South Africa: The relative contribution of aeolian dust, industrial emissions, and biomass burning

    NASA Astrophysics Data System (ADS)

    Piketh, S. J.; Annegarn, H. J.; Tyson, P. D.

    1999-01-01

    The southern African haze layer is a ubiquitous subcontinental-scale feature of the lower atmosphere that extends to a depth of ˜5 km(˜500 hPa level) on non rain days, particularly in winter. Aerosols derived from biomass burning are commonly thought to contribute substantially to the total background aerosol loading within the layer. It is shown that in both summer and winter this supposition is without foundation over South Africa. Summer and winter aerosol loadings are derived from gravimetric analysis of stacked filter units and from proton-induced X ray emission (PIXE) analysis of one to four hourly resolved streaker samples. From concentrations of eleven inorganic elements, apportionment into four primary sources, biomass burning particulates, aeolian dust, industrial sulphur aerosols, and marine aerosols, has been effected. It is shown that the background biomass burning component of the total aerosol loading over South Africa in general, and within the plume of material being recirculated over South Africa and from there exported from the subcontinent south of 22°S to the Indian Ocean in particular, is minimal in both summer and winter. Except over coastal and adjacent inland areas, marine aerosols likewise make up a small fraction of the total loading. This is particularly so over the inland plateau areas. Crustally-derived aeolian dust and industrially-produced sulphur aerosols are demonstrated to be the major summer and winter constituents of the haze layer over South Africa and the particulate material being transported to the Indian Ocean region. Sulphur is transported within the aerosol plume exiting southern Africa to the Indian Ocean as agglomerates on aeolian dust nuclei.

  15. A comparison of minor trace gas retrievals from the Tropospheric Emission Spectrometer (TES) and the Infrared Atmospheric Sounding Interferometer (IASI)

    NASA Astrophysics Data System (ADS)

    Cady-Pereira, K. E.; Shephard, M. W.; Henze, D. K.; Millet, D. B.; Gombos, D.; Van Damme, M.; Clarisse, L.; Coheur, P. F.; Pommier, M.; Clerbaux, C.

    2014-12-01

    The advent of hyperspectral infrared instruments orbiting the Earth has allowed for detecting and measuring numerous trace gas species that play important roles in atmospheric chemistry and impact air quality, but for which there is a dearth of information on their distribution and temporal variability. Here we will present global and regional comparisons of measurements from the NASA TES and the European MetOp IASI instruments of three of these gases: ammonia (NH3), formic acid (HCOOH) and methanol (CH3OH). Ammonia is highly reactive and thus very variable in space and time, while the sources and sinks of methanol and formic acid are poorly quantified: thus space-based measurements have the potential of significantly increasing our knowledge of the emissions and distributions of these gases. IASI and TES have many similarities but some significant differences. TES has significantly higher spectral resolution (0.06 cm-1), and its equator crossing times are ~1:30 am and 1:30 pm, local time, while IASI has lower resolution (0.5 cm-1) and an earlier equator crossing time (9:30 am and 9:30 pm), which leads to lower thermal contrast; however IASI provides much greater temporal and spatial coverage due to its cross-track scanning. Added to the instrumental differences are the differences in retrieval algorithms. The IASI team uses simple but efficient methods to estimate total column amounts of the species above, while the TES team performs full optimal estimation retrievals. We will compare IASI and TES total column measurements averaged on a 2.5x2.5 degree global grid for each month in 2009, and we will examine the seasonal cycle in some regions of interest, such as South America, eastern China, and the Midwest and the Central Valley in the US. In regions where both datasets are in agreement this analysis will provide confidence that the results are robust and reliable. In regions where there is disagreement we will look for the causes of the discrepancies, which will

  16. Upper Troposphere/Lower Stratosphere (UTLS) Trace Gas Evolution in Recent Satellite Datasets: Relationships to Stratospheric and Upper Tropospheric Jets

    NASA Astrophysics Data System (ADS)

    Manney, G. L.; Hegglin, M. I.; Daffer, W. H.; Santee, M. L.; Bernath, P. F.; Boone, C. D.; Gille, J. C.; Kinnison, D.; Krueger, K.; Livesey, N. J.; Minschwaner, K.; Nardi, B.; Pawson, S.; Walker, K. A.

    2008-12-01

    A method has been developed for categorizing the location and characteristics of upper tropospheric jets and of the lower reaches of the stratospheric polar night jet (PNJ) that extend into the upper troposphere/lower stratosphere (UTLS). This method is applied to define the position, width and dynamical characteristics (e.g., windspeed/direction, potential vorticity, temperature, static stability, etc) of the primary subtropical jet (STJ) core, as well as similar information on multiple jets in the extratropical (ET) UTLS. The PNJ in the UTLS is characterized at each level by its position, width, and dynamical characteristics. Jet characteristics during quasi-isentropic stratosphere-troposphere exchange (STE) events and seasonal evolution of jet structure are investigated in Goddard Earth Observing System Version 5 (GEOS-5) and other meteorological analyses. Satellite trace gas measurements from several current instruments, including the Aura Microwave Limb Sounder (MLS), Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) and the Aura High Resolution Dynamics Limb Sounder (HIRDLS), are studied to further our understanding of the seasonal evolution of the ET tropopause layer in relation to the STJ and the tropopause.

  17. 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.

  18. 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.

  19. Decadal Regional Trends in Trace Gases and Reflectance As Measured with the Ozone Monitoring Instrument (OMI) on Eos Aura

    NASA Astrophysics Data System (ADS)

    Veefkind, J. P.; Boersma, F. F.; Kleipool, Q.; Desmedt, I.; Levelt, P.

    2014-12-01

    The Dutch-Finnish Ozone Monitoring Instrument (OMI) is a UV-visible spectrometer on board of the NASA EOS Aura mission. Due to its innovative design, OMI combines a high spatial resolution (13x24km2 at nadir) with a wide swath of 2600 km that enables daily global coverage. The OMI science data record started in October 2004 and already spans a decade. The instrument shows very low optical degradation: after 10 years in orbit the throughput at its shortest UV wavelengths has only been reduced by a few percent and at longer wavelengths this degradation is about 1%. This stability makes the instrument extremely valuable for trend analysis, although due to the so-called "row anomaly" part of the swath is no longer providing science-quality data since 2009. Both the optical degradation and the row anomaly are well characterized. The OMI data record shows that in the past decade the emissions of trace gases have changed considerably. Over most of the industrialized countries in Europe, North America and Asia emissions of NOx and SO2 have been reduced, whereas in the developing countries the emissions have generally increased. These changes in emissions directly affect the air quality, including the concentration of secondary aerosol particles. Due to the direct and indirect effect of aerosols, it is expected that the radiation balance is also affected, resulting in changes in shortwave radiance at the surface and at the top of the atmosphere. In this contribution we will present time series analysis of tropospheric NO2 and formaldehyde columns from OMI, in combination with aerosol optical depth time series from MODIS on EOS Aqua. We concentrate on mega-cities in India, China and the U.S.A., because in these densely populated regions the effects of air quality are the largest. To quantify the local effects of aerosols on the radiation balance, we combine the trends in the aerosol optical depth with trends of the reflectance at the top of the atmosphere, as measured by OMI.

  20. A Multi-sensor Upper Tropospheric Ozone Product (MUTOP) based on TES ozone and GOES water vapor: derivation

    NASA Astrophysics Data System (ADS)

    Felker, S. R.; Moody, J. L.; Wimmers, A. J.; Osterman, G.; Bowman, K.

    2010-12-01

    The Tropospheric Emission Spectrometer (TES), a hyperspectral infrared instrument on the Aura satellite, retrieves a vertical profile of tropospheric ozone. However, polar-orbiting instruments like TES provide limited nadir-view coverage. This work illustrates the value of these observations when taken in context with information about synoptic-scale weather patterns. The goal of this study is to create map-view products of upper troposphere (UT) ozone through the integration of TES ozone measurements with two synoptic dynamical tracers of stratospheric influence: specific humidity derived from the GOES Imager, and potential vorticity from an operational forecast model. As a mixing zone between tropospheric and stratospheric reservoirs, the upper troposphere (UT) exhibits a complex chemical makeup. Determination of ozone mixing ratios in this layer is especially difficult without direct in-situ measurement. However, it is well understood that UT ozone is correlated with dynamical tracers like low specific humidity and high potential vorticity. Blending the advantages of two remotely sensed quantities (GOES water vapor and TES ozone) is at the core of the Multi-sensor Upper Tropospheric Ozone Product (MUTOP). Our approach results in the temporal and spatial coverage of a geostationary platform, a major improvement over individual polar overpasses, while retaining TES's ability to characterize UT ozone. Results suggest that over 70% of TES-observed UT ozone variability can be explained by correlation with the two dynamical tracers. MUTOP reproduces TES retrievals across the GOES-West domain with a root mean square error (RMSE) of 19.2 ppbv. There are several advantages to this multi-sensor derived product approach: (1) it is calculated from 2 operational fields (GOES specific humidity and GFS PV), so the layer-average ozone can be created and used in near real-time; (2) the product provides the spatial resolution and coverage of a geostationary platform as it depicts

  1. A multi-sensor upper tropospheric ozone product (MUTOP) based on TES Ozone and GOES water vapor: derivation

    NASA Astrophysics Data System (ADS)

    Felker, S. R.; Moody, J. L.; Wimmers, A. J.; Osterman, G.; Bowman, K.

    2011-07-01

    The Tropospheric Emission Spectrometer (TES), a hyperspectral infrared instrument on the Aura satellite, retrieves a vertical profile of tropospheric ozone. However, polar-orbiting instruments like TES provide limited nadir-view coverage. This work illustrates the value of these observations when taken in context with geostationary imagery describing synoptic-scale weather patterns. The goal of this study is to create map-view products of upper troposphere (UT) ozone through the integration of TES ozone measurements with two synoptic dynamic tracers of stratospheric influence: specific humidity derived from the GOES Imager water vapor absorption channel, and potential vorticity (PV) from an operational forecast model. As a mixing zone between tropospheric and stratospheric reservoirs, the upper troposphere (UT) exhibits a complex chemical makeup. Determination of ozone mixing ratios in this layer is especially difficult without direct in situ measurement. However, it is well understood that UT ozone is correlated with dynamical tracers like low specific humidity and high potential vorticity. Blending the advantages of two remotely sensed quantities (GOES water vapor and TES ozone) is at the core of the Multi-sensor Upper Tropospheric Ozone Product (MUTOP). Our results suggest that 72 % of TES-observed UT ozone variability can be explained by its correlation with dry air and high PV. MUTOP reproduces TES retrievals across the GOES-West domain with a root mean square error (RMSE) of 18 ppbv (part per billion by volume). There are several advantages to this multi-sensor derived product approach: (1) it is calculated from two operational fields (GOES specific humidity and GFS PV), so maps of layer-average ozone can be created and used in near real-time; (2) the product provides the spatial resolution and coverage of a geostationary image as it depicts the variable distribution of ozone in the UT; and (3) the 6 h temporal resolution of the derived product imagery allows

  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. 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.

  4. 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.

  5. (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.

  6. 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.

  7. 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.

  8. Data Assimilation at High Spatial Resolution in a Study of Tropospheric ozone and Stratosphere-Troposphere Exchange

    NASA Astrophysics Data System (ADS)

    Wargan, K.; Pawson, S.

    2011-12-01

    Assimilation of retrieved statellite ozone data is a statisticaly optimal way to combine high-quality observations with transport model output. It has been shown that assimilated ozone fields can exhibit a good agreement with independent data including satellite, ground-based and sonde measurements. Assimilation at high vertical and horizontal resolutions provides a unique opportunity to map and study the occurence and evolution of finer scale features of a tracer field on a global scale. This paper presents results of a long assimilation constrained by the ozone data from two EOS Aura sensors: the total column ozone from the Ozone Monitoring Instrument (OMI) and high vertical resolution stratospheric profiles from Microwave Limb Sounder (MLS, version 3.3). The experiment uses GMAO's GEOS-5 data assimilation system run at a 0.5 degree horizontal resolution on 72 terrain-following levels. Our focus is on the the upper troposphere - lower stratosphere (UTLS) layer and tropospheric ozone column. The UTLS is especially important for correct representation of radiative forcing in forecast models with interactive ozone such as GEOS-5, as well as for scientific understanding of the tropospheric ozone budget. The UTLS results are interpreted using different definitions of the tropopause in order to identify stratosphere-troposphere exchange events. For the tropospheric column, the advantages of combining high horizontal resolution of the model with the small footprint of the OMI instruments are highlighted.

  9. Alleviation of Brain Hypoperfusion after Preventative Treatment with Lomerizine in an Elderly Migraineur with Aura

    PubMed Central

    Aoyagi, Joe; Ikeda, Ken; Kiyozuka, Tetsuhito; Hirayama, Takehisa; Ishikawa, Yuichi; Sato, Ryuta; Yoshii, Yasuhiro; Kawabe, Kiyokazu; Iwasaki, Yasuo

    2011-01-01

    Previous studies of brain single-photon emission tomography (SPECT) showed changes of regional cerebral blood flow (rCBF) in migraineurs during prodromes or headache attacks. Little is known about how successful medication of migraine prevention can reflect rCBF in migraineurs. We highlighted alternation of brain SPECT findings in a migraineur with aura before and after prophylactic treatment with lomerizine, a calcium channel blocker. A 70-year-old man with migraine developed visual disturbance frequently at walking exercise for the recent 3 months. After this visual attack, a mild-degree of throbbing headache occured occasionally. Brain SPECT using 99mTc-ethyl cysteinate dimer was performed at interictal time of migraine. Brain SPECT before lomerizine treatment revealed hypoperfusion in the frontal, parietal, and occipital regions. He was diagnosed with recurrence of migraine with aura (MA). Lomerizine (10 mg/day, po) was administered for 3 months. MA and visual aura without headache were dramatically improved. Migraine attacks and visual disturbance were not induced at exercise. At 3 months after lomerizine medication, brain SPECT showed remarkable increase of rCBF. These SPECT changes of our patient indicated that antimigraine mechanism of lomerizine could contribute to restoration of cerebral hypoperfusion. PMID:21490733

  10. 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. PMID:22197149

  11. Satellite observations of tropospheric formaldehyde combining GOME-2 and OMI measurements.

    NASA Astrophysics Data System (ADS)

    De Smedt, Isabelle; Van Roozendael, Michel; Stavrakou, Trissevgeny; Müller, Jean-François; Pinardi, Gaia; Hendrick, François

    2014-05-01

    This work addresses the observation of tropospheric formaldehyde (H2CO) at the global scale using multiple nadir UV sensors, in an attempt to characterize the variability and long-term changes in NMVOC emissions, related to pollution, climate and land use changes. We present an updated version (v13) of the TEMIS formaldehyde data products retrieved from GOME-2 on METOP-A and B at mid-morning, and from OMI on AURA in the early afternoon. Consistent retrieval settings are used for all sensors following an algorithm baseline described in De Smedt et al. (2012), which is also the reference algorithm for the future TROPOMI/Sentinel-5 Precursor instrument to be launched in 2015. The satellite columns are validated using MAX-DOAS measurements in Eastern China (Xiang He), Europe (Uccle and OHP) and Equatorial Africa (Bujumbura). We show that the diurnal variation of the formaldehyde column as measured by the MAX-DOAS instruments is well reproduced by the morning and afternoon satellite measurements. This suggests that a good level of inter-sensor consistency has been achieved for H2CO column measurements from GOME-2 and OMI. Furthermore, regional trends in the formaldehyde columns are estimated from the different satellite datasets. Common features are observed such as a decrease of the formaldehyde columns in the Amazonian forest during the last decade, or lower 2009-2011 levels of pollution-related H2CO columns in industrialized regions.

  12. 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.

  13. 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.

  14. 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

  15. A total ozone-dependent ozone profile climatology based on ozonesondes and Aura MLS data

    NASA Astrophysics Data System (ADS)

    Labow, Gordon J.; Ziemke, Jerald R.; McPeters, Richard D.; Haffner, David P.; Bhartia, Pawan K.

    2015-03-01

    Ozone profiles measured with the Aura Microwave Limb Sounder (MLS) and ozonesondes are used to create a new ozone climatology that can be used for satellite retrievals and radiative transfer studies. The climatology is binned according to total column ozone amount and latitude rather than with season. Because of high correlation between ozone profile shape and total ozone, the ozone profiles in this climatology capture ozone variations well, especially near the tropopause. This climatology has been constructed from nearly a million individual MLS ozone profile measurements taken between 2004 and 2013 as well as over 55,000 ozonesonde measurements from 1988 to 2011. The MLS profiles were sorted by total column ozone as measured by Ozone Monitoring Instrument in observations that were coincident with the MLS measurements. The data from the sondes were used in the troposphere and lower stratosphere and MLS in the middle and upper stratosphere. These two data sets were blended together between 13 and 17 km (~159-88 hPa). This climatology consists of average ozone profiles as a function of total ozone for six 30° latitude bands covering altitudes between 0 and 75 km (in Z* pressure altitude coordinates) as well as the corresponding standard deviations for each layer. There is no seasonal component. This new climatology shows some remarkable and somewhat unexpected correlations between the total column ozone and the ozone amount at some layers, particularly in the lower and middle troposphere in some latitude bands.

  16. A Total Ozone Dependent Ozone Profile Climatology Based on Ozone-Sondes and Aura MLS Data

    NASA Astrophysics Data System (ADS)

    Labow, G. J.; McPeters, R. D.; Ziemke, J. R.

    2014-12-01

    A new total ozone-based ozone profile climatology has been created for use in satellite and/or ground based ozone retrievals. This climatology was formed by combining data from the Microwave Limb Sounder (MLS) with data from balloon sondes and binned by zone and total ozone. Because profile shape varies with total column ozone, this climatology better captures the ozone variations than the previously used seasonal climatologies, especially near the tropopause. This is significantly different than ozone climatologies used in the past as there is no time component. The MLS instrument on Aura has excellent latitude coverage and measures ozone profiles daily from the upper troposphere to the lower mesosphere at ~3.5 km resolution. Almost a million individual MLS ozone measurements are merged with data from over 55,000 ozonesondes which are then binned as a function of total ozone. The climatology consists of average ozone profiles as a function of total ozone for six 30 degree latitude bands covering altitudes from 0-75 km (in Z* pressure altitude coordinates). This new climatology better represents the profile shape as a function of total ozone than previous climatologies and shows some remarkable and somewhat unexpected correlations between total ozone and ozone in the lower altitudes, particularly in the lower and middle troposphere. These data can also be used to infer biases and errors in either the MLS retrievals or ozone sondes.

  17. Constraints on Asian ozone using Aura TES, OMI and Terra MOPITT

    NASA Astrophysics Data System (ADS)

    Jiang, Z.; Worden, J. R.; Jones, D. B. A.; Lin, J.-T.; Verstraeten, W. W.; Henze, D. K.

    2015-01-01

    Rapid industrialization in Asia in the last two decades has resulted in a significant increase in Asian ozone (O3) precursor emissions with likely a corresponding increase in the export of O3 and its precursors. However, the relationship between this increasing O3, the chemical environment, O3 production efficiency, and the partitioning between anthropogenic and natural precursors is unclear. In this work, we use satellite measurements of O3, CO and NO2 from TES (Tropospheric Emission Spectrometer), MOPITT (Measurement of Pollution In The Troposphere) and OMI (Ozone Monitoring Instrument) to quantify O3 precursor emissions for 2006 and their impact on free tropospheric O3 over northeastern Asia, where pollution is typically exported globally due to strong westerlies. Using the GEOS-Chem (Goddard Earth Observing System Chemistry) global chemical transport model, we test the modeled seasonal and interannual variation of O3 based on prior and updated O3 precursor emissions where the updated emissions of CO and NOx are based on satellite measurements of CO and NO2. We show that the observed TES O3 variability and amount are consistent with the model for these updated emissions. However, there is little difference in the modeled ozone between the updated and prior emissions. For example, for the 2006 June time period, the prior and posterior NOx emissions were 14% different over China but the modeled ozone in the free troposphere was only 2.5% different. Using the adjoint of GEOS-Chem we partition the relative contributions of natural and anthropogenic sources to free troposphere O3 in this region. We find that the influence of lightning NOx in the summer is comparable to the contribution from surface emissions but smaller for other seasons. China is the primary contributor of anthropogenic CO, emissions and their export during the summer. While the posterior CO emissions improved the comparison between model and TES by 32%, on average, this change also had only a small

  18. 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

  19. 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.

  20. 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…

  1. 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.

  2. AURA 2: Empowering discovery of post-transcriptional networks.

    PubMed

    Dassi, Erik; Re, Angela; Leo, Sara; Tebaldi, Toma; Pasini, Luigi; Peroni, Daniele; Quattrone, Alessandro

    2014-01-01

    Post-transcriptional regulation (PTR) of gene expression is now recognized as a major determinant of cell phenotypes. The recent availability of methods to map protein-RNA interactions in entire transcriptomes such as RIP, CLIP and their variants, together with global polysomal and ribosome profiling techniques, are driving the exponential accumulation of vast amounts of data on mRNA contacts in cells, and of corresponding predictions of PTR events. However, this exceptional quantity of information cannot be exploited at its best to reconstruct potential PTR networks, as it still lies scattered throughout several databases and in isolated reports of single interactions. To address this issue, we developed the second and vastly enhanced version of the Atlas of UTR Regulatory Activity (AURA 2), a meta-database centered on mapping interaction of trans-factors with human and mouse UTRs. AURA 2 includes experimentally demonstrated binding sites for RBPs, ncRNAs, thousands of cis-elements, variations, RNA epigenetics data and more. Its user-friendly interface offers various data-mining features including co-regulation search, network generation and regulatory enrichment testing. Gene expression profiles for many tissues and cell lines can be also combined with these analyses to display only the interactions possible in the system under study. AURA 2 aims at becoming a valuable toolbox for PTR studies and at tracing the road for how PTR network-building tools should be designed. AURA 2 is available at http://aura.science.unitn.it. PMID:26779400

  3. 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.

  4. CAFS ozone column data for validation of the AURA ozone products

    NASA Astrophysics Data System (ADS)

    Shetter, R.; Petropavlovskikh, I.; Hall, S. R.; Froidevaux, L.; Bhartia, P. K.; Kroon, M.

    2005-12-01

    Highly resolved UV and Visible actinic flux measurements were taken by the CCD Actinic Flux Spectrometer (CAFS) instrument (R. Shetter, NCAR) on board of the WB-57 aircraft as part of the Aura Validation Experiment (AVE) campaign in Texas in 2004. The algorithm was developed and field-tested to derive partial ozone column products from the CAFS measurements. An intensive data set of partial ozone columns measured along the tracks of the Aura satellite has been provided for the first-round satellite validation. Preliminary analysis of the CAFS measurements revealed that small corrections to the instrument-weighted solar spectrum data were required. On its second deployment in January 2005, the CAFS instrument was flown on board of the DC-8 aircraft as part of the Polar AVE campaign. Partial ozone column data above 12 km were derived under the difficult conditions of low-sun and high ozone variability. The tropospheric ozone climatology (McPeters et al, 2004) was used for the unaccounted lower part of the ozone column below the aircraft altitude. The set of combined CAFS and climatological data was successfully used for validation of the OMI total ozone column under low-sun conditions (solar zenith angle larger than 80-degrees). Prior to the third AVE campaign in June of 2005, the CAFS instrument was modified to reduce sensitivity of the measurement to the variability of scattered light over inhomogeneous background. New look-up tables were developed and CAFS measurements have been analyzed. The preliminary results suggest that the measurement has become more sensitive to the aircraft roll and pitch movements. We will present results of the OMI total ozone column validation at different atmospheric conditions including a large range of total ozone columns and solar zenith angles, multiple altitudes, and underlying surface albedo. The MLS/Aura ozone profiles have been derived for the last three AVE campaigns. The co-incidental MLS ozone profiles were integrated above

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.