WorldWideScience

Sample records for wintertime gome observations

  1. Estimates of lightning NOx production from GOME satellite observations

    NARCIS (Netherlands)

    Boersma, K.F.; Eskes, H.J.; Meijer, E.W.; Kelder, H.M.

    2005-01-01

    Tropospheric NO2 column retreivals from the Global Ozone Monitoring Expeiment (GOME) satellite spectrometer are used to quantify the source strength and 3-D distribution of lightning produced nitrogen oxides (NOx=NO+NO2). A sharp increase of NO2 is observed at convective cloud tops with increasing

  2. Estimates of lightning NOx production from GOME satellite observations

    Directory of Open Access Journals (Sweden)

    K. F. Boersma

    2005-01-01

    Full Text Available Tropospheric NO2 column retrievals from the Global Ozone Monitoring Experiment (GOME satellite spectrometer are used to quantify the source strength and 3-D distribution of lightning produced nitrogen oxides (NOx=NO+NO2. A sharp increase of NO2 is observed at convective cloud tops with increasing cloud top height, consistent with a power-law behaviour with power 5±2. Convective production of clouds with the same cloud height are found to produce NO2 with a ratio 1.6/1 for continents compared to oceans. This relation between cloud properties and NO2 is used to construct a 10:30 local time global lightning NO2 production map for 1997. An extensive statistical comparison is conducted to investigate the capability of the TM3 chemistry transport model to reproduce observed patterns of lightning NO2 in time and space. This comparison uses the averaging kernel to relate modelled profiles of NO2 to observed NO2 columns. It exploits a masking scheme to minimise the interference of other NOx sources on the observed total columns. Simulations are performed with two lightning parameterizations, one relating convective preciptation (CP scheme to lightning flash distributions, and the other relating the fifth power of the cloud top height (H5 scheme to lightning distributions. The satellite-retrieved NO2 fields show significant correlations with the simulated lightning contribution to the NO2 concentrations for both parameterizations. Over tropical continents modelled lightning NO2 shows remarkable quantitative agreement with observations. Over the oceans however, the two model lightning parameterizations overestimate the retrieved NO2 attributed to lightning. Possible explanations for these overestimations are discussed. The ratio between satellite-retrieved NO2 and modelled lightning NO2 is used to rescale the original modelled lightning NOx production. Eight estimates of the lightning NOx production in 1997 are obtained from spatial and temporal

  3. Intercomparison of 4 Years of Global Formaldehyde Observations from the GOME-2 and OMI Sensors

    Science.gov (United States)

    De Smedt, Isabelle; Van Roozendael, Michel; Stravrakou, Trissevgeni; Muller, Jean-Francois; Chance, Kelly; Kurosu, Thomas

    2012-11-01

    Formaldehyde (H2CO) tropospheric columns have been retrieved since 2007 from backscattered UV radiance measurements performed by the GOME-2 instrument on the EUMETSAT METOP-A platform. This data set extends the successful time-series of global H2CO observations established with GOME/ ERS-2 (1996-2003), SCIAMACHY/ ENVISAT (2003-2012), and OMI on the NASA AURA platform (2005-now). In this work, we perform an intercomparison of the H2CO tropospheric columns retrieved from GOME-2 and OMI between 2007 and 2010, respectively at BIRA-IASB and at Harvard SAO. We first compare the global formaldehyde data products that are provided by each retrieval group. We then investigate each step of the retrieval procedure: the slant column fitting, the reference sector correction and the air mass factor calculation. New air mass factors are computed for OMI using external parameters consistent with those used for GOME-2. By doing so, the impacts of the different a priori profiles and aerosol corrections are quantified. The remaining differences are evaluated in view of the expected diurnal variations of the formaldehyde concentrations, based on ground-based measurements performed in the Beijing area.

  4. SO2 columns over China: Temporal and spatial variations using OMI and GOME-2 observations

    Science.gov (United States)

    Huanhuan, Yan; Liangfu, Chen; Lin, Su; Jinhua, Tao; Chao, Yu

    2014-03-01

    Enhancements of SO2 column amounts due to anthropogenic emission sources over China were shown in this paper by using OMI and GOME-2 observations. The temporal and spatial variations of SO2 columns over China were analyzed for the time period 2005-2010. Beijing and Chongqing showed a high concentration in the SO2 columns, attributable to the use of coal for power generation in China and the characteristic of terrain and meteorology. The reduction of SO2 columns over Beijing and surrounding provinces in 2008 was observed by OMI, which confirms the effectiveness of strict controls on pollutant emissions and motor vehicle traffic before and during 2008 Olympic and Paralympic Games. The SO2 columns over China from GOME-2 (0.2-0.5 DU) were lower than those from OMI (0.6-1 DU), but both showed a decrease in SO2 columns over northern China since 2008 (except an increase in OMI SO2 in 2010).

  5. Observing lowermost tropospheric ozone pollution with a new multispectral synergic approach of IASI infrared and GOME-2 ultraviolet satellite measurements

    Science.gov (United States)

    Cuesta, Juan; Foret, Gilles; Dufour, Gaëlle; Eremenko, Maxim; Coman, Adriana; Gaubert, Benjamin; Beekmann, Matthias; Liu, Xiong; Cai, Zhaonan; Von Clarmann, Thomas; Spurr, Robert; Flaud, Jean-Marie

    2014-05-01

    Tropospheric ozone is currently one of the air pollutants posing greatest threats to human health and ecosystems. Monitoring ozone pollution at the regional, continental and global scale is a crucial societal issue. Only spaceborne remote sensing is capable of observing tropospheric ozone at such scales. The spatio-temporal coverage of new satellite-based instruments, such as IASI or GOME-2, offer a great potential for monitoring air quality by synergism with regional chemistry-transport models, for both inter-validation and full data assimilation. However, current spaceborne observations using single-band either UV or IR measurements show limited sensitivity to ozone in the atmospheric boundary layer, which is the major concern for air quality. Very recently, we have developed an innovative multispectral approach, so-called IASI+GOME-2, which combines IASI and GOME-2 observations, respectively in the IR and UV. This unique multispectral approach has allowed the observation of ozone plumes in the lowermost troposphere (LMT, below 3 km of altitude) over Europe, for the first time from space. Our first analyses are focused on typical ozone pollution events during the summer of 2009 over Europe. During these events, LMT ozone plumes at different regions are produced photo-chemically in the boundary layer, transported upwards to the free troposphere and also downwards from the stratosphere. We have analysed them using IASI+GOME-2 observations, in comparison with single-band methods (IASI, GOME-2 and OMI). Only IASI+GOME-2 depicts ozone plumes located below 3 km of altitude (both over land and ocean). Indeed, the multispectral sensitivity in the LMT is greater by 40% and it peaks at 2 to 2.5 km of altitude over land, thus at least 0.8 to 1 km below that for all single-band methods. Over Europe during the summer of 2009, IASI+GOME-2 shows 1% mean bias and 21% precision for direct comparisons with ozonesondes and also good agreement with CHIMERE model simulations

  6. Global observations of tropospheric BrO columns using GOME-2 satellite data

    Science.gov (United States)

    Theys, N.; van Roozendael, M.; Hendrick, F.; Yang, X.; de Smedt, I.; Richter, A.; Begoin, M.; Errera, Q.; Johnston, P. V.; Kreher, K.; de Mazière, M.

    2011-02-01

    Measurements from the GOME-2 satellite instrument have been analyzed for tropospheric BrO using a residual technique that combines measured BrO columns and estimates of the stratospheric BrO content from a climatological approach driven by O3 and NO2 observations. Comparisons between the GOME-2 results and BrO vertical columns derived from correlative ground-based and SCIAMACHY nadir observations, present a good level of consistency. We show that the adopted technique enables separation of stratospheric and tropospheric fractions of the measured total BrO columns and allows quantitative study of the BrO plumes in polar regions. While some satellite observed plumes of enhanced BrO can be explained by stratospheric descending air, we show that most BrO hotspots are of tropospheric origin, although they are often associated to regions with low tropopause heights as well. Elaborating on simulations using the p-TOMCAT tropospheric chemical transport model, this result is found to be consistent with the mechanism of bromine release through sea salt aerosols production during blowing snow events. No definitive conclusion can be drawn however on the importance of blowing snow sources in comparison to other bromine release mechanisms. Outside polar regions, evidence is provided for a global tropospheric BrO background with column of 1-3 × 1013 molec cm-2, consistent with previous estimates.

  7. Global observations of tropospheric BrO columns using GOME-2 satellite data

    Directory of Open Access Journals (Sweden)

    N. Theys

    2011-02-01

    Full Text Available Measurements from the GOME-2 satellite instrument have been analyzed for tropospheric BrO using a residual technique that combines measured BrO columns and estimates of the stratospheric BrO content from a climatological approach driven by O3 and NO2 observations. Comparisons between the GOME-2 results and BrO vertical columns derived from correlative ground-based and SCIAMACHY nadir observations, present a good level of consistency. We show that the adopted technique enables separation of stratospheric and tropospheric fractions of the measured total BrO columns and allows quantitative study of the BrO plumes in polar regions. While some satellite observed plumes of enhanced BrO can be explained by stratospheric descending air, we show that most BrO hotspots are of tropospheric origin, although they are often associated to regions with low tropopause heights as well. Elaborating on simulations using the p-TOMCAT tropospheric chemical transport model, this result is found to be consistent with the mechanism of bromine release through sea salt aerosols production during blowing snow events. No definitive conclusion can be drawn however on the importance of blowing snow sources in comparison to other bromine release mechanisms. Outside polar regions, evidence is provided for a global tropospheric BrO background with column of 1–3 × 1013 molec cm−2, consistent with previous estimates.

  8. Global observations of BrO in the troposphere using GOME-2 satellite data

    Science.gov (United States)

    Theys, N.; van Roozendael, M.; Hendrick, F.; Xin, Y.; Isabelle, D.; Richter, A.; Mathias, B.; Quentin, E.; Johnston, P. V.; Kreher, K.; Martine, D.

    2010-12-01

    Measurements from the GOME-2 satellite instrument have been analyzed for tropospheric BrO using a residual technique that combines measured BrO columns and estimates of the stratospheric BrO content from a climatological approach driven by O3 and NO2 observations. Comparisons between the GOME-2 results and correlative data including ground-based BrO vertical columns and total BrO columns derived from SCIAMACHY nadir observations, present a good level of consistency. We show that the adopted technique enables to separate the stratospheric and tropospheric fractions of the measured total BrO columns and allows studying the BrO plumes in polar region in more detail. While several satellite BrO plumes can largely be explained by an influence of stratospheric descending air, we show that numerous tropospheric BrO hotspots are associated to regions with low tropopause heights as well. Elaborating on simulations using the p-TOMCAT tropospheric chemical transport model, this finding is found to be consistent with the mechanism of bromine release through sea salt aerosols production during blowing snow events. Outside the polar region, evidences are provided for a global tropospheric BrO background with columns of 1-3 x 1013 molec/cm2.

  9. SO2 columns over China: Temporal and spatial variations using OMI and GOME-2 observations

    International Nuclear Information System (INIS)

    Huanhuan, Yan; Liangfu, Chen; Lin, Su; Jinhua, Tao; Chao, Yu

    2014-01-01

    Enhancements of SO 2 column amounts due to anthropogenic emission sources over China were shown in this paper by using OMI and GOME-2 observations. The temporal and spatial variations of SO 2 columns over China were analyzed for the time period 2005–2010. Beijing and Chongqing showed a high concentration in the SO 2 columns, attributable to the use of coal for power generation in China and the characteristic of terrain and meteorology. The reduction of SO 2 columns over Beijing and surrounding provinces in 2008 was observed by OMI, which confirms the effectiveness of strict controls on pollutant emissions and motor vehicle traffic before and during 2008 Olympic and Paralympic Games. The SO 2 columns over China from GOME-2 (0.2–0.5 DU) were lower than those from OMI (0.6–1 DU), but both showed a decrease in SO 2 columns over northern China since 2008 (except an increase in OMI SO 2 in 2010)

  10. Variability in tropical tropospheric ozone: analysis with GOME observations and a global model

    NARCIS (Netherlands)

    Valks, P.J.M.; Koelemeijer, R.B.A.; Weele, van M.; Velthoven, van P.F.J.; Fortuin, J.P.F.; Kelder, H.M.

    2003-01-01

    Tropical tropospheric ozone columns (TTOCs) have been determined with a convective-cloud-differential (CCD) method, using ozone column and cloud measurements from the Global Ozone Monitoring Experiment (GOME) instrument. GOME cloud top pressures, derived with the Fast Retrieval Scheme for Clouds

  11. Observational Evidence for Enhanced Greenhouse Effect Reinforcing Wintertime Arctic Amplification and Sea Ice Melting Onset

    Science.gov (United States)

    Cao, Y.; Liang, S.

    2017-12-01

    Despite an apparent hiatus in global warming, the Arctic climate continues to experience unprecedented changes. Summer sea ice is retreating at an accelerated rate, and surface temperatures in this region are rising at a rate double that of the global average, a phenomenon known as Arctic amplification. Although a lot of efforts have been made, the causes this unprecedented phenomenon remain unclear and are subjects of considerable debate. In this study, we report strong observational evidence, for the first time from long-term (1984-2014) spatially complete satellite records, that increased cloudiness and atmospheric water vapor in winter and spring have caused an extraordinary downward longwave radiative flux to the ice surface, which may then amplify the Arctic wintertime ice-surface warming. In addition, we also provide observed evidence that it is quite likely the enhancement of the wintertime greenhouse effect caused by water vapor and cloudiness has advanced the time of onset of ice melting in mid-May through inhibiting sea-ice refreezing in the winter and accelerating the pre-melting process in the spring, and in turn triggered the positive sea-ice albedo feedback process and accelerated the sea ice melting in the summer.

  12. GOME-2 observations of oxygenated VOCs: what can we learn from the ratio glyoxal to formaldehyde on a global scale?

    Directory of Open Access Journals (Sweden)

    M. Vrekoussis

    2010-11-01

    Full Text Available Collocated data sets of glyoxal (CHO.CHO and formaldehyde (HCHO were retrieved for the first time from measurements of the Global Ozone Monitoring Experiment-2 (GOME-2 during the first two years of operation in 2007 and 2008. Both oxygenated Volatile Organic Compounds, OVOC, are key intermediate species produced during the oxidation of precursor hydrocarbons. Their short lifetime of a few hours in the lower troposphere links them to emission sources and makes them useful tracers of photochemical activity. The global composite maps of GOME-2 HCHO and CHO.CHO have strong similarities confirming their common atmospheric and/or surface sources. The highest column amounts of these OVOCs are recorded over regions with enhance biogenic emissions (e.g. tropical forests in South America, Africa and Indonesia. Enhanced OVOC values are also present over areas of anthropogenic activity and biomass burning (e.g. over China, N. America, Europe and Australia. The ratio of CHO.CHO to HCHO, RGF, has been used, for the first time on a global scale, to classify the sources according to biogenic and/or anthropogenic emissions of the precursors; RGF between 0.040 to 0.060 point to the existence of biogenic emissions with the highest values being observed at the highest Enhanced Vegetation Index, EVI. RGFs below 0.040 are indicative of anthropogenic emissions and associated with high levels of NO2. This decreasing tendency of RGF with increasing NO2 is also observed when analyzing data for individual large cities, indicating that it is a common feature. The results obtained for RGF from GOME-2 data are compared with the findings based on regional SCIAMACHY observations showing good agreement. This is explained by the excellent correlation of the global retrieved column amounts of CHO.CHO and HCHO from the GOME-2 and SCIAMACHY instruments for the period 2007

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

    Science.gov (United States)

    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

  14. Hydroxyl radical observations during the wintertime in Beijing and comparison with steady state model calculations.

    Science.gov (United States)

    Slater, E.; Whalley, L.; Woodward-Massey, R.; Ye, C.; Crilley, L.; Kramer, L. J.; Vu, T.; Bloss, W.; Squires, F. A.; Dunmore, R.; Lee, J. D.; Heard, D. E.

    2017-12-01

    In Beijing poor urban air quality has a demonstrable effect on human health. During the wintertime, anthropogenic emissions from fossil fuel combustion can lead to high aerosol loadings and haze events. A high oxidation capacity on hazy days has previously been inferred from the significant contribution secondary organic aerosol (SOA) make to total PM2.5 (Huang et al., 2014). The hydroxyl radical (OH) mediates virtually all of the oxidative chemistry in the atmosphere, being responsible for the transformation of primary emissions into secondary pollutants such as NO2, O3 and SOA. Understanding the sources and sinks of OH in the atmosphere is essential in improving predictions of the lifetimes and chemical processing of pollutants and their transport within urban areas. We will present OH and HO2 measurements made in central Beijing during the recent `An Integrated Study of AIR Pollution PROcesses in Beijing (AIRPRO)' project which took place in November and December 2016. OH measurements were made using the FAGE (Fluorescence Assay by Gas Expansion) technique, with the use of an inlet pre injector (IPI) which provides an alternative method to determine the background by injecting a scavenger (propane) to remove ambient OH. The OH measurements were made over a range of meteorological conditions including a number of haze days, with the average maximum OH concentration measured for the campaign being 2.5 x 106 cm-3 and for haze days the OH concentration reached levels of 3.5 x 106 cm-3 which is comparable to OH levels in non-haze days. We will compare the OH observations to steady state calculations constrained to the total OH reactivity and key OH precursors that were measured alongside OH. Through this comparison we will identify the major OH sources which sustain the wintertime oxidation capacity. The current understanding is that gas-phase oxidation via the OH radical becomes less important in haze events due to lower light and ozone levels, making photochemistry

  15. Observational Insights into N2O5 Heterogeneous Chemistry: Influencing Factors and Contribution to Wintertime Air Pollution

    Science.gov (United States)

    McDuffie, E. E.; Fibiger, D. L.; Womack, C.; Dube, W. P.; Lopez-Hilfiker, F.; Goldberger, L.; Thornton, J. A.; Shah, V.; Jaegle, L.; Guo, H.; Weber, R. J.; Schroder, J. C.; Campuzano Jost, P.; Jimenez, J. L.; Franchin, A.; Middlebrook, A. M.; Baasandorj, M.; Brown, S. S.

    2017-12-01

    Chemical mechanisms that underlie wintertime air pollution, including tropospheric ozone and aerosol nitrate, are poorly characterized. Due to colder temperatures and fewer hours of solar radiation, nocturnal heterogeneous uptake of N2O5 plays a relatively larger role during wintertime in controlling the oxidation of NOx (=NO+NO2) and its influence on ozone and soluble nitrate. After uptake to aerosol, N2O5 can act as both a nocturnal NOx reservoir and sink depending on the partitioning between its nitric acid and photo labile, ClNO2 reaction products. In addition, N2O5 itself can act as a NOx reservoir if the aerosol uptake coefficient is small. As a result, the nocturnal fate of N2O5 dictates the amount of NOx in an air parcel and the subsequent formation of aerosol nitrate and following-day ozone. Models of winter air pollution therefore require accurate parameterization of the N2O5 uptake coefficient, as well as factors that control its magnitude and N2O5 product partitioning. There are currently only a small number of ambient N2O5 and ClNO2 observations during the winter season concurrent with measurements of relevant variables such as aerosol size distributions and composition. The Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER) campaign conducted 10 nighttime research flights with the NCAR C-130 over the eastern U.S. during February and March, 2015. The more recent Utah Wintertime Fine Particulate Study (UWFPS) conducted over 20 research flights with the NOAA twin otter aircraft during January-February 2017 in three mountain basins near and including Salt Lake City, Utah. The two campaigns were similarly instrumented and have provided the first aircraft observations of N2O5, ClNO2, and aerosol composition in the wintertime boundary layer in these urban-influenced regions. Analysis of heterogeneous chemistry under a wide range of real environmental conditions provides insight into the factors controlling the N2O5 uptake coefficient

  16. Observing atmospheric formaldehyde (HCHO from space: validation and intercomparison of six retrievals from four satellites (OMI, GOME2A, GOME2B, OMPS with SEAC4RS aircraft observations over the southeast US

    Directory of Open Access Journals (Sweden)

    L. Zhu

    2016-11-01

    Full Text Available Formaldehyde (HCHO column data from satellites are widely used as a proxy for emissions of volatile organic compounds (VOCs, but validation of the data has been extremely limited. Here we use highly accurate HCHO aircraft observations from the NASA SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys campaign over the southeast US in August–September 2013 to validate and intercompare six retrievals of HCHO columns from four different satellite instruments (OMI, GOME2A, GOME2B and OMPS; for clarification of these and other abbreviations used in the paper, please refer to Appendix A and three different research groups. The GEOS-Chem chemical transport model is used as a common intercomparison platform. All retrievals feature a HCHO maximum over Arkansas and Louisiana, consistent with the aircraft observations and reflecting high emissions of biogenic isoprene. The retrievals are also interconsistent in their spatial variability over the southeast US (r  =  0.4–0.8 on a 0.5°  ×  0.5°  grid and in their day-to-day variability (r  =  0.5–0.8. However, all retrievals are biased low in the mean by 20–51 %, which would lead to corresponding bias in estimates of isoprene emissions from the satellite data. The smallest bias is for OMI-BIRA, which has high corrected slant columns relative to the other retrievals and low scattering weights in its air mass factor (AMF calculation. OMI-BIRA has systematic error in its assumed vertical HCHO shape profiles for the AMF calculation, and correcting this would eliminate its bias relative to the SEAC4RS data. Our results support the use of satellite HCHO data as a quantitative proxy for isoprene emission after correction of the low mean bias. There is no evident pattern in the bias, suggesting that a uniform correction factor may be applied to the data until better understanding is achieved.

  17. Aircraft-based Observations and Modeling of Wintertime Submicron Aerosol Composition over the Northeastern U.S.

    Science.gov (United States)

    Shah, V.; Jaegle, L.; Schroder, J. C.; Campuzano-Jost, P.; Jimenez, J. L.; Guo, H.; Sullivan, A.; Weber, R. J.; Green, J. R.; Fiddler, M.; Bililign, S.; Lopez-Hilfiker, F.; Lee, B. H.; Thornton, J. A.

    2017-12-01

    Submicron aerosol particles (PM1) remain a major air pollution concern in the urban areas of northeastern U.S. While SO2 and NOx emission controls have been effective at reducing summertime PM1 concentrations, this has not been the case for wintertime sulfate and nitrate concentrations, suggesting a nonlinear response during winter. During winter, organic aerosol (OA) is also an important contributor to PM1 mass despite low biogenic emissions, suggesting the presence of important urban sources. We use aircraft-based observations collected during the Wintertime INvestigation of Transport, Emissions and Reactivity (WINTER) campaign (Feb-March 2015), together with the GEOS-Chem chemical transport model, to investigate the sources and chemical processes governing wintertime PM1 over the northeastern U.S. The mean observed concentration of PM1 between the surface and 1 km was 4 μg m-3, about 30% of which was composed of sulfate, 20% nitrate, 10% ammonium, and 40% OA. The model reproduces the observed sulfate, nitrate and ammonium concentrations after updates to HNO3 production and loss, SO2 oxidation, and NH3 emissions. We find that 65% of the sulfate formation occurs in the aqueous phase, and 55% of nitrate formation through N2O5 hydrolysis, highlighting the importance of multiphase and heterogeneous processes during winter. Aqueous-phase sulfate production and the gas-particle partitioning of nitrate and ammonium are affected by atmospheric acidity, which in turn depends on the concentration of these species. We examine these couplings with GEOS-Chem, and assess the response of wintertime PM1 concentrations to further emission reductions based on the U.S. EPA projections for the year 2023. For OA, we find that the standard GEOS-Chem simulation underestimates the observed concentrations, but a simple parameterization developed from previous summer field campaigns is able to reproduce the observations and the contribution of primary and secondary OA. We find that

  18. The ESA GOME-Evolution "Climate" water vapor product: a homogenized time series of H2O columns from GOME, SCIAMACHY, and GOME-2

    Science.gov (United States)

    Beirle, Steffen; Lampel, Johannes; Wang, Yang; Mies, Kornelia; Dörner, Steffen; Grossi, Margherita; Loyola, Diego; Dehn, Angelika; Danielczok, Anja; Schröder, Marc; Wagner, Thomas

    2018-03-01

    We present time series of the global distribution of water vapor columns over more than 2 decades based on measurements from the satellite instruments GOME, SCIAMACHY, and GOME-2 in the red spectral range. A particular focus is the consistency amongst the different sensors to avoid jumps from one instrument to another. This is reached by applying robust and simple retrieval settings consistently. Potentially systematic effects due to differences in ground pixel size are avoided by merging SCIAMACHY and GOME-2 observations to GOME spatial resolution, which also allows for a consistent treatment of cloud effects. In addition, the GOME-2 swath is reduced to that of GOME and SCIAMACHY to have consistent viewing geometries.Remaining systematic differences between the different sensors are investigated during overlap periods and are corrected for in the homogenized time series. The resulting Climate product v2.2 (https://doi.org/10.1594/WDCC/GOME-EVL_water_vapor_clim_v2.2" target="_blank">https://doi.org/10.1594/WDCC/GOME-EVL_water_vapor_clim_v2.2) allows the study of the temporal evolution of water vapor over the last 20 years on a global scale.

  19. Ice formation and development in aged, wintertime cumulus over the UK : observations and modelling

    Science.gov (United States)

    Crawford, I.; Bower, K. N.; Choularton, T. W.; Dearden, C.; Crosier, J.; Westbrook, C.; Capes, G.; Coe, H.; Connolly, P.; Dorsey, J. R.; Gallagher, M. W.; Williams, P.; Trembath, J.; Cui, Z.; Blyth, A.

    2011-11-01

    In-situ high resolution aircraft measurements of cloud microphysical properties were made in coordination with ground based remote sensing observations of Radar and Lidar as part of the Aerosol Properties, PRocesses And InfluenceS on the Earth's climate (APPRAISE) project. A narrow but extensive line (~100 km long) of shallow convective clouds over the southern UK was studied. Cloud top temperatures were observed to be higher than ~-8 °C, but the clouds were seen to consist of supercooled droplets and varying concentrations of ice particles. No ice particles were observed to be falling into the cloud tops from above. Current parameterisations of ice nuclei (IN) numbers predict too few particles will be active as ice nuclei to account for ice particle concentrations at the observed near cloud top temperatures (~-7 °C). The role of biological particles, consistent with concentrations observed near the surface, acting as potential efficient high temperature IN is considered important in this case. It was found that very high concentrations of ice particles (up to 100 L-1) could be produced by powerful secondary ice particle production emphasising the importance of understanding primary ice formation in slightly supercooled clouds. Aircraft penetrations at -3.5 °C, showed peak ice crystal concentrations of up to 100 L-1 which together with the characteristic ice crystal habits observed (generally rimed ice particles and columns) suggested secondary ice production had occurred. To investigate whether the Hallett-Mossop (HM) secondary ice production process could account for these observations, ice splinter production rates were calculated. These calculated rates and observations could only be reconciled provided the constraint that only droplets >24 μm in diameter could lead to splinter production, was relaxed slightly by 2 μm. Model simulations of the case study were also performed with the WRF (Weather, Research and Forecasting) model and ACPIM (Aerosol Cloud and

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

    Science.gov (United States)

    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

  1. Comparison of GOME total ozone data with ground data from the Spanish Brewer spectroradiometers

    Directory of Open Access Journals (Sweden)

    M. Antón

    2008-03-01

    Full Text Available This paper compares total ozone measurements from five Brewer spectroradiometers located at the Iberian Peninsula with satellite observations given by the GOME (Global Ozone Monitoring Experiment sensor. The analyzed period covers simultaneous ozone values from July 1995 until December 2004. The regression analysis shows an excellent agreement between Brewer-GOME values in the five locations; the coefficient of correlation is always higher than 0.92 and the root mean square error is about 3%. Moreover, the comparison shows that the satellite retrieval accuracy is within the uncertainty of current ground-based instruments. In addition, the effects of several variables, such as cloudiness, solar zenith angle (SZA, effective temperature and total ozone values in Brewer-GOME differences are analyzed. The results indicate that clouds induce a minor dependence of GOME values on the SZA. For example, during heavy cloudy conditions in Madrid station, GOME observations overestimate ground-based Brewer data for low AMF (low SZA values by 2% while for high AMF (high SZA values the satellite underestimates ground-based ozone values by 1%. Moreover, the dependence of Brewer-GOME differences with respect to SZA for cloud-free conditions may be due to the variability of effective temperature. This fact could indicate that the effective temperature estimated by GOME does not fully reflect the actual atmospheric temperature variability. Finally, GOME ozone observations slightly underestimate the highest values measured by the Brewer spectrophotometers and overestimates the lowest ground-based measurements.

  2. Geophysical validation and long-term consistency between GOME-2/MetOp-A total ozone column and measurements from the sensors GOME/ERS-2, SCIAMACHY/ENVISAT and OMI/Aura

    Directory of Open Access Journals (Sweden)

    M. E. Koukouli

    2012-09-01

    Full Text Available The main aim of the paper is to assess the consistency of five years of Global Ozone Monitoring Experiment-2/Metop-A [GOME-2] total ozone columns and the long-term total ozone satellite monitoring database already in existence through an extensive inter-comparison and validation exercise using as reference Brewer and Dobson ground-based measurements. The behaviour of the GOME-2 measurements is being weighed against that of GOME (1995–2011, Ozone Monitoring Experiment [OMI] (since 2004 and the Scanning Imaging Absorption spectroMeter for Atmospheric CartograpHY [SCIAMACHY] (since 2002 total ozone column products. Over the background truth of the ground-based measurements, the total ozone columns are inter-evaluated using a suite of established validation techniques; the GOME-2 time series follow the same patterns as those observed by the other satellite sensors. In particular, on average, GOME-2 data underestimate GOME data by about 0.80%, and underestimate SCIAMACHY data by 0.37% with no seasonal dependence of the differences between GOME-2, GOME and SCIAMACHY. The latter is expected since the three datasets are based on similar DOAS algorithms. This underestimation of GOME-2 is within the uncertainty of the reference data used in the comparisons. Compared to the OMI sensor, on average GOME-2 data underestimate OMI_DOAS (collection 3 data by 1.28%, without any significant seasonal dependence of the differences between them. The lack of seasonality might be expected since both the GOME data processor [GDP] 4.4 and OMI_DOAS are DOAS-type algorithms and both consider the variability of the stratospheric temperatures in their retrievals. Compared to the OMI_TOMS (collection 3 data, no bias was found. We hence conclude that the GOME-2 total ozone columns are well suitable to continue the long-term global total ozone record with the accuracy needed for climate monitoring studies.

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

    Science.gov (United States)

    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.

  4. Highly resolved global distribution of tropospheric NO2 using GOME narrow swath mode data

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    S. Beirle

    2004-01-01

    Full Text Available The Global Ozone Monitoring Experiment (GOME allows the retrieval of tropospheric vertical column densities (VCDs of NO2 on a global scale. Regions with enhanced industrial activity can clearly be detected, but the standard spatial resolution of the GOME ground pixels (320x40km2 is insufficient to resolve regional trace gas distributions or individual cities. Every 10 days within the nominal GOME operation, measurements are executed in the so called narrow swath mode with a much better spatial resolution (80x40km2. We use this data (1997-2001 to construct a detailed picture of the mean global tropospheric NO2 distribution. Since - due to the narrow swath - the global coverage of the high resolution observations is rather poor, it has proved to be essential to deseasonalize the single narrow swath mode observations to retrieve adequate mean maps. This is done by using the GOME backscan information. The retrieved high resolution map illustrates the shortcomings of the standard size GOME pixels and reveals an unprecedented wealth of details in the global distribution of tropospheric NO2. Localised spots of enhanced NO2 VCD can be directly associated to cities, heavy industry centers and even large power plants. Thus our result helps to check emission inventories. The small spatial extent of NO2 'hot spots' allows us to estimate an upper limit of the mean lifetime of boundary layer NOx of 17h on a global scale. The long time series of GOME data allows a quantitative comparison of the narrow swath mode data to the nominal resolution. Thus we can analyse the dependency of NO2 VCDs on pixel size. This is important for comparing GOME data to results of new satellite instruments like SCIAMACHY (launched March 2002 on ENVISAT, OMI (launched July 2004 on AURA or GOME II (to be launched 2005 with an improved spatial resolution.

  5. Temperature dependent O3 absorption cross sections for GOME, SCIAMACHY and GOME-2: II. New laboratory measurements

    Science.gov (United States)

    Serdyuchenko, Anna; Gorshelev, Victor; Chehade, Wissam; Weber, Mark; Burrows, John P.

    We report on the work devoted to the up-to-date measurements of the ozone absorption cross-sections. The main goal of the project is to produce a consolidated and consistent set of high resolution cross-sections for satellite spectrometers series that allows a derivation of the harmonized long term data set. The generation of long-term datasets of atmospheric trace gases is a major need and prerequisite for climate and air quality related studies. At present there are three atmospheric chemistry instruments (GOME1, SCIAMACHY and GOME2) in operation and two more spectrometers (GOME2) to be launched five years apart in the next decade resulting in a time series covering two or more decades of ozone observations. Information from different sensors has to be com-bined for a consistent long-term data record, since the lifetime of individual satellite missions is limited. The harmonization of cross-sections is carried out by combination of new experimental work with re-evaluation of the existing cross-sections data. New laboratory measurements of ozone cross-section are underway that will improve a) absolute scaling of cross-sections, b) temper-ature dependence of cross-sections (using very low temperatures starting at 190 K and higher sampling of temperatures up to room temperature) and c) improved wavelength calibration. We take advantage of a Fourier transform spectrometer (visible, near IR) and Echelle spectropho-tometer (UV, visible) to extend the dynamic range of the system (covering several orders of magnitude in cross-sections from UV up to the near IR). We plan to cover the spectral range 220 -1000 nm at a spectral resolution of 0.02 nm in UV/VIS with absolute intensity accuracy of at least 2%, and wavelength accuracy better than 0.001 nm in the temperature range 193-293 K in 10 K steps. A lot of attention is paid to the accuracy of determining the temperature of the ozone flow and new methods for absolute calibration of relative spectra. This work is in

  6. California Wintertime Precipitation in Regional and Global Climate Models

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, P M

    2009-04-27

    In this paper, wintertime precipitation from a variety of observational datasets, regional climate models (RCMs), and general circulation models (GCMs) is averaged over the state of California (CA) and compared. Several averaging methodologies are considered and all are found to give similar values when model grid spacing is less than 3{sup o}. This suggests that CA is a reasonable size for regional intercomparisons using modern GCMs. Results show that reanalysis-forced RCMs tend to significantly overpredict CA precipitation. This appears to be due mainly to overprediction of extreme events; RCM precipitation frequency is generally underpredicted. Overprediction is also reflected in wintertime precipitation variability, which tends to be too high for RCMs on both daily and interannual scales. Wintertime precipitation in most (but not all) GCMs is underestimated. This is in contrast to previous studies based on global blended gauge/satellite observations which are shown here to underestimate precipitation relative to higher-resolution gauge-only datasets. Several GCMs provide reasonable daily precipitation distributions, a trait which doesn't seem tied to model resolution. GCM daily and interannual variability is generally underpredicted.

  7. A fast H2O total column density product from GOME – Validation with in-situ aircraft measurements

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2003-01-01

    Full Text Available Atmospheric water vapour is the most important greenhouse gas which is responsible for about 2/3 of the natural greenhouse effect, therefore changes in atmospheric water vapour in a changing climate (the water vapour feedback is subject to intense debate. H2O is also involved in many important reaction cycles of atmospheric chemistry, e.g. in the production of the OH radical. Thus, long time series of global H2O data are highly required. Since 1995 the Global Ozone Monitoring Experiment (GOME continuously observes atmospheric trace gases. In particular it has been demonstrated that GOME as a nadir looking UV/vis-instrument is sensitive to many tropospheric trace gases. Here we present a new, fast H2O algorithm for the retrieval of vertical column densities from GOME measurements. In contrast to existing H2O retrieval algorithms it does not depend on additional information like e.g. the climatic zone, aerosol content or ground albedo. It includes an internal cloud-, aerosol-, and albedo correction which is based on simultaneous observations of the oxygen dimer O4. From sensitivity studies using atmospheric radiative modelling we conclude that our H2O retrieval overestimates the true atmospheric H2O vertical column density (VCD by about 4% for clear sky observations in the tropics and sub-tropics, while it can lead to an underestimation of up to -18% in polar regions. For measurements over (partly cloud covered ground pixels, however, the true atmospheric H2O VCD might be in general systematically underestimated. We compared the GOME H2O VCDs to ECMWF model data over one whole GOME orbit (extending from the Arctic to the Antarctic including also totally cloud covered measurements. The correlation of the GOME observations and the model data yield the following results: a slope of 0.96 (r2 = 0.86 and an average bias of 5%. Even for measurements with large cloud fractions between 50% and 100% an average underestimation of only -18% was found. This

  8. Seven years of global retrieval of cloud properties using space-borne data of GOME

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    L. Lelli

    2012-07-01

    Full Text Available We present a global and regional multi-annual (June 1996–May 2003 analysis of cloud properties (spherical cloud albedo – CA, cloud optical thickness – COT and cloud top height – CTH of optically thick (COT > 5 clouds, derived using measurements from the GOME instrument on board the ESA ERS-2 space platform. We focus on cloud top height, which is obtained from top-of-atmosphere backscattered solar light measurements in the O2 A-band using the Semi-Analytical CloUd Retrieval Algorithm SACURA. The physical framework relies on the asymptotic equations of radiative transfer. The dataset has been validated against independent ground- and satellite-based retrievals and is aimed to support trace-gases retrievals as well as to create a robust long-term climatology together with SCIAMACHY and GOME-2 ensuing retrievals. We observed the El Niño-Southern Oscillation anomaly in the 1997–1998 record through CTH values over the Pacific Ocean. The global average CTH as derived from GOME is 5.6 ± 3.2 km, for a corresponding average COT of 19.1 ± 13.9.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  11. Contiguous polarisation spectra of the Earth from 300-850 nm measured by GOME-2 onboard MetOp-A

    Science.gov (United States)

    Tilstra, L. G.; Lang, R.; Munro, R.; Aben, I.; Stammes, P.

    2013-12-01

    In this paper we present the first contiguous high-resolution spectra of the Earth's polarisation observed by a satellite instrument. The measurements of the Stokes fraction Q/I are performed by the spectrometer GOME-2 onboard the MetOp-A satellite. Polarisation measurements by GOME-2 are performed by onboard polarisation measurement devices (PMDs) and the high-resolution measurements discussed in this paper are taken in the special "PMD RAW" mode of operation. The spectral resolution of these PMD RAW polarisation measurements varies from 3 nm in the ultraviolet (UV) to 35 nm in the near-infrared wavelength range. We first compare measurements of the polarisation from cloud-free scenes with radiative transfer calculations for a number of cases. We find good agreement but also a spectral discrepancy at 800 nm, which we attribute to remaining imperfections in the calibration key data. Secondly, we study the polarisation of scenes with special scattering geometries that normally lead to near-zero Q/I. The GOME-2 polarisation spectra indeed show this behaviour and confirm the existence of the small discrepancy found earlier. Thirdly, we study the Earth polarisation for a variety of scenes. This provides a blueprint of Q/I over land and sea surfaces for various degrees of cloud cover. Fourthly, we compare the spectral dependence of measurements of Q/I in the UV with the generalised distribution function that was proposed in the past (Schutgens and Stammes, 2002) to describe the shape of the UV polarisation spectrum. The GOME-2 data confirm that these functions match the spectral behaviour captured by the GOME-2 PMD RAW mode.

  12. Contiguous polarisation spectra of the Earth from 300 to 850 nm measured by GOME-2 onboard MetOp-A

    Science.gov (United States)

    Tilstra, L. G.; Lang, R.; Munro, R.; Aben, I.; Stammes, P.

    2014-07-01

    In this paper we present the first contiguous high-resolution spectra of the Earth's polarisation observed by a satellite instrument. The measurements of the Stokes fraction Q/I are performed by the spectrometer GOME-2 onboard the MetOp-A satellite. Polarisation measurements by GOME-2 are performed by onboard polarisation measurement devices (PMDs) and the high-resolution measurements discussed in this paper are taken in the special "PMD RAW" mode of operation. The spectral resolution of these PMD RAW polarisation measurements varies from 3 nm in the ultraviolet (UV) to 35 nm in the near-infrared wavelength range. We first compare measurements of the polarisation from cloud-free scenes with radiative transfer calculations for a number of cases. We find good agreement but also a spectral discrepancy at 800 nm, which we attribute to remaining imperfections in the calibration key data. Secondly, we study the polarisation of scenes with special scattering geometries that normally lead to near-zero Q/I. The GOME-2 polarisation spectra indeed show this behaviour and confirm the existence of the small discrepancy found earlier. Thirdly, we study the Earth polarisation for a variety of scenes. This provides a blueprint of Q/I over land and sea surfaces for various degrees of cloud cover. Fourthly, we compare the spectral dependence of measurements of Q/I in the UV with the generalised distribution function proposed by Schutgens and Stammes (2002) to describe the shape of the UV polarisation spectrum. The GOME-2 data confirm that these functions match the spectral behaviour captured by the GOME-2 PMD RAW mode.

  13. Wintertime Boundary Layer Structure in the Grand Canyon.

    Science.gov (United States)

    Whiteman, C. David; Zhong, Shiyuan; Bian, Xindi

    1999-08-01

    Wintertime temperature profiles in the Grand Canyon exhibit a neutral to isothermal stratification during both daytime and nighttime, with only rare instances of actual temperature inversions. The canyon warms during daytime and cools during nighttime more or less uniformly through the canyon's entire depth. This weak stability and temperature structure evolution differ from other Rocky Mountain valleys, which develop strong nocturnal inversions and exhibit convective and stable boundary layers that grow upward from the valley floor. Mechanisms that may be responsible for the different behavior of the Grand Canyon are discussed, including the possibility that the canyon atmosphere is frequently mixed to near-neutral stratification when cold air drains into the top of the canyon from the nearby snow-covered Kaibab Plateau. Another feature of canyon temperature profiles is the sharp inversions that often form near the canyon rims. These are generally produced when warm air is advected over the canyon in advance of passing synoptic-scale ridges.Wintertime winds in the main canyon are not classical diurnal along-valley wind systems. Rather, they are driven along the canyon axis by the horizontal synoptic-scale pressure gradient that is superimposed along the canyon's axis by passing synoptic-scale weather disturbances. They may thus bring winds into the canyon from either end at any time of day.The implications of the observed canyon boundary layer structure for air pollution dispersion are discussed.

  14. Free-tropospheric BrO investigations based on GOME

    Science.gov (United States)

    Post, P.; van Roozendael, M.; Backman, L.; Damski, J.; Thölix, L.; Fayt, C.; Taalas, P.

    2003-04-01

    Bromine compounds contribute significantly to the stratospheric ozone depletion. However measurements of most bromine compounds are sparse or non-existent, and experimental studies essentially rely on BrO observations. The differences between balloon and ground based measurements of stratospheric BrO columns and satellite total column measurements are too large to be explained by measurement uncertainties. Therefore, it has been assumed that there is a concentration of BrO in the free troposphere of about 1-3 ppt. In a previous work, we have calculated the tropospheric BrO abundance as the difference between total BrO and stratospheric BrO columns. The total vertical column densities of BrO are extracted from GOME measurements using IASB-BIRA algorithms. The stratospheric amount has been calculated using chemical transport models (CTM). Results from SLIMCAT and FinROSE simulations are used for this purpose. SLIMCAT is a widely used 3D CTM that has been tested against balloon measurements. FinROSE is a 3D CTM developed at FMI. We have tried several different tropospheric BrO profiles. Our results show that a profile with high BrO concentrations in the boundary layer usually gives unrealistically high tropospheric column values over areas of low albedo (like oceans). This suggests that the tropospheric BrO would be predominantly distributed in the free troposphere. In this work, attempts are made to identify the signature of a free tropospheric BrO content when comparing cloudy and non-cloudy scenes. The possible impact of orography on measured BrO columns is also investigated.

  15. Chlorophyll induced fluorescence retrieved from GOME2 for improving gross primary productivity estimates of vegetation

    Science.gov (United States)

    van Leth, Thomas C.; Verstraeten, Willem W.; Sanders, Abram F. J.

    2014-05-01

    Mapping terrestrial chlorophyll fluorescence is a crucial activity to obtain information on the functional status of vegetation and to improve estimates of light-use efficiency (LUE) and global primary productivity (GPP). GPP quantifies carbon fixation by plant ecosystems and is therefore an important parameter for budgeting terrestrial carbon cycles. Satellite remote sensing offers an excellent tool for investigating GPP in a spatially explicit fashion across different scales of observation. The GPP estimates, however, still remain largely uncertain due to biotic and abiotic factors that influence plant production. Sun-induced fluorescence has the ability to enhance our knowledge on how environmentally induced changes affect the LUE. This can be linked to optical derived remote sensing parameters thereby reducing the uncertainty in GPP estimates. Satellite measurements provide a relatively new perspective on global sun-induced fluorescence, enabling us to quantify spatial distributions and changes over time. Techniques have recently been developed to retrieve fluorescence emissions from hyperspectral satellite measurements. We use data from the Global Ozone Monitoring Instrument 2 (GOME2) to infer terrestrial fluorescence. The spectral signatures of three basic components atmospheric: absorption, surface reflectance, and fluorescence radiance are separated using reference measurements of non-fluorescent surfaces (desserts, deep oceans and ice) to solve for the atmospheric absorption. An empirically based principal component analysis (PCA) approach is applied similar to that of Joiner et al. (2013, ACP). Here we show our first global maps of the GOME2 retrievals of chlorophyll fluorescence. First results indicate fluorescence distributions that are similar with that obtained by GOSAT and GOME2 as reported by Joiner et al. (2013, ACP), although we find slightly higher values. In view of optimizing the fluorescence retrieval, we will show the effect of the references

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

    Science.gov (United States)

    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.; hide

    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

  17. An Analysis of Wintertime Winds in Washington, D.C.

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Larry K.; Allwine, K Jerry

    2006-06-20

    This report consists of a description of the wintertime climatology of wind speed and wind direction around the National Mall in Washington, D.C. Meteorological data for this study were collected at Ronald Reagan Washington National Airport (Reagan National), Dulles International Airport (Dulles), and a set of surface meteorological stations that are located on a number of building tops around the National Mall. A five-year wintertime climatology of wind speed and wind direction measured at Reagan National and Dulles are presented. A more detailed analysis was completed for the period December 2003 through February 2004 using data gathered from stations located around the National Mall, Reagan National, and Dulles. Key findings of our study include the following: * There are systematic differences between the wind speed and wind direction observed at Reagan National and the wind speed and wind direction measured by building top weather stations located in the National Mall. Although Dulles is located much further from the National Mall than Reagan National, there is better agreement between the wind speed and wind direction measured at Dulles and the weather stations in the National Mall. * When the winds are light (less than 3 ms-1 or 7 mph), there are significant differences in the wind directions reported at the various weather stations within the Mall. * Although the mean characteristics of the wind are similar at the various locations, significant, short-term differences are found when the time series are compared. These differences have important implications for the dispersion of airborne contaminants. In support of wintertime special events in the area of the National Mall, we recommend placing four additional meteorological instruments: three additional surface stations, one on the east bank of the Potomac River, one south of the Reflecting Pool (to better define the flow within the Mall), and a surface station near the Herbert C. Hoover Building; and wind

  18. Quantitative spectroscopy for the analysis of GOME data

    Science.gov (United States)

    Chance, K.

    1997-01-01

    Accurate analysis of the global ozone monitoring experiment (GOME) data to obtain atmospheric constituents requires reliable, traceable spectroscopic parameters for atmospheric absorption and scattering. Results are summarized for research that includes: the re-determination of Rayleigh scattering cross sections and phase functions for the 200 nm to 1000 nm range; the analysis of solar spectra to obtain a high-resolution reference spectrum with excellent absolute vacuum wavelength calibration; Ring effect cross sections and phase functions determined directly from accurate molecular parameters of N2 and O2; O2 A band line intensities and pressure broadening coefficients; and the analysis of absolute accuracies for ultraviolet and visible absorption cross sections of O3 and other trace species measurable by GOME.

  19. Validation of GOME (ERS-2) NO2 vertical column data with ground-based measurements at Issyk-Kul (Kyrgyzstan)

    Science.gov (United States)

    Ionov, D.; Sinyakov, V.; Semenov, V.

    Starting from 1995 the global monitoring of atmospheric nitrogen dioxide is carried out by the measurements of nadir-viewing GOME spectrometer aboard ERS-2 satellite. Continuous validation of that data by means of comparisons with well-controlled ground-based measurements is important to ensure the quality of GOME data products and improve related retrieval algorithms. At the station of Issyk-Kul (Kyrgyzstan) the ground-based spectroscopic observations of NO2 vertical column have been started since 1983. The station is located on the northern shore of Issyk-Kul lake, 1650 meters above the sea level (42.6 N, 77.0 E). The site is equipped with grating spectrometer for the twilight measurements of zenith-scattered solar radiation in the visible range, and applies the DOAS technique to retrieve NO2 vertical column. It is included in the list of NDSC stations as a complementary one. The present study is focused on validation of GOME NO2 vertical column data, based on 8-year comparison with correlative ground-based measurements at Issyk-Kul station in 1996-2003. Within the investigation, an agreement of both individual and monthly averaged GOME measurements with corresponding twilight ground-based observations is examined. Such agreement is analyzed with respect to different conditions (season, sun elevation), temporal/spatial criteria choice (actual overpass location, correction for diurnal variation) and data processing (GDP version 2.7, 3.0). In addition, NO2 vertical columns were integrated from simultaneous stratospheric profile measurements by NASA HALOE and SAGE-II/III satellite instruments and introduced to explain the differences with ground-based observations. In particular cases, NO2 vertical profiles retrieved from the twilight ground-based measurements at Issuk-Kul were also included into comparison. Overall, summertime GOME NO2 vertical columns were found to be systematicaly lower than ground-based data. This work was supported by International Association

  20. Aerosol optical thickness retrieval over land and water using Global Ozone Monitoring Experiment (GOME) data

    NARCIS (Netherlands)

    Kusmierczyk-Michulec, J.; Leeuw, G. de

    2005-01-01

    An algorithm for the retrieval of the aerosol optical thickness over land and over water from Global Ozone Monitoring Experiment (GOME) data is presented. The cloud fraction in the GOME pixels is determined using the Fast Retrieval Scheme for Clouds From the Oxygen A Band (FRESCO) algorithm. Surface

  1. Evaluation of Global Ozone Monitoring Experiment (GOME) ozone profiles from nine different algorithms

    NARCIS (Netherlands)

    Meijer, Y.J.; Swart, D.P.J.; Baier, F.; Bhartia, P.K.; Bodeker, G.E.; Casadio, S.; Chance, K.; Frate, Del F.; Erbertseder, T.; Felder, M.D.; Flynn, L.E.; Godin-Beekmann, S.; Hansen, G.; Hasekamp, O.P.; Kaifel, A.; Kelder, H.M.; Kerridge, B.J.; Lambert, J.-C.; Landgraf, J.; Latter, B.G.; Liu, X.; McDermid, I.S.; Pachepsky, Y.; Rozanov, V.; Siddans, R.; Tellmann, S.; A, van der R.J.; Oss, van R.F.; Weber, M.; Zehner, C.

    2006-01-01

    An evaluation is made of ozone profiles retrieved from measurements of the nadir-viewing Global Ozone Monitoring Experiment (GOME) instrument. Currently, four different approaches are used to retrieve ozone profile information from GOME measurements, which differ in the use of external information

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

    Energy Technology Data Exchange (ETDEWEB)

    Anton, M.; Serrano, A. [Universidad de Extremadura, Badajoz (Spain). Dept. de Fisica; Loyola, D.; Zimmer, W. [German Aerospace Center (DLR), Wessling (DE). Remote Sensing Technology Inst. (IMF); Lopez, M.; Banon, M. [Agencia Estatal de Meteorologia (AEMet), Madrid (Spain); Vilaplana, J.M. [Instituto Nacional de Tecnica Aeroespacial (INTA), Huelva (Spain). Estacion de Sondeos Atmosferico ' ' El Arenosillo' '

    2009-07-01

    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. (orig.)

  3. Godiva, a European Project for Ozone and Trace Gas Measurements from GOME

    Science.gov (United States)

    Goede, A. P. H.; Tanzi, C. P.; Aben, I.; Burrows, J. P.; Weber, M.; Perner, D.; Monks, P. S.; Llewellyn-Jones, D.; Corlett, G. K.; Arlander, D. W.; Platt, U.; Wagner, T.; Pfeilsticker, K.; Taalas, P.; Kelder, H.; Piters, A.

    GODIVA (GOME Data Interpretation, Validation and Application) is a European Commission project aimed at the improvement of GOME (Global Ozone Monitoring Experiment) data products. Existing data products include global ozone, NO2 columns and (ir)radiances. Advanced data products include O3 profiles, BrO, HCHO and OCIO columns. These data are validated by ground-based and balloon borne instruments. Calibration issues are investigated by in-flight monitoring using several complementary calibration sources, as well as an on-ground replica of the GOME instrument. The results will lead to specification of operational processing of the EUMETSAT ozone Satellite Application Facility as well as implementation of the improved and new GOME data products in the NILU database for use in the European THESEO (Third European Stratospheric Experiment on Ozone) campaign of 1999

  4. GOME and Sciamachy data access using the Netherlands Sciamachy Data Center

    Science.gov (United States)

    Som de Cerff, Wim; de Vreede, Ernst; van de Vegte, John; van Hees, Ricard; van der Neut, Ian; Stammes, Piet; Pieters, Ankie; van der A, Ronald

    2010-05-01

    The Netherlands Sciamachy Data Center (NL-SCIA-DC) provides access to satellite data from the GOME and Sciamachy instruments for over 10 years now. GOME and Sciamachy both measure trace gases like Ozone, Methane, NO2 and aerosols, which are important for climate and air quality monitoring. Recently (February 2010) a new release of the NL-SCIA-DC provides an improved processing and archiving structure and an improved user interface. This Java Webstart application allows the user to browse, query and download GOME and Sciamachy data products, including KNMI and SRON GOME and Sciamachy products (cloud products, CH4, NO2, CO). Data can be searched on file and pixel level, and can be graphically displayed. The huge database containing all pixel information of GOME and Sciamachy is unique and allows specific selection, e.g., selecting cloud free pixels. Ordered data is delivered by FTP or email. The data available spans the mission times of GOME and Sciamachy, and is constantly updated as new data becomes available. The data services future upgrades include offering additional functionality to end-users of Sciamachy data. One of the functionalities provided will be the possibility to select and process Sciamachy products using different data processors, using Grid technology. This technology was successfully researched and will be made operationally available in the near future.

  5. Snow bands over the Gulf of Finland in wintertime

    Directory of Open Access Journals (Sweden)

    Jordi Mazon

    2015-01-01

    Full Text Available Large shore-parallel, quasi-stationary snow bands are occasionally observed over the Gulf of Finland during wintertime when the sea is not frozen. On the basis of Weather Research and Forecasting mesoscale model experiments and radar observations of snow bands formed in January 2006 and February 2012, we show that their dynamics share common characteristics: (1 the sea gulf that produces the known lake effect, (2 cold easterly large-scale flow along the gulf and (3 a cold local flow from the two near and opposite coastlines of Estonia and Finland in the form of two land-breeze cells which collide offshore. The associated fronts, which have strong rising motions, are maintained by the convergence of the land-breeze cells. In addition to these factors, the concave shape of the coast in the eastern part of the Gulf of Finland promotes offshore convergence and the formation of several secondary bands of precipitation that are adjacent to the eastern part of the main band. When the easterlies turn to southerlies, horizontal convective rolls appear over the sea. The Estonian land breeze is enhanced while the cold air remains stagnant inland over the Finnish coast, acting as an orographic barrier lifting the marine air mass upwards. Consequently, a line of convective precipitation composed of several cells is formed along the Finnish coast. In both events, the simulations also show two low-level jets generated by the combined effects of the land-breeze cells and baroclinicity over the coast of Finland and Estonia.

  6. FLAVOR BIOGENERATION IN MANGABA (Hancornia speciosa Gomes FRUIT

    Directory of Open Access Journals (Sweden)

    Narenda Narain

    2007-11-01

    Full Text Available Most of the volatile flavoring substances are formed during maturation of fruit when it ripens. In this study, the mangaba (Hancornia speciosa Gomes fruit was harvested at half-ripe and ripe stages of maturity and analyzed for its volatile components. The extracts were obtained from the fruit pulp by using simultaneous distillation and extraction technique. Several extraction parameters such as weight of the pulp, dilution with water, solvent volume and extraction period were standardized to obtain highly characteristic fruit aroma extracts. The extracts were analyzed for the identification of volatile compounds by using a system of high resolution gas chromatograph coupled with mass spectrometer. Eighty-six components were separated out of which 46 compounds were positively identified. The volatile flavoring substances pertaining to classes of esters and terpenes increased from 6.19 to 35.487% and from 7.51 to 10.40%, respectively. The principal volatile compounds present in the pulp of ripe mangaba fruit were isopropyl acetate (19.23%, 3-hexanol (10.74%, linalool (7.38%, ä-limonene (2.43%, 3-pentanol (3.80%, 3-ethyl 2-buten-1-ol (2.53% and furfural (1.52%. Biogeneration of mangaba flavor is mainly characterized due to the presence of compounds pertaining to esters, aldehydes and terpenes.

  7. Detection of polar stratospheric clouds with ERS2/GOME data

    International Nuclear Information System (INIS)

    Meerkoetter, R.; Schumann, U.

    1994-01-01

    Based on radiative transfer calculations it is studied whether Polar Stratospheric Clouds (PSCs) can be detected by the new Global Ozone Monitoring Experiment (GOME) onboard the second European Research Satellite (ERS-2) planned to be launched in winter 1994/95. It is proposed to identify PSC covered areas by use of an indicator, the Normalized Radiance Difference (NRD), which relates the difference of two spectral radiances at 0.5 μm and 0.7 μm to one radiance measured in the center of the oxygen A-band at 0.76 μm. The presence of PSCs and under conditions of large solar zenith angles Θ>80 the NRD values are clearly below those derived under conditions of a cloud free stratosphere. In this case the method is successful for PSCs with optical depths greater than 0.03 at 0.55 μm. It is not affected by existing tropospheric clouds and by different tropospheric aerosol loadings or surface albedoes. For solar zenith angles Θ<80 PSCs located above a cloud free troposphere are detectable. PSC detection becomes difficult for Θ<80 when highly reflecting tropospheric clouds like dense cirrus or stratus clouds affect spectral radiances measured at the top of the atmosphere. (orig.)

  8. Enhanced wintertime greenhouse effect reinforcing Arctic amplification and initial sea-ice melting.

    Science.gov (United States)

    Cao, Yunfeng; Liang, Shunlin; Chen, Xiaona; He, Tao; Wang, Dongdong; Cheng, Xiao

    2017-08-16

    The speeds of both Arctic surface warming and sea-ice shrinking have accelerated over recent decades. However, the causes of this unprecedented phenomenon remain unclear and are subjects of considerable debate. In this study, we report strong observational evidence, for the first time from long-term (1984-2014) spatially complete satellite records, that increased cloudiness and atmospheric water vapor in winter and spring have caused an extraordinary downward longwave radiative flux to the ice surface, which may then amplify the Arctic wintertime ice-surface warming. In addition, we also provide observed evidence that it is quite likely the enhancement of the wintertime greenhouse effect caused by water vapor and cloudiness has advanced the time of onset of ice melting in mid-May through inhibiting sea-ice refreezing in the winter and accelerating the pre-melting process in the spring, and in turn triggered the positive sea-ice albedo feedback process and accelerated the sea ice melting in the summer.

  9. Forcing of the wintertime atmospheric circulation by the multidecadal fluctuations of the North Atlantic ocean

    International Nuclear Information System (INIS)

    Peings, Yannick; Magnusdottir, Gudrun

    2014-01-01

    The North Atlantic sea surface temperature exhibits fluctuations on the multidecadal time scale, a phenomenon known as the Atlantic Multidecadal Oscillation (AMO). This letter demonstrates that the multidecadal fluctuations of the wintertime North Atlantic Oscillation (NAO) are tied to the AMO, with an opposite-signed relationship between the polarities of the AMO and the NAO. Our statistical analyses suggest that the AMO signal precedes the NAO by 10–15 years with an interesting predictability window for decadal forecasting. The AMO footprint is also detected in the multidecadal variability of the intraseasonal weather regimes of the North Atlantic sector. This observational evidence is robust over the entire 20th century and it is supported by numerical experiments with an atmospheric global climate model. The simulations suggest that the AMO-related SST anomalies induce the atmospheric anomalies by shifting the atmospheric baroclinic zone over the North Atlantic basin. As in observations, the positive phase of the AMO results in more frequent negative NAO—and blocking episodes in winter that promote the occurrence of cold extreme temperatures over the eastern United States and Europe. Thus, it is plausible that the AMO plays a role in the recent resurgence of severe winter weather in these regions and that wintertime cold extremes will be promoted as long as the AMO remains positive. (paper)

  10. Wintertime Ambient Ammonia Concentrations in Northern Utah's Urban Valleys

    Science.gov (United States)

    Hammond, I. A.; Martin, R. S.; Silva, P.; Baasandorj, M.

    2017-12-01

    Many of the population centers in northern Utah are currently classified as non-attainment or serious non-attainment, Wasatch Front, for PM2.5 and previous studies have shown ammonium nitrate to often be the largest contributor to the particulate mass. Furthermore, measurements have shown several of the Wasatch Front cities and Cache Valley (UT/ID) consistently recorded some of the highest ambient ammonia (NH3) concentrations in the continental United States. As a part of the multi-organization 2017 Utah Winter Fine Particulate Study real-time NH3 concentrations were monitored in the Cache Valley at the Logan, UT site, collocated at an EPA sampling trailer near the Utah State University (USU) campus. A Picarro model G2508 was to used collect 5-sec averaged concentrations of NH3, carbon dioxide (CO2), and methane (CH4) from January 16th to February 14th, 2017. Parts of three inversion events, wherein the PM2.5 concentrations approached or exceeded the National Ambient Air Quality Standards, were captured during the sampling period, including a 10-day event from January 25th to February 4th. Concentrations of all three of the observed species showed significant accumulation during the events, with NH3 concentrations ranging from below the detection limit (70 ppb. Preliminary analysis suggested the temporal NH3 changes tracked the increase in PM2.5 throughout the inversion events; however, a one-day period of NH3 depletion during the main inversion event was observed while PM2.5 continued to increase. Additionally, a network of passive NH3 samplers (Ogawa Model 3300) were arrayed at 25 sites throughout the Cache Valley and at 11 sites located along the Wasatch Front. These networks sampled for three 7-day periods, during the same study time frame. Ion chromatographic (IC) analyses of the sample pads are not yet finalized; however, preliminary results show concentrations in the tens of ppb and seemingly spatially correlate with previous studies showing elevated

  11. Interdisciplinary study of the panel painting depicting the "Pentecostes", attributed to Fernão Gomes

    Directory of Open Access Journals (Sweden)

    Diana Conde

    2010-01-01

    Full Text Available This paper presents a study on the technique and materials used in the panel painting entitled Pentecostes, attributed to the artist Fernão Gomes (XVIIth century, housed in the Museu Nacional de Arte Antiga, in Lisbon. The study also includes the diagnosis of the conservation state of the painting and the description of the cleaning intervention. For identification of the materials and determination of the conservation state, several analytical techniques were used: micro-FTIR and GC-MS, for identification of the binder and varnish; micro-Raman and micro-FTIR, for identification of fillers and pigments; micro-XRF and SEM-EDX, for elemental analysis; optical microscopy, with visible and fluorescent radiation, and infrared photography, for morphological observation and study of pictorial technique. The analytical approach led to the identification of materials common at the time: gypsum with animal glue, lead white, yellow and red ochres, black earths (based on Mn, Bi, Fe, azurite, possible green earth, lead red, oil and oily varnish with residues of cholesterol. After various cleaning tests, a gel suggested by the literature was chosen (recipe no. 105.4 developed by R. Wolbers and proved to be effective in the removal of the aged and polymerized varnish.

  12. Coherent changes of wintertime surface air temperatures over North Asia and North America.

    Science.gov (United States)

    Yu, Bin; Lin, Hai

    2018-03-29

    The surface temperature variance and its potential change with global warming are most prominent in winter over Northern Hemisphere mid-high latitudes. Consistent wintertime surface temperature variability has been observed over large areas in Eurasia and North America on a broad range of time scales. However, it remains a challenge to quantify where and how the coherent change of temperature anomalies occur over the two continents. Here we demonstrate the coherent change of wintertime surface temperature anomalies over North Asia and the central-eastern parts of North America for the period from 1951 to 2015. This is supported by the results from the empirical orthogonal function analysis of surface temperature and temperature trend anomalies over the Northern Hemisphere extratropical lands and the timeseries analysis of the regional averaged temperature anomalies over North Asia and the Great Plains and Great Lakes. The Asian-Bering-North American (ABNA) teleconnection provides a pathway to connect the regional temperature anomalies over the two continents. The ABNA is also responsible for the decadal variation of the temperature relationship between North Asia and North America.

  13. Neural networks for the dimensionality reduction of GOME measurement vector in the estimation of ozone profiles

    International Nuclear Information System (INIS)

    Del Frate, F.; Iapaolo, M.; Casadio, S.; Godin-Beekmann, S.; Petitdidier, M.

    2005-01-01

    Dimensionality reduction can be of crucial importance in the application of inversion schemes to atmospheric remote sensing data. In this study the problem of dimensionality reduction in the retrieval of ozone concentration profiles from the radiance measurements provided by the instrument Global Ozone Monitoring Experiment (GOME) on board of ESA satellite ERS-2 is considered. By means of radiative transfer modelling, neural networks and pruning algorithms, a complete procedure has been designed to extract the GOME spectral ranges most crucial for the inversion. The quality of the resulting retrieval algorithm has been evaluated by comparing its performance to that yielded by other schemes and co-located profiles obtained with lidar measurements

  14. A preliminary comparison between TOVS and GOME level 2 ozone data

    Science.gov (United States)

    Rathman, William; Monks, Paul S.; Llewellyn-Jones, David; Burrows, John P.

    1997-09-01

    A preliminary comparison between total column ozone concentration values derived from TIROS Operational Vertical Sounder (TOVS) and Global Ozone Monitoring Experiment (GOME) has been carried out. Two comparisons of ozone datasets have been made: a) TOVS ozone analysis maps vs. GOME level 2 data; b) TOVS data located at Northern Hemisphere Ground Ozone Stations (NHGOS) vs. GOME data. Both analyses consistently showed an offset in the value of the total column ozone between the datasets [for analyses a) 35 Dobson Units (DU); and for analyses b) 10 DU], despite a good correlation between the spatial and temporal features of the datasets. A noticeably poor correlation in the latitudinal bands 10°/20° North and 10°/20° South was observed—the reasons for which are discussed. The smallest region which was statistically representative of the ozone value correlation dataset of TOVS data at NHGOS and GOME level-2 data was determined to be a region that was enclosed by effective radius of 0.75 arc-degrees (83.5km).

  15. Measurements of O3, NO2 and BrO during the INDOEX campaign using ground based DOAS and GOME satellite data

    Directory of Open Access Journals (Sweden)

    A. Ladstätter-Weißenmayer

    2007-01-01

    Full Text Available The INDian Ocean EXperiment (INDOEX was an international, multi-platform field campaign to measure long-range transport of air masses from South and South-East-(SE Asia towards the Indian Ocean. During the dry monsoon season between January and March 1999, local measurements were carried out from ground based platforms and were compared with satellite based data. The objective of this study was to characterise stratospheric and tropospheric trace gas amounts in the equatorial region, and to investigate the impact of air pollution at this remote site. For the characterisation of the chemical composition of the outflow from the S-SE-Asian region, we performed ground based dual-axis-DOAS (Differential Optical Absorption Spectroscopy measurements at the KCO (Kaashidhoo Climate Observatory in the Maldives (5.0° N, 73.5° E. The measurements were conducted using two different observation modes (off-axis and zenith-sky. This technique allows the separation of the tropospheric and stratospheric columns for different trace gases like O3 and NO2. These dual-axis DOAS data were compared with O3-sonde measurements performed at KCO and satellite based GOME (Global Ozone Measuring Experiment data during the intensive measuring phase of the INDOEX campaign in February and March 1999. From GOME observations, tropospheric and stratospheric columns for O3 and NO2 were retrieved. In addition, the analysis of the O3-sonde measurements allowed the determination of the tropospheric O3 amount. The comparison shows that the results of all three measurement systems agree within their error limits. During the INDOEX campaign, mainly background conditions were observed, but in a single case an increase of tropospheric NO2 during a short pollution event was observed from the ground and the impact on the vertical columns was calculated. GOME measurements showed evidence for small tropospheric contributions to the BrO budget, probably located in the free troposphere and

  16. Wintertime Emissions from Produced Water Ponds

    Science.gov (United States)

    Evans, J.; Lyman, S.; Mansfield, M. L.

    2013-12-01

    Every year oil and gas drilling in the U.S. generates billions of barrels of produced water (water brought to the surface during oil or gas production). Efficiently disposing of produced water presents a constant financial challenge for producers. The most noticeable disposal method in eastern Utah's Uintah Basin is the use of evaporation ponds. There are 427 acres of produced water ponds in the Uintah Basin, and these were used to evaporate more than 5 million barrels of produced water in 2012, 6% of all produced water in the Basin. Ozone concentrations exceeding EPA standards have been observed in the Uintah Basin during winter inversion conditions, with daily maximum 8 hour average concentrations at some research sites exceeding 150 parts per billion. Produced water contains ozone-forming volatile organic compounds (VOC) which escape into the atmosphere as the water is evaporated, potentially contributing to air quality problems. No peer-reviewed study of VOC emissions from produced water ponds has been reported, and filling this gap is essential for the development of accurate emissions inventories for the Uintah Basin and other air sheds with oil and gas production. Methane, carbon dioxide, and VOC emissions were measured at three separate pond facilities in the Uintah Basin in February and March of 2013 using a dynamic flux chamber. Pond emissions vary with meteorological conditions, so measurements of VOC emissions were collected during winter to obtain data relevant to periods of high ozone production. Much of the pond area at evaporation facilities was frozen during the study period, but areas that actively received water from trucks remained unfrozen. These areas accounted for 99.2% of total emissions but only 9.5% of the total pond area on average. Ice and snow on frozen ponds served as a cap, prohibiting VOC from being emitted into the atmosphere. Emissions of benzene, toluene, and other aromatic VOCs averaged over 150 mg m-2 h-1 from unfrozen pond

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

    Science.gov (United States)

    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

  18. Global monitoring of terrestrial chlorophyll fluorescence from moderate-spectral-resolution near-infrared satellite measurements: methodology, simulations, and application to GOME-2

    Directory of Open Access Journals (Sweden)

    J. Joiner

    2013-10-01

    Full Text Available 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

  19. Evaluation of the hydrological cycle of MATCH driven by NCEP reanalysis data: comparison with GOME water vapor measurements

    Directory of Open Access Journals (Sweden)

    R. Lang

    2005-01-01

    Full Text Available This study examines two key parameters of the hydrological cycle, water vapor (WV and precipitation rates (PR, as modelled by the chemistry transport model MATCH (Model of Atmospheric Transport and Chemistry driven by National Centers for Environmental Prediction (NCEP reanalysis data (NRA. For model output evaluation we primarily employ WV total column data from the Global Ozone Monitoring Experiment (GOME on ERS-2, which is the only instrument capable measuring WV on a global scale and over all surface types with a substantial data record from 1995 to the present. We find that MATCH and NRA WV and PR distributions are closely related, but that significant regional differences in both parameters exist in magnitude and distribution patterns when compared to the observations. We also find that WV residual patterns between model and observations show remarkable similarities to residuals observed in the PR when comparing MATCH and NRA output to observations comprised by the Global Precipitation Climatology Project (GPCP. We conclude that deficiencies in model parameters shared by MATCH and NRA, like in the surface evaporation rates and regional transport patterns, are likely to lead to the observed differences. Monthly average regional differences between MATCH modelled WV columns and the observations can be as large as 2 cm, based on the analysis of three years. Differences in the global mean WV values are, however, below 0.1 cm. Regional differences in the PR between MATCH and GPCP can be above 0.5 cm per day and MATCH computes on average a higher PR than what has been observed. The lower water vapor content of MATCH is related to shorter model WV residence times by up to 1 day as compared to the observations. We find that MATCH has problems in modelling the WV content in regions of strong upward convection like, for example, along the Inter Tropical Convergence Zone, where it appears to be generally too dry as compared to the observations. We

  20. Interpretation of ozone vertical profiles and their variations in the Northern hemisphere on the basis of GOME satellite data. Final report; Interpretation von Ozon-Vertikalprofilen und deren Variationen in der noerdlichen Hemisphaere unter Benutzung von GOME Satellitendaten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Eichmann, K.U.; Bramstedt, K.; Weber, M.; Rozanov, V.; Debeek, R.; Hoogen, R.; Burrows, J.P.

    2000-07-04

    Semiglobal ozone vertical profiles based on GOME measurements were established and evaluated systematically. GOME (Global Ozone Monitoring Experiment), carried by the ERS-2 satellite, is the first European passive optical sensor for long-term monitoring of ozone, other trace elements, and aerosols. Especially the vertical distribution of ozone in the Arctic region was measured and interpreted with a view to enhanced ozone degradation in the Arctic winter and spring seasons. Apart from the regional variations, also the time variations of the profiles are to provide further information on the dynamics and chemical processes in the polar vortex. The retrieval algorithm used for assessing the ozone vertical profiles, FURM (FUll Retrieval Method), is based on the GOMETRAN radiation transport model developed at Bremen university especially for evaluation of the GOME data. The GOME ozone profiles were validated with ozone probes and other satellite experiments. [German] Ziel des Projektes war eine systematische Bestimmung und Auswertung von semiglobalen Ozonvertikalprofilen aus den Messdaten von GOME. Das auf dem Satelliten ERS-2 fliegende Spektrometer GOME (Global Ozone Monitoring Experiment) ist der erste europaeische, passive, optische Sensor, der fuer Langzeitmessungen von Ozon, anderen Spurenstoffen und Aerosolen konzipiert wurde. Im Projekt wurde insbesondere die vertikale Verteilung von Ozon in der Arktis bestimmt und interpretiert hinsichtlich des verstaerkten Ozonabbaus im arktischen Winter und Fruehjahr. Neben der raeumlichen Variation sollen auch die zeitlichen Ablaeufe und Veraenderungen der Profile weitere Erkenntnise hinsichtlich der Dynamik und der chemischen Prozesse im Polarwirbel liefern. Der Retrievalalgorithmus zur Bestimmung des Ozonhoehenprofils, FURM (Full Retrieval Method) genannt, basiert auf dem Strahlungstransportmodell GOMETRAN, das an der Universitaet Bremen speziell fuer die Auswertung der Daten des GOME Instrumentes entwickelt wurde

  1. Studies on calibration and validation of data provided by the Global Ozone Monitoring Experiment GOME on ERS-2 (CAVEAT). Final report; Studie zur Kalibrierung und Validation von Daten des Global Ozone Monitoring Experiments GOME auf ERS-2 (CAVEAT). Endbericht

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, J.P.; Kuenzi, K.; Ladstaetter-Weissenmayer, A.; Langer, J. [Bremen Univ. (Germany). Inst. fuer Umweltphysik; Neuber, R.; Eisinger, M. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Potsdam (Germany)

    2000-04-01

    The Global Ozone Monitoring Experiment (GOME) was launched on 21 April 1995 as one of six scientific instruments on board the second European remote sensing satellite (ERS-2) of the ESA. The investigations presented here aimed at assessing and improving the accuracy of the GOME measurements of sun-standardized and absolute radiation density and the derived data products. For this purpose, the GOME data were compared with measurements pf terrestrial, airborne and satellite-borne systems. For scientific reasons, the measurements will focus on the medium and high latitudes of both hemispheres, although equatorial regions were investigated as well. In the first stage, operational data products of GOME were validated, i.e. radiation measurements (spectra, level1 product) and trace gas column densities (level2 product). [German] Am 21. April 1995 wurde das Global Ozone Monitoring Experiment (GOME) als eines von insgesamt sechs wissenschaftlichen Instrumenten an Bord des zweiten europaeischen Fernerkundungssatelliten (ERS-2) der ESA ins All gebracht. Das Ziel dieses Vorhabens ist es, die Genauigkeit der von GOME durchgefuehrten Messungen von sonnennormierter und absoluter Strahlungsdichte sowie der aus ihnen abgeleiteten Datenprodukte zu bewerten und zu verbessern. Dazu sollten die GOME-Daten mit Messungen von boden-, flugzeug- und satellitengestuetzten Systemen verglichen werden. Aus wissenschaftlichen Gruenden wird der Schwerpunkt auf Messungen bei mittleren und hohen Breitengraden in beiden Hemisphaeren liegen. Jedoch wurden im Laufe des Projektzeitraumes auch Regionen in Aequatornaehe untersucht. Im ersten Schritt sollen operationelle Datenprodukte von GOME validiert werden. Dieses sind Strahlungsmessungen (Spektren, Level1-Produkt) und Spurengas-Saeulendichten (Level2-Produkt). (orig.)

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

    Science.gov (United States)

    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).

  3. Wintertime sea surface temperature fronts in the Taiwan Strait

    Science.gov (United States)

    Chang, Yi; Shimada, Teruhisa; Lee, Ming-An; Lu, Hsueh-Jung; Sakaida, Futoki; Kawamura, Hiroshi

    2006-12-01

    We present wintertime variations and distributions of sea surface temperature (SST) fronts in the Taiwan Strait by applying an entropy-based edge detection method to 10-year (1996-2005) satellite SST images with grid size of 0.01°. From climatological monthly mean maps of SST gradient magnitude in winter, we identify four significant SST fronts in the Taiwan Strait. The Mainland China Coastal Front is a long frontal band along the 50-m isobath near the Chinese coast. The sharp Peng-Chang Front appears along the Peng-Hu Channel and extends northward around the Chang-Yuen Ridge. The Taiwan Bank Front evolves in early winter. As the winter progresses, the front becomes broad and moves toward the Chinese coast, connecting to the Mainland China Coastal Front. The Kuroshio Front extends northeastward from the northeastern tip of Taiwan with a semicircle-shape curving along the 100-m isobath.

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

    OpenAIRE

    J. Kujanpää; N. Kalakoski

    2015-01-01

    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 EUMETSA...

  5. Eleven years of tropospheric NO2 measured by GOME, SCIAMACHY and OMI

    Science.gov (United States)

    Eskes, H.; Boersma, F.; Dirksen, R.; van der A, R.; Veefkind, P.; Levelt, P.; Brinksma, E.; van Roozendael, M.; de Smedt, I.; Gleason, J.

    2006-12-01

    Based on measurements of GOME on ESA ERS-2, SCIAMACHY on ESA-ENVISAT, and Ozone Monitoring Instrument (OMI) on the NASA EOS-Aura satellite there is now a unique 11-year dataset of global tropospheric nitrogen dioxide measurements from space. The retrieval approach consists of two steps. The first step is an application of the DOAS (Differential Optical Absorption Spectroscopy) approach which delivers the total absorption optical thickness along the light path (the slant column). For GOME and SCIAMACHY this is based on the DOAS implementation developed by BIRA/IASB. For OMI the DOAS implementation was developed in a collaboration between KNMI and NASA. The second retrieval step, developed at KNMI, estimates the tropospheric vertical column of NO2 based on the slant column, cloud fraction and cloud top height retrieval, stratospheric column estimates derived from a data assimilation approach and vertical profile estimates from space-time collocated profiles from the TM chemistry-transport model. The second step was applied with only minor modifications to all three instruments to generate a uniform 11-year data set. In our talk we will address the following topics: - A short summary of the retrieval approach and results - Comparisons with other retrievals - Comparisons with global and regional-scale models - OMI-SCIAMACHY and SCIAMACHY-GOME comparisons - Validation with independent measurements - Trend studies of NO2 for the past 11 years

  6. New Methods for Retrieval of Chlorophyll Red Fluorescence from Hyperspectral Satellite Instruments: Simulations and Application to GOME-2 and SCIAMACHY

    Science.gov (United States)

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

    2016-01-01

    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 736nm. From ocean surfaces, phytoplankton fluorescence emissions are entirely from the red region (683nm peak). Studies using satellite-derived SIF over land have focused almost exclusively on measurements in the far red (wavelengths greater than 712nm), 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 less than 712nm) 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 (0.5nm). 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 andor solar absorption spectral features by SIF. Our approach makes use of the oxygen (O2) gamma band that is not affected by SIF. The SIF-free O2 gamma 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

  7. Minimizing the wintertime low bias of Northern Hemisphere carbon monoxide in global model simulations

    Science.gov (United States)

    Stein, Olaf; Schultz, Martin G.; Bouarar, Idir; Clark, Hannah; Huijnen, Vincent; Gaudel, Audrey; George, Maya; Clerbaux, Cathy

    2015-04-01

    Carbon monoxide (CO) is a product of incomplete combustion and is also produced from oxidation of volatile organic compounds (VOC) in the atmosphere. It is of interest as an indirect greenhouse gas and an air pollutant causing health effects and is thus subject to emission restrictions. CO acts as a major sink for the OH radical and as a precursor for tropospheric ozone and affects the oxidizing capacity of the atmosphere as well as regional air quality. Despite the developments in the global modelling of chemistry and of the parameterization of the physical processes, CO concentrations remain underestimated during NH winter by most state-of-the-art chemical transport models. The resulting model bias can in principle originate from either an underestimation of CO sources or an overestimation of its sinks. We address both the role of sources and sinks with a series of MOZART chemistry transport model sensitivity simulations for the year 2008 and compare our results to observational data from ground-based stations, satellite observations, and from MOZAIC tropospheric profile measurements on passenger aircraft. Our base case simulation using the MACCity emission inventory (Granier et al. 2011) underestimates the near-surface Northern Hemispheric CO mixing ratios by more than 20 ppb from December to April with a maximal bias of 40 ppb in January. The bias is strongest for the European region (up to 75 ppb in January). From our sensitivity studies the mismatch between observed and modelled atmospheric CO concentrations can be explained by a combination of the following emission inventory shortcuts: (i) missing anthropogenic wintertime CO emissions from traffic or other combustion processes, (ii) missing anthropogenic VOC emissions, (iii) an exaggerated downward trend in the RCP8.5 scenario underlying the MACCity inventory, (iv) a lack of knowledge about the seasonality of emissions. Deficiencies in the parameterization of the dry deposition velocities can also lead to

  8. Structure and dynamics of a wave train along the wintertime Asian jet and its impact on East Asian climate

    Science.gov (United States)

    Hu, Kaiming; Huang, Gang; Wu, Renguang; Wang, Lin

    2017-04-01

    Based on observational and reanalysis datasets, this study investigates the structure and dynamics of a wave-like atmospheric teleconnection pattern along the wintertime Asian jet and its influence on East Asian climate. Along the jet, the leading empirical orthogonal function (EOF) mode of monthly meridional winds at 250-hPa in winter (December, January, and February) is organized as a wave train with maximum anomalies at upper troposphere. The wave train propagates northeastward from the North Atlantic to Europe, turns southeastward to the Middle East with amplifying amplitude, propagates along the jet to South China, and reaches Japan, which is partly induced by sea surface temperature (SST) anomalies in the equatorial eastern Pacific and the North Atlantic Oscillation. Over the sector from Europe to the Middle East, the anomalous vortices in the wave train tilt northwestward with height and tilt northeast/southwest in horizontal at 250 hPa, favoring for extracting available potential energy and kinetic energy from mean flows effectively. In addition, there exists a positive feedback between transient eddies and the wave train-related anomalous circulation over the North Atlantic and Europe. These processes help to maintain and amplify the wave train. Moreover, the wave train can exert significant influences on the wintertime climate in East Asia. When it is in the phase with a cyclone (anticyclone) over South China (Japan), rainfall tends to be above normal in South and East China and surface air temperature tends to be above normal around Japan and the Korea peninsula.

  9. Impacts of Four SO2 Oxidation Pathways on Wintertime Sulfate Concentrations

    Science.gov (United States)

    Sarwar, G.; Fahey, K.; Zhang, Y.; Kang, D.; Mathur, R.; Xing, J.; Wei, C.; Cheng, Y.

    2017-12-01

    Air quality models tend to under-estimate winter-time sulfate concentrations compared to observed data. Such under-estimations are particularly acute in China where very high concentrations of sulfate have been measured. Sulfate is produced by oxidation of sulfur dioxide (SO2) in gas-phase by hydroxyl radical and in aqueous-phase by hydrogen peroxide, ozone, etc. and most air quality models employ such typical reactions. Several additional SO2 oxidation pathways have recently been proposed. Heterogeneous reaction on dust has been suggested to be an important sink for SO2. Oxidation of SO2 on fine particles in presence of nitrogen dioxide (NO2) and ammonia (NH3) at high relative humidity has been implicated for sulfate formation in Chinese haze and London fog. Reactive nitrogen chemistry in aerosol water has also been suggested to produce winter-time sulfate in China. Specifically, high aerosol water can trap SO2 which can be subsequently oxidized by NO2 to form sulfate. Aqueous-phase (in-cloud) oxidation of SO2 by NO2 can also produce sulfate. Here, we use the hemispheric Community Multiscale Air Quality (CMAQ) modeling system to examine the potential impacts of these SO2 oxidation pathways on sulfate formation. We use anthropogenic emissions from the Emissions Database for Global Atmospheric Research and biogenic emissions from Global Emissions InitiAtive. We performed simulations without and with these SO2 oxidation pathways for October-December of 2014 using meteorological fields obtained from the Weather Research and Forecasting model. The standard CMAQ model contains one gas-phase chemical reaction and five aqueous-phase chemical reactions for SO2 oxidation. We implement four additional SO2 oxidation pathways into the CMAQ model. Our preliminary results suggest that the dust chemistry enhances mean sulfate over parts of China and Middle-East, the in-cloud SO2 oxidation by NO2 enhances sulfate over parts of western Europe, oxidation of SO2 by NO2 and NH3 on

  10. The Siberian High and Arctic Sea Ice: Long-term Climate Change and Impacts on Air Pollution during Wintertime in China

    Science.gov (United States)

    Long, X.; Zhao, S.; Feng, T.; Tie, X.; Li, G.

    2017-12-01

    China has undergone severe air pollution during wintertime as national industrialization and urbanization have been increasingly developed in the past three decades. It has been suggested that high emission and adverse weather patterns contribute to wintertime air pollution. Recent studies propose that climate change and Arctic sea ice loss likely lead to extreme haze events in winter. Here we use two reanalysis and observational datasets to present the trends of Siberian High (SH) intensity over Eurasia, and Arctic temperature and sea ice. The results show the Arctic region of Asia is becoming warming accompanied by a rapid decline of sea ice while Eurasia is cooling and SH intensity is gradually enhancing. Wind patterns induced by these changes cause straight westerly prevailing over Eurasia at the year of weak SH while strengthened northerly winds at the year of strong SH. Therefore, we utilize regional dynamical and chemical WRF-Chem model to determine the impact of SH intensity difference on wintertime air pollution in China. As a result, enhancing northerly winds at the year of strong SH rapidly dilute and transport air pollution, causing a decline of 50 - 400 µg m-3 PM2.5 concentrations relative to that at the year of weak SH. We also assess the impact of emission reduction to half the current level on air pollution. The results show that emission reduction by 50% has an equivalent impact as the variability of SH intensity. This suggests that climate change over Eurasia has largely offset the negative impact of emission on air pollution and it is urgently needed to take measures to mitigate air pollution. In view of current high emission scenario in China, it will be a long way to effectively mitigate, or ultimately prevent wintertime air pollution.

  11. Reconstructed Solar-Induced Fluorescence: A Machine Learning Vegetation Product Based on MODIS Surface Reflectance to Reproduce GOME-2 Solar-Induced Fluorescence

    Science.gov (United States)

    Gentine, P.; Alemohammad, S. H.

    2018-04-01

    Solar-induced fluorescence (SIF) observations from space have resulted in major advancements in estimating gross primary productivity (GPP). However, current SIF observations remain spatially coarse, infrequent, and noisy. Here we develop a machine learning approach using surface reflectances from Moderate Resolution Imaging Spectroradiometer (MODIS) channels to reproduce SIF normalized by clear sky surface irradiance from the Global Ozone Monitoring Experiment-2 (GOME-2). The resulting product is a proxy for ecosystem photosynthetically active radiation absorbed by chlorophyll (fAPARCh). Multiplying this new product with a MODIS estimate of photosynthetically active radiation provides a new MODIS-only reconstruction of SIF called Reconstructed SIF (RSIF). RSIF exhibits much higher seasonal and interannual correlation than the original SIF when compared with eddy covariance estimates of GPP and two reference global GPP products, especially in dry and cold regions. RSIF also reproduces intense productivity regions such as the U.S. Corn Belt contrary to typical vegetation indices and similarly to SIF.

  12. Wintertime phytoplankton bloom in the Subarctic Pacific supported by continental margin iron

    International Nuclear Information System (INIS)

    Lam, Phoebe J.; Bishop, James K.B.; Henning, Cara C.; Marcus, Matthew A.; Waychunas, Glenn A.; Fung, Inez

    2004-01-01

    Heightened biological activity was observed in February 1996 in the high-nutrient low-chlorophyll (HNLC) subarctic North Pacific Ocean, a region that is thought to be iron-limited. Here we provide evidence supporting the hypothesis that Ocean Station Papa (OSP) in the subarctic Pacific received a lateral supply of particulate iron from the continental margin off the Aleutian Islands in the winter, coincident with the observed biological bloom. Synchrotron X-ray analysis was used to describe the physical form, chemistry, and depth distributions of iron in size fractionated particulate matter samples. The analysis reveals that discrete micron-sized iron-rich hotspots are ubiquitous in the upper 200m at OSP, more than 900km from the closest coast. The specifics of the chemistry and depth profiles of the Fe hot spots trace them to the continental margins. We thus hypothesize that iron hotspots are a marker for the delivery of iron from the continental margin. We confirm the delivery of continental margin iron to the open ocean using an ocean general circulation model with an iron-like tracer source at the continental margin. We suggest that iron from the continental margin stimulated a wintertime phytoplankton bloom, partially relieving the HNLC condition

  13. Wintertime pytoplankton bloom in the Subarctic Pacific supportedby continental margin iron

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Phoebe J.; Bishop, James K.B.; Henning, Cara C.; Marcus,Matthew A.; Waychunas, Glenn A.; Fung, Inez

    2004-06-08

    Heightened biological activity was observed in February 1996in the high-nutrient low-chlorophyll (HNLC) subarctic North PacificOcean, a region that is thought to beiron-limited. Here we provideevidence supporting the hypothesis that Ocean Station Papa (OSP) in thesubarctic Pacific received a lateral supply of particulate iron from thecontinental margin off the Aleutian Islands in the winter, coincidentwith the observed biological bloom. Synchrotron X-ray analysis was usedto describe the physical form, chemistry, and depth distributions of ironin size fractionated particulate matter samples. The analysis revealsthat discrete micron-sized iron-rich hotspots are ubiquitous in the upper200m at OSP, more than 900km from the closest coast. The specifics of thechemistry and depth profiles of the Fe hot spots trace them to thecontinental margins. We thus hypothesize that iron hotspots are a markerfor the delivery of iron from the continental margin. We confirm thedelivery of continental margin iron to the open ocean using an oceangeneral circulation model with an iron-like tracer source at thecontinental margin. We suggest that iron from the continental marginstimulated a wintertime phytoplankton bloom, partially relieving the HNLCcondition.

  14. Barriers to outdoor physical activity in wintertime among Somali youth.

    Science.gov (United States)

    Rothe, Elizabeth; Holt, Christina; Kuhn, Celine; McAteer, Timothy; Askari, Isabella; O'Meara, Mary; Sharif, Abdimajid; Dexter, William

    2010-10-01

    To identify barriers to outdoor physical activity in winter among Somali youth in Maine. Despite the many proven health benefits of physical activity among children, such as cardiovascular fitness and health status as an adult, there has been a decrease in physical activity among children in recent years. Specifically, children who are of low socio-economic status or are from communities where many immigrants are at increased risk for developing obesity. Immigrants are also less likely to be physically active. There are many potential barriers to wintertime physical activity among Somali youth in Maine, such as lack of financial resources, transportation, proper winter clothing, and appropriate knowledge of winter safety, and language and cultural barriers. For females, different attire required for outdoor activity may be a barrier. Somali parents and children were recruited from Portland, Maine to participate in focus groups led by a trained facilitator with a Somali translator and cultural broker. Transcripts were coded using NVIVO software to identify barriers to physical activity among Somali youth outside in winter. Eight focus groups were conducted. Sixty-one Somali community members were recruited. Participants felt outdoor physical activity is important, but note that it is decreased in winter. Barriers to outdoor activity in winter cited by focus group participants were lack of resources, health concerns, gender barriers for females, and knowledge barriers. Concern over lack of supervision while children play outside was also cited. This study revealed many of the underlying beliefs, barriers and cultural issues that impact Somali families' intention to be active and ability to be active outdoors in winter. These findings can be used to generate research hypotheses and public health interventions regarding outdoor physical activity among Somali youth.

  15. Transport and build-up of tropospheric trace gases during the MINOS campaign: comparision of GOME, in situ aircraft measurements and MATCH-MPIC-data

    Directory of Open Access Journals (Sweden)

    A. Ladstätter-Weißenmayer

    2003-01-01

    Full Text Available The MINOS (Mediterranean INtensive Oxidant Study campaign was an international, multi-platform field campaign to measure long-range transport of air-pollution and aerosols from South East Asia and Europe towards the Mediterranean basin during August 2001. High pollution events were observed during this campaign. For the Mediterranean region enhanced tropospheric nitrogen dioxide (NO2 and formaldehyde (HCHO, which are precursors of tropospheric ozone (O3, were detected by the satellite based GOME (Global Ozone Monitoring Experiment instrument and compared with airborne in situ measurements as well as with the output from the global 3D photochemistry-transport model MATCH-MPIC (Model of Atmospheric Transport and CHemistry - Max Planck Institute for Chemistry. The increase of pollution in that region leads to severe air quality degradation with regional and global implications.

  16. Multi-model ensemble simulations of troposheric NO2 compared with GOME retrievals for the year 2000

    NARCIS (Netherlands)

    Noije, van T.P.C.; Eskes, H.J.; Dentener, F.J.; Stevenson, D.S.; Ellingsen, K.; Schultz, M.G.; Wild, O.; Amann, M.; Atherton, C.S.; Bergmann, D.; Bey, I.; Boersma, K.F.; Butler, T.; Cofala, J.; Drevet, J.; Fiore, A.M.; Gauss, M.; Hauglustaine, D.A.; Horowitz, L.W.; Isaksen, I.S.A.; Krol, M.C.; Lamarque, J.F.; Lawrence, M.G.; Martin, R.V.; Montanaro, V.; Muller, J.F.; Pitari, G.; Prather, M.J.; Pyle, J.A.; Richter, A.; Rodriguez, J.M.; Savage, N.H.; Strahan, S.E.; Sudo, K.; Szopa, S.; Roozendael, van M.

    2006-01-01

    We present a systematic comparison of tropospheric NO2 from 17 global atmospheric chemistry models with three state-of-the-art retrievals from the Global Ozone Monitoring Experiment (GOME) for the year 2000. The models used constant anthropogenic emissions from IIASA/EDGAR3.2 and monthly emissions

  17. Wintertime dynamics in the coastal northeastern Adriatic Sea: the NAdEx 2015 experiment

    Science.gov (United States)

    Vilibić, Ivica; Mihanović, Hrvoje; Janeković, Ivica; Denamiel, Cléa; Poulain, Pierre-Marie; Orlić, Mirko; Dunić, Natalija; Dadić, Vlado; Pasarić, Mira; Muslim, Stipe; Gerin, Riccardo; Matić, Frano; Šepić, Jadranka; Mauri, Elena; Kokkini, Zoi; Tudor, Martina; Kovač, Žarko; Džoić, Tomislav

    2018-03-01

    The paper investigates the wintertime dynamics of the coastal northeastern Adriatic Sea and is based on numerical modelling and in situ data collected through field campaigns executed during the winter and spring of 2015. The data were collected with a variety of instruments and platforms (acoustic Doppler current profilers, conductivity-temperature-depth probes, glider, profiling float) and are accompanied by the atmosphere-ocean ALADIN/ROMS modelling system. The research focused on the dense-water formation (DWF), thermal changes, circulation, and water exchange between the coastal and open Adriatic. According to both observations and modelling results, dense waters are formed in the northeastern coastal Adriatic during cold bora outbreaks. However, the dense water formed in this coastal region has lower densities than the dense water formed in the open Adriatic due to lower salinities. Since the coastal area is deeper than the open Adriatic, the observations indicate (i) balanced inward-outward exchange at the deep connecting channels of denser waters coming from the open Adriatic DWF site and less-dense waters coming from the coastal region and (ii) outward flow of less-dense waters dominating in the intermediate and surface layers. The latter phenomenon was confirmed by the model, even if it significantly underestimates the currents and transports in the connecting channels. The median residence time of the coastal area is estimated to be approximately 20 days, indicating that the coastal area may be renewed relatively quickly by the open Adriatic waters. The data that were obtained represent a comprehensive marine dataset that can be used to calibrate atmospheric and oceanic numerical models and point to several interesting phenomena to be investigated in the future.

  18. Wintertime dynamics in the coastal northeastern Adriatic Sea: the NAdEx 2015 experiment

    Directory of Open Access Journals (Sweden)

    I. Vilibić

    2018-03-01

    Full Text Available The paper investigates the wintertime dynamics of the coastal northeastern Adriatic Sea and is based on numerical modelling and in situ data collected through field campaigns executed during the winter and spring of 2015. The data were collected with a variety of instruments and platforms (acoustic Doppler current profilers, conductivity–temperature–depth probes, glider, profiling float and are accompanied by the atmosphere–ocean ALADIN/ROMS modelling system. The research focused on the dense-water formation (DWF, thermal changes, circulation, and water exchange between the coastal and open Adriatic. According to both observations and modelling results, dense waters are formed in the northeastern coastal Adriatic during cold bora outbreaks. However, the dense water formed in this coastal region has lower densities than the dense water formed in the open Adriatic due to lower salinities. Since the coastal area is deeper than the open Adriatic, the observations indicate (i balanced inward–outward exchange at the deep connecting channels of denser waters coming from the open Adriatic DWF site and less-dense waters coming from the coastal region and (ii outward flow of less-dense waters dominating in the intermediate and surface layers. The latter phenomenon was confirmed by the model, even if it significantly underestimates the currents and transports in the connecting channels. The median residence time of the coastal area is estimated to be approximately 20 days, indicating that the coastal area may be renewed relatively quickly by the open Adriatic waters. The data that were obtained represent a comprehensive marine dataset that can be used to calibrate atmospheric and oceanic numerical models and point to several interesting phenomena to be investigated in the future.

  19. Wintertime westward-traveling planetary-scale perturbations over the Euro-Atlantic region

    Energy Technology Data Exchange (ETDEWEB)

    Doblas-Reyes, F.J. [Centro de Astrobiologia, INTA, Madrid (Spain); Pastor, M.A.; Casado, M.J. [Instituto Nacional de Meteorologia, Madrid (Spain); Deque, M. [CNRM, Meteo-France, Toulouse (France)

    2001-07-01

    The features of the wintertime westward-traveling planetary scale perturbations over the Euro-Atlantic region are examined through the use of space-time spectral analysis applied to the 500 hPa geopotential height field. The intention is to understand the nature of these phenomena and the performance of climate models. Data from both ECMWF re-analyses and a simulation from the ARPEGE general circulation model are used. Westward-traveling planetary scale transients are found over the region as local perturbations resembling Rossby normal modes, with a maximum power over the Eastern Atlantic. The westward-traveling planetary scale transients north of 40 {sup circle} N have periods larger than 20 days. South of this latitude, wave periods are shifted to a band around 10 days, so that they can be related to subtropical transient waves. The atmospheric model used, like other models which exhibit reasonable mean climatic properties, tend to have less overall intraseasonal variability than observed. Nevertheless, the model is able to capture most of the features of the westward-traveling low-frequency transients. The differences in basic state, partially produced by scale interactions, would lead to the generation of westward-traveling waves in the model distinct from the observed. However, it is suggested that the improvement of the present model version with regard to previous model versions is due to a better simulation of the time-mean state. The reasonable simulation of the synoptic-scale variability south of 50 {sup circle} N, and thus of its barotropic forcing on the basic state, may also help to explain the realistic westward-traveling transients in the model. (orig.)

  20. Antioxidant, Antimicrobial and Cytotoxic Properties as Well as the Phenolic Content of the Extract from Hancornia speciosa Gomes.

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    Uilson P Santos

    Full Text Available Hancornia speciosa Gomes (Apocynaceae is a fruit tree, popularly known as mangabeira, and it is widely distributed throughout Brazil. Several parts of the plant are used in folk medicine, and the leaf and bark extracts have anti-inflammatory, antihypertensive, antidiabetic, and antimicrobial properties. In this study, we investigated the chemical composition of the ethanolic extract of Hancornia speciosa leaves (EEHS and its antioxidant, antimicrobial, and cytotoxic activities as well as the mechanisms involved in cell death. The chemical compounds were identified by liquid chromatography coupled to mass spectrometry (LC-MS/MS. The antioxidant activity of the EEHS was investigated using the method that involves the scavenging of 2,2-diphenyl-1-picrylhydrazyl free radicals as well as the inhibition of oxidative hemolysis and lipid peroxidation induced by 2,2'-azobis (2-amidinopropane in human erythrocytes. The antimicrobial activity was determined by calculating the minimum inhibitory concentration, minimum bactericidal concentration, minimum fungicidal concentration, and zone of inhibition. Kasumi-1 leukemic cells were used to assess the cytotoxic activity and mechanisms involved in cell death promoted by the EEHS. The chemical compounds identified were quinic acid, chlorogenic acid, catechin, rutin, isoquercitrin, kaempferol-rutinoside, and catechin-pentoside. The EEHS demonstrated antioxidant activity via the sequestration of free radicals, inhibition of hemolysis, and inhibition of lipid peroxidation in human erythrocytes incubated with an oxidizing agent. The antimicrobial activity was observed against American Type Culture Collection (ATCC and hospital strains of bacteria and fungi, filamentous fungi and dermatophytes. The cytotoxic activity of the EEHS was induced by apoptosis, reduction of the mitochondrial membrane potential, and activation of cathepsins. Together, these results indicate the presence of phenolic compounds and flavonoids

  1. Magalhães Gomes, físico e humanista

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    Ângela Vaz Leão

    2002-10-01

    Full Text Available Este trabalho tem dois objetivos: primeiro apresentar aos leitores da revista Scripta e aos jovens universitários a figura de um grande pesquisador na área da Física que foi também um humanista eminente, o Professor Francisco de Assis Magalhães Gomes; depois, publicar um erudito trabalho seu, de crítica etimológica, intitulado “Um erro etimológico: a origem do vocábulo gallium para designar o elemento 31 da classificação periódica”. Esse trabalho, apenas introduzido no presente artigo, será transcrito no artigo seguinte.

  2. Climatology and Spatio-Temporal Variability of Wintertime Total and Extreme Rainfall in Thailand during 1970-2012

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    Atsamon Limsakul

    2017-07-01

    Full Text Available This study aims at examining wintertime (December-January-February; DJF climatology and spatio-temporal variability of Thailand’s total and extreme rainfall during 1970-2012. Analysis showed that the area along the Gulf of Thailand’s eastern coast not only received much amount of rainfall but also underwent great extremes and variances during the northeast monsoon (NEM winters. Empirical Orthogonal Function (EOF analysis similarly revealed that the leading mode of each DJF total or extreme rainfall index was marked by maximum loadings concentrated at the stations located at the exposed area of the NEM flow. Correlation analysis indicated that the leading EOF mode of DJF total and extreme indices in Thailand tended to be higher (lower than normal during strong (weak East Asian Winter Monsoon (EAWM. On longer timescales, the recent decadal change observed in the leading EOF mode of all rainfall indices has been coincident with re-amplification of the EAWM taken place since the early/mid 2000. The leading EOF mode of DJF total and extreme rainfall indices in Thailand also exhibited strong correlations with the tropical-subtropical Pacific Ocean surface temperatures. It was characterized as the Pacific Decadal Oscillation (PDO/El Niño Southern Oscillation (ENSO-related boomerang-shaped spatial patterns, resembling the typical mature phases of the La Niña event and the PDO cool epoch. Based on our analysis, it is reasonable to believe that the anomalies of the NEM and other key EAWM-related circulations are likely to be the possible causes of DJF total and extreme rainfall variations in Thailand. In addition, the ENSO and PDO as the primary global atmospheric external forcing are likely to exert their influence on wintertime Thailand’s climate via modulating the EAWM/NEM-related circulations anomalies.

  3. Comparison of GOME tropospheric NO2 columns with NO2 profiles deduced from ground-based in situ measurements

    Science.gov (United States)

    Schaub, D.; Boersma, K. F.; Kaiser, J. W.; Weiss, A. K.; Folini, D.; Eskes, H. J.; Buchmann, B.

    2006-08-01

    Nitrogen dioxide (NO2) vertical tropospheric column densities (VTCs) retrieved from the Global Ozone Monitoring Experiment (GOME) are compared to coincident ground-based tropospheric NO2 columns. The ground-based columns are deduced from in situ measurements at different altitudes in the Alps for 1997 to June 2003, yielding a unique long-term comparison of GOME NO2 VTC data retrieved by a collaboration of KNMI (Royal Netherlands Meteorological Institute) and BIRA/IASB (Belgian Institute for Space Aeronomy) with independently derived tropospheric NO2 profiles. A first comparison relates the GOME retrieved tropospheric columns to the tropospheric columns obtained by integrating the ground-based NO2 measurements. For a second comparison, the tropospheric profiles constructed from the ground-based measurements are first multiplied with the averaging kernel (AK) of the GOME retrieval. The second approach makes the comparison independent from the a priori NO2 profile used in the GOME retrieval. This allows splitting the total difference between the column data sets into two contributions: one that is due to differences between the a priori and the ground-based NO2 profile shapes, and another that can be attributed to uncertainties in both the remaining retrieval parameters (such as, e.g., surface albedo or aerosol concentration) and the ground-based in situ NO2 profiles. For anticyclonic clear sky conditions the comparison indicates a good agreement between the columns (n=157, R=0.70/0.74 for the first/second comparison approach, respectively). The mean relative difference (with respect to the ground-based columns) is -7% with a standard deviation of 40% and GOME on average slightly underestimating the ground-based columns. Both data sets show a similar seasonal behaviour with a distinct maximum of spring NO2 VTCs. Further analysis indicates small GOME columns being systematically smaller than the ground-based ones. The influence of different shapes in the a priori and

  4. Comparison of GOME tropospheric NO2 columns with NO2 profiles deduced from ground-based in situ measurements

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    D. Schaub

    2006-01-01

    Full Text Available Nitrogen dioxide (NO2 vertical tropospheric column densities (VTCs retrieved from the Global Ozone Monitoring Experiment (GOME are compared to coincident ground-based tropospheric NO2 columns. The ground-based columns are deduced from in situ measurements at different altitudes in the Alps for 1997 to June 2003, yielding a unique long-term comparison of GOME NO2 VTC data retrieved by a collaboration of KNMI (Royal Netherlands Meteorological Institute and BIRA/IASB (Belgian Institute for Space Aeronomy with independently derived tropospheric NO2 profiles. A first comparison relates the GOME retrieved tropospheric columns to the tropospheric columns obtained by integrating the ground-based NO2 measurements. For a second comparison, the tropospheric profiles constructed from the ground-based measurements are first multiplied with the averaging kernel (AK of the GOME retrieval. The second approach makes the comparison independent from the a priori NO2 profile used in the GOME retrieval. This allows splitting the total difference between the column data sets into two contributions: one that is due to differences between the a priori and the ground-based NO2 profile shapes, and another that can be attributed to uncertainties in both the remaining retrieval parameters (such as, e.g., surface albedo or aerosol concentration and the ground-based in situ NO2 profiles. For anticyclonic clear sky conditions the comparison indicates a good agreement between the columns (n=157, R=0.70/0.74 for the first/second comparison approach, respectively. The mean relative difference (with respect to the ground-based columns is −7% with a standard deviation of 40% and GOME on average slightly underestimating the ground-based columns. Both data sets show a similar seasonal behaviour with a distinct maximum of spring NO2 VTCs. Further analysis indicates small GOME columns being systematically smaller than the ground-based ones. The influence of different shapes in the a

  5. Quality of Hancornia speciosa Gomes seeds in function of drying periods / Qualidade de sementes de Hancornia speciosa Gomes em função do tempo de secagem

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    Cosmo Rufino de Lima

    2010-07-01

    Full Text Available A mangabeira (Hancornia speciosa Gomes, da família Apocynaceae é originária do Brasil. Seus frutos são obtidos principalmente de forma extrativista e sua propagação é realizada por meio de sementes. O objetivo da pesquisa foi avaliar o efeito da secagem da semente na emergência e crescimento inicial de plântulas de H. speciosa. O trabalho foi conduzido no Laboratório de Análises de Sementes do Centro de Ciências Agrárias da Universidade Federal da Paraíba (CCA/UFPB, onde as sementes foram postas para secar sobre papel toalha em condições de laboratório pelos seguintes períodos: 0 (sem secagem, 24, 48, 72, 96, 120 e 144 horas. Determinou-se o teor de água, a porcentagem, primeira contagem e índice de velocidade de emergência, bem como o comprimento e a massa seca de plântulas. O delineamento experimental foi inteiramente ao acaso, com sete tratamentos em quatro repetições de 25 sementes. O teor de água das sementes foi reduzido de 56 para 12% após 144 horas de secagem; a emergência máxima (73% ocorreu após 33 horas de secagem; na primeira contagem as maiores porcentagens de emergência (67% foram obtidas após 16 horas de secagem; os maiores índices de velocidade de emergência (0,62 ocorreram após 21 horas de secagem; o comprimento da raiz reduziu linearmente ao longo da secagem, enquanto constatou-se maior comprimento da parte aérea (4,96 cm quando as sementes foram submetidas à secagem por 57 horas. A secagem das sementes de H. speciosa é recomendada por até 48 horas.Hancornia speciosa Gomes (Apocynaceae, a fruiting plant originated from Brazil, has fruits obtained mainly by extractivism and its main form of propagation is by seeds. The objective of this research work was to evaluate the effect of drying on emergency and initial growth of seedlings of H. speciosa. The work was developed in the Laboratory of Analyses of Seeds (CCA/UFPB, where the seeds were put to dry on towel paper in the laboratory

  6. Modeling a typical winter-time dust event over the Arabian Peninsula and the Red Sea

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    S. Kalenderski

    2013-02-01

    Full Text Available We used WRF-Chem, a regional meteorological model coupled with an aerosol-chemistry component, to simulate various aspects of the dust phenomena over the Arabian Peninsula and Red Sea during a typical winter-time dust event that occurred in January 2009. The model predicted that the total amount of emitted dust was 18.3 Tg for the entire dust outburst period and that the two maximum daily rates were ~2.4 Tg day−1 and ~1.5 Tg day−1, corresponding to two periods with the highest aerosol optical depth that were well captured by ground- and satellite-based observations. The model predicted that the dust plume was thick, extensive, and mixed in a deep boundary layer at an altitude of 3–4 km. Its spatial distribution was modeled to be consistent with typical spatial patterns of dust emissions. We utilized MODIS-Aqua and Solar Village AERONET measurements of the aerosol optical depth (AOD to evaluate the radiative impact of aerosols. Our results clearly indicated that the presence of dust particles in the atmosphere caused a significant reduction in the amount of solar radiation reaching the surface during the dust event. We also found that dust aerosols have significant impact on the energy and nutrient balances of the Red Sea. Our results showed that the simulated cooling under the dust plume reached 100 W m−2, which could have profound effects on both the sea surface temperature and circulation. Further analysis of dust generation and its spatial and temporal variability is extremely important for future projections and for better understanding of the climate and ecological history of the Red Sea.

  7. Modeling a typical winter-time dust event over the Arabian Peninsula and the Red Sea

    KAUST Repository

    Kalenderski, Stoitchko

    2013-02-20

    We used WRF-Chem, a regional meteorological model coupled with an aerosol-chemistry component, to simulate various aspects of the dust phenomena over the Arabian Peninsula and Red Sea during a typical winter-time dust event that occurred in January 2009. The model predicted that the total amount of emitted dust was 18.3 Tg for the entire dust outburst period and that the two maximum daily rates were ?2.4 Tg day-1 and ?1.5 Tg day-1, corresponding to two periods with the highest aerosol optical depth that were well captured by ground-and satellite-based observations. The model predicted that the dust plume was thick, extensive, and mixed in a deep boundary layer at an altitude of 3-4 km. Its spatial distribution was modeled to be consistent with typical spatial patterns of dust emissions. We utilized MODIS-Aqua and Solar Village AERONET measurements of the aerosol optical depth (AOD) to evaluate the radiative impact of aerosols. Our results clearly indicated that the presence of dust particles in the atmosphere caused a significant reduction in the amount of solar radiation reaching the surface during the dust event. We also found that dust aerosols have significant impact on the energy and nutrient balances of the Red Sea. Our results showed that the simulated cooling under the dust plume reached 100 W m-2, which could have profound effects on both the sea surface temperature and circulation. Further analysis of dust generation and its spatial and temporal variability is extremely important for future projections and for better understanding of the climate and ecological history of the Red Sea.

  8. The dependence of wintertime Mediterranean precipitation on the atmospheric circulation response to climate change

    Science.gov (United States)

    Zappa, Giuseppe; Hoskins, Brian; Shepherd, Ted

    2016-04-01

    Climate models indicate a future wintertime precipitation reduction in the Mediterranean region which may have large socio-economic impacts. However, there is large uncertainty in the amplitude of the projected precipitation reduction and this limits the possibility to inform effective adaptation planning. We analyse CMIP5 climate model output to quantify the role of atmospheric circulation in the precipitation change and the time of emergence of the Mediterranean precipitation response. It is found that a simple circulation index, i.e. the 850 hPa zonal wind (U850) in North Africa, well describes the year to year fluctuations in the area-averaged Mediterranean precipitation, with positive (i.e. westerly) U850 anomalies in North Africa being associated with positive precipitation anomalies. Under climate change, U850 in North Africa and the Mediterranean precipitation are both projected to decrease consistently with the relationship found in the inter-annual variability. This enables us to estimate that about 85% of the CMIP5 mean precipitation response and 80% of the variance in the inter-model spread are related to changes in the atmospheric circulation. In contrast, there is no significant correlation between the mean precipitation response and the global-mean surface warming across the models. We also find that the precipitation response to climate change might already emerge from internal variability by 2025 relative to 1960-1990 according to the climate models with a large circulation response. This implies that it might soon be possible to test model projections using observations. Finally, some of the mechanisms which are important for the Mediterranean circulation response in the CMIP5 models are discussed.

  9. Interannual variations and future change of wintertime extratropical cyclone activity over North America in CCSM3

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Haiyan; Washington, Warren M.; Meehl, Gerald A. [National Center for Atmospheric Research, PO Box 3000, Boulder, CO (United States)

    2008-06-15

    Climatology and interannual variations of wintertime extratropical cyclone frequency in CCSM3 twentieth century simulation are compared with the NCEP/NCAR reanalysis during 1950-1999. CCSM3 can simulate the storm tracks reasonably well, although the model produces slightly less cyclones at the beginning of the Pacific and Atlantic storm tracks and weaker poleward deflection over the Pacific. As in the reanalysis, frequency of cyclones stronger than 980 hPa shows significant correlation with the Pacific/North America (PNA) teleconnection pattern over the Pacific region and with the North Atlantic Oscillation (NAO) in the Atlantic sector. Composite maps are constructed for opposite phases of El Nino-Southern Oscillation (ENSO) and the NAO and all anomalous patterns coincide with observed. One CCSM3 twenty-first century A1B scenario realization indicates there is significant increase in the extratropical cyclone frequency on the US west coast and decrease in Alaska. Meanwhile, cyclone frequency increases from the Great Lakes region to Quebec and decreases over the US east coast, suggesting a possible northward shift of the Atlantic storm tracks under the warmer climate. The cyclone frequency anomalies are closely linked to changes in seasonal mean states of the upper-troposphere zonal wind and baroclinicity in the lower troposphere. Due to lack of 6-hourly outputs, we cannot apply the cyclone-tracking algorithm to the other eight CCSM3 realizations. Based on the linkage between the mean state change and the cyclone frequency anomalies, it is likely a common feature among the other ensemble members that cyclone activity is reduced on the East Coast and in Alaska as a result of global warming. (orig.)

  10. Model study on acidifying wet deposition in East Asia during wintertime

    Science.gov (United States)

    Han, Zhiwei; Ueda, Hiromasa; Sakurai, Tatsuya

    A regional air quality model (RAQM) has been developed and applied together with an aerosol model to investigate the states and characteristics of wet deposition in East Asia in December 2001. Model simulation is performed with monthly based emission inventory [Streets, D.G., Bond, T.C., Carmichael, G.R., Fernandes, S.D., Fu, Q., He, D., Klimont, Z., Nelson, S. M., Tsai, N.Y., Wang, M.Q., Woo, J.-H., Yarber, K.F., 2003. An inventory of gaseous and primary emissions in Asia in the year 2000. Journal of Geophysical Research 108(D21), 8809] and meteorological fields derived from MM5. Model results are compared with extensive monitoring data including relevant gaseous species and ions in precipitation. The validation demonstrates that this model system is able to represent most of the major physical and chemical processes involved in acid deposition and reproduces concentrations reasonably well, within a factor of 2 of observations in general. The study shows that the regions with pH less than 4.5 are mainly located in southwestern China, parts of the Yangtze Delta, the Yellow Sea and the Korean peninsula, indicating wide regions of acid precipitation in East Asia in wintertime. Japan islands mainly exhibit pH values of 4.5-5.0, whereas over wide areas of northern China, pH values are relatively high (⩾5.0) due to neutralization by alkaline materials such as calcium-laden particles and ammonia, which are more abundant in northern China than that in southern China. While acid rain over most of China is still characterized by sulfur-induced type, considerable areas of eastern China and the western Pacific Rim are found to be more affected by nitric acid than sulfuric acid in acidification of precipitation, which is supposed to result from a combined effect of variations in photochemistry and emission, suggesting the increasing importance of NO x emission in these regions.

  11. Glyoxal Vertical Column Retrievals from the GOME-2/METOP-A European Spaceborne Sensor and Comparisons with the IMAGESv2 CT Model

    Science.gov (United States)

    Lerot, C.; Stavrakou, T.; de Smedt, I.; Muller, J. J.; van Roozendael, M.

    2010-12-01

    Glyoxal is mostly formed in our atmosphere as an intermediate product in the oxidation of non-methane volatile organic compounds (NMVOC). To a lesser extent, it is also directly emitted from biomass burning events and from fossil- and bio-fuel combustion processes. Several studies have estimated its atmospheric lifetime to 2-3 hours, which makes of glyoxal a good indicator for short-lived NMVOC emissions. Glyoxal is also known to be a precursor for secondary organic aerosols and could help to reduce the gap between observations and models for organic aerosol abundances. The three absorption bands of glyoxal in the visible region allow applying the DOAS (Differential Optical Absorption Spectroscopy) technique to retrieve its vertical column densities from the nadir backscattered light measurements performed by the GOME-2 satellite sensor. This instrument has been launched in October 2006 on board of the METOP-A platform and is characterized by a spatial resolution of 80 km x 40 km and by a large scan-width (1920 km) leading to a global coverage reached in 1.5 day. The GOME-2 glyoxal retrieval algorithm developed at BIRA-IASB accounts for the liquid water absorption and provides geophysically sound column measurements not only over lands but also over oceanic regions where spectral interferences between glyoxal and liquid water have been shown to be significant. The a-priori glyoxal vertical distribution required for the slant to vertical column conversion is provided by the global chemical transport model IMAGESv2. The highest glyoxal vertical column densities are mainly observed in continental tropical regions, while the mid-latitude columns strongly depend on the season with maximum values during warm months. An anthropogenic signature is also observed in highly populated regions of Asia. Comparisons with glyoxal columns simulated with IMAGESv2 in different regions of the world generally point to a missing glyoxal source in current models. As already reported from

  12. GOME-2A retrievals of tropospheric NO2 in different spectral ranges – influence of penetration depth

    Directory of Open Access Journals (Sweden)

    L. K. Behrens

    2018-05-01

    Full Text Available In this study, we present a novel nitrogen dioxide (NO2 differential optical absorption spectroscopy (DOAS retrieval in the ultraviolet (UV spectral range for observations from the Global Ozone Monitoring Instrument 2 on board EUMETSAT's MetOp-A (GOME-2A satellite. We compare the results to those from an established NO2 retrieval in the visible (vis spectral range from the same instrument and investigate how differences between the two are linked to the NO2 vertical profile shape in the troposphere.As expected, radiative transfer calculations for satellite geometries show that the sensitivity close to the ground is higher in the vis than in the UV spectral range. Consequently, NO2 slant column densities (SCDs in the vis are usually higher than in the UV if the NO2 is close to the surface. Therefore, these differences in NO2 SCDs between the two spectral ranges contain information on the vertical distribution of NO2 in the troposphere. We combine these results with radiative transfer calculations and simulated NO2 fields from the TM5-MP chemistry transport model to evaluate the simulated NO2 vertical distribution.We investigate regions representative of both anthropogenic and biomass burning NO2 pollution. Anthropogenic air pollution is mostly located in the boundary layer close to the surface, which is reflected by large differences between UV and vis SCDs of  ∼  60 %. Biomass burning NO2 in contrast is often uplifted into elevated layers above the boundary layer. This is best seen in tropical Africa south of the Equator, where the biomass burning NO2 is well observed in the UV, and the SCD difference between the two spectral ranges is only  ∼  36 %. In tropical Africa north of the Equator, however, the biomass burning NO2 is located closer to the ground, reducing its visibility in the UV.While not enabling a full retrieval of the vertical NO2 profile shape in the troposphere, our results can help to constrain the vertical

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

    Science.gov (United States)

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

    2014-09-01

    The main goal of this article 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 Center (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 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), the correlation exhibits a remarkable improvement (R2 ~ 0.95). Nevertheless, analyzing the six datasets together, the relative differences between GOME-2 and GRUAN data shows mean values (in absolute term) of 19% for all-sky conditions and 14% for cloud-free cases, which evidences a notable bias in the satellite TWVC data against the reference balloon-borne measurements. The satellite-sounding TWVC differences show a strong solar zenith angle (SZA) dependence for values above 50° with a stable behaviour for values below this zenith angle. The smallest relative differences found in the inter-comparison (between -5 and +3%) are achieved for those cloud-free cases with SZA below 50°. Furthermore, 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 +5 to -20% when CTA rises from 0.3 to 0.9. Finally, the satellite-sounding differences also show a negative dependence on the reference TWVC values, changing from

  14. The Passy-2015 field experiment: wintertime atmospheric dynamics and air quality in a narrow alpine valley

    Science.gov (United States)

    Paci, Alexandre; Staquet, Chantal

    2016-04-01

    Wintertime anticyclonic conditions lead to the formation of persistent stable boundary layers which may induce severe air pollution episodes in urban or industrialized area, particularly in mountain regions. The Arve river valley in the Northern Alps is very sensitive to this phenomenon, in particular close to the city of Passy (Haute-Savoie), 20 km down valley past Chamonix. This place is indeed one of the worst place in France regarding air quality, the concentration of fine particles and Benzo(a)pyrene (a carcinogenic organic compound) regularly exceeding the EU legal admissible level during winter. Besides air quality measurements, such as the ones presently carried in the area by the local air quality agency Air Rhône-Alpes or in the DECOMBIO project led by LGGE, it is crucial to improve our knowledge of the atmospheric boundary layer dynamics and processes at the valley scale under these persistent stable conditions in order to improve our understanding on how it drives pollutant dispersion. These issues motivated the Passy-2015 field experiment which took place during the winter 2014-2015. A relatively large set-up of instruments was deployed on a main measurement site in the valley center and on four other satellite sites. It includes several remote sensing instruments, a surface flux station, a 10 m instrumented tower, a large aperture scintillometer, a fog monitoring station among others. Most of the instruments were present from early January to the end of February. During two intensive observation periods, 6-14 February and 17-20 February, the instrumental set-up was completed on the main site with high frequency radio-soundings (up to one per 1h30), a tethered balloon, a remote controlled drone quadcopter and a sodar. The field campaign, the instruments, the meteorological situations observed and preliminary results will be presented. This field experiment is part of the Passy project funded by ADEME through the French national programme LEFE/INSU and

  15. Characterization of nutrient deficiency in Hancornia speciosa Gomes seedlings by omitting micronutrients from the nutrient solution

    Directory of Open Access Journals (Sweden)

    Layara Alexandre Bessa

    2013-06-01

    Full Text Available Hancornia speciosa Gomes (Mangaba tree is a fruit tree belonging to the Apocynaceae family and is native to Brazil. The production of seedlings of this species is limited by a lack of technical and nutritional expertise. To address this deficiency, this study aimed to characterize the visual symptoms of micronutrient deficiency and to assess growth and leaf nutrient accumulation in H. speciosa seedlings supplied with nutrient solutions that lack individual micronutrients. H. speciosa plants were grown in nutrient solution in a greenhouse according to a randomized block design, with four replicates. The treatments consisted of a group receiving complete nutrient solution and groups treated with a nutrient solution lacking one of the following micronutrients: boron (B, copper (Cu, iron (Fe, manganese (Mn, zinc (Zn, and molybdenum (Mo. The visual symptoms of nutrient deficiency were generally easy to characterize. Dry matter production was affected by the omission of micronutrients, and the treatment lacking Fe most limited the stem length, stem diameter, root length, and number of leaves in H. speciosa seedlings as well as the dry weight of leaves, the total dry weight, and the relative growth in H. speciosa plants. The micronutrient contents of H. speciosa leaves from plants receiving the complete nutrient solution treatment were, in decreasing order, Fe>Mn>Cu>Zn>B.

  16. An integrated campaign for investigation of winter-time continental haze over Indo-Gangetic Basin and its radiative effects

    International Nuclear Information System (INIS)

    Das, Sanat Kumar; Chatterjee, Abhijit; Ghosh, Sanjay K.; Raha, Sibaji

    2015-01-01

    An outflow of continental haze occurs from Indo-Gangetic Basin (IGB) in the North to Bay of Bengal (BoB) in the South. An integrated campaign was organized to investigate this continental haze during December 2013–February 2014 at source and remote regions within IGB to quantify its radiative effects. Measurements were carried out at three locations in eastern India; 1) Kalas Island, Sundarban (21.68°N, 88.57°E) — an isolated island along the north-east coast of BoB, 2) Kolkata (22.57°N, 88.42°E) — an urban metropolis and 3) Siliguri (26.70°N, 88.35°E) — an urban region at the foothills of eastern Himalayas. Ground-based AOD (at 0.5 μm) is observed to be maximum (1.25 ± 0.18) over Kolkata followed by Siliguri (0.60 ± 0.17) and minimum over Sundarban (0.53 ± 0.18). Black carbon concentration is found to be maximum at Kolkata (21.6 ± 6.6 μg·m −3 ) with almost equal concentrations at Siliguri (12.6 ± 5.2 μg·m −3 ) and Sundarban (12.3 ± 3.0 μg·m −3 ). Combination of MODIS-AOD and back-trajectories analysis shows an outflow of winter-time continental haze originating from central IGB and venting out through Sundarban towards BoB. This continental haze with high extinction coefficient is identified up to central BoB using CALIPSO observations and is found to contribute ~ 75% to marine AOD over central BoB. This haze produces significantly high aerosol radiative forcing within the atmosphere over Kolkata (75.4 Wm −2 ) as well as over Siliguri and Sundarban (40 Wm −2 ) indicating large forcing over entire IGB, from foothills of the Himalayas to coastal region. This winter-time continental haze also causes about similar radiative heating (1.5 K·day −1 ) from Siliguri to Sundarban which is enhanced over Kolkata (3 K·day −1 ) due to large emission of local urban aerosols. This high aerosol heating over entire IGB and coastal region of BoB can have considerable impact on the monsoonal circulation and more importantly, such haze

  17. An integrated campaign for investigation of winter-time continental haze over Indo-Gangetic Basin and its radiative effects

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sanat Kumar, E-mail: sanatkrdas@gmail.com [Environmental Sciences Section, Bose Institute, Kolkata (India); Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata (India); Chatterjee, Abhijit [Environmental Sciences Section, Bose Institute, Kolkata (India); Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata (India); National Facility on Astroparticle Physics and Space Science, Darjeeling (India); Ghosh, Sanjay K. [Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata (India); National Facility on Astroparticle Physics and Space Science, Darjeeling (India); Raha, Sibaji [Environmental Sciences Section, Bose Institute, Kolkata (India); Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata (India); National Facility on Astroparticle Physics and Space Science, Darjeeling (India)

    2015-11-15

    An outflow of continental haze occurs from Indo-Gangetic Basin (IGB) in the North to Bay of Bengal (BoB) in the South. An integrated campaign was organized to investigate this continental haze during December 2013–February 2014 at source and remote regions within IGB to quantify its radiative effects. Measurements were carried out at three locations in eastern India; 1) Kalas Island, Sundarban (21.68°N, 88.57°E) — an isolated island along the north-east coast of BoB, 2) Kolkata (22.57°N, 88.42°E) — an urban metropolis and 3) Siliguri (26.70°N, 88.35°E) — an urban region at the foothills of eastern Himalayas. Ground-based AOD (at 0.5 μm) is observed to be maximum (1.25 ± 0.18) over Kolkata followed by Siliguri (0.60 ± 0.17) and minimum over Sundarban (0.53 ± 0.18). Black carbon concentration is found to be maximum at Kolkata (21.6 ± 6.6 μg·m{sup −3}) with almost equal concentrations at Siliguri (12.6 ± 5.2 μg·m{sup −3}) and Sundarban (12.3 ± 3.0 μg·m{sup −3}). Combination of MODIS-AOD and back-trajectories analysis shows an outflow of winter-time continental haze originating from central IGB and venting out through Sundarban towards BoB. This continental haze with high extinction coefficient is identified up to central BoB using CALIPSO observations and is found to contribute ~ 75% to marine AOD over central BoB. This haze produces significantly high aerosol radiative forcing within the atmosphere over Kolkata (75.4 Wm{sup −2}) as well as over Siliguri and Sundarban (40 Wm{sup −2}) indicating large forcing over entire IGB, from foothills of the Himalayas to coastal region. This winter-time continental haze also causes about similar radiative heating (1.5 K·day{sup −1}) from Siliguri to Sundarban which is enhanced over Kolkata (3 K·day{sup −1}) due to large emission of local urban aerosols. This high aerosol heating over entire IGB and coastal region of BoB can have considerable impact on the monsoonal circulation and more

  18. Nitrous acid formation in a snow-free wintertime polluted rural area

    Science.gov (United States)

    Tsai, Catalina; Spolaor, Max; Fedele Colosimo, Santo; Pikelnaya, Olga; Cheung, Ross; Williams, Eric; Gilman, Jessica B.; Lerner, Brian M.; Zamora, Robert J.; Warneke, Carsten; Roberts, James M.; Ahmadov, Ravan; de Gouw, Joost; Bates, Timothy; Quinn, Patricia K.; Stutz, Jochen

    2018-02-01

    Nitrous acid (HONO) photolysis is an important source of hydroxyl radicals (OH) in the lower atmosphere, in particular in winter when other OH sources are less efficient. The nighttime formation of HONO and its photolysis in the early morning have long been recognized as an important contributor to the OH budget in polluted environments. Over the past few decades it has become clear that the formation of HONO during the day is an even larger contributor to the OH budget and additionally provides a pathway to recycle NOx. Despite the recognition of this unidentified HONO daytime source, the precise chemical mechanism remains elusive. A number of mechanisms have been proposed, including gas-phase, aerosol, and ground surface processes, to explain the elevated levels of daytime HONO. To identify the likely HONO formation mechanisms in a wintertime polluted rural environment we present LP-DOAS observations of HONO, NO2, and O3 on three absorption paths that cover altitude intervals from 2 to 31, 45, and 68 m above ground level (a.g.l.) during the UBWOS 2012 experiment in the Uintah Basin, Utah, USA. Daytime HONO mixing ratios in the 2-31 m height interval were, on average, 78 ppt, which is lower than HONO levels measured in most polluted urban environments with similar NO2 mixing ratios of 1-2 ppb. HONO surface fluxes at 19 m a.g.l., calculated using the HONO gradients from the LP-DOAS and measured eddy diffusivity coefficient, show clear upward fluxes. The hourly average vertical HONO flux during sunny days followed solar irradiance, with a maximum of (4.9 ± 0.2) × 1010 molec. cm-2 s-1 at noontime. A photostationary state analysis of the HONO budget shows that the surface flux closes the HONO budget, accounting for 63 ± 32 % of the unidentified HONO daytime source throughout the day and 90 ± 30 % near noontime. This is also supported by 1-D chemistry and transport model calculations that include the measured surface flux, thus clearly identifying chemistry at the

  19. Observation of Atmospheric Constituents From Space

    Science.gov (United States)

    Burrows, J. P.

    Remote sensing of the atmosphere from space is a growing research field. Surprisingly but for good physical reasons, the mesosphere and stratosphere are easier to probe from space than the troposphere. GOME (Global Ozone Monitoring Experiment) and SCIAMACHY (Scanning Imaging absorption spectroMeter for Atmospheric CHartographY) are related European instruments, which were proposed and been designed to measure atmospheric constituents (gases, aerosols and clouds) by passive remote sensing of the up-welling solar radiation leaving atmosphere. GOME is a smaller version of SCIAMACHY and was launched as part of the core payload of the second European research satellite (ERS-2) on the 20th April 1995. GOME comprises four spectral channels and measures simultaneously the earthshine radiance or solar extra terrestrial irradiance between 240 and 790 nm. Inversion of GOME measurements using the DOAS (Differential Optical Absorption Spectroscopy) yields the total column of trace gases (e.g. O3, NO2, HCHO, BrO and OClO). Application of the FURM (Full Retrieval Method) enables the profiles of O3 to be retrieved. One of the important achievements of GOME has been the separation of tropopsheirc columns of trace gases using TEM (Tropospheric Excess Method). SCIAMACHY has been developed as Germa n, Dutch and Belgian contribution to ENVISAT. It has significantly enhanced capability compared to GOME, measuring a larger spectral range, 220-2380 nm, and observing in alternate nadir and limb modes as well as solar and lunar occultation. ENVISAT is to be launched into a sun synchronous polar orbit, having an equator crossing time of 10.00 a.m. at the beginning of March 2002. SCIAMACHY is thereby able to measure many more species and vertical profiles than GOME. This facilitates improved tropospheric retrievals. Finally GeoTROPE (Geostationary TROPospheric Explorer) is a new mission, which is proposed for launch within the ESA Earth Explorer Opportunity Mission. It comprises two national

  20. SO2 plume height retrieval from direct fitting of GOME-2 backscattered radiance measurements

    Science.gov (United States)

    van Gent, J.; Spurr, R.; Theys, N.; Lerot, C.; Brenot, H.; Van Roozendael, M.

    2012-04-01

    The use of satellite measurements for SO2 monitoring has become an important aspect in the support of aviation control. Satellite measurements are sometimes the only information available on SO2 concentrations from volcanic eruption events. The detection of SO2 can furthermore serve as a proxy for the presence of volcanic ash that poses a possible hazard to air traffic. In that respect, knowledge of both the total vertical column amount and the effective altitude of the volcanic SO2 plume is valuable information to air traffic control. The Belgian Institute for Space Aeronomy (BIRA-IASB) hosts the ESA-funded Support to Aviation Control Service (SACS). This system provides Volcanic Ash Advisory Centers (VAACs) worldwide with near real-time SO2 and volcanic ash data, derived from measurements from space. We present results from our algorithm for the simultaneous retrieval of total vertical columns of O3 and SO2 and effective SO2 plume height from GOME-2 backscattered radiance measurements. The algorithm is an extension to the GODFIT direct fitting algorithm, initially developed at BIRA-IASB for the derivation of improved total ozone columns from satellite data. The algorithm uses parameterized vertical SO2 profiles which allow for the derivation of the peak height of the SO2 plume, along with the trace gas total column amounts. To illustrate the applicability of the method, we present three case studies on recent volcanic eruptions: Merapi (2010), Grímsvotn (2011), and Nabro (2011). The derived SO2 plume altitude values are validated with the trajectory model FLEXPART and with aerosol altitude estimations from the CALIOP instrument on-board the NASA A-train CALIPSO platform. We find that the effective plume height can be obtained with a precision as fine as 1 km for moderate and strong volcanic events. Since this is valuable information for air traffic, we aim at incorporating the plume height information in the SACS system.

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

    Directory of Open Access Journals (Sweden)

    S. Beirle

    2006-01-01

    Full Text Available Nitrogen oxides (NOxNO+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 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 (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 column densities 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 90 (32-240 moles of NOx, or 1.3 (0.4-3.4 kg [N], per flash. If simply extrapolated, this corresponds to a global LNOx production of 1.7 (0.6-4.7Tg [N]/yr.

  2. Comparison of wintertime CO to NOx ratios to MOVES and MOBILE6.2 on-road emissions inventories

    Science.gov (United States)

    Wallace, H. W.; Jobson, B. T.; Erickson, M. H.; McCoskey, J. K.; VanReken, T. M.; Lamb, B. K.; Vaughan, J. K.; Hardy, R. J.; Cole, J. L.; Strachan, S. M.; Zhang, W.

    2012-12-01

    The CO-to-NOx molar emission ratios from the US EPA vehicle emissions models MOVES and MOBILE6.2 were compared to urban wintertime measurements of CO and NOx. Measurements of CO, NOx, and volatile organic compounds were made at a regional air monitoring site in Boise, Idaho for 2 months from December 2008 to January 2009. The site is impacted by roadway emissions from a nearby busy urban arterial roads and highway. The measured CO-to-NOx ratio for morning rush hour periods was 4.2 ± 0.6. The average CO-to-NOx ratio during weekdays between the hours of 08:00 and 18:00 when vehicle miles travelled were highest was 5.2 ± 0.5. For this time period, MOVES yields an average hourly CO-to-NOx ratio of 9.1 compared to 20.2 for MOBILE6.2. Off-network emissions are a significant fraction of the CO and NOx emissions in MOVES, accounting for 65% of total CO emissions, and significantly increase the CO-to-NOx molar ratio. Observed ratios were more similar to the average hourly running emissions for urban roads determined by MOVES to be 4.3.

  3. Typical synoptic situations and their impacts on the wintertime air pollution in the Guanzhong basin, China

    Directory of Open Access Journals (Sweden)

    N. Bei

    2016-06-01

    Full Text Available Rapid industrialization and urbanization have caused severe air pollution in the Guanzhong basin, northwestern China, with heavy haze events occurring frequently in recent winters. Using the NCEP reanalysis data, the large-scale synoptic situations influencing the Guanzhong basin during wintertime of 2013 are categorized into six types to evaluate the contribution of synoptic situations to the air pollution, including “north-low”, “southwest-trough”, “southeast-high”, “transition”, “southeast-trough”, and “inland-high”. The FLEXPART model has been utilized to demonstrate the corresponding pollutant transport patterns for the typical synoptic situations in the basin. Except for “southwest-trough” and “southeast-high” (defined as favorable synoptic situations, the other four synoptic conditions (defined as unfavorable synoptic situations generally facilitate the accumulation of air pollutants, causing heavy air pollution in the basin. In association with the measurement of PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm in the basin, the unfavorable synoptic situations correspond to high PM2.5 mass concentrations or poor air quality and vice versa. The same analysis has also been applied to winters of 2008–2012, which shows that the basin was mainly influenced by the unfavorable synoptic situations during wintertime leading to poor air quality. The WRF-CHEM model has further been applied to simulate the selected 6 days representing the typical synoptic situations during the wintertime of 2013, and the results generally show a good agreement between the modeled distributions and variations of PM2.5 and the corresponding synoptic situations, demonstrating reasonable classification for the synoptic situations in the basin. Detailed meteorological conditions, such as temperature inversion, low-level horizontal wind speed, and planetary boundary layer, all contribute to heavy air pollution

  4. Process-scale modeling of elevated wintertime ozone in Wyoming.

    Energy Technology Data Exchange (ETDEWEB)

    Kotamarthi, V. R.; Holdridge, D. J.; Environmental Science Division

    2007-12-31

    Measurements of meteorological variables and trace gas concentrations, provided by the Wyoming Department of Environmental Quality for Daniel, Jonah, and Boulder Counties in the state of Wyoming, were analyzed for this project. The data indicate that highest ozone concentrations were observed at temperatures of -10 C to 0 C, at low wind speeds of about 5 mph. The median values for nitrogen oxides (NOx) during these episodes ranged between 10 ppbv and 20 ppbv (parts per billion by volume). Measurements of volatile organic compounds (VOCs) during these periods were insufficient for quantitative analysis. The few available VOCs measurements indicated unusually high levels of alkanes and aromatics and low levels of alkenes. In addition, the column ozone concentration during one of the high-ozone episodes was low, on the order of 250 DU (Dobson unit) as compared to a normal column ozone concentration of approximately 300-325 DU during spring for this region. Analysis of this observation was outside the scope of this project. The data analysis reported here was used to establish criteria for making a large number of sensitivity calculations through use of a box photochemical model. Two different VOCs lumping schemes, RACM and SAPRC-98, were used for the calculations. Calculations based on this data analysis indicated that the ozone mixing ratios are sensitive to (a) surface albedo, (b) column ozone, (c) NOx mixing ratios, and (d) available terminal olefins. The RACM model showed a large response to an increase in lumped species containing propane that was not reproduced by the SAPRC scheme, which models propane as a nearly independent species. The rest of the VOCs produced similar changes in ozone in both schemes. In general, if one assumes that measured VOCs are fairly representative of the conditions at these locations, sufficient precursors might be available to produce ozone in the range of 60-80 ppbv under the conditions modeled.

  5. Measurement of sulfur dioxide oxidation rates in wintertime orographic clouds

    International Nuclear Information System (INIS)

    Snider, J.R.

    1990-01-01

    SO2-reaction studies in the clouds are examined and summarized to experimentally confirm model predictions and previous field studies regarding dominant SO2-reaction pathways. Controlled amounts of SO2 were released into nonprecipitating orographic clouds, and sulfate yields are compared to oxidant depletions. The sulfate yields were taken from cloud-water samples and liquid-water-concentration measurements, and oxidant-depletion data were generated from continuous gas-phase measurements. Comparisons of Y sub SO4 and D sub H2O2 suggest that H2O2 is the dominant oxidant, and the in-cloud reaction between H2O2 and the bisulfite ion can be expressed by a simple rate that agrees with predictions and laboratory results. The rate measurements are found to be inconsistent with the rate law proposed by Hegg and Hobbs (1982) and with some observational data. The present conclusions are of interest to evaluating the effects of sulfur dioxide emissions on sulfuric acid deposition. 30 refs

  6. Modeling the impact of wintertime rain events on the thermal regime of permafrost

    Directory of Open Access Journals (Sweden)

    S. Westermann

    2011-10-01

    Full Text Available In this study, we present field measurements and numerical process modeling from western Svalbard showing that the ground surface temperature below the snow is impacted by strong wintertime rain events. During such events, rain water percolates to the bottom of the snow pack, where it freezes and releases latent heat. In the winter season 2005/2006, on the order of 20 to 50% of the wintertime precipitation fell as rain, thus confining the surface temperature to close to 0 °C for several weeks. The measured average ground surface temperature during the snow-covered period is −0.6 °C, despite of a snow surface temperature of on average −8.5 °C. For the considered period, the temperature threshold below which permafrost is sustainable on long timescales is exceeded. We present a simplified model of rain water infiltration in the snow coupled to a transient permafrost model. While small amounts of rain have only minor impact on the ground surface temperature, strong rain events have a long-lasting impact. We show that consecutively applying the conditions encountered in the winter season 2005/2006 results in the formation of an unfrozen zone in the soil after three to five years, depending on the prescribed soil properties. If water infiltration in the snow is disabled in the model, more time is required for the permafrost to reach a similar state of degradation.

  7. Field performance evaluation during fog-dominated wintertime of a newly developed denuder-equipped PM1 sampler.

    Science.gov (United States)

    Singh, Dharmendra Kumar; Lakshay; Gupta, Tarun

    2014-03-01

    This study presents the performance evaluation of a novel denuder-equipped PM1 (particles having aerodynamic diameter less than 1 μm) sampler, tested during fog-dominated wintertime, in the city of Kanpur, India. One PM1 sampler and one denuder-equipped PM1 sampler were co-located to collect ambient PM1 for 25 days. The mean PM1 mass concentration measured on foggy days with the PM1 sampler and the denuder-equipped PM1 sampler was found to be 165.95 and 135.48 μg/m(3), respectively. The mean PM1 mass concentration measured on clear days with the PM1 sampler and the denuder-equipped PM1 sampler was observed to be 159.66 and 125.14 μg/m(3), respectively. The mass concentration with denuder-fitted PM1 sampler for both foggy and clear days was always found less than the PM1 sampler. The same drift was observed in the concentrations of water-soluble ions and water-soluble organic carbon (WSOC). Moreover, it was observed that the use of denuder leads to a significant reduction in the PM positive artifact. The difference in the concentration of chemical species obtained by two samplers indicates that the PM1 sampler without denuder had overestimated the concentrations of chemical species in a worst-case scenario by almost 40 %. Denuder-fitted PM1 sampler can serve as a useful sampling tool in estimating the true values for nitrate, ammonium, potassium, sodium and WSOC present in the ambient PM.

  8. Biografia como história social: o clã Ferreira Gomes e os mundos da escravização no Atlântico Sul

    Directory of Open Access Journals (Sweden)

    Roquinaldo Ferreira

    2013-12-01

    Full Text Available Este artigo analisa as conexões econômicas e sociais engendradas pelo tráfico de escravos entre Angola e Brasil, assim como o abolicionismo português na primeira metade do século XIX. Neste sentido, o artigo usa como ponto de partida a trajetória pessoal de José Ferreira Gomes, um homem negro, nascido em Benguela, cuja mãe, Florinda José Gaspar, era filha de um chefe africano da Catumbela e cujo pai, Francisco Ferreira Gomes, foi um homem negro nascido no Brasil que tinha sido um dos traficantes de escravos mais ativos em Benguela. Tendo como base a biografia de Gomes Júnior, o artigo discute os laços sociais e culturais que os traficantes de escravos angolanos mantinham com o Brasil e com as populações africanas, a transição do tráfico de escravos para o comércio lícito, e as mudanças na políticas portuguesas em relação ao tráfico de escravos na década de 1840. Para entender o recrudescimento do colonialismo em Angola, o artigo examina acusações de que membros da família Ferreira Gomes teriam participado de sedições raciais e anti-coloniais contra os portugueses.

  9. On the use of harmonized HCHO and NO2 MAXDOAS measurements for the validation of GOME-2 and OMI satellite sensors

    Science.gov (United States)

    Pinardi, Gaia; Hendrick, François; Gielen, Clio; Van Roozendael, Michel; De Smedt, Isabelle; Lambert, Jean-Christopher; Granville, José; Compernolle, Steven; Richter, Andreas; Peters, Enno; Piters, Ankie; Wagner, Thomas; Wang, Yang; Drosoglou, Theano; Bais, Alkis; Wang, Shanshan; Saiz-Lopez, Alfonso

    2017-04-01

    During the last decade, the MAXDOAS technique has been increasingly recognized as a source of Fiducial Reference Measurements (FRM) suitable for the validation of satellite nadir observations of species relevant for climate and air quality like NO2 and HCHO. As part of the EU FP7 QA4ECV (Quality Assurance for Essential Climate Variables; see http://www.qa4ecv.eu/) project, efforts have been recently made to harmonize a network of a dozen of MAXDOAS spectrometers in view of their use to assess the quality of satellite climate data records generated within the same project. Harmonization tasks have addressed both retrieval steps involved in MAXDOAS retrievals, i.e. the DOAS spectral fit providing the differential slant column densities (DSCDs) and the conversion of the retrieved DSCDs into vertical profiles and/or vertical column densities (VCDs). In this work, we illustrate the successive harmonization steps and present the resulting QA4ECV MAXDOAS database v2. The approach adopted for the conversion of slant to vertical columns is based on a simplified look-up-table approach. The strength and limitation of this approach are discussed using reference data retrieved using an optimal estimation scheme. The QA4ECV MAXDOAS database is then used to validate satellite data sets of NO2 and HCHO columns derived from the Aura/OMI and MetOp/GOME-2 sensors. The methodology of comparison, which is also a subject of the QA4ECV project, is reviewed with respect to co-location criteria, impact of vertical and horizontal smoothing and representativeness of validation sites. We conclude by assessing the current strengths and limitations of the existing MAXDOAS datasets for NO2 and HCHO satellite validation.

  10. A multimethodological approach to study the spatial distribution of air pollution in an Alpine valley during wintertime

    Directory of Open Access Journals (Sweden)

    R. Schnitzhofer

    2009-05-01

    Full Text Available In order to investigate the spatial distribution of air pollutants in the Inn valley (Tyrol, Austria during wintertime, a joint field campaign of the three research projects ALPNAP (Monitoring and Minimisation of Traffic-Induced Noise and Air Pollution Along Major Alpine Transport Routes, INNAP (Boundary Layer Structure in the Inn Valley during high Air Pollution and INNOX (NOx-structure in the Inn Valley during High Air Pollution was carried out in January/February 2006. In addition to continuous ground based measurements, vertical profiles of various air pollutants and meteorological parameters were obtained on six selected days. For in-situ investigations, a tethered balloon was used to analyse the lowest atmospheric layers, 0–500 m above the valley bottom (a.v.b., and a research aircraft sampled at 150–2200 m a.v.b. An aircraft equipped with an aerosol backscatter lidar performed nadir measurements at 3000 m a.v.b. Combined results from a typical day show a strongly polluted layer up to about 125 m a.v.b. in the morning. Around midday concentrations on the valley floor decrease indicating some vertical air exchange despite thermally stable conditions. Strong vertical and horizontal gradients with enhanced pollution levels along the sunny side of the valley up to 1300 m a.v.b. were observed in the afternoon. This vertical mixing due to thermally or dynamically driven slope winds reduces the concentration of air pollutants at the bottom of the valley and causes the formation of elevated pollution layers.

  11. THE THIRD MARGIN OF HISTORY. NOTES ON THE TWO FACES OF WAR BY DIANA ANDRINGA AND FLORA GOMES

    Directory of Open Access Journals (Sweden)

    Livia Apa

    2010-11-01

    Full Text Available The essay intends to approach, taking the documentary authored by the Portuguese journalist Diana Andringa and the Guinea producer Flora Gomes as a starting point, the theme of the memories in conflict, and to reflect upon the manners in which the image archives may function in the process of construction of a collective and shared memory. In this sense, the Portuguese documentary in question seems to present a route that passes by the issue of the “war of memories” proposing a common reading of the histories which occurred on the Guinean front during the colonial war; proposing a reading of the facts which stress how, in accordance to what Amílcar Cabral affirmed, the fate of the two sides, in this particular case, Portugal and Guinea- Bissau, were indissolubly connected.

  12. Modeled aerosol nitrate formation pathways during wintertime in the Great Lakes region of North America

    Science.gov (United States)

    Kim, Yoo Jung; Spak, Scott N.; Carmichael, Gregory R.; Riemer, Nicole; Stanier, Charles O.

    2014-11-01

    Episodic wintertime particle pollution by ammonium nitrate is an important air quality concern across the Midwest U.S. Understanding and accurately forecasting PM2.5 episodes are complicated by multiple pathways for aerosol nitrate formation, each with uncertain rate parameters. Here, the Community Multiscale Air Quality model (CMAQ) simulated regional atmospheric nitrate budgets during the 2009 LADCO Winter Nitrate Study, using integrated process rate (IPR) and integrated reaction rate (IRR) tools to quantify relevant processes. Total nitrate production contributing to PM2.5 episodes is a regional phenomenon, with peak production over the Ohio River Valley and southern Great Lakes. Total nitrate production in the lower troposphere is attributed to three pathways, with 57% from heterogeneous conversion of N2O5, 28% from the reaction of OH and NO2, and 15% from homogeneous conversion of N2O5. TNO3 formation rates varied day-to-day and on synoptic timescales. Rate-limited production does not follow urban-rural gradients and NOx emissions due, to counterbalancing of urban enhancement in daytime HNO3 production with nocturnal reductions. Concentrations of HNO3 and N2O5 and nighttime TNO3 formation rates have maxima aloft (100-500 m), leading to net total nitrate vertical flux during episodes, with substantial vertical gradients in nitrate partitioning. Uncertainties in all three pathways are relevant to wintertime aerosol modeling and highlight the importance of interacting transport and chemistry processes during ammonium nitrate episodes, as well as the need for additional constraint on the system through field and laboratory experiments.

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

    Science.gov (United States)

    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.; hide

    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 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.

  14. Effect of the tropical Pacific and Indian Ocean warming since the late 1970s on wintertime Northern Hemispheric atmospheric circulation and East Asian climate interdecadal changes

    Science.gov (United States)

    Chu, Cuijiao; Yang, Xiu-Qun; Sun, Xuguang; Yang, Dejian; Jiang, Yiquan; Feng, Tao; Liang, Jin

    2018-04-01

    Observation reveals that the tropical Pacific-Indian Ocean (TPIO) has experienced a pronounced interdecadal warming since the end of the 1970s. Meanwhile, the wintertime midlatitude Northern Hemispheric atmospheric circulation and East Asian climate have also undergone substantial interdecadal changes. The effect of the TPIO warming on these interdecadal changes are identified by a suite of AMIP-type atmospheric general circulation model experiments in which the model is integrated from September 1948 to December 1999 with prescribed historical, observed realistic sea surface temperature (SST) in a specific region and climatological SST elsewhere. Results show that the TPIO warming reproduces quite well the observed Northern Hemispheric wintertime interdecadal changes, suggesting that these interdecadal changes primarily originate from the TPIO warming. However, each sub-region of TPIO has its own distinct contribution. Comparatively, the tropical central-eastern Pacific (TCEP) and tropical western Pacific (TWP) warming makes dominant contributions to the observed positive-phase PNA-like interdecadal anomaly over the North Pacific sector, while the tropical Indian Ocean (TIO) warming tends to cancel these contributions. Meanwhile, the TIO and TWP warming makes dominant contributions to the observed positive NAO-like interdecadal anomaly over the North Atlantic sector as well as the interdecadal anomalies over the Eurasian sector, although the TWP warming's contribution is relatively small. These remote responses are directly attributed to the TPIO warming-induced tropical convection, rainfall and diabatic heating increases, in which the TIO warming has the most significant effect. Moreover, the TPIO warming excites a Gill-type pattern anomaly over the tropical western Pacific, with a low-level anticyclonic circulation anomaly over the Philippine Sea. Of three sub-regions, the TIO warming dominates such a pattern, although the TWP warming tends to cancel this effect

  15. The impact of monthly variation of the Pacific–North America (PNA teleconnection pattern on wintertime surface-layer aerosol concentrations in the United States

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    J. Feng

    2016-04-01

    Full Text Available The Pacific–North America teleconnection (PNA is the leading general circulation pattern in the troposphere over the region of North Pacific to North America during wintertime. This study examined the impacts of monthly variations of the PNA phase (positive or negative phase on wintertime surface-layer aerosol concentrations in the United States (US by analyzing observations during 1999–2013 from the Air Quality System of the Environmental Protection Agency (EPA-AQS and the model results for 1986–2006 from the global three-dimensional Goddard Earth Observing System (GEOS chemical transport model (GEOS-Chem. The composite analyses on the EPA-AQS observations over 1999–2013 showed that the average concentrations of PM2.5, sulfate, nitrate, ammonium, organic carbon, and black carbon aerosols over the US were higher in the PNA positive phases (25 % of the winter months examined, and this fraction of months had the highest positive PNA index values than in the PNA negative phases (25 % of the winter months examined, and this fraction of months had the highest negative PNA index values by 1.0 µg m−3 (8.7 %, 0.01 µg m−3 (0.5 %, 0.3 µg m−3 (29.1 %, 0.1 µg m−3 (11.9 %, 0.6 µg m−3 (13.5 %, and 0.2 µg m−3 (27.8 %, respectively. The simulated geographical patterns of the differences in concentrations of all aerosol species between the PNA positive and negative phases were similar to observations. Based on the GEOS-Chem simulation, the pattern correlation coefficients were calculated to show the impacts of PNA-induced variations in meteorological fields on aerosol concentrations. The PNA phase was found (i to influence sulfate concentrations mainly through changes in planetary boundary layer height (PBLH, precipitation (PR, and temperature; (ii to influence nitrate concentrations mainly through changes in temperature; and (iii to influence concentrations of ammonium, organic carbon, and black

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

    Science.gov (United States)

    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.

  17. Influence of stratospheric airmasses on tropospheric vertical O3 columns based on GOME (Global Ozone Monitoring Experiment measurements and backtrajectory calculation over the Pacific

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    A. Ladstätter-Weißenmayer

    2004-01-01

    Full Text Available Satellite based GOME (Global Ozone Measuring experiment data are used to characterize the amount of tropospheric ozone over the tropical Pacific. Tropospheric ozone was determined from GOME data using the Tropospheric Excess Method (TEM. In the tropical Pacific a significant seasonal variation is detected. Tropospheric excess ozone is enhanced during the biomass burning season from September to November due to outflow from the continents. In September 1999 GOME data reveal an episode of increased excess ozone columns over Tahiti (18.0° S; 149.0° W (Eastern Pacific compared to Am. Samoa (14.23° S; 170.56° W and Fiji (18.13° S; 178.40° E, both situated in the Western Pacific. Backtrajectory calculations show that none of the airmasses arriving over the three locations experienced anthropogenic pollution (e. g. biomass burning. Consequently other sources of ozone have to be considered. One possible process leading to an increase of tropospheric ozone is stratosphere-troposphere-exchange. An analysis of the potential vorticity along trajectories arriving above each of the locations reveals that airmasses at Tahiti are subject to enhanced stratospheric influence, compared to Am. Samoa and Fiji. As a result this study shows clear incidents of transport of airmasses from the stratosphere into the troposphere.

  18. Chemical compositions, sources and evolution processes of the submicron aerosols in Nanjing, China during wintertime

    Science.gov (United States)

    Wu, Y.; He, Y.; Ge, X.; Wang, J.; Yu, H.; Chen, M.

    2016-12-01

    Elevated atmospheric particulate matter pollution is one of the most significant environmental issues in the Yangtze River Delta (YRD), China. Thus it is important to unravel the characteristics, sources and evolution processes of the ambient aerosols in order to improve the air quality. In this study, we report the real-time monitoring results on submicron aerosol particles (PM1) in suburban Nanjing during wintertime of 2015, using an Aerodyne soot particle aerosol mass spectrometer (SP-AMS). This instrument allows the fast measurement of refractory black carbon simultaneously with other aerosol components. Results show that organics was on average the most abundant species of PM1 (25.9%), but other inorganic species, such as nitrate (23.7%) and sulfate (23.3%) also comprised large mass fractions. As the sampling site is heavily influenced by various sources including industrial, traffic and other anthropogenic emissions, etc., six organic aerosol (OA) factors were identified from Positive matrix factorization (PMF) analysis of the SP-AMS OA mass spectra. These factors include three primary OA factors - a hydrocarbon-like OA, an industry-related OA (IOA) and a cooking OA (COA), and three secondary OA factors, i.e., a local OOA (LSOA), a semi-volatile OOA (SV-OOA) and a low-volatility OOA (LV-OOA). Overall, the primary organic aerosol (POA) (HOA, IOA and COA) dominated the total OA mass. Behaviors and evolution processes of these OA factors will be discussed in combining with the other supporting data.

  19. Constraining wintertime sources of inorganic chlorine over the northeast United States

    Science.gov (United States)

    Haskins, J.; Jaegle, L.; Shah, V.; Lopez-Hilfiker, F.; Lee, B. H.; Campuzano Jost, P.; Schroder, J. C.; Day, D. A.; Fiddler, M. N.; Holloway, J. S.; Sullivan, A.; Veres, P. R.; Weber, R. J.; Dibb, J. E.; Brown, S. S.; Jimenez, J. L.; Thornton, J. A.

    2017-12-01

    Wintertime multiphase chlorine chemistry is thought to play a significant role in the regional distribution of oxidants, the lifetime of VOCs, and the transport of NOx downwind of urban sources. However, the sources and chemistry of reactive chlorine remain highly uncertain. During the WINTER 2015 aircraft campaign, the inorganic chlorine budget was dominated by HCl (g) and total particulate chloride, accounting for greater than 85% of the total chlorine budget within the boundary layer. The total concentration of inorganic chlorine compounds found over marine regions was 1014 pptv and 609 pptv over continental regions with variability found to be driven by changes in meteorological conditions, particle liquid water content, particle pH, and proximity to large anthropogenic sources. However, displacement of particle chloride was often not a large enough source to fully explain the concentrations of gas phase Cly compounds. We use the GEOS-Chem global chemical transport model to simulate the emissions, gas-particle partitioning, and downwind transport and deposition of Cly during winter. Simulated concentrations of HCl, particle chloride, and other dominant Cly compounds are compared to measurements made during the WINTER aircraft campaign. The relative roles of Cly sources from sea-salt aerosol and anthropogenic sources such as power plants, biomass burning and road salt are explored.

  20. Anticorpos para enterovirus na localidade de Ferreira Gomes, no Território Federal do Amapá

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    Hermann G. Schatzmayr

    1972-02-01

    Full Text Available Sôros coletados no Território Federal do Amapá, localidade de Ferreira Gomes, foram, testados para anticorpos neutralizantes de enterovírus Poliovírus 1, 2 e 3 e Coxsackie B1 a B6, em população autóctone. Os resultados apresentados na Tabela 1, indicam alta circulação do vírus da poliomielite na região atingindo-se níveis tão elevados como em escolares do Estado da Guanabara. Em relação a Coxsackie B, alcançaram-se também resultados semelhantes nas duas populações exceto com Coxsackie B., o qual apresentou-se em valôres bem mais altos nos sôros coletados na região norte. Os autores chamam atenção da necessidade de vacinação contra a poliomielite de grandes segmentos da população susceptível em curto prazo, tendo em vista a ampla disseminação das infecções por poliovírus em tôdas as regiões do país onde forem pesquisadas.

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

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    N. Theys

    2013-06-01

    Full Text Available 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.

  2. Wintertime Overnight NOx Removal in a Southeastern United States Coal-fired Power Plant Plume: A Model for Understanding Winter NOx Processing and its Implications

    Science.gov (United States)

    Fibiger, Dorothy L.; McDuffie, Erin E.; Dubé, William P.; Aikin, Kenneth C.; Lopez-Hilfiker, Felipe D.; Lee, Ben H.; Green, Jaime R.; Fiddler, Marc N.; Holloway, John S.; Ebben, Carlena; Sparks, Tamara L.; Wooldridge, Paul; Weinheimer, Andrew J.; Montzka, Denise D.; Apel, Eric C.; Hornbrook, Rebecca S.; Hills, Alan J.; Blake, Nicola J.; DiGangi, Josh P.; Wolfe, Glenn M.; Bililign, Solomon; Cohen, Ronald C.; Thornton, Joel A.; Brown, Steven S.

    2018-01-01

    Nitric oxide (NO) is emitted in large quantities from coal-burning power plants. During the day, the plumes from these sources are efficiently mixed into the boundary layer, while at night, they may remain concentrated due to limited vertical mixing during which they undergo horizontal fanning. At night, the degree to which NO is converted to HNO3 and therefore unable to participate in next-day ozone (O3) formation depends on the mixing rate of the plume, the composition of power plant emissions, and the composition of the background atmosphere. In this study, we use observed plume intercepts from the Wintertime INvestigation of Transport, Emissions and Reactivity campaign to test sensitivity of overnight NOx removal to the N2O5 loss rate constant, plume mixing rate, background O3, and background levels of volatile organic compounds using a 2-D box model of power plant plume transport and chemistry. The factor that exerted the greatest control over NOx removal was the loss rate constant of N2O5. At the lowest observed N2O5 loss rate constant, no other combination of conditions converts more than 10% of the initial NOx to HNO3. The other factors did not influence NOx removal to the same degree.

  3. Wintertime Overnight NOx Removal in a Southeastern United States Coal-Fired Power Plant Plume: A Model for Understanding Winter NOx Processing and Its Implications

    Science.gov (United States)

    Fibiger, Dorothy L.; McDuffie, Erin E.; Dube, William P.; Aikin, Kenneth C.; Lopez-Hilifiker, Felipe D.; Lee, Ben H.; Green, Jaime R.; Fiddler, Marc N.; Holloway, John S.; Ebben, Carlena; hide

    2018-01-01

    Nitric oxide (NO) is emitted in large quantities from coal-�burning power plants. During the day, the plumes from these sources are efficiently mixed into the boundary layer, while at night, they may remain concentrated due to limited vertical mixing during which they undergo horizontal fanning. At night, the degree to which NO is converted to HNO3 and therefore unable to participate in next-�day ozone (O3) formation depends on the mixing rate of the plume, the composition of power plant emissions, and the composition of the background atmosphere. In this study, we use observed plume intercepts from the Wintertime INvestigation of Transport, Emissions and Reactivity (WINTER) campaign to test sensitivity of overnight NOx removal to the N2O5 loss rate constant, plume mixing rate, background O3, and background levels of volatile organic compounds using a 2-�D box model of power plant plume transport and chemistry. The factor that exerted the greatest control over NOx removal was the loss rate constant of N2O5. At the lowest observed N2O5 loss rate constant, no other combination of conditions converts more than 10 percent of the initial NOx to HNO3. The other factors did not influence NOx removal to the same degree.

  4. Source Estimation of Wintertime Soot Particles for an Urban Site Varanasi (25.30 N, 83.00 E) in Central Indo-Gangetic Plain Region

    Science.gov (United States)

    Singh, A. K.; Srivastava, M. K.; Dumka, U. C.; Singh, R. K.; Singh, R. S.; Tiwari, S.; Mehrotra, B. J.; Srivastava, A. K.

    2017-12-01

    Black carbon particles (BC: also called Soot) are formed by incomplete combustion of hydrocarbon based fuels (fossil fuel: coal, diesel, petrol, etc.) as well as due to burning of biomass and bio-fuels (wood, shrubs, dry leaves, etc.). Soot particles are warming agent to the atmosphere that gained wide attention in recent years due to their direct and indirect impacts on local, regional as well as global climate. The climatic effects due to soot are not well understood as indicated by large uncertainties in their climate forcing estimation, particularly in South and East Asian region, possibly due to unavailability of adequate database and information about the source. Measurement of wintertime BC mass concentrations for urban site in central IGP, `Varanasi' (25.30 N, 83.00 E), using a seven wavelength Aethalometer is reported in this work. Delta-C (=BC370 - BC880), which is an indicator of biomass/bio-fuels or residential coal burning is used to understand the source. Aethalometer based source apportionment model "Aethalometer model" was used to apportion the fossil fuel/traffic and wood/biomass burning mass concentration to the total BC mass. The preliminary results for representative month (January-2015) show that daily-average BC mass ranged from 4.47 to 20.70 μg m-3 (Average: 9.45 ± 4.15 μg m-3). The daily Absorption Ångström Exponent (AAE) and the ratio of BCff/BC and BCff/BCwb varied between 1.09 - 1.32, 0.67 - 0.92 and 2 - 40, respectively, due to the changes in BC emissions rates. The total BC, BC from fossil fuel (BCff) and BC from wood/biomass burning (BCwb) behaved in the remarkable diurnal pattern, behaving opposite to the mixing layer heights (MLHs). During daytime, MLHs are higher due to surface based solar warming and causes more volume of atmosphere for the BC dispersion. This phenomenon causes the surface measurement of lower BC mass during the daytime. The data is, however, still being processed for multi-year wintertime observations and the

  5. Emissions of Volatile Organic Compounds from Oil and Gas Operations in Northeastern Oklahoma - Wintertime Ambient Air Studies from Three Consecutive Years

    Science.gov (United States)

    Ghosh, B.

    2017-12-01

    Volatile organic compounds (VOCs) are emitted into the atmosphere from a variety of sources including oil and gas (O&G) operations, vehicle exhausts, industrial processes, and biogenic sources. Understanding of emission sources and their air quality impact is crucial for effective environmental policymaking and its implementation. Three consecutive wintertime campaigns to study ambient air were conducted in Northeastern Oklahoma during February-March of 2015, 2016, and 2017. The goals of these campaigns were to study ambient VOCs in the region, estimate their air quality impact, and understand how the impact changes over a span of three years. This presentation highlights results from the 2017 campaign. In-situ measurements of methane, ethane, and CO were conducted by an Aerodyne Dual QCL Analyzer while ozone and NOx were measured using Teledyne monitors. In addition, 392 whole air samples were collected and non-methane hydrocarbons (NMHCs) in the samples were analyzed using GC-MS (Agilent). High levels of methane (> 8 ppm) were observed during the study. Correlation with ethane indicated that methane primarily originated from O&G operations with little biogenic contributions. Among NMHCs, C2-C5 alkanes were the most dominant with mean mixing ratios ranging from 0.9 to 6.8 ppb. Chemical tracers (propane, ethyne, CO) and isomeric ratios (iC5/nC5, Figure 1) identified oil and gas activity as the primary source of NMHCs. Photochemical age was calculated to estimate emission source composition. Ozone showed strong diurnal variation characteristic of photochemical production with a maximum mixing ratio of 58 ppb. The results from the 2017 study will be compared with results from studies in 20151 and 20162 and their significance on local air quality will be discussed. References Ghosh, B.; Volatile Organic Compound Emissions from Oil and Gas Production Sources: A Pilot Study in Northeastern Oklahoma; Poster presentation at AGU Fall Meeting; 2015; A11M-0249; (Link) Ghosh

  6. Overview of VOC emissions and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign: high acetaldehyde, isoprene and isocyanic acid in wintertime air of the Kathmandu Valley

    Science.gov (United States)

    Sarkar, Chinmoy; Sinha, Vinayak; Kumar, Vinod; Rupakheti, Maheswar; Panday, Arnico; Mahata, Khadak S.; Rupakheti, Dipesh; Kathayat, Bhogendra; Lawrence, Mark G.

    2016-03-01

    The Kathmandu Valley in Nepal suffers from severe wintertime air pollution. Volatile organic compounds (VOCs) are key constituents of air pollution, though their specific role in the valley is poorly understood due to insufficient data. During the SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley-Atmospheric Brown Clouds) field campaign conducted in Nepal in the winter of 2012-2013, a comprehensive study was carried out to characterise the chemical composition of ambient Kathmandu air, including the determination of speciated VOCs, by deploying a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) - the first such deployment in South Asia. In the study, 71 ion peaks (for which measured ambient concentrations exceeded the 2σ detection limit) were detected in the PTR-TOF-MS mass scan data, highlighting the chemical complexity of ambient air in the valley. Of the 71 species, 37 were found to have campaign average concentrations greater than 200 ppt and were identified based on their spectral characteristics, ambient diel profiles and correlation with specific emission tracers as a result of the high mass resolution (m / Δm > 4200) and temporal resolution (1 min) of the PTR-TOF-MS. The concentration ranking in the average VOC mixing ratios during our wintertime deployment was acetaldehyde (8.8 ppb) > methanol (7.4 ppb) > acetone + propanal (4.2 ppb) > benzene (2.7 ppb) > toluene (1.5 ppb) > isoprene (1.1 ppb) > acetonitrile (1.1 ppb) > C8-aromatics ( ˜ 1 ppb) > furan ( ˜ 0.5 ppb) > C9-aromatics (0.4 ppb). Distinct diel profiles were observed for the nominal isobaric compounds isoprene (m / z = 69.070) and furan (m / z = 69.033). Comparison with wintertime measurements from several locations elsewhere in the world showed mixing ratios of acetaldehyde ( ˜ 9 ppb), acetonitrile ( ˜ 1 ppb) and isoprene ( ˜ 1 ppb) to be among the highest reported to date. Two "new" ambient compounds, namely formamide (m / z = 46.029) and acetamide (m / z

  7. Predação de sementes de Allagoptera arenaria (Gomes O'Kuntze (Arecaceae por Pachymerus nucleorum Fabricius (Coleoptera, Chrysomelidae, Bruchinae Seed predation on Allagoptera arenaria (Gomes O'Kuntze (Arecaceae by Pachymerus nucleorum Fabricius (Coleoptera, Chrysomelidae, Bruchinae

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    Viviane Grenha

    2008-01-01

    Full Text Available A predação de sementes da palmeira Allagoptera arenaria (Gomes O'Kuntze, 1891(Arecaceae por Pachymerus nucleorum Fabricius, 1972 foi avaliada de setembro de 2003 a setembro de 2005 no Parque Nacional da Restinga de Jurubatiba (RJ. A biologia e o comportamento de P. nucleorum em A. arenaria e as taxas de predação de sementes foram descritas. Frutos encontrados sob 50 palmeiras foram coletados, mensalmente, em cada uma das duas áreas amostradas no PNRJ (mata de cordão arenoso e formação arbustiva aberta de Clusia Sclthdl, Clusiaceae. A avaliação dos cocos predados foi feita a partir da contagem dos orifícios de saída dos bruquíneos no campo, da emergência dos insetos no laboratório e da abertura dos frutos remanescentes. Através de observações e experimentos em 60 infrutescências, verificou-se que a oviposição de Pachymerus nucleorum em A. arenaria ocorre na infrutescência ainda em desenvolvimento diferentemente de registros na literatura em outras espécies de palmeiras, onde a oviposição ocorre nos frutos no chão. A predação dos frutos por P. nucleorum foi de 29,3% na área de mata de cordão arenoso e 20,6% na formação arbustiva aberta de Clusia. O ciclo de vida de P. nucleorum foi bastante longo e com amplitudes bem grandes dentro de uma mesma amostra, o que sugere uma possível diapausa em alguma fase do seu ciclo de vida.Seed predation on Allagoptera arenaria (Gomes O'Kuntze, 1891(Arecaceae palm by Pachymerus nucleorum Fabricius, 1972 was evaluated from September 2003 to September 2005 at the Parque Nacional da Restinga de Jurubatiba (PNRJ, Rio de Janeiro, Brazil. The biology and behaviour of P. nucleorum on A. arenaria and predation rates were described. Fruits found beneath 50 palms were collected, monthly, for each one of the two sampled areas at PNRJ (ridge forest and Clusia Sclthdl (Clusiaceae open shrubland formation. The evaluation of preyed fruits was done by counting exit holes of Bruchinae in the field

  8. Organização estrutural da folha de Pimenta pseudocaryophyllus (Gomes L.R. Landrum, Myrtaceae Leaf structural organization of Pimenta pseudocaryophyllus (Gomes L.R. Landrum, Myrtaceae

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    Vanessa de Farias

    2009-06-01

    Full Text Available Com grande distribuição no Brasil e ocorrência principalmente no cerrado, caatinga e floresta atlântica, Pimenta pseudocaryophyllus (Gomes L.R. Landrum, que está inclusa em um dos menores gêneros de Myrtaceae, é popularmente conhecida como craveiro-do-mato, louro-cravo ou chá-de-bugre. Trata-se de uma espécie nativa e suas folhas são usadas na culinária substituindo o cravo-da-índia (Syzygium aromaticum devido ao aroma semelhante. O estudo tem o objetivo de caracterizar anatomicamente a folha dessa espécie. Para a confecção do laminário, amostras da região mediana da folha e do pecíolo foram seccionadas em micrótomo de rotação e coradas com azul de toluidina a 1%. Em vista frontal, a epiderme é glabra na face adaxial e pilosa na face abaxial, com tricomas unicelulares. A folha é hipoestomática e os complexos estomáticos são anomocíticos. Em secção transversal, a epiderme é uniestratificada revestida por cutícula espessa e camada subepidérmica formada por 1-2 estratos celulares. O mesofilo é dorsiventral e bainha esclerenquimática envolve o feixe vascular bicolateral. Na folha e no pecíolo observam-se colênquima lacunar, flanges cuticulares, canais secretores e idioblastos contendo drusas e monocristais. Concluise que a espécie possui características freqüentes para Myrtaceae, com exceção da camada subepidérmica e flanges cuticulares, e que os resultados obtidos contribuem com novas informações que podem subsidiar estudos futuros no que se refere à identificação e delimitação do táxon.Pimenta pseudocaryophyllus (Gomes L.R. Landrum is a native species from Brazil and occurs mainly in cerrado, caatinga and Atlantic rainforest vegetation. It is commonly known as "craveiro-do-mato", "louro-cravo" or "chá-de-bugre". It is a tree species whose leaves are used for cooking; they smell and taste like cloves (Syzygium aromaticum. This study describes the leaf anatomy of the species. The leaves were sliced

  9. Identification of amines in wintertime ambient particulate material using high resolution aerosol mass spectrometry

    Science.gov (United States)

    Bottenus, Courtney L. H.; Massoli, Paola; Sueper, Donna; Canagaratna, Manjula R.; VanderSchelden, Graham; Jobson, B. Thomas; VanReken, Timothy M.

    2018-05-01

    Significant amounts of amines were detected in fine particulate matter (PM) during ambient wintertime conditions in Yakima, WA, using a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Positive matrix factorization (PMF) of the organic aerosol (OA) signal resulted in a six-factor solution that included two previously unreported amine OA factors. The contributions of the amine factors were strongly episodic, but the concentration of the combined amine factors was as high as 10-15 μg m-3 (2-min average) during those episodes. In one occasion, the Amine-II component was 45% of total OA signal. The Amine-I factor was dominated by spectral peaks at m/z 86 (C5H12N+) and m/z 100 (C6H14N+), while the Amine-II factor was dominated by spectral peaks at m/z 58 (C3H8N+ and C2H6N2+) and m/z 72 (C4H10N+ and C3H8N2+). The ions dominating each amine factor showed distinct time traces, suggesting different sources or formation processes. Investigation into the chemistry of the amine factors suggests a correlation with inorganic anions for Amine-I, but no evidence that the Amine-II was being neutralized by the same inorganic ions. We also excluded the presence of organonitrates (ON) in the OA. The presence of C2H4O2+ at m/z 60 (a levoglucosan fragment) in the Amine-I spectrum suggests some influence of biomass burning emissions (more specifically residential wood combustion) in this PMF factor, but wind direction suggested that the most likely sources of these amines were agricultural activities and feedlots to the S-SW of the site.

  10. High-Latitude Wintertime Urban Pollution: Particulate Matter Composition and Temporal Trends in Fairbanks, Alaska

    Science.gov (United States)

    Simpson, W. R.; Nattinger, K.; Hooper, M.

    2017-12-01

    High latitude cities often experience severe pollution episodes during wintertime exacerbated by thermal inversion trapping of pollutant emissions. Fairbanks, Alaska is an extreme example of this problem, currently being classified by the US Environmental Protection Agency (EPA) as a "serious" non-attainment area for fine particulate matter (PM2.5). For this reason, we have studied the chemical composition of PM2.5 at multiple EPA monitoring sites in the non-attainment area from 2006 to the present. The chemical composition is dominated by organic carbon with lesser amounts of black carbon and inorganic ionic species such as ammonium, sulfate, and nitrate. We find large spatial differences in composition and amount of PM2.5 that indicate a different mix of sources in residential areas as compared to the city center. Specifically, the difference in composition is consistent with increased wood smoke source in the residential areas. The extent to which organic matter could be secondary (formed through conversion of emitted gases) is also an area needing study. Ammonium sulfate is responsible for about a fifth to a quarter of the particles mass during the darkest months, possibly indicating a non-photochemical source of sulfate, but the chemical mechanism for this possible transformation is unclear. Therefore, we quantified the relationship between particulate sulfate concentrations and gas-phase sulfur dioxide concentrations along with particulate metals and inferred particulate acidity with the hopes that these data can assist in elucidation of the mechanism of particulate sulfate formation. We also analyze temporal trends in PM2.5 composition in an attempt to understand how the problem is changing over time and find most trends are small despite regulatory changes. Improving mechanistic understanding of particulate formation under cold and dark conditions could assist in reducing air-quality-related health effects.

  11. Pedestrians in wintertime-effects of using anti-slip devices.

    Science.gov (United States)

    Berggård, Glenn; Johansson, Charlotta

    2010-07-01

    Pedestrians slipping and falling is a major safety problem around the world, not least in countries with long winters such as Sweden. About 25000-30000 people need medical care every year for treatment of fall injuries in Sweden. Use of appropriate shoes and anti-slip devices are examples of individual measures that have been suggested to prevent slipping and falling. An intervention study was performed during the period February to April 2008. The study, which focused on healthy adults in northern Sweden, examined the effect of using anti-slip devices on daily walking journeys and prevention of slip and falls. The respondents were divided into three groups: an Intervention Group, a Control Group, with similar distribution of gender and age, and a Comparison Group. Four questionnaires were distributed: (1) background, (2) daily diary of distance walked and occurrence of incidents or accidents reported weekly, (3) detailed incident or fall report and (4) experiences of using anti-slip devices for those who used these devices during the trial period. Half of the respondents stated that they had previous experience of using anti-slip devices. In this study, 52% of the respondents used anti-slip devices. Anti-slip devices improve the walking capability during wintertime. Among those using appropriate anti-slip devices, the average daily walking distance was found to be statistically significantly longer compared to people not using anti-slip devices. This study indicates that an increase in daily walking distance can be made without increasing the risk of slips/falls when using anti-slip devices. The study also indicates that by using appropriate anti-slip devices and having information about when and where to use them, based on their design, people avoid having slips and falls. The respondents experienced in using anti-slip devices in this study will continue to use them and will also recommend others to use anti-slip devises. Copyright 2010 Elsevier Ltd. All rights

  12. Wintertime organic and inorganic aerosols in Lanzhou, China: sources, processes, and comparison with the results during summer

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    J. Xu

    2016-12-01

    Full Text Available Lanzhou, which is located in a steep alpine valley in western China, is one of the most polluted cities in China during the wintertime. In this study, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS, a seven-wavelength aethalometer, and a scanning mobility particle sizer (SMPS were deployed during 10 January to 4 February 2014 to study the mass concentrations, chemical processes, and sources of submicrometer particulate matter (PM1. The average PM1 concentration during this study was 57.3 µg m−3 (ranging from 2.1 to 229.7 µg m−3 for hourly averages, with organic aerosol (OA accounting for 51.2 %, followed by nitrate (16.5 %, sulfate (12.5 %, ammonium (10.3 %, black carbon (BC, 6.4 %, and chloride (3.0 %. The mass concentration of PM1 during winter was more than twice the average value observed at the same site in summer 2012 (24.5 µg m−3, but the mass fraction of OA was similar in the two seasons. Nitrate contributed a significantly higher fraction to the PM1 mass in winter than summer (16.5 % vs. 10 %, largely due to more favored partitioning to the particle phase at low air temperature. The mass fractions of both OA and nitrate increased by  ∼  5 % (47 to 52 for OA and 13 to 18 % for nitrate with the increase of the total PM1 mass loading, while the average sulfate fraction decreased by 6 % (17 to 11 %, indicating the importance of OA and nitrate for the heavy air pollution events in Lanzhou. The size distributions of OA, nitrate, sulfate, ammonium, and chloride all peaked at  ∼  500 nm, with OA being slightly broader, suggesting that aerosol particles were internally mixed during winter, likely due to frequently calm and stagnant air conditions during wintertime in Lanzhou (average wind speed: 0.82 m s−1.The average mass spectrum of OA showed a medium oxidation degree (average O ∕ C ratio of 0.28, which was lower than that during summer

  13. Volatility of source apportioned wintertime organic aerosol in the city of Athens

    Science.gov (United States)

    Louvaris, Evangelos E.; Florou, Kalliopi; Karnezi, Eleni; Papanastasiou, Dimitrios K.; Gkatzelis, Georgios I.; Pandis, Spyros N.

    2017-06-01

    The volatility distribution of ambient organic aerosol (OA) and its components was measured during the winter of 2013 in the city of Athens combining a thermodenuder (TD) and a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). Positive Matrix Factorization (PMF) analysis of both the ambient and the thermodenuder AMS-spectra resulted in a four-factor solution for the OA, namely: hydrocarbon-like OA (HOA), biomass burning OA (BBOA), cooking OA (COA), and oxygenated OA (OOA). The thermograms of the four factors were analyzed and the corresponding volatility distributions were estimated using the volatility basis set (VBS). All four factors included compounds with a wide range of effective volatilities from 10 to less than 10-4 μg m-3 at 298 K. Almost 40% of the HOA consisted of low-volatility organic compounds (LVOCs) with the semi-volatile compounds (SVOCs) representing roughly 30%, while the remaining 30% consisted of extremely low volatility organic compounds (ELVOCs). BBOA was more volatile than the HOA factor on average, with 10% ELVOCs, 40% LVOCs, and 50% SVOCs. 10% of the COA consisted of ELVOCs, another 65% LVOCs, and 50% SVOCs. Finally, the OOA was the least volatile factor and included 40% ELVOCs, 25% LVOCs, and 35% SVOCs. Combining the volatility distributions and the O:C ratios of the various factors, we placed our results in the 2D-VBS analysis framework of Donahue et al. (2012). HOA and BBOA are in the expected region but also include an ELVOC component. COA is in similar range as HOA, but on average is half an order of magnitude more volatile. The OOA in these wintertime conditions had a moderate O:C ratio and included both semi-volatile and extremely low volatility components. The above results are sensitive to the assumed values of the effective vaporization enthalpy and the accommodation coefficient. A reduction of the accommodation coefficient by an order of magnitude or the reduction of the vaporization enthalpy by 20 kJ mol-1

  14. Dicarboxylic acids and levoglucosan in aerosols from Indo-Gangetic Plain: Inferences from day night variability during wintertime.

    Science.gov (United States)

    Sorathia, Fena; Rajput, Prashant; Gupta, Tarun

    2018-05-15

    This study assesses daytime and nighttime atmospheric abundance and molecular distribution of dicarboxylic acids (DCA: C 2 -C 10 ) and biomass burning tracers (levoglucosan and biomass burning derived potassium: K + BB ) in PM 10 (particulate matter with aerodynamic diameter≤10μm) from an urban location, Kanpur (in central Indo-Gangetic Plain: IGP) during wintertime (December 2015-February 2016). In this study, PM 10 varied from 130 to 242 and 175-388μgm -3 during daytime and nighttime, respectively. The average ratios of OC/EC (day: 12.3; night: 9.3) and WSOC/OC (day: 0.74; night: 0.48) were relatively high during daytime (OC: organic carbon; EC: elemental carbon; WSOC: water-soluble organic carbon). Strong linear correlations (R 2 ≥0.6; pformation involving aqueous-phase chemistry. Strong linear correlations of C 2 with C 3 and C 4 plausibly suggest that C 2 can have predominant formation pathways via decomposition of higher congeners of DCA. Overall, strong linear correlations of C 2 with levoglucosan and sulphate suggest that biomass burning emission and secondary transformations are predominant sources of DCA over IGP during wintertime. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Potential impacts of wintertime soil moisture anomalies from agricultural irrigation at low latitudes on regional and global climates

    Science.gov (United States)

    Wey, Hao-Wei; Lo, Min-Hui; Lee, Shih-Yu; Yu, Jin-Yi; Hsu, Huang-Hsiung

    2015-10-01

    Anthropogenic water management can change surface energy budgets and the water cycle. In this study, we focused on impacts of Asian low-latitude irrigation on regional and global climates during boreal wintertime. A state-of-the-art Earth system model is used to simulate the land-air interaction processes affected by irrigation and the consequent responses in atmospheric circulation. Perturbed experiments show that wet soil moisture anomalies at low latitudes can reduce the surface temperature on a continental scale through atmospheric feedback. The intensity of prevailing monsoon circulation becomes stronger because of larger land-sea thermal contrast. Furthermore, anomalous upper level convergence over South Asia and midlatitude climatic changes indicate tropical-extratropical teleconnections. The wintertime Aleutian low is deepened and an anomalous warm surface temperature is found in North America. Previous studies have noted this warming but left it unexplained, and we provide plausible mechanisms for these remote impacts coming from the irrigation over Asian low-latitude regions.

  16. Increases in wintertime PM2.5 sodium and chloride linked to snowfall and road salt application

    Science.gov (United States)

    Kolesar, Katheryn R.; Mattson, Claire N.; Peterson, Peter K.; May, Nathaniel W.; Prendergast, Rashad K.; Pratt, Kerri A.

    2018-03-01

    The application of salts and salty brines to roads is common practice during the winter in many urban environments. Road salts can become aerosolized, thereby injecting sodium and chloride particulate matter (PM) into the atmosphere. Here, data from the United States Environmental Protection Agency Chemical Speciation Monitoring Network were used to assess temporal trends of sodium and chloride PM2.5 (PM road salt aerosols. Sodium and chloride PM2.5 concentrations were an average of three times higher in the winter, as compared to the summer, for locations with greater than 25 cm of average annual snowfall. Winter urban chloride PM2.5 concentrations attributed to road salt can even sometimes rival those of coastal sea spray aerosol-influenced sites. In most snow-influenced cities, chloride and sodium PM2.5 concentrations were positively correlated with snowfall; however, this relationship is complicated by differences in state and local winter maintenance practices. This study highlights the ubiquity of road salt aerosols in the United States and their potential impact on wintertime urban air quality, particularly due to the potential for multiphase reactions to liberate chlorine from the particle-phase. Since road salt application is a common practice in wintertime urban environments across the world, it is imperative that road salt application emissions, currently not included in inventories, and its impacts be investigated through measurements and modeling.

  17. Expressões ecofisiológicas de germoplasma de Hancornia speciosa Gomes cultivado no Litoral de Pernambuco Physiological expressions in Hancornia speciosa Gomes germoplasm from the coastal region, Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Rejane Jurema Mansur Custódio Nogueira

    1999-12-01

    Full Text Available Objetivou-se avaliar in loco as relações hídricas e respectivas correlações em quatro acessos de mangaba (M-UFRPE 1, M-UFRPE 2, M-UFRPE 3 e M-UFRPE 4 cultivados na região litorânea do Estado de Pernambuco. As medidas foram tomadas em folhas adultas, completamente expandidas, em duas situações de exposição à luminosidade: exposição solar plena e sombreamento natural. As variáveis analisadas foram: temperatura foliar (Tf, transpiração (E e resistência difusiva (Rs. Verificou-se que as folhas sombreadas de M-UFRPE 2 transpiraram mais do que as expostas diretamente ao sol, diferindo do comportamento dos demais acessos. A Rs em folhas expostas ao sol variou de 1,1 a 4,5s.cm-1, enquanto que nas folhas sombreadas, essa variação foi de 1,7 a 3,5s.cm-1. Os efeitos de ExRs foram inversos e altamente significativos para ambos os tratamentos estudados. Para as folhas expostas ao sol, a Tf, e a E foram influenciadas muito mais pela umidade relativa do que pela radiação fotossinteticamente ativa.A study was carried out with tropical fruit germoplasm (Hancornia speciosa Gomes to evaluate "in loco" water relations and their respectives correlations in four acesses (M-UFRPE 1, M-UFRPE 2, M-UFRPE 3 and M-UFRPE 4 cultivated at the coastal region, in Brazil. The datas were taken from fully expanded adults leaves. Two treatments were studied: leaves fully exposed to the sun and shadow leaves. The following characters were analized: leaf temperature (Tf, transpiration (E and diffusive resistance (Rs. The shadow leaves of the M-UFRPE 2 showed higher transpiration rate than fully exposed leaves to the sun. This behaviour was different compared to the other treatment. The variation between fully exposed leaves to the sun and shadow leaves for Rs was 1.1 to 4.5s.cm-1 and 1.7 to 3.5s.cm-1, respectively. The ExRs correlation was more significant and negative. The Tf and E correlation was longer influenced by relative humidity than photosynthetically

  18. Single-particle investigation of summertime and wintertime Antarctic sea spray aerosols using low-Z particle EPMA, Raman microspectrometry, and ATR-FTIR imaging techniques

    Science.gov (United States)

    Eom, Hyo-Jin; Gupta, Dhrubajyoti; Cho, Hye-Rin; Hwang, Hee Jin; Do Hur, Soon; Gim, Yeontae; Ro, Chul-Un

    2016-11-01

    Two aerosol samples collected at King Sejong Korean scientific research station, Antarctica, on 9 December 2011 in the austral summer (sample S1) and 23 July 2012 in the austral winter (sample S2), when the oceanic chlorophyll a levels on the collection days of the samples were quite different, by ˜ 19 times (2.46 vs. 0.13 µg L-1, respectively), were investigated on a single-particle basis using quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), called low-Z particle EPMA, Raman microspectrometry (RMS), and attenuated total reflection Fourier transform infrared (ATR-FTIR) imaging techniques to obtain their characteristics based on the elemental chemical compositions, molecular species, and mixing state. X-ray analysis showed that the supermicron summertime and wintertime Antarctic aerosol samples have different elemental chemical compositions, even though all the individual particles analyzed were sea spray aerosols (SSAs); i.e., the contents of C, O, Ca, S, and Si were more elevated, whereas Cl was more depleted, for sample S1 than for sample S2. Based on qualitative analysis of the chemical species present in individual SSAs by the combined application of RMS and ATR-FTIR imaging, different organic species were observed in samples S1 and S2; i.e., Mg hydrate salts of alanine were predominant in samples S1 and S2, whereas Mg salts of fatty acids internally mixed with Mg hydrate salts of alanine were significant in sample S2. Although CaSO4 was observed significantly in both samples S1 and S2, other inorganic species, such as Na2SO4, NaNO3, Mg(NO3)2, SiO2, and CH3SO3Mg, were observed more significantly in sample S1, suggesting that those compounds may be related to the higher phytoplankton activity in summer.

  19. Diversity and genetic structure in natural populations of Hancornia speciosa var. speciosa Gomes in northeastern Brazil Diversidade e estrutura genética em populações naturais de Hancornia speciosa var. speciosa Gomes no nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    Georgia Vilela Martins

    2012-12-01

    Full Text Available Hancornia speciosa Gomes is a fruit tree native from Brazil that belongs to Apocinaceae family, and is popularly known as Mangabeira. Its fruits are widely consumed raw or processed as fruit jam, juices and ice creams, which have made it a target of intense exploitation. The extractive activities and intense human activity on the environment of natural occurrence of H. speciosa has caused genetic erosion in the species and little is known about the ecology or genetic structure of natural populations. The objective of this research was the evaluation of the genetic diversity and genetic structure of H. speciosa var. speciosa. The genetic variability was assessed using 11 allozyme loci with a sample of 164 individuals distributed in six natural populations located in the States of Pernambuco and Alagoas, Northeastern Brazil. The results showed a high level of genetic diversity within the species (e= 0.36 seeing that the most of the genetic variability of H. speciosa var. speciosa is within its natural populations with low difference among populations ( or = 0.081. The inbreeding values within ( = -0.555 and among populations ( =-0.428 were low showing lacking of endogamy and a surplus of heterozygotes. The estimated gene flow ( m was high, ranging from 2.20 to 13.18, indicating to be enough to prevent the effects of genetic drift and genetic differentiation among populations. The multivariate analyses indicated that there is a relationship between genetic and geographical distances, which was confirmed by a spatial pattern analysis using Mantel test (r = 0.3598; p = 0.0920 with 1000 random permutations. The high genetic diversity index in these populations indicates potential for in situ genetic conservation.Hancornia speciosa Gomes é uma árvore frutífera nativa do Brasil, pertencente à família Apocinaceae, e é conhecida popularmente como Mangabeira. Seus frutos são amplamente consumidos in natura ou processados como sucos, sorvetes e

  20. Receptor model source attributions for Utah’s Salt Lake City airshed and the impacts of wintertime secondary ammonium nitrate and ammonium chloride aerosol.

    Science.gov (United States)

    Communities along Utah’s Wasatch Front are currently developing strategies to reduce daily average PM2.5 levels to below National Ambient Air Quality Standards during wintertime, persistent, multi-day stable atmospheric conditions or cold-air pools. Speciated PM2.5 data from the ...

  1. Wintertime aerosol chemical composition, volatility, and spatial variability in the greater London area

    Directory of Open Access Journals (Sweden)

    L. Xu

    2016-02-01

    Full Text Available The composition of PM1 (particulate matter with diameter less than 1 µm in the greater London area was characterized during the Clean Air for London (ClearfLo project in winter 2012. Two high-resolution time-of-flight aerosol mass spectrometers (HR-ToF-AMS were deployed at a rural site (Detling, Kent and an urban site (North Kensington, London. The simultaneous and high-temporal resolution measurements at the two sites provide a unique opportunity to investigate the spatial distribution of PM1. We find that the organic aerosol (OA concentration is comparable between the rural and urban sites, but the contribution from different sources is distinctly different between the two sites. The concentration of solid fuel OA at the urban site is about twice as high as at the rural site, due to elevated domestic heating in the urban area. While the concentrations of oxygenated OA (OOA are well-correlated between the two sites, the OOA concentration at the rural site is almost twice that of the urban site. At the rural site, more than 70 % of the carbon in OOA is estimated to be non-fossil, which suggests that OOA is likely related to aged biomass burning considering the small amount of biogenic SOA in winter. Thus, it is possible that the biomass burning OA contributes a larger fraction of ambient OA in wintertime than what previous field studies have suggested. A suite of instruments was deployed downstream of a thermal denuder (TD to investigate the volatility of PM1 species at the rural Detling site. After heating at 250 °C in the TD, 40 % of the residual mass is OA, indicating the presence of non-volatile organics in the aerosol. Although the OA associated with refractory black carbon (rBC; measured by a soot-particle aerosol mass spectrometer only accounts for < 10 % of the total OA (measured by a HR-ToF-AMS at 250 °C, the two measurements are well-correlated, suggesting that the non-volatile organics have similar sources or have

  2. Effect of influenza-like illness and other wintertime respiratory illnesses on worker productivity: The child and household influenza-illness and employee function (CHIEF) study.

    Science.gov (United States)

    Palmer, Liisa A; Rousculp, Matthew D; Johnston, Stephen S; Mahadevia, Parthiv J; Nichol, Kristin L

    2010-07-12

    Acute respiratory illnesses (ARI), comprising influenza-like illness (ILI) and other wintertime respiratory illnesses (ORI), impose substantial health and economic burdens on the United States. Little is known about the impact of ILI among household members (HHM), particularly children, on employees' productivity. To quantify the impact of employee and HHM-ILI and ARI on employee productivity, a prospective, observational cohort study was conducted among employees from three large US companies. Employees who had at least one child living at home (N=2013) completed a monthly survey during the 2007-2008 influenza season, reporting the number of days missed from work and hours of presenteeism due to: (1) personal ILI, (2) HHM-ILI, and (3) personal and HHM-ARI. Employee ILI ranged from 4.8% (April) to 13.5% (February). Employees reporting ILI reported more absences than employees not reporting ILI (72% vs 30%, respectively; Pemployees surveyed had at least one child with an ILI; these employees missed more days of work due to HHM illness than employees without an ARI-ill child (0.9 days vs 0.3 days, respectively; PEmployees with ILI were less productive, on average, for 4.8h each day that they worked while sick, 2.5h of which was attributable to ILI. HHM illnesses accounted for 17.7% (1389/7868 days) of employee absenteeism, over half of which was due to HHM-ARI. ILI causes a significant amount of employee absence. Household members, particularly children, comprise a sizable proportion of general illness and injury-related employee absences. Copyright 2010 Elsevier Ltd. All rights reserved.

  3. Impact of Climate Change on Siberian High and Wintertime Air Pollution in China in Past Two Decades

    Science.gov (United States)

    Zhao, Shuyu; Feng, Tian; Tie, Xuexi; Long, Xin; Li, Guohui; Cao, Junji; Zhou, Weijian; An, Zhisheng

    2018-02-01

    China has suffered severe air pollutions during wintertime as national industrialization and urbanization have been increasingly developed in the past decades. Recent studies suggest that climate change has important impacts on extreme haze events in northern China. This study uses reanalysis datasets to analyze the trend and variability of Siberian High (SiH) intensity, and its relationship with the Arctic temperature and sea ice cover (SIC) in past two decades. The results show that Arctic is warming accompanied by a rapid decline of SIC, while Eurasia is cooling and SiH intensity is gradually enhancing. The statistics illustrates that the SiH has a significantly positive correlation to the temperature (R = 0.70), and a significant anticorrelation to the SIC (R = -0.69), and this is because the warming Arctic and the reducing SIC enhanced the SiH. The enhanced SiH leads to strengthened northerly winds in the North China Plain (NCP). The WRF-Chem model calculation reveals the strengthened northerly winds during the stronger SiH period in January 2016 produce a significant decrease in PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm) concentrations by 100-200 µg m-3 than that during the weaker one in January 2013. A sensitivity calculation figures out the reduction of PM2.5 concentrations due to a decrease of 50% in emissions is comparable to changes from the weak SiH condition to the strong SiH condition, suggesting that extreme climate variability in the past few years could have an equivalent impact as a consequence of a large emission reduction on wintertime air pollution in the NCP.

  4. The Wintertime Covariation of CO2 and Criteria Pollutants in an Urban Valley of the Western United States

    Science.gov (United States)

    Bares, Ryan; Lin, John C.; Hoch, Sebastian W.; Baasandorj, Munkhbayar; Mendoza, Daniel L.; Fasoli, Ben; Mitchell, Logan; Catharine, Douglas; Stephens, Britton B.

    2018-03-01

    Numerous mountain valleys experience wintertime particulate pollution events, when persistent cold air pools (PCAPs) develop and inhibit atmospheric mixing, leading to the accumulation of pollutants. Here we examine the relationships between trace gases and criteria pollutants during winter in Utah's Salt Lake Valley, in an effort to better understand the roles of transport versus chemical processes during differing meteorological conditions as well as insights into how targeted reductions in greenhouse gases will impact local air quality in varying meteorological conditions. CO2 is a chemically inert gas that is coemitted during fossil fuel combustion with pollutants. Many of these coemitted pollutants are precursors that react chemically to form secondary particulate matter. Thus, CO2 can serve as a stable tracer and potentially help distinguish transport versus chemical influences on pollutants. During the winter of 2015-2016, we isolated enhancements in CO2 over baseline levels due to urban emissions ("CO2ex"). CO2ex was paired with similar excesses in other pollutant concentrations. These relationships were examined during different wintertime conditions and stages of pollution episodes: (a) Non-PCAP, (b) beginning, and (c) latter stages of an episode. We found that CO2ex is a good indicator of the presence of gaseous criteria pollutants and a reasonable indicator of PM2.5. Additionally, the relationships between CO2ex and criteria pollutants differ during different phases of PCAP events which provide insight into meteorological and transport processes. Lastly, we found a slight overestimation of CO:CO2 emission ratios and a considerable overestimation of NOx:CO2 by existing inventories for the Salt Lake Valley.

  5. Roles of tropical SST patterns during two types of ENSO in modulating wintertime rainfall over southern China

    Science.gov (United States)

    Xu, Kang; Huang, Qing-Lan; Tam, Chi-Yung; Wang, Weiqiang; Chen, Sheng; Zhu, Congwen

    2018-03-01

    The impacts of the eastern-Pacific (EP) and central-Pacific (CP) El Niño-Southern Oscillation (ENSO) on the southern China wintertime rainfall (SCWR) have been investigated. Results show that wintertime rainfall over most stations in southern China is enhanced (suppressed) during the EP (CP) El Niño, which are attributed to different atmospheric responses in the western North Pacific (WNP) and South China Sea (SCS) during two types of ENSO. When EP El Niño occurs, an anomalous low-level anticyclone is present over WNP/the Philippines region, resulting in stronger-than-normal southwesterlies over SCS. Such a wind branch acts to suppress East Asian winter monsoon (EAWM) and enhance moisture supply, implying surplus SCWR. During CP El Niño, however, anomalous sinking and low-level anticyclonic flow are found to cover a broad region in SCS. These circulation features are associated with moisture divergence over the northern part of SCS and suppressed SCWR. General circulation model experiments have also been conducted to study influence of various tropical sea surface temperature (SST) patterns on the EAWM atmospheric circulation. For EP El Niño, formation of anomalous low-level WNP anticyclone is jointly attributed to positive/negative SST anomalies (SSTA) over the central-to-eastern/ western equatorial Pacific. However, both positive and negative CP Niño-related-SSTA, located respectively over the central Pacific and WNP/SCS, offset each other and contribute a weak but broad-scale anticyclone centered at SCS. These results suggest that, besides the vital role of SST warming, SST cooling over SCS/WNP during two types of El Niño should be considered carefully for understanding the El Niño-EAWM relationship.

  6. Opera, Imagination and Society. Mexico and Brazil, Nineteenth Century. Connected Histories: “Ildegonda” by Melesio Morales and “Il Guarany” by Carlos Gomes

    Directory of Open Access Journals (Sweden)

    Verónica Zárate Toscano

    2008-10-01

    Full Text Available This paper examines the role played by opera during the nineteenth century in Mexico and Brazil, with views to start a joint reflection on these two Latin American countries based on the career of two musicians: the Brazilian Carlos Gomes and the Mexican Melesio Morales. This essay does not aspire to be a paper on comparative history, let alone on musicology. It rather  seeks to sketch an anal- ysis in the line of the “connected histories” introduced by Sanjay Subrahmanayam. My starting points are the bonds that tied Mexico, Brazil and Italy during the nineteenth century in the field of opera. The rivalry between these two musicians made us bring together and relate two rarely compared histories, two pasts, and two historiographies.

  7. Single-particle investigation of summertime and wintertime Antarctic sea spray aerosols using low-Z particle EPMA, Raman microspectrometry, and ATR-FTIR imaging techniques

    Directory of Open Access Journals (Sweden)

    H.-J. Eom

    2016-11-01

    Full Text Available Two aerosol samples collected at King Sejong Korean scientific research station, Antarctica, on 9 December 2011 in the austral summer (sample S1 and 23 July 2012 in the austral winter (sample S2, when the oceanic chlorophyll a levels on the collection days of the samples were quite different, by  ∼  19 times (2.46 vs. 0.13 µg L−1, respectively, were investigated on a single-particle basis using quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA, called low-Z particle EPMA, Raman microspectrometry (RMS, and attenuated total reflection Fourier transform infrared (ATR-FTIR imaging techniques to obtain their characteristics based on the elemental chemical compositions, molecular species, and mixing state. X-ray analysis showed that the supermicron summertime and wintertime Antarctic aerosol samples have different elemental chemical compositions, even though all the individual particles analyzed were sea spray aerosols (SSAs; i.e., the contents of C, O, Ca, S, and Si were more elevated, whereas Cl was more depleted, for sample S1 than for sample S2. Based on qualitative analysis of the chemical species present in individual SSAs by the combined application of RMS and ATR-FTIR imaging, different organic species were observed in samples S1 and S2; i.e., Mg hydrate salts of alanine were predominant in samples S1 and S2, whereas Mg salts of fatty acids internally mixed with Mg hydrate salts of alanine were significant in sample S2. Although CaSO4 was observed significantly in both samples S1 and S2, other inorganic species, such as Na2SO4, NaNO3, Mg(NO32, SiO2, and CH3SO3Mg, were observed more significantly in sample S1, suggesting that those compounds may be related to the higher phytoplankton activity in summer.

  8. Fluctuations in the large-scale atmospheric circulation and ocean conditions associated with the dominant modes of wintertime precipitation variability for the contiguous United States

    International Nuclear Information System (INIS)

    Mitchell, T.P.; Blier, W.

    1994-01-01

    The historical Climatic Division record of monthly- and seasonal-mean wintertime precipitation totals are analyzed to document the dominant patterns of precipitation variability for the contiguous United States. The analysis technique employed is the Rotated Principal Component analysis. Time series for the leading patterns are related to global sea-surface temperatures (SSTs), and to gridded surface and upper-air analyses for the Northern Hemisphere

  9. The levels, variation characteristics, and sources of atmospheric non-methane hydrocarbon compounds during wintertime in Beijing, China

    Directory of Open Access Journals (Sweden)

    C. Liu

    2017-09-01

    Full Text Available Atmospheric non-methane hydrocarbon compounds (NMHCs were measured at a sampling site in Beijing city from 15 December 2015 to 14 January 2016 to recognize their pollution levels, variation characteristics, and sources. We quantified 53 NMHCs, and the proportions of alkanes, alkenes, acetylene, and aromatics to the total NMHCs were 49.8–55.8, 21.5–24.7, 13.5–15.9, and 9.3–10.7 %, respectively. The variation trends in the NMHC concentrations were basically identical and exhibited remarkable fluctuation, which was mainly ascribed to the variation in meteorological conditions, especially wind speed. The diurnal variations in NMHCs on clear days exhibited two peaks during the morning and evening rush hours, whereas the rush hours' peaks diminished or even disappeared on the haze days, implying that the relative contribution of the vehicular emissions to atmospheric NMHCs depended on the pollution status. Two evident peaks of the propane ∕ propene ratios appeared in the early morning before sun rise and at noontime on clear days, whereas only one peak occurred in the afternoon during the haze days, which were attributed to the relatively fast reactions of propene with OH, NO3, and O3. Based on the chemical kinetic equations, the daytime OH concentrations were calculated to be in the range of 3. 47 × 105–1. 04 × 106 molecules cm−3 on clear days and 6. 42 × 105–2. 35 × 106 molecules cm−3 on haze days. The nighttime NO3 concentrations were calculated to be in the range of 2. 82 × 109–4. 86 × 109 molecules cm−3 on clear days. The correlation coefficients of typical hydrocarbon pairs (benzene ∕ toluene, o-xylene ∕ m,p-xylene, isopentane ∕ n-pentane, etc. revealed that vehicular emissions and coal combustion were important sources for atmospheric NMHCs in Beijing during the wintertime. Five major emission sources for atmospheric NMHCs in Beijing during

  10. The levels, variation characteristics, and sources of atmospheric non-methane hydrocarbon compounds during wintertime in Beijing, China

    Science.gov (United States)

    Liu, Chengtang; Ma, Zhuobiao; Mu, Yujing; Liu, Junfeng; Zhang, Chenglong; Zhang, Yuanyuan; Liu, Pengfei; Zhang, Hongxing

    2017-09-01

    Atmospheric non-methane hydrocarbon compounds (NMHCs) were measured at a sampling site in Beijing city from 15 December 2015 to 14 January 2016 to recognize their pollution levels, variation characteristics, and sources. We quantified 53 NMHCs, and the proportions of alkanes, alkenes, acetylene, and aromatics to the total NMHCs were 49.8-55.8, 21.5-24.7, 13.5-15.9, and 9.3-10.7 %, respectively. The variation trends in the NMHC concentrations were basically identical and exhibited remarkable fluctuation, which was mainly ascribed to the variation in meteorological conditions, especially wind speed. The diurnal variations in NMHCs on clear days exhibited two peaks during the morning and evening rush hours, whereas the rush hours' peaks diminished or even disappeared on the haze days, implying that the relative contribution of the vehicular emissions to atmospheric NMHCs depended on the pollution status. Two evident peaks of the propane / propene ratios appeared in the early morning before sun rise and at noontime on clear days, whereas only one peak occurred in the afternoon during the haze days, which were attributed to the relatively fast reactions of propene with OH, NO3, and O3. Based on the chemical kinetic equations, the daytime OH concentrations were calculated to be in the range of 3. 47 × 105-1. 04 × 106 molecules cm-3 on clear days and 6. 42 × 105-2. 35 × 106 molecules cm-3 on haze days. The nighttime NO3 concentrations were calculated to be in the range of 2. 82 × 109-4. 86 × 109 molecules cm-3 on clear days. The correlation coefficients of typical hydrocarbon pairs (benzene / toluene, o-xylene / m,p-xylene, isopentane / n-pentane, etc.) revealed that vehicular emissions and coal combustion were important sources for atmospheric NMHCs in Beijing during the wintertime. Five major emission sources for atmospheric NMHCs in Beijing during the wintertime were further identified by positive matrix factorization (PMF), including gasoline-related emissions

  11. Branca Dias: uma cristã-nova quinhentista na Paraíba de 1750 – História e ficção em O santo inquérito, de Dias Gomes

    OpenAIRE

    CHAVES, ROSANA RAMOS; UESC; Pereira, André Luis Mitidieri; UESC

    2013-01-01

    RESUMO: A peça teatral O santo inquérito, do dramaturgo baiano Dias Gomes, conta a saga da cristã-nova Branca Dias e sua família, perseguidos pela Inquisição, no ano de 1750, na Paraíba. A família Dias é acusada e condenada devido à suposta prática de judaísmo, embora a protagonista afirme ser cristã. Ainda que a personalidade Branca Dias e seu esposo Diogo Fernandes, famoso casal judaizante do século XVI, tenham numerosos detalhes de suas vidas registrados na história, Dias Gomes (re)criou s...

  12. Influence of the sunspot cycle on the Northern Hemisphere wintertime circulation from long upper-air data sets

    Directory of Open Access Journals (Sweden)

    Y. Brugnara

    2013-07-01

    Full Text Available Here we present a study of the 11 yr sunspot cycle's imprint on the Northern Hemisphere atmospheric circulation, using three recently developed gridded upper-air data sets that extend back to the early twentieth century. We find a robust response of the tropospheric late-wintertime circulation to the sunspot cycle, independent from the data set. This response is particularly significant over Europe, although results show that it is not directly related to a North Atlantic Oscillation (NAO modulation; instead, it reveals a significant connection to the more meridional Eurasian pattern (EU. The magnitude of mean seasonal temperature changes over the European land areas locally exceeds 1 K in the lower troposphere over a sunspot cycle. We also analyse surface data to address the question whether the solar signal over Europe is temporally stable for a longer 250 yr period. The results increase our confidence in the existence of an influence of the 11 yr cycle on the European climate, but the signal is much weaker in the first half of the period compared to the second half. The last solar minimum (2005 to 2010, which was not included in our analysis, shows anomalies that are consistent with our statistical results for earlier solar minima.

  13. Lung function after cold-water dives with a standard scuba regulator or full-face-mask during wintertime.

    Science.gov (United States)

    Uhlig, Florian; Muth, Claus-Martin; Tetzlaff, Kay; Koch, Andreas; Leberle, Richard; Georgieff, Michael; Winkler, Bernd E

    2014-06-01

    Full-face-masks (FFM) prevent the diver's face from cold and can support nasal breathing underwater. The aim of the study was to evaluate the effect of the use of FFMs on lung function and wellbeing. Twenty-one, healthy, non-asthmatic divers performed two cold-water dives (4⁰C, 25 min, 10 metres' depth) - one with a FFM and the other with a standard scuba regulator (SSR). Spirometry was performed before and after each dive and well-being and cold sensation were assessed after the dives. Significant decreases in forced vital capacity (FVC), forced expiratory volume in one second (FEV₁) and midexpiratory flow at 75% of FVC (MEF₇₅) occurred after both FFM and SSR dives. Changes in FVC and FEV₁ did not differ significantly between FFM and SSR dives. However, the mid-expiratory flows measured at 50% and 25% of FVC (MEF₅₀ and MEF₂₅) were significantly lower 10 minutes after the FFM dive compared to 10 minutes after the SSR dive. The wellbeing and cold sensation of the divers were significantly improved with FFM dives compared to SSR dives. Cold-water dives during wintertime can be associated with airway narrowing. During cold-water dives, the use of a FFM appears to reduce the cold sensation and enhance the well-being of the divers. However, a FFM does not appear to prevent airway narrowing in healthy, non-asthmatic subjects.

  14. The ammonium nitrate particle equivalent of NOx emissions for wintertime conditions in Central California's San Joaquin Valley

    International Nuclear Information System (INIS)

    Stockwell, W.R.; Watson, J.G.; Robinson, N.F.; Sylte, W.W.

    2000-01-01

    A new method has been developed to assess the aerosol particle formation reactivity of nitrogen oxide (NO x ) emissions. The method involves using a photochemical box model with gas-phase photochemistry, aerosol production and deposition to calculate the ammonium nitrate particle equivalent of NO x emissions. The yields of ammonium nitrate particles used in the box model were determined from parametric simulations made with an equilibrium model that calculated the fraction of nitric acid that reacts to produce ammonium nitrate from the temperature, relative humidity and ammonium-to-nitrate ratios. For the wintertime conditions of emissions and meteorology in the San Joaquin Valley of central California, approximately 80% of the moles of nitric acid produced was found to be in the particulate nitrate phase and about 33% of the moles of emitted NO x was converted to particulate nitrate. The particle equivalent of NO x emissions was found to be on the order of 0.6 g of ammonium nitrate for each gram of NO x emitted (the mass of NO x calculated as NO 2 ). This estimate is in reasonable agreement with an analysis of field measurements made in central California. (author)

  15. Overview of VOC emissions and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign: high acetaldehyde, isoprene and isocyanic acid in wintertime air of the Kathmandu Valley

    Directory of Open Access Journals (Sweden)

    C. Sarkar

    2016-03-01

    Full Text Available The Kathmandu Valley in Nepal suffers from severe wintertime air pollution. Volatile organic compounds (VOCs are key constituents of air pollution, though their specific role in the valley is poorly understood due to insufficient data. During the SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley–Atmospheric Brown Clouds field campaign conducted in Nepal in the winter of 2012–2013, a comprehensive study was carried out to characterise the chemical composition of ambient Kathmandu air, including the determination of speciated VOCs, by deploying a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS – the first such deployment in South Asia. In the study, 71 ion peaks (for which measured ambient concentrations exceeded the 2σ detection limit were detected in the PTR-TOF-MS mass scan data, highlighting the chemical complexity of ambient air in the valley. Of the 71 species, 37 were found to have campaign average concentrations greater than 200 ppt and were identified based on their spectral characteristics, ambient diel profiles and correlation with specific emission tracers as a result of the high mass resolution (m ∕ Δm  >  4200 and temporal resolution (1 min of the PTR-TOF-MS. The concentration ranking in the average VOC mixing ratios during our wintertime deployment was acetaldehyde (8.8 ppb  >  methanol (7.4 ppb  >  acetone + propanal (4.2 ppb  >  benzene (2.7 ppb  >  toluene (1.5 ppb  >  isoprene (1.1 ppb  >  acetonitrile (1.1 ppb  >  C8-aromatics ( ∼ 1 ppb  >  furan ( ∼ 0.5 ppb  >  C9-aromatics (0.4 ppb. Distinct diel profiles were observed for the nominal isobaric compounds isoprene (m ∕ z  =  69.070 and furan (m ∕ z  =  69.033. Comparison with wintertime measurements from several locations elsewhere in the world showed mixing ratios of acetaldehyde ( ∼  9 ppb, acetonitrile ( ∼  1 ppb and isoprene

  16. The wintertime deposition in the Helsinki city area during 1995- 1996: assessment using snow analyses; Laskeuma Helsingin seudulla lumesta maeaeritettynae talvikaudella 1995-1996

    Energy Technology Data Exchange (ETDEWEB)

    Soveri, J.; Peltonen, K.; Jaervinen, O.

    1998-09-01

    Snow cover forms a natural base for the deposition of atmospheric impurities, which are stored practically constant in the snowpack during the winter season. In this study the deposition of different constituents, including trace metals, was measured. Analyses were carried out with inductively coupled plasma-massspectrometry (ICP-MS). The regional variations in the deposition of different constituents within an urban environment were evaluated. The impacts of local emission sources to the quality of snow were also estimated. The estimates of wintertime deposition are based one 4 month period (1.1.1995-31.3.1996). The vacations in spatial distributions of nitrate nitrogen and sulphate were comparatively small due to large proportional share of long-range transport. However, deposition rates of nitrate nitrogen were 36 % above the median level in the southwest part of the study are a nearby the Salmisaari energy plant and 12 % above the median level nearby the Hanasaari energy plant. The deposition rate of sulphate was 50 % higher in Ruoholahti-Seurasaari and Hermanninranta-Herttoniemi areas compared with the mean level of deposited sulphate. Nitrate deposition in Helsinki was only 70 % higher compared with background level, and accordingly the major part of deposited nitrate comes from distant sources. The local impacts of sulphate deposition were somewhat higher compared with nitrate deposition. According to correlation analysis the pH of the snowpack was principally higher near the roads than the average owing to the alkaline dust raised by motorvehicles. Additionally the depositions of iron, calcium, aluminium, cobalt, molybdenum, zink, copper and chromium correlated with the vicinity of roads. Certain components of steel alloys, such as chromium and molybdenum are probably largely originated from rusted vehicle bodyworks and snowploughs. The most distinct impact of motorvehicles became apparently high cobalt concentrations. In addition of exhaust emissions

  17. ESTUDO DA PREVALÊNCIA DE ENTEROPARASITOSES NO MUNICÍPIO DE FERREIRA GOMES/AP APÓS A ENCHENTE EM 2011

    Directory of Open Access Journals (Sweden)

    Nathalye Dias Martins

    2014-10-01

    Full Text Available O objetivo deste trabalho foi investigar a prevalência de enteroparasitoses quando da enchente no município de Ferreira Gomes no estado do Amapá no período de abril e maio de 2011. Foi realizado estudo epidemiológico de natureza retrospectiva, cujas variáveis de análise foram os exames coproparasitológicos realizados na população no período de observação (abril a maio/2011, durante ação promovida pelo Laboratório Central de Saúde Pública do Estado do Amapá (LACEN/AP, realizada em parceria com a Secretaria Estadual de Saúde. Foram realizados 203 exames coprológicos evidenciando-se 64,04% de positividade para uma, duas ou três espécies parasitárias e 35,96% com resultado negativo. Maior frequência de casos positivos se deu no sexo feminino (64,62% contra (35,38% para o masculino. Evidenciou-se a faixa etária entre 01 a 20 anos com maior ocorrência de enteroparasitos, representando (50,77% dos casos. Foram identificadas oito espécies diferentes de parasitos nas amostras analisadas. As mais frequentes foram Endolimax nana (35,63%, Entamoeba histolytica (24,70%, Entamoeba coli (17,81% e Giardia intestinalis (12,96%. Além de Ascaris lumbricoides (4,45%, Trichuris trichiura (3,24%, Pentatrichomonas hominis (0,81% e Hymenolepis nana (0,40%. Observação marcante foi a detecção de poliparasitados (62,31% em particular pela associação E. histolytica/E. nana e (37,69% monoparasitados, principalmente pela E. histolytica (21,86%. As enteroparasitoses evidenciadas no âmbito desse estudo, considerando sobretudo as circunstâncias eco ambientais presentes, sugerem que a intensidade e diversidade de parasitos e respectivas incidências podem estar relacionadas também a ausência de drenagem de águas pluviais, ocupação desordenada da área e rede de água e esgoto deficientes. Palavras-chave: Parasitas intestinais, população, Ferreira Gomes. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v4n3p15-24

  18. Observing the Anthropocene from Space

    Science.gov (United States)

    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.

  19. City and School: the Visible Construction of the Fernando Gomes Elementary School in Porto Alegre/RS - Brazil (1913-1935

    Directory of Open Access Journals (Sweden)

    Tatiane De Freitas Ermel

    2016-07-01

    Full Text Available In the context of studies about space and school architecture, this article analyses the visual construction of the Fernando Gomes Elementary School, which was located in downtown Porto Alegre/RS, Brazil between 1913 and 1935. Designed by the engineer Afonso Hébert, head of the Department of Public Works in the State of Rio Grande do Sul/RS, the building was completed in 1922. In addition to functional elements, i.e., a large number of classrooms that would serve to increase the access of children to primary school, its monumental proportions incorporated a series of symbolic elements aligned with the ideals of the First Brazilian Republic (1889–1930. The documentary analysis was performed on the archives of the Directorship of Public Education and the Directorship of Public Works of Rio Grande do Sul, as well as various iconographic sources, capital improvement plans and periodicals of the time. The construction of the school inaugurated a new conception of the space and architecture of public elementary schools in the State, as the visible improvement and sanitation of the cities were considered of great importance in the period. The construction of school buildings was also one of the greatest advertising tools of the new Republican political regime.

  20. Pimenta pseudocaryophyllus (Gomes Landrum: aspectos botânicos, ecológicos, etnobotânicos e farmacológicos

    Directory of Open Access Journals (Sweden)

    A.S.R. D'angelis

    2014-09-01

    Full Text Available Pimenta pseudocaryophyllus (Gomes Landrum é a única espécie representante brasileira deste gênero de Myrtaceae. Tem sido popularmente utilizada no tratamento de diversas enfermidades, assim como condimento e aromatizante de bebidas, por seu sabor muito similar ao cravo-da-índia. Em menor escala, é empregada em carpintaria e na arborização urbana. Diversos autores analisaram a composição química do óleo essencial da espécie em diferentes regiões do Brasil, encontrando eugenol, metileugenol, (E metilisoeugenol, chavibetol, geranial e neral como composto predominante nos espécimes estudados. Visando ressaltar a importância de P. pseudocaryophyllus como potencial fonte de recursos assim como subsidiar ações de manejo adequado esta revisão apresenta os principais aspectos botânicos, ecológicos, etnobotânicos e farmacológicos da espécie.

  1. North American wintertime temperature anomalies: the role of El Niño diversity and differential teleconnections

    Science.gov (United States)

    Beyene, Mussie T.; Jain, Shaleen

    2018-06-01

    El Niño-Southern Oscillation (ENSO) teleconnections induced wintertime surface air temperature (SAT) anomalies over North America show inter-event variability, asymmetry, and nonlinearity. This diagnostic study appraises the assumption that ENSO-induced teleconnections are adequately characterized as symmetric shifts in the SAT probability distributions for North American locations. To this end, a new conditional quantile functional estimation approach presented here incorporates: (a) the detailed nature of location and amplitude of SST anomalies—in particular the Eastern Pacific (EP), Central Pacific (CP) ENSO events—based on its two leading principal components, and (b) over the entire range of SATs, characterize the differential sensitivity to ENSO. Statistical significance is assessed using a wild bootstrap approach. Conditional risk at upper and lower quartile SAT conditioned on archetypical ENSO states is derived. There is marked asymmetry in ENSO effects on the likelihood of upper and lower quartile winter SATs for most North American regions. CP El Niño patterns show 20-80% decrease in the likelihood of lower quartile SATs for Canada and US west coast and a 20-40% increase across southeastern US. However, the upper quartile SAT for large swathes of Canada shows no sensitivity to CP El Niño. Similarly, EP El Niño is linked to a 40-80% increase in the probability of upper quartile winter SATs for Canada and northern US and a 20% decrease for southern US and northern Mexico regions; however, little or no change in the risk of lower quartile winter temperatures for southern parts of North America. Localized estimate of ENSO-related risk are also presented.

  2. Chemical composition, sources and evolution processes of aerosol at an urban site in Yangtze River Delta, China during wintertime

    Science.gov (United States)

    Zhang, Yunjiang; Tang, Lili; Yu, Hongxia; Wang, Zhuang; Sun, Yele; Qin, Wei; Chen, Wentai; Chen, Changhong; Ding, Aijun; Wu, Jing; Ge, Shun; Chen, Cheng; Zhou, Hong-cang

    2015-12-01

    To investigate the composition, sources and evolution processes of submicron aerosol during wintertime, a field experiment was conducted during December 1-31, 2013 in urban Nanjing, a megacity in Yangtze River Delta of China. Non-refractory submicron aerosol (NR-PM1) species were measured with an Aerodyne Aerosol Chemical Speciation Monitor. NR-PM1 is dominated by secondary inorganic aerosol (55%) and organic aerosol (OA, 42%) during haze periods. Six OA components were identified by positive matrix factorization of the OA mass spectra. The hydrocarbon-like OA and cooking-related OA represent the local traffic and cooking sources, respectively. A highly oxidized factor related to biomass burning OA accounted for 15% of the total OA mass during haze periods. Three types of oxygenated OA (OOA), i.e., a less-oxidized OOA (LO-OOA), a more-oxidized OOA (MO-OOA), and a low-volatility OOA (LV-OOA), were identified. LO-OOA is likely associated with fresh urban secondary OA. MO-OOA likely represents photochemical products showing a similar diurnal cycle to nitrate with a pronounced noon peak. LV-OOA appears to be a more oxidized factor with a pronounced noon peak. The OA composition is dominated by secondary species, especially during haze events. LO-OOA, MO-OOA and LV-OOA on average account for 11%, (18%), 24% (21%) and 23% (18%) of the total OA mass for the haze (clean) periods respectively. Analysis of meteorological influence suggested that regional transport from the northern and southeastern areas of the city is responsible for large secondary and low-volatility aerosol formation.

  3. Wintertime slope winds and its turbulent characteristics in the Yeongdong region of Korea

    Science.gov (United States)

    Jeon, H. R.; Eun, S. H.; Kim, B. G.; Lee, Y. H.

    2015-12-01

    The Yeongdong region has various meteorological phenomenons by virtue of complicated geographical characteristics with high Taebaek Mountains running from the north to the south and an adjacent East Sea to the east. There are few studies on the slope winds and its turbulent characteristics over the complex terrain, which are critical information in mountain climbing, hiking, paragliding, even winter sports such as alpine skiing and ski jump etc. For the understanding of diverse mountain winds in the complex terrain in Yeongdong, hot-wire anemometers (Campbell Scientific) have been installed at a couple of sites since October 2014 and several automatic weather stations at several sites around the mountainous region in Yeongdong since November 2012.WRF model simulations have been also done with an ultra-fine horizontal resolution of 300 m for 10 years. Generally, model and observation show that the dominant wind is westerly, approximately more than 75%. It is quite consistent that wind fields from both model and observation agree with each other in the valley region and at the top of the mountain, but there is a significant disagreement in wind direction specifically in the slide slope. Probably this implies model's performance with even an ultra-fine resolution is still not enough for the slide slope domain of complex terrains. Despite that, the observation clearly showed up- and down slope winds for the weak synoptic conditions carefully selected such as strong insolation and a synoptic wind less than 5m/s in the 850 hPa. The up- and down slope flows are also demonstrated in the snow-covered condition as well as grass ground. Further, planar fit transformation algorithm against the coordinate tilt has been applied to raw wind data (10Hz) of the slope site for the analysis of turbulence properties. Turbulence also increases with synoptic wind strength. Detailed analysis of mechanical turbulence and buoyance will be discussed for different surface properties (grass

  4. The removal of nitric acid to atmospheric particles during a wintertime field study

    Science.gov (United States)

    Dasch, Jean Muhlbaier; Cadle, Steven H.

    A field was conducted in Warren, MI, during the 1987/88 winter period to examined the reaction of HNO 3 with particulate salt from road deicing. Samples of gases and particles were collected on a daily basis over a 4-month period. If HNO 3 reacts with particulate salt, particles of sodium nitrate will be formed and gaseous hydrochloric acid will be released. Thus, during the periods of high salt concentrations, one would expect increases in HCl and particulate NO 3- and a decrease in HNO 3. The effect was observed, although the total amount of NaNO 3 formed was not large. The increase in particulate NO 3- did not appear in the large particle mode. Although more than 40% of the salt was present as very large particles (> 8 μm), most of the surface area was associated with small particles. Since the reaction occurred at the particle surface, the NO 3- appeared in the small particle mode. Large-particle nitrate has been observed in association with sea salt and crustal particles and has also been attributed to reactions with HNO 3. These cases will be reconsidered based on the road salt results.

  5. Wintertime component of the THORPEX Pacific-Asian Regional Campaign (T-PARC)

    Science.gov (United States)

    Song, Y.; Toth, Z.; Asuma, Y.; Reynolds, C.; Lngland, R.; Szunyogh, I.; Colle, B.; Chang, E.; Doyle, C.; Kats, A.

    2009-04-01

    The winter component of the T-PARC is an international field project that aims at improving high impact weather event forecasts for North America. The main objective is to understand how perturbations from the tropics, Eurasia and polar fronts travel through waveguide and turn into high impact weather events. Through adaptive observations by using manned aircrafts (NOAA G-IV and US Air force C-130s) and Russian rawinsonde network over data sparse regions, it is expected that accurate initial conditions will improve the numerical weather forecasts. Non-adaptive aircraft measurements over the Pacific Rim and part of India are also deployed through E-AMDAR program, which is expected to improve the background field over Asia where perturbations are initiated. The campaign is led by NOAA and joined by agencies and universities from US, Canada, Mexico, Japan, ECWMF, and Russia. While most observational data will be assimilated by operational centers to improve real time numerical weather predictions, post field studies will focus on aspects such as: data impact on forecast and analysis, dry and moist processes that affect the formation and propagation of perturbations, meso-scale storm structure, error growth, forecast "busts" under certain atmospheric regimes, and socio-economic applications such as costs and benefits of improved forecasts and their use by the public for high impact weather events. In particular, a Winter Olympics demonstration project (February 12 - February 28) is expected to be a test bed during winter T-PARC for real user outreach and application purposes. Effectiveness of existing targeting methods as well as new targeting methods in the 3-5 day lead time range will be pursued and other aspects related to data assimilation and numerical forecasts (both deterministic and ensemble forecasts) will be investigated within this project as well.

  6. Wintertime Arctic Ocean sea water properties and primary marine aerosol concentrations

    Directory of Open Access Journals (Sweden)

    J. Zábori

    2012-11-01

    Full Text Available Sea spray aerosols are an important part of the climate system through their direct and indirect effects. Due to the diminishing sea ice, the Arctic Ocean is one of the most rapidly changing sea spray aerosol source areas. However, the influence of these changes on primary particle production is not known.

    In laboratory experiments we examined the influence of Arctic Ocean water temperature, salinity, and oxygen saturation on primary particle concentration characteristics. Sea water temperature was identified as the most important of these parameters. A strong decrease in sea spray aerosol production with increasing water temperature was observed for water temperatures between −1°C and 9°C. Aerosol number concentrations decreased from at least 1400 cm−3 to 350 cm−3. In general, the aerosol number size distribution exhibited a robust shape with one mode close to dry diameter Dp 0.2 μm with approximately 45% of particles at smaller sizes. Changes in sea water temperature did not result in pronounced change of the shape of the aerosol size distribution, only in the magnitude of the concentrations. Our experiments indicate that changes in aerosol emissions are most likely linked to changes of the physical properties of sea water at low temperatures. The observed strong dependence of sea spray aerosol concentrations on sea water temperature, with a large fraction of the emitted particles in the typical cloud condensation nuclei size range, provide strong arguments for a more careful consideration of this effect in climate models.

  7. Dispersal of Sediment in the Western Adriatic during Energetic Wintertime Forcing

    Science.gov (United States)

    Harris, C. K.; Sherwood, C. R.; Mullenbach, B. L.; Pullen, J. D.

    2003-12-01

    EuroSTRATAFORM aims to relate sediment delivery and reworking to seabed morphology and stratigraphy through observations and modeling of water column transport. The Po River dominates buoyancy and sediment input into the Adriatic Sea, but small Apeninne rivers (the Chienti, Pescara, etc.) may produce locally important signals. Sedimentation is influenced by fluvial supply, resuspension by waves and currents, and transport by oceanographic currents forced by winds and buoyancy. Transport is likely highest during times of energetic forcing; including Bora events with northeasterly winds and Sirocco events with southeasterly winds. It is difficult, from field measurements alone, to characterize dispersal and convergence patterns over the relevant spatial scales. We applied a three-dimensional hydrodynamic model that includes fluvial delivery, transport, resuspension, and deposition of sediment to quantify sediment dispersal with a 2-km resolution over the entire Adriatic. Circulation calculations were driven by spatially- and temporally-varying wind fields for the Fall / Winter of 2002 / 2003 and realistic Po and Apennine river discharges. Waves were hindcast with the SWAN model. Dispersion of both resuspended and river-derived sediment was estimated for periods that contained intense Bora and Sirocco winds. Predicted sediment dispersal rates and patterns are sensitive to forcing winds, buoyancy flux, and wave patterns. Higher sediment flux was predicted during Bora conditions than during Sirocco conditions. Sirocco winds weaken the Western Adriatic Coastal Current (WACC), and because they tend to concentrate over the Eastern Adriatic, they often fail to create especially energetic waves in the Western Adriatic. Bora wind conditions, on the other hand, intensify the WACC and can build high wave energies over the northwestern Adriatic. Most of the sediment transport occurs during Bora, with a net southward flux. These predictions will be compared to field observations

  8. Measuring wintertime surface fluxes at the Tiksi observatory in northern Sakha (Yakutia)

    Science.gov (United States)

    Laurila, Thomas; Aurela, Mika; Hatakka, Juha; Tuovinen, Juha-Pekka; Asmi, Eija; Kondratyev, Vladimir; Ivakhov, Victor; Reshetnikov, Alexander; Makshtas, Alexander; Uttal, Taneil

    2013-04-01

    Tiksi hydrometeorological observatory has been equipped by new instrumentation for meteorology, turbulence, trace gas and aerosols studies as a joint effort by National Oceanic and Atmospheric Administration (NOAA), Roshydromet (Yakutian Hydrometeorological Service, Arctic and Antarctic Research Institute and Voeikov Main Geophysical Observatory units) and the Finnish Meteorological Institute (FMI). The site is close to the coast of the Laptev Sea on deep permafrost soil with low tundra vegetation and patches of arctic semidesert. Near-by terrain is gently sloping to the south. Further away they are hills in the NE- and W-directions. Turbulence (3-d wind components and sonic temperature) was measured at 10 Hz by USA-1Scientific sonic by Metek, Gmbh. Concentrations of CO2 and H2O were measured by LiCor LI7000 analyzer and CH4 concentrations by Los Gatos RMT200 analyzer. Measurement height was 2.5m. Active layer freeze up took place in extended October period. Methane and carbon dioxide emissions were observed up to early December. Emissions to the atmosphere were enhanced by turbulence created by high wind speeds. Midwinter conditions existed from the end of October to the beginning of April based on rather constant negative net radiation between 20-30 Wm-2 that cools the surface and forms highly stable stratification. Weather conditions are characterized by either low or high wind speed modes. Roughly half of the time wind speed was low, below 2 ms-1. Then, katabatic winds were common and air temperature was between -40..-30°C. High wind speeds, up to 24 ms-1, were observed during synoptic disturbances which lasted typically a few days. In this presentation we will show climatology of surface layer characteristics in late autumn and winter. We will show frequency of well-developed turbulence vs. katabatic low wind speed conditions and related atmospheric stability. The effect of wind speed on methane and carbon dioxide emissions during the freezing period will be

  9. Physical and chemical characterization of urban winter-time aerosols by mobile measurements in Helsinki, Finland

    Science.gov (United States)

    Pirjola, Liisa; Niemi, Jarkko V.; Saarikoski, Sanna; Aurela, Minna; Enroth, Joonas; Carbone, Samara; Saarnio, Karri; Kuuluvainen, Heino; Kousa, Anu; Rönkkö, Topi; Hillamo, Risto

    2017-06-01

    A two-week measurement campaign by a mobile laboratory van was performed in urban environments in the Helsinki metropolitan area, Finland, in winter 2012, to obtain a comprehensive view on aerosol properties and sources. The abundances and physico-chemical properties of particles varied strongly in time and space, depending on the main sources of aerosols. Four major types of winter aerosol were recognized: 1) clean background aerosol with low particle number (Ntot) and lung deposited surface area (LDSA) concentrations due to marine air flows from the Atlantic Ocean; 2) long-range transported (LRT) pollution aerosol due to air flows from eastern Europe where the particles were characterized by the high contribution of oxygenated organic aerosol (OOA) and inorganic species, particularly sulphate, but low BC contribution, and their size distribution possessed an additional accumulation mode; 3) fresh smoke plumes from residential wood combustion in suburban small houses, these particles were characterized by high biomass burning organic aerosol (BBOA) and black carbon (BC) concentrations; and 4) fresh emissions from traffic while driving on busy streets in the city centre and on the highways during morning rush hours. This aerosol was characterized by high concentration of Ntot, LDSA, small particles in the nucleation mode, as well as high hydrocarbon-like organic aerosol (HOA) and BC concentrations. In general, secondary components (OOA, NO3, NH4, and SO4) dominated the PM1 chemical composition during the LRT episode accounting for 70-80% of the PM1 mass, whereas fresh primary emissions (BC, HOA and BBOA) dominated the local traffic and wood burning emissions. The major individual particle types observed with electron microscopy analysis (TEM/EDX) were mainly related to residential wood combustion (K/S/C-rich, soot, other C-rich particles), traffic (soot, Si/Al-rich, Fe-rich), heavy fuel oil combustion in heat plants or ships (S with V-Ni-Fe), LRT pollutants (S

  10. Wintertime measurements of aerosol acidity and trace elements in wuhan, a city in central china

    International Nuclear Information System (INIS)

    Waldman, J.M.; Lioy, P.J.; Zelenka, M.; Jing, L.; Lin, Y.N.

    1991-01-01

    In the People's Republic of China (P.R.C.), the pervasive use of soft coal leads to situations where the concentrations of SO2 and particulate matter approach or surpass those historically observed in London. A cooperative investigation of the effects of air pollution upon the lung function of children in five Chinese cities has been developed among China EPA, U.S. EPA and Robert Wood Johnson Medical School. The paper presents initial results of a winter air pollution field study conducted in Wuhan, one of the selected cities. A 2-week intensive ambient aerosol study was conducted in December 1988 in Wuhan (Hubei Province), a city of nearly 2 million located on the Yangtze River in central China (P.R.C.). This is an industrial region where soft coal burning is widespread, and emission controls for vehicles and industrial facilities are minimal. The sampling site was located in one of the civic centers where residential and commercial density is highest. The purpose of this initial intensive study period was to obtain information on the chemical and physical characteristics of the aerosol species in the urban P.R.C. setting. The focus was the composition and acidity of fine particulate material

  11. Agricultural Influences on Cache Valley, Utah Air Quality During a Wintertime Inversion Episode

    Science.gov (United States)

    Silva, P. J.

    2017-12-01

    Several of northern Utah's intermountain valleys are classified as non-attainment for fine particulate matter. Past data indicate that ammonium nitrate is the major contributor to fine particles and that the gas phase ammonia concentrations are among the highest in the United States. During the 2017 Utah Winter Fine Particulate Study, USDA brought a suite of online and real-time measurement methods to sample particulate matter and potential gaseous precursors from agricultural emissions in the Cache Valley. Instruments were co-located at the State of Utah monitoring site in Smithfield, Utah from January 21st through February 12th, 2017. A Scanning mobility particle sizer (SMPS) and aerodynamic particle sizer (APS) acquired size distributions of particles from 10 nm - 10 μm in 5-min intervals. A URG ambient ion monitor (AIM) gave hourly concentrations for gas and particulate ions and a Chromatotec Trsmedor gas chromatograph obtained 10 minute measurements of gaseous sulfur species. High ammonia concentrations were detected at the Smithfield site with concentrations above 100 ppb at times, indicating a significant influence from agriculture at the sampling site. Ammonia is not the only agricultural emission elevated in Cache Valley during winter, as reduced sulfur gas concentrations of up to 20 ppb were also detected. Dimethylsulfide was the major sulfur-containing gaseous species. Analysis indicates that particle growth and particle nucleation events were both observed by the SMPS. Relationships between gas and particulate concentrations and correlations between the two will be discussed.

  12. Atmospheric Simulations Using OGCM-Assimilation SST: Influence of the Wintertime Japan Sea on Monthly Precipitation

    Directory of Open Access Journals (Sweden)

    Masaru Yamamoto Naoki Hirose

    2010-01-01

    Full Text Available Temperature data for the Japan Sea obtained from ocean data assimilation modeling is applied to atmospheric simulations of monthly precipitation for January 2005. Because the volume of flow of the Tsushima Warm Current was large during the winter season, the sea surface temperature (SST and coastal precipitation were higher in comparison with those in 2003. In order to evaluate influence of SST on monthly precipitation, we use surface temperatures of the Japan Sea in 2003 and 2005 for comparative simulations of precipitation for January 2005. The precipitation in experiment C (using cool SST data in 2003 is smaller than that in experiment W (using warm SST data in 2005 in a large part of the sea area, since the small evaporation results from the low SST over the upstream area of northwesterly winter monsoon. In the domain of 33.67 - 45.82°N and 125.89 - 142.9°E, the averaged evaporation and precipitation in experiment C are 10% and 13% smaller than those in experiment W, respectively. About half of the difference between the precipitations observed for January 2003 and 2005 in a heavy snow area is equal to the difference between the two simulations. Our results show that the mesoscale SST difference between 2003 and 2005 is related to the local difference of monthly precipitation.

  13. Comparison between summertime and wintertime Arctic Ocean primary marine aerosol properties

    Directory of Open Access Journals (Sweden)

    J. Zábori

    2013-05-01

    Full Text Available Primary marine aerosols (PMAs are an important source of cloud condensation nuclei, and one of the key elements of the remote marine radiative budget. Changes occurring in the rapidly warming Arctic, most importantly the decreasing sea ice extent, will alter PMA production and hence the Arctic climate through a set of feedback processes. In light of this, laboratory experiments with Arctic Ocean water during both Arctic winter and summer were conducted and focused on PMA emissions as a function of season and water properties. Total particle number concentrations and particle number size distributions were used to characterize the PMA population. A comprehensive data set from the Arctic summer and winter showed a decrease in PMA concentrations for the covered water temperature (Tw range between −1°C and 15°C. A sharp decrease in PMA emissions for a Tw increase from −1°C to 4°C was followed by a lower rate of change in PMA emissions for Tw up to about 6°C. Near constant number concentrations for water temperatures between 6°C to 10°C and higher were recorded. Even though the total particle number concentration changes for overlapping Tw ranges were consistent between the summer and winter measurements, the distribution of particle number concentrations among the different sizes varied between the seasons. Median particle number concentrations for a dry diameter (DpDp > 0.125μm, the particle number concentrations during winter were mostly higher than in summer (up to 50%. The normalized particle number size distribution as a function of water temperature was examined for both winter and summer measurements. An increase in Tw from −1°C to 10°C during winter measurements showed a decrease in the peak of relative particle number concentration at about a Dp of 0.180μm, while an increase was observed for particles with Dp > 1μm. Summer measurements exhibited a relative shift to smaller particle sizes for an increase of Tw in the range

  14. SIMULAÇÃO DE CURVAS ISOFÔNICAS PARA UM PLANO DE ZONEAMENTO DE RUÍDO DO AEROPORTO INTERNACIONAL EDUARDO GOMES, EM MANAUS, AMAZONAS

    Directory of Open Access Journals (Sweden)

    Clive Reis Nascimento

    2015-10-01

    Full Text Available O presente trabalho visa simular curvas isofônicas aeronáuticas para o Aeroporto Internacional de Manaus/Eduardo Gomes seguindo a metodologia determinada pelo RBAC Nº 161, assim como tecer comparações com as curvas isofônicas atualmente em vigor. O software utilizado na simulação foi o INM. Foi simulado um conjunto de cinco curvas, sendo elas as de: 85, 80, 75, 70, 65 dB(A, que se propagaram por uma área de 2.214,7 hectares sobre a cidade de Manaus. Atualmente há um conjunto de duas curvas em vigência, uma de 75 e outra de 65 dB(A que abrangem 1.249,49 hectares. A quantidade de curvas em cada conjunto diverge devido a atualizações na legislação aeronáutica, que deu um novo cenário à problemática do ruído aeronáutico sobre as áreas no entorno dos aeroportos. O maior número delimita uma área de 1.074,75 hectares sobre a cidade de Manaus, onde as edificações necessitariam de tratamento acústico. Em trabalhos futuros seria interessante a realização de comparações de dados obtidos em estações de monitoramento de ruído das aeronaves que operam nesse aeroporto com os dados gerados pelo INM, assim como buscar conhecer como os habitantes abrangidos pelas curvas de ruído aeronáutico reagem a esse impacto ambiental.

  15. Régimen Dictadura Autoritaria Década de Brasil de 1960 y Violaciónes Derechos Humanos Reconocidos en Gomes Lund Caso y Otras que Falta en la Guerrilla Araguaia

    Directory of Open Access Journals (Sweden)

    Eudes Vitor Bezerra

    2016-06-01

    Full Text Available La premisa de que la Corte Interamericana de Derechos Humanos ha desempeñado un papel importante en la escena latinoamericana. En caso de condena "Gome Lund y otros" que resonaron en la reparabilidad de las personas desaparecidas. Vamos a utilizar el método hipotético-deductivo , con inversiones en la investigación dogmática y jurisprudencial, con la hipótesis inicial a través de un estudio evaluó la efectividad de los Derechos Humanos y la (inaplicabilidad de la Ley 9.140/95 .

  16. Caracterização hidráulica, hidrológica e de transporte sólido do evento de 20 de fevereiro de 2010 na Ribeira de João Gomes - Ilha da Madeira

    OpenAIRE

    Castro, João Nélio Remêsso

    2011-01-01

    O presente trabalho surge em resultado do evento de 20 de Fevereiro de 2010, com o objectivo de caracterizar a bacia hidrográfica da Ribeira de João Gomes, nas suas vertentes hidráulicas, hidrológicas e de transporte sólido. Inicialmente este trabalho relata as condições climáticas, geológicas e hidrológicas da ilha da Madeira, inclusive nos recursos hídricos e nas situações hidrológicas extremas. Em seguida é apresentado uma breve cronologia dos eventos aluviais presentes na ilha da Madei...

  17. Total ozone trends from 1979 to 2016 derived from five merged observational datasets - the emergence into ozone recovery

    Science.gov (United States)

    Weber, Mark; Coldewey-Egbers, Melanie; Fioletov, Vitali E.; Frith, Stacey M.; Wild, Jeannette D.; Burrows, John P.; Long, Craig S.; Loyola, Diego

    2018-02-01

    We report on updated trends using different merged datasets from satellite and ground-based observations for the period from 1979 to 2016. Trends were determined by applying a multiple linear regression (MLR) to annual mean zonal mean data. Merged datasets used here include NASA MOD v8.6 and National Oceanic and Atmospheric Administration (NOAA) merge v8.6, both based on data from the series of Solar Backscatter UltraViolet (SBUV) and SBUV-2 satellite instruments (1978-present) as well as the Global Ozone Monitoring Experiment (GOME)-type Total Ozone (GTO) and GOME-SCIAMACHY-GOME-2 (GSG) merged datasets (1995-present), mainly comprising satellite data from GOME, the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and GOME-2A. The fifth dataset consists of the monthly mean zonal mean data from ground-based measurements collected at World Ozone and UV Data Center (WOUDC). The addition of four more years of data since the last World Meteorological Organization (WMO) ozone assessment (2013-2016) shows that for most datasets and regions the trends since the stratospheric halogen reached its maximum (˜ 1996 globally and ˜ 2000 in polar regions) are mostly not significantly different from zero. However, for some latitudes, in particular the Southern Hemisphere extratropics and Northern Hemisphere subtropics, several datasets show small positive trends of slightly below +1 % decade-1 that are barely statistically significant at the 2σ uncertainty level. In the tropics, only two datasets show significant trends of +0.5 to +0.8 % decade-1, while the others show near-zero trends. Positive trends since 2000 have been observed over Antarctica in September, but near-zero trends are found in October as well as in March over the Arctic. Uncertainties due to possible drifts between the datasets, from the merging procedure used to combine satellite datasets and related to the low sampling of ground-based data, are not accounted for in the trend

  18. Efeito de diferentes meios de cultura na germinação in vitro de sementes de mangabeira (Hancornia speciosa Gomes

    Directory of Open Access Journals (Sweden)

    Kívia Soares de Oliveira

    2014-08-01

    Full Text Available A mangabeira, pertencente à família Apocynaceae, é uma espécie nativa do Cerrado e dos tabuleiros costeiros, sendo bastante conhecida pela importância social, econômica e cultural. O objetivo deste trabalho foi avaliar o efeito de diferentes meios de cultura na germinação in vitro de sementes de mangabeira, visando contribuir cientificamente para o conhecimento da espécie. Os tratamentos utilizados foram: T1 - vermiculita (+40 mL de água; T2 - vermiculita + areia (1:1 + 40 mL de água; T3 - vermiculita + areia barrada (1:1 + 40 mL de água; T4 - vermiculita + MS básico (40 ml; T5 - vermiculita + ½ MS (40 ml; T6 - areia (+40 mL de água; T7 - areia barrada (+40 mL de água; e T8 - areia + areia barrada (1:1 + 40 mL de água. Para tanto, realizou-se um experimento com oito tratamentos, incluindo oito repetições com 80 sementes por tratamento. Foram analisadas as seguintes variáveis: porcentagem de germinação, tempo médio de germinação e índice de velocidade de germinação. O delineamento experimental foi inteiramente casualizado e as médias, comparadas pelo teste de Tukey a 5% de significância. Observaram-se diferenças significativas para a porcentagem de germinação, sendo T3 estatisticamente superior, e para o IVG, com o melhor resultado, os tratamentos T1, T2 e T3. Entretanto, os valores de tempo médio de germinação não apresentaram diferença significativa. Diante dos resultados, pôde-se concluir que os tratamentos dotados de vermiculita e combinações, T1, T2 e T3, exercem influência positiva na emergência de Hancornia speciosa Gomes.

  19. DIETA DO MANDUBÉ, Ageneiosus ucayalensis (CASTELNAU, 1855, (OSTEICHTHYES: AUCHENIPTERIDAE DO RESERVATÓRIO DA USINA HIDRELÉTRICA COARACY NUNES, FERREIRA GOMES-AMAPÁ, BRASIL

    Directory of Open Access Journals (Sweden)

    Júlio César Sá-Oliveira

    2014-10-01

    Full Text Available O objetivo deste trabalho foi analisar a dieta de Ageneiosus ucayalensis do reservatório da Usina Hidrelétrica Coaracy Nunes, no município de Ferreira Gomes/AP. As amostragens foram feitas bimestralmente em três estações de coleta na área do reservatório entre julho/2009 e julho/2010. As coletas foram realizadas utilizando redes de espera, organizadas em baterias com sete redes cada e diferentes distâncias entre nós. Após a captura, foi realizada a biometria dos exemplares, sendo seus estômagos retirados, fixados e conservados para análise em laboratório. A proporção sexual foi realizada no intuito de verificar se houve diferença significativa entre os sexos. Os itens alimentares do conteúdo estomacal foram agrupados em categorias amplas e analisados através dos métodos de frequência de ocorrência e volumétrico, combinados no Índice de Importância Alimentar (IAi, por período sazonal. Os resultados evidenciaram que a proporção entre os sexos foi de 1:1, com uma leve predominância de fêmeas. Quanto à alimentação, a espécie mostrou-se carnívora, com a dieta baseada principalmente em microcrustáceos, crustáceos, peixes e material não identificável. Variações sazonais na dieta não foram nítidas e, provavelmente, estão relacionadas tanto à disponibilidade das presas na área quanto à manipulação do nível da água do reservatório pelo controle de comportas. Palavras-chave: alimentação, UHE, peixes, Siluriformes, IAi. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v4n3p73-82

  20. AVALIAÇÃO DA QUALIDADE DA ÁGUA DA RESERVA PARTICULAR DO PATRIMÔNIO NATURAL (RPPN SERINGAL TRIUNFO, RIO ARAGUARÍ, FERREIRA GOMES - AP - BRASIL

    Directory of Open Access Journals (Sweden)

    Erineide Silva Silva

    2014-08-01

    Full Text Available RESUMO: O presente estudo teve como verificar a qualidade da água de um trecho do rio Araguari na área da RPPN Seringal Triunfo através da análise de parâmetros químicos, físicos e microbiológicos exigidos em legislação, aplicando-se um índice de qualidade da água (IQA.  As amostras foram realizadas em oito pontos de monitoramento com coletas realizadas em dois períodos sazonais (seca e cheia, sendo o mês de dezembro de 2012 representando o período seco e o mês de junho de 2013 representando o período de cheia. Os parâmetros selecionados para a formulação do índice foram: temperatura da água, pH, turbidez, coliformes termotolerantes, DBO, OD, nitrato, fosfato e sólidos totais. Os dados obtidos foram confrontados com os limites definidos pela Resolução CONAMA 357/2005. Os padrões de qualidade da água foram levemente superiores no período seco em relação ao período de cheia. Através da aplicação do teste ANOVA observou-se que houve diferença significativa entre os oitos pontos para a maioria dos parâmetros analisados nos dois períodos estudados. O IQA apresentou nível de qualidade entre Bom e Médio durante os períodos. O teste t mostrou que houve diferença significativa (p<0,05 de IQA entre o período de cheia e seca. De forma geral a qualidade da água superficial da RPPN Seringal Triunfo foi considerada com o nível de qualidade ‘média’ estando os parâmetros estudados,em sua maioria, dentro dos permitidos pela legislação para águas de classe2. Palavras-chave: Rio Araguarí, Qualidade da Água, Reserva Particular, Ferreira Gomes. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v4n2p28-42

  1. 20 Years of Total and Tropical Ozone Time Series Based on European Satellite Observations

    Science.gov (United States)

    Loyola, D. G.; Heue, K. P.; Coldewey-Egbers, M.

    2016-12-01

    Ozone is an important trace gas in the atmosphere, while the stratospheric ozone layer protects the earth surface from the incident UV radiation, the tropospheric ozone acts as green house gas and causes health damages as well as crop loss. The total ozone column is dominated by the stratospheric column, the tropospheric columns only contributes about 10% to the total column.The ozone column data from the European satellite instruments GOME, SCIAMACHY, OMI, GOME-2A and GOME-2B are available within the ESA Climate Change Initiative project with a high degree of inter-sensor consistency. The tropospheric ozone columns are based on the convective cloud differential algorithm. The datasets encompass a period of more than 20 years between 1995 and 2015, for the trend analysis the data sets were harmonized relative to one of the instruments. For the tropics we found an increase in the tropospheric ozone column of 0.75 ± 0.12 DU decade^{-1} with local variations between 1.8 and -0.8. The largest trends were observed over southern Africa and the Atlantic Ocean. A seasonal trend analysis led to the assumption that the increase is caused by additional forest fires.The trend for the total column was not that certain, based on model predicted trend data and the measurement uncertainty we estimated that another 10 to 15 years of observations will be required to observe a statistical significant trend. In the mid latitudes the trends are currently hidden in the large variability and for the tropics the modelled trends are low. Also the possibility of diverging trends at different altitudes must be considered; an increase in the tropospheric ozone might be accompanied by decreasing stratospheric ozone.The European satellite data record will be extended over the next two decades with the atmospheric satellite missions Sentinel 5 Precursor (launch end of 2016), Sentinel 4 and Sentinel 5.

  2. Observing the Anthropocene from Space: Selected Megacities

    Science.gov (United States)

    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

  3. Measurements of total and tropospheric ozone from IASI: comparison with correlative satellite, ground-based and ozonesonde observations

    Directory of Open Access Journals (Sweden)

    A. Boynard

    2009-08-01

    Full Text Available In this paper, we present measurements of total and tropospheric ozone, retrieved from infrared radiance spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI, which was launched on board the MetOp-A European satellite in October 2006. We compare IASI total ozone columns to Global Ozone Monitoring Experiment-2 (GOME-2 observations and ground-based measurements from the Dobson and Brewer network for one full year of observations (2008. The IASI total ozone columns are shown to be in good agreement with both GOME-2 and ground-based data, with correlation coefficients of about 0.9 and 0.85, respectively. On average, IASI ozone retrievals exhibit a positive bias of about 9 DU (3.3% compared to both GOME-2 and ground-based measurements. In addition to total ozone columns, the good spectral resolution of IASI enables the retrieval of tropospheric ozone concentrations. Comparisons of IASI tropospheric columns to 490 collocated ozone soundings available from several stations around the globe have been performed for the period of June 2007–August 2008. IASI tropospheric ozone columns compare well with sonde observations, with correlation coefficients of 0.95 and 0.77 for the [surface–6 km] and [surface–12 km] partial columns, respectively. IASI retrievals tend to overestimate the tropospheric ozone columns in comparison with ozonesonde measurements. Positive average biases of 0.15 DU (1.2% and 3 DU (11% are found for the [surface–6 km] and for the [surface–12 km] partial columns respectively.

  4. Global long-term ozone trends derived from different observed and modelled data sets

    Science.gov (United States)

    Coldewey-Egbers, M.; Loyola, D.; Zimmer, W.; van Roozendael, M.; Lerot, C.; Dameris, M.; Garny, H.; Braesicke, P.; Koukouli, M.; Balis, D.

    2012-04-01

    The long-term behaviour of stratospheric ozone amounts during the past three decades is investigated on a global scale using different observed and modelled data sets. Three European satellite sensors GOME/ERS-2, SCIAMACHY/ENVISAT, and GOME-2/METOP are combined and a merged global monthly mean total ozone product has been prepared using an inter-satellite calibration approach. The data set covers the 16-years period from June 1995 to June 2011 and it exhibits an excellent long-term stability, which is required for such trend studies. A multiple linear least-squares regression algorithm using different explanatory variables is applied to the time series and statistically significant positive trends are detected in the northern mid latitudes and subtropics. Global trends are also estimated using a second satellite-based Merged Ozone Data set (MOD) provided by NASA. For few selected geographical regions ozone trends are additionally calculated using well-maintained measurements of individual Dobson/Brewer ground-based instruments. A reasonable agreement in the spatial patterns of the trends is found amongst the European satellite, the NASA satellite, and the ground-based observations. Furthermore, two long-term simulations obtained with the Chemistry-Climate Models E39C-A provided by German Aerospace Center and UMUKCA-UCAM provided by University of Cambridge are analysed.

  5. Observations of fine particulate nitrated phenols in four sites in northern China: concentrations, source apportionment, and secondary formation

    Science.gov (United States)

    Wang, Liwei; Wang, Xinfeng; Gu, Rongrong; Wang, Hao; Yao, Lan; Wen, Liang; Zhu, Fanping; Wang, Weihao; Xue, Likun; Yang, Lingxiao; Lu, Keding; Chen, Jianmin; Wang, Tao; Zhang, Yuanghang; Wang, Wenxing

    2018-03-01

    Filter samples of fine particulate matters were collected at four sites in northern China (urban, rural, and mountain) in summer and winter, and the contents of nine nitrated phenols were quantified in the laboratory with the use of ultra-high-performance liquid chromatography coupled with mass spectrometry. During the sampling periods, the concentrations of particulate nitrated phenols exhibited distinct temporal and spatial variation. On average, the total concentration of particulate nitrated phenols in urban Jinan in the wintertime reached 48.4 ng m-3, and those in the summertime were 9.8, 5.7, 5.9, and 2.5 ng m-3 in urban Jinan, rural Yucheng and Wangdu, and Mt. Tai, respectively. The elevated concentrations of nitrated phenols in wintertime and in urban areas demonstrate the apparent influences of anthropogenic sources. The positive matrix factorization receptor model was then applied to determine the origins of particulate nitrated phenols in northern China. The five major source factors were traffic, coal combustion, biomass burning, secondary formation, and aged coal combustion plume. Among them, coal combustion played a vital role, especially at the urban site in the wintertime, with a contribution of around 55 %. In the summertime, the observed nitrated phenols were highly influenced by aged coal combustion plumes at all of the sampling sites. Meanwhile, in remote areas, contributions from secondary formation were significant. Further correlation analysis indicates that nitrosalicylic acids were produced mostly from secondary formation that was dominated by NO2 nitration.

  6. Effect of High-Dose vs Standard-Dose Wintertime Vitamin D Supplementation on Viral Upper Respiratory Tract Infections in Young Healthy Children.

    Science.gov (United States)

    Aglipay, Mary; Birken, Catherine S; Parkin, Patricia C; Loeb, Mark B; Thorpe, Kevin; Chen, Yang; Laupacis, Andreas; Mamdani, Muhammad; Macarthur, Colin; Hoch, Jeffrey S; Mazzulli, Tony; Maguire, Jonathon L

    2017-07-18

    Epidemiological studies support a link between low 25-hydroxyvitamin D levels and a higher risk of viral upper respiratory tract infections. However, whether winter supplementation of vitamin D reduces the risk among children is unknown. To determine whether high-dose vs standard-dose vitamin D supplementation reduces the incidence of wintertime upper respiratory tract infections in young children. A randomized clinical trial was conducted during the winter months between September 13, 2011, and June 30, 2015, among children aged 1 through 5 years enrolled in TARGet Kids!, a multisite primary care practice-based research network in Toronto, Ontario, Canada. Three hundred forty-nine participants were randomized to receive 2000 IU/d of vitamin D oral supplementation (high-dose group) vs 354 participants who were randomized to receive 400 IU/d (standard-dose group) for a minimum of 4 months between September and May. The primary outcome was the number of laboratory-confirmed viral upper respiratory tract infections based on parent-collected nasal swabs over the winter months. Secondary outcomes included the number of influenza infections, noninfluenza infections, parent-reported upper respiratory tract illnesses, time to first upper respiratory tract infection, and serum 25-hydroxyvitamin D levels at study termination. Among 703 participants who were randomized (mean age, 2.7 years, 57.7% boys), 699 (99.4%) completed the trial. The mean number of laboratory-confirmed upper respiratory tract infections per child was 1.05 (95% CI, 0.91-1.19) for the high-dose group and 1.03 (95% CI, 0.90-1.16) for the standard-dose group, for a between-group difference of 0.02 (95% CI, -0.17 to 0.21) per child. There was no statistically significant difference in number of laboratory-confirmed infections between groups (incidence rate ratio [RR], 0.97; 95% CI, 0.80-1.16). There was also no significant difference in the median time to the first laboratory-confirmed infection: 3.95 months

  7. Wintertime pollution level, size distribution and personal daily exposure to particulate matters in the northern and southern rural Chinese homes and variation in different household fuels.

    Science.gov (United States)

    Du, Wei; Shen, Guofeng; Chen, Yuanchen; Zhuo, Shaojie; Xu, Yang; Li, Xinyue; Pan, Xuelian; Cheng, Hefa; Wang, Xilong; Tao, Shu

    2017-12-01

    This study investigated and compared wintertime air pollution and personal exposure in the rural northern and southern Chinese homes. Daily indoor and outdoor particle samples were simultaneously collected by using stationary samplers, and personal exposure was directly measured using portable carried samplers. The daily average concentrations of indoor and outdoor PM 2.5 were 521 ± 234 and 365 ± 185 μg/m 3 in the northern village, that were about 2.3-2.7 times of 188 ± 104 and 150 ± 29 μg/m 3 in indoor and outdoor air in the southern villages. Particle size distribution was similar between indoor and outdoor air, and had relatively smaller difference between the two sites, relative to the particle mass concentration difference. PM 2.5 contributed to ∼80% of the TSP mass, and in PM 2.5 , near 90% were PM 1.0 . In homes using electricity in the southern villages, outdoor air pollution could explain 70-80% of the variation in indoor air pollution. The daily exposure to PM 2.5 measured using personal carried samplers were 451 ± 301 μg/m 3 in the northern villages with traditional solid fuels used for daily cooking and heating, and in the southern villages without heating, the exposure to PM 2.5 were 184 ± 83 and 166 ± 45 μg/m 3 , respectively, for the population using wood and electricity for daily cooking. Time-weighted daily average exposure estimated from area concentration and time spent indoor and outdoor was generally correlated the directly measured exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. [The comprehensive evaluation of the bioclimatic comfort at the territories of the Russian Far East with reference to winter-time recreational activities and primary wellness tourism].

    Science.gov (United States)

    Pestereva, N M; Khechumyan, A F; Vorozbit, N

    2018-05-21

    in the framework of the current tendency toward the further development of the socio-economic sphere in the Russian Far East (RFE), the relevant investigations aimed at creating the comfortable conditions for recreational and touristic activities as well as for rehabilitative therapy of the local population acquire the increasingly greater importance. The objective of the present study was the comprehensive evaluation of the bioclimatic comfort at the territories of interest with special reference to winter-time recreational activities and primary wellness tourism. This study was designed to evaluate the health resort, recreational, and therapeutic resources of the selected areas of the Russian Far East with special reference to the data provided by the climate monitoring stations during the periods from December to March of 1965-2014. The following methods were used for the purpose: the comparative analysis of climatic information and elementary methods of mathematical statistics. The evaluation of the study territory in terms of the bioclimatic comfort gave evidence that the southern regions of Primorye as well as Sakhalin island, and Kamchatka peninsula provide the most favorable conditions for the therapeutic and recreational activities, leisure and sports in the winter seasons. The analysis of the studied bioclimatic indices of comfort at different territories of the Russian Far East has demonstrated their great potential for the further development of recreation services, rehabilitation, sporting and touristic activities. The study has revealed the new opportunities for the enhancement of bioclimatic comfort of the region and for the improvement of the quality of life and employment of the local population.

  9. The reduction of summer sulfate and switch from summertime to wintertime PM2.5 concentration maxima in the United States

    Science.gov (United States)

    Chan, Elizabeth A. W.; Gantt, Brett; McDow, Stephen

    2018-02-01

    Exposure to particulate matter air pollution with a nominal mean aerodynamic diameter less than or equal to 2.5 μm (PM2.5) has been associated with health effects including cardiovascular disease and death. Here, we add to the understanding of urban and rural PM2.5 concentrations over large spatial and temporal scales in recent years. We used high-quality, publicly-available air quality monitoring data to evaluate PM2.5 concentration patterns and changes during the years 2000-2015. Compiling and averaging measurements collected across the U.S. revealed that PM2.5 concentrations from urban sites experienced seasonal maxima in both winter and summer. Within each year from 2000 to 2008, the maxima of urban summer peaks were greater than winter peaks. However, from 2012 to 2015, the maxima of urban summertime PM2.5 peaks were smaller than the urban wintertime PM2.5 maxima, due to a decrease in the magnitude of summertime maxima with no corresponding decrease in the magnitude of winter maxima. PM2.5 measurements at rural sites displayed summer peaks with magnitudes relatively similar to those of urban sites, and negligible to no winter peaks through the time period analyzed. Seasonal variations of urban and rural PM2.5 sulfate, PM2.5 nitrate, and PM2.5 organic carbon (OC) were also assessed. Summer peaks in PM2.5 sulfate decreased dramatically between 2000 and 2015, whereas seasonal PM2.5 OC and winter PM2.5 nitrate concentration maxima remained fairly consistent. These findings demonstrate that PM2.5 concentrations, especially those occurring in the summertime, have declined in the U.S. from 2000 to 2015. In addition, reduction strategies targeting sulfate have been successful and the decrease in PM2.5 sulfate contributed to the decline in total PM2.5.

  10. Winter-time size distribution and source apportionment of total suspended particulate matter and associated metals in Delhi

    Science.gov (United States)

    Srivastava, Arun; Gupta, Sandeep; Jain, V. K.

    2009-03-01

    A study of the winter time size distribution and source apportionment of total suspended particulate matter (TSPM) and associated heavy metal concentrations have been carried out for the city of Delhi. This study is important from the point of view of implementation of compressed natural gas (CNG) as alternate of diesel fuel in the public transport system in 2001 to reduce the pollution level. TSPM were collected using a five-stage cascade impactor at six sites in the winters of 2005-06. The results of size distribution indicate that a major portion (~ 40%) of TSPM concentration is in the form of PM0.7 (heavy metals associated with various size fractions of TSPM. A very good correlation between coarse and fine size fraction of TSPM was observed. It was also observed that the metals associated with coarse particles have more chances of correlation with other metals; rather they are associated with fine particles. Source apportionment was carried out separately in coarse and fine size modes of TSPM by Chemical Mass Balance Receptor Model (CMB8) as well as by Principle Component Analysis (PCA) of SPSS. Source apportionment by PCA reveals that there are two major sources (possibly vehicular and crustal re-suspension) in both coarse and fine size fractions. Results obtained by CMB8 show the dominance of vehicular pollutants and crustal dust in fine and coarse size mode respectively. Noticeably the dominance of vehicular pollutants are now confined to fine size only whilst during pre CNG era it dominated both coarse and fine size mode. An increase of 42.5, 44.4, 48.2, 38.6 and 38.9% in the concentrations of TSPM, PM10.9, coarse particles, fine particles and lead respectively was observed during pre (2001) to post CNG (2005-06) period.

  11. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2011-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...

  12. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2010-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...

  13. Chemical composition and source-apportionment of sub-micron particles during wintertime over Northern India: New insights on influence of fog-processing.

    Science.gov (United States)

    Rajput, Prashant; Singh, Dharmendra Kumar; Singh, Amit Kumar; Gupta, Tarun

    2018-02-01

    A comprehensive study was carried out from central part of Indo-Gangetic Plain (IGP; at Kanpur) to understand abundance, temporal variability, processes (secondary formation and fog-processing) and source-apportionment of PM 1 -bound species (PM 1 : particulate matter of aerodynamic diameter ≤ 1.0 μm) during wintertime. A total of 50 PM 1 samples were collected of which 33 samples represent submicron aerosol characteristics under non-foggy condition whereas 17 samples represent characteristics under thick foggy condition. PM 1 mass concentration during non-foggy episodes varied from 24-393 (Avg.: 247) μg m -3 , whereas during foggy condition it ranged from 42-243 (Avg.: 107) μg m -3 . With respect to non-foggy condition, the foggy conditions were associated with higher contribution of PM 1 -bound organic matter (OM, by 23%). However, lower fractional contribution of SO 4 2- , NO 3 - and NH 4 + during foggy conditions is attributable to wet-scavenging owing to their high affinity to water. Significant influence of fog-processing on organic aerosols composition is also reflected by co-enhancement in OC/EC and WSOC/OC ratio during foggy condition. A reduction by 5% in mineral dust fraction under foggy condition is associated with a parallel decrease in PM 1 mass concentration. However, mass fraction of elemental carbon (EC) looks quite similar (≈3% of PM 1 ) but the mass absorption efficiency (MAE) of EC is higher by 30% during foggy episodes. Thus, it is evident from this study that fog-processing leads to quite significant enhancement in OM (23%) contribution (and MAE of EC) with nearly equal and parallel decrease in SO 4 2- , NO 3 - and NH 4 + and mineral dust fractions (totaling to 24%). Characteristic features of mineral dust remain similar under foggy and non-foggy conditions; inferred from similar ratios of Fe/Al (≈0.3), Ca/Al (0.35) and Mg/Al (0.22). Positive matrix factorization (PMF) resolves seven sources: biomass burning (19.4%), coal

  14. Protection from wintertime rainfall reduces nutrient losses and greenhouse gas emissions during the decomposition of poultry and horse manure-based amendments.

    Science.gov (United States)

    Maltais-Landry, Gabriel; Neufeld, Katarina; Poon, David; Grant, Nicholas; Nesic, Zoran; Smukler, Sean

    2018-04-01

    Manure-based soil amendments (herein "amendments") are important fertility sources, but differences among amendment types and management can significantly affect their nutrient value and environmental impacts. A 6-month in situ decomposition experiment was conducted to determine how protection from wintertime rainfall affected nutrient losses and greenhouse gas (GHG) emissions in poultry (broiler chicken and turkey) and horse amendments. Changes in total nutrient concentration were measured every 3 months, changes in ammonium (NH 4 + ) and nitrate (NO 3 - ) concentrations every month, and GHG emissions of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) every 7-14 days. Poultry amendments maintained higher nutrient concentrations (except for K), higher emissions of CO 2 and N 2 O, and lower CH 4 emissions than horse amendments. Exposing amendments to rainfall increased total N and NH 4 + losses in poultry amendments, P losses in turkey and horse amendments, and K losses and cumulative N 2 O emissions for all amendments. However, it did not affect CO 2 or CH 4 emissions. Overall, rainfall exposure would decrease total N inputs by 37% (horse), 59% (broiler chicken), or 74% (turkey) for a given application rate (wet weight basis) after 6 months of decomposition, with similar losses for NH 4 + (69-96%), P (41-73%), and K (91-97%). This study confirms the benefits of facilities protected from rainfall to reduce nutrient losses and GHG emissions during amendment decomposition. The impact of rainfall protection on nutrient losses and GHG emissions was monitored during the decomposition of broiler chicken, turkey, and horse manure-based soil amendments. Amendments exposed to rainfall had large ammonium and potassium losses, resulting in a 37-74% decrease in N inputs when compared with amendments protected from rainfall. Nitrous oxide emissions were also higher with rainfall exposure, although it had no effect on carbon dioxide and methane emissions

  15. Characterization and health risk assessment of airborne pollutants in commercial restaurants in northwestern China: Under a low ventilation condition in wintertime.

    Science.gov (United States)

    Dai, Wenting; Zhong, Haobin; Li, Lijuan; Cao, Junji; Huang, Yu; Shen, Minxia; Wang, Liqin; Dong, Jungang; Tie, Xuexi; Ho, Steven Sai Hang; Ho, Kin Fai

    2018-03-22

    Impacts on indoor air quality of dining areas from cooking activities were investigated in eight categories of commercial restaurants including Szechwan Hotpot, Hunan, Shaanxi Noodle, Chinese Barbecue, Chinese Vegetarian, Korean Barbecue, Italian, and Indian, in Northwestern China during December 2011 to January 2012. Chemical characterization and health risk assessment for airborne carbonyls, and particulate-bound polycyclic aromatic hydrocarbons (PAHs) and heavy metals were conducted under low ventilation conditions in wintertime. The highest total quantified carbonyls (Σ carbonyls ) concentration of 313.6μgm -3 was found in the Chinese Barbecue, followed by the Szechwan Hotpot (222.6μgm -3 ) and Indian (221.9μgm -3 ) restaurants. However, the highest Σ carbonyls per capita was found at the Indian restaurant (4500μgcapita -1 ), suggesting that cooking methods such as stir-fly and bake for spices ingredients released more carbonyls from thermal cooking processes. Formaldehyde, acetaldehyde, and acetone were the three most abundant species, totally accounting for >60% of mass concentrations of the Σ carbonyls . Phenanthrene, chrysene, and benzo[a]anthracene were the three most abundant PAHs. Low molecular weight fraction (ΣPAHs ≤178 ) had the highest contributions accounting for 40.6%-65.7%, much greater than their heaver counterparts. Diagnostic PAHs ratios suggest that cooking fuel and environmental tobacco smoke (ETS) contribute to the indoor PAHs profiles. Lead was the most abundant heavy metal in all sampled restaurants. High quantity of nickel was also found in samples due to the emissions from stainless-steel made kitchen utensils and cookware and ETS. Cancer risk assessments on the toxic substances demonstrate that the working environment of dining areas were hazard to health. Formation of reactive organic species (ROS) from the cooking activities was evidenced by measurement of hydroxyl radical (OH) formed from simulating particulate matter (PM

  16. Contribuição para a padronização química de Hancornia speciosa Gomes: desenvolvimento e validação de métodos analíticos para a quantificação de marcadores químicos

    OpenAIRE

    Ana Barbara Dias Pereira

    2012-01-01

    Hancornia speciosa Gomes, popularmente conhecida como mangaba, tem uso etnomédico para o tratamento de hipertensão e diabetes, entre outros. A potencial atividade anti-hipertensiva da espécie foi relatada em trabalhos anteriores de nosso grupo em modelos in vitro, ex vivo e in vivo, sendo rutina, L-(+)-bornesitol e ácido quínico identificados como constituintes bioativos. O presente trabalho teve como objetivo uantificar os principais constituintes químicos em extratos de folhas da espécie, v...

  17. Development of the Wintertime Sr/Ca-SST Record from Red Sea Corals as a Proxy for the North Atlantic Oscillation

    Science.gov (United States)

    Bernstein, W. N.; Hughen, K. A.

    2009-12-01

    The North Atlantic Oscillation (NAO) is one of the most pronounced and influential patterns in winter atmospheric circulation variability. This meridional redistribution of atmospheric mass across the Atlantic Ocean produces large changes in the intensity, number and direction of storms generated within the basin, and the regional climate of surrounding continents. The NAO exerts a significant impact on society, through influences on agriculture, fisheries, water management, energy generation and coastal development. NAO effects on climate extend from eastern North America across Europe to the eastern Mediterranean and Middle East. Changes in NAO behavior during the late 20th century have been linked to global warming; yet despite its importance, the causes and long-term patterns of NAO variability in the past remain poorly understood. In order to better predict the influence of the NAO on climate in the future, it is critical to examine multi-century NAO variability. The Red Sea is an excellent location from which to generate long NAO records for two reasons. First, patterns of wintertime sea surface temperature (SST) and salinity (SSS) in the Red Sea are highly correlated with NAO variability (Visbeck et al. 2001; Hurrell et al. 2003). Second, the tropical/subtropical Red Sea region contains fast growing long-lived massive Porites spp. corals with annually banded skeletons. These corals are ideal for generating well-dated high-resolution paleoclimatic records that extend well beyond the instrumental period. Here we present a study of winter SST and NAO variability in the Red sea region based on coral Sr/Ca data. In 2008, we collected multiple drill cores ranging in length from 1 to 4.1 meters from Porites corals at six sites spanning a large SST gradient. Sr/Ca measurements from multiple corals will be regressed against 23 years of satellite SST data, expanding the SST range over which we calibrate. A sampling resolution of 0.5mm will yield greater than bi

  18. Comparison of seasonal variation between anthropogenic and natural emission inventory and Satellite observation in Southeast Asia

    Science.gov (United States)

    Kurata, G.; Lalitaporn, P.

    2012-12-01

    Since the economic growth of the countries in Southeast Asia is significantly rapid, the emission of air pollutant from the anthropogenic activity, such as industry, power generation and transportation is rapidly increasing. Moreover, biomass burning due to unsuitable agricultural management, deforestation and expansion of farmland are discharging large amount of pollutants, such as Carbon monoxide, volatile organic compound and particulate matter. Especially, the particulate matter from biomass burning causes the serious haze pollution in surrounding area in Southeast Asia. Furthermore, the biomass fuel used for cooking at residential sector discharges harmful pollutants including a particulate matter, and causes the adverse health impact to people on indoor and outdoor. In this study, we evaluated the spatial distribution and the seasonal variation of emission inventory for Southeast Asia region by comparing with satellite observation data in order to improve the accuracy of the impact assessment of air pollution by regional atmospheric chemistry transport model (WRF and CMAQ). As an emission inventory data, we used our original regional emission inventory for Southeast Asia region developed from detail transportation and industry data sets as well as a several existing emission inventories. As satellite observation data, the vertical column density of NO2, Particulate matter and Carbon monoxide obtained by various satellite, such as GOME, GOME2, SCIAMACY, OMI and so on. As a result of comparisons between satellite observation and emission inventories from 1996 to 2011, in the case of anthropogenic emission, seasonal variation was comparatively well in agreement with the seasonal variation of satellite data. However, the uncertainty of the seasonal variation was large on several large cities. In the case of emission from biomass burning, the seasonal variation was clear, but inter-annual variation was also large due to large scale climate condition.

  19. Angular Normalization of Ground and Satellite Observations of Sun-induced Chlorophyll Fluorescence for Assessing Vegetation Productivity

    Science.gov (United States)

    Chen, J. M.; He, L.; Chou, S.; Ju, W.; Zhang, Y.; Joiner, J.; Liu, J.; Mo, G.

    2017-12-01

    Sun-induced chlorophyll fluorescence (SIF) measured from plant canopies originates mostly from sunlit leaves. Observations of SIF by satellite sensors, such as GOME-2 and GOSAT, are often made over large view zenith angle ranges, causing large changes in the viewed sunlit leaf fraction across the scanning swath. Although observations made by OCO-2 are near nadir, the observed sunlit leaf fraction could still vary greatly due to changes in the solar zenith angle with latitude and time of overpass. To demonstrate the importance of considering the satellite-target-view geometry in using SIF for assessing vegetation productivity, we conducted multi-angle measurements of SIF using a hyperspectral sensor mounted on an automated rotating system over a rice field near Nanjing, China. A method is developed to separate SIF measurements at each angle into sunlit and shaded leaf components, and an angularly normalized canopy-level SIF is obtained as the weighted sum of sunlit and shaded SIF. This normalized SIF is shown to be a much better proxy of GPP of the rice field measured by an eddy covariance system than the unnormalized SIF observations. The same normalization scheme is also applied to the far-red GOME-2 SIF observations on sunny days, and we found that the normalized SIF is better correlated with model-simulated GPP than the original SIF observations. The coefficient of determination (R2) is improved by 0.07±0.04 on global average using the normalization scheme. The most significant improvement in R2 by 0.09±0.04 is found in deciduous broadleaf forests, where the observed sunlit leaf fraction is highly sensitive to solar zenith angle.

  20. Identification of tropospheric emissions sources from satellite observations: Synergistic use of HCHO, NO2, and SO2 trace gas measurements

    Science.gov (United States)

    Marbach, T.; Beirle, S.; Khokhar, F.; Platt, U.

    2005-12-01

    We present case studies for combined HCHO, NO2, and SO2 satellite observations, derived from GOME measurements. Launched on the ERS-2 satellite in April 1995, GOME has already performed continuous operations over 8 years providing global observations of the different trace gases. In this way, satellite observations provide unique opportunities for the identifications of trace gas sources. The satellite HCHO observations provide information concerning the localization of biomass burning (intense source of HCHO). The principal biomass burning areas can be observed in the Amazon basin region and in central Africa Weaker HCHO sources (south east of the United States, northern part of the Amazon basin, and over the African tropical forest), not correlated with biomass burning, could be due to biogenic isoprene emissions. The HCHO data can be compared with NO2 and SO2 results to identify more precisely the tropospheric sources (biomass burning events, human activities, additional sources like volcanic emissions). Biomass burning are important tropospheric sources for both HCHO and NO2. Nevertheless HCHO reflects more precisely the biomass burning as it appears in all biomass burning events. NO2 correlate with HCHO over Africa (grassland fires) but not over Indonesia (forest fires). In south America, an augmentation of the NO2 concentrations can be observed with the fire shift from the forest to grassland vegetation. So there seems to be a dependence between the NO2 emissions during biomass burning and the vegetation type. Other high HCHO, SO2, and NO2 emissions can be correlated with climatic events like the El Nino in 1997, which induced dry conditions in Indonesia causing many forest fires.

  1. Observations of fine particulate nitrated phenols in four sites in northern China: concentrations, source apportionment, and secondary formation

    Directory of Open Access Journals (Sweden)

    L. Wang

    2018-03-01

    Full Text Available Filter samples of fine particulate matters were collected at four sites in northern China (urban, rural, and mountain in summer and winter, and the contents of nine nitrated phenols were quantified in the laboratory with the use of ultra-high-performance liquid chromatography coupled with mass spectrometry. During the sampling periods, the concentrations of particulate nitrated phenols exhibited distinct temporal and spatial variation. On average, the total concentration of particulate nitrated phenols in urban Jinan in the wintertime reached 48.4 ng m−3, and those in the summertime were 9.8, 5.7, 5.9, and 2.5 ng m−3 in urban Jinan, rural Yucheng and Wangdu, and Mt. Tai, respectively. The elevated concentrations of nitrated phenols in wintertime and in urban areas demonstrate the apparent influences of anthropogenic sources. The positive matrix factorization receptor model was then applied to determine the origins of particulate nitrated phenols in northern China. The five major source factors were traffic, coal combustion, biomass burning, secondary formation, and aged coal combustion plume. Among them, coal combustion played a vital role, especially at the urban site in the wintertime, with a contribution of around 55 %. In the summertime, the observed nitrated phenols were highly influenced by aged coal combustion plumes at all of the sampling sites. Meanwhile, in remote areas, contributions from secondary formation were significant. Further correlation analysis indicates that nitrosalicylic acids were produced mostly from secondary formation that was dominated by NO2 nitration.

  2. Intercomparison of AIRS and HIRDLS stratospheric gravity wave observations

    Science.gov (United States)

    Meyer, Catrin I.; Ern, Manfred; Hoffmann, Lars; Trinh, Quang Thai; Alexander, M. Joan

    2018-01-01

    statistical basis. The complete HIRDLS measurement period from January 2005 to March 2008 is covered. The seasonal and latitudinal distributions of gravity wave activity as observed by AIRS and HIRDLS agree well. A strong annual cycle at mid- and high latitudes is found in time series of gravity wave variances at 42 km, which has its maxima during wintertime and its minima during summertime. The variability is largest during austral wintertime at 60° S. Variations in the zonal winds at 2.5 hPa are associated with large variability in gravity wave variances. Altogether, gravity wave variances of AIRS and HIRDLS are complementary to each other. Large parts of the gravity wave spectrum are covered by joint observations. This opens up fascinating vistas for future gravity wave research.

  3. Intercomparison of AIRS and HIRDLS stratospheric gravity wave observations

    Directory of Open Access Journals (Sweden)

    C. I. Meyer

    2018-01-01

    compared on a statistical basis. The complete HIRDLS measurement period from January 2005 to March 2008 is covered. The seasonal and latitudinal distributions of gravity wave activity as observed by AIRS and HIRDLS agree well. A strong annual cycle at mid- and high latitudes is found in time series of gravity wave variances at 42 km, which has its maxima during wintertime and its minima during summertime. The variability is largest during austral wintertime at 60° S. Variations in the zonal winds at 2.5 hPa are associated with large variability in gravity wave variances. Altogether, gravity wave variances of AIRS and HIRDLS are complementary to each other. Large parts of the gravity wave spectrum are covered by joint observations. This opens up fascinating vistas for future gravity wave research.

  4. Autonomous Gliders Observed Physical and Biogeochemical Interplay at Submesoscale during Deep Convection in the Gulf of Lions (NW Mediterranean)

    Science.gov (United States)

    Bosse, A.; Testor, P.; Damien, P.; D'Ortenzio, F.; Prieur, L. M.; Estournel, C.; Marsaleix, P.; Mortier, L.

    2016-02-01

    Since 2010, sustained observations of the circulation and water properties of the NW Mediterranean Sea have been carried out by gliders in the framework of the MOOSE observatory (Mediterranean Ocean Observatory System for the Environment: http://www.moose-network.fr/). They regularly sampled the wintertime Northern Current (NC), the deep convection zone as well as the North Balearic Front (NBF) collecting a great amount of physical and biogeochemical measurements.During periods of deep convection, the offshore mixed layer can reach great depths (>2300 m) in the Gulf of Lions. Baroclinic fronts then become very intense and reveal a lot of variability at submesoscale in the upper 500 m or so. In terms of process, symmetric instability has been evidenced to occurr during strong wind events by gliders measurements. Complementary analysis performed with the help of a high-resolution regional model (dx,dy=1 km) highlight the prominent role of downfront winds in triggering this instability. Important vertical exchanges of oceanic tracers at the front approximately aligned with isopycnals of magnitude O(100m/day) occur in response to this strong atmospheric forcing. Finally, gliders measurements of Chl-a fluorescence show how this frontal instability seems to stimulate phytoplankton growth in frontal regions during harsh wintertime conditions.

  5. Explaining CO2 fluctuations observed in snowpacks

    Science.gov (United States)

    Graham, Laura; Risk, David

    2018-02-01

    Winter soil carbon dioxide (CO2) respiration is a significant and understudied component of the global carbon (C) cycle. Winter soil CO2 fluxes can be surprisingly variable, owing to physical factors such as snowpack properties and wind. This study aimed to quantify the effects of advective transport of CO2 in soil-snow systems on the subdiurnal to diurnal (hours to days) timescale, use an enhanced diffusion model to replicate the effects of CO2 concentration depletions from persistent winds, and use a model-measure pairing to effectively explore what is happening in the field. We took continuous measurements of CO2 concentration gradients and meteorological data at a site in the Cape Breton Highlands of Nova Scotia, Canada, to determine the relationship between wind speeds and CO2 levels in snowpacks. We adapted a soil CO2 diffusion model for the soil-snow system and simulated stepwise changes in transport rate over a broad range of plausible synthetic cases. The goal was to mimic the changes we observed in CO2 snowpack concentration to help elucidate the mechanisms (diffusion, advection) responsible for observed variations. On subdiurnal to diurnal timescales with varying winds and constant snow levels, a strong negative relationship between wind speed and CO2 concentration within the snowpack was often identified. Modelling clearly demonstrated that diffusion alone was unable to replicate the high-frequency CO2 fluctuations, but simulations using above-atmospheric snowpack diffusivities (simulating advective transport within the snowpack) reproduced snow CO2 changes of the observed magnitude and speed. This confirmed that wind-induced ventilation contributed to episodic pulsed emissions from the snow surface and to suppressed snowpack concentrations. This study improves our understanding of winter CO2 dynamics to aid in continued quantification of the annual global C cycle and demonstrates a preference for continuous wintertime CO2 flux measurement systems.

  6. Spatio-temporal variability of the polar middle atmosphere. Insights from over 30 years of research satellite observations

    Energy Technology Data Exchange (ETDEWEB)

    Lahoz, W.A.; Orsolini, Y.J.; Manney, G.L.; Minschwaner, K.; Allen, D.R.; Errera, Q.; Jackson, D.R.; Lambert, A.; Lee, J.; Pumphrey, H.; Schwartz, M.; Wu, D.

    2012-07-01

    We discuss the insights that research satellite observations from the last 30 years have provided on the spatio-temporal variability of the polar middle atmosphere. Starting from the time of the NASA LIMS (Limb Infrared Monitor of the Stratosphere) and TOMS (Total Ozone Mapping Spectrometer) instruments, both launched in 1978, we show how these observations have augmented our knowledge of the polar middle atmosphere, in particular how information on ozone and tracers has augmented our knowledge of: (i) the spatial and temporal characteristics of the wintertime polar stratosphere and the summertime circulation; and (ii) the roles of chemistry and transport in determining the stratospheric ozone distribution. We address the increasing joint use of observations and models, in particular in data assimilation, in contributing to this understanding. Finally, we outline requirements to allow continuation of the wealth of information on the polar middle atmosphere provided by research satellites over the last 30 years.(Author)

  7. A twenty-first century California observing network for monitoring extreme weather events

    Science.gov (United States)

    White, A.B.; Anderson, M.L.; Dettinger, M.D.; Ralph, F.M.; Hinojosa, A.; Cayan, D.R.; Hartman, R.K.; Reynolds, D.W.; Johnson, L.E.; Schneider, T.L.; Cifelli, R.; Toth, Z.; Gutman, S.I.; King, C.W.; Gehrke, F.; Johnston, P.E.; Walls, C.; Mann, Dorte; Gottas, D.J.; Coleman, T.

    2013-01-01

    During Northern Hemisphere winters, the West Coast of North America is battered by extratropical storms. The impact of these storms is of paramount concern to California, where aging water supply and flood protection infrastructures are challenged by increased standards for urban flood protection, an unusually variable weather regime, and projections of climate change. Additionally, there are inherent conflicts between releasing water to provide flood protection and storing water to meet requirements for water supply, water quality, hydropower generation, water temperature and flow for at-risk species, and recreation. In order to improve reservoir management and meet the increasing demands on water, improved forecasts of precipitation, especially during extreme events, is required. Here we describe how California is addressing their most important and costliest environmental issue – water management – in part, by installing a state-of-the-art observing system to better track the area’s most severe wintertime storms.

  8. Observations of high droplet number concentrations in Southern Ocean boundary layer clouds

    Directory of Open Access Journals (Sweden)

    T. Chubb

    2016-01-01

    Full Text Available Cloud physics data collected during the NSF/NCAR High-performance Instrumented Airborne Platform for Environmental Research (HIAPER Pole-to-Pole Observations (HIPPO campaigns provide a snapshot of unusual wintertime microphysical conditions in the boundary layer over the Southern Ocean. On 29 June 2011, the HIAPER sampled the boundary layer in a region of pre-frontal warm air advection between 58 and 48° S to the south of Tasmania. Cloud droplet number concentrations were consistent with climatological values in the northernmost profiles but were exceptionally high for wintertime in the Southern Ocean at 100–200 cm−3 in the southernmost profiles. Sub-micron (0.06  < D <  1 µm aerosol concentrations for the southern profiles were up to 400 cm−3. Analysis of back trajectories and atmospheric chemistry observations revealed that while conditions in the troposphere were more typical of a clean remote ocean airmass, there was some evidence of continental or anthropogenic influence. However, the hypothesis of long-range transport of continental aerosol fails to explain the magnitude of the aerosol and cloud droplet concentration in the boundary layer. Instead, the gale force surface winds in this case (wind speed at 167 m above sea level was  > 25 m s−1 were most likely responsible for production of sea spray aerosol which influenced the microphysical properties of the boundary layer clouds. The smaller size and higher number concentration of cloud droplets is inferred to increase the albedo of these clouds, and these conditions occur regularly, and are expected to increase in frequency, over windy parts of the Southern Ocean.

  9. Changes in the Winter-Time Storminess over the North Atlantic, Associated with the 1.5°C and 2°C Levels of Global Warming.

    Science.gov (United States)

    Barcikowska, M. J.; Weaver, S. J.; Feser, F.; Schenk, F.

    2017-12-01

    This study investigates the changes in extreme winter-time weather conditions over the NH midlatitudes. These conditions are to a large degree caused by extratropical storms, often associated with very intense and hazardous precipitation and wind. Although the skill of CMIP5 models in capturing these extremes is improved when compared to the previous generations, the spatial and temporal resolution of the models still remains a primary reason for the deficiencies. Therefore, many features of the storms projected for the future remain inconsistent. Here we are using the high-res horizontal (0.25° lat x lon) and temporal (3hr) output of the HAPPI experiment. This output facilitates not only an implicit extraction of storm tracks but also an analysis of the storm intensity, in terms of their maximum wind and rainfall, at subdaily time-scales. The analysis of simulated present climate shows an improved spatial pattern of large-scale circulation over North America and Europe, as compared to the CMIP5-generation models, and consequently a reduced zonal bias in storm tracks pattern. The information provided at subdaily time scale provides much more realistic representation of the magnitude of the extremes. These advances significantly contribute to our understanding of differential climate impacts between 1.5°C and 2°C levels of global warming. The spatial pattern of the north-eastward shift of storm tracks, derived from the recent CMIP5 future projections, is remarkably refined here. For example, increasing storminess expands towards Scandinavia, and not towards the north-central Europe. Derived spatial features of the storm intensity, e.g. increase in wind and precipitation on the west coasts of both the British Isles and Scandinavia underlines the relevancy of the results for the local communities and potential climate change adaptation initiatives.

  10. Satellite observations of air quality of megacities in China

    Science.gov (United States)

    Hao, N.; Valks, P.; Smedt, I. D.; Loyola, D.; Roozendael, M. V.; Zhou, B.; Zimmer, W.

    2012-04-01

    In the last three decades, air pollution has become a major environmental issue in metropolitan areas of China as a consequence of fast industrialization and urbanization, and the rapid increase of the vehicle ownership. Now in China there are 3 megacities (Beijing, Shanghai and Guangzhou) in existence. A recent study of Asian megacities showed that they cover less than 2% of the land area, hold more than 30% of the population and produce about 10% of the anthropogenic gas and aerosol emissions. Therefore, it is important to qualify and understand current air pollution distribution and development in and around the megacities of China. Satellite observations provide unique insight into the regional air quality around megacities and air pollution transport from surrounding areas. In this work, we present an investigation of air quality over Beijing, Shanghai and Guangzhou combining satellite and ground-based measurements. Aerosol optical thickness (AOT), precursors of ozone (notably NO2 and CH2O), and SO2 are observed from space. The operational GOME-2 trace gases products developed at German Aerospace Center and MODIS AOT products will be used. Moreover, near surface concentrations of particular matter (PM), NO2 and SO2 in Beijing, Shanghai and Guangzhou are investigated. The effect of air pollution transport from neighboring areas to megacities will be researched using satellite measurements. Initial comparison between satellite and ground-based measurements of air pollutants in Beijing, Shanghai and Guangzhou will be shown. We will present the relationship between AOT and PM concentrations in megacities. The use of AOT, tropospheric NO2 and CH2O columns for air quality applications will also be shown.

  11. Nitrogen, Aerosol Composition, and Halogens on a Tall Tower (NACHTT): Overview of a wintertime air chemistry field study in the front range urban corridor of Colorado

    Science.gov (United States)

    Brown, Steven S.; Thornton, Joel A.; Keene, William C.; Pszenny, Alexander A. P.; Sive, Barkley C.; Dubé, William P.; Wagner, Nicholas L.; Young, Cora J.; Riedel, Theran P.; Roberts, James M.; VandenBoer, Trevor C.; Bahreini, Roya; Öztürk, Fatma; Middlebrook, Ann M.; Kim, Saewung; Hübler, Gerhard; Wolfe, Daniel E.

    2013-07-01

    The Nitrogen, Aerosol Composition, and Halogens on a Tall Tower (NACHTT) field experiment took place during late winter, 2011, at a site 33 km north of Denver, Colorado. The study included fixed-height measurements of aerosols, soluble trace gases, and volatile organic compounds near surface level, as well as vertically resolved measurements of nitrogen oxides, aerosol composition, soluble gas-phase acids, and halogen species from 3 to 270 m above ground level. There were 1928 individual profiles during the three-week campaign to characterize trace gas and aerosol distributions in the lower levels of the boundary layer. Nitrate and ammonium dominated the ionic composition of aerosols and originated primarily from local or regional sources. Sulfate and organic matter were also significant and were associated primarily with longer-range transport to the region. Aerosol chloride was associated primarily with supermicron size fractions and was always present in excess of gas-phase chlorine compounds. The nighttime radical reservoirs, nitryl chloride, ClNO2, and nitrous acid, HONO, were both consistently present in nighttime urban air. Nitryl chloride was especially pronounced in plumes from large point sources sampled aloft at night. Nitrous acid was typically most concentrated near the ground surface and was the dominant contributor (80%) to diurnally averaged primary OH radical production in near-surface air. Large observed mixing ratios of light alkanes, both in near-surface air and aloft, were attributable to local emissions from oil and gas activities.

  12. Numerical Representation of Wintertime Near-Surface Inversions in the Arctic with a 2.5-km Version of the Global Environmental Multiscale (GEM) Model

    Science.gov (United States)

    Dehghan, A.; Mariani, Z.; Gascon, G.; Bélair, S.; Milbrandt, J.; Joe, P. I.; Crawford, R.; Melo, S.

    2017-12-01

    Environment and Climate Change Canada (ECCC) is implementing a 2.5-km resolution version of the Global Environmental Multiscale (GEM) model over the Canadian Arctic. Radiosonde observations were used to evaluate the numerical representation of surface-based temperature inversion which is a major feature in the Arctic region. Arctic surface-based inversions are often created by imbalance between radiative cooling processes at surface and warm air advection above. This can have a significant effect on vertical mixing of pollutants and moisture, and ultimately, on cloud formation. It is therefore important to correctly predict the existence of surface inversions along with their characteristics (i.e., intensity and depth). Previous climatological studies showed that the frequency and intensity of surface-based inversions are larger during colder months in the Arctic. Therefore, surface-based inversions were estimated using radiosonde measurements during winter (December 2015 to February 2016) at Iqaluit (Nunavut, Canada). Results show that the inversion intensity can exceed 10 K with depths as large as 1 km. Preliminary evaluation of GEM outputs reveals that the model tends to underestimate the intensity of near-surface inversions, and in some cases, the model failed to predict an inversion. This study presents the factors contributing to this bias including surface temperature and snow cover.

  13. Sustained Increase of 25-Hydroxyvitamin D Levels in Healthy Young Women during Wintertime after Three Suberythemal UV Irradiations-The MUVY Pilot Study.

    Directory of Open Access Journals (Sweden)

    Maria Gudrun Biersack

    Full Text Available Vitamin D (VitD deficiency is a health problem prevalent not only in the elderly but also in young adults. The primary objective of our observational pilot study "MUVY" (Mood, UVR, Vitamin D in Young women was to test both the short-term and long-term effects of a series of three suberythemal UV radiation (UVR exposures on the VitD status and well-being of young healthy women during winter in a repeat measure design.20 healthy young women (Fitzpatrick skin types I-III, aged 21-25 years received three full body broad band UVR exposures with an escalating erythemally weighted dose schedule during one week in winter, and completed self-report questionnaires monitoring symptoms of depression (Beck Depression Inventory, BDI and affective state/well-being (Profile of Mood States, POMS at baseline and three days after the last UVR exposure. 25-hydroxyvitamin D (25(OHD and 1,25-dihydroxyvitamin D (1,25(OH2D were measured in serum at baseline, and at study days 8, 36 and 50.Mean baseline 25(OHD level was 54.3 nmol/L (standard deviation (s.d. = 24.1, with seven women having VitD deficient status. Relevant symptoms of depression, as indicated by low BDI total scores (0-8, were absent. After the three UVR exposures the increment of 25(OHD was an average of 13.9 nmol/L (95% confidence interval (CI = 9.4-18.4 and 26.2 pmol/L (95%CI = 7.2-45.1 for 1,25(OH2D. Δ25(OHD, and corresponding baseline levels were significantly and inversely associated (rho = -0.493, p = 0.027. Only 25(OHD remained significantly increased above baseline for at least six weeks after the last UVR exposure. A strong inverse correlation of the POMS subscale "Vigor/Activity" and the increment in 1,25(OH2D was found (rho = -0.739, p<0.001 at day 8.Three suberythemal whole body UVR exposures during one week are a simple and suitable method for improving 25(OHD levels during winter, for at least six weeks, and especially in young women with VitD deficient status.German Clinical Trials

  14. Observational assessment of the role of nocturnal residual-layer chemistry in determining daytime surface particulate nitrate concentrations

    Directory of Open Access Journals (Sweden)

    G. Prabhakar

    2017-12-01

    Full Text Available This study discusses an analysis of combined airborne and ground observations of particulate nitrate (NO3−(p concentrations made during the wintertime DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically resolved observations relevant to Air Quality study at one of the most polluted cities in the United States – Fresno, CA – in the San Joaquin Valley (SJV and focuses on developing an understanding of the various processes that impact surface nitrate concentrations during pollution events. The results provide an explicit case-study illustration of how nighttime chemistry can influence daytime surface-level NO3−(p concentrations, complementing previous studies in the SJV. The observations exemplify the critical role that nocturnal chemical production of NO3−(p aloft in the residual layer (RL can play in determining daytime surface-level NO3−(p concentrations. Further, they indicate that nocturnal production of NO3−(p in the RL, along with daytime photochemical production, can contribute substantially to the buildup and sustaining of severe pollution episodes. The exceptionally shallow nocturnal boundary layer (NBL heights characteristic of wintertime pollution events in the SJV intensify the importance of nocturnal production aloft in the residual layer to daytime surface concentrations. The observations also demonstrate that dynamics within the RL can influence the early-morning vertical distribution of NO3−(p, despite low wintertime wind speeds. This overnight reshaping of the vertical distribution above the city plays an important role in determining the net impact of nocturnal chemical production on local and regional surface-level NO3−(p concentrations. Entrainment of clean free-tropospheric (FT air into the boundary layer in the afternoon is identified as an important process that reduces surface-level NO3−(p and limits buildup during pollution episodes. The influence of dry deposition of HNO

  15. Observing nebulae

    CERN Document Server

    Griffiths, Martin

    2016-01-01

    This book enables anyone with suitable instruments to undertake an examination of nebulae and see or photograph them in detail. Nebulae, ethereal clouds of gas and dust, are among the most beautiful objects to view in the night sky. These star-forming regions are a common target for observers and photographers. Griffiths describes many of the brightest and best nebulae and includes some challenges for the more experienced observer. Readers learn the many interesting astrophysical properties of these clouds, which are an important subject of study in astronomy and astrobiology. Non-mathematical in approach, the text is easily accessible to anyone with an interest in the subject. A special feature is the inclusion of an observational guide to 70 objects personally observed or imaged by the author. The guide also includes photographs of each object for ease of identification along with their celestial coordinates, magnitudes and other pertinent information. Observing Nebulae provides a ready resource to allow an...

  16. Observations of fluorescent aerosol-cloud interactions in the free troposphere at the Sphinx high Alpine research station, Jungfraujoch

    Science.gov (United States)

    Crawford, I.; Lloyd, G.; Bower, K. N.; Connolly, P. J.; Flynn, M. J.; Kaye, P. H.; Choularton, T. W.; Gallagher, M. W.

    2015-09-01

    The fluorescent nature of aerosol at a high Alpine site was studied using a wide-band integrated bioaerosol (WIBS-4) single particle multi-channel ultra violet-light induced fluorescence (UV-LIF) spectrometer. This was supported by comprehensive cloud microphysics and meteorological measurements with the aims of cataloguing concentrations of bio-fluorescent aerosols at this high altitude site and also investigating possible influences of UV-fluorescent particle types on cloud-aerosol processes. Analysis of background free tropospheric air masses, using a total aerosol inlet, showed there to be a minor but statistically insignificant increase in the fluorescent aerosol fraction during in-cloud cases compared to out of cloud cases. The size dependence of the fluorescent aerosol fraction showed the larger aerosol to be more likely to be fluorescent with 80 % of 10 μm particles being fluorescent. Whilst the fluorescent particles were in the minority (NFl/NAll = 0.27±0.19), a new hierarchical agglomerative cluster analysis approach, Crawford et al. (2015) revealed the majority of the fluorescent aerosol were likely to be representative of fluorescent mineral dust. A minor episodic contribution from a cluster likely to be representative of primary biological aerosol particles (PBAP) was also observed with a wintertime baseline concentration of 0.1±0.4 L-1. Given the low concentration of this cluster and the typically low ice active fraction of studied PBAP (e.g. pseudomonas syringae) we suggest that the contribution to the observed ice crystal concentration at this location is not significant during the wintertime.

  17. Observational astrophysics

    CERN Document Server

    Léna, Pierre; Lebrun, François; Mignard, François; Pelat, Didier

    2012-01-01

    This is the updated, widely revised, restructured and expanded third edition of Léna et al.'s successful work Observational Astrophysics. It presents a synthesis on tools and methods of observational astrophysics of the early 21st century. Written specifically for astrophysicists and graduate students, this textbook focuses on fundamental and sometimes practical limitations on the ultimate performance that an astronomical system may reach, rather than presenting particular systems in detail. In little more than a decade there has been extraordinary progress in imaging and detection technologies, in the fields of adaptive optics, optical interferometry, in the sub-millimetre waveband, observation of neutrinos, discovery of exoplanets, to name but a few examples. The work deals with ground-based and space-based astronomy and their respective fields. And it also presents the ambitious concepts behind space missions aimed for the next decades. Avoiding particulars, it covers the whole of the electromagnetic spec...

  18. Observable supertranslations

    Science.gov (United States)

    Bousso, Raphael; Porrati, Massimo

    2017-10-01

    We show that large gauge transformations in asymptotically flat spacetime can be implemented by sandwiching a shell containing the ingoing hard particles between two finite-width shells of soft gauge excitations. Integration of the graviton Dirac bracket implies that our observable soft degrees of freedom obey the algebra imposed by Strominger et al. on unobservable boundary degrees of freedom. Thus, we provide both a derivation and an observable realization of this algebra. We recently showed that soft charges fail to constrain the hard scattering problem, and so cannot be relevant to the black hole information paradox. By expressing the Bondi-van der Burg-Metzner-Sachs (BMS) algebra in terms of observable quantities, the present work shows that this conclusion was not an artifact of working with strictly zero frequency soft modes. The conservation laws associated with asymptotic symmetries are seen to arise physically from free propagation of infrared modes.

  19. Observational astrophysics

    CERN Document Server

    Smith, Robert C

    1995-01-01

    Combining a critical account of observational methods (telescopes and instrumentation) with a lucid description of the Universe, including stars, galaxies and cosmology, Smith provides a comprehensive introduction to the whole of modern astrophysics beyond the solar system. The first half describes the techniques used by astronomers to observe the Universe: optical telescopes and instruments are discussed in detail, but observations at all wavelengths are covered, from radio to gamma-rays. After a short interlude describing the appearance of the sky at all wavelengths, the role of positional astronomy is highlighted. In the second half, a clear description is given of the contents of the Universe, including accounts of stellar evolution and cosmological models. Fully illustrated throughout, with exercises given in each chapter, this textbook provides a thorough introduction to astrophysics for all physics undergraduates, and a valuable background for physics graduates turning to research in astronomy.

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

    Science.gov (United States)

    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

  1. Observational cosmology

    International Nuclear Information System (INIS)

    Partridge, R.B.

    1977-01-01

    Some sixty years after the development of relativistic cosmology by Einstein and his colleagues, observations are finally beginning to have an important impact on our views of the Universe. The available evidence seems to support one of the simplest cosmological models, the hot Big Bang model. The aim of this paper is to assess the observational support for certain assumptions underlying the hot Big Bang model. These are that the Universe is isobaric and homogeneous on a large scale; that it is expanding from an initial state of high density and temperature; and that the proper theory to describe the dynamics of the Universe is unmodified General Relativity. The properties of the cosmic microwave background radiation and recent observations of the abundance of light elements, in particular, support these assumptions. Also examined here are the data bearing on the related questions of the geometry and the future of the Universe (is it ever-expanding, or fated to recollapse). Finally, some difficulties and faults of the standard model are discussed, particularly various aspects of the 'initial condition' problem. It appears that the simplest Big Bang cosmological model calls for a highly specific set of initial conditions to produce the presently observed properties of the Universe. (Auth.)

  2. Flare Observations

    Directory of Open Access Journals (Sweden)

    Benz Arnold O.

    2008-02-01

    Full Text Available Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays at 100 MeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, and SOHO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections (CMEs, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting reconnection of magnetic field lines as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth’s lower ionosphere. While flare scenarios have slowly converged over the past decades, every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

  3. Flare Observations

    Science.gov (United States)

    Benz, Arnold O.

    2017-12-01

    Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays beyond 1 GeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, SOHO, and more recently Hinode and SDO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s) of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting magnetic reconnection as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth's ionosphere. Flare scenarios have slowly converged over the past decades, but every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

  4. Fast emission estimates in China and South Africa constrained by satellite observations

    Science.gov (United States)

    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

  5. Fast Emission Estimates in China Constrained by Satellite Observations (Invited)

    Science.gov (United States)

    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

  6. Observational astrophysics.

    Science.gov (United States)

    Léna, P.; Lebrun, F.; Mignard, F.

    This book is the 2nd edition of an English translation published in 1988 (45.003.105) of the French original "Astrophysique: Méthodes physiques de l'observation" published in 1986 (42.003.048). Written specifically for physicists and graduate students in astronomy, this textbook focuses on astronomical observation and on the basic physical principles that astronomers use to conceive, build and exploit their instruments at their ultimate limits in sensitivity or resolution. This second edition has been entirely restructured and almost doubled in size, in order to improve its clarity and to account for the great progress achieved in the last 15 years. It deals with ground-based and space-based astronomy and their respective fields. It presents the new generation of giant ground-based telescopes, with the new methods of optical interferometry and adaptive optics, and also the ambitious concepts behind planned space missions for the next decades. Avoiding particulars, it covers the whole of the electromagnetic spectrum and touches upon the "new astronomies" becoming possible with gravitational waves and neutrinos.

  7. Rocket observations

    Science.gov (United States)

    1984-05-01

    The Institute of Space and Astronautical Science (ISAS) sounding rocket experiments were carried out during the periods of August to September, 1982, January to February and August to September, 1983 and January to February, 1984 with sounding rockets. Among 9 rockets, 3 were K-9M, 1 was S-210, 3 were S-310 and 2 were S-520. Two scientific satellites were launched on February 20, 1983 for solar physics and on February 14, 1984 for X-ray astronomy. These satellites were named as TENMA and OHZORA and designated as 1983-011A and 1984-015A, respectively. Their initial orbital elements are also described. A payload recovery was successfully carried out by S-520-6 rocket as a part of MINIX (Microwave Ionosphere Non-linear Interaction Experiment) which is a scientific study of nonlinear plasma phenomena in conjunction with the environmental assessment study for the future SPS project. Near IR observation of the background sky shows a more intense flux than expected possibly coming from some extragalactic origin and this may be related to the evolution of the universe. US-Japan cooperative program of Tether Experiment was done on board US rocket.

  8. Satellite-derived SIF and CO2 Observations Show Coherent Responses to Interannual Climate Variations

    Science.gov (United States)

    Butterfield, Z.; Hogikyan, A.; Kulawik, S. S.; Keppel-Aleks, G.

    2017-12-01

    Gross primary production (GPP) is the single largest carbon flux in the Earth system, but its sensitivity to changes in climate is subject to significant uncertainty. Satellite measurements of solar-induced chlorophyll fluorescence (SIF) offer insight into spatial and temporal patterns in GPP at a global scale and, combined with other satellite-derived datasets, provide unprecedented opportunity to explore interactions between atmospheric CO2, GPP, and climate variability. To explore potential drivers of GPP in the Northern Hemisphere (NH), we compare monthly-averaged SIF data from the Global Ozone Monitoring Experiment 2 (GOME-2) with observed anomalies in temperature (T; CRU-TS), liquid water equivalent (LWE) from the Gravity Recovery and Climate Experiment (GRACE), and photosynthetically active radiation (PAR; CERES SYN1deg). Using observations from 2007 through 2015 for several NH regions, we calculate month-specific sensitivities of SIF to variability in T, LWE, and PAR. These sensitivities provide insight into the seasonal progression of how productivity is affected by climate variability and can be used to effectively model the observed SIF signal. In general, we find that high temperatures are beneficial to productivity in the spring, but detrimental in the summer. The influences of PAR and LWE are more heterogeneous between regions; for example, higher LWE in North American temperate forest leads to decreased springtime productivity, while exhibiting a contrasting effect in water-limited regions. Lastly, we assess the influence of variations in terrestrial productivity on atmospheric carbon using a new lower tropospheric CO2 product derived from the Greenhouse Gases Observing Satellite (GOSAT). Together, these data shed light on the drivers of interannual variability in the annual cycle of NH atmospheric CO2, and may provide improved constraints on projections of long-term carbon cycle responses to climate change.

  9. Chemical characteristics of N2O5 observed at a rural site in Beijing winter 2016: from clean to polluted air mass

    Science.gov (United States)

    Wang, H.; Lu, K.; Tan, Z.; Chen, X.; Wu, Z.; Zhu, Q.; Li, X.; Liu, Y.; Shang, D.; Wu, Y.; Min, H.; Zeng, L.; Schmitt, S. H.; Rohrer, F.; Kiendler-Scharr, A.; Wahner, A.; Zhang, Y.

    2017-12-01

    Dinitrogen pentoxide (N2O5) plays a vital role in the atmospheric oxidation, the NOX removal and the nitrate formation. A comprehensive campaign was conducted in the wintertime of 2016 in Beijing to focus on the atmospheric oxidation, new particle formation and aerosol light extinctions during the wintertime in Beijing. The site is located at a rural area in the northeast of Beijing and about 60 km away from the city center. A newly developed instrument based on the cavity enhanced absorption spectroscopy (CEAS) was deployed to measure ambient N2O5. Simultaneous measurements of the properties of particles and the relevant trace gases are available. The daily peaks of N2O5 in the clean episodes was lower than that of polluted episodes, the campaign maximum of 1.4 ppbv were captured in the most serious pollution episode. The averaged N2O5 maximum was about 120 pptv near 20:00, which is higher than that observed in summer. The uptake coefficient of N2O5 was derived from an iterative box model approach based on the Regional Atmospheric Chemical Mechanism version 2 (RACM2), constrained to observed trace gas compounds as well as the aerosol surface concentrations. The mechanisms of the chemical compounds of aerosols (measured by AMS) affects the N2O5 uptake coefficient are explored in several chemical coordinate systems. The chemical behaviors of the ambient N2O5 concentrations for this campaign is further discussed in the context of other campaigns performed in the urban and suburban areas in Beijing.

  10. Epidemiologic Observations on Diarrhea Developing in U.S. and Mexican Students Living in Guadalajara, Mexico.

    Science.gov (United States)

    Ericsson; DuPont; Mathewson

    1995-03-01

    Background: A previous study suggested that U.S. students who lived in Mexico for 1 year had a risk of diarrhea intermediate between the rate for newly arrived U.S. students and Mexican students; however, the study was not controlled for changes of risky behavior over time. Methods: An analysis of acute diarrhea occurring among U.S. and Mexican student groups living in Guadalajara, Mexico was conducted to explore the association of diarrhea developing during selected 28-day periods with length of residence, season, and risk factors such as locations of food consumption, consumption of tap water, unsafe ice, alcohol, and antibiotics. Results: Compared to U.S. and Mexican student groups, newly arrived U.S. college students in July had the highest rate of diarrhea (55%), highest enteropathogen isolation rate (46%), and most consumption of alcohol and antibiotics; they also ate most frequently at restaurants and in Mexican family homes. Compared to a 34% rate of diarrhea among newly arrived U.S. medical students in August, the rate was only 6% among established medical students in January. This drop in attack rate was attended by less tap water and unsafe ice consumption by established students in January compared to the habits of newly arrived students in January or August when risky behavior was otherwise similar among these groups. The role of tap water and unsafe ice in the acquisition of wintertime diarrhea is further supported by the relatively high 29% rate of diarrhea among U.S. medical students newly arrived in January, who also consumed more tap water and ice than established students in January. Enterotoxigenic E. coli disease was observed only during the summer months; whereas, Campylobacter jejuni disease and disease associated with no detected pathogen were more common in winter. Conclusions: These data imply that wintertime diarrhea in Guadalajara is more likely than summertime diarrhea to be waterborne and to be caused by agents such as viruses or

  11. Satellite observations of ozone and nitrogen dioxide : from retrievals to emission estimates

    NARCIS (Netherlands)

    Mijling, B.

    2012-01-01

    In the last decades, measurements of atmospheric composition from satellites have become very important for scientific research as well as applications for monitoring and forecasting the state of the atmosphere. Instruments such as GOME-2, and OMI look at backscattered sunlight in nadir view,

  12. Influence of the North Atlantic Oscillation on European tropospheric composition: an observational and modelling study

    Science.gov (United States)

    Pope, R.; Chipperfield, M.

    2017-12-01

    The North Atlantic Oscillation (NAO) has a strong influence on winter-time North Atlantic and European circulation patterns. Under the positive phase of the NAO (NAO+), intensification of the climatological Icelandic low and Azores high pressure systems results in strong westerly flow across the Atlantic into Europe. Under the NAO negative phase (NAO-), there is a weakening of this meridional pressure gradient resulting in a southerly shift in the westerlies flow towards the sub-tropical Atlantic. Therefore, NAO+ and NAO- introduce unstable stormy and drier stable conditions into Europe, respectively. Under NAO+ conditions, the strong westerlies tend to enhance transport of European pollution (e.g. nitrogen oxides) away from anthropogenic source regions. While during NAO-, the more stable conditions lead to a build up of pollutants. However, secondary pollutants (i.e. tropospheric ozone) show the opposite signal where NAO+, while transporting primary pollutants away, introduces Atlantic ozone enriched air into Europe. Here ozone can form downwind of pollution from continental North America and be transported into Europe via the westerly flow. Under NAO-, this westerly ozone transport is reduced yielding lower European ozone concentrations also depleted further by ozone loss through the reaction with NOx, which has accumulated over the continent. Peroxyacetyl nitrate (PAN), observed in the upper troposphere - lower stratosphere (UTLS) by satellite, peaks over Iceland/Southern Greenland in NAO-, between 200-100 hPa, consistent with trapping by an anticyclone at this altitude. During NAO+, PAN is enhanced over the sub-tropical Atlantic and Arctic. Model simulations show that enhanced PAN over Iceland/Southern Greenland in NAO- is associated with vertical transport from the troposphere into the UTLS, while peak Arctic PAN in NAO+ is its accumulation given the strong northerly meridional transport in the UTLS. UTLS ozone spatial anomalies, relative to the winter-time

  13. Optimal dimensioning model of water distribution systems | Gomes ...

    African Journals Online (AJOL)

    This study is aimed at developing a pipe-sizing model for a water distribution system. The optimal solution minimises the system's total cost, which comprises the hydraulic network capital cost, plus the capitalised cost of pumping energy. The developed model, called Lenhsnet, may also be used for economical design when ...

  14. Phacoemulsification of bilateral cataracts in two pet rabbits | Gomes ...

    African Journals Online (AJOL)

    Two 3 year-old, healthy, client-owned Lop rabbits presented with bilateral cataracts. After performing a physical examination, bloodwork, ocular ultrasonography and electroretinography, both animals were deemed good surgical candidates for phacoemulsification. Bilateral cataract surgery was performed and both rabbits ...

  15. VizieR Online Data Catalog: FADO code (Gomes+, 2017)

    Science.gov (United States)

    Gomes, J. M.; Papaderos, P.

    2017-03-01

    FADO comes from the Latin word "fatum" that means fate or destiny. It is also a well known genre of Portuguese music, and by choosing this acronym for this spectral synthesis tool we would like to pay tribute to Portugal. The main goal of FADO is to explore the star-formation and chemical enrichment history (the "Fado") of galaxies based on two hitherto unique elements in spectral fitting models: a) self-consistency between the best-fitting star formation history (SFH) and the nebular characteristics of a galaxy (e.g., hydrogen Balmer-line luminosities and equivalent widths; shape of the nebular continuum, including the Balmer and Paschen discontinuity) and b) genetic optimization and artificial intelligence algorithms. This document is part of the FADO v.1 distribution package, which contains two different ascii files, ReadMe and Read_F, and one tarball archive FADOv1.tar.gz. FADOv1.tar.gz contains the binary (executable) compiled in both OpenSuSE 13.2 64bit LINUX (FADO) and MAC OS X (FADO_MACOSX). The former is compatible with most LINUX distributions, while the latter was only tested for Yosemite 10.10.3. It contains the configuration files for running FADO: FADO.config and PLOT.config, as well as the "Simple Stellar Population" (SSP) base library with the base file list Base.BC03.L, the FADO v.1 short manual Read_F and this file (in the ReadMe directory) and, for testing purposes, three characteristic de-redshifted spectra from SDSS-DR7 in ascii format, corresponding to a star-forming (spec1.txt), composite (spec2.txt) and LINER (spec3.txt) galaxy. Auxiliary files needed for execution of FADO (.HIfboundem.ascii, .HeIIfbound.ascii, .HeIfboundem.ascii, grfont.dat and grfont.txt) are also included in the tarball. By decompressing the tarball the following six directories are created: input, output, plots, ReadMe, SSPs and tables (see below for a brief explanation). (2 data files).

  16. Drying and osmotic conditioning in Hancornia speciosa Gomes seeds

    Directory of Open Access Journals (Sweden)

    Tathiana Elisa Masetto

    Full Text Available Hancornia speciosa is a native tree species of the Brazilian Cerrado whose seeds are desiccation sensitive. In this study, we aimed to evaluate drying and osmotic conditioning in H. speciosa seeds. We used fresh seeds with 48% moisture content, which were slowly dried until they attained contents of 20%, 15%, 10% and 5%. To evaluate osmotic conditioning, the seeds were imbibed in 12 mL osmotic solutions at 0.0; -0.2; -0.4 and -0.6 MPa for two days. After that, they were dehydrated until their original moisture content. The experiments were carried out in a completely randomized design with four repetitions with 50 seeds each. Reduction in moisture content from 20% to 5% decreased the physiological potential of seeds. H. speciosa seeds do not require osmotic priming with PEG solutions, because imbibition of seeds in osmotic solutions of up to -0.6 MPa results in reduction of germination rate and seedling length.

  17. Nitrous oxide emission estimates using atmospheric observations of vertical profiles in a polluted agricultural region

    Science.gov (United States)

    Herrera, S.; Diskin, G. S.; Pusede, S.

    2016-12-01

    Nitrous oxide (N2O) is a long-lived and highly potent greenhouse gas that also destroys stratospheric ozone. Largely attributed to changes in agricultural sources, N2O concentrations are increasing at a steady rate of 0.8 ppb y-1 globally. Emission rates of N2O remain poorly constrained, with N2O sources arguably among the most uncertain of the long-lived greenhouse gases. This study quantifies N2O emissions at the kilometer-spatial scale in the wintertime in a region with both agricultural and urban sources, the San Joaquin Valley of California. To do this, we use the large number vertical profiles of N2O and other relevant trace gases measured by the P3 aircraft during the NASA DISCOVER-AQ campaign that took place throughout the San Joaquin Valley in January-February 2013. We exploit the observed variability in profile shape by time of day, day to day, and location (over urban versus agricultural sources), along with chemical and physical constraints on mixing and the timing of decoupling between the surface boundary layer and residual layers aloft.

  18. Real-Time Estimation of Volcanic ASH/SO2 Cloud Height from Combined Uv/ir Satellite Observations and Numerical Modeling

    Science.gov (United States)

    Vicente, Gilberto A.

    An efficient iterative method has been developed to estimate the vertical profile of SO2 and ash clouds from volcanic eruptions by comparing near real-time satellite observations with numerical modeling outputs. The approach uses UV based SO2 concentration and IR based ash cloud images, the volcanic ash transport model PUFF and wind speed, height and directional information to find the best match between the simulated and the observed displays. The method is computationally fast and is being implemented for operational use at the NOAA Volcanic Ash Advisory Centers (VAACs) in Washington, DC, USA, to support the Federal Aviation Administration (FAA) effort to detect, track and measure volcanic ash cloud heights for air traffic safety and management. The presentation will show the methodology, results, statistical analysis and SO2 and Aerosol Index input products derived from the Ozone Monitoring Instrument (OMI) onboard the NASA EOS/Aura research satellite and from the Global Ozone Monitoring Experiment-2 (GOME-2) instrument in the MetOp-A. The volcanic ash products are derived from AVHRR instruments in the NOAA POES-16, 17, 18, 19 as well as MetOp-A. The presentation will also show how a VAAC volcanic ash analyst interacts with the system providing initial condition inputs such as location and time of the volcanic eruption, followed by the automatic real-time tracking of all the satellite data available, subsequent activation of the iterative approach and the data/product delivery process in numerical and graphical format for operational applications.

  19. Anthropogenic Sulphur Dioxide Load over China as Observed from Different Satellite Sensors

    Science.gov (United States)

    Koukouli, M. E.; Balis, D. S.; Johannes Van Der A, Ronald; Theys, N.; Hedelt, P.; Richter, A.; Krotkov, N.; Li, Can; Taylor, M.

    2016-01-01

    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.

  20. Global Partitioning of NOx Sources Using Satellite Observations: Relative Roles of Fossil Fuel Combustion, Biomass Burning and Soil Emissions

    Science.gov (United States)

    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.

  1. Observations of the Breakdown of Mountain Waves Over the Andes Lidar Observatory at Cerro Pachon on 8/9 July 2012

    Science.gov (United States)

    Hecht, J. H.; Fritts, D. C.; Wang, L.; Gelinas, L. J.; Rudy, R. J.; Walterscheid, R. L.; Taylor, M. J.; Pautet, P. D.; Smith, S.; Franke, S. J.

    2018-01-01

    Although mountain waves (MWs) are thought to be a ubiquitous feature of the wintertime southern Andes stratosphere, it was not known whether these waves propagated up to the mesopause region until Smith et al. (2009) confirmed their presence via airglow observations. The new Andes Lidar Observatory at Cerro Pachon in Chile provided the opportunity for a further study of these waves. Since MWs have near-zero phase speed, and zero wind lines often occur in the winter upper mesosphere (80 to 100 km altitude) region due to the reversal of the zonal mean and tidal wind, MW breakdown may routinely occur at these altitudes. Here we report on very high spatial/temporal resolution observations of the initiation of MW breakdown in the mesopause region. Because the waves are nearly stationary, the breakdown process was observed over several hours; a much longer interval than has previously been observed for any gravity wave breakdown. During the breakdown process observations were made of initial horseshoe-shaped vortices, leading to successive vortex rings, as is also commonly seen in Direct Numerical Simulations (DNS) of idealized and multiscale gravity wave breaking. Kelvin-Helmholtz instability (KHI) structures were also observed to form. Comparing the structure of observed KHI with the results of existing DNS allowed an estimate of the turbulent kinematic viscosity. This viscosity was found to be around 25 m2/s, a value larger than the nominal viscosity that is used in models.

  2. Characteristics and sources of nitrous acid in an urban atmosphere of northern China: Results from 1-yr continuous observations

    Science.gov (United States)

    Li, Dandan; Xue, Likun; Wen, Liang; Wang, Xinfeng; Chen, Tianshu; Mellouki, Abdelwahid; Chen, Jianmin; Wang, Wenxing

    2018-06-01

    Nitrous acid (HONO) is a key reservoir of the hydroxyl radical (OH) and plays a central role in the atmospheric chemistry. To understand the sources and impact of HONO in the polluted atmosphere of northern China, continuous measurements of HONO and related parameters were conducted from September 2015 to August 2016 at an urban site in Ji'nan, the capital city of Shandong province. HONO showed well-defined seasonal and diurnal variation patterns with clear wintertime and nighttime concentration peaks. Elevated HONO concentrations (e.g., over 5 ppbv) were frequently observed with a maximum value of 8.36 ppbv. The HONO/NOX ratios of direct vehicle emissions varied in the range of 0.29%-0.87%, with a mean value of 0.53%. An average NO2-to-HONO nighttime conversion frequency (khet) was derived to be 0.0068 ± 0.0045 h-1 from 107 HONO formation cases. A detailed HONO budget analysis suggests an unexplained daytime missing source of 2.95 ppb h-1 in summer, which is about seven times larger than the homogeneous reaction of NO with OH. The effect of HONO on OH production was also quantified. HONO photolysis was the uppermost source of local OH radical throughout the daytime. This study provides the year-round continuous record of ambient HONO in the North China Plain, and offers some insights into the characteristics, sources and impacts of HONO in the polluted atmospheres of China.

  3. A note on sea level variability at Clipperton Island from GEOSAT and in-situ observations

    Science.gov (United States)

    Maul, George A.; Hansen, Donald V.; Bravo, Nicolas J.

    During the 1986-1989 Exact Repeat Mission (ERM) of GEOSAT, in-situ observations of sea level at Clipperton Island (10°N/109°W) and satellite-tracked free-drifting drogued buoys in the eastern tropical Pacific Ocean are concurrently available. A map of the standard deviations of GEOSAT sea surface heights (2.9 years) shows a variance maximum along ˜12°N from Central America, past Clipperton to ˜160°W. Sea floor pressure gauge observations from a shallow (10m depth) site on Clipperton Island and an ERM crossover point in deep water nearby show a correlation of r = 0.76 with a residual of ±6.7 cm RMS. Approximately 17% of the difference (GEOSAT minus sea level) is characterized by a 4 cm amplitude 0° phase annual harmonic, which is probably caused by unaccounted-for tropospheric water vapor affecting the altimeter and/or ERM orbit error removal. Wintertime anticyclonic mesoscale eddies advecting past Clipperton Island each year have GEOSAT sea surface height and in-situ sea level signals of more than 30 cm, some of which are documented by the satellite-tracked drifters. Meridional profiles of the annual harmonic of zonal geostrophic current from GEOSAT and from the drifters both show synchronous maxima in the North Equatorial Countercurrent and the North Equatorial Current. Other Clipperton sea level maxima seen during late spring of each year may involve anticyclonic vortices formed along Central America the previous winter.

  4. Two-year concurrent observation of isoprene at 20 sites over China: comparison with MEGAN-REAM model simulation

    Science.gov (United States)

    Zhang, Y.; Yang, W.; Zhang, R.; Zhang, Z.; Lyu, S.; Yu, J.; Wang, Y.; Wang, G.; Wang, X.

    2017-12-01

    Isoprene, the most abundant non-methane hydrocarbon emitted from plants, directly and indirectly affects atmospheric photochemistry and radiative forcing, yet narrowing its emission uncertainties is a continuous challenge. Comparison of observed and modelled isoprene on large spatiotemporal scales would help recognize factors that control isoprene variability, systematic field observation data are however quite lacking. Here we collected ambient air samples with 1 L silonite-treated stainless steel canisters simultaneously at 20 sites over China on every Wednesday at approximately 14:00 pm Beijing time from 2012 to 2014, and analyzed isoprene mixing ratios by preconcentrator-GC-MSD/FID. Observed isoprene mixing ratios were also compared with that simulated by coupling MEGAN 2.0 (Guenther et al., 2006) with a 3-D Regional chEmical trAnsport Model (REAM) (Zhang et al., 2017). Similar seasonal variations between observation and model simulation were obtained for most of sampling sites, but overall the average isoprene mixing ratios during growing months (May to October) was 0.37 ± 0.08 ppbv from model simulation, about 32% lower than that of 0.54 ± 0.20 ppbv based on ground-based observation, and this discrepancy was particularly significant in north China during wintertime. Further investigation demonstrated that emission of biogenic isoprene in northwest China might be underestimated and non-biogenic emission, such burning biomass/biofuel, might contribute to the elevated levels of isoprene during winter time. The observation-based empirical formulas for changing isoprene emission with solar radiation and temperature were also derived for different regions of China.

  5. SMM Observations of Saturn

    Science.gov (United States)

    Schnopper, Herbert; Mushotzky, Richard (Technical Monitor)

    2001-01-01

    During the past year I have participated in a series of team telecons to I plan our observation of Saturn with SMM. The observation, scheduled for this month (September), was canceled and a new observation is being planned for 2002.

  6. Six years of total ozone column measurements from SCIAMACHY nadir observations

    Science.gov (United States)

    Lerot, C.; van Roozendael, M.; van Geffen, J.; van Gent, J.; Fayt, C.; Spurr, R.; Lichtenberg, G.; von Bargen, A.

    2009-04-01

    Total O3 columns have been retrieved from six years of SCIAMACHY nadir UV radiance measurements using SDOAS, an adaptation of the GDOAS algorithm previously developed at BIRA-IASB for the GOME instrument. GDOAS and SDOAS have been implemented by the German Aerospace Center (DLR) in the version 4 of the GOME Data Processor (GDP) and in version 3 of the SCIAMACHY Ground Processor (SGP), respectively. The processors are being run at the DLR processing centre on behalf of the European Space Agency (ESA). We first focus on the description of the SDOAS algorithm with particular attention to the impact of uncertainties on the reference O3 absorption cross-sections. Second, the resulting SCIAMACHY total ozone data set is globally evaluated through large-scale comparisons with results from GOME and OMI as well as with ground-based correlative measurements. The various total ozone data sets are found to agree within 2% on average. However, a negative trend of 0.2-0.4%/year has been identified in the SCIAMACHY O3 columns; this probably originates from instrumental degradation effects that have not yet been fully characterized.

  7. Six years of total ozone column measurements from SCIAMACHY nadir observations

    Directory of Open Access Journals (Sweden)

    G. Lichtenberg

    2009-04-01

    Full Text Available Total O3 columns have been retrieved from six years of SCIAMACHY nadir UV radiance measurements using SDOAS, an adaptation of the GDOAS algorithm previously developed at BIRA-IASB for the GOME instrument. GDOAS and SDOAS have been implemented by the German Aerospace Center (DLR in the version 4 of the GOME Data Processor (GDP and in version 3 of the SCIAMACHY Ground Processor (SGP, respectively. The processors are being run at the DLR processing centre on behalf of the European Space Agency (ESA. We first focus on the description of the SDOAS algorithm with particular attention to the impact of uncertainties on the reference O3 absorption cross-sections. Second, the resulting SCIAMACHY total ozone data set is globally evaluated through large-scale comparisons with results from GOME and OMI as well as with ground-based correlative measurements. The various total ozone data sets are found to agree within 2% on average. However, a negative trend of 0.2–0.4%/year has been identified in the SCIAMACHY O3 columns; this probably originates from instrumental degradation effects that have not yet been fully characterized.

  8. Classroom observation and feedback

    Directory of Open Access Journals (Sweden)

    Ana GOREA

    2016-12-01

    Full Text Available Classroom observation is a didactic activity from which both the observer and the observed teacher are to win. The present article comments on and discusses the aims of observation, the stages of observation, the methodological recommendations of offering feedback and the need to introduce a system of classroom observation at institutional or even national level, which would contribute to improving the teaching/learning process.

  9. ALMA observing strategies

    OpenAIRE

    Biggs, Andy

    2018-01-01

    The ALMA Observing Tool (OT) is a Java-based tool used to prepare ALMA observations. In this talk, I highlight the particular features relevant to setting up single dish observations when these are needed to observe sources where the largest angular scale requires the addition of the total power antennas.

  10. ALMA Observing Strategies

    Science.gov (United States)

    Biggs, Andy

    2018-03-01

    The ALMA Observing Tool (OT) is a Java-based tool used to prepare ALMA observations. In this talk, I highlight the particular features relevant to setting up single dish observations when these are needed to observe sources where the largest angular scale requires the addition of the total power antennas.

  11. 2009 Observer Survey Report

    Science.gov (United States)

    Crimmins, Theresa M.; Rosemartin, Alyssa H.; Lincicome, Alexis; Weltzin, Jake F.

    2010-01-01

    The USA‐National Phenology Network (USA‐NPN) seeks to engage volunteer observers in collecting phenological observations of plants and animals using consistent standards and to contribute their observations to a national data repository. In March 2009, the National Coordinating Office staff implemented an online monitoring program for 213 plant species. In this pilot year of the program, 547 observers reported phenology observations on one or more plants via the online interface.

  12. Observational study of generation conditions of substorm-associated low-frequency AKR emissions

    Directory of Open Access Journals (Sweden)

    A. Olsson

    2004-11-01

    Full Text Available It has lately been shown that low-frequency bursts of auroral kilometric radiation (AKR are nearly exclusively associated with substorm expansion phases. Here we study low-frequency AKR using Polar PWI and Interball POLRAD instruments to constrain its possible generation mechanisms. We find that there are more low-frequency AKR emission events during wintertime and equinoxes than during summertime. The dot-AKR emission radial distance range coincides well with the region where the deepest density cavities are seen statistically during Kp>2. We suggest that the dot-AKR emissions originate in the deepest density cavities during substorm onsets. The mechanism for generating dot-AKR is possibly strong Alfvén waves entering the cavity from the magnetosphere and changing their character to more inertial, which causes the Alfvén wave associated parallel electric field to increase. This field may locally accelerate electrons inside the cavity enough to produce low-frequency AKR emission. We use Interball IESP low-frequency wave data to verify that in about half of the cases the dot-AKR is accompanied by low-frequency wave activity containing a magnetic component, i.e. probably inertial Alfvén waves. Because of the observational geometry, this result is consistent with the idea that inertial Alfvén waves might always be present in the source region when dot-AKR is generated. The paper illustrates once more the importance of radio emissions as a powerful remote diagnostic tool of auroral processes, which is not only relevant for the Earth's magnetosphere but may be relevant in the future in studying extrasolar planets.

  13. Tropospheric NO2 over China

    NARCIS (Netherlands)

    A, van der R.J.; Peters, D.H.M.U.; Kuenen, J.J.P.; Eskes, H.J.; Boersma, K.F.; Roozendael, Van M.; Smedt, de I.; Zhang, P.; Kelder, H.M.; Lacoste, H.; Ouwehand, L.

    2006-01-01

    The results are presented of a study to tropospheric NO2 over China, based on measurements from the satellite instruments GOME and SCIAMACHY. A data set of 10 year tropospheric NO2 has been processed from GOME and SCIAMACHY observations using a combined retrieval/assimilation approach. This approach

  14. Meteorological characteristics and overland precipitation impacts of atmospheric rivers affecting the West coast of North America based on eight years of SSM/I satellite observations

    Science.gov (United States)

    Neiman, P.J.; Ralph, F.M.; Wick, G.A.; Lundquist, J.D.; Dettinger, M.D.

    2008-01-01

    The pre-cold-frontal low-level jet within oceanic extratropical cyclones represents the lower-tropospheric component of a deeper corridor of concentrated water vapor transport in the cyclone warm sector. These corridors are referred to as atmospheric rivers (ARs) because they are narrow relative to their length scale and are responsible for most of the poleward water vapor transport at midlatitudes. This paper investigates landfalling ARs along adjacent north- and south-coast regions of western North America. Special Sensor Microwave Imager (SSM/ I) satellite observations of long, narrow plumes of enhanced integrated water vapor (IWV) were used to detect ARs just offshore over the eastern Pacific from 1997 to 2005. The north coast experienced 301 AR days, while the south coast had only 115. Most ARs occurred during the warm season in the north and cool season in the south, despite the fact that the cool season is climatologically wettest for both regions. Composite SSM/I IWV analyses showed landfalling wintertime ARs extending northeastward from the tropical eastern Pacific, whereas the summertime composites were zonally oriented and, thus, did not originate from this region of the tropics. Companion SSM/I composites of daily rainfall showed significant orographic enhancement during the landfall of winter (but not summer) ARs. The NCEP-NCAR global reanalysis dataset and regional precipitation networks were used to assess composite synoptic characteristics and overland impacts of landfalling ARs. The ARs possess strong vertically integrated horizontal water vapor fluxes that, on average, impinge on the West Coast in the pre-cold-frontal environment in winter and post-cold-frontal environment in summer. Even though the IWV in the ARs is greater in summer, the vapor flux is stronger in winter due to much stronger flows associated with more intense storms. The landfall of ARs in winter and north-coast summer coincides with anomalous warmth, a trough offshore, and

  15. Connecting Participant Observation Positions

    DEFF Research Database (Denmark)

    McCurdy, Patrick; Uldam, Julie

    2014-01-01

    In this article, we argue for the importance of considering participant observation roles in relation to both insider/outsider and overt/covert roles. Through combining key academic debates on participant observation, which have separately considered insider/outsider and overt/covert participant...... observation, we develop a reflexive framework to assist researchers in (1) locating the type of participant observation research; (2) identifying implications of participant observation for both the research and the subjects under study; and (3) reflecting on how one’s role as participant observer shifts over...

  16. Uruguay - Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface weather observation forms for 26 stations in Uruguay. Period of record 1896-2005, with two to eight observations per day. Files created through a...

  17. Lightship Daily Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations taken on board lightships along the United States coasts from 1936 - 1983. Generally 4-6 observations daily. Also includes deck logs, which give...

  18. Bottomfish Observer Database - Legacy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data collected by at sea observers in the Bottomfish Observer Program in the Northwestern Hawaiian Islands from October 2003 - April 2006.

  19. Surface Weather Observations Hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard hourly observations taken at Weather Bureau/National Weather Service offices and airports throughout the United States. Hourly observations began during the...

  20. Radar Weather Observation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Radar Weather Observation is a set of archived historical manuscripts stored on microfiche. The primary source of these radar weather observations manuscript records...

  1. OBSCAN Observer Scanning System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Paper logs are the primary data collection tool used by observers of the Northeast Fisheries Observer Program deployed on commercial fishing vessels. After the data...

  2. JAPANSE LONGLINE OBSERVER JPLL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data that were collected by trained observers aboard Japanese pelagic longline vessels operating in the US EEZ. Observers collected...

  3. Regional National Cooperative Observer

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA publication dedicated to issues, news and recognition of observers in the National Weather Service Cooperative Observer program. Issues published regionally...

  4. Cloning of observables

    International Nuclear Information System (INIS)

    Ferraro, Alessandro; Galbiati, Matteo; Paris, Matteo G A

    2006-01-01

    We introduce the concept of cloning for classes of observables and classify cloning machines for qubit systems according to the number of parameters needed to describe the class under investigation. A no-cloning theorem for observables is derived and the connections between cloning of observables and joint measurements of noncommuting observables are elucidated. Relationships with cloning of states and non-demolition measurements are also analysed. (letter to the editor)

  5. Cloning of observables

    OpenAIRE

    Ferraro, Alessandro; Galbiati, Matteo; Paris, Matteo G. A.

    2005-01-01

    We introduce the concept of cloning for classes of observables and classify cloning machines for qubit systems according to the number of parameters needed to describe the class under investigation. A no-cloning theorem for observables is derived and the connections between cloning of observables and joint measurements of noncommuting observables are elucidated. Relationships with cloning of states and non-demolition measurements are also analyzed.

  6. Radioactive sampler observation device

    International Nuclear Information System (INIS)

    Tanaka, Norihiko; Saito, Norihisa.

    1996-01-01

    When an object of observation is a fuel rod and if a specimen in a fuel pool is small, it takes much labor for the observation and micro-observation images at a high ratio can not be displayed. A pipe for containing an observing camera in a water-sealed state, a jack capable of adjusting the focus of the observation camera by remote control and a horizontal bed capable of controlling the position of the observation camera for observing the specimen are disposed on a rail formed on lead block shielding walls. The magnification ratio for the observation can be increased by exchanging a die for securing the specimen and a lens, and a transparent acrylic resin plate, or a transparent lead-incorporated glass plate is joined to the bottom of the pipe. Since the sampled specimen can be observed as it is irrespective of the shape or the size of the specimen to be observed, danger of radiation exposure caused such as upon cutting, transportation or fabrication of the radioactive specimen can be reduced. Further, observation underwater can be conducted by the water sealing treatment of the pipe for the observing camera. (N.H.)

  7. Being observed magnifies action

    NARCIS (Netherlands)

    Steinmetz, J.; Xu, Q.; Fishbach, A.; Zhang, Y.

    2016-01-01

    We test the hypothesis that people, when observed, perceive their actions as more substantial because they add the audience’s perspective to their own perspective. We find that participants who were observed while eating (Study 1) or learned they were observed after eating (Study 2) recalled eating

  8. Shelf sea tidal currents and mixing fronts determined from ocean glider observations

    Science.gov (United States)

    Sheehan, Peter M. F.; Berx, Barbara; Gallego, Alejandro; Hall, Rob A.; Heywood, Karen J.; Hughes, Sarah L.; Queste, Bastien Y.

    2018-03-01

    Tides and tidal mixing fronts are of fundamental importance to understanding shelf sea dynamics and ecosystems. Ocean gliders enable the observation of fronts and tide-dominated flows at high resolution. We use dive-average currents from a 2-month (12 October-2 December 2013) glider deployment along a zonal hydrographic section in the north-western North Sea to accurately determine M2 and S2 tidal velocities. The results of the glider-based method agree well with tidal velocities measured by current meters and with velocities extracted from the TPXO tide model. The method enhances the utility of gliders as an ocean-observing platform, particularly in regions where tide models are known to be limited. We then use the glider-derived tidal velocities to investigate tidal controls on the location of a front repeatedly observed by the glider. The front moves offshore at a rate of 0.51 km day-1. During the first part of the deployment (from mid-October until mid-November), results of a one-dimensional model suggest that the balance between surface heat fluxes and tidal stirring is the primary control on frontal location: as heat is lost to the atmosphere, full-depth mixing is able to occur in progressively deeper water. In the latter half of the deployment (mid-November to early December), a front controlled solely by heat fluxes and tidal stirring is not predicted to exist, yet a front persists in the observations. We analyse hydrographic observations collected by the glider to attribute the persistence of the front to the boundary between different water masses, in particular to the presence of cold, saline, Atlantic-origin water in the deeper portion of the section. We combine these results to propose that the front is a hybrid front: one controlled in summer by the local balance between heat fluxes and mixing and which in winter exists as the boundary between water masses advected to the north-western North Sea from diverse source regions. The glider observations

  9. Shelf sea tidal currents and mixing fronts determined from ocean glider observations

    Directory of Open Access Journals (Sweden)

    P. M. F. Sheehan

    2018-03-01

    regions. The glider observations capture the period when the front makes the transition from its summertime to wintertime state. Fronts in other shelf sea regions with oceanic influence may exhibit similar behaviour, with controlling processes and locations changing over an annual cycle. These results have implications for the thermohaline circulation of shelf seas.

  10. Satellite Soil Moisture and Water Storage Observations Identify Early and Late Season Water Supply Influencing Plant Growth in the Missouri Watershed

    Science.gov (United States)

    A, G.; Velicogna, I.; Kimball, J. S.; Du, J.; Kim, Y.; Colliander, A.; Njoku, E. G.

    2017-12-01

    We employ an array of continuously overlapping global satellite sensor observations including combined surface soil moisture (SM) estimates from SMAP, AMSR-E and AMSR-2, GRACE terrestrial water storage (TWS), and satellite precipitation measurements, to characterize seasonal timing and inter-annual variations of the regional water supply pattern and its associated influence on vegetation growth estimates from MODIS enhanced vegetation index (EVI), AMSR-E/2 vegetation optical depth (VOD) and GOME-2 solar-induced florescence (SIF). Satellite SM is used as a proxy of plant-available water supply sensitive to relatively rapid changes in surface condition, GRACE TWS measures seasonal and inter-annual variations in regional water storage, while precipitation measurements represent the direct water input to the analyzed ecosystem. In the Missouri watershed, we find surface SM variations are the dominant factor controlling vegetation growth following the peak of the growing season. Water supply to growth responds to both direct precipitation inputs and groundwater storage carry-over from prior seasons (winter and spring), depending on land cover distribution and regional climatic condition. For the natural grassland in the more arid central and northwest watershed areas, an early season anomaly in precipitation or surface temperature can have a lagged impact on summer vegetation growth by affecting the surface SM and the underlying TWS supplies. For the croplands in the more humid eastern portions of the watershed, the correspondence between surface SM and plant growth weakens. The combination of these complementary remote-sensing observations provides an effective means for evaluating regional variations in the timing and availability of water supply influencing vegetation growth.

  11. Linking atmospheric synoptic transport, cloud phase, surface energy fluxes, and sea-ice growth: observations of midwinter SHEBA conditions

    Science.gov (United States)

    Persson, P. Ola G.; Shupe, Matthew D.; Perovich, Don; Solomon, Amy

    2017-08-01

    Observations from the Surface Heat Budget of the Arctic Ocean (SHEBA) project are used to describe a sequence of events linking midwinter long-range advection of atmospheric heat and moisture into the Arctic Basin, formation of supercooled liquid water clouds, enhancement of net surface energy fluxes through increased downwelling longwave radiation, and reduction in near-surface conductive heat flux loss due to a warming of the surface, thereby leading to a reduction in sea-ice bottom growth. The analyses provide details of two events during Jan. 1-12, 1998, one entering the Arctic through Fram Strait and the other from northeast Siberia; winter statistics extend the results. Both deep, precipitating frontal clouds and post-frontal stratocumulus clouds impact the surface radiation and energy budget. Cloud liquid water, occurring preferentially in stratocumulus clouds extending into the base of the inversion, provides the strongest impact on surface radiation and hence modulates the surface forcing, as found previously. The observations suggest a minimum water vapor threshold, likely case dependent, for producing liquid water clouds. Through responses to the radiative forcing and surface warming, this cloud liquid water also modulates the turbulent and conductive heat fluxes, and produces a thermal wave penetrating into the sea ice. About 20-33 % of the observed variations of bottom ice growth can be directly linked to variations in surface conductive heat flux, with retarded ice growth occurring several days after these moisture plumes reduce the surface conductive heat flux. This sequence of events modulate pack-ice wintertime environmental conditions and total ice growth, and has implications for the annual sea-ice evolution, especially for the current conditions of extensive thinner ice.

  12. Observation of online communities

    DEFF Research Database (Denmark)

    Nørskov, Sladjana V.; Rask, Morten

    2011-01-01

    This paper addresses the application of observation to online settings with a special focus on observer roles. It draws on a study of online observation of a virtual community, i.e. an open source software (OSS) community. The paper examines general and specific advantages and disadvantages...... of the observer roles in online settings by relating these roles to the same roles assumed in offline settings. The study suggests that under the right circumstances online and offline observation may benefit from being combined as they complement each other well. Quality issues and factors important to elicit...... trustworthy observational data from online study settings, such as OSS communities, are discussed. A proposition is made concerning how threats to credibility and transferability in relation to online observation (i.e. lack of richness and detail, risk of misunderstandings) can be diminished, while...

  13. BOOK REVIEW: Observational Cosmology Observational Cosmology

    Science.gov (United States)

    Howell, Dale Andrew

    2013-04-01

    Observational Cosmology by Stephen Serjeant fills a niche that was underserved in the textbook market: an up-to-date, thorough cosmology textbook focused on observations, aimed at advanced undergraduates. Not everything about the book is perfect - some subjects get short shrift, in some cases jargon dominates, and there are too few exercises. Still, on the whole, the book is a welcome addition. For decades, the classic textbooks of cosmology have focused on theory. But for every Sunyaev-Zel'dovich effect there is a Butcher-Oemler effect; there are as many cosmological phenomena established by observations, and only explained later by theory, as there were predicted by theory and confirmed by observations. In fact, in the last decade, there has been an explosion of new cosmological findings driven by observations. Some are so new that you won't find them mentioned in books just a few years old. So it is not just refreshing to see a book that reflects the new realities of cosmology, it is vital, if students are to truly stay up on a field that has widened in scope considerably. Observational Cosmology is filled with full-color images, and graphs from the latest experiments. How exciting it is that we live in an era where satellites and large experiments have gathered so much data to reveal astounding details about the origin of the universe and its evolution. To have all the latest data gathered together and explained in one book will be a revelation to students. In fact, at times it was to me. I've picked up modern cosmological knowledge through a patchwork of reading papers, going to colloquia, and serving on grant and telescope allocation panels. To go back and see them explained from square one, and summarized succinctly, filled in quite a few gaps in my own knowledge and corrected a few misconceptions I'd acquired along the way. To make room for all these graphs and observational details, a few things had to be left out. For one, there are few derivations

  14. Observing Double Stars

    Science.gov (United States)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  15. Dominant winter-time mesospheric wave signatures over a low ...

    Indian Academy of Sciences (India)

    10.1016/j.jastp.2008.09.017. Taori A, Taylor M J and Franke S 2005 Terdiurnal wave signatures in the upper mesospheric tempera- ture and their association with the wind fields at low latitudes (20. °. N); J. Geophys. Res. 110 D09S06, doi: 10.1029/2004JD004564. Taori A and Taylor M J 2006 Characteristics of wave.

  16. Wintertime hygroscopicity and volatility of ambient urban aerosol particles

    Science.gov (United States)

    Enroth, Joonas; Mikkilä, Jyri; Németh, Zoltán; Kulmala, Markku; Salma, Imre

    2018-04-01

    Hygroscopic and volatile properties of atmospheric aerosol particles with dry diameters of (20), 50, 75, 110 and 145 nm were determined in situ by using a volatility-hygroscopicity tandem differential mobility analyser (VH-TDMA) system with a relative humidity of 90 % and denuding temperature of 270 °C in central Budapest during 2 months in winter 2014-2015. The probability density function of the hygroscopic growth factor (HGF) showed a distinct bimodal distribution. One of the modes was characterised by an overall mean HGF of approximately 1.07 (this corresponds to a hygroscopicity parameter κ of 0.033) independently of the particle size and was assigned to nearly hydrophobic (NH) particles. Its mean particle number fraction was large, and it decreased monotonically from 69 to 41 % with particle diameter. The other mode showed a mean HGF increasing slightly from 1.31 to 1.38 (κ values from 0.186 to 0.196) with particle diameter, and it was attributed to less hygroscopic (LH) particles. The mode with more hygroscopic particles was not identified. The probability density function of the volatility GF (VGF) also exhibited a distinct bimodal distribution with an overall mean VGF of approximately 0.96 independently of the particle size, and with another mean VGF increasing from 0.49 to 0.55 with particle diameter. The two modes were associated with less volatile (LV) and volatile (V) particles. The mean particle number fraction for the LV mode decreased from 34 to 21 % with particle diameter. The bimodal distributions indicated that the urban atmospheric aerosol contained an external mixture of particles with a diverse chemical composition. Particles corresponding to the NH and LV modes were assigned mainly to freshly emitted combustion particles, more specifically to vehicle emissions consisting of large mass fractions of soot likely coated with or containing some water-insoluble organic compounds such as non-hygroscopic hydrocarbon-like organics. The hygroscopic particles were ordinarily volatile. They could be composed of moderately transformed aged combustion particles consisting of partly oxygenated organics, inorganic salts and soot. The larger particles contained internally mixed non-volatile chemical species as a refractory residual in 20-25 % of the aerosol material (by volume).

  17. Wintertime hygroscopicity and volatility of ambient urban aerosol particles

    Directory of Open Access Journals (Sweden)

    J. Enroth

    2018-04-01

    Full Text Available Hygroscopic and volatile properties of atmospheric aerosol particles with dry diameters of (20, 50, 75, 110 and 145 nm were determined in situ by using a volatility–hygroscopicity tandem differential mobility analyser (VH-TDMA system with a relative humidity of 90 % and denuding temperature of 270 °C in central Budapest during 2 months in winter 2014–2015. The probability density function of the hygroscopic growth factor (HGF showed a distinct bimodal distribution. One of the modes was characterised by an overall mean HGF of approximately 1.07 (this corresponds to a hygroscopicity parameter κ of 0.033 independently of the particle size and was assigned to nearly hydrophobic (NH particles. Its mean particle number fraction was large, and it decreased monotonically from 69 to 41 % with particle diameter. The other mode showed a mean HGF increasing slightly from 1.31 to 1.38 (κ values from 0.186 to 0.196 with particle diameter, and it was attributed to less hygroscopic (LH particles. The mode with more hygroscopic particles was not identified. The probability density function of the volatility GF (VGF also exhibited a distinct bimodal distribution with an overall mean VGF of approximately 0.96 independently of the particle size, and with another mean VGF increasing from 0.49 to 0.55 with particle diameter. The two modes were associated with less volatile (LV and volatile (V particles. The mean particle number fraction for the LV mode decreased from 34 to 21 % with particle diameter. The bimodal distributions indicated that the urban atmospheric aerosol contained an external mixture of particles with a diverse chemical composition. Particles corresponding to the NH and LV modes were assigned mainly to freshly emitted combustion particles, more specifically to vehicle emissions consisting of large mass fractions of soot likely coated with or containing some water-insoluble organic compounds such as non-hygroscopic hydrocarbon-like organics. The hygroscopic particles were ordinarily volatile. They could be composed of moderately transformed aged combustion particles consisting of partly oxygenated organics, inorganic salts and soot. The larger particles contained internally mixed non-volatile chemical species as a refractory residual in 20–25 % of the aerosol material (by volume.

  18. Geo-neutrino Observation

    International Nuclear Information System (INIS)

    Dye, S. T.; Alderman, M.; Batygov, M.; Learned, J. G.; Matsuno, S.; Mahoney, J. M.; Pakvasa, S.; Rosen, M.; Smith, S.; Varner, G.; McDonough, W. F.

    2009-01-01

    Observations of geo-neutrinos measure radiogenic heat production within the earth, providing information on the thermal history and dynamic processes of the mantle. Two detectors currently observe geo-neutrinos from underground locations. Other detection projects in various stages of development include a deep ocean observatory. This paper presents the current status of geo-neutrino observation and describes the scientific capabilities of the deep ocean observatory, with emphasis on geology and neutrino physics.

  19. Observing Classroom Practice

    Science.gov (United States)

    Danielson, Charlotte

    2012-01-01

    Classroom observation is a crucial aspect of any system of teacher evaluation. No matter how skilled a teacher is in other aspects of teaching--such as careful planning, working well with colleagues, and communicating with parents--if classroom practice is deficient, that individual cannot be considered a good teacher. Classroom observations can…

  20. The observer's sky atlas

    CERN Document Server

    Karkoschka, E

    2007-01-01

    This title includes a short introduction to observing, a thorough description of the star charts and tables, a glossary and much more. It is perfect for both the beginner and seasoned observer. It is fully revised edition of a best-selling and highly-praised sky atlas.

  1. Optimized tomography of observables

    International Nuclear Information System (INIS)

    D'Ariano, G.M.; Paris, G. A.

    1998-01-01

    Tomographic measurement of observables is revisited and an adaptive optimization of the kernel functions suggested. The method is based on the existence of a class of null functions, which have zero tomographic average for any state of radiation. The general procedure is illustrated, and application to relevant observables analyzed in details for coherent, squeezed and 'cat' states.(author)

  2. Green Thunderstorms Observed.

    Science.gov (United States)

    Gallagher, Frank W., III; Beasley, William H.; Bohren, Craig F.

    1996-12-01

    Green thunderstorms have been observed from time to time in association with deep convection or severe weather events. Often the green coloration has been attributed to hail or to reflections of light from green foliage on the ground. Some skeptics who have not personally observed a green thunderstorm do not believe that green thunderstorms exist. They suggest that the green storms may be fabrications by excited observers. The authors have demonstrated the existence of green thunderstorms objectively using a spectrophotometer. During the spring and summer of 1995 the authors observed numerous storms and recorded hundreds of spectra of the light emanating corn these storms. It was found that the subjective judgment of colors can vary somewhat between observers, but the variation is usually in the shade of green. The authors recorded spectra of green and nongreen thunderstorms and recorded spectral measurements as a storm changed its appearance from dark blue to a bluish green. The change in color is gradual when observed from a stationary position. Also, as the light from a storm becomes greener, the luminance decreases. The authors also observed and recorded the spectrum of a thunderstorm during a period of several hours as they flew in an aircraft close to a supercell that appeared somewhat green. The authors' observations refute the ground reflection hypothesis and raise questions about explanations that require the presence of hail.

  3. Does observability affect prosociality?

    Science.gov (United States)

    Bradley, Alex; Lawrence, Claire; Ferguson, Eamonn

    2018-03-28

    The observation of behaviour is a key theoretical parameter underlying a number of models of prosociality. However, the empirical findings showing the effect of observability on prosociality are mixed. In this meta-analysis, we explore the boundary conditions that may account for this variability, by exploring key theoretical and methodological moderators of this link. We identified 117 papers yielding 134 study level effects (total n = 788 164) and found a small but statistically significant, positive association between observability and prosociality ( r = 0.141, 95% confidence interval = 0.106, 0.175). Moderator analysis showed that observability produced stronger effects on prosociality: (i) in the presence of passive observers (i.e. people whose role was to only observe participants) versus perceptions of being watched, (ii) when participants' decisions were consequential (versus non-consequential), (iii) when the studies were performed in the laboratory (as opposed to in the field/online), (iv) when the studies used repeated measures (instead of single games), and (v) when the studies involved social dilemmas (instead of bargaining games). These effects show the conditions under which observability effects on prosociality will be maximally observed. We describe the theoretical and practical significance of these results. © 2018 The Authors.

  4. Extraterrestial radioastronomical observations

    International Nuclear Information System (INIS)

    Screiber, R.

    1975-01-01

    The review is an attempt to describe the achievements of extraterrestrial radioastronomy during the last 10 years. Substantial progress, especially in the observations of the solar corona and the interplanetary space is reported. Observations of planets and Galaxy are also mentioned. Some remarks concerning the future experiments are briefly outlined. (author)

  5. Maximally incompatible quantum observables

    Energy Technology Data Exchange (ETDEWEB)

    Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Toigo, Alessandro, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Ziman, Mario, E-mail: ziman@savba.sk [RCQI, Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 84511 Bratislava (Slovakia); Faculty of Informatics, Masaryk University, Botanická 68a, 60200 Brno (Czech Republic)

    2014-05-01

    The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

  6. Paying for observable luck

    NARCIS (Netherlands)

    Feriozzi, F.

    2011-01-01

    This article examines why CEOs are rewarded for luck, namely for observable shocks beyond their control. I propose a simple hidden action model where the agent has implicit incentives to avoid bankruptcy. After signing the contract, but before acting, the agent observes a signal on future luck.

  7. Working Group 1: Observations

    International Nuclear Information System (INIS)

    Trenberth, K.; Angell, J.; Barry, R.; Bradley, R.; Diaz, H.; Elliott, W.; Etkins, R.; Folland, C.; Jenne, R.; Jones, P.; Karl, T.; Levitus, S.; Oort, A.; Parker, D.; Ropelewski, C.; Vinnikov, K.; Wigley, T.

    1991-01-01

    Topics of discussion include the following: the need for observations; issues in establishing global climate trends; climate variables such as surface air temperature over land, marine temperature, precipitation, circulation, upper air measurements, historical observations, subsurface ocean data, sea level, cryosphere, clouds, solar radiation, and aerosols; future considerations and recommendations which focuses on the establishment of a global benchmark climate monitoring network and data management

  8. Maximally incompatible quantum observables

    International Nuclear Information System (INIS)

    Heinosaari, Teiko; Schultz, Jussi; Toigo, Alessandro; Ziman, Mario

    2014-01-01

    The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

  9. Working Group 1: Observations

    International Nuclear Information System (INIS)

    Trenberth, K.; Angell, J.; Barry, R.; Bradley, R.; Diaz, H.; Elliott, W.; Etkins, R.; Folland, C.; Jenne, R.; Jones, P.; Karl, T.; Levitus, S.; Oort, A.; Parker, D.; Ropelewski, C.; Vinnikov, K.; Wigley, T.

    1990-01-01

    Topics of discussion include the following: the need for observations; issues in establishing global climate trends; climate variables such as surface air temperature over land, marine temperature, precipitation, circulation, upper air measurements, historical observations, subsurface ocean data, sea level, cryosphere, clouds, solar radiation, and aerosols; future considerations and recommendations which focuses on the establishment of a global benchmark climate monitoring network and data management

  10. Toward observational neutrino astrophysics

    International Nuclear Information System (INIS)

    Koshiba, M.

    1988-01-01

    It is true that: (1) The first observation of the neutrino burst from the supernova SN1987a by Kamiokande-II which was immediately confirmed by IBM; and (2) the first real-time, directional, and spectral observation of solar 8 B neutrinos also by Kamiokande-II could perhaps be considered as signalling the birth of observational astrophysics. The field, however, is still in its infancy and is crying out for tender loving care. Namely, while the construction of astronomy requires the time and the direction of the signal and that of astrophysics requires, in addition to the spectral information, the observations of (1) could not give the directional information and the results of both (1) and (2) are still suffering from the meager statistics. How do we remedy this situation to let this new born science of observational neutrino astrophysics grow healthy. This is what the author addresses in this talk. 15 refs., 8 figs

  11. Near-bed observations of high-concentration sediment transport in the Changjiang Estuary

    Science.gov (United States)

    Zhou, Z.; Ge, J.; Ding, P.

    2017-12-01

    The North Passage, the core of turbidity maximum in the Changjiang Estuary, is now under the strong sedimentation due to the abundant sediment supply from the upstream Changjiang River and the river-tide interacted dynamics. Recent studies suggested that strong siltation could be attributed to bottom high-concentration sediment transport, which however is very difficult to be detected and observed by vessel-anchored survey methods. To better understand the mechanisms of sediment transport and deposition in the channel region of the North Passage and its adjacent areas, we conducted continuous field observations which covered spring and neap tide period in the wintertime of 2016, the summertime of 2015 and 2017, focusing on near-bottom sediment transport. Tripods mounted with multiple instruments, including up-looking and down-looking Acoustic Doppler Current Profilers(ADCP), Vector Current Meter(ADV), Optical Backscatter Sensor(OBS), ASM, ALEC and RBR were used to observe the near-bottom physical process and its induced sediment dynamics. Results of these observations clearly described the current-wave-sediment interaction, which produced different patterns of bottom mud suspension at different tripods. Both hydrodynamic features and suspended sediment showed variations between spring and neap tide. Taking data of 2016 as an example, averaged suspended sediment concentration(SSC) at two tripods was 1.52 g/L and 2.13 g/L during the neap tide, 4.51 g/L and 5.75 g/L with the peak value reaching 25 g/L during the spring tide. At the tripod which was closer to the channel region, three peaks of SSC during the spring tide occurred near the flood slack with notable salinity increase, indicating the impact of saltwater intrusion on the bottom hydrodynamics. The results showed the occurrence of high-concentration suspended sediment was probably related to combined effects of bottom salinity intrusion, turbulent kinetic energy(TKE) and local stratification due to density

  12. Characterising fifteen years of continuous atmospheric radon activity observations at Cape Point (South Africa)

    Science.gov (United States)

    Botha, R.; Labuschagne, C.; Williams, A. G.; Bosman, G.; Brunke, E.-G.; Rossouw, A.; Lindsay, R.

    2018-03-01

    This paper describes and discusses fifteen years (1999-2013) of continuous hourly atmospheric radon (222Rn) monitoring at the coastal low-altitude Southern Hemisphere Cape Point Station in South Africa. A strong seasonal cycle is evident in the observed radon concentrations, with maxima during the winter months, when air masses arriving at the Cape Point station from over the African continental surface are more frequently observed, and minima during the summer months, when an oceanic fetch is predominant. An atmospheric mean radon activity concentration of 676 ± 2 mBq/m3 is found over the 15-year record, having a strongly skewed distribution that exhibits a large number of events falling into a compact range of low values (corresponding to oceanic air masses), and a smaller number of events with high radon values spread over a wide range (corresponding to continental air masses). The mean radon concentration from continental air masses (1 004 ± 6 mBq/m3) is about two times higher compared to oceanic air masses (479 ± 3 mBq/m3). The number of atmospheric radon events observed is strongly dependent on the wind direction. A power spectral Fast Fourier Transform analysis of the 15-year radon time series reveals prominent peaks at semi-diurnal, diurnal and annual timescales. Two inter-annual radon periodicities have been established, the diurnal 0.98 ± 0.04 day-1 and half-diurnal 2.07 ± 0.15 day-1. The annual peak reflects major seasonal changes in the patterns of offshore versus onshore flow associated with regional/hemispheric circulation patterns, whereas the diurnal and semi-diurnal peaks together reflect the influence of local nocturnal radon build-up over land, and the interplay between mesoscale sea/land breezes. The winter-time diurnal radon concentration had a significant decrease of about 200 mBq/m3 (17%) while the summer-time diurnal radon concentration revealed nearly no changes. A slow decline in the higher radon percentiles (75th and 95th) for the

  13. Observing Convective Aggregation

    Science.gov (United States)

    Holloway, Christopher E.; Wing, Allison A.; Bony, Sandrine; Muller, Caroline; Masunaga, Hirohiko; L'Ecuyer, Tristan S.; Turner, David D.; Zuidema, Paquita

    2017-11-01

    Convective self-aggregation, the spontaneous organization of initially scattered convection into isolated convective clusters despite spatially homogeneous boundary conditions and forcing, was first recognized and studied in idealized numerical simulations. While there is a rich history of observational work on convective clustering and organization, there have been only a few studies that have analyzed observations to look specifically for processes related to self-aggregation in models. Here we review observational work in both of these categories and motivate the need for more of this work. We acknowledge that self-aggregation may appear to be far-removed from observed convective organization in terms of time scales, initial conditions, initiation processes, and mean state extremes, but we argue that these differences vary greatly across the diverse range of model simulations in the literature and that these comparisons are already offering important insights into real tropical phenomena. Some preliminary new findings are presented, including results showing that a self-aggregation simulation with square geometry has too broad distribution of humidity and is too dry in the driest regions when compared with radiosonde records from Nauru, while an elongated channel simulation has realistic representations of atmospheric humidity and its variability. We discuss recent work increasing our understanding of how organized convection and climate change may interact, and how model discrepancies related to this question are prompting interest in observational comparisons. We also propose possible future directions for observational work related to convective aggregation, including novel satellite approaches and a ground-based observational network.

  14. Daily supplementation with 15 μg vitamin D2 compared with vitamin D3 to increase wintertime 25-hydroxyvitamin D status in healthy South Asian and white European women: a 12-wk randomized, placebo-controlled food-fortification trial.

    Science.gov (United States)

    Tripkovic, Laura; Wilson, Louise R; Hart, Kathryn; Johnsen, Sig; de Lusignan, Simon; Smith, Colin P; Bucca, Giselda; Penson, Simon; Chope, Gemma; Elliott, Ruan; Hyppönen, Elina; Berry, Jacqueline L; Lanham-New, Susan A

    2017-08-01

    serum 25(OH)D in the wintertime. Vitamin D 3 may therefore be a preferential form to optimize vitamin D status within the general population. This trial was registered at www.controlled-trials.com as ISRCTN23421591. © 2017 American Society for Nutrition.

  15. Observation of Quasichanneling Oscillations

    International Nuclear Information System (INIS)

    Wistisen, T. N.; Mikkelsen, R. E.; Uggerhoj, University I.; Wienands, University; Markiewicz, T. W.

    2017-01-01

    Here, we report on the first experimental observations of quasichanneling oscillations, recently seen in simulations and described theoretically. Although above-barrier particles penetrating a single crystal are generally seen as behaving almost as in an amorphous substance, distinct oscillation peaks nevertheless appear for particles in that category. The quasichanneling oscillations were observed at SLAC National Accelerator Laboratory by aiming 20.35 GeV positrons and electrons at a thin silicon crystal bent to a radius of R = 0.15 m, exploiting the quasimosaic effect. For electrons, two relatively faint quasichanneling peaks were observed, while for positrons, seven quasichanneling peaks were clearly identified.

  16. XMM observations of Pluto

    Science.gov (United States)

    Lisse, C.; McNutt, R.; Dennerl, K.

    2017-10-01

    We have used XMM to observe the Pluto system in late March 2017. Following up on the reported detection of 7 photons representing X-ray emission by Chandra (Lisse et al., Icarus 287, 103), XMM searched for emission from the system, expecting approximately 10 times as many photons in 1/3 the observing time. If the results of the XMM measurements are as expected, then detections of other large KBOs with lossy atmospheres should be possible, ushering in the era of XMM KBO X-ray astronomy. In this talk we describe the preliminary results of our March 2017 XMM Pluto observations.

  17. Substantial Underestimation of Post-harvest Burning Emissions in East China as Seen by Multi-species Space Observations

    Science.gov (United States)

    Stavrakou, T.; Muller, J. F.; Bauwens, M.; De Smedt, I.; Lerot, C.; Van Roozendael, M.

    2015-12-01

    columns from the GOME-2 instrument. The contribution of crop fires to the observed glyoxal and NO2 columns from OMI, and methanol columns from IASI is also investigated and discussed.

  18. Simultaneous Marine Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations from Naval vessels, primarily American, taken once daily at Greenwich Noon time. Forms are monthly and were captured from records held at the National...

  19. Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Surface Weather Observation Collection consists primarily of hourly, synoptic, daily, and monthly forms submitted to the archive by the National Weather Service...

  20. Observation, innovation and triangulation

    DEFF Research Database (Denmark)

    Hetmar, Vibeke

    2007-01-01

    on experiences from a pilot project in three different classrooms methodological possibilities and problems are presented and discussed: 1) educational criticism, including the concepts of positions, perspectives and connoisseurship, 2) classroom observations and 3) triangulation as a methodological tool....

  1. Observations of central stars

    International Nuclear Information System (INIS)

    Lutz, J.H.

    1978-01-01

    Difficulties occurring in the observation of central stars of planetary nebulae are reviewed with emphasis on spectral classifications and population types, and temperature determination. Binary and peculiar central stars are discussed. (U.M.G.)

  2. NWS Corrections to Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Form B-14 is the National Weather Service form entitled 'Notice of Corrections to Weather Records.' The forms are used to make corrections to observations on forms...

  3. Oil Rig Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weather observations taken at offshore platforms along the United States coastlines. The majority are located in oil-rich areas of the Gulf of Mexico, Gulf of...

  4. Longline Observer Data System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LODS, the Hawaii Longline Observer Data System, is a complete suite of tools designed to collect, process, and manage quality fisheries data and information. Guided...

  5. Land Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — METAR is the international standard code format for hourly surface weather observations. The acronym roughly translates from French as Aviation Routine Weather...

  6. Observer's Report - Okinawa Operation

    National Research Council Canada - National Science Library

    Todd, W. N., Jr

    1945-01-01

    ... for temporary duty in connection with the Okinawa Operation. By verbal agreement between observers, it was decided that each officer would cover certain activities and thus have a complete coverage without duplication...

  7. The REM Observing Software

    Directory of Open Access Journals (Sweden)

    Mauro Stefanon

    2010-01-01

    Together they grant the system safety, automatically schedule and perform observations with two simultaneous cameras of user-defined targets, and drive fast reaction to satellite alerts. Subsequent data reduction is left to pipelines managed by each camera.

  8. Mexico - Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Mexican Surface Daily Observations taken at 94 observatories located throughout Mexico, beginning in 1872 and going up through 1981. The data resided on paper...

  9. Cooperative Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly logs include a daily account of temperature extremes and precipitation, along with snow data at some locations. U.S. Cooperative Observer Program (COOP)...

  10. Surface Weather Observations Monthly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface Weather Observation 1001 Forms is a set of historical manuscript records for the period 1893-1948. The collection includes two very similar form types: Form...

  11. Visually observing comets

    CERN Document Server

    Seargent, David A J

    2017-01-01

    In these days of computers and CCD cameras, visual comet observers can still contribute scientifically useful data with the help of this handy reference for use in the field. Comets are one of the principal areas for productive pro-amateur collaboration in astronomy, but finding comets requires a different approach than the observing of more predictable targets. Principally directed toward amateur astronomers who prefer visual observing or who are interested in discovering a new comet or visually monitoring the behavior of known comets, it includes all the advice needed to thrive as a comet observer. After presenting a brief overview of the nature of comets and how we came to the modern understanding of comets, this book details the various types of observations that can usefully be carried out at the eyepiece of a telescope. Subjects range from how to search for new comets to visually estimating the brightness of comets and the length and orientation of tails, in addition to what to look for in comet heads a...

  12. Observations to information

    Science.gov (United States)

    Cox, S. J.

    2013-12-01

    Observations provide the fundamental constraint on natural science interpretations. Earth science observations originate in many contexts, including in-situ field observations and monitoring, various modes of remote sensing and geophysics, sampling for ex-situ (laboratory) analysis, as well as numerical modelling and simulation which also provide estimates of parameter values. Most investigations require a combination of these, often sourced from multiple initiatives and archives, so data discovery and re-organization can be a significant project burden. The Observations and Measurements (O&M) information model was developed to provide a common vocabulary that can be applied to all these cases, and thus provide a basis for cross-initiative and cross-domain interoperability. O&M was designed in the context of the standards for geographic information from OGC and ISO. It provides a complementary viewpoint to the well-known feature (object oriented) and coverage (property field) views, but prioritizes the property determination process. Nevertheless, use of O&M implies the existence of well defined feature types. In disciplines such as geology and ecosystem sciences the primary complexity is in their model of the world, for which the description of each item requires access to diverse observation sets. On the other hand, geophysics and earth observations work with simpler underlying information items, but in larger quantities over multiple spatio-temporal dimensions, acquired using complex sensor systems. Multiple transformations between the three viewpoints are involved in the data flows in most investigations, from collection through analysis to information and story. The O&M model classifies observations: - from a provider viewpoint: in terms of the sensor or procedure involved; - from a consumer viewpoint: in terms of the property being reported, and the feature with which it is associated. These concerns carry different weights in different applications

  13. Observed Barium Emission Rates

    Science.gov (United States)

    Stenbaek-Nielsen, H. C.; Wescott, E. M.; Hallinan, T. J.

    1993-01-01

    The barium releases from the CRRES satellite have provided an opportunity for verifying theoretically calculated barium ion and neutral emission rates. Spectra of the five Caribbean releases in the summer of 1991 were taken with a spectrograph on board a U.S. Air Force jet aircraft. Because the line of sight release densities are not known, only relative rates could be obtained. The observed relative rates agree well with the theoretically calculated rates and, together with other observations, confirm the earlier detailed theoretical emission rates. The calculated emission rates can thus with good accuracy be used with photometric observations. It has been postulated that charge exchange between neutral barium and oxygen ions represents a significant source for ionization. If so. it should be associated with emissions at 4957.15 A and 5013.00 A, but these emissions were not detected.

  14. Pion observables and QCD

    International Nuclear Information System (INIS)

    Roberts, C.D.

    1995-01-01

    Herein the application of the DSE approach to the calculation of pion observables is described using: the π-π scattering lengths (a 0 0 , a 2 0 , a 1 1 , a 0 2 , a 2 2 ) and associated partial wave amplitudes; the π 0 → γγ decay width; and the charged pion form factor, F π (q 2 ), as illustrative examples. Since this approach provides a straightforward, microscopic description of dynamical chiral symmetry breaking (DχSB) and confinement, the calculation of pion observables is a simple and elegant illustrative example of its power and efficacy. (orig.)

  15. Confronting theory with observations

    DEFF Research Database (Denmark)

    Bergström... [], Lars; Bjerrum-Bohr, N. Emil J.; Butt, Sharaz

    2011-01-01

    This workshop exposed theoretical cosmologists to some of the important observations that are being made of our universe. The goal was to encourage theorists to think concretely about the questions being raised by these new discoveries and also to acquire a sense of the realistic constaints on th...... on theoretical ideas and models that will be possible from the coming generation of cosmological observations. The atmosphere was kept lively and informal, with relatively few talks each day, which provided plenty of time for discussion and callaboration among the participants...

  16. Observations from Sarmizegetusa Sanctuary

    Science.gov (United States)

    Barbosu, M.

    2000 years ago, Sarmizegetusa Regia was the capital of ancient Dacia (today: Romania). It is known that the Dacian high priests used the Sanctuary of Sarmizegetusa not only for religious ceremonies, but also for astronomical observations. After having completed geodesic measurements, we analyzed the architecture of the sanctuary with its main points, directions and circles. We discuss here what kind of astronomical observations could have been made with the scientific knowledge of that time. The final section of this work is dedicated to the remarkable resemblance between Sarmizegztusa and Stonehenge.

  17. Observation of carbonaceous aerosols and carbon monoxide in Mid-Atlantic region: Seasonal and inter-annual variations

    Science.gov (United States)

    Chen, L. A.; Doddridge, B. G.; Doddridge, B. G.; Dickerson, R. R.; Dickerson, R. R.

    2001-05-01

    As part of Maryland Aerosol Research and Characterization (MARCH-Atlantic) study, a long-term monitoring of ambient elemental and organic carbon (EC and OC) aerosols has been made at Fort Meade, MD (39.16° N 76.51° W; elevation 46 m MSL), a suburban site within the Baltimore-Washington (B-W) corridor, since July 1999. 24-hr average EC and OC are measured every day during the season-representative months (July 1999, October 1999, January 2000, April 2000 and July 2000). Carbon monoxide (CO) was also measured nearly continuously over the period. Strong correlation between EC and CO (r = 0.7 ~ 0.9) in every month suggests common or proximate sources, likely traffic emissions. The EC versus CO slope, however, varies in different seasons and is found to increase nonlinearly with the ambient temperature. EC source strength may peak in summer. OC shows strong correlation with EC (r ~ 0.95) only in winter, suggesting that OC is also of the same primary sources during wintertime. The Interagency Monitoring of Protected Visual Environments (IMPROVE) network has been measuring EC and OC around the United States since 1988. The FME data during July 1999 are also compared with simultaneous measurements at nearby IMPROVE sites, showing B-W corridor could be a major contributor to the carbonaceous aerosols in the Mid-Atlantic region. A decreasing trend of EC level is found in three IMPROVE sites in this region. This actually agrees with the decreasing trend of CO observed previously at Big Meadow, Shenandoah National Park if CO and EC are both influenced by traffic emissions.

  18. Observability of quarks

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1985-12-01

    Even if stable hadrons with fractional charge do not exist, most of the criteria of observability used for ordinary elementary particles apply in principle to quarks as well. This is especially true in a simplified world containing only hadrons made of top quarks and gluons. In the real world containing light quarks, essential complications do occur, but most of the conclusions survive

  19. Noise storm coordinated observations

    International Nuclear Information System (INIS)

    Elgaroey, Oe.; Tlamicha, A.

    1983-01-01

    The usually accepted bipolar model of noise storm centers is irrelevant for the present observations. An alternative model has been proposed in which the different sources of a noise storm center are located in different flux tubes connecting active regions with their surroundings. Radio emission is observed from the wide, descending branch of the flux tubes, opposite to the flaring site. The relation between the sense of circular polarization of the radio emission and the magnetic polarity, has been more precisely defined. The radiation is in the ordinary mode with respect to the underlying large scale photospheric magnetic polarity. Thus the ''irregular'' polarity of noice storm center ''B'' is explained. As regards center ''C'', one should note that although the observed radio emission is polarized in the ordinary mode with respect to the leading spot of region HR 17653, center ''C'' is not situated in flux tubes originating from the leading part of this region according to the proposed model. Rather, the radio sources are located in the wide and descending part of flux tubes connecting a large, quiet area of south magnetic polarity with the following part of the region HR 17653 (of north magnetic polarity). Thus it is the polarity of the extended area which determines the polarization of the radio emission. The observed polarization should result rather from the emission process than from complicated conditions of propagation for the radio waves

  20. A Prospective Observational Study

    African Journals Online (AJOL)

    Methods: This was a prospective, questionnaire-based observational study. Printed questionnaires were distributed to the visitors of medical, surgical and neurosurgical ICU patients to determine awareness of basic infection control practices among visitors to an ICU. All the ICU staff, including nurses, doctors, consultant ...

  1. Observing farming systems

    DEFF Research Database (Denmark)

    Noe, Egon; Alrøe, Hugo Fjelsted

    2012-01-01

    of analysis from individual farmers to communication and social relations. This is where Luhmann’s social systems theory can offer new insights. Firstly, it can help observe and understand the operational closure and system logic of a farming system and how this closure is produced and reproduced. Secondly...

  2. Methods Evolved by Observation

    Science.gov (United States)

    Montessori, Maria

    2016-01-01

    Montessori's idea of the child's nature and the teacher's perceptiveness begins with amazing simplicity, and when she speaks of "methods evolved," she is unveiling a methodological system for observation. She begins with the early childhood explosion into writing, which is a familiar child phenomenon that Montessori has written about…

  3. A Simple Spectral Observer

    Directory of Open Access Journals (Sweden)

    Lizeth Torres

    2018-05-01

    Full Text Available The principal aim of a spectral observer is twofold: the reconstruction of a signal of time via state estimation and the decomposition of such a signal into the frequencies that make it up. A spectral observer can be catalogued as an online algorithm for time-frequency analysis because is a method that can compute on the fly the Fourier transform (FT of a signal, without having the entire signal available from the start. In this regard, this paper presents a novel spectral observer with an adjustable constant gain for reconstructing a given signal by means of the recursive identification of the coefficients of a Fourier series. The reconstruction or estimation of a signal in the context of this work means to find the coefficients of a linear combination of sines a cosines that fits a signal such that it can be reproduced. The design procedure of the spectral observer is presented along with the following applications: (1 the reconstruction of a simple periodical signal, (2 the approximation of both a square and a triangular signal, (3 the edge detection in signals by using the Fourier coefficients, (4 the fitting of the historical Bitcoin market data from 1 December 2014 to 8 January 2018 and (5 the estimation of a input force acting upon a Duffing oscillator. To round out this paper, we present a detailed discussion about the results of the applications as well as a comparative analysis of the proposed spectral observer vis-à-vis the Short Time Fourier Transform (STFT, which is a well-known method for time-frequency analysis.

  4. The CarboCount CH sites: characterization of a dense greenhouse gas observation network

    Directory of Open Access Journals (Sweden)

    B. Oney

    2015-10-01

    Full Text Available We describe a new rural network of four densely placed (2, CH4, and CO measurement sites in north-central Switzerland and analyze its suitability for regional-scale (~ 100–500 km carbon flux studies. We characterize each site for the period from March 2013 to February 2014 by analyzing surrounding land cover, observed local meteorology, and sensitivity to surface fluxes, as simulated with the Lagrangian particle dispersion model FLEXPART-COSMO (FLEXible PARTicle dispersion model-Consortium for Small-Scale Modeling. The Beromünster measurements are made on a tall tower (212 m located on a gentle hill. At Beromünster, regional CO2 signals (measurement minus background vary diurnally from −4 to +4 ppmv, on average, and are simulated to come from nearly the entire Swiss Plateau, where 50 % of surface influence is simulated to be within 130–260 km distance. The Früebüel site measurements are made 4 m above ground on the flank of a gently sloping mountain. Nearby (2 signals varying diurnally from −5 to +12 ppmv and elevated summer daytime CH4 signals (+30 ppbv above other sites. The Gimmiz site measurements are made on a small tower (32 m in flat terrain. Here, strong summertime regional signals (−5 to +60 ppmv CO2 stem from large, nearby (2. Here, considerable anthropogenic influence from the nearby industrialized region near Zurich causes the average wintertime regional CO2 signals to be 5 ppmv above the regional signals simultaneously measured at the Früebüel site. We find that the suitability of the data sets from our current observation network for regional carbon budgeting studies largely depends on the ability of the high-resolution (2 km atmospheric transport model to correctly capture the temporal dynamics of the stratification of the lower atmosphere at the different sites. The current version of the atmospheric transport model captures these dynamics well, but it clearly reaches its limits at the sites in steep topography

  5. Gamma Ray Bursts - Observations

    Science.gov (United States)

    Gehrels, N.; Cannizzo, J. K.

    2010-01-01

    We are in an exciting period of discovery for gamma-ray bursts. The Swift observatory is detecting 100 bursts per year, providing arcsecond localizations and sensitive observations of the prompt and afterglow emission. The Fermi observatory is observing 250 bursts per year with its medium-energy GRB instrument and about 10 bursts per year with its high-energy LAT instrument. In addition, rapid-response telescopes on the ground are providing new capabilities to study optical emission during the prompt phase and spectral signatures of the host galaxies. The combined data set is enabling great advances in our understanding of GRBs including afterglow physics, short burst origin, and high energy emission.

  6. Awareness as observational heterarchy

    Directory of Open Access Journals (Sweden)

    Kohei eSonoda

    2013-10-01

    Full Text Available Libet et al. (1983 revealed that brain activity precedes conscious intention. For convenience in this study, we divide brain activity into two parts: a conscious field (CF and an unconscious field (UF. Most studies have assumed a comparator mechanism or an illusion of CF and discuss the difference of prediction and postdiction. We propose that problems to be discussed here are a twisted sense of agency between CF and UF, and another definitions of prediction and postdiction in a mediation process for the twist. This study specifically examines the definitions throughout an observational heterarchy model based on internal measurement. The nature of agency must be emergence that involves observational heterarchy. Consequently, awareness involves processes having duality in the sense that it is always open to the world (postdiction and that it also maintains self robustly (prediction.

  7. Factorization of Observables

    Science.gov (United States)

    Eliaš, Peter; Frič, Roman

    2017-12-01

    Categorical approach to probability leads to better understanding of basic notions and constructions in generalized (fuzzy, operational, quantum) probability, where observables—dual notions to generalized random variables (statistical maps)—play a major role. First, to avoid inconsistencies, we introduce three categories L, S, and P, the objects and morphisms of which correspond to basic notions of fuzzy probability theory and operational probability theory, and describe their relationships. To illustrate the advantages of categorical approach, we show that two categorical constructions involving observables (related to the representation of generalized random variables via products, or smearing of sharp observables, respectively) can be described as factorizing a morphism into composition of two morphisms having desired properties. We close with a remark concerning products.

  8. Observation of WZ production.

    Science.gov (United States)

    Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenaro, C; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; DaRonco, S; Datta, M; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdeckerc, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; DiTuro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McCarthy, K; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojma, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; Vanguri, R; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

    2007-04-20

    We report the first observation of the associated production of a W boson and a Z boson. This result is based on 1.1 fb;-1 of integrated luminosity from pp collisions at sqrt[s]=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We observe 16 WZ candidates passing our event selection with an expected background of 2.7+/-0.4 events. A fit to the missing transverse energy distribution indicates an excess of events compared to the background expectation corresponding to a significance equivalent to 6 standard deviations. The measured cross section is sigma(pp-->WZ)=5.0(-1.6)(+1.8) pb, consistent with the standard model expectation.

  9. High resolution solar observations

    International Nuclear Information System (INIS)

    Title, A.

    1985-01-01

    Currently there is a world-wide effort to develop optical technology required for large diffraction limited telescopes that must operate with high optical fluxes. These developments can be used to significantly improve high resolution solar telescopes both on the ground and in space. When looking at the problem of high resolution observations it is essential to keep in mind that a diffraction limited telescope is an interferometer. Even a 30 cm aperture telescope, which is small for high resolution observations, is a big interferometer. Meter class and above diffraction limited telescopes can be expected to be very unforgiving of inattention to details. Unfortunately, even when an earth based telescope has perfect optics there are still problems with the quality of its optical path. The optical path includes not only the interior of the telescope, but also the immediate interface between the telescope and the atmosphere, and finally the atmosphere itself

  10. Observations of gravitational lenses

    International Nuclear Information System (INIS)

    Fort, B.

    1990-01-01

    During the last tow years a burst of results has come from radio and optical surveys of ''galaxy lenses'' (where the main deflector is a galaxy). These are reviewed. On the other hand, in September 1985 we pointed out a very strange blue ring-like structure on a Charge-Coupled Device image of the cluster of galaxies Abell 370. This turned out to be Einstein arcs discovery. Following this discovery, new observational results have shown that many rich clusters of galaxies can produce numerous arclets: tangentially distorted images of an extremely faint galaxy population probably located at redshift larger than 1. This new class of gravitational lenses proves to be an important observational topic and this will be discussed in the second part of the paper. (author)

  11. Multicolour Observations, Inhomogeneity & Evolution

    OpenAIRE

    Hellaby, Charles

    2000-01-01

    We propose a method of testing source evolution theories that is independent of the effects of inhomogeneity, and thus complementary to other studies of evolution. It is suitable for large scale sky surveys, and the new generation of large telescopes. In an earlier paper it was shown that basic cosmological observations - luminosity versus redshift, area distance versus redshift and number counts versus redshift - cannot separate the effects of cosmic inhomogeneity, cosmic evolution and sourc...

  12. Observational evidence for mergers

    International Nuclear Information System (INIS)

    Schweizer, F.

    1983-01-01

    Theory has long suggested that dynamical friction between colliding galaxies must lead to mergers. The problem for observers has been to find which galaxies are mergers. The author first reviews the available evidence for mergers in various kinds of galaxies, then proposes a tentative classification scheme for mergers, and finally discusses mergers in giant ellipticals and their relation to the evolution and perhaps even the formation of ellipticals. (Auth.)

  13. Observations of Surfzone Albedo

    Science.gov (United States)

    Sinnett, G.; Feddersen, F.

    2014-12-01

    The surfzone environment (where waves break) contains several unique and previously unconsidered processes that affect the heat budget. Entering short-wave radiation is a dominant term in both shelf and surfzone heat budgets. In contrast to the shelf, however, depth limited wave breaking in the surfzone generates spray, whitewater and suspended sediments, elevating the surface albedo (ratio of reflected to incident short-wave radiation). Elevated albedo reduces the level of solar short-wave radiation entering the water, potentially resulting in less heating. Additionally, surfzone water quality is often impacted by fecal bacteria contamination. As bacteria mortality is related to short-wave solar radiation, elevated surfzone albedo could reduce pathogen mortality, impacting human health. Albedo in the open ocean has been frequently studied and parameterizations often consider solar zenith angle, wind speed and ocean chlorophyll concentration, producing albedo values typically near 0.06. However, surfzone albedo observations have been extremely sparse, yet show depth limited wave breaking may increase the albedo by nearly a factor of 10 up to 0.5. Here, we present findings from a field study at the Scripps Institution of Oceanography pier to observe the affect of waves on surfzone albedo. Concurrent measurements were taken with a four-way radiometer (to measure both downwelling and upwelling short-wave and long wave radiation) mounted above the surfzone. A co-located GoPro camera was used to relate visual aspects of the surfzone to measured reflectance, and wave height and period were observed with a bottom mounted pressure sensor in 5 m water depth just outside the surfzone. Wind speed and direction were observed on the pier 10 m above the water surface. Here, we will examine the surfzone albedo dependence on surfzone parameters, such as wave height.

  14. Interaction and observation, categorically

    Directory of Open Access Journals (Sweden)

    Vincenzo Ciancia

    2011-07-01

    Full Text Available This paper proposes to use dialgebras to specify the semantics of interactive systems in a natural way. Dialgebras are a conservative extension of coalgebras. In this categorical model, from the point of view that we provide, the notions of observation and interaction are separate features. This is useful, for example, in the specification of process equivalences, which are obtained as kernels of the homomorphisms of dialgebras. As an example we present the asynchronous semantics of the CCS.

  15. Observations of barred spirals

    International Nuclear Information System (INIS)

    Elmegreen, D.M.

    1990-01-01

    Observations of barred spiral galaxies are discussed which show that the presence of a bar increases the likelihood for grand design spiral structure only in early Hubble types. This result is contrary to the more common notion that grand design spiral structure generally accompanies bars in galaxies. Enhanced deprojected color images are shown which reveal that a secondary set of spiral arms commonly occurs in barred galaxies and also occasionally in ovally distorted galaxies. 6 refs

  16. Exoplanet Biosignatures: Observational Prospects

    Science.gov (United States)

    Angerhausen, Daniel; Deitrick, Russell; Domagal-Goldman, Shawn; Grenfell, John Lee; Hori, Yasunori; Kane, Stephen R.; Pallé, Enric; Rauer, Heike; Siegler, Nicholas; Stapelfeldt, Karl; Stevenson, Kevin B.

    2018-01-01

    Abstract Exoplanet hunting efforts have revealed the prevalence of exotic worlds with diverse properties, including Earth-sized bodies, which has fueled our endeavor to search for life beyond the Solar System. Accumulating experiences in astrophysical, chemical, and climatological characterization of uninhabitable planets are paving the way to characterization of potentially habitable planets. In this paper, we review our possibilities and limitations in characterizing temperate terrestrial planets with future observational capabilities through the 2030s and beyond, as a basis of a broad range of discussions on how to advance “astrobiology” with exoplanets. We discuss the observability of not only the proposed biosignature candidates themselves but also of more general planetary properties that provide circumstantial evidence, since the evaluation of any biosignature candidate relies on its context. Characterization of temperate Earth-sized planets in the coming years will focus on those around nearby late-type stars. The James Webb Space Telescope (JWST) and later 30-meter-class ground-based telescopes will empower their chemical investigations. Spectroscopic studies of potentially habitable planets around solar-type stars will likely require a designated spacecraft mission for direct imaging, leveraging technologies that are already being developed and tested as part of the Wide Field InfraRed Survey Telescope (WFIRST) mission. Successful initial characterization of a few nearby targets will be an important touchstone toward a more detailed scrutiny and a larger survey that are envisioned beyond 2030. The broad outlook this paper presents may help develop new observational techniques to detect relevant features as well as frameworks to diagnose planets based on the observables. Key Words: Exoplanets—Biosignatures—Characterization—Planetary atmospheres—Planetary surfaces. Astrobiology 18, 739–778. PMID:29938537

  17. Optical observation of comets

    International Nuclear Information System (INIS)

    Tanabe, Hiroyoshi

    1974-01-01

    The observation of comets is proposed to study the state of interplanetary space. The behavior of the tails of comets shows the state of solar wind. On July 4, 1964, large bending was seen in the tail of the Tomita-Gerber-Handa comet. Then, on July 7, 1964, geomagnetic disturbance was observed. Disturbance in the tail of Kohoutek comet was seen on Jan. 19, 1974, and Ksub(p)--5 on the ground on Jan. 25. The effort for the quantitative measurement of the parameters of solar wind has been continued in various countries. Recently, the large scale observation of the Kohoutek comet was carried out in the world. Preliminary report is presented in this paper. Waving in the type 1 tail of the comet was seen, and this phenomenon may show some instability due to the interaction between the tail and the solar wind. Periodic variation of the direction of the tail has been reported. The present result also confirmed this report. In case of small comets, flare-up occurs and original luminous intensity is regained after several days. Measurement of the spectrum at the time of flare-up may show information concerning temporary variation of the state of interplanetary space. For the tracking of time variation of comets, cooperation of a number of stations at different positions is required. (Kato, T.)

  18. COBE observations and results

    International Nuclear Information System (INIS)

    Smoot, G.F.

    1999-01-01

    This paper summarizes the results from the COBE satellite mission. Nine years have passed since the launch of COBE and six years since the announcement of the discovery of cosmic microwave background anisotropies by the COBE DMR instrument. This is still a relatively short time to look back and understand the implications of COBE and the anisotropy discovery; however, this 3K Cosmology Conference provides some context. The Cosmic Background Explorer (COBE) satellite has made a major contribution to the field of cosmology and has help create the confidence and high level of interest that propels the field today. Two major CMB observations, the thermal spectrum of the CMB and the CMB anisotropies, plus a host of other observations and conclusions are the basis and a major but not exclusive portion of the legacy of COBE. The recent detection and observation of the cosmic infrared background (CIB) are also part of COBE close-quote s major contribution to cosmology. copyright 1999 American Institute of Physics

  19. R Aqr observing campaign

    Science.gov (United States)

    Waagen, Elizabeth O.

    2016-01-01

    Dr. George Wallerstein (University of Washington) has requested AAVSO coverage of the long period/symbiotic variable R Aquarii beginning immediately in support of high resolution spectroscopic observations planned for 2016 January 19 and 21. Several other astronomers, including Drs. Lee Anne Willson (Iowa State University), Ulisse Munari (INAF, Astronomical Observatory of Padua, Italy), and Fred Walter (Stony Brook University) are studying R Aqr closely and additional spectroscopic and other observations are planned for the near future. R Aqr is both a Mira (M) and a symbiotic (ZAND) - it is a close binary system consisting of a hot star and a late-type star (the Mira), both enveloped in nebulosity. As a result, the very interesting light curve shows not only the Mira pulsation but also complex eclipse behavior as the two stars interact. The period of Mira variation is 387.0 days; the eclipse period is 43.6-44 years. The cause of the eclipse is unknown; several theories h! ave been proposed, including a focused accretion stream, a disk or cloud around the secondary, and a triggered mass loss that produces an opaque cloud. Careful investigation of this upcoming event should help to resolve this question. The last eclipse of R Aqr was in 1978. The next eclipse is predicted for 2022, but may be early. The current behavior of R Aqr suggests that the eclipse, which lasts for several years, may either be beginning or its beginning may be imminent. R Aqr was at minimum in early December 2015 at magnitude V=11.4, and is currently at visual magnitude 11.0. During this phase of the approximately 44-year eclipse cycle, at maximum it may be as bright as V 6.0-6.5 but is not expected to become brighter. Beginning immediately, nightly BVRI CCD and DSLR photometry and visual observations are requested. As R Aqr brightens towards maximum and is in range, PEP observations are also requested. Ongoing spectroscopy over the next several years will be interesting to see as the system

  20. Radar observations of Mercury

    International Nuclear Information System (INIS)

    Harmon, J.K.; Campbell, D.B.

    1988-01-01

    Some of the radar altimetry profiles of Mercury obtained on the basis of data from the Arecibo Observatory are presented. In these measurements, the delay-Doppler method was used to measure altitudes along the Doppler equator, rather than to map radar reflectivity. The profiles, derived from observations made over a 6-yr period, provide extensive coverage over a restricted equatorial band and permit the identification of radar signatures for features as small as 50-km diameter craters and 1-km-high arcuate scarps. The data allowed identification of large-scale topographic features such as smooth plains subsidence zones and major highland regions

  1. Meteoroid Orbits from Observations

    Science.gov (United States)

    Campbell-Brown, Margaret

    2018-04-01

    Millions of orbits of meteoroids have been measured over the last few decades, and they comprise the largest sample of orbits of solar system bodies which exists. The orbits of these objects can shed light on the distribution and evolution of comets and asteroids in near-Earth space (e.g. Neslusan et al. 2016). If orbits can be measured at sufficiently high resolution, individual meteoroids can be traced back to their parent bodies and, in principle, even to their ejection time (Rudawska et al. 2012). Orbits can be measured with multi-station optical observations or with radar observations.The most fundamental measured quantities are the speed of the meteor and the two angles of the radiant, or point in the sky from which the meteor appears to come. There are many methods used to determine these from observations, but not all produce the most accurate results (Egal et al. 2017). These three measured quantities, along with the time and location of the observation, are sufficient to obtain an orbit (see, e.g., Clark & Wiegert 2011), but the measurements must be corrected for the deceleration of the meteoroid in the atmosphere before it was detected, the rotation of the Earth, and the gravitational attraction of the Earth (including higher order moments if great precision is necessary).Once meteor orbits have been determined, studies of the age and origin of meteor showers (Bruzzone et al., 2015), the parent bodies of sporadic sources (Pokorny et al. 2014), and the dynamics of the meteoroid complex as a whole can be constrained.Bruzzone, J. S., Brown, P., Weryk, R., Campbell-Brown, M., 2015. MNRAS 446, 1625.Clark, D., Wiegert, P., 2011. M&PS 46, 1217.Egal, A., Gural, P., Vaubaillon, J., Colas, F., Thuillot, W., 2017. Icarus 294, 43.Neslusan, L., Vaubaillon, J., Hajdukova, M., 2016. A&A 589, id.A100.Pokorny, P., Vokrouhlicky, D., Nesvorny, D., Campbell-Brown, M., Brown, P., 2014. ApJ 789, id.25.Rudawska, R., Vaubaillon, J., Atreya, P., 2012. A&A 541, id.A2

  2. Stereoscopically Observing Manipulative Actions.

    Science.gov (United States)

    Ferri, S; Pauwels, K; Rizzolatti, G; Orban, G A

    2016-08-01

    The purpose of this study was to investigate the contribution of stereopsis to the processing of observed manipulative actions. To this end, we first combined the factors "stimulus type" (action, static control, and dynamic control), "stereopsis" (present, absent) and "viewpoint" (frontal, lateral) into a single design. Four sites in premotor, retro-insular (2) and parietal cortex operated specifically when actions were viewed stereoscopically and frontally. A second experiment clarified that the stereo-action-specific regions were driven by actions moving out of the frontoparallel plane, an effect amplified by frontal viewing in premotor cortex. Analysis of single voxels and their discriminatory power showed that the representation of action in the stereo-action-specific areas was more accurate when stereopsis was active. Further analyses showed that the 4 stereo-action-specific sites form a closed network converging onto the premotor node, which connects to parietal and occipitotemporal regions outside the network. Several of the specific sites are known to process vestibular signals, suggesting that the network combines observed actions in peripersonal space with gravitational signals. These findings have wider implications for the function of premotor cortex and the role of stereopsis in human behavior. © The Author 2016. Published by Oxford University Press.

  3. Superposition and macroscopic observation

    International Nuclear Information System (INIS)

    Cartwright, N.D.

    1976-01-01

    The principle of superposition has long plagued the quantum mechanics of macroscopic bodies. In at least one well-known situation - that of measurement - quantum mechanics predicts a superposition. It is customary to try to reconcile macroscopic reality and quantum mechanics by reducing the superposition to a mixture. To establish consistency with quantum mechanics, values for the apparatus after a measurement are to be distributed in the way predicted by the superposition. The distributions observed, however, are those of the mixture. The statistical predictions of quantum mechanics, it appears, are not borne out by observation in macroscopic situations. It has been shown that, insofar as specific ergodic hypotheses apply to the apparatus after the interaction, the superposition which evolves is experimentally indistinguishable from the corresponding mixture. In this paper an idealized model of the measuring situation is presented in which this consistency can be demonstrated. It includes a simplified version of the measurement solution proposed by Daneri, Loinger, and Prosperi (1962). The model should make clear the kind of statistical evidence required to carry of this approach, and the role of the ergodic hypotheses assumed. (Auth.)

  4. Observations of cold antihydrogen

    CERN Document Server

    Tan, J N; Gabrielse, G; Oxley, P; Speck, A; Storry, C H; Wessels, M; Grzonka, D; Oelert, W; Schepers, G; Sefzick, T; Walz, J; Pittner, H; Hänsch, T W; Hessels, E A

    2004-01-01

    ATRAP's e/sup +/ cooling of p in a nested Penning trap has led to reports of cold H produced during such cooling by the ATHENA and ATRAP collaborations. To observe H, ATHENA uses coincident annihilation detection and ATRAP uses field ionization followed by p storage. Advantages of ATRAP's field ionization method include the complete absence of any background events, and the first way to measure which H states are produced. ATRAP enhances the H production rate by driving many cycles of e/sup +/ cooling in the nested trap, with more H counted in an hour than the sum of all the other antimatter atoms ever reported. The number of H counted per incident high energy p is also higher than ever observed. The first measured distribution of H states is made using a pre-ionizing electric field between separated production and detection regions. The high rate and the high Rydberg states suggest that the H is formed via three-body recombination, as expected. (22 refs).

  5. Observations of cold antihydrogen

    International Nuclear Information System (INIS)

    Tan, J.N.; Bowden, N.S.; Gabrielse, G.; Oxley, P.; Speck, A.; Storry, C.H.; Wessels, M.; Grzonka, D.; Oelert, W.; Schepers, G.; Sefzick, T.; Walz, J.; Pittner, H.; Haensch, T.W.; Hessels, E.A.

    2004-01-01

    ATRAP's e + cooling of p-bar in a nested Penning trap has led to reports of cold H-bar produced during such cooling by the ATHENA and ATRAP collaborations. To observe H-bar, ATHENA uses coincident annihilation detection and ATRAP uses field ionization followed by p-bar storage. Advantages of ATRAP's field ionization method include the complete absence of any background events, and the first way to measure which H-bar states are produced. ATRAP enhances the H-bar production rate by driving many cycles of e + cooling in the nested trap, with more H-bar counted in an hour than the sum of all the other antimatter atoms ever reported. The number of H-bar counted per incident high energy p-bar is also higher than ever observed. The first measured distribution of H-bar states is made using a pre-ionizing electric field between separated production and detection regions. The high rate and the high Rydberg states suggest that the H-bar is formed via three-body recombination, as expected

  6. Global observations from PHOBOS

    Science.gov (United States)

    Phobos Collaboration; Baker, Mark D.; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Bal, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwon, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kan, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stodulski, G. S. T. M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2003-03-01

    Particle production in Au+Au collisions has been measured in the PHOBOS experiment at RHIC for a range of collision energies. Three empirical observations have emerged from this dataset which require theoretical examination. First, there is clear evidence of limiting fragmentation. Namely, particle production in central Au+Au collisions, when expressed as $dN/d\\eta'$ ($\\eta' \\equiv \\eta-y_{beam}$), becomes energy independent at high energy for a broad region of $\\eta'$ around $\\eta'=0$. This energy-independent region grows with energy, allowing only a limited region (if any) of longitudinal boost-invariance. Second, there is a striking similarity between particle production in e+e- and Au+Au collisions (scaled by the number of participating nucleon pairs). Both the total number of produced particles and the longitudinal distribution of produced particles are approximately the same in e+e- and in scaled Au+Au. This observation was not predicted and has not been explained. Finally, particle production has been found to scale approximately with the number of participating nucleon pairs for $N_{part}>65$. This scaling occurs both for the total multiplicity and for high $\\pT$ particles (3 $<\\pT<$ 4.5 GeV/c).

  7. Semantic Observation Integration

    Directory of Open Access Journals (Sweden)

    Werner Kuhn

    2012-09-01

    Full Text Available Although the integration of sensor-based information into analysis and decision making has been a research topic for many years, semantic interoperability has not yet been reached. The advent of user-generated content for the geospatial domain, Volunteered Geographic Information (VGI, makes it even more difficult to establish semantic integration. This paper proposes a novel approach to integrating conventional sensor information and VGI, which is exploited in the context of detecting forest fires. In contrast to common logic-based semantic descriptions, we present a formal system using algebraic specifications to unambiguously describe the processing steps from natural phenomena to value-added information. A generic ontology of observations is extended and profiled for forest fire detection in order to illustrate how the sensing process, and transformations between heterogeneous sensing systems, can be represented as mathematical functions and grouped into abstract data types. We discuss the required ontological commitments and a possible generalization.

  8. VERITAS Galactic Observations

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Gareth

    2013-06-15

    We report on recent Galactic results and discoveries made by the VERITAS collaboration. The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is a ground-based gamma-ray observatory, located in southern Arizona, able to detect gamma rays of energies from 100 GeV up to 30 TeV. VERITAS has been fully operational since 2007 and its current sensitivity enables the detection of a 1% Crab Nebula flux at 5 sigma in under 30 hours. The observatory is well placed to view large parts of the galactic plane including its center, resulting in a strong galactic program. Objects routinely observed include Pulsars, Pulsar Wind Nebula, X-ray binaries and sources with unidentified counterparts in other wavelengths.

  9. Participation beyond observation

    DEFF Research Database (Denmark)

    Chimirri, Niklas Alexander

    The past decades of child research have seen a rising number of practice-based studies which investigate the children’s perspectives on a multitude of everyday life phenomena. Researchers accompany children around and across contexts, become part of their sociomaterial interactions with peers......, however, the researchers typically uphold the notion that all they methodically engage in is participant observation. The paper argues that important aspects of children’s living and understanding may be lost when considering them mere objects of one’s visual and verbal research practices. First I delve...... into empirical material from my own participatory study in a daycare center in order to discuss how the child researcher ineluctably contributes to co-arranging the children’s lives under scrutiny and thereby the respective study’s insights. Then I draw on Svend Brinkmann & Lene Tanggaard’s critique...

  10. Overflow Water Pathways in the Subpolar North Atlantic Observed with Deep Floats

    Science.gov (United States)

    Bower, Amy; Furey, Heather; Lozier, Susan

    2017-04-01

    As part of the Overturning in the Subpolar North Atlantic Program (OSNAP), a total of 135 acoustically tracked RAFOS floats have been deployed in the deep boundary currents of the Iceland, Irminger and Labrador Basins, and in the Charlie-Gibbs Fracture Zone, to investigate the pathways of Iceland-Scotland Overflow Water (ISOW) and Denmark Strait Overflow Water (DSOW). Floats were released annually in 2014, 2015 and 2016 at depths between 1800 and 2800 m for two-year missions. The array of sound sources used for tracking was expanded from 10 to 13 moorings in 2016 when it was discovered that wintertime surface roughness was negatively impacting acoustic ranges. The floats from the first setting reveal several examples of persistent , deep coherent eddy motion, including a cyclonic eddy spinning off the tip of Eirik Ridge (southwest of Cape Farewell), a cyclonic eddy in the northeastern Labrador Basin near where anticyclonic Irminger Rings are formed, and an anticyclonic eddy under the North Atlantic Current (NAC) in the central Iceland Basin. A consistent region of boundary-interior exchange was observed near Hamilton Bank on the western boundary of the Labrador Sea. Deep cyclonic recirculation gyres are revealed in all three basins. Floats released in the southward-flowing deep boundary current over the eastern flank of the Reykjanes Ridge show that shallower layers of ISOW peel off to the west and cross the Ridge into the Irminger Basin through various gaps south of 60°N, including the Bight Fracture Zone. These floats tend to turn northward and continue along the slope in the Irminger Basin. Interestingly, floats released at the ISOW level in the CGFZ did not turn into the Irminger Basin as often depicted in deep circulation schematics, but rather drifted west-northwestward toward the Labrador Sea, or eddied around west of the CGFZ and (in some cases) turned southward. This result is consistent with some previous hydrographic and high-resolution model results

  11. Observing Geohazards from Space

    Directory of Open Access Journals (Sweden)

    Francesca Cigna

    2018-02-01

    Full Text Available With a wide spectrum of imaging capabilities—from optical to radar sensors, low to very high resolution, continental to local scale, single-image to multi-temporal approaches, yearly to sub-daily acquisition repeat cycles—Earth Observation (EO offers several opportunities for the geoscience community to map and monitor natural and human-induced Earth hazards from space. The Special Issue “Observing Geohazards from Space” of Geosciences gathers 12 research articles on the development, validation, and implementation of satellite EO data, processing methods, and applications for mapping and monitoring of geohazards such as slow moving landslides, ground subsidence and uplift, and active and abandoned mining-induced ground movements. Papers published in this Special Issue provide novel case studies demonstrating how EO and remote sensing data can be used to detect and delineate land instability and geological hazards in different environmental contexts and using a range of spatial resolutions and image processing methods. Remote sensing datasets used in the Special Issue papers encompass satellite imagery from the ERS-1/2, ENVISAT, RADARSAT-1/2, and Sentinel-1 C-band, TerraSAR-X and COSMO-SkyMed X-band, and ALOS L-band SAR missions; Landsat 7, SPOT-5, WorldView-2/3, and Sentinel-2 multi-spectral data; UAV-derived RGB and near infrared aerial photographs; LiDAR surveying; and GNSS positioning data. Techniques that are showcased include, but are not limited to, differential Interferometric SAR (InSAR and its advanced approaches such as Persistent Scatterers (PS and Small Baseline Subset (SBAS methods to estimate ground deformation, Object-Based Image Analysis (OBIA to identify landslides in high resolution multi-spectral data, UAV and airborne photogrammetry, Structure-from-Motion (SfM for digital elevation model generation, aerial photo-interpretation, feature extraction, and time series analysis. Case studies presented in the papers focus on

  12. Precisely predictable Dirac observables

    CERN Document Server

    Cordes, Heinz Otto

    2006-01-01

    This work presents a "Clean Quantum Theory of the Electron", based on Dirac’s equation. "Clean" in the sense of a complete mathematical explanation of the well known paradoxes of Dirac’s theory, and a connection to classical theory, including the motion of a magnetic moment (spin) in the given field, all for a charged particle (of spin ½) moving in a given electromagnetic field. This theory is relativistically covariant, and it may be regarded as a mathematically consistent quantum-mechanical generalization of the classical motion of such a particle, à la Newton and Einstein. Normally, our fields are time-independent, but also discussed is the time-dependent case, where slightly different features prevail. A "Schroedinger particle", such as a light quantum, experiences a very different (time-dependent) "Precise Predictablity of Observables". An attempt is made to compare both cases. There is not the Heisenberg uncertainty of location and momentum; rather, location alone possesses a built-in uncertainty ...

  13. CMS tracker observes muons

    CERN Multimedia

    2006-01-01

    A computer image of a cosmic ray traversing the many layers of the TEC+ silicon sensors. The first cosmic muon tracks have been observed in one of the CMS tracker endcaps. On 14 March, a sector on one of the two large tracker endcaps underwent a cosmic muon run. Since then, thousands of tracks have been recorded. These data will be used not only to study the tracking, but also to exercise various track alignment algorithms The endcap tested, called the TEC+, is under construction at RWTH Aachen in Germany. The endcaps have a modular design, with silicon strip modules mounted onto wedge-shaped carbon fibre support plates, so-called petals. Up to 28 modules are arranged in radial rings on both sides of these plates. One eighth of an endcap is populated with 18 petals and called a sector. The next major step is a test of the first sector at CMS operating conditions, with the silicon modules at a temperature below -10°C. Afterwards, the remaining seven sectors have to be integrated. In autumn 2006, TEC+ wil...

  14. Destiny's Earth Observation Window

    Science.gov (United States)

    2002-01-01

    Astronaut Michael J. Bloomfield, STS-110 mission commander, looks through the Earth observation window in the Destiny laboratory aboard the International Space Station (ISS). The STS-110 mission prepared the ISS for future spacewalks by installing and outfitting the S0 (S-zero) truss and the Mobile Transporter. The 43-foot-long S0 Truss, weighing in at 27,000 pounds, was the first of 9 segments that will make up the Station's external framework that will eventually stretch 356 feet (109 meters), or approximately the length of a football field. This central truss segment also includes a flatcar called the Mobile Transporter and rails that will become the first 'space railroad,' which will allow the Station's robotic arm to travel up and down the finished truss for future assembly and maintenance. The completed truss structure will hold solar arrays and radiators to provide power and cooling for additional international research laboratories from Japan and Europe that will be attached to the Station. Milestones of the STS-110 mission included the first time the ISS robotic arm was used to maneuver spacewalkers around the Station and marked the first time all spacewalks were based out of the Station's Quest Airlock. It was also the first Shuttle to use three Block II Main Engines. The Space Shuttle Orbiter Atlantis, STS-110 mission, was launched April 8, 2002 and returned to Earth April 19, 2002.

  15. Observability of wind power

    International Nuclear Information System (INIS)

    Gonot, J.P.; Fraisse, J.L.

    2009-01-01

    The total installed capacity of wind power grows from a few hundred MW at the beginning of 2005 to 3400 MW at the end of 2008. With such a trend, a total capacity of 7000 MW could be reached by 2010. The natural variability of wind power and the difficulty of its predictability require a change in the traditional way of managing supply/demand balance, day-ahead margins and the control of electrical flows. As a consequence, RTE operators should be informed quickly and reliably of the real time output power of wind farms and of its evolvement some hours or days ahead to ensure the reliability of the French electrical power system. French specificities are that wind farms are largely spread over the territory, that 95 % of wind farms have an output power below 10 MW and that they are connected to the distribution network. In this context, new tools were necessary to acquire as soon as possible data concerning wind power. In two years long, RTE set up an observatory of wind production 'IPES system' enable to get an access to the technical characteristics of the whole wind farms, to observe in real time 75 % of the wind generation and to implement a forecast model related to wind generation. (authors)

  16. Characteristics of tropospheric ozone depletion events in the Arctic spring: analysis of the ARCTAS, ARCPAC, and ARCIONS measurements and satellite BrO observations

    Directory of Open Access Journals (Sweden)

    J.-H. Koo

    2012-10-01

    Full Text Available Arctic ozone depletion events (ODEs are caused by halogen catalyzed ozone loss. In situ chemistry, advection of ozone-poor air mass, and vertical mixing in the lower troposphere are important factors affecting ODEs. To better characterize the ODEs, we analyze the combined set of surface, ozonesonde, and aircraft in situ measurements of ozone and bromine compounds during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS, the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC, and the Arctic Intensive Ozonesonde Network Study (ARCIONS experiments (April 2008. Tropospheric BrO columns retrieved from satellite measurements and back trajectory calculations are also used to investigate the characteristics of observed ODEs. In situ observations from these field experiments are inadequate to validate tropospheric BrO columns derived from satellite measurements. In view of this difficulty, we construct an ensemble of tropospheric column BrO estimates from two satellite (OMI and GOME-2 measurements and with three independent methods of calculating stratospheric BrO columns. Furthermore, we select analysis methods that do not depend on the absolute magnitude of column BrO, such as time-lagged correlation analysis of ozone and tropospheric column BrO, to understand characteristics of ODEs. Time-lagged correlation analysis between in situ (surface and ozonesonde measurements of ozone and satellite derived tropospheric BrO columns indicates that the ODEs are due to either local halogen-driven ozone loss or short-range (∼1 day transport from nearby regions with ozone depletion. The effect of in situ ozone loss is also evident in the diurnal variation difference between low (10th and 25th percentiles and higher percentiles of surface ozone concentrations at Alert, Canada. Aircraft observations indicate low-ozone air mass transported from adjacent high-BrO regions. Correlation analyses of ozone

  17. Spatial and seasonal distribution of Arctic aerosols observed by the CALIOP satellite instrument (2006–2012

    Directory of Open Access Journals (Sweden)

    M. Di Pierro

    2013-07-01

    Full Text Available We use retrievals of aerosol extinction from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP onboard the CALIPSO satellite to examine the vertical, horizontal and temporal variability of tropospheric Arctic aerosols during the period 2006–2012. We develop an empirical method that takes into account the difference in sensitivity between daytime and nighttime retrievals over the Arctic. Comparisons of the retrieved aerosol extinction to in situ measurements at Barrow (Alaska and Alert (Canada show that CALIOP reproduces the observed seasonal cycle and magnitude of surface aerosols to within 25 %. In the free troposphere, we find that daytime CALIOP retrievals will only detect the strongest aerosol haze events, as demonstrated by a comparison to aircraft measurements obtained during NASA's ARCTAS mission during April 2008. This leads to a systematic underestimate of the column aerosol optical depth by a factor of 2–10. However, when the CALIOP sensitivity threshold is applied to aircraft observations, we find that CALIOP reproduces in situ observations to within 20% and captures the vertical profile of extinction over the Alaskan Arctic. Comparisons with the ground-based high spectral resolution lidar (HSRL at Eureka, Canada, show that CALIOP and HSRL capture the evolution of the aerosol backscatter vertical distribution from winter to spring, but a quantitative comparison is inconclusive as the retrieved HSRL backscatter appears to overestimate in situ observations by a factor of 2 at all altitudes. In the High Arctic (>70° N near the surface (−1, followed by a sharp decline and a minimum in May–September (1–4 Mm−1, thus providing the first pan-Arctic view of Arctic haze seasonality. The European and Asian Arctic sectors display the highest wintertime extinctions, while the Atlantic sector is the cleanest. Over the Low Arctic (60–70° N near the surface, CALIOP extinctions reach a maximum over land in summer due to

  18. Satellite Observations of Declining Aerosol Burden in The Twenty-First Century in the Southeast United States

    Science.gov (United States)

    Feng, N.; Tosca, M.; Kalashnikova, O. V.; Campbell, J. R.; Garay, M. J.; Seidel, F. C.

    2017-12-01

    The Southeast US (SEUS) has long been recognized as a region where the climatic effect of atmospheric aerosols can cool the Earth and have thus reduced the effect of greenhouse warming. However, previous studies have assessed that abundant carbonaceous aerosols over SEUS from a combination of anthropogenic and natural sources are systematically underestimated by most atmospheric models, especially during summer when the average carbon concentration in SEUS is the highest in the country. In this study, we utilize an ensemble of surface (AERONET) and satellite (MISR, CALIPSO) observations over the SEUS from 2001 to 2015 to better understand the spatially and vertically-resolved decadal trend of SEUS aerosol burden. Results from CALIOP show significant aerosol loading extending from the surface to 5km year-round. Additionally, these data show aerosol extinction coefficients as large as 0.01 km-1 extending well above 8km during the summertime. CALIOP measurements corroborate seasonal observations from MISR and indicate that much of the aerosol burden in the SEUS is comprised of smoke, polluted continental and polluted dust species. Using boundary layer heights from the ERA Interim dataset, CALIOP data show that while summertime aerosol burden above the boundary layer (elevated) is equal to about half of the AOD in the surface layer (0.17 vs. 0.08), during wintertime, the vast majority of aerosols are below the boundary layer (0.12 vs. 0.03). Despite strong seasonality in overall aerosol burden, decadal trends in AOD did not exhibit similarly large seasonal differences; data show AOD decreasing between 2001 and 2015 during both summer and winter and in both the MISR and CALIOP datasets. Between 2001 and 2015, the average summertime aerosol optical depth (AOD) from MISR fell from 0.23 to 0.15, and the trend was -0.05 decade-1 (23% decade-1). The fit was statistically significant, with an r2=0.53. Measurement campaigns such as SEAC4RC will be extensively leveraged, which

  19. Spectropolarimetric Imaging Observations

    Science.gov (United States)

    Bradley, Christine Lavella

    The capability to map anthropogenic aerosol quantities and properties over land can provide significant insights for climate and environmental studies on global and regional scales. One of the primary challenges in aerosol information monitoring is separating two signals measured by downward-viewing airborne or spaceborne instruments: the light scattered from the aerosols and light reflected from the Earth's surface. In order to study the aerosols independently, the surface signal needs to be subtracted out from the measurements. Some observational modalities, such as multispectral and multiangle, do not provide enough information to uniquely define the Earth's directional reflectance properties for this task due to the high magnitude and inhomogeneity of albedo for land surface types. Polarization, however, can provide additional information to define surface reflection. To improve upon current measurement capabilities of aerosols over urban areas, Jet Propulsion Laboratory developed the Multiangle SpectroPolarimetric Imager (MSPI) that can accurately measure the Degree of Linear Polarization to 0.5%. In particular, data acquired by the ground-based prototype, GroundMSPI, is used for directional reflectance studies of outdoor surfaces in this dissertation. This work expands upon an existing model, the microfacet model, to characterize the polarized bidirectional reflectance distribution function (pBRDF) of surfaces and validate an assumption, the Spectral Invariance Hypothesis, on the surface pBRDF that is used in aerosol retrieval algorithms. The microfacet model is commonly used to represent the pBRDF of Earth's surface types, such as ocean and land. It represents a roughened surface comprised of randomly oriented facets that specularly reflect incoming light into the upward hemisphere. The analytic form of the pBRDF for this model assumes only a single reflection of light from the microfaceted surface. If the incoming illumination is unpolarized, as it is with

  20. Summer to Winter Diurnal Variabilities of Temperature and Water Vapour in the Lowermost Troposphere as Observed by HAMSTRAD over Dome C, Antarctica

    Science.gov (United States)

    Ricaud, P.; Genthon, C.; Durand, P.; Attié, J.-L.; Carminati, F.; Canut, G.; Vanacker, J.-F.; Moggio, L.; Courcoux, Y.; Pellegrini, A.; Rose, T.

    2012-04-01

    The HAMSTRAD (H2O Antarctica Microwave Stratospheric and Tropospheric Radiometers) microwave radiometer operating at 60 GHz (oxygen line, thus temperature) and 183 GHz (water vapour line) has been permanently deployed at the Dome C station, Concordia, Antarctica [75°06'S, 123°21'E, 3,233 m above mean sea level] in January 2010 to study long-term trends in tropospheric absolute humidity and temperature. The great sensitivity of the instrument in the lowermost troposphere helped to characterize the diurnal cycle of temperature and H2O from the austral summer (January 2010) to the winter (June 2010) seasons from heights of 10 to 200 m in the planetary boundary layer (PBL). The study has characterized the vertical resolution of the HAMSTRAD measurements: 10-20 m for temperature and 25-50 m for H2O. A strong diurnal cycle in temperature and H2O (although noisier) has been measured in summertime at 10 m, decreasing in amplitude with height, and phase-shifted by about 4 h above 50 m with a strong H2O-temperature correlation (>0.8) throughout the entire PBL. In autumn, whilst the diurnal cycle in temperature and H2O is less intense, a 12-h phase shift is observed above 30 m. In wintertime, a weak diurnal signal measured between 10 to 200 m is attributed to the methodology employed, which consists of monthly averaged data, and that combines air masses from different origins (sampling effect) and not to the imprint of the null solar irradiation. In situ sensors scanning the entire 24-h period, radiosondes launched at 2000 local solar time (LST) and European Centre for Medium-Range Weather Forecasts (ECMWF) analyses at 0200, 0800, 1400 and 2000 LST agree very well with the HAMSTRAD diurnal cycles for temperature and relatively well for absolute humidity. For temperature, HAMSTRAD tends to be consistent with all the other datasets but shows a smoother vertical profile from 10 to 100 m compared to radiosondes and in-situ data, with ECMWF profiles even smoother than HAMSTRAD

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

    Science.gov (United States)

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

    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

  2. Observations

    DEFF Research Database (Denmark)

    Rossiter, John R.; Percy, Larry

    2013-01-01

    as requiring a new model of how advertising communicates and persuades, which, as the authors' textbooks explain, is sheer nonsense and contrary to the goal of integrated marketing. We provide in this article a translation of practitioners' jargon into more scientifically acceptable terminology as well...... as a classification of the new advertising formats in terms of traditional analogs with mainstream media advertising....

  3. Preparing astronomical observations and observing with OHP facilities

    Directory of Open Access Journals (Sweden)

    Patris J.

    2010-12-01

    Full Text Available In addition to the general introduction to observational astronomy given in a past paper (J. Phys. IV France, ERCA 07 (2006 pp 373-390 some tools are given to the observer. These include the general knowledge of what is going to be observed and of the instruments used. A guideline is given to prepare an observing program and to follow it as efficiently as possible. Finally, some examples are given of observations to be made by ERCA participants at OHP observatory.

  4. US Naval Observatory Hourly Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly observations journal from the National Observatory in Washington DC. The observatory is the first station in the United States to produce hourly observations...

  5. OBPRELIM Observer Preliminary Data System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Paper logs are the primary data collection tool used by observers of the Northeast Fisheries Observer Program and Industry Funded Scallop Program deployed on...

  6. US Daily Pilot Balloon Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pilot Balloon observational forms for the United States. Taken by Weather Bureau and U.S. Army observers. Period of record 1918-1960. Records scanned from the NCDC...

  7. Lightship Daily Observations - NARA Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations taken on board lightships along the United States coasts from 1893 - 1943. Generally 4-6 observations daily. Also includes deck logs, which give...

  8. Central American and Caribbean Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weather and soil temperature observations from foreign countries, taken by foreign and American observers. Includes NOAA forms collected and archived at NCDC, and...

  9. US Air Force Base Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly observations taken by U.S. Air Force personnel at bases in the United States and around the world. Foreign observations concentrated in the Middle East and...

  10. A Primer on Observational Measurement.

    Science.gov (United States)

    Girard, Jeffrey M; Cohn, Jeffrey F

    2016-08-01

    Observational measurement plays an integral role in a variety of scientific endeavors within biology, psychology, sociology, education, medicine, and marketing. The current article provides an interdisciplinary primer on observational measurement; in particular, it highlights recent advances in observational methodology and the challenges that accompany such growth. First, we detail the various types of instrument that can be used to standardize measurements across observers. Second, we argue for the importance of validity in observational measurement and provide several approaches to validation based on contemporary validity theory. Third, we outline the challenges currently faced by observational researchers pertaining to measurement drift, observer reactivity, reliability analysis, and time/expense. Fourth, we describe recent advances in computer-assisted measurement, fully automated measurement, and statistical data analysis. Finally, we identify several key directions for future observational research to explore.

  11. Ship Observations - VOS and Navy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Combination of Voluntary Observing Ship (VOS) and US Navy Ship weather observations. Obs generally taken 2-4 times daily at 00, 06, 12, and 18z.

  12. Field observations and lessons learned

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Joh B [Los Alamos National Laboratory

    2010-01-01

    This presentation outlines observations and lessons learned from the Megaports program. It provides: (1) details of field and technical observations collected during LANL field activities at ports around the world and details of observations collected during radiation detections system testing at Los Alamos National Laboratory; (2) provides suggestions for improvement and efficiency; and (3) discusses possible program execution changes for more effective operations.

  13. Hydroxymethane sulfonate as a possible explanation for observed high levels of particulate sulfur during severe winter haze episodes in Beijing, China.

    Science.gov (United States)

    Moch, J.; Jacob, D.; Mickley, L. J.; Cheng, Y.; Li, M.; Munger, J. W.; Wang, Y.

    2017-12-01

    Observed PM2.5 during severe winter haze in Beijing, China, may reach levels as high as 880 μg m-3, with sulfur compounds contributing significantly to PM2.5 composition. Such sulfur has been traditionally assumed to be sulfate, even though models fail to generate such large sulfate enhancements under cold and hazy conditions. We show that particulate sulfur in wintertime Beijing possibly occurs as an S(IV)-HCHO adduct, hydroxymethane sulfonate (HMS), formed by reaction of aqueous-phase HCHO and S(IV) in cloud droplets. We use a 1-D chemistry model extending from the surface through the boundary layer to examine the potential role of HMS during the Beijing haze events of December 2011 and January 2013. Observed and assimilated meteorological fields including cloud liquid water were applied to the model, and we test the sensitivity of HMS formation to cloud pH and ambient SO2 and HCHO. Surface observations from the two haze events show excess ammonium in the aerosol, indicating cloud pH may be relatively high. Model results show that once cloud pH exceeds 4.5, HMS can accumulate rapidly, reaching a few hundred μg m-3 in a few hours. The timing of HMS formation is controlled by the presence of cloud liquid water, with eddy driven diffusion bringing HMS to the surface. The magnitude of HMS peaks is limited by the supply of HCHO. HMS episodes in the model end gradually over 1-3 days as fresh air is entrained into the boundary layer; in observations these episodes typically end when increasing wind speeds destabilize the boundary layer and disperses pollution. We find that consideration of HMS as a source of particulate sulfur significantly improves model match with observations. For example, assuming cloud pH of 5 and average surface SO2 and HCHO levels of 50 ppb and 5.5 ppb, we calculate mean HMS as 43.8 μg m-3 in January 2013, within 7 μg m-3 of observed particulate sulfur. Our 1-D model also captures the timing and magnitude of peak particulate sulfur in January

  14. astroplan: Observation Planning for Astronomers

    Science.gov (United States)

    Morris, Brett

    2016-03-01

    Astroplan is an observation planning package for astronomers. It is an astropy-affiliated package which began as a Google Summer of Code project. Astroplan facilitates convenient calculation of common observational quantities, like target altitudes and azimuths, airmasses, and rise/set times. Astroplan also computes when targets are observable given various extensible observing constraints, for example: within a range of airmasses or altitudes, or at a given separation from the Moon. Astroplan is taught in the undergraduate programming for astronomy class, and enables observational Pre- MAP projects at the University of Washington. In the near future, we plan to implement scheduling capabilities in astroplan on top of the constraints framework.

  15. Dependency Ordering of Atomic Observables

    Science.gov (United States)

    Cīrulis, Jānis

    2015-12-01

    The notion of atomic observable was introduced by S.Gudder for effect test spaces in 1997. In this paper an observable is a σ-homomorphism from the Borel algebra on a line to some logic. Roughly, an observable on a logic is atomic, if it is completely determined by its restriction to one-element subsets of its point spectrum. In particular, every discrete observable is atomic. We study some elementary properties of such observables, and discuss a possible notion of functional dependency between them. Algebraically, a dependency is a certain preorder relation on the set of all atomic observables, which induces an order relation on the set of all maximal orthogonal subsets of the logic. Several properties, as well as characteristics in terms of the underlying logic, of these relations are stated.

  16. NS&T Management Observations

    Energy Technology Data Exchange (ETDEWEB)

    Gianotto, David [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2014-09-01

    The INL Management Observation Program (MOP) is designed to improve managers and supervisors understanding of work being performed by employees and the barriers impacting their success. The MOP also increases workers understanding of managements’ expectations as they relate to safety, security, quality, and work performance. Management observations (observations) are designed to improve the relationship and trust between employees and managers through increased engagement and interactions between managers and researchers in the field. As part of continuous improvement, NS&T management took initiative to focus on the participation and quality of observations in FY 14. This quarterly report is intended to (a) summarize the participation and quality of management’s observations, (b) assess observations for commonalities or trends related to facility or process barriers impacting research, and (c) provide feedback and make recommendations for improvements NS&T’s MOP.

  17. Eigenstate Thermalization for Degenerate Observables

    Science.gov (United States)

    Anza, Fabio; Gogolin, Christian; Huber, Marcus

    2018-04-01

    Under unitary time evolution, expectation values of physically reasonable observables often evolve towards the predictions of equilibrium statistical mechanics. The eigenstate thermalization hypothesis (ETH) states that this is also true already for individual energy eigenstates. Here we aim at elucidating the emergence of the ETH for observables that can realistically be measured due to their high degeneracy, such as local, extensive, or macroscopic observables. We bisect this problem into two parts, a condition on the relative overlaps and one on the relative phases between the eigenbases of the observable and Hamiltonian. We show that the relative overlaps are unbiased for highly degenerate observables and demonstrate that unless relative phases conspire to cumulative effects, this makes such observables verify the ETH. Through this we elucidate potential pathways towards proofs of thermalization.

  18. GENETIC DIVERSITY ANALYSIS OF MANGABA (Hancornia speciosa Gomes, AN EXOTIC BRAZILIAN TROPICAL SPECIES

    Directory of Open Access Journals (Sweden)

    Ana Veruska Cruz da Silva

    2012-05-01

    Full Text Available Twenty genotypes from natural population of mangaba located in Itaporanga D’Ajuda (Sergipe state - Brazil were subjected to analysis using RAPD markers. Polymorphism, genetic diversity and structure parameters were determined to characterize the differences between plants. 60 DNA fragments were generated by 10 primers, 85% of which were polymorphic. Results show a quantitative genetic diversity value of 0.35 and a Shannon index of 0.46 in the population. The similarity among the specimens according to Jaccard’s coefficient ranged from 0.36 to 0.87. Using cluster analysis it was possible to indentify five groups. Three individuals also stand out since they presented significant divergence from the groups. The PCoA formed four groups, with three of the groups isolated from the others. This investigation showed that genetic diversity was relatively large among these individuals. In addition, the results demonstrated that RAPD markers are a useful tool for evaluating the genetic diversity and relationships among mangaba.

  19. Aerosol optical thickness retrieval over land and water using SCIAMACHY/GOME data

    NARCIS (Netherlands)

    Kusmierczyk-Michulec, J.; Leeuw, G. de

    2005-01-01

    An algorithm for the retrieval of the aerosol optical thickness over land and over water from SCIAMACHY (SCanning Imaging Absorption SpectroMeter for Atmospheric ChartographY) is presented. Because calibrated data are not yet available for the SCIAMACHY channels used by the algorithm, the concepts

  20. Sobre uma alternativa composicional de Antônio Carlos Gomes na ópera Condor

    Directory of Open Access Journals (Sweden)

    Marcos da Cunha Lopes Virmond

    2007-05-01

    duet in the first act of the opera Condor. Through musicological transcription and musical analysis, this study aims at investigating the compositional rationale for such a lengthy modification and deepening our understanding of Gomes’s compositional processes. We conclude that the composer mastered the tools of the operatic métier and was deeply concerned with providing a refined polishing to his musical product.

  1. Accelerator, superplasticiter and silica gome by wet shotcrete; Hormigon Proyectado por Via Humeda

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This project has been carried out by Geocontrol during the period September 1997-november 2000. The main target of this project was to establish a better knowledgement about the influence of the accelerator, silica fume, steel fibres and super plasticizer on the wet shotcrete properties. This project has been developed in three phases focused in three specifical targets: I. Effect of the accelerator, superplasticizer and silica fume dosages on shotcrete strength. II. Influence of steel fibres and silica fume on shotcrete characteristics. III. Steel fibres dosages and type effect of shotcrete absorbed energy. The main conclusions obtained from this research are the following. 1. Accelerators free of alkalis have a very little influence on the shotcrete strength reduction. 2. The best results are obtained when the accelerator dosage is the lowest, with a reference of the 4% of cement weigh. 3. The superplasticizer is very important in order to reach the lowest water/cement ratio. 4. Silica fume has a strong and positive influence on shotcrete characteristics but only if the dosages is higher than 30 kg/m''3. 5. The best results with silica fume are obtained when this product is added as a separate product, instead to be missed with other additive as superplasticizer. 6. Steel fibres addition improves dramatically the shotcrete post-failure characteristics. 7. A shotcrete without steel fibres and with a strength ranged between 25 and 40 MPa absorbers 130-180 Joules and another one with a steel mesh of 150x150x6 mm absorbers 1100 Joules. 8. Steel fibres shotcrete can reach the same energy absorption that another one reinforced with wire mesh. 9. During shotcreting the steel fibres dosages has a loss of 10 to 30 % due to shotcrete rebound. This research project allows to improve the knowledgement os shotcreting technique in order to use it with more efficiency than in the past. (Author)

  2. Reptilia, Serpentes, Dipsadidae, Gomesophis brasiliensis (Gomes, 1918: Distribution extension in state of Santa Catarina, Brazil.

    Directory of Open Access Journals (Sweden)

    Fortes, V. B.

    2010-01-01

    Full Text Available The Brazilian burrowing snake, Gomesophis brasiliensis, occurs in aquatic habitats such as swamps, from MinasGerais and Distrito Federal until Rio Grande do Sul. In spite of this wide distribution, the species’ geographic range stillremains unclear. This note reports the occurrence of G. brasiliensis in the municipality of Vargem Bonita, state of SantaCatarina, south Brazil, extending the species’ range ca. 80 km to the west in this state.

  3. Uncertainty enabled Sensor Observation Services

    Science.gov (United States)

    Cornford, Dan; Williams, Matthew; Bastin, Lucy

    2010-05-01

    Almost all observations of reality are contaminated with errors, which introduce uncertainties into the actual observation result. Such uncertainty is often held to be a data quality issue, and quantification of this uncertainty is essential for the principled exploitation of the observations. Many existing systems treat data quality in a relatively ad-hoc manner, however if the observation uncertainty is a reliable estimate of the error on the observation with respect to reality then knowledge of this uncertainty enables optimal exploitation of the observations in further processes, or decision making. We would argue that the most natural formalism for expressing uncertainty is Bayesian probability theory. In this work we show how the Open Geospatial Consortium Sensor Observation Service can be implemented to enable the support of explicit uncertainty about observations. We show how the UncertML candidate standard is used to provide a rich and flexible representation of uncertainty in this context. We illustrate this on a data set of user contributed weather data where the INTAMAP interpolation Web Processing Service is used to help estimate the uncertainty on the observations of unknown quality, using observations with known uncertainty properties. We then go on to discuss the implications of uncertainty for a range of existing Open Geospatial Consortium standards including SWE common and Observations and Measurements. We discuss the difficult decisions in the design of the UncertML schema and its relation and usage within existing standards and show various options. We conclude with some indications of the likely future directions for UncertML in the context of Open Geospatial Consortium services.

  4. Timed Testing under Partial Observability

    DEFF Research Database (Denmark)

    David, Alexandre; Larsen, Kim Guldstrand; Li, Shuhao

    2009-01-01

    observability of SUT using a set of predicates over the TGA state space, and specify the test purposes in Computation Tree Logic (CTL) formulas. A recently developed partially observable timed game solver is used to generate winning strategies, which are used as test cases. We propose a conformance testing...

  5. Electrophotometric observations of artificial satellites

    International Nuclear Information System (INIS)

    Vovchyk, Yeva; Blagodyr, Yaroslav; Kraynyuk, Gennadiy; Bilinsky, Andriy; Lohvynenko, Alexander; Klym, Bogdan; Pochapsky, Yevhen

    2004-01-01

    Problems associated with polarimetric observations of low Earth orbit artificial satellites as important solar system objects are discussed. The instrumentation (the optical and mechanical parts, the control and drive electronics, and the application software) for performing such observations is also described

  6. Fault detection using (PI) observers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, J.; Shafai, B.

    1997-01-01

    The fault detection and isolation (FDI) problem in connection with Proportional Integral (PI) Observers is considered in this paper. A compact formulation of the FDI design problem using PI observers is given. An analysis of the FDI design problem is derived with respectt to the time domain...

  7. The INTEGRAL Core Observing Programme

    DEFF Research Database (Denmark)

    Winkler, C.; Gehrels, N.; Lund, Niels

    1999-01-01

    The Core Programme of the INTEGRAL mission is defined as the portion of the scientific programme covering the guaranteed time observations for the INTEGRAL Science Working Team. This paper describes the current status of the Core Programme preparations and summarizes the key elements...... of the observing programme....

  8. Frontier of solar observation. Solar activity observed by 'HINODE' mission

    International Nuclear Information System (INIS)

    Watanabe, Tetsuya

    2008-01-01

    After launched in September 2006, solar observation satellite 'HINODE' has been a solar observatory on orbit with the scientific instruments well operated and its continuous observation was conducted steadily on almost all solar atmospheres from photosphere to corona. 'HINODE' was equipped with the solar optical telescope, extreme-ultraviolet imaging spectrometer and x-ray telescope and aimed at clarifying the mystery of solar physics related with coronal heating and magnetic reconnection. Present state of 'HINODE' was described from observations made in initial observation results, which have made several discoveries, such as Alfven waves in the corona, unexpected dynamics in the chromosphere and photosphere, continuous outflowing plasma as a possible source of solar wind, and fine structures of magnetic field in sunspots and solar surface. (T. Tanaka)

  9. Global Mercury Observation System (GMOS) surface observation data.

    Data.gov (United States)

    U.S. Environmental Protection Agency — GMOS global surface elemental mercury (Hg0) observations from 2013 & 2014. This dataset is associated with the following publication: Sprovieri, F., N. Pirrone,...

  10. Radon observation for earthquake prediction

    Energy Technology Data Exchange (ETDEWEB)

    Wakita, Hiroshi [Tokyo Univ. (Japan)

    1998-12-31

    Systematic observation of groundwater radon for the purpose of earthquake prediction began in Japan in late 1973. Continuous observations are conducted at fixed stations using deep wells and springs. During the observation period, significant precursory changes including the 1978 Izu-Oshima-kinkai (M7.0) earthquake as well as numerous coseismic changes were observed. At the time of the 1995 Kobe (M7.2) earthquake, significant changes in chemical components, including radon dissolved in groundwater, were observed near the epicentral region. Precursory changes are presumably caused by permeability changes due to micro-fracturing in basement rock or migration of water from different sources during the preparation stage of earthquakes. Coseismic changes may be caused by seismic shaking and by changes in regional stress. Significant drops of radon concentration in groundwater have been observed after earthquakes at the KSM site. The occurrence of such drops appears to be time-dependent, and possibly reflects changes in the regional stress state of the observation area. The absence of radon drops seems to be correlated with periods of reduced regional seismic activity. Experience accumulated over the two past decades allows us to reach some conclusions: 1) changes in groundwater radon do occur prior to large earthquakes; 2) some sites are particularly sensitive to earthquake occurrence; and 3) the sensitivity changes over time. (author)

  11. Observability of global rivers with future SWOT observations

    Science.gov (United States)

    Fisher, Colby; Pan, Ming; Wood, Eric

    2017-04-01

    The Surface Water and Ocean Topography (SWOT) mission is designed to provide global observations of water surface elevation and slope from which river discharge can be estimated using a data assimilation system. This mission will provide increased spatial and temporal coverage compared to current altimeters, with an expected accuracy for water level elevations of 10 cm on rivers greater than 100 m wide. Within the 21-day repeat cycle, a river reach will be observed 2-4 times on average. Due to the relationship between the basin orientation and the orbit, these observations are not evenly distributed in time, which will impact the derived discharge values. There is, then, a need for a better understanding of how the mission will observe global river basins. In this study, we investigate how SWOT will observe global river basins and how the temporal and spatial sampling impacts the discharge estimated from assimilation. SWOT observations can be assimilated using the Inverse Streamflow Routing (ISR) model of Pan and Wood [2013] with a fixed interval Kalman smoother. Previous work has shown that the ISR assimilation method can be used to reproduce the spatial and temporal dynamics of discharge within many global basins: however, this performance was strongly impacted by the spatial and temporal availability of discharge observations. In this study, we apply the ISR method to 32 global basins with different geometries and crossing patterns for the future orbit, assimilating theoretical SWOT-retrieved "gauges". Results show that the model performance varies significantly across basins and is driven by the orientation, flow distance, and travel time in each. Based on these properties, we quantify the "observability" of each basin and relate this to the performance of the assimilation. Applying this metric globally to a large variety of basins we can gain a better understanding of the impact that SWOT observations may have across basin scales. By determining the

  12. The SIRTF Legacy Observing Program

    Science.gov (United States)

    Greenhouse, M. A.; Leisawitz, D.; Gehrz, R. D.; Clemens, D. P.; Force, Sirtf Community Task

    1997-12-01

    Legacy Observations and General Observations(GO)are separate categories in which SIRTF observing time will be allocated through peer reviewed community proposals. The Legacy Program will embrace several projects, each headed by a Legacy Principal Investigator. Legacy Observations are distinguished from General Observations by the following three criteria: [1] the project is a large, coherent investigation whose scientific goals can not be met by a number of smaller, uncoordinated projects; [2] the data will be of both general and lasting importance to the broad astronomical community and of immediate utility in motivating and planning follow-on GO investigations with SIRTF; and [3] the data (unprocessed, fully processed, and at intermediate steps in processing) will be placed in a public data base immediately and with no proprietary period. The goals of the SIRTF Legacy program are: [1] enable community use of SIRTF for large coherent survey observations, [2] provide prompt community access to SIRTF survey data, and [3] enable GO program observations based on Legacy program results. A likely attribute (but not a requirement) for Legacy projects is that they may involve hundreds, and perhaps thousands, of hours of observing time. It is anticipated that as much as 6000 hours of telescope time will be allocated through the Legacy program. To meet Legacy program goal [3], allocation of as much as 70% of SIRTF's first year on orbit to Legacy projects may be necessary, and the observing phase of the Legacy program will be completed during the following year. A Legacy call for proposals will be issued 1 year prior to launch or sooner, and will be open to all scientists and science topics. In this poster, we display Legacy program definition and schedule items that will be of interest to those intending to propose under this unique opportunity.

  13. Observation of relativistic antihydrogen atoms

    International Nuclear Information System (INIS)

    Blanford, Glenn DelFosse

    1998-01-01

    An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 0 production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e + e - pair creation near a nucleus with the e + being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure

  14. Analytic observables in nuclear physics

    International Nuclear Information System (INIS)

    Borbely, I.

    1980-05-01

    The analytical dependence of quantum mechanical observables on their variables is discussed by using the assumption that the corresponding probability amplitudes are analytic functions. The properties of the cross section in the energy plane for spinless particles as well as the properties of the most general polarization observables in the cosdelta plane are considered in detail. In particular, the strength of the transfer pole for polarization observables is given. The practical possibilities to extract the different orbital momentum components of nuclei by extrapolation techniques are briefly outlined. (author)

  15. The ESO Observing Programmes Committee

    Science.gov (United States)

    Westerlund, B. E.

    1982-06-01

    Since 1978 the ESO Observing Programmes Committee (OPC) has "the function to inspect and rank the proposals made for observing programmes at La Silla, and thereby to advise the Director General on the distribution of observing time". The members (one from each member country) and their alternates are nominated by the respective national committees for five-year terms (not immediately renewable). The terms are staggered so that each year one or two persons are replaced. The Chairman is appointed annually by the Council. He is invited to attend Council meetings and to report to its members.

  16. Observer variation in skeletal radiology

    Energy Technology Data Exchange (ETDEWEB)

    Cockshott, W.P.; Park, W.M.

    1983-08-01

    The factors that affect observer variation in bone radiology are analysed from data in the literature and on the basis of studies carried out at McMaster University on the hands and sacroiliac joints. A plea is made for presenting results in terms of Kappa statistics so that agreement due purely to chance is eliminated. In the conclusions the main variables that affect concordance are listed so that strategies can be developed to reduce observer variation. This is important in serial studies to ensure that the observer variations are smaller than the effect one wishes to measure.

  17. PHOTOELECTRIC OBSERVATIONS OF HD 8358

    Directory of Open Access Journals (Sweden)

    Woo-Baik Lee

    1989-06-01

    Full Text Available UBV photoelectric observations of RS CVn type variable star HD 8358 were made using the 61cm reflector at Sobaeksan Astronomical Observatory. The data were obtained on 15 nights from October 1987 to December 1988. Double peaks of maximum light is seen from the light curve and continuous change of phase in notified from the times of maximum lights. The colors of October, 1987 - January, 1988 observations are bluer in ∆(b-u, but redder in ∆(u-b, than those of November -December, 1988 observations.

  18. Observational methodology in sport sciences

    Directory of Open Access Journals (Sweden)

    M. Teresa Anguera

    2013-11-01

    Full Text Available This paper reviews the conceptual framework, the key literature and the methods (observation tools, such as category systems and field formats, and coding software, etc. that should be followed when conducting research from the perspective of observational methodology. The observational designs used by the authors’ research group over the last twenty years are discussed, and the procedures for analysing data and assessing their quality are described. Mention is also made of the latest methodological trends in this field, such as the use of mixed methods.

  19. Photoelectric observations of CH Cygni

    Energy Technology Data Exchange (ETDEWEB)

    Luud, L; Ruusalepp, M; Vennik, Ya

    1977-01-01

    UBV observations of the peculiar variable star CH Cygni from 1968 up to 1974 are presented. HD 182691 served as a comparison star. It turned out that the colours are in accordance with a model for a symbiotic star. The colour-magnitude diagrams of CH Cygni allow dividing the period of the observations into two parts in dependence on the activity of CH Cygni. Observed brightness variations are analyzed by using autocorrelation, crosscorrelation, and power spectral density functions. It has been found that brightness variations have some periods which are given.

  20. Sliding mode control and observation

    CERN Document Server

    Shtessel, Yuri; Fridman, Leonid; Levant, Arie

    2014-01-01

    The sliding mode control methodology has proven effective in dealing with complex dynamical systems affected by disturbances, uncertainties and unmodeled dynamics. Robust control technology based on this methodology has been applied to many real-world problems, especially in the areas of aerospace control, electric power systems, electromechanical systems, and robotics. Sliding Mode Control and Observation represents the first textbook that starts with classical sliding mode control techniques and progresses toward newly developed higher-order sliding mode control and observation algorithms and their applications. The present volume addresses a range of sliding mode control issues, including: *Conventional sliding mode controller and observer design *Second-order sliding mode controllers and differentiators *Frequency domain analysis of conventional and second-order sliding mode controllers *Higher-order sliding mode controllers and differentiators *Higher-order sliding mode observers *Sliding mode disturbanc...

  1. Pre-1947 Marine Daily Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations taken on board U.S. Navy and merchant marine vessels and submitted to the U.S. Weather Bureau. Merchant ships are of many nationalities, and mainly...

  2. Pre-1947 Marine Monthly Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations taken on board U.S. Navy and merchant marine vessels and submitted to the U.S. Weather Bureau. Merchant ships are of many nationalities, and mainly...

  3. Observability during planetary approach navigation

    Science.gov (United States)

    Bishop, Robert H.; Burkhart, P. Daniel; Thurman, Sam W.

    1993-01-01

    The objective of the research is to develop an analytic technique to predict the relative navigation capability of different Earth-based radio navigation measurements. In particular, the problem is to determine the relative ability of geocentric range and Doppler measurements to detect the effects of the target planet gravitational attraction on the spacecraft during the planetary approach and near-encounter mission phases. A complete solution to the two-dimensional problem has been developed. Relatively simple analytic formulas are obtained for range and Doppler measurements which describe the observability content of the measurement data along the approach trajectories. An observability measure is defined which is based on the observability matrix for nonlinear systems. The results show good agreement between the analytic observability analysis and the computational batch processing method.

  4. Window observers for linear systems

    Directory of Open Access Journals (Sweden)

    Utkin Vadim

    2000-01-01

    Full Text Available Given a linear system x ˙ = A x + B u with output y = C x and a window function ω ( t , i.e., ∀ t , ω ( t ∈ {0,1 }, and assuming that the window function is Lebesgue measurable, we refer to the following observer, x ˆ = A x + B u + ω ( t L C ( x − x ˆ as a window observer. The stability issue is treated in this paper. It is proven that for linear time-invariant systems, the window observer can be stabilized by an appropriate design under a very mild condition on the window functions, albeit for linear time-varying system, some regularity of the window functions is required to achieve observer designs with the asymptotic stability. The corresponding design methods are developed. An example is included to illustrate the possible applications

  5. CalNex Observational Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Observations made during the 2010 CalNex measurement campaign. This dataset is associated with the following publication: Woody , M., K. Baker , P. Hayes, J....

  6. Mobile Source Observation Database (MSOD)

    Science.gov (United States)

    The Mobile Source Observation Database (MSOD) is a relational database developed by the Assessment and Standards Division (ASD) of the U.S. EPA Office of Transportation and Air Quality (formerly the Office of Mobile Sources).

  7. An introduction to observational astrophysics

    CERN Document Server

    Gallaway, Mark

    2016-01-01

    Observational Astrophysics follows the general outline of an astrophysics undergraduate curriculum targeting practical observing information to what will be covered at the university level. This includes the basics of optics and coordinate systems to the technical details of CCD imaging, photometry, spectography and radio astronomy.  General enough to be used by students at a variety of institutions and advanced enough to be far more useful than observing guides targeted at amateurs, the author provides a comprehensive and up-to-date treatment of observational astrophysics at undergraduate level to be used with a university’s teaching telescope.  The practical approach takes the reader from basic first year techniques to those required for a final year project. Using this textbook as a resource, students can easily become conversant in the practical aspects of astrophysics in the field as opposed to the classroom.

  8. Bulletin of International Simultaneous Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The publication of the Bulletin of International Simultaneous Observations, began July 1, 1875, with daily maps added in 1877. It was published for distribution...

  9. Mobile Source Observation Database (MSOD)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Mobile Source Observation Database (MSOD) is a relational database being developed by the Assessment and Standards Division (ASD) of the US Environmental...

  10. COOP Wind and Radiation Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind and radiation data from stations in the National Weather Service Cooperative Observers Network. Some precipitation and pressure forms are mistakenly placed in...

  11. NILU-UV multi-filter radiometer total ozone columns: Comparison with satellite observations over Thessaloniki, Greece.

    Science.gov (United States)

    Zempila, Melina Maria; Taylor, Michael; Koukouli, Maria Elissavet; Lerot, Christophe; Fragkos, Konstantinos; Fountoulakis, Ilias; Bais, Alkiviadis; Balis, Dimitrios; van Roozendael, Michel

    2017-07-15

    This study aims to construct and validate a neural network (NN) model for the production of high frequency (~1min) ground-based estimates of total ozone column (TOC) at a mid-latitude UV and ozone monitoring station in the Laboratory of Atmospheric Physics of the Aristotle University of Thessaloniki (LAP/AUTh) for the years 2005-2014. In the first stage of model development, ~30,000 records of coincident solar UV spectral irradiance measurements from a Norsk Institutt for Luftforskning (NILU)-UV multi-filter radiometer and TOC measurements from a co-located Brewer spectroradiometer are used to train a NN to learn the nonlinear functional relation between the irradiances and TOC. The model is then subjected to sensitivity analysis and validation. Close agreement is obtained (R 2 =0.94, RMSE=8.21 DU and bias=-0.15 DU relative to the Brewer) for the training data in the correlation of NN estimates on Brewer derived TOC with 95% of the coincident data differing by less than 13 DU. In the second stage of development, a long time series (≥1 million records) of high frequency (~1min) NILU-UV ground-based measurements are presented as inputs to the NN model to generate high frequency TOC estimates. The advantage of the NN model is that it is not site dependent and is applicable to any NILU input data lying within the range of the training data. GOME/ERS-2, SCIAMACHY/Envisat, OMI/Aura and GOME2/MetOp-A TOC records are then used to perform a precise cross-validation analysis and comparison with the NILU TOC estimates over Thessaloniki. All 4 satellite TOC dataset are retrieved using the GOME Direct Fitting algorithm, version 3 (GODFIT_v3), for reasons of consistency. The NILU TOC estimates within ±30min of the overpass times agree well with the satellite TOC retrievals with coefficient of determination in the range 0.88≤R 2 ≤0.90 for all sky conditions and 0.95≤R 2 ≤0.96 for clear sky conditions. The mean fractional differences are found to be -0.67%±2.15%, -1

  12. Observations of Local Seychelles Circulation

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Observations of Local Seychelles Circulation Geno...goal for the proposed work is to develop predictive capabilities for physical oceanography for the Seychelles region in support of locally relevant...observations in the Seychelles region that will lead to long-term data collection efforts. In collaboration with local partnerships, we will carry out

  13. Observing the very early universe

    CERN Document Server

    Steinhardt, Paul Joseph

    1995-01-01

    Cosmology is entering an historic epoch in which a dazzling array of new observations will decisively test our theories of the origin and evolution of the Universe. Many of the theoretical proposals have profound implications for our understanding of high-energy physics. This lecture series will review some of the leading ideas, especially the inflationary model of the universe, and explain the astrophysical and cosmological observations anticipated for the next decade that will be critical in determining their validity.

  14. Filtering with Discrete State Observations

    International Nuclear Information System (INIS)

    Dufour, F.; Elliott, R. J.

    1999-01-01

    The problem of estimating a finite state Markov chain observed via a process on the same state space is discussed. Optimal solutions are given for both the 'weak' and 'strong' formulations of the problem. The 'weak' formulation proceeds using a reference probability and a measure change for the Markov chain. The 'strong' formulation considers an observation process related to perturbations of the counting processes associated with the Markov chain. In this case the 'small noise' convergence is investigated

  15. Observation models in radiocarbon calibration

    International Nuclear Information System (INIS)

    Jones, M.D.; Nicholls, G.K.

    2001-01-01

    The observation model underlying any calibration process dictates the precise mathematical details of the calibration calculations. Accordingly it is important that an appropriate observation model is used. Here this is illustrated with reference to the use of reservoir offsets where the standard calibration approach is based on a different model to that which the practitioners clearly believe is being applied. This sort of error can give rise to significantly erroneous calibration results. (author). 12 refs., 1 fig

  16. Observations and hypotheses in cosmology

    International Nuclear Information System (INIS)

    Alfven, H.

    1978-05-01

    The existing observational material of cosmological significance is reviewed. It is found that because of the general acceptance of the Big Bang hypothesis a large number of ad hoc assumptions have been made in order to accomodate the observational facts into its framework. Discriminating between speculative conclusions and conclusions which can be drawn with a reasonable degree of certainty, it is found that no convincing proof of the Big Bang hypothesis exists today

  17. Olson Order of Quantum Observables

    Science.gov (United States)

    Dvurečenskij, Anatolij

    2016-11-01

    M.P. Olson, Proc. Am. Math. Soc. 28, 537-544 (1971) showed that the system of effect operators of the Hilbert space can be ordered by the so-called spectral order such that the system of effect operators is a complete lattice. Using his ideas, we introduce a partial order, called the Olson order, on the set of bounded observables of a complete lattice effect algebra. We show that the set of bounded observables is a Dedekind complete lattice.

  18. Flare Seismology from SDO Observations

    Science.gov (United States)

    Lindsey, Charles; Martinez Oliveros, Juan Carlos; Hudson, Hugh

    2011-10-01

    Some flares release intense seismic transients into the solar interior. These transients are the sole instance we know of in which the Sun's corona exerts a conspicuous influence on the solar interior through flares. The desire to understand this phenomenon has led to ambitious efforts to model the mechanisms by which energy stored in coronal magnetic fields drives acoustic waves that penetrate deep into the Sun's interior. These mechanisms potentially involve the hydrodynamic response of the chromosphere to thick-target heating by high-energy particles, radiative exchange in the chromosphere and photosphere, and Lorentz-force transients to account for acoustic energies estimated up to at 5X10^27 erg and momenta of order 6X10^19 dyne sec. An understanding of these components of flare mechanics promises more than a powerful diagnostic for local helioseismology. It could give us fundamental new insight into flare mechanics themselves. The key is appropriate observations to match the models. Helioseismic observations have identified the compact sources of transient seismic emission at the foot points of flares. The Solar Dynamics Observatory is now giving us high quality continuum-brightness and Doppler observations of acoustically active flares from HMI concurrent with high-resolution EUV observations from AIA. Supported by HXR observations from RHESSI and a broad variety of other observational resources, the SDO promises a leading role in flare research in solar cycle 24.

  19. VLBI Observations of Geostationary Satellites

    Science.gov (United States)

    Artz, T.; Nothnagel, A.; La Porta, L.

    2013-08-01

    For a consistent realization of a Global Geodetic Observing System (GGOS), a proper tie between the individual global reference systems used in the analysis of space-geodetic observations is a prerequisite. For instance, the link between the terrestrial, the celestial and the dynamic reference system of artificial Earth orbiters may be realized by Very Long O Baseline Interferometry (VLBI) observations of one or several satellites. In the preparation phase for a dedicated satellite mission, one option to realize this is using a geostationary (GEO) satellite emitting a radio signal in X-Band and/or S-Band and, thus, imitating a quasar. In this way, the GEO satellite can be observed by VLBI together with nearby quasars and the GEO orbit can, thus, be determined in a celestial reference frame. If the GEO satellite is, e.g., also equipped with a GNSS-type transmitter, a further tie between GNSS and VLBI may be realized. In this paper, a concept for the generation of a radio signal is shown. Furthermore, simulation studies for estimating the GEO position are presented with a GEO satellite included in the VLBI schedule. VLBI group delay observations are then simulated for the quasars as well as for the GEO satellite. The analysis of the simulated observations shows that constant orbit changes are adequately absorbed by estimated orbit parameters. Furthermore, the post-fit residuals are comparable to those from real VLBI sessions.

  20. Translating PI observing proposals into ALMA observing scripts

    Science.gov (United States)

    Liszt, Harvey S.

    2014-08-01

    The ALMA telescope is a complex 66-antenna array working in the specialized domain of mm- and sub-mm aperture synthesis imaging. To make ALMA accessible to technically inexperienced but scientifically expert users, the ALMA Observing Tool (OT) has been developed. Using the OT, scientifically oriented user input is formatted as observing proposals that are packaged for peer-review and assessment of technical feasibility. If accepted, the proposal's scientifically oriented inputs are translated by the OT into scheduling blocks, which function as input to observing scripts for the telescope's online control system. Here I describe the processes and practices by which this translation from PI scientific goals to online control input and schedule block execution actually occurs.

  1. Observations of TT Ari requested in support of MOST observations

    Science.gov (United States)

    Waagen, Elizabeth O.

    2012-08-01

    Dr. Nikolaus Vogt (Universidad de Valparaiso, Chile) requested simultaneous photometry and spectroscopy of the novalike (VY Scl subtype) cataclysmic variable TT Ari in support of upcoming observations with the Canadian Microvariability and Oscillations of Stars (MOST) satellite 2012 September 13 through October 20. The Departamento de Fisica y Astronomia of the Valparaiso University will carry out photometry with small telescopes in central Chile but the assistance of other observers, particularly in other latitudes and longitudes, is requested. The observations are being carried out to study superhump behavior, which is still not well understood despite the amount of research done in all classes of cataclysmic variables. TT Ari exibits superhumps - both positive (the superhump period is longer than the orbital period) and negative (the superhump period is shorter than the orbital period). While positive superhumps are thought probably to be the result of an eccentric configuration in the accretion disk, the mechanism for negative superhumps is not yet understood except that it may be related to the disk's being warped out of the orbital plane, leading to complex torque phenomena. TT Ari, one of the brightest cataclysmic variables, exhibits occasional fadings of several magnitudes, from its usual high-state (maximum) magnitude of ~10.5V to a low-state magnitude as faint as 16V. These fadings occur every 20-25 years, and last between 500 and 1000 days. According to observations in the AAVSO International Database, TT Ari is currently magnitude 10.5V. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details, particularly regarding goals of the campaign, and observing instructions.

  2. Extratropical response to Fast and Slow episodes of Madden-Julian Oscillation in observation and using intervention experiments with CFSv2

    Science.gov (United States)

    Yadav, P.; Straus, D. M.

    2017-12-01

    The Madden-Julian Oscillation (MJO) is a potential source of predictability in the extratropics in extended range weather forecasting. The nature of MJO is sporadic and therefore, the mid-latitude response may depend on the nature of the MJO event, in particular the phase speed. We discuss the results of our observational and modeling study of mid-latitude circulation response to Fast and Slow MJO episodes using wintertime ERA-Interim reanalysis data and the CFSv2 coupled model of NOAA. The observational study shows that the mid-latitude response to different propagating speeds is not the same. The propagation speed is defined by the time the OLR takes to propagate from phase 3 to phase 6. The mid-latitude response is assessed in terms of composite maps and frequency of occurrence of robust circulation regimes. Fast episode composite anomalies of 500hPa height show a developing Rossby wave in the mid-Pacific with downstream propagation through MJO phases 2- 4. Development of NAO+ teleconnection pattern is stronger in Slow that in Fast MJO episodes, and occurs with a greater time lag after MJO heating is in the Indian Ocean (phase 3). Previous results find an increase in occurrence of NAO- regime following phase 6. We have found that much of this behavior is due to the slow episodes. Based on these observational results, intervention experiments using CFSv2 are designed to better understand the impact of heating/cooling and to estimate mid-latitude response to Fast and Slow MJO episodes. The added heating experiments consist of 31 year reforecasts for December 1 initial conditions from CFS reanalysis (1980-2011) in which the identical MJO evolution of three-dimensional diabatic heating has been added, thus producing fast and slow MJO episodes with well-defined phase speeds. We will discuss the results of these experiments with a focus on understanding the role of phase speed and interference in setting up the response, and to understand the mechanisms that

  3. The AUSTRAL VLBI observing program

    Science.gov (United States)

    Plank, L.; Lovell, J. E. J.; McCallum, J. N.; Mayer, D.; Reynolds, C.; Quick, J.; Weston, S.; Titov, O.; Shabala, S. S.; Böhm, J.; Natusch, T.; Nickola, M.; Gulyaev, S.

    2017-07-01

    The AUSTRAL observing program was started in 2011, performing geodetic and astrometric very long baseline interferometry (VLBI) sessions using the new Australian AuScope VLBI antennas at Hobart, Katherine, and Yarragadee, with contribution from the Warkworth (New Zealand) 12 m and Hartebeesthoek (South Africa) 15 m antennas to make a southern hemisphere array of telescopes with similar design and capability. Designed in the style of the next-generation VLBI system, these small and fast antennas allow for a new way of observing, comprising higher data rates and more observations than the standard observing sessions coordinated by the International VLBI Service for Geodesy and Astrometry (IVS). In this contribution, the continuous development of the AUSTRAL sessions is described, leading to an improvement of the results in terms of baseline length repeatabilities by a factor of two since the start of this program. The focus is on the scheduling strategy and increased number of observations, aspects of automated operation, and data logistics, as well as results of the 151 AUSTRAL sessions performed so far. The high number of the AUSTRAL sessions makes them an important contributor to VLBI end-products, such as the terrestrial and celestial reference frames and Earth orientation parameters. We compare AUSTRAL results with other IVS sessions and discuss their suitability for the determination of baselines, station coordinates, source coordinates, and Earth orientation parameters.

  4. Comparison of performance of biodiesels of mahua oil and gingili oil in dual fuel engine

    Directory of Open Access Journals (Sweden)

    Nadar Kapilan N.

    2008-01-01

    Full Text Available In this work, an experimental work was carried out to compare the performance of biodiesels made from non edible mahua oil and edible gingili oil in dual fuel engine. A single cylinder diesel engine was modified to work in dual fuel mode and liquefied petroleum gas was used as primary fuel. Biodiesel was prepared by transesterification process and mahua oil methyl ester (MOME and gingili oil methyl ester (GOME were used as pilot fuels. The viscosity of MOME is slightly higher than GOME. The dual fuel engine runs smoothly with MOME and GOME. The test results show that the performance of the MOME is close to GOME, at the pilot fuel quantity of 0.45 kg/h and at the advanced injection timing of 30 deg bTDC. Also it is observed that the smoke, carbon monoxide and unburnt hydro carbon emissions of GOME lower than the MOME. But the GOME results in slightly higher NOx emissions. From the experimental results it is concluded that the biodiesel made from mahua oil can be used as a substitute for diesel in dual fuel engine.

  5. Infrared observations of AE Aquarii

    Science.gov (United States)

    Tanzi, E. G.; Chincarini, G.; Tarenghi, M.

    1981-01-01

    Broadband infrared observations of the cataclysmic variable AE Aquarii are reported. The observations were obtained in the J, H, K and L filters with the InSb photometer attached to the 1-m telescope of the European Southern Observatory. The infrared energy distribution observed from 0.35 to 3.5 microns for phase 0.5 suggests a spectral type of K5 V for the secondary and a distance to the system of approximately 70 pc if an absolute magnitude of 7.3 is assumed. Monitoring of the flux at 2.2 microns reveals a variability with an amplitude of approximately 0.3 magnitude over one third of the orbital period, the nature of which is under investigation.

  6. Incremental Observer Relative Data Extraction

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    2004-01-01

    The visual exploration of large databases calls for a tight coupling of database and visualization systems. Current visualization systems typically fetch all the data and organize it in a scene tree that is then used to render the visible data. For immersive data explorations in a Cave...... or a Panorama, where an observer is data space this approach is far from optimal. A more scalable approach is to make the observer-aware database system and to restrict the communication between the database and visualization systems to the relevant data. In this paper VR-tree, an extension of the R......-tree, is used to index visibility ranges of objects. We introduce a new operator for incremental Observer Relative data Extraction (iORDE). We propose the Volatile Access STructure (VAST), a lightweight main memory structure that is created on the fly and is maintained during visual data explorations. VAST...

  7. Observational tests of modified gravity

    International Nuclear Information System (INIS)

    Jain, Bhuvnesh; Zhang Pengjie

    2008-01-01

    Modifications of general relativity provide an alternative explanation to dark energy for the observed acceleration of the Universe. Modified gravity theories have richer observational consequences for large-scale structures than conventional dark energy models, in that different observables are not described by a single growth factor even in the linear regime. We examine the relationships between perturbations in the metric potentials, density and velocity fields, and discuss strategies for measuring them using gravitational lensing, galaxy cluster abundances, galaxy clustering/dynamics, and the integrated Sachs-Wolfe effect. We show how a broad class of gravity theories can be tested by combining these probes. A robust way to interpret observations is by constraining two key functions: the ratio of the two metric potentials, and the ratio of the gravitational 'constant' in the Poisson equation to Newton's constant. We also discuss quasilinear effects that carry signatures of gravity, such as through induced three-point correlations. Clustering of dark energy can mimic features of modified gravity theories and thus confuse the search for distinct signatures of such theories. It can produce pressure perturbations and anisotropic stresses, which break the equality between the two metric potentials even in general relativity. With these two extra degrees of freedom, can a clustered dark energy model mimic modified gravity models in all observational tests? We show with specific examples that observational constraints on both the metric potentials and density perturbations can in principle distinguish modifications of gravity from dark energy models. We compare our result with other recent studies that have slightly different assumptions (and apparently contradictory conclusions).

  8. Metrology and ionospheric observation standards

    Science.gov (United States)

    Panshin, Evgeniy; Minligareev, Vladimir; Pronin, Anton

    Accuracy and ionospheric observation validity are urgent trends nowadays. WMO, URSI and national metrological and standardisation services bring forward requirements and descriptions of the ionospheric observation means. Researches in the sphere of metrological and standardisation observation moved to the next level in the Russian Federation. Fedorov Institute of Applied Geophysics (IAG) is in charge of ionospheric observation in the Russian Federation and the National Technical Committee, TC-101 , which was set up on the base of IAG- of the standardisation in the sphere. TC-101 can be the platform for initiation of the core international committee in the network of ISO The new type of the ionosounde “Parus-A” is engineered, which is up to the national requirements. “Parus-A” calibration and test were conducted by National metrological Institute (NMI) -D.I. Mendeleyev Institute for Metrology (VNIIM), signed CIMP MRA in 1991. VNIIM is a basic NMI in the sphere of Space weather (including ionospheric observations), the founder of which was celebrated chemist and metrologist Dmitriy I. Mendeleyev. Tests and calibration were carried out for the 1st time throughout 50-year-history of ionosonde exploitation in Russia. The following metrological characteristics were tested: -measurement range of radiofrequency time delay 0.5-10 ms; -time measurement inaccuracy of radio- frequency pulse ±12mcs; -frequency range of radio impulse 1-20 MHz ; -measurement inaccuracy of radio impulse carrier frequency± 5KHz. For example, the sound impulse simulator that was built-in in the ionosounde was used for measurement range of radiofrequency time delay testing. The number of standards on different levels is developed. - “Ionospheric observation guidance”; - “The Earth ionosphere. Terms and definitions”.

  9. Solar polarimetry: observations and theories

    Energy Technology Data Exchange (ETDEWEB)

    Rees, D E [Sydney Univ. (Australia). Dept. of Applied Mathematics

    1982-01-01

    This review surveys some recent observations of polarization in solar spectral lines with emphasis on their theoretical interpretation. Observations of non-magnetic resonance line polarization offer a new approach to temperature and density modelling of the atmosphere. They also provide a basis for comparison in Hanle effect studies of weak magnetic fields on the solar disk. Measurements of the Hanle effect are being used to deduce vector magnetic fields in prominences. It is now feasible to try to infer the vector field distribution in an active region such as a sunspot from analysis of the stokes parameter profiles of a Zeeman split line.

  10. Observable Zitterbewegung in curved spacetimes

    Science.gov (United States)

    Kobakhidze, Archil; Manning, Adrian; Tureanu, Anca

    2016-06-01

    Zitterbewegung, as it was originally described by Schrödinger, is an unphysical, non-observable effect. We verify whether the effect can be observed in non-inertial reference frames/curved spacetimes, where the ambiguity in defining particle states results in a mixing of positive and negative frequency modes. We explicitly demonstrate that such a mixing is in fact necessary to obtain the correct classical value for a particle's velocity in a uniformly accelerated reference frame, whereas in cosmological spacetime a particle does indeed exhibit Zitterbewegung.

  11. Observable Zitterbewegung in curved spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Kobakhidze, Archil, E-mail: archilk@physics.usyd.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Sydney, NSW 2006 (Australia); Manning, Adrian, E-mail: a.manning@physics.usyd.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Sydney, NSW 2006 (Australia); Tureanu, Anca, E-mail: anca.tureanu@helsinki.fi [Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki (Finland)

    2016-06-10

    Zitterbewegung, as it was originally described by Schrödinger, is an unphysical, non-observable effect. We verify whether the effect can be observed in non-inertial reference frames/curved spacetimes, where the ambiguity in defining particle states results in a mixing of positive and negative frequency modes. We explicitly demonstrate that such a mixing is in fact necessary to obtain the correct classical value for a particle's velocity in a uniformly accelerated reference frame, whereas in cosmological spacetime a particle does indeed exhibit Zitterbewegung.

  12. Ground level cosmic ray observations

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, S.A. [Tata Institute of Fundamental Research, Bombay (International Commission on Radiation Units and Measurements); Grimani, C.; Brunetti, M.T.; Codino, A. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Papini, P.; Massimo Brancaccio, F.; Piccardi, S. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Basini, G.; Bongiorno, F. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Hof, M. [Siegen Univ. (Germany). Fachbereich Physik

    1995-09-01

    Cosmic rays at ground level have been collected using the NMSU/Wizard - MASS2 instrument. The 17-hr observation run was made on September 9. 1991 in Fort Sumner, New Mexico, Usa. Fort Sumner is located at 1270 meters a.s.l., corresponding to an atmospheric depth of about 887 g/cm{sup 2}. The geomagnetic cutoff is 4.5 GV/c. The charge ratio of positive and negative muons and the proton to muon ratio have been determined. These observations will also be compared with data collected at a higher latitude using the same basic apparatus.

  13. Automated processing of pulsar observations

    Energy Technology Data Exchange (ETDEWEB)

    Byzhlov, B.V.; Ivanova, V.V.; Izvekova, V.A.; Kuz' min, A.D.; Kuz' min, Yu.P.; Malofeev, V.M.; Popov, Yu.M.; Solomin, N.S.; Shabanova, T.V.; Shitov, Yu.P.

    1977-01-01

    Digital computer technology which processes observation results in a real time scale is used on meter-range radiotelescopes DKR-100 of the USSR Academy of Sciences Physics Institute and the BSA of the Physics Institute to study pulsars. A method which calls for the accumulation of impulses with preliminary compensation of pulsar dispersion in a broad band is used to increase sensitivity and resolution capability. Known pulsars are studied with the aid of a ''neuron'' type analyzer. A system for processing observations in an on-line set-up was created on the M-6000 computer for seeking unknown pulsars. 8 figures, 1 table, references.

  14. Turbulence Heating ObserveR – satellite mission proposal

    Czech Academy of Sciences Publication Activity Database

    Vaivads, A.; Retinò, A.; Souček, Jan; Khotyaintsev, Y. V.; Valentini, F.; Escoubet, C. P.; Alexandrova, O.; André, M.; Bale, S. D.; Balikhin, M.; Burgess, D.; Camporeale, E.; Caprioli, D.; Chen, C. H. K.; Clacey, E.; Cully, C. M.; Keyser de, J.; Eastwood, J. P.; Fazakerley, A. N.; Eriksson, S.; Goldstein, M. L.; Graham, D. B.; Haaland, S.; Hoshino, M.; Ji, H.; Karimabadi, H.; Kucharek, H.; Lavraud, B.; Marcucci, F.; Matthaeus, W. H.; Moore, T. E.; Nakamura, R.; Narita, Y.; Němeček, Z.; Norgren, C.; Opgenoorth, H.; Palmroth, M.; Perrone, D.; Pinçon, J.-L.; Rathsman, P.; Rothkaehl, H.; Sahraoui, F.; Servidio, S.; Sorriso-Valvo, L.; Vainio, L.; Vörös, Z.; Wimmer-Schweingruber, R. F.

    2016-01-01

    Roč. 82, č. 5 (2016), 905820501/1-905820501/16 ISSN 0022-3778 Institutional support: RVO:68378289 Keywords : plasma heating * plasma properties * space plasma physics Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.160, year: 2016 https://www.cambridge.org/core/journals/journal-of-plasma-physics/article/div-classtitleturbulence-heating-observer-satellite-mission-proposaldiv/01BB69B09206CE04C48BEDA8F24ED33C/core-reader

  15. Trends in Classroom Observation Scores

    Science.gov (United States)

    Casabianca, Jodi M.; Lockwood, J. R.; McCaffrey, Daniel F.

    2015-01-01

    Observations and ratings of classroom teaching and interactions collected over time are susceptible to trends in both the quality of instruction and rater behavior. These trends have potential implications for inferences about teaching and for study design. We use scores on the Classroom Assessment Scoring System-Secondary (CLASS-S) protocol from…

  16. Observed spectral features of dust

    International Nuclear Information System (INIS)

    Willner, S.P.

    1984-01-01

    The author concentrates on the observed properties of dust spectral features. Identifications, based on laboratory data, are given whenever plausible ones exist. There are a very large number of papers in the literature of even such a young field as infrared spectroscopy, and therefore the author refers only to the most recent paper on a topic or to another review. (Auth.)

  17. Observation Methods on Water Ecosystems

    International Nuclear Information System (INIS)

    Gulashvili, Z.

    2005-01-01

    In present work current situation of hydrometric network on the rivers of Georgia and division of observational stations, categorized according to economico-ecological principles, which study water hydrometric and physico-chemical characteristics, are considered. The necessity of searching of new methodology of taking hydrometric measurements and developing optimal plan of allocation of the stations, based on the modern standards, is proved. (author)

  18. Ultraviolet observations of AM Herculis

    International Nuclear Information System (INIS)

    Tanzi, E.G.; Treves, A.; Milan Univ.; Sandford, M.C.W.; Willis, A.J.; Wilson, R.

    1980-01-01

    Seven ultraviolet spectra (1100-3200 Angstroem) of AM Her were obtained with the low resolution spectrometer of the IUE satellite. Strong emission features appear superimposed on a well defined continuum which is well fitted by a Fsub(lambda) D lambda -2 law. The observations are compared with the expectations from models of the source. (orig.) 891 WL/orig. 892 HIS

  19. Observational constraints on interstellar chemistry

    International Nuclear Information System (INIS)

    Winnewisser, G.

    1984-01-01

    The author points out presently existing observational constraints in the detection of interstellar molecular species and the limits they may cast on our knowledge of interstellar chemistry. The constraints which arise from the molecular side are summarised and some technical difficulties encountered in detecting new species are discussed. Some implications for our understanding of molecular formation processes are considered. (Auth.)

  20. Infrared observations of planetary atmospheres

    International Nuclear Information System (INIS)

    Orton, G.S.; Baines, K.H.; Bergstralh, J.T.

    1988-01-01

    The goal of this research in to obtain infrared data on planetary atmospheres which provide information on several aspects of structure and composition. Observations include direct mission real-time support as well as baseline monitoring preceding mission encounters. Besides providing a broader information context for spacecraft experiment data analysis, observations will provide the quantitative data base required for designing optimum remote sensing sequences and evaluating competing science priorities. In the past year, thermal images of Jupiter and Saturn were made near their oppositions in order to monitor long-term changes in their atmospheres. Infrared images of the Jovian polar stratospheric hot spots were made with IUE observations of auroral emissions. An exploratory 5-micrometer spectrum of Uranus was reduced and accepted for publication. An analysis of time-variability of temperature and cloud properties of the Jovian atomsphere was made. Development of geometric reduction programs for imaging data was initiated for the sun workstation. Near-infrared imaging observations of Jupiter were reduced and a preliminary analysis of cloud properties made. The first images of the full disk of Jupiter with a near-infrared array camera were acquired. Narrow-band (10/cm) images of Jupiter and Saturn were obtained with acousto-optical filters

  1. Observational modeling of topological spaces

    International Nuclear Information System (INIS)

    Molaei, M.R.

    2009-01-01

    In this paper a model for a multi-dimensional observer by using of the fuzzy theory is presented. Relative form of Tychonoff theorem is proved. The notion of topological entropy is extended. The persistence of relative topological entropy under relative conjugate relation is proved.

  2. Observing Two Important Teaching Variables.

    Science.gov (United States)

    Gustafson, John A.

    1986-01-01

    Two behaviors essential to good teaching, teacher expectation and teacher flexibility, have been incorporated into the observation system used in the student teacher program at the University of New Mexico. The importance of these behaviors in teaching and in evaluating student teachers is discussed. (MT)

  3. Overall whistler observation by RTWA

    International Nuclear Information System (INIS)

    Okada, Toshimi; Iwai, Akira; Otsu, Jinsuke; Hayakawa, Masashi

    1978-01-01

    Both time- and space-wise characteristics of occurrence of whistlers were studied by general ground observations, i.e. routine observation and combined RTWA (real time whistler analyzer) and direction search. Thereby the basic data of the position, move and lifetime of duct were obtained in an attempt to look into the processes of duct formation and disappearance. Observations were made for six months from November, 1977, to April, 1978, at the Moshiri Observatory at magnetic latitude of 34.5 deg. N, Hokkaido. The apparatus operated well as expected, providing useful data. During the period, a relatively large magnetic storm of ΣK = 40 occurred on January 3, so that intriguing whistler phenomena were able to be observed. The lifetime of ducts permitting effective whistler trap differs widely. Considering duct construction, the enhancement factor of each duct is excited to different value in the formation process. The formation process is followed by decay process, and the duration falling to minimum enhancement for whistler trapping differs individually. (J.P.N.)

  4. Observable cosmology and cosmological models

    International Nuclear Information System (INIS)

    Kardashev, N.S.; Lukash, V.N.; Novikov, I.D.

    1987-01-01

    Modern state of observation cosmology is briefly discussed. Among other things, a problem, related to Hibble constant and slowdown constant determining is considered. Within ''pancake'' theory hot (neutrino) cosmological model explains well the large-scale structure of the Universe, but does not explain the galaxy formation. A cold cosmological model explains well light object formation, but contradicts data on large-scale structure

  5. Observing Galaxy Mergers in Simulations

    Science.gov (United States)

    Snyder, Gregory

    2018-01-01

    I will describe results on mergers and morphology of distant galaxies. By mock-observing 3D cosmological simulations, we aim to contrast theory with data, design better diagnostics of physical processes, and examine unexpected signatures of galaxy formation. Recently, we conducted mock surveys of the Illustris Simulations to learn how mergers would appear in deep HST and JWST surveys. With this approach, we reconciled merger rates estimated using observed close galaxy pairs with intrinsic merger rates predicted by theory. This implies that the merger-pair observability time is probably shorter in the early universe, and therefore that major mergers are more common than implied by the simplest arguments. Further, we show that disturbance-based diagnostics of late-stage mergers can be improved significantly by combining multi-dimensional image information with simulated merger identifications to train automated classifiers. We then apply these classifiers to real measurements from the CANDELS fields, recovering a merger fraction increasing with redshift in broad agreement with pair fractions and simulations, and with statistical errors smaller by a factor of two than classical morphology estimators. This emphasizes the importance of using robust training sets, including cosmological simulations and multidimensional data, for interpreting observed processes in galaxy evolution.

  6. Kepler observations of Am stars

    DEFF Research Database (Denmark)

    Balona, L. A.; Ripepi, V.; Cantanzaro, G.

    2011-01-01

    on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fondación Galileo Galilei of the Istituto Nazionale di Astrofisica (INAF), at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, and with the Mercator...

  7. Baryon observables and color confinement

    International Nuclear Information System (INIS)

    Jackson, A.D.

    1987-01-01

    Calculations of baryon observables within the framework of the chiral bag model are reviewed. The results of such calculations are found to be remarkably insensitive to the radius of color confinement and indicate the difficulty of finding unambiguous evidence for quarks in nuclei. 13 refs.; 5 figs

  8. Indirect Reciprocity under Incomplete Observation

    Science.gov (United States)

    Nakamura, Mitsuhiro; Masuda, Naoki

    2011-01-01

    Indirect reciprocity, in which individuals help others with a good reputation but not those with a bad reputation, is a mechanism for cooperation in social dilemma situations when individuals do not repeatedly interact with the same partners. In a relatively large society where indirect reciprocity is relevant, individuals may not know each other's reputation even indirectly. Previous studies investigated the situations where individuals playing the game have to determine the action possibly without knowing others' reputations. Nevertheless, the possibility that observers of the game, who generate the reputation of the interacting players, assign reputations without complete information about them has been neglected. Because an individual acts as an interacting player and as an observer on different occasions if indirect reciprocity is endogenously sustained in a society, the incompleteness of information may affect either role. We examine the game of indirect reciprocity when the reputations of players are not necessarily known to observers and to interacting players. We find that the trustful discriminator, which cooperates with good and unknown players and defects against bad players, realizes cooperative societies under seven social norms. Among the seven social norms, three of the four suspicious norms under which cooperation (defection) to unknown players leads to a good (bad) reputation enable cooperation down to a relatively small observation probability. In contrast, the three trustful norms under which both cooperation and defection to unknown players lead to a good reputation are relatively efficient. PMID:21829335

  9. [Observation of critically ill patients

    DEFF Research Database (Denmark)

    Fuhrmann, L.; Hesselfeldt, R.; Lippert, A.

    2009-01-01

    . MATERIAL AND METHODS: Prospective observational study at Herlev Hospital, Copenhagen, Denmark. Study personnel measured vital signs on all patients present on five wards during the evening and night and interviewed nursing staff about patients with abnormal vital signs. Subsequently, patient records were...

  10. Observation of an antimatter hypernucleus

    NARCIS (Netherlands)

    Abelev, B.I.; Braidot, E; Mischke, A.; Peitzmann, T.; van Leeuwen, M.

    2010-01-01

    Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons—comprising an antiproton, an antineutron, and an

  11. Mesopause Jumps: Observations and Explanation

    Science.gov (United States)

    Luebken, F. J.; Becker, E.; Höffner, J.; Viehl, T. P.; Latteck, R.

    2017-12-01

    Recent high resolution temperature measurements by resonance lidar at Davis (69°S) occasionally showed a sudden mesopause altitude increase by 5km and an associated mesopause temperature decrease by 10K. We present further observations which are closely related to this `mesopause jump', namely the increase of mean height of polar mesospheric summer echoes (PMSE) observed by a VHF radar, very strong westward winds in the upper mesosphere measured by an MF radar, and relatively large eastward winds in the stratosphere taken from reanalysis. We compare to similar observations in the Northern Hemisphere, namely at ALOMAR (69°N) where such mesopause jumps have never been observed. We present a detailed explanation of mesopause jumps. They occur only when stratospheric winds are moderately eastward and mesospheric winds are very large (westward). Under these conditions, gravity waves with comparatively large eastward phase speeds can pass the stratosphere and propagate to the lower thermosphere because their vertical wavelengths in the mesosphere are rather large which implies reduced dynamical stability. When finally breaking in the lower thermosphere, these waves drive an enhanced residual circulation that causes a cold and high-altitude mesopause. The conditions for a mesopause jump occur only in the Southern Hemisphere (SH) and are associated with the late breakdown of the polar vortex.Mesopause jumps are primarily, but not only, observed prior and close to solstice. We also show that during the onset of PMSE in the SH, stratospheric zonal winds are still eastward (up to 30m/s), and that the onset is not closely related to the transition of the stratospheric circulation.

  12. IUE observations of V Sagittae

    Science.gov (United States)

    Koch, R. H.; Corcoran, M. F.; Holenstein, B. D.; Mccluskey, G. E., Jr.

    1986-01-01

    Observations of the nova-like variable V Sge are discussed, and the ground-based light curve is analyzed, compensating for the component interaction effect. Low-dispersion IUE spectra indicate that interstellar reddening is smaller than suggested from visible-band observations. The UV and visible continuum are modeled by a He-rich model and by a simple accretion disk, and the UV spectrum emission lines are used to determine ionization temperatures and a lower N(e) limit. The present data are consistent with the picture of the companion to the He star being embedded in an accretion disk, with the disk being large (of dimension comparable to that of the embedding Roche lobe as a result of vigorous mass transfer) at the time of the ground-based data, and with the disk having been diminished to a radius of the order of 200 times of the neutron star, at the time of the IUE spectra.

  13. Moving Observer Support for Databases

    DEFF Research Database (Denmark)

    Bukauskas, Linas

    Interactive visual data explorations impose rigid requirements on database and visualization systems. Systems that visualize huge amounts of data tend to request large amounts of memory resources and heavily use the CPU to process and visualize data. Current systems employ a loosely coupled...... architecture to exchange data between database and visualization. Thus, the interaction of the visualizer and the database is kept to the minimum, which most often leads to superfluous data being passed from database to visualizer. This Ph.D. thesis presents a novel tight coupling of database and visualizer....... The thesis discusses the VR-tree, an extension of the R-tree that enables observer relative data extraction. To support incremental observer position relative data extraction the thesis proposes the Volatile Access Structure (VAST). VAST is a main memory structure that caches nodes of the VR-tree. VAST...

  14. Observational homogeneity of the Universe

    International Nuclear Information System (INIS)

    Bonnor, W.B.; Ellis, G.F.R.

    1986-01-01

    A new approach to observational homogeneity is presented. The observation that stars and galaxies in distant regions appear similar to those nearby may be taken to imply that matter has had a similar thermodynamic history in widely separated parts of the Universe (the Postulate of Uniform Thermal Histories, or PUTH). The supposition is now made that similar thermodynamic histories imply similar dynamical histories. Then the distant apparent similarity is evidence for spatial homogeneity of the Universe. General Relativity is used to test this idea, taking a perfect fluid model and implementing PUTH by the condition that the density and entropy per baryon shall be the same function of the proper time along all galaxy world-lines. (author)

  15. Interpretation of coronal synoptic observations

    International Nuclear Information System (INIS)

    Munro, R.H.; Fisher, R.R.

    1986-01-01

    Three-dimensional reconstruction techniques used to determine coronal density distributions from synoptic data are complicated and time consuming to employ. Current techniques also assume time invariant structures and thus mix both temporal and spatial variations present in the coronal data. The observed distribution of polarized brightness, pB, and brightness, B, of coronal features observed either at eclipses or with coronagraphs depends upon both the three-dimensional distribution of electron density within the structure and the location of the feature with respect to the plane-of-the-sky. By theoretically studying the signature of various coronal structures as they would appear during a limb transit, it is possible to recognize these patterns in real synoptic data as well as estimate temporal evolutionary effects

  16. INTEGRAL Observations of GW170104

    DEFF Research Database (Denmark)

    Savchenko, V.; Ferrigno, C.; Bozzo, E.

    2017-01-01

    We used data from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) to set upper limits on the γ-ray and hard X-ray prompt emission associated with the gravitational-wave event GW170104, discovered by the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo collaboration...... the INTEGRAL observations range from F γ = 1.9 × 10−7 erg cm−2 to F γ = 10−6 erg cm−2 (75 keV–2 MeV energy range). This translates into a ratio between the prompt energy released in γ-rays along the direction to the observer and the gravitational-wave energy of E γ /E GW

  17. IRAS observations of starburst galaxies

    International Nuclear Information System (INIS)

    Sekiguchi, K.

    1987-01-01

    Far infrared properties of Starburst galaxies were analyzed using IRAS observations at 25, 60, and 100 micrometers. Seventy-nine of 102 Starburst galaxies from the list of Balzano were detected. These galaxies have high IR luminosities of up to a few 10 to the 12th power L sub 0 and concentrate in a small area of the IR color - color diagram. The IR power law spectral indices, alpha, lie within the ranges -2.5 < alpha(60,25)< -1.5 and -1.5 < alpha(100,60)< 0. These observed indices can be interpreted in terms of a cold disk component and a warm component. More than 80% of the 60 micrometer emission comes from the warm component. The fraction of the 60 micrometer emission attributable to the warm component can be used as an activity indicator

  18. Observation of an antimatter hypernucleus.

    Science.gov (United States)

    Abelev, B I; Aggarwal, M M; Ahammed, Z; Alakhverdyants, A V; Alekseev, I; Anderson, B D; Arkhipkin, D; Averichev, G S; Balewski, J; Barnby, L S; Baumgart, S; Beavis, D R; Bellwied, R; Betancourt, M J; Betts, R R; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Biritz, B; Bland, L C; Bonner, B E; Bouchet, J; Braidot, E; Brandin, A V; Bridgeman, A; Bruna, E; Bueltmann, S; Bunzarov, I; Burton, T P; Cai, X Z; Caines, H; Calderon, M; Catu, O; Cebra, D; Cendejas, R; Cervantes, M C; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Choi, K E; Christie, W; Chung, P; Clarke, R F; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Das, D; Dash, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; DePhillips, M; Derevschikov, A A; Derradi de Souza, R; Didenko, L; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Dunlop, J C; Dutta Mazumdar, M R; Efimov, L G; Elhalhuli, E; Elnimr, M; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Eun, L; Evdokimov, O; Fachini, P; Fatemi, R; Fedorisin, J; Fersch, R G; Filip, P; Finch, E; Fine, V; Fisyak, Y; Gagliardi, C A; Gangadharan, D R; Ganti, M S; Garcia-Solis, E J; Geromitsos, A; Geurts, F; Ghazikhanian, V; Ghosh, P; Gorbunov, Y N; Gordon, A; Grebenyuk, O; Grosnick, D; Grube, B; Guertin, S M; Gupta, A; Gupta, N; Guryn, W; Haag, B; Hamed, A; Han, L-X; Harris, J W; Hays-Wehle, J P; Heinz, M; Heppelmann, S; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Hofman, D J; Hollis, R S; Huang, B; Huang, H Z; Humanic, T J; Huo, L; Igo, G; Iordanova, A; Jacobs, P; Jacobs, W W; Jakl, P; Jena, C; Jin, F; Jones, C L; Jones, P G; Joseph, J; Judd, E G; Kabana, S; Kajimoto, K; Kang, K; Kapitan, J; Kauder, K; Keane, D; Kechechyan, A; Kettler, D; Kikola, D P; Kiryluk, J; Kisiel, A; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kollegger, T; Konzer, J; Kopytine, M; Koralt, I; Koroleva, L; Korsch, W; Kotchenda, L; Kouchpil, V; Kravtsov, P; Krueger, K; Krus, M; Kumar, L; Kurnadi, P; Lamont, M A C; Landgraf, J M; LaPointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lee, J H; Leight, W; Levine, M J; Li, C; Li, L; Li, N; Li, W; Li, X; Li, Y; Li, Z; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Luo, X; Ma, G L; Ma, Y G; Mahapatra, D P; Majka, R; Mal, O I; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Masui, H; Matis, H S; Matulenko, Yu A; McDonald, D; McShane, T S; Meschanin, A; Milner, R; Minaev, N G; Mioduszewski, S; Mischke, A; Mitrovski, M K; Mohanty, B; Mondal, M M; Morozov, B; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Ng, M J; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okada, H; Okorokov, V; Olson, D; Pachr, M; Page, B S; Pal, S K; Pandit, Y; Panebratsev, Y; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Pile, P; Planinic, M; Ploskon, M A; Pluta, J; Plyku, D; Poljak, N; Poskanzer, A M; Potukuchi, B V K S; Powell, C B; Prindle, D; Pruneau, C; Pruthi, N K; Pujahari, P R; Putschke, J; Qiu, H; Raniwala, R; Raniwala, S; Ray, R L; Redwine, R; Reed, R; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Sahoo, R; Sakai, S; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sangaline, E; Schambach, J; Scharenberg, R P; Schmitz, N; Schuster, T R; Seele, J; Seger, J; Selyuzhenkov, I; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shi, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, T D S; Staszak, D; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarini, L H; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Timoshenko, S; Tlusty, D; Tokarev, M; Trainor, T A; Tram, V N; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van Leeuwen, M; van Nieuwenhuizen, G; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Videbaek, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Walker, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, Q; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wingfield, E; Wissink, S W; Witt, R; Wu, Y; Xie, W; Xu, H; Xu, N; Xu, Q H; Xu, W; Xu, Y; Xu, Z; Xue, L; Yang, Y; Yepes, P; Yip, K; Yoo, I-K; Yue, Q; Zawisza, M; Zbroszczyk, H; Zhan, W; Zhang, J; Zhang, S; Zhang, W M; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, J; Zhong, C; Zhou, J; Zhou, W; Zhu, X; Zhu, Y H; Zoulkarneev, R; Zoulkarneeva, Y

    2010-04-02

    Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons--comprising an antiproton, an antineutron, and an antilambda hyperon--produced by colliding gold nuclei at high energy. Our analysis yields 70 +/- 17 antihypertritons ((Lambda)(3)-H) and 157 +/- 30 hypertritons (Lambda3H). The measured yields of Lambda3H ((Lambda)(3)-H) and 3He (3He) are similar, suggesting an equilibrium in coordinate and momentum space populations of up, down, and strange quarks and antiquarks, unlike the pattern observed at lower collision energies. The production and properties of antinuclei, and of nuclei containing strange quarks, have implications spanning nuclear and particle physics, astrophysics, and cosmology.

  19. Observing urban forests in Australia

    Science.gov (United States)

    E.G. McPherson

    2009-01-01

    From February 13 to 28, 2009 I had the good fortune of visiting Australia, and touring urban forests in Sydney, Canberra, Brisbane, and Melbourne. My visits were only a day or two in each city, so in no case did I get an in-depth view of the urban forest resource or its management. The following observations are based on rather superficial field assessments and brief...

  20. How to observe the invisible

    International Nuclear Information System (INIS)

    Destefanis, G.; Peyret, O.; Darier, P.

    2000-01-01

    The observation of events and objects by images resulted from the detection of invisible radiation (infrared, X and gamma ray) emitted from these objects, is now more possible. This is mainly due to the progress in the microelectronics and semiconductors devices. With these advanced devices, it is possible to manufacture cameras with TV display size image and high resolution, which have many applications in military, medical and industrial sectors. (author)

  1. Observation Predicates in Flow Logic

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Sun, Hongyan

    2003-01-01

    in such a way that the hard constraints are satisfi ed exactly when the observation predicates report no violations. The development is carried out in a large fragment of a first order logic with negation and also takes care of the transformations necessary in order to adhere to the stratification restrictions...... inherent in Alternation-free Least Fixed Point Logic and similar formalisms such as Datalog....

  2. Roentgenographical observation of impacted teeth

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hi Sup; Ahn, Hyung Kyu [College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1972-11-15

    The author observed on the impacted teeth of 11 cases from 484 full-mouth roentgenograms of dental students S.N.U. (except 3rd molar). These studies are very significant in oral surgery and orthodontic problems. Most of the impacted teeth are located in maxilla and among them 7 cases are impacted central incisors the others are lateral incisors, and cuspids. The form of impactions are vertical, horizontal and inverted positions.

  3. Observational constraints on undulant cosmologies

    Energy Technology Data Exchange (ETDEWEB)

    Barenboim, Gabriela; /Valencia U.; Mena Requejo, Olga; Quigg, Chris; /Fermilab

    2005-10-01

    In an undulant universe, cosmic expansion is characterized by alternating periods of acceleration and deceleration. We examine cosmologies in which the dark-energy equation of state varies periodically with the number of e-foldings of the scale factor of the universe, and use observations to constrain the frequency of oscillation. We find a tension between a forceful response to the cosmic coincidence problem and the standard treatment of structure formation.

  4. UAS Developments Supporting Wildfire Observations

    Science.gov (United States)

    Ambrosia, V. G.; Dahlgren, R. P.; Watts, A.; Reynolds, K. W.; Ball, T.

    2014-12-01

    Wildfires are regularly occurring emergency events that threaten life, property, and natural resources in every U.S. State and many countries around the world. Despite projections that $1.8 billion will be spent by U.S. Federal agencies alone on wildfires in 2014, the decades-long trend of increasing fire size, severity, and cost is expected to continue. Furthermore, the enormous potential for UAS (and concomitant sensor systems) to serve as geospatial intelligence tools to improve the safety and effectiveness of fire management, and our ability to forecast fire and smoke movements, remains barely tapped. Although orbital sensor assets are can provide the geospatial extent of wildfires, generally those resources are limited in use due to their spatial and temporal resolution limitations. These two critical elements make orbital assets of limited utility for tactical, real-time wildfire management, or for continuous scientific analysis of the temporal dynamics related to fire energy release rates and plume concentrations that vary significantly thru a fire's progression. Large UAS platforms and sensors can and have been used to monitor wildfire events at improved temporal, spatial and radiometric scales, but more focus is being placed on the use of small UAS (sUAS) and sensors to support wildfire observation strategies. The use of sUAS is therefore more critical for TACTICAL management purposes, rather than strategic observations, where small-scale fire developments are critical to understand. This paper will highlight the historical development and use of UAS for fire observations, as well as the current shift in focus to smaller, more affordable UAS for more rapid integration into operational use on wildfire events to support tactical observation strategies, and support wildfire science measurement inprovements.

  5. Distracted Biking: An Observational Study.

    Science.gov (United States)

    Wolfe, Elizabeth Suzanne; Arabian, Sandra Strack; Breeze, Janis L; Salzler, Matthew J

    2016-01-01

    Commuting via bicycle is a very popular mode of transportation in the Northeastern United States. Boston, MA, has seen a rapid increase in bicycle ridership over the past decade, which has raised concerns and awareness about bicycle safety. An emerging topic in this field is distracted bicycle riding. This study was conducted to provide descriptive data on the prevalence and type of distracted bicycling in Boston at different times of day. This was a cross-sectional study in which observers tallied bicyclists at 4 high traffic intersections in Boston during various peak commuting hours for 2 types of distractions: auditory (earbuds/phones in or on ears), and visual/tactile (electronic device or other object in hand). Nineteen hundred seventy-four bicyclists were observed and 615 (31.2%), 95% CI [29, 33%], were distracted. Of those observed, auditory distractions were the most common (N = 349; 17.7%), 95% CI [16, 19], p = .0003, followed by visual/tactile distractions (N = 266; 13.5%), 95% CI [12, 15]. The highest proportion (40.7%), 95% CI [35, 46], of distracted bicyclists was observed during the midday commute (between 13:30 and 15:00). Distracted bicycling is a prevalent safety concern in the city of Boston, as almost a third of all bicyclists exhibited distracted behavior. Education and public awareness campaigns should be designed to decrease distracted bicycling behaviors and promote bicycle safety in Boston. An awareness of the prevalence of distracted biking can be utilized to promote bicycle safety campaigns dedicated to decreasing distracted bicycling and to provide a baseline against which improvements can be measured.

  6. Complexity of infimal observable superlanguages

    Czech Academy of Sciences Publication Activity Database

    Masopust, Tomáš

    2018-01-01

    Roč. 63, č. 1 (2018), s. 249-254 ISSN 0018-9286 Institutional support: RVO:67985840 Keywords : discrete event systems * observable language * complexity Subject RIV: BA - General Mathematics OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 4.270, year: 2016 http://ieeexplore.ieee.org/document/7962165/

  7. Observational cinema and embodied vision

    OpenAIRE

    Uslu, Ayşe

    2011-01-01

    Ankara : The Department of Communication and Design, İhsan Doğramacı Bilkent University, 2011. Thesis (Master's) -- Bilkent University, 2011. Includes bibliographical references leaves 87-89. The aim of this study is to discuss the notion of embodiment in respect of Merleau Ponty's philosophy of phenomenology and its relation to observational cinema. For this aim, this thesis dwells on the embodied nature of perception of seeing and its relation to epistemological approaches...

  8. IRAS observations of the Pleiades

    Science.gov (United States)

    Cox, P.; he ultraviolet.

    1987-01-01

    The Infrared Astronomy Satellite (IRAS) observations of the Pleiades region are reported. The data show large flux densities at 12 and 25 microns, extended over the optical nebulosity. This strong excess emission, implying temperatures of a few hundred degrees Kelvin, indicates a population of very small grains in the Pleiades. It is suggested that these grains are similar to the small grains needed to explain the surface brightness measurements made in the ultraviolet.

  9. IRAS observations of the Pleiades

    International Nuclear Information System (INIS)

    Cox, P.; Leene, A.

    1987-01-01

    The Infrared Astronomy Satellite (IRAS) observations of the Pleiades region are reported. The data show large flux densities at 12 and 25 microns, extended over the optical nebulosity. This strong excess emission, implying temperatures of a few hundred degrees Kelvin, indicates a population of very small grains in the Pleiades. It is suggested that these grains are similar to the small grains needed to explain the surface brightness measurements made in the ultraviolet

  10. Solar radio observations and interpretations

    International Nuclear Information System (INIS)

    Rosenberg, H.

    1976-01-01

    The recent solar radio observations related to flares are reviewed for the frequency range of a few kilohertz to several gigahertz. The analysis of the radio data leads to boundary conditions on the acceleration processes which are responsible for the fast particles which cause radio emission. The role and cause of plasma turbulence at the plasma-frequency and at much lower frequencies is discussed in relation to the acceleration processes and the radio emission mechanisms for the various radio bursts. (author)

  11. Infrared spectral observation of stars

    International Nuclear Information System (INIS)

    Komaki, Kazuo; Kodaira, Keiichi; Tanaka, W.; Suemoto, Zenzaburo

    1976-01-01

    The atmosphere of fixed stars must be studied in a supplementary way with both observation and theory. In case of low-temperature stars, however, there are difficulties in both two aspects. Under the situation, the multi-color measurement of the near infrared region was performed with a balloon telescope BAT-1 (the aperture of 15 cm) on June 17 and 18, 1975. For the red supergiant αSco, the data of light measurement was able to be obtained. (mori, K.)

  12. Astrometric Observation of Delta Cepheus

    Science.gov (United States)

    Warren, Naomi; Wilson, Betsie; Estrada, Chris; Crisafi, Kim; King, Jackie; Jones, Stephany; Salam, Akash; Warren, Glenn; Collins, S. Jananne; Genet, Russell

    2012-04-01

    Members of a Cuesta College astronomy research seminar used a manually-controlled 10-inch Newtonian Reflector telescope to determine the separation and position angle of the binary star Delta Cepheus. It was observed on the night of Saturday, October 29, 2011, at Star Hill in Santa Margarita, California. Their values of 40.2 arc seconds and 192.4 degrees were similar to those reported in the WDS (1910).

  13. Electron cloud observations: a retrospective

    International Nuclear Information System (INIS)

    Harkay, K.

    2004-01-01

    A growing number of observations of electron cloud effects (ECEs) have been reported in positron and proton rings. Low-energy, background electrons ubiquitous in high-intensity particle accelerators. Amplification of electron cloud (EC) can occur under certain operating conditions, potentially giving rise to numerous effects that can seriously degrade accelerator performance. EC observations and diagnostics have contributed to a better understanding of ECEs, in particular, details of beam-induced multipacting and cloud saturation effects. Such experimental results can be used to provide realistic limits on key input parameters for modeling efforts and analytical calculations to improve prediction capability. Electron cloud effects are increasingly important phenomena in high luminosity, high brightness, or high intensity machines - Colliders, Storage rings, Damping rings, Heavy ion beams. EC generation and instability modeling increasingly complex and benchmarked against in situ data: (delta), (delta) 0 , photon reflectivity, and SE energy distributions important. Surface conditioning and use of solenoidal windings in field-free regions are successful cures: will they be enough? What are new observations and how do they contribute to body of work and understanding physics of EC?

  14. Odds of observing the multiverse

    International Nuclear Information System (INIS)

    Dahlen, A.

    2010-01-01

    Eternal inflation predicts that our observable universe lies within a bubble (or pocket universe) embedded in a volume of inflating space. The interior of the bubble undergoes inflation and standard cosmology, while the bubble walls expand outward and collide with other neighboring bubbles. The collisions provide either an opportunity to make a direct observation of the multiverse or, if they produce unacceptable anisotropy, a threat to inflationary theory. The probability of an observer in our bubble detecting the effects of collisions has an absolute upper bound set by the odds of being in the part of our bubble that lies in the forward light cone of a collision; in the case of collisions with bubbles of identical vacua, this bound is given by the bubble nucleation rate times (H O /H I ) 2 , where H O is the Hubble scale outside the bubbles and H I is the scale of the second round of inflation that occurs inside our bubble. Similar results were obtained by Freigovel et al. using a different method for the case of collisions with bubbles of much larger cosmological constant; here, it is shown to hold in the case of collisions with identical bubbles as well.

  15. Spectrophotometric observations of symbiotic stars

    International Nuclear Information System (INIS)

    Ipatov, A.P.; Yudin, B.F.

    1985-01-01

    The data of spectrophotometric observations of symbiotic stars Z And, AX Per, CI Cyg, BF Cyg, YY Her, V 443 Her, AG Dra, AG Peg, AS 296, EG And, V 1016 Cyg, and HM Sge are presented. The spectral range of observations is 3300-7500 A, resolution is 50 A. The data obtained allowed to reveal specific characteristics inherent to the radiation of symbiotic stars and to estimate the parameters of their individual components. Analysis of the spectra of symbiotic stars in the range of 1300-7500 A wavelengths suggests a hypothesis, according to which a hot source in the Rayleigh - Jeans spectral range has a less steep inclination in the energy distribution, than a black-body one. A disk, formed during cold star substance accretion through an internal Lagrangian point onto a denser component of the system, can play the role of the source. In this case one manages to obtain the energy distribution in the symbiotic star spectrum consistent with the observed distribution

  16. Observer perspective imagery with stuttering.

    Science.gov (United States)

    Lowe, Robyn; Menzies, Ross; Packman, Ann; O'Brian, Sue; Onslow, Mark

    2015-01-01

    Adults who stutter are at risk of developing a range of psychological conditions. Social anxiety disorder is the most common anxiety disorder associated with stuttering. Observer perspective imagery is one cognitive process involved in the maintenance of some anxiety disorders. This involves viewing images as if looking at the self from the perspective of another. In contrast, the field perspective involves looking out from the self at the surrounding environment. The purpose of this study was to assess the presence of observer perspective imagery with stuttering. The authors administered the Hackmann, Surawy and Clark (1998) semi-structured interview to 30 adults who stutter and 30 controls. Group images and impressions were compared for frequency, perspective recalled and emotional valence. The stuttering group was significantly more likely than controls to recall images and impressions from an observer rather than a field perspective for anxious situations. It is possible the present results could reflect the same attentional processing bias that occurs with anxiety disorders in the non-stuttering population. These preliminary results provide an explanation for the persistence of conditions such as social anxiety disorder with stuttering. Clinical implications are discussed.

  17. Hue discrimination in Iberoamerican Observers

    Science.gov (United States)

    Carranza, Jazmín; Medina, Juana

    2008-04-01

    In this work we analyze the Farnsworth Munsell 100 Hue Test results, this test offers a simple method for testing color discrimination and was applied to a sample of 129 observers, with natural daylight in the same conditions (the observers were men and women), all of these were participants in colorimetric training courses, and aged 20 to 76, with two to twenty five years experience in the color control manufacturer laboratories (of plastics, rugs, dyes, textiles, and paints). Their job titles included mixers, inspectors, shaders, matchers, passers, and dyers. The test was applied twice and the results here presented are the comparison between both tests, taking into account errors by mistakes incidence in each hue position, as well as the redeeming of each participant in both test. The comparison shows us that most of the mistakes are in the green hue in both tests, but in the second test, approximately 20 percent of the observers reduced those. Also we can to separate persons with normal color vision of those which have zones of color confusion. In this work it is show some ones results of the comparison between men and women.

  18. Observed characteristics of auroral forms

    International Nuclear Information System (INIS)

    Davis, T.N.

    1978-01-01

    Observations indicate that the extended auroral arc is the basic form of the discrete aurora, the brightest and most obvious kind of aurora. Both motions of auroral arcs and their distortions into convoluted forms indicate the presence of shear processes involving substantial charge excesses and magnetic field-aligned currents. Consequently, strong electric fields, both horizontal and vertical, characterize the discrete aurora. The observations of auroral arcs and observations of associated charged-particle fluxes, electric fields and currents fit together into a relatively cohesive description of the auroral arc which is compatible with at least one proposed model of the causative processes. On the other hand, an equally important type of aurora - pulsating aurora - exhibits quite different characteristics which distinguish it from the discrete aurora and which are difficult to interpret satisfactorily in terms of existing proposed models of particle precipitation and excitation of auroral emission. The lack of shearing behavior in the pulsating aurora indicates that substantial electric fields are not associated with it. Transitional forms of auroras exhibit an intermediate degree of shear motion. (Auth.)

  19. The Earth Observation Technology Cluster

    Science.gov (United States)

    Aplin, P.; Boyd, D. S.; Danson, F. M.; Donoghue, D. N. M.; Ferrier, G.; Galiatsatos, N.; Marsh, A.; Pope, A.; Ramirez, F. A.; Tate, N. J.

    2012-07-01

    The Earth Observation Technology Cluster is a knowledge exchange initiative, promoting development, understanding and communication about innovative technology used in remote sensing of the terrestrial or land surface. This initiative provides an opportunity for presentation of novel developments from, and cross-fertilisation of ideas between, the many and diverse members of the terrestrial remote sensing community. The Earth Observation Technology Cluster involves a range of knowledge exchange activities, including organisation of technical events, delivery of educational materials, publication of scientific findings and development of a coherent terrestrial EO community. The initiative as a whole covers the full range of remote sensing operation, from new platform and sensor development, through image retrieval and analysis, to data applications and environmental modelling. However, certain topical and strategic themes have been selected for detailed investigation: (1) Unpiloted Aerial Vehicles, (2) Terrestrial Laser Scanning, (3) Field-Based Fourier Transform Infra-Red Spectroscopy, (4) Hypertemporal Image Analysis, and (5) Circumpolar and Cryospheric Application. This paper presents general activities and achievements of the Earth Observation Technology Cluster, and reviews state-of-the-art developments in the five specific thematic areas.

  20. Biologic relativity: Who is the observer and what is observed?

    Science.gov (United States)

    Torday, John S; Miller, William B

    2016-05-01

    When quantum physics and biological phenomena are analogously explored, it emerges that biologic causation must also be understood independently of its overt appearance. This is similar to the manner in which Bohm characterized the explicate versus the implicate order as overlapping frames of ambiguity. Placed in this context, the variables affecting epigenetic inheritance can be properly assessed as a key mechanistic principle of evolution that significantly alters our understanding of homeostasis, pleiotropy, and heterochrony, and the purposes of sexual reproduction. Each of these become differing manifestations of a new biological relativity in which biologic space-time becomes its own frame. In such relativistic cellular contexts, it is proper to question exactly who has observer status, and who and what are being observed. Consideration within this frame reduces biology to cellular information sharing through cell-cell communication to resolve ambiguities at every scope and scale. In consequence, it becomes implicit that eukaryotic evolution derives from the unicellular state, remaining consistently adherent to it in a continuous evolutionary arc based upon elemental, non-stochastic physiologic first principles. Furthermore, the entire cell including its cytoskeletal apparatus and membranes that participate in the resolution of biological uncertainties must be considered as having equivalent primacy with genomes in evolutionary terms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Remote Observational Techniques in Education

    Science.gov (United States)

    Thieman, J.; Mayo, L.

    2002-09-01

    The ability to observe celestial objects remotely is making a major impact into classroom access to astronomical instrumentation previously impossible to encorporate into curriculum. Two programs, Radio Jove and Telescopes In Education have made important contributions in this field. Radio JOVE is an interactive, hands-on, educational activity for learning the scientific method through the medium of radio observations of Jupiter, the Sun, and the galactic radio background. Students build radio receivers from relatively inexpensive non-profit kits (about \\$125 plus shipping) and use them to record data, analyze the data, and share the results with others. Alternatively, for no cost, the students can record and analyze data from remote radio receivers connected to the web. The projects are useful adjuncts to activities in optical observing since students should recognize that we learn about the universe through more than just the optical spectrum. The projects are mini-electronics courses and also teach about charged particles and magnetic fields. The Radio JOVE web site (http://radiojove.gsfc.nasa.gov) should be consulted for further information. The NASA-sponsored Telescopes In Education (TIE) network (http://tie.jpl.nasa.gov) has been wildly successful in engaging the K-12 education community in real-time, hands-on, interactive astronomy activities. Hundreds of schools in the US, Australia, Canada, England, and Japan have participated in the TIE program, remotely controlling the 24-inch telescope at the Mount Wilson Observatory from their classrooms. In recent years, several (approximately 20 to date) other telescopes have been, or are in the process of being, outfitted for remote use as TIE affiliates. These telescopesare integrated seamlessly into one virtual observatory providing the services required to operate this facility, including a scheduling service, tools for data manipulation, an online proposal review environment, an online "Virtual TIE Student Ap J

  2. Observing the Anthropocene from Space

    Science.gov (United States)

    Dittus, Hansjörg

    2016-07-01

    Influence of mankind on Earth's climate is evident. The growing population using the resources available, especially by burning goal, oil and gas, changes the composition of the Earth's atmosphere with the result of a continuously increasing temperature. Effects are not limited to the regional scale but are evident on the whole planet, meanwhile named Anthropocene. According to this global influence, it's necessary to also extend monitoring to the entire planet. Space-based observation systems are not limited by any artificial borders and are in principle able, to cover the whole Earth. In principle, two different ways of observation can be selected: Either a dedicated spacecraft will be send into low earth orbit (LEO) or existing platforms are used. Advantages of satellites are the more or less freely selectable orbit (with orbits covering also the polar regions) and the possible adaption of spacecraft platform for the dedicated instrument. On the other hand platforms like the ISS space station enable continuous long term coverage with different instruments. The drawback of an only limited coverage based on the orbit inclination is made up by the possibility to service systems on the station. Furthermore different generations of sensors can be run in parallel and therefore cross calibrated if needed. This paper reviews the currently available sensors types and discusses potential future needs. Included in this discussion is the international space station as an already available platform for earth observation. Furthermore, discussion should also take into account, that an increasing number of constellations with dozens or even thousand satellites are planned. Are these constellations also an option for an increased temporal and spatial monitoring of the Earth?

  3. INTEGRAL Observations of GW170104

    Energy Technology Data Exchange (ETDEWEB)

    Savchenko, V.; Ferrigno, C.; Bozzo, E.; Courvoisier, T. J.-L. [ISDC, Department of Astronomy, University of Geneva, chemin d’Écogia, 16 CH-1290 Versoix (Switzerland); Bazzano, A. [INAF-Institute for Space Astrophysics and Planetology, Via Fosso del Cavaliere 100, I-00133-Rome (Italy); Brandt, S.; Chenevez, J.; Ubertini, P. [DTU Space—National Space Institute Elektrovej, Building 327, DK-2800 Kongens Lyngby (Denmark); Diehl, R.; Von Kienlin, A. [Max-Planck-Institut für Extraterrestrische Physik, Garching (Germany); Hanlon, L.; Martin-Carillo, A. [Space Science Group, School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Kuulkers, E. [European Space Research and Technology Centre (ESA/ESTEC), Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Laurent, P. [APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris Sorbonne Paris Cité, 10 rue Alice Domont et Léonie Duquet, F-75205 Paris Cedex 13 (France); Lebrun, F. [DSM/Irfu/Service d’Astrophysique, Bat. 709 Orme des Merisiers CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); Lutovinov, A.; Sunyaev, R. [Space Research Institute of Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow (Russian Federation); Mereghetti, S. [INAF, IASF-Milano, via E.Bassini 15, I-20133 Milano (Italy); Roques, J. P. [Université Toulouse, UPS-OMP, CNRS, IRAP, 9 Av. Roche, BP 44346, F-31028 Toulouse (France)

    2017-09-10

    We used data from the International Gamma-Ray Astrophysics Laboratory ( INTEGRAL ) to set upper limits on the γ -ray and hard X-ray prompt emission associated with the gravitational-wave event GW170104, discovered by the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo collaboration. The unique omnidirectional viewing capability of the instruments on board INTEGRAL allowed us to examine the full 90% confidence level localization region of the LIGO trigger. Depending on the particular spectral model assumed and the specific position within this region, the upper limits inferred from the INTEGRAL observations range from F {sub γ} = 1.9 × 10{sup −7} erg cm{sup −2} to F {sub γ} = 10{sup −6} erg cm{sup −2} (75 keV–2 MeV energy range). This translates into a ratio between the prompt energy released in γ -rays along the direction to the observer and the gravitational-wave energy of E {sub γ} / E {sub GW} < 2.6 × 10{sup −5}. Using the INTEGRAL results, we cannot confirm the γ -ray proposed counterpart to GW170104 by the Astro—Rivelatore Gamma a Immagini Leggero (AGILE) team with the mini-Calorimeter (MCAL) instrument. The reported flux of the AGILE/MCAL event, E2, is not compatible with the INTEGRAL upper limits within most of the 90% LIGO localization region. There is only a relatively limited portion of the sky where the sensitivity of the INTEGRAL instruments was not optimal and the lowest-allowed fluence estimated for E2 would still be compatible with the INTEGRAL results. This region was also observed independently by Fermi /Gamma-ray Burst Monitor and AstroSAT, from which, as far as we are aware, there are no reports of any significant detection of a prompt high-energy event.

  4. Observations of Early Optical Afterglows

    OpenAIRE

    Roming, Peter W. A.; Mason, Keith O.

    2006-01-01

    The Swift Ultra-Violet/Optical Telescope (UVOT) has performed extensive follow-up on 71 Swift Burst Alert Telescope triggered gamma-ray bursts (GRBs) in its first ten months of operations. In this paper, we discuss some of the UV and optical properties of UVOT detected afterglows such as XRF 050406, the bright GRB 050525A, the high redshift GRB 050730, the early flaring GRB 050801, and others. We also discuss some of the implications of why 75% of GRB afterglows observed by UVOT in less than ...

  5. STM observations of ferromagnetic clusters

    International Nuclear Information System (INIS)

    Wawro, A.; Kasuya, A.

    1998-01-01

    Co, Fe and Ni clusters of nanometer size, deposited on silicon and graphite (highly oriented pyrolytic graphite), were observed by a scanning tunneling microscope. Deposition as well as the scanning tunneling microscope measurements were carried out in an ultrahigh vacuum system at room temperature. Detailed analysis of Co cluster height was done with the scanning tunneling microscope equipped with a ferromagnetic tip in a magnetic field up to 70 Oe. It is found that bigger clusters (few nanometers in height) exhibit a dependence of their apparent height on applied magnetic field. We propose that such behaviour originates from the ferromagnetic ordering of cluster and associate this effect to spin polarized tunneling. (author)

  6. Observations involving broadband impedance modelling

    Energy Technology Data Exchange (ETDEWEB)

    Berg, J S [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1996-08-01

    Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impedance. This paper discusses three aspects of broadband impedance modelling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f. cavity. The last is a discussion of requirements for the mathematical form of an impedance which follow from the general properties of impedances. (author)

  7. Recent progress in observational cosmology

    OpenAIRE

    Gangui, Alejandro

    2017-01-01

    We present here a short update of some topics on observational cosmology, with special emphasis given to the latest results on the cosmic microwave background radiation anisotropies and polarization. Fil: Gangui, Alejandro. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Físi...

  8. Observations involving broadband impedance modelling

    International Nuclear Information System (INIS)

    Berg, J.S.

    1995-08-01

    Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impendance. This paper discusses three aspects of broadband impendance modeling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f cavity. The last is a discussion of requirements for the mathematical form of an impendance which follow from the general properties of impendances

  9. From observational to dynamic genetics

    Directory of Open Access Journals (Sweden)

    Claire M. A. Haworth

    2014-01-01

    Full Text Available Twin and family studies have shown that most traits are at least moderately heritable. But what are the implications of finding genetic influence for the design of intervention and prevention programs? For complex traits, heritability does not mean immutability, and research has shown that genetic influences can change with age, context and in response to behavioural and drug interventions. The most significant implications for intervention will come when we move from observational genetics to investigating dynamic genetics, including genetically sensitive interventions. Future interventions should be designed to overcome genetic risk and draw upon genetic strengths by changing the environment.

  10. Korea Earth Observation Satellite Program

    Science.gov (United States)

    Baek, Myung-Jin; Kim, Zeen-Chul

    via Korea Aerospace Research Institute (KARI) as the prime contractor in the area of Korea earth observation satellite program to enhance Korea's space program development capability. In this paper, Korea's on-going and future earth observation satellite programs are introduced: KOMPSAT- 1 (Korea Multi Purpose Satellite-1), KOMPSAT-2 and Communication, Broadcasting and Meteorological Satellite (CBMS) program. KOMPSAT-1 satellite successfully launched in December 1999 with Taurus launch vehicle. Since launch, KOMPSAT-1 is downlinking images of Korea Peninsular every day. Until now, KOMPSAT-1 has been operated more than 2 and half years without any major hardware malfunction for the mission operation. KOMPSAT-1 payload has 6.6m panchromatic spatial resolution at 685 km on-orbit and the spacecraft bus had NASA TOMS-EP (Total Ozone Mapping Spectrometer-Earth Probe) spacecraft bus heritage designed and built by TRW, U.S.A.KOMPSAT-1 program was international co-development program between KARI and TRW funded by Korean Government. be launched in 2004. Main mission objective is to provide geo-information products based on the multi-spectral high resolution sensor called Multi-Spectral Camera (MSC) which will provide 1m panchromatic and 4m multi-spectral high resolution images. ELOP of Israel is the prime contractor of the MSC payload system and KARI is the total system prime contractor including spacecraft bus development and ground segment. KARI also has the contract with Astrium of Europe for the purpose of technical consultation and hardware procurement. Based on the experience throughout KOMPSAT-1 and KOMPSAT-2 space system development, Korea is expecting to establish the infrastructure of developing satellite system. Currently, KOMPSAT-2 program is in the critical design stage. are scheduled to launch in 2008 and in 2014, respectively. The mission of CBMS consists of two areas. One is of space technology test for the communications mission, and the other is of a real

  11. Functional observer and state feedback

    International Nuclear Information System (INIS)

    Zhang, S.Y.

    1986-01-01

    In this paper, we show the relation between state space approach and transfer function approach for functional observer and state feedback design. Two approaches can be transformed into each other, based on this result. More importantly, we find that the state space approach introduces some severe, unnecessary restrictions in solving the problem. The restrictions are, however, reduced to be a trivial condition in transfer function approach. It is believed that the result presented in this paper will be useful in developing both approaches, and motivate some new results for solving the problem

  12. Binary evolution and observational constraints

    International Nuclear Information System (INIS)

    Loore, C. de

    1984-01-01

    The evolution of close binaries is discussed in connection with problems concerning mass and angular momentum losses. Theoretical and observational evidence for outflow of matter, leaving the system during evolution is given: statistics on total masses and mass ratios, effects of the accretion of the mass gaining component, the presence of streams, disks, rings, circumstellar envelopes, period changes, abundance changes in the atmosphere. The effects of outflowing matter on the evolution is outlined, and estimates of the fraction of matter expelled by the loser, and leaving the system, are given. The various time scales involved with evolution and observation are compared. Examples of non conservative evolution are discussed. Problems related to contact phases, on mass and energy losses, in connection with entropy changes are briefly analysed. For advanced stages the disruption probabilities for supernova explosions are examined. A global picture is given for the evolution of massive close binaries, from ZAMS, through WR phases, X-ray phases, leading to runaway pulsars or to a binary pulsar and later to a millisecond pulsar. (Auth.)

  13. Wake effect in rocket observation

    International Nuclear Information System (INIS)

    Matsumoto, Haruya; Kaya, Nobuyuki; Yamanaka, Akira; Hayashi, Tomomasa

    1975-01-01

    The mechanism of the wake phenomena due to a probe and in rocket observation is discussed on the basis of experimental data. In the low energy electron measurement performed with the L-3H-5 rocket, the electron count rate changed synchronously with the rocket spin. This seems to be a wake effect. It is also conceivable that the probe itself generates the wake of ion beam. The latter problem is considered in the first part. Experiment was performed with laboratory plasma, in which a portion of the electron component of the probe current was counted with a CEM (a channel type multiplier). The change of probe voltage-count rate charactersitics due to the change of relative position of the ion source was observed. From the measured angular distributions of electron density and electron temperature around the probe, it is concluded that anisotropy exists around the probe, which seems to be a kinds of wake structure. In the second part, the wake effect due to a rocket is discussed on the basis of the measurement of leaking electrons with L-3H-5 rocket. Comparison between the theory of wake formation and the measured results is also shortly made in the final part. (Aoki, K.)

  14. Solar Observations at Submillimeter Wavelengths

    Science.gov (United States)

    Kaufmann, P.

    We review earlier to recent observational evidences and theoretical motivations leading to a renewed interest to observe flares in the submillimeter (submm) - infrared (IR) range of wavelengths. We describe the new solar dedicated submillimeter wave telescope which began operations at El Leoncito in the Argentina Andes: the SST project. It consists of focal plane arrays of two 405 GHz and four 212 GHz radiometers placed in a 1.5-m radome-enclosed Cassegrain antenna, operating simultaneously with one millisecond time resolution. The first solar events analyzed exhibited the onset of rapid submm-wave spikes (100-300 ms), well associated to other flare manifestations, especially at X-rays. The spikes positions were found scattered over the flaring source by tens of arcseconds. For one event an excellent association was found between the gamma-ray emission time profile and the rate of occurrence of submm-wave rapid spikes. The preliminary results favour the idea that bulk burst emissions are a response to numerous fast energetic injections, discrete in time, produced at different spatial positions over the flaring region. Coronal mass ejections were associated to the events studied. Their trajectories extrapolated to the solar surface appear to correspond to the onset time of the submm-wave spikes, which might represent an early signature of the CME's initial acceleration process.

  15. Spanish Earth Observation Satellite System

    Science.gov (United States)

    Borges, A.; Cerezo, F.; Fernandez, M.; Lomba, J.; Lopez, M.; Moreno, J.; Neira, A.; Quintana, C.; Torres, J.; Trigo, R.; Urena, J.; Vega, E.; Vez, E.

    2010-12-01

    The Spanish Ministry of Industry, Tourism and Trade (MITyC) and the Ministry of Defense (MoD) signed an agreement in 2007 for the development of a "Spanish Earth Observation Satellite System" based, in first instance, on two satellites: a high resolution optical satellite, called SEOSAT/Ingenio, and a radar satellite based on SAR technology, called SEOSAR/Paz. SEOSAT/Ingenio is managed by MITyC through the Centre for the Development of Industrial Technology (CDTI), with technical and contractual support from the European Space Agency (ESA). HISDESA T together with the Spanish Instituto Nacional de Técnica Aeroespacial (INTA, National Institute for Aerospace Technology) will be responsible for the in-orbit operation and the commercial operation of both satellites, and for the technical management of SEOSAR/Paz on behalf of the MoD. In both cases EADS CASA Espacio (ECE) is the prime contractor leading the industrial consortia. The ground segment development will be assigned to a Spanish consortium. This system is the most important contribution of Spain to the European Programme Global Monitoring for Environment and Security, GMES. This paper presents the Spanish Earth Observation Satellite System focusing on SEOSA T/Ingenio Programme and with special emphasis in the potential contribution to the ESA Third Party Missions Programme and to the Global Monitoring for Environment and Security initiative (GMES) Data Access.

  16. Heliospheric Observations of Energetic Particles

    Science.gov (United States)

    Summerlin, Errol J.

    2011-01-01

    Heliospheric observations of energetic particles have shown that, on long time averages, a consistent v^-5 power-law index arises even in the absence of transient events. This implies an ubiquitous acceleration process present in the solar wind that is required to generate these power-law tails and maintain them against adiabatic losses and coulomb-collisions which will cool and thermalize the plasma respectively. Though the details of this acceleration process are being debated within the community, most agree that the energy required for these tails comes from fluctuations in the magnetic field which are damped as the energy is transferred to particles. Given this source for the tail, is it then reasonable to assume that the turbulent LISM should give rise to such a power-law tail as well? IBEX observations clearly show a power-law tail of index approximately -5 in energetic neutral atoms. The simplest explanation for the origins of these ENAs are that they are energetic ions which have charge-exchanged with a neutral atom. However, this would imply that energetic ions possess a v^-5 power-law distribution at keV energies at the source of these ENAs. If the source is presumed to be the LISM, it provides additional options for explaining the, so called, IBEX ribbon. This presentation will discuss some of these options as well as potential mechanisms for the generation of a power-law spectrum in the LISM.

  17. Jet observables without jet algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, Daniele; Chan, Tucker; Thaler, Jesse [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States)

    2014-04-02

    We introduce a new class of event shapes to characterize the jet-like structure of an event. Like traditional event shapes, our observables are infrared/collinear safe and involve a sum over all hadrons in an event, but like a jet clustering algorithm, they incorporate a jet radius parameter and a transverse momentum cut. Three of the ubiquitous jet-based observables — jet multiplicity, summed scalar transverse momentum, and missing transverse momentum — have event shape counterparts that are closely correlated with their jet-based cousins. Due to their “local” computational structure, these jet-like event shapes could potentially be used for trigger-level event selection at the LHC. Intriguingly, the jet multiplicity event shape typically takes on non-integer values, highlighting the inherent ambiguity in defining jets. By inverting jet multiplicity, we show how to characterize the transverse momentum of the n-th hardest jet without actually finding the constituents of that jet. Since many physics applications do require knowledge about the jet constituents, we also build a hybrid event shape that incorporates (local) jet clustering information. As a straightforward application of our general technique, we derive an event-shape version of jet trimming, allowing event-wide jet grooming without explicit jet identification. Finally, we briefly mention possible applications of our method for jet substructure studies.

  18. Observational Bounds on Cosmic Doomsday

    Energy Technology Data Exchange (ETDEWEB)

    Shmakova, Marina

    2003-07-11

    Recently it was found, in a broad class of models, that the dark energy density may change its sign during the evolution of the universe. This may lead to a global collapse of the universe within the time t{sub c} {approx} 10{sup 10}-10{sup 11} years. Our goal is to find what bounds on the future lifetime of the universe can be placed by the next generation of cosmological observations. As an example, we investigate the simplest model of dark energy with a linear potential V({phi}) = V{sub 0}(1 + {alpha}{phi}). This model can describe the present stage of acceleration of the universe if {alpha} is small enough. However, eventually the field {phi} rolls down, V({phi}) becomes negative, and the universe collapses. The existing observational data indicate that the universe described by this model will collapse not earlier than t{sub c} {approx_equal} 10 billion years from the present moment. We show that the data from SNAP and Planck satellites may extend the bound on the ''doomsday'' time to tc 40 billion years at the 95% confidence level.

  19. Ocean Observations of Climate Change

    Science.gov (United States)

    Chambers, Don

    2016-01-01

    The ocean influences climate by storing and transporting large amounts of heat, freshwater, and carbon, and exchanging these properties with the atmosphere. About 93% of the excess heat energy stored by the earth over the last 50 years is found in the ocean. More than three quarters of the total exchange of water between the atmosphere and the earth's surface through evaporation and precipitation takes place over the oceans. The ocean contains 50 times more carbon than the atmosphere and is at present acting to slow the rate of climate change by absorbing one quarter of human emissions of carbon dioxide from fossil fuel burning, cement production, deforestation and other land use change.Here I summarize the observational evidence of change in the ocean, with an emphasis on basin- and global-scale changes relevant to climate. These include: changes in subsurface ocean temperature and heat content, evidence for regional changes in ocean salinity and their link to changes in evaporation and precipitation over the oceans, evidence of variability and change of ocean current patterns relevant to climate, observations of sea level change and predictions over the next century, and biogeochemical changes in the ocean, including ocean acidification.

  20. Fluid observers and tilting cosmology

    International Nuclear Information System (INIS)

    Coley, A A; Hervik, S; Lim, W C

    2006-01-01

    We study perfect fluid cosmological models with a constant equation of state parameter γ in which there are two naturally defined timelike congruences, a geometrically defined geodesic congruence and a non-geodesic fluid congruence. We establish an appropriate set of boost formulae relating the physical variables, and consequently the observed quantities, in the two frames. We study expanding spatially homogeneous tilted perfect fluid models, with an emphasis on future evolution with extreme tilt. We show that for ultra-radiative equations of state (i.e. γ > 4/3), generically the tilt becomes extreme at late times and the fluid observers will reach infinite expansion within a finite proper time and experience a singularity similar to that of the big rip. In addition, we show that for sub-radiative equations of state (i.e. γ < 4/3), the tilt can become extreme at late times and give rise to an effective quintessential equation of state. To establish the connection with phantom cosmology and quintessence, we calculate the effective equation of state in the models under consideration and we determine the future asymptotic behaviour of the tilting models in the fluid frame variables using the boost formulae. We also discuss spatially inhomogeneous models and tilting spatially homogeneous models with a cosmological constant