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Sample records for abarema cochliacarpos gomes

  1. Abarema cochliacarpos Extract Decreases the Inflammatory Process and Skeletal Muscle Injury Induced by Bothrops leucurus Venom

    PubMed Central

    Saturnino-Oliveira, Jeison; Santos, Daiana Do Carmo; Guimarães, Adriana Gibara; Santos Dias, Antônio; Tomaz, Marcelo Amorim; Monteiro-Machado, Marcos; Estevam, Charles Santos; Lucca Júnior, Waldecy De; Maria, Durvanei Augusto; Melo, Paulo A.; Araújo, Adriano Antunes de Souza; Santos, Márcio Roberto Viana; Almeida, Jackson Roberto Guedes da Silva; Oliveira, Rita de Cássia Meneses; Pereira de Oliveira, Aldeidia; Quintans Júnior, Lucindo José

    2014-01-01

    Snakebites are a public health problem, especially in tropical countries. However, treatment with antivenom has limited effectiveness against venoms' local effects. Here, we investigated the ability of Abarema cochliacarpos hydroethanolic extract (EAc) to protect mice against injection of Bothrops leucurus venom. Swiss mice received perimuscular venom injection and were subsequently treated orally with EAc in different doses. Treatment with EAc 100, 200, and 400 mg/kg reduced the edema induced by B. leucurus in 1%, 13%, and 39%, respectively. Although lower doses showed no antihypernociceptive effect in the Von Frey test, the higher dose significantly reduced hyperalgesia induced by the venom. Antimyotoxic activity of EAc was also observed by microscopy assessment, with treated muscles presenting preserved structures, decreased edema, and inflammatory infiltrate as compared to untreated ones. Finally, on the rotarod test, the treated mice showed better motor function, once muscle fibers were preserved and there were less edema and pain. Treated mice could stand four times more time on the rotating rod than untreated ones. Our results have shown that EAc presented relevant activities against injection of B. leucurus venom in mice, suggesting that it can be considered as an adjuvant in the treatment of envenomation. PMID:25136627

  2. Abarema cochliacarpos extract decreases the inflammatory process and skeletal muscle injury induced by Bothrops leucurus venom.

    PubMed

    Saturnino-Oliveira, Jeison; Santos, Daiana Do Carmo; Guimarães, Adriana Gibara; Santos Dias, Antônio; Tomaz, Marcelo Amorim; Monteiro-Machado, Marcos; Estevam, Charles Santos; De Lucca Júnior, Waldecy; Maria, Durvanei Augusto; Melo, Paulo A; Araújo, Adriano Antunes de Souza; Santos, Márcio Roberto Viana; Almeida, Jackson Roberto Guedes da Silva; Oliveira, Rita de Cássia Meneses; Pereira de Oliveira, Aldeidia; Quintans Júnior, Lucindo José

    2014-01-01

    Snakebites are a public health problem, especially in tropical countries. However, treatment with antivenom has limited effectiveness against venoms' local effects. Here, we investigated the ability of Abarema cochliacarpos hydroethanolic extract (EAc) to protect mice against injection of Bothrops leucurus venom. Swiss mice received perimuscular venom injection and were subsequently treated orally with EAc in different doses. Treatment with EAc 100, 200, and 400 mg/kg reduced the edema induced by B. leucurus in 1%, 13%, and 39%, respectively. Although lower doses showed no antihypernociceptive effect in the Von Frey test, the higher dose significantly reduced hyperalgesia induced by the venom. Antimyotoxic activity of EAc was also observed by microscopy assessment, with treated muscles presenting preserved structures, decreased edema, and inflammatory infiltrate as compared to untreated ones. Finally, on the rotarod test, the treated mice showed better motor function, once muscle fibers were preserved and there were less edema and pain. Treated mice could stand four times more time on the rotating rod than untreated ones. Our results have shown that EAc presented relevant activities against injection of B. leucurus venom in mice, suggesting that it can be considered as an adjuvant in the treatment of envenomation. PMID:25136627

  3. Formaldehyde from GOME-2

    NASA Astrophysics Data System (ADS)

    Comyn-Platt, Edward; Hewson, Will; Bösch, Hartmut; Barkley, Mike

    2014-05-01

    Isoprene is the most abundant non-methane biogenic volatile organic compound (BVOC) emitted into the atmosphere with emissions roughly equal to global methane emissions from all sources. Isoprene strongly influences the oxidation capacity in the troposphere hence influences levels of methane and tropospheric ozone, and is also a precursor to secondary organic aerosol. Isoprene, therefore, plays a significant role in radiative forcing and determining Earth's climate trends. However, the exact mechanisms of isoprene emission from vegetation are poorly understood and current land-surface models often use different parameterisation and meteorological fields to drive such schemes. Furthermore, isoprene emissions measurements are rare and are difficult to extrapolate to regional and continental scales thus resulting in large uncertainties in the total global emissions. Formaldehyde (HCHO) is formed as an intermediate product during the isoprene oxidation process and can be used as a proxy for isoprene emission. Global satellite observations of formaldehyde are now available from a number of satellite sensors which offer a unique ability to study isoprene emissions over large regions. Here, we use formaldehyde observations from the Global Ozone Monitoring Experiment 2 (GOME-2) instrument retrieved with the University of Leicester retrieval (Hewson et al. 2013) to: 1) test state-of-the-art model calculations using the GEOS-CHEM global transport model; 2) investigate the key drivers for regional year-to-year anomalies in formaldehyde (or isoprene) emissions and 3) assess the ability of current land surface models (MEGAN, JULES) to reproduce the observed anomalies and their dependence on climate variations.

  4. GOME Calibration and Validation Using Backscatter UV Techniques

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.; Gleason, J.; Janz, S.; Gu, X.-y.; Cebula, R. P.; Chance, K. V.; Hoekstra, R.

    1996-01-01

    GOME radiance, irradiance, and ozone products were validated by NASA Goddard Space Flight Center through three tasks which included, pre-launch calibration comparisons with SBUV and TOMS radiometric standards, validation of GOME Level-1 irradiance and radiance and Level 2 total ozone data products using SBUV/2 and TOMS algorithms and data, and studies of GOME data using the Goddard radiative transfer code. The prelaunch calibration using the NASA large aperture integrating sphere was checked against that provided by TPD. Agreement in the calibration constants, derived in air, between the Goddard and TPD system were better than 3%. Validation of Level-1 irradiance data included comparison of GOME and SSBUV and the UARS solar irradiances measurements. Large wavelength dependent differences, as high as 10%, were noted between GOME and the US instruments. This discrepancy has now been attributed to radiometric sensitivity changes experienced by GOME when operating in a vacuum. GOME Earth radiance data were then compared to the NOAA-14 SBUV/2 radiances. These results show that between 340 and 400 nm the differences in GOME and SBUV/2 data are less than 5% with some wavelength dependence. At wavelengths shorter than 300 nm, differences are of the order of 10% or more where the GOME radiances are larger. To test GOME DOAS retrieved total ozone values, these values were compared with ozone amounts retrieved using GOME radiances in the TOMS version-7 algorithm. The differences showed a solar zenith angle dependence ranging from 0 to 10% where the TOMS algorithm values were higher. GOME radiances below 300 nm were further validated by selecting radiances at wavelengths normally used by SBUV and processing them through the SBUV ozone profile algorithm and then compared to climatological values. The GOME ozone profiles ranged from 10-30% lower over altitude compared to climatological values. This is consistent with the offsets detected in the SBUV/2 radiance comparisons at

  5. Ozone profile retrievals from the ESA GOME instrument

    NASA Technical Reports Server (NTRS)

    Munro, Rosemary; Kerridge, Brian J.; Burrows, John P.; Chance, Kelly

    1994-01-01

    The potential of the ESA Global Ozone Monitoring Experiment (GOME) to produce ozone profile information has been examined by carrying out two sample retrievals using simulated GOME data. The first retrieval examines the potential of the GOME instrument to produce stratospheric ozone profiles using the traditional back-scatter ultraviolet technique, while the second examines the possibility of obtaining tropospheric profile information, and improving the quality of the stratospheric profile retrievals, by exploiting the temperature dependence of the ozone Huggins bands.

  6. US Participation in the GOME and SCIAMACHY Projects

    NASA Technical Reports Server (NTRS)

    Chance, K. V.; Geary, J. C.; Spurr, R. J. D.

    1998-01-01

    This report summarizes research done under NASA Grant NAGW-2541 through September 30, 1997. The research performed under this grant includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, sensitivity and instrument studies to define GOME and SCIAMACHY instruments, consultation on optical and detector issues for both GOME and SCIAMACHY, consultation and development for SCIAMACHY near-real-time (NRT) and off-line (OL) data products, and development of infrared line-by-line atmospheric modeling and retrieval capability for SCIAMACHY. The European Space Agency selected the SAO to participate in GOME validation and science studies, part of the overall ERS AO. This provided access to all GOME data; The SAO activities that are carried out as a result of selection by ESA were funded by the present grant. The Global Ozone Monitoring Experiment was successfully launched on the ERS- 2 satellite on April 20, 1995, and remains working in normal fashion. SCIAMACHY is currently scheduled for launch in early 2000. The first two European ozone monitoring instruments (OMI), to fly on the q series of operational meteorological satellites being planned by Eumetsat, have been selected to be GOME-type instruments (the first, in fact, will be the refurbished GOME flight spare). K. Chance is the U.S. member of the OMI Users Advisory Group.

  7. U.S. Participation in the GOME and SCIAMACHY Projects

    NASA Technical Reports Server (NTRS)

    Chance, K. V.

    1996-01-01

    This report summarizes research done under NASA Grant NAGW-2541 from April 1, 1996 through March 31, 1997. The research performed during this reporting period includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, consultation and development for SCIAMACHY near-real-time (NRT) and off-line (OL) data products, and development of infrared line-by-line atmospheric modeling and retrieval capability for SCIAMACHY. SAO also continues to participate in GOME validation studies, to the limit that can be accomplished at the present level of funding. The Global Ozone Monitoring Experiment was successfully launched on the ERS-2 satellite on April 20, 1995, and remains working in normal fashion. SCIAMACHY is currently in instrument characterization. The first two European ozone monitoring instruments (OMI), to fly on the Metop series of operational meteorological satellites being planned by Eumetsat, have been selected to be GOME-type instruments (the first, in fact, will be the refurbished GOME flight spare). K. Chance is the U.S. member of the OMI Users Advisory Group.

  8. SAO Participation in the GOME and SCIAMACHY Satellite Instrument Programs

    NASA Technical Reports Server (NTRS)

    Chance, Kelly; Kurosu, Thomas

    2003-01-01

    This report summarizes the progress on our three-year program of research to refine the measurement capability for satellite-based instruments that monitor ozone and other trace species in the Earth's stratosphere and troposphere, to retrieve global distributions of these and other constituents from the GOME and SCIAMACHY satellite instruments, and to conduct scientific studies for the ILAS instruments. This continues our involvements as a U.S. participant in GOME and SCIAMACHY since their inception, and as a member of the ILAS-II Science Team. These programs have led to the launch of the first satellite instrument specifically designed to measure height-resolved ozone, including the tropospheric component (GOME), and the development of the first satellite instrument that will measure tropospheric ozone simultaneously with NO2, CO, HCHO, N2O, H2O, and CH4 (SCIAMACHY). The GOME program now includes the GOME-2 instruments, to be launched on the Eumetsat Metop satellites, providing long-term continuity in European measurements of global ozone that complement the measurements of the TOMS, SBW, OMI, OMPS instruments. The research primarily focuses on two areas: Data analysis, including algorithm development and validation studies that will improve the quality of retrieved data products, in support for future field campaigns (to complement in situ and airborne campaigns with satellite measurements), and scientific analyses to be interfaced to atmospheric modeling studies.

  9. SAO Participation in the GOME and SCIAMACHY Satellite Instrument Programs

    NASA Technical Reports Server (NTRS)

    Hilsenrath, Ernest (Technical Monitor); Chance, Kelly; Kurosu, Thomas

    2004-01-01

    This report summarizes the progress on our three-year program of research to refine the measurement capability for satellite-based instruments that monitor ozone and other trace species in the Earth's stratosphere and troposphere, to retrieve global distributions of these and other constituents h m the GOME and SCIAMACHY satellite instruments, and to conduct scientific studies for the ILAS instruments. This continues our involvements as a U.S. participant in GOME and SCIAMACHY since their inception, and as a member of the ILAS-II Science Team. These programs have led to the launch of the first satellite instrument specifically designed to measure height-resolved ozone, including the tropospheric component (GOME), and the development of the first satellite instrument that will measure tropospheric ozone simultaneously with NO2, CO, HCHO, N2O, H2O, and CH4 (SCIAMACHY). The GOME program now includes the GOME-2 instruments, to be launched on the Eumetsat Metop satellites, providing long-term continuity in European measurements of global ozone that complement the measurements of the TOMS, SBUV, OMI, OMPS instruments. The research primarily focuses on two areas: Data analysis, including algorithm development and validation studies that will improve the quality of retrieved data products, in support for future field campaigns (to complement in situ and airborne campaigns with satellite measurements), and scientific analyses to be interfaced to atmospheric modeling studies.

  10. GOME Observations of OClO in the Arctic Stratosphere

    NASA Astrophysics Data System (ADS)

    Kühl, S.; Wilms-Grabe, W.; Beirle, S.; Frankenberg, C.; Hollwedel, J.; Kraus, S.; Platt, U.; Wagner, T.

    2003-04-01

    The GOME instrument onboard the ERS-2 satellit consists of a set of four spectrometers covering the wavelength range between 240 and 790 nm. By applying the DOAS method to the GOME measurements, the integrated concentration of several trace gases along the light path, the so called Slant Column Densities (SCDs), can be derived. Since GOME has a global coverage every three days, the SCDs of OClO give a good overview of the intensity and the extension of the chlorine activation. The OClO SCDs for the arctic winters 1995/96 to 2002/03 are discussed with respect to the minimum temperature at the Tpot = 475 K level, the occurrence of polar stratospheric clouds (PSCs) and the chemical ozone depletion. For certain interesting periods, the effect of stratospheric mountain waves and denitrification on the activation and deactivation of chlorine is examined.

  11. US Participation in the GOME and SCIAMACHY Projects

    NASA Technical Reports Server (NTRS)

    Chance, K. V.; Geary, J. C.

    1996-01-01

    The research performed during this reporting period includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, further sensitivity and instrument studies to help finalize the definition of the SCIAMACHY instrument, and consultation on optical and detector issues for both GOME and SCIAMACHY. The Global Ozone Monitoring Experiment was successfully launched on the ERS-2 satellite on April 20, 1995, during this reporting period, and is working in the expected fashion. The European Space Agency has made their selections from responses to the Announcement of Opportunity for GOME validation and science studies, part of the overall ERS AO. The Smithsonian Astrophysical Observatory (SAO) proposal has been selected. These proposals are primarily for access to the data; ESA does not provide research funding for the selected investigations. The SAO activities that are carried out as a result of selection by ESA are funded by the present grant, to the limit that can be accomplished at the present level of funding. SCIAMACHY is currently in Phase C/D. Instrument design is almost finalized and selection of infrared detectors from the initial production run has been made.

  12. A question of reliability or of boundary conditions? Comment on Gomes and McCullough (2015).

    PubMed

    Shariff, Azim F; Norenzayan, Ara

    2015-12-01

    Gomes and McCullough (2015) are to be commended on their high-powered attempt to replicate our earlier research (Shariff & Norenzayan, 2007). We suggest that notable differences between the two studies indicate that Gomes and McCullough were testing a different question. Here we place Gomes and McCullough's results in context with other studies and discuss how their findings may point to an interesting boundary condition of the original effect. PMID:26595843

  13. Spectral surface albedo derived from GOME-2/Metop measurements

    NASA Astrophysics Data System (ADS)

    Pflug, Bringfried; Loyola, Diego

    2009-09-01

    Spectral surface albedo is an important input for GOME-2 trace gas retrievals. An algorithm was developed for estimation of spectral surface albedo from top-of-atmosphere (TOA)-radiances measured by the Global Ozone Monitoring Experiment GOME-2 flying on-board MetOp-A. The climatologically version of this algorithm estimates Minimum Lambert-Equivalent Reflectivity (MLER) for a fixed time window and can use data of many years in contrast to the Near-real time version. Accuracy of surface albedo estimated by MLER-computation increases with the amount of available data. Unfortunately, most of the large GOME pixels are partly covered by clouds, which enhance the LER-data. A plot of LER-values over cloud fraction is used within this presentation to account for this influence of clouds. This "cloud fraction plot" can be applied over all surface types. Surface albedo obtained using the "cloud fraction plot" is compared with reference surface albedo spectra and with the FRESCO climatology. There is a general good agreement; however there are also large differences for some pixels.

  14. An Improved Retrieval of Tropospheric Nitrogen Dioxide from GOME

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  15. Development of a prototype algorithm for the operational retrieval of height-resolved products from GOME

    NASA Technical Reports Server (NTRS)

    Spurr, Robert J. D.

    1997-01-01

    Global ozone monitoring experiment (GOME) level 2 products of total ozone column amounts have been generated on a routine operational basis since July 1996. These products and the level 1 radiance products are the major outputs from the ERS-2 ground segment GOME data processor (GDP) at DLR in Germany. Off-line scientific work has already shown the feasibility of ozone profile retrieval from GOME. It is demonstrated how the retrievals can be performed in an operational context. Height-resolved retrieval is based on the optimal estimation technique, #and cloud-contaminated scenes are treated in an equivalent reflecting surface approximation. The prototype must be able to handle GOME measurements routinely on a global basis. Requirements for the major components of the algorithm are described: this incorporates an overall strategy for operational height-resolved retrieval from GOME.

  16. Intercomparison of reflectances observed by GOME and SCIAMACHY in the visible wavelength range.

    PubMed

    Tilstra, Lieuwe G; Stammes, Piet

    2006-06-10

    We compare the Earth reflectances of the spectrometers Global Ozone Monitoring Experiment (GOME) and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) over their overlapping wavelength range (240-800 nm). The goal is to investigate the quality of the radiometric calibration of SCIAMACHY using calibrated GOME data as a reference. However, severe degradation of the GOME instrument in the UV since 2001 prevents it from being a reliable reference below 500 nm. Above 500 nm, GOME is reliable and we find substantial disagreement between GOME and SCIAMACHY, of the order of 15%-20%, which we can attribute completely to the current calibration problems of SCIAMACHY. These numbers are supported by a previous study in which SCIAMACHY was compared with the imager Medium Resolution Imaging Spectrometer (MERIS) onboard the Envisat satellite.

  17. Retrieval and Analysis of Stratospheric NO2 from GOME

    NASA Technical Reports Server (NTRS)

    Wenig, M.; Kuehl, S.; Beirle, S.; Wagner, T.; Jaehne, B.; Platt, U.

    2003-01-01

    In this paper we describe the retrieval of stratospheric NO2 from the GOME (Global Ozone Monitoring Experiment) spectrometer. For this retrieval the Differential Optical Absorption Spectroscopy (DOAS) is used and we describe the influence of the instrument s characteristics on this measurement technique. This analysis led to an improved version of the DOAS algorithm resulting in results with lower systematic errors. Subsequently these results were used to separate the tropospheric and stratospheric fraction of the measured NO;! in the atmosphere. This paper is focusing on the annual variations of the stratospheric distribution of nitrogen oxides. For this examination the satellite data from beginning of 1996 to the end of 2001 was used and has been visualized in a plot zonal means versus time of the year, a visualization which proved to be very useful for Ozone. Additionally the so called "Noxon Cliff", a drop of NO2 column densities Noxon measured in 1975-77 while traveling northwards towards the pole in Canada, is shown. Also its southern equivalent could be discovered in the GOME data.

  18. An empirical sun-glint index for GOME-2

    NASA Astrophysics Data System (ADS)

    Beirle, Steffen; Penning de Vries, Marloes; Lang, Rüdiger; Wagner, Thomas

    2014-05-01

    Sun-glint has high impact on several kinds of remote sensing applications over oceans, e.g. ocean color, detection of oil spills, retrieval of cloud and aerosol properties, or the retrieval of trace gas columns from spectral measurements. Here we investigate to what extent information about sun-glint can be derived from spectrally resolved measurements from satellite, e.g. GOME-2, covering the UV/vis spectral range, but with rather coarse spatial resolution. Several different quantities are investigated, e.g. radiance, operational cloud products, a color index, polarization state (Stokes fraction), and the oxygen column density. From the combination of color index and Stokes fraction, it is possible to differentiate between the occurrence of sun-glint and clouds, and an empirical sun-glint flag can be defined on the high spatial resolution of GOME-2 PMD measurements. This flag can be used to either exclude sun-glint situations, or to explicitly select them for their well-defined radiative transfer conditions and high reflectance. Going beyond simple flagging, a float sun-glint index might allow for a gradual quantification or correction of sun-glint effects, with potential applications in various fields of research (work in progress).

  19. Validation of GOME-2/Metop total column water vapour with ground-based and in situ measurements

    NASA Astrophysics Data System (ADS)

    Kalakoski, Niilo; Kujanpää, Jukka; Sofieva, Viktoria; Tamminen, Johanna; Grossi, Margherita; Valks, Pieter

    2016-04-01

    The total column water vapour product from the Global Ozone Monitoring Experiment-2 on board Metop-A and Metop-B satellites (GOME-2/Metop-A and GOME-2/Metop-B) produced by the Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF) is compared with co-located radiosonde observations and global positioning system (GPS) retrievals. The validation is performed using recently reprocessed data by the GOME Data Processor (GDP) version 4.7. The time periods for the validation are January 2007-July 2013 (GOME-2A) and December 2012-July 2013 (GOME-2B). The radiosonde data are from the Integrated Global Radiosonde Archive (IGRA) maintained by the National Climatic Data Center (NCDC). The ground-based GPS observations from the COSMIC/SuomiNet network are used as the second independent data source. We find a good general agreement between the GOME-2 and the radiosonde/GPS data. The median relative difference of GOME-2 to the radiosonde observations is -2.7 % for GOME-2A and -0.3 % for GOME-2B. Against the GPS, the median relative differences are 4.9 % and 3.2 % for GOME-2A and B, respectively. For water vapour total columns below 10 kg m-2, large wet biases are observed, especially against the GPS retrievals. Conversely, at values above 50 kg m-2, GOME-2 generally underestimates both ground-based observations.

  20. Comparison of GOME-2/MetOp total ozone data with Brewer spectroradiometer data over the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Antón, M.; Loyola, D.; López, M.; Vilaplana, J. M.; Bañón, M.; Zimmer, W.; Serrano, A.

    2009-04-01

    The main objective of this article is to compare the total ozone data from the new Global Ozone Monitoring Experiment instrument (GOME-2/MetOp) with reliable ground-based measurement recorded by five Brewer spectroradiometers in the Iberian Peninsula. In addition, a similar comparison for the predecessor instrument GOME/ERS-2 is described. The period of study is a whole year from May 2007 to April 2008. The results show that GOME-2/MetOp ozone data already has a very good quality, total ozone columns are on average 3.05% lower than Brewer measurements. This underestimation is higher than that obtained for GOME/ERS-2 (1.46%). However, the relative differences between GOME-2/MetOp and Brewer measurements show significantly lower variability than the differences between GOME/ERS-2 and Brewer data. Dependencies of these relative differences with respect to the satellite solar zenith angle (SZA), the satellite scan angle, the satellite cloud cover fraction (CF), and the ground-based total ozone measurements are analyzed. For both GOME instruments, differences show no significant dependence on SZA. However, GOME-2/MetOp data show a significant dependence on the satellite scan angle (+1.5%). In addition, GOME/ERS-2 differences present a clear dependence with respect to the CF and ground-based total ozone; such differences are minimized for GOME-2/MetOp. The comparison between the daily total ozone values provided by both GOME instruments shows that GOME-2/MetOp ozone data are on average 1.46% lower than GOME/ERS-2 data without any seasonal dependence. Finally, deviations of a priori climatological ozone profile used by the satellite retrieval algorithm from the true ozone profile are analyzed. Although excellent agreement between a priori climatological and measured partial ozone values is found for the middle and high stratosphere, relative differences greater than 15% are common for the troposphere and lower stratosphere.

  1. Sulfur dioxide retrievals from OMI and GOME-2 in preparation of TROPOMI

    NASA Astrophysics Data System (ADS)

    Theys, Nicolas; De Smedt, Isabelle; Danckaert, Thomas; Yu, Huan; van Gent, Jeroen; Van Roozendael, Michel

    2016-04-01

    The TROPOspheric Monitoring Instrument (TROPOMI) will be launched in 2016 onboard the ESA Sentinel-5 Precursor (S5P) platform and will provide global observations of atmospheric trace gases, with unprecedented spatial resolution. Sulfur dioxide (SO2) measurements from S5P will significantly improve the current capabilities for anthropogenic and volcanic emissions monitoring, and will extend the long-term datasets from past and existing UV sensors (TOMS, GOME, SCIAMACHY, OMI, GOME-2, OMPS). This work presents the SO2 retrieval schemes performed at BIRA-IASB as part of level-2 algorithm prototyping activities for S5P and tested on OMI and GOME-2. With a focus on anthropogenic sources, we show comparisons between OMI and GOME-2 as well as ground-based measurements, and discuss the possible reasons for the differences.

  2. An improved NO2 retrieval for the GOME-2 satellite instrument

    NASA Astrophysics Data System (ADS)

    Richter, A.; Begoin, M.; Hilboll, A.; Burrows, J. P.

    2011-01-01

    Satellite observations of nitrogen dioxide (NO2) provide valuable information on both stratospheric and tropospheric composition. Nadir measurements from GOME, SCIAMACHY, OMI, and GOME-2 have been used in many studies on tropospheric NO2 burdens, the importance of different NOx emissions sources and their change over time. The observations made by the three GOME-2 instruments will extend the existing data set by more than a decade, and a high quality of the data as well as their good consistency with existing time series is of high importance. In this paper, an improved GOME-2 NO2 retrieval is described which reduces the scatter of the individual NO2 columns globally but in particular in the region of the Southern Atlantic Anomaly. This is achieved by using a larger fitting window including more spectral points, and by applying a two step spike removal algorithm in the fit. The new GOME-2 data set is shown to have good consistency with SCIAMACHY NO2 columns. Remaining small differences are shown to be linked to changes in the daily solar irradiance measurements used in both GOME-2 and SCIAMACHY retrievals. In the large retrieval window, a not previously identified spectral signature was found which is linked to deserts and other regions with bare soil. Inclusion of this empirically derived pseudo cross-section significantly improves the retrievals and potentially provides information on surface properties and desert aerosols. Using the new GOME-2 NO2 data set, a long-term average of tropospheric columns was computed and high-pass filtered. The resulting map shows evidence for pollution from several additional shipping lanes, not previously identified in satellite observations. This illustrates the excellent signal to noise ratio achievable with the improved GOME-2 retrievals.

  3. An improved NO2 retrieval for the GOME-2 satellite instrument

    NASA Astrophysics Data System (ADS)

    Richter, A.; Begoin, M.; Hilboll, A.; Burrows, J. P.

    2011-06-01

    Satellite observations of nitrogen dioxide (NO2) provide valuable information on both stratospheric and tropospheric composition. Nadir measurements from GOME, SCIAMACHY, OMI, and GOME-2 have been used in many studies on tropospheric NO2 burdens, the importance of different NOx emissions sources and their change over time. The observations made by the three GOME-2 instruments will extend the existing data set by more than a decade, and a high quality of the data as well as their good consistency with existing time series is of particular importance. In this paper, an improved GOME-2 NO2 retrieval is described which reduces the scatter of the individual NO2 columns globally but in particular in the region of the Southern Atlantic Anomaly. This is achieved by using a larger fitting window including more spectral points, and by applying a two step spike removal algorithm in the fit. The new GOME-2 data set is shown to have good consistency with SCIAMACHY NO2 columns. Remaining small differences are shown to be linked to changes in the daily solar irradiance measurements used in both GOME-2 and SCIAMACHY retrievals. In the large retrieval window, a not previously identified spectral signature was found which is linked to deserts and other regions with bare soil. Inclusion of this empirically derived pseudo cross-section significantly improves the retrievals and potentially provides information on surface properties and desert aerosols. Using the new GOME-2 NO2 data set, a long-term average of tropospheric columns was computed and high-pass filtered. The resulting map shows evidence for pollution from several additional shipping lanes, not previously identified in satellite observations. This illustrates the excellent signal to noise ratio achievable with the improved GOME-2 retrievals.

  4. Tropical tropospheric ozone columns from nadir retrievals of GOME-1/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A (1996-2012)

    NASA Astrophysics Data System (ADS)

    Leventidou, Elpida; Eichmann, Kai-Uwe; Weber, Mark; Burrows, John P.

    2016-07-01

    Tropical tropospheric ozone columns are retrieved with the convective cloud differential (CCD) technique using total ozone columns and cloud parameters from different European satellite instruments. Monthly-mean tropospheric column amounts [DU] are calculated by subtracting the above-cloud ozone column from the total column. A CCD algorithm (CCD_IUP) has been developed as part of the verification algorithm developed for TROPOspheric Monitoring Instrument (TROPOMI) on Sentinel 5-precursor (S5p) mission, which was applied to GOME/ERS-2 (1995-2003), SCIAMACHY/Envisat (2002-2012), and GOME-2/MetOp-A (2007-2012) measurements. Thus a unique long-term record of monthly-mean tropical tropospheric ozone columns (20° S-20° N) from 1996 to 2012 is now available. An uncertainty estimation has been performed, resulting in a tropospheric ozone column uncertainty less than 2 DU ( < 10 %) for all instruments. The dataset has not been yet harmonised into one consistent; however, comparison between the three separate datasets (GOME/SCIAMACHY/GOME-2) shows that GOME-2 overestimates the tropical tropospheric ozone columns by about 8 DU, while SCIAMACHY and GOME are in good agreement. Validation with Southern Hemisphere ADditional OZonesondes (SHADOZ) data shows that tropospheric ozone columns from the CCD_IUP technique and collocated integrated ozonesonde profiles from the surface up to 200 hPa are in good agreement with respect to range, interannual variations, and variances. Biases within ±5 DU and root-mean-square (RMS) deviation of less than 10 DU are found for all instruments. CCD comparisons using SCIAMACHY data with tropospheric ozone columns derived from limb/nadir matching have shown that the bias and RMS deviation are within the range of the CCD_IUP comparison with the ozonesondes. The 17-year dataset can be helpful for evaluating chemistry models and performing climate change studies.

  5. GOME Total Ozone and Calibration Error Derived Usign Version 8 TOMS Algorithm

    NASA Technical Reports Server (NTRS)

    Gleason, J.; Wellemeyer, C.; Qin, W.; Ahn, C.; Gopalan, A.; Bhartia, P.

    2003-01-01

    The Global Ozone Monitoring Experiment (GOME) is a hyper-spectral satellite instrument measuring the ultraviolet backscatter at relatively high spectral resolution. GOME radiances have been slit averaged to emulate measurements of the Total Ozone Mapping Spectrometer (TOMS) made at discrete wavelengths and processed using the new TOMS Version 8 Ozone Algorithm. Compared to Differential Optical Absorption Spectroscopy (DOAS) techniques based on local structure in the Huggins Bands, the TOMS uses differential absorption between a pair of wavelengths including the local stiucture as well as the background continuum. This makes the TOMS Algorithm more sensitive to ozone, but it also makes the algorithm more sensitive to instrument calibration errors. While calibration adjustments are not needed for the fitting techniques like the DOAS employed in GOME algorithms, some adjustment is necessary when applying the TOMS Algorithm to GOME. Using spectral discrimination at near ultraviolet wavelength channels unabsorbed by ozone, the GOME wavelength dependent calibration drift is estimated and then checked using pair justification. In addition, the day one calibration offset is estimated based on the residuals of the Version 8 TOMS Algorithm. The estimated drift in the 2b detector of GOME is small through the first four years and then increases rapidly to +5% in normalized radiance at 331 nm relative to 385 nm by mid 2000. The lb detector appears to be quite well behaved throughout this time period.

  6. The Global Ozone Monitoring Experiment (GOME): Mission Concept and First Scientific Results.

    NASA Astrophysics Data System (ADS)

    Burrows, John P.; Weber, Mark; Buchwitz, Michael; Rozanov, Vladimir; Ladstätter-Weißenmayer, Annette; Richter, Andreas; Debeek, Rüdiger; Hoogen, Ricarda; Bramstedt, Klaus; Eichmann, Kai-Uwe; Eisinger, Michael; Perner, Dieter

    1999-01-01

    The Global Ozone Monitoring Experiment (GOME) is a new instrument aboard the European Space Agency's (ESA) Second European Remote Sensing Satellite (ERS-2), which was launched in April 1995. The main scientific objective of the GOME mission is to determine the global distribution of ozone and several other trace gases, which play an important role in the ozone chemistry of the earth's stratosphere and troposphere. GOME measures the sunlight scattered from the earth's atmosphere and/or reflected by the surface in nadir viewing mode in the spectral region 240-790 nm at a moderate spectral resolution of between 0.2 and 0.4 nm. Using the maximum 960-km across-track swath width, the spatial resolution of a GOME ground pixel is 40 × 320 km2 for the majority of the orbit and global coverage is achieved in three days after 43 orbits.Operational data products of GOME as generated by DLR-DFD, the German Data Processing and Archiving Facility (D-PAF) for GOME, comprise absolute radiometrically calibrated earthshine radiance and solar irradiance spectra (level 1 products) and global distributions of total column amounts of ozone and NO2 (level 2 products), which are derived using the DOAS approach (Differential Optical Absorption Spectroscopy). (Under certain conditions and some restrictions, the operational data products are publically available from the European Space Agency via the ERS Helpdesk.)In addition to the operational data products, GOME has delivered important information about other minor trace gases such as OClO, volcanic SO2, H2CO from biomass burning, and tropospheric BrO. Using an iterative optimal estimation retrieval scheme, ozone vertical profiles can be derived from the inversion of the UV/VIS spectra. This paper reports on the GOME instrument, its operation mode, and the retrieval techniques, the latter with particular emphasis on DOAS (total column retrieval) and advanced optimal estimation (ozone profile retrieval).Observation of ozone depletion in the

  7. GOME-2 total ozone columns from MetOp-A/MetOp-B and assimilation in the MACC system

    NASA Astrophysics Data System (ADS)

    Hao, N.; Koukouli, M. E.; Inness, A.; Valks, P.; Loyola, D. G.; Zimmer, W.; Balis, D. S.; Zyrichidou, I.; Van Roozendael, M.; Lerot, C.; Spurr, R. J. D.

    2014-09-01

    The two Global Ozone Monitoring Instrument (GOME-2) sensors operated in tandem are flying onboard EUMETSAT's (European Organisation for the Exploitation of Meteorological Satellites) MetOp-A and MetOp-B satellites, launched in October 2006 and September 2012 respectively. This paper presents the operational GOME-2/MetOp-A (GOME-2A) and GOME-2/MetOp-B (GOME-2B) total ozone products provided by the EUMETSAT Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). These products are generated using the latest version of the GOME Data Processor (GDP version 4.7). The enhancements in GDP 4.7, including the application of Brion-Daumont-Malicet ozone absorption cross sections, are presented here. On a global scale, GOME-2B has the same high accuracy as the corresponding GOME-2A products. There is an excellent agreement between the ozone total columns from the two sensors, with GOME-2B values slightly lower with a mean difference of only 0.55±0.29%. First global validation results for 6 months of GOME-2B total ozone using ground-based measurements show that on average the GOME-2B total ozone data obtained with GDP 4.7 are slightly higher than, both, Dobson observations by about 2.0±1.0% and Brewer observations by about 1.0±0.8%. It is concluded that the total ozone columns (TOCs) provided by GOME-2A and GOME-2B are consistent and may be used simultaneously without introducing systematic effects, which has been illustrated for the Antarctic ozone hole on 18 October 2013. GOME-2A total ozone data have been used operationally in the Copernicus atmospheric service project MACC-II (Monitoring Atmospheric Composition and Climate - Interim Implementation) near-real-time (NRT) system since October 2013. The magnitude of the bias correction needed for assimilating GOME-2A ozone is reduced (to about -6 DU in the global mean) when the GOME-2 ozone retrieval algorithm changed to GDP 4.7.

  8. Sixteen years of GOME/ERS-2 total ozone data: The new direct-fitting GOME Data Processor (GDP) version 5—Algorithm description

    NASA Astrophysics Data System (ADS)

    Van Roozendael, M.; Spurr, R.; Loyola, D.; Lerot, C.; Balis, D.; Lambert, J.-C.; Zimmer, W.; van Gent, J.; van Geffen, J.; Koukouli, M.; Granville, J.; Doicu, A.; Fayt, C.; Zehner, C.

    2012-02-01

    The Global Ozone Monitoring Instrument (GOME) was launched in April 1995 on ESA's ERS-2 platform, and the GOME Data Processor (GDP) operational retrieval algorithm has produced total ozone columns since July 1995. We report on the new GDP5 spectral fitting algorithm used to reprocess the 16-year GOME data record. Previous GDP total ozone algorithms were based on the DOAS method. In contrast, GDP5 uses a direct-fitting algorithm without high-pass filtering of radiances; there is no air mass factor conversion to vertical column amount. GDP5 includes direct radiative transfer simulation of earthshine radiances and Jacobians with respect to total ozone, albedo closure and other ancillary fitting parameters - a temperature profile shift, and amplitudes for undersampling and Ring-effect interference signals. Simulations are based on climatological ozone profiles extracted from the TOMS Version 8 database, classified by total column. GDP5 uses the high-resolution Brion-Daumont-Malicet ozone absorption cross-sections, replacing older GOME-measured flight model data. The semi-empirical molecular Ring correction developed for GDP4 has been adapted for direct fitting. Cloud preprocessing for GDP5 is done using updated versions of cloud-correction algorithms OCRA and ROCINN. The reprocessed GOME GDP5 record maintains the remarkable long-term stability of time series already achieved with GDP4. Furthermore, validation results show a clear improvement in the accuracy of the ozone product with reduced solar zenith angle and seasonal dependences, particularly in comparison with correlative observations from the ground-based network of Brewer spectrophotometers.

  9. Improvement of total and tropospheric NO2 column retrieval for GOME-2

    NASA Astrophysics Data System (ADS)

    Liu, Song; Valks, Pieter; Pinardi, Gaia; De Smedt, Isabelle; Huan, Yu; Beirle, Steffen

    2016-04-01

    This contribution focuses on the development and refinement of novel scientific algorithms for the retrieval of total and tropospheric nitrogen dioxide (NO2) columns for the GOME-2 satellite instrument. NO2 plays significant roles in atmospheric chemistry. It is strongly related to ozone destruction in the stratosphere, and is regarded as an important air pollutant and ozone precursor in the troposphere. Total NO2 columns from GOME-2 are retrieved with the Differential Optical Absorption Spectroscopy (DOAS) method using the large 425-497 nm wavelength fitting window in order to increase the signal to noise ratio. The tropospheric NO2 column is derived using an improved Stratospheric-Tropospheric separation (STS) algorithm, followed by an air mass factor (AMF) conversion calculated with the LIDORT model. For the calculation of the tropospheric AMF, improved GOME-2 cloud parameters are used and a new surface albedo (LER) climatology based on GOME-2 observations for 2007-2013 is applied. We present the improvements in the NO2 retrieval algorithm, and we show examples of air quality applications with GOME-2 NO2 data.

  10. OCRA radiometric cloud fractions for GOME-2 on MetOp-A/B

    NASA Astrophysics Data System (ADS)

    Lutz, R.; Loyola, D.; Gimeno García, S.; Romahn, F.

    2015-12-01

    This paper describes an approach for cloud parameter retrieval (radiometric cloud fraction estimation) using the polarization measurements of the Global Ozone Monitoring Experiment-2 (GOME-2) on-board the MetOp-A/B satellites. The core component of the Optical Cloud Recognition Algorithm (OCRA) is the calculation of monthly cloud-free reflectances for a global grid (resolution of 0.2° in longitude and 0.2° in latitude) and to derive radiometric cloud fractions. These cloud fractions will serve as a priori information for the retrieval of cloud top height (CTH), cloud top pressure (CTP), cloud top albedo (CTA) and cloud optical thickness (COT) with the Retrieval Of Cloud Information using Neural Networks (ROCINN) algorithm. This approach is already being implemented operationally for the GOME/ERS-2 and SCIAMACHY/ENVISAT sensors and here we present version 3.0 of the OCRA algorithm applied to the GOME-2 sensors. Based on more than six years of GOME-2A data (February 2007-June 2013), reflectances are calculated for ≈ 35 000 orbits. For each measurement a degradation correction as well as a viewing angle dependent and latitude dependent correction is applied. In addition, an empirical correction scheme is introduced in order to remove the effect of oceanic sun glint. A comparison of the GOME-2A/B OCRA cloud fractions with co-located AVHRR geometrical cloud fractions shows a general good agreement with a mean difference of -0.15±0.20. From operational point of view, an advantage of the OCRA algorithm is its extremely fast computational time and its straightforward transferability to similar sensors like OMI (Ozone Monitoring Instrument), TROPOMI (TROPOspheric Monitoring Instrument) on Sentinel 5 Precursor, as well as Sentinel 4 and Sentinel 5. In conclusion, it is shown that a robust, accurate and fast radiometric cloud fraction estimation for GOME-2 can be achieved with OCRA by using the polarization measurement devices (PMDs).

  11. Homogenized total ozone data records from the European sensors GOME/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A

    NASA Astrophysics Data System (ADS)

    Lerot, C.; Van Roozendael, M.; Spurr, R.; Loyola, D.; Coldewey-Egbers, M.; Kochenova, S.; Gent, J.; Koukouli, M.; Balis, D.; Lambert, J.-C.; Granville, J.; Zehner, C.

    2014-02-01

    Within the European Space Agency's Climate Change Initiative, total ozone column records from GOME (Global Ozone Monitoring Experiment), SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CartograpHY), and GOME-2 have been reprocessed with GODFIT version 3 (GOME-type Direct FITting). This algorithm is based on the direct fitting of reflectances simulated in the Huggins bands to the observations. We report on new developments in the algorithm from the version implemented in the operational GOME Data Processor v5. The a priori ozone profile database TOMSv8 is now combined with a recently compiled OMI/MLS tropospheric ozone climatology to improve the representativeness of a priori information. The Ring procedure that corrects simulated radiances for the rotational Raman inelastic scattering signature has been improved using a revised semi-empirical expression. Correction factors are also applied to the simulated spectra to account for atmospheric polarization. In addition, the computational performance has been significantly enhanced through the implementation of new radiative transfer tools based on principal component analysis of the optical properties. Furthermore, a soft-calibration scheme for measured reflectances and based on selected Brewer measurements has been developed in order to reduce the impact of level-1 errors. This soft-calibration corrects not only for possible biases in backscattered reflectances, but also for artificial spectral features interfering with the ozone signature. Intersensor comparisons and ground-based validation indicate that these ozone data sets are of unprecedented quality, with stability better than 1% per decade, a precision of 1.7%, and systematic uncertainties less than 3.6% over a wide range of atmospheric states.

  12. GOME level 1-to-2 data processor version 3.0: a major upgrade of the GOME/ERS-2 total ozone retrieval algorithm.

    PubMed

    Spurr, Robert; Loyola, Diego; Thomas, Werner; Balzer, Wolfgang; Mikusch, Eberhard; Aberle, Bernd; Slijkhuis, Sander; Ruppert, Thomas; van Roozendael, Michel; Lambert, Jean-Christopher; Soebijanta, Trisnanto

    2005-11-20

    The global ozone monitoring experiment (GOME) was launched in April 1995, and the GOME data processor (GDP) retrieval algorithm has processed operational total ozone amounts since July 1995. GDP level 1-to-2 is based on the two-step differential optical absorption spectroscopy (DOAS) approach, involving slant column fitting followed by air mass factor (AMF) conversions to vertical column amounts. We present a major upgrade of this algorithm to version 3.0. GDP 3.0 was implemented in July 2002, and the 9-year GOME data record from July 1995 to December 2004 has been processed using this algorithm. The key component in GDP 3.0 is an iterative approach to AMF calculation, in which AMFs and corresponding vertical column densities are adjusted to reflect the true ozone distribution as represented by the fitted DOAS effective slant column. A neural network ensemble is used to optimize the fast and accurate parametrization of AMFs. We describe results of a recent validation exercise for the operational version of the total ozone algorithm; in particular, seasonal and meridian errors are reduced by a factor of 2. On a global basis, GDP 3.0 ozone total column results lie between -2% and +4% of ground-based values for moderate solar zenith angles lower than 70 degrees. A larger variability of about +5% and -8% is observed for higher solar zenith angles up to 90 degrees.

  13. Comparison of GOME-2/Metop-A ozone profiles with GOMOS, OSIRIS and MLS measurements

    NASA Astrophysics Data System (ADS)

    Määttä, A.; Tuinder, O. N. E.; Tukiainen, S.; Sofieva, V.; Tamminen, J.

    2015-07-01

    This paper presents a comparison of vertical ozone profiles retrieved by the Ozone ProfilE Retrieval Algorithm (OPERA) from the Global Ozone Monitoring Experiment 2 (GOME-2) measurements on board Metop-A with high-vertical-resolution ozone profiles by Global Ozone Monitoring by Occultation of Stars (GOMOS), Optical Spectrograph and Infrared Imager System (OSIRIS) and Microwave Limb Sounder (MLS). The comparison, with global coverage, focuses on the stratosphere and the lower mesosphere and covers the period from March 2008 until the end of 2011. The comparison shows an agreement of the GOME-2 ozone profiles with those of GOMOS, OSIRIS and MLS within ±15 % in the altitude range from 15 km up to ~ 35-40 km depending on latitude. The GOME-2 ozone profiles from non-degradation corrected radiances have a tendency to a systematic negative bias with respect to the reference data above ~ 30 km. The GOME-2 bias with respect to the high-vertical resolution instruments depends on season, with the strongest dependence observed at high latitudes.

  14. Sources and trends of Tropospheric Formaldehyde (HCHO) derived from GOME-1 and -2

    NASA Astrophysics Data System (ADS)

    Marbach, T.; Beirle, S.; Penning de Vries, M. J.; Wagner, T.

    2010-12-01

    Launched on the ERS-2 satellite 1995, GOME-1 has already performed continuous operations over 8 years providing global observations of different trace gases. GOME-2 has been launched onboard of METOP-A in October 2006. This instrument allow an improvement in the trace gas observations through a better resolution (80x40 km2, 320x40 km2 for GOME-1) with an almost daily earth coverage at equator (3 days needed for GOME-1). This long term satellite observations provide the opportunity to establish trends over specific regions for various trace gases. Here, the satellite observations of HCHO are analyzed providing information concerning different types of sources: The biogenic sources of HCHO are in many cases the strongest HCHO sources (e.g. over rain forest). The biomass burning source typically shows pronounced seasonal patterns or is even of sporadic nature. We investigated the time series of monthly mean values for selected regions of the world. Besides the satellite measurements of HCHO, the fire counts (from ATSR) and temperature are taken as proxy for biomass burning events and vegetation activity, respectively. In addition we plan to compare the satellite observations of HCHO also to other trace gases measured from satellite instruments (e.g CO as proxy for fires counts or also NO2 which is emitted from biomass burning but not to biogenic emissions) as well as the comparison with aerosols scattering index. Anthropogenic HCHO emissions are shown with a case study linked to shipping emission. The line of enhanced HCHO in the Indian Ocean as seen in the 7-year composite of cloud free GOME-1 observations clearly coincides with the distinct ship track corridor from Sri Lanka to Indonesia (single narrow track in the same east-west direction as used for the GOME-1 pixel scanning). Compared to the simultaneously observed NO2 values over the shipping route, those of HCHO are substantially higher; also the HCHO peaks are found at larger distance from the ship routes

  15. Sources and trends of Tropospheric Formaldehyde (HCHO) derived from GOME-1 and -2

    NASA Astrophysics Data System (ADS)

    Marbach, T.; Beirle, S.; Penning de Vries, M.; Liu, C.; Wagner, T.

    2009-12-01

    We present sources and trends for tropospheric Formaldehyde (HCHO) derived from satellite observations made by the GOME-1 and -2 instruments as well as synergistic use of the HCHO results with other satellite data. Launched on the ERS-2 satellite 1995, GOME-1 has already performed continuous operations over 8 years providing global observations of different trace gases. GOME-2 has been launched onboard of METOP-A in October 2006. This instrument allow an improvement in the trace gas observations through a better resolution (80x40 km2, 320x40 km2 for GOME-1) with an almost daily earth coverage at equator (3 days needed for GOME-1). The datasets from SCIAMACHY (launched in 2002 onboard ENVISAT) have an overlap with both GOME-1and -2 datasets. That gives the possibility to have time-series over one decade. This long term satellite observations provide the opportunity to establish trends over specific regions for various trace gases. Here, the satellite observations of HCHO are analyzed providing information concerning different types of sources: The biogenic sources of HCHO are in many cases the strongest HCHO sources (e.g. over evergreen forest). The biomass burning source typically shows pronounced seasonal patterns or is even of sporadic nature. We investigated the time series of monthly mean values for selected regions of the world. Besides the satellite measurements of HCHO, the fire counts (from ATSR) and temperature are taken as proxy for biomass burning events and vegetation activity, respectively. In addition we plan to compare the satellite observations of HCHO also to other trace gases measured from satellite instruments (e.g CO as proxy for fires counts or also NO2 which is emitted from biomass burning but not to biogenic emissions) as well as the comparison with aerosols scattering index. Anthropogenic HCHO emissions are shown with a case study linked to shipping emission. The line of enhanced HCHO in the Indian Ocean as seen in the 7-year composite of

  16. OCRA radiometric cloud fractions for GOME-2 on MetOp-A/B

    NASA Astrophysics Data System (ADS)

    Lutz, Ronny; Loyola, Diego; Gimeno García, Sebastián; Romahn, Fabian

    2016-05-01

    This paper describes an approach for cloud parameter retrieval (radiometric cloud-fraction estimation) using the polarization measurements of the Global Ozone Monitoring Experiment-2 (GOME-2) onboard the MetOp-A/B satellites. The core component of the Optical Cloud Recognition Algorithm (OCRA) is the calculation of monthly cloud-free reflectances for a global grid (resolution of 0.2° in longitude and 0.2° in latitude) to derive radiometric cloud fractions. These cloud fractions will serve as a priori information for the retrieval of cloud-top height (CTH), cloud-top pressure (CTP), cloud-top albedo (CTA) and cloud optical thickness (COT) with the Retrieval Of Cloud Information using Neural Networks (ROCINN) algorithm. This approach is already being implemented operationally for the GOME/ERS-2 and SCIAMACHY/ENVISAT sensors and here we present version 3.0 of the OCRA algorithm applied to the GOME-2 sensors. Based on more than five years of GOME-2A data (April 2008 to June 2013), reflectances are calculated for ≈ 35 000 orbits. For each measurement a degradation correction as well as a viewing-angle-dependent and latitude-dependent correction is applied. In addition, an empirical correction scheme is introduced in order to remove the effect of oceanic sun glint. A comparison of the GOME-2A/B OCRA cloud fractions with colocated AVHRR (Advanced Very High Resolution Radiometer) geometrical cloud fractions shows a general good agreement with a mean difference of -0.15 ± 0.20. From an operational point of view, an advantage of the OCRA algorithm is its very fast computational time and its straightforward transferability to similar sensors like OMI (Ozone Monitoring Instrument), TROPOMI (TROPOspheric Monitoring Instrument) on Sentinel 5 Precursor, as well as Sentinel 4 and Sentinel 5. In conclusion, it is shown that a robust, accurate and fast radiometric cloud-fraction estimation for GOME-2 can be achieved with OCRA using polarization measurement devices (PMDs).

  17. Combined Characterisation of GOME and TOMS Total Ozone Using Ground-Based Observations from the NDSC

    NASA Technical Reports Server (NTRS)

    Lambert, J.-C.; VanRoozendael, M.; Simon, P. C.; Pommereau, J.-P.; Goutail, F.; Andersen, S. B.; Arlander, D. W.; BuiVan, N. A.; Claude, H.; deLaNoee, J.; DeMaziere, M.; Dorokhov, V.; Eriksen, P.; Gleason, J. F.; Tornkvist, K. Karlsen; Hoiskar, B. A. Kastad; Kyroe, E.; Leveau, J.; Merienne, M.-F.; Milinevsky, G.

    1998-01-01

    Several years of total ozone measured from space by the ERS-2 GOME, the Earth Probe Total Ozone Mapping Spectrometer (TOMS), and the ADEOS TOMS, are compared with high-quality ground-based observations associated with the Network for the Detection of Stratospheric Change (NDSC), over an extended latitude range and a variety of geophysical conditions. The comparisons with each spaceborne sensor are combined altogether for investigating their respective solar zenith angle (SZA) dependence, dispersion, and difference of sensitivity. The space- and ground-based data are found to agree within a few percent on average. However, the analysis highlights for both Global Ozone Monitoring Experiment (GOME) and TOMS several sources of discrepancies, including a dependence on the SZA at high latitudes and internal inconsistencies.

  18. Tropospheric ozone and ozone profiles retrieved from GOME-2 and their validation

    NASA Astrophysics Data System (ADS)

    Miles, G. M.; Siddans, R.; Kerridge, B. J.; Latter, B. G.; Richards, N. A. D.

    2015-01-01

    This paper describes and assesses the performance of the RAL (Rutherford Appleton Laboratory) ozone profile retrieval scheme for the Global Ozone Monitoring Experiment 2 (GOME-2) with a focus on tropospheric ozone. Developments to the scheme since its application to GOME-1 measurements are outlined. These include the approaches developed to account sufficiently for UV radiometric degradation in the Hartley band and for inadequacies in knowledge of instrumental parameters in the Huggins bands to achieve the high-precision spectral fit required to extract information on tropospheric ozone. The assessment includes a validation against ozonesondes (sondes) sampled worldwide over 2 years (2007-2008). Standard deviations of the ensemble with respect to the sondes are considerably lower for the retrieved profiles than for the a priori, with the exception of the lowest subcolumn. Once retrieval vertical smoothing (averaging kernels) has been applied to the sonde profiles there is a retrieval bias of 6% (1.5 DU) in the lower troposphere, with smaller biases in the subcolumns above. The bias in the troposphere varies with latitude. The retrieval underestimates lower tropospheric ozone in the Southern Hemisphere (SH) (15-20% or ~ 1-3 DU) and overestimates it in the Northern Hemisphere (NH) (10% or 2 DU). The ability of the retrieval to reflect the geographical distribution of lower tropospheric ozone, globally (rather than just ozonesonde launch sites) is demonstrated by comparison with the chemistry transport model TOMCAT. For a monthly mean of cloud-cleared GOME-2 pixels, a correlation of 0.66 is found between the retrieval and TOMCAT sampled accordingly, with a bias of 0.7 Dobson Units. GOME-2 estimates higher concentrations in NH pollution centres but lower ozone in the Southern Ocean and South Pacific, which is consistent with the comparison to ozonesondes.

  19. Retrieval Of Cloud Pressure And Chlorophyll Content Using Raman Scattering In GOME Ultraviolet Spectra

    NASA Technical Reports Server (NTRS)

    Atlas, Robert (Technical Monitor); Joiner, Joanna; Vasikov, Alexander; Flittner, David; Gleason, James; Bhartia, P. K.

    2002-01-01

    Reliable cloud pressure estimates are needed for accurate retrieval of ozone and other trace gases using satellite-borne backscatter ultraviolet (buv) instruments such as the global ozone monitoring experiment (GOME). Cloud pressure can be derived from buv instruments by utilizing the properties of rotational-Raman scattering (RRS) and absorption by O2-O2. In this paper we estimate cloud pressure from GOME observations in the 355-400 nm spectral range using the concept of a Lambertian-equivalent reflectivity (LER) surface. GOME has full spectral coverage in this range at relatively high spectral resolution with a very high signal-to-noise ratio. This allows for much more accurate estimates of cloud pressure than were possible with its predecessors SBUV and TOMS. We also demonstrate the potential capability to retrieve chlorophyll content with full-spectral buv instruments. We compare our retrieved LER cloud pressure with cloud top pressures derived from the infrared ATSR instrument on the same satellite. The findings confirm results from previous studies that showed retrieved LER cloud pressures from buv observations are systematically higher than IR-derived cloud-top pressure. Simulations using Mie-scattering radiative transfer algorithms that include O2-O2 absorption and RRS show that these differences can be explained by increased photon path length within and below cloud.

  20. Development of an OClO Slant Column Product for the GOME-2 Sensors

    NASA Astrophysics Data System (ADS)

    Richter, Andreas; Wittrock, Folkard; Burrows, John P.

    2016-04-01

    Stratospheric ozone depletion by catalytic reactions involving halogens is one of the most prominent examples of anthropogenic impacts on the atmosphere. In spite of the rapid and successful international action to reduce emissions of CFCs and other ozone depleting substances leading to the Montreal Protocol and its amendments, ozone depletion in polar spring is still observed in both hemispheres on a regular basis. For the coming years, slow ozone recovery is expected but individual years will still see very low ozone columns depending on meteorology and possible interactions with climate change. Monitoring of both ozone and ozone depleting substances in the stratosphere remains a priority to ensure that the predicted reduction in halogen levels and recovery of ozone columns is taking place as predicted. One way to observe stratospheric chlorine activation is by measurements of OClO which can be detected by UV/visible remote sensing from the ground and from satellite. While the link between OClO levels and chlorine activation is complicated by the fact that a) OClO is not directly involved in ozone depletion but is produced by reaction of BrO and ClO and b) is rapidly photolysed at daylight, the long existing data series from both ground-based and satellite observations makes it an interesting tracer of chlorine activation. The GOME-2 instruments on the MetOp series of satellites are nadir viewing UV/vis spectrometers having the spectral coverage and resolution needed for Differential Optical Absorption Spectroscopy retrievals of OClO. With their combined lifetime of more than 15 years, they can provide a long-term data set. However, previous attempts to create an OClO product for GOME-2 suffered from large scatter in the OClO data and time-dependent offsets. Here we present an improved OClO slant column retrieval for the two instruments GOME2-A and GOME2-B. The data is shown to be of similar quality as for earlier instruments such as SCIAMACHY, and is consistent

  1. Evaluating a New Homogeneous Total Ozone Climate Data Record from GOME/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A

    NASA Technical Reports Server (NTRS)

    Koukouli, M.E.; Lerot, C.; Granville, J.; Goutail, F.; Lambert, J.-C.; Pommereau, J.-P.; Balis, D.; Zyrichidou, I.; Van Roozendael, M.; Coldewey-Egbers, M.; Loyola, D.; Labow, G.; Frith, S.; Spurr, R.; Zehner, C.

    2015-01-01

    The European Space Agency's Ozone Climate Change Initiative (O3-CCI) project aims at producing and validating a number of high-quality ozone data products generated from different satellite sensors. For total ozone, the O3-CCI approach consists of minimizing sources of bias and systematic uncertainties by applying a common retrieval algorithm to all level 1 data sets, in order to enhance the consistency between the level 2 data sets from individual sensors. Here we present the evaluation of the total ozone products from the European sensors Global Ozone Monitoring Experiment (GOME)/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A produced with the GOME-type Direct FITting (GODFIT) algorithm v3. Measurements from the three sensors span more than 16 years, from 1996 to 2012. In this work, we present the latest O3-CCI total ozone validation results using as reference ground-based measurements from Brewer and Dobson spectrophotometers archived at the World Ozone and UV Data Centre of the World Meteorological Organization as well as from UV-visible differential optical absorption spectroscopy (DOAS)/Système D'Analyse par Observations Zénithales (SAOZ) instruments from the Network for the Detection of Atmospheric Composition Change. In particular, we investigate possible dependencies in these new GODFIT v3 total ozone data sets with respect to latitude, season, solar zenith angle, and different cloud parameters, using the most adequate type of ground-based instrument. We show that these three O3-CCI total ozone data products behave very similarly and are less sensitive to instrumental degradation, mainly as a result of the new reflectance soft-calibration scheme. The mean bias to the ground-based observations is found to be within the 1 plus or minus 1 percent level for all three sensors while the near-zero decadal stability of the total ozone columns (TOCs) provided by the three European instruments falls well within the 1-3 percent requirement of the European Space

  2. Evaluating a new homogeneous total ozone climate data record from GOME/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A

    NASA Astrophysics Data System (ADS)

    Koukouli, M. E.; Lerot, C.; Granville, J.; Goutail, F.; Lambert, J.-C.; Pommereau, J.-P.; Balis, D.; Zyrichidou, I.; Van Roozendael, M.; Coldewey-Egbers, M.; Loyola, D.; Labow, G.; Frith, S.; Spurr, R.; Zehner, C.

    2015-12-01

    The European Space Agency's Ozone Climate Change Initiative (O3-CCI) project aims at producing and validating a number of high-quality ozone data products generated from different satellite sensors. For total ozone, the O3-CCI approach consists of minimizing sources of bias and systematic uncertainties by applying a common retrieval algorithm to all level 1 data sets, in order to enhance the consistency between the level 2 data sets from individual sensors. Here we present the evaluation of the total ozone products from the European sensors Global Ozone Monitoring Experiment (GOME)/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A produced with the GOME-type Direct FITting (GODFIT) algorithm v3. Measurements from the three sensors span more than 16 years, from 1996 to 2012. In this work, we present the latest O3-CCI total ozone validation results using as reference ground-based measurements from Brewer and Dobson spectrophotometers archived at the World Ozone and UV Data Centre of the World Meteorological Organization as well as from UV-visible differential optical absorption spectroscopy (DOAS)/Système D'Analyse par Observations Zénithales (SAOZ) instruments from the Network for the Detection of Atmospheric Composition Change. In particular, we investigate possible dependencies in these new GODFIT v3 total ozone data sets with respect to latitude, season, solar zenith angle, and different cloud parameters, using the most adequate type of ground-based instrument. We show that these three O3-CCI total ozone data products behave very similarly and are less sensitive to instrumental degradation, mainly as a result of the new reflectance soft-calibration scheme. The mean bias to the ground-based observations is found to be within the 1 ± 1% level for all three sensors while the near-zero decadal stability of the total ozone columns (TOCs) provided by the three European instruments falls well within the 1-3% requirement of the European Space Agency's Ozone Climate Change

  3. Long-term global observations of UV-absorbing aerosols from ERS-2/GOME data

    NASA Astrophysics Data System (ADS)

    de Graaf, M.; Stammes, P.

    2003-04-01

    Absorbing aerosols are important in the Earth's climate system, as they absorb solar radiation in the Earth's atmosphere. The main species of UV-absorbing aerosols are desert dust and biomass burning aerosols. Their lifetimes in the atmosphere are usually short, in the order of days to weeks, resulting in strong temporal and spatial variations in aerosol concentrations with peak concentrations near the source, creating a necessity for long-term global observations of aerosol properties and concentrations. Global distributions of UV-absorbing aerosols are obtained using the absorbing aerosol index (AAI), which measures the departure of the observed spectral contrast at 340 nm and 380 nm from that of a molecular atmosphere. It is a measure for the presence of elevated absorbing aerosols in the Earth's atmosphere using space-borne sensors operating in the UV, like TOMS, and recently GOME and SCIAMACHY. The Global Ozone Monitoring Experiment (GOME) on board the ERS-2 satellite has been observing the atmosphere continuously since 1995. It is a nadir-looking spectrometer measuring from about 240 to 790 nm, with a resolution of 0.2 nm in the UV range. The basic quantities observed by GOME are the spectral irradiance of the Sun and the spectral radiance of the Earth at the Top Of Atmosphere (TOA). These data were used to create a long-term data set of global AAI distributions, ranging from 1995 to 2002. Sensitivity studies have shown that polarisation has a considerable effect on the AAI computation. Therefore, the molecular atmosphere radiation is calculated with the Doubling-Adding KNMI (DAK) radiative transfer code in which polarisation effects are included. Here the results of the data set are presented.

  4. Overview of the O3M SAF GOME-2 operational atmospheric composition and UV radiation data products and data availability

    NASA Astrophysics Data System (ADS)

    Hassinen, S.; Balis, D.; Bauer, H.; Begoin, M.; Delcloo, A.; Eleftheratos, K.; Gimeno Garcia, S.; Granville, J.; Grossi, M.; Hao, N.; Hedelt, P.; Hendrick, F.; Hess, M.; Heue, K.-P.; Hovila, J.; Jønch-Sørensen, H.; Kalakoski, N.; Kiemle, S.; Kins, L.; Koukouli, M. E.; Kujanpää, J.; Lambert, J.-C.; Lerot, C.; Loyola, D.; Määttä, A.; Pedergnana, M.; Pinardi, G.; Romahn, F.; van Roozendael, M.; Lutz, R.; De Smedt, I.; Stammes, P.; Steinbrecht, W.; Tamminen, J.; Theys, N.; Tilstra, L. G.; Tuinder, O. N. E.; Valks, P.; Zerefos, C.; Zimmer, W.; Zyrichidou, I.

    2015-07-01

    The three GOME-2 instruments will provide unique and long data sets for atmospheric research and applications. The complete time period will be 2007-2022, including the period of ozone depletion as well as the beginning of ozone layer recovery. Besides ozone chemistry, the GOME-2 products are important e.g. for air quality studies, climate modeling, policy monitoring and hazard warnings. The heritage for GOME-2 is in the ERS/GOME and Envisat/SCIAMACHY instruments. The current Level 2 (L2) data cover a wide range of products such as trace gas columns (NO2, BrO, H2CO, H2O, SO2), tropospheric columns of NO2, total ozone columns and vertical ozone profiles in high and low spatial resolution, absorbing aerosol indices from the main science channels as well as from the polarization channels (AAI, AAI-PMD), Lambertian-equivalent reflectivity database, clear-sky and cloud-corrected UV indices and surface UV fields with different weightings and photolysis rates. The Ozone Monitoring and Atmospheric Composition Satellite Application Facility (O3M SAF) processing and data dissemination is operational and running 24/7. Data quality is quarantined by the detailed review processes for the algorithms, validation of the products as well as by a continuous quality monitoring of the products and processing. This is an overview paper providing the O3M SAF project background, current status and future plans to utilization of the GOME-2 data. An important focus is the provision of summaries of the GOME-2 products including product principles and validation examples together with the product sample images. Furthermore, this paper collects the references to the detailed product algorithm and validation papers.

  5. Consistent interpretation of ground based and GOME BrO slant column data

    NASA Astrophysics Data System (ADS)

    Mueller, R. W.; Bovensmann, H.; Kaiser, J. W.; Richter, A.; Rozanov, A.; Wittrock, F.; Burrows, J. P.

    Model computations of slant column densities (SCD) enable the comparison between ground based and satellite based absorption measurements of scattered light and are therefore a good basis to investigate the presence of tropospheric BrO amounts. In this study ground based zenith sky and GOME nadir measurements of BrO SCD are compared with simulations for the 19-21 March 1997 at Ny-Ålesund. The vertical columns of tropospheric BrO amounts are estimated to be in the range 4 ±0.8 ∗ 10 13 [molecules/cm 2] for the investigated period and location.

  6. Total column water vapour measurements from GOME-2 MetOp-A and MetOp-B

    NASA Astrophysics Data System (ADS)

    Grossi, M.; Valks, P.; Loyola, D.; Aberle, B.; Slijkhuis, S.; Wagner, T.; Beirle, S.; Lang, R.

    2015-03-01

    Knowledge of the total column water vapour (TCWV) global distribution is fundamental for climate analysis and weather monitoring. In this work, we present the retrieval algorithm used to derive the operational TCWV from the GOME-2 sensors aboard EUMETSAT's MetOp-A and MetOp-B satellites and perform an extensive inter-comparison in order to evaluate their consistency and temporal stability. For the analysis, the GOME-2 data sets are generated by DLR in the framework of the EUMETSAT O3M-SAF project using the GOME Data Processor (GDP) version 4.7. The retrieval algorithm is based on a classical Differential Optical Absorption Spectroscopy (DOAS) method and combines a H2O and O2 retrieval for the computation of the trace gas vertical column density. We introduce a further enhancement in the quality of the H2O total column by optimizing the cloud screening and developing an empirical correction in order to eliminate the instrument scan angle dependencies. The overall consistency between measurements from the newer GOME-2 instrument on board of the MetOp-B platform and the GOME-2/MetOp-A data is evaluated in the overlap period (December 2012-June 2014). Furthermore, we compare GOME-2 results with independent TCWV data from the ECMWF ERA-Interim reanalysis, with SSMIS satellite measurements during the full period January 2007-June 2014 and against the combined SSM/I + MERIS satellite data set developed in the framework of the ESA DUE GlobVapour project (January 2007-December 2008). Global mean biases as small as ±0.035 g cm-2 are found between GOME-2A and all other data sets. The combined SSM/I-MERIS sample and the ECMWF ERA-Interim data set are typically drier than the GOME-2 retrievals, while on average GOME-2 data overestimate the SSMIS measurements by only 0.006 g cm-2. However, the size of these biases is seasonally dependent. Monthly average differences can be as large as 0.1 g cm-2, based on the analysis against SSMIS measurements, which include only data over

  7. Calculation of smoke plume mass from passive UV satellite measurements by GOME-2 polarization measurement devices

    NASA Astrophysics Data System (ADS)

    Penning de Vries, M. J. M.; Tuinder, O. N. E.; Wagner, T.; Fromm, M.

    2012-04-01

    The Wallow wildfire of 2011 was one of the most devastating fires ever in Arizona, burning over 2,000 km2 in the states of Arizona and New Mexico. The fire originated in the Bear Wallow Wilderness area in June, 2011, and raged for more than a month. The intense heat of the fire caused the formation of a pyro-convective cloud. The resulting smoke plume, partially located above low-lying clouds, was detected by several satellite instruments, including GOME-2 on June 2. The UV Aerosol Index, indicative of aerosol absorption, reached a maximum of 12 on that day, pointing to an elevated plume with moderately absorbing aerosols. We have performed extensive model calculations assuming different aerosol optical properties to determine the total aerosol optical depth of the plume. The plume altitude, needed to constrain the aerosol optical depth, was obtained from independent satellite measurements. The model results were compared with UV Aerosol Index and UV reflectances measured by the GOME-2 polarization measurement devices, which have a spatial resolution of roughly 10x40 km2. Although neither the exact aerosol optical properties nor optical depth can be obtained with this method, the range in aerosol optical depth values that we calculate, combined with the assumed specific extinction mass factor of 5 m2/kg lead us to a rough estimate of the smoke plume mass that cannot, at present, be assessed in another way.

  8. Comparative study on the technological properties of latex and natural rubber from Hancornia speciosa Gomes and Hevea brasiliensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work reports a systematic comparative study of the properties of natural lattices and rubbers extracted from Hancornia speciosa Gomes and Hevea brasiliensis [(Willd. ex Adr. de Juss.) Muell.-Arg.] (clone RRIM 600) trees from 11 collections in Brazil throughout 2004. Natural rubber latex particl...

  9. The GOME-type Total Ozone Essential Climate Variable (GTO-ECV) data record from the ESA Climate Change Initiative

    NASA Astrophysics Data System (ADS)

    Coldewey-Egbers, M.; Loyola, D. G.; Koukouli, M.; Balis, D.; Lambert, J.-C.; Verhoelst, T.; Granville, J.; van Roozendael, M.; Lerot, C.; Spurr, R.; Frith, S. M.; Zehner, C.

    2015-09-01

    We present the new GOME-type Total Ozone Essential Climate Variable (GTO-ECV) data record which has been created within the framework of the European Space Agency's Climate Change Initiative (ESA-CCI). Total ozone column observations - based on the GOME-type Direct Fitting version 3 algorithm - from GOME (Global Ozone Monitoring Experiment), SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY), and GOME-2 have been combined into one homogeneous time series, thereby taking advantage of the high inter-sensor consistency. The data record spans the 15-year period from March 1996 to June 2011 and it contains global monthly mean total ozone columns on a 1°× 1° grid. Geophysical ground-based validation using Brewer, Dobson, and UV-visible instruments has shown that the GTO-ECV level 3 data record is of the same high quality as the equivalent individual level 2 data products that constitute it. Both absolute agreement and long-term stability are excellent with respect to the ground-based data, for almost all latitudes apart from a few outliers which are mostly due to sampling differences between the level 2 and level 3 data. We conclude that the GTO-ECV data record is valuable for a variety of climate applications such as the long-term monitoring of the past evolution of the ozone layer, trend analysis and the evaluation of chemistry-climate model simulations.

  10. The GOME-type Total Ozone Essential Climate Variable (GTO-ECV) data record from the ESA Climate Change Initiative

    NASA Astrophysics Data System (ADS)

    Coldewey-Egbers, M.; Loyola, D. G.; Koukouli, M.; Balis, D.; Lambert, J.-C.; Verhoelst, T.; Granville, J.; van Roozendael, M.; Lerot, C.; Spurr, R.; Frith, S. M.; Zehner, C.

    2015-05-01

    We present the new GOME-type Total Ozone Essential Climate Variable (GTO-ECV) data record which has been created within the framework of the European Space Agency's Climate Change Initiative (ESA-CCI). Total ozone column observations - based on the GOME-type Direct Fitting version 3 algorithm - from GOME (Global Ozone Monitoring Experiment), SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY), and GOME-2 have been combined into one homogeneous time series, thereby taking advantage of the high inter-sensor consistency. The data record spans the 15-year period from March 1996 to June 2011 and it contains global monthly mean total ozone columns on a 1° × 1° grid. Geophysical ground-based validation using Brewer, Dobson, and UV-visible instruments has shown that the GTO-ECV level 3 data record is of the same high quality as the equivalent individual level 2 data products that constitute it. Both absolute agreement and long-term stability are excellent with respect to the ground-based data, for almost all latitudes apart from a few outliers which are mostly due to sampling differences between the level 2 and level 3 data. We conclude that the GTO-ECV data record is valuable for a variety of climate applications such as the long-term monitoring of the past evolution of the ozone layer, trend analysis and the evaluation of Chemistry-Climate Model simulations.

  11. Total ozone column derived from GOME and SCIAMACHY using KNMI retrieval algorithms: Validation against Brewer measurements at the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Antón, M.; Kroon, M.; López, M.; Vilaplana, J. M.; Bañón, M.; van der A, R.; Veefkind, J. P.; Stammes, P.; Alados-Arboledas, L.

    2011-11-01

    This article focuses on the validation of the total ozone column (TOC) data set acquired by the Global Ozone Monitoring Experiment (GOME) and the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) satellite remote sensing instruments using the Total Ozone Retrieval Scheme for the GOME Instrument Based on the Ozone Monitoring Instrument (TOGOMI) and Total Ozone Retrieval Scheme for the SCIAMACHY Instrument Based on the Ozone Monitoring Instrument (TOSOMI) retrieval algorithms developed by the Royal Netherlands Meteorological Institute. In this analysis, spatially colocated, daily averaged ground-based observations performed by five well-calibrated Brewer spectrophotometers at the Iberian Peninsula are used. The period of study runs from January 2004 to December 2009. The agreement between satellite and ground-based TOC data is excellent (R2 higher than 0.94). Nevertheless, the TOC data derived from both satellite instruments underestimate the ground-based data. On average, this underestimation is 1.1% for GOME and 1.3% for SCIAMACHY. The SCIAMACHY-Brewer TOC differences show a significant solar zenith angle (SZA) dependence which causes a systematic seasonal dependence. By contrast, GOME-Brewer TOC differences show no significant SZA dependence and hence no seasonality although processed with exactly the same algorithm. The satellite-Brewer TOC differences for the two satellite instruments show a clear and similar dependence on the viewing zenith angle under cloudy conditions. In addition, both the GOME-Brewer and SCIAMACHY-Brewer TOC differences reveal a very similar behavior with respect to the satellite cloud properties, being cloud fraction and cloud top pressure, which originate from the same cloud algorithm (Fast Retrieval Scheme for Clouds from the Oxygen A-Band (FRESCO+)) in both the TOSOMI and TOGOMI retrieval algorithms.

  12. Overview of the O3M SAF GOME-2 operational atmospheric composition and UV radiation data products and data availability

    NASA Astrophysics Data System (ADS)

    Hassinen, S.; Balis, D.; Bauer, H.; Begoin, M.; Delcloo, A.; Eleftheratos, K.; Gimeno Garcia, S.; Granville, J.; Grossi, M.; Hao, N.; Hedelt, P.; Hendrick, F.; Hess, M.; Heue, K.-P.; Hovila, J.; Jønch-Sørensen, H.; Kalakoski, N.; Kauppi, A.; Kiemle, S.; Kins, L.; Koukouli, M. E.; Kujanpää, J.; Lambert, J.-C.; Lang, R.; Lerot, C.; Loyola, D.; Pedergnana, M.; Pinardi, G.; Romahn, F.; van Roozendael, M.; Lutz, R.; De Smedt, I.; Stammes, P.; Steinbrecht, W.; Tamminen, J.; Theys, N.; Tilstra, L. G.; Tuinder, O. N. E.; Valks, P.; Zerefos, C.; Zimmer, W.; Zyrichidou, I.

    2016-02-01

    The three Global Ozone Monitoring Experiment-2 instruments will provide unique and long data sets for atmospheric research and applications. The complete time period will be 2007-2022, including the period of ozone depletion as well as the beginning of ozone layer recovery. Besides ozone chemistry, the GOME-2 (Global Ozone Monitoring Experiment-2) products are important e.g. for air quality studies, climate modelling, policy monitoring and hazard warnings. The heritage for GOME-2 is in the ERS/GOME and Envisat/SCIAMACHY instruments. The current Level 2 (L2) data cover a wide range of products such as ozone and minor trace gas columns (NO2, BrO, HCHO, H2O, SO2), vertical ozone profiles in high and low spatial resolution, absorbing aerosol indices, surface Lambertian-equivalent reflectivity database, clear-sky and cloud-corrected UV indices and surface UV fields with different weightings and photolysis rates. The Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF) processes and disseminates data 24/7. Data quality is guaranteed by the detailed review processes for the algorithms, validation of the products as well as by a continuous quality monitoring of the products and processing. This paper provides an overview of the O3M SAF project background, current status and future plans for the utilisation of the GOME-2 data. An important focus is the provision of summaries of the GOME-2 products including product principles and validation examples together with sample images. Furthermore, this paper collects references to the detailed product algorithm and validation papers.

  13. The GOME-2 Level 1 Instrument Degradation Model Version 1 and its Application for Atmospheric Composition Retrievals

    NASA Astrophysics Data System (ADS)

    Huckle, R.; Lang, R.; Retscher, C.; Poli, G.; Lindstrot, R.; Lacan, A.; Trollope, E.; Munro, R.

    2015-12-01

    GOME-2 on Metop-A and -B is suffering from signal degradation in the shorter wavelength regime below 420 nm, like many instruments of this type. During its 8 years in orbit to date, GOME-2 on Metop-A has acquired enough data to enable correction of most (though not all) aspects of its signal degradation using a combination of empirical and instrument model correction. We present the first version of the GOME-2 Metop-A degradation model which covers the full spectral range between 240 nm and 790 nm and also includes signal correction for two polarisation measurement devices (PMDs). We discuss the individual model components, including a correction of the solar-spectrum and the calibration of the solar diffuser, a stray-light correction in the region below 295 nm, an angular correction of all earthshine data, as well as a correction in the spectral domain for low frequency patterns. The first version of the dataset covers the time period from launch until the start of tandem operations in July 2013, when the swath of GOME-2 Metop-A was reduced from 1920 km to 960 km. We will discuss the individual degradation components accounted for, their physical origin, and will show the first results of the corrected spectra and their impact on level-2 retrieval quality. We also present the roadmap towards the implementation of a near real-time correction scheme of GOME-2 level-1 data and discuss various options concerning its potential operational and offline functionalities.

  14. NO2 evolution at global level using the space instruments SCIAMACHY, OMI and GOME-2

    NASA Astrophysics Data System (ADS)

    Rosu, Adrian; Constantin, Daniel-Eduard; Bocaneala, Corina; Voiculescu, Mirela; Puiu Georgescu, Lucian

    2016-04-01

    The main objective of this study is to evaluate the amount of NO2 at global level above twenty five worldwide urban agglomerations or station during 2002-2015. Tropospheric NO2 Vertical Column Density (VCD) are derived from various satellite UV-Vis instruments: SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric ChartographY) onboard Envisat, OMI (Ozone Monitoring Instrument) onboard AURA and GOME-2 (Global Ozone Monitoring Experiment Measurements-2) onboard Metop-A& B. Possible dependence of the evolution of the density of NO2 molecules above the major cities on demographic, economic, industry characteristics are investigated. Causes for various trends of the NO2 column, depending on geographical characteristics, altitude, are also analysed.

  15. Effective cloud fractions of GOME-2 measurements using an enhanced HICRU implementation

    NASA Astrophysics Data System (ADS)

    Sihler, Holger; Beirle, Steffen; Grzegorski, Michael; Hörmann, Christoph; Lampel, Johannes; Penning de Vries, Marloes; Wagner, Thomas

    2016-04-01

    The physics of clouds is one of the most important drivers of meteorology and the climate system. Apart from this, the distribution of clouds interferes with the majority of satellite measurement techniques. Tropospheric trace gas retrievals are particularly sensitivity to the distribution of clouds within the field-of-view of the instrument, because already small cloud fractions have the potential to alter the measurement error and significantly increase the uncertainty of the measurement. Hence, the accuracy of tropospheric trace gas retrievals depends on the accuracy of the cloud fraction, particularly for small cloud fractions. The original HICRU Iterative Cloud Retrieval Utilities (HICRU) algorithm has been specifically developed for the retrieval of small cloud fractions at high accuracy. This is achieved by inferring a clear sky top of atmosphere reflectance map from the dataset itself, minimising the influence of instrument degradation and/or insufficient calibration. HICRU thus requires a minimum of a-priori knowledge. So far, this approach was limited to measurements at sufficiently small viewing angles, such as GOME and SCIAMACHY, for which the use of a single, viewing-angle independent background albedo map is justified. Here, we demonstrate how this empirical approach may be enhanced by parametrising the viewing angle dependence of the TOA reflectance. It then becomes applicable to satellite instruments like GOME-2, OMI, and the upcoming TROPOMI/S5P with viewing angles up to 45 or even 70 degrees, by parametrising the viewing angle dependence of the TOA reflectance. Furthermore, the enhanced HICRU algorithm comprises an advanced treatment of the temporal evolution using a spatially averaged Fourier series fit. The enhanced HICRU has the potential to be applied also to instruments with moderate spectral resolution like MERIS, MODIS, or AVHRR as well.

  16. Monitoring the Bardarbunga eruption using GOME-2/Metop-A & -B

    NASA Astrophysics Data System (ADS)

    Hedelt, Pascal; Valks, Pieter; Loyola, Diego

    2015-04-01

    We will present here the results of the Bardarbunga eruption monitored by the GOME-2 instrument aboard MetOp-A & -B. After increased seismic activity in August, the Icelandic volcano Bardarbunga (Bárðarbunga) erupted on 31 August 2014. Since 1 September the GOME-2 instruments aboard the MetOp-A and -B satellites detect a continuous emission of sulphur-dioxide (SO2) emitted from the Holuhraun fissure at the flanks of the Bardarbunga volcano. At the beginning the emitted SO2 was mainly transported to the north-eastern direction over Scandinavia and Russia. However, on September 22 an SO2 cloud was even moving over Europe and could be detected at the Hohenpeissenberg and Schneefernerhaus observatories. SO2 emissions are a good indicator for volcanic activity, since besides weak anthropogenic emissions there are no other known sources for atmospheric SO2, which can cause respiratory problems in the local population and the aircraft passengers. Furthermore in form of acid rain it increases the oxidation of aircraft components. It was found that for some volcanic eruptions SO2 can be a good proxy for the much harder to detect volcanic ash. Volcanic ash can be hazardous not only for the local population but also for aviation since it can cause total engine failure if it melts and then congeals in the engine. Furthermore ash is highly abrasive to engine turbine vanes and propellers. Under the leadership of IMF, DLR-EOC provides operational trace gas measurements, including total SO2 columns, in near-real-time (i.e., within 2 hours of recording) in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF).

  17. Improvement of GOME-2 Tropospheric Ozone Profile Retrievals from Joint UV/Visible Measurements

    NASA Astrophysics Data System (ADS)

    Liu, X.; Zoogman, P.; Chance, K.; Cai, Z.; Nowlan, C. R.

    2015-12-01

    It has been shown that adding visible measurements in the Chappuis band to UV measurements in the Hartley/Huggins bands can significantly enhance retrieval sensitivity to lower tropospheric ozone from backscattered solar radiances due to deeper photon penetration in the visible to the surface than in the ultraviolet. The first NASA EVI TEMPO (Tropospheric Emissions: Monitoring of Pollution) instrument is being developed to measure backscattered solar radiation in two channels (~290-490 and 540-740 nm) and make atmospheric pollution measurements over North America from the Geostationary orbit. However, this retrieval enhancement has yet to be solidly demonstrated from existing measurements due to the weak ozone absorption in the visible and strong interference from surface reflectance and the requirement of accurate radiometric calibration across different spectral channels. We present GOME-2 retrievals from joint UV/visible measurements using the SAO optimal estimation based ozone profile retrieval algorithm, to directly explore the retrieval improvement in lower tropospheric ozone from additional visible measurements. To reduce the retrieval interference from surface reflectance, we add characterization of surface spectral reflectance in the visible based on ASTER and other surface reflectance spectra and MODIS BRDF climatology into the ozone profile algorithm using two approaches: fitting several EOFs (Empirical Orthogonal Functions) and scaling reflectance spectra. We also perform empirical radiometric calibration of the GOME-2 data based on radiative transfer simulations. We evaluate the retrieval improvement of joint UV/visible retrieval over the UV retrieval. These results clearly show the potential of using the visible to improve lower tropospheric ozone retrieval.

  18. Comparison of total water vapor column from GOME-2 on MetOp-A against ground-based GPS measurements at the Iberian Peninsula.

    PubMed

    Román, R; Antón, M; Cachorro, V E; Loyola, D; Ortiz de Galisteo, J P; de Frutos, A; Romero-Campos, P M

    2015-11-15

    Water vapor column (WVC) obtained by GOME-2 instrument (GDP-4.6 version) onboard MetOp-A satellite platform is compared against reference WVC values derived from GPS (Global Positioning System) instruments from 2007 to 2012 at 21 places located at Iberian Peninsula. The accuracy and precision of GOME-2 to estimate the WVC is studied for different Iberian Peninsula zones using the mean (MBE) and the standard deviation (SD) of the GOME-2 and GPS differences. A direct comparison of all available data shows an overestimation of GOME-2 compared to GPS with a MBE of 0.7 mm (10%) and a precision quantified by a SD equals to 4.4mm (31%). South-Western zone presents the highest overestimation with a MBE of 1.9 mm (17%), while Continental zone shows the lowest SD absolute value (3.3mm) due mainly to the low WVC values reached at this zone. The influence of solar zenith angle (SZA), cloud fraction (CF), and the type of surface and its albedo on the differences between GOME-2 and GPS is analyzed in detail. MBE and SD increase when SZA increases, but MBE decreases (taking negative values) when CF increases and SD shows no significant dependence on CF. Under cloud-free conditions, the differences between WVC from GOME-2 and GPS are within the WVC error given by GOME-2. The changes of MBE and SD on Surface Albedo are not so evident, but MBE slightly decreases when the Surface Albedo increases. WVC from GOME-2 is, in general, more precise for land than for sea pixels.

  19. Comparison of total water vapor column from GOME-2 on MetOp-A against ground-based GPS measurements at the Iberian Peninsula.

    PubMed

    Román, R; Antón, M; Cachorro, V E; Loyola, D; Ortiz de Galisteo, J P; de Frutos, A; Romero-Campos, P M

    2015-11-15

    Water vapor column (WVC) obtained by GOME-2 instrument (GDP-4.6 version) onboard MetOp-A satellite platform is compared against reference WVC values derived from GPS (Global Positioning System) instruments from 2007 to 2012 at 21 places located at Iberian Peninsula. The accuracy and precision of GOME-2 to estimate the WVC is studied for different Iberian Peninsula zones using the mean (MBE) and the standard deviation (SD) of the GOME-2 and GPS differences. A direct comparison of all available data shows an overestimation of GOME-2 compared to GPS with a MBE of 0.7 mm (10%) and a precision quantified by a SD equals to 4.4mm (31%). South-Western zone presents the highest overestimation with a MBE of 1.9 mm (17%), while Continental zone shows the lowest SD absolute value (3.3mm) due mainly to the low WVC values reached at this zone. The influence of solar zenith angle (SZA), cloud fraction (CF), and the type of surface and its albedo on the differences between GOME-2 and GPS is analyzed in detail. MBE and SD increase when SZA increases, but MBE decreases (taking negative values) when CF increases and SD shows no significant dependence on CF. Under cloud-free conditions, the differences between WVC from GOME-2 and GPS are within the WVC error given by GOME-2. The changes of MBE and SD on Surface Albedo are not so evident, but MBE slightly decreases when the Surface Albedo increases. WVC from GOME-2 is, in general, more precise for land than for sea pixels. PMID:26172599

  20. Validation of Four Total Ozone Values From The Satellite Instruments Gome and Ep-toms With Measurements From The Dobson Network 1996A~é­2000

    NASA Astrophysics Data System (ADS)

    Bramstedt, K.; Gleason, J.; Bracher, A.; Weber, M.; Loyola, D.; Burrows, J. P.

    Over the last 3 decades, satellite data have been used to monitor long-term global changes in stratospheric ozone. The TOMS series and GOME are two very important instruments in this context. Here, TOMS total ozone and three approaches to derive ozone column from GOME measurements are validated with the ground-based Dob- son network data. Beyond the operational products of both instruments, e.g. TOMS Version 7 and GOME Data Processor Version 2.7, total ozone is calculated by integrat- ing FURM ozone profiles and by applying the TOMS algorithm to the GOME spec- tra. All algorithm show in general good agreement with ground-based measurements. The operational GOME total ozone shows seasonal variations, most likely introduced by difficulties in the derivation of the airmass factor. Some small seasonal variations observed within all GOME datasets are shown to be caused by instrument effects. The TOMS algorithm estimates on average 2 % higher total ozone in the Southern hemisphere than in the Northern for both instrument, indicating that the source of the problems has to be part of the algorithm.

  1. Is success a sin? A conversation with the reverend Peter J. Gomes. Interview by David A. Light.

    PubMed

    Gomes, P J

    2001-09-01

    The difficult task of achieving worldly success while also storing up spiritual treasure is perennially with us, in good times and in bad. Today, however, as the economy has cooled and companies have demonstrated their mortality, questions about meaning and value appear more relevant, even urgent. HBR associate editor David A. Light recently spoke with the Reverend Peter J. Gomes, one of the nation's best-known preachers and the minister at Harvard University's Memorial Church, about why and how it is both possible and necessary to reconcile a life of success with a life of faith. To do so, says Gomes, you must first "get used to it"--come to terms with the age-old tension between being rich in spirit and rich in worldly goods. Second, you should "get over it"--arrive at an understanding of the value and responsibilities associated with power and wealth. Finally, "get on with it"--figure out how you can live your life spiritually while continuing to lead in the business world. For those wondering how to get on with spiritual development, Gomes cites the growing phenomenon of senior executives gathering with peers--out of shared need, not shared accomplishment--to pray, study sacred texts, and share their religious life together. He counsels that it's never too late to get on with it: We can amend life at any time, whether we're 35, 45, or 75. Gomes concludes that business will continue to be one of the most significant forces in American culture, but it will always struggle against people's need for a perspective that is beyond this world's.

  2. Validation of GOME-2/MetOp-A total water vapour column using reference radiosonde data from the GRUAN network

    NASA Astrophysics Data System (ADS)

    Antón, M.; Loyola, D.; Román, R.; Vömel, H.

    2015-03-01

    The main goal of this paper is to validate the total water vapour column (TWVC) measured by the Global Ozone Monitoring Experiment-2 (GOME-2) satellite sensor and generated using the GOME Data Processor (GDP) retrieval algorithm developed by the German Aerospace Centre (DLR). For this purpose, spatially and temporally collocated TWVC data from highly accurate sounding measurements for the period January 2009-May 2014 at six sites are used. These balloon-borne data are provided by the GCOS Reference Upper-Air Network (GRUAN). The correlation between GOME-2 and sounding TWVC data is reasonably good (determination coefficient, R2, of 0.89) when all available radiosondes (1400) are employed in the inter-comparison. When cloud-free cases (544) are selected by means of the satellite cloud fraction (CF < 5%), the correlation exhibits a remarkable improvement (R2 ~ 0.95). Nevertheless, the analysis of the relative differences between GOME-2 and GRUAN data shows a mean absolute bias error (weighted with the combined uncertainty derived from the estimated errors of both data sets) of 15% for all-sky conditions (9% for cloud-free cases). These results evidence a notable bias in the satellite TWVC data against the reference balloon-borne measurements, partially related to the cloudy conditions during the satellite overpass. The detailed analysis of the influence of cloud properties - CF, cloud top albedo (CTA) and cloud top pressure (CTP) - on the satellite-sounding differences reveals, as expected, a large effect of clouds in the GOME-2 TWVC data. For instance, the relative differences exhibit a large negative dependence on CTA, varying from -6 to -23% when CTA rises from 0.3 to 0.8. Furthermore, the satellite-sounding TWVC differences show a strong dependence on the satellite solar zenith angle (SZA) for values above 50°. Hence the smallest relative differences found in this satellite-sounding comparison are achieved for those cloud-free cases with satellite SZA below 50

  3. Genetic diversity of the Neotropical tree Hancornia speciosa Gomes in natural populations in Northeastern Brazil.

    PubMed

    Jimenez, H J; Martins, L S S; Montarroyos, A V V; Silva Junior, J F; Alzate-Marin, A L; Moraes Filho, R M

    2015-01-01

    Mangabeira (Hancornia speciosa Gomes) is a fruit tree of the Apocynaceae family, which is native to Brazil and is a very important food resource for human populations in its areas of occurrence. Mangabeira fruit is collected as an extractive activity, and no domesticated varieties or breeding programs exist. Due to a reduction in the area of ecosystems where it occurs, mangabeira is threatened by genetic erosion in Brazil. The objective of this study was to characterize and evaluate the genetic diversity of 38 mangabeira individuals collected from natural populations in Pernambuco State using inter-simple sequence repeat (ISSR) molecular markers. The ISSR methodology generated a total of 93 loci; 10 were monomorphic and 83 were polymorphic. The average number of loci per primer was 15.5, ranging from 9 (#UBC 866) to 21 (#UBC 834). The results showed a high level of genetic diversity (0.30), and found that only around 30% of genetic variability is distributed among populations (GST = 0.29, ФST = 0.30), with the remainder (ФCT = 70%) found within each population, as expected for forest outcrossing species. Estimates for historic gene flow (1.18) indicate that there is some isolation of these populations, and some degree of genetic differentiation. PMID:26782420

  4. Comparison of NO2 long-range transport events in GOME-2 observations and CTM simulations

    NASA Astrophysics Data System (ADS)

    Zien, A.; Hilboll, A.; Richter, A.; Burrows, J. P.

    2012-04-01

    Atmospheric long-range transport (LRT) events relocate trace gases from emission to downwind regions on an intercontinental scale, drastically altering the atmospheric chemistry in remote regions. Tropospheric NO2 is a very short-lived, mainly anthropogenic trace gas with strong impact on the ozone chemistry. Emissions are very localized and allow identification of individual LRT events. Here, the phenomenon of NO2 LRT is investigated by satellite remote sensing observations and global chemical transport modelling, which both provide good spatial and temporal coverage as well as sufficient resolution for the identification of large-scale, multi-day events. This allows the modelled and measured estimation of seasonal, regional and global LRT statistics. We use a non-cloud-filtered GOME-2 NO2 observational data set and model data from global GEOS-Chem simulations. A dedicated algorithm is used to identify and verify LRT events in observational and model data. We present the comparison of these results concerning the occurrence of NO2 LRT events. We discuss seasonalities in frequency and typical routes of LRTs and compare estimations of the transported mass from observations to results from the model. Further, we discuss peculiarities in the comparison between results from models and observations.

  5. Estimating the NOx produced by lightning from GOME and NLDN data: a case study in the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Beirle, S.; Spichtinger, N.; Stohl, A.; Cummins, K. L.; Turner, T.; Boccippio, D.; Cooper, O. R.; Wenig, M.; Grzegorski, M.; Platt, U.; Wagner, T.

    2005-11-01

    Nitrogen oxides (NOx=NO+NO2) play an important role in tropospheric chemistry, in particular in catalytic ozone production. Lightning provides a natural source of nitrogen oxides, dominating the production in the tropical upper troposphere, with strong impact on tropospheric ozone and the atmosphere's oxidizing capacity. Recent estimates of lightning produced NOx (LNOx) are of the order of 5 Tg [N] per year with still high uncertainties in the range of one order of magnitude. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows the retrieval of tropospheric vertical column densities (TVCDs) of NO2 on a global scale. Here we present the GOME NO2 measurement directly over a large convective system over the Gulf of Mexico. Simultaneously, cloud-to-ground (CG) flashes are counted by the U.S. National Lightning Detection Network (NLDNTM), and extrapolated to include intra-cloud (IC)+CG flashes based on a climatological IC:CG ratio derived from NASA's space-based lightning sensors. A series of 14 GOME pixels shows largely enhanced TVCDs over thick and high clouds, coinciding with strong lightning activity. The enhancements can not be explained by transport of anthropogenic NOx and must be due to fresh production of LNOx. A quantitative analysis, accounting in particular for the visibility of LNOx from satellite, yields a LNOx production of 77 (27-230) moles of NOx, or 1.1 (0.4-3.2) kg [N], per flash. If simply extrapolated, this corresponds to a global LNOx production of 1.5 (0.5-4.5) Tg [N]/yr.

  6. Anthropogenic emissions of NOx over China: Reconciling the difference of inverse modeling results using GOME-2 and OMI measurements

    SciTech Connect

    Gu, Dasa; Wang, Yuhang; Smeltzer, Charles; Boersma, K. Folkert

    2014-06-27

    Inverse modeling using satellite observations of nitrogen dioxide (NO2) columns has been extensively used to estimate nitrogen oxides (NOx) emissions in China. Recently, the Global Ozone Monitoring Experiment-2 (GOME-2) and Ozone Monitoring Instrument (OMI) provide independent global NO2 column measurements on a nearly daily basis at around 9:30 and 13:30 local time across the equator, respectively. Anthropogenic NOx emission estimates by applying previously developed monthly inversion (MI) or daily inversion (DI) methods to these two sets of measurements show substantial differences. We improve the DI method by conducting model simulation, satellite retrieval, and inverse modeling sequentially on a daily basis. After each inversion, we update anthropogenic NOx emissions in the model simulation with the newly obtained a posteriori results. Consequently, the inversion-optimized emissions are used to compute the a priori NO2 profiles for satellite retrievals. As such, the a priori profiles used in satellite retrievals are now coupled to inverse modeling results. The improved procedure was applied to GOME-2 and OMI NO2 measurements in 2011. The new daily retrieval-inversion (DRI) method estimates an average NOx emission of 6.9 Tg N/yr over China, and the difference between using GOME-2 and OMI measurements is 0.4 Tg N/yr, which is significantly smaller than the difference of 1.3 Tg N/yr using the previous DI method. Using the more consistent DRI inversion results, we find that anthropogenic NOx emissions tend to be higher in winter and summer than spring (and possibly fall) and the weekday-to-weekend emission ratio tends to increase with NOx emission in China.

  7. Development and characterisation of a state-of-the-art GOME-2 formaldehyde air-mass factor algorithm

    NASA Astrophysics Data System (ADS)

    Hewson, W.; Barkley, M. P.; Gonzalez Abad, G.; Bösch, H.; Kurosu, T.; Spurr, R.; Tilstra, L. G.

    2015-10-01

    Space-borne observations of formaldehyde (HCHO) are frequently used to derive surface emissions of isoprene, an important biogenic volatile organic compound. The conversion of retrieved HCHO slant column concentrations from satellite line-of-sight measurements to vertical columns is determined through application of an air mass factor (AMF), accounting for instrument viewing geometry, radiative transfer, and vertical profile of the absorber in the atmosphere. This step in the trace gas retrieval is subject to large errors. This work presents the AMF algorithm in use at the University of Leicester (UoL), which introduces scene-specific variables into a per-observation full radiative transfer AMF calculation, including increasing spatial resolution of key environmental parameter databases, input variable area weighting, instrument-specific scattering weight calculation, and inclusion of an ozone vertical profile climatology. Application of these updates to HCHO slant columns from the GOME-2 instrument is shown to typically adjust the AMF by ±20 %, compared to a reference algorithm without these advanced parameterisations. On average the GOME-2 AMFs increase by 4 %, with over 70 % of locations having an AMF of 0-20 % larger than originally, largely resulting from the use of the latest GOME-2 reflectance product. Furthermore, the new UoL algorithm also incorporates a full radiative transfer error calculation for each scene to help characterise AMF uncertainties. Global median AMF errors are typically 50-60 %, and are driven by uncertainties in the HCHO profile shape and its vertical distribution relative to clouds and aerosols. If uncertainty on the a priori HCHO profile is relatively small (< 10 %) then the median AMF total error decreases to about 30-40 %.

  8. Relationship between MODIS fire counts and GOME-2 tropospheric NO2 measurements

    NASA Astrophysics Data System (ADS)

    Schreier, S. F.; Richter, A.; Schönhardt, A.; Burrows, J. P.

    2012-04-01

    Biomass burning has an ongoing role in determining the composition of Earth's surface and atmosphere. The term biomass burning comprises prescribed and wild fires (vegetation fires), as well as biofuel use, such as wood or peat for heating and cooking. Biomass burning represents an important source of aerosol particles and greenhouse gases such as CO2, CH4 and N2O, but also chemically active gases such as CO and NO2 are observed in the plumes. Even though vegetation fire emission inventories have improved considerably in recent years, large uncertainties remain in the temporally and spatially highly variable biomass burning emissions, especially due to uncertainties in input parameters. While satellite observed CO emissions from biomass burning have been investigated in great detail in the last years, NO2 has received much less attention. This can be explained by difficulties posed by the short atmospheric lifetime of NO2 and its photochemical equilibrium with NO but also the complicated retrieval of NO2 due to the presence of smoke and aerosols in the biomass burning plumes. Here, we present the relationship between observed fire counts and NO2 tropospheric vertical column densities from MODIS and GOME-2 measurements, respectively. The MOZART model for 1997 was used to determine monthly averaged air-mass factors and cloud fraction was derived by the FRESCO algorithm from SCIAMACHY measurements. The results show good correlation values (> 0.7) in many parts of the world, especially in the Subtropics. Future work will be further improvement of the retrieval for specific biomass burning situations in order to estimate total emissions from biomass burning for representative biomass burning regions by the use of appropriate models.

  9. Operational surface UV radiation product from GOME-2 and AVHRR/3 data

    NASA Astrophysics Data System (ADS)

    Kujanpää, J.; Kalakoski, N.

    2015-10-01

    The surface ultraviolet (UV) radiation product, version 1.20, generated operationally in the framework of the Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF) of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) is described. The product is based on the total ozone column derived from the measurements of the second Global Ozone Monitoring Experiment (GOME-2) instrument aboard EUMETSAT's polar orbiting meteorological operational (Metop) satellites. Cloud cover is taken into account by retrieving cloud optical depth from the channel 1 reflectance of the third Advanced Very High-Resolution Radiometer (AVHRR/3) instrument aboard both Metop in the morning orbit and Polar Orbiting Environmental Satellites (POES) of the National Oceanic and Atmospheric Administration (NOAA) in the afternoon orbit. In addition, more overpasses are used at high latitudes where the swaths of consecutive orbits overlap. The input satellite data are received from EUMETSAT's Multicast Distribution System (EUMETCast). The surface UV product includes daily maximum dose rates and integrated daily doses with different biological weighting functions, integrated ultraviolet B (UVB) and ultraviolet A (UVA) radiation, solar noon UV index and daily maximum photolysis frequencies of ozone and nitrogen dioxide at the surface level. The quantities are computed in a 0.5°×0.5° regular latitude-longitude grid and stored as daily files in the hierarchical data format (HDF5) within 2 weeks from sensing. The product files are archived in the O3M SAF distributed archive and can be ordered via the EUMETSAT Data Centre.

  10. Operational Monitoring of GOME-2 and IASI Level 1 Product Processing at EUMETSAT

    NASA Astrophysics Data System (ADS)

    Livschitz, Y.; Munro, R.; Lang, R.; Fiedler, L.; Dyer, R.; Eisinger, M.

    2009-12-01

    The growing complexity of operational level 1 radiance products from Low Earth Orbiting (LEO) platforms like EUMETSATs Metop series makes near-real-time monitoring of product quality a challenging task. The main challenge is to provide a monitoring system which is flexible and robust enough to identify and to react to anomalies which may be previously unknown to the system, as well as to provide all means and parameters necessary in order to support efficient ad-hoc analysis of the incident. The operational monitoring system developed at EUMETSAT for monitoring of GOME-2 and IASI level 1 data allows to perform near-real-time monitoring of operational products and instrument’s health in a robust and flexible fashion. For effective information management, the system is based on a relational database (Oracle). An Extract, Transform, Load (ETL) process transforms products in EUMETSAT Polar System (EPS) format into relational data structures. The identification of commonalities between products and instruments allows for a database structure design in such a way that different data can be analyzed using the same business intelligence functionality. An interactive analysis software implementing modern data mining techniques is also provided for a detailed look into the data. The system is effectively used for day-to-day monitoring, long-term reporting, instrument’s degradation analysis as well as for ad-hoc queries in case of an unexpected instrument or processing behaviour. Having data from different sources on a single instrument and even from different instruments, platforms or numerical weather prediction within the same database allows effective cross-comparison and looking for correlated parameters. Automatic alarms raised by checking for deviation of certain parameters, for data losses and other events significantly reduce time, necessary to monitor the processing on a day-to-day basis.

  11. Operational Monitoring of GOME-2 and IASI Level 1 Product Processing at EUMETSAT

    NASA Astrophysics Data System (ADS)

    Livschitz, Yakov; Munro, Rosemary; Lang, Rüdiger; Fiedler, Lars; Dyer, Richard; Eisinger, Michael

    2010-05-01

    The growing complexity of operational level 1 radiance products from Low Earth Orbiting (LEO) platforms like EUMETSATs Metop series makes near-real-time monitoring of product quality a challenging task. The main challenge is to provide a monitoring system which is flexible and robust enough to identify and to react to anomalies which may be previously unknown to the system, as well as to provide all means and parameters necessary in order to support efficient ad-hoc analysis of the incident. The operational monitoring system developed at EUMETSAT for monitoring of GOME-2 and IASI level 1 data allows to perform near-real-time monitoring of operational products and instrument's health in a robust and flexible fashion. For effective information management, the system is based on a relational database (Oracle). An Extract, Transform, Load (ETL) process transforms products in EUMETSAT Polar System (EPS) format into relational data structures. The identification of commonalities between products and instruments allows for a database structure design in such a way that different data can be analyzed using the same business intelligence functionality. An interactive analysis software implementing modern data mining techniques is also provided for a detailed look into the data. The system is effectively used for day-to-day monitoring, long-term reporting, instrument's degradation analysis as well as for ad-hoc queries in case of an unexpected instrument or processing behaviour. Having data from different sources on a single instrument and even from different instruments, platforms or numerical weather prediction within the same database allows effective cross-comparison and looking for correlated parameters. Automatic alarms raised by checking for deviation of certain parameters, for data losses and other events significantly reduce time, necessary to monitor the processing on a day-to-day basis.

  12. Macrophytobenthic flora of the Abrolhos Archipelago and the Sebastião Gomes Reef, Brazil

    NASA Astrophysics Data System (ADS)

    Torrano-Silva, Beatriz N.; Oliveira, Eurico C.

    2013-11-01

    The Abrolhos Bank, located on the coast of Bahia, Brazil, harbors the largest coral reef system in the South Atlantic. This area has attracted the attention of biologists because of its peculiar mushroom-shaped structures, locally known as "chapeirões", and endemic species of corals and other organisms. The macrophytobenthos compartment plays an important ecological role in the functioning of the bank, and some reports on the presence of seaweeds and seagrasses have been published; however, the data are fragmentary, and a more detailed survey of the macrophytobenthos compartment is lacking. Here we consolidate the information available and add new data obtained from two expeditions focused on seaweed and seagrass diversity from two sectors of the bank: the islands of the Abrolhos archipelago (AA) and the Sebastião Gomes Reef (SG). These sites were selected for their contrasting characteristics. Specifically, SG (15 km off the mouth of the Caravelas River) is subjected to a broader range of anthropogenic impacts and to input of terrigenous sediments, while the AA (54 km offshore) is surrounded by calcareous biogenic sediments, has clearer water and is less affected by human activities. Macrophytobenthic species richness on both reference areas is larger than previously thought. Considering previous records, there are 164 species of macrophytes in AA and 111 species in SG, of which 59 and 74 species are first records for each respective location. The higher species richness at the AA may result from a higher habitat complexity and lower turbidity, but a potential negative effect of enhanced human impacts at SG cannot be ruled out. Considering that macroalgae are relevant components of the benthic community, as producers and structurer organisms, the data presented herein provide a reliable baseline for future environmental studies, and thus may contribute to improve management policies within the unique ecosystem of Abrolhos.

  13. Weekly cycle of NO2 by GOME measurements: A signature of anthropogenic sources

    NASA Astrophysics Data System (ADS)

    Beirle, S.; Platt, U.; Wenig, M.; Wagner, T.

    2003-07-01

    Nitrogen oxides (NO+NO2=NOx) are important trace gases in the troposphere with impact on human health, atmospheric chemistry and climate. Besides natural sources (lightning, soil emissions) and biomass burning, fossil fuel combustion is estimated to be responsible for about 50% of the total production of NOx. Since human activity in industrialized countries largely follows an artificial seven-day cycle, fossil fuel combustion is expected to be reduced during weekends. This "weekend effect" is well known from local, ground based measurements, but has never been analysed on a global scale before. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows measurements of NO2 column densities. Applying sophisticated algorithms, vertical column densities (VCD) of tropospheric NO2 can be determined. We demonstrate the statistical analysis of weekly cycles of tropospheric NO2 VCDs for different regions of the world. In the cycles of the industrialized regions and cities in the US, Europe and Japan a clear Sunday minimum of tropospheric NO2 VCD can be seen. Sunday NO2 VCDs are about 25-50% lower than working day levels. Metropolitan areas with other religious and cultural backgrounds (Jerusalem, Mecca) show different weekly patterns corresponding to different days of rest. In China, no weekly pattern can be found. The presence of a weekly cycle in the measured tropospheric NO2 VCD allows the identification of anthropogenic sources. In addition, the fraction of emissions subjected to a weekly cycle (mainly transport, power generation) with respect to a constant background (all kind of natural sources, biomass burning, heavy industry) can be estimated. Furthermore, we estimated the lifetime of tropospheric NO2 by analysing the mean weekly cycle over Germany in detail, obtaining a value of about 12 h.

  14. Overview of the O3M-SAF validation facility for operational GOME-2 NO2 column data

    NASA Astrophysics Data System (ADS)

    Pinardi, Gaia; Lambert, Jean-Christopher; Granville, Jos; van Roozendael, Michel; Delcloo, Andy; Debacker, Hugo; Valks, Pieter; Hao, Nan

    In the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF,) nitrogen dioxide (NO2) total column and tropospheric column data are generated operationally from GOME-2 measurements in near-real-time (within 2:30 hours after sensing). NO2 column data are retrieved from the Earth radiance and solar irradiance spectra by a chain of several modules (currently, the level-0-to-1 processor v4.0 and the level-1-to-2 DOAS retrieval processor GDP v4.3). These intermediate modules calculates the parameters needed to derive the final column data: the slant column density along the optical path, the fractional cover and top pressure of clouds affecting the measurement scene, the geometrical enhancement factor (AMF, needed to convert slant into vertical columns), and the NO2 stratospheric reference to be subtracted from the total column to obtain the tropospheric column. In order to validate the final product (the total and tropospheric NO2 columns) in the best way, and due to the complexity of the GOME-2 retrieval chain and the existing issues related to the set-up of a validation strategy in an operational environment, an end-to-end validation ap-proach has been developed, as recommended by Reference Protocols and Guidelines. To ensure meaningful and continuous quality assessment of GOME-2 NO2 data products, the end-to-end validation approach performs the verification and validation of critical individual components of the level-1-to-2 retrieval chain. Particular interest is given to recurring validation issues, such as the particular way remote sensing samples and smoothes the significant variability of atmospheric NO2, the diurnal cycle of NO2, the poor availability of correlative measure-ments (especially for tropospheric column), as well as the current lack of homogenisation of the validation methods. The end-to-end validation process of GOME-2 NO2 data is based on a set of correlative obser-vations performed by

  15. Round-robin evaluation of nadir ozone profile retrievals: methodology and application to MetOp-A GOME-2

    NASA Astrophysics Data System (ADS)

    Keppens, A.; Lambert, J.-C.; Granville, J.; Miles, G.; Siddans, R.; van Peet, J. C. A.; van der A, R. J.; Hubert, D.; Verhoelst, T.; Delcloo, A.; Godin-Beekmann, S.; Kivi, R.; Stübi, R.; Zehner, C.

    2014-11-01

    A methodology for the round-robin evaluation and geophysical validation of ozone profile data retrieved from nadir UV backscatter satellite measurements is detailed and discussed, consisting of dataset content studies, information content studies, co-location studies, and comparisons with reference measurements. Within ESA's Climate Change Initiative on ozone (Ozone_cci project), the proposed round-robin procedure is applied to two nadir ozone profile datasets retrieved at KNMI and RAL, using their respective OPERA v1.26 and RAL v2.1 optimal estimation algorithms, from MetOp-A GOME-2 measurements taken in 2008. The ground-based comparisons use ozonesonde and lidar profiles as reference data, acquired by the Network for the Detection of Atmospheric Composition Change (NDACC), Southern Hemisphere Additional Ozonesonde programme (SHADOZ), and other stations of WMO's Global Atmosphere Watch. This direct illustration highlights practical issues that inevitably emerge from discrepancies in e.g. profile representation and vertical smoothing, for which different recipes are investigated and discussed. Several approaches for information content quantification, vertical resolution estimation, and reference profile resampling are compared and applied as well. The paper concludes with compliance estimates of the two GOME-2 ozone profile datasets with user requirements from GCOS and from climate modellers.

  16. Round-robin evaluation of nadir ozone profile retrievals: methodology and application to MetOp-A GOME-2

    NASA Astrophysics Data System (ADS)

    Keppens, A.; Lambert, J.-C.; Granville, J.; Miles, G.; Siddans, R.; van Peet, J. C. A.; van der A, R. J.; Hubert, D.; Verhoelst, T.; Delcloo, A.; Godin-Beekmann, S.; Kivi, R.; Stubi, R.; Zehner, C.

    2015-05-01

    A methodology for the round-robin evaluation and the geophysical validation of ozone profile data retrieved from nadir UV backscatter satellite measurements is detailed and discussed, consisting of data set content studies, information content studies, co-location studies, and comparisons with reference measurements. Within the European Space Agency's Climate Change Initiative on ozone (Ozone_cci project), the proposed round-robin procedure is applied to two nadir ozone profile data sets retrieved at the Royal Netherlands Meteorological Institute (KNMI) and the Rutherford Appleton Laboratory (RAL, United Kingdom), using their respective OPERA v1.26 and RAL v2.1 optimal estimation algorithms, from MetOp-A GOME-2 (i.e. the second generation Global Ozone Monitoring Experiment on the first Meteorological Operational Satellite) measurements taken in 2008. The ground-based comparisons use ozonesonde and lidar profiles as reference data, acquired by the Network for the Detection of Atmospheric Composition Change (NDACC), Southern Hemisphere Additional Ozonesonde programme (SHADOZ), and other stations of the World Meteorological Organisation's Global Atmosphere Watch (WMO GAW). This direct illustration highlights practical issues that inevitably emerge from discrepancies in e.g. profile representation and vertical smoothing, for which different recipes are investigated and discussed. Several approaches for information content quantification, vertical resolution estimation, and reference profile resampling are compared and applied as well. The paper concludes with compliance estimates of the two GOME-2 ozone profile data sets with user requirements from the Global Climate Observing System (GCOS) and from climate modellers.

  17. Application of OMI, SCIAMACHY and GOME-2 Satellite SO2 Retrievals for Detection of Large Emission Sources

    NASA Technical Reports Server (NTRS)

    Fioletov, V.E.; McLinden, C. A.; Krotkov, N.; Yang, K.; Loyola, D. G.; Valks, P.; Theys, N.; Van Roozendael, M.; Nowlan, C. R.; Chance, K.; Liu, X.; Lee, C.; Martin, R. V.

    2013-01-01

    Retrievals of sulfur dioxide (SO2) from space-based spectrometers are in a relatively early stage of development. Factors such as interference between ozone and SO2 in the retrieval algorithms often lead to errors in the retrieved values. Measurements from the Ozone Monitoring Instrument (OMI), Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and Global Ozone Monitoring Experiment-2 (GOME-2) satellite sensors, averaged over a period of several years, were used to identify locations with elevated SO2 values and estimate their emission levels. About 30 such locations, detectable by all three sensors and linked to volcanic and anthropogenic sources, were found after applying low and high spatial frequency filtration designed to reduce noise and bias and to enhance weak signals to SO2 data from each instrument. Quantitatively, the mean amount of SO2 in the vicinity of the sources, estimated from the three instruments, is in general agreement. However, its better spatial resolution makes it possible for OMI to detect smaller sources and with additional detail as compared to the other two instruments. Over some regions of China, SCIAMACHY and GOME-2 data show mean SO2 values that are almost 1.5 times higher than those from OMI, but the suggested spatial filtration technique largely reconciles these differences.

  18. Tropospheric ozone and nitrogen dioxide measurements in urban and rural regions as seen by IASI and GOME-2

    NASA Astrophysics Data System (ADS)

    Safieddine, S.; Clerbaux, C.; George, M.; Hadji-Lazaro, J.; Hurtmans, D.; Coheur, P.-F.; Wespes, C.; Loyola, D.; Valks, P.; Hao, N.

    2013-09-01

    ozone (O3) columns in urban and rural regions as seen by the Infrared Atmospheric Sounding Interferometer (IASI) are analyzed along with the Global Ozone Monitoring Experiment (GOME-2) tropospheric nitrogen dioxide (NO2) columns. Results over nine cities of the Northern Hemisphere for the period 2008-2011 show a typical seasonal behavior of tropospheric O3, with a first maximum reached in late spring because of stratospheric intrusion mainly and a continuous rise till the summer because of the anthropogenic-based ozone production. Over the East Asian cities, a decrease in the O3 tropospheric column is detected during the monsoon period. Seasonal cycling of tropospheric NO2 shows consistent higher values during winter because of the higher anthropogenic sources and longer lifetime. In rural regions, a complex relation between the O3 and NO2 columns is found, with good correlation in summer and winter. O3 concentrations in rural sites are found to be comparable to those closest to the anthropogenic emission sources, with peak values in spring and summer. Furthermore, the effect of the reduction of pollutant emissions in the Beijing region during the Olympic Games of 2008 compared to the same summer period in the following 3 years is studied. GOME-2 NO2 measurements show a reduction up to 54% above Beijing during this period compared to the following 3 years. IASI O3 measurements show an increase of 12% during July 2008 followed by a decrease of 5-6% during the months of August and September.

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

    NASA Astrophysics Data System (ADS)

    Stavrakou, T.; Müller, J.-F.; Bauwens, M.; De Smedt, I.; Van Roozendael, M.; De Mazière, M.; Vigouroux, C.; Hendrick, F.; George, M.; Clerbaux, C.; Coheur, P.-F.; Guenther, A.

    2015-10-01

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

  20. Operational surface UV radiation product from GOME-2 and AVHRR/3 data

    NASA Astrophysics Data System (ADS)

    Kujanpää, J.; Kalakoski, N.

    2015-05-01

    The surface ultraviolet (UV) radiation product, version 1.20, generated operationally in the framework of the Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M SAF) of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) is described. The product is based on the total ozone column derived from the measurements of the second Global Ozone Monitoring Experiment (GOME-2) instrument aboard EUMETSAT's polar orbiting meteorological operational (Metop) satellites. The input total ozone product is generated by the German Aerospace Center (DLR) also within the O3M SAF framework. Polar orbiting satellites provide global coverage but infrequent sampling of the diurnal cloud cover. The diurnal variation of the surface UV radiation is extremely strong due to modulation by solar elevation and rapidly changing cloud cover. At the minimum, one sample of the cloud cover in the morning and another in the afternoon are needed to derive daily maximum and daily integrated surface UV radiation quantities. This is achieved by retrieving cloud optical depth from the channel 1 reflectance of the third Advanced Very High Resolution Radiometer (AVHRR/3) instrument aboard both Metop in the morning orbit (daytime descending node around 09:30 LT) and Polar Orbiting Environmental Satellites (POES) of the National Oceanic and Atmospheric Administration (NOAA) in the afternoon orbit (daytime ascending node around 14:30 LT). In addition, more overpasses are used at high latitudes where the swaths of consecutive orbits overlap. The input satellite data are received from EUMETSAT's Multicast Distribution System (EUMETCast) using commercial telecommunication satellites for broadcasting the data to the user community. The surface UV product includes daily maximum dose rates and integrated daily doses with different biological weighting functions, integrated UVB and UVA radiation, solar noon UV Index and daily maximum photolysis

  1. The direct fitting approach for total ozone column retrievals: a sensitivity study on GOME-2/MetOp-A measurements

    NASA Astrophysics Data System (ADS)

    Wassmann, A.; Borsdorff, T.; aan de Brugh, J. M. J.; Hasekamp, O. P.; Aben, I.; Landgraf, J.

    2015-10-01

    We present a sensitivity study of the direct fitting approach to retrieve total ozone columns from the clear sky Global Ozone Monitoring Experiment 2/MetOp-A (GOME-2/MetOp-A) measurements between 325 and 335 nm in the period 2007-2010. The direct fitting of the measurement is based on adjusting the scaling of a reference ozone profile and requires accurate simulation of GOME-2 radiances. In this context, we study the effect of three aspects that introduce forward model errors if not addressed appropriately: (1) the use of a clear sky model atmosphere in the radiative transfer demanding cloud filtering, (2) different approximations of Earth's sphericity to address the influence of the solar zenith angle, and (3) the need of polarization in radiative transfer modeling. We conclude that cloud filtering using the operational GOME-2 FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A band) cloud product, which is part of level 1B data, and the use of pseudo-spherical scalar radiative transfer is fully sufficient for the purpose of this retrieval. A validation with ground-based measurements at 36 stations confirms this showing a global mean bias of -0.1 % with a standard deviation (SD) of 2.7 %. The regularization effect inherent to the profile scaling approach is thoroughly characterized by the total column averaging kernel for each individual retrieval. It characterizes the effect of the particular choice of the ozone profile to be scaled by the inversion and is part of the retrieval product. Two different interpretations of the data product are possible: first, regarding the retrieval product as an estimate of the true column, a direct comparison of the retrieved column with total ozone columns from ground-based measurements can be done. This requires accurate a priori knowledge of the reference ozone profile and the column averaging kernel is not needed. Alternatively, the retrieval product can be interpreted as an effective column defined by the total column

  2. Diurnal, seasonal and long-term variations of global formaldehyde columns inferred from combined OMI and GOME-2 observations

    NASA Astrophysics Data System (ADS)

    De Smedt, I.; Stavrakou, T.; Hendrick, F.; Danckaert, T.; Vlemmix, T.; Pinardi, G.; Theys, N.; Lerot, C.; Gielen, C.; Vigouroux, C.; Hermans, C.; Fayt, C.; Veefkind, P.; Müller, J.-F.; Van Roozendael, M.

    2015-11-01

    We present the new version (v14) of the BIRA-IASB algorithm for the retrieval of formaldehyde (H2CO) columns from spaceborne UV-visible sensors. Applied to OMI measurements from Aura and to GOME-2 measurements from MetOp-A and MetOp-B, this algorithm is used to produce global distributions of H2CO representative of mid-morning and early afternoon conditions. Its main features include (1) a new iterative DOAS scheme involving three fitting intervals to better account for the O2-O2 absorption, (2) the use of earthshine radiances averaged in the equatorial Pacific as reference spectra, and (3) a destriping correction and background normalisation resolved in the across-swath position. For the air mass factor calculation, a priori vertical profiles calculated by the IMAGES chemistry transport model at 09:30 and 13:30 LT are used. Although the resulting GOME-2 and OMI H2CO vertical columns are found to be highly correlated, some systematic differences are observed. Afternoon columns are generally larger than morning ones, especially in mid-latitude regions. In contrast, over tropical rainforests, morning H2CO columns significantly exceed those observed in the afternoon. These differences are discussed in terms of the H2CO column variation between mid-morning and early afternoon, using ground-based MAX-DOAS measurements available from seven stations in Europe, China and Africa. Validation results confirm the capacity of the combined satellite measurements to resolve diurnal variations in H2CO columns. Furthermore, vertical profiles derived from MAX-DOAS measurements in the Beijing area and in Bujumbura are used for a more detailed validation exercise. In both regions, we find an agreement better than 15 % when MAX-DOAS profiles are used as a priori for the satellite retrievals. Finally, regional trends in H2CO columns are estimated for the 2004-2014 period using SCIAMACHY and GOME-2 data for morning conditions, and OMI for early afternoon conditions. Consistent features

  3. Diurnal, seasonal and long-term variations of global formaldehyde columns inferred from combined OMI and GOME-2 observations

    NASA Astrophysics Data System (ADS)

    De Smedt, I.; Stavrakou, T.; Hendrick, F.; Danckaert, T.; Vlemmix, T.; Pinardi, G.; Theys, N.; Lerot, C.; Gielen, C.; Vigouroux, C.; Hermans, C.; Fayt, C.; Veefkind, P.; Müller, J.-F.; Van Roozendael, M.

    2015-04-01

    We present the new version (v14) of the BIRA-IASB algorithm for the retrieval of formaldehyde (H2CO) columns from spaceborne UV-Visible sensors. Applied to OMI measurements from Aura and to GOME-2 measurements from MetOp-A and B, this algorithm is used to produce global distributions of H2CO representative of mid-morning and early afternoon conditions. Its main features include (1) a new iterative DOAS scheme involving three fitting intervals to better account for the O2-O2 absorption, (2) the use of earthshine radiances averaged in the equatorial Pacific as reference spectra, (3) a destriping correction and background normalisation resolved in the along-swath position. For the air mass factor calculation, a priori vertical profiles calculated by the IMAGES chemistry transport model at 9.30 a.m. and 13.30 p.m. are used. Although the resulting GOME-2 and OMI H2CO vertical columns are found to be highly correlated, some systematic differences are observed. Afternoon columns are generally larger than morning ones, especially in mid-latitude regions. In contrast, over tropical rainforests, morning H2CO columns significantly exceed those observed in the afternoon. These differences are discussed in terms of the H2CO column variation between mid-morning and early afternoon, using ground-based MAX-DOAS measurements available from seven stations in Europe, China and Africa. Validation results confirm the capacity of the combined satellite measurements to resolve diurnal variations in H2CO columns. Furthermore, vertical profiles derived from MAX-DOAS measurements in the Beijing area and in Bujumbura are used for a more detailed validation exercise. In both regions, we find an agreement better than 15% when MAX-DOAS profiles are used as a priori for the satellite retrievals. Finally regional trends in H2CO columns are estimated for the 2004-2014 period using SCIAMACHY and GOME-2 data for morning conditions, and OMI for early afternoon conditions. Consistent features are

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

    SciTech Connect

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

    2015-10-26

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

  5. The GOME-2 instrument on the Metop series of satellites: instrument design, calibration, and level 1 data processing - an overview

    NASA Astrophysics Data System (ADS)

    Munro, Rosemary; Lang, Rüdiger; Klaes, Dieter; Poli, Gabriele; Retscher, Christian; Lindstrot, Rasmus; Huckle, Roger; Lacan, Antoine; Grzegorski, Michael; Holdak, Andriy; Kokhanovsky, Alexander; Livschitz, Jakob; Eisinger, Michael

    2016-03-01

    The Global Ozone Monitoring Experiment-2 (GOME-2) flies on the Metop series of satellites, the space component of the EUMETSAT Polar System. In this paper we will provide an overview of the instrument design, the on-ground calibration and characterization activities, in-flight calibration, and level 0 to 1 data processing. The current status of the level 1 data is presented and points of specific relevance to users are highlighted. Long-term level 1 data consistency is also discussed and plans for future work are outlined. The information contained in this paper summarizes a large number of technical reports and related documents containing information that is not currently available in the published literature. These reports and documents are however made available on the EUMETSAT web pages and readers requiring more details than can be provided in this overview paper will find appropriate references at relevant points in the text.

  6. First Directly Retrieved Global Distribution of Tropospheric Column Ozone from GOME: Comparison with the GEOS-CHEM Model

    NASA Technical Reports Server (NTRS)

    Liu, Xiong; Chance, Kelly; Sioris, Christopher E.; Kurosu, Thomas P.; Spurr, Robert J. D.; Martin, Randall V.; Fu, Tzung-May; Logan, Jennifer A.; Jacob, Daniel J.; Palmer, Paul I.; Newchurch, Michael J.; Megretskaia, Inna A.; Chatfield, Robert B.

    2006-01-01

    We present the first directly retrieved global distribution of tropospheric column ozone from Global Ozone Monitoring Experiment (GOME) ultraviolet measurements during December 1996 to November 1997. The retrievals clearly show signals due to convection, biomass burning, stratospheric influence, pollution, and transport. They are capable of capturing the spatiotemporal evolution of tropospheric column ozone in response to regional or short time-scale events such as the 1997-1998 El Nino event and a 10-20 DU change within a few days. The global distribution of tropospheric column ozone displays the well-known wave-1 pattern in the tropics, nearly zonal bands of enhanced tropospheric column ozone of 36-48 DU at 20degS-30degS during the austral spring and at 25degN-45degN during the boreal spring and summer, low tropospheric column ozone of <30 DU uniformly distributed south of 35 S during all seasons, and relatively high tropospheric column ozone of >33 DU at some northern high-latitudes during the spring. Simulation from a chemical transport model corroborates most of the above structures, with small biases of <+/-5 DU and consistent seasonal cycles in most regions, especially in the southern hemisphere. However, significant positive biases of 5-20 DU occur in some northern tropical and subtropical regions such as the Middle East during summer. Comparison of GOME with monthly-averaged Measurement of Ozone and Water Vapor by Airbus in-service Aircraft (MOZAIC) tropospheric column ozone for these regions usually shows good consistency within 1 a standard deviations and retrieval uncertainties. Some biases can be accounted for by inadequate sensitivity to lower tropospheric ozone, the different spatiotemporal sampling and the spatiotemporal variations in tropospheric column ozone.

  7. Tropospheric ozone and nitrogen dioxide measurements in urban and rural regions as seen by IASI and GOME-2

    NASA Astrophysics Data System (ADS)

    Safieddine, S.; Clerbaux, C.; George, M.; Hadji-Lazaro, J.; Hurtmans, D.; Coheur, P.; Wespes, C.; Layola, D.; Valks, P.; Hao, N.

    2013-05-01

    Tropospheric ozone (O3) columns in urban and rural regions as seen by the infrared sounder IASI are analyzed along with GOME-2 tropospheric nitrogen dioxide (NO2) columns. Results over nine cities of the Northern Hemisphere for the period 2008-2011 show a typical seasonal behavior of tropospheric O3, with a first maximum reached in late spring because of stratospheric intrusion mainly, and a continuous rise till the summer because of the anthropogenic based ozone production. Over the East Asian cities, a decrease in the O3 tropospheric column is detected during monsoon period. Seasonal cycling of tropospheric NO2 shows consistent higher values during winter because of the higher anthropogenic sources and longer lifetime. In rural regions, a complex relation between the O3 and NO2 column is found, with higher linearity in summer. O3 concentrations in rural sites are found to be comparable to those found closest to the anthropogenic emission sources, with peak values in spring and summer. Furthermore, the effect of the reduction of pollutant emissions in China during the Olympic games of 2008 is studied. GOME-2 NO2 measurements show a reduction up to 54% above Beijing during this period compared to the following three years. IASI O3 measurements show an increase of 12% during July 2008 followed by a decrease of 5-6% during the months of August and September. A significant reduction in O3 tropospheric column values is also detected in the area downwind, few hundreds of kilometers to the south of Beijing.

  8. [Luís Gomes Ferreira reports on the health of slaves in his work entitled Erário mineral (1735)].

    PubMed

    Eugênio, Alisson

    2015-01-01

    The article analyzes the reports of Luís Gomes Ferreira published in his manual on practical medicine entitled Erário mineral, of 1735, on the most common illnesses in captivity. It is shown that such reports can be interpreted as a criticism of the social relations of the slave era by issuing some warnings to the landowners who failed to look after the health of their slaves.

  9. OMI/Aura, SCIAMACHY/Envisat and GOME2/MetopA Sulphur Dioxide Estimate; The Case of Eastern Asia

    NASA Astrophysics Data System (ADS)

    Koukouli, M. E.; Balis, D. S.; Theys, N.; Brenot, H.; van Gent, J.; Hendrick, F.; Wang, T.; Valks, P.; Hedelt, P.; Lichtenberg, G.; Richter, A.; Krotkov, N.; Li, C.; van der A, R.

    2015-06-01

    The EU FP7 Monitoring and Assessment of Regional air quality in China using space Observations, Project Of Long-term sino-european co-Operation, MarcoPolo, project focuses on deriving emission estimates from space, http://www.marcopolo-panda.eu. Long term satellite observations of Sulphur Dioxide, SO2, over the greater China area from the SCIAMACHY/Envisat, GOME2/MetopA and OMI/Aura missions are compared and their relative strong points and limitations are discussed. For each satellite instrument, two different datasets are being analyzed in the same manner. Rigorous spatiotemporal statistical analysis based on novel analysis techniques is performed for each data set in order to reduce noise and biases and enhance pollution signals in satellite datasets. Furthermore, identification of point sources such as power plants, smelters and urban agglomerations, as well as definition of their relative contribution to the regional SO2 levels, form the main findings of this investigation. Trend analyses and their statistical representation help locate regions of interesting SO2 loading in China.

  10. Development and characterisation of a state-of-the-art GOME-2 formaldehyde air-mass factor algorithm

    NASA Astrophysics Data System (ADS)

    Hewson, W.; Barkley, M. P.; Gonzalez Abad, G.; Bösch, H.; Kurosu, T.; Spurr, R.

    2015-01-01

    Space-borne observations of formaldehyde (HCHO) are frequently used to derive surface emissions of isoprene, an important biogenic volatile organic compound. The conversion of retrieved HCHO slant column concentrations from satellite line of sight measurements to vertical columns is determined through application of an air mass factor (AMF), accounting for instrument viewing geometry, radiative transfer, and vertical profile of the absorber in the atmosphere. This step in the trace gas retrieval is subject to large errors. This work presents the AMF algorithm in use at the University of Leicester (UoL), which introduces scene specific variables into a per-observation full radiative transfer AMF calculation, including increasing spatial resolution of key environmental parameter databases, input variable area weighting, instrument specific scattering weight calculation, and inclusion of an ozone vertical profile climatology. Application of these updates to HCHO slant columns from the GOME-2 instrument is shown to typically adjust the AMF by ±10%, compared to a~reference algorithm without these advanced parameterisations. Furthermore, the new UoL algorithm also incorporates a full radiative transfer error calculation for each scene to help characterise AMF uncertainties. Global median AMF errors are typically 50-60%, and are dominated by uncertainties in the HCHO profile shape and its corresponding seasonal variation.

  11. Systematic analysis of tropospheric NO2 long-range transport events detected in GOME-2 satellite data

    NASA Astrophysics Data System (ADS)

    Zien, A. W.; Richter, A.; Hilboll, A.; Blechschmidt, A.-M.; Burrows, J. P.

    2014-07-01

    Intercontinental long-range transport (LRT) events of NO2 relocate the effects of air pollution from emission regions to remote, pristine regions. We detect transported plumes in tropospheric NO2 columns measured by the GOME-2/MetOp-A instrument with a specialized algorithm and trace the plumes to their sources using the HYSPLIT Lagrangian transport model. With this algorithm we find 3808 LRT events over the ocean for the period 2007 to 2011. LRT events occur frequently in the mid-latitudes, emerging usually from coastal high-emission regions. In the free troposphere, plumes of NO2 can travel for several days to the polar oceanic atmosphere or to other continents. They travel along characteristic routes and originate from both continuous anthropogenic emission and emission events such as bush fires. Most NO2 LRT events occur during autumn and winter months, when meteorological conditions and emissions are most favorable. The evaluation of meteorological data shows that the observed NO2 LRT is often linked to cyclones passing over an emission region.

  12. Systematic analysis of tropospheric NO2 long-range transport events detected in GOME-2 satellite data

    NASA Astrophysics Data System (ADS)

    Zien, A. W.; Richter, A.; Hilboll, A.; Blechschmidt, A.-M.; Burrows, J. P.

    2013-11-01

    Intercontinental long-range transport (LRT) events of NO2 relocate the effects of air pollution from emission regions to remote, pristine regions. We detect transported plumes in tropospheric NO2 columns measured by the GOME-2/MetOp-A instrument with a specialized algorithm and trace the plumes to their sources using the HYSPLIT lagrangian transport model. With this algorithm we find 3808 LRT events over the ocean for the period 2007 to 2011. LRT events occur frequently in the mid-latitudes, emerging usually from coastal high-emission regions. In the free troposphere, plumes of NO2 can travel for several days to the polar oceanic atmosphere or to other continents. They travel along characteristic routes and originate from both continuous anthropogenic emission and emission events such as bush fires. Most NO2 LRT events occur during autumn and winter months, when meteorological conditions and emissions are most favorable. The evaluation of meteorological data shows that the observed NO2 LRT is often linked to cyclones passing over an emission region.

  13. Volcanic SO2 fluxes derived from satellite data: a survey using OMI, GOME-2, IASI and MODIS

    NASA Astrophysics Data System (ADS)

    Theys, N.; Campion, R.; Clarisse, L.; Brenot, H.; van Gent, J.; Dils, B.; Corradini, S.; Merucci, L.; Coheur, P.-F.; Van Roozendael, M.; Hurtmans, D.; Clerbaux, C.; Tait, S.; Ferrucci, F.

    2013-06-01

    Sulphur dioxide (SO2) fluxes of active degassing volcanoes are routinely measured with ground-based equipment to characterize and monitor volcanic activity. SO2 of unmonitored volcanoes or from explosive volcanic eruptions, can be measured with satellites. However, remote-sensing methods based on absorption spectroscopy generally provide integrated amounts of already dispersed plumes of SO2 and satellite derived flux estimates are rarely reported. Here we review a number of different techniques to derive volcanic SO2 fluxes using satellite measurements of plumes of SO2 and investigate the temporal evolution of the total emissions of SO2 for three very different volcanic events in 2011: Puyehue-Cordón Caulle (Chile), Nyamulagira (DR Congo) and Nabro (Eritrea). High spectral resolution satellite instruments operating both in the ultraviolet-visible (OMI/Aura and GOME-2/MetOp-A) and thermal infrared (IASI/MetOp-A) spectral ranges, and multispectral satellite instruments operating in the thermal infrared (MODIS/Terra-Aqua) are used. We show that satellite data can provide fluxes with a sampling of a day or less (few hours in the best case). Generally the flux results from the different methods are consistent, and we discuss the advantages and weaknesses of each technique. Although the primary objective of this study is the calculation of SO2 fluxes, it also enables us to assess the consistency of the SO2 products from the different sensors used.

  14. Volcanic SO2 fluxes derived from satellite data: a survey using OMI, GOME-2, IASI and MODIS

    NASA Astrophysics Data System (ADS)

    Theys, N.; Campion, R.; Clarisse, L.; Brenot, H.; van Gent, J.; Dils, B.; Corradini, S.; Merucci, L.; Coheur, P.-F.; Van Roozendael, M.; Hurtmans, D.; Clerbaux, C.; Tait, S.; Ferrucci, F.

    2012-12-01

    Sulphur dioxide (SO2) fluxes of active degassing volcanoes are routinely measured with ground-based equipment to characterize and monitor volcanic activity. SO2 of unmonitored volcanoes or from explosive volcanic eruptions, can be measured with satellites. However, remote-sensing methods based on absorption spectroscopy generally provide integrated amounts of already dispersed plumes of SO2 and satellite derived flux estimates are rarely reported. Here we review a number of different techniques to derive volcanic SO2 fluxes using satellite measurements of dispersed and large-scale plumes of SO2 and investigate the temporal evolution of the total emissions of SO2 for three very different volcanic events in 2011: Puyehue-Cordón Caulle (Chile), Nyamulagira (DR Congo) and Nabro (Eritrea). High spectral resolution satellite instruments operating both in the UV-visible (OMI/Aura and GOME-2/MetOp-A) and thermal infrared (IASI/MetOp-A) spectral ranges, and multispectral satellite instruments operating in the thermal infrared (MODIS/Terra-Aqua) are used. We show that satellite data can provide fluxes with a sampling of a day or less (few hours in the best case). Generally the flux results from the different methods are consistent, and we discuss the advantages and weaknesses of each technique. Although the primary objective of this study is the calculation of SO2 fluxes, it also enables to assess the consistency of the SO2 products from the different sensors used.

  15. Solar Induced Vegetation Fluorescence Retrieval Using SCIAMACHY and GOME-2 Measurements And Its Correlation To GPP And FAPAR

    NASA Astrophysics Data System (ADS)

    Vountas, M.; Khosravi, N.; Rozanov, V. V.; Burrows, J. P.

    2015-12-01

    Global carbon cycle is connected to terrestrial vegetation as an important sink of CO2. Plants contribute to the global carbon cycle both through photosynthesis and respiration processes. Fluorescence is a fraction of surplus energy, emitted to the environment by Chlorophyll molecules as a side-product of photosynthesis. As a result, Sun-Induced plant Fluorescence (SIF) is a reliable indicator of photosynthesis efficiency and therefore, important for vegetation observation, forest monitoring, global carbon uptake formulation and even agriculture.In our study, a newly developed retrieval scheme is used to quantify SIF from non-invasive satellite measurements of Top of Atmosphere (TOA) Earthshine radiances. Our method has been developed and tested on simulated data, created by the comprehensive radiative transfer model, SCIATRAN. Sensitivity studies showed that the method is capable of assessing SIF. The method is then applied on long-term data of 10 years from SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) and GOME-2 (Global Ozone Monitoring Experiment-2) instruments and produced promising results.Furthermore, the relationship between the retrieved SIF values and vegetation's contribution to the global CO2 uptake is investigated by comparing monthly variation of SIF against GPP (Gross Primary Production) and FAPAR (Fraction of Absorbed Photosynthetically Active Radiation) for selected regions.

  16. Estimating the NO(x) produced by lightning from GOME and NLDN data: A case study in the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Beirle, S.; Spichtinger, N.; Stohl, A.; Cummins, K. L.; Turner, T.; Boccippio, D.; Cooper, O. R.; Wenig, M.; Grzegorski, M.; Platt, U.

    2006-01-01

    Nitrogen oxides (NO(x)=NO+NO2) play an important role in tropospheric chemistry, in particular in catalytic ozone production. Lightning provides a natural source of nitrogen oxides, dominating the production in the tropical upper troposphere, with strong impact on tropospheric ozone and the atmosphere s oxidizing capacity. Recent estimates of lightning produced NO(x) (LNO(x)) are of the order of 5 Tg [N] per year with still high uncertainties in the range of one order of magnitude. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows the retrieval of tropospheric column densities of NO2 on a global scale. Here we present the GOME NO2 measurement directly over a large convective system over the Gulf of Mexico. Simultaneously, cloud-to-ground (CG) flashes are counted by the U.S. National Lightning Detection Network (NLDN(TradeMark)), and extrapolated to include intracloud (IC)+CG flashes based on a climatological IC:CG ratio derived from NASA s space-based lightning sensors. A series of 14 GOME pixels shows largely enhanced column densities over thick and high clouds, coinciding with strong lightning activity. The enhancements can not be explained by transport of anthropogenic NO(x) and must be due to fresh production of LNO(x). A quantitative analysis, accounting in particular for the visibility of LNO, from satellite, yields a LNO, production of 90 (32-240) moles of NO(x), or 1.3 (0.4-3.4) kg [N], per flash. If simply extrapolated, this corresponds to a global LNO(x) production of 1.7 (0.6-4.7) Tg [N]/yr.

  17. Global Monitoring of Terrestrial Chlorophyll Fluorescence from Moderate-Spectral-Resolution Near-Infrared Satellite Measurements: Methodology, Simulations, and Application to GOME-2

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Guanter, L.; Lindstrot, R.; Voigt, M.; Vasilkov, A. P.; Middleton, E. M.; Huemmrich, K. F.; Yoshida, Y.; Frankenberg, C.

    2013-01-01

    Globally mapped terrestrial chlorophyll fluorescence retrievals are of high interest because they can provide information on the functional status of vegetation including light-use efficiency and global primary productivity that can be used for global carbon cycle modeling and agricultural applications. Previous satellite retrievals of fluorescence have relied solely upon the filling-in of solar Fraunhofer lines that are not significantly affected by atmospheric absorption. Although these measurements provide near-global coverage on a monthly basis, they suffer from relatively low precision and sparse spatial sampling. Here, we describe a new methodology to retrieve global far-red fluorescence information; we use hyperspectral data with a simplified radiative transfer model to disentangle the spectral signatures of three basic components: atmospheric absorption, surface reflectance, and fluorescence radiance. An empirically based principal component analysis approach is employed, primarily using cloudy data over ocean, to model and solve for the atmospheric absorption. Through detailed simulations, we demonstrate the feasibility of the approach and show that moderate-spectral-resolution measurements with a relatively high signal-to-noise ratio can be used to retrieve far-red fluorescence information with good precision and accuracy. The method is then applied to data from the Global Ozone Monitoring Instrument 2 (GOME-2). The GOME-2 fluorescence retrievals display similar spatial structure as compared with those from a simpler technique applied to the Greenhouse gases Observing SATellite (GOSAT). GOME-2 enables global mapping of far-red fluorescence with higher precision over smaller spatial and temporal scales than is possible with GOSAT. Near-global coverage is provided within a few days. We are able to show clearly for the first time physically plausible variations in fluorescence over the course of a single month at a spatial resolution of 0.5 0.5. We also show

  18. Global Monitoring of Terrestrial Chlorophyll Fluorescence from Moderate-spectral-resolution Near-infrared Satellite Measurements: Methodology, Simulations, and Application to GOME-2

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Gaunter, L.; Lindstrot, R.; Voigt, M.; Vasilkov, A. P.; Middleton, E. M.; Huemmrich, K. F.; Yoshida, Y.; Frankenberg, C.

    2013-01-01

    Globally mapped terrestrial chlorophyll fluorescence retrievals are of high interest because they can provide information on the functional status of vegetation including light-use efficiency and global primary productivity that can be used for global carbon cycle modeling and agricultural applications. Previous satellite retrievals of fluorescence have relied solely upon the filling-in of solar Fraunhofer lines that are not significantly affected by atmospheric absorption. Although these measurements provide near-global coverage on a monthly basis, they suffer from relatively low precision and sparse spatial sampling. Here, we describe a new methodology to retrieve global far-red fluorescence information; we use hyperspectral data with a simplified radiative transfer model to disentangle the spectral signatures of three basic components: atmospheric absorption, surface reflectance, and fluorescence radiance. An empirically based principal component analysis approach is employed, primarily using cloudy data over ocean, to model and solve for the atmospheric absorption. Through detailed simulations, we demonstrate the feasibility of the approach and show that moderate-spectral-resolution measurements with a relatively high signal-to-noise ratio can be used to retrieve far-red fluorescence information with good precision and accuracy. The method is then applied to data from the Global Ozone Monitoring Instrument 2 (GOME-2). The GOME-2 fluorescence retrievals display similar spatial structure as compared with those from a simpler technique applied to the Greenhouse gases Observing SATellite (GOSAT). GOME-2 enables global mapping of far-red fluorescence with higher precision over smaller spatial and temporal scales than is possible with GOSAT. Near-global coverage is provided within a few days. We are able to show clearly for the first time physically plausible variations in fluorescence over the course of a single month at a spatial resolution of 0.5 deg × 0.5 deg

  19. The NOAA-NASA OMI/GOME-2 Near-Real-Time Monitoring System of Volcanic SO2 and Aerosol Clouds

    NASA Astrophysics Data System (ADS)

    Vicente, G.; Schroeder, W.; Krueger, A. J.; Yang, K.; Carn, S. A.; Krotkov, N. A.; Guffanti, M.; Levelt, P.

    2009-12-01

    The Ozone Monitoring Instrument (OMI) on the NASA EOS/Aura research satellite and the Global Ozone Monitoring Experiment-2 (GOME-2) instrument on the Metop-A satellite allow measurement of SO2 concentrations at UV wavelengths with daily global coverage. SO2 is detected from space using its strong absorption band structure in the near UV (300-320 nm) as well as in IR bands near 7.3 and 8.6 μm. UV SO2 measurements are very robust and are insensitive to the factors that confound IR data. SO2 and ash can be detected in a very fresh volcanic eruption cloud due to sunlight backscattering and ash presence can be confirmed by UV derived aerosol index measurements. When detected in Near Real-Time (NRT) it can be used as aviation alerts to the Federal Aviation Administration (FAA) with reduced false alarm ratios and permit more robust detection and tracking of volcanic clouds. NRT observations of SO2 and volcanic ash using UV measurements (OMI and GOME-2) and well as IR measurements can be incorporated into data products compatible with Decision Support Tools (DSTs) in use at Volcanic Ash Advisory Centers (VAACs) in Washington and Anchorage, and the USGS Volcano Observatories. In this presentation we show the latest NASA and NOAA Office of Satellite Data Processing and Distribution (OSDPD) developments of an online NRT image and data product distribution system. The system generates eruption alerts, NRT global composite images and SO2, Aerosol Index and Cloud Reflectivity images for 28 volcano regions, as well as up to 15 days of digital data files in McIDAS, NetCDF, GeoTIFF and gif formats for the OMI and GOME-2 instruments. Products are infused into DSTs including the Volcanic Ash Coordination Tool (VACT), under development by the NOAA Forecast Systems Laboratory and the FAA’s Oceanic Weather Product Development Team (OWPDT), to monitor and track, drifting volcanic clouds and aerosol index.

  20. Bromine oxide in polar regions: Possible origin of BrO seen from GOME-2 satellite observations

    NASA Astrophysics Data System (ADS)

    Begoin, Mathias; Richter, Andreas; Burrows, John P.

    As all halogens, bromine plays an important role in atmospheric ozone chemistry. In polar regions during springtime, a nearly complete destruction of ozone can be observed in widespread parts of Arctic and Antarctic polar boundary layer. Bromine has been identified as key halogen in this process and can be rapidly released from sea salt to the gas phase by autocatalytic heterogeneous reactions (so called bromine explosion). Together with ozone it reacts among others to bromine monoxide, which can be observed In-Situ or by absorption spectroscopy from the ground and from satellite. Further BrO has a large impact on deposition of gaseous mercury to the surface, from where it can easily enter the sensitive polar ecosystem. The exact mechanism leading to initial bromine release as well as the influence of transport and chemical recycling processes for the evolution of observed BrO concentrations is still not completely understood. Satellite observations of BrO columns contain both, the tropospheric and the stratospheric amounts. Usually the stratospheric BrO is quite homogeneous and can be removed by assuming climatological values. However, in cases of strongly varying tropopause heights, the influence of stratospheric BrO on the signal can be underestimated leading to uncertainties in the derived tropospheric BrO amounts. In this study, BrO measurements of the satellite instrument GOME-2 on MetOp-A in com-bination with calculations of the particle dispersion model FLEXPART are used to gain new information about the vertical spreading of BrO. By using distinctive BrO events observable for several days and over large areas and considering variations in tropopause heights the origin of bromine during events with enhanced BrO values is investigated and conclusions are drawn on the applicability of satellite observations.

  1. Global observations of glyoxal columns from OMI/Aura and GOME-2/Metop-A sensors and comparison with multi-year simulations by the IMAGES model

    NASA Astrophysics Data System (ADS)

    Lerot, Christophe; Stavrakou, Trissevgeni; Hendrick, François; De Smedt, Isabelle; Müller, Jean-François; Volkamer, Rainer; Van Roozendael, Michel

    2015-04-01

    Volatile organic compounds (VOCs) originating from both natural and human activities play a key role in air quality. Information on their atmospheric concentrations can be derived using remote sensing techniques for a limited number of species, including formaldehyde (HCHO) and glyoxal (CHOCHO). The latter is mostly produced in the atmosphere as an intermediate product in the oxidation of other non-methane VOCs. It is also directly emitted from fire events and combustion processes. Owing to its short lifetime, elevated glyoxal concentrations are observed near emission sources. Measurements of atmospheric glyoxal concentrations therefore provide quantitative information on the different types of VOC emission and can help to better assess the quality of current inventories. In addition, glyoxal is also known to significantly contribute to the total budget of secondary organic aerosols. Global observations of glyoxal columns have been realized from different space-borne spectrometers using the well-known DOAS retrieval technique. In the past, we developed an algorithm to retrieve glyoxal columns from spectra measured by the GOME-2 instrument aboard METOP-A (Lerot et al., 2010). Specificities of this algorithm were an original two-step approach in the DOAS fit to minimize the impact of spectral interferences with the liquid water absorption as well as the use of a priori information from the Chemical Transport Model IMAGES in the air mass factor calculation. In this work, we present the adaptation of this algorithm to the OMI sensor on the AURA platform. The time series of glyoxal columns derived from OMI and GOME-2 are compared in different parts of the world and a high level of consistency is found. The OMI glyoxal data product is found to be very stable over the entire duration of the mission, in contrast to the GOME-2 product which is affected by instrumental degradation. We present validation results using several years of MAX-DOAS glyoxal measurements

  2. Retrieval of Ozone Column Content from Airborne Sun Photometer Measurements During SOLVE II: Comparison with SAGE III, POAM III,THOMAS and GOME Measurements. Comparison with SAGE 111, POAM 111, TOMS and GOME Measurements

    NASA Technical Reports Server (NTRS)

    Livingston, J.; Schmid, B.; Russell, P.; Eilers, J.; Kolyer, R.; Redemann, J.; Yee, J.-H.; Trepte, C.; Thomason, L.; Pitts, M.

    2003-01-01

    retrievals during selected DC-8 latitudinal and longitudinal transects with total column ozone data acquired by the Total Ozone Mapping Spectrometer (TOMS) and the Global Ozone Monitoring Experiment (GOME) satellite sensors. To enable this comparison, the amount of ozone in the column below the aircraft is estimated by combining SAGE and/or POAM data with high resolution, fast response in-situ ozone measurements acquired during the DC-8 ascent at the start of each science flight.

  3. First validation of SCIAMACHY O3 and NO2 products with collocated measurements from satellite sensors GOME, HALOE and SAGE II

    NASA Astrophysics Data System (ADS)

    Bracher, A.; Weber, M.; Bramstedt, K.; Richter, A.; Rozanov, A.; von Savigny, C.; von Koenig, M.; Burrows, J. P.

    2003-04-01

    Various operational versions and scientific products of ozone and NO2 columns and profiles from SCIAMACHY on ENVISAT are validated by comparison with the space borne instruments Global-Ozone-Monitoring-Experiment (GOME, version 2.7), Halogen Occultation Experiment (HALOE, data version v19) and Stratospheric Aerosol and Gas Experiment II (SAGE II, data version 6.10) in order to assess the level-2 data retrieval accuracy of these selected trace gas products. Coincident measurements are identified by limiting time differences and distance between two observation points. Since there are large amounts of coincident measurements for the comparisons of O3 and NO2 columns from SCIAMACHY and GOME, data are spatially divided into regular latitudinal and longitudinal square grids in order to save computing time. Where both instruments have measurements in the same spatial square grid, the means of the data of each instrument within one grid are compared to each other. For the comparisons of O3 and NO2 profiles columns from SCIAMACHY with HALOE and SAGE II data, collocations were identified where measurements of the two satellite instruments were taken at the same day and using a spatial collocation tolerance which ensures that the tangent point of HALOE or SAGE II is covered by the SCIAMACHY ground pixel. For the comparisons of NO2 profiles, additionally a scaling factor is applied, because NO2 has a strong diurnal variability and the HALOE and SAGE II measurements are performed during local sunrise or sunset.

  4. Tropospheric O3 over Indonesia during biomass burning events measured with GOME (Global Ozone Monitoring Experiment) and compared with backtrajectory calculation

    NASA Astrophysics Data System (ADS)

    Ladstaetter-Weissenmayer, A.; Meyer-Arnek, J.; Burrows, J. P.

    During the dry season, biomass burning is an important source of ozone precursors for the tropical troposphere, and ozone formation can occur in biomass burning plumes originating in Indonesia and northern Australia. Satellite based GOME (Global Ozone Measuring experiment) data are used to characterize the amount of tropospheric ozone production over this region during the El Niño event in September 1997 compared to a so called "normal" year 1998. Large scale biomass burning occurred over Kalimantan in 1997 caused by the absence of the northern monsoon rains, leading to significant increases in tropospheric ozone. Tropospheric ozone was determined from GOME data using the Tropospheric Excess Method (TEM). Backtrajectory calculations show that Indonesia is influenced every summer by the emissions of trace gases from biomass buring over northern Australia. But in 1997 over Indonesia an increasing of tropospheric ozone amounts can be observed caused by the fires over Indonesia itself as well as by northern Australia. The analysis of the measurements of BIBLE-A (Biomass Burning and Lightning Experiment) and using ATSR (Along the Track Scanning Radiometer) data show differences in the view to the intensity of fire counts and therefore in the amount of the emission of precursors of tropospheric ozone comparing September 1997 to September 1998.

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

    NASA Astrophysics Data System (ADS)

    Schreier, Stefan; Richter, Andreas; Burrows, John

    2013-04-01

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

  6. A Model-Data Fusion Approach for Constraining Modeled GPP at Global Scales Using GOME2 SIF Data

    NASA Astrophysics Data System (ADS)

    MacBean, N.; Maignan, F.; Lewis, P.; Guanter, L.; Koehler, P.; Bacour, C.; Peylin, P.; Gomez-Dans, J.; Disney, M.; Chevallier, F.

    2015-12-01

    Predicting the fate of the ecosystem carbon, C, stocks and their sensitivity to climate change relies heavily on our ability to accurately model the gross carbon fluxes, i.e. photosynthesis and respiration. However, there are large differences in the Gross Primary Productivity (GPP) simulated by different land surface models (LSMs), not only in terms of mean value, but also in terms of phase and amplitude when compared to independent data-based estimates. This strongly limits our ability to provide accurate predictions of carbon-climate feedbacks. One possible source of this uncertainty is from inaccurate parameter values resulting from incomplete model calibration. Solar Induced Fluorescence (SIF) has been shown to have a linear relationship with GPP at the typical spatio-temporal scales used in LSMs (Guanter et al., 2011). New satellite-derived SIF datasets have the potential to constrain LSM parameters related to C uptake at global scales due to their coverage. Here we use SIF data derived from the GOME2 instrument (Köhler et al., 2014) to optimize parameters related to photosynthesis and leaf phenology of the ORCHIDEE LSM, as well as the linear relationship between SIF and GPP. We use a multi-site approach that combines many model grid cells covering a wide spatial distribution within the same optimization (e.g. Kuppel et al., 2014). The parameters are constrained per Plant Functional type as the linear relationship described above varies depending on vegetation structural properties. The relative skill of the optimization is compared to a case where only satellite-derived vegetation index data are used to constrain the model, and to a case where both data streams are used. We evaluate the results using an independent data-driven estimate derived from FLUXNET data (Jung et al., 2011) and with a new atmospheric tracer, Carbonyl sulphide (OCS) following the approach of Launois et al. (ACPD, in review). We show that the optimization reduces the strong positive

  7. Evaluation of the operational Aerosol Layer Height retrieval algorithm for Sentinel-5 Precursor: application to O2 A band observations from GOME-2A

    NASA Astrophysics Data System (ADS)

    Sanders, A. F. J.; de Haan, J. F.; Sneep, M.; Apituley, A.; Stammes, P.; Vieitez, M. O.; Tilstra, L. G.; Tuinder, O. N. E.; Koning, C. E.; Veefkind, J. P.

    2015-06-01

    An algorithm setup for the operational Aerosol Layer Height product for TROPOMI on the Sentinel-5 Precursor mission is described and discussed, applied to GOME-2A data, and evaluated with lidar measurements. The algorithm makes a spectral fit of reflectance at the O2 A band in the near-infrared and the fit window runs from 758 to 770 nm. The aerosol profile is parameterized by a scattering layer with constant aerosol volume extinction coefficient and aerosol single scattering albedo and with a fixed pressure thickness. The algorithm's target parameter is the height of this layer. In this paper, we apply the algorithm to observations from GOME-2A in a number of systematic and extensive case studies and we compare retrieved aerosol layer heights with lidar measurements. Aerosol scenes cover various aerosol types, both elevated and boundary layer aerosols, and land and sea surfaces. The aerosol optical thicknesses for these scenes are relatively moderate. Retrieval experiments with GOME-2A spectra are used to investigate various sensitivities, in which particular attention is given to the role of the surface albedo. From retrieval simulations with the single-layer model, we learn that the surface albedo should be a fit parameter when retrieving aerosol layer height from the O2 A band. Current uncertainties in surface albedo climatologies cause biases and non-convergences when the surface albedo is fixed in the retrieval. Biases disappear and convergence improves when the surface albedo is fitted, while precision of retrieved aerosol layer pressure is still largely within requirement levels. Moreover, we show that fitting the surface albedo helps to ameliorate biases in retrieved aerosol layer height when the assumed aerosol model is inaccurate. Subsequent retrievals with GOME-2A spectra confirm that convergence is better when the surface albedo is retrieved simultaneously with aerosol parameters. However, retrieved aerosol layer pressures are systematically low (i

  8. Evaluation of the operational Aerosol Layer Height retrieval algorithm for Sentinel-5 Precursor: application to O2 A band observations from GOME-2A

    NASA Astrophysics Data System (ADS)

    Sanders, A. F. J.; de Haan, J. F.; Sneep, M.; Apituley, A.; Stammes, P.; Vieitez, M. O.; Tilstra, L. G.; Tuinder, O. N. E.; Koning, C. E.; Veefkind, J. P.

    2015-11-01

    An algorithm setup for the operational Aerosol Layer Height product for TROPOMI on the Sentinel-5 Precursor mission is described and discussed, applied to GOME-2A data, and evaluated with lidar measurements. The algorithm makes a spectral fit of reflectance at the O2 A band in the near-infrared and the fit window runs from 758 to 770 nm. The aerosol profile is parameterised by a scattering layer with constant aerosol volume extinction coefficient and aerosol single scattering albedo and with a fixed pressure thickness. The algorithm's target parameter is the height of this layer. In this paper, we apply the algorithm to observations from GOME-2A in a number of systematic and extensive case studies, and we compare retrieved aerosol layer heights with lidar measurements. Aerosol scenes cover various aerosol types, both elevated and boundary layer aerosols, and land and sea surfaces. The aerosol optical thicknesses for these scenes are relatively moderate. Retrieval experiments with GOME-2A spectra are used to investigate various sensitivities, in which particular attention is given to the role of the surface albedo. From retrieval simulations with the single-layer model, we learn that the surface albedo should be a fit parameter when retrieving aerosol layer height from the O2 A band. Current uncertainties in surface albedo climatologies cause biases and non-convergences when the surface albedo is fixed in the retrieval. Biases disappear and convergence improves when the surface albedo is fitted, while precision of retrieved aerosol layer pressure is still largely within requirement levels. Moreover, we show that fitting the surface albedo helps to ameliorate biases in retrieved aerosol layer height when the assumed aerosol model is inaccurate. Subsequent retrievals with GOME-2A spectra confirm that convergence is better when the surface albedo is retrieved simultaneously with aerosol parameters. However, retrieved aerosol layer pressures are systematically low (i

  9. New methods for the retrieval of chlorophyll red fluorescence from hyperspectral satellite instruments: simulations and application to GOME-2 and SCIAMACHY

    NASA Astrophysics Data System (ADS)

    Joiner, Joanna; Yoshida, Yasuko; Guanter, Luis; Middleton, Elizabeth M.

    2016-08-01

    Global satellite measurements of solar-induced fluorescence (SIF) from chlorophyll over land and ocean have proven useful for a number of different applications related to physiology, phenology, and productivity of plants and phytoplankton. Terrestrial chlorophyll fluorescence is emitted throughout the red and far-red spectrum, producing two broad peaks near 683 and 736 nm. From ocean surfaces, phytoplankton fluorescence emissions are entirely from the red region (683 nm peak). Studies using satellite-derived SIF over land have focused almost exclusively on measurements in the far red (wavelengths > 712 nm), since those are the most easily obtained with existing instrumentation. Here, we examine new ways to use existing hyperspectral satellite data sets to retrieve red SIF (wavelengths < 712 nm) over both land and ocean. Red SIF is thought to provide complementary information to that from the far red for terrestrial vegetation. The satellite instruments that we use were designed to make atmospheric trace-gas measurements and are therefore not optimal for observing SIF; they have coarse spatial resolution and only moderate spectral resolution (0.5 nm). Nevertheless, these instruments, the Global Ozone Monitoring Instrument 2 (GOME-2) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY), offer a unique opportunity to compare red and far-red terrestrial SIF at regional spatial scales. Terrestrial SIF has been estimated with ground-, aircraft-, or satellite-based instruments by measuring the filling-in of atmospheric and/or solar absorption spectral features by SIF. Our approach makes use of the oxygen (O2) γ band that is not affected by SIF. The SIF-free O2 γ band helps to estimate absorption within the spectrally variable O2 B band, which is filled in by red SIF. SIF also fills in the spectrally stable solar Fraunhofer lines (SFLs) at wavelengths both inside and just outside the O2 B band, which further helps to estimate red SIF

  10. Dynamical contibution of Mean Potential Vorticity pseudo-observations derived from MetOp/GOME2 Ozone data into weather forecast, a Mediterranean High Precipitation Event study.

    NASA Astrophysics Data System (ADS)

    Sbii, Siham; Zazoui, Mimoun; Semane, Noureddine

    2015-04-01

    In the absence of observations covering the upper troposphere - lower stratophere, headquarters of several disturbances, and knowing that satellites are uniquely capable of providing uniform data coverage globally, a methodology is followed [1] to convert Total Column Ozone, observed by MetOp/GOME2, into pseudo-observations of Mean Potential Vorticity (MPV). The aim is to study the dynamical impact of Ozone data in the prediction of a Mediterranean Heavy Precipitation Event observed during 28-29 September 2012 in the context of HYMEX1. This study builds on a previously described methodology [2] that generates numerical weather prediction model initial conditions from ozone data. Indeed, the assimilation of MPV in a 3D-var framework is based on a linear regression between observed Ozone and vertical integrated Ertel PV. The latter is calculated using dynamical fields from the moroccan operational limited area model ALADIN-MAROC according to [3]: δθ fp p0 -R δU δV P V = - gξaδp- g-R-(p )Cp [(δp-)2 + (δp-)2] (1) Where ξa is the vertical component of the absolute vorticity, U and V the horizontal wind components, θ the potential temperature, R gas constant, Cp specific heat at constant pressure, p the pressure, p0 a reference pressure, g the gravity and f is the Coriolis parameter. The MPV is estimated using the following expression: --1--∫ P2 M PV = P1 - P2 P P V.δp 1 (2) With P1 = 500hPa and P2 = 100hPa In the present study, the linear regression is performed over September 2012 with a correlation coefficient of 0.8265 and is described as follows: M P V = 5.314610- 2 *O3 - 13.445 (3) where O3 and MPV are given in Dobson Unit (DU) and PVU (1 PV U = 10-6 m2 K kg-1 s-1), respectively. It is found that the ozone-influenced upper-level initializing fields affect the precipitation forecast, as diagnosed by a comparison with the ECMWF model. References [1] S. Sbii, N. Semane, Y. Michel, P. Arbogast and M. Zazoui (2012). Using METOP/GOME-2 data and MSG ozone

  11. Can One Satellite Data Set Validation Another? Validation of Envisat SCIAMACHY Data by Comparisons with NOAA-16 SBUV/2 and ERS-2 GOME

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.; Bojkov, B. R.; Labow, G.; Weber, M.; Burrows, J.

    2004-01-01

    Validation of satellite data remains a high priority for the construction of climate data sets. Traditionally ground based measurements have provided the primary comparison data for validation. For some atmospheric parameters such as ozone, a thoroughly validated satellite data record can be used to validate a new instrument s data product in addition to using ground based data. Comparing validated data with new satellite data has several advantages; availability of much more data, which will improve precision, larger geographical coverage, and the footprints are closer in size, which removes uncertainty due to different observed atmospheric volumes. To demonstrate the applicability and some limitations of this technique, observations from the newly launched SCIAMACHY instrument were compared with the NOM-16 SBW/2 and ERS-2 GOME instruments. The SBW/2 data had all ready undergone validation by comparing to the total ozone ground network. Overall the SCIAMACHY data were found to low by 3% with respect to satellite data and 1% low with respect to ground station data. There appears to be seasonal and or solar zenith angle dependences in the comparisons with SBW/2 where differences increase with higher solar zenith angles. It is known that accuracies in both satellite and ground based total ozone algorithms decrease at high solar zenith angles. There is a strong need for more accurate measurement from and the ground under these conditions. At the present time SCIAMACHY data are limited and longer data set with more coverage in both hemispheres is needed to unravel the cause of these differences.

  12. Macrofauna associated with the brown algae Dictyota spp. (Phaeophyceae, Dictyotaceae) in the Sebastião Gomes Reef and Abrolhos Archipelago, Bahia, Brazil

    NASA Astrophysics Data System (ADS)

    Cunha, Tauana Junqueira; Güth, Arthur Ziggiatti; Bromberg, Sandra; Sumida, Paulo Yukio Gomes

    2013-11-01

    The taxonomic richness and distributional patterns of the macrofauna associated with the algae genus Dictyota from the Abrolhos Bank (Eastern Brazilian coast) are analyzed. Macrofauna comprised a total of 9586 specimens; a complete faunal list of the most abundant taxa (Crustacea, Polychaeta and Mollusca, accounting for 95.6%) resulted in 64 families and 120 species. Forty six species are registered for the first time for the Abrolhos Bank, of which 3 are also new for the Brazilian coast. The most abundant families were Ampithoidae amphipods (with Ampithoe ramondi as the main faunal component), Janiridae isopods, Rissoellidae gastropods and Syllidae polychaetes. Comparisons were made between summer and winter periods and among sites from Sebastião Gomes Reef, near the coast, and from Siriba Island, in the Abrolhos Archipelago, away from the mainland. Algae size was lower in the summer, when faunal density was higher, suggesting a possible effect of grazing. Macrofaunal communities were significantly different among sites and periods. Coastal and external communities were markedly different and winter had the greatest effects on the fauna. Environmental conditions related to sediment type and origin and turbidity appear to be a good scenario for our macrofauna distribution results.

  13. Global trends of cloud cover and cloud height derived from GOME satellite observations 1996-2003 and their relation to surface-near temperature

    NASA Astrophysics Data System (ADS)

    Wagner, T.; Beirle, S.; Grzegorski, M.; Platt, U.

    2006-12-01

    We analyzed global data sets of the atmospheric O2 absorption and the effective cloud fraction from GOME satellite observations for the period 1996-2003. The O2 absorption is a measure of the average photon path- length, it can be retrieved with high precision from the measured spectra of back-scattered sunlight by differential optical absorption spectroscopy (DOAS) and is almost not affected by instrument degradation. Thus it is especially well suited for trend studies. the effective cloud fraction from broad band intensity measurements. From the combination with the effective cloud fraction, in particular information on the cloud altitude can be derived. We find that an increase of the surface-near temperatures in general leads to a decrease of the O2 absorption; this dependency is especially strong over the tropical oceans and the northern hemispheric continents. For the globally averaged values we find a negative trend of the O2 absorption (-0.8 percent over 7 years), while for the effective cloud fraction the analyzed trend (+0.33 percent over 7 years) is not significant. During the same period the surface-near temperatures increased by +0.1K. The decrease of the O2 absorption can be mainly attributed to an increase of the average cloud top height indicating a positive cloud feedback.

  14. Analysing spatio-temporal patterns of the global NO2-distribution retrieved from GOME satellite observations using a generalized additive model

    NASA Astrophysics Data System (ADS)

    Hayn, M.; Beirle, S.; Hamprecht, F. A.; Platt, U.; Menze, B. H.; Wagner, T.

    2009-04-01

    With the increasing availability of observations from different space-borne sensors, the joint analysis of observational data from multiple sources becomes more and more attractive. For such an analysis - oftentimes with little prior knowledge about local and global interactions between the different observational variables available - an explorative data-driven analysis of the remote sensing data may be of particular relevance. In the present work we used generalized additive models (GAM) in this task, in an exemplary study of spatio-temporal patterns in the tropospheric NO2-distribution derived from GOME satellite observations (1996 to 2001) at global scale. We modelled different temporal trends in the time series of the observed NO2, but focused on identifying correlations between NO2 and local wind fields. Here, our nonparametric modelling approach had several advantages over standard parametric models: While the model-based analysis allowed to test predefined hypotheses (assuming, for example, sinusoidal seasonal trends) only, the GAM allowed to learn functional relations between different observational variables directly from the data. This was of particular interest in the present task, as little was known about relations between the observed NO2 distribution and transport processes by local wind fields, and the formulation of general functional relationships to be tested remained difficult. We found the observed temporal trends - weekly, seasonal and linear changes - to be in overall good agreement with previous studies and alternative ways of data analysis. However, NO2 observations showed to be affected by wind-dominated processes over several areas, world wide. Here we were able to estimate the extent of areas affected by specific NO2 emission sources, and to highlight likely atmospheric transport pathways. Overall, using a nonparametric model provided favourable means for a rapid inspection of this large spatio-temporal data set,with less bias than

  15. Analysing spatio-temporal patterns of the global NO2-distribution retrieved from GOME satellite observations using a generalized additive model

    NASA Astrophysics Data System (ADS)

    Hayn, M.; Beirle, S.; Hamprecht, F. A.; Platt, U.; Menze, B. H.; Wagner, T.

    2009-09-01

    With the increasing availability of observational data from different sources at a global level, joint analysis of these data is becoming especially attractive. For such an analysis - oftentimes with little prior knowledge about local and global interactions between the different observational variables at hand - an exploratory, data-driven analysis of the data may be of particular relevance. In the present work we used generalized additive models (GAM) in an exemplary study of spatio-temporal patterns in the tropospheric NO2-distribution derived from GOME satellite observations (1996 to 2001) at global scale. We focused on identifying correlations between NO2 and local wind fields, a quantity which is of particular interest in the analysis of spatio-temporal interactions. Formulating general functional, parametric relationships between the observed NO2 distribution and local wind fields, however, is difficult - if not impossible. So, rather than following a model-based analysis testing the data for predefined hypotheses (assuming, for example, sinusoidal seasonal trends), we used a GAM with non-parametric model terms to learn this functional relationship between NO2 and wind directly from the data. The NO2 observations showed to be affected by wind-dominated processes over large areas. We estimated the extent of areas affected by specific NO2 emission sources, and were able to highlight likely atmospheric transport "pathways". General temporal trends which were also part of our model - weekly, seasonal and linear changes - showed to be in good agreement with previous studies and alternative ways of analysing the time series. Overall, using a non-parametric model provided favorable means for a rapid inspection of this large spatio-temporal NO2 data set, with less bias than parametric approaches, and allowing to visualize dynamical processes of the NO2 distribution at a global scale.

  16. Chemical ozone loss and ozone mini-hole event during the Arctic winter 2010/2011 as observed by SCIAMACHY and GOME-2

    NASA Astrophysics Data System (ADS)

    Hommel, R.; Eichmann, K.-U.; Aschmann, J.; Bramstedt, K.; Weber, M.; von Savigny, C.; Richter, A.; Rozanov, A.; Wittrock, F.; Khosrawi, F.; Bauer, R.; Burrows, J. P.

    2014-04-01

    Record breaking loss of ozone (O3) in the Arctic stratosphere has been reported in winter-spring 2010/2011. We examine in detail the composition and transformations occurring in the Arctic polar vortex using total column and vertical profile data products for O3, bromine oxide (BrO), nitrogen dioxide (NO2), chlorine dioxide (OClO), and polar stratospheric clouds (PSC) retrieved from measurements made by SCIAMACHY (Scanning Imaging Absorption SpectroMeter for Atmospheric CHartography) on-board Envisat (Environmental Satellite), as well as total column ozone amount, retrieved from the measurements of GOME-2 (Global Ozone Monitoring Experiment) on MetOp-A (Meteorological Experimental Satellite). Similarly we use the retrieved data from DOAS (Differential Optical Absorption Spectroscopy) measurements made in Ny-Ålesund (78.55° N, 11.55° E). A chemical transport model (CTM) has been used to relate and compare Arctic winter-spring conditions in 2011 with those in the previous year. In late winter-spring 2010/2011 the chemical ozone loss in the polar vortex derived from SCIAMACHY observations confirms findings reported elsewhere. More than 70% of O3 was depleted by halogen catalytic cycles between the 425 and 525 K isentropic surfaces, i.e. in the altitude range ~16-20 km. In contrast, during the same period in the previous winter 2009/2010, a typical warm Arctic winter, only slightly more than 20% depletion occurred below 20 km, while 40% of O3 was removed above the 575 K isentrope (~23 km). This loss above 575 K is explained by the catalytic destruction by NOx descending from the mesosphere. In both Arctic winters 2009/2010 and 2010/2011, calculated O3 losses from the CTM are in good agreement to our observations and other model studies. The mid-winter 2011 conditions, prior to the catalytic cycles being fully effective, are also investigated. Surprisingly, a significant loss of O3 around 60%, previously not discussed in detail, is observed in mid-January 2011 below

  17. Eutetrarhynchid trypanorhynchs (Cestoda) from elasmobranchs off Argentina, including the description of Dollfusiella taminii sp. n. and Parachristianella damiani sp. n., and amended description of Dollfusiella vooremi (São Clemente et Gomes, 1989).

    PubMed

    Menoret, Adriana; Ivanov, Verónica A

    2014-10-01

    During a parasitological survey of teleosts and elasmobranchs in the Argentine Sea, 3 species of eutetrarhynchids were collected from the batoids Myliobatis goodei Garman and Psammobatis bergi Marini, and the shark Mustelus schmitti Springer. The specimens collected from Mu. schmitti were identified as Dollfusiela vooremi (Sπo Clemente et Gomes, 1989), whereas the specimens from My. goodei and Ps. bergi resulted in new species of Dollfusiella Campbell et Beveridge, 1994 and Parachristianella Dollfus, 1946, respectively. Dollfusiella taminii sp. n. from Ps. bergi is characterised by a distinct basal armature with basal swelling and a heteroacanthous homeomorphous metabasal armature with 7-9 falcate hooks per principal row. Parachristianella damiani sp. n. from My. goodei lacks a distinct basal armature, having 2-3 initial rows of uncinate hooks, a heteroacanthous heteromorphous metabasal armature with the first principal row of small hooks, followed by rows with 10-14 large hooks. This is the first record of Parachristianella in the southwestern Atlantic. The amended description of D. vooremi includes the detailed description of the tentacular armature, including SEM micrographs of all tentacular surfaces. This species is characterised by a basal armature consisting of rows of uncinate and falcate hooks, a basal swelling and a metabasal armature with billhooks on the antibothrial surface and uncinate hooks on the bothrial surface. The scolex peduncle of D. vooremi is covered with enlarged spinitriches. This species is restricted to carcharhiniform sharks, since the report of D. vooremi in Sympterygia bonapartii Müller et Henle off Bahia Blanca (Argentina) is dubious. PMID:25549498

  18. Comparison of Profile Total Ozone from SBUV (v8.6) with GOME-Type and Ground-Based Total Ozone for a 16-Year Period (1996 to 2011)

    NASA Technical Reports Server (NTRS)

    Chiou, E. W.; Bhartia, P. K.; McPeters, R. D.; Loyola, D. G.; Coldewey-Egbers, M.; Fioletov, V. E.; Van Roozendael, M.; Spurr, R.; Lerot, C.; Frith, S. M.

    2014-01-01

    This paper describes the comparison of the variability of total column ozone inferred from the three independent multi-year data records, namely, (i) Solar Backscatter Ultraviolet Instrument (SBUV) v8.6 profile total ozone, (ii) GTO (GOME-type total ozone), and (iii) ground-based total ozone data records covering the 16-year overlap period (March 1996 through June 2011). Analyses are conducted based on area-weighted zonal means for 0-30degS, 0-30degN, 50-30degS, and 30-60degN. It has been found that, on average, the differences in monthly zonal mean total ozone vary between -0.3 and 0.8% and are well within 1 %. For GTO minus SBUV, the standard deviations and ranges (maximum minus minimum) of the differences regarding monthly zonal mean total ozone vary between 0.6-0.7% and 2.8-3.8% respectively, depending on the latitude band. The corresponding standard deviations and ranges regarding the differences in monthly zonal mean anomalies show values between 0.4-0.6% and 2.2-3.5 %. The standard deviations and ranges of the differences ground-based minus SBUV regarding both monthly zonal means and anomalies are larger by a factor of 1.4-2.9 in comparison to GTO minus SBUV. The ground-based zonal means demonstrate larger scattering of monthly data compared to satellite-based records. The differences in the scattering are significantly reduced if seasonal zonal averages are analyzed. The trends of the differences GTO minus SBUV and ground-based minus SBUV are found to vary between -0.04 and 0.1%/yr (-0.1 and 0.3DU/yr). These negligibly small trends have provided strong evidence that there are no significant time-dependent differences among these multiyear total ozone data records. Analyses of the annual deviations from pre-1980 level indicate that, for the 15-year period of 1996 to 2010, all three data records show a gradual increase at 30-60degN from -5% in 1996 to -2% in 2010. In contrast, at 50-30degS and 30degS- 30degN there has been a leveling off in the 15 years after

  19. Effects of Pimenta pseudocaryophyllus (Gomes) L. R. Landrum, on melanized and non-melanized Cryptococcus neoformans.

    PubMed

    de Fátima Lisboa Fernandes, Orionalda; Costa, Carolina Rodrigues; de Souza Lino Junior, Ruy; Vinaud, Marina Clare; Hasimoto E Souza, Lúcia Kioko; de Paula, Joelma Abadia Marciano; do Rosário Rodrigues Silva, Maria

    2012-12-01

    In the present study, the in vitro susceptibility and capsular width from both melanized and non-melanized Cryptococcus neoformans cells in the presence of Pimenta pseudocaryophyllus crude extract were determined. The results were compared with those obtained for voriconazole and amphotericin B. Melanization was obtained in minimal medium broth with the addition of L-dopa, and the antifungal susceptibility tests were performed using the broth microdilution method. Capsular width of 30 cells of each one of the isolates in medium with crude extracts of P. pseudocaryophyllus or voriconazole or amphotericin B at a concentration corresponding to 0.5 times the minimal inhibitory concentration (MIC) was measured, and the mean was calculated. The MICs and minimal fungicidal concentrations (MFCs) for plant extract and voriconazole were identical for both melanized and non-melanized C. neoformans isolates, but for amphotericin, the MFCs for melanized cells were up to 8 times higher than for non-melanized cells. The capsular width of C. neoformans cells was smaller (p < 0.001) in the presence crude extract of P. pseudocaryophyllus and of voriconazole regardless melanization. The findings of capsule alterations of C. neoformans verified in this study provide fertile ways for future research into the effects of antifungal agents on the pathogenesis of cryptococcosis.

  20. VizieR Online Data Catalog: Positions of satellites of giant planets (Gomes-Junior+, 2015)

    NASA Astrophysics Data System (ADS)

    Gomes-Junior, A. R.; Assafin, M.; Vieira Martins, R.; Arlot, J.-E.; Camargo, J. I. B.; Braga-Ribas, F.; da Silva Neto, D. N.; Andrei, A. H.; Dias-Oliveira, A.; Morgado, B. E.; Benedetti-Rossi, G.; Duchemin, Y.; Desmars, J.; Lainey, V.; Thuillot, W.

    2015-05-01

    Tables contain the topocentric ICRS coordinates of the irregular satellites, the position error estimated from the dispersion of the ephemeris offsets of the night of observation, the UTC time of the frame's mid-exposure in julian date, the estimated magnitude, the filter used, the telescope origin and correspondent IAU code. The filters may be U, B, V, R or I following the Johnson system; C stands for clear (no filter used), resulting in a broader R band magnitude, RE for the broad-band R filter ESO#844 with λ=651.725nm and Δλ=162.184nm (full width at half maximum) and "un" for unknown filter. E, OH, PE, BC and Z stand respectively for the ESO, OHP (Observatoire de Haute-Provence), Perkin-Elmer, Bollen & Chivens and Zeiss telescopes from the Observatorio do Pico dos Dias. (2 data files).

  1. The Impact of Global Climate Change on the Geographic Distribution and Sustainable Harvest of Hancornia speciosa Gomes (Apocynaceae) in Brazil

    NASA Astrophysics Data System (ADS)

    Nabout, João Carlos; Magalhães, Mara Rúbia; de Amorim Gomes, Marcos Aurélio; da Cunha, Hélida Ferreira

    2016-04-01

    The global Climate change may affect biodiversity and the functioning of ecosystems by changing the appropriate locations for the development and establishment of the species. The Hancornia speciosa, popularly called Mangaba, is a plant species that has potential commercial value and contributes to rural economic activities in Brazil. The aim of this study was to evaluate the impact of global climate change on the potential geographic distribution, productivity, and value of production of H. speciosa in Brazil. We used MaxEnt to estimate the potential geographic distribution of the species in current and future (2050) climate scenarios. We obtained the productivity and value of production for 74 municipalities in Brazil. Moreover, to explain the variation the productivity and value of production, we constructed 15 models based on four variables: two ecological (ecological niche model and the presence of Unity of conservation) and two socio-economic (gross domestic product and human developed index). The models were selected using Akaike Information Criteria. Our results suggest that municipalities currently harvesting H. speciosa will have lower harvest rates in the future (mainly in northeastern Brazil). The best model to explain the productivity was ecological niche model; thus, municipalities with higher productivity are inserted in regions with higher environmental suitability (indicated by niche model). Thus, in the future, the municipalities harvesting H. speciosa will produce less because there will be less suitable habitat for H. speciosa, which in turn will affect the H. speciosa harvest and the local economy.

  2. The Impact of Global Climate Change on the Geographic Distribution and Sustainable Harvest of Hancornia speciosa Gomes (Apocynaceae) in Brazil.

    PubMed

    Nabout, João Carlos; Magalhães, Mara Rúbia; de Amorim Gomes, Marcos Aurélio; da Cunha, Hélida Ferreira

    2016-04-01

    The global Climate change may affect biodiversity and the functioning of ecosystems by changing the appropriate locations for the development and establishment of the species. The Hancornia speciosa, popularly called Mangaba, is a plant species that has potential commercial value and contributes to rural economic activities in Brazil. The aim of this study was to evaluate the impact of global climate change on the potential geographic distribution, productivity, and value of production of H. speciosa in Brazil. We used MaxEnt to estimate the potential geographic distribution of the species in current and future (2050) climate scenarios. We obtained the productivity and value of production for 74 municipalities in Brazil. Moreover, to explain the variation the productivity and value of production, we constructed 15 models based on four variables: two ecological (ecological niche model and the presence of Unity of conservation) and two socio-economic (gross domestic product and human developed index). The models were selected using Akaike Information Criteria. Our results suggest that municipalities currently harvesting H. speciosa will have lower harvest rates in the future (mainly in northeastern Brazil). The best model to explain the productivity was ecological niche model; thus, municipalities with higher productivity are inserted in regions with higher environmental suitability (indicated by niche model). Thus, in the future, the municipalities harvesting H. speciosa will produce less because there will be less suitable habitat for H. speciosa, which in turn will affect the H. speciosa harvest and the local economy.

  3. Satellite-Based Stratospheric and Tropospheric Measurements: Determination of Global Ozone and other Trace Species

    NASA Technical Reports Server (NTRS)

    Chance, K. V.

    2001-01-01

    This report summarizes research done under NASA Grant NAG5-3461 from November 1, 1996 through December 31, 2000. The research performed during this reporting period includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, sensitivity and instrument studies to help finalize the definition of the SCIAMACHY instrument, leading the development of the SCIAMACHY Scientific Requirements Document for Data and Algorithm Development, consultation and development for SCIAMACHY near-real-time (NRT) and off-line (OL) data products, radiative transfer model development for utilization in GOME, SCIAMACHY and other programs, development of infrared line-by-line atmospheric modeling and retrieval capability for SCIAMACHY, and participation in GOME and SCIAMACHY validation studies. The Global Ozone Monitoring Experiment was successfully launched on the ERS-2 satellite on April 20, 1995, and remains working in normal fashion. SCIAMACHY is currently planned for launch in late 2001 on the ESA Envisat satellite. Three GOME-2 instruments are now scheduled to fly on the Metop series of operational meteorological satellites (Eumetsat). K. Chance is a member of the reconstituted GOME Scientific Advisory Group, which will guide the GOME-2 program as well as the continuing ERS-2 GOME program.

  4. Gold Nanosphere Gated Mesoporous Silica Nanoparticle Responsive to Near-Infrared Light and Redox Potential as a Theranostic Platform for Cancer Therapy.

    PubMed

    Cheng, Bei; He, Huacheng; Huang, Tao; Berr, Stuart S; He, Jiang; Fan, Daping; Zhang, Jiajia; Xu, Peisheng

    2016-03-01

    A gold/mesoporous silica hybrid nanoparticle (GoMe), which possesses the best of both conventional gold nanoparticles and mesoporous silica nanoparticles, such as excellent photothermal converting ability as well as high drug loading capacity and triggerable drug release, has been developed. In contrast to gold nanorod and other heat generating gold nanoparticles, GoMe is photothermal stable and can be repetitively activated through NIR irradiation. Doxorubicin loaded GoMe (DOX@GoMe) is sensitive to both NIR irradiation and intracellularly elevated redox potential. DOX@GoMe coupled with NIR irradiation exhibits a synergistic effect of photothermal therapy and chemotherapy in killing cancer cells. Furthermore, 64Cu-labeled GoMe can successfully detect the existence of clinically relevant spontaneous lung tumors in a urethane-induced lung cancer mouse model through PET imaging. Altogether, GoMe can be utilized as an effective theranostic platform for cancer therapy.

  5. Gold Nanosphere Gated Mesoporous Silica Nanoparticle Responsive to Near-Infrared Light and Redox Potential as a Theranostic Platform for Cancer Therapy.

    PubMed

    Cheng, Bei; He, Huacheng; Huang, Tao; Berr, Stuart S; He, Jiang; Fan, Daping; Zhang, Jiajia; Xu, Peisheng

    2016-03-01

    A gold/mesoporous silica hybrid nanoparticle (GoMe), which possesses the best of both conventional gold nanoparticles and mesoporous silica nanoparticles, such as excellent photothermal converting ability as well as high drug loading capacity and triggerable drug release, has been developed. In contrast to gold nanorod and other heat generating gold nanoparticles, GoMe is photothermal stable and can be repetitively activated through NIR irradiation. Doxorubicin loaded GoMe (DOX@GoMe) is sensitive to both NIR irradiation and intracellularly elevated redox potential. DOX@GoMe coupled with NIR irradiation exhibits a synergistic effect of photothermal therapy and chemotherapy in killing cancer cells. Furthermore, 64Cu-labeled GoMe can successfully detect the existence of clinically relevant spontaneous lung tumors in a urethane-induced lung cancer mouse model through PET imaging. Altogether, GoMe can be utilized as an effective theranostic platform for cancer therapy. PMID:26949379

  6. Satellite-Based Stratospheric and Tropospheric Measurements: Determination of Global Ozone and Other Trace Species

    NASA Technical Reports Server (NTRS)

    Chance, Kelly

    2003-01-01

    This grant is an extension to our previous NASA Grant NAG5-3461, providing incremental funding to continue GOME (Global Ozone Monitoring Experiment) and SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY) studies. This report summarizes research done under these grants through December 31, 2002. The research performed during this reporting period includes development and maintenance of scientific software for the GOME retrieval algorithms, consultation on operational software development for GOME, consultation and development for SCIAMACHY near-real-time (NRT) and off-line (OL) data products, and participation in initial SCIAMACHY validation studies. The Global Ozone Monitoring Experiment was successfully launched on the ERS-2 satellite on April 20, 1995, and remains working in normal fashion. SCIAMACHY was launched March 1, 2002 on the ESA Envisat satellite. Three GOME-2 instruments are now scheduled to fly on the Metop series of operational meteorological satellites (Eumetsat). K. Chance is a member of the reconstituted GOME Scientific Advisory Group, which will guide the GOME-2 program as well as the continuing ERS-2 GOME program.

  7. Quantifying the Seasonal and Interannual Variability of North American Isoprene Emissions Using Satellite Observations of the Formaldehyde Column

    NASA Technical Reports Server (NTRS)

    Palmer, Paul I.; Abbot, Dorian S.; Fu, Tzung-May; Jacob, Daniel J.; Chance, Kelly; Kurosu, Thomas P.; Guenther, Alex; Wiedinmyer, Christine; Stanton, Jenny C.; Pilling, Michael J.; Pressley, Shelley N.; Lamb, Brian; Sumner, Anne Louise

    2006-01-01

    Quantifying isoprene emissions using satellite observations of the formaldehyde (HCHO) columns is subject to errors involving the column retrieval and the assumed relationship between HCHO columns and isoprene emissions, taken here from the GEOS-CHEM chemical transport model. Here we use a 6-year (1996-2001) HCHO column data set from the Global Ozone Monitoring Experiment (GOME) satellite instrument to (1) quantify these errors, (2) evaluate GOME-derived isoprene emissions with in situ flux measurements and a process-based emission inventory (Model of Emissions of Gases and Aerosols from Nature, MEGAN), and (3) investigate the factors driving the seasonal and interannual variability of North American isoprene emissions. The error in the GOME HCHO column retrieval is estimated to be 40%. We use the Master Chemical Mechanism (MCM) to quantify the time-dependent HCHO production from isoprene, alpha- and beta-pinenes, and methylbutenol and show that only emissions of isoprene are detectable by GOME. The time-dependent HCHO yield from isoprene oxidation calculated by MCM is 20-30% larger than in GEOS-CHEM. GOME-derived isoprene fluxes track the observed seasonal variation of in situ measurements at a Michigan forest site with a -30% bias. The seasonal variation of North American isoprene emissions during 2001 inferred from GOME is similar to MEGAN, with GOME emissions typically 25% higher (lower) at the beginning (end) of the growing season. GOME and MEGAN both show a maximum over the southeastern United States, but they differ in the precise location. The observed interannual variability of this maximum is 20-30%, depending on month. The MEGAN isoprene emission dependence on surface air temperature explains 75% of the month-to-month variability in GOME-derived isoprene emissions over the southeastern United States during May-September 1996-2001.

  8. Retrieval and molecule sensitivity studies for the global ozone monitoring experiment and the scanning imaging absorption spectrometer for atmospheric chartography

    NASA Technical Reports Server (NTRS)

    Chance, Kelly V.; Burrows, John P.; Schneider, Wolfgang

    1991-01-01

    The Global Ozone Monitoring Experiment (GOME) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) are diode based spectrometers that will make atmospheric constituent and aerosol measurements from European satellite platforms beginning in the mid 1990's. GOME measures the atmosphere in the UV and visible in nadir scanning, while SCIAMACHY performs a combination of nadir, limb, and occultation measurements in the UV, visible, and infrared. A summary is presented of the sensitivity studies that were performed for SCIAMACHY measurements. As the GOME measurement capability is a subset of the SCIAMACHY measurement capability, the nadir, UV, and visible portion of the studies is shown to apply to GOME as well.

  9. Mapping Isoprene Emissions over North America using Formaldehyde Column Observations from Space

    NASA Technical Reports Server (NTRS)

    Palmer, Paul I.; Jacob, Daniel J.; Fiore, Arlene M.; Martin, Randall V.; Chance, Kelly; Kurosu, Thomas P.

    2004-01-01

    I] We present a methodology for deriving emissions of volatile organic compounds (VOC) using space-based column observations of formaldehyde (HCHO) and apply it to data from the Global Ozone Monitoring Experiment (GOME) satellite instrument over North America during July 1996. The HCHO column is related to local VOC emissions, with a spatial smearing that increases with the VOC lifetime. lsoprene is the dominant HCHO precursor over North America in summer, and its lifetime (approx. = 1 hour) is sufficiently short that the smearing can be neglected. We use the Goddard Earth Observing System global 3-D model of tropospheric chemistry (GEOS-CHEM) to derive the relationship between isoprene emissions and HCHO columns over North America and use these relationships to convert the GOME HCHO columns to isoprene emissions. We also use the GEOS-CHEM model as an intermediary to validate the GOME HCHO column measurements by comparison with in situ observations. The GEOS-CHEM model including the Global Emissions Inventory Activity (GEIA) isoprene emission inventory provides a good simulation of both the GOME data (r(sup 2) = 0.69, n = 756, bias = +l1 %) and the in situ summertime HCHO measurements over North America (r(sup 2) = 0.47, n = 10, bias = -3%). The GOME observations show high values over regions of known high isoprene emissions and a day-to-day variability that is consistent with the temperature dependence of isoprene emission. Isoprene emissions inferred from the GOME data are 20% less than GEIA on average over North America and twice those from the U S . EPA Biogenic Emissions Inventory System (BEIS2) inventory. The GOME isoprene inventory when implemented in the GEOS-CHEM model provides a better simulation of the HCHO in situ measurements thaneitherGEIAorBEIS2 (r(sup 2) = 0.71,n= 10, bias = -10 %).

  10. Participation in the TOMS Science Team

    NASA Technical Reports Server (NTRS)

    Chance, Kelly; Hilsenrath, Ernest (Technical Monitor)

    2002-01-01

    Because of the nominal funding provided by this grant, some of the relevant research is partially funded by other sources. Research performed for this funding period included the following items: We have investigated errors in TOMS ozone measurements caused by the uncertainty in wavelength calibration, coupled with the ozone cross sections in the Huggins bands and their temperature dependence. Preliminary results show that 0.1 nm uncertainty in TOMS wavelength calibration at the ozone active wavelengths corresponds to approx. 1% systematic error in O3, and thus potential 1% biases among ozone trends from the various TOMS instruments. This conclusion will be revised for absolute O3 Measurements as cross sections are further investigated for inclusion in the HITRAN database at the SAO, but the potential for relative errors remains. In order to aid further comparisons among TOMS and GOME ozone measurements, we have implemented our method of direct fitting of GOME radiances (BOAS) for O3, and now obtain the best fitting precision to date for GOME O3 Columns. This will aid in future comparisons of the actual quantities measured and fitted for the two instrument types. We have made comparisons between GOME ICFA cloud fraction and cloud fraction determined from GOME data using the Ring effect in the Ca II lines. There is a strong correlation, as expected, but there are substantial systematic biases between the determinations. This study will be refined in the near future using the recently-developed GOME Cloud Retrieval Algorithm (GOMECAT). We have improved the SAO Ring effect determination to include better convolution with instrument transfer functions and inclusion of interferences by atmospheric absorbers (e.g., O3). This has been made available to the general community.

  11. Guido Beck, Alexandre Proca, and the Oporto Theoretical Physics Seminar

    NASA Astrophysics Data System (ADS)

    Dos Santos Fitas, Augusto José; Passos Videira, António Augusto

    2007-01-01

    We describe the pioneering attempts made by Ruy Luís Gomes (1905 1984) and other Portuguese physicists to develop a research and teaching seminar in theoretical physics at the University of Oporto in 1942 1944 under the leadership first of the refugee Austrian theoretical physicist Guido Beck (1903 1988) and then of the Romanian-French theoretical physicist Alexandre Proca (1896 1955). These efforts failed, however, owing to lack of sustained financial support from the Portuguese government and to the political repression of the Salazar regime, which dismissed Gomes and other prominent Portuguese physicists and other scientists from their university positions.

  12. Improvement of OMI Ozone Profile Retrievals in the Troposphere and Lower Troposphere by the Use of the Tropopause-Based Ozone Profile Climatology

    NASA Technical Reports Server (NTRS)

    Bak, Juseon; Liu, X.; Wei, J.; Kim, J. H.; Chance, K.; Barnet, C.

    2011-01-01

    An advance algorithm based on the optimal estimation technique has beeen developed to derive ozone profile from GOME UV radiances and have adapted it to OMI UV radiances. OMI vertical resolution : 7-11 km in the troposphere and 10-14 km in the stratosphere. Satellite ultraviolet measurements (GOME, OMI) contain little vertical information for the small scale of ozone, especially in the upper troposphere (UT) and lower stratosphere (LS) where the sharp O3 gradient across the tropopause and large ozone variability are observed. Therefore, retrievals depend greatly on the a-priori knowledge in the UTLS

  13. More than Just Hot Air: How Hairdryers and Role Models Inspire Girls in Engineering

    ERIC Educational Resources Information Center

    Kekelis, Linda; Larkin, Molly; Gomes, Lyn

    2014-01-01

    This article describes a reverse-engineering project where female students take a part a hair dryer--giving them an opportunity to see the many different kinds of engineering disciplines involved in making a hairdryer and that they work together. Mechanical Engineer, Lyn Gome, describes her experience leading a group of middle school girls through…

  14. Isolation of chavibetol from essential oil of Pimenta pseudocaryophyllus leaf by high-speed counter-current chromatography.

    PubMed

    dos Santos, Bruna C B; da Silva, Júlio César T; Guerrero, Palimécio G; Leitão, Gilda G; Barata, Lauro E S

    2009-05-01

    Counter-current chromatography (CCC) was used to isolate chavibetol from the essential oil of leaves of Pimenta pseudocaryophyllus (Gomes) Landrum. Chavibetol was obtained in high purity (98%) and mass recovery (94.4%). Methyleugenol was also isolated. The CCC biphasic solvent system used was composed of hexane:n-butanol:methanol:water (12:4:4:3, v/v/v/v).

  15. P(URI)fying Novel Drivers of NASH and HCC: A Feedforward Loop of IL17A via White Adipose Tissue.

    PubMed

    Weber, Achim; Heikenwalder, Mathias

    2016-07-11

    How obesity and metabolic syndrome trigger non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) remains elusive. In this issue, Gomes and colleagues describe that nutrient surplus induces hepatic URI expression, triggering genotoxicity and IL17A expression, thus leading to insulin resistance, NASH, and HCC. IL17A signaling blockers might become a readily translatable therapy.

  16. ESA DUE GlobVapour water vapor products: Validation

    SciTech Connect

    Schneider, Nadine; Schroeder, Marc; Stengel, Martin; Lindstrot, Ramus; Preusker, Rene; Collaboration: ESA DUE GlobVapour Consortium

    2013-05-10

    The main objective of the European Space Agency (ESA) Data User Element (DUE) GlobVapour project was the development of multi-annual global water vapor data sets. Since water vapour is a key climate variable it is important to have a good understanding of its behavior in the climate system. The ESA DUE GlobVapour project provides water vapor data, including error estimates, based on carefully calibrated and inter-calibrated satellite radiances in response to user requirements for long time series satellite observations. ESA DUE GlobVapour total columnar water vapor (TCWV) products derived from GOME/SCIA/GOME-2 (1996-2008) and SSM/I+MERIS (2003-2008) have been validated for the mentioned period, using satellite-based (AIRS, ATOVS) and ground-based measurements (radiosondes and microwave radiometer). The validation results are discussed in the following. The technical specifications on bias (1 kg/m{sup 2} for SSMI+MERIS and 2 kg/m{sup 2} for GOME/SCIA/GOME-2) are generally met. For more information, documents and data download follow the link: www.globvapour.info.

  17. Analysis of Solar Spectral Irradiance Measurements from the SBUV/2-Series and the SSBUV Instruments

    NASA Technical Reports Server (NTRS)

    Cebula, Richard P.; DeLand, Matthew T.; Hilsenrath, Ernest

    1996-01-01

    The purpose of this research is to develop a NOAA-11 SBUV/2 solar spectral irradiance data set which is free from long-term instrument drift, then perform scientific analysis using the data set. During the current period of performance, 29 February 1996 through 31 August 1996, we finalized the NOAA-11 SBUV/2 characterization using internal data. This included updating the instrument's electronic, photomultiplier tube gain, wavelength, diffuser degradation, and goniometric calibrations. We have also completed the SSBUV characterization, 1989-1994, and produced SSBUV irradiances for the first seven SSBUV flights. Both of these steps were needed before the long-term calibration of the NOAA-11 SBUV/2 solar spectral irradiance data set via SSBUV can be undertaken. A second major aspect of this work is to compare solar spectral irradiances from the SBUV/2 instruments and SSBUV with corresponding data from other instruments. In the preceding six months, SSBUV data from the ATLAS-3 (November 1994) mission were compared to coincident SUSIM ATLAS-3 data. The GOME instrument was launched by the European Space Agency in early 1995 and began making solar irradiance measurements in May 1995. Working with GOME scientists, we are using SSBUV data to validate the GOME solar irradiance data. Based in part on those findings, the GOME absolute calibration data were reanalyzed.

  18. 78 FR 58320 - National Institute on Drug Abuse; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-23

    ... HUMAN SERVICES National Institutes of Health National Institute on Drug Abuse; Notice of Closed Meetings... Committee: National Institute on Drug Abuse Special Emphasis Panel GOMED: Grand Opportunity in Medications... of Extramural Affairs, National Institute on Drug Abuse, NIH, Room 4228, MSC 9550, 6001...

  19. Homogenization of UV-Visible NDACC spectrometers reprocessing for ozone and NO2

    NASA Astrophysics Data System (ADS)

    Pazmino, Andrea

    2010-05-01

    SAOZ is a ground-based UV-Visible zenith-sky spectrometer deployed since 1988 at a number of NDACC (Network for the Detection of Atmospheric Composition Change) stations at all latitudes on the globe. The instrument is providing ozone and NO2 total columns at sunrise and sunset using the Differential Optical Absorption Spectroscopy (DOAS) technique in the visible spectral range. SAOZ observations have been used extensively to validate various atmospheric chemistry satellite instruments such as nadir viewing TOMS, GOME, SCIAMACHY, OMI and GOME-2. The NDACC UV-Visible working group initiated a tentative homogenization of ozone and NO2 processing of all UV-Vis zenith sky spectrometers as one of its objectives. The first recommendation is concerning the total ozone retrieval. A significant change for the SAOZ network is the use of different cross-sections (O3, NO2, H2O, O4, and Ring calculations) and different spectral window fitting range, which leads to a recalculation of the slant columns. In addition, it is recommended to use a climatological air mass factor (AMF) instead of an annual AMF usually used in standard SAOZ processing. Here we present the results of comparisons between TOMS (since 1988), GOME (since 1995), SCIAMACHY (since 2002), OMI (since 2004), GOME-2 (since 2006) and SAOZ at all latitudes - tropics, mid-latitudes and Polar Regions - in both hemispheres. In the case of ozone, the NDACC recommendations resulted in a significant improvement of the differences between ground-based SAOZ and measurements from space. Preliminary results of NO2 SAOZ columns, using climatological AMF, are also presented and compared to different satellites, such as GOME, SCIAMACHY and OMI.

  20. Observations of the moon by the global ozone monitoring experiment: radiometric calibration and lunar albedo.

    PubMed

    Dobber, M R; Goede, A P; Burrows, J P

    1998-11-20

    The Global Ozone Monitoring Experiment (GOME) is a new instrument, which was launched aboard the second European Remoting Sensing satellite ESA-ERS2 in 1995. For its long-term radiometric and spectral calibration the GOME observes the sun and less frequently the moon on a regular basis. These measurements of the lunar radiance and solar irradiance have been used in a study to determine, for the first time to the authors' knowledge, the geometric lunar albedo from 240 to 800 nm at high spectral resolution from space. For a waning moon there is good agreement with ground-based measurements in the visible region and with recent space-based measurements in the ultraviolet region. In addition, the use of these measurements for the characterization of in-orbit degradation of instruments operating in this spectral region has been adequately demonstrated.

  1. Satellite Observations of NO2 Trend over Romania

    PubMed Central

    Voiculescu, Mirela; Georgescu, Lucian

    2013-01-01

    Satellite-based measurements of atmospheric trace gases loading give a realistic image of atmospheric pollution at global, regional, and urban level. The aim of this paper is to investigate the trend of atmospheric NO2 content over Romania for the period 1996–2010 for several regions which are generally characterized by different pollutant loadings, resulting from GOME-1, SCIAMACHY, OMI, and GOME-2 instruments. Satellite results are then compared with ground-based in situ measurements made in industrial and relatively clean areas of one major city in Romania. This twofold approach will help in estimating whether the trend of NO2 obtained by means of data satellite retrievals can be connected with the evolution of national industry and transportation. PMID:24453819

  2. Tunable far infrared studies of molecular parameters in support of stratospheric measurements

    NASA Technical Reports Server (NTRS)

    Chance, Kelly V.; Evenson, K. M.; Park, K.; Radostitz, J. V.; Jennings, D. A.; Nolt, I. G.; Vanek, M. D.

    1991-01-01

    Lab studies were made in support of far infrared spectroscopy of the stratosphere using the Tunable Far InfraRed (TuFIR) method of ultrahigh resolution spectroscopy and, more recently, spectroscopic and retrieval calculations performed in support of satellite-based atmospheric measurement programs: the Global Ozone Monitoring Experiment (GOME), and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY).

  3. The Multi-TASTE Validation System: Tasting the Evolution of Reactive and Greenhouse Gas Data Products from Envisat and Third Party Missions

    NASA Astrophysics Data System (ADS)

    Hubert, D.; Keppens, A.; Lambert, J.-C.; Granville, J.; Hendrick, F.; Verhoelst, T.

    2015-06-01

    Over the past two decades the Multi-TASTE validation system has proven its value in the characterisation and support to the development of atmospheric composition measurements by ESA’s GOME, Envisat and Third Party Missions (TPMs). We give an overview of the capabilities and the latest results of this comprehensive, versatile and semi-operational system and address its relevance regarding the recommendations voiced at ATMOS 2012.

  4. Satellite observations of OClO from 1995 to 2011 in comparison to ECMWF data and EMAC simulations

    NASA Astrophysics Data System (ADS)

    Kühl, S.; Pukite, J.; Dörner, S.; Jöckel, P.; Kirner, O.; Wagner, T.

    2012-04-01

    Satellite instruments like GOME, GOME-2 and SCIAMACHY measure the spectral intensity of the sunlight, scattered back from Earths atmosphere, on an almost global and daily scale. By applying the DOAS method to the spectral measurements, the integrated concentration along the light path, the so called Slant Column Density (SCD), can be derived for a wide range of absorbers. Chlorine dioxide (OClO) is an important indicator for stratospheric chlorine activation, the basis for massive ozone depletion in polar spring. Due to the daily coverage of the Polar regions, the OClO measurements give a good overview of the intensity and the extension of the chlorine activation. While the observations in nadir geometry (i.e. perpendicular to Earths surface) provide a (indirect) measurement of the total column, the limb observations (i.e. tangential view) can be inverted to vertical profiles. We investigated GOME, GOME-2 and SCIAMACHY data from 1995 to 2011, covering Arctic and Antarctic winters with very different meteorological situations (very cold and very warm winters; early and major warmings). In particular, the long lasting cold stratospheric temperatures inside the vortex for the Arctic winter 2010/11 led to large levels of chlorine activation until mid of March, also observed in the OClO data. The derived OClO columns and vertical profiles are compared to ECMWF analysis data, looking at inter-hemispheric and inter-annual differences and studying the dependence of the OClO enhancements on meteorological parameters like stratospheric temperatures, potential vorticity, PSC area and volume. Also, the OClO observations are compared to correlated ECHAM5/MESSy2 (EMAC) simulations, which were calculated for the exact time and place of the satellite observations. We investigate the agreement of the observed and simulated OClO profiles for the dataset from 2003 to 2009 (regarding the magnitude, the altitude of the profile peak and their evolution throughout the winter).

  5. Satellite observations of OClO from 1995 to 2012 in comparison to ECMWF data and EMAC simulations

    NASA Astrophysics Data System (ADS)

    Kühl, Sven; Pukite, Janis; Dörner, Steffen; Jöckel, Patrick; Ziegler, Marc; Wagner, Thomas

    2013-04-01

    Satellite instruments like GOME, GOME-2 and SCIAMACHY measure the spectral intensity of the sunlight, scattered back from Earths atmosphere, on an almost global and daily scale. By applying the DOAS method to the spectral measurements, the integrated concentration along the light path, the so called Slant Column Density (SCD), can be derived for a wide range of absorbers. Chlorine dioxide (OClO) is an important indicator for stratospheric chlorine activation, the basis for massive ozone depletion in polar spring. Due to the daily coverage of the Polar regions, the OClO measurements give a good overview of the intensity and the extension of the chlorine activation. While the observations in nadir geometry (i.e. perpendicular to Earths surface) provide a (indirect) measurement of the total column, the limb observations (i.e. tangential view) can be inverted to vertical profiles. We investigated GOME, GOME-2 and SCIAMACHY data from 1995 to 2012, covering Arctic and Antarctic winters with very different meteorological situations (very cold and very warm winters; early and major warmings). In particular, the long lasting cold stratospheric temperatures inside the vortex for the Arctic winter 2010/11 led to large levels of chlorine activation until mid of March, also observed in the OClO data. The derived OClO columns and vertical profiles are compared to ECMWF analysis data, looking at inter-hemispheric and inter-annual differences and studying the dependence of the OClO enhancements on meteorological parameters like stratospheric temperatures, potential vorticity, PSC area and volume. Also, the OClO observations are compared to correlated ECHAM5/MESSy2 (EMAC) simulations, which were calculated for the exact time and place of the satellite observations. We investigate the agreement of the observed and simulated OClO profiles for the dataset from 2003 to 2012 (regarding the magnitude, the altitude of the profile peak and their evolution throughout the winter).

  6. Satellite Mapping of Rain-Induced Nitric Oxide Emissions from Soils

    NASA Technical Reports Server (NTRS)

    Jaegle, L.; Martin, R. V.; Chance, K.; Steinberger, L.; Kurosu, T. P.; Jacob, D. J.; Modi, A. I.; Yoboue, V.; Sigha-Nkamdjou, L.; Galy-Lacaux, C.

    2004-01-01

    We use space-based observations of NO2 columns from the Global Ozone Monitoring Experiment (GOME) to map the spatial and seasonal variations of NOx emissions over Africa during 2000. The GOME observations show not only enhanced tropospheric NO2 columns from biomass burning during the dry season but also comparable enhancements from soil emissions during the rainy season over the Sahel. These soil emissions occur in strong pulses lasting 1-3 weeks following the onset of rain, and affect 3 million sq km of semiarid sub-Saharan savanna. Surface observations of NO2 from the International Global Atmospheric Chemistry (IGAC)/Deposition of Biochemically Important Trace Species (DEBITS)/Africa (IDAF) network over West Africa provide further evidence for a strong role for microbial soil sources. By combining inverse modeling of GOME NO2 columns with space-based observations of fires, we estimate that soils contribute 3.3+/-1.8 TgN/year, similar to the biomass burning source (3.8+/-2.1 TgN/year), and thus account for 40% of surface NO(x) emissions over Africa. Extrapolating to all the tropics, we estimate a 7.3 TgN/year biogenic soil source, which is a factor of 2 larger compared to model-based inventories but agrees with observation-based inventories. These large soil NO(x) emissions are likely to significantly contribute to the ozone enhancement originating from tropical Africa.

  7. MERIS albedo climatology and its effect on the FRESCO+ O2 A-band cloud retrieval from SCIAMACHY data

    NASA Astrophysics Data System (ADS)

    Popp, Christoph; Wang, Ping; Brunner, Dominik; Stammes, Piet; Zhou, Yipin

    2010-05-01

    Accurate cloud information is an important prerequisite for the retrieval of atmospheric trace gases from spaceborne UV/VIS sensors. Errors in the estimated cloud fraction and cloud height (pressure) result in an erroneous air mass factor and thus can lead to inaccuracies in the vertical column densities of the retrieved trace gas. In ESA's TEMIS (Tropospheric Emission Monitoring Internet Service) project, the FRESCO+ (Fast Retrieval Scheme for Clouds from the Oxygen A-band) cloud retrieval is applied to, amongst others, SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric CartograpHY) data to determine these quantities. Effective cloud fraction and pressure are inverted by (i) radiative transfer simulations of top-of-atmosphere reflectance based on O2 absorption, single Rayleigh scattering, surface and cloud albedo in three spectral windows covering the O2 A-band and (ii) a subsequent fitting of the simulated to the measured spectrum. However, FRESCO+ relies on a relatively coarse resolution surface albedo climatology (1° x 1°) compiled from GOME (Global Ozone Monitoring Experiment) measurements in the 1990's which introduces several artifacts, e.g. an overestimation of cloud fraction at coastlines or over some mountainous regions. Therefore, we test the substitution of the GOME climatology with a new land surface albedo climatology compiled for every month from MEdium Resolution Imaging Spectrometer (MERIS) Albedomap data (0.05° x 0.05°) covering the period January 2003 to October 2006. The MERIS channels at 754nm and 775nm are located spectrally close to the corresponding GOME channels (758nm and 772nm) on both sides of the O2 A-band. Further, the increased spatial resolution of the MERIS product allows to better account for SCIAMACHY's pixel size of approximately 30x60km. The aim of this study is to describe and assess (i) the compilation and quality of the MERIS climatology (ii) the differences to the GOME climatology, and (iii) possible

  8. Long-term changes of tropospheric NO2 over megacities derived from multiple satellite instruments

    NASA Astrophysics Data System (ADS)

    Hilboll, A.; Richter, A.; Burrows, J. P.

    2012-12-01

    Tropospheric NO2, a key pollutant in particular in cities, has been measured from space since the mid-1990s by the GOME, SCIAMACHY, OMI, and GOME-2 instruments. These data provide a unique global long-term data set of tropospheric pollution. However, the measurements differ in spatial resolution, local time of measurement, and measurement geometry. All these factors can severely impact the retrieved NO2 columns, which is why they need to be taken into account when analysing time series spanning more than one instrument. In this study, we present several ways to explicitly account for the instrumental differences in trend analyses of the NO2 columns derived from satellite measurements, while preserving their high spatial resolution. Both a physical method, based on spatial averaging of the measured earthshine spectra and extraction of a resolution pattern, and statistical methods, including instrument-dependent offsets in the fitted trend function, are developed. These methods are applied to data from GOME and SCIAMACHY separately, to the combined time series and to an extended data set comprising also GOME-2 and OMI measurements. All approaches show consistent trends of tropospheric NO2 for a selection of areas on both regional and city scales, for the first time allowing consistent trend analysis of the full time series at high spatial resolution and significantly reducing the uncertainties of the retrieved trend estimates compared to previous studies. We show that measured tropospheric NO2 columns have been strongly increasing over China, the Middle East, and India, with values over East Central China triplicating from 1996 to 2011. All parts of the developed world, including Western Europe, the United States, and Japan, show significantly decreasing NO2 amounts in the same time period. On a megacity level, individual trends can be as large as +27 ± 3.7% yr-1 and +20 ± 1.9% yr-1 in Dhaka and Baghdad, respectively, while Los Angeles shows a very strong decrease

  9. Long-term changes of tropospheric NO2 over megacities derived from multiple satellite instruments

    NASA Astrophysics Data System (ADS)

    Hilboll, A.; Richter, A.; Burrows, J. P.

    2013-04-01

    Tropospheric NO2, a key pollutant in particular in cities, has been measured from space since the mid-1990s by the GOME, SCIAMACHY, OMI, and GOME-2 instruments. These data provide a unique global long-term dataset of tropospheric pollution. However, the observations differ in spatial resolution, local time of measurement, viewing geometry, and other details. All these factors can severely impact the retrieved NO2 columns. In this study, we present three ways to account for instrumental differences in trend analyses of the NO2 columns derived from satellite measurements, while preserving the individual instruments' spatial resolutions. For combining measurements from GOME and SCIAMACHY into one consistent time series, we develop a method to explicitly account for the instruments' difference in ground pixel size (40 × 320 km2 vs. 30 × 60 km2). This is especially important when analysing NO2 changes over small, localised sources like, e.g. megacities. The method is based on spatial averaging of the measured earthshine spectra and extraction of a spatial pattern of the resolution effect. Furthermore, two empirical corrections, which summarise all instrumental differences by including instrument-dependent offsets in a fitted trend function, are developed. These methods are applied to data from GOME and SCIAMACHY separately, to the combined time series, and to an extended dataset comprising also GOME-2 and OMI measurements. All approaches show consistent trends of tropospheric NO2 for a selection of areas on both regional and city scales, for the first time allowing consistent trend analysis of the full time series at high spatial resolution. Compared to previous studies, the longer study period leads to significantly reduced uncertainties. We show that measured tropospheric NO2 columns have been strongly increasing over China, the Middle East, and India, with values over east-central China tripling from 1996 to 2011. All parts of the developed world, including Western

  10. The impact of satellite-adjusted NOx emissions on simulated NOx and O3 discrepancies in the urban and outflow areas of the Pacific and Lower Middle US

    NASA Astrophysics Data System (ADS)

    Choi, Y.

    2013-08-01

    We analyze the simulation results from a CMAQ model and GOME-2 NO2 retrievals over the United States for August~2009 to estimate the model-simulated biases of NOx concentrations over six geological regions (Pacific Coast = PC, Rocky Mountains = RM, Lower Middle = LM, Upper Middle = UM, Southeast = SE, Northeast = NE). By comparing GOME-2 NO2 columns to corresponding CMAQ NO2 columns, we produced satellite-adjusted NOx emission ("GOME2009") and compared baseline emission ("BASE2009") CMAQ simulations with GOME2009 CMAQ runs. We found that the latter exhibited decreases of -5.6%, -12.3%, -21.3%, and -15.9% over the PC, RM, LM, and SE regions, respectively, and increases of +2.3% and +10.0% over the UM and NE regions. In addition, we found that changes in NOx emissions generally mitigate discrepancies between the surface NOx concentrations of baseline CMAQ and those of AQS at EPA AQS stations (mean bias of +19.8% to -13.7% over PC, -13.8% to -36.7% over RM, +149.7% to -1.8% over LM, +22.5% to -7.8% over UM, +31.3% to -7.9% over SE, and +11.6% to +0.7% over NE). The relatively high simulated NOx biases from baseline CMAQ over LM (+149.7%) are likely the results of over-predictions of simulated NOx emissions, which could shed light on those from global/regional Chemical Transport Models. We also perform more detailed investigations on surface NOx and O3 concentrations in two urban and outflow areas, PC (e.g., Los Angeles, South Pasadena, Anaheim, La Habra and Riverside) and LM (e.g., Houston, Beaumont and Sulphur). From two case studies, we found that the GOME2009 emissions decreased surface NOx concentrations significantly in the urban areas of PC (up to 30 ppbv) and in those of LM (up to 10 ppbv) during the daytime and that simulated NOx concentrations from CMAQ with GOME2009 compare well to those of in-situ AQS observations. A significant reduction in NOx concentrations resulted in a comparable increase in surface O3 concentrations in the urban areas of PC (up to 30

  11. The impact of satellite-adjusted NOx emissions on simulated NOx and O3 discrepancies in the urban and outflow areas of the Pacific and Lower Middle US

    NASA Astrophysics Data System (ADS)

    Choi, Y.

    2014-01-01

    We analyze the simulation results from a CMAQ model and GOME-2 NO2 retrievals over the United States for August 2009 to estimate the model-simulated biases of NOx concentrations over six geological regions (Pacific Coast = PC, Rocky Mountains = RM, Lower Middle = LM, Upper Middle = UM, Southeast = SE, Northeast = NE). By comparing GOME-2 NO2 columns to corresponding CMAQ NO2 columns, we produced satellite-adjusted NOx emission ("GOME2009") and compared baseline emission ("BASE2009") CMAQ simulations with GOME2009 CMAQ runs. We found that the latter exhibited decreases of -5.6%, -12.3%, -21.3%, and -15.9 % over the PC, RM, LM, and SE regions, respectively, and increases of +2.3% and +10.0% over the UM and NE regions. In addition, we found that changes in NOx emissions generally mitigate discrepancies between the surface NOx concentrations of baseline CMAQ and those of AQS at EPA AQS stations (mean bias of +19.8% to -13.7% over PC, -13.8% to -36.7% over RM, +149.7% to -1.8% over LM, +22.5% to -7.8% over UM, +31.3% to -7.9% over SE, and +11.6% to +0.7% over NE). The relatively high simulated NOx biases from baseline CMAQ over LM (+149.7%) are likely the results of over-predictions of simulated NOx emissions, which could shed light on those from global/regional Chemical Transport Models. We also perform more detailed investigations on surface NOx and O3 concentrations in two urban and outflow areas, PC (e.g., Los Angeles, South Pasadena, Anaheim, La Habra and Riverside) and LM (e.g., Houston, Beaumont and Sulphur). From two case studies, we found that the GOME2009 emissions decreased surface NOx concentrations significantly in the urban areas of PC (up to 30 ppbv) and in those of LM (up to 10 ppbv) during the daytime and that simulated NOx concentrations from CMAQ with GOME2009 compare well to those of in-situ AQS observations. A significant reduction in NOx concentrations resulted in a comparable increase in surface O3 concentrations in the urban areas of PC (up to 30

  12. Satellite retrieval of cloud properties from the O2 A-band for air quality and climate applications

    NASA Astrophysics Data System (ADS)

    Wang, P.; Stammes, P.; van der A, R.

    2009-04-01

    The FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm has been used to retrieve cloud information from measurements of the O2 A-band around 760 nm by GOME, SCIAMACHY and GOME-2. The cloud parameters retrieved by FRESCO are the effective cloud fraction and cloud pressure, which are used for cloud correction in the retrieval of trace gases like O3 and NO2. To improve the cloud pressure retrieval for partly cloudy scenes, single Rayleigh scattering has been included in an improved version of the algorithm, called FRESCO+. FRESCO+ gives more reliable cloud pressures over partly cloudy pixels. Simulations and comparisons with ground-based radar measurements of clouds shows that the FRESCO+ cloud pressure is about the optical midlevel of the cloud. Globally averaged, the FRESCO+ cloud pressure is about 50 hPa higher than the FRESCO cloud pressure, while the FRESCO+ effective cloud fraction is about 0.01 larger. From ground-based validation (P. Wang et al., Atmos. Chem. Phys., 8, 6565-6576, 2008) it appears that the FRESCO+ cloud retrievals improve the retrieval of tropospheric NO2 as compared to FRESCO. So FRESCO+ contributes to better monitoring of air quality from space. The FRESCO+ cloud algorithm has been applied to GOME and SCIAMACHY measurements since the beginning of the missions. Monthly averaged SCIAMACHY FRESCO+ effective cloud fraction and cloud pressure maps show similar patterns as the ISCCP cloud maps, although there are some differences, due to the different meaning of the cloud products and due to the fact that photons in the O2 A-band penetrate into clouds. The 6-year averaged seasonal cloud maps from SCIAMACHY data have good agreement with the global circulation patterns. Therefore, the FRESCO+ products are not only efficient for cloud correction of trace gas retrievals but also contribute additional information for climate research.

  13. FRESCO+: an improved O2 A-band cloud retrieval algorithm for tropospheric trace gas retrievals

    NASA Astrophysics Data System (ADS)

    Wang, P.; Stammes, P.; van der A, R.; Pinardi, G.; van Roozendael, M.

    2008-11-01

    The FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm has been used to retrieve cloud information from measurements of the O2 A-band around 760 nm by GOME, SCIAMACHY and GOME-2. The cloud parameters retrieved by FRESCO are the effective cloud fraction and cloud pressure, which are used for cloud correction in the retrieval of trace gases like O3 and NO2. To improve the cloud pressure retrieval for partly cloudy scenes, single Rayleigh scattering has been included in an improved version of the algorithm, called FRESCO+. We compared FRESCO+ and FRESCO effective cloud fractions and cloud pressures using simulated spectra and one month of GOME measured spectra. As expected, FRESCO+ gives more reliable cloud pressures over partly cloudy pixels. Simulations and comparisons with ground-based radar/lidar measurements of clouds show that the FRESCO+ cloud pressure is about the optical midlevel of the cloud. Globally averaged, the FRESCO+ cloud pressure is about 50 hPa higher than the FRESCO cloud pressure, while the FRESCO+ effective cloud fraction is about 0.01 larger. The effect of FRESCO+ cloud parameters on O3 and NO2 vertical column density (VCD) retrievals is studied using SCIAMACHY data and ground-based DOAS measurements. We find that the FRESCO+ algorithm has a significant effect on tropospheric NO2 retrievals but a minor effect on total O3 retrievals. The retrieved SCIAMACHY tropospheric NO2 VCDs using FRESCO+ cloud parameters (v1.1) are lower than the tropospheric NO2VCDs which used FRESCO cloud parameters (v1.04), in particular over heavily polluted areas with low clouds. The difference between SCIAMACHY tropospheric NO2 VCDs v1.1 and ground-based MAXDOAS measurements performed in Cabauw, The Netherlands, during the DANDELIONS campaign is about -2.12×1014molec cm-2.

  14. The Seasonal Cycle of Satellite Chlorophyll Fluorescence Observations and its Relationship to Vegetation Phenology and Ecosystem Atmosphere Carbon Exchange

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Yoshida, Y.; Vasilkov, A. P.; Schaefer, K.; Jung, M.; Guanter, L.; Zhang, Y; Garrity, S.; Middleton, E. M.; Huemmrich, K. F.; Gu, L.; Marchesini, L. Belelli

    2014-01-01

    Mapping of terrestrial chlorophyll uorescence from space has shown potentialfor providing global measurements related to gross primary productivity(GPP). In particular, space-based fluorescence may provide information onthe length of the carbon uptake period that can be of use for global carboncycle modeling. Here, we examine the seasonal cycle of photosynthesis asestimated from satellite fluorescence retrievals at wavelengths surroundingthe 740nm emission feature. These retrievals are from the Global OzoneMonitoring Experiment 2 (GOME-2) flying on the MetOp A satellite. Wecompare the fluorescence seasonal cycle with that of GPP as estimated froma diverse set of North American tower gas exchange measurements. Because the GOME-2 has a large ground footprint (40 x 80km2) as compared with that of the flux towers and requires averaging to reduce random errors, we additionally compare with seasonal cycles of upscaled GPP in the satellite averaging area surrounding the tower locations estimated from the Max Planck Institute for Biogeochemistry (MPI-BGC) machine learning algorithm. We also examine the seasonality of absorbed photosynthetically-active radiation(APAR) derived with reflectances from the MODerate-resolution Imaging Spectroradiometer (MODIS). Finally, we examine seasonal cycles of GPP as produced from an ensemble of vegetation models. Several of the data-driven models rely on satellite reflectance-based vegetation parameters to derive estimates of APAR that are used to compute GPP. For forested sites(particularly deciduous broadleaf and mixed forests), the GOME-2 fluorescence captures the spring onset and autumn shutoff of photosynthesis as delineated by the tower-based GPP estimates. In contrast, the reflectance-based indicators and many of the models tend to overestimate the length of the photosynthetically-active period for these and other biomes as has been noted previously in the literature. Satellite fluorescence measurements therefore show potential for

  15. Satellite-observed NO2, SO2, and HCHO Vertical Column Densities in East Asia: Recent Changes and Comparisons with Regional Model

    NASA Astrophysics Data System (ADS)

    Kim, H. C.; Lee, P.; Kim, S.; Mok, J.; Yoo, H. L.; Bae, C.; Kim, B. U.; Lim, Y. K.; Woo, J. H.; Park, R.

    2015-12-01

    This study reports the recent changes in tropospheric NO2, SO2, and HCHO vertical column densities (VCD) in East Asia observed from multiple satellites, highlighting especially the annual trend changes of NO2 and SO2 over Beijing-Tianjin-Hebei (BTH) region of China since 2010. Tropospheric VCD data from Global Ozone Monitoring Experiment (GOME), SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY), Ozone Monitoring Instrument (OMI) and GOME-2, retrieved from the Royal Netherlands Meteorological Institute (KNMI) and OMI National Aeronautics and Space Administration (NASA) standard products, are utilized to investigate the annual trends of NO2, SO2, and HCHO VCDs from 2001 to 2015. They are also compared with simulations from Community Multi-scale Air Quality Model (CMAQ) based forecast system by the Integrated Multi-scale Air Quality System for Korea (IMAQS-K) of Ajou University. Until 2011, the changes in NO2 VCD over East Asian countries agree well with the findings of previous research, including the impact of the economic downturn during 2008-2009 and the subsequent quick recovery in China. After peaking in 2011, the NO2 VCD observations from active instruments (OMI and GOME-2) over China started to show a slower decreasing trend, mostly led by the rapid changes in the BTH region in northern China. On the other hand, SO2 started to decline earlier, from 2007, but inclined back from 2010 to 2012, and then back to declining trend since 2012. While satellite observations show dramatic recent changes, the model could not reproduce those changes mostly due to its use of fixed emission inventory. We conclude that rapid update of latest emission inventory is necessary for an accurate forecast of regional air quality in east Asia, especially for upcoming international sports events in PyeongChang (Korea), Tokyo (Japan) and Beijing (China) in 2018, 2020 and 2022, respectively.

  16. Total Ozone from the Ozone Monitoring System (OMI) using TOMS and DOAS Methods

    NASA Technical Reports Server (NTRS)

    Veefkind, J. P.; Bhartia, P. K.; Gleason, J.; deHaan, J. F.; Wellemeyer, C.; Levelt, P. F.

    2003-01-01

    The Ozone Monitoring Instrument (OMI) is the Dutch-Finnish contribution to NASA's EOS-Aura satellite scheduled for launch in January 2004. OMI is an imaging spectrometer that will measure the back-scattered Solar radiance in the wavelength range of 270 to 500 nm. The instrument provides near global coverage in one day with a spatial resolution of 13x24 square kilometers. OMI is a new instrument, with a heritage from TOMS, SBW, GOME, GOMOS and SCIAMACHY. OMI'S unique capabilities for measuring important trace gases and aerosols 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 provide data continuity with the 23-year ozone record of TOMS. There are three ozone products planned for OMI: total column ozone, ozone profile and tropospheric column ozone. We are developing two different algorithms for total column ozone: one similar to the algorithm currently being used to process the TOMS data, and the other an improved version of the differential optical absorption spectroscopy (DOAS) method, which has been applied to GOME and SCIAMACHY data. The main reasons for starting with two algorithms for total ozone have to do with heritage and past experience; our long-term goal is to combine the two to develop a more accurate and reliable total ozone product for OMI. We will compare the performance of these two algorithms by applying both of them to the GOME data. We will examine where and how the results differ, and use the extensive TOMS-Dobson comparison studies to assess the performance of the DOAS algorithm.

  17. Development of a harmonised multi sensor retrieval scheme for HCHO within the Quality Assurance For Essential Climate Variables (QA4ECV) project

    NASA Astrophysics Data System (ADS)

    De Smedt, Isabelle; Richter, Andreas; Beirle, Steffen; Danckaert, Thomas; Van Roozendael, Michel; Yu, Huan; Bösch, Tim; Hilboll, Andreas; Peters, Enno; Doerner, Steffen; Wagner, Thomas; Wang, Yang; Lorente, Alba; Eskes, Henk; Van Geffen, Jos; Boersma, Folkert

    2016-04-01

    One of the main goals of the QA4ECV project is to define community best-practices for the generation of multi-decadal ECV data records from satellite instruments. QA4ECV will develop retrieval algorithms for the Land ECVs surface albedo, leaf area index (LAI), and fraction of active photosynthetic radiation (fAPAR), as well as for the Atmosphere ECV ozone and aerosol precursors nitrogen dioxide (NO2), formaldehyde (HCHO), and carbon monoxide (CO). Here we assess best practices and provide recommendations for the retrieval of HCHO. Best practices are established based on (1) a detailed intercomparison exercise between the QA4ECV partner's for each specific algorithm processing steps, (2) the feasibility of implementation, and (3) the requirement to generate consistent multi-sensor multi-decadal data records. We propose a fitting window covering the 328.5-346 nm spectral interval for the morning sensors (GOME, SCIAMACHY and GOME-2) and an extension to 328.5-359 nm for OMI and GOME-2, allowed by improved quality of the recorded spectra. A high level of consistency between group algorithms is found when the retrieval settings are carefully aligned. However, the retrieval of slant columns is highly sensitive to any change in the selected settings. The use of a mean background radiance as DOAS reference spectrum allows for a stabilization of the retrievals. A background correction based on the reference sector method is recommended for implementation in the QA4ECV HCHO algorithm as it further reduces retrieval uncertainties. HCHO AMFs using different radiative transfer codes show a good overall consistency when harmonized settings are used. As for NO2, it is proposed to use a priori HCHO profiles from the TM5 model. These are provided on a 1°x1° latitude-longitude grid.

  18. Data series of total columns of H2O measured from the ground and from space at Observatoire de Haute-Provence in France (44° N)

    NASA Astrophysics Data System (ADS)

    Alkasm, Sulaf; Sarkissian, Alain; Keckhut, Philippe; Pazmino, Andrea; Goutail, Florence; Noel, Stephan

    2013-04-01

    Water vapour is an atmospheric constituent having a determinant effect on the climate and on the weather. It presents the two third of the greenhouse gases, and is mostly located in the troposphere. It is the key element of the hydrological cycle, conditioned by exchanges between its three phases in the atmosphere, the ocean and the continents, and also directed by the transport of energy between the surface and the atmosphere, by evaporation and condensation. However, because of its large temporal and spatial variability, the measure of this component is a demanding task. For this reason, many different techniques have been developed to estimate water vapour in the atmosphere. Also, the accuracy of the measurements changes from one instrument to another as the mode of observation, the period of observation, the condition of measurement, and the retrieval method are different between them. Note that these instruments were not specialised initially to water vapour measurements and the extraction of H2O was not the principle objective. This paper compares measurements of total vertical column density (VCD) of water vapour, i.e. the amount of water vapour in a vertical atmospheric column, obtained above Observatoire de Haute-Provence (OHP), south of France (5°42'E, +43°55'N) from five different instruments. This work compares results from two ground based and three satellite instruments: the SAOZ (système d'analyse par observation zénithale) an automated UV-VIS spectrometer; Elodie, a cross-dispersed echelle spectrograph and its 1.92 m telescope; SCIAMACHY, a scanning imaging absorption spectrometer for atmospheric cartography; GOME, a nadir scanning ultraviolet and visible spectrometer for global monitoring of atmospheric ozone; and GOME2, a second generation of GOME.

  19. Monitoring vegetation using DOAS satellite observations

    NASA Astrophysics Data System (ADS)

    Eigemeier, Ellen; Beirle, Steffen; Marbach, Thierry; Platt, Ulrich; Wagner, Thomas

    2010-05-01

    Vegetation-cycles are of general interest for many applications. Be it for harvest-predictions, global monitoring of climate-change or as input to atmospheric models. From novel spectrally resolving UV/vis satellite instruments (like GOME or SCIAMACHY) the spectral signatures of different types of vegetation can be identified and analysed. Although the spatial resolution of GOME and SCIAMACHY observations is much coarser than those of conventional satellite instruments for vegetation monitoring, our data sets on different vegetation types add new and useful information, not obtainable from other sources. Common vegetation indices are based on the fact that the difference between Red and Near Infrared reflection is higher than in any other material on Earth's surface. This gives a very high degree of confidence for vegetation-detection. The spectrally resolving data from GOME and SCIAMACHY provide the chance to concentrate on finer spectral features throughout the red and near infrared spectrum. We look at these features using a technique known as Differential Optical Absorption Spectroscopy (DOAS). Although originally developed to retrieve information on trace gases, it can also be used to gain information on vegetation. Another advantage is that this method automatically corrects for atmospheric effects. This renders the vegetation-information easily comparable over long time-spans. In addition, high-frequency-structures from vegetation also effect the retrieval of tropospheric trace-gases and aerosols. To optimize vegetation monitoring with DOAS we produce spectrally resolved reference spectra from different vegetation types using our own instrumentation. We analyze the effect of different Pigments on high-frequency-structures of the DOAS Retrieval. Applying these results we investigate how well we can distinguish vegetation types from space.

  20. Monitoring vegetation using DOAS satellite observations

    NASA Astrophysics Data System (ADS)

    Eigemeier, E.; Beirle, S.; Marbach, T.; Platt, U.; Wagner, T.

    2009-04-01

    Vegetation-cycles are of general interest for many applications. Be it for harvest-predictions, global monitoring of climate-change or as input to atmospheric models. From novel spectrally resolving UV/vis satellite instruments (like GOME of SCIAMACHY) the spectral signatures of different types of vegetation can be identified and analysed. Although the spatial resolution of GOME and SCIAMACHY observations is much coarser than those of conventional satellite instruments for vegetation monitoring, our data sets on different vegetation types add new and useful information, not obtainable from other sources. Common Vegetation Indices use the fact that the difference between Red and Near Infrared reflection is higher than in any other material on Earth's surface. This gives a very high degree of confidence for vegetation-detection. The spectrally resolving data from GOME and SCIAMACHY provide the chance to concentrate on finer spectral features throughout the Red and Near Infrared spectrum. We look at these using a technique known as Differential Optical Absorption Spectroscopy (DOAS). Although originally developed to retrieve information on trace gases, it can also be used to gain information on vegetation. Another advantage is that this method automatically corrects for changes in the atmosphere. This renders the vegetation-information easily comparable over long time-spans. In addition, high-frequency-structures from vegetation also effect the retrieval of tropospheric trace-gases and aerosols. To optimize vegetation monitoring with DOAS we produce spectrally resolved reference spectra from different vegetation types. We investigate how well we will be able to distinguish vegetation types from space. This will also be valuable for monitoring global vegetation-cycles over long time spans. Preliminary results will be presented here.

  1. Monitoring vegetation using DOAS satellite observations

    NASA Astrophysics Data System (ADS)

    Eigemeier, E.; Beirle, S.; Marbach, T.; Platt, U.; Wagner, T.

    2009-12-01

    Vegetation-cycles are of general interest for many applications. Be it for harvest-predictions, global monitoring of climate-change or as input to atmospheric models. From novel spectrally resolving UV/vis satellite instruments (like GOME or SCIAMACHY) the spectral signatures of different types of vegetation can be identified and analysed. Although the spatial resolution of GOME and SCIAMACHY observations is much coarser than those of conventional satellite instruments for vegetation monitoring, our data sets on different vegetation types add new and useful information, not obtainable from other sources. Common vegetation indices are based on the fact that the difference between Red and Near Infrared reflection is higher than in any other material on Earth’s surface. This gives a very high degree of confidence for vegetation-detection. The spectrally resolving data from GOME and SCIAMACHY provide the chance to concentrate on finer spectral features throughout the red and near infrared spectrum. We look at these features using a technique known as Differential Optical Absorption Spectroscopy (DOAS). Although originally developed to retrieve information on trace gases, it can also be used to gain information on vegetation. Another advantage is that this method automatically corrects for atmospheric effects. This renders the vegetation-information easily comparable over long time-spans. In addition, high-frequency-structures from vegetation also effect the retrieval of tropospheric trace-gases and aerosols. To optimize vegetation monitoring with DOAS we produce spectrally resolved reference spectra from different vegetation types using our own instrumentation. We analyze the effect of different Pigments on high-frequency-structures of the DOAS Retrieval. Applying these results we investigate how well we can distinguish vegetation types from space.

  2. FRESCO+: an improved O2 A-band cloud retrieval algorithm for tropospheric trace gas retrievals

    NASA Astrophysics Data System (ADS)

    Wang, P.; Stammes, P.; van der A, R.; Pinardi, G.; van Roozendael, M.

    2008-05-01

    The FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm has been used to retrieve cloud information from measurements of the O2 A-band around 760 nm by GOME, SCIAMACHY and GOME-2. The cloud parameters retrieved by FRESCO are the effective cloud fraction and cloud pressure, which are used for cloud correction in the retrieval of trace gases like O3 and NO2. To improve the cloud pressure retrieval for partly cloudy scenes, single Rayleigh scattering has been included in an improved version of the algorithm, called FRESCO+. We compared FRESCO+ and FRESCO effective cloud fractions and cloud pressures using simulated spectra and one month of GOME measured spectra. As expected, FRESCO+ gives more reliable cloud pressures over partly cloudy pixels. Simulations and comparisons with ground-based radar/lidar measurements of clouds shows that the FRESCO+ cloud pressure is about the optical midlevel of the cloud. Globally averaged, the FRESCO+ cloud pressure is about 50 hPa higher than the FRESCO cloud pressure, while the FRESCO+ effective cloud fraction is about 0.01 larger. The effect of FRESCO+ cloud parameters on O3 and NO2 vertical column densities (VCD) is studied using SCIAMACHY data and ground-based DOAS measurements. We find that the FRESCO+ algorithm has a significant effect on tropospheric NO2 retrievals but a minor effect on total O3 retrievals. The retrieved SCIAMACHY tropospheric NO2 VCDs using FRESCO+ cloud parameters (v1.1) are lower than the tropospheric NO2 VCDs which used FRESCO cloud parameters (v1.04), in particular over heavily polluted areas with low clouds. The difference between SCIAMACHY tropospheric NO2 VCDs v1.1 and ground-based MAXDOAS measurements performed in Cabauw, The Netherlands, during the DANDELIONS campaign is about -2.12×1014 molec cm-2.

  3. Temporal trends of anthropogenic SO2 emitted by non-ferrous metal smelters in Peru and Russia estimated from Satellite observations

    NASA Astrophysics Data System (ADS)

    Khokhar, M. F.; Platt, U.; Wagner, T.

    2008-09-01

    We report on satellite observations of atmospheric Sulfur Dioxide (SO2) emitted from metal smelting industries in Peru, South America and Siberia, Russia. Most of the non-ferrous metal ores are sulfidic and during the smelting process the sulfur is emitted as SO2. In addition to Norilsk, Russia, Peruvian copper smelters are among the most polluting point sources in the world. We retrieve SO2 column amounts from spectra of the Global Ozone Monitoring Experiment (GOME) on the Earth Research Satellite 2 (ERS-2) for the years 1996 to 2002 using an algorithm based on differential Optical Absorption Spectroscopy (DOAS). Areas of enhanced SO2 column amounts are clearly identified on a 7-years mean map of GOME observations over the regions with La Oroya and Ilo copper smelters of Peru and Norilsk smelters of Russia. Since the instrument sensitivity is highly dependent on surface albedo, SO2 vertical profile, solar zenith angle (SZA), wavelength, clouds, and aerosol, radiative transfer modelling is used to convert the analysed slant column densities into vertical column densities. In this study, the full spherical Monte-Carlo radiative transport model TRACY-II is used for SO2 AMF calculation. GOME data is analysed in further detail by calculating time series over these regions. For the different locations, the results demonstrate both, increasing and decreasing trends in the SO2 column amounts over the time period of 1996 2002. The decreasing trend for the Ilo copper smelter is in good agreement with implemented measures for emission reductions. However, even for the cases with decreasing trends, these point sources are still a dominant source of anthropogenic SO2 emissions in their region. For the smelters in Peru, the potential influence due to SO2 emission by the nearby volcanoes is investigated and found to be negligible.

  4. Consistency Between Sun-Induced Chlorophyll Fluorescence and Gross Primary Production of Vegetation in North America

    NASA Technical Reports Server (NTRS)

    Zhang, Yao; Xiao, Xiangming; Jin, Cui; Dong, Jinwei; Zhou, Sha; Wagle, Pradeep; Joiner, Joanna; Guanter, Luis; Zhang, Yongguang; Zhang , Geli; Qin, Yuanwei; Wang, Jie; Moore, Berrien, III

    2016-01-01

    Accurate estimation of the gross primary production (GPP) of terrestrial ecosystems is vital for a better understanding of the spatial-temporal patterns of the global carbon cycle. In this study,we estimate GPP in North America (NA) using the satellite-based Vegetation Photosynthesis Model (VPM), MODIS (Moderate Resolution Imaging Spectrometer) images at 8-day temporal and 500 meter spatial resolutions, and NCEP-NARR (National Center for Environmental Prediction-North America Regional Reanalysis) climate data. The simulated GPP (GPP (sub VPM)) agrees well with the flux tower derived GPP (GPPEC) at 39 AmeriFlux sites (155 site-years). The GPP (sub VPM) in 2010 is spatially aggregated to 0.5 by 0.5-degree grid cells and then compared with sun-induced chlorophyll fluorescence (SIF) data from Global Ozone Monitoring Instrument 2 (GOME-2), which is directly related to vegetation photosynthesis. Spatial distribution and seasonal dynamics of GPP (sub VPM) and GOME-2 SIF show good consistency. At the biome scale, GPP (sub VPM) and SIF shows strong linear relationships (R (sup 2) is greater than 0.95) and small variations in regression slopes ((4.60-5.55 grams Carbon per square meter per day) divided by (milliwatts per square meter per nanometer per square radian)). The total annual GPP (sub VPM) in NA in 2010 is approximately 13.53 petagrams Carbon per year, which accounts for approximately 11.0 percent of the global terrestrial GPP and is within the range of annual GPP estimates from six other process-based and data-driven models (11.35-22.23 petagrams Carbon per year). Among the seven models, some models did not capture the spatial pattern of GOME-2 SIF data at annual scale, especially in Midwest cropland region. The results from this study demonstrate the reliable performance of VPM at the continental scale, and the potential of SIF data being used as a benchmark to compare with GPP models.

  5. Multi-sensor satellite monitoring of ash and SO2 volcanic plume in support to aviation control

    NASA Astrophysics Data System (ADS)

    Brenot, Hugues; Theys, Nicolas; Clarisse, Lieven; van Geffen, Jos; van Gent, Jeroen; Van Roozendael, Michel; van der A, Ronald; Hurtmans, Daniel; Coheur, Pierre-Francois; Clerbaux, Cathy; Valks, Pieter; Hedelt, Pascal; Prata, Fred; Rasson, Olivier; Sievers, Klaus; Zehner, Claus

    2014-05-01

    The 'Support to Aviation Control Service' (SACS; http://sacs.aeronomie.be) is an ESA-funded project hosted by the Belgian Institute for Space Aeronomy since 2007. The service provides near real-time (NRT) global volcanic ash and SO2 observations, as well as notifications in case of volcanic eruptions (success rate >95% for ash and SO2). SACS is based on the combined use of UV-visible (OMI, GOME-2 MetOp-A, GOME-2 MetOp-B) and infrared (AIRS, IASI MetOp-A, IASI MetOp-B) satellite instruments. The SACS service is primarily designed to support the Volcanic Ash Advisory Centers (VAACs) in their mandate to gather information on volcanic clouds and give advice to airline and air traffic control organisations. SACS also serves other users that subscribe to the service, in particular local volcano observatories, research scientists and airliner pilots. When a volcanic eruption is detected, SACS issues a warning that takes the form of a notification sent by e-mail to users. The SACS notification points to a dedicated web page where all relevant information is available and can be visualised with user-friendly tools. Information about the volcanic plume height from GOME-2 (MetOp-A and MetOp-B) are also available. The strength of a multi-sensor approach relies in the use of satellite data with different overpasses times, minimising the time-lag for detection and enhancing the reliability of such alerts. This presentation will give an overview of the SACS service, and of the different techniques used to detect volcanic plumes (ash, SO2 and plume height). It will also highlight the strengths and limitations of the service and measurements, and some perspectives.

  6. Improvements in the DOAS Based Total Ozone Column Algorithm for OMI

    NASA Astrophysics Data System (ADS)

    de Haan, J. F.; Veefkind, J. P.; Valks, P.; Brinksma, E.; Levelt, P. F.

    2003-12-01

    The Ozone Monitoring Instrument is a nadir pointing imaging spectrometer with a wide swath (about 2600 km) that records reflected radiance spectra in the wavelength range 270-500 nm with a spectral resolution of about 0.5 nm. The high spatial resolution (13x24 km at nadir) makes it possible to obtain information on tropospheric ozone as problems due to (partly) cloudy pixels are reduced compared with instruments like GOME and SCIAMACHY. OMI is scheduled for launch early 2004 as part of the NASA EOS-Aura mission. To obtain accurate total ozone columns from OMI spectra an improved DOAS based algorithm is used as compared to the algorithm used in the operational processor for GOME and SCIAMACHY data. The following improvements have been implemented. First, the DOAS fit window is changed from 325-335 nm to 331.6 - 336.6 nm, making the retrieved columns less sensitive to the temperature and ozone profile. To further improve the accuracy we adopt a so-called empirical procedure to calculate air mass factors. In this procedure the DOAS method is applied to simulated spectra. These air mass factors are exact if the atmospheric model used in the calculations corresponds to the actual atmosphere. The third improvement is that the air mass factor is regarded as a function of the slant column density that results from the DOAS fit of a measured spectrum. These improvements have been implemented in the operational algorithm for OMI. We are currently investigating further improvements by handling rotational Raman scattering in a more advanced manner. In this poster presentation the improvements are discussed and some results based on GOME spectra will be presented.

  7. A multi-site intercomparison of integrated water vapour observations for climate change analysis

    NASA Astrophysics Data System (ADS)

    Van Malderen, R.; Brenot, H.; Pottiaux, E.; Beirle, S.; Hermans, C.; De Mazière, M.; Wagner, T.; De Backer, H.; Bruyninx, C.

    2014-08-01

    Water vapour plays a dominant role in the climate change debate. However, observing water vapour over a climatological time period in a consistent and homogeneous manner is challenging. On one hand, networks of ground-based instruments able to retrieve homogeneous integrated water vapour (IWV) data sets are being set up. Typical examples are Global Navigation Satellite System (GNSS) observation networks such as the International GNSS Service (IGS), with continuous GPS (Global Positioning System) observations spanning over the last 15+ years, and the AErosol RObotic NETwork (AERONET), providing long-term observations performed with standardized and well-calibrated sun photometers. On the other hand, satellite-based measurements of IWV already have a time span of over 10 years (e.g. AIRS) or are being merged to create long-term time series (e.g. GOME, SCIAMACHY, and GOME-2). This study performs an intercomparison of IWV measurements from satellite devices (in the visible, GOME/SCIAMACHY/GOME-2, and in the thermal infrared, AIRS), in situ measurements (radiosondes) and ground-based instruments (GPS, sun photometer), to assess their use in water vapour trends analysis. To this end, we selected 28 sites world-wide for which GPS observations can directly be compared with coincident satellite IWV observations, together with sun photometer and/or radiosonde measurements. The mean biases of the different techniques compared to the GPS estimates vary only between -0.3 to 0.5 mm of IWV. Nevertheless these small biases are accompanied by large standard deviations (SD), especially for the satellite instruments. In particular, we analysed the impact of clouds on the IWV agreement. The influence of specific issues for each instrument on the intercomparison is also investigated (e.g. the distance between the satellite ground pixel centre and the co-located ground-based station, the satellite scan angle, daytime/nighttime differences). Furthermore, we checked if the properties of

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

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.

    2006-01-01

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

  9. Reply to 'Comment on 'Quantum time-of-flight distribution for cold trapped atoms''

    SciTech Connect

    Ali, Md. Manirul; Home, Dipankar; Pan, Alok K.; Majumdar, A. S.

    2008-02-15

    In their comment Gomes et al. [Phys. Rev. A 77, 026101 (2008)] have questioned the possibility of empirically testable differences existing between the semiclassical time of flight distribution for cold trapped atoms and a quantum distribution discussed by us recently [Ali et al., Phys. Rev. A 75, 042110 (2007).]. We argue that their criticism is based on a semiclassical treatment having restricted applicability for a particular trapping potential. Their claim does not preclude, in general, the possibility of differences between the semiclassical calculations and fully quantum results for the arrival time distribution of freely falling atoms.

  10. Potential of the multispectral synergism for observing ozone pollution combining measurements of IASI-NG and UVNS onboard EPS-SG

    NASA Astrophysics Data System (ADS)

    Costantino, Lorenzo; Cuesta, Juan; Emili, Emanuele; Foret, Gilles; Dufour, Gaëlle; Eremenko, Maxim; Chailleux, Yohann; Beekmann, Matthias; Flaud, Jean-Marie

    2016-04-01

    Current and future satellite observations offer a great potential for monitoring air quality on daily and global basis. However, measurements from currently in orbit sensors offer a limited capacity to probe surface concentrations of gaseous pollutants such as tropospheric ozone. Using single-band approaches based on IASI spaceborne thermal infrared measurements, only ozone down to the lower troposphere (3-4 km of altitude at lowest) may be observed (Eremenko et al., 2008). A recent multispectral method combining IASI and GOME-2 (both onboard MetOp satellites) spectra, respectively from the IR and UV, has shown enhanced sensitivity for probing ozone at the lowermost troposphere, but with maximum sensitivity around 2 km at lowest (Cuesta et al., 2013). Future spatial missions will be launched in the upcoming years, such as EPS-SG, carrying new generation sensors like IASI-NG and UVNS that will enhance the capacity to observe ozone pollution, and particularly when combining them through a multispectral synergism. This work presents an analysis of the potential of the multispectral synergism of IASI-NG and UVNS future spaceborne measurements for observing ozone pollution, performed in the framework of SURVEYOZON project (funded by the French Space Agency, CNES). For this, we develop a simulator of synthetic multispectral retrievals or pseudo-observations (referred as OSSE, Observing System Simulation Experiment) derived from IASI-NG+UVNS that will be compared to those from IASI+GOME2. In the first step of the OSSE, we create a pseudo-reality with simulations from the chemical-transport model MOCAGE (provided by CERFACS laboratory), where real O3 data from IASI and surface network stations have been assimilated for a realistic representation of ozone variability at the surface and the free troposphere. We focus on the high pollution event occurred in Europe on 10 July 2010. We use the coupled algorithms KOPRA+VLIDORT to simulate the spectra emitted, scattered and

  11. Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons

    NASA Astrophysics Data System (ADS)

    Verhoelst, T.; Granville, J.; Hendrick, F.; Köhler, U.; Lerot, C.; Pommereau, J.-P.; Redondas, A.; Van Roozendael, M.; Lambert, J.-C.

    2015-12-01

    Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement errors but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs), named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently, also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC) comparisons between GOME-type direct fitting (GODFITv3) satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and ground-based direct-sun and zenith-sky reference measurements such as those from Dobsons, Brewers, and zenith-scattered light (ZSL-)DOAS instruments, respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC). The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing difference errors only play a role in the

  12. The impact of the ozone effective temperature on satellite validation using the Dobson spectrophotometer network

    NASA Astrophysics Data System (ADS)

    Elissavet Koukouli, Maria; Zara, Marina; Lerot, Christophe; Fragkos, Konstantinos; Balis, Dimitris; van Roozendael, Michel; Antonius Franciscus Allart, Marcus; van der A, Ronald Johannes

    2016-05-01

    The main aim of the paper is to demonstrate an approach for post-processing of the Dobson spectrophotometers' total ozone columns (TOCs) in order to compensate for their known stratospheric effective temperature (Teff) dependency and its resulting effect on the usage of the Dobson TOCs for satellite TOCs' validation. The Dobson observations employed are those routinely submitted to the World Ozone and Ultraviolet Data Centre (WOUDC) of the World Meteorological Organization, whereas the effective temperatures have been extracted from two sources: the European Space Agency, ESA, Ozone Climate Change Initiative, Ozone-CCI, GODFIT version 3 (GOME-type Direct FITting) algorithm applied to the GOME2/MetopA, GOME2A, observations as well as the one derived from the European Centre for Medium-Range Weather Forecasts (ECMWF) outputs. Both temperature sources are evaluated utilizing co-located ozonesonde measurements also retrieved from the WOUDC database. Both GODFIT_v3 and ECMWF Teffs are found to be unbiased against the ozonesonde observations and to agree with high correlation coefficients, especially for latitudes characterized by high seasonal variability in Teff. The validation analysis shows that, when applying the GODFIT_v3 effective temperatures in order to post-process the Dobson TOC, the mean difference between Dobson and GOME2A GODFIT_v3 TOCs moves from 0.63 ± 0.66 to 0.26 ± 0.46 % in the Northern Hemisphere and from 1.25 ± 1.20 to 0.80 ± 0.71 % in the Southern Hemisphere. The existing solar zenith angle dependency of the differences has been smoothed out, with near-zero dependency up to the 60-65° bin and the highest deviation decreasing from 2.38 ± 6.6 to 1.37 ± 6.4 % for the 80-85° bin. We conclude that the global-scale validation of satellite TOCs against collocated Dobson measurements benefits from a post-correction using suitably estimated Teffs.

  13. Trend analysis of satellite-observed tropospheric NO2 vertical column densities over East Asia for 2005-2014

    NASA Astrophysics Data System (ADS)

    Muto, T.; Irie, H.; Itahashi, S.

    2015-12-01

    Nitrogen dioxide (NO2) plays a central role in the troposphere as a toxic substance for the respiratory system and a precursor for ozone and aerosols. Furthermore, the OH concentration is dependent on the NO2 concentration. While trend analysis for tropospheric NO2 concentrations in several specific regions all over the world was made in literature for period until 2011, the latest trends after 2011 have not been reported yet. The time period after 2011 is of interest, because it corresponds to the 12th 5-year-plan regulating NOx emissions in China and the period with the power substitution of thermal power generation for the nuclear power generation in Japan. In this study, we first compared satellite-observed tropospheric NO2 VCDs (Vertical Column Densities) with those observed by ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instruments installed at Chiba University in order to clarify whether or not there is degradation in OMI and GOME-2 NO2 VCDs data after 2011. We concluded that there is no significant degradation in OMI and GOME-2 data, since the comparison results are similar to those reported by previous validation studies. Based on the results, tropospheric NO2 VCD trends over Central Eastern China (CEC; 30-40°N, 110.0-123.0°E) and Japan (JPN; 33.5-37.0°N, 133.0-141.0°E) regions were estimated using the regression analysis for annual mean values. Although an increase in NO2 VCDs occurred at a rate of 6%(8%) per year in OMI (GOME-2) data from 2005(2007) to 2011 over CEC, we found a decrease at a rate of 10%(11%) per year from 2011 to 2014. This reduction may be a result from the regulation of NOx emissions from coal fired power generation, iron foundry, cement plant, etc., and installation of the denitrification units during the period of 12th 5-year-plan. For JPN, both OMI and GOME-2 data sets showed that the NO2 VCDs decreased at a rate of 4% per year before 2011. The decreasing trends continued until 2014, with a

  14. Satellite observations of OClO from 1995 to 2010 in comparison to ECMWF data and EMAC simulations

    NASA Astrophysics Data System (ADS)

    Kühl, Sven; Pukite, Janis; Steffen, D.; Jöckel, Patrick; Wagner, Thomas

    Satellite instruments like GOME, GOME-2 and SCIAMACHY measure the spectral intensity of the sunlight, scattered back from Earths atmosphere, on an almost global and daily scale. By applying the DOAS method to the spectral measurements, the integrated concentration of several trace gases along the light path, the so called Slant Column Densitiy (SCD), can be derived. Chlorine dioxide (OClO) is an important indicator for stratospheric chlorine activa-tion, the basis for massive ozone depletion in polar spring. Due to the daily coverage of the polar regions, the OClO measurements give a good overview of the intensity and the extension of the chlorine activation. While the observations in nadir geometry (i.e. perpendicular to Earths surface) provide a (indirect) measurement of the total column, the limb observations (i.e. tangential view) can be inverted to vertical profiles. We investigated GOME, GOME-2 and SCIAMACHY data from 1995 to 2010, covering Arctic and Antarctic winters with very dif-ferent meteorological situations (very cold and very warm winters; early and major warmings). The derived OClO columns are compared to ECMWF analysis data, studying the dependence of the OClO enhancements on meteorological parameters like stratospheric temperatures and potential vorticity. Also, the interaction of stratospheric OClO with NO2 and BrO is investi-gated for selected meteorological situations as well as for long term correlations for different seasons and latitudes, considering in particular the impact on the ozone chemistry. In addition the OClO SCDs are compared to correlated ECHAM5/MESSy1 (EMAC) simulations, which were calculated for the time of the satellite observations. We investigate the inter-hemispheric differences in the observed and simulated OClO profile (e.g. regarding the magnitude, the altitude of the profile peak and their evolution throughout the winter). For the Arctic, we study the inter-annual differences and investigate the dependence of the

  15. Satellite observations of OClO from 1995 to 2010 in comparison to ECMWF data and EMAC simulations

    NASA Astrophysics Data System (ADS)

    Kühl, Sven; Pukite, Janis; Dörner, Steffen; Jöckel, Patrick; Sörensen, Rüdiger; Wagner, Thomas

    2010-05-01

    Satellite instruments like GOME, GOME-2 and SCIAMACHY measure the spectral intensity of the sunlight, scattered back from Earths atmosphere, on an almost global and daily scale. By applying the DOAS method to the spectral measurements, the integrated concentration of several trace gases along the light path, the so called Slant Column Densitiy (SCD), can be derived. Chlorine dioxide (OClO) is an important indicator for stratospheric chlorine activation, the basis for massive ozone depletion in polar spring. Due to the daily coverage of the polar regions, the OClO measurements give a good overview of the intensity and the extension of the chlorine activation. While the observations in nadir geometry (i.e. perpendicular to Earths surface) provide a (indirect) measurement of the total column, the limb observations (i.e. tangential view) can be inverted to vertical profiles. We investigated GOME, GOME-2 and SCIAMACHY data from 1995 to 2010, covering Arctic and Antarctic winters with very different meteorological situations (very cold and very warm winters; early and major warmings). The derived OClO columns are compared to ECMWF analysis data, studying the dependence of the OClO enhancements on meteorological parameters like stratospheric temperatures and potential vorticity. Also, the interaction of stratospheric OClO with NO2 and BrO is investigated for selected meteorological situations as well as for long term correlations for different seasons and latitudes, considering in particular the impact on the ozone chemistry. In addition the OClO SCDs are compared to model results calculated (in a nudged setup) with the ECHAM5/MESSy Atmospheric Chemistry (EMAC) general circulation model for the time of the satellite observations. We investigate the inter-hemispheric differences in the observed and simulated OClO profile (e.g. regarding the magnitude, the altitude of the profile peak and their evolution throughout the winter). For the Arctic, we study the inter

  16. An improved glyoxal retrieval from OMI measurements

    NASA Astrophysics Data System (ADS)

    Alvarado, L. M. A.; Richter, A.; Vrekoussis, M.; Wittrock, F.; Hilboll, A.; Schreier, S. F.; Burrows, J. P.

    2014-06-01

    Satellite observations from the SCIAMACHY, GOME-2, and OMI spectrometers have been used to retrieve atmospheric columns of glyoxal (CHOCHO) with the DOAS method. High CHOCHO levels are found over regions with large biogenic and pyrogenic emissions, and hot-spots have been identified over areas of anthropogenic activities. This study focuses on the development of an improved retrieval for CHOCHO from measurements by the OMI instrument. From sensitivity tests, an optimal fitting window and polynomial degree are determined. Two different approaches to reduce the interference of liquid water absorption over oceanic regions are evaluated, achieving significant reduction of negative columns over clear water regions. Moreover, a high temperature absorption cross-section of nitrogen dioxide (NO2) is introduced in the DOAS retrieval to account for potential interferences of NO2 over regions with large anthropogenic emissions, leading to improved fit quality over these areas. A comparison with vertical CHOCHO columns retrieved from measurements of the GOME-2 and SCIAMACHY instruments over continental regions is performed, showing overall good consistency. Using the new OMI CHOCHO data set, the link between fires and glyoxal columns is investigated for two selected regions in Africa. In addition, mapped averages are computed for a fire event in the east of Moscow between mid-July and mid-August 2010. In both cases, enhanced CHOCHO levels are found in close spatial and temporal proximity to MODIS fire radiative power, demonstrating that pyrogenic emissions can be clearly identified in the OMI CHOCHO product.

  17. Potential of the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor for the monitoring of terrestrial chlorophyll fluorescence

    NASA Astrophysics Data System (ADS)

    Guanter, L.; Aben, I.; Tol, P.; Krijger, J. M.; Hollstein, A.; Köhler, P.; Damm, A.; Joiner, J.; Frankenberg, C.; Landgraf, J.

    2015-03-01

    Global monitoring of sun-induced chlorophyll fluorescence (SIF) is improving our knowledge about the photosynthetic functioning of terrestrial ecosystems. The feasibility of SIF retrievals from spaceborne atmospheric spectrometers has been demonstrated by a number of studies in the last years. In this work, we investigate the potential of the upcoming TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor satellite mission for SIF retrieval. TROPOMI will sample the 675-775 nm spectral window with a spectral resolution of 0.5 nm and a pixel size of 7 km × 7 km. We use an extensive set of simulated TROPOMI data in order to assess the uncertainty of single SIF retrievals and subsequent spatio-temporal composites. Our results illustrate the enormous improvement in SIF monitoring achievable with TROPOMI with respect to comparable spectrometers currently in-flight, such as the Global Ozone Monitoring Experiment-2 (GOME-2) instrument. We find that TROPOMI can reduce global uncertainties in SIF mapping by more than a factor of 2 with respect to GOME-2, which comes together with an approximately 5-fold improvement in spatial sampling. Finally, we discuss the potential of TROPOMI to map other important vegetation parameters at a global scale with moderate spatial resolution and short revisit time. Those include leaf photosynthetic pigments and proxies for canopy structure, which will complement SIF retrievals for a self-contained description of vegetation condition and functioning.

  18. Satellite remote sensing of vegetation

    NASA Astrophysics Data System (ADS)

    Mahr, Tobias; Peper, Eva; Schubert, Alexander; Warnach, Simon; Pöhler, Denis; Horbanski, Martin; Beirle, Steffen; Mies, Kornelia; Platt, Ulrich; Wagner, Thomas

    2013-04-01

    DOAS (Differential Optical Absorption Spectroscopy) allows to determine the concentration of trace gases based on their specific absorptions cross-sections along a light path. Since 1995, this principle is employed successfully on satellite-based instruments like GOME, GOME-2 and SCIAMACHY for the global measurement of stratospheric and tropospheric trace gases like ozone and nitrogen oxides. Usually, spectral signatures from the ground, where a big part of the sunlight is reflected, are neglected in the evaluation. This can lead to errors in the trace gas determination. However, these structures offer the opportunity to identify surface properties of the earth and different types of vegetation. To analyse spectral reflectance properties, high resolved reflection spectra (FWHM 0.29 nm) from 95 plants were measured between 350 and 1050 nm. They can serve as a basis for the analysis of satellite data. Including different vegetation reference spectra, it is possible to determine groups of plants with similar optical properties. This allows to derive global maps of the spatio-temporal variation of plant distribution by satellite remote sensing. We present first results of this technique based on SCIAMACHY observations.

  19. Rapid economic growth leads to boost in NO2 pollution over India, as seen from space

    NASA Astrophysics Data System (ADS)

    Hilboll, Andreas; Richter, Andreas; Burrows, John P.

    2016-04-01

    Over the past decades, the Indian economy has been growing at an exceptional pace. This growth was induced and accompanied by a strong increase of the Indian population. Consequently, traffic, electricity consumption, and industrial production have soared over the past decades, leading to a strong increase in fuel consumption and thus pollutant emissions. Nitrogen oxides (NO+NO2) are a major component of anthropogenic air pollution, playing key part in reaction cycles leading to the formation of tropospheric ozone. They are mainly emitted by the combustion of fossil fuels; other sources include production by lightning, biomass burning, and microbial activity in soils. Since the mid-1990s, space-borne measurements of tropospheric nitrogen dioxide (NO2) have been conducted by the GOME, SCIAMACHY, GOME-2, and OMI instruments. These instruments perform hyperspectral measurements of scattered and reflected sunlight. Their measurements are then analyzed using differential optical absorption spectroscopy (DOAS) to yield vertically integrated columnar trace gas abundances. Here, we will present the results of 20 years of NO2 measurements over the Indian subcontinent. After showing the spatial distribution of NO2 pollution over India, we will present time series for individual states and urban agglomerations. These time series will then be related to various indicators of economic development. Finally, we will highlight several instances where single industrial pollution sources and their development can clearly be identified from the NO2 maps and estimate their NO2 emissions.

  20. Layer Trends in Earth's Cloud Cover

    NASA Astrophysics Data System (ADS)

    Hearty, T. J.; Kahn, B. H.; Fishbein, E. F.

    2006-12-01

    Clouds are an important component to the Earth's radiation budget. Depending on their height and type they can either cool or warm the Earth's surface and atmosphere. Recent Earthshine observations indicate an increase in Earth's albedo, suggesting an increase in reflective clouds. This increase in cloudiness is corroborated by ISCCP, GOME, and SCIAMACHY observations. However, the CERES instrument on Terra has observed a decrease in Earth's albedo. The discrepancies in the observations could be due to temporal, spatial, or physical differences in the clouds to which each method is sensitive. We utilize the vertical resolution of the AIRS/AMSU down-looking effective cloudfraction and cloud height retrieval to understand changes in the vertical distribution of clouds that might account for the observed discrepancy. We find that AIRS/AMSU observations may suggest a slight decrease in the total effective cloud fraction of Earth. However, the effective cloud fraction is decreasing from ~400-700 mbar and it is increasing from ~700 mbar to the surface. This would be consistent with the Earthshine, ISCCP, GOME, and SCIAMACHY observations being more sensitive to low clouds, while CERES and AIRS/AMSU are more sensitive to all clouds.

  1. Validation of SCIAMACHY Radiances and Ozone Products Using Ground and Space Observations

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.; Bhartia, P. K.; Bojkov, B. R.; Kowalewski, M.; Labow, G.; Ahmad, Z.

    2004-01-01

    Validation of SCIAMACHY data products are is key element for the detecting a stratospheric ozone recovery, which is a high priority for environmental research and environmental policy. Models predict an ozone recovery at a much lower rate than the measured depletion rate observed to date. Therefore improved precision of the satellite and ground ozone observing systems are required over the long term to verify its recovery. We show that validation of satellite radiances from space and from the ground can be an effective means for correcting long term drifts of backscatter type satellite measurements such as SCIAMACHY and can be used to cross calibrate all BUV instruments in orbit (TOMS, SBUV/2, GOME, OMI, GOME-2, OMPS). This method bypasses the retrieval algorithms used for both satellite and ground based measurements that are normally used to validate and correct the satellite data. This approach however requires well calibrated instruments and an accurate radiative transfer model that accounts for aerosols. In addition to comparing radiances, validation of SCIAMACHY ozone products will conducted by comparing total and profile ozone with TOMS and SBUV/2.

  2. A climatology of visible surface reflectance spectra

    NASA Astrophysics Data System (ADS)

    Zoogman, Peter; Liu, Xiong; Chance, Kelly; Sun, Qingsong; Schaaf, Crystal; Mahr, Tobias; Wagner, Thomas

    2016-09-01

    We present a high spectral resolution climatology of visible surface reflectance as a function of wavelength for use in satellite measurements of ozone and other atmospheric species. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is planned to measure backscattered solar radiation in the 290-740 nm range, including the ultraviolet and visible Chappuis ozone bands. Observation in the weak Chappuis band takes advantage of the relative transparency of the atmosphere in the visible to achieve sensitivity to near-surface ozone. However, due to the weakness of the ozone absorption features this measurement is more sensitive to errors in visible surface reflectance, which is highly variable. We utilize reflectance measurements of individual plant, man-made, and other surface types to calculate the primary modes of variability of visible surface reflectance at a high spectral resolution, comparable to that of TEMPO (0.6 nm). Using the Moderate-resolution Imaging Spectroradiometer (MODIS) Bidirection Reflectance Distribution Function (BRDF)/albedo product and our derived primary modes we construct a high spatial resolution climatology of wavelength-dependent surface reflectance over all viewing scenes and geometries. The Global Ozone Monitoring Experiment-2 (GOME-2) Lambertian Equivalent Reflectance (LER) product provides complementary information over water and snow scenes. Preliminary results using this approach in multispectral ultraviolet+visible ozone retrievals from the GOME-2 instrument show significant improvement to the fitting residuals over vegetated scenes.

  3. The polarisation correction for space-borne grating spectrometers

    NASA Astrophysics Data System (ADS)

    Zhao, Fa-cai; Sun, Quan-she; Chen, Kun-feng; Zhu, Xing-bang; Wang, Shao-shui; Wang, Guo-quan; Zheng, Xiang-liang; Han, Zhong

    2014-02-01

    Satellite measurements of backscattered sunlight contain essential information about the global distribution of atmospheric constituents. Light reflected from the Earth's atmosphere is linearly or partially linearly polarized because of scattering of unpolarized sunlight by air molecules and aerosols. In the ultraviolet and visible part of the spectrum, measurements of space-borne grating spectrometers are in general sensitive to the state of polarization of the observed light. The interaction of polarized light with polarization-sensitive optical devices yields a different radiance that is measured by the detectors than the radiance that enters the instrument. In the OMI and the SBUV/2 instruments the problem of instrument polarization sensitivity is avoided because the polarized backscattered sunlight is depolarized before it interacts with the polarization-sensitive optical components. For GOME, SCIAMACHY, and GOME-2 it is intended to eliminate the polarization response of the instrument from the polarization-sensitive measurement. This paper discusses the basic concept of the polarisation correction of the space-borne grating spectrometers by using Mueller matrix calculus. A model was developed using the Mueller Matrices formulation to evaluate the polarization sensitivity of the space-borne grating spectrometers. The optical components are treated as general diattenuators with phase retardance. The correction for this polarization sensitivity is based on broadband polarization measurements. Accurate preflight polarisation calibration of space-borne grating spectrometers is essential for the observational objectives of the instrument, and a special facility has been developed in order to allow the instrument to be calibrated.

  4. Tropospheric Composition Change observed from Space (Invited)

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  5. A comprehensive study over the recent important reduction in SO2 and NO2 emissions from the power plants located in S-E Europe using space observations

    NASA Astrophysics Data System (ADS)

    Bocǎnealǎ, Corina; Constantin, Daniel-Eduard; Theys, Nicolas; Merlaud, Alexis; Van Roozendael, Michel

    2016-04-01

    The aim of this study is to investigate the recent important reduction of atmospheric SO2 and NO2 emissions from several power plants located in S-E Europe during 2005-2014 using space observations. The study is focused over three large power plants which are located in Romania and Bulgaria: Turceni (44.66°N, 23.38°E), Rovinari (44.9°N, 23.15°E) and Stara Zagora (42.43°N, 25.65°E). The space observations used in this work are based on OMI (Ozone Monitoring Instrument) and GOME-2 (Global Ozone Monitoring Experiment Measurements) measurements. The results obtained using data from satellites are compared with in-situ observations and calculated emissions. The OMI and GOME-2 observed SO2 and NO2 content is well correlated with the in-situ data and calculated SO2 and NOx emissions. This study investigates the potential of using satellite observations as an instrument to check quality air as a standard procedure by governmental and non-governmental institutions. To this aim, we compared the emissions calculated from ground and space with the European Directive 2001/80/EC which refers to the limitation of emissions of certain pollutants by large combustion plants.

  6. Retrieval of aerosol optical properties over land using PMAp

    NASA Astrophysics Data System (ADS)

    Grzegorski, Michael; Munro, Rosemary; Lang, Ruediger; Poli, Gabriele; Holdak, Andriy

    2015-04-01

    The retrieval of aerosol optical properties is an important task for industry and climate forecasting. An ideal instrument should include observations with moderate spectral and high spatial resolutions for a wide range of wavelengths (from the UV to the TIR), measurements of the polarization state at different wavelengths and measurements of the same scene for different observation geometries. As such an ideal instrument is currently unavailable the usage of different instruments on one satellite platform is an alternative choice. Since February 2014, the Polar Multi sensor Aerosol product (PMAp) is delivered as operational GOME product to our customers. The algorithms retrieve aerosol optical properties over ocean (AOD, volcanic ash, aerosol type) using a multi-sensor approach (GOME, AVHRR, IASI). The next releases of PMAp will provide an extended set of aerosol and cloud properties which include AOD over land and an improved volcanic ash retrieval combining AVHRR and IASI. This presentation gives an overview on the existing product and the prototypes in development. The major focus is the discussion of the AOD retrieval over land implemented in the upcoming PMAp2 release. In addition, the results of our current validation studies (e.g. comparisons to AERONET, other satellite platforms and model data) are shown.

  7. Analysis of stratospheric NO2 trends above Kiruna using ground-based zenith sky DOAS observations

    NASA Astrophysics Data System (ADS)

    Gu, Myojeong; Enell, Carl-Fredrik; Hendrick, François; Platt, Ulrich; Pukite, Janis; Raffalski, Uwe; Van Roozendael, Michel; Wagner, Thomas

    2016-04-01

    Stratospheric NO2 not only destroys ozone but acts as a buffer against halogen catalyzed ozone loss by converting halogen species into stable nitrates. To a better understanding of the impacts of stratospheric NO2 and O3 chemistry, we need long-term measurement data. In this study, ground-based zenith sky DOAS has successfully monitored trace gases related to stratospheric ozone chemistry since 1997. In this study, we shows the trend in stratospheric NO2 vertical column densities (VCDs) at Kiruna, Sweden (68.84°N, 20.41°E) as derived from ground-based zenith sky DOAS over the period 1997 to 2015. The results will be compared with satellite data measured from GOME on ERS-2, SCIAMACHY on EnviSAT, and GOME-2 on METOP-A. To calculate the trends, we apply a multiple linear regression model including variables to describe effects caused by the quasi-biennial oscillation (QBO), solar activity, and stratospheric aerosol amount.

  8. Long-term observations of tropospheric NO2 from satellite

    NASA Astrophysics Data System (ADS)

    Richter, Andreas; Hilboll, Andreas; Noguchi, Katsuyuki; Leitao, Joana; Burrows, John P.

    Nitrogen oxides (NOx = NO + NO2 ) are key species in atmospheric chemistry. Together with volatile organic compounds they determine the amount of ozone present in the troposphere. Through the formation of nitric acid they are involved in acid rain formation and in addition they contribute to radiative forcing both directly and indirectly. As nitrogen dioxide adversely affects human health it is also regulated by environmental laws. While ground-based networks provide long-term data of surface concentrations of nitrogen oxides at high temporal resolution in many countries, truly global observations can only be performed from space. By using the Differential Optical Absorption Spectroscopy (DOAS) method on spectrally resolved UV/vis measurements of scattered sunlight, column amounts of NO2 can be determined from nadir satellite observations. With additional assumptions on stratospheric NO2 and the radiative transfer, the tropospheric NO2 amounts can be retrieved. In this work, satellite observations of NO2 from several sensors (GOME, SCIAMACHY, OMI, and GOME-2) are used to study the long-term evolution of tropospheric NO2 amounts on a global scale. A particular focus is on the comparison of results retrieved from the different sensors in times of overlapping measurements and the degree of consistency achieved in regions of both large and small pollution signals. The effects of sampling statistics, time of overpass and spatial resolution are discussed as well as the influence of clouds.

  9. A new operational EUMETSAT product for the retrieval of aerosol optical properties over land (PMAp v2)

    NASA Astrophysics Data System (ADS)

    Grzegorski, Michael; Munro, Rosemary; Poli, Gabriele; Holdak, Andriy; Lang, Ruediger

    2016-04-01

    The retrieval of aerosol optical properties is an important task to provide data for industry and climate forecasting. An ideal instrument should include observations with moderate spectral and high spatial resolution for a wide range of wavelengths (from the UV to the TIR), measurements of the polarization state at different wavelengths and measurements of the same scene for different observation geometries. As such an ideal instrument is currently unavailable the usage of different instruments on one satellite platform is an alternative choice. Since February 2014, the Polar Multi sensor Aerosol product (PMAp) has been delivered as an operational GOME product to our customers. The algorithm retrieves aerosol optical properties over ocean (AOD, volcanic ash, aerosol type) using a multi-sensor approach (GOME, AVHRR, IASI). The product is now extended to pixels over land using a new release of the operational PMAp processor (PMAp v2). The pre-operational data dissemination of the new PMAp v2 data to our users is scheduled for March 2016. This presentation gives an overview on the new operational product PMAp v2 with a focus on the validation of the PMAp aerosol optical depth over land. The impact of different error sources on the results (e.g. surface contribution to the TOA reflectance) is discussed. We also show first results of upcoming extensions of our PMAp processor, in particular the improvement of the cloud/aerosol discrimination of thick aerosol events (e.g. volcanic ash plumes, desert dust outbreaks).

  10. Towards a NNORSY Ozone Profile ECV from European Nadir UV/VIS Measurements

    NASA Astrophysics Data System (ADS)

    Felder, Martin; Kaifel, Anton; Huckle, Roger

    2010-12-01

    The Neural Network Ozone Retrieval System (NNORSY) has been adapted and applied to several different satellite instruments, including the backscatter UV/VIS instruments ERS2-GOME, SCIAMACHY and METOP-GOME-2. The retrieved long term ozone field hence spans the years 1995 till now. To provide target data for training the neural networks, the lower parts of the atmosphere are sampled by ozone sondes from the WOUDC and SHADOZ data archives. Higher altitudes are covered by a variety of limb-sounding instruments, including the SAGE and POAM series, HALOE, ACE-FTS and AURA-MLS. In this paper, we show ozone profile time series over the entire time range to demonstrate the "out-of-the-box" consistency and homogeneity of our data across the three different nadir sounders, i.e. without any kind of tuning applied. These features of Essential Climate Variable (ECV) datasets [1] also lie at the heart of the recently announced ESA Climate Change Initiative, to which we hope to contribute in the near future.

  11. Satellites and SAOZ total ozone comparison in the tropics

    NASA Astrophysics Data System (ADS)

    Frihi, Aymen; Pommereau, Jean-Pierre; Pazmino, Andrea; Goutail, Florence; Bekki, Slimane

    2016-04-01

    All satellites total ozone measurements available from SBUV, OMI-T, OMI-D, OMI-CCI, GOME-CCI, GOME2-CCI, SCIAMACHY-CCI, NPP and IASI, since 2004 until 2015 now are compared to those provided by the UV-Vis SAOZ/NDACC spectrometer at two tropical stations of Reunion Island in the Indian Ocean and Bauru in Southern Brazil. The differences between satellites and SAOZ show systematic seasonal variations of 2-3% (6-9 DU) amplitude and sharp negative peaks in Jan-Mar in the austral summer. The largest low peaks seen on IASI, OMI-T, NPP and OMI-CCI at Reunion are shown to be due to hurricanes. In turn, those seen in Brazil correlate with high altitude overshooting convective clouds. The origin of the seasonality of the Sat-SAOZ difference is still unknown. Surprisingly and though there has been no change in either SAOZ instruments or data analysis processes, the amplitude of the seasonal cycle of the Sat-SAOZ difference reduces in 2012 and drops to less than ± 0.5% (1.5 DU) after 2013 in Reunion Island and less than ±1% in Bauru, reduction for which there is no clear explanation. Shown in the presentation will be the demonstration of the impact of hurricanes and high altitude clouds on satellites ozone retrievals, followed by a discussion of possible causes of seasonality of Sat-SAOZ difference and the its amplitude drop after 2012.

  12. Observing the Impact of the Anthropocene from Space: the Evolution of Atmospheric Observation

    NASA Astrophysics Data System (ADS)

    Burrows, John P.

    2016-04-01

    From the Neolithic revolution to the industrial revolution over ~ 10 000 years, the earth's population rose from several millions to 1 Billion powered by energy from a mixture of biofuels, water and solar power and a limited amount of the combustion of coal. The industrial revolution began in the UK in the late 18th century, and has been fuelled by the combustion of fossil fuels, initially coal but then oil and gas. This has led to a dramatic rise in both the human population, now comprising over 7 Billion with more than 50% living in urban areas, and its standard of living. The expectation is that by 2050 population will be of the order of 10 Billion with 75% dwelling in urban areas. Anthropogenic activity has resulted in pollution from the local to the global scale, changes in land use, the destruction of stratospheric ozone, the modification of biogeochemical cycling, the destruction of species, ecosystems and ecosystem services and climate change. The earth has entered a new geological epoch the anthropocene. The observation of atmospheric composition provides a unique early warning of the natural and anthropogenic origins of change. Consistent and consolidated measurements from the local to the global scale are required to test our knowledge of the biogeochemical cycles, which determine atmospheric composition, and to assess and attribute accurately their modification by anthropogenic activity. To achieve global measurements of atmospheric constituents (trace gases, aerosol and cloud parameters) the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY), Project was initiated in the early 1980s. This was the first passive remote sensing space based instrumentation, designed to make simultaneous contiguous measurements of the solar upwelling radiation at the top of the atmosphere from the ultraviolet to the shortwave infrared. The SCIAMACHY project resulted in measurements of the instruments GOME, originally called SCIA-mini, on ESA

  13. Assessing potential changes of chestnut productivity in Europe under future climate conditions

    NASA Astrophysics Data System (ADS)

    Calheiros, T.; Pereira, M. G.; Pinto, J. G.; Caramelo, L.; Gomes-Laranjo, J.; Dacamara, C. C.

    2012-04-01

    The European chestnut is cultivated for its nuts and wood. Several studies point to the dependency of chestnut productivity on specific soil and climate characteristics. For instance, this species dislikes chalky and poorly drained soils, appreciates sedimentary, siliceous and acidic to neutral soils. Chestnut trees also seems to appreciate annual mean values of sunlight spanning between 2400 and 2600 h, rainfall ranging between 600 and 1500 mm, mean annual temperature between 9 and 13°C, 27°C being the mean of the maximum temperature (Heiniger and Conedera, 1992; Gomes-Laranjo et al.,2008). The amount of heat between May and October must range between 1800°D and 2400°D (Dinis et al., 2011) . In Poland, the growing season is defined as the period of time when the mean 24-h temperature is greater than 5°C (Wilczynski and Podalski, 2007). In Portugal, maximum photosynthetic activity occurs at 24-28°C for adult trees, but exhibits more than 50% of termoinhibition when the air temperature is above 32°C, which is frequent during summer (Gomes- Laranjo et al., 2006, 2008). Recently Pereira et al (2011) identified a set of meteorological variables/parameters with high impact on chestnut productivity. The main purpose of this work is to assess the potential impacts of future climate change on chestnut productivity in Portugal as well as on European chestnut orchards. First, observed data from the European Climate assessment (ECA) and simulations with the Regional Circulation Model (RCM) COSMO-CLM for recent climate conditions are used to assess the ability of the RCM to model the actual meteorological conditions. Then, ensemble projections from the ECHAM5/COSMO-CLM model chain for two climate scenarios (A1B and B1) are used to estimate the values of relevant meteorological variables and parameters und future climate conditions. Simulated values are then compared with those obtained for present climate. Results point to changes in the spatial and temporal

  14. Evaluation of Satellites Total Ozone and NO2 columns retrievals using the NDACC-SAOZ UV-Vis Network

    NASA Astrophysics Data System (ADS)

    Pommereau, Jean-Pierre; Hendrick, Francois; Van Roozendael, Michel; Goutail, Florence; Pazmino, Andrea; Ionov, Dmitry

    2012-07-01

    Among the main objectives of the Network for Detection of Atmospheric Composition Changes (NDACC) are the validation and eventually the correction of biases between long-term series of data provided by various satellite instruments. This presentation deals with the evaluation of satellite total ozone retrievals using observations performed by the NDACC/SAOZ UV-Vis spectrometers at all latitudes since 1988. Recently, the full series of SAOZ total ozone measurements in the visible Chappuis bands has been revised according to the spectral analysis and Air Mass Factor (AMF) settings recommended by the NDACC UV-Vis Working Group (Hendrick et al., 2011). The comparison involves overpass observations from the TOMS, GOME-GDP4, SCIAMACHY-TOSOMI, SCIAMACHY-OL3, OMI-TOMS, OMI-DOAS and METOP-GOME-2 satellite instruments. Significant improvement is obtained after applying the new O3 AMFs, although systematic seasonal differences between SAOZ and all other instruments still remain. These are shown to originate from (i) stratospheric temperature and solar zenith angle (SZA) dependences in the satellites retrievals, (ii) longitudinal modulations and seasonal variations of tropospheric ozone columns not accounted for in the ozone profile climatology used for calculating the AMFs, and (iii) uncertainties on the climatological stratospheric ozone profiles in polar winter conditions. For those measurements mostly sensitive to stratospheric temperature like TOMS, OMI-TOMS or to SZA like SCIAMACHY-TOSOMI, the application of temperature and SZA corrections results in the almost complete removal of the seasonal difference with SAOZ, improving significantly the consistency between satellite and ground-based total ozone series. However, small but sometimes significant biases still remain after applying those corrections. A similar exercise is in progress with SAOZ NO2 data sets, using AMFs calculated from a profile climatology based on HALOE, SAGE II, POAM III and SAOZ balloon profiles. The

  15. The CEOS Atmospheric Composition Constellation (ACC), an Integrated Observing System

    NASA Astrophysics Data System (ADS)

    Hilsenrath, E.; Langen, J.; Zehner, C.

    2008-05-01

    participating space agencies. These include 1) Time of day changes in NO2 using Aura/OMI and Metop/GOME-2. 2) Near-real-time fire detection and smoke forecasts using multiple satellites (A-Train, GOES, GOME-2, MSG, etc) and trajectory model, and 3) Improved volcanic ash alerts for aviation hazard avoidance from satellite SO2 and ash data from SCIAMACHY, OMI, GOME-2, AIRS and SEVIRI. Each of the three projects will address the GEO SBAs with consideration to discovery and interoperability of their data products. The status of the ACC studies will be reviewed with a progress report on the above three projects.

  16. A comparative analysis of UV nadir-backscatter and infrared limb-emission ozone data assimilation

    NASA Astrophysics Data System (ADS)

    Dragani, Rossana

    2016-07-01

    This paper presents a comparative assessment of ultraviolet nadir-backscatter and infrared limb-emission ozone profile assimilation. The Meteorological Operational Satellite A (MetOp-A) Global Ozone Monitoring Experiment 2 (GOME-2) nadir and the ENVISAT Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) limb profiles, generated by the ozone consortium of the European Space Agency Climate Change Initiative (ESA O3-CCI), were individually added to a reference set of ozone observations and assimilated in the European Centre for Medium-Range Weather Forecasts (ECMWF) data assimilation system (DAS). The two sets of resulting analyses were compared with that from a control experiment, only constrained by the reference dataset, and independent, unassimilated observations. Comparisons with independent observations show that both datasets improve the stratospheric ozone distribution. The changes inferred by the limb-based observations are more localized and, in places, more important than those implied by the nadir profiles, albeit they have a much lower number of observations. A small degradation (up to 0.25 mg kg-1 for GOME-2 and 0.5 mg kg-1 for MIPAS in the mass mixing ratio) is found in the tropics between 20 and 30 hPa. In the lowermost troposphere below its vertical coverage, the limb data are found to be able to modify the ozone distribution with changes as large as 60 %. Comparisons of the ozone analyses with sonde data show that at those levels the assimilation of GOME-2 leads to about 1 Dobson Unit (DU) smaller root mean square error (RMSE) than that of MIPAS. However, the assimilation of MIPAS can still improve the quality of the ozone analyses and - with a reduction in the RMSE of up to about 2 DU - outperform the control experiment thanks to its synergistic assimilation with total-column ozone data within the DAS. High vertical resolution ozone profile observations are essential to accurately monitor and forecast ozone concentrations in a DAS

  17. ESA's atmospheric composition and dynamics mission

    NASA Astrophysics Data System (ADS)

    Fehr, Thorsten; Laur, Henri; Hoersch, Bianca; Ingmann, Paul; Wehr, Tobias; Langen, Joerg; Veihelmann, Ben

    For almost 15 years, ESA is providing atmospheric chemistry and composition information to the user community. In 1995, this commitment started with the GOME instrument on-board ERS-2. This mission was continued and extended with the GOMOS, MIPAS and SCIAMACHY instruments on-board of ENVISAT launched in 2002. ESA is prepared to continue Envisat through 2013 in the frame of the mission extension. To respond to GMES requirements, ESA develops the Sentinel 5 Precursor mission to be launched in 2014, to continue and improve the European measurement capabilities initiated with GOME and SCIAMACHY, and continued with EUMETSAT's GOME-2 and the Dutch OMI instrument on the NASA Aura platform. In addition the Sentinel 4 and 5 missions are prepared, further improving the monitoring capabilities with geostationary observation capabilities and continuing the Low Earth Orbit Sentinel 5 Precursor well beyond 2025. At the same time, ESA is preparing two atmospheric Earth Explorer Missions. With ADM-Aeolus, a novel lidar system for the retrieval of wind speed vectors from space is being developed and planned to be launched in 2012. EarthCARE will investigate the Clouds-Aerosol-radiation-interaction with a lidar, cloud radar (provided by JAXA), multi-spectral imager and broad band radiometric instruments collocated on one platform. A major goal is the development of synergistic retrievals exploiting information from different sensors in one algorithm. The mission is planned to start in 2014. In parallel the Phase A studies for the ESA Earth Explorer 7 are ongoing. One of the three candidate missions is PREMIER, an infrared limb-imaging spectrometer and millimetre-wave limb-sounder planned to be launched in 2016. In addition the call of ideas for the Earth Explorer 8 has been published and the corresponding Letters of Intend have been received, including a number of proposals for mission in the atmospheric composition and dynamics domain. At the same time, the access to ESA Third

  18. Terrestrial planet formation with strong dynamical friction

    NASA Astrophysics Data System (ADS)

    O'Brien, David P.; Morbidelli, Alessandro; Levison, Harold F.

    2006-09-01

    We have performed 8 numerical simulations of the final stages of accretion of the terrestrial planets, each starting with over 5× more gravitationally interacting bodies than in any previous simulations. We use a bimodal initial population spanning the region from 0.3 to 4 AU with 25 roughly Mars-mass embryos and an equal mass of material in a population of ˜1000 smaller planetesimals, consistent with models of the oligarchic growth of protoplanetary embryos. Given the large number of small planetesimals in our simulations, we are able to more accurately treat the effects of dynamical friction during the accretion process. We find that dynamical friction can significantly lower the timescales for accretion of the terrestrial planets and leads to systems of terrestrial planets that are much less dynamically excited than in previous simulations with fewer initial bodies. In addition, we study the effects of the orbits of Jupiter and Saturn on the final planetary systems by running 4 of our simulations with the present, eccentric orbits of Jupiter and Saturn (the EJS simulations) and the other 4 using a nearly circular and co-planar Jupiter and Saturn as predicted in the Nice Model of the evolution of the outer Solar System [Gomes, R., Levison, H.F., Tsiganis, K., Morbidelli, A., 2005. Nature 435, 466-469; Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F., 2005. Nature 435, 459-461; Morbidelli, A., Levison, H.F., Tsiganis, K., Gomes, R., 2005. Nature 435, 462-465] (the CJS simulations). Our EJS simulations provide a better match to our Solar System in terms of the number and average mass of the final planets and the mass-weighted mean semi-major axis of the final planetary systems, although increased dynamical friction can potentially improve the fit of the CJS simulations as well. However, we find that in our EJS simulations, essentially no water-bearing material from the outer asteroid belt ends up in the final terrestrial planets, while a large amount is

  19. New Developments in the SCIAMACHY Level 2 Ground Processor Towards Version 7

    NASA Astrophysics Data System (ADS)

    Meringer, Markus; Noël, Stefan; Lichtenberg, Günter; Lerot, Christophe; Theys, Nicolas; Fehr, Thorsten; Dehn, Angelika; Liebing, Patricia; Gretschany, Sergei

    2016-07-01

    SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric ChartographY) aboard ESA's environmental satellite ENVISAT observed the Earth's atmosphere in limb, nadir, and solar/lunar occultation geometries covering the UV-Visible to NIR spectral range. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002. SCIAMACHY doubled its originally planned in-orbit lifetime of five years before the communication to ENVISAT was severed in April 2012, and the mission entered its post-operational phase. In order to preserve the best quality of the outstanding data recorded by SCIAMACHY, data processors are still being updated. This presentation will highlight three new developments that are currently being incorporated into the forthcoming version 7 of ESA's operational level 2 processor: 1. Tropospheric BrO, a new retrieval based on the scientific algorithm of (Theys et al., 2011). This algorithm had originally been developed for the GOME-2 sensor and was later adapted for SCIAMACHY. The main principle of the new algorithm is to split BrO total columns, which are already an operational product, into stratospheric VCD_{strat} and tropospheric VCD_{trop} fractions. BrO VCD_{strat} is determined from a climatological approach, driven by SCIAMACHY O_3 and NO_2 observations. Tropospheric vertical column densities are then determined as difference VCD_{trop}=VCD_{total}-VCD_{strat}. 2. Improved cloud flagging using limb measurements (Liebing, 2015). Limb cloud flags are already part of the SCIAMACHY L2 product. They are currently calculated employing the scientific algorithm developed by (Eichmann et al., 2015). Clouds are categorized into four types: water, ice, polar stratospheric and noctilucent clouds. High atmospheric aerosol loadings, however, often lead to spurious cloud flags, when aerosols had been misidentified as clouds. The new algorithm will better discriminate between aerosol and clouds. It will also have a higher

  20. Overview of Global Monitoring of Terrestrial Chlorophyll Fluorescence from Space

    NASA Technical Reports Server (NTRS)

    Guanter, Luis; Zhang, Yongguang; Kohler, Philipp; Walther, Sophia; Frankenberg, Christian; Joiner, Joanna

    2016-01-01

    Despite the critical importance of photosynthesis for the Earth system, understanding how it is influenced by factors such as climate variability, disturbance history, and water or nutrient availability remains a challenge because of the complex interactions and the lack of GPP measurements at various temporal and spatial scales. Space observations of the sun-induced chlorophyll fluorescence (SIF) electromagnetic signal emitted by plants in the 650-850nm spectral range hold the promise of providing a new view of vegetation photosynthesis on a global basis. Global retrievals of SIF from space have recently been achieved from a number of spaceborne spectrometers originally intended for atmospheric research. Despite not having been designed for land applications, such instruments have turned out to provide the necessary spectral and radiometric sensitivity for SIF retrieval from space. The first global measurements of SIF were achieved in 2011 from spectra acquired by the Japanese GOSAT mission launched in 2009. The retrieval takes advantage of the high spectral resolution provided by GOSATs Fourier Transform Spectrometer (FTS) which allows the evaluation of the in-filling of solar Fraunhofer lines by SIF. Unfortunately, GOSAT only provides a sparse spatial sampling with individual soundings separated by several hundred kilometers. Complementary, the Global Ozone Monitoring Experiment-2 (GOME-2) instruments onboard MetOp-A and MetOp-B enable SIF retrievals since 2007 with a continuous and global spatial coverage. GOME-2 measures in the red and near-infrared (NIR) spectral regions with a spectral resolution of 0.5 nm and a pixel size of up to 40x40 km2. Most recently, another global and spatially continuous data set of SIF retrievals at 740 nm spanning the 2003-2012 time frame has been produced from ENVISATSCIAMACHY. This observational scenario has been completed by the first fluorescence data from the NASA-JPL OCO-2 mission (launched in July 2014) and the upcoming

  1. Rain-induced emission pulses of NOx and HCHO from soils in African regions after dry spells as viewed by satellite sensors

    NASA Astrophysics Data System (ADS)

    Zörner, Jan; Penning de Vries, Marloes; Beirle, Steffen; Veres, Patrick; Williams, Jonathan; Wagner, Thomas

    2014-05-01

    Outside industrial areas, soil emissions of NOx (stemming from bacterial emissions of NO) represent a considerable fraction of total NOx emissions, and may even dominate in remote tropical and agricultural areas. NOx fluxes from soils are controlled by abiotic and microbiological processes which depend on ambient environmental conditions. Rain-induced spikes in NOx have been observed by in-situ measurements and also satellite observations. However, the estimation of soil emissions over broad geographic regions remains uncertain using bottom-up approaches. Independent, global satellite measurements can help constrain emissions used in chemical models. Laboratory experiments on soil fluxes suggest that significant HCHO emissions from soil can occur. However, it has not been previously attempted to detect HCHO emissions from wetted soils by using satellite observations. This study investigates the evolution of tropospheric NO2 (as a proxy for NOx) and HCHO column densities before and after the first rain fall event following a prolonged dry period in semi-arid regions, deserts as well as tropical regions in Africa. Tropospheric NO2 and HCHO columns retrieved from OMI aboard the AURA satellite, GOME-2 aboard METOP and SCIAMACHY aboard ENVISAT are used to study and inter-compare the observed responses of the trace gases with multiple space-based instruments. The observed responses are prone to be affected by other sources like lightning, fire, influx from polluted air masses, as well measurement errors in the satellite retrieval caused by manifold reasons such as an increased cloud contamination. Thus, much care is taken verify that the observed spikes reflect enhancements in soil emissions. Total column measurements of H2O from GOME-2 give further insight into the atmospheric state and help to explain the increase in humidity before the first precipitation event. The analysis is not only conducted for averages of distinct geographic regions, i.e. the Sahel, but also

  2. Measurements of tropospheric NO2 in Romania using a zenith-sky mobile DOAS system and comparisons with satellite observations.

    PubMed

    Constantin, Daniel-Eduard; Merlaud, Alexis; Van Roozendael, Michel; Voiculescu, Mirela; Fayt, Caroline; Hendrick, François; Pinardi, Gaia; Georgescu, Lucian

    2013-01-01

    In this paper we present a new method for retrieving tropospheric NO2 Vertical Column Density (VCD) from zenith-sky Differential Optical Absorption Spectroscopy (DOAS) measurements using mobile observations. This method was used during three days in the summer of 2011 in Romania, being to our knowledge the first mobile DOAS measurements peformed in this country. The measurements were carried out over large and different areas using a mobile DOAS system installed in a car. We present here a step-by-step retrieval of tropospheric VCD using complementary observations from ground and space which take into account the stratospheric contribution, which is a step forward compared to other similar studies. The detailed error budget indicates that the typical uncertainty on the retrieved NO2tropospheric VCD is less than 25%. The resulting ground-based data set is compared to satellite measurements from the Ozone Monitoring Instrument (OMI) and the Global Ozone Monitoring Experiment-2 (GOME-2). For instance, on 18 July 2011, in an industrial area located at 47.03°N, 22.45°E, GOME-2 observes a tropospheric VCD value of (3.4 ± 1.9) × 1015 molec./cm2, while average mobile measurements in the same area give a value of (3.4 ± 0.7) × 10(15) molec./cm2. On 22 August 2011, around Ploiesti city (44.99°N, 26.1°E), the tropospheric VCD observed by satellites is (3.3 ± 1.9) × 10(15) molec./cm2 (GOME-2) and (3.2 ± 3.2) × 10(15) molec./cm2 (OMI), while average mobile measurements give (3.8 ± 0.8) × 10(15) molec./cm2. Average ground measurements over "clean areas", on 18 July 2011, give (2.5 ± 0.6) × 10(15) molec./cm2 while the satellite observes a value of (1.8 ± 1.3) × 10(15) molec./cm2. PMID:23519349

  3. Measurements of Tropospheric NO2 in Romania Using a Zenith-Sky Mobile DOAS System and Comparisons with Satellite Observations

    PubMed Central

    Constantin, Daniel-Eduard; Merlaud, Alexis; Van Roozendael, Michel; Voiculescu, Mirela; Fayt, Caroline; Hendrick, François; Pinardi, Gaia; Georgescu, Lucian

    2013-01-01

    In this paper we present a new method for retrieving tropospheric NO2 Vertical Column Density (VCD) from zenith-sky Differential Optical Absorption Spectroscopy (DOAS) measurements using mobile observations. This method was used during three days in the summer of 2011 in Romania, being to our knowledge the first mobile DOAS measurements peformed in this country. The measurements were carried out over large and different areas using a mobile DOAS system installed in a car. We present here a step-by-step retrieval of tropospheric VCD using complementary observations from ground and space which take into account the stratospheric contribution, which is a step forward compared to other similar studies. The detailed error budget indicates that the typical uncertainty on the retrieved NO2tropospheric VCD is less than 25%. The resulting ground-based data set is compared to satellite measurements from the Ozone Monitoring Instrument (OMI) and the Global Ozone Monitoring Experiment-2 (GOME-2). For instance, on 18 July 2011, in an industrial area located at 47.03°N, 22.45°E, GOME-2 observes a tropospheric VCD value of (3.4 ± 1.9) × 1015 molec./cm2, while average mobile measurements in the same area give a value of (3.4 ± 0.7) × 1015 molec./cm2. On 22 August 2011, around Ploiesti city (44.99°N, 26.1°E), the tropospheric VCD observed by satellites is (3.3 ± 1.9) × 1015 molec./cm2 (GOME-2) and (3.2 ± 3.2) × 1015 molec./cm2 (OMI), while average mobile measurements give (3.8 ± 0.8) × 1015 molec./cm2. Average ground measurements over “clean areas”, on 18 July 2011, give (2.5 ± 0.6) × 1015 molec./cm2 while the satellite observes a value of (1.8 ± 1.3) × 1015 molec./cm2. PMID:23519349

  4. MERIS albedo climatology for FRESCO+ O2 A-band cloud retrieval

    NASA Astrophysics Data System (ADS)

    Popp, C.; Wang, P.; Brunner, D.; Stammes, P.; Zhou, Y.; Grzegorski, M.

    2011-03-01

    A new global albedo climatology for Oxygen A-band cloud retrievals is presented. The climatology is based on MEdium Resolution Imaging Spectrometer (MERIS) Albedomap data and its favourable impact on the derivation of cloud fraction is demonstrated for the FRESCO+ (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm. To date, a relatively coarse resolution (1° × 1°) surface reflectance dataset from GOME (Global Ozone Monitoring Experiment) Lambert-equivalent reflectivity (LER) is used in FRESCO+. The GOME LER climatology does not account for the usually higher spatial resolution of UV/VIS instruments designed for trace gas remote sensing which introduces several artefacts, e.g. in regions with sharp spectral contrasts like coastlines or over bright surface targets. Therefore, MERIS black-sky albedo (BSA) data from the period October 2002 to October 2006 were aggregated to a grid of 0.25° × 0.25° for each month of the year and for different spectral channels. In contrary to other available surface reflectivity datasets, MERIS includes channels at 754 nm and 775 nm which are located close to the spectral windows required for O2 A-band cloud retrievals. The MERIS BSA in the near-infrared compares well to Moderate Resolution Imaging Spectroradiometer (MODIS) derived BSA with an average difference lower than 1% and a correlation coefficient of 0.98. However, when relating MERIS BSA to GOME LER a distinctly lower correlation (0.80) and enhanced scatter is found. Effective cloud fractions from two exemplary months (January and July 2006) of Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) data were subsequently derived with FRESCO+ and compared to those from the Heidelberg Iterative Cloud Retrieval Utilities (HICRU) algorithm. The MERIS climatology generally improves FRESCO+ effective cloud fractions. In particular small cloud fractions are in better agreement with HICRU. This is of importance for atmospheric trace gas

  5. MERIS albedo climatology for FRESCO+ O2 A-band cloud retrieval

    NASA Astrophysics Data System (ADS)

    Popp, C.; Wang, P.; Brunner, D.; Stammes, P.; Zhou, Y.; Grzegorski, M.

    2010-10-01

    A new global albedo climatology for Oxygen A-band cloud retrievals is presented. The climatology is based on MEdium Resolution Imaging Spectrometer (MERIS) Albedomap data and its favourable impact on the derivation of cloud fraction is demonstrated for the FRESCO+ (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm. To date, a relatively coarse resolution (1° × 1°) surface reflectance dataset from GOME (Global Ozone Monitoring Experiment) Lambert-equivalent reflectivity (LER) is used in FRESCO+. The GOME LER climatology does not account for the usually higher spatial resolution of UV/VIS instruments designed for trace gas remote sensing which introduces several artefacts, e.g. in regions with sharp spectral contrasts like coastlines or over bright surface targets. Therefore, MERIS black-sky albedo (BSA) data from the period October 2002 to October 2006 were aggregated to a grid of 0.25° × 0.25° for each month of the year and for different spectral channels. In contrary to other available surface reflectivity datasets, MERIS includes channels at 754 nm and 775 nm which are located close to the spectral windows required for O2 A-band cloud retrievals. The MERIS BSA in the near infrared compares well to Moderate Resolution Imaging Spectroradiometer (MODIS) derived BSA with an average difference lower than 1% and a correlation coefficient of 0.98. However, when relating MERIS BSA to GOME LER a distinctly lower correlation (0.80) and enhanced scatter is found. Effective cloud fractions from two exemplary months (January and July 2006) of Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) data were subsequently derived with FRESCO+ and compared to those from the Heidelberg Iterative Cloud Retrieval Utilities (HICRU) algorithm. The MERIS climatology generally improves FRESCO+ effective cloud fractions. In particular small cloud fractions are in better agreement with HICRU. This is of importance for atmospheric trace gas

  6. PREFACE: High Performance Computing Symposium 2013 (HPCS 2013)

    NASA Astrophysics Data System (ADS)

    Dursi, Jonathan; Mohieddin Abukhdeir, Nasser; Daley, Mark; Jurisica, Igor; Mewhort, Doug; Meyer, Ralf; Slater, Gary

    2014-10-01

    The Program committee of HPCS2013 would like to thank those who contributed to HPCS2013, through the technical program, the Birds of Feather sessions, the vendor overviews, the networking sessions, or for attending and grilling the speakers in all of theses sessions with great questions and contributing to fantastic discussions. We'd particularly like to highlight the best paper award presented at the conference, going to ''The Making of Big Brain'', presented by Marc-Étienne Rousseau for the Big Brain team; the best student paper for ''Towards a Resource Reservation Approach for an Opportunistic Computing Environment'', presented by Eliza Gomes; and the best visualization, to a movie of an amazing globe-to-individual-building level simulation of the evolution of a toxic plume over a city, presented by Bertrand Denis of the Canadian Meteorological Centre. It was a great conference, and we look forward to seeing you in Halifax for HPCS2014!

  7. Applications of Solar Induced Fluorescence (SIF) to Constrain Global Photosynthesis

    NASA Astrophysics Data System (ADS)

    Parazoo, N.; Frankenberg, C.; Bowman, K. W.

    2015-12-01

    Chlorophyll fluorescence has been a major tool for basic research in photosynthesis for nearly a century. Recently, it was discovered that solar induced fluorescence (SIF) can be accurately retrieved from space using high spectral resolution radiances from the Japanese GOSAT and European GOME-2 instruments. Over the last five years, global SIF measurements have provided key new insights into the global distribution and functioning of plant photosynthesis, providing a new way to quantify global gross primary production (GPP), detect regional-scale changes in plant productivity in relation to light use efficiency and water stress, disentangle biological contributions to atmospheric CO2 mole fractions, and refine process understanding in terrestrial biosphere models. OCO-2, launched in July 2014, promises to drive further scientific advances through unprecedented sampling density and smaller ground pixel sizes. We highlight some of the key recent research applications of satellite SIF, discuss future research directions, and present first results from OCO-2.

  8. Will modeling demographic differences in xylem vulnerability and stomatal closure in tropical trees improve drought response predictions of tropical forests?

    NASA Astrophysics Data System (ADS)

    Powell, T.; da Costa, A. C. L.; Meir, P.; Saleska, S. R.; Moorcroft, P. R.

    2014-12-01

    Chlorophyll fluorescence has been a major tool for basic research in photosynthesis for nearly a century. Recently, it was discovered that solar induced fluorescence (SIF) can be accurately retrieved from space using high spectral resolution radiances from the Japanese GOSAT and European GOME-2 instruments. Over the last five years, global SIF measurements have provided key new insights into the global distribution and functioning of plant photosynthesis, providing a new way to quantify global gross primary production (GPP), detect regional-scale changes in plant productivity in relation to light use efficiency and water stress, disentangle biological contributions to atmospheric CO2 mole fractions, and refine process understanding in terrestrial biosphere models. OCO-2, launched in July 2014, promises to drive further scientific advances through unprecedented sampling density and smaller ground pixel sizes. We highlight some of the key recent research applications of satellite SIF, discuss future research directions, and present first results from OCO-2.

  9. Advances in Remote Sensing of Vegetation Merging NDVI, Soil Moisture, and Chlorophyll Fluorescence

    NASA Astrophysics Data System (ADS)

    Tucker, Compton

    2016-04-01

    I will describe an advance in remote sensing of vegetation in the time domain that combines simultaneous measurements of the normalized difference vegetation index, soil moisture, and chlorophyll fluorescence, all from different satellite sensors but acquired for the same areas at the same time step. The different sensor data are MODIS NDVI data from both Terra and Aqua platforms, soil moisture data from SMOS & SMP (aka SMAP but with only the passive radiometer), and chlorophyll fluorescence data from GOME-2. The complementary combination of these data provide important crop yield information for agricultural production estimates at critical phenological times in the growing season, provide a scientific basis to map land degradation, and enable quantitative determination of the end of the growing season in temperate zones.

  10. Flux Calculation Using CARIBIC DOAS Aircraft Measurements: SO2 Emission of Norilsk

    NASA Technical Reports Server (NTRS)

    Walter, D.; Heue, K.-P.; Rauthe-Schoech, A.; Brenninkmeijer, C. A. M.; Lamsal, L. N.; Krotkov, N. A.; Platt, U.

    2012-01-01

    Based on a case-study of the nickel smelter in Norilsk (Siberia), the retrieval of trace gas fluxes using airborne remote sensing is discussed. A DOAS system onboard an Airbus 340 detected large amounts of SO2 and NO2 near Norilsk during a regular passenger flight within the CARIBIC project. The remote sensing data were combined with ECMWF wind data to estimate the SO2 output of the Norilsk industrial complex to be around 1 Mt per year, which is in agreement with independent estimates. This value is compared to results using data from satellite remote sensing (GOME, OMI). The validity of the assumptions underlying our estimate is discussed, including the adaptation of this method to other gases and sources like the NO2 emissions of large industries or cities.

  11. Undersampling Correction for Array Detector-Based Satellite Spectrometers

    NASA Technical Reports Server (NTRS)

    Chance, Kelly; Kurosu, Thomas P.; Sioris, Christopher E.

    2004-01-01

    Array detector-based instruments are now fundamental to measurements of ozone and other atmospheric trace gases from space in the ultraviolet, visible, and infrared. The present generation of such instruments suffers, to a greater or lesser degree, from undersampling of the spectra, leading to difficulties in the analysis of atmospheric radiances. We provide extended analysis of the undersampling suffered by modem satellite spectrometers, which include Global Ozone Monitoring Experiment (GOME), Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), Ozone Monitoring Instrument (OMI), and Ozone Mapping and Profiler Suite (OMPS). The analysis includes basic undersampling, the effects of binning into separate detector pixels, and the application of high-resolution Fraunhofer spectral data to correct for undersampling in many useful cases.

  12. Gastric Cancer in the Excluded Stomach 10 Years after Gastric Bypass

    PubMed Central

    Tinoco, Augusto; Gottardi, Lorena F.; Boechat, Eduardo D.

    2015-01-01

    According to the Brazilian health authorities, around 2,000 new cases of gastric cancer emerge in Brazil per year (Instituto Nacional de Câncer José Alencar Gomes da Silva, 2014). Indeed, gastric cancer constitutes the second most common cause of cancer-related mortality worldwide and 95% of such malignancies are adenocarcinomas (De Roover et al., 2006, and Clark et al., 2006). Roux-en-Y gastric bypass (RYGB) is a procedure frequently employed in bariatric surgery but restricted access to the excluded stomach means that discovery of gastric lesions is difficult, and diagnosis and treatment may be delayed. We report herein a case of gastric adenocarcinoma in the excluded stomach of a patient submitted to RYGB with the purpose of illustrating the difficulty of diagnosing and treating this rare condition. PMID:26229705

  13. [Satisfaction and motivation in nursing].

    PubMed

    Antunes, A V; Sant Anna, L R

    1996-01-01

    Something which affects the internal balance of a hospital system is its workers satisfaction/motivation rate. According to observed and discussed facts regarding our professional environment and also according to some authors assessments (Alcântara and Ribas Gomes), it seems that there is an insatisfaction among those people in relation to their chores. Therefore, based on Herzberg et all. two factors theory and more specifically on Maximiano interpretation of that theory, we made a research aiming at verifying the satisfaction and motivation in nurse work; on how satisfied/insatisfied nurses feel in their work, and if there is a relationship between job conditions (hygienic factors) with satisfaction, and between job features (motivation factors) with motivation.

  14. Total ozone trends and variability during 1979-2012 from merged datasets of various satellites

    NASA Astrophysics Data System (ADS)

    Chehade, W.; Burrows, J. P.; Weber, M.

    2013-11-01

    The study presents a~long term statistical trend analysis of total ozone datasets obtained from various satellites. A multi-variate linear regression was applied to annual mean zonal mean data using various natural and anthropogenic explanatory variables that represent dynamical and chemical processes which modify global ozone distributions in a changing climate. The study investigated the magnitude and zonal distribution of the different atmospheric chemical and dynamical factors to long-term total ozone changes. The regression model included the equivalent effective stratospheric chlorine (EESC), the 11 yr solar cycle, the Quasi-Biennial Oscillation (QBO), stratospheric aerosol loading describing the effects from major volcanic eruptions, the El Niño/Southern Oscillation (ENSO), the Arctic and Antarctic Oscillation (AO/AAO), and accumulated eddy heat flux (EHF), the latter representing changes due to the Brewer-Dobson circulation. The total ozone column dataset used here comprises the SBUV/TOMS/OMI merged data (1979-2012) MOD V8.0, the SBUV/SBUV-2 merged V8.6 and the merged GOME/SCIAMACHY/GOME-2 (GSG) WFDOAS merged data (1995-2012). The trend analysis was performed for twenty six 5° wide latitude bands from 65° S to 65° N, the analysis explained most of the ozone variability. The results show that QBO dominates the ozone variability in the tropics (±7 DU) while at higher latitudes, the dynamical indices, AO/AAO and eddy heat flux, have substantial influence on total ozone variations by up to ±10 DU. Volcanic aerosols are only prominent during the eruption periods and these together with the ENSO signal are more evident in the Northern Hemisphere. The signature of the solar cycle is evident over all latitudes and contributes about 10 DU from solar maximum to solar minimum. EESC is found to be a main contributor to the long-term ozone decline and the trend changes after the end of 1990s. A positive significant trend in total ozone columns is found after 1997

  15. Estimating the volcanic emission rate and atmospheric lifetime of SO2 from space: a case study for Kīlauea volcano, Hawai'i

    USGS Publications Warehouse

    Beirle, Steffen; Hörmann, Christoph; Penning de Vries, Malouse; Dörner, Stefan; Kern, Christoph; Wagner, Thomas

    2014-01-01

    We present an analysis of SO2 column densities derived from GOME-2 satellite measurements for the Kīlauea volcano (Hawai`i) for 2007–2012. During a period of enhanced degassing activity in March–November 2008, monthly mean SO2 emission rates and effective SO2 lifetimes are determined simultaneously from the observed downwind plume evolution and meteorological wind fields, without further model input. Kīlauea is particularly suited for quantitative investigations from satellite observations owing to the absence of interfering sources, the clearly defined downwind plumes caused by steady trade winds, and generally low cloud fractions. For March–November 2008, the effective SO2 lifetime is 1–2 days, and Kīlauea SO2 emission rates are 9–21 kt day−1, which is about 3 times higher than initially reported from ground-based monitoring systems.

  16. Global 3-D Modeling Studies Of Tropospheric Ozone And Related Gases

    NASA Technical Reports Server (NTRS)

    Jacob, Daniel J.; Logan, Jennifer A.

    2003-01-01

    Our research was targeted at three issues: (1) the factors controlling ozone in the tropical troposphere, (2) the Asian outflow of ozone and its precursors, and (3) the causes of decadal trends observed in ozone and CO. We have also used support from this ACMAP grant to (1) work with Kelly Chance on the retrieval and interpretation of HCHO and NO2 observations from GOME, and (2) develop GEOS-CHEM into a versatile model supporting the work of a large number of users including outside Harvard. ACMAP has provided the core support for GEOS-CHEM development. Applications of the GEOS-CHEM model with primary support from ACMAP are discussed below. A list of publications resulting from this grant is given at the end of the report.

  17. Assessing potential changes of weather-related risk on chestnut productivity

    NASA Astrophysics Data System (ADS)

    Pereira, Mário; Calheiros, Tomas; Pinto, Joaquim; Caramelo, Liliana

    2013-04-01

    Weather conditions play an important role during different phases of the vegetative cycle of the chestnut trees and, consequently, several meteorological parameters seem to be associated chestnut productivity (Heiniger and Conedera, 1992, Cesaraccio et al., 2001, Wilczynski and Podalski, 2007, Gomes-Laranjo et al., 2008, Dinis et al., 2011, Pereira et al., 2011). Observed data from European Climate Assessment and simulated data by COSMO-CLM model for the actual (C20) and future (A1B and B1) climate scenarios were used in this study to: (i) assess the model ability to reproduce weather parameters distribution; and, (ii) to assess future changes in the distribution of meteorological parameters which play an important role in the productivity of chestnut for different future periods. Results points to statistical significant changes in the mean and in variance in the future, more prominent in temperature than in precipitation based parameters. Changes in precipitation will be more significant in Northwestern Iberian Peninsula and France in the end of the 21st century for A1B scenario conditions. As expected, more significant changes will be expected to occur during spring and summer, in the Mediterranean areas and in the later period. The number of days with Tmax<28°C will generally decrease in both scenarios, while the changes in the number of days with 24°C

  18. Bioactive Compounds Found in Brazilian Cerrado Fruits

    PubMed Central

    Bailão, Elisa Flávia Luiz Cardoso; Devilla, Ivano Alessandro; da Conceição, Edemilson Cardoso; Borges, Leonardo Luiz

    2015-01-01

    Functional foods include any natural product that presents health-promoting effects, thereby reducing the risk of chronic diseases. Cerrado fruits are considered a source of bioactive substances, mainly phenolic compounds, making them important functional foods. Despite this, the losses of natural vegetation in the Cerrado are progressive. Hence, the knowledge propagation about the importance of the species found in Cerrado could contribute to the preservation of this biome. This review provides information about Cerrado fruits and highlights the structures and pharmacologic potential of functional compounds found in these fruits. Compounds detected in Caryocar brasiliense Camb. (pequi), Dipteryx alata Vog. (baru), Eugenia dysenterica DC. (cagaita), Eugenia uniflora L. (pitanga), Genipa americana L. (jenipapo), Hancornia speciosa Gomes (mangaba), Mauritia flexuosa L.f. (buriti), Myrciaria cauliflora (DC) Berg (jabuticaba), Psidium guajava L. (goiaba), Psidium spp. (araçá), Solanum lycocarpum St. Hill (lobeira), Spondias mombin L. (cajá), Annona crassiflora Mart. (araticum), among others are reported here. PMID:26473827

  19. Arctic tropospheric ozone depletion during spring 2008 : Source regions and transport

    NASA Astrophysics Data System (ADS)

    Koo, J.; Wang, Y.; Choi, S.; Kurosu, T. P.; Chance, K.; Weinheimer, A. J.; Ryerson, T. B.; Oltmans, S. J.; Hair, J. W.

    2009-12-01

    Ozone depletion events (ODEs) during the ARCTAS and ARCPAC experiments in spring 2008 are analyzed using backtrajectory analysis with meteorological fields simulated by the polar version of MM5. Satellite observations of BrO by OMI and GOME2 instruments are also used. We identify two common ODE source regions in the Canadian archipelagoes and north of Alaska and Siberia. The vertical distribution of backtrajectories indicates that ODEs occur mainly in the lower atmosphere. Correlation analysis suggests that ODEs at Barrow are more transport-driven than those at Alert. The combination of NASA DC-8 and NOAA WP-3D in situ observations implies a large gradient of BrO within a relatively small spatial scale; this feature was not apparent in satellite BrO measurements. The backtrajectory analysis also identifies a region with a high probability of enhanced BrO concentrations, contrary to satellite observations.

  20. Bioactive Compounds Found in Brazilian Cerrado Fruits.

    PubMed

    Bailão, Elisa Flávia Luiz Cardoso; Devilla, Ivano Alessandro; da Conceição, Edemilson Cardoso; Borges, Leonardo Luiz

    2015-01-01

    Functional foods include any natural product that presents health-promoting effects, thereby reducing the risk of chronic diseases. Cerrado fruits are considered a source of bioactive substances, mainly phenolic compounds, making them important functional foods. Despite this, the losses of natural vegetation in the Cerrado are progressive. Hence, the knowledge propagation about the importance of the species found in Cerrado could contribute to the preservation of this biome. This review provides information about Cerrado fruits and highlights the structures and pharmacologic potential of functional compounds found in these fruits. Compounds detected in Caryocar brasiliense Camb. (pequi), Dipteryx alata Vog. (baru), Eugenia dysenterica DC. (cagaita), Eugenia uniflora L. (pitanga), Genipa americana L. (jenipapo), Hancornia speciosa Gomes (mangaba), Mauritia flexuosa L.f. (buriti), Myrciaria cauliflora (DC) Berg (jabuticaba), Psidium guajava L. (goiaba), Psidium spp. (araçá), Solanum lycocarpum St. Hill (lobeira), Spondias mombin L. (cajá), Annona crassiflora Mart. (araticum), among others are reported here. PMID:26473827

  1. Assessment of weather risk on chestnut production

    NASA Astrophysics Data System (ADS)

    Pereira, M. G.; Gomes-Laranjo, J.; Caramelo, L.

    2009-04-01

    Meteorological conditions play a fundamental role during entire chestnut tree vegetative cycle. Chestnut trees are well adapted to mean year temperatures of 8-15°C, requires monthly mean temperatures greater than 10°C during 6 months (Gomes-Laranjo et al. 2008) and its pollen only germinates at relatively high temperatures of 27-30°C (Bounous, 2002). Photosynthesis of an adult tree is highly dependent of temperature. Photosynthesis is maximal at 24-28°C but it is inhibited for temperatures greater than 32°C (Gomes-Laranjo et al., 2005, 2006). Furthermore, there are significant differences between chestnut trees cultivated in northfaced orchads in relation to those cultivated in the southfaced and between leaves from different sides of the chestnut canopy because they receive different amounts of radiant energy and consequently they grow under different mean daily air temperature. The objective of this work was to assess the role of weather on chestnut production variability. This study was performed for the 28 years period defined between 1980 and 2007 and it was based on annual values of chestnut production and total area of production, at national level, provided by INE, the National Institute of Statistics of Portugal. The meteorological data used was provided by Meteored (http://www.meteored.com/) and includes daily values of precipitation, wind speed, and mean, maximum and minimum air temperature. All meteorological variables were tested as potential predictors by means of a simple correlation analysis. Multiple time intervals were considered in this the analysis, which consist in moving intervals of constant length and forward and backward evolutionary intervals. Results show that some meteorological variables present significant correlation with chestnut productivity particularly in the most relevant periods of the chestnut tree cycle, like the previous winter, the flushing phase and the maturation period. A regression model based on the winter (January

  2. The evolution of a Pluto-like system during the migration of the ice giants

    NASA Astrophysics Data System (ADS)

    Pires, Pryscilla; Giuliatti Winter, Silvia M.; Gomes, Rodney S.

    2015-01-01

    The planetary migration of the Solar System giant planets in the framework of the Nice model (Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F. [2005]. Nature 435,459-461; Morbidelli, A., Levison, H.F., Tsiganis, K., Gomes, R. [2005]. Nature 435, 462-465; Gomes, R., Levison, H.F., Tsiganis, K., Morbidelli, A. [2005]. Nature 435, 466-469) creates a dynamical mechanism which can be used to explain the distribution of objects currently observed in the Kuiper belt (e.g., Levison, H.F., Morbidelli, A., Vanlaerhoven, C., Gomes, R., Tsiganis, K. [2008]. Icarus 196, 258-273). Through this mechanism the planetesimals within the disk, heliocentric distance ranging from beyond Neptune's orbit to approximately 34 AU, are delivered to the belt after a temporary eccentric phase of Uranus and Neptune's orbits. We reproduced the mechanism proposed by Levison et al. to implant bodies into the Kuiper belt. The capture of Pluto into the external 3:2 mean motion resonance with Neptune is associated with this gravitational scattering model. We verified the existence of several close encounters between the ice giants and the planetesimals during their outward radial migration, then we believe that the analysis of the dynamical history of the plutonian satellites during this kind of migration is important, and would provide some constrains about their place of formation - within the primordial planetesimal disk or in situ. We performed N-body simulations and recorded the trajectories of the planetesimals during close approaches with Uranus and Neptune. Close encounters with Neptune are the most common, reaching approximately 1200 in total. A Pluto similarly sized body assumed the hyperbolic trajectories of the former primordial planetesimal with respect to those giant planets. We assumed the current mutual orbital configuration and sizes for Pluto's satellites, then we found that the rate of destruction of systems similar to that of Pluto with closest approaches to Uranus or Neptune

  3. Quantifying Aerosol Types and Their Impact on Trace Gas Retrievals From Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Natraj, V.; Boesch, H.; Yung, Y. L.

    2005-12-01

    One of the major sources of uncertainty in the retrieval of trace gas abundances from space-borne measurements is the type, amount and vertical distribution of aerosols in the atmosphere. Optical properties were derived for the broad classification of aerosol types investigated by Kahn et al. (2001), taking polarization into account. Examination of the scattering matrix elements resulted in a smaller set of independent aerosol types whose radiative effects were different. Weighting functions were then calculated for each of these types, assuming exponentially tailing aerosol concentration in the troposphere and a Junge distribution for the stratosphere. The different shapes of the weighting functions indicate different amount and distribution of the information content. Implications for trace gas retrievals from satellite-based measurements made by polarization-sensitive instruments (such as those on OMI, GOME, SCIAMACHY and OCO) will be discussed.

  4. [Satisfaction and motivation in nursing].

    PubMed

    Antunes, A V; Sant Anna, L R

    1996-01-01

    Something which affects the internal balance of a hospital system is its workers satisfaction/motivation rate. According to observed and discussed facts regarding our professional environment and also according to some authors assessments (Alcântara and Ribas Gomes), it seems that there is an insatisfaction among those people in relation to their chores. Therefore, based on Herzberg et all. two factors theory and more specifically on Maximiano interpretation of that theory, we made a research aiming at verifying the satisfaction and motivation in nurse work; on how satisfied/insatisfied nurses feel in their work, and if there is a relationship between job conditions (hygienic factors) with satisfaction, and between job features (motivation factors) with motivation. PMID:9295747

  5. Comparison of Spectral Radiance Calibration Techniques Used for Backscatter Ultraviolet Satellite Instruments

    NASA Technical Reports Server (NTRS)

    Kowalewski, Matthew G.; Janz, Scott

    2014-01-01

    Methods for determining the absolute radiometric calibration sensitivities of backscatter ultraviolet (BUV) satellite instruments are compared as part of an effort to minimize pre-launch calibration errors. An internally illuminated integrating sphere source has been used for the Shuttle Solar BUV (SSBUV), Total Ozone Mapping Spectrometer (TOMS), Ozone Mapping Instrument (OMI), and Global Ozone Monitoring Experiment 2 (GOME-2) using standardized procedures traceable to national standards. These sphere-based sensitivities agree to within three percent [k equals 2] relative to calibrations performed using an external diffuser illuminated by standard irradiance sources, the customary radiance calibration method for BUV instruments. The uncertainty for these calibration techniques as implemented at the NASA Goddard Space Flight Centers Radiometric Calibration and Development Laboratory is shown to be 4 percent at 250nm [k equals 2] when using a single traceable calibration standard. Significant reduction in the uncertainty of nearly 1 percent is demonstrated when multiple calibration standards are used.

  6. What's that smell? Hydrogen sulphide transport from Bardarbunga to Scandinavia

    NASA Astrophysics Data System (ADS)

    Grahn, Håkan; von Schoenberg, Pontus; Brännström, Niklas

    2015-09-01

    On Sep 9 2014 several incidences of foul smell (rotten eggs) were reported on the coast of Norway (in particular in the vicinity of Molde) and then on Sep 10 in the interior parts of county Västerbotten, Sweden. One of the theories that were put forward was that the foul smell was due to degassing of the Bardarbunga volcano on Iceland. Using satellite images (GOME-1,-2) of the sulphur dioxide, SO2, contents in the atmosphere surrounding Iceland to estimate flux of SO2 from the volcano and an atmospheric transport model, PELLO, we vindicate this theory: we argue that the cause for the foul smell was hydrogen sulphide originating from Bardarbunga. The model concentrations are also compared to SO2 concentration measurements from Muonio, Finland.

  7. Semiannual NO2 plumes during the monsoon transition periods over the central Indian Ocean

    NASA Astrophysics Data System (ADS)

    Kunhikrishnan, T.; Lawrence, Mark G.; von Kuhlmann, Rolf; Richter, Andreas; Ladstätter-Weißenmayer, Annette; Burrows, John P.

    2004-04-01

    In this study we identify recurring plumes of tropospheric NO2 originating from Africa and Indonesia during the monsoon transition periods over the central Indian Ocean (CIO, 5°N-30°S, 55°E-95°E), based on GOME satellite observations and global model (MATCH-MPIC) simulations. Despite the relatively short lifetime of NOx, these strong plumes can develop due to the pronounced anti-cyclonic circulation over the CIO, and the weak maritime convection, which limits vertical mixing. Model results indicate that the plumes are mainly transported in the middle troposphere (MT). Thus, the CIO in the Southern Hemisphere (SH) is not always as pristine as found in INDOEX during the winter monsoon.

  8. Retrieval Studies with LIDORT

    NASA Technical Reports Server (NTRS)

    Bhartia, P. K. (Technical Monitor); Spurr, Robert J. D.; Chance, K. V.

    2003-01-01

    This short program of LIDORT-based research in atmospheric trace gas retrieval was conducted over the 1 year period 01 July 2002 to 30 June 2003. After consultation with the NASA reporting officer, the first of the two original proposal activities (development of a direct-fitting total O3 column retrieval algorithm with operational capability for GOME data) was replaced by other tasks. The three activities addressed were: (1) Sensitivity studies for column and profile retrieval of NO2 distributions from a new generation of multi-axis ground-based spectrometers; (2) use of the LIDORT-RRS model to determine the effect of inelastic rotational Raman scattering at SBUV wavelengths; (3) an examination of ozone profile weighting functions in the presence of optically thick tropospheric clouds.

  9. Validation of the Updated SAO OMI Formaldehyde Retrieval

    NASA Astrophysics Data System (ADS)

    Gonzalez Abad, G.; Liu, X.; Liu, C.; Nowlan, C. R.; Chance, K.; Fried, A.; Janz, S. J.; Kanaya, Y.; Puentedura, O.

    2014-12-01

    The new SAO OMI formaldehyde retrieval, version v3.0.2 publicly released in June 2014, introduces major changes with respect to the previous version of the product. These changes include optimization of fitting window and fitting parameters, update of reference cross sections, reference sector normalization to the Pacific Ocean and a new air mass factor calculation. In this context it is necessary to assess the accuracy of the new product and perform a validation exercise. We compare the new data with other satellite retrievals from OMI, GOME-2 and SCIAMACHY performed by the Belgian Institute for Space Aeronomy, with in situ airborne measurements recorded using a Difference Frequency Generation Absorption Spectrometer (DFGAS) instrument, with aircraft passive remote sensing retrievals from the ACAM and GeoTASO instruments recorded during the DISCOVER-AQ field campaigns in Maryland and Texas and with ground-based DOAS measurements.

  10. Abrolhos Bank Reef Health Evaluated by Means of Water Quality, Microbial Diversity, Benthic Cover, and Fish Biomass Data

    PubMed Central

    Bruce, Thiago; Meirelles, Pedro M.; Garcia, Gizele; Paranhos, Rodolfo; Rezende, Carlos E.; de Moura, Rodrigo L.; Filho, Ronaldo-Francini; Coni, Ericka O. C.; Vasconcelos, Ana Tereza; Amado Filho, Gilberto; Hatay, Mark; Schmieder, Robert; Edwards, Robert; Dinsdale, Elizabeth; Thompson, Fabiano L.

    2012-01-01

    The health of the coral reefs of the Abrolhos Bank (southwestern Atlantic) was characterized with a holistic approach using measurements of four ecosystem components: (i) inorganic and organic nutrient concentrations, [1] fish biomass, [1] macroalgal and coral cover and (iv) microbial community composition and abundance. The possible benefits of protection from fishing were particularly evaluated by comparing sites with varying levels of protection. Two reefs within the well-enforced no-take area of the National Marine Park of Abrolhos (Parcel dos Abrolhos and California) were compared with two unprotected coastal reefs (Sebastião Gomes and Pedra de Leste) and one legally protected but poorly enforced coastal reef (the “paper park” of Timbebas Reef). The fish biomass was lower and the fleshy macroalgal cover was higher in the unprotected reefs compared with the protected areas. The unprotected and protected reefs had similar seawater chemistry. Lower vibrio CFU counts were observed in the fully protected area of California Reef. Metagenome analysis showed that the unprotected reefs had a higher abundance of archaeal and viral sequences and more bacterial pathogens, while the protected reefs had a higher abundance of genes related to photosynthesis. Similar to other reef systems in the world, there was evidence that reductions in the biomass of herbivorous fishes and the consequent increase in macroalgal cover in the Abrolhos Bank may be affecting microbial diversity and abundance. Through the integration of different types of ecological data, the present study showed that protection from fishing may lead to greater reef health. The data presented herein suggest that protected coral reefs have higher microbial diversity, with the most degraded reef (Sebastião Gomes) showing a marked reduction in microbial species richness. It is concluded that ecological conditions in unprotected reefs may promote the growth and rapid evolution of opportunistic microbial

  11. Observing the Anthropocene from Space

    NASA Astrophysics Data System (ADS)

    Burrows, John

    The industrial revolution, which began in the UK in the late 18th century, has been fuelled by the use of cheap energy from fossil fuel combustion. It has facilitated a dramatic rise in both the human population, now above 7 Billion with 50% now living in urban agglomerations, and its standard of living. It is anticipated that by 2050 there will be of the order of 8.3 to 10 billion people, 75% living in cities. Anthropogenic activity has resulted in pollution from the local to the global scale changes in land use, the destruction of stratospheric ozone, the modification of biogeochemical cycling, acid deposition, impacted on ecosystems and ecosystem services, destruction of biodiversity and climate change. The impact of man has moved the earth from the Holocene to the new geological epoch of the Anthropocene. To improve our understanding of the earth atmosphere system and the accuracy of the prediction of its future changes, knowledge of the amounts and distributions of trace atmospheric constituents are essential -“One cannot manage what is not measured”. An integrated observing system, comprising ground and space based segments is required to improve our science and to provide an evidence base needed for environmental policymakers. Passive remote sensing measurements made of the up-welling radiation at the top of the atmosphere from instrumentation on space borne platforms provide a unique opportunity to retrieve globally atmospheric composition. This presentation describes results from the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY on ESA Envsiat 2002 to 2012) and its spin offs GOME (Global Ozone Monitoring Experiment ESA ERS-2 1995 to 2011) and GOME-2 (ESA/EUMETSAT Metop series). The potential of the SCIAMACHY successors Sentinel 5, CarbonSat, and SCIA-ISS will also be addressed.

  12. Clustering of gene ontology terms in genomes.

    PubMed

    Tiirikka, Timo; Siermala, Markku; Vihinen, Mauno

    2014-10-25

    Although protein coding genes occupy only a small fraction of genomes in higher species, they are not randomly distributed within or between chromosomes. Clustering of genes with related function(s) and/or characteristics has been evident at several different levels. To study how common the clustering of functionally related genes is and what kind of functions the end products of these genes are involved, we collected gene ontology (GO) terms for complete genomes and developed a method to detect previously undefined gene clustering. Exhaustive analysis was performed for seven widely studied species ranging from human to Escherichia coli. To overcome problems related to varying gene lengths and densities, a novel method was developed and a fixed number of genes were analyzed irrespective of the genome span covered. Statistically very significant GO term clustering was apparent in all the investigated genomes. The analysis window, which ranged from 5 to 50 consecutive genes, revealed extensive GO term clusters for genes with widely varying functions. Here, the most interesting and significant results are discussed and the complete dataset for each analyzed species is available at the GOme database at http://bioinf.uta.fi/GOme. The results indicated that clusters of genes with related functions are very common, not only in bacteria, in which operons are frequent, but also in all the studied species irrespective of how complex they are. There are some differences between species but in all of them GO term clusters are common and of widely differing sizes. The presented method can be applied to analyze any genome or part of a genome for which descriptive features are available, and thus is not restricted to ontology terms. This method can also be applied to investigate gene and protein expression patterns. The results pave a way for further studies of mechanisms that shape genome structure and evolutionary forces related to them. PMID:24995610

  13. An exemplary case of a bromine explosion event linked to cyclone development in the Arctic

    NASA Astrophysics Data System (ADS)

    Blechschmidt, A.-M.; Richter, A.; Burrows, J. P.; Kaleschke, L.; Strong, K.; Theys, N.; Weber, M.; Zhao, X.; Zien, A.

    2015-09-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by GOME-2 on board the MetOp-A satellite over Arctic sea ice in polar spring. These plumes are often transported by high latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. However, only few studies have focused on the role of polar weather systems in the development, duration and transport of tropospheric BrO plumes during bromine explosion events. The latter are caused by an autocatalytic chemical chain reaction associated with tropospheric ozone depletion and initiated by the release of bromine from cold brine covered ice or snow to the atmosphere. In this manuscript, a case study investigating a comma-shaped BrO plume which developed over the Beaufort Sea and was observed by GOME-2 for several days is presented. By making combined use of satellite data and numerical models, it is shown that the occurrence of the plume was closely linked to frontal lifting in a polar cyclone and that it most likely resided in the lowest 3 km of the troposphere. In contrast to previous case studies, we demonstrate that the dry conveyor belt, a potentially bromine-rich stratospheric air stream which can complicate interpretation of satellite retrieved tropospheric BrO, is spatially separated from the observed BrO plume. It is concluded that weather conditions associated with the polar cyclone favored the bromine activation cycle and blowing snow production, which may have acted as a bromine source during the bromine explosion event.

  14. An improved glyoxal retrieval from OMI measurements

    NASA Astrophysics Data System (ADS)

    Alvarado, L. M. A.; Richter, A.; Vrekoussis, M.; Wittrock, F.; Hilboll, A.; Schreier, S. F.; Burrows, J. P.

    2014-12-01

    Satellite observations from the SCIAMACHY, GOME-2 and OMI spectrometers have been used to retrieve atmospheric columns of glyoxal (CHOCHO) with the DOAS method. High CHOCHO levels were found over regions with large biogenic and pyrogenic emissions, and hot-spots have been identified over areas of anthropogenic activities. This study focuses on the development of an improved retrieval for CHOCHO from measurements by the OMI instrument. From sensitivity tests, a fitting window and a polynomial degree are determined. Two different approaches to reduce the interference of liquid water absorption over oceanic regions are evaluated, achieving significant reduction of the number of negative columns over clear water regions. The impact of using different absorption cross-sections for water vapour is evaluated and only small differences are found. Finally, a high-temperature (boundary layer ambient: 294 K) absorption cross-section of nitrogen dioxide (NO2) is introduced in the DOAS retrieval to account for potential interferences of NO2 over regions with large anthropogenic emissions, leading to improved fit quality over these areas. A comparison with vertical CHOCHO columns retrieved from GOME-2 and SCIAMACHY measurements over continental regions is performed, showing overall good consistency. However, SCIAMACHY CHOCHO columns are systematically higher than those obtained from the other instruments. Using the new OMI CHOCHO data set, the link between fires and glyoxal columns is investigated for two selected regions in Africa. In addition, mapped averages are computed for a fire event in Russia between mid-July and mid-August 2010. In both cases, enhanced CHOCHO levels are found in close spatial and temporal proximity to elevated levels of MODIS fire radiative power, demonstrating that pyrogenic emissions can be clearly identified in the new OMI CHOCHO product.

  15. Effects of cloud variability on TROPOMI molecular and cloud property products

    NASA Astrophysics Data System (ADS)

    Gimeno García, Sebastián; Schreier, Franz; Trautmann, Thomas; Loyola, Diego; Heinze, Rieke

    In order to guarantee high signal-to-noise ratios, the design of spectrometers aboard spaceborne platforms is a tradeoff between spectral and spatial resolution. Since molecular absorption is highly spectrally dependent, atmospheric composition instruments favor spectral over spatial resolution. The TROPOMI instrument aboard Sentinel 5 Precursor (S5P) will have a spatial resolution of about 7x7 km2 at nadir, which clearly outperforms the resolution of previous atmospheric missions (320x40 km2 for GOME/ERS-2, 120x30 km2 for SCIAMACHY/ENVISAT and 80x40 km2 for GOME-2/Metop-A,B). However, inside a TROPOMI ground pixel there may still be a considerable amount of unresolved cloud variability. In this work, we present a sensitivity study of measured reflectivities as a function of the unresolved cloud variability. For this purpose, we simulate virtual measurements of a TROPOMI-like instrument in cloudy scenes at different spatial resolutions by means of the three-dimensional (3D) radiative transfer model MoCaRT (Monte Carlo Radiative Transfer). The reference inside-pixel cloud microphysical properties are provided by the PArallelized Large-Eddy-Simulation Model (PALM) at a spatial resolution of 10x10 m2 in a 6.4x6.4 km2 domain. The retrieval algorithms of both, atmospheric molecules and cloud properties rely on one-dimensional radiative transfer (RT) models which do not account for neither cloud variability nor 3D RT effects. Moreover, the quality of atmospheric gas retrievals strongly depends on the accuracy of the cloud information. Accordingly, we first analyze the 3D effects on the cloud products by ingesting the 3D simulated spectra (around the oxygen A-band) to the ROCINN_CAL cloud algorithm. In a second step, the impact of the cloud variability on the ozone product is assessed (which also include the indirect impact on cloud properties).

  16. An exemplary case of a bromine explosion event linked to cyclone development in the Arctic

    NASA Astrophysics Data System (ADS)

    Blechschmidt, A.-M.; Richter, A.; Burrows, J. P.; Kaleschke, L.; Strong, K.; Theys, N.; Weber, M.; Zhao, X.; Zien, A.

    2016-02-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by GOME-2 on board the MetOp-A satellite over Arctic sea ice in polar spring. These plumes are often transported by high-latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. However, only few studies have focused on the role of polar weather systems in the development, duration and transport of tropospheric BrO plumes during bromine explosion events. The latter are caused by an autocatalytic chemical chain reaction associated with tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. In this manuscript, a case study investigating a comma-shaped BrO plume which developed over the Beaufort Sea and was observed by GOME-2 for several days is presented. By making combined use of satellite data and numerical models, it is shown that the occurrence of the plume was closely linked to frontal lifting in a polar cyclone and that it most likely resided in the lowest 3 km of the troposphere. In contrast to previous case studies, we demonstrate that the dry conveyor belt, a potentially bromine-rich stratospheric air stream which can complicate interpretation of satellite retrieved tropospheric BrO, is spatially separated from the observed BrO plume. It is concluded that weather conditions associated with the polar cyclone favoured the bromine activation cycle and blowing snow production, which may have acted as a bromine source during the bromine explosion event.

  17. Tropospheric NO2 and HCHO columns derived from ground-based MAX-DOAS system in Guangzhou, China and comparison with satellite observations: First results within the EU FP7 project MarcoPolo

    NASA Astrophysics Data System (ADS)

    Drosoglou, Theano; Kouremeti, Natalia; Bais, Alkis; Zyrichidou, Irene; Li, Shu; Balis, Dimitris; Huang, Zhonghui

    2016-04-01

    A miniature MAX-DOAS system, Phaethon, has been developed at the Laboratory of Atmospheric Physics of the Aristotle University of Thessaloniki, Greece, for ground-based monitoring of column densities of atmospheric gases. Simultaneous measurements with two Phaethon systems at the city centre of Thessaloniki and at a rural location about 30 km away have shown that Phaethon provides NO2 and HCHO tropospheric column measurements of acceptable accuracy under both low and high air-pollution levels. Currently three systems have been deployed in areas with different pollution patterns to support air quality and satellite validation studies. In the framework of the EU FP7 Monitoring and Assessment of Regional air quality in China using space Observations, Project Of Long-term sino-european co-Operation, MarcoPolo project, one of the Phaethon systems has been installed since April 2015 in the Guangzhou region in China. Tropospheric NO2 and HCHO columns derived at Guangzhou during the first 10 months of operation are compared with corresponding retrievals from OMI/Aura and GOME-2/Metop-A and /Metop-B satellite sensors. The area is characterized by humid subtropical monsoon climate and cloud-free conditions are rather rare from early March to mid-October. Despite this limitation and the short period of operation of Phaethon in Guangzhou, the agreement between ground-based and satellite observations is generally good for both NO2 and HCHO. It appears that GOME-2 sensors seem to underestimate the tropospheric NO2, possibly due to their large pixel size, whereas the comparison with OMI data is better, especially when a small cloud fraction (< 0.2) is used for cloud screening.

  18. Global simulation of canopy scale sun-induced chlorophyll fluorescence with a 3 dimensional radiative transfer model

    NASA Astrophysics Data System (ADS)

    Kobayashi, H.; Yang, W.; Ichii, K.

    2015-12-01

    Global simulation of canopy scale sun-induced chlorophyll fluorescence with a 3 dimensional radiative transfer modelHideki Kobayashi, Wei Yang, and Kazuhito IchiiDepartment of Environmental Geochemical Cycle Research, Japan Agency for Marine-Earth Science and Technology3173-25, Showa-machi, Kanazawa-ku, Yokohama, Japan.Plant canopy scale sun-induced chlorophyll fluorescence (SIF) can be observed from satellites, such as Greenhouse gases Observation Satellite (GOSAT), Orbiting Carbon Observatory-2 (OCO-2), and Global Ozone Monitoring Experiment-2 (GOME-2), using Fraunhofer lines in the near infrared spectral domain [1]. SIF is used to infer photosynthetic capacity of plant canopy [2]. However, it is not well understoond how the leaf-level SIF emission contributes to the top of canopy directional SIF because SIFs observed by the satellites use the near infrared spectral domain where the multiple scatterings among leaves are not negligible. It is necessary to quantify the fraction of emission for each satellite observation angle. Absorbed photosynthetically active radiation of sunlit leaves are 100 times higher than that of shaded leaves. Thus, contribution of sunlit and shaded leaves to canopy scale directional SIF emission should also be quantified. Here, we show the results of global simulation of SIF using a 3 dimensional radiative transfer simulation with MODIS atmospheric (aerosol optical thickness) and land (land cover and leaf area index) products and a forest landscape data sets prepared for each land cover category. The results are compared with satellite-based SIF (e.g. GOME-2) and the gross primary production empirically estimated by FLUXNET and remote sensing data.

  19. Analysis of Satellite-Derived Arctic Tropospheric BrO Columns in Conjunction with Aircraft Measurements During ARCTAS and ARCPAC

    NASA Technical Reports Server (NTRS)

    Choi, S.; Wang, Y.; Salawitch, R. J.; Canty, T.; Joiner, J.; Zeng, T.; Kurosu, T. P.; Chance, K.; Richter, A.; Huey, L. G.; Liao, J.; Neuman, J. A.; Nowak, J. B.; Dibb, J. E.; Weinheimer, A. J.; Diskin, G.; Ryerson, T. B.; da Silva, A.; Curry, J.; Kinnison, D.; Tilmes, S.; Levelt, P. F.

    2012-01-01

    We derive tropospheric column BrO during the ARCTAS and ARCPAC field campaigns in spring 2008 using retrievals of total column BrO from the satellite UV nadir sensors OMI and GOME-2 using a radiative transfer model and stratospheric column BrO from a photochemical simulation. We conduct a comprehensive comparison of satellite-derived tropospheric BrO column to aircraft in-situ observations ofBrO and related species. The aircraft profiles reveal that tropospheric BrO, when present during April 2008, was distributed over a broad range of altitudes rather than being confined to the planetary boundary layer (PBL). Perturbations to the total column resulting from tropospheric BrO are the same magnitude as perturbations due to longitudinal variations in the stratospheric component, so proper accounting of the stratospheric signal is essential for accurate determination of satellite-derived tropospheric BrO. We find reasonably good agreement between satellite-derived tropospheric BrO and columns found using aircraft in-situ BrO profiles, particularly when satellite radiances were obtained over bright surfaces (albedo> 0.7), for solar zenith angle < 80 and clear sky conditions. The rapid activation of BrO due to surface processes (the bromine explosion) is apparent in both the OMI and GOME-2 based tropospheric columns. The wide orbital swath of OMI allows examination of the evolution of tropospheric BrO on about hourly time intervals near the pole. Low surface pressure, strong wind, and high PBL height are associated with an observed BrO activation event, supporting the notion of bromine activation by high winds over snow.

  20. Intercomparison among tropospheric ozone and nitrogen dioxide data obtained by satellite- and ground-based measurements

    NASA Astrophysics Data System (ADS)

    Noguchi, K.; Urita, N.; Ohta, E.; Hayashida, S.; Richter, A.; Burrows, J. P.; Liu, X.; Chance, K.; Ziemke, J. R.

    2005-12-01

    Rapid economical growth and industrial development in East Asian regions are causing serious air pollution. The influence of such air pollution is not limited to a local scale but reaches an intercontinental or hemispheric scale. Satellite-borne observations can monitor the behaviors of air pollutants in a global scale for long periods with a single instrument. In particular, ozone and nitrogen dioxide in the troposphere have a crucial role in air pollution, and many studies have tried to derive those species. Recently, instrumentations and retrieval techniques have made a lot of progress in measurements of tropospheric constituents. However, tropospheric observations from space need careful validation because of difficulties in detecting signals from the lower atmosphere through the middle atmosphere. In the present study, we intercompare the tropospheric ozone and nitrogen dioxide data obtained by satellite- and ground-based measurements in order to validate the satellite measurements. For the validation of tropospheric ozone, we utilize ozonesonde data provided by WOUDC, and three satellite-borne data (Tropospheric Ozone Residual (TOR), Cloud Slicing, and GOME) are intercompared. For nitrogen dioxide, we compare GOME observations with ground-based air monitoring measurements in Japan which are operationally conducted by the Ministry of the Environment Japan. This study demonstrates the validity and potential of those satellite datasets to apply for quantitative analysis of dispersion of air pollutants and their chemical lifetime. Acknowledgments. TOR data is provided by J. Fishman via http://asd-www.larc.nasa.gov/TOR/data.html. The ground observation data of nitrogen dioxide over Japan is provided by National Institute for Environmental Studies (NIES) under the collaboration study with NIES and Nara Women's University.

  1. Global fire emission estimates (2007-2012) derived from inversion of formaldehyde columns

    NASA Astrophysics Data System (ADS)

    Bauwens, Maite; Stavrakou, Trissevgeni; Müller, Jean-Francois; De Smedt, Isabelle; Van Roozendael, Michel

    2014-05-01

    Wildfires have a strong impact on the chemistry and composition of the atmosphere and the radiative forcing. The fire emission estimates bear, however, important uncertainties due to the limited amount of field measurements, uncertainties in satellite burned area products, as well as empirical relations used for fuel type allocations. Atmospheric inversions are an alternative approach that provides new independent constraints on the fire estimates. This method involves measurements of trace gases combined with atmospheric models, where optimization algorithms are used to minimize the discrepancy between the model and the observations by adjusting the emission estimates. In this communication, we present global emission estimates of non-methane volatile organic compounds (NMVOCs), inferred from inversion of formaldehyde (HCHO) columns retrieved from the Global Ozone Monitoring Experiment-2 (GOME-2) instrument (De Smedt et al., 2012). The IMAGESv2 global CTM provides the relationship between the emissions and the vertical columns. The Global Fire Emissions Database version 3 (GFEDv3, van der Werf et al., 2010) is used as a priori bottom-up inventory in the model. The agreement between formaldehyde columns calculated by the IMAGESv2 model and the formaldehyde columns from GOME-2 is optimized using the adjoint modelling technique (Stavrakou et al., 2009). The obtained top-down fire emission estimates between 2007 and 2012 are available at the GlobEmission data portal (http://www.globemission.eu) on a monthly basis and at 0.5°x0.5° spatial resolution. The emission estimates are evaluated against three independent emission inventories: GFEDv3 (van der Werf et al., 2010), GFAS (Kaiser et al., 2012) and FINN (Wiedinmyer et al., 2011). Furthermore, simulated CO columns over the fire-affected regions will be compared with CO columns retrieved from the IASI sensor (George et al., 2009).

  2. Prospects for Chlorophyll Fluorescence Remote Sensing from the Orbiting Carbon Observatory-2

    NASA Technical Reports Server (NTRS)

    Frankenberg, Christian; Odell, Chris; Berry, Joseph; Guanter, Luis; Joiner, Joanna; Kohler, Philipp; Pollock, Randy; Taylor, Thomas E.

    2014-01-01

    The Orbiting Carbon Observatory-2 (OCO-2), scheduled to launch in July 2014, is a NASA mission designed to measure atmospheric CO2. Its main purpose is to allow inversions of net flux estimates of CO2 on regional to continental scales using the total column CO2 retrieved using high-resolution spectra in the 0.76, 1.6, and 2.0 nm ranges. Recently, it was shown that solar-induced chlorophyll fluorescence (SIF), a proxy for gross primary production (GPP, carbon uptake through photosynthesis), can be accurately retrieved from space using high spectral resolution radiances in the 750 nm range from the Japanese GOSAT and European GOME-2 instruments. Here, we use real OCO-2 thermal vacuum test data as well as a full repeat cycle (16 days) of simulated OCO-2 spectra under realistic conditions to evaluate the potential of OCO-2 for retrievals of chlorophyll fluorescence and also its dependence on clouds and aerosols. We find that the single-measurement precision is 0.3-0.5 Wm(exp -2)sr(exp -1) nm(exp -1) (15-25% of typical peak values), better than current measurements from space but still difficult to interpret on a single-sounding basis. The most significant advancement will come from smaller ground-pixel sizes and increased measurement frequency, with a 100-fold increase compared to GOSAT (and about 8 times higher than GOME-2). This will largely decrease the need for coarse spatial and temporal averaging in data analysis and pave the way to accurate local studies.We also find that the lack of full global mapping from the OCO-2 only incurs small representativeness errors on regional averages. Eventually, the combination of net ecosystem exchange (NEE) derived from CO2 source/sink inversions and SIF as proxy for GPP from the same satellite will provide a more process-based understanding of the global carbon cycle.

  3. Partial reversal of skeletal muscle aging by restoration of normal NAD⁺ levels.

    PubMed

    Mendelsohn, Andrew R; Larrick, James W

    2014-02-01

    That some aging-associated phenotypes may be reversible is an emerging theme in contemporary aging research. Gomes et al. report that age-associated oxidative phosphorylation (OXPHOS) defects in murine skeletal muscle are biphasic. In the first phase, OXPHOS is decreased because of reduced expression of mitochondrially encoded genes. Treatment of moderately old mice (first-phase OXPHOS defects) with nicotinamide adenine dinucleotide (NAD⁺) precursor nicotinamide mononucleotide (NMN) for 1 week restores oxidative phosphorylation activity and other markers of mitochondrial function in skeletal muscle. However, muscle strength is not restored. In very old animals (second-phase OXPHOS defects), expression of OXPHOS genes from both the nucleus and mitochondria is reduced and mitochondrial DNA integrity is diminished. Gomes et al. propose a model linking decreased NAD⁺ to loss of nuclear SIRT1 activity to stabilization of the hypoxia-associated transcription factor hypoxia-inducible factor 1-alpha (HIF-1a). HIF-1a promotes an hypoxic-like (Warburg effect) state in the cell. The HIF-1a protein interacts with c-Myc, decreasing c-Myc-regulated transcription of the key mitochondrial regulator mitochondrial transcription factor A (TFAM). Low levels of TFAM lead to first-phase OXPHOS dysfunction. The transition to irreversible phase 2 dysfunction remains to be characterized, but may be related to increased reactive oxygen species (ROS) production. This model suggests that intervention in mitochondrial aging may be possible using appropriate NAD⁺ precursors such as nicotinamide riboside. Restoring NAD⁺ levels may be beneficial throughout the organism. For example, aging-associated disturbances in circadian rhythm are linked to diminished SIRT1 activity, and loss of hematopoietic stem cell function to reduced SIRT3. Work to elucidate other biphasic aging mechanisms is strongly encouraged. PMID:24410488

  4. Observing BVOC emissions from Space

    NASA Astrophysics Data System (ADS)

    Oetjen, Hilke; Hewson, William; Comyn-Platt, Edward M.; Barkley, Michael P.; Bösch, Hartmut

    2016-04-01

    Formaldehyde (HCHO) is formed in the atmosphere as an intermediate from the oxidation of methane and other hydrocarbons such as isoprene, but also from combustion processes. Further, global and accurate measurements of HCHO from space are important since they can be used to infer global isoprene emission (e.g. Barkley et al., 2013), the primary biogenic volatile organic compound (BVOC) that cannot be monitored from space directly. However, isoprene is an important source of ozone and secondary organic aerosol, and a sink for the hydroxyl radical. HCHO absorbs in the ultraviolet wavelengths range and can therefore be detected by scattered sunlight absorption spectroscopy. Here we present measurements with the GOME-2 instrument. The first of the 3 GOME-2 instruments has been flying on MetOp-A since 2006 and MetOp-B has been launched in 2012. MetOp-C is expected to be launched in 2018. The University of Leicester retrieval (Hewson et al., 2015) is a well characterised state-of-the-art algorithm which has been used to infer HCHO vertical columns from MetOp-A, and more recently from MetOp-B. The results have been employed for creating a global, multi-year time series. This dataset has been exploited to analyse regional year-to-year variations in HCHO abundances and also to test emission models via comparisons to GEOS-Chem simulations. Barkley, M. P., et al. (2013), J. Geophys. Res. Atmos., 118, 6849-6868, doi:10.1002/jgrd.50552 Hewson, W., et al. (2015), Atmos. Meas. Tech., 8, 4055-4074, doi:10.5194/amt-8-4055-2015

  5. Integrating Satellite Observations, Chemical Transport Modeling, and Population Data to Estimate Decadal Trends in Ground-Level NO2 Exposure Worldwide.

    NASA Astrophysics Data System (ADS)

    Geddes, J.; Martin, R.; Boys, B.

    2014-12-01

    Nitrogen dioxide (NO2) is a common component of air pollution and can act as a tracer for other constituents associated with combustion emissions. An approach to unify observations of NO2 tropospheric vertical column densities from three separate satellite instruments (GOME, SCIAMACHY, GOME-2) was used in combination with chemical transport modeling (GEOS-Chem) to produce a global 17-year record of ground-level NO2 at 0.1° x 0.1° resolution. This data set was combined with maps of population density at the same temporal and spatial resolution, allowing a novel exploration of changing human exposure to air pollution worldwide. Population-weighted mean concentrations (PWMC) were calculated by region, and cumulative distribution plots were used to illustrate the changing spatial allocation of NO2 extremes. The most significant decrease in PWMC occurred in North America, with a decline of 60% between 1996 and 2012. This is 1.5 times greater than the rate of decrease in reported total anthropogenic NOx emissions. PWMC have also decreased by 32% in Western Europe, but have increased by 128% in East Asia. Historically, the highest PWMC occurred in Asia Pacific, although levels have decreased by 36% since 1996. However, exposure to the most extreme concentrations has varied by region over time, moving from North America in 1996 to East Asia in 2012. This unique merging of satellite observations, modeled vertical profiles, and population data offers an innovative approach to investigating pollution trends globally and by region that could relate more directly to health cost expectations over other observational datasets alone.

  6. All satellites total ozone evaluation in the tropics by comparison with SAOZ-NDACC ground-based measurements

    NASA Astrophysics Data System (ADS)

    Pommereau, Jean-Pierre; Lerot, Christophe; Van Roozendael, Michel; Goutail, Florence; Pazmino, Andrea; Frihi, Aymen; Bekki, Slimane; Clerbaux, Cathy

    2016-07-01

    All satellites total ozone measurements available from SBUV, OMI-T, OMI-D, OMI-CCI, GOME-CCI, GOME2-CCI, SCIAMACHY-CCI, NPP and IASI, since 2001 until 2015 are compared to those provided by the UV-Vis SAOZ/NDACC spectrometer at the two tropical stations of Reunion Island in the Indian Ocean and Bauru in Southern Brazil. The differences between satellites and SAOZ except IASI do show systematic seasonal variations of 0-3% (0-9 DU) amplitude and sharp negative peaks in Jan-Mar in Reunion Is in the austral summer. Whereas the summer negative peaks seen particularly on IASI, OMI-T, NPP and OMI-CCI at Reunion are shown to correlate with hurricanes and those seen in Brazil with high altitude overshooting convective clouds both not properly removed, ozone minima outside these events are shown to correlate with high altitude volcanic plumes impacting all satellites as well as ground-based total ozone measurements The seasonality of the Sat-SAOZ difference of varying amplitude from 0 to 3% with the satellite is attributed to the satellite retrieval. Surprisingly and though there has been no change in either SAOZ instruments or data analysis processes, the amplitude of the seasonal cycle of the Sat-SAOZ difference reduces in 2012 and drops to less than ± 0.5% (1.5 DU) after 2013 in Reunion Island and less than ±1% in Bauru, reduction for which there is no clear explanation yet. Shown in the presentation will be the demonstration of the impact of hurricanes, high altitude convective clouds and volcanic plumes on satellites total ozone retrievals, followed by a discussion of possible causes of seasonality of Sat-SAOZ amplitude drop after 2012.

  7. Global Monitoring of Terrestrial Chlorophyll Fluorescence from Space: Status and Potential for Carbon Cycle Research

    NASA Astrophysics Data System (ADS)

    Guanter, L.; Koehler, P.; Walther, S.; Zhang, Y.; Joiner, J.; Frankenberg, C.

    2015-12-01

    Gross primary production (GPP), or the amount of atmospheric CO2 fixed by vegetation through photosynthesis, represents the largest carbon flux between terrestrial ecosystems and the atmosphere. Despite its importance, large-scale estimates of GPP remain highly uncertain for some terrestrial ecosystems. In this context, measurements of sun-induced chlorophyll fluorescence (SIF), which is emitted in the 650-850nm spectral range by the photosynthetic apparatus of green plants, have the potential to provide a new view on vegetation photosynthesis. Global monitoring of SIF from space have been achieved in the last years by means of a number of atmospheric spectrometers, which have turned out to provide the necessary spectral and radiometric sensitivity for SIF retrieval. The first global measurements of SIF were achieved in 2011 from spectra acquired by the Japanese GOSAT mission. This breakthorugh was followed by retrievals from the Global Ozone Monitoring Experiment-2 (GOME-2) instruments onboard MetOp-A and MetOp-B, which enable a continuous spatial sampling, and lately from ENVISAT/SCIAMACHY. This observational scenario is completed by the first SIF data from the NASA-JPL OCO-2 mission (launched in July 2014) and the upcoming Copernicus' Sentinel 5-Precursor to be launched by early 2016. OCO-2 and TROPOMI offer the possibility of monitoring SIF globally with a 100-fold improvement in spatial and temporal resolution with respect to GOSAT, GOME-2 and SCIAMACHY.In this contribution, we will provide an overview of global SIF monitoring and will illustrate the potential of SIF data to improve our knowledge of vegetation photosynthesis and GPP at the synoptic scale. We will show examples of ongoing research exploiting SIF data for an improved monitoring of photosynthetic activity at different ecosystems, highlighting the usefulness of SIF to constrain estimates of CO2 uptake by vegetation through photosynthesis.

  8. Drought onset mechanisms revealed by satellite solar-induced chlorophyll fluorescence: Insights from two contrasting extreme events

    NASA Astrophysics Data System (ADS)

    Sun, Ying; Fu, Rong; Dickinson, Robert; Joiner, Joanna; Frankenberg, Christian; Gu, Lianhong; Xia, Youlong; Fernando, Nelun

    2015-11-01

    This study uses the droughts of 2011 in Texas and 2012 over the central Great Plains as case studies to explore the potential of satellite-observed solar-induced chlorophyll fluorescence (SIF) for monitoring drought dynamics. We find that the spatial patterns of negative SIF anomalies from the Global Ozone Monitoring Experiment 2 (GOME-2) closely resembled drought intensity maps from the U.S. Drought Monitor for both events. The drought-induced suppression of SIF occurred throughout 2011 but was exacerbated in summer in the Texas drought. This event was characterized by a persistent depletion of root zone soil moisture caused by yearlong below-normal precipitation. In contrast, for the central Great Plains drought, warmer temperatures and relatively normal precipitation boosted SIF in the spring of 2012; however, a sudden drop in precipitation coupled with unusually high temperatures rapidly depleted soil moisture through evapotranspiration, leading to a rapid onset of drought in early summer. Accordingly, SIF reversed from above to below normal. For both regions, the GOME-2 SIF anomalies were significantly correlated with those of root zone soil moisture, indicating that the former can potentially be used as proxy of the latter for monitoring agricultural droughts with different onset mechanisms. Further analyses indicate that the contrasting dynamics of SIF during these two extreme events were caused by changes in both fraction of absorbed photosynthetically active radiation fPAR and fluorescence yield, suggesting that satellite SIF is sensitive to both structural and physiological/biochemical variations of vegetation. We conclude that the emerging satellite SIF has excellent potential for dynamic drought monitoring.

  9. Abrolhos bank reef health evaluated by means of water quality, microbial diversity, benthic cover, and fish biomass data.

    PubMed

    Bruce, Thiago; Meirelles, Pedro M; Garcia, Gizele; Paranhos, Rodolfo; Rezende, Carlos E; de Moura, Rodrigo L; Filho, Ronaldo-Francini; Coni, Ericka O C; Vasconcelos, Ana Tereza; Amado Filho, Gilberto; Hatay, Mark; Schmieder, Robert; Edwards, Robert; Dinsdale, Elizabeth; Thompson, Fabiano L

    2012-01-01

    The health of the coral reefs of the Abrolhos Bank (Southwestern Atlantic) was characterized with a holistic approach using measurements of four ecosystem components: (i) inorganic and organic nutrient concentrations, [1] fish biomass, [1] macroalgal and coral cover and (iv) microbial community composition and abundance. The possible benefits of protection from fishing were particularly evaluated by comparing sites with varying levels of protection. Two reefs within the well-enforced no-take area of the National Marine Park of Abrolhos (Parcel dos Abrolhos and California) were compared with two unprotected coastal reefs (Sebastião Gomes and Pedra de Leste) and one legally protected but poorly enforced coastal reef (the "paper park" of Timbebas Reef). The fish biomass was lower and the fleshy macroalgal cover was higher in the unprotected reefs compared with the protected areas. The unprotected and protected reefs had similar seawater chemistry. Lower vibrio CFU counts were observed in the fully protected area of California Reef. Metagenome analysis showed that the unprotected reefs had a higher abundance of archaeal and viral sequences and more bacterial pathogens, while the protected reefs had a higher abundance of genes related to photosynthesis. Similar to other reef systems in the world, there was evidence that reductions in the biomass of herbivorous fishes and the consequent increase in macroalgal cover in the Abrolhos Bank may be affecting microbial diversity and abundance. Through the integration of different types of ecological data, the present study showed that protection from fishing may lead to greater reef health. The data presented herein suggest that protected coral reefs have higher microbial diversity, with the most degraded reef (Sebastião Gomes) showing a marked reduction in microbial species richness. It is concluded that ecological conditions in unprotected reefs may promote the growth and rapid evolution of opportunistic microbial pathogens

  10. Observing the Anthropocene from Space: Selected Megacities

    NASA Astrophysics Data System (ADS)

    Burrows, John P.; Hilboll, Andreas; Richter, Andreas

    2014-05-01

    From the beginning of the Neolithic revolution around 10000 BC and 1800 A.D., the earth's human population is estimated to have risen from several million nomadic hunter gathers to 1 Billion rural settlement and city dwellers. This population increase and its related raising of the standard of living increase and life expectancy were fuelled by energy from the exploitation of biofuel and some use of coal. This rapid development is dwarfed by the impact of the industrial revolution over the past two centuries. There are no over 7 Billion people on earth with over half living in cities and urban areas, e.g. there are ~ 3 billion more citizens than when the author was born and 2 million more than when the project SCIAMACHY (SCanning Imaging and Absorption spectroMeter for Atmospheric ChartographY) was proposed! This industrialisation and urbanisation has been fuelled by the use of cheap energy from fossil fuel combustion. It has resulted in large scale changes in land use, air pollution, and the destruction of stratospheric ozone, the anthropogenic modification of biogeochemical cycling, the destruction of species, ecosystems and ecosystem services. In order to test our knowledge and understanding of the Earth system, accurate long term global measurements of atmospheric constituents and surface parameters are essential. The remote sounding of the atmosphere from instrumentation on satellite platforms provides a unique opportunity to retrieve regional and global observations of key trace atmospheric constituents (gases, aerosol and clouds) and surface parameters (ocean colour, ice extent, flora etc.). This talk describes results from the SCIAMACHY project and its spin offs, GOME (originally SCIA-mini - Global Ozone Monitoring Experiment), GOME-2, and their successors ESA Sentinel 4 (originally GeoSCIA), Sentinel 5, CarbonSat and SCIA-ISS. The interpretation of the data from these instruments has provided a paradigm shift in our understanding of global atmospheric

  11. Inter-annual variation in NO2 over the United States

    NASA Astrophysics Data System (ADS)

    Chand, D.; McClure, S.; Schichtel, B. A.; Huddleston, J.; Malm, W. C.; Moore, T.

    2009-12-01

    Nitrogen dioxide (NO2) plays a key part in atmospheric photochemical processes, including catalytic production of ozone. Emissions of nitrogen oxides also result in nitric acid deposition and increase radiative forcing effects due to the absorption of downward propagating visible light. Recent studies based on GOME and SCIAMACHY satellites observations have shown that NO2 concentrations over the United States have been decreasing by 1-2% per year [Richter et al., 2005; Ghude et al., 2009]. To overcome the detection and sensitivity limitations of these satellites, an improved satellite (Ozone Monitoring Instrument - OMI) was launched in 2004 on the Aura platform as a part of the A-train constellation of satellites. In this study we are using four years (2005-08) of OMI observations to study short-term trends by assessing the spatial and temporal patterns of variation in NO2 over the United States. The focus of this study is over the subdomain 30N-50N, 70W-125W. Our initial analysis suggests that NO2 over the eastern as well as western United States continues to decrease from 2005 through 2008; however, the rate of decrease is higher over the eastern United States. This analysis of Inter-annual variation in NO2 using OMI observations will be used to compare the existing results from GOME and SCIAMACHY satellites. Detail results will be presented in the AGU meeting. References: Richter et al., Increase in tropospheric nitrogen dioxide over China observed from space, Nature, volume 437, doi:10.1038/nature04092, 2005. Ghude et al., Satellite derived trends in NO2 over the major global hotspot regions during the past decade and their inter-comparison, Environmental Pollution, volume 157 Page 1873-1878, 2009.

  12. Total ozone column, aerosol optical depth and precipitable water effects on solar erythemal ultraviolet radiation recorded in Malta.

    NASA Astrophysics Data System (ADS)

    Bilbao, Julia; Román, Roberto; Yousif, Charles; Mateos, David; Miguel, Argimiro

    2013-04-01

    The Universities of Malta and Valladolid (Spain) developed a measurement campaign, which took place in the Institute for Energy Technology in Marsaxlokk (Southern Malta) between May and October 2012, and it was supported by the Spanish government through the Project titled "Measurement campaign about Solar Radiation, Ozone, and Aerosol in the Mediterranean area" (with reference CGL2010-12140-E). This campaign provided the first ground-based measurements in Malta of erythemal radiation and UV index, which indicate the effectiveness of the sun exposure to produce sunburn on human skin. A wide variety of instruments was involved in the campaign, providing a complete atmospheric characterization. Data of erythemal radiation and UV index (from UVB-1 pyranometer), total shortwave radiaton (global and diffuse components from CM-6B pyranometers), and total ozone column, aerosol optical thickness, and precitable water column (from a Microtops-II sunphotometer) were available in the campaign. Ground-based and satellite instruments were used in the analysis, and several intercomparisons were carried out to validate remote sensing data. OMI, GOME, GOME-2, and MODIS instruments, which provide data of ozone, aerosol load and optical properties, were used to this end. The effects on solar radiation, ultraviolet and total shortwave ranges, of total ozone column, aerosol optical thickness and precipitable water column were obtained using radiation measurements at different fixed solar zenith angles. The empirical results shown a determinant role of the solar position, a negligible effect of ozone on total shortwave radiation, and a stronger attenuation provided by aerosol particles in the erythemal radiation. A variety of aerosol types from different sources (desert dust, biomass burning, continental, and maritime) reach Malta, in this campaign several dust events from the Sahara desert occurred and were analyzed establishing the air mass back-trajectories ending at Malta at

  13. Satellite Solar-induced Chlorophyll Fluorescence Reveals Drought Onset Mechanisms: Insights from Two Contrasting Extreme Events

    NASA Astrophysics Data System (ADS)

    Sun, Y.; Fu, R.; Dickinson, R. E.; Joiner, J.; Frankenberg, C.; Gu, L.; Xia, Y.; Fernando, N.

    2015-12-01

    This study uses the droughts of 2011 in Texas and 2012 over the central Great Plains as case studies to explore the potential of satellite-observed solar-induced chlorophyll fluorescence (SIF) for monitoring drought dynamics. We find that the spatial patterns of negative SIF anomalies from the Global Ozone Monitoring Instrument 2 (GOME-2) closely resembled drought intensity maps from the US Drought Monitor for both events. The drought-induced suppression of SIF occurred throughout 2011 but was exacerbated in summer in the Texas drought. This event was characterized by a persistent depletion of root-zone soil moisture caused by year-long below-normal precipitation. In contrast, for the central Great Plains drought, warmer temperatures and ample precipitation boosted SIF in the spring of 2012; however, a sudden drop in precipitation coupled with unusually high temperatures rapidly depleted soil moisture through evapotranspiration, leading to a rapid onset of drought in early summer. Accordingly, SIF reversed from above to below normal. For both regions, the GOME-2 SIF anomalies were significantly correlated with those of root-zone soil moisture, indicating that the former can potentially be used as proxy of the latter for monitoring agricultural droughts with different onset mechanisms. Further analyses indicate that the contrasting dynamics of SIF during these two extreme events were caused by changes in both fraction of absorbed photosynthetically active radiation (fPAR) and fluorescence yield, suggesting that satellite SIF is sensitive to both structural and physiological/biochemical variations of vegetation. We conclude that the emerging satellite SIF has excellent potential for dynamic drought monitoring.

  14. Combined Ozone Retrieval From METOP Sensors Using META-Training Of Deep Neural Networks

    NASA Astrophysics Data System (ADS)

    Felder, Martin; Sehnke, Frank; Kaifel, Anton

    2013-12-01

    The newest installment of our well-proven Neural Net- work Ozone Retrieval System (NNORSY) combines the METOP sensors GOME-2 and IASI with cloud information from AVHRR. Through the use of advanced meta- learning techniques like automatic feature selection and automatic architecture search applied to a set of deep neural networks, having at least two or three hidden layers, we have been able to avoid many technical issues normally encountered during the construction of such a joint retrieval system. This has been made possible by harnessing the processing power of modern consumer graphics cards with high performance graphic processors (GPU), which decreases training times by about two orders of magnitude. The system was trained on data from 2009 and 2010, including target ozone profiles from ozone sondes, ACE- FTS and MLS-AURA. To make maximum use of tropospheric information in the spectra, the data were partitioned into several sets of different cloud fraction ranges with the GOME-2 FOV, on which specialized retrieval networks are being trained. For the final ozone retrieval processing the different specialized networks are combined. The resulting retrieval system is very stable and does not show any systematic dependence on solar zenith angle, scan angle or sensor degradation. We present several sensitivity studies with regard to cloud fraction and target sensor type, as well as the performance in several latitude bands and with respect to independent validation stations. A visual cross-comparison against high-resolution ozone profiles from the KNMI EUMETSAT Ozone SAF product has also been performed and shows some distinctive features which we will briefly discuss. Overall, we demonstrate that a complex retrieval system can now be constructed with a minimum of ma- chine learning knowledge, using automated algorithms for many design decisions previously requiring expert knowledge. Provided sufficient training data and computation power of GPUs is available, the

  15. Assessment of the chestnut production weather dependence

    NASA Astrophysics Data System (ADS)

    Pereira, Mário; Caramelo, Liliana; Gouveia, Célia; Gomes-Laranjo, José

    2010-05-01

    The vegetative cycle of chestnut trees is highly dependent on weather. Photosynthesis and pollen germination are mainly conditioned by the air temperature while heavy precipitation and strong wind have significant impacts during the flushing phase period (Gomes-Laranjo et al., 2005, 2006). In Portugal, chestnut tree orchads are located in mountainous areas of the Northeast region of Trás-os-Montes, between 600 and 1000 m of altitude. Topography controls the atmospheric environment and assures adequate conditions for the chestnut production. In the above mentioned context, remote sensing plays an important role because of its ability to monitor and characterise vegetation dynamics. A number of studies, based on remote sensing, have been conducted in Europe to analyse the year-to-year variations in European vegetation greenness as a function of precipitation and temperature (Gouveia et al., 2008). A previous study focusing on the relationship between meteorological variables and chestnut productivity provides indication that simulation models may benefit from the incorporation of such kind of relationships. The aim of the present work is to provide a detailed description of recent developments, in particular of the added value that may be brought by using satellite data. We have relied on regional fields of the Normalized Difference Vegetation Index (NDVI) dataset, at 8-km resolution, provided by the Global Inventory Monitoring and Modelling System (GIMMS) group. The data are derived from the Advanced Very High Resolution Radiometers (AVHRR), and cover the period from 1982 to 2006. Additionally we have used the chestnut productivity dataset, which includes the annual values of chestnut production and area of production provided by INE, the National Institute of Statistics of Portugal and the meteorological dataset which includes values of several variables from different providers (Meteorod, NCEP/NCAR, ECA&D and national Meteorological Institute). Results show that

  16. One decade of space-based isoprene emission estimates: Interannual variations and emission trends between 2005 and 2014

    NASA Astrophysics Data System (ADS)

    Bauwens, Maite; Stavrakou, Trissevgeni; Müller, Jean-François; De Smedt, Isabelle; Van Roozendael, Michel

    2016-04-01

    Isoprene is one of the most largely emitted hydrocarbons in the atmosphere, with global annual emissions estimated at about 500 Tg, but with large uncertainties (Arneth et al., 2011). Here we use the source inversion approach to derive top-down biogenic isoprene emission estimates for the period between 2005 and 2014 constrained by formaldehyde observations, a high-yield intermediate in the oxidation of isoprene in the atmosphere. Formaldehyde columns retrieved from the Ozone Monitoring Instrument (OMI) are used to constrain the IMAGESv2 global chemistry-transport model and its adjoint code (Stavrakou et al., 2009). The MEGAN-MOHYCAN isoprene emissions (Stavrakou et al., 2014) are used as bottom-up inventory in the model. The inversions are performed separately for each year of the study period, and monthly emissions are derived for every model grid cell. The inversion results are compared to independent isoprene emissions from GUESS-ES (Arneth et al., 2007) and MEGAN-MACC (Sinderalova et al., 2014) and to top-down fluxes based on GOME-2 formaldehyde columns (Bauwens et al., 2014; Stavrakou et al., 2015). The mean global annual OMI-based isoprene flux for the period 2005-2014 is estimated to be 270 Tg, with small interannual variation. This estimate is by 20% lower with regard to the a priori inventory on average, but on the regional scale strong emission updates are inferred. The OMI-based emissions are substantially lower than the MEGAN-MACC and the GUESS-ES inventory, but agree well with the isoprene fluxes constrained by GOME-2 formaldehyde columns. Strong emission reductions are derived over tropical regions. The seasonal pattern of isoprene emissions is generally well preserved after inversion and relatively consistent with other inventories, lending confidence to the MEGAN parameterization of the a priori inventory. In boreal regions the isoprene emission trend is positive and reinforced after inversion, whereas the inversion suggests negative trends in the

  17. New Developments in the SCIAMACHY L2 Ground Processor

    NASA Astrophysics Data System (ADS)

    Gretschany, Sergei; Lichtenberg, Günter; Meringer, Markus; Theys, Nicolas; Lerot, Christophe; Liebing, Patricia; Noel, Stefan; Dehn, Angelika; Fehr, Thorsten

    2016-04-01

    SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric ChartographY) aboard ESA's environmental satellite ENVISAT observed the Earth's atmosphere in limb, nadir, and solar/lunar occultation geometries covering the UV-Visible to NIR spectral range. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002. SCIAMACHY doubled its originally planned in-orbit lifetime of five years before the communication to ENVISAT was severed in April 2012, and the mission entered its post-operational phase. In order to preserve the best quality of the outstanding data recorded by SCIAMACHY, data processors are still being updated. This presentation will highlight three new developments that are currently being incorporated into the forthcoming Version 7 of ESA's operational Level 2 processor: 1. Tropospheric BrO, a new retrieval based on the scientific algorithm of (Theys et al., 2011). This algorithm had been originally developed for the GOME-2 sensor and later adapted for SCIAMACHY. The main principle of the new algorithm is to utilize BrO total columns (already an operational product) and split them into stratospheric VCDstrat and tropospheric VCDtrop fractions. BrO VCDstrat is determined from a climatological approach, driven by SCIAMACHY O3 and NO2 observations. VCDtrop is then determined simply as a difference: VCDtrop = VCDtotal - VCDstrat. 2. Improved cloud flagging using limb measurements (Liebing, 2015). Limb cloud flags are already part of the SCIAMACHY L2 product. They are currently calculated employing the scientific algorithm developed by (Eichmann et al., 2015). Clouds are categorized into four types: water, ice, polar stratospheric and noctilucent clouds. High atmospheric aerosol loadings, however, often lead to spurious cloud flags, when aerosols had been misidentified as clouds. The new algorithm will better discriminate between aerosol and clouds. It will also have a higher sensitivity w.r.t. thin clouds. 3. A new

  18. Critical Evaluation of 0-30 km Profile Information in Ground-Based Zenith-Sky and Satellite-Measured Backscattered UV Radiation

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan; Petropavlovskikh, Irina; Deluishi, John; Einaudi, Franco (Technical Monitor)

    2000-01-01

    We now have several decades of experience in deriving vertical ozone profiles from the measurements of diffuse ultraviolet radiation by both ground and satellite-based instruments using Umkehr and BUV techniques. Continuing technological advances are pushing the state-of-the-art of these measurements to high spectral resolution and broader wavelength coverage. These modern instruments include the ground-based Brewer and satellite-based Global Ozone Monitoring Experiment (GOME) instruments, as well as advanced instruments being developed by ESA(SCIAMACHY), Netherlands(OMI) and Japan(ODUS). However, one of the issues that remains unresolved is the 0-30 km ozone profile information retrievable from these measurements. Though it is commonly believed that both the Umkehr and the satellite-based BUV techniques have very limited profile information below 30 km, there are those who argue that the data from these instruments should continue to be reported in this altitude range for they compare well with ozonesondes and hence there is useful scientific information. Others claim that the limitations of the Umkehr and BUV techniques are largely due to their low spectral resolution, and that the profile information below 30 km can be greatly improved by going to high spectral resolution instruments, such as Brewer and GOME. The purpose of this paper is to provide a critical evaluation of the 0-30 km ozone profile information in the various UV remote sensing techniques. We use a database of individual ozone profiles created using ozonesondes and SAGE and 4D ozone fields generated by data assimilation techniques to simulate radiances measured by the various techniques. We then apply a common inversion approach to all the methods to systematically examine how much profile information is available simply from the knowledge of total ozone, how much additional profile information is added by the traditional Dobson Umkehr and satellite buv techniques, and how much better one can do

  19. A global aerosol classification algorithm incorporating multiple satellite data sets of aerosol and trace gas abundances

    NASA Astrophysics Data System (ADS)

    Penning de Vries, M. J. M.; Beirle, S.; Hörmann, C.; Kaiser, J. W.; Stammes, P.; Tilstra, L. G.; Tuinder, O. N. E.; Wagner, T.

    2015-09-01

    Detecting the optical properties of aerosols using passive satellite-borne measurements alone is a difficult task due to the broadband effect of aerosols on the measured spectra and the influences of surface and cloud reflection. We present another approach to determine aerosol type, namely by studying the relationship of aerosol optical depth (AOD) with trace gas abundance, aerosol absorption, and mean aerosol size. Our new Global Aerosol Classification Algorithm, GACA, examines relationships between aerosol properties (AOD and extinction Ångström exponent from the Moderate Resolution Imaging Spectroradiometer (MODIS), UV Aerosol Index from the second Global Ozone Monitoring Experiment, GOME-2) and trace gas column densities (NO2, HCHO, SO2 from GOME-2, and CO from MOPITT, the Measurements of Pollution in the Troposphere instrument) on a monthly mean basis. First, aerosol types are separated based on size (Ångström exponent) and absorption (UV Aerosol Index), then the dominating sources are identified based on mean trace gas columns and their correlation with AOD. In this way, global maps of dominant aerosol type and main source type are constructed for each season and compared with maps of aerosol composition from the global MACC (Monitoring Atmospheric Composition and Climate) model. Although GACA cannot correctly characterize transported or mixed aerosols, GACA and MACC show good agreement regarding the global seasonal cycle, particularly for urban/industrial aerosols. The seasonal cycles of both aerosol type and source are also studied in more detail for selected 5° × 5° regions. Again, good agreement between GACA and MACC is found for all regions, but some systematic differences become apparent: the variability of aerosol composition (yearly and/or seasonal) is often not well captured by MACC, the amount of mineral dust outside of the dust belt appears to be overestimated, and the abundance of secondary organic aerosols is underestimated in comparison

  20. MERIS albedo data set with improved spatial resolution for SCIAMACHY NO2 retrieval over the European Alpine region

    NASA Astrophysics Data System (ADS)

    Popp, Christoph; Brunner, Dominik; Zhou, Yipin; Wang, Ping; Stammes, Piet

    Despite NOx emissions have been reduced in the past two decades in Switzerland, the NO2 concentrations today still occasionally exceed their threshold as in most other European coun-tries. In addition, the neighboring Po Valley in Northern Italy is well known for generally high levels of air pollutants which are often transported to the southern part of Switzerland. Vertical tropospheric column (VTC) densities of NO2 obtained from spaceborne UV/VIS sensors pro-vide spatially homogeneous information complementing local ground-based measurements. For instance, SCIAMACHY (Scanning Imaging Absorption SpectroMeter for Atmospheric Cartog-raphY) derived NO2-VTC are available from 2002 onward potentially enabling trend analysis as well as monitoring of air quality in our region of interest. In general, a large part of the NO2-VTC retrieval uncertainty can be assigned to the air mass factor which, in turn, depends on model parameters such as surface albedo, surface pressure, cloud fraction and cloud pres-sure. Previous studies indicated that improving the spatial resolution of these forward param-eters can lead to more accurate estimates of NO2-VTC. Herein, we concentrate on the surface albedo. In ESA's TEMIS (Tropospheric Emission Monitoring Internet Service) project, the SCIAMACHY NO2-VTC retrieval makes use of combined GOME/TOMS Lambertian equiva-lent reflectance data mapped onto a grid with a spatial resolution of 1x1. However, variations of surface albedo at the scale of individual satellite pixels (30x60km2 for SCIAMACHY) are difficult to be resolved with this grid size, especially in areas like the European Alps and ad-jacent regions characterized by heterogeneous land cover. For these reasons, we compiled a new land surface albedo climatology for each month of the year from MERIS (The Medium Resolution Imaging Spectrometer) Albedomap data covering the period October 2002 to Oc-tober 2006 with a spatial resolution of 0.25x0.25. The wavelength bands considered are

  1. Validation of OMPS Ozone Profile Data with Expanded Dataset from Brewer and Automated Dobson Network.

    NASA Astrophysics Data System (ADS)

    Petropavlovskikh, I.; Weatherhead, E.; Cede, A.; Oltmans, S. J.; Kireev, S.; Maillard, E.; Bhartia, P. K.; Flynn, L. E.

    2005-12-01

    The first NPOESS satellite is scheduled to be launched in 2010 and will carry the Ozone Mapping and Profiler Suite (OMPS) instruments for ozone monitoring. Prior this, the OMPS instruments and algorithms will be tested by flight on the NPOESS/NPP satellite, scheduled for launch in 2008. Pre-launch planning for validation, post launch data validation and verification of the nadir and limb profile algorithm are key components for insuring that the NPOESS will produce a high quality, reliable ozone profile data set. The heritage of satellite instrument validation (TOMS, SBUV, GOME, SCIAMACHY, SAGE, HALOE, ATMOS, etc) has always relied upon surface-based observations. While the global coverage of satellite observations is appealing for validating another satellite, there is no substitute for the hard reference point of a ground-based system such as the Dobson or Brewer network, whose instruments are routinely calibrated and intercompared to standard references. The standard solar occultation instruments, SAGE II and HALOE are well beyond their planned lifetimes and might be inoperative during the OMPS period. The Umkehr network has been one of the key data sets for stratospheric ozone trend calculations and has earned its place as a benchmark network for stratospheric ozone profile observations. The normalization of measurements at different solar zenith angle (SZAs) to the measurement at the smallest SZA cancels out many calibration parameters, including the extra-terrestrial solar flux and instrumental constant, thus providing a "self-calibrating" technique in the same manner relied upon by the occultation sensors on satellites. Moreover, the ground-based Umkehr measurement is the only technique that provides data with the same altitude resolution and in the same units (DU) as do the UV-nadir instruments (SBUV-2, GOME-2, OMPS-nadir), i.e., as ozone amount in pressure layers, whereas, occultation instruments measure ozone density with height. A new Umkehr algorithm

  2. The new record of daily precipitation in Lisbon since 1864: diagnosis and impacts of an exceptional precipitation episode

    NASA Astrophysics Data System (ADS)

    Fragoso, M.; Trigo, R. M.; Zêzere, J. L.; Valente, M. A.

    2009-04-01

    On 18 February 2008 the city of Lisbon had its rainiest day on record, i.e. since the establishment of the D. Luís Observatory in 1853 (continuous observations of meteorological variables are only available since 1864). Fortunately a Portuguese funded project (SIGN) allowed to digitize all the data between 1864 and 1941, allowing a proper comparison with previous extreme events and also to compute more significant return periods. We can now state that a new absolute maximum of daily precipitation at this station occurred last 18 February, when 118.4 mm were registered, surpassing the previous maximum of 110.7 mm (observed on 5 December 1876). Interestingly, these record breaking characteristics were confined to the city of Lisbon, not being observed in rural and suburban neighborhoods, where the anterior maxima recorded in 26 November 1967 or 18 November 1983 were not achieved. In fact, this extreme event was relatively uncharacteristic when compared with typical extreme precipitation events in southern Portugal (Fragoso and Tildes Gomes, 2008). These extreme episodes tend to occur preferably in fall (late September until early December) and covering a wider area. In this work we present an extensive analysis of the large-scale and synoptic atmospheric circulation environment leading to this extreme rainstorm as well as the consequences, namely floods and landslides that produced relevant socio-economic impacts (including 4 casualties). This will be achieved through the characterization of the extreme precipitation episode, describing its temporal structure and the geographic incidence of the event and also assessing statistically the exceptionality of the daily rainfall. The study of the atmospheric context of the episode will be performed with Satellite and radar data, complemented by several large-scale fields obtained from the NCAR/NCEP Reanalyses dataset, including sea level pressure, 500 hPa Geopotential height, precipitation rate, CAPE index. FRAGOSO, M

  3. Iceless Icy Moons: Is the Nice Model In Trouble?

    NASA Astrophysics Data System (ADS)

    Dones, Henry C. Luke; Levison, H. F.

    2012-05-01

    Nimmo and Korycansky (2012; henceforth NK12) stated that if the outer Solar System underwent a Late Heavy Bombardment (LHB) in the Nice model, the mass striking the icy satellites at speeds up to tens of km/s would have vaporized so much ice that moons such as Mimas, Enceladus, and Miranda would have been devolatilized. NK12's possible explanations of this apparent discrepancy with observations include (1) the mass influx was a factor of 10 less than that in the Nice model; (2) the mass distribution of the impactors was top-heavy, so that luck might have saved some of the moons from suffering large, vapor-removing impacts; or (3) the inner moons formed after the LHB. NK12 calculated the mass influx onto the satellites from the lunar impact rate estimated by Gomes et al. (2005) and scaling factors calculated by Zahnle et al. (1998, 2003; also see Barr and Canup 2010). Production of vapor in hypervelocity impacts is calculated from Kraus et al. (2011). Our preliminary results show that there is about an order-of-magnitude uncertainty in the mass striking the satellites during the LHB, with NK12's estimate at the upper end of the range. We will discuss how the mass influx depends on the velocity and mass distributions of the impactors. The Nice model lives. We thank the NASA Lunar Science Institute (http://lunarscience.nasa.gov/) for support. Barr, A.C., Canup, R.M., Nature Geoscience 3, 164-167 (2010). Gomes, R., Levison, H.F., Tsiganis, K., Morbidelli, A., Nature 435, 466-469 (2005). Kraus, R.G., Senft, L.E., Stewart, S.T., Icarus 214, 724-738 (2011). Nimmo, F., Korycansky, D.G., Icarus, in press, http://www.sciencedirect.com/science/article/pii/S0019103512000310 (2012). Zahnle, K., Dones, L., Levison, H.F., Icarus 136, 202-222 (1998). Zahnle, K., Schenk, P., Levison, H.F., Dones, L., Icarus 163, 263-289 (2003).

  4. The drought impact on satellite solar-induced chlorophyll fluorescence in China during 2007-2015

    NASA Astrophysics Data System (ADS)

    Li, Ruitao

    2016-04-01

    Drought is one of the most damaging and complicated natural hazards in the world. China is one of the countries which are most severely affected by drought. And there is a severe drought event in China every 2-3 years. From the beginning of the 1980s, some vegetation indices have been used to monitor vegetation under water stress. With the development of remote sensing technology, satellite solar-induced chlorophyll fluorescence (SIF) has emerged as a new method to monitor vegetation in recent years. Some studies have shown that compared with vegetation indices, SIF is more sensitive for vegetation functioning. However, the related studies using the satellite SIF is relatively limited in China. The objective of this study is to investigate the impact of drought on SIF by analyzing the relationships of SIF and crucial land surface parameter under the drought condition and to assess the adaption of satellite SIF in China. The SIF data are from the Global Ozone Monitoring Experiment 2 (GOME-2). Firstly, the widely used Palmer Drought Severity Index (PDSI) was used for drought events identification from 2007 to 2015 in China. On the basis of the identification results, we chose a number of areas of interest according to different land cover types and drought intensity. Then, we analyzed the relationships of SIF and land surface variables, i.e. normalized difference vegetation index (NDVI), the fraction of absorbed photosynthetically active radiation (fPAR), root-zone soil moisture (SMC) and surface skin temperatures (Tskin). The results show that the spatial patterns of negative SIF anomalies are closely relevant to the drought intensity. The decrease of SIF is aggravated in the phase of drought occurs. Moreover we find that the GOME-2 SIF is sensitive to fPAR and fluorescence yield. And the SIF is strongly correlated with SMC, Tskin and NDVI. But the SIF decreases more rapidly during the early time of drought events than NDVI. In other words, the SIF can well capture

  5. Revising the Global Budget of Glyoxal (OCHCHO) Based on OMI Vertical Columns

    NASA Astrophysics Data System (ADS)

    Muller, J. F.; Stavrakou, T.; Lerot, C.; Van Roozendael, M.

    2015-12-01

    Glyoxal is, like formaldehyde, a short-lived intermediate in the oxidation of non-methane VOCs emitted by plants, vegetation fires and anthropogenic activities. It is also a precursor of secondary organic aerosols. Both compounds absorb in the UV-visible spectral region and have been measured by the SCIAMACHY satellite sensor since 2003, and more recently, by OMI and GOME-2. Previous modelling studies using SCIAMACHY data have pointed to the existence of large additional sources, in particular over forests (Stavrakou et al. 2009), and more recently over Eastern China, most likely due to aromatic hydrocarbons (Liu et al. 2012), suggesting that glyoxal can serve as an indirect estimator of urban VOC sources. The current study is motivated by (i) recent advances in our understanding of chemical pathways leading to glyoxal formation, in particular from the oxidation of isoprene, the most largely emitted NMVOC, (ii) the existence of numerous in situ concentration measurements for the key anthropogenic glyoxal precursors (e.g. acetylene, aromatics) over industrialized areas, which can be used to narrow down the anthropogenic emission estimates in these regions, and (iii) substantial improvements in retrieval algorithms for glyoxal columns from UV-visible satellite instruments, which has led to an significant reductions of the number of unphysical negative columns over the oceans as well as to generally lower glyoxal columns over continents. In this study, the chemical mechanism and NMVOC emission inventories of the global CTM IMAGESv2 are revised based on recent investigations. The relative importance and possible uncertainties of different chemical pathways leading to glyoxal formation in the oxidation of isoprene are determined by box model simulations. Next, OMI (also possibly GOME-2) glyoxal and formaldehyde data are used to constrain the emissions of biogenic, pyrogenic and anthropogenic VOCs. To that effect, the inverse modelling technique using the adjoint model

  6. An upgraded version of the Eta Model applied to Antarctic case studies

    NASA Astrophysics Data System (ADS)

    Morelli, S.

    2012-04-01

    Upgrades have been implemented over a number of years in an open source version of the Eta Model, posted at its CPTEC web site (http://etamodel.cptec.inpe.br/). They were summarized in Mesinger et al. (2011) and examined in detail in Mesinger et al.( 2012). In short: within dynamics, two major upgrades are the introduction of "sloping steps" and the use of the piecewise-linear vertical advection of dynamic variables. Several refinements on the calculation of exchange coefficients, conservation in the vertical diffusion, and diagnostic calculation of 10-m winds have been made. Vapor and hydrometeor loading in the hydrostatic equation were included. Within physics, efforts in refining the two Eta convection schemes received most attention. This recent version of the Eta Model has been applied to polynya events, accompanied by katabatic wind, at Terra Nova Bay (TNB), Antarctica. The TNB polynya is an area of coupling between the components of the sea ice-ocean-atmosphere system. Locally enhanced surface exchange processes are considered to have important consequences for the atmosphere (Morelli, 2011) and ocean processes, as well as for ice formation and the associated brine release. Adjustments of the Eta pre-processor have been made to allow for the distinctive polar conditions and for the use of ECMWF data as initial and boundary conditions. It is also being developed a thermodynamic model of sea ice interaction for a more realistic treatment of the sea ice-atmosphere. The numerical simulations have a horizontal resolution of about 8 Km. The results will be compared with observational data at the surface, with soundings and satellite images. The observations, used for the comparison, are available by Antarctic Meteorological Research Center, Space Science and Engineering Center, University of Wisconsin-Madison and the Programma Nazionale di Ricerche in Antartide (P.N.R.A.), Osservatorio Meteo-Climatologico. F Mesinger, Chou S C, Gomes J, Jovic D, Lazic L, Lyra A

  7. A Comparison of Sulfur Dioxide Column Content Between Aircraft and Satellite Over the U.S. Mid-Atlantic

    NASA Astrophysics Data System (ADS)

    Hains, J. C.; Dickerson, R. R.; Doddridge, B. G.; Burrows, J. P.; Richter, A.

    2002-12-01

    Sulfur Dioxide (SO2) is a major contributor to air pollution in the mid-Atlantic region of the United States. Sources of SO2 include coal fired power plants as well as diesel engines. Fine particulate sulfate (with diameter less than 2.5 mm) formed from SO2 can cause health problems as well as decreased visibility. Reliable measurements of SO2 within the lower troposphere are needed to determine sources, test emission inventories and to evaluate federal air quality standards. Monthly averages of SO2 lower-tropospheric column content for various points in the mid-Atlantic region of the United States have been calculated from episodic aircraft measurements during the summer months of 2000 and 2001 (http://www.meto.umd.edu/~umdair/rammpp01.html). A Thermo Environmental Instruments 4 3C SO2 analyzer was used to obtain data during aircraft spiral profiles, usually made from the near-surface to an altitude in the range of 2.3 to 3.1 km. From June to August 2000, 44 columns of SO2 were calculated from aircraft profiles over 11 different locations between North Carolina and Pennsylvania. Individual column concentrations of SO2 ranged from 0.10 to 2.31 Dobson Units (DU). Monthly averaged column concentrations were made for each location and the average concentrations for 2000 ranged from 0.02 to 1.18 DU. In 2001, 149 columns of SO2 were obtained from 36 different locations for the months of May through August. The individual column concentrations ranged from 0.01 to 3.40 DU and the monthly averaged columns ranged from 0.05 to 3.40 DU. UV-visible spectra collected by the Global Ozone Monitoring Experiment (GOME) have been analyzed for SO2 by the research group at the University of Bremen in Germany (http://www.iup.physik.uni-bremen.de/gome/). The period of data collection by the University of Maryland team coincide with data collection by the University of Bremen. The monthly averages of SO2 determined from aircraft measurements are compared with measurements from the

  8. Extended and refined multi sensor reanalysis of total ozone for the period 1970-2012

    NASA Astrophysics Data System (ADS)

    van der A, R. J.; Allaart, M. A. F.; Eskes, H. J.

    2015-03-01

    The ozone multi-sensor reanalysis (MSR) is a multi-decadal ozone column data record constructed using all available ozone column satellite datasets, surface Brewer and Dobson observations and a data assimilation technique with detailed error modelling. The result is a high-resolution time series of 6 hourly global ozone column fields and forecast error fields that may be used for ozone trend analyses as well as detailed case studies. The ozone MSR is produced in two steps. First, the latest reprocessed versions of all available ozone column satellite datasets are collected, and are corrected for biases as function of solar zenith angle, viewing angle, time (trend), and stratospheric temperature using Brewer/Dobson ground measurements from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC; http://www.woudc.org/). Subsequently the debiased satellite observations are assimilated within the ozone chemistry and data assimilation model TMDAM driven by meteorological analyses of the European Centre for Medium-Range Weather Forecasts (ECMWF). The MSR2 (MSR version 2) reanalysis upgrade described in this paper consists of an ozone record for the 43 year period 1970-2012. The chemistry-transport model and data assimilation system have been adapted to improve the resolution, error modelling and processing speed. BUV satellite observations have been included for the period 1970-1977. The total record is extended with 13 years compared to the first version of the ozone multi sensor reanalysis, the MSR1. The latest total ozone retrievals of 15 satellite instruments are used: BUV-Nimbus4, TOMS-Nimbus7, TOMS-EP, SBUV-7, -9, -11, -14, -16, -17, -18, -19, GOME, SCIAMACHY, OMI and GOME-2. The resolution of the model runs, assimilation and output is increased from 2° x 3° to 1° x 1°. The analysis is driven by three-hourly meteorology from the ERA-interim reanalysis of ECMWF starting from 1979, and ERA-40 before that date. The chemistry parameterization has been updated

  9. The Use of Meteosat Second Generation Satellite Data Within A New Type of Solar Irradiance Calculation Scheme

    NASA Astrophysics Data System (ADS)

    Mueller, R. W.; Beyer, H. G.; Cros, S.; Dagestad, K. F.; Dumortier, D.; Ineichen, P.; Hammer, A.; Heinemann, D.; Kuhlemann, R.; Olseth, J. A.; Piernavieja, G.; Reise, C.; Schroedter, M.; Skartveit, A.; Wald, L.

    1-University of Oldenburg, 2-University of Appl. Sciences Magdeburg, 3-Ecole des Mines de Paris, 4-University of Bergen, 5-Ecole Nationale des Travaux Publics de l'Etat, 6-University of Geneva, 7-Instituto Tecnologico de Canarias, 8-Fraunhofer Institute for Solar Energy Systems, 9-German Aerospace Center Geostationary satellites such as Meteosat provide cloud information with a high spatial and temporal resolution. Such satellites are therefore not only useful for weather fore- casting, but also for the estimation of solar irradiance since the knowledge of the light reflected by clouds is the basis for the calculation of the transmitted light. Additionally an the knowledge of atmospheric parameters involved in scattering and absorption of the sunlight is necessary for an accurate calculation of the solar irradiance. An accurate estimation of the downward solar irradiance is not only of particular im- portance for the assessment of the radiative forcing of the climate system, but also necessary for an efficient planning and operation of solar energy systems. Currently, most of the operational calculation schemes for solar irradiance are semi- empirical. They use cloud information from the current Meteosat satellite and clima- tologies of atmospheric parameters e.g. turbidity (aerosols and water vapor). The Me- teosat Second Generation satellites (MSG, to be launched in 2002) will provide not only a higher spatial and temporal resolution, but also the potential for the retrieval of atmospheric parameters such as ozone, water vapor and with restrictions aerosols. With this more detailed knowledge about atmospheric parameters it is evident to set up a new calculation scheme based on radiative transfer models using the retrieved atmospheric parameters as input. Unfortunately the possibility of deriving aerosol in- formation from MSG data is limited. As a cosequence the use of data from additional satellite instruments ( e.g. GOME/ATSR-2) is neeeded. Within this

  10. Air Quality Observations from Space: Results from the Ozone Monitoring Instrument (OMI) and Expected Results from the TROPOspheric Monitoring Instrument (TROPOMI)

    NASA Astrophysics Data System (ADS)

    Veefkind, J. P.; Boersma, F. F.; van der A, R. J.; Eskes, H. J.; de Haan, J. F.; Kleipool, Q.; Krotkov, N. A.; Aben, I.; de Vries, J.; Ingmann, P.; Tamminen, J.; Joiner, J.; Bhartia, P. K.; Levelt, P.

    2011-12-01

    Air quality is one of the largest societal challenges, especially in large urbanized and industrialized regions of the world. Reduced air quality has adverse health effects, and also results in reduced crop yields. In addition, there are strong links between air quality and climate change. Traditionally, air quality has been monitored by ground-based networks. In the previous decade the observation capabilities have been extended with measurements from space, most notable from the Ozone Monitoring Instrument (OMI), the SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) and the Global Ozone Monitoring Experiment (GOME-1/2). Whereas the satellite instruments do not provide concentrations at the surface level, they provide unique global information on the spatial distribution and transport of pollutants. Over the last decade the quality of the satellite data for tropospheric species like nitrogen dioxide, carbon monoxide, sulfur dioxide, formaldehyde and aerosols have matured rapidly. Several data products now contribute to the monitoring and forecasting of air quality through data assimilation techniques, most notably as developed in the EU GEMS and MACC (http://www.gmes-atmosphere.eu/) projects. Apart from directly contributing through data assimilation, satellite data is also used for the top-down quantification of emission sources and understanding of atmospheric processes, thus improving chemistry transport models. The OMI instrument, which was launched in July 2004, was the first instrument that combined daily global coverage with high spatial resolution of 13x24 km2 at nadir. The OMI data have attracted many new users and has resulted in several new applications. The TROPOMI instrument, planned for launch in late 2014, will be the first in a series of European satellite sensors dedicated for monitoring atmospheric composition changes in the timeframe 2015-2030. The TROPOMI instrument has a heritage to both OMI and SCIAMACHY. With a

  11. Characterisation of Central-African emissions based on MAX-DOAS measurements, satellite observations and model simulations over Bujumbura, Burundi.

    NASA Astrophysics Data System (ADS)

    Gielen, Clio; Hendrick, Francois; Pinardi, Gaia; De Smedt, Isabelle; Stavrakou, Trissevgeni; Yu, Huan; Fayt, Caroline; Hermans, Christian; Bauwens, Maité; Ndenzako, Eugene; Nzohabonayo, Pierre; Akimana, Rachel; Niyonzima, Sébastien; Müller, Jean-Francois; Van Roozendael, Michel

    2016-04-01

    Central Africa is known for its strong biogenic, pyrogenic, and to a lesser extent anthropogenic emissions. Satellite observations of species like nitrogen dioxide (NO2) and formaldehyde (HCHO), as well as inverse modelling results have shown that there are large uncertainties associated with the emissions in this region. There is thus a need for additional measurements, especially from the ground, in order to better characterise the biomass-burning and biogenic products emitted in this area. We present MAX-DOAS measurements of NO2, HCHO, and aerosols performed in Central Africa, in the city of Bujumbura, Burundi (3°S, 29°E, 850m). A MAX-DOAS instrument has been operating at this location by BIRA-IASB since late 2013. Aerosol-extinction and trace-gases vertical profiles are retrieved by applying the optimal-estimation-based profiling tool bePRO to the measured O4, NO2 and HCHO slant-column densities. The MAX-DOAS vertical columns and profiles are used for investigating the diurnal and seasonal cycles of NO2, HCHO, and aerosols. Regarding the aerosols, the retrieved AODs are compared to co-located AERONET sun photometer measurements for verification purpose, while in the case of NO2 and HCHO, the MAX-DOAS vertical columns and profiles are used for validating GOME-2 and OMI satellite observations. To characterise the biomass-burning and biogenic emissions in the Bujumbura region, the trace gases and aerosol MAX-DOAS retrievals are used in combination to MODIS fire counts/radiative-power and GOME-2/OMI NO2 and HCHO satellite data, as well as simulations from the NOAA backward trajectory model HYSPLIT. First results show that HCHO seasonal variation around local noon is driven by the alternation of rain and dry periods, the latter being associated with intense biomass-burning agricultural activities and forest fires in the south/south-east and transport from this region to Bujumbura. In contrast, NO2 is seen to depend mainly on local emissions close to the city, due

  12. Information On Tropospheric Ozone From Space Borne Polarization Measurements

    NASA Astrophysics Data System (ADS)

    Hasekamp, O. P.; Landgraf, J.

    Tropospheric ozone retrieval from reflectance spectra is an important issue for many current and future satellite instruments.However, it is difficult to distinguish between stratospheric and tropospheric ozone on the basis of reflectance spectra only, because the reflectance is a quantity that is more sensitive to stratospheric ozone than to tro- pospheric ozone. In this paper we show that satellite measurements of the state of polarization of backscattered light contain valuable additional information on tropo- spheric ozone. The reason for this is the high sensitivity of the state of polarization to tropospheric ozone. This is because the state of polarization is most sensitive to ozone at that altitude where most scattering takes place, which is in the troposphere for wavelengths >300 nm. Retrievals performed on synthetic GOME-2 data show that the vertical resolution of the tropospheric ozone profile is significantly improved if a polarization measurement is used in addition to the reflectance spectrum. Prob- lems that are currently encountered in tropospheric ozone retrieval from reflectance spectra may be solved by using additional polarization measurements.

  13. Internannual variability in chemistry and transport and its possible link to climate change: stratospheric ozone and water vapor

    NASA Astrophysics Data System (ADS)

    Weber, Mark; Burrows, John P.; Dhomse, Sandip

    Both transport via the Brewer-Dobson circulation and chemistry changes driven by stratospheric temperature variations contribute to the observed interannual variability in middle to high latitude total ozone as observed from 12 years of data from GOME and SCIAMACHY. The high correlation between the winter average eddy heat flux, which is a common measure of the strength of the Brewer-Dobson circulation and the accumulated winter transport, correlates well with spring total ozone, on one hand, and anti correlates with OClO observations, a measure of the chlorine activation (and cold temperatures) inside the polar vortex, on the other hand. Despite the interannual variability, it is evident that SH total ozone over the polar cap do not show yet a clear sign of recovery. This is not unexpected since the stratospheric chlorine load has just reached its maximum during this decade assuming a stratospheric age of 5-6 years over the polar region. Both transport and chemical ozone loss are closely tied and an important question is how they will evolve in a changing climate. A very sensitive indicator of circulation and transport changes is stratospheric water vapor near the tropical tropopause. Observations from HALOE and SAGE II indicated a drop in tropical lower stratospheric water vapor after year 2000 related to an enhancement in the winter BD circulation in both hemispheres. Extending satellite time series with water vapor observations from other available satellites, we investigate the question if the dry period in tropical stratospheric water vapor still persists.

  14. Interpretation of FRESCO cloud retrievals in case of absorbing aerosol events

    NASA Astrophysics Data System (ADS)

    Wang, P.; Tuinder, O. N. E.; Tilstra, L. G.; de Graaf, M.; Stammes, P.

    2012-10-01

    Cloud and aerosol information is needed in trace gas retrievals from satellite measurements. The Fast REtrieval Scheme for Clouds from the Oxygen A band (FRESCO) cloud algorithm employs reflectance spectra of the O2 A band around 760 nm to derive cloud pressure and effective cloud fraction. In general, clouds contribute more to the O2 A band reflectance than aerosols. Therefore, the FRESCO algorithm does not correct for aerosol effects in the retrievals and attributes the retrieved cloud information entirely to the presence of clouds, and not to aerosols. For events with high aerosol loading, aerosols may have a dominant effect, especially for almost cloud free scenes. We have analysed FRESCO cloud data and Absorbing Aerosol Index (AAI) data from the Global Ozone Monitoring Experiment (GOME-2) instrument on the Metop-A satellite for events with typical absorbing aerosol types, such as volcanic ash, desert dust and smoke. We find that the FRESCO effective cloud fractions are correlated with the AAI data for these absorbing aerosol events and that the FRESCO cloud pressure contains information on aerosol layer pressure. For cloud free scenes, the derived FRESCO cloud pressure is close to the aerosol layer pressure, especially for optically thick aerosol layers. For cloudy scenes, if the strongly absorbing aerosols are located above the clouds, then the retrieved FRESCO cloud pressure may represent the height of the aerosol layer rather than the height of the clouds. Combining FRESCO and AAI data, an estimate for the aerosol layer pressure can be given.

  15. Global surface solar irradiance product derived from SCIAMACHY FRESCO cloud fraction

    NASA Astrophysics Data System (ADS)

    Wang, Ping; Stammes, Piet; Müller, Richard

    The FRESCO cloud retrieval algorithm has been developed as a simple but fast and efficient algorithm for GOME and SCIAMACHY (Koelemeijer et al., 2001; Fournier et al., 2006; Wang et al., 2008). FRESCO employs the O2 A band at 760 nm to retrieve the effective cloud fraction and cloud pressure using a simple Lambertian cloud model. The effective cloud fraction is a combination of geometric cloud fraction and cloud optical thickness, which yield the same reflectance at the top of the atmosphere as the cloud in the scene. It is well-known that clouds reduce the surface solar irradiance. Therefore the all-sky irradiance can be derived from the clear-sky irradiance with a scaling factor related to the cloud index. The cloud index is very similar to the effective cloud fraction by definition. The MAGIC (Mesoscale Atmospheric Global Irradiance Code) software converts the cloud index to the surface solar irradiance using the Heliosat method (Mueller et al. 2009). The MAGIC algorithm is also used by the CM-SAF surface solar irradiance product for clear sky cases. We applied the MAGIC software to FRESCO effective cloud fraction with slight modifications. In this presentation we will show the FRESCO-SSI monthly mean product and the comparison with the BSRN global irradiance data at Cabauw, the Netherlands and surface solar irradiance measurement at Tibetan plateau in China.

  16. Recent studies of halogen activation in the Arctic and the role of sea ice types (Invited)

    NASA Astrophysics Data System (ADS)

    Shepson, P. B.

    2009-12-01

    It has long been known that chemical processes occur at sea ice surfaces that lead to the emission of photolabile halogen species such as Br2 and BrCl, and that subsequent photolysis of those species starts a halogen atom chain reaction that can lead to near-total destruction of ozone and elemental mercury in the lower atmosphere, in springtime. These processes have been observed through satellite remote sensing via the OMI, GOME and SCIAMACHY satellite instruments. While there are numerous hypotheses about the types of surfaces that are important (e.g. first year sea ice, frost flowers, salt-laden snowpacks, sea salt aerosol) to the initiation of this process, there is to date little information that points to any one of these as being dominant. In recent years there has been a significant change in the nature of sea ice cover, with relatively much more seasonal ice, and much less multi-year ice. These changes, along with the satellite data, present an opportunity, and the need, to investigate these questions. Here I discuss recent field measurements, and how they compare to satellite observations, and review what we know and yet need to learn.

  17. Multi-phenotypic Role of Serum Response Factor in the Gastrointestinal System

    PubMed Central

    Ro, Seungil

    2016-01-01

    Serum response factor (SRF) is a master transcription factor of the actin cytoskeleton that binds to highly conserved CArG boxes located within the majority of smooth muscle cell (SMC)-restricted promoters/enhancers. Although most studies of SRF focus on skeletal muscle, cardiac muscle, and vascular SMCs, SRF research has recently expanded into the gastrointestinal (GI) system. Genome scale analyses of GI SMC transcriptome and CArG boxes (CArGome) have identified new SRF target genes. In addition to circular and longitudinal smooth muscle layers, SRF is also expressed in GI mucosa and cancers. In the GI tract, SRF is the central regulator of genes involved in apoptosis, dedifferentiation, proliferation, and migration of cells. Since SRF is the cell phenotypic modulator, it may play an essential role in the development of myopathy, hypertrophy, ulcers, gastric and colon cancers within the GI tract. Given the multi-functional role displayed by SRF in the digestive system, SRF has received more attention emerging as a potential therapeutic target. This review summarizes the findings in SRF research pertaining to the GI tract and provides valuable insight into future directions. PMID:26727951

  18. MAX-DOAS measurements of nitrogen dioxide at the high altitude sites Zugspitze (2964 m) and Pico Espejo (4765 m)

    NASA Astrophysics Data System (ADS)

    Schreier, Stefan F.; Richter, Andreas; Wittrock, Folkard; Burrows, John P.

    2015-04-01

    Spectral measurements at two mountain sites were performed with a MAX-DOAS (Multi AXis Differential Optical Absorption Spectroscopy) instrument from February to July 2003 (Zugspitze, Germany) and from March 2004 to November 2008 (Pico Espejo, Venezuela). Here, these measurements are used for the retrieval of slant column densities (SCDs) of nitrogen dioxide (NO2). While at the altitude of observations the NO2 levels are usually small, uplifting of anthropogenic emissions from the valley and in Venezuela also transport of emissions from biomass burning can lead to significant enhancements. Daily, weekly, and seasonal cycles of NO2 SCDs are shown for the two stations, linked to different meteorological conditions and compared between the two sites. In a next step, a preliminary approach to derive vertical column densities (VCDs) is presented. VCDs of NO2 from ground-based MAX-DOAS instruments provide useful information for the validation of satellite instruments such as SCIAMACHY, OMI, and GOME-2. Comparisons between ground-based and satellite-based NO2 VCDs are shown for selected periods.

  19. The Sodankylä Total Ozone Intercomparison and Validation Campaign (SAUNA)

    NASA Astrophysics Data System (ADS)

    McPeters, R. D.; Bojkov, B.; Bhartia, P. K.; Kyro, E.; Zehner, C.

    2006-05-01

    Years of comparisons of space born measurements of total column ozone with ground based measurements show a pattern of large differences at high latitudes under conditions of high ozone amounts and low sun angles. These persistent differences are likely due in part to the problems with the accuracy of the groundbased measurements, in part to observational differences between satellite and groundbased techniques, and in part to problems with the accuracy of the various satellite algorithms. This intense campaign of measurements at high latitudes in March is designed to establish the accuracy of the different ground based measurement systems. The secondary objective of SAUNA is the validation of EOS-Aura instruments (OMI, TES, MLS, and HIRDLS) the ERS-GOME, and Envisat-Sciamachy, by performing satellite coincident measurements. SAUNA took place at Sodankylä, Finland (67.4° N, 26.6° E) from March 20 through April 13, 2006. A wide variety of groundbased instruments from nine institutes in eight countries participated. Instruments included three Brewer spectrophotometers, two Dobson instruments, two DOAS, a SAOZ, and the NDSC traveling standard stratospheric ozone LIDAR. Daily ozonesonde launches gave the ozone vertical distribution. An overview of the campaign and preliminary results will be presented.

  20. Obesity and craniofacial variables in subjects with obstructive sleep apnea syndrome: comparisons of cephalometric values

    PubMed Central

    Cuccia, Antonino M; Campisi, Giuseppina; Cannavale, Rosangela; Colella, Giuseppe

    2007-01-01

    Background The aim of this paper was to determine the most common craniofacial changes in patients suffering Obstructive Sleep Apnea Syndrome (OSAS) with regards to the degree of obesity. Accordingly, cephalometric data reported in the literature was searched and analyzed. Methods After a careful analysis of the literature from 1990 to 2006, 5 papers with similar procedural criteria were selected. Inclusion criteria were: recruitment of Caucasian patients with an apnea-hypopnea index (AHI) >10 as grouped in non-obese (Body Mass Index – [BMI] < 30) vs. obese (BMI ≥ 30). Results A low position of the hyoid bone was present in both groups. In non-obese patients, an increased value of the ANB angle and a reduced dimension of the cranial base (S-N) were found to be the most common finding, whereas major skeletal divergence (ANS-PNS ^Go-Me) was evident among obese patients. No strict association was found between OSAS and length of the soft palate. Conclusion In both non-obese and obese OSAS patients, skeletal changes were often evident; with special emphasis of intermaxillary divergence in obese patients. Unexpectedly, in obese OSAS patients, alterations of oropharyngeal soft tissue were not always present and did not prevail. PMID:18154686

  1. Using Cloud Top Pressures Derived from Raman Scattering in the UV for the OMI Total Column Ozone Retrievals

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Vasilkov, A. P.; Bhartia, P. K.; Yang, K.

    2003-01-01

    The OMI cloud pressure product is necessary for accounting for cloud effects on the mission- critical total ozone product. One of the OM1 cloud pressure algorithms uses UV measurements to derive cloud pressures from the high frequency structure of top- of-atmosphere reflectance caused by rotational Raman scattering (RRS) in the atmosphere. RRS results in filling-in of Fraunhofer lines in the backscatter UV spectra (also known as the Ring effect). The magnitude of filling-in of the Fraunhofer lines is roughly proportional to the average number of solar photon scatterings in the atmosphere above the clouds. This property of RRS is used to deduce an effective cloud pressure. The cloud pressure algorithm retrieves the cloud pressure and cloud fraction using a concept of the Mixed Lambert Equivalent Reflectivity (MLER) also used for the TOMS-V8 OM1 total column ozone algorithm. Currently, this OMI total column ozone algorithm utilizes information about cloud top pressures from a climatology based on IR measurements. The IR-derived cloud top pressure is known to be lower than UV-derived cloud top pressure because UV radiation penetrates clouds deeper than IR radiation. That is why the UV-derived cloud pressure may be more consistent withthe total ozone algorithm. We estimate total column ozone differences caused by replacing the cloud pressure climatology with cloud pressures retrieved from GOME data same as used for retrieval of ozone.

  2. The 'Ajuda Paralyses': history of a neuropsychiatric debate in mid-19th-century Portugal.

    PubMed

    Fontoura, Paulo

    2010-10-01

    The second half of the 19th century witnessed an increasing interest in neurology and psychiatry by Portuguese physicians, in parallel with the overall development of these disciplines in other countries. This process is reflected in the numerous case report publications as well as in debates taking place at the Lisbon Society of Medical Sciences, the major scientific forum of that time. The 'Ajuda Paralyses' were a mysterious succession of epidemics that occurred during 1860-64 in the Ajuda asylum for cholera and yellow fever orphans, which were extensively discussed during 1865-66 by Bernardino Antonio Gomes, Antonio Maria Barbosa, Abel Jordão and Eduardo Motta. Studying this debate helps understand the initial stages of development and the great interest that 'nervous diseases' had for Portuguese clinicians in the mid-19th century and possibly provides one of the first modern descriptions of nutrition-related polyradiculoneuropathy and the ocular findings associated with avitaminosis A. This debate took place at a decisive time for the scientific development of neurology and psychiatry, concurrent with the widespread application of the clinical-anatomical method and neuropathology to the study of diseases of the nervous system, which would set the foundations for our own modern pathophysiological framework. Therefore, the 'Ajuda paralyses' debate also provides a good basis for a discussion on the evolution of the concepts of hysteria and psychosomatic disease and the description of peripheral neuropathy from among a wealth of other entities that did not withstand the test of science.

  3. PREFACE: XXXVI Symposium on Nuclear Physics (Cocoyoc 2013)

    NASA Astrophysics Data System (ADS)

    Barrón-Palos, Libertad; Morales-Agiss, Irving; Martínez-Quiroz, Enrique

    2014-03-01

    logo The XXXVI Symposium on Nuclear Physics, organized by the Division of Nuclear Physics of the Mexican Physical Society, took place from 7-10 January, 2013. As it is customary, the Symposium was held at the Hotel Hacienda Cocoyoc, in the state of Morelos, Mexico. Conference photograph This international venue with many years of tradition was attended by outstanding physicists, some of them already regulars to this meeting and others who joined us for the first time; a total of 45 attendees from different countries (Argentina, Brazil, Canada, China, Germany, Italy, Japan, Mexico and the United States). A variety of topics related to nuclear physics (nuclear reactions, radioactive beams, nuclear structure, fundamental neutron physics, sub-nuclear physics and nuclear astrophysics, among others) were presented in 26 invited talks and 10 contributed posters. Local Organizing Committee Libertad Barrón-Palos (IF-UNAM)) Enrique Martínez-Quíroz (ININ)) Irving Morales-Agiss (ICN-UNAM)) International Advisory Committee Osvaldo Civitarese (UNLP, Argentina) Jerry P Draayer (LSU, USA)) Alfredo Galindo-Uribarri (ORNL, USA)) Paulo Gomes (UFF, Brazil)) Piet Van Isacker (GANIL, France)) James J Kolata (UND, USA)) Reiner Krücken (TRIUMF, Canada)) Jorge López (UTEP, USA)) Stuart Pittel (UD, USA)) W Michael Snow (IU, USA)) Adam Szczepaniak (IU, USA)) Michael Wiescher (UND, USA)) A list of participants is available in the PDF

  4. Evaluation of cytotoxicity and genotoxicity of Hancornia speciosa latex in Allium cepa root model.

    PubMed

    Ribeiro, T P; Sousa, T R; Arruda, A S; Peixoto, N; Gonçalves, P J; Almeida, L M

    2016-02-01

    The latex obtained from Hancornia speciosa Gomes (Mangabeira tree) is widely used in traditional medicine to treat a variety of diseases, including diarrhea, ulcer, gastritis, tuberculosis, acne and warts. In this study, the cytotoxicity and genotoxicity effects of H. speciosa latex on the root meristem cells of Allium cepa were examined. Onion bulbs were exposed to different concentrations of latex and then submitted to microscopic analysis using Giemsa stain. Water was used as a negative control and sodium azide as a positive control. The results showed that, under the testing conditions, the mitotic index (MI) of the onion roots submitted to latex treatment did not differ significantly from the negative control, which suggests that the latex is not cytotoxic. Low incidence of chromosome aberrations in the cells treated with H. speciosa latex was also observed, indicating that the latex does not have genotoxic effect either. The MI and the chromosome aberration frequency responded to the latex concentration, requiring more studies to evaluate the dosage effect on genotoxicity. The results indicate that in tested concentrations H. speciosa latex is probably not harmful to human health and may be potentially used in medicine. PMID:26909640

  5. The Rock Record of the Chronology of Lunar Impacts

    NASA Astrophysics Data System (ADS)

    Swindle, Timothy D.

    2008-09-01

    The idea of a "lunar cataclysm” or "late heavy bombardment” arose when Turner et al. (1973) and Tera et al. (1974) found that the ages of the samples returned by the Apollo astronauts clustered at slightly less than 4 Ga when measured by a variety of isotope geochronology systems. Since then, 40Ar-39Ar analyses of impact melt clasts from lunar meteorites, glass spherules from the Apollo sites and heavily-shocked meteorites from asteroidal parent bodies have all contributed to a more nuanced picture of the impact record in rocks. There continues to be a dearth of impact ages between 4.4 and 4.0 Ga, but most of the sample sets contain ages between 3.5 and 4.0 Ga. The "Nice” model provides an elegant dynamical explanation for a "cataclysm” (Gomes et al., 2005), but the details of the rock record appear to be inconsistent with the simplest version of such a model. This work is supported by the NASA Cosmochemistry program.

  6. Systematic Quantitative Analysis of NO2 Long-Range Transport Events and Comparison to Model Data

    NASA Astrophysics Data System (ADS)

    Zien, A. W.; Richter, A.; Hilboll, A.; Burrows, J. P.; Inness, A.

    2012-12-01

    Atmospheric long-range transport (LRT) events relocate trace gases from emission to downwind regions on an intercontinental scale, drastically altering the atmospheric chemistry in remote regions. Tropospheric NO2 is a very short-lived, mainly anthropogenic trace gas with strong impact on the ozone chemistry. Emissions are very localized and allow identification of individual LRT events. In this study, we use non-cloud-filtered remote sensing observations from the GOME-2 satellite instrument to identify trans-oceanic NO2 LRT events. The LRT analysis is performed by a specialized algorithm, spotting anomalies in the vertical slant column data. LRT routes are obtained via Lagrangian back-tracing with the HYSPLIT model. We also implement a radiance cloud-fraction and model the NO2 air-mass factor in LRTs to allow the quantification of NO2 content under cloudy conditions which frequently accompany LRTs. Sample LRT events over the North Atlantic and the Southern Ocean illustrate the process and results of this analysis. The spatial and temporal coverage of the used observations also allows for a statistical analysis, showing regional and seasonal features in both LRT occurrence and properties in a 5-year data set (2007 to 2011), giving typical routes of transport. We compare these to results from a similar analysis of data from a global chemical transport model, the MACC reanalysis data.

  7. Astronomy in Brazilian music and poetry

    NASA Astrophysics Data System (ADS)

    de Freitas Mourão, Ronaldo Rogério

    2011-06-01

    The rôle of astronomy in the Brazilian cultural diversity -though little known world- has been enormous. Thus, the different forms of popular music and erudite, find musical compositions and lyrics inspired by the stars, the eclipses in rare phenomena such as the transit of Venus in front of the sun in 1882, the appearance of Halley's Comet in 1910, in the Big Bang theory. Even in the carnival parades of the blocks at the beginning of the century astronomy was present. More recently, the parade of 1997, the samba school Unidos do Viradouro, under the direction of Joãozinho Trinta, offered a new picture of the first moments of the creation of the universe to join in the white and dark in the components of their school, the idea of matter and anti-matter that reigned in the early moments of the creation of the universe in an explosion of joy. Examples in classical music include Dawn of Carlos Gomes and Carta Celeste by Almeida Prado. Unlike The Planets by Gustav Holst -who between 1914 and 1916 composed a symphonical tribute to the solar system based on astrology- Almeida Prado composed a symphony that is not limited to the world of planets, penetrating the deep cosmos of galaxies. Using various resources of the technique for the piano on the clusters and static movements, violent conflicts between the records of super acute and serious instrument, harpejos cross, etc . . .

  8. Monitoring of volcanic emissions of SO2 and ash

    NASA Astrophysics Data System (ADS)

    Theys, Nicolas; Clarisse, Lieven; Brenot, Hugues; van Gent, Jeroen; Campion, Robin; van der A, Ronald; Valks, Pieter; Corradini, Stefano; Merucci, Luca; Van Roozendael, Michel; Coheur, Pierre-François; Hurtmans, Daniel; Clerbaux, Cathy; Tait, Steve; Ferrucci, Fabrizio

    2013-04-01

    Volcanic eruptions can emit large quantities of fine particles (ash) into the atmosphere as well as several trace gases, such as water vapour, carbon dioxide, sulphur species (SO2, H2S) and halogens (HCl, HBr, HF). These volcanic ejecta can have a considerable impact on the atmosphere, human health and society. Volcanic ash in particular is known to be a major threat for aviation, especially after dispersion over long distances (>1000 km) from the erupting volcano. In this respect, the continuous monitoring of volcanic ash from space is playing an essential role for the mitigation of aviation hazards. Compared to ash, SO2 is less critical for aviation safety, but is much easier to measure. Therefore, SO2 observations are often use as a marker of volcanic ash in the atmosphere. Moreover, SO2 yields information on the processes occurring in the magmatic system and is used as a proxy for the eruptive rate. In this presentation we give an overview of recent developments of the Support to Aviation Control Service (SACS). The focus is on the near-real time detection and monitoring of volcanic plumes of ash and SO2 using polar-orbiting instruments GOME-2, OMI, IASI and AIRS. The second part of the talk is dedicated to the determination of volcanic SO2 fluxes from satellite measurements. We review different techniques and investigate the temporal evolution of the total emissions of SO2 for recent volcanic events.

  9. Viper and cobra venom neutralization by beta-sitosterol and stigmasterol isolated from the root extract of Pluchea indica Less. (Asteraceae).

    PubMed

    Gomes, A; Saha, Archita; Chatterjee, Ipshita; Chakravarty, A K

    2007-09-01

    We reported previously that the methanolic root extract of the Indian medicinal plant Pluchea indica Less. (Asteraceae) could neutralize viper venom-induced action [Alam, M.I., Auddy, B., Gomes, A., 1996. Viper venom neutralization by Indian medicinal plant (Hemidesmus indicus and P. indica) root extracts. Phytother. Res. 10, 58-61]. The present study reports the neutralization of viper and cobra venom by beta-sitosterol and stigmasterol isolated from the root extract of P. indica Less. (Asteraceae). The active fraction (containing the major compound beta-sitosterol and the minor compound stigmasterol) was isolated and purified by silica gel column chromatography and the structure was determined using spectroscopic analysis (EIMS, (1)H NMR, (13)C NMR). Anti-snake venom activity was studied in experimental animals. The active fraction was found to significantly neutralize viper venom-induced lethal, hemorrhagic, defibrinogenation, edema and PLA(2) activity. Cobra venom-induced lethality, cardiotoxicity, neurotoxicity, respiratory changes and PLA(2) activity were also antagonized by the active component. It potentiated commercial snake venom antiserum action against venom-induced lethality in male albino mice. The active fraction could antagonize venom-induced changes in lipid peroxidation and superoxide dismutase activity. This study suggests that beta-sitosterol and stigmasterol may play an important role, along with antiserum, in neutralizing snake venom-induced actions.

  10. Wandering Gas Giants and Lunar Bombardment

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2006-08-01

    There may have been a dramatic event early in the history of the Solar System--the intense bombardment of the inner planets and the Moon by planetesimals during a narrow interval between 3.92 and 3.85 billion years ago, called the late heavy bombardment, but also nicknamed the lunar cataclysm. The evidence for this event comes from Apollo lunar samples and lunar meteorites. While not proven, it makes for an interesting working hypothesis. If correct, what caused it to happen? A group of physicists from the Observatoire de la Côte d'Azur (Nice, France), GEA/OV/Universidade Federal do Rio de Janeiro and Observatorio Nacional/MTC (Rio de Janeiro, Brazil), and the Southwest Research Institute (Boulder, Colorado) conducted a series of studies of the dynamics of the early Solar System. Alessandro Morbidelli, Kleomenis Tsiganis, Rodney Gomes, and Harold Levison simulated the migration of Saturn and Jupiter. When the orbits of these giant planets reached the special condition of Saturn making one trip around the Sun for every two trips by Jupiter (called the 1:2 resonance), violent gravitational shoves made the orbits of Neptune and Uranus unstable, causing them to migrate rapidly and scatter countless planetesimals throughout the Solar System. This dramatic event could have happened in a short interval, anywhere from 200 million years to a billion years after planet formation, causing the lunar cataclysm, which would have affected all the inner planets.

  11. Effect of some viticultural parameters on the grape carotenoid profile.

    PubMed

    Oliveira, Carla; Ferreira, António César; Costa, Paulo; Guerra, Joaquim; Guedes De Pinho, Paula

    2004-06-30

    The effect of some viticultural parameters on the grape carotenoid profile was investigated. Grape cultivar, ripeness stage, sunlight and shade exposure, altitude, and vegetative height were studied. Differences between cultivars were observed in eight different black grape varieties: Touriga Brasileira (TBR), Tinta Barroca (TB), Tinta Amarela (TA), Souzão (S), Touriga Franca (TF), Touriga Nacional (TN), Tinta Roriz (TR), and Tinto Cão (TC), from the Douro region. TA and TBR clearly produced higher concentrations of carotenoids. Results showed that carotenoid content decreased during ripening. Decreases of lutein were observed until 66%, whereas beta-carotene slowly decreased, having a constant level until the harvest date. Carotenoid contents were consistently higher in grapes exposed to shade than in those exposed to direct sunlight in both studied white grape varieties, Maria Gomes (MG) and Loureiro (L). In the Douro Valley, high-elevation terraces, which presented a lower temperature and higher humidity during the maturation period, appeared to produce grapes with higher carotenoid values. Grapes grown with higher vegetative height seem to have higher carotenoid levels; furthermore, grapes grown with lower vegetative height had higher weight and sugar concentrations. PMID:15212466

  12. Estimation of the SO2 source term for the Holuhraun event and its influence on central Europe air quality

    NASA Astrophysics Data System (ADS)

    Arnold, Delia; Iren Kristiansen, Nina; Theys, Nicolas; Brenot, Hugues; Maurer, Christian; Wotawa, Gerhard; Stebel, Kerstin; Holla, Robert; Gilge, Stefan; Flemming, Johannes; Stohl, Andreas; Hirtl, Marcus

    2015-04-01

    On 29 August 2014 a fissure eruption began in Holuhraun, Northeastern Iceland, associated with increased volcanic activity in the Bárdarbunga system. For more than 150 days, the eruption released large quantities of SO2 into the atmosphere affecting not only the local Icelandic air quality, but also leading to periods of increased ambient SO2 concentrations in parts of mainland Europe. During the second half of September, significant amounts of SO2 were rapidly transported southward by favourable meteorological conditions and several countries in Central Europe experienced high ground-level SO2 concentrations. The measured concentrations reached and even exceeded the EC directive health thresholds. In this work, we evaluate the air quality effects in Europe during this targeted period using both ground-based and satellite observations (GOME2B and OMI) as well as dispersion modelling with the Lagrangian particle model FLEXPART. We estimate the volcanic SO2 source emissions by comparing the satellite observations with atmospheric transport model simulations in an inverse modelling approach. The estimated source term is evaluated against independent ground-based observational data (e.g. MAX-DOAS, Brewer) and used as emission term in dispersion model forecasts for evaluating the air quality effects in Europe. In addition, the potential use of air quality data to perform the source term estimation by inversion with ground-based data will also be investigated.

  13. The STRatospheric Estimation Algorithm from Mainz (STREAM): Estimating stratospheric NO2 from nadir-viewing satellites by weighted convolution

    NASA Astrophysics Data System (ADS)

    Beirle, Steffen; Hörmann, Christoph; Jöckel, Patrick; Penning de Vries, Marloes; Pozzer, Andrea; Sihler, Holger; Valks, Pieter; Wagner, Thomas

    2016-04-01

    The STRatospheric Estimation Algorithm from Mainz (STREAM) determines stratospheric columns of NO2 which are needed for the retrieval of tropospheric columns from satellite observations. It is based on the total column measurements over clean, remote regions as well as over clouded scenes where the tropospheric column is effectively shielded. The contribution of individual satellite measurements to the stratospheric estimate is controlled by various weighting factors. STREAM is a flexible and robust algorithm and does not require input from chemical transport models. It was developed as verification algorithm for the upcoming satellite instrument TROPOMI, as complement to the operational stratospheric correction based on data assimilation. STREAM was successfully applied to the UV/vis satellite instruments GOME 1/2, SCIAMACHY, and OMI. It overcomes some of the artefacts of previous algorithms, as it is capable of reproducing gradients of stratospheric NO2, e.g. related to the polar vortex, and reduces interpolation errors over continents. Based on synthetic input data, the uncertainty of STREAM was quantified as about 0.1-0.2 ×1015 molecules cm‑2, in accordance to the typical deviations between stratospheric estimates from different algorithms compared in this study.

  14. A sleep inducing factor from common Indian toad (Bufo melanostictus, Schneider) skin extract.

    PubMed

    Das, M; Mallick, B N; Dasgupta, S C; Gomes, A

    2000-09-01

    Bufo melanostictus (common Indian toad) acquire different bioactive substances in their skin during their life-time in wide ecological habitat. Earlier investigation from this laboratory revealed that toad (B. melanostictus) skin extract (TSE) posses different bioactive compounds of different diversity (Das, M., Auddy, B. and Gomes, A., 1996. Pharmacological study of the toad skin extract on experimental animals. Indian J. Pharmacol. 28, 72-76). Among these sleep induction and sleep potentiation indicated the possibility of sleep inducing factor(s) in TSE. One such sleep inducing factor (SIF) was isolated and purified by neutral alumina column chromatography followed by HPLC. Spectroscopy (UV, IR, FAB-MASS) study indicated that the sleep inducing factor was a 880 Dalton conjugated aromatic compound with a hydroxyl and carbonyl functional group. Biological study showed that SIF produced no lethality in male albino mice upto the dose of 8 mg/kg, i.v. Cyproheptadine antagonised SIF induced contraction of isolated smooth muscle indicating histamine/serotonin receptor mediated action of SIF. EEG studies showed that SIF increased sleep and decreased awakening condition of freely moving rats. Biochemical studies showed that SIF produced significant alteration of brain biogenic amine levels, monoamine oxidase (MAO) and tryptophan hydroxylase (TH) activity. This may be the reason of SIF induced sleep, although the SIF induced sleep mechanism needs further detail investigation. PMID:10736480

  15. Phytochemical Analysis and Antimicrobial, Antinociceptive, and Anti-Inflammatory Activities of Two Chemotypes of Pimenta pseudocaryophyllus (Myrtaceae)

    PubMed Central

    de Paula, Joelma Abadia Marciano; Silva, Maria do Rosário Rodrigues; Costa, Maysa P.; Diniz, Danielle Guimarães Almeida; Sá, Fabyola A. S.; Alves, Suzana Ferreira; Costa, Élson Alves; Lino, Roberta Campos; de Paula, José Realino

    2012-01-01

    Preparations from Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae) have been widely used in Brazilian folk medicine. This study aims to evaluate the antimicrobial activity of the crude ethanol extracts, fractions, semipurified substances, and essential oils obtained from leaves of two chemotypes of P. pseudocaryophyllus and to perform the antinociceptive and anti-inflammatory screening. The ethanol extracts were purified by column chromatography and main compounds were spectrally characterised (1D and 2D 1H and 13C NMR). The essential oils constituents were identified by GC/MS. The broth microdilution method was used for testing the antimicrobial activity. The abdominal contortions induced by acetic acid and the ear oedema induced by croton oil were used for screening of antinociceptive and anti-inflammatory activities, respectively. The phytochemical analysis resulted in the isolation of pentacyclic triterpenes, flavonoids, and phenol acids. The oleanolic acid showed the best profile of antibacterial activity for Gram-positive bacteria (31.2–125 μg mL−1), followed by the essential oil of the citral chemotype (62.5–250 μg mL−1). Among the semipurified substances, Ppm5, which contained gallic acid, was the most active for Candida spp. (31.2 μg mL−1) and Cryptococcus spp. (3.9–15.6 μg mL−1). The crude ethanol extract and fractions from citral chemotype showed antinociceptive and anti-inflammatory effects. PMID:23082081

  16. Total ozone trends and variability during 1979-2012 from merged data sets of various satellites

    NASA Astrophysics Data System (ADS)

    Chehade, W.; Weber, M.; Burrows, J. P.

    2014-07-01

    The study presents a long-term statistical trend analysis of total ozone data sets obtained from various satellites. A multi-variate linear regression was applied to annual mean zonal mean data using various natural and anthropogenic explanatory variables that represent dynamical and chemical processes which modify global ozone distributions in a changing climate. The study investigated the magnitude and zonal distribution of the different atmospheric chemical and dynamical factors contributing to long-term total ozone changes. The regression model included the equivalent effective stratospheric chlorine (EESC), the 11-year solar cycle, the quasi-biennial oscillation (QBO), stratospheric aerosol loading describing the effects from major volcanic eruptions, the El Niño-Southern Oscillation (ENSO), the Arctic and Antarctic oscillation (AO/AAO), and accumulated eddy heat flux (EHF), the latter representing changes due to the Brewer-Dobson circulation. The total ozone column data set used here comprises the Solar Backscater Ultraviolet SBUV/SBUV-2 merged ozone data set (MOD) V8.6, the merged data set of the Solar Backscaterr Ultraviolet, the Total Ozone Mapping Spectrometer and the Ozone Monitoring Instrument SBUV/TOMS/OMI (1979-2012) MOD V8.0 and the merged data set of the Global Ozone Monitoring Experiment, the Scanning Imaging Absorption spectroMeter for Atmospheric ChartograpHY and the Global Ozone Monitoring Experiment 2 GOME/SCIAMACHY/GOME-2 (GSG) (1995-2012). The trend analysis was performed for twenty-six 5° wide latitude bands from 65° S to 65° N, and the analysis explained most of the ozone variability to within 70 to 90%. The results show that QBO dominates the ozone variability in the tropics (±7 DU) while at higher latitudes, the dynamical indices, AO/AAO and eddy heat flux, have substantial influence on total ozone variations by up to ±10 DU. The contribution from volcanic aerosols is only prominent during the major eruption periods (El Chichón and

  17. Gilbert damping and anisotropic magnetoresistance in iron-based alloys

    NASA Astrophysics Data System (ADS)

    Berger, L.

    2016-07-01

    We use the two-current model of Campbell and Fert to understand the compositional dependence of the Gilbert damping parameter in certain iron alloys. In that model, spin-up and spin-down carriers have different resistivities ρ↑ and ρ↓. We emphasize the part of the Gilbert parameter, called Gsf, generated by spin-flip interband processes. Both Gsf and the anisotropic magnetoresistance Δρ are proportional to the square of the spin-orbit parameter, and also proportional to ρ↑. In bcc alloys of iron with V, Cr, Mo, etc. solutes on the left of iron in the periodic table, ρ↑ is increased by a scattering resonance (Gomes and Campbell, 1966, 1968). Then ρ↑, Δρ, and Gsf all exhibit a peak at the same moderate concentration of the solute. We find the best fit between this theory and existing experimental data of Gilbert damping for Fe-V epitaxial films at room temperature (Cheng, 2006; Scheck et al., 2007). At room temperature, the predicted Gsf peak is masked by a background arising from non-flip intraband processes. At elevated temperatures, the peak is expected to become more prominent, and less hidden in the background.

  18. Smooth Muscle Cell Genome Browser: Enabling the Identification of Novel Serum Response Factor Target Genes.

    PubMed

    Lee, Moon Young; Park, Chanjae; Berent, Robyn M; Park, Paul J; Fuchs, Robert; Syn, Hannah; Chin, Albert; Townsend, Jared; Benson, Craig C; Redelman, Doug; Shen, Tsai-Wei; Park, Jong Kun; Miano, Joseph M; Sanders, Kenton M; Ro, Seungil

    2015-01-01

    Genome-scale expression data on the absolute numbers of gene isoforms offers essential clues in cellular functions and biological processes. Smooth muscle cells (SMCs) perform a unique contractile function through expression of specific genes controlled by serum response factor (SRF), a transcription factor that binds to DNA sites known as the CArG boxes. To identify SRF-regulated genes specifically expressed in SMCs, we isolated SMC populations from mouse small intestine and colon, obtained their transcriptomes, and constructed an interactive SMC genome and CArGome browser. To our knowledge, this is the first online resource that provides a comprehensive library of all genetic transcripts expressed in primary SMCs. The browser also serves as the first genome-wide map of SRF binding sites. The browser analysis revealed novel SMC-specific transcriptional variants and SRF target genes, which provided new and unique insights into the cellular and biological functions of the cells in gastrointestinal (GI) physiology. The SRF target genes in SMCs, which were discovered in silico, were confirmed by proteomic analysis of SMC-specific Srf knockout mice. Our genome browser offers a new perspective into the alternative expression of genes in the context of SRF binding sites in SMCs and provides a valuable reference for future functional studies.

  19. Testing and Improving OMI Tropospheric NO2 Using Observations from the DANDELIONS and INTEX-B Validation Campaigns

    NASA Astrophysics Data System (ADS)

    Hains, J.

    2009-04-01

    We present a validation of tropospheric NO2 columns from the Ozone Monitoring Instrument (OMI) using measurements from the Dutch Aerosol and Nitrogen Dioxide Experiments for vaLIdation of OMI and SCIAMACHY (DANDELIONS) and Intercontinental Transport Experiment (INTEX-B) campaigns held in 2006. These unique campaigns covered a wide range of pollution scenarios and provided detailed information on the vertical distribution of NO2. We examine how changes in the a priori profiles and albedo assumptions affect the OMI NO2 retrieval. The absolute average change in tropospheric columns retrieved with measured profiles and improved albedos is 23% with a standard deviation of 31%. We present two case studies related to pollution in the Southeastern US and Anchorage, Alaska to exemplify these changes. For most cases, using improved a priori information improves the OMI retrievals. This validation study lays the groundwork for examining trends in tropospheric NO2. We analyze changes in tropospheric NO2 observed from OMI between 2004 and 2008 in the United States and China. Our results suggest that the EPA Clean Air Act is taking effect in a number of states in the eastern United States with an average decrease of 19% (from 2004-2008), whereas previously reported increasing levels of air pollution in China, determined from GOME and SCIAMACHY, appear to continue at a high pace of 28% from 2004 to 2008.

  20. Polvo en la Región de los Troyanos

    NASA Astrophysics Data System (ADS)

    Gilhutton, R.; Brunini, A.; Coldwell, G.

    La posible existencia de un anillo de polvo en la resonancia 1:1 con Júpiter formado por partículas provenientes de colisiones de asteroides fue propuesta por Liou and Zook (Icarus 113, 403, 1995) y estudiada extensamente por Vieira Martins and Gomes (VIII Reunión Regional Latinoamericana de Astronomía, Montevideo,1995). Si bien las partículas quedarían atrapadas sólo por períodos de algunos miles de años, el proceso colisional continuo en el cinturón de asteroides mantendría constante la densidad, presentándose una mayor concentración en la región de los troyanos. En el presente trabajo se presentan resultados preliminares sobre observaciones polarimétricas realizadas desde CASLEO de la región de L5 que confirmarían la existencia y variaciones de densidad en el anillo de polvo.

  1. Retrieval of Ozone Total Columns over Evora-Portugal Using Remote Sensing Instruments During 2007-2011

    NASA Astrophysics Data System (ADS)

    Domingues, A. F.; Bortoli, D.; Silva, A. M.; Kulkarni, P.; Mendes, R.

    2015-04-01

    The present study deals with the retrieval of Ozone (O3) Total Column (TOC) and analysis of its variability over the Observatory of the Geophysics Centre of Evora (CGE-UE) -Portugal (38.5°N; 7.9 °W, 300 m a.s.l.) for the period comprised 2007-2011. The data presented in this study are obtained applying the Differential Optical Absorption Spectroscopy (DOAS) methodology to the measurements of diffused spectral sky radiation carried out along the zenith direction performed with the multipurpose UV-Vis. Spectrometer for Atmospheric Tracers Monitoring (SPATRAM) in the 250-900 nm spectral range. This ground-based spectrometer is installed at CGE-UE performing daily and automatic measurements since 2004. Other products of this scanning spectrometer are the vertical profiles of some trace gases (e.g. NO2) and monitoring of air quality. The O3 retrieved with the SPATRAM instrument confirm the typical seasonal cycle for middle latitudes reaching the maximum during the spring and the minimum during the autumn. The ground-based results obtained for O3 column are also compared with data from SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) and Global Ozone Monitoring Experiment (GOME) instruments aboard ENVISAT and ERS-2 satellites, respectively. The results show a good agreement between the datasets. The main reasons for the observed differences are discussed.

  2. The use of microsatellites for germplasm management in a Portuguese grapevine collection.

    PubMed

    Lopes, M S; Sefc, K M; Eiras Dias, E; Steinkellner, H; Laimer Câmara Machado, M; Câmara Machado, A

    1999-08-01

    To initiate the characterization of the Portuguese grapevine genepool, we have genotyped 49 Portuguese grapevine cultivars at 11 microsatellite loci. The markers proved to be informative in the Portuguese cultivars, with expected heterozygosity ranging from 0.67 to 0.84. At most loci, an excess of heterozygous individuals was observed, while the deficiency of heterozygotes at 1 locus (VVMD6) indicated the presence of null alleles. On the basis of the microsatellite allele data several previously assumed synonyms were verified: (1) 'Fernão Pires'='Maria Gomes', (2) 'Moscatel de Setúbal'='Muscat of Alexandria', (3) 'Boal Cachudo'='Boal da Madeira'='Malvasia Fina', (4) 'Síria'='Crato Branco'= 'Roupeiro' and (5) 'Periquita'='Castelão Francês'='João de Santarém'='Trincadeira'. Although the three varieties 'Verdelho da Madeira', 'Verdelho dos Açores', and 'Verdelho roxo' are regarded by the Lista Nacional de Sinónimos as distinct cultivars, they displayed identical SSR profiles at 17 loci and appear to represent types of 1 single cultivar. The genetic profiles of all 49 cultivars were searched for possible parent-offspring groups. The data obtained revealed the descendence of 'Boal Ratinho' from 'Malvasia Fina' and 'Síria'.

  3. New orbits of irregular satellites designed for the predictions of stellar occultations up to 2020, based on thousands of new observations

    NASA Astrophysics Data System (ADS)

    Gomes-Júnior, A. R.; Assafin, M.; Beauvalet, L.; Desmars, J.; Vieira-Martins, R.; Camargo, J. I. B.; Morgado, B. E.; Braga-Ribas, F.

    2016-10-01

    Gomes-Júnior et al. published 3613 positions for the eight largest irregular satellites of Jupiter and 1787 positions for the largest irregular satellite of Saturn, Phoebe. These observations were made between 1995 and 2014 and have an estimated error of about 60-80 mas. Based on this set of positions, we derived new orbits for the eight largest irregular satellites of Jupiter: Himalia, Elara, Pasiphae, Carme, Lysithea, Sinope, Ananke and Leda. For Phoebe we updated the ephemeris from Desmars et al. using 75 per cent more positions than the previous one. Because of their orbital characteristics, it is common belief that the irregular satellites were captured by the giant planets in the early Solar system, but there is no consensus for a single model explaining where they were formed. Size, shape, albedo and composition would help to trace back their true origin, but these physical parameters are yet poorly known for irregular satellites. The observation of stellar occultations would allow for the determination of such parameters. Indeed Jupiter will cross the galactic plane in 2019-2020 and Saturn in 2018, improving a lot the chances of observing such events in the near future. Using the derived ephemerides and the UCAC4 catalogue we managed to identify 5442 candidate stellar occultations between 2016 January and 2020 December for the nine satellites studied here. We discussed how the successful observation of a stellar occultation by these objects is possible and present some potential occultations.

  4. Toward Rotational State-Selective Photoionization of ThF+ Ions

    NASA Astrophysics Data System (ADS)

    Zhou, Yan; Ng, Kia Boon; Gresh, Dan; Cairncross, William; Grau, Matt; Ni, Yiqi; Cornell, Eric; Ye, Jun

    2016-06-01

    ThF+ has been chosen to replace HfF+ for a second-generation measurement of the electric dipole moment of the electron (eEDM). Compared to the currently running HfF+ eEDM experiment, ThF+ has several advantages: (i) the eEDM-sensitive state (3Δ1) is the ground state, which facilitates a long coherence time [1]; (ii) its effective electric field (35 GV/cm) is 50% larger than that of HfF+, which promises a direct increase of the eEDM sensitivity [2]; and (iii) the ionization energy of neutral ThF is lower than its dissociation energy, which introduces greater flexibility in rotational state-selective photoionization via core-nonpenetrating Rydberg states [3]. In this talk, we first present our strategy of preparing and utilizing core-nonpenetrating Rydberg states for rotational state-selective ionization. Then, we report spectroscopic data of laser-induced fluorescence of neutral ThF, which provides critical information for multi-photon ionization spectroscopy. [1] D. N. Gresh, K. C. Cossel, Y. Zhou, J. Ye, E. A. Cornell, Journal of Molecular Spectroscopy, 319 (2016), 1-9 [2] M. Denis, M. S. Nørby, H. J. A. Jensen, A. S. P. Gomes, M. K. Nayak, S. Knecht, T. Fleig, New Journal of Physics, 17 (2015) 043005. [3] Z. J. Jakubek, R. W. Field, Journal of Molecular Spectroscopy 205 (2001) 197-220.

  5. TOMS UV Algorithm: Problems and Enhancements. 2

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay; Herman, Jay; Bhartia, P. K.; Seftor, Colin; Arola, Antti; Kaurola, Jussi; Kroskinen, Lasse; Kalliskota, S.; Taalas, Petteri; Geogdzhaev, I.

    2002-01-01

    Satellite instruments provide global maps of surface ultraviolet (UV) irradiance by combining backscattered radiance measurements with radiative transfer models. The models are limited by uncertainties in input parameters of the atmosphere and the surface. We evaluate the effects of possible enhancements of the current Total Ozone Mapping Spectrometer (TOMS) surface UV irradiance algorithm focusing on effects of diurnal variation of cloudiness and improved treatment of snow/ice. The emphasis is on comparison between the results of the current (version 1) TOMS UV algorithm and each of the changes proposed. We evaluate different approaches for improved treatment of pixel average cloud attenuation, with and without snow/ice on the ground. In addition to treating clouds based only on the measurements at the local time of the TOMS observations, the results from other satellites and weather assimilation models can be used to estimate attenuation of the incident UV irradiance throughout the day. A new method is proposed to obtain a more realistic treatment of snow covered terrain. The method is based on a statistical relation between UV reflectivity and snow depth. The new method reduced the bias between the TOMS UV estimations and ground-based UV measurements for snow periods. The improved (version 2) algorithm will be applied to re-process the existing TOMS UV data record (since 1978) and to the future satellite sensors (e.g., Quik/TOMS, GOME, OMI on EOS/Aura and Triana/EPIC).

  6. Status Report on Evaluation of OMPS SDR

    NASA Astrophysics Data System (ADS)

    Wu, X.; Pan, C.; Flynn, L. E.; Jaross, G.; Seftor, C. J.; Buss, R. H.; Caponi, M. Z.; Qian, H.

    2012-12-01

    The Ozone Mapper Profiler Suite (OMPS) is a new generation of satellite instrument. The first OMPS was successfully launched in October 2011 onboard the Suomi National Polar-orbiting Partnership (NPP) satellite. After a series of post-launch verification and validation, it will join the previous (TOMS) and current (SBUV/2, OMI, GOME-2, SCIAMACHY) satellite instruments to continue monitoring the global distribution of stratospheric ozone in time and space. OMPS is consisted of three separate sensors, including the Nadir Mapper, the Nadir Profiler, and the Limb Profiler. The National Oceanic and Atmospheric Administration (NOAA) is responsible for the product generation from the two nadir instruments. Since launch, NOAA has led the OMPS Sensor Data Record (SDR) Team to conduct an Independent Verification and Validation (IV&V) of the OMPS nadir instruments. Part of the IV&V is to verify that the instrument performance as established during pre-launch tests has been successfully transferred to orbit; this will be reported in a companion paper. Another part of the IV&V is to validate the quality of OMPS SDR; this will be reported in this paper. The IV&V will establish baselines for instrument performance and data quality, which will be continuously monitored by the Integrated Calibration and Validation System (ICVS) at the Center for Satellite Applications and Research (STAR) of NOAA.

  7. A satellite based study of tropospheric bromine explosion events and their linkages to polar cyclone development

    NASA Astrophysics Data System (ADS)

    Blechschmidt, Anne-Marlene; Richter, Andreas; Burrows, John P.; Kaleschke, Lars; Strong, Kimberly; Theys, Nicolas; Weber, Mark; Zhao, Xiaoyi; Zien, Achim; Hodges, Kevin I.

    2016-04-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by the UV-vis satellite instruments GOME-2/MetOp-A and SCIAMACHY/Envisat over Arctic and Antarctic sea ice in polar spring. The plumes are associated with an autocatalytic chemical chain reaction involving tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. This influences atmospheric chemistry as it affects the oxidising capacity of the troposphere through OH production and may also influence the local weather/temperature of the polar atmosphere, as ozone is a major greenhouse gas. Here, we make combined use of satellite retrievals and numerical model simulations to study individual BrO plume cases in the polar atmosphere. In agreement with previous studies, our analysis shows that the plumes are often transported by high latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. Moreover, general characteristics of bromine explosion events linked to transport by polar weather systems, such as frequency, spatial distribution and favourable weather conditions are derived based on a new detection method. Our results show that BrO cyclone transport events are by far more common in the Antarctic than in the Arctic.

  8. The origin and evolution of the zodiacal dust cloud

    NASA Astrophysics Data System (ADS)

    Dermott, Stanley F.; Durda, Daniel D.; Gustafson, Bo A. S.; Jayaraman, S.; Xu, Y. L.; Gomes, R. S.; Nicholson, P. D.

    1992-12-01

    We have now analyzed a substantial fraction of the IRAS observations of the zodiacal cloud, particularly in the 25 micron waveband. We have developed a gravitational perturbation theory that incorporates the effects of Poynting-Robertson light drag (Gomes and Dermott, 1992). We have also developed a numerical model, the SIMUL mode, that reproduces the exact viewing geometry of the IRAS telescope and calculates the distribution of thermal flux produced by any particular distribution of dust particle orbits (Dermott and Nicholson, 1989). With these tools, and using a distribution of orbits based on those of asteroidal particles with 3.4 micron radii whose orbits decay due to Poynting-Robertson light drag and are perturbed by the planets, we have been able to: (1) account for the inclination and node of the background zodiacal cloud observed by IRAS in the 25 micron waveband; (2) relate the distribution of orbits in the Hirayama asteroid families to the observed shapes of the IRAS solar system dustbands; and (3) show that there is observational evidence in the IRAS data for the transport of asteroidal particles from the main belt to the Earth by Poynting-Robertson light drag.

  9. The origin and evolution of the zodiacal dust cloud

    NASA Technical Reports Server (NTRS)

    Dermott, Stanley F.; Durda, Daniel D.; Gustafson, Bo A. S.; Jayaraman, S.; Xu, Y. L.; Gomes, R. S.; Nicholson, P. D.

    1992-01-01

    We have now analyzed a substantial fraction of the IRAS observations of the zodiacal cloud, particularly in the 25 micron waveband. We have developed a gravitational perturbation theory that incorporates the effects of Poynting-Robertson light drag (Gomes and Dermott, 1992). We have also developed a numerical model, the SIMUL mode, that reproduces the exact viewing geometry of the IRAS telescope and calculates the distribution of thermal flux produced by any particular distribution of dust particle orbits (Dermott and Nicholson, 1989). With these tools, and using a distribution of orbits based on those of asteroidal particles with 3.4 micron radii whose orbits decay due to Poynting-Robertson light drag and are perturbed by the planets, we have been able to: (1) account for the inclination and node of the background zodiacal cloud observed by IRAS in the 25 micron waveband; (2) relate the distribution of orbits in the Hirayama asteroid families to the observed shapes of the IRAS solar system dustbands; and (3) show that there is observational evidence in the IRAS data for the transport of asteroidal particles from the main belt to the Earth by Poynting-Robertson light drag.

  10. Characterization of the fishes and of subsistence fishing in the Pantanal of Mato Grosso, Brazil.

    PubMed

    de Oliveira, R D; de B Nogueira, F M

    2000-08-01

    Fishing is one of the oldest human activities in the Pantanal of Mato Grosso in Central Brazil. In the of Bento Gomes River Basin (Pantanal of Poconé) the presence of fishermen is very common. The objective of this study is to describe the fishing activity in the basin in view of the elaboration of proposals for the sustainable use of this natural resource. Of the 256 fishermen that were registered most are fishing for their subsistence (92%) and the rest (8%) are occasional fishermen (locally called "de lufada" fishermen). "Traíra" (Hoplias malabaricus) and "piranhas" (Serrasalmus marginatus, Serrasalmus spilopleura and Pygocentrus nattereri) were the species most frequently captured for human consumption. The fishing is more intensive during the ebb season and at the beginning of the drought season, when the waters begin to recede for the river channel, as the catch is facilitated by the concentration of fishes at the river margin. The fishermen and their families consume fish three to four times a week, twice a day. Fish meat is one of the only means of obtaining animal protein for dozens of poor families in the area. The number of fishermen, as well as the actual number of catches do not appear to compromise the natural fish stocks, although no specific capture criteria is obeyed by the fishing activity. PMID:11188869

  11. Evaluation of the cytotoxic activity of some Brazilian medicinal plants.

    PubMed

    Ribeiro, Sandra S; de Jesus, Aline M; dos Anjos, Charlene S; da Silva, Thanany B; Santos, Alan D C; de Jesus, Jemmyson R; Andrade, Moacir S; Sampaio, Tais S; Gomes, Wesley F; Alves, Péricles B; Carvalho, Adriana A; Pessoa, Claudia; de Moraes, Manoel O; Pinheiro, Maria L B; Prata, Ana Paula N; Blank, Arie F; Silva-Mann, Renata; Moraes, Valeria R S; Costa, Emmanoel V; Nogueira, Paulo Cesar L; Bezerra, Daniel P

    2012-09-01

    Plants are promising sources of new bioactive compounds. The aim of this study was to investigate the cytotoxic potential of nine plants found in Brazil. The species studied were: Annona pickelii Diels (Annonaceae), Annona salzmannii A. DC. (Annonaceae), Guatteria blepharophylla Mart. (Annonaceae), Guatteria hispida (R. E. Fr.) Erkens & Maas (Annonaceae), Hancornia speciosa Gomes (Apocynaceae), Jatropha curcas L. (Euphorbiaceae), Kielmeyera rugosa Choisy (Clusiaceae), Lippia gracilis Schauer (Verbenaceae), and Hyptis calida Mart. Ex Benth (Lamiaceae). Different types of extractions from several parts of plants resulted in 43 extracts. Their cytotoxicity was tested against HCT-8 (colon carcinoma), MDA-MB-435 (melanoma), SF-295 (glioblastoma), and HL-60 (promielocitic leukemia) human tumor cell lines, using the thiazolyl blue test (MTT) assay. The active extracts were those obtained from G. blepharophylla, G. hispida, J. curcas, K. rugosa, and L. gracilis. In addition, seven compounds isolated from the active extracts were tested; among them, β-pinene found in G. hispida and one coumarin isolated from K. rugora showed weak cytotoxic activity. In summary, this manuscript contributes to the understanding of the potentialities of Brazilian plants as sources of new anticancer drugs.

  12. Retrieval of CHOCHO from MAX-DOAS measurements in the Beijing area

    NASA Astrophysics Data System (ADS)

    Hendrick, Francois; Lerot, Christophe; Stavrakou, Trissevgeni; De Smedt, Isabelle; Fayt, Caroline; Gielen, Clio; Hermans, Christian; Müller, Jean-Francois; Pinardi, Gaia; Van Roozendael, Michel

    2015-04-01

    Glyoxal (CHOCHO) is one of the most important carbonyl compounds in the atmosphere. It is produced mainly by the oxidation of biogenic and anthropogenic non-methane volatile organic compounds (NMVOCs) which participate to the formation of tropospheric ozone and secondary organic aerosols. CHOCHO is also directly released by biomass burning and fossil fuel combustion. Measuring this species is therefore of major importance for air quality monitoring, especially given the scarcity of available CHOCHO observational data sets. In this presentation, CHOCHO vertical profiles and corresponding column densities are retrieved from MAX-DOAS measurements in the Beijing city center and at the suburban site of Xianghe located at 60km East of Beijing. The periods covered by the observations are June 2008-April 2009 in Beijing and March 2010-December 2014 in Xianghe. We first investigate the capability of the MAX-DOAS technique to measure this species in such highly-polluted environment. Then the diurnal and seasonal cycles of CHOCHO near-surface concentrations and vertical column densities as well as the corresponding CHOCHO/HCHO ratios are examined on a long-term basis at both locations. The CHOCHO/HCHO ratios are derived from MAX-DOAS HCHO vertical profiles retrieved in parallel to the CHOCHO profiles. These diurnal and seasonal cycles are further assessed using simulations from the 3D-CTM IMAGES and observations from the OMI and GOME-2 satellite nadir instruments. The impact of these results on our knowledge about the CHOCHO budget is discussed.

  13. Enteric glial cells protect neurons from oxidative stress in part via reduced glutathione.

    PubMed

    Abdo, Hind; Derkinderen, Pascal; Gomes, Priya; Chevalier, Julien; Aubert, Philippe; Masson, Damien; Galmiche, Jean-Paul; Vanden Berghe, Pieter; Neunlist, Michel; Lardeux, Bernard

    2010-04-01

    Enteric glial cells (EGCs) are essential in the control of gastrointestinal functions. Although lesions of EGCs are associated with neuronal degeneration in animal models, their direct neuroprotective role remains unknown. Therefore, the aims of this study were to demonstrate the direct neuroprotective effects of EGCs and to identify putative glial mediators involved. First, viral targeted ablation of EGCs in primary cultures of enteric nervous system increased neuronal death both under basal conditions and in the presence of oxidative stress (dopamine, hydrogen peroxide). Second, direct or indirect coculture experiments of EGC lines with primary cultures of enteric nervous system or neuroblastoma cell lines (SH-SY5Y) prevented neurotoxic effects induced by oxidative stress (increased membrane permeability, release of neuronal specific enolase, caspase-3 immunoreactivity, changes in [Ca(2+)](i) response). Finally, combining pharmacological inhibition and mRNA silencing methods, we demonstrated that neuroprotective effects of EGCs were mediated in part by reduced glutathione but not by oxidized glutathione or by S-nitrosoglutathione. Our study identified the neuroprotective effects of EGCs via their release of reduced glutathione, extending their critical role in physiological contexts and in enteric neuropathies.-Abdo, H., Derkinderen, P., Gomes, P., Chevalier, J., Aubert, P., Masson, D., Galmiche, J.-P., Vanden Berghe, P., Neunlist, M., Lardeux, B. Enteric glial cells protect neurons from oxidative stress in part via reduced glutathione.

  14. Common Calibration Source for Monitoring Long-term Ozone Trends

    NASA Technical Reports Server (NTRS)

    Kowalewski, Matthew

    2004-01-01

    Accurate long-term satellite measurements are crucial for monitoring the recovery of the ozone layer. The slow pace of the recovery and limited lifetimes of satellite monitoring instruments demands that datasets from multiple observation systems be combined to provide the long-term accuracy needed. A fundamental component of accurately monitoring long-term trends is the calibration of these various instruments. NASA s Radiometric Calibration and Development Facility at the Goddard Space Flight Center has provided resources to minimize calibration biases between multiple instruments through the use of a common calibration source and standardized procedures traceable to national standards. The Facility s 50 cm barium sulfate integrating sphere has been used as a common calibration source for both US and international satellite instruments, including the Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet 2 (SBUV/2) instruments, Shuttle SBUV (SSBUV), Ozone Mapping Instrument (OMI), Global Ozone Monitoring Experiment (GOME) (ESA), Scanning Imaging SpectroMeter for Atmospheric ChartographY (SCIAMACHY) (ESA), and others. We will discuss the advantages of using a common calibration source and its effects on long-term ozone data sets. In addition, sphere calibration results from various instruments will be presented to demonstrate the accuracy of the long-term characterization of the source itself.

  15. Volcanic iodine monoxide observed from satellite

    NASA Astrophysics Data System (ADS)

    Schönhardt, Anja; Richter, Andreas; Theys, Nicolas; Burrows, John P.

    2016-04-01

    Halogen species are injected into the atmosphere by volcanic eruptions. Previous studies have reported observations of chlorine and bromine oxides in volcanic plumes. These emissions have a significant impact on the chemistry within the plume as well as on upper troposphere and lower stratosphere composition, e.g. through ozone depletion. Volcanic halogen oxides have been observed from different platforms, from ground, aircraft and from satellite. The present study reports on satellite observations of iodine monoxide, IO, following the eruption of the Kasatochi volcano, Alaska, in August 2008. Satellite measurements from the SCIAMACHY sensor onboard ENVISAT are used. In addition, the volcanic IO plume is also retrieved from GOME-2 / MetOP-A measurements. Largest IO column amounts reach up to more than 4×1013 molec/cm2, the results from both instruments being consistent. The IO plume has a very similar shape as the BrO plume and is observed for several days following the eruption. The present observations are the first evidence that besides chlorine and bromine oxides also iodine oxides can be emitted by volcanic eruptions. This has important implications for atmospheric composition and background iodine levels. Together with the simultaneous observations of BrO and SO2, iodine monoxide columns can possibly provide insights into the composition of the magma.

  16. Internal Gravity Wave Activity Hotspot and Implications for the Middle Atmospheric Dynamics

    NASA Astrophysics Data System (ADS)

    Sacha, Petr; Pisoft, Petr; Lilienthal, Friederike; Jacobi, Christoph

    2015-06-01

    Internal gravity waves are widely recognized to contribute significantly to the energy and angular momentum transport. They play a significant role in affecting many of the middle atmospheric phenomena (like the QBO or Brewer-Dobson circulation). Using GPS RO density profiles, we have discovered a localized area of enhanced IGW activity and breaking in the lower stratosphere of Eastern Asia/North-western Pacific region. With a 3D primitive equation model of the middle atmosphere we studied the effects of such a localized breaking region on large-scale dynamics and transport. Possible forcing and propagation directions of planetary waves caused by such a localized IGW forcing were investigated and consequences for the polar vortex stability and stratosphere-troposphere exchange in the tropical region were discussed. Finally, applying 3D EP flux and 3D residual circulation diagnostics, we investigated the possible role of this area in the longitudinal variability of the Brewer-Dobson circulation with a hypothesis of its enhanced downwelling branch in this region. In the proces, model results were compared with the ozone and tracer distribution data from GOME, GOMOS, MIPAS and SCIAMACHY further confirming the importance of the Eastern Asia/North-western Pacific region for middle atmospheric dynamics.

  17. Model Study of IGW Hotspot Implications for the Middle Atmospheric Dynamics and Transport

    NASA Astrophysics Data System (ADS)

    Pisoft, P.; Šácha, P.; Jacobi, C.; Lilienthal, F.

    2015-12-01

    Internal gravity waves are widely recognized to contribute significantly to the energy and angular momentum transport. They play a significant role in affecting many of the middle atmospheric phenomena (like the QBO or Brewer-Dobson circulation). Using GPS RO density profiles, we have discovered a localized area of enhanced IGW activity and breaking in the lower stratosphere of Eastern Asia/North-western Pacific region. With a 3D primitive equation model of the middle atmosphere we studied the effects of such a localized breaking region on large-scale dynamics and transport. Enhancing artificially a gravity wave drag in the lover stratosphere of the EA/NP region we show that such a localized IGW forcing creates planetary waves propagating both equatorward and poleward and upward along the edge of the polar vortex. Possible consequences for the polar vortex stability and stratosphere-troposphere exchange in the tropical region are discussed. Finally, applying 3D wave activity flux and 3D residual circulation diagnostics, we investigated the possible role of this area in the longitudinal variability of the Brewer- Dobson circulation with a hypothesis of its enhanced downwelling branch in this region. In the process, model results were compared with the ozone and tracer distribution data from GOME, GOMOS, MIPAS and SCIAMACHY further confirming an importance of the Eastern Asia/North-western Pacific region for the middle atmospheric dynamics.

  18. Current Applications of OMI Tropospheric NO2 Data for Air Quality and a Look to the Future

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Bucsela, E.; Allen, D.; Prados, A.; Gleason, J.; Kondragunta, S.

    2010-01-01

    Ozone Monitoring Instrument (OMI) Tropospheric NO2 products are being used to enhance the ability to monitor changes in NO2 air quality, update emission inventories, and evaluate regional air quality models. Trends in tropospheric column NO2 have been examined over the eastern United States in relation to emissions changes mandated by regulatory actions. Decreases of 20 to 40 percent over the period 2005 to 2008 were noted, largely in response to major emission reductions at power plants. The OMI data have been used to identify regions in which the opposite trend has been found. We have also used OMI NO2 in efforts to improve emission inventories for NOx emissions from soil. Lightning NOx emissions have been added to CMAQ, the US Environmental Protection Agency's regional air quality model. Evaluation of the resulting NO2 columns in the model is being conducted using the OMI NO2 observations. Community Multiscale Air Quality (CMAQ) together with the OMI NO2 data comprise a valuable tool for monitoring and predicting air quality. Looking to the future, we expect that the combination of Global Ozone Monitoring Experiment-2 (GOME-2) (morning) and OMI (afternoon) data sets obtained through use of the same retrieval algorithms will substantially increase the possibility of successful integration of satellite information into regional air quality forecast models. Farther down the road, we anticipate the Geostationary Coastal and Air Pollution Events (GEO-CAPE) platform to supply data possibly on an hourly basis, allowing much more comprehensive analysis of air quality from space.

  19. The effect of Delaire cheilorhinoplasty on midfacial growth in patients with unilateral cleft lip and palate.

    PubMed

    Rullo, Rosario; Laino, Gregorio; Cataneo, Marisa; Mazzarella, Nicoletta; Festa, Vincenzo Maria; Gombos, Fernando

    2009-02-01

    The aim of this research was to evaluate the effect of the Delaire surgical technique on the midfacial morphology in a group of subjects with a congenital unilateral cleft of lip and palate (UCLP), prior to orthodontic treatment. Thirty-five UCLP (15 left and 20 right) patients (16 males and 19 females, mean age 7.03+/-0.9 years; age range 8.7-5.0 years), treated for the correction of congenital malformation, were retrospectively selected. Analysis of midfacial growth was undertaken on lateral cephalograms, and the data were compared with reference values (Ricketts analysis). A Mann-Whitney ranked sum test was used to detect significant differences between the findings and reference values. P Go-Me distance). Vertically, there was a trend to a posterior rotation of the mandible (P<0.01), resulting in a hyperdivergent profile. This trend was confirmed by the increase in SpA-SpP/Go-Me (P<0.05). In agreement with previous studies, the effects of surgical closure of a cleft lip might be responsible for excessive maxillary retropositioning with a downward rotation.

  20. Exploring the Capabilities of Satellite Observation of Anthropogenic Sulfur Dioxide (SO2) in the Lower Atmosphere

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    Anthropogenic activities, such as fuel combustion, oil refining, and metal smelting, emit sulfur dioxide (SO2) into the atmospheric planetary boundary layer (PBL), leading to air quality degradation near the source regions. SO2 in the air is oxidized to form sulfate aerosols, which may have a significant impact on regional air quality and climate. Sulfate aerosols are usually removed from the atmosphere through acid deposition, which can damage the environment and ecosystems. SO2 and sulfate aerosols are sometimes lifted into the middle or upper troposphere and subsequently transported over long distances, affecting remote regions. Space-borne UV instruments, such as Aura/OMI, MetOp/GOME-2, and NPP/OMPS, provide a unique perspective on the spatial and temporal distribution of SO2 over the globe. In this presentation, we will describe the recent advances in retrieval algorithm that provide improved detection and quantification of PBL SO2, and compare the new retrievals with the operational OMI SO2 products to show significant reduction in noise and bias. We will also present validation results obtained by the comparisons with co-located in-situ aircraft measurements to illustrate improved accuracy achieved with the advanced algorithm.

  1. Assessment of the Impact of The East Asian Summer Monsoon on the Air Quality Over China

    NASA Astrophysics Data System (ADS)

    Hao, Nan; Ding, Aijun; Safieddine, Sarah; Valks, Pieter; Clerbaux, Cathy; Trautmann, Thomas

    2016-04-01

    Air pollution is one of the most important environmental problems in developing Asian countries like China. In this region, studies showed that the East Asian monsoon plays a significant role in characterizing the temporal variation and spatial patterns of air pollution, since monsoon is a major atmospheric system affecting air mass transport, convection, and precipitation. Knowledge gaps still exist in the understanding of Asian monsoon impact on the air quality in China under the background of global climate change. For the first time satellite observations of tropospheric ozone and its precursors will be integrated with the ground-based, aircraft measurements of air pollutants and model simulations to study the impact of the East Asian monsoon on air quality in China. We apply multi-platform satellite observations by the GOME-2, IASI, and MOPITT instruments to analyze tropospheric ozone and CO, precursors of ozone (NO2, HCHO and CHOCHO) and other related trace gases over China. Two years measurements of air pollutants including NO2, HONO, SO2, HCHO and CHOCHO at a regional back-ground site in the western part of the Yangtze River Delta (YRD) in eastern China will be presented. The potential of using the current generation of satellite instruments, ground-based instruments and aircraft to monitor air quality changes caused by the East Asian monsoon circulation will be presented. Preliminary comparison results between satellite measurement and limited but valuable ground-based and aircraft measurements will also be showed.

  2. The STRatospheric Estimation Algorithm from Mainz (STREAM): estimating stratospheric NO2 from nadir-viewing satellites by weighted convolution

    NASA Astrophysics Data System (ADS)

    Beirle, Steffen; Hörmann, Christoph; Jöckel, Patrick; Liu, Song; Penning de Vries, Marloes; Pozzer, Andrea; Sihler, Holger; Valks, Pieter; Wagner, Thomas

    2016-07-01

    The STRatospheric Estimation Algorithm from Mainz (STREAM) determines stratospheric columns of NO2 which are needed for the retrieval of tropospheric columns from satellite observations. It is based on the total column measurements over clean, remote regions as well as over clouded scenes where the tropospheric column is effectively shielded. The contribution of individual satellite measurements to the stratospheric estimate is controlled by various weighting factors. STREAM is a flexible and robust algorithm and does not require input from chemical transport models. It was developed as a verification algorithm for the upcoming satellite instrument TROPOMI, as a complement to the operational stratospheric correction based on data assimilation. STREAM was successfully applied to the UV/vis satellite instruments GOME 1/2, SCIAMACHY, and OMI. It overcomes some of the artifacts of previous algorithms, as it is capable of reproducing gradients of stratospheric NO2, e.g., related to the polar vortex, and reduces interpolation errors over continents. Based on synthetic input data, the uncertainty of STREAM was quantified as about 0.1-0.2 × 1015 molecules cm-2, in accordance with the typical deviations between stratospheric estimates from different algorithms compared in this study.

  3. Effect of temperature and surfactant on the control release of microencapsulated dye in lecithin liposomes. I.

    PubMed

    Baptista, A L F; Coutinho, P J G; Real Oliveira, M E C D; Gomes, J I N Rocha

    2003-05-01

    The objective of our work has been the microencapsulation of dyes with lecithin from soybean, with the formation of liposomes, as a substitute for synthetic auxiliaries so as to improve the quality of the effluent. Current scenarios promote the disintegration and leakage of the liposomes, such as, changes in temperature, pH and the use of surfactants. Since dyeing process is a mix of all these parameters, we pretended to study each one separately. Rhodamine 6G fluorescence is known to be concentration quenched through the formation of non-fluorescent dimmers and, additionally, through the energy transfer from rhodamine monomer to these dimmers (Baptista ALF, Coutinho PJG, Real Oliveira MECD, Gomes JINR. Proceedings of 13th International Symposium of Surfactants, SIS 2000, Gainesville, USA, 2000). The temperature, the surfactant and pH induce a release of the encapsulated dye resulting in rhodamine dilution and consequently alterations in the dimerization/binding equilibrium. The experimental spectra indicate that rhodamine binds almost completely to liposomes. The decomposition of the rhodamine fluorescence spectra allowed us to determine the percentage of released dye during a simulated dyeing process, and allowed us to conclude that the dimerization process occurs mainly at the inner interfaces. The amount of dye released induced by temperature changes was greater in the presence of surfactant.

  4. Satellite derived trends in NO2 over the major global hotspot regions during the past decade and their inter-comparison.

    PubMed

    Ghude, Sachin D; Van der A, R J; Beig, G; Fadnavis, S; Polade, S D

    2009-06-01

    We assessed satellite derived tropospheric NO(2) distribution on a global scale and identified the major NO(2) hotspot regions. Combined GOME and SCIAMACHY measurements for the period 1996-2006 have been used to compute the trends over these regions. Our analysis shows that tropospheric NO(2) column amounts have increased over the newly and rapidly developing regions like China (11+/-2.6%/year), south Asia (1.76+/-1.1%/year), Middle East (2.3+/-1%/year) and South Africa (2.4+/-2.2%/year). Tropospheric NO(2) column amounts show some decrease over the eastern US (-2+/-1.5%/year) and Europe (0.9+/-2.1%/year). We found that although tropospheric NO(2) column amounts decreased over the major developed regions in the past decade, the present tropospheric NO(2) column amounts over these regions are still significantly higher than those observed over newly and rapidly developing regions (except China). Tropospheric NO(2) column amounts show some decrease over South America and Central Africa, which are major biomass burning regions in the Southern Hemisphere.

  5. Trends of total water vapor column above the Arctic from satellites observations

    NASA Astrophysics Data System (ADS)

    Alraddawi, Dunya; Sarkissian, Alain; Keckhut, Philippe; Bock, Olivier; Claud, Chantal; Irbah, Abdenour

    2016-04-01

    Atmospheric water vapor (H2O) is the most important natural (as opposed to man-made) greenhouse gas, accounting for about two-thirds of the natural greenhouse effect. Despite this importance, its role in climate and its reaction to climate change are still difficult to assess. Many details of the hydrological cycle are poorly understood, such as the process of cloud formation and the transport and release of latent heat contained in the water vapor. In contrast to other important greenhouse gases like carbon dioxide (CO2) and methane, water vapor has a much higher temporal and spatial variability. Total precipitable water (TPW) or the total column of water vapor (TCWV) is the amount of liquid water that would result if all the water vapor in the atmospheric column of unit area were condensed. TCWV distribution contains valuable information on the vigor of the hydrological processes and moisture transport in the atmosphere. Measurement of TPW can be obtained based on atmospheric water vapor absorption or emission of radiation in the spectral range from UV to MW. TRENDS were found over the terrestrial Arctic by means of TCWV retrievals (using Moderate Resolution Imaging Spectro-radiometer (MODIS) near-infrared (2001-2015) records). More detailed approach was made for comparisons with ground based instruments over Sodankyla - Finland (TCWV from: SCIAMACHY 2003-2011, GOME-2A 2007-2011, SAOZ 2003-2011, GPS 2003-2011, MODIS 2003-2011)

  6. Atmospheric COS measurements and satellite-derived vegetation fluorescence data to evaluate the terrestrial gross primary productivity of CMIP5 model

    NASA Astrophysics Data System (ADS)

    Peylin, Philippe; MacBean, Natasha; Launois, Thomas; Belviso, Sauveur; Cadule, Patricia; Maignan, Fabienne

    2016-04-01

    Predicting the fate of the ecosystem carbon stocks and their sensitivity to climate change strongly relies on our ability to accurately model the gross carbon fluxes, i.e. photosynthesis and respiration. The Gross Primary Productivity (GPP) simulated by the different terrestrial models used in CMIP5 show large differences however, not only in terms of mean value but also in terms of phase and amplitude, thus hampering accurate investigations into carbon-climate feedbacks. While the net C flux of an ecosystem (NEE) can be measured in situ with the eddy covariance technique, the GPP is not directly accessible at larger scales and usually estimates are based on indirect measurements combining different tracers. Recent measurements of a new atmospheric tracer, the Carbonyl sulphide (COS), as well as the global measurement of Solar Induced Fluorescence (SIF) from satellite instruments (GOSAT, GOME2) open a new window for evaluating the GPP of earth system models. The use of COS relies on the fact that it is absorbed by the leaves in a similar manner to CO2, while there seems to be nothing equivalent to respiration for COS. Following recent work by Launois et al. (ACP, 2015), there is a potential to evaluate model GPP from atmospheric COS and CO2 measurements, using a transport model and recent parameterizations for the non-photosynthetic sinks (oxic soils, atmospheric oxidation) and biogenic sources (oceans and anoxic soils) of COS. Vegetation uptake of COS is modeled as a linear function of GPP and the ratio of COS to CO2 rate of uptake by plants. For the fluorescence, recent measurements of SIF from space appear to be highly correlated with monthly variations of data-driven GPP estimates (Guanter et al., 2012), following a strong dependence of vegetation SIF on photosynthetic activity. These global measurements thus provide new indications on the timing of canopy carbon uptake. In this work, we propose a dual approach that combines the strength of both COS and SIF

  7. Multi-satellite sensor study on precipitation-induced emission pulses of NOx from soils in semi-arid ecosystems

    NASA Astrophysics Data System (ADS)

    Zörner, Jan; Penning de Vries, Marloes; Beirle, Steffen; Veres, Patrick; Williams, Jonathan; Wagner, Thomas

    2016-04-01

    Soil emissions of NOx (≡ NO + NO2), stemming from biotic emissions of NO, represent a considerable fraction of total NOx emissions, and may even dominate in agricultural and remote areas. Rain-induced spikes in NOx have been observed by in-situ measurements and also satellite observations. However, the estimation of soil emissions over broad geographic regions and on short time scales remains uncertain. This study presents a top-down approach to estimate pulsed soil emissions of trace gases on a global scale using tropospheric NO2 column densities (as a proxy for NOx) as observed by OMI, GOME-2 and SCIAMACHY. We introduce an optimized algorithm that synchronizes and averages multiple time series of atmospheric variables either from one location only, or also from different grid pixels, by aligning them on a relative scale to each other. This method allows investigating changes in the evolution of NO2 VCDs around the first day of rainfall after a prolonged dry period with a temporal resolution of one day and a spatial resolution of 0.25° . We find enhancements in NO2 VCDs on the day of first rainfall in many semi-arid regions in the world which are highly dependent on the season and land cover type. Strongest and most clustered enhancements are found in the distinct band of the Sahel region during the onset of the wet season in April-May-June. Absolute enhancements averaged over the Sahel region for four seasons from 2007 to 2010 range from 0.3*1015molec cm-2 for OMI to 0.4*1015molec cm-2 for GOME-2 and SCIAMACHY on the first day of rainfall. A thorough analysis of other influences on the retrieved signal as well as sensitivity studies are conducted which help to better characterize these short term enhancements. Translating the observed enhancements in NO2 VCDs to emission rates, leads to estimates between 5 and 65 ng N m-2 s-1 for the first day of rainfall which is in line with previous literature. We find that the enhancement in NO2 VCDs already starts to

  8. Standardizing Interfaces for External Access to Data and Processing for the NASA Ozone Product Evaluation and Test Element (PEATE)

    NASA Technical Reports Server (NTRS)

    Tilmes, Curt A.; Fleig, Albert J.

    2008-01-01

    NASA's traditional science data processing systems have focused on specific missions, and providing data access, processing and services to the funded science teams of those specific missions. Recently NASA has been modifying this stance, changing the focus from Missions to Measurements. Where a specific Mission has a discrete beginning and end, the Measurement considers long term data continuity across multiple missions. Total Column Ozone, a critical measurement of atmospheric composition, has been monitored for'decades on a series of Total Ozone Mapping Spectrometer (TOMS) instruments. Some important European missions also monitor ozone, including the Global Ozone Monitoring Experiment (GOME) and SCIAMACHY. With the U.S.IEuropean cooperative launch of the Dutch Ozone Monitoring Instrument (OMI) on NASA Aura satellite, and the GOME-2 instrumental on MetOp, the ozone monitoring record has been further extended. In conjunction with the U.S. Department of Defense (DoD) and the National Oceanic and Atmospheric Administration (NOAA), NASA is now preparing to evaluate data and algorithms for the next generation Ozone Mapping and Profiler Suite (OMPS) which will launch on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) in 2010. NASA is constructing the Science Data Segment (SDS) which is comprised of several elements to evaluate the various NPP data products and algorithms. The NPP SDS Ozone Product Evaluation and Test Element (PEATE) will build on the heritage of the TOMS and OM1 mission based processing systems. The overall measurement based system that will encompass these efforts is the Atmospheric Composition Processing System (ACPS). We have extended the system to include access to publically available data sets from other instruments where feasible, including non-NASA missions as appropriate. The heritage system was largely monolithic providing a very controlled processing flow from data.ingest of

  9. Multiannual tropical tropospheric ozone columns and the case of the 2015 el Niño event

    NASA Astrophysics Data System (ADS)

    Leventidou, Elpida; Eichmann, Kai-Uwe; Weber, Mark; Burrows, John P.

    2016-04-01

    Stratospheric ozone is well known for protecting the surface from harmful ultraviolet solar radiation whereas ozone in the troposphere plays a more complex role. In the lower troposphere ozone can be extremely harmful for human health as it can oxidize biological tissues and causes respiratory problems. Several studies have shown that the tropospheric ozone burden (300±30Tg (IPCC, 2007)) increases by 1-7% per decade in the tropics (Beig and Singh, 2007; Cooper et al., 2014) which makes the need to monitor it on a global scale crucial. Remote sensing from satellites has been proven to be very useful in providing consistent information of tropospheric ozone concentrations over large areas. Tropical tropospheric ozone columns can be retrieved with the Convective Cloud Differential (CCD) technique (Ziemke et al. 1998) using retrieved total ozone columns and cloud parameters from space-borne observations. We have developed a CCD-IUP algorithm which was applied to GOME/ ERS-2 (1995-2003), SCIAMACHY/ Envisat (2002-2012), and GOME-2/ MetOpA (2007-2012) weighting function DOAS (Coldewey-Egbers et al., 2005, Weber et al., 2005) total ozone data. A unique long-term record of monthly averaged tropical tropospheric ozone columns (20°S - 20°N) was created starting in 1996. This dataset has been extensively validated by comparisons with SHADOZ (Thompson et al., 2003) ozonesonde data and limb-nadir Matching (Ebojie et al. 2014) tropospheric ozone data. The comparison shows good agreement with respect to range, inter-annual variation, and variance. Biases where found to be within 5DU and the RMS errors less than 10 DU. This 17-years dataset has been harmonized into one consistent time series, taking into account the three instruments' difference in ground pixel size. The harmonised dataset is used to determine tropical tropospheric ozone trends and climatological values. The 2015 el Niño event has been characterised as one of the top three strongest el Niños since 1950. El Ni

  10. The ESA DUE GlobVapour Project

    NASA Astrophysics Data System (ADS)

    Schröder, M.; ESA Due Globvapour Project Team

    2010-12-01

    DUE GlobVapour project is the preparation of recognised data sets and successful concepts that can be used to ensure a sustainable provision of such data from operational entities such as the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Satellite Application Facility (SAF) network. Key scientific questions which GlobVapour data can contribute to are climate monitoring and attribution, assimilation of different water vapour datasets to form a consistent analysis, model process studies, evaluation of in-situ water vapour measurements, validation of climate models and reanalyses, assessing the relationship between water vapour and dynamics, research and development for operational applications and input to atmospheric reanalyses. This presentation will introduce the GlobVapour project and concept as well as the products which are the global total column water vapour (TCWV) time series from a combination of MERIS and SSM/I as well as TCWV data sets derived from the GOME/SCIAMACHY/GOME-2 and the (A)ATSR instruments. A shorter time series of water vapour profiles will be derived from a combination of IASI and SEVIRI. The retrieval and combination methods as well as first validation results will also be discussed.

  11. Composition and meteorological changes associated with a strong stratospheric intrusion event in the Canadian High Arctic

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoyi; Strong, Kimberly; Conway, Stephanie; Tarasick, David; Osman, Mohammed; Richter, Andreas; Blechschmidt, Anne; Manney, Gloria

    2015-04-01

    Stratosphere-troposphere exchange (STE) provides a mechanism for trace gas transport between the lower stratosphere and the troposphere. Intense downward stratospheric intrusions may significantly affect the oxidizing capacity of the troposphere. Most STE events occur in tropical and mid-latitude regions, with less known about STE in the polar regions. In this work, we present an observation and modelling study of a strong stratospheric intrusion in the high Arctic (Eureka, 80°N) in March 2013, which led to an increase of total ozone and BrO columns observed by both ground-based and satellite instruments. The meteorological conditions for this event were similar to those observed for STEs associated with cold fronts. Before the cold front arrived at Eureka, the surface temperature first increased from -25.3°C (25 March 13:00 UTC) to -14.5°C (27 March 20:00 UTC) and then dropped to -36.4°C (29 March 6:00 UTC) after the front passed by. Meanwhile, the ground-level pressure decreased from 103.8 kPa to 101.8 kPa, then rose back to 102.6 kPa. Ozonesonde data (27 March 23:15 UTC) showed unusually high ozone (>100 ppbv) above ~3 km altitude, while the relative humidity profile indicated that the airmass was of stratospheric origin (very low relative humidity). The thermal tropopause height was ~9 km, based on a uniform lapse rate of 3.9 K/km from surface to 9 km. From ECMWF Interim data, the airmass with high relative potential vorticity (4 pvu) extended down to 3 km. In addition, HYSPLIT model ensemble back-trajectories show a clear Rossby wave signature in the upper troposphere during this event, which could explain the intrusion. However, there are no strong downwelling layers along the trajectories, which indicates that the intrusion may have occurred close to Eureka. Trace gas composition data from three ground-based spectrometers and the GOME-2 satellite instrument are presented in this work. Ozone vertical column densities (VCDs) measured by two Zenith

  12. Ozarks Isoprene Experiment (OZIE): Measurements and modeling of the ``isoprene volcano''

    NASA Astrophysics Data System (ADS)

    Wiedinmyer, Christine; Greenberg, Jim; Guenther, Alex; Hopkins, Brian; Baker, Kirk; Geron, Chris; Palmer, Paul I.; Long, Bryan P.; Turner, Jay R.; PéTron, Gabrielle; Harley, Peter; Pierce, Thomas E.; Lamb, Brian; Westberg, Hal; Baugh, William; Koerber, Mike; Janssen, Mark

    2005-09-01

    The Ozarks Isoprene Experiment (OZIE) was conducted in July 1998 in Missouri, Illinois, Indiana, and Oklahoma. OZIE was designed to investigate the presumed strong isoprene emission rates from the Missouri Ozarks, where there is a high density of oak trees that are efficient isoprene emitters. Ground, balloon, and aircraft measurements were taken over a three-week study period; 0-D and 3-D chemical models were subsequently used to better understand the observed isoprene emissions from the Ozarks and to investigate their potential regional-scale impacts. Leaf-level measurements for two oak tree species yielded normalized average isoprene emission capacities of 66 mgC g-1 h-1, in good agreement with values used in current biogenic emissions models. However, the emission capacities exhibited a temperature dependence that is not captured by commonly used biogenic emission models. Isoprene mixing ratios measured aloft from tethered balloon systems were used to estimate isoprene fluxes. These measurement-derived fluxes agreed with BEIS3 estimates within the relatively large uncertainties in the estimates. Ground-level isoprene mixing ratios exhibited substantial spatial heterogeneity, ranging from <1 to 35 ppbv. The agreement between measured isoprene mixing ratios and regional-scale chemical transport model estimates was improved upon averaging the ground-level isoprene data observed at several sites within a representative area. Ground-level formaldehyde (HCHO) mixing ratios were very high (up to 20 ppbv) and were consistently higher than mixing ratios predicted by a regional chemical transport model. The spatial distribution and magnitude of the elevated HCHO concentrations showed good agreement with GOME satellite column observations of HCHO.

  13. Economical crisis detected from space: Trends in air quality of Athens in Greece

    NASA Astrophysics Data System (ADS)

    Vrekoussis, Mihalis; Richter, Andreas; Hilboll, Andreas; Burrows, John P.; Zerefos, Christos; Gerasopoulos, Evangelos; Lelieveld, Jos; Barrie, Leonard; Mihalopoulos, Nikos

    2013-04-01

    Data from three satellite spectrometers (SCIAMACHY, GOME2 and OMI) have been analyzed together with a number of economic metrics to investigate the impact of the economic crisis (from 2008 onward) on air quality over Greece, and Athens in particular. Athens is a heavily polluted city due to the extensive number of registered vehicles, the presence of industrial regions close to the city, the complex topography of the area favouring pollutant accumulation, the intense photochemical processes favoured by high temperature and insolation and the reception of transboundary pollution. The multiannual analysis shows a significant 30-40% reduction of primary gaseous pollutants in the form of NO2 tropospheric columnar densities observed over Athens, during the economic recession period, indicating large reductions in pollutant emissions. This decline is further supported by surface measurements of atmospheric NO2 mixing ratios. Additionally, the declining local concentrations of NO, CO, SO2 are associated with an increase in ozone due to reduced titration by NO. In particular, regression analysis revealed that the reduction of NO2 (0.3±0.2 ppbv y-1) and SO2 (0.2±0.1ppbv y-1) during the period 2000-2007, significantly accelerated during the economic crisis period (from 2008 onward), reaching 2.3±0.2 ppbv y-1 and 0.7±0.1 ppbv y-1, respectively. The strong correlations between pollutant concentrations and economic indicators show that economic recession has resulted in proportionally lower levels of pollutants not only in Athens but also in large parts of Greece.

  14. NO{sub x} emission trends for China, 1995-2004 : the view from the ground and the view from space.

    SciTech Connect

    Zhang, Q.; Streets, D. G.; He, K.; Wang, Y.; Richter, A.; Burrows, J. P.; Uno, I.; Jang, C. J.; Chen, D.; Yao, Z.; Lei, Y.; Decision and Information Sciences; Tsinghua Univ.; Harvard Univ.; Univ. of Bremen; Kyushu Univ.; U.S. EPA

    2007-11-29

    A rapid increase of NO{sub 2} columns over China has been observed by satellite instruments in recent years. We present a 10-a regional trend of NO{sub x} emissions in China from 1995 to 2004 using a bottom-up methodology and compare the emission trends with the NO{sub 2} column trends observed from GOME and SCIAMACHY, the two spaceborne instruments. We use a dynamic methodology to reflect the dramatic change in China's NO{sub x} emissions caused by energy growth and technology renewal. We use a scenario analysis approach to identify the possible sources of uncertainties in the current bottom-up inventory, in comparison with the satellite observation data. Our best estimates for China's NO{sub x} emissions are 10.9 Tg in 1995 and 18.6 Tg in 2004, increasing by 70% during the period considered. NO{sub x} emissions and satellite-based NO{sub 2} columns show broad agreement in temporal evolution and spatial distribution. Both the emission inventory data and the satellite observations indicate a continuous and accelerating growth rate between 1996 and 2004 over east central China. However, the growth rate from the emission inventory is lower than that from the satellite observations. From 1996 to 2004, NO{sub x} emissions over the region increased by 61% according to the inventory, while a 95% increase in the NO{sub 2} columns measured by satellite was observed during the same period. We found good agreement during summertime but a large discrepancy during wintertime. The consistency between the summertime trends suggests that the bias cannot be due to systematic error of activity data or emission factors. The reasons for the discrepancy cannot yet be fully identified, but possible explanations include an underestimation in seasonal emission variations, variability of meteorology, NO{sub x} injection height, and the increasing trend of sulfate aerosols.

  15. Regional nitrogen oxides emission trends in East Asia observed from space

    NASA Astrophysics Data System (ADS)

    Mijling, B.; van der A, R. J.; Zhang, Q.

    2013-12-01

    Due to changing economic activity, emissions of air pollutants in East Asia are changing rapidly in space and time. Monthly emission estimates of nitrogen oxides derived from satellite observations provide valuable insight into the evolution of anthropogenic activity on a regional scale. We present the first results of a new emission estimation algorithm, specifically designed to use daily satellite observations of column concentrations for fast updates of emissions of short-lived atmospheric constituents on a mesoscopic scale (~ 0.25° × 0.25°). The algorithm is used to construct a monthly NOx emission time series for the period 2007-2011 from tropospheric NO2 observations of GOME-2 for East Chinese provinces and surrounding countries. The new emission estimates correspond well with the bottom-up inventory of EDGAR v4.2, but are smaller than the inventories of INTEX-B and MEIC. They reveal a strong positive trend during 2007-2011 for almost all Chinese provinces, related to the country's economic development. We find a 41% increment of NOx emissions in East China during this period, which shows the need to update emission inventories in this region on a regular basis. Negative emission trends are found in Japan and South Korea, which can be attributed to a combined effect of local environmental policy and global economic crises. Analysis of seasonal variation distinguishes between regions with dominant anthropogenic or biogenic emissions. For regions with a mixed anthropogenic and biogenic signature, the opposite seasonality can be used for an estimation of the separate emission contributions. Finally, the non-local concentration/emission relationships calculated by the algorithm are used to quantify the direct effect of regional NOx emissions on tropospheric NO2 concentrations outside the region. For regions such as North Korea and the Beijing municipality, a substantial part of the tropospheric NO2 originates from emissions elsewhere.

  16. Regional nitrogen oxides emission trends in East Asia observed from space

    NASA Astrophysics Data System (ADS)

    Mijling, B.; van der A, R. J.; Zhang, Q.

    2013-07-01

    Due to changing economic activity, emissions of air pollutants in East Asia change rapidly in space and time. Monthly emission estimates of nitrogen oxides derived from satellite observations provide valuable insight in the evolution of anthropogenic activity on a regional scale. We present the first results of a new emission estimation algorithm, specifically designed to use daily satellite observations of column concentrations for fast updates of emissions of short-lived atmospheric constituents on a~mesoscopic scale (~ 0.25° × 0.25°). The algorithm is used to construct a monthly NOx emission time series for 2007-2011 from tropospheric NO2 observations of GOME-2 for East Chinese provinces and surrounding countries. The new emission estimates correspond well with the bottom-up inventory of EDGAR v4.2, but are smaller than the inventories of INTEX-B and MEIC. They reveal a strong positive trend during 2007-2011 for almost all Chinese provinces, related to the country's economic development. We find a 41% increment of NOx emissions in East China during this period, which shows the need to update emission inventories in this region on a regular basis. Negative emission trends are found in Japan and South Korea, which can be attributed to a combined effect of local environmental policy and global economic crises. Analysis of seasonal variation distinguishes between regions with dominant anthropogenic or biogenic emissions. For regions with a mixed anthropogenic and biogenic signature, the opposite seasonality can be used for an estimation of the separate emission contributions. Finally, the non-local concentration/emission relationships calculated by the algorithm are used to quantify the direct effect of regional NOx emissions on tropospheric NO2 concentrations outside the region. For regions such as North Korea and Beijing province, a substantial part of the tropospheric NO2 originates from emissions elsewhere.

  17. Interpretation of FRESCO cloud retrievals in case of absorbing aerosol events

    NASA Astrophysics Data System (ADS)

    Wang, P.; Tuinder, O. N. E.; Tilstra, L. G.; Stammes, P.

    2011-12-01

    Cloud and aerosol information is needed in trace gas retrievals from satellite measurements. The Fast REtrieval Scheme for Clouds from the Oxygen A band (FRESCO) cloud algorithm employs reflectance spectra of the O2 A band around 760 nm to derive cloud pressure and effective cloud fraction. In general, clouds contribute more to the O2 A band reflectance than aerosols. Therefore, the FRESCO algorithm does not correct for aerosol effects in the retrievals and attributes the retrieved cloud information entirely to the presence of clouds, and not to aerosols. For events with high aerosol loading, aerosols may have a dominant effect, especially for almost cloud-free scenes. We have analysed FRESCO cloud data and Absorbing Aerosol Index (AAI) data from the Global Ozone Monitoring Experiment (GOME-2) instrument on the Metop-A satellite for events with typical absorbing aerosol types, such as volcanic ash, desert dust and smoke. We find that the FRESCO effective cloud fractions are correlated with the AAI data for these absorbing aerosol events and that the FRESCO cloud pressures contain information on aerosol layer pressure. For cloud-free scenes, the derived FRESCO cloud pressures are close to those of the aerosol layer for optically thick aerosols. For cloudy scenes, if the strongly absorbing aerosols are located above the clouds, then the retrieved FRESCO cloud pressures may represent the height of the aerosol layer rather than the height of the clouds. Combining FRESCO cloud data and AAI, an estimate for the aerosol layer pressure can be given, which can be beneficial for aviation safety and operations in case of e.g. volcanic ash plumes.

  18. Science Requirements Document for OMI-EOS. 2

    NASA Technical Reports Server (NTRS)

    Levelt, P. F.; vanderA, R.; Bhartia, P. K.; Boersma, F.; Brinksma, E.; Carpay, J.; Chance, K.; deHaan, J.; Hilsenrath, E.; Isaksen, I.

    2000-01-01

    A Dutch-Finnish scientific and industrial consortium is supplying the Ozone Monitoring Instrument (OMI) for Earth Observing System-Aura (EOS-Aura). EOS-Aura is the next NASA mission to study the Earth's atmosphere extensively, and successor to the highly successful UARS (Upper Atmospheric Research Satellite) mission. The 'Science Requirements Document for OMI-EOS' presents an overview of the Aura and OMI mission objectives. It describes how OMI fits into the Aura mission and it reviews the synergy with the other instruments onboard Aura to fulfill the mission. This evolves in the Scientific Requirements for OMI (Chapter 3), stating which trace gases have to be measured with what necessary accuracy, in order for OMI to meet Aura's objectives. The most important data product of OMI, the ozone vertical column, densities shall have a better accuracy and an improved global coverage than the predecessor instruments TOMS (Total Ozone Monitoring Spectrometer) and GOME (Global Ozone Monitoring Experiment), which is a.o. achieved by a better signal to noise ratio, improved calibration and a wide field-of-view. Moreover, in order to meet its role on Aura, OMI shall measure trace gases, such as NO2, OClO, BrO, HCHO and SO2, aerosols, cloud top height and cloud coverage. Improved accuracy, better coverage, and finer ground grid than has been done in the past are goals for OMI. After the scientific requirements are defined, three sets of subordinate requirements are derived. These are: the algorithm requirements, i.e. what do the algorithms need in order to meet the scientific requirements; the instrument and calibration requirements, i.e. what has to be measured and how accurately in order to provide the quality of data necessary for deriving the data products; and the validation requirements, i.e. a strategy of how the OMI program will assure that its data products are valid in the atmosphere, at least to the required accuracy.

  19. Modeling Gross Primary Production in North America with MODIS Images and Reanalysis Climate Data

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Xiao, X.; Jin, C.; Dong, J.; Zhou, S.; Wagle, P.; Joiner, J.; Guanter, L.; Zhang, Y.; Zhang, G.; Qin, Y.; Wang, J.; Moore, B., III

    2015-12-01

    Accurate estimation of gross primary production (GPP) of terrestrial ecosystems is vital for a better understanding of the spatial-temporal patterns of the global carbon cycle. In this study we estimated GPP in North America (NA), using the satellite-based Vegetation Photosynthesis Model (VPM), MODIS images at 8-day temporal and 500 m spatial resolution, and NCEP-NARR reanalysis climate data. The simulated GPP (GPPVPM) agreed well with the flux tower derived GPP (GPPEC) at 39 AmeriFlux sites (155 site-years). The GPPVPM in 2010 was spatially aggregated to 0.5 by 0.5 degree grid cell, and then evaluated with solar-induced chlorophyll fluorescence (SIF) data from GOME-2, which is often regarded as the proxy of direct measurement of vegetation photosynthesis. There were good agreements in spatial distribution and seasonal dynamics between GPPVPM and SIF. At biome scale, the relationship between GPPVPM and SIF showed strong linear correlations (R2 > 0.95) and small variations of slopes (4.60 - 5.55 g C m-2 year-1 / (mW m-2 nm-1 sr-1)). The total annual GPPVPM in NA in 2010 was approximately 13.53 Pg C year-1, which accounted for ~11.0% of the global terrestrial GPP and was within the range of annual GPP estimates from several other process-based and data-driven models (11.35 - 22.23 Pg C year-1). Forests contributed most (4.17 Pg C year-1) to the annual GPP in NA. Evergreen broadleaf forests were most productive with an average annual GPP exceeding 2000 g C m-2 year-1. The results from this study has demonstrated the reliable performance of VPM at the continental scale, and the resultant GPP product at 500-m spatial resolution provides more opportunities to improve the studies of carbon cycle, model inter-comparison, and benchmarking.

  20. Using satellite fluorescence data to drive a global carbon cycle model: Impacts on atmospheric CO2.

    NASA Astrophysics Data System (ADS)

    Collatz, G. J.; Joiner, J.; Kawa, S. R.; Ivanoff, A.; Liu, Y.; Yoshida, Y.; Berry, J. A.; Badgley, G. M.

    2014-12-01

    Atmospheric CO2 variability is markedly influenced by biospheric fluxes (photosynthesis and respiration) from the land surface at seasonal, to annual, to decadal time scales. Process models of photosynthesis and respiration have considerable uncertainty as only the sum of these fluxes can be constrained on the bases of atmospheric CO2 measurements alone. An independent proxy for photosynthesis or gross primary productivity (GPP) has recently become available from measurement of solar induced fluorescence (SIF). We report here on the first (to our knowledge) simulations of global atmospheric CO2 concentration driven by GPP estimated from observations of SIF. A baseline model uses satellite derived FPAR, incident solar radiation, temperature, and moisture stress scalars to estimate net primary productivity (NPP). The fluorescence driven model uses only fluorescence from GOME-2 scaled to the mean annual NPP at every grid cell and assumes a constant NPP/GPP ratio. Respiration was modeled identically in the two simulations. This preserves the spatial distribution of production capacity but allows for independent seasonal cycle and interannual variability from the baseline model. The flux models were run at ½ degree monthly resolution for 2007-2012 and fluxes were reaggregated along with fossil fuel and ocean fluxes to 3-hourly, 1 x 1.25 degree resolution for the atmospheric transport model. Here, we compare the model's skill at predicting CO2 variability at 40 NOAA CO2 flask network sites. The baseline model shows good skill at matching the seasonal cycle at the flask sites but is not as good at producing monthly and interannual anomalies. The fluorescence model shows similar (or even improved) performance even though solar radiation, FPAR, precipitation and temperature effects on GPP are not included in the simulation. The results demonstrate the capability of the fluorescence data to integrate physiological and biophysical controls on GPP into a single measured

  1. Evaluation of the Wound Healing Properties of Hancornia speciosa Leaves.

    PubMed

    Geller, Fabiana Cristina; Teixeira, Marina Rodrigues; Pereira, Ana Bárbara Dias; Dourado, Luana Pereira Antunes; Souza, Danielle G; Braga, Fernão Castro; Simões, Cláudia Maria Oliveira

    2015-12-01

    The leaves of Hancornia speciosa Gomes (Apocynaceae), a medicinal species found in the Brazilian cerrado biome, are traditionally used to treat wounds and inflammatory disorders. The goal of the present study was to investigate the in vitro wound healing properties of ethanolic extract of H. speciosa leaves and its isolated compounds, using the scratch assay, and to evaluate their effects on the release of the pro-inflammatory cytokine tumor necrosis factor (TNF-α) by lipopolysaccharide (LPS)-stimulated human acute monocytic (THP-1) cells. H. speciosa ethanolic extract significantly increased (42.8% ± 5.4 at 25 µg/mL) cell migration and proliferation of fibroblasts compared with control cells, as well as the isolated compounds bornesitol (80.8% ± 5.1) and quinic acid (69.1% ± 6.2), both assayed at 50 μM. TNF-α release by LPS-stimulated THP-1 cells was significantly reduced by the ethanolic extract (62.9% ± 8.2, i.e. 1791.1 ± 394.7 pg/mL) at 10 µg/mL, bornesitol (48.9% ± 0.9, i.e. 2461.6 ± 43.1 pg/mL) at 50 μM, and quinic acid (90.2% ± 3.4, i.e. 473.5 ± 164.4 pg/mL) and rutin (82.4% ± 5.6, i.e. 847.0 ± 271.8 pg/mL) at 10 μM. These results provided evidences to support the traditional use of H. speciosa leaves to treat wounds and inflammatory disorders.

  2. Fast emission estimates in China and South Africa constrained by satellite observations

    NASA Astrophysics Data System (ADS)

    Mijling, Bas; van der A, Ronald

    2013-04-01

    Emission inventories of air pollutants are crucial information for policy makers and form important input data for air quality models. Unfortunately, bottom-up emission inventories, compiled from large quantities of statistical data, are easily outdated for emerging economies such as China and South Africa, where rapid economic growth change emissions accordingly. Alternatively, top-down emission estimates from satellite observations of air constituents have important advantages of being spatial consistent, having high temporal resolution, and enabling emission updates shortly after the satellite data become available. However, constraining emissions from observations of concentrations is computationally challenging. Within the GlobEmission project (part of the Data User Element programme of ESA) a new algorithm has been developed, specifically designed for fast daily emission estimates of short-lived atmospheric species on a mesoscopic scale (0.25 × 0.25 degree) from satellite observations of column concentrations. The algorithm needs only one forward model run from a chemical transport model to calculate the sensitivity of concentration to emission, using trajectory analysis to account for transport away from the source. By using a Kalman filter in the inverse step, optimal use of the a priori knowledge and the newly observed data is made. We apply the algorithm for NOx emission estimates in East China and South Africa, using the CHIMERE chemical transport model together with tropospheric NO2 column retrievals of the OMI and GOME-2 satellite instruments. The observations are used to construct a monthly emission time series, which reveal important emission trends such as the emission reduction measures during the Beijing Olympic Games, and the impact and recovery from the global economic crisis. The algorithm is also able to detect emerging sources (e.g. new power plants) and improve emission information for areas where proxy data are not or badly known (e

  3. Using daily satellite observations to estimate emissions of short-lived air pollutants on a mesoscopic scale

    NASA Astrophysics Data System (ADS)

    Mijling, B.; van der A, R. J.

    2012-09-01

    Emission inventories of air pollutants are crucial information for policy makers and form important input data for air quality models. Using satellite observations for emission estimates has important advantages over bottom-up emission inventories: they are spatially consistent, have high temporal resolution, and enable updates shortly after the satellite data become available. We present a new algorithm specifically designed to use daily satellite observations of column concentrations for fast updates of emission estimates of short-lived atmospheric constituents on a mesoscopic scale (˜25 × 25 km2). The algorithm needs only one forward model run from a chemical transport model to calculate the sensitivity of concentration to emission, using trajectory analysis to account for transport away from the source. By using a Kalman filter in the inverse step, optimal use of the a priori knowledge and the newly observed data is made. We apply the algorithm for NOx emission estimates of East China, using the CHIMERE model on a 0.25 degree resolution together with tropospheric NO2column retrievals of the OMI and GOME-2 satellite instruments. Closed loop tests show that the algorithm is capable of reproducing new emission scenarios. Applied with real satellite data, the algorithm is able to detect emerging sources (e.g., new power plants), and improves emission information for areas where proxy data are not or badly known (e.g., shipping emissions). Chemical transport model runs with the daily updated emission estimates provide better spatial and temporal agreement between observed and simulated concentrations, facilitating improved air quality forecasts.

  4. Anthropogenic sulphur dioxide load over China as observed from different satellite sensors

    NASA Astrophysics Data System (ADS)

    Koukouli, M. E.; Balis, D. S.; van der A, Ronald Johannes; Theys, N.; Hedelt, P.; Richter, A.; Krotkov, N.; Li, C.; Taylor, M.

    2016-11-01

    China, with its rapid economic growth and immense exporting power, has been the focus of many studies during this previous decade quantifying its increasing emissions contribution to the Earth's atmosphere. With a population slowly shifting towards enlarged power and purchasing needs, the ceaseless inauguration of new power plants, smelters, refineries and industrial parks leads infallibly to increases in sulphur dioxide, SO2, emissions. The recent capability of next generation algorithms as well as new space-borne instruments to detect anthropogenic SO2 loads has enabled a fast advancement in this field. In the following work, algorithms providing total SO2 columns over China based on SCIAMACHY/Envisat, OMI/Aura and GOME2/MetopA observations are presented. The need for post-processing and gridding of the SO2 fields is further revealed in this work, following the path of previous publications. Further, it is demonstrated that the usage of appropriate statistical tools permits studying parts of the datasets typically excluded, such as the winter months loads. Focusing on actual point sources, such as megacities and known power plant locations, instead of entire provinces, monthly mean time series have been examined in detail. The sharp decline in SO2 emissions in more than 90%-95% of the locations studied confirms the recent implementation of government desulphurisation legislation; however, locations with increases, even for the previous five years, are also identified. These belong to provinces with emerging economies which are in haste to install power plants and are possibly viewed leniently by the authorities, in favour of growth. The SO2 load seasonality has also been examined in detail with a novel mathematical tool, with 70% of the point sources having a statistically significant annual cycle with highs in winter and lows in summer, following the heating requirements of the Chinese population.

  5. Science verification of operational aerosol and cloud products for TROPOMI on Sentinel-5 precursor

    NASA Astrophysics Data System (ADS)

    Lelli, Luca; Gimeno-Garcia, Sebastian; Sanders, Abram; Sneep, Maarten; Rozanov, Vladimir V.; Kokhanvosky, Alexander A.; Loyola, Diego; Burrows, John P.

    2016-04-01

    With the approaching launch of the Sentinel-5 precursor (S-5P) satellite, scheduled by mid 2016, one preparatory task of the L2 working group (composed by the Institute of Environmental Physics IUP Bremen, the Royal Netherlands Meteorological Institute KNMI De Bilt, and the German Aerospace Center DLR Oberpfaffenhofen) has been the assessment of biases among aerosol and cloud products, that are going to be inferred by the respective algorithms from measurements of the platform's payload TROPOspheric Monitoring Instrument (TROPOMI). The instrument will measure terrestrial radiance with varying moderate spectral resolutions from the ultraviolet throughout the shortwave infrared. Specifically, all the operational and verification algorithms involved in this comparison exploit the sensitivity of molecular oxygen absorption (the A-band, 755-775 nm, with a resolution of 0.54 nm) to changes in optical and geometrical parameters of tropospheric scattering layers. Therefore, aerosol layer height (ALH) and thickness (AOT), cloud top height (CTH), thickness (COT) and albedo (CA) are the targeted properties. First, the verification of these properties has been accomplished upon synchronisation of the respective forward radiative transfer models for a variety of atmospheric scenarios. Then, biases against independent techniques have been evaluated with real measurements of selected GOME-2 orbits. Global seasonal bias assessment has been carried out for CTH, CA and COT, whereas the verification of ALH and AOT is based on the analysis of the ash plume emitted by the icelandic volcanic eruption Eyjafjallajökull in May 2010 and selected dust scenes off the Saharan west coast sensed by SCIAMACHY in year 2009.

  6. Comparison of cone-beam computed tomography cephalometric measurements using a midsagittal projection and conventional two-dimensional cephalometric measurements

    PubMed Central

    Jung, Pil-Kyo; Lee, Gung-Chol

    2015-01-01

    Objective This study investigated whether it is possible to use a two-dimensional (2D) standard in three-dimensional (3D) analysis, by comparing the angles and lengths measured from a midsagittal projection in 3D cone-beam computed tomography (CBCT) with those measured by 2D lateral cephalometric radiography (LCR). Methods Fifty patients who underwent both LCR and CBCT were selected as subjects. CBCT was reoriented in 3 different methods and the measuring-points were projected onto the midsagittal plane. Twelve angle values and 8 length values were measured on both LCR and CBCT and compared. Results Repeated measures analysis of the variance revealed statistically significant differences in 7 angular and 5 linear measurements among LCR and 3 types of CBCT (p < 0.05). Of these 12 measurements, multiple comparisons showed that 6 measurements (ANB, AB to FH, IMPA, FMA, Co-Gn, Go-Me) were not significantly different in pairwise comparisons. LCR was significantly different from 3 types of CBCT in 3 angular (SN to FH, interincisal angle, FMIA) and 2 linear (S-Go, Co-ANS) measurements. The CBCT method was similar for all measurements, except for 1 linear measurement, i.e., S-N. However, the disparity between the mean values for all parameters was within the range of clinical measurement error. Conclusions 3D-CBCT analysis, using midsagittal projection, is a useful method in which the 2D-LCR normative values can be used. Although the measurements changed with reorientation, these changes were not clinically significant. PMID:26629474

  7. Satellite chlorophyll fluorescence measurements reveal large-scale decoupling of photosynthesis and greenness dynamics in boreal evergreen forests.

    PubMed

    Walther, Sophia; Voigt, Maximilian; Thum, Tea; Gonsamo, Alemu; Zhang, Yongguang; Köhler, Philipp; Jung, Martin; Varlagin, Andrej; Guanter, Luis

    2016-09-01

    Mid-to-high latitude forests play an important role in the terrestrial carbon cycle, but the representation of photosynthesis in boreal forests by current modelling and observational methods is still challenging. In particular, the applicability of existing satellite-based proxies of greenness to indicate photosynthetic activity is hindered by small annual changes in green biomass of the often evergreen tree population and by the confounding effects of background materials such as snow. As an alternative, satellite measurements of sun-induced chlorophyll fluorescence (SIF) can be used as a direct proxy of photosynthetic activity. In this study, the start and end of the photosynthetically active season of the main boreal forests are analysed using spaceborne SIF measurements retrieved from the GOME-2 instrument and compared to that of green biomass, proxied by vegetation indices including the Enhanced Vegetation Index (EVI) derived from MODIS data. We find that photosynthesis and greenness show a similar seasonality in deciduous forests. In high-latitude evergreen needleleaf forests, however, the length of the photosynthetically active period indicated by SIF is up to 6 weeks longer than the green biomass changing period proxied by EVI, with SIF showing a start-of-season of approximately 1 month earlier than EVI. On average, the photosynthetic spring recovery as signalled by SIF occurs as soon as air temperatures exceed the freezing point (2-3 °C) and when the snow on the ground has not yet completely melted. These findings are supported by model data of gross primary production and a number of other studies which evaluated in situ observations of CO2 fluxes, meteorology and the physiological state of the needles. Our results demonstrate the sensitivity of space-based SIF measurements to light-use efficiency of boreal forests and their potential for an unbiased detection of photosynthetic activity even under the challenging conditions interposed by evergreen

  8. On the Nature and Timing of Giant Planet Migration in the Solar System

    NASA Astrophysics Data System (ADS)

    Agnor, Craig B.

    2016-05-01

    Giant planet migration is a natural outcome of gravitational scattering and planet formation processes (Fernandez & Ip 1984). There is compelling evidence that the solar system's giant planets experienced large-scale migration involving close approaches between planets as well as smooth radial migration via planetesimal scattering. Aspects of giant planet migration have been invoked to explain many features of the outer solar system including the resonant structure of the Kuiper Belt (e.g., Malhotra 1993, Levison et al. 2008), the eccentricities of Jupiter and Saturn (Tsiganis et al. 2005, Morbidelli et al. 2009), the capture of Jupiter's Trojan companions (Morbidelli et al. 2005) and the capture of irregular planetary satellites (e.g., Nesvorny et al. 2007) to name a few. If this migration epoch occurred after the formation of the inner planets, then it may also explain the so-called lunar Late Heavy Bombardment (Gomes et al. 2005). This scenario necessarily requires coeval terrestrial and migrating giant planets. Recent N-body integrations exploring this issue have shown that giant planet migration may excite the terrestrial system via nodal and apsidal secular resonances (e.g., Brasser et al. 2013), may drive the terrestrial planets to crossing orbits (Kaib & Chambers 2016) or alternatively leave the inner solar system in a state closely resembling the observed one (Roig et al. 2016). The factors accounting for the large range of outcomes remain unclear. Using linear secular models and N-body simulations I am identifying and characterising the principal aspects of giant planet migration that excite the terrestrial planets' orbits. I will present these results and discuss how they inform the nature and timing of giant planet migration in the solar system.

  9. Prospects for chlorophyll fluorescence and vegetation remote sensing from the Orbiting Carbon Observatory-2

    NASA Astrophysics Data System (ADS)

    Frankenberg, C.; O'Dell, C.; Berry, J. A.; Guanter, L.; Joiner, J.; Pollock, H.; Taylor, T.

    2013-12-01

    The Orbiting Carbon Observatory-2 is a NASA mission designed to measure atmospheric CO2 and is scheduled to launch in July 2014. It's main purpose is to allow inversions of net flux estimates of CO2 on regional to continental scales using the total column CO2 retrieved using high-resolution spectra in the 0.76,1.6 and 2.0 μm range. Recently, it was shown that solar-induced chlorophyll fluorescence, a proxy for gross primary production (GPP, carbon uptake through photosynthesis), could be accurately retrieved from space using high-resolution spectra in the 750 nm range. Here, we use real OCO-2 thermal vacuum test data as well as a full repeat cycle (16 days) of simulated OCO-2 spectra under realistic conditions to evaluate the potential of OCO-2 for retrievals of chlorophyll fluorescence and also its dependence on clouds and aerosols. We find that the single-measurement precision is 0.3-0.5Wm-2sr-1μm-1, better than current measurements from space but still difficult to interpret on a single-sounding basis. The most significant advancement will come from smaller ground-pixel sizes and increased measurement frequency, with a 100-fold increase compared to GOSAT (and about 8 times higher than GOME-2). This will largely decrease the need for coarse spatial and temporal averaging in data analysis and pave the way to accurate local studies. We also find that the lack of full global mapping from the OCO-2 only incurs small errors for global carbon cycle research. Eventually, the combination of net ecosystem exchange (NEE) and proxy-estimates of GPP from the same satellite will provide a more process-based understanding of the global carbon cycle. Highlights from fluorescence results of the GOSAT satellite will be shown to emphasize the potential of OCO-2.

  10. Mission Objectives Of The Atmospheric Composition Related Sentinels S5p, S4, And S5

    NASA Astrophysics Data System (ADS)

    Ingmann, Paul; Veihelmann, Ben; Langen, Jorg; Meijer, Yasjka

    2013-12-01

    Atmospheric chemistry observations from space have been made for over 30 years, in the beginning mainly by US missions. These missions have always been motivated by the concern about a number of environmental issues. At present European instruments like GOME-2 on MetOp/EPS-A and -B and OMI on NASA's Aura are in space and, despite being designed for research purposes, perform routine observations. The space instruments have helped improving our understanding of processes that govern stratospheric ozone depletion, climate change and the transport of pollutants. However, long-term continuous time series of atmospheric trace gas data have been limited to stratospheric ozone and a few related species. According to current planning, meteorological satellites will maintain these observations over the next decade. They will also add some measurements of tropospheric trace gases critical for climate forcing. However, as their measurements have been motivated by meteorology, vertical sensitivities and accuracies are marginal for atmospheric chemistry applications. With the exception of stratospheric ozone, reliable long-term space-based monitoring of atmospheric constituents with quality attributes sufficient to serve atmospheric chemistry applications still need to be established. The need for a GMES atmospheric service (GAS), its scope and high level requirements were laid down in an orientation papers organised by the European Commission and then updated by an Implementation Group (IG) [1], backed by four working groups, advising the Commission on scope, architecture, in situ and space requirements. The goal of GAS is to provide coherent information on atmospheric variables in support of European policies and for the benefit of European citizens. Services cover air quality, climate change/forcing, stratospheric ozone and solar radiation. To meet the needs of the user community atmospheric composition mission concepts for GEO and LEO have been defined usually referred to

  11. Tropospheric Bromine Chemistry: Implications for Present and Pre-industrial Ozone and Mercury

    NASA Technical Reports Server (NTRS)

    Parella, J. P.; Jacob, D. J.; Liang, Q.; Zhang, Y.; Mickley, L. J.; Miller, B.; Evans, M. J.; Yang, X.; Pyle, J. A.; Theys, N.; VanRoozendael, M.

    2012-01-01

    We present a new model for the global tropospheric chemistry of inorganic bromine (Bry) coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM). Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone mixing ratios by <1-8 nmol/mol (6.5% globally), with the largest effects in the northern extratropics in spring. The global mean tropospheric OH concentration decreases by 4 %. Inclusion of bromine chemistry improves the ability of global models (GEOS-Chem and p-TOMCAT) to simulate observed 19th-century ozone and its seasonality. Bromine effects on tropospheric ozone are comparable in the present-day and pre-industrial atmospheres so that estimates of anthropogenic radiative forcing are minimally affected. Br atom concentrations are 40% higher in the pre-industrial atmosphere due to lower ozone, which would decrease by a factor of 2 the atmospheric lifetime of elemental mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  12. Year-round records of sea salt, gaseous, and particulate inorganic bromine in the atmospheric boundary layer at coastal (Dumont d'Urville) and central (Concordia) East Antarctic sites

    NASA Astrophysics Data System (ADS)

    Legrand, Michel; Yang, Xin; Preunkert, Susanne; Theys, Nicolas

    2016-01-01

    Multiple year-round records of bulk and size-segregated compositions of aerosol were obtained at the coastal Dumont d'Urville (DDU) and inland Concordia sites located in East Antarctica. They document the sea-salt aerosol load and composition including, for the first time in Antarctica, the bromide depletion of sea-salt aerosol relative to sodium with respect to seawater. In parallel, measurements of bromide trapped in mist chambers and denuder tubes were done to investigate the concentrations of gaseous inorganic bromine species. These data are compared to simulations done with an off-line chemistry transport model, coupled with a full tropospheric bromine chemistry scheme and a process-based sea-salt production module that includes both sea-ice-sourced and open-ocean-sourced aerosol emissions. Observed and simulated sea-salt concentrations sometime differ by up to a factor of 2 to 3, particularly at DDU possibly due to local wind pattern. In spite of these discrepancies, both at coastal and inland Antarctica, the dominance of sea-ice-related processes with respect to open ocean emissions for the sea-salt aerosol load in winter is confirmed. For summer, observations and simulations point out sea salt as the main source of gaseous inorganic bromine species. Investigations of bromide in snow pit samples do not support the importance of snowpack bromine emissions over the Antarctic Plateau. To evaluate the overall importance of the bromine chemistry over East Antarctica, BrO simulations were also discussed with respect data derived from GOME-2 satellite observations over Antarctica.

  13. A comparison study between model-predicted and OMI-retrieved tropospheric NO 2 columns over the Korean peninsula

    NASA Astrophysics Data System (ADS)

    Han, K. M.; Lee, C. K.; Lee, J.; Kim, J.; Song, C. H.

    2011-06-01

    In this study, Community Multi-scale Air Quality (CMAQ) model simulations, using the INTEX-B (Intercontinental Chemical Transport Experiment-Phase B) emission inventory for North Korea and China, CAPSS (Clean Air Policy Support System) emission inventory for South Korea, and REAS (Regional Emission Inventory in Asia) emission inventory for Japan, were carried out over four seasonal episodes from 2006, with a fine grid resolution of 30 km × 30 km, in order to evaluate the accuracy of the NO x emissions over the Korean peninsula. The tropospheric NO 2 columns from the CMAQ model simulations were then compared with those retrieved from a satellite sensor, Ozone Monitoring Instrument (OMI), over the Korean peninsula as well as briefly over East Asia. The results showed that the CMAQ modeling, using the NO x emissions from the CAPSS inventory over South Korea, produced tropospheric NO 2 columns that were over-predicted by factors between 1.38 and 1.87 compared to the OMI-retrieved tropospheric NO 2 columns. This appears to be in line with the findings from a previous study, i.e. when the ACE-ASIA emission inventory was used for the episodes from 2001 to 2003, the CMAQ modeling tended to produce NO 2 columns that were ˜1.46 times larger than the GOME-derived NO 2 columns over South Korea. On the other hand, over North Korea, the NO x emissions of the INTEX-B emission inventory appear to be overestimated by factors between 1.55 and 7.46 (3.18 over the four seasonal episodes), based on the comparison study between the CMAQ-simulated and OMI-retrieved tropospheric NO 2 columns. This may be caused by the large uncertainty in the NO x emission fluxes from North Korea due to insufficient information on the economic activity and energy consumption related to the political instability in North Korea.

  14. Analysis of the Origin and Evolution of the Small Satellites of Pluto

    NASA Astrophysics Data System (ADS)

    Pires Dos Santos, Pryscilla Maria; Morbidelli, A.; Nesvorny, D.; Giuliatti Winter, S. M.

    2012-10-01

    At this time the origin of the small satellites of Pluto remains elusive. In this work we envisioned an alternative scenario. Pluto-Charon was already formed and embedded into a massive planetesimal disk, then planetesimals got captured by Pluto-Charon binary from the heliocentric disk. For a dynamically "cold" disk, temporary capture in the Pluto-Charon system can occur with non-negligible probability. We conjecture that if the captured planetesimals got disrupted during their Pluto-bound phase by a collision with other planetesimals of the disk, then these events could have generated a debris disk. This disk damped under internal collisional evolution, until turning itself into an accretional disk that could form small satellites on circular orbits, co-planar with Charon. Objects large enough to carry a sufficient amount of mass to generate the small satellites of Pluto have collisional lifetimes orders of magnitude longer than the typical capture time ( 100 years). Thus, this scenario, although add new arguments to an unsolved problem, cannot also explain the origin of the small satellites of Pluto, which remains elusive. Additionality, we will also present some preliminary results on the analysis of the evolution of the Pluto system in the framework of the "new" Nice model (see, e.g. Levison et al, 2008). Their results explain very well the distribution of Plutinos, bodies trapped in 2:3 mean motion resonance with Neptune. By assuming that the bodies observed today in the Pluto system were put together before the Late Heavy Bombardment period (Gomes et al, 2005), through encounter histories of Pluto and its members during the dynamical evolution of the giant planets, we analyse if this multiple system is destroyed by such interactions. In fact, understanding the evolution of the plutinos provides hints to the understanding of the history of the outer Solar system.

  15. Mercury distribution in organs of fish species and the associated risk in traditional subsistence villagers of the Pantanal wetland.

    PubMed

    Ceccatto, Ana P S; Testoni, Magalei C; Ignácio, Aurea R A; Santos-Filho, Manoel; Malm, Olaf; Díez, Sergi

    2016-06-01

    This study evaluated the risk to human health from mercury (Hg) exposure through fish consumption in the Pantanal, Brazil. In order to address these risks, Hg concentrations and accumulation patterns were determined in target organs of predatory fish (Crenicichla lepidota and Pygocentrus nattereri). Levels of Hg were analysed during the two phases of the flood pulse (flood and drought) in fish from different local ecosystems, such as the Bento Gomes and Paraguay rivers. Although the former study area is directly affected by gold mining, a higher, but not significantly different, Hg concentration in fish was found compared with fish at the Paraguay River, which is regarded as pristine area. Moreover, no seasonal variability was found in either river. Although total mercury levels in fish did not exceed the maximum FAO/WHO threshold (0.5 μg g(-1)), according to dietary habits in riverine communities of the Pantanal (up to 6 oz of fish per day), there is reason for concern over the potential for deleterious health effects that could be caused by high Hg intake. In fact, the estimated daily intake in the present study ranged from 0.49 to 1.08 μg Hg kg(-1) day(-1), for adults (including women of childbearing age) and children, respectively. Because of high Hg intakes in riverine groups, which exceed the recommended reference dose value, these communities could be considered at risk. Therefore, it is necessary to consider regulatory measures and public education regarding fish consumption, particularly in vulnerable groups (i.e. children, pregnant women and women of childbearing age). PMID:26337755

  16. Cloud and aerosol classification for 2 1/2 years of MAX-DOAS observations in Wuxi (China) and comparison to independent data sets

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Penning de Vries, M.; Xie, P. H.; Beirle, S.; Dörner, S.; Remmers, J.; Li, A.; Wagner, T.

    2015-05-01

    Multi-Axis-Differential Optical Absorption Spectroscopy (MAX-DOAS) observations of trace gases can be strongly influenced by clouds and aerosols. Thus it is important to identify clouds and characterise their properties. In a recent study Wagner et al. (2014) developed a cloud classification scheme based on the MAX-DOAS measurements themselves with which different "sky conditions" (e.g. clear sky, continuous clouds, broken clouds) can be distinguished. Here we apply this scheme to long term MAX-DOAS measurements from 2011 to 2013 in Wuxi, China (31.57° N, 120.31° E). The original algorithm has been modified, in particular in order to account for smaller solar zenith angles (SZA). Instrumental degradation is accounted for to avoid artificial trends of the cloud classification. We compared the results of the MAX-DOAS cloud classification scheme to several independent measurements: aerosol optical depth from a nearby AERONET station and from MODIS, visibility derived from a visibility meter; and various cloud parameters from different satellite instruments (MODIS, OMI, and GOME-2). The most important findings from these comparisons are: (1) most cases characterized as clear sky with low or high aerosol load were associated with the respective AOD ranges obtained by AERONET and MODIS, (2) the observed dependences of MAX-DOAS results on cloud optical thickness and effective cloud fraction from satellite indicate that the cloud classification scheme is sensitive to cloud (optical) properties, (3) separation of cloudy scenes by cloud pressure shows that the MAX-DOAS cloud classification scheme is also capable of detecting high clouds, (4) some clear sky conditions, especially with high aerosol load, classified from MAX-DOAS observations corresponding to the optically thin and low clouds derived by satellite observations probably indicate that the satellite cloud products contain valuable information on aerosols.

  17. First Global Observations of HCHO from the Suomi National Polar-orbiting Partnership Ozone Mapping and Profiler Suite

    NASA Astrophysics Data System (ADS)

    Li, C.; Joiner, J.; Krotkov, N. A.; Bhartia, P. K.; Dunlap, L.

    2014-12-01

    Global retrievals of formaldehyde (HCHO) from satellite UV instruments such as the Aura/Ozone Monitoring Instrument (OMI) and MetOp/Global Ozone Monitoring Experiment-2 (GOME-2) have provided important constraints on the emissions of biogenic isoprene. Here we present the first results of HCHO retrievals from the Suomi National Polar-orbiting Partnership (NPP) Ozone Mapping and Profiler Suite (OMPS). We apply an innovative principal component analysis (PCA) retrieval algorithm to extract a set of principal components (PCs) from OMPS-measured radiances between 325.0 and 356.5 nm over presumably clean oceanic regions. Since the background loading of HCHO due to methane oxidation is very small over these areas, the leading PCs (that explain the most variation in radiances) represent spectral features associated with various physical processes (e.g., ozone absorption, rotational Raman scattering) and measurement details (e.g., wavelength shift) other than those related to HCHO absorption. The vertical column density of HCHO is then derived by fitting the PCs and HCHO Jacobians calculated with a radiative transfer model to OMPS-measured radiance spectra. Our retrievals highlight the diverse nature of HCHO sources. Summertime maxima in HCHO detected over the eastern U.S. are likely due to biogenic emissions, while seasonal hot spots observed over West and Central Africa and Russia are mainly attributed to biomass burning emissions. Efforts have also been made to distinguish between anthropogenic and biogenic precursors of HCHO. Finally, the OMPS PCA HCHO retrievals are compared to OMI HCHO data produced with different Differential Optical Absorption Spectroscopy (DOAS) algorithms, in an effort to understand and reconcile the differences between various satellite HCHO datasets.

  18. 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.

  19. Global Partitioning of NOx Sources Using Satellite Observations: Relative Roles of Fossil Fuel Combustion, Biomass Burning and Soil Emissions

    NASA Technical Reports Server (NTRS)

    Jaegle, Lyatt; Steinberger, Linda; Martin, Randall V.; Chance, Kelly

    2005-01-01

    This document contains the following abstract for the paper "Global partitioning of NOx sources using satellite observations: Relative roles of fossil fuel combustion, biomass burning and soil emissions." Satellite observations have been used to provide important new information about emissions of nitrogen oxides. Nitrogen oxides (NOx) are significant in atmospheric chemistry, having a role in ozone air pollution, acid deposition and climate change. We know that human activities have led to a three- to six-fold increase in NOx emissions since pre-industrial times, and that there are three main surface sources of NOx: fuel combustion, large-scale fires, and microbial soil processes. How each of these sources contributes to the total NOx emissions is subject to some doubt, however. The problem is that current NOx emission inventories rely on bottom-up approaches, compiling large quantities of statistical information from diverse sources such as fuel and land use, agricultural data, and estimates of burned areas. This results in inherently large uncertainties. To overcome this, Lyatt Jaegle and colleagues from the University of Washington, USA, used new satellite observations from the Global Ozone Monitoring Experiment (GOME) instrument. As the spatial and seasonal distribution of each of the sources of NOx can be clearly mapped from space, the team could provide independent topdown constraints on the individual strengths of NOx sources, and thus help resolve discrepancies in existing inventories. Jaegle's analysis of the satellite observations, presented at the recent Faraday Discussion on "Atmospheric Chemistry", shows that fuel combustion dominates emissions at northern mid-latitudes, while fires are a significant source in the Tropics. Additionally, she discovered a larger than expected role for soil emissions, especially over agricultural regions with heavy fertilizer use. Additional information is included in the original extended abstract.

  20. Ozone column density determination from direct irradiance measurements in the ultraviolet performed by a four-channel precision filter radiometer.

    PubMed

    Ingold, T; Mätzler, C; Wehrli, C; Heimo, A; Kämpfer, N; Philipona, R

    2001-04-20

    Ultraviolet light was measured at four channels (305, 311, 318, and 332 nm) with a precision filter radiometer (UV-PFR) at Arosa, Switzerland (46.78 degrees , 9.68 degrees , 1850 m above sea level), within the instrument trial phase of a cooperative venture of the Swiss Meteorological Institute (MeteoSwiss) and the Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center. We retrieved ozone-column density data from these direct relative irradiance measurements by adapting the Dobson standard method for all possible single-difference wavelength pairs and one double-difference pair (305/311 and 305/318) under conditions of cloud-free sky and of thin clouds (cloud optical depth <2.5 at 500 nm). All UV-PFR retrievals exhibited excellent agreement with those of collocated Dobson and Brewer spectrophotometers for data obtained during two months in 1999. Combining the results of the error analysis and the findings of the validation, we propose to retrieve ozone-column density by using the 305/311 single difference pair and the double-difference pair. Furthermore, combining both retrievals by building the ratio of ozone-column density yields information that is relevant to data quality control. Estimates of the 305/311 pair agree with measurements by the Dobson and Brewer instruments within 1% for both the mean and the standard deviation of the differences. For the double pair these values are in a range up to 1.6%. However, this pair is less sensitive to model errors. The retrieval performance is also consistent with satellite-based data from the Earth Probe Total Ozone Mapping Spectrometer (EP-TOMS) and the Global Ozone Monitoring Experiment instrument (GOME).

  1. Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation Hazards: Part I. Validation of satellite-derived Volcanic Ash Levels.

    NASA Astrophysics Data System (ADS)

    Koukouli, MariLiza; Balis, Dimitris; Simopoulos, Spiros; Siomos, Nikos; Clarisse, Lieven; Carboni, Elisa; Wang, Ping; Siddans, Richard; Marenco, Franco; Mona, Lucia; Pappalardo, Gelsomina; Spinetti, Claudia; Theys, Nicolas; Tampellini, Lucia; Zehner, Claus

    2014-05-01

    The 2010 eruption of the Icelandic volcano Eyjafjallajökull attracted the attention of the public and the scientific community to the vulnerability of the European airspace to volcanic eruptions. Major disruptions in European air traffic were observed for several weeks surrounding the two eruptive episodes, which had a strong impact on the everyday life of many Europeans as well as a noticable economic loss of around 2-3 billion Euros in total. The eruptions made obvious that the decision-making bodies were not informed properly and timely about the commercial aircraft capabilities to ash-leaden air, and that the ash monitoring and prediction potential is rather limited. After the Eyjafjallajökull eruptions new guidelines for aviation, changing from zero tolerance to newly established ash threshold values, were introduced. Within this spirit, the European Space Agency project Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation Hazards, called for the creation of an optimal End-to-End System for Volcanic Ash Plume Monitoring and Prediction . This system is based on improved and dedicated satellite-derived ash plume and sulphur dioxide level assessments, as well as an extensive validation using auxiliary satellite, aircraft and ground-based measurements. The validation of volcanic ash levels extracted from the sensors GOME-2/MetopA, IASI/MetopA and MODIS/Terra and MODIS/Aqua is presented in this work with emphasis on the ash plume height and ash optical depth levels. Co-located aircraft flights, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation [CALIPSO] soundings and well as European Aerosol Research Lidar Network [EARLINET] measurements were compared to the different satellite estimates for the those two eruptive episodes. The validation results are extremely promising with most satellite sensors performing quite well and within the estimated uncertainties compared to the comparative datasets. The findings are

  2. Solar Spectral Irradiance Changes During Cycle 24

    NASA Technical Reports Server (NTRS)

    Marchenko, Sergey; Deland, Matthew

    2014-01-01

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

  3. Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation Hazards: Part II. Validation of satellite-derived Volcanic Sulphur Dioxide Levels.

    NASA Astrophysics Data System (ADS)

    Koukouli, MariLiza; Balis, Dimitris; Dimopoulos, Spiros; Clarisse, Lieven; Carboni, Elisa; Hedelt, Pascal; Spinetti, Claudia; Theys, Nicolas; Tampellini, Lucia; Zehner, Claus

    2014-05-01

    The eruption of the Icelandic volcano Eyjafjallajökull in the spring of 2010 turned the attention of both the public and the scientific community to the susceptibility of the European airspace to the outflows of large volcanic eruptions. The ash-rich plume from Eyjafjallajökull drifted towards Europe and caused major disruptions of European air traffic for several weeks affecting the everyday life of millions of people and with a strong economic impact. This unparalleled situation revealed limitations in the decision making process due to the lack of information on the tolerance to ash of commercial aircraft engines as well as limitations in the ash monitoring and prediction capabilities. The European Space Agency project Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation Hazards, was introduced to facilitate the development of an optimal End-to-End System for Volcanic Ash Plume Monitoring and Prediction. This system is based on comprehensive satellite-derived ash plume and sulphur dioxide [SO2] level estimates, as well as a widespread validation using supplementary satellite, aircraft and ground-based measurements. The validation of volcanic SO2 levels extracted from the sensors GOME-2/MetopA and IASI/MetopA are shown here with emphasis on the total column observed right before, during and after the Eyjafjallajökull 2010 eruptions. Co-located ground-based Brewer Spectrophotometer data extracted from the World Ozone and Ultraviolet Radiation Data Centre, WOUDC, were compared to the different satellite estimates. The findings are presented at length, alongside a comprehensive discussion of future scenarios.

  4. Characterisation of a stratospheric sulphate plume from the Nabro volcano using a combination of passive satellite measurements in nadir and limb geometry

    NASA Astrophysics Data System (ADS)

    Penning de Vries, M. J. M.; Dörner, S.; Puķīte, J.; Hörmann, C.; Fromm, M. D.; Wagner, T.

    2014-03-01

    The eruption of the Nabro volcano (Eritrea), which started on 12 June 2011, caused the introduction of large quantities of SO2 into the lower stratosphere. The subsequently formed sulphate aerosols could be detected for several months following the eruption. It is generally assumed that the formation of sulphate aerosols in the stratosphere takes about a month, but in plumes from explosive eruptions significant amounts of aerosols have been seen to form within a few hours. We show that sulphate aerosols were present in the lower stratosphere within hours of the onset of the eruption of Nabro. Evidence comes from nadir UV Aerosol Index (UVAI) and SO2 measurements by SCIAMACHY, GOME-2 and OMI, and limb aerosol measurements by SCIAMACHY. The sulphate plume displays negative UVAI in the western part of OMI's swath and positive UVAI in the eastern part - an effect that is due to the strong viewing angle dependence of UVAI and can only be caused by a high-altitude (>11 km), non-absorbing (single-scattering albedo >0.97) aerosol plume. For the retrieval of the aerosol profile from limb measurements, the horizontal dimensions and the position of the aerosol plume need to be taken into account, otherwise both extinction and layer height may be underestimated appreciably. By combining nadir SO2 column density and UVAI with limb aerosol profiles, a stratospheric plume from Nabro could be tracked from 13 to 17 June, before the plumes from later, lower-altitude explosions started interfering with the signal. Our findings are in agreement with ground-based lidar and sun-photometer data from an MPLNET/AERONET station in Israel and with data from the satellite-borne CALIOP lidar.

  5. Characterisation of a stratospheric sulfate plume from the Nabro volcano using a combination of passive satellite measurements in nadir and limb geometry

    NASA Astrophysics Data System (ADS)

    Penning de Vries, M. J. M.; Dörner, S.; Puķīıte, J.; Hörmann, C.; Fromm, M. D.; Wagner, T.

    2014-08-01

    The eruption of the Nabro volcano (Eritrea), which started on 12 June 2011, caused the introduction of large quantities of SO2 into the lower stratosphere. The subsequently formed sulfate aerosols could be detected for several months following the eruption. It is generally assumed that the formation of sulfate aerosols in the stratosphere is a relatively slow process, but in plumes from explosive eruptions significant amounts of aerosols have been seen to form within a few hours. We show that sulfate aerosols were present in the lower stratosphere within hours of the onset of the eruption of Nabro. Evidence comes from nadir UV Aerosol Index (UVAI) and SO2 measurements by SCIAMACHY, GOME-2 and OMI, and limb aerosol measurements by SCIAMACHY. The sulfate plume displays negative UVAI in the western part of OMI's swath and positive UVAI in the eastern part - an effect that is due to the strong viewing angle dependence of UVAI and can only be caused by a high-altitude (>11 km), non-absorbing (single-scattering albedo >0.97) aerosol plume. For the retrieval of the aerosol profile from limb measurements, the horizontal dimensions and the position of the aerosol plume need to be taken into account, otherwise both extinction and layer height may be underestimated appreciably. By combining nadir SO2 column density and UVAI with limb aerosol profiles, a stratospheric plume from Nabro could be tracked from 13 to 17 June, before the plumes from later, lower-altitude explosions started interfering with the signal. Our findings are in agreement with ground-based lidar and sun-photometer data from an MPLNET/AERONET station in Israel and with data from the satellite-borne CALIOP lidar.

  6. Applications of OMI Tropospheric NO(Sub 2) Data: Air Quality Trends in the US and Lightning NO(x) Source Strength

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth; Prados, Ana; Bucsela, Eric

    2010-01-01

    This talk will be presented in two parts: 1) an analysis of tropospheric column NO2 trends in the eastern half of the United States over the period 2005 to 2009 and 2) estimation of lightning NO(x) production rates based on OMI observations and lightning flash rate data. The air quality trends in the eastern US will be determined for specific subregions using tropospheric column NO2 data from OMI for 2005 through 2008 and from GOME-2 for 2007 through 2009. This period is characterized by significant NO(x) emission reductions at power plants within most of this region. The air quality trends will be compared with those estimated from continuous emission monitoring data from the power plants compiled by the US Environmental Protection Agency. OMI NO2 data have also been used to estimate lightning NOx production per flash in selected storms near Costa Rica and Panama during the 2007 NASA TC4 field campaign and over the continental US, Gulf of Mexico, and western Atlantic during the summers of 2005 and 2006. The lightning signal is extracted from the OMI data through a custom retrieval in which an NO2 profile representative of convective outflow is used in the airmass factor calculation and the background NO2 column is subtracted from the tropospheric column. When combined with NO(x)/NO2 ratios from the NASA GMT model and observed flash rates, the resulting estimates of NO(x) production per flash are comparable to those estimated obtained from analyses of aircraft data and cloud-resolving modeling.

  7. Estimated global nitrogen deposition using NO2 column density

    USGS Publications Warehouse

    Lu, Xuehe; Jiang, Hong; Zhang, Xiuying; Liu, Jinxun; Zhang, Zhen; Jin, Jiaxin; Wang, Ying; Xu, Jianhui; Cheng, Miaomiao

    2013-01-01

    Global nitrogen deposition has increased over the past 100 years. Monitoring and simulation studies of nitrogen deposition have evaluated nitrogen deposition at both the global and regional scale. With the development of remote-sensing instruments, tropospheric NO2 column density retrieved from Global Ozone Monitoring Experiment (GOME) and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) sensors now provides us with a new opportunity to understand changes in reactive nitrogen in the atmosphere. The concentration of NO2 in the atmosphere has a significant effect on atmospheric nitrogen deposition. According to the general nitrogen deposition calculation method, we use the principal component regression method to evaluate global nitrogen deposition based on global NO2 column density and meteorological data. From the accuracy of the simulation, about 70% of the land area of the Earth passed a significance test of regression. In addition, NO2 column density has a significant influence on regression results over 44% of global land. The simulated results show that global average nitrogen deposition was 0.34 g m−2 yr−1 from 1996 to 2009 and is increasing at about 1% per year. Our simulated results show that China, Europe, and the USA are the three hotspots of nitrogen deposition according to previous research findings. In this study, Southern Asia was found to be another hotspot of nitrogen deposition (about 1.58 g m−2 yr−1 and maintaining a high growth rate). As nitrogen deposition increases, the number of regions threatened by high nitrogen deposits is also increasing. With N emissions continuing to increase in the future, areas whose ecosystem is affected by high level nitrogen deposition will increase.

  8. The protective effects of oral low-dose quercetin on diabetic nephropathy in hypercholesterolemic mice

    PubMed Central

    Gomes, Isabele B. S.; Porto, Marcella L.; Santos, Maria C. L. F. S.; Campagnaro, Bianca P.; Gava, Agata L.; Meyrelles, Silvana S.; Pereira, Thiago M. C.; Vasquez, Elisardo C.

    2015-01-01

    Aims: Diabetic nephropathy (DN) is one of the most important causes of chronic renal disease, and the incidence of DN is increasing worldwide. Considering our previous report (Gomes et al., 2014) indicating that chronic treatment with oral low-dose quercetin (10 mg/Kg) demonstrated anti-oxidative, anti-apoptotic and renoprotective effects in the C57BL/6J model of DN, we investigated whether this flavonoid could also have beneficial effects in concurrent DN and spontaneous atherosclerosis using the apolipoprotein E-deficient mouse (apoE−/−). Methods: Streptozotocin was used to induce diabetes (100 mg/kg/day, 3 days) in male apoE−/− mice (8 week-old). After 6 weeks, the mice were randomly separated into DQ: diabetic apoE−/− mice treated with quercetin (10 mg/kg/day, 4 weeks, n = 8), DV: diabetic ApoE−/− mice treated with vehicle (n = 8) and ND: non-treated non-diabetic mice (n = 8). Results: Quercetin treatment diminished polyuria (~30%; p < 0.05), glycemia (~25%, p < 0.05), normalized the hypertriglyceridemia. Moreover, this bioflavonoid diminished creatininemia (~30%, p < 0.01) and reduced proteinuria but not to normal levels. We also observed protective effects on the renal structural changes, including normalization of the index of glomerulosclerosis and kidney weight/body weight. Conclusions: Our data revealed that quercetin treatment significantly reduced DN in hypercholesterolemic mice by inducing biochemical changes (decrease in glucose and triglycerides serum levels) and reduction of glomerulosclerosis. Thus, this study highlights the relevance of quercetin as an alternative therapeutic option for DN, including in diabetes associated with dyslipidemia. PMID:26388784

  9. Designing artificial two dimensional electron lattice on metal surface: a Kagome-like lattice as an example

    NASA Astrophysics Data System (ADS)

    Li, Shuai; Qiu, Wen-Xuan; Gao, Jin-Hua

    2016-06-01

    Recently, a new kind of artificial two dimensional (2D) electron lattice on the nanoscale, i.e. molecular graphene, has drawn a lot of interest, where the metal surface electrons are transformed into a honeycomb lattice via absorbing a molecular lattice on the metal surface [Gomes et al., Nature, 2012, 438, 306; Wang et al., Phys. Rev. Lett., 2014, 113, 196803]. In this work, we theoretically demonstrate that this technique can be readily used to build other complex 2D electron lattices on a metal surface, which are of high interest in the field of condensed matter physics. The main challenge to build a complex 2D electron lattice is that this is a quantum antidot system, where the absorbed molecule normally exerts a repulsive potential on the surface electrons. Thus, there is no straightforward corresponding relation between the molecular lattice pattern and the desired 2D lattice of surface electrons. Here, we give an interesting example about the Kagome lattice, which has exotic correlated electronic states. We design a special molecular pattern and show that this molecular lattice can transform the surface electrons into a Kagome-like lattice. The numerical simulation is conducted using a Cu(111) surface and CO molecules. We first estimate the effective parameters of the Cu/CO system by fitting experimental data of the molecular graphene. Then, we calculate the corresponding energy bands and LDOS of the surface electrons in the presence of the proposed molecular lattice. Finally, we interpret the numerical results by the tight binding model of the Kagome lattice. We hope that our work can stimulate further theoretical and experimental interest in this novel artificial 2D electron lattice system.

  10. Mercury distribution in organs of fish species and the associated risk in traditional subsistence villagers of the Pantanal wetland.

    PubMed

    Ceccatto, Ana P S; Testoni, Magalei C; Ignácio, Aurea R A; Santos-Filho, Manoel; Malm, Olaf; Díez, Sergi

    2016-06-01

    This study evaluated the risk to human health from mercury (Hg) exposure through fish consumption in the Pantanal, Brazil. In order to address these risks, Hg concentrations and accumulation patterns were determined in target organs of predatory fish (Crenicichla lepidota and Pygocentrus nattereri). Levels of Hg were analysed during the two phases of the flood pulse (flood and drought) in fish from different local ecosystems, such as the Bento Gomes and Paraguay rivers. Although the former study area is directly affected by gold mining, a higher, but not significantly different, Hg concentration in fish was found compared with fish at the Paraguay River, which is regarded as pristine area. Moreover, no seasonal variability was found in either river. Although total mercury levels in fish did not exceed the maximum FAO/WHO threshold (0.5 μg g(-1)), according to dietary habits in riverine communities of the Pantanal (up to 6 oz of fish per day), there is reason for concern over the potential for deleterious health effects that could be caused by high Hg intake. In fact, the estimated daily intake in the present study ranged from 0.49 to 1.08 μg Hg kg(-1) day(-1), for adults (including women of childbearing age) and children, respectively. Because of high Hg intakes in riverine groups, which exceed the recommended reference dose value, these communities could be considered at risk. Therefore, it is necessary to consider regulatory measures and public education regarding fish consumption, particularly in vulnerable groups (i.e. children, pregnant women and women of childbearing age).

  11. Fire emissions in Euro-Mediterranean area: evaluation of the impact on trace gases composition using satellite and surface observations

    NASA Astrophysics Data System (ADS)

    Messina, P.; Turquety, S.; Stromatas, S.; Menut, L.; Anav, A.; Coheur, P.-F.; R'honi, Y.; Bessagnet, B.; Clerbaux, C.

    2012-04-01

    Wildfires are one of the main sources of trace gases and aerosols. However, their impact remains poorly quantified due to large uncertainties especially on the emissions, as well as on the transport processes and chemical evolution of the pollution plumes. In the framework of APIFLAME project a new high resolution fire emission inventory is developed. Simulations performed with the regional chemistry transport model CHIMERE, are carried out in order to assess the effect of the emissions scenarios on air quality in Europe and Mediterranean basin. For a comprehensive evaluation of the processes involved with fire emissions and a validation of simulations, the modeled species are compared to satellite observations and ground measurements. The latter data have good accuracy with high temporal resolution, but they are collected at specific locations and, in general for our case study, are far away from the location where wildfires occur. On the other hand, the satellite data, due to their high spatial coverage, can be a useful tool for monitoring pollution plumes transport, but their vertical resolution is often limited to a total column amount. In this study, the modeled concentrations are compared to the ground measurements (CO, O3 and NO2 concentrations) that come from AirBase database, and to CO partial columns and CO, NH3 and C2H4 total columns from the IASI instrument, to NO2 and CH2O total columns from GOME2 (both on MetOp-A satellite) and to NO2 total columns from OMI (on Aura). In the presented work we focus on strong biomass burning episodes that occurred in summer 2007. Particular attention is given to the evolution of the plume characteristics. The same fire inventory setup is used for both reanalysis and near-real time analysis. The first evaluation of the air quality forecasting system including fires will be presented.

  12. Improving the estimation of terrestrial gross primary productivity by downscaling global sun-induced chlorophyll fluorescence

    NASA Astrophysics Data System (ADS)

    Cescatti, A.; Duveiller, G.

    2015-12-01

    The synoptic nature of satellite remote sensing makes this technique a key tool to contribute to estimating the amount of Carbon fixed by vegetation at global scale. From the various types of information that can be derived from space, the recent capacity to create global datasets of sun-induced chlorophyll fluorescence (SIF) may prove to be a game-changer. SIF is a signal emitted by the photosynthetic machinery itself that, under the illumination conditions in which it can be estimated by satellite, has been shown to be proportional to gross primary productivity (GPP). However, this relationship is dependent on vegetation types that are typically spatially mixed at the coarse spatial resolution of SIF datasets (at best 0.5°), which in turn is a consequence of the complexity of the SIF retrieval itself. This study demonstrates how 0.5° SIF derived from GOME-2 data can be downscaled to a more adequate spatial resolution of 0.05° by combining 3 explanatory biophysical variables derived from the MODIS sensor (NDVI, land surface temperature and evapotranspiration) under a semi-empirical light-use efficiency framework. The finer spatial resolution results in a cleaner signal when aggregating it per land cover type. The signal is also better correlated in time with GPP estimated from flux towers, reaching the same level of performance than global GPP products calibrated on such flux towers and driven by meteorological and remote sensing variables (other than SIF). Establishing linear relationships between SIF and flux-tower GPP at vegetation type level allows to estimate values of global terrestrial vegetation gross productivity that have different magnitude but similar temporal patterns as other GPP products. Based on downscaled SIF, the mean global GPP values over the period 2007 to 2013 are (for deciduous broadleaf and mixed forests) 13.7, (for evergreen needleleaf forests) 2.5, (for grasslands) 12.5 and (savannahs and woody savannas) 36.8 Pg of Carbon per year.

  13. Validation of ash optical depth and layer height retrieved from passive satellite sensors using EARLINET and airborne lidar data: the case of the Eyjafjallajökull eruption

    NASA Astrophysics Data System (ADS)

    Balis, Dimitris; Koukouli, Maria-Elissavet; Siomos, Nikolaos; Dimopoulos, Spyridon; Mona, Lucia; Pappalardo, Gelsomina; Marenco, Franco; Clarisse, Lieven; Ventress, Lucy J.; Carboni, Elisa; Grainger, Roy G.; Wang, Ping; Tilstra, Gijsbert; van der A, Ronald; Theys, Nicolas; Zehner, Claus

    2016-05-01

    The vulnerability of the European airspace to volcanic eruptions was brought to the attention of the public and the scientific community by the 2010 eruptions of the Icelandic volcano Eyjafjallajökull. As a consequence of this event, ash concentration thresholds replaced the "zero tolerance to ash" rule, drastically changing the requirements on satellite ash retrievals. In response to that, the ESA funded several projects aiming at creating an optimal end-to-end system for volcanic ash plume monitoring and prediction. Two of them, namely the SACS-2 and SMASH projects, developed and improved dedicated satellite-derived ash plume and sulfur dioxide level assessments. The validation of volcanic ash levels and height extracted from the GOME-2 and IASI instruments on board the MetOp-A satellite is presented in this work. EARLINET lidar measurements are compared to different satellite retrievals for two eruptive episodes in April and May 2010. Comparisons were also made between satellite retrievals and aircraft lidar data obtained with the UK's BAe-146-301 Atmospheric Research Aircraft (managed by the Facility for Airborne Atmospheric Measurements, FAAM) over the United Kingdom and the surrounding regions. The validation results are promising for most satellite products and are within the estimated uncertainties of each of the comparative data sets, but more collocation scenes would be desirable to perform a comprehensive statistical analysis. The satellite estimates and the validation data sets are better correlated for high ash optical depth values, with correlation coefficients greater than 0.8. The IASI retrievals show a better agreement concerning the ash optical depth and ash layer height when compared with the ground-based and airborne lidar data.

  14. Dollfusiella qeshmiensis n. sp. (Cestoda: Trypanorhyncha) from the cowtail stingray Pastinachus sephen (Forsskål) in the Persian Gulf, with a key to the species of Dollfusiella Campbell & Beveridge, 1994.

    PubMed

    Haseli, Mohammad; Palm, Harry W

    2015-10-01

    A new species of the genus Dollfusiella Campbell & Beveridge, 1994 is described from Pastinachus sephen (Forsskål) in the Persian Gulf. Dollfusiella qeshmiensis n. sp. is allocated to the genus Dollfusiella based on the possession of two bothria, prebulbar organs, a heteroacanthous typical armature with tightly spaced rows of hollow hooks, a basal swelling and a characteristic basal armature without prominent macrohooks. The presence of an enlarged external seminal vesicle in Dollfusiella qeshmiensis n. sp. distinguishes this species from D. michiae (Southwell, 1929), D. bareldsi (Beveridge, 1990), D. owensi (Beveridge, 1990), D. geraschmidti (Dollfus, 1974), D. angustiformis Schaeffner & Beveridge, 2013, D. hemispinosa Schaeffner & Beveridge, 2013, D. spinosa Schaeffner & Beveridge, 2013 and D. taminii Menoret & Ivanov, 2014. The new species is distinguished from the remaining species within the genus by a combination of the following morphological features: the number of testes per segment, the number of testis columns and the number of homeomorphous hooks per half spiral row in the metabasal region. In the most recent taxonomic key to the species of Dollfusiella, the presence or absence of enlarged, microscopically visible spinitriches on the scolex was used as the first distinguishing character dividing the congeners into two groups. Since the existence of visible microtriches on the scolex peduncle of D. vooremi (São Clemente & Gomes, 1989), a species so far grouped among the species lacking visible microtriches on the scolex, has been recently demonstrated, and given the fact that the presence of microscopically visible microtriches on the scolex is variable in some eutetrarhynchid species, a new key to the species of Dollfusiella is provided in which the spinitriches have been given less priority. PMID:26358075

  15. Validation of Ozone Monitoring Instrument level 1b data products

    NASA Astrophysics Data System (ADS)

    Dobber, M.; Kleipool, Q.; Dirksen, R.; Levelt, P.; Jaross, G.; Taylor, S.; Kelly, T.; Flynn, L.; Leppelmeier, G.; Rozemeijer, N.

    2008-08-01

    The validation of the collection 2 level 1b radiance and irradiance data measured with the Ozone Monitoring Instrument (OMI) on NASA's Earth Observing System (EOS) Aura satellite is investigated and described. A number of improvements from collection 2 data to collection 3 data are identified and presented. It is shown that with these improvements in the calibration and in the data processing the accuracy of the geophysically calibrated level 1b radiance and irradiance is improved in the collection 3 data. It is shown that the OMI level 1b irradiance product can be reproduced from a high-resolution solar reference spectrum convolved with the OMI spectral slit functions within 3% for the Fraunhofer structure and within 0.5% for the offset. The agreement of the OMI level 1b irradiance data product with other available literature irradiance spectra is within 4%. The viewing angle dependence of the irradiance and the irradiance goniometry are discussed, and improvements in the collection 3 data are described. The in-orbit radiometric degradation since launch is shown to be smaller than 0.5% above 310 nm and increases to about 1.2% at 270 nm. It is shown how the viewing angle dependence of the radiance is improved in the collection 3 data. The calculation of the surface albedo from OMI measurement data is discussed, and first results are presented. The OMI surface albedo values are compared to literature values from the Total Ozone Mapping Spectrometer (TOMS) and the Global Ozone Monitoring Experiment (GOME). Finally, improvements in the spectral and spatial stray light corrections from collection 2 data to collection 3 data are presented and discussed.

  16. The EUMETSAT Polar System - Achievements Two Years after Launch of Metop- A

    NASA Astrophysics Data System (ADS)

    Munro, R.; Holmlund, K.; Klaes, D.; Schmetz, J.

    2008-12-01

    Metop-A, the first of the Metop series of polar-orbiting operational meteorological satellites was launched on the 19th October 2006. The remaining two satellites in the series will be launched in 2011 and 2015. Metop is Europe's first polar-orbiting satellite dedicated to operational meteorology. It represents the European contribution to a new cooperative venture with the United States - the Initial Joint Polar System IJPS - providing data that is used to monitor our climate and improve weather forecasting. Europe serves the mid- morning orbit, whereas NOAA will continue to serve the afternoon orbit. A new generation of European instruments that offer improved remote sensing capabilities to both meteorologists and climatologists are carried along with a set of "heritage" instruments provided by the United States. The new European instruments have been respectively developed by ESA (ASCAT, GRAS, GOME-2), CNES (IASI) and EUMETSAT (MHS) and will offer advanced sounding capabilities, the measurement of ocean surface wind as well as improved observation of ozone and other trace gases. Providing unprecedented accuracy in meteorological data, the European contribution will lead to a better understanding of our climate. Meteorological "heritage" instruments provided by the United States are part of the complement of American instruments provided by the National Oceanic and Atmospheric Administration (NOAA) to fly on Metop-A and -B, and, with the exception of HIRS, also on Metop-C. They are the AMSU-A1 and A2 Advanced Microwave Sounding Units, the HIRS/4 High Resolution Infrared Sounder and the AVHRR Advanced Very High Resolution Radiometer. They fly also on the NOAA afternoon satellites (NOAA-18 and NOAA-N'). More than two years after the launch of Metop-A the achievements and perspectives for the Metop series of satellites will be presented.

  17. Five Years of Ground-Based MAX-DOAS Observations of CHOCHO and HCHO in the Beijing Area

    NASA Astrophysics Data System (ADS)

    Hendrick, F.; Lerot, C.; De Smedt, I.; Stavrakou, T.; Fayt, C.; Gielen, C.; Hermans, C.; Muller, J. F.; Pinardi, G.; Van Roozendael, M.

    2015-12-01

    Glyoxal (CHOCHO) and formaldehyde (HCHO) are among the most important carbonyl compounds in the atmosphere. Given their short lifetime (typically a few hours) and since they are mainly produced by the oxidation of biogenic and anthropogenic volatile organic compounds (VOCs), they are very good proxy for detecting active VOCs chemistry which can be responsible for the formation of pollutants such as tropospheric ozone and secondary organic aerosols. Both CHOCHO and HCHO are also directly released by biomass burning and fossil fuel combustion. Measuring these species is therefore of major importance for air quality monitoring, especially given the scarcity of available observational data sets. In this presentation, CHOCHO and HCHO vertical profiles and corresponding column densities are retrieved from ground-based MAX-DOAS (Multi-AXis Differential Optical Absorption Spectroscopy) measurements in the Beijing city center and at the suburban site of Xianghe located at 60km East of Beijing. The periods covered by the observations are June 2008-April 2009 in Beijing and March 2010-December 2014 in Xianghe. We first investigate the capability of the MAX-DOAS technique to measure these species in such highly-polluted environment. Then the diurnal and seasonal cycles of CHOCHO and HCHO near-surface concentrations and vertical column densities as well as the corresponding CHOCHO/HCHO ratios (RGF) are examined on a long-term basis at both locations. This RGF ratio is often used as an indicator of changes in the atmospheric VOC mixture. Finally, these diurnal and seasonal cycles are further assessed using simulations from the 3D chemistry transport model IMAGES and observations from the OMI and GOME-2 satellite nadir sensors.

  18. Trends, seasonal variability and dominant NOx source derived from a ten year record of NO2 measured from space

    NASA Astrophysics Data System (ADS)

    van der A, R. J.; Eskes, H. J.; Boersma, K. F.; van Noije, T. P. C.; van Roozendael, M.; de Smedt, I.; Peters, D. H. M. U.; Meijer, E. W.

    2008-02-01

    For the period 1996-2006, global distributions of tropospheric nitrogen dioxide (NO2) have been derived from radiances measured with the satellite instruments GOME (Global Ozone Monitoring Experiment) and SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY). A statistical analysis is applied to derive trends and seasonal variability for this period on a global scale. The time series of the monthly NO2 columns for these ten years have been fitted with a linear function superposed on an annual seasonal cycle on a grid with a spatial resolution of 1° by 1°. We see significant reductions (up to 7% per year) in NO2 in Europe and parts of the eastern United States, and a strong increase in Asia, most particularly in China (up to 29% per year) but also in Iran and Russia. By comparing the data with the cloud information derived from the same satellite observations, the contribution of lightning to the total column of NO2 is estimated. The estimated NO2 from lightning is, especially in the tropics, in good agreement with lightning flash rate observations from space. The satellite observed seasonal variability of NO2 generally correlates well with independent observations and estimates of the seasonal cycle of specific NOx sources. Source categories considered are anthropogenic (fossil fuel and biofuel), biomass burning, soil emissions and lightning. Using the characteristics of the seasonal variability of these source categories, the dominant source of NOx emissions has been identified on a global scale and on a 1° by 1° grid.

  19. Mapping the Distribution of Wildfire Fuels Using AVIRIS in the Santa Monica Mountains

    NASA Technical Reports Server (NTRS)

    Roberts, Dar; Gardner, M.; Regelbrugge, J.; Pedreros, D.; Ustin, S.

    1998-01-01

    Catastrophic wildfires, such as the 1990 Painted Cave Fire in Santa Barbara or Oakland fire of 1991, attest to the destructive potential of fire in the wildland/urban interface. For example, during the Painted Cave Fire, 673 structures were consumed over a period of only six hours at an estimated cost of 250 million dollars (Gomes et al., 1993). One of the primary sources of fuels is chaparral, which consists of plant species that are adapted to frequent fires and may actually promote its ignition and spread of through volatile organic compounds in foliage. As one of the most widely distributed plant communities in Southern California, and one of the most common vegetation types along the wildland urban interface, chaparral represents one of the greatest sources of wildfire hazard in the region. An ongoing NASA funded research project was initiated in 1994 to study the potential of AVIRIS for mapping wildfire fuel properties in Southern California chaparral. The project was initiated in the Santa Monica Mountains, an east-west trending range in western Los Angeles County that has experienced extremely high fire frequencies over the past 70 years. The Santa Monica Mountains were selected because they exemplify many of the problems facing the southwest, forming a complex mosaic of land ownership intermixed with a diversity of chaparral age classes and fuel loads. Furthermore, the area has a wide diversity of chaparral community types and a rich background in supporting geographic information including fire history, soils and topography. Recent fires in the Santa Monica Mountains, including several in 1993 and the Calabasas fire of 1996 attest to the active fire regime present in the area. The long term objectives of this project are to improve existing maps of wildland fuel properties in the area, link AVIRIS derived products to fuel models under development for the region, then predict fire hazard through models that simulate fire spread. In this paper, we describe

  20. SCIAMACHY: The new Level 0-1 Processor

    NASA Astrophysics Data System (ADS)

    Lichtenberg, Günter; Slijkhuis, Sander; Aberle, Bernd; Sherbakov, Denis; Meringer, Markus; Noel, Stefan; Bramstedt, Klaus; Liebing, Patricia; Bovensmann, Heinrich; Snel, Ralph; Krijger, Mathijs; van Hees, Richard; van der Meer, Pieter; Lerot, Christophe; Dehn, Angelika; Fehr, Thorsten

    2016-04-01

    SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) is a scanning nadir and limb spectrometer covering the wavelength range from 212 nm to 2386 nm in 8 channels. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002 on the ENVISAT platform. After the platform failure in April 2012, SCIAMACHY is now in the postprocessing phase F. SCIAMACHYs originally specified in-orbit lifetime was double the planned lifetime. SCIAMACHY was designed to measure column densities and vertical profiles of trace gas species in the mesosphere, in the stratosphere and in the troposphere (Bovensmann et al., 1999). It can detect O3 , H2CO, SO2 , BrO, OClO, NO2 , H2 O, CO, CO2 , CH4 , N2 O , O2 , (O2)2 and can provide information about aerosols and clouds. The operational processing of SCIAMACHY is split into Level 0-1 processing (essentially providing calibrated radiances) and Level 1-2 processing providing geophysical products. The operational Level 0-1 processor has been completely re-coded and embedded in a newly developed framework that speeds up processing considerably. Currently Version 9 of the Level 0-1 processor is implemented. It will include - An updated degradation correction - Several improvements in the SWIR spectral range like a better dark correction, an improved dead & bad pixel characterisation and an improved spectral calibration - Improvements to the polarisation correction algorithm - Improvements to the geolocation by a better pointing characterisation Additionally a new format for the Level 1b and Level 1c will be implemented. The version 9 products will be available in netCDF version 4 that is aligned with the formats of the GOME-1 and Sentinel missions. We will present the first results of the new Level 0-1 processing in this paper.

  1. Solar-induced Fluorescence as a Proxy for Canopy Photosynthesis in a Temperate Deciduous Forest: Comparisons between Observations and Model Results

    NASA Astrophysics Data System (ADS)

    Yang, X.; Lee, J. E.; Berry, J. A.; Tang, J.; Mustard, J. F.; Van der Tol, C.; Kellner, J. R.; Silva, C. E.

    2015-12-01

    Photosynthesis in the terrestrial ecosystems contributes to the largest carbon flux in the global carbon cycle. The use of solar-induced fluorescence (SIF) as a proxy of photosynthesis at the ecosystem scale (Gross Primary Production, GPP) is a critical emerging technology. Satellite measurements of SIF were found to be significantly correlated with GPP, and several ground campaigns suggested that SIF could improve the GPP estimation. However, it remains unclear to what extent this relationship is due to absorbed photosynthetically active radiation (APAR) and/or light use efficiency (LUE). In addition, models that simulate SIF have not been rigorously validated. Here we present the first time-series of near-surface measurement of canopy-scale SIF at 760nm in temperate deciduous forests during year 2013-2014. SIF correlated with GPP estimated with eddy covariance at diurnal and seasonal scales (r2=0.82 and 0.73, respectively), as well as with APAR diurnally and seasonally (r2=0.90 and 0.80, respectively). SIF/APAR is significantly positively correlated with LUE and is higher during cloudy days than sunny days. Weekly tower-based SIF agreed with SIF from GOME-2 (The Global Ozone Monitoring Experiment-2, r2 = 0.82). We further compared SIF observations with those simulated by Soil Canopy Observation Photochemistry and Energy fluxes (SCOPE) model. We found that key parameters in SCOPE including Vcmax, LAI, chlorophyll content, and viewing angles determine the agreement between observations and model. Our results provide support to the use of SIF to estimate canopy photosynthetic activities, and present a framework of validating fluorescence simulated by canopy radiative transfer models.

  2. Measurement of Gas-phase Acids in Diesel Exhaust

    NASA Astrophysics Data System (ADS)

    Wentzell, J. J.; Liggio, J.; Li, S.; Vlasenko, A. L.; Staebler, R. M.; Brook, J.; Lu, G.; Poitras, M.; Chan, T.

    2012-12-01

    Gas-phase acids were measured using chemical ionization mass spectrometry (CIMS) as part of the Diesel Engine Emission Research Experiment (DEERE). The CIMS technique, utilizing acetate ion (CH3COO-) as a reagent ion, proved to be a rapid (measurements on the order of seconds) and sensitive (several counts/pptv) method of quantifying the acid emissions. Diluted diesel exhaust measurements were made from a Constant Volume Sampling dilution tunnel using a light duty (1.9L turbocharged Volkswagen Jetta TDI) diesel engine equipped with an OEM diesel oxidation catalyst and exhaust gas recirculation, mounted on an engine dynamometer. Acids measured included isocyanic, nitrous, nitric, propionic and sum of lactic and oxalic, as well as other unidentified compounds. Complimentary measurements of CO, CO2, Total Hydrocarbon (THC), and NOx, were also performed. Several engine modes (different engine rpm and torque outputs) at steady state were examined to determine their effect on acid emissions. Emission rates with respect to NOx and fuel based emission factors were determined. Measurements of HONO fuel emission factors agree well with real-world measurements within a traffic tunnel.1 The first estimate of isocyanic acid emission factors from a diesel engine is reported, and suggests that the emission of this highly toxic compound in diesel exhaust should not be ignored. 1. Kurtenbach, R., Becker, K. H., Gomes, J. A. G., Kleffmann, J.,Lorzer, J. C., Spittler, M., Wiesen, P., Ackermann, R., Geyer, A.,and Platt, U.: Investigations of emissions and heterogeneous formation of HONO in a road traffic tunnel, Atmos. Environ., 35, 3385-3394, doi:10.1016/S1352-2310(01)00138-8, 2001.

  3. Ozone and Aerosol Retrieval from Backscattered Ultraviolet Radiation

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.

    2004-01-01

    In this presentation we will discuss the techniques to estimate total column ozone and aerosol absorption optical depth from the measurements of backscattered ultraviolet (buv) radiation. The total ozone algorithm has been used to create a unique record of the ozone layer, spanning more than 3 decades, from a series of instruments (BUV, SBUV, TOMS, SBUV/2) flown on NASA, NOAA, Japanese and Russian satellites. We will discuss how this algorithm can be considered a generalization of the well-known Dobson/Brewer technique that has been used to process data from ground-based instruments for many decades, and how it differs from the DOAS techniques that have been used to estimate vertical column densities of a host of trace gases from data collected by GOME and SCIAMACHY instruments. The BUV aerosol algorithm is most suitable for the detection of UV absorbing aerosols (smoke, desert dust, volcanic ash) and is the only technique that can detect aerosols embedded in clouds. This algorithm has been used to create a quarter century record of aerosol absorption optical depth using the BUV data collected by a series of TOMS instruments. We will also discuss how the data from the OM1 instrument launched on July 15,2004 will be combined with data from MODIS and CALIPSO lidar data to enhance the accuracy and information content of satellite-derived aerosol measurements. The OM1 and MODIS instruments are currently flying on EOS Aura and EOS Aqua satellites respectively, part of a constellation of satellites called the "A-train". The CALIPSO satellite is expected to join this constellation in mid 2005.

  4. Ozone and Aerosol Retrieval from Backscattered Ultraviolet Radiation

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.

    2012-01-01

    In this presentation we will discuss the techniques to estimate total column ozone and aerosol absorption optical depth from the measurements of back scattered ultraviolet (buv) radiation. The total ozone algorithm has been used to create a unique record of the ozone layer, spanning more than 3 decades, from a series of instruments (BUV, SBUV, TOMS, SBUV/2) flown on NASA, NOAA, Japanese and Russian satellites. We will discuss how this algorithm can be considered a generalization of the well-known Dobson/Brewer technique that has been used to process data from ground-based instruments for many decades, and how it differs from the DOAS techniques that have been used to estimate vertical column densities of a host of trace gases from data collected by GOME and SCIAMACHY instruments. The buv aerosol algorithm is most suitable for the detection of UV absorbing aerosols (smoke, desert dust, volcanic ash) and is the only technique that can detect aerosols embedded in clouds. This algorithm has been used to create a quarter century record of aerosol absorption optical depth using the buv data collected by a series of TOMS instruments. We will also discuss how the data from the OMI instrument launched on July 15, 2004 will be combined with data from MODIS and CALIPSO lidar data to enhance the accuracy and information content of satellite-derived aerosol measurements. The OMI and MODIS instruments are currently flying on EOS Aura and EOS Aqua satellites respectively, part of a constellation of satellites called the "A-train".

  5. Domestic Rhodnius ecuadoriensis (Hemiptera, Reduviidae) infestation in Northern Peru: a comparative trial of detection methods during a six-month follow-up.

    PubMed

    Cuba Cuba, César Augusto; Vargas, Franklin; Roldan, Judith; Ampuero, Cynthia

    2003-01-01

    Two passive methods in the assessment of intradomiciliary infestation by Rhodnius ecuadoriensis were tested: (i) the Gomes Nu ez sensor box (GN), (ii) sheets of white typing paper and (iii) one active timed manual method. The study was carried out in the Alto Chicama River Valley, Province of Gran Chim , Department of La Libertad. The study design consisted of an initial searching of triatomines inside of the domestic environment by the manual capture active procedure (man/hour) covering all the studied houses. Then, matched pairs of GN boxes and paper sheets were simultaneously installed in the bedrooms of 207 households distributed in 19 localities. A comparative prospective trial of these passive detection devices were monitored at 2, 4 and, finally 6 months follow-up. Parasitological Trypanosoma rangeli and/or T. cruzi infections were investigated in two houses with high level of infestation by R. ecuadoriensis. 16.9% of the 207 households investigated by an initial active manual method were infested with R. ecuadoriensis. The proportion of infested houses fluctuated from 6.2 to 55.5% amongst the 19 localities investigated. T. rangeli natural infection was detected in R. ecuadoriensis specimens collected in two households. Parasite rates in the bugs ranged from 16.6 to 21.7% respectively. The most striking fact was an average rate of salivary gland infection ranging from 7.4 to 8.3%. At the end of the sixth month period, a cumulative incidence of 31.4% of positive GN boxes against 15.9% for paper sheets was recorded. All three methods combined detected domestic infestation in 129 (62.3%) of the 207 houses studied in the 19 localities. The range of houses infested varies from 6.7% to 92.9%. In areas with low bug density infestation rates, the methodology experienced in our studies, seems to be the best choice for investigations on domestic R. ecuadoriensis populations.

  6. Analysis of volcanic bromine monoxide emissions in the southwestern Pacific region in 2005 based on satellite observations from OMI

    NASA Astrophysics Data System (ADS)

    Popp, Christoph; McCormick, Brendan; Suleiman, Raid; Chance, Kelly; Andrews, Benjamin; Cottrell, Elizabeth

    2015-04-01

    In this study, we analyze the potential of the Ozone Monitoring Instrument (OMI) for the detection and quantification of volcanic bromine monoxide (BrO) from space. Compared to other available UV/VIS satellite sensors with similar trace gas retrieval capability (like GOME-2) OMI has better spatial resolution and global coverage, likely leading to a better detection limit of BrO. In addition, the now more than ten years long OMI data record exceeds others in time and can be exploited for different volcanological applications. We chose the southwestern Pacific as our study region, including the Marianas, Papua New Guinea, and Vanuatu because volcanic activity of different magnitude has been reported in the Global Volcanism Program data base in this area. We analyze measurements acquired during the entire year of 2005. We use the standard level-2 OMI BrO data product available from NASA GES DISC. In addition, we take advantage of coincident OMI SO2 retrievals as a proxy for the plume extent and to calculate BrO/SO2 ratios. We explore spatial variations in BrO/SO2 ratios and interpret these in terms of atmospheric chemical processing. For example, the Anatahan eruption in March 2005 clearly reveals lower BrO/SO2 values closer to the source that increase downwind before leveling-off at a certain distance from the vent. We also report the first BrO measurements from several volcanoes in the southwestern Pacific, including Anatahan, Manam, and Bagana where the plume BrO vertical column densities (VCD) clearly exceed background values and where plume BrO and SO2 VCD are highly correlated (R>0.8). Finally, our analysis suggests that several volcanoes emitting BrO may have an as-yet unappreciated contribution to global halogen emissions from volcanoes.

  7. An improved retrieval of tropospheric NO2 from space over polluted regions using an Earth radiance reference

    NASA Astrophysics Data System (ADS)

    Anand, J. S.; Monks, P. S.; Leigh, R. J.

    2015-03-01

    A novel tropospheric NO2 DOAS retrieval algorithm optimised for a nadir-viewing satellite instrument imaging polluted areas is proposed in this work. Current satellite DOAS retrievals have relied on using a solar reference spectrum to derive a total slant column, then using either model assimilation or spatial filtering to derive the tropospheric component. In the ERrs-DOAS (Earth radiance reference sector DOAS) algorithm, tropospheric NO2 slant columns are derived using spectra averaged from measurements over unpolluted regions, thus removing the need for post-hoc separation techniques, though some residual stratospheric biases may still remain. To validate the ERrs-DOAS algorithm, DOAS retrievals were performed on modelled spectra created by the radiative transfer model SCIATRAN, as well as L1B Earth radiance data measured by the NASA/KNMI Ozone Monitoring Instrument (OMI). It was found that retrievals using an Earth radiance reference produce spatial distributions of tropospheric NO2 over eastern China during June 2005 that highly correlate with those derived using existing retrieval algorithms. Comparisons with slant columns retrieved by the operational NO2 retrieval algorithm for OMI (OMNO2A) show that the ERrs-DOAS algorithm greatly reduces the presence of artificial across-track biases (stripes) caused by calibration errors, as well as the removal of path length enhancement in off-nadir pixels. Analysis of Pacific SCDs suggests that the algorithm also produces a 27% reduction in retrieval uncertainty, though this may be partially due to biases introduced by differences in the retrieval algorithm settings. The ERrs-DOAS technique also reveals absorption features over the Sahara and similar regions characteristic of sand and liquid H2O absorption, as first discovered in the analysis of GOME-2 NO2 retrievals.

  8. Detection from space of a reduction in anthropogenic emissions of nitrogen oxides during the Chinese economic downturn

    NASA Astrophysics Data System (ADS)

    Lin, J.-T.; McElroy, M. B.

    2011-08-01

    Rapid economic and industrial development in China and relatively weak emission controls have resulted in significant increases in emissions of nitrogen oxides (NOx) in recent years, with the exception of late 2008 to mid 2009 when the economic downturn led to emission reductions detectable from space. Here vertical column densities (VCDs) of tropospheric NO2 retrieved from satellite observations by SCIAMACHY, GOME-2 and OMI (both by KNMI and by NASA) are used to evaluate changes in emissions of NOx from October 2004 to February 2010 identifying impacts of the economic downturn. Data over polluted regions of Northern East China suggest an increase of 27-33 % in 12-month mean VCD of NO2 prior to the downturn, consistent with an increase of 49 % in thermal power generation (TPG) reflecting the economic growth. More detailed analysis is used to quantify changes in emissions of NOx in January over the period 2005-2010 when the effect of the downturn was most evident. The GEOS-Chem model is employed to evaluate the effect of changes in chemistry and meteorology on VCD of NO2. This analysis indicates that emissions decreased by 20 % from January 2008 to January 2009, close to the reduction of 18 % in TPG that occurred over the same interval. A combination of three independent approaches indicates that the economic downturn was responsible for a reduction in emissions by 9-11 % in January 2009 with an additional decrease of 10 % attributed to the slow-down in industrial activity associated with the coincident celebration of the Chinese New Year; errors in the estimate are most likely less than 3.4 %.

  9. Detection from space of a reduction in anthropogenic emissions of nitrogen oxides during the Chinese economic downturn

    NASA Astrophysics Data System (ADS)

    Lin, J.-T.; McElroy, M. B.

    2011-01-01

    Rapid economic and industrial development in China and relatively weak emission controls have resulted in significant increases in emissions of nitrogen oxides (NOx) in recent years, with the exception of late 2008 to mid 2009 when the economic downturn led to emission reductions detectable from space. Here vertical column densities (VCDs) of tropospheric NO2 retrieved from satellite observations by SCIAMACHY, GOME-2 and OMI (both by KNMI and by NASA) are used to evaluate changes in emissions of NOx from October 2004 to February 2010 identifying impacts of the economic downturn. Data over polluted regions of Northern East China suggest an increase of 27-33% in annual mean VCD of NO2 prior to the downturn, consistent with an increase of 49% in thermal power generation (TPG) reflecting the economic growth. More detailed analysis is used to quantify changes in emissions of NOx in January over the period 2005-2010 when the effect of the downturn was most evident. The GEOS-Chem model is employed to evaluate the effect of changes in chemistry and meteorology on VCD of NO2. This analysis indicates that emissions decreased by 20% from January 2008 to January 2009, close to the reduction of 18% in TPG that occurred over the same interval. A combination of three relatively independent approaches indicates that the economic downturn was responsible for a~reduction in emissions by 9-11% in January 2009 with an additional decrease of 10% attributed to the slow-down in industrial activity associated with the coincident celebration of the Chinese New Year.

  10. Craniofacial morphology and otitis media with effusion in children.

    PubMed

    Di Francesco, Renata; Paulucci, Bruno; Nery, Claudio; Bento, Ricardo Ferreira

    2008-08-01

    Otitis media with effusion (OME) affects 28-38% of pre-school children, and it occurs due to the dysfunction of the auditory tube. Anatomical development of the auditory tube depends on the craniofacial growth and development. Deviations of normal craniofacial morphology and growth using cephalometric studies, may predict the evolution of otitis. Our goal in this paper is to determine if there are differences in craniofacial morphology between children with adenoid enlargement, with and without otitis media with effusion. This is a prospective study in which the sample consisted of 67 children (male and female) from 5 to 10 years old. All patients presented chronic upper airway obstruction due to tonsil and adenoid enlargement (>80% degree of obstruction). Thirty-three patients presented otitis media with effusion, for more than 3 months and 34 did not. The latter composed the control group. Standardized lateral head radiographs were obtained for all subjects. Radiographs were taken with patient positioned by a cephalostat and stayed with mandibles in centric occlusion and lips at rest. Radiographs were digitalized and specific landmarks were identified using a computer program Radiocef 2003, 5th edition. Measurements, angles and lines were taken of the basicranium, maxilla and mandible according to the modified Ricketts analysis. In addition, facial height and facial axis were determined. Children with otitis media with effusion present differences in the morphology of the face, regarding these measures: N-S (anterior cranial base length), N-ANS (upper facial height), ANS-PNS (size of the hard palate), Po-Or.N-Pog (facial depth), Ba-N.Ptm-Gn (facial axis), Go-Me (mandibular length) and Vaia--Vaip (inferior pharyngeal airway).

  11. Satellite chlorophyll fluorescence measurements reveal large-scale decoupling of photosynthesis and greenness dynamics in boreal evergreen forests.

    PubMed

    Walther, Sophia; Voigt, Maximilian; Thum, Tea; Gonsamo, Alemu; Zhang, Yongguang; Köhler, Philipp; Jung, Martin; Varlagin, Andrej; Guanter, Luis

    2016-09-01

    Mid-to-high latitude forests play an important role in the terrestrial carbon cycle, but the representation of photosynthesis in boreal forests by current modelling and observational methods is still challenging. In particular, the applicability of existing satellite-based proxies of greenness to indicate photosynthetic activity is hindered by small annual changes in green biomass of the often evergreen tree population and by the confounding effects of background materials such as snow. As an alternative, satellite measurements of sun-induced chlorophyll fluorescence (SIF) can be used as a direct proxy of photosynthetic activity. In this study, the start and end of the photosynthetically active season of the main boreal forests are analysed using spaceborne SIF measurements retrieved from the GOME-2 instrument and compared to that of green biomass, proxied by vegetation indices including the Enhanced Vegetation Index (EVI) derived from MODIS data. We find that photosynthesis and greenness show a similar seasonality in deciduous forests. In high-latitude evergreen needleleaf forests, however, the length of the photosynthetically active period indicated by SIF is up to 6 weeks longer than the green biomass changing period proxied by EVI, with SIF showing a start-of-season of approximately 1 month earlier than EVI. On average, the photosynthetic spring recovery as signalled by SIF occurs as soon as air temperatures exceed the freezing point (2-3 °C) and when the snow on the ground has not yet completely melted. These findings are supported by model data of gross primary production and a number of other studies which evaluated in situ observations of CO2 fluxes, meteorology and the physiological state of the needles. Our results demonstrate the sensitivity of space-based SIF measurements to light-use efficiency of boreal forests and their potential for an unbiased detection of photosynthetic activity even under the challenging conditions interposed by evergreen

  12. Intercomparison of spectral irradiance measurements and provision of alternative radiation scheme for CCMs of middle atmosphere

    NASA Astrophysics Data System (ADS)

    Pagaran, Joseph; Weber, Mark; Burrows, John P.

    The Sun's radiative output (total solar irradiance or TSI) determines the thermal structure of the Earth's atmosphere. Its variability is a strong function of wavelength, which drives the photochemistry and general circulation. Contributions to TSI variability from UV wavelengths below 400 nm, i.e. 0.227-day solar rotation or 0.1to be in the 40-60three decades of UV and about a decade of vis-IR observations. Significant progress in UV/vis-IR regions has been achieved with daily monitoring from SCIAMACHY aboard Envisat (ESA) in 2002 and by SIM aboard SORCE (NASA) about a year after. In this contribution, we intercompare SSI measurements from SCIAMACHY and SIM and RGB filters of SPM/VIRGO SoHO: same (a) day and (b) few 27-day time series of spectral measurements in both irradiance and integrated irradiance over selected wavelength intervals. Finally, we show how SSI measurements from GOME, SOLSTICE, in addition to SCIAMACHY and SIM, can be modeled together with solar proxies F10.7 cm, Mg II and sunspot index (PSI) to derive daily SSI variability in the period 1947-2008. The derived variabilities are currently being used as solar input to Bremen's 3D-CTM and are to be recommended as extended alternative to Berlin's FUBRaD radiation scheme. This proxy-based radiation scheme are compared with SATIRE, NRLSSI (or Lean et al.), SUSIM, SSAI (or DeLand et al), and SIP (or Solar2000) models. The use of realistic spectrally resolved solar input to CCMs is to better understand the effects of solar variability on chemistry and temperature in the middle atmosphere over several decades.

  13. An overview of the AROMAT campaigns

    NASA Astrophysics Data System (ADS)

    Merlaud, Alexis; Dekemper, Emmanuel; Van Roozendael, Michel; Constantin, Daniel; Georgescu, Lucian; Meier, Andreas; Richter, Andreas; Den Hoed, Mirjam; Allaart, Marc; Boscornea, Andreea; Vajaiac, Sorin; Bellegante, Livio; Nemuc, Anca; Nicolae, Doina; Shaifangar, Reza; Dörner, Steffen; Wagner, Thomas; Stebel, Kerstin; Schuettemeyer, Dirk

    2016-04-01

    The Airborne ROmanian Measurements of Aerosols and Trace gases (AROMAT) campaign and its follow-up AROMAT-2 were held in September 2014 and August 2015, respectively. Both campaigns focused on two geophysical targets: the city of Bucharest and the large power plants of the Jiu Valley, which are located in a rural area 170 km West of Bucharest. These two areas are complementary in terms of emitted chemical species and their spatial distributions. The objectives of the AROMAT campaigns were (i) to test recently developed airborne observation systems dedicated to air quality satellite validation studies such as the AirMAP imaging DOAS system (University of Bremen), the NO2 sonde (KNMI), and the compact SWING whiskbroom imager (BIRA), and (ii) to prepare the validation programme of the future Atmospheric Sentinels, starting with Sentinel-5 Precursor (S5P) to be launched in early summer 2016. We present results from the different airborne instrumentations and from coincident ground-based measurements (lidar, in-situ, and mobile DOAS systems) performed during both campaigns. The AROMAT dataset addresses several of the mandatory products of TROPOMI/S5P, in particular NO2 and SO2 (horizontal distribution and profile from aircraft, plume image with ground-based SO2 and NO2 cameras, transects with mobile DOAS, in-situ), H2CO (mobile MAX-DOAS), and aerosols (lidar, airborne FUBISS-ASA2 sun-photometer, and aircraft in-situ). We investigate the information content of the AROMAT dataset for satellite validation studies based on co-located OMI and GOME-2 data, and simulations of TROPOMI measurements. The experience gained during AROMAT and AROMAT-2 will be used in support of a large-scale TROPOMI/S5P validation campaign in Romania scheduled for summer 2017.

  14. Designing artificial two dimensional electron lattice on metal surface: a Kagome-like lattice as an example.

    PubMed

    Li, Shuai; Qiu, Wen-Xuan; Gao, Jin-Hua

    2016-07-01

    Recently, a new kind of artificial two dimensional (2D) electron lattice on the nanoscale, i.e. molecular graphene, has drawn a lot of interest, where the metal surface electrons are transformed into a honeycomb lattice via absorbing a molecular lattice on the metal surface [Gomes et al., Nature, 2012, 438, 306; Wang et al., Phys. Rev. Lett., 2014, 113, 196803]. In this work, we theoretically demonstrate that this technique can be readily used to build other complex 2D electron lattices on a metal surface, which are of high interest in the field of condensed matter physics. The main challenge to build a complex 2D electron lattice is that this is a quantum antidot system, where the absorbed molecule normally exerts a repulsive potential on the surface electrons. Thus, there is no straightforward corresponding relation between the molecular lattice pattern and the desired 2D lattice of surface electrons. Here, we give an interesting example about the Kagome lattice, which has exotic correlated electronic states. We design a special molecular pattern and show that this molecular lattice can transform the surface electrons into a Kagome-like lattice. The numerical simulation is conducted using a Cu(111) surface and CO molecules. We first estimate the effective parameters of the Cu/CO system by fitting experimental data of the molecular graphene. Then, we calculate the corresponding energy bands and LDOS of the surface electrons in the presence of the proposed molecular lattice. Finally, we interpret the numerical results by the tight binding model of the Kagome lattice. We hope that our work can stimulate further theoretical and experimental interest in this novel artificial 2D electron lattice system. PMID:27279292

  15. An Empirical Approach to Determining the Boundary Layer Bromine Monoxide (BrO) Abundance from Satellite Total Column Measurements

    NASA Astrophysics Data System (ADS)

    Simpson, W. R.; Donohoue, D.; Carlson, D. A.

    2009-12-01

    Unique chemistry in the Arctic boundary layer during springtime liberates bromine from sea salt, producing reactive halogen gases (e.g. atomic bromine and bromine monoxide radicals) that then drastically alter atmospheric oxidation pathways. This phenomenon causes ozone depletion events and affects mercury deposition to the snowpack. Satellite remote sensing (e.g. OMI and GOME2 observations) techniques can detect the total column abundance of BrO, which is generally the primary species of the reactive bromine family. However, BrO is also present in the stratosphere, so it is necessary to partition the satellite-observed BrO column abundance into boundary layer and non-boundary layer (primarily stratospheric) partial columns to be able to infer boundary layer abundances and hence chemical affects near the Earth's surface (i.e. ozone and mercury impacts). In this presentation, we describe an empirical method for partitioning the BrO total column and apply it globally during spring 2008. The method indicates that some BrO total column enhancements ("hotspots") are not actually enhancements in the boundary layer BrO abundance but occur aloft. Movies and a statistical analysis of the inferred boundary layer BrO abundance are presented. The method has been tested and performs well at the Barrow field site. However, in areas that lack routine ground truth BrO measurements (e.g. Hudson Bay, Canada), large tropospheric BrO abundances are indicated. It is not clear if these inferred boundary layer BrO events are real or if the simple empirical method described here is failing in those locations. Verification of this method over large spatial regions of the Arctic is needed.

  16. Validation and application of synergetic aerosol retrieval for ENVISAT

    NASA Astrophysics Data System (ADS)

    Holzer-Popp, Thomas; Schroedter-Homscheidt, Marion; Martynenko-Homscheidt, Dmytro

    At the German Remote Sensing Data Center of DLR a synergetic aerosol retrieval method SYNAER was developed (Holzer-Popp, et al., JGR 2002), which exploits the complementary information of the radiometer ATSR-2 and the spectrometer GOME onboard one satellite platform (ERS-2) to extract aerosol optical depth (AOD) and speciation (as choice from a representative set of 40 pre-defined mixtures of water-soluble, soot, mineral dust, and sea salt components). Recently, the algorithm was transferred to a new sensor combination onboard the European environmental satellite platform ENVISAT to achieve better coverage (Holzer-Popp, et al., ACPD, 2008). During the transfer a thorough evaluation of the results against multispectral ground-based observations from AERONET was conducted, which was then used to improve the methodology. The evaluation included a stringent analysis of the information content for different surface-atmosphere conditions and illuminations as well as the investigation of critical steps of the algorithm. A preliminary validation of the new version shows the potential to estimate the aerosol type from space (AOD error around 0.1 from UV to NIR, which is in perfect match with the expected noise level for the exploited pixel size of 60x30 km2). This paper provides a comprehensive summary of the SYNAER/ENVISAT methodology and an analysis of its information content as well as a detailed validation against AERONET observations. Finally, an improved pixel-wise screening for erroneous retrieval results by several combinations of quality parameters (such as aerosol type ambiguity in the retrieval, spectral fit error, retrieved surface albedo, observation geometry) is presented.

  17. Effects of a beta-blocker on ventricular late potentials in patients with acute anterior myocardial infarction receiving successful thrombolytic therapy.

    PubMed

    Evrengul, Harun; Dursunoglu, Dursun; Kayikcioglu, Meral; Can, Levent; Tanriverdi, Halil; Kaftan, Asuman; Kilic, Mustafa

    2004-01-01

    Late potentials (LP) detected on the signal-averaged electrocardiogram (SAECG) predict arrhythmic events after acute myocardial infarction (AMI). It is also well established that successful thrombolytic therapy reduces the incidence of LP. Our aim was to evaluate the effects of a beta-blocker on LP in patients receiving thrombolytic therapy. We studied 40 patients presenting with anteroseptal AMI (< 6 hours). All patients received thrombolytic therapy and were evaluated with coronary angiography at predischarge. Eighteen patients received metoprolol (5 mg IV on admission followed by 50 mg BID). SAECG recordings were obtained serially using an ART system (40-250 Hz filter, noise < 0.5 mV) prior to thrombolytic therapy, after 48 hours and after 10 days. LP was defined as posi-tive if the SAECG met at least 2 of the Gomes criteria. Changes observed in SAECG recordings after thrombolytic therapy were correlated with angiographic and clinical data with regard to the usage of BB. The frequencies of LP before and after thrombolytic therapy were compared with the McNemar test. There were no significant differences between the clinical characteristics, risk factors, and angiographic findings (including infarct related artery patency and LV functions) of the groups. Baseline SAECG findings were also similar between the groups. The incidence of LP significantly decreased after TT in the BB group, however, this change was not observed in patients who did not receive BB (P = 0.012, McNemar test). Beta-blockers reduce the incidence of LPs following thrombolytic therapy in patients with anterior AMI. This might be explained by the possible beneficial effect of BB on the arrhythmogenic substrate.

  18. Ten years of satellite observations reveal highly variable sulphur dioxide emissions at Anatahan Volcano, Mariana Islands

    NASA Astrophysics Data System (ADS)

    McCormick, Brendan; Popp, Christoph; Andrews, Benjamin; Cottrell, Elizabeth

    2015-07-01

    Satellite remote sensing enables continuous multiyear observations of volcanic activity in remote settings. Anatahan (Mariana Islands) is a remote volcano in the western North Pacific. Available ground-based measurements of sulphur dioxide (SO2) gas emissions at Anatahan place it among thelargest volcanic SO2 sources worldwide. These ground-based measurements, however, are restricted to eruptive intervals. Anatahan's activity since 2003 has been dominated temporally by prolonged periods of quiescence. Using 10 years of satellite observations from OMI, AIRS, SCIAMACHY, and GOME-2, we report highly variable SO2 emissions within and between eruptive and quiescent intervals at Anatahan. We find close correspondence between levels of activity reported at the volcano and levels of SO2 emissions detected from space. Eruptive SO2 emission rates have a mean value of ˜6400 t d-1, but frequently are in excess of 20,000 t d-1. Conversely, SO2 emissions during quiescent intervals are below the detection limit of space-based sensors and therefore are not likely to exceed ˜300 t d-1. We show that while Anatahan occupies a quiescent state for 85% of the past 10 years, only ˜15% of total SO2 emissions over this interval occur during quiescence, with the remaining ˜85% released in short duration but intense syn-eruptive degassing. We propose that the integration of multiyear satellite data sets and activity histories are a powerful complement to targeted ground-based campaign measurements in better describing the long-term degassing behavior of remote volcanoes.

  19. Characterization of Spectral Absorption Properties of Aerosols Using Satellite Observations

    NASA Technical Reports Server (NTRS)

    Torres, O.; Jethva, H.; Bhartia, P. K.; Ahn, C.

    2012-01-01

    The wavelength-dependence of aerosol absorption optical depth (AAOD) is generally represented in terms of the Angstrom Absorption Exponent (AAE), a parameter that describes the dependence of AAOD with wavelength. The AAE parameter is closely related to aerosol composition. Black carbon (BC) containing aerosols yield AAE values near unity whereas Organic carbon (OC) aerosol particles are associated with values larger than 2. Even larger AAE values have been reported for desert dust aerosol particles. Knowledge of spectral AAOD is necessary for the calculation of direct radiative forcing effect of aerosols and for inferring aerosol composition. We have developed a satellitebased method of determining the spectral AAOD of absorbing aerosols. The technique uses high spectral resolution measurements of upwelling radiation from scenes where absorbing aerosols lie above clouds as indicated by the UV Aerosol Index. For those conditions, the satellite measured reflectance (rho lambda) is approximately given by Beer's law rho lambda = rho (sub 0 lambda) e (exp -mtau (sub abs lambda)) where rho(sub 0 lambda) is the cloud reflectance, m is the geometric slant path and tau (sub abs lambda) is the spectral AAOD. The rho (sub 0 lambda) term is determined by means of radiative transfer calculations using as input the cloud optical depth derived as described in Torres et al. [JAS, 2012] that accounts for the effects of aerosol absorption. In the second step, corrections for molecular and aerosol scattering effects are applied to the cloud reflectance term, and the spectral AAOD is then derived by inverting the equation above. The proposed technique will be discussed in detail and application results will be presented. The technique can be easily applied to hyper-spectral satellite measurements that include UV such as OMI, GOME and SCIAMACHY, or to multi-spectral visible measurements by other sensors provided that the aerosol-above-cloud events are easily identified.

  20. Solar spectral irradiance changes during cycle 24

    SciTech Connect

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

    2014-07-10

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

  1. Determining volcanic SO2 plume heights in satellite observations using meteorological wind fields

    NASA Astrophysics Data System (ADS)

    Keicher, Viktoria; Hörmann, Christoph; Sihler, Holger; Platt, Ulrich; Wagner, Thomas

    2016-04-01

    Satellite observations nowadays provide the global monitoring of volcanic plumes via sulphur dioxide (SO2) that is injected into the Earth's atmosphere. In turn, SO2 may lead to the formation of sulphate aerosols that can influence climate via direct and indirect radiative effects. The retrieval of SO2 requires an accurate plume height estimate in order to constrain total amounts for such events. One of the main difficulties for the retrieval is the typically unknown atmospheric profile resulting from unknown initial conditions (individual explosions over an extended time period leading to different gas layer altitudes and influencing the atmospheric transport pattern). In recent years, satellite observations helped to improve global SO2 estimates, but still large uncertainties exist. Passive satellite remote sensing using measurements in the UV/vis spectral range for example offers the opportunity to observe the location of a plume in two dimensions, but information about the corresponding height is sparse. Furthermore, information about these plume profiles is not only interesting in itself (e.g. to assess the radiative effect of volcanic plumes). It is also important for the quantitative interpretation of satellite observations. Here, we present first results for a newly developed approach using the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) in combination with data for different volcanic SO2 plumes as observed by the second generation Global Ozone Monitoring Instrument (GOME-2). The main plume information that can be retrieved by the satellite (i.e. plume location and observation time) are used as initial input parameters in order to estimate the plume's profile at the time of the measurements. For selected case studies we use these trajectories to further estimate values the eruption time and height. The correspondingly modelled values can also be used to verify the results when they are compared to direct local observations and

  2. Injection of Lightning-Produced NOx, Water Vapor, Wildfire Emissions, and Stratospheric Air to the UT/LS as Observed from DC3 Measurements

    NASA Astrophysics Data System (ADS)

    Huntrieser, H.; Lichtenstern, M.; Scheibe, M.; Aufmhoff, H.; Schlager, H.; Minikin, A.; Weinzierl, B.; Pollack, I. B.; Peischl, J.; Ryerson, T. B.; Weinheimer, A. J.; Honomichl, S.; Ridley, B. A.; Hair, J. W.; Schwartz, M. J.; Rappenglück, B.; Pickering, K. E.; Cummings, K.; Biggerstaff, M. I.; Heimerl, K.; Pucik, T.; Fütterer, D.; Ackermann, L.; Betten, D.; Butler, C. F.; Barth, M. C.

    2014-12-01

    In summer 2012 the Deep Convective Clouds and Chemistry Project (DC3) field campaign investigated a number of severe thunderstorms over the Central U.S. and their impact on the upper tropospheric (UT) - lower stratospheric (LS) composition and chemistry. In addition, during DC3 some of the largest and most destructive wildfires in New Mexico and Colorado state history were burning, influencing the air quality in the DC3 thunderstorm inflow and outflow region. Besides three instrumented aircraft platforms measuring a variety of trace species in-situ and remotely (e.g. CO, O3, SO2, NOx, VOC, CN, and black carbon), dense networks of ground-based instruments (e.g. radar and lightning) complemented the airborne measurements. Satellite measurements (e.g. GOES, MODIS, and GOME-2) and model forecasts (e.g. WRF-Chem and FLEXPART) were used to monitor the rapid development of the thunderstorms (which frequently developed huge anvils with overshooting tops) and the spread of smoke plumes in the vicinity of the storms. In-situ probing of fresh and aged (12-24 h) anvil outflows showed injection of lightning-produced NOx and wildfire emissions into the UTLS. Vertical cross sections of lidar and Doppler radar measurements supported these observations and gave detailed information on dynamical processes within and in the vicinity of the storms. Besides very strong updrafts in the storm core, surrounding downdrafts caused a direct in-mixing of O3-rich LS air masses into the boundaries of the anvil outflow. The wrapping of O3-rich LS air masses around and below the anvil outflow was also a prominent feature in several storms. The in-situ probing of the aged anvil outflow showed a pronounced influence on the UT composition and chemistry with average O3 enhancements in the range of 20-50 nmol mol-1 and evidence of new particle formation. A 10-year global climatology of H2O data from Aura-MLS confirms that the Central U.S. is a preferred region for convective injection into the LS.

  3. Tropospheric Bro In The Antarctic Marine Boundary Layer

    NASA Astrophysics Data System (ADS)

    Friess, U.; Wagner, T.; Platt, U.

    Sudden enhancements of bromine monoxide (BrO) in the polar marine boundary layer during spring are known to be caused by the autocatalytic release of BrO from sea ice surfaces. BrO subsequently leads to the destruction of boundary layer ozone (the 'tropospheric ozone hole'). Here we present observations of BrO at the German Antarctic research station Neu- mayer using DOAS measurements of zenith-scattered sunlight. During austral spring 1999 and 2000, numerous strong and sudden enhancements in the BrO slant column density were observed, indicating the occurrence of BrO in the troposphere. This find- ing is supported by satellite borne GOME measurements, showing huge clouds of enhanced BrO over the sea ice around the Antarctic continent (covering 106 km2). The observation of tropospheric BrO is often accompanied by a sudden drop in surface ozone mixing ratios. However, BrO enhancements are also observed in the absence of surface ozone deple- tion, indicating that the detected BrO is located above the ground. To gain information on altitude distribution and source regions of the BrO enriched air masses, we combine our DOAS measurements with back trajectory calculations in high spatial and tempo- ral resolution in combination with sea ice maps and with observations of the oxygen dimer (O4). Our analysis shows that (1) BrO enhancements always coincide with the observation of air masses which were previously exposed to sea ice, (2) surface ozone depletion is found to occur whenever the air at ground comes from sea ice surfaces, and (3) the presence of strong light path enhancements during BrO events are prob- ably caused by the transport of sea salt aerosols from the ocean to the measurement site, on which heterogeneous release of BrO may take place in situ. These findings strongly suggest that the phenomenon of ozone depletion due to BrO is not restricted to the marine boundary layer, but also occurs in the free troposphere: the local mete- orology frequently leads to

  4. Space-borne constraints on SO2 fluxes for recent volcanic eruptions in 2011

    NASA Astrophysics Data System (ADS)

    Theys, N.; Campion, R.; Clarisse, L.; Brenot, H.; van Gent, J.; Coheur, P.; Van Roozendael, M.; Tait, S.; Ferrucci, F.

    2012-04-01

    Magmatic gases (H2O, CO2, sulphur and halogenated species) are the driving forces of volcanic eruptions. These emissions can strongly impact the local biosphere (through acid deposition) and also affect significantly the chemical composition of the atmosphere and climate. Sulphur dioxide (SO2) measurements have been used to characterize and monitor volcanic activity for decades. However, remote-sensing methods based on absorption spectroscopy generally provide integrated concentration of already dispersed plumes of SO2. In the last years, consolidated measurements of total emission fluxes of SO2 have been made possible for active degassing volcanoes using ground-based measurements. For non-monitored volcanoes or explosive volcanic eruptions, space-based measurements of SO2 are more adequate but unfortunately fluxes estimates are sparse. The motivation for this study is an effort to constrain volcanic SO2 fluxes using satellite measurements of dispersed and large-scale plumes of SO2. We combine different approaches and investigate the temporal evolution of the total emissions of SO2 for a number of recent volcanic events in 2011: Nyamuragira (Congo), Nabro (Eritrea) and Puyehue (Chili). High spectral resolution satellite instruments operating both in the UV-visible (OMI/Aura and GOME-2/MetOp-A) and thermal Infrared (IASI/MetOp-A) spectral ranges are used in a synergistic way. Although the primary objective of this study is the calculation of SO2 fluxes, it also enables to assess the consistency of the SO2 products from the different sensors used. Moreover, our estimates of SO2 fluxes are confronted to magma fluxes constraints obtained from independent thermal measurements. This work is performed in the frame of the European Volcano Observatory Space Services (EVOSS) EU FP7 project whose aim is to develop and demonstrate a portfolio of GMES Downstream Services, based on Earth Observation data products, to monitor volcanic activity and relevant hazards at a global

  5. Differences in satellite-derived NOx emission factors between Eurasian and North American boreal forest fires

    NASA Astrophysics Data System (ADS)

    Schreier, S. F.; Richter, A.; Schepaschenko, D.; Shvidenko, A.; Hilboll, A.; Burrows, J. P.

    2015-11-01

    Current fire emission inventories apply universal emission factors (EFs) for the calculation of NOx emissions over large biomes such as boreal forest. However, recent satellite-based studies over tropical and subtropical regions have indicated spatio-temporal variations in EFs within specific biomes. In this study, satellite measurements of tropospheric NO2 vertical columns (TVC NO2) from the GOME-2 instrument and fire radiative power (FRP) from MODIS are used for the estimation of fire emission rates (FERs) of NOx over Eurasian and North American boreal forests. The retrieval of TVC NO2 is based on a stratospheric correction using simulated stratospheric NO2 instead of applying the reference sector method, which was used in a previous study. The model approach is more suitable for boreal latitudes. TVC NO2 and FRP are spatially aggregated to a 1° × 1° horizontal resolution and temporally averaged to monthly values. The conversion of the satellite-derived tropospheric NO2 columns into production rates of NOx from fire (Pf) is based on the NO2/NOx ratio as obtained from the MACC reanalysis data set and an assumed lifetime of NOx. A global land cover map is used to define boreal forests across these two regions in order to evaluate the FERs of NOx for this biome. The FERs of NOx, which are derived from the gradients of the linear relationship between Pf and FRP, are more than 30% lower for North American than for Eurasian boreal forest fires. We speculate that these discrepancies are mainly related to the variable nitrogen content in plant tissues, which is higher in deciduous forests dominating large parts in Eurasia. In order to compare the obtained values with EFs found in the literature, the FERs are converted into EFs. The satellite-based EFs of NOx are estimated at 0.83 and 0.61 g kg-1 for Eurasian and North American boreal forests, respectively, which is in good agreement with the value found in a recent emission factor compilation. However, recent fire

  6. Chlorophyll Fluorescence Is a Better Proxy for Sunlit Leaf Than Total Canopy Photosynthesis

    NASA Astrophysics Data System (ADS)

    Chen, J. M.; Wang, Z.; Zhang, F.; Mo, G.

    2015-12-01

    Chlorophyll fluorescence (CF) results from non-photochemical quenching during plant photosynthesis under excessive radiation. We explore the relationship between gross primary productivity (GPP) and CF using a process ecosystem model, which separates a vegetation canopy into sunlit and shaded leaf groups and simulates the total canopy GPP as the sum of sunlit and shaded leaf GPP. Using GOME-2 and GOSAT data acquired in 2010 over the global land surface, we found that measured CF signals gridded in 1 degree resolution are well correlated with simulated total GPP and its sunlit and shaded components, but the correlation coefficients (R) are largest for the sunlit GPP and smallest for shaded GPP. The seasonal R2 values vary from 0.57 to 0.74, 0.58 to 0.71, and 0.48 to 0.56 for sunlit, total and shaded GPP, respectively. The significance levels for these correlations are all greater than p<0.01. Averaged over the globe, the total simulated shaded GPP is 39% of the total GPP. Theoretically, CF from vegetation comes mostly from sunlit leaves. The significant correlation between measured canopy-level CF and the shaded GPP is likely due to the correlation between shaded and sunlit GPP as both increase with leaf area index. Our simulation confirms the validity of using canopy-level CF measurements to assess the total GPP as the first approximation, although these measurements are a consistently better indicator of sunlit GPP than total GPP. In previous studies, the R2 values for the correlation between CF and total GPP were found to range from 0.76 to 0.88, 0.56 to 0.78, and 0.57 to 0.77 for MPI-BGC, MODIS and CASA model results, respectively. These values are similar or larger than those for sunlit GPP simulated in our study, but are considerably larger than those for total GPP in our study because the correlation for total GPP is contaminated by the inclusion of shaded GPP. All these three models use canopy total light use efficiency without considering the differences

  7. Investigating ambient ozone formation regimes in neighboring cities of shale plays in the Northeast United States using photochemical modeling and satellite retrievals

    NASA Astrophysics Data System (ADS)

    Chang, Chih-Yuan; Faust, Eric; Hou, Xiangting; Lee, Pius; Kim, Hyun Cheol; Hedquist, Brent C.; Liao, Kuo-Jen

    2016-10-01

    This study investigates long-term (i.e., 2007-2014) fluctuations in ambient ozone formation regimes for cities adjacent to shale plays in the Northeast United States (U.S.). Ozone air quality in many cities of the Northeast U.S. does not meet the U.S. National Ambient Air Quality Standards (NAAQS), and understanding ambient ozone formation regimes is essential to develop effective air pollution mitigation strategies for cities violating the air quality standards. Since 2013, the U.S. has become the world's largest producer of tight oil and natural gas from shale rock, and previous studies show that emissions of air pollutant precursors from shale oil and gas-related activities would have the potential to affect ambient ozone air quality in adjacent cities of shale plays. This work leveraged (1) satellite-retrieved column densities of formaldehyde (HCHO) and nitrogen dioxide (NO2) from multiple instruments (i.e., Ozone Monitoring Instrument (OMI) and Global Ozone Monitoring Experiment-2 (GOME-2)); (2) photochemical air quality modeling and sensitivity analysis; and (3) ratios of satellite-retrieved air pollutant column densities to investigate ambient ozone formation regimes in neighboring cities of shale plays (i.e., Marcellus Shale) in the Northeast U.S. from 2007 to 2014. Our results show that ambient ozone formation in Boston, Pittsburgh, Philadelphia and Washington, D.C. (which are close to Marcellus Shale) was in the NOx -limited or transition regime during the period of study. Ambient ozone formation in New York City was in the transition regime during 2010-2013 and VOC -limited regime during 2007-2009 and in 2014. Based on the result of this study, we conclude that controls NOx emissions would mitigate ozone air pollution from 2007 to 2014 in most of the cities examined in this study. Controls of local VOC emissions would ease ozone air pollution in New York City during the study period. With projected increases in oil and gas production from shale plays in

  8. Comparison of tropospheric NO2 columns from ground based MAX-DOAS systems with satellite retrievals: A case study in the greater area of Thessaloniki.

    NASA Astrophysics Data System (ADS)

    Drosoglou, Theano; Bais, Alkis; Kouremeti, Natalia; Koukouli, Mariliza; Balis, Dimitris

    2015-04-01

    Phaethon is a low-cost ground-based MAX-DOAS system that is used to acquire fast direct solar irradiance and sky radiance spectrally resolved measurements in the region 300-450 nm and deliver total and tropospheric columns of atmospheric trace gases. Phaethon, which comprises a cooled miniature CCD spectrograph (AvaSpec-ULS2048LTEC) and a 2-axes tracker, was designed for easy deployment at different sites to address specific air quality problems and to support satellite validation studies at locations of particular scientific interest. In the framework of the Optimization and expansion of ground infrastructure for the validation of satellite-derived column densities of atmospheric species, AVANTI project, three Phaethon systems have been deployed in the greater area of Thessaloniki, Greece, within an area of about 15 km by 30 km, comparable to the size of a satellite pixel, with the aim to link modeling of tropospheric trace gases with satellite products. The locations of the three systems are characterized by diverse local atmospheric pollution loadings representing urban, industrial and rural conditions. The systems have been first operated for a few days in parallel at the station in the University campus to establish their inter-comparison behaviour and possible systematic differences. Tropospheric NO2 columns derived at these different locations are presented and compared with the "area-averaged" columns derived from OMI/Aura and GOME-2/MetopA and /MetopB satellites. During days with high levels of NO2 at the urban site, the measurements at the rural site compare better with the satellite products. This finding has been attributed to the fact that the satellite products are representative of the average pollution levels in the sub-satellite pixel area which, in the case of Thessaloniki, corresponds mostly to rural conditions. This validation campaign precedes a full-scale validation to be performed within the EU FP7 Monitoring and Assessment of Regional air

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  10. 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

  11. 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

  12. A space-borne, multi-parameter, Virtual Volcano Observatory for the real-time, anywhere-anytime support to decision-making during eruptive crises

    NASA Astrophysics Data System (ADS)

    Ferrucci, F.; Tampellini, M.; Loughlin, S. C.; Tait, S.; Theys, N.; Valks, P.; Hirn, B.

    2013-12-01

    The EVOSS consortium of academic, industrial and institutional partners in Europe and Africa, has created a satellite-based volcano observatory, designed to support crisis management within the Global Monitoring for Environment and Security (GMES) framework of the European Commission. Data from 8 different payloads orbiting on 14 satellite platforms (SEVIRI on-board MSG-1, -2 and -3, MODIS on-board Terra and Aqua, GOME-2 and IASI onboard MetOp-A, OMI on-board Aura, Cosmo-SkyMED/1, /2, /3 and /4, JAMI on-board MTSAT-1 and -2, and, until April 8th2012, SCHIAMACHY on-board ENVISAT) acquired at 5 different down-link stations, are disseminated to and automatically processed at 6 locations in 4 countries. The results are sent, in four separate geographic data streams (high-temperature thermal anomalies, volcanic Sulfur dioxide daily fluxes, volcanic ash and ground deformation), to a central facility called VVO, the 'Virtual Volcano Observatory'. This system operates 24H/24-7D/7 since September 2011 on all volcanoes in Europe, Africa, the Lesser Antilles, and the oceans around them, and during this interval has detected, measured and monitored all subaerial eruptions occurred in this region (44 over 45 certified, with overall detection and processing efficiency of ~97%). EVOSS borne realtime information is delivered to a group of 14 qualified end users, bearing the direct or indirect responsibility of monitoring and managing volcano emergencies, and of advising governments in Comoros, DR Congo, Djibouti, Ethiopia, Montserrat, Uganda, Tanzania, France and Iceland. We present the full set of eruptions detected and monitored - from 2004 to present - by multispectral payloads SEVIRI onboard the geostationary platforms of the MSG constellation, for developing and fine tuning-up the EVOSS system along with its real-time, pre- and post-processing automated algorithms. The set includes 91% of subaerial eruptions occurred at 15 volcanoes (Piton de la Fournaise, Karthala, Jebel al

  13. Ozone in the Boundary Layer air over the Arctic Ocean: Measurements During the TARA Expedition.

    NASA Astrophysics Data System (ADS)

    Bottenheim, J. W.; Netcheva, S.; Morin, S.; Gascard, J.; Weber, M.; de Marliave, C.; Trouble, R.

    2007-12-01

    It is now well established that after sunrise in polar regions, the atmospheric boundary layer experiences episodes where dramatic loss of ozone can be observed. Virtually all measurements in this respect have been made at coastal observatories on land, but there is strong evidence to surmise that such episodes originate over the frozen ocean. Satellite measurements (GOME, SCIAMACHY, OMI) invariably indicate large areas over the ocean with increased concentrations of BrO which can be interpreted as a smoking gun for ozone depletion processes, but no systematic in-situ measurements of ozone do exist to corroborate the satellite data. The TARA expedition (www.taraexpeditions.org) (IPY project # 238) has enabled us for the first time to make long term ozone measurements in the surface air over the Arctic Ocean, and we report here the first results. As expected ozone was found to be stable at approx. 35 ± 5 nmol~mol-1 during the winter, but shortly after local sunrise in mid March, large depletions of ozone were observed which lasted until well into June. A particularly long episode (> 15 days) of virtually no ozone (mole fraction below or near 1 nmol~mol-1) was experienced during late April. 10-day back trajectories were calculated in an attempt to obtain more insight into the potential origin of the depletion episodes. To place the TARA ozone data into context we will compare the data with land based and satellite observations in 2007 when they become available, as well as the limited record of previous observations made from ice islands. Taking all evidence together it is plausible to speculate that large areas over the Arctic Ocean are devoid of ozone in the atmospheric boundary layer in the first months after polar sunrise, and that if anything, this will increase in the coming years. We speculate what the implications might be. This work is a contribution to IPY project #038 (OASIS, Ocean Atmosphere Sea-Ice and Snow interactions in polar regions), sponsored by

  14. Assessment of the stratospheric NO2 column using long-term ground-based UV-visible and satellite nadir observations

    NASA Astrophysics Data System (ADS)

    Pinardi, Gaia; Van Roozendael, Michel; Lambert, Jean-Christopher; Hendrick, Francois; Granville, José; Tack, Frederik; Goutail, Florence; Pommereau, Jean-Pierre; Pazmino, Andrea; Wittrock, Folkard; Richter, Andreas; Wagner, Thomas; Gu, Myojeong; Friess, Udo; Navarro, Monica; Puentedura, Olga

    2015-04-01

    Zenith-sky UV-visible instruments have been used to monitor stratospheric NO2 columns from pole to pole for more than 2 decades, as part of the Network for the Detection of Atmospheric Composition Change (NDACC). Long-term monitoring and fit-for-purpose data quality are essential commitments of the network. Recently, recommendations were made for a better harmonization of the retrieval of NO2 stratospheric vertical columns (Van Roozendael and Hendrick 2012, http://ndacc-uvvis-wg.aeronomie.be/tools/NDACC_UVVIS-WG_NO2settings_v4.pdf). Those include, in addition to the use of harmonized SCD settings, a common approach to the air-mass factor (AMF) calculation, based on pre-calculated look-up tables of climatological AMFs resolved in latitude, time, wavelength, surface albedo, solar zenith angle and station altitude. The impact of the NDACC recommendations on the quality of the zenith-sky UV-visible stratospheric NO2 columns is first illustrated based on 10 SAOZ (Système d'Analyse par Observations Zénithales) instruments deployed from the Arctic to the Antarctic. The long-term time-series of SAOZ and other ground-based NDACC zenith-sky measurements are then used in synergy with data from an ensemble of satellite UV-vis nadir sensors (GOME-2, SCIAMACHY and OMI), for characterising the stratospheric NO2 columns on the global scale. Appropriate photochemical state matching is applied whenever necessary to combine/compare the different data sets. Results are interpreted in terms of ground-based network data homogeneity, and accuracy, consistency and long-term stability of space-borne stratospheric NO2 columns. The consistency with previously published studies including stratospheric NO2 column measurements from limb sensors such as MIPAS and SCIAMACHY is also discussed. These quality-assessed ground-based and satellite data sets offer new perspectives for the analysis of the variability and trends of stratospheric NO2 at the global scale.

  15. Cloud and aerosol classification for 2.5 years of MAX-DOAS observations in Wuxi (China) and comparison to independent data sets

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Penning de Vries, M.; Xie, P. H.; Beirle, S.; Dörner, S.; Remmers, J.; Li, A.; Wagner, T.

    2015-12-01

    Multi-axis differential optical absorption spectroscopy (MAX-DOAS) observations of trace gases can be strongly influenced by clouds and aerosols. Thus it is important to identify clouds and characterize their properties. In a recent study Wagner et al. (2014) developed a cloud classification scheme based on the MAX-DOAS measurements themselves with which different "sky conditions" (e.g., clear sky, continuous clouds, broken clouds) can be distinguished. Here we apply this scheme to long-term MAX-DOAS measurements from 2011 to 2013 in Wuxi, China (31.57° N, 120.31° E). The original algorithm has been adapted to the characteristics of the Wuxi instrument, and extended towards smaller solar zenith angles (SZA). Moreover, a method for the determination and correction of instrumental degradation is developed to avoid artificial trends of the cloud classification results. We compared the results of the MAX-DOAS cloud classification scheme to several independent measurements: aerosol optical depth from a nearby Aerosol Robotic Network (AERONET) station and from two Moderate Resolution Imaging Spectroradiometer (MODIS) instruments, visibility derived from a visibility meter and various cloud parameters from different satellite instruments (MODIS, the Ozone Monitoring Instrument (OMI) and the Global Ozone Monitoring Experiment (GOME-2)). Here it should be noted that no quantitative comparison between the MAX-DOAS results and the independent data sets is possible, because (a) not exactly the same quantities are measured, and (b) the spatial and temporal sampling is quite different. Thus our comparison is performed in a semi-quantitative way: the MAX-DOAS cloud classification results are studied as a function of the external quantities. The most important findings from these comparisons are as follows: (1) most cases characterized as clear sky with low or high aerosol load were associated with the respective aerosol optical depth (AOD) ranges obtained by AERONET and MODIS

  16. The BRomine, Ozone, and Mercury EXperiment (BROMEX)

    NASA Astrophysics Data System (ADS)

    Nghiem, S. V.; Shepson, P. B.; Simpson, W. R.; Perovich, D. K.; Sturm, M.; Douglas, T. A.; Rigor, I. G.; Clemente-Colon, P.; Burrows, J. P.; Richter, A.; Bottenheim, J. W.; Steffen, A.; Barber, D. G.; Kaleschke, L.; Hall, D. K.; Markus, T.; Eicken, H.; Neumann, G.

    2011-12-01

    In the decade of the 2000s, Arctic perennial (multi-year) sea ice has diminished drastically, whereas seasonal (first-year) sea ice has become the dominant ice class. This change effectively increases the overall surface salinity of the sea ice cover and in the overlying snowpack. Satellite results in 2010 and 2011 show the extent of perennial sea ice remains minimal with significant bromine explosions in the springtime. Key science questions still remain to be answered to understand the impact of the Arctic perennial sea ice reduction on low-atmospheric physical and chemical processes. Of the highest priority is to investigate the impact on bromine explosion events that lead to depletion of ozone and gaseous elementary mercury in the atmosphere. With that objective, we present the development of the BRomine, Ozone, and Mercury EXperiment in (BROMEX) in spring 2012 around Barrow, extending out to 200 km offshore and inland. In BROMEX, chemical, sea ice, snow, and ocean measurements will be made across sea ice leads both upwind and downwind areas of newly opened leads. Chemical-measurement buoys and other types of buoys will be deployed with helicopter flights to both sides of the leads. Various flight patterns of aircraft carrying ozone and bromine-measuring sensors will be used to characterize the chemical distribution over sea ice, land, and mountainous regions. Our approach will use data from multiple satellite instruments including MODIS, AMSR-E, QuikSCAT, GOME-2, SCIAMACHY, OMI, RADARSAT-2, Envisat ASAR, TerraSAR-X, TanDEM-X, SMOS, CryoSat-2 altimeter, and Oceansat-2 scatterometer. Moreover, results from recent field campaigns such as the IPY OASIS, INCATPA, CFL, SALT, and IceBridge, from sea ice and snow products generated by the U.S. Naval and National Ice Center, from NASA cryospheric observations, and from surface observation networks such as SIZONet will be utilized together with new measurements from BROMEX. Further collaborations with the international

  17. Study of Impacts of Arctic Sea Ice Reduction on Atmospheric Chemical Processes - The BROMEX 2012 Field Campaign

    NASA Astrophysics Data System (ADS)

    Nghiem, S. V.

    2012-12-01

    Arctic perennial sea ice has decreased drastically in the last decade and still remained low in spring 2012 as observed from scatterometer datasets acquired by QuikSCAT and Oceansat-2 satellites. In particular, the thinner, weaker, and saltier seasonal sea ice has dominated over the perennial ice in the Chukchi Sea and Beaufort Sea. To investigate impacts of sea ice reduction on atmospheric chemical processes, we conducted the BRomine, Ozone, and Mercury EXperiment in (BROMEX) in March-April 2012 around Barrow, extending out to a large region offshore and inland. Here we present overview results from BROMEX, which was successfully carried out by about 30 scientists, researchers, and field workers from multiple international institutions. For BROMEX, we coordinated and collected satellite data, including a number of near-real-time products, from multiple satellite instruments including MODIS, AMSR-E, GOME-2, SCIAMACHY, OMI, RADARSAT-2, Envisat ASAR, TanDEM-X, SMOS, CryoSat-2, and Oceansat-2. Over the BROMEX field region, we made measurements and collected sea ice, snow, ocean, and air samples for physical, meteorological, chemical, biological, and acoustic studies. A helicopter was used to deploy chemical and meteorological buoys in the Chukchi Sea and the Beaufort Sea. Measurements were also made with airborne sensors across sea ice, leads, lagoon, and tundra along various flight patterns of the ALAR aircraft. Furthermore, we coordinated with the NASA IceBridge P3 aircraft to collect surface temperature, surface height, snow depth, and ice thickness measurements. We set up and maintained field sites on sea ice and in the tundra to measure bromine, ozone, mercury, and other chemical species. Moreover, we obtained temperature data from many different types of temperature sensors for temperature accuracy assessment to identify potential issues that might cause errors or biases in temperature measurements. An enormous amount of in-situ snow and ice data was collected

  18. Fast Emission Estimates in China Constrained by Satellite Observations (Invited)

    NASA Astrophysics Data System (ADS)

    Mijling, B.; van der A, R.

    2013-12-01

    Emission inventories of air pollutants are crucial information for policy makers and form important input data for air quality models. Unfortunately, bottom-up emission inventories, compiled from large quantities of statistical data, are easily outdated for an emerging economy such as China, where rapid economic growth changes emissions accordingly. Alternatively, top-down emission estimates from satellite observations of air constituents have important advantages of being spatial consistent, having high temporal resolution, and enabling emission updates shortly after the satellite data become available. Constraining emissions from concentration measurements is, however, computationally challenging. Within the GlobEmission project of the European Space Agency (ESA) a new algorithm has been developed, specifically designed for fast daily emission estimates of short-lived atmospheric species on a mesoscopic scale (0.25 × 0.25 degree) from satellite observations of column concentrations. The algorithm needs only one forward model run from a chemical transport model to calculate the sensitivity of concentration to emission, using trajectory analysis to account for transport away from the source. By using a Kalman filter in the inverse step, optimal use of the a priori knowledge and the newly observed data is made. We apply the algorithm for NOx emission estimates in East China, using the CHIMERE model together with tropospheric NO2 column retrievals of the OMI and GOME-2 satellite instruments. The observations are used to construct a monthly emission time series, which reveal important emission trends such as the emission reduction measures during the Beijing Olympic Games, and the impact and recovery from the global economic crisis. The algorithm is also able to detect emerging sources (e.g. new power plants) and improve emission information for areas where proxy data are not or badly known (e.g. shipping emissions). The new emission estimates result in a better

  19. Atmospheric replacement and late formation of N2 on undifferentiated Titan during the Late Heavy Bombardment

    NASA Astrophysics Data System (ADS)

    Sekine, Y.; Genda, H.; Sugita, S.; Kadono, T.; Matsui, T.

    2010-12-01

    , Science 201, 611. (2) McKay et al. 1988, Nature 332, 520. (3) Glein et al. 2009, Icarus 204, 637. (4) Iess et al. 2010, Science 327, 1367. (5) Gomes et al. 2005, Nature 435, 466. (6) Fukuzaki et al. 2010, Icarus, in press. (7) Niemann et al. 2005, Nature 438, 779.

  20. Dust emission parameterization scheme over the MENA region: Sensitivity analysis to soil moisture and soil texture

    NASA Astrophysics Data System (ADS)

    Gherboudj, Imen; Beegum, S. Naseema; Marticorena, Beatrice; Ghedira, Hosni

    2015-10-01

    The mineral dust emissions from arid/semiarid soils were simulated over the MENA (Middle East and North Africa) region using the dust parameterization scheme proposed by Alfaro and Gomes (2001), to quantify the effect of the soil moisture and clay fraction in the emissions. For this purpose, an extensive data set of Soil Moisture and Ocean Salinity soil moisture, European Centre for Medium-Range Weather Forecasting wind speed at 10 m height, Food Agricultural Organization soil texture maps, MODIS (Moderate Resolution Imaging Spectroradiometer) Normalized Difference Vegetation Index, and erodibility of the soil surface were collected for the a period of 3 years, from 2010 to 2013. Though the considered data sets have different temporal and spatial resolution, efforts have been made to make them consistent in time and space. At first, the simulated sandblasting flux over the region were validated qualitatively using MODIS Deep Blue aerosol optical depth and EUMETSAT MSG (Meteosat Seciond Generation) dust product from SEVIRI (Meteosat Spinning Enhanced Visible and Infrared Imager) and quantitatively based on the available ground-based measurements of near-surface particulate mass concentrations (PM10) collected over four stations in the MENA region. Sensitivity analyses were performed to investigate the effect of soil moisture and clay fraction on the emissions flux. The results showed that soil moisture and soil texture have significant roles in the dust emissions over the MENA region, particularly over the Arabian Peninsula. An inversely proportional dependency is observed between the soil moisture and the sandblasting flux, where a steep reduction in flux is observed at low friction velocity and a gradual reduction is observed at high friction velocity. Conversely, a directly proportional dependency is observed between the soil clay fraction and the sandblasting flux where a steep increase in flux is observed at low friction velocity and a gradual increase is

  1. Multi-satellite sensor study on precipitation-induced emission pulses of NOx from soils in semi-arid ecosystems

    NASA Astrophysics Data System (ADS)

    Zörner, Jan; Penning de Vries, Marloes; Beirle, Steffen; Sihler, Holger; Veres, Patrick R.; Williams, Jonathan; Wagner, Thomas

    2016-07-01

    We present a top-down approach to infer and quantify rain-induced emission pulses of NOx ( ≡ NO + NO2), stemming from biotic emissions of NO from soils, from satellite-borne measurements of NO2. This is achieved by synchronizing time series at single grid pixels according to the first day of rain after a dry spell of prescribed duration. The full track of the temporal evolution several weeks before and after a rain pulse is retained with daily resolution. These are needed for a sophisticated background correction, which accounts for seasonal variations in the time series and allows for improved quantification of rain-induced soil emissions. The method is applied globally and provides constraints on pulsed soil emissions of NOx in regions where the NOx budget is seasonally dominated by soil emissions. We find strong peaks of enhanced NO2 vertical column densities (VCDs) induced by the first intense precipitation after prolonged droughts in many semi-arid regions of the world, in particular in the Sahel. Detailed investigations show that the rain-induced NO2 pulse detected by the OMI (Ozone Monitoring Instrument), GOME-2 and SCIAMACHY satellite instruments could not be explained by other sources, such as biomass burning or lightning, or by retrieval artefacts (e.g. due to clouds). For the Sahel region, absolute enhancements of the NO2 VCDs on the first day of rain based on OMI measurements 2007-2010 are on average 4 × 1014  molec cm-2 and exceed 1 × 1015  molec cm-2 for individual grid cells. Assuming a NOx lifetime of 4 h, this corresponds to soil NOx emissions in the range of 6 up to 65 ng N m-2 s-1, which is in good agreement with literature values. Apart from the clear first-day peak, NO2 VCDs are moderately enhanced (2 × 1014  molec cm-2) compared to the background over the following 2 weeks, suggesting potential further emissions during that period of about 3.3 ng N m-2 s-1

  2. Observation of the volcanic plume of Eyjafjallajökull over continental Europe by Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS)

    NASA Astrophysics Data System (ADS)

    Yilmaz, S.; Friess, U.; Kern, C.; Vogel, L.; Hoermann, C.; Wagner, T.; Platt, U.

    2010-12-01

    The recent eruption of Eyjafjallajökull Volcano (Iceland) and the emitted ash plume which disrupted commercial air traffic over Europe for an extended period of time has led to an exhaustive debate on how to improve our ability to quantitatively determine the ash load in the atmosphere as a function of time and geographical location in the aftermath of future eruptions. A combination of satellite remote sensing instruments detecting ash and SO2 and ground-based LIDAR stations can help constrain atmospheric transport and meteorology models used to predict ash dispersion. However, multi-axis Differential Optical Absorption Spectroscopy (MAX-DOAS) represents an additional and often neglected tool with considerable potential for the quantitative detection of elevated volcanic ash and SO2 plumes. It performs especially well during weather conditions in which satellites and LIDARs are impeded in their effectiveness, e.g. in the case of dense clouds above or below the plume, respectively. Here, the advantages and disadvantages of the DOAS technique are discussed, and its potential for monitoring of volcanic ash hazards explored. Results of ash and SO2 measurements of the Eyjafjallajökull plume as it passed over the city of Heidelberg, Germany are presented as an example of a positive detection of a highly diluted volcanic plume. SO2 was detected on several days with differential slant column densities (dSCD) of up to (3.33 ± 0.35) × 1017 molec/cm2. The occurrence of these high dSCDs is in good agreement with model predictions (FLEXPART), in-situ background (Schauinsland, Germany) and remote sensing measurements (GOME-2). For cloud free conditions, also the aerosol optical depth at 350 nm was retrieved from the MAX-DOAS measurements. The retrieved values of up to 1.31 ± 0.02 are in good agreement with Sun photometer measurements. Their relatively low cost and complementary nature in respect to other SO2/ash detection techniques makes multi-axis DOAS a promising

  3. Fate of elemental mercury in the Arctic during atmospheric mercury depletion episodes and the load of atmospheric mercury to the Arctic.

    PubMed

    Skov, Henrik; Christensen, Jesper H; Goodsite, Michael E; Heidam, Niels Z; Jensen, Bjarne; Wåhlin, Peter; Geernaert, Gerald

    2004-04-15

    Atmospheric mercury depletion episodes (AMDEs) were studied at Station Nord, Northeast Greenland, 81 degrees 36' N, 16 degrees 40' W, during the Arctic Spring. Gaseous elemental mercury (GEM) and ozone were measured starting from 1998 and 1999, respectively, until August 2002. GEM was measured with a TEKRAN 2735A automatic mercury analyzer based on preconcentration of mercury on a gold trap followed by detection using fluorescence spectroscopy. Ozone was measured by UV absorption. A scatter plot of GEM and ozone concentrations confirmed that also at Station Nord GEM and ozone are linearly correlated during AMDEs. The relationship between ozone and GEM is further investigated in this paper using basic reaction kinetics (i.e., Cl, ClO, Br, and BrO have been suggested as reactants for GEM). The analyses in this paper show that GEM in the Arctic troposphere most probably reacts with Br. On the basis of the experimental results of this paper and results from the literature, a simple parametrization for AMDE was included into the Danish Eulerian Hemispheric Model (DEHM). In the model, GEM is converted linearly to reactive gaseous mercury (RGM) over sea ice with temperature below -4 degrees C with a lifetime of 3 or 10 h. The new AMDE parametrization was used together with the general parametrization of mercury chemistry [Petersen, G.; Munthe, J.; Pleijel, K.; Bloxam, R.; Vinod Kumar, A. Atmos. Environ. 1998, 32, 829-843]. The obtained model results were compared with measurements of GEM at Station Nord. There was good agreement between the start and general features periods with AMDEs, although the model could not reproduce the fast concentration changes, and the correlation between modeled and measured values decreased from 2000 to 2001 and further in 2002. The modeled RGM concentrations over the Arctic in 2000 were found to agree well with the temporal and geographical variability of the boundary column of monthly average BrO observed by the GOME satellite. Scenario

  4. Preliminary Results on the 2015 Eruption of Wolf Volcano, Isabela Island, Galápagos: Chronology, Dispersion of the Volcanic Products, and Insight into the Eruptive Dynamics

    NASA Astrophysics Data System (ADS)

    Wright, H. M. N.; Bernard, B.; Ramon, P.; Guevara, A.; Hidalgo, S.; Pacheco, D. A.; Narváez, D.; Vásconez, F.

    2015-12-01

    After 33 years of quiescence, Wolf volcano, located in the northernmost tip of Isabela Island (Galápagos Islands, Ecuador), started a new eruption on May 25, 2015. The first signs of activity were recorded at 5:50 UTC (23:50 on May 24, Local Time in Galápagos) by a seismic station installed on Fernandina island. The first visual observation was reported at 7:38 UTC (1:38 LT). Based on amateur film footage, the vent was a >800 m-long circumferential fissure that produced a >100 m-high lava curtain. The eruption also released a 15 km-high gas plume with a large amount of SO2 and minimal ash content. Lightning was observed in the plume but not near the vent. Due to complex wind directions at high altitude, the gas cloud drifted in all directions eventually coming toward the continent and producing an extremely small ashfall in Quito that was detected only through the use of homemade ashmeters. The ash sample included lava droplets, scoria, and one small fragment of reticulite, indicating high lava fountaining during the first days of the eruption. The active vents on the circumferential fissure, initially located on the SE side of the caldera outer rim, moved progressively northward, eventually extending for a total of 2 km. One week later on June 02, satellite imagery (OMI, GOME, MODIS) documented decreased volcanic activity, leaving two new lava fields covering over 17 km2 on the SE (10 km-long and up to 2 km-wide) and E (7 km-long and up to 1 km-wide, reaching the sea) flanks of the volcano. Volcanic activity resumed on June 11, and on June 13 it shifted into the caldera, apparently emerging from a fissure close to the vent from the 1982 eruption, about 4 km W of the circumferential fissure. This new lava flow covered approximately 3.5 km2 of the caldera floor. Finally, volcanic activity waned at the end of June and appeared to have ended by July 11, accounting for one of the largest eruptions in the Galápagos since 1968 based on remote sensing.

  5. Emerging roles of the myocardin family of proteins in lipid and glucose metabolism.

    PubMed

    Swärd, Karl; Stenkula, Karin G; Rippe, Catarina; Alajbegovic, Azra; Gomez, Maria F; Albinsson, Sebastian

    2016-09-01

    Members of the myocardin family bind to the transcription factor serum response factor (SRF) and act as coactivators controlling genes of relevance for myogenic differentiation and motile function. Binding of SRF to DNA is mediated by genetic elements called CArG boxes, found often but not exclusively in muscle and growth controlling genes. Studies aimed at defining the full spectrum of these CArG elements in the genome (i.e. the CArGome) have in recent years, unveiled unexpected roles of the myocardin family proteins in lipid and glucose homeostasis. This coactivator family includes the protein myocardin (MYOCD), the myocardin-related transcription factors A and B (MRTF-A/MKL1 and MRTF-B/MKL2) and MASTR (MAMSTR). Here we discuss growing evidence that SRF-driven transcription is controlled by extracellular glucose through activation of the Rho-kinase pathway and actin polymerization. We also describe data showing that adipogenesis is influenced by MLK activity through actions upstream of peroxisome proliferator-activated receptor γ with consequences for whole body fat mass and insulin sensitivity. The recently demonstrated involvement of myocardin coactivators in the biogenesis of caveolae, Ω-shaped membrane invaginations of importance for lipid and glucose metabolism, is finally discussed. These novel roles of myocardin proteins may open the way for new unexplored strategies to combat metabolic diseases such as diabetes, which, at the current incidence, is expected to reach 333 million people worldwide by 2025. This review highlights newly discovered roles of myocardin-related transcription factors in lipid and glucose metabolism as well as novel insights into their well-established role as mediators of stretch-dependent effects in smooth muscle. As co-factors for serum response factor (SRF), MKLs regulates transcription of genes involved in the contractile function of smooth muscle cells. In addition to mechanical stimuli, this regulation has now been found to

  6. Relationship Between the Thickness of Cortical Bone at Maxillary Mid-palatal Area and Facial Height Using CBCT

    PubMed Central

    Johari, Masume; Kaviani, Farzaneh; Saeedi, Arman

    2015-01-01

    Introduction : Orthodontic mini-implants have been incorporated into orthodontic treatment modalities. Adequate bone at mini-implant placement site can influence the success or failure of anchorage. The present study was to determine the thickness of cortical bone in the maxillary mid-palatal area at predetermined points for the placement of orthodontic mini-implants using Cone Beam CT technique in order to evaluate the relationship of these values with the facial height. Materials and Methods : A total of 161 patients, consisting of 63 males (39.13%) and 98 females (60.87%), were evaluated in the present study; 38% of the subjects had normal facial height, 29% had short face and 33% had long face. In order to determine which patient belongs to which facial height category, i.e. normal, long or short, two angular and linear evaluations were used: the angle between S-N and Go-Me lines and the S-Go/N-Me ratio. Twenty points were evaluated in all the samples. First the incisive foramen was located. The paracoronal cross-sections were prepared at distances of 4, 8, 16 and 24 mm from the distal wall of the incisive foramen and on each cross-section the mid-sagittal and para-sagittal areas were determined bilaterally at 3- and 6-mm distances (a total of 5 points). The thicknesses of the cortical plate of bone were determined at the predetermined points. Results : There was a significant relationship between the mean cortical bone thickness and facial height (p<0.01), with significantly less thickness in long faces compared to short faces. However, the thickness of cortical bone in normal faces was similar to that in long and short faces. Separate evaluation of the points showed that at point a16 subjects with short faces had thicker cortical bone compared to subjects with long and normal faces. At point b8 in long faces, the thickness of the cortical bone was significantly less than that in short and normal faces. At point d8, the thickness of the cortical bone in

  7. Invertability of ozone stratospheric column measurements by means of potential vorticity

    NASA Astrophysics Data System (ADS)

    Elbern, H.; Baier, F.

    2003-04-01

    Vertical ozone profile information for the stratosphere is not only necessary for chemistry transport models (CTMs) but today also regarded as beneficial for the radiative transport calculation in weather forecast models. However, mostly only column density data of ozone from satellite retrievals are readily available for assimilation in real time. Nevertheless, in large areas of the stratosphere correlations between ozone concentrations and potential vorticity (PV) exist, which can be exploited for profile estimates. In total the following sources of information at disposal in close real time: begin{enumerate} total ozone columns, potential vorticity for each geolocated GOME column, useful in the middle and lower stratosphere (except in a small latitude belt at the equator), and (potentially a priori information of CTM ozone column profile forecasts.) Detailed error covariances are established by 1996 SAGE profile retrievals obtained from DFD-DFD. Using these as system learning data in combination with given PV values, ROSE-CTM model profiles and inferred ozone columns, a statistical profile model can be developed. The retrieval model is a combination of stochastic models, based on the regression coefficients linking PV and ozone, and an algebraic model, exploiting the ozone column information. As statistical models, three approaches were tested: levelwise monovariate regression, levelwise multivariate regressions, and full Givens rotation. The mathematical procedure required is the general inversion of an ill-posed heteroscedatic problem. Depending on access to and quality of the ROSE-CTM model simulated ozone profiles, two different algorithms are pertinent: If the model simulations are not available or inferior to a recently available reference data set, a "optimal filtering" (or "stochastic inverse") algorithm is used. In contrast, for model simulations of useful quality, the Bayesian "Maximum A Posteriori" estimator (MAP) has been applied. Generally, the PV

  8. Observational evidence of planetary wave influences on ozone enhancements over upper troposphere North Africa

    NASA Astrophysics Data System (ADS)

    Mengistu Tsidu, Gizaw; Ture, Kassahun; Sivakumar, V.

    2013-07-01

    MOZAIC instrument measured enhanced ozone on two occasions in February, 1996 and 1997 at cruise altitude over North Africa. The cause and source of ozone enhancements over the region are investigated using additional reanalysis data from ERA-Interim. The ERA-Interim reprocessed GOME ozone indicated existence of enhancement as well. Both observational data revealed that the increase in ozone has wider latitudinal coverage extending from North Europe upto North Africa. The geopotential heights and zonal wind from ERA-Interim have indicated existence of planetary-scale flow that allowed meridional airmass exchanges between subtropics and higher latitudes. The presence of troughs-ridge pattern are attributable to large amplitude waves of zonal wavenumber 1-5 propagating eastward in the winter hemisphere westerly current as determined from Hayashi spectra as well as local fractional variance spectra determined from Multitaper Method-Singular Value Decomposition (MTM-SVD) spectral method. MTM-SVD is also used to understand the role of these waves on ozone enhancement and variability during the observation period in a mechanistic approach. A joint analysis of driving field, such as wind and potential vorticity (PV) for which only signals of the dominant zonal wavenumbers of prevailing planetary waves are retained, has revealed strong linkage between wave activity and ozone enhancement over the region at a temporal cycle of 5.8 days. One of these features is the displacement of the polar vortex southward during the enhancements, allowing strong airmass, energy and momentum exchanges. Evidence of cutoff laws that are formed within the deep trough, characteristics of Rossby wave breaking, is also seen in the ozone horizontal distribution at different pressure levels during the events. The reconstruction of signals with the cycle of 5.8 days has shown that the time and strength of enhancement depend on the circulation patterns dictated by planetary-scale flow relative to the

  9. Study of Atmospheric Trace Gas Amounts at the Stara Zagora Ground-Based Station

    NASA Astrophysics Data System (ADS)

    Werner, R.; Valev, D.; Kostadinov, I.; Atanassov, At.; Giovanelli, G.; Petritoli, A.; Bortoli, D.; Ravegnani, F.

    2006-03-01

    Since the end of August 1999 twilight daily measurements of scattered zenith sky radiation have been carried out at Stara Zagora for determination of trace gas amounts, deploying GASCOD instrument. It was developed at the Institute of Atmospheric Science and Climate, Bologna. Reference spectra are obtained at midday. The instrument, appearing a UV-VIS spectrometer, registers the zenith sky spectra automatically and 410 nm to 460 nm spectral interval is used to retrieve NO2 and O3 slant column amounts (SCA) by application of the DOAS methodology. The spectral analysis uses minimum least squares fitting of the cross sections at the expected absorbers to a logarithm of the twilight spectrum and a reference spectrum. The accumulated time series show the well-known typical seasonal variations, caused by the solar insulation. The residual time series of the removed semi-annual seasonal cycles from the measured original series show many different variations, with short periods up to inter-annual variations. Single spikes of SCA are detected and we consider them a result of over-passing weather fronts and/or lightning. Variations of SCA with time scale up to about 10 days are the consequence of weather cyclones. Some short-term variations of NO2 and O3 SCA are a result of intensive stratospheric-tropospheric exchange. Other residual time series periods are caused by Rossby waves, by over-passing of the polar vortex filaments. The inter-annual variations can be affected by QBO and NAO. Applying wavelet analysis of the obtained NO2 slant column amount data series, and the total O3 amount obtained by the GOME instrument, during the 23-rd solar cycle maximum, time intervals are found with periods of 27 days on the time scale. The applied cross-correlation analysis demonstrates a phase lag of some days of the NO2 and O3 response to the 27-days solar cycle. The calculated vertical column amounts of NO2 are used for validation of the satellite measurements, e.g. SCIAMACHY NO2

  10. An improved retrieval of tropospheric NO2 columns from the Ozone Monitoring Instrument

    NASA Astrophysics Data System (ADS)

    Boersma, Folkert; Dirksen, Ruud; Brunner, Dominik; Zhou, Yipin; Huijnen, Vincent; Eskes, Henk; Veefkind, Pepijn; Kleipool, Quintus; Dobber, Marcel; Stammes, Piet

    2010-05-01

    Recent studies using Dutch OMI NO2 (DOMINO) retrievals have established the current data quality and provided information on how to improve future retrievals. OMI generally shows modest to good agreement with independent observations, but appears to be biased high by 0%-40%. We improve retrievals with more accurate radiative transfer calculations that better account for the sensitivity in the lowest atmosphere model layer, and use a more realistic set of atmospheric pressure and temperature profiles, surface albedos and surface pressure levels. The improved representation of radiative transfer alone leads to a reduction in tropospheric columns of 10%-20% in polluted regions. A better representation of terrain height in the retrieval (based on 3 x 3 km2 elevation data rather than the 3˚ x 2˚ model data) increases tropospheric columns (up to 10%) in valleys that were previously attributed too high a terrain height (such as the Po Valley, Beijing area), and reduces NO2 columns over elevated areas that previously had too low terrain height (Mexico City, Highveld Plateau). The implementation of a new surface reflectivity database from OMI shows that the frequently higher surface reflectivity in the OMI than in the TOMS/GOME dataset leads to lower cloud fractions and higher cloud pressures in the cloud-retrieval. We will show the direct impact of better surface albedos on retrievals (clear-sky scenes) as well as the impact via the cloud correction (partly clouded scenes). A better representation of vertical mixing of NO2 in the TM4 model results in a better match with observed NO2 profiles; the impact of this improvement but also the effect of a priori NO2 profiles with better spatial resolution (CHIMERE) on retrievals will be discussed. We conclude by proposing a simple method (vicarious calibration) to evaluate and correct for the stripes apparent in the OMI NO2 retrievals. The combined effect of all improvements is anticipated to lead to a significantly improved

  11. Monitoring of atmospheric ozone and nitrogen dioxide over the south of Portugal by ground-based and satellite observations.

    PubMed

    Bortoli, Daniele; Silva, Ana Maria; Costa, Maria João; Domingues, Ana Filipa; Giovanelli, Giorgio

    2009-07-20

    The SPATRAM (Spectrometer for Atmospheric TRAcers Monitoring) instrument has been developed as a result of the collaboration between CGE-UE, ISAC-CNR and Italian National Agency for New Technologies, Energy and the Environment (ENEA). SPATRAM is a multi-purpose UV-Vis-scanning spectrometer (250 - 950 nm) and it is installed at the Observatory of the CGE, in Evora, since April 2004. A brief description of the instrument is given, highlighting the technological innovations with respect to the previous version of similar equipment. The need for such measurements automatically taken on a routine basis in south-western European regions, specifically in Portugal, has encouraged the development and installation of the equipment and constitutes a major driving force for the present work. The main features and some improvements introduced in the DOAS (Differential Optical Absorption Spectroscopy) algorithms are discussed. The results obtained applying DOAS methodology to the SPATRAM spectrometer measurements of diffused spectral sky radiation are presented in terms of diurnal and seasonal variations of nitrogen dioxide (NO(2)) and ozone (O(3)). NO(2) confirms the typical seasonal cycle reaching the maximum of (6.5 +/- 0.3) x 10(+15) molecules cm(-2) for the sunset values (PM), during the summer season, and the minimum of (1.55 +/- 0.07) x 10(+15) molecules cm(-2) for the sunrise values (AM) in winter. O(3) presents the maximum total column of (433 +/- 5) Dobson Unit (DU) in the spring season and the minimum of (284 +/- 3) DU during the fall period. The huge daily variations of the O(3) total column during the spring season are analyzed and discussed. The ground-based results obtained for NO(2) and O(3) column contents are compared with data from satellite-borne equipment (GOME - Global Ozone Monitoring Experiment; SCIAMACHY - Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY; TOMS - Total Ozone Monitoring Spectrometer) and it is shown that the two data

  12. Advanced Outage and Control Center: Strategies for Nuclear Plant Outage Work Status Capabilities

    SciTech Connect

    Gregory Weatherby

    2012-05-01

    The research effort is a part of the Light Water Reactor Sustainability (LWRS) Program. LWRS is a research and development program sponsored by the Department of Energy, performed in close collaboration with industry to provide the technical foundations for licensing and managing the long-term, safe and economical operation of current nuclear power plants. The LWRS Program serves to help the US nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. The Outage Control Center (OCC) Pilot Project was directed at carrying out the applied research for development and pilot of technology designed to enhance safe outage and maintenance operations, improve human performance and reliability, increase overall operational efficiency, and improve plant status control. Plant outage management is a high priority concern for the nuclear industry from cost and safety perspectives. Unfortunately, many of the underlying technologies supporting outage control are the same as those used in the 1980’s. They depend heavily upon large teams of staff, multiple work and coordination locations, and manual administrative actions that require large amounts of paper. Previous work in human reliability analysis suggests that many repetitive tasks, including paper work tasks, may have a failure rate of 1.0E-3 or higher (Gertman, 1996). With between 10,000 and 45,000 subtasks being performed during an outage (Gomes, 1996), the opportunity for human error of some consequence is a realistic concern. Although a number of factors exist that can make these errors recoverable, reducing and effectively coordinating the sheer number of tasks to be performed, particularly those that are error prone, has the potential to enhance outage efficiency and safety. Additionally, outage management requires precise coordination of work groups that do not always share similar objectives. Outage

  13. Aerosol Plume during a Polluted Event Occuring Over Paris Area and its Potential Photochemical Effect

    NASA Astrophysics Data System (ADS)

    Randriamiarisoa, H.; Chazette, P.; Sanak, J.; Hauglustaine, D.

    2002-12-01

    As in many big cities, there are several pollution events in Paris area. A thorough understanding of the processes leading on the formation of pollutants and their transport during pollution episodes is necessary. One of the pertinent factors, which contributions on atmospheric chemistry and radiative effect are not yet well known, is the aerosol. ESQUIF (Etude et Simulation de la QUalité de l?air en Ile de France) is the first program dedicated to study such issues over the Paris area. It was carried out from summer 1998 to winter 2000 (Menut et al., 2000). To characterize all the properties of the urban aerosol, many campaigns were coordinated using both ground and airborne measurements (Chazette et al., 2000). We are focusing on the 31st of July 2000 where a well-defined polluted plume has been observed. Aerosol number concentrations in different size classes were measured and show that urban aerosol in Paris area is mainly submicronic. The absorbent part of the aerosol, mainly associated to the black carbon component, has been observed to be associated to particles with diameter less than 0.1 æm. The single scattering albedo has been assessed to be close to 0.85 leading to a significant influence on the photochemical chemistry. Indeed, a significant decrease of the daily maximum ozone concentration has been calculated using the INCA model and will be presented. ACKNOWLEDGEMENTS The Programme National de Chimie Atmosphérique, INSU supported this work. REFERENCES Chazette P., H. Randriamiarisoa, J. Sanak, C. Flamant, J. Pelon, M. Sicard, H. Cachier, F. Aulagnier, R. Sarda-Esteve, L. Gomes, S. Alfaro and A. Gaudichet (2001). ESQUIF 2000 : Aerosol survey over the Ile-de-France area, J. Aerosol Sci ., 32/suppl. 1, S439-S440. Menut, L., R. Vautard, C. Flamant, A. Abonnel, M. Beekmann, P. Chazette, P.H. Flamant, D. Gombert, D. Guédalia, D. Kley, M.P. Lefebvre, B. Lossec, D. Martin, G. Mégie, P. Perros, M. Sicard and G. Toupance (2000). Measurements and modelling

  14. Sensitivity of spectral climate signals to the emissions of atmospheric dust

    NASA Astrophysics Data System (ADS)

    Xu, X.; Wang, J.; Wang, Y.; Henze, D. K.; Zhang, L.

    2015-12-01

    Mineral dust particles profoundly influence the Earth climate due to their varied affects on the radiation and cloud physics. The knowledge of dust emissions from daily to seasonal scales is thus important for interpreting the past and predicting the future climate changes. Satellite measured radiances in the shortwave and thermal infrared are sensitive to the amount and properties of mineral dust present in the atmosphere. Therefore, the climate (i.e., monthly averages) of these reflectance spectra could contain valuable information on the change of dust emissions. In this work, we investigate the feasibility of using the climate of spectral radiances for recovering dust emissions. An observation simulation system (OSS) that incorporates the Unified Linearized Vector Radiative Transfer Model (UNL-VRTM) with forward and adjoint global chemistry transport models (GEOS-Chem and FIM-Chem) has been applied to generate synthetic hyperspectral climate data in the shortwave and thermal infrared (TIR) for summer 2008. Along with the calculation of radiances at the top of the atmosphere (TOA), the OSS also computes their Jacobians of these synthetic data to dust optical depth, plume height, and effective radius, as well as the adjoint gradients of spectral radiances to dust emissions. We found that the brightness temperature (BT) in the TIR spectra at TOA is sensitive to both of the dust plume height and particle size. For the same relative changes of these parameters, BT shows largest change with respect to particle size at the wavenumber of 890-1200 cm-1. This demonstrates the potential for retrieving three-dimensional dust information along with the particle size from hyperspectral TIR measurements. We also assess the information content of monthly versus instantaneous radiances for constraining dust emissionsthe from the calculated adjoint gradients. Our analysis may guide new applications of long-term spectral radiance measurements (such as those from GOME, AIRS, IASI

  15. Phobos' Low Bulk Density: Evidence Against a Capture Origin?

    NASA Astrophysics Data System (ADS)

    Dalle Ore, C.; Pajola, M.; Lazzarin, M.; Roush, T. L.; Cruikshank, D. P.; Pendleton, Y. J.; Carli, C.; Bertini, I.; Magrin, S.; La Forgia, F.; Barbieri, C.

    2014-12-01

    Phobos' low density of 1.876 ± 0.02 g/cm3 (Andert et al., 2010, Witasse et al., 2013, Paetzold et al., 2013) supports its formation from a disk of debris (Peale 2007). The disk would either be a remnant of the formation of Mars (Safronov et al., 1986) or the result of a collision between Mars and a large body (Craddock 1994, 2011; Singer 2007). Within this scenario a large interior porosity would be responsible for the low density of the re-accreted material forming Phobos. Thermal emission spectra of Phobos suggest an ultramafic composition with the presence of phyllosilicates and feldspathoids in some regions (Giuranna et al., 2011), consistent with Phobos' in situ formation (Giuranna et al., 2011). However, the 0.3-4.0 μm surface spectra taken from multiple areas of the body in more than 43 years of observations (Duxbury et al., 2013), show physical characteristics similar to low-albedo asteroids such as C-type (Masursky et al., 1972, Pang et al., 1980) or D-type (Murchie 1999, Rivkin et al., 2002, Lynch et al., 2007, Pajola et al., 2012). They argue in favor of an asteroidal capture scenario that could be explained by binary asteroid dissociation (Landis 2009) or by collisional capture in the Martian orbital region (Pajola et al., 2012). Finally recent work by Schmedemann et al., (2014) indicates Phobos' surface to be ~ 4.3 - 3.7 Ga, dating back to a period where there was an intensification in the number of impactors in the inner Solar System (Gomes et al., 2005), and supporting both the in-situ and the capture scenario. Pajola et al. (2013) match the surface reflectance of Phobos from 0.4 to 4.0 μm with a mineralogical model composed of a mixture of Tagish Lake meteorite (TL) and Pyroxene Glass (PM80). Based on the published model, we adopted the weighted TL and PM80 densities to investigate if the low bulk density of Phobos could conform with these components reconciling both inner properties and surface spectra. While the TL density is available from

  16. Seasonal variation of bromine monoxide over the Rann of Kutch salt marsh seen from space

    NASA Astrophysics Data System (ADS)

    Hörmann, Christoph; Beirle, Steffen; Penning de Vries, Marloes; Sihler, Holger; Platt, Ulrich; Wagner, Thomas

    2015-04-01

    around ~13:30) are compared to corresponding results from the Global Ozone Monitoring Instrument (GOME-2, local overflight time at ~9:30).