Science.gov

Sample records for atmospheric greenhouse effect

  1. Greenhouse effect in the atmosphere

    NASA Astrophysics Data System (ADS)

    Smirnov, B. M.

    2016-04-01

    Average optical atmospheric parameters for the infrared spectrum range are evaluated on the basis of the Earth energetic balance and parameters of the standard atmosphere. The average optical thickness of the atmosphere is u ≈ 2.5 and this atmospheric emission is originated at altitudes below 10 km. Variations of atmospheric radiative fluxes towards the Earth and outward are calculated as a function of the concentration of \\text{CO}2 molecules for the regular model of molecular spectrum. As a result of doubling of the \\text{CO}2 concentration the change of the global Earth temperature is (0.4 +/- 0.2) \\text{K} if other atmospheric parameters are conserved compared to the value (3.0 +/- 1.5) \\text{K} under real atmospheric conditions with the variation of the amount of atmospheric water. An observed variation of the global Earth temperature during the last century (0.8 ^\\circ \\text{C}) follows from an increase of the mass of atmospheric water by 7% or by conversion of 1% of atmospheric water in aerosols.

  2. Greenhouse effect due to atmospheric nitrous oxide

    NASA Technical Reports Server (NTRS)

    Yung, Y. L.; Wang, W. C.; Lacis, A. A.

    1976-01-01

    The greenhouse effect due to nitrous oxide in the present atmosphere is about 0.8 K. Increase in atmospheric N2O due to perturbation of the nitrogen cycle by man may lead to an increase in surface temperature as large as 0.5 K by 2025, or 1.0 K by 2100. Other climatic effects of N2O are briefly discussed.

  3. Atmospheric greenhouse effect and climates on various planets

    SciTech Connect

    Kondratev, K.Y.; Moskalenko, N.I.

    1985-01-01

    The greenhouse effect of the planetary atmospheres is considered and its evolution as a result of variations in the chemical composition and in gas abundances of the atmospheres as well as in the chemical composition, size distribution and concentration of aerosol components. A computer modelling gave the values of the greenhouse effect of the atmospheres of the Earth, Mars, Venus, Jupiter, and Titan. It is shown that the atmospheric greenhouse effect plays a decisive role in the formation of the planetary climates and that it has substantially changed in the process of the planetary evolution. The greenhouse effect mechanism has always been and still is a major factor of the mean global planetary climate.

  4. Effect of noble gases on an atmospheric greenhouse /Titan/.

    NASA Technical Reports Server (NTRS)

    Cess, R.; Owen, T.

    1973-01-01

    Several models for the atmosphere of Titan have been investigated, taking into account various combinations of neon and argon. The investigation shows that the addition of large amounts of Ne and/or Ar will substantially reduce the hydrogen abundance required for a given greenhouse effect. The fact that a large amount of neon should be present if the atmosphere is a relic of the solar nebula is an especially attractive feature of the models, because it is hard to justify appropriate abundances of other enhancing agents.

  5. The greenhouse effect in a gray planetary atmosphere.

    NASA Technical Reports Server (NTRS)

    Wildt, R.

    1966-01-01

    Hopf analytical solution for values of ratio of gray absorption coefficients for insolating and escaping radiation /greenhouse parameter/ assumed constant at all depths, presenting temperature distribution graphs

  6. Greenhouse gases and greenhouse effect

    NASA Astrophysics Data System (ADS)

    Chilingar, G. V.; Sorokhtin, O. G.; Khilyuk, L.; Gorfunkel, M. V.

    2009-09-01

    Conventional theory of global warming states that heating of atmosphere occurs as a result of accumulation of CO2 and CH4 in atmosphere. The writers show that rising concentration of CO2 should result in the cooling of climate. The methane accumulation has no essential effect on the Earth’s climate. Even significant releases of the anthropogenic carbon dioxide into the atmosphere do not change average parameters of the Earth’s heat regime and the atmospheric greenhouse effect. Moreover, CO2 concentration increase in the atmosphere results in rising agricultural productivity and improves the conditions for reforestation. Thus, accumulation of small additional amounts of carbon dioxide and methane in the atmosphere as a result of anthropogenic activities has practically no effect on the Earth’s climate.

  7. CO/sub 2/ greenhouse effect and the thermal history of the atmosphere

    SciTech Connect

    Marx, G.; Miskolci, F.

    1981-01-01

    The absorption spectrum of CO/sub 2/ for a wide range of atmospheric concentrations has been computed in an attempt to study the effects of atmospheric CO/sub 2/ concentrations (which are currently increasing at a rate of 1 ppM/year) on terrestrial temperature and to contribute to the understanding of the CO/sub 2/ greenhouse effect on Venus. The atmospheric absorption of thick CO/sub 2/ layers was determined in order to understand the thermal stability on the earth's surface in spite of atmospheric composition changes (the mean chemical composition changed from CO/sub 2/ to O/sub 2/ to N/sub 2/ in the last 0.75 billion years). The calculated greenhouse effect was then combined with other long-term phenomena which influenced the temperature. It was estimated that the surface temperature increase did not reach the boiling point of water for CO/sub 2/ concentrations that were thousands of times larger than the present concentrations, however, higher energy CO/sub 2/ bands and/or an increase in atmospheric H/sub 2/O may have changed the greenhouse effect.

  8. Falsification of the Atmospheric CO2 Greenhouse Effects Within the Frame of Physics

    NASA Astrophysics Data System (ADS)

    Gerlich, Gerhard; Tscheuschner, Ralf D.

    The atmospheric greenhouse effect, an idea that many authors trace back to the traditional works of Fourier (1824), Tyndall (1861), and Arrhenius (1896), and which is still supported in global climatology, essentially describes a fictitious mechanism, in which a planetary atmosphere acts as a heat pump driven by an environment that is radiatively interacting with but radiatively equilibrated to the atmospheric system. According to the second law of thermodynamics, such a planetary machine can never exist. Nevertheless, in almost all texts of global climatology and in a widespread secondary literature, it is taken for granted that such a mechanism is real and stands on a firm scientific foundation. In this paper, the popular conjecture is analyzed and the underlying physical principles are clarified. By showing that (a) there are no common physical laws between the warming phenomenon in glass houses and the fictitious atmospheric greenhouse effects, (b) there are no calculations to determine an average surface temperature of a planet, (c) the frequently mentioned difference of 33° is a meaningless number calculated wrongly, (d) the formulas of cavity radiation are used inappropriately, (e) the assumption of a radiative balance is unphysical, (f) thermal conductivity and friction must not be set to zero, the atmospheric greenhouse conjecture is falsified.

  9. The CO2 greenhouse effect and the thermal history of the atmosphere.

    PubMed

    Marx, G; Miskolci, F

    1981-01-01

    The influence of the expected rise of CO2 content in our atmosphere upon terrestrial temperature is uncertain. A significant increase in temperature could be threatening to certain aspects of terrestrial biology. On the other hand, it is a general consensus among paleobiologists that the Earth possessed a CO2 atmosphere in the past billion years, without dramatic temperature variations endangering the continuity of life. In order to clarify this problem, and to contribute to the understanding of the CO2 greenhouse effect on Venus we have computed the absorption spectrum of CO2 for a wide range of atmospheric concentrations. More than 2500 spectral lines of the 15 micron band were taken into account in our line-by-line calculation. We have used an empirical exponential line-shape function at the line edges. Our results agree with the experimental data of F. W. Taylor. The estimated increase in surface temperature does not reach the boiling point of water even for CO2 concentrations thousands of times larger than the present concentrations. Higher energy (>666 cm-1) CO2 bands and/or an increase in atmospheric H2O may, however, amplify the greenhouse effect.

  10. Global warming: Experimental study about the effect of accumulation of greenhouse gases in the atmosphere

    NASA Astrophysics Data System (ADS)

    Molto, Carlos; Mas, Miquel

    2010-05-01

    The project presented here was developed by fifteen year old students of the Institut Sabadell (Sabadell Secondary School. Spain). The objective of this project was to raise the students awareness' about the problem of climate change, mainly caused by the accumulation of greenhouse gases in the atmosphere. It is also intended that students use the scientific method as an effective system of troubleshooting and that they use the ICTs (Information and Communication Technologies) to elicit data and process information. To develop this project, four lessons of sixty minutes each were needed. The first lesson sets out the role of the atmosphere as an Earth's temperature regulator, highlighting the importance of keeping the levels of carbon dioxide, methane and water steam in balance. The second lesson is focused on the experimental activity that students will develop in the following lesson. In lesson two, students will present and justify their hypothesis about the experiment. Some theoretical concepts, necessary to carry out the experiment, will also be explained. The third lesson involves the core of the project, that is the experiment in the laboratory. The experiment consists on performing the atmosphere heating on a little scale. Four different atmospheres are created inside four plastic boxes heated by an infrared lamp. Students work in groups (one group for each atmosphere) and have to monitor the evolution of temperature by means of a temperature sensor (Multilog software). The first group has to observe the relationship between temperature and carbon dioxide levels increase, mainly caused by the widespread practice of burning fossil fuels by growing human populations. The task of this group is to measure simultaneously the temperature of an empty box (without CO2) and the temperature of a box with high carbon dioxide concentration. The carbon dioxide concentration is the result of the chemical reaction when sodium carbonate mixes with hydrochloric acid. The

  11. Ammonia photolysis and the greenhouse effect in the primordial atmosphere of the earth

    NASA Technical Reports Server (NTRS)

    Kuhn, W. R.; Atreya, S. K.

    1979-01-01

    Photochemical calculations indicate that in the prebiotic atmosphere of earth ammonia would have been irreversibly converted to N2 in less than 40 years if the ammonia surface mixing ratio were no more than 0.0001. However, if a continuous outgassing of ammonia were maintained, radiative-equilibrium calculations indicate that a surface mixing ratio of ammonia of 0.0001 or greater would provide a sufficient greenhouse effect to keep the surface temperature above freezing. With a 0.0001 mixing ratio of ammonia, 60% to 70% of the present-day solar luminosity would be adequate to maintain surface temperatures above freezing. A lower limit to the time constant for accumulation of an amount of nitrogen equivalent to the present day value is 10 my if the outgassing were such as to provide a continuous surface mixing ratio of ammonia of at least 0.00001.

  12. Greenhouse models of the atmosphere of Titan.

    NASA Technical Reports Server (NTRS)

    Pollack, J. B.

    1973-01-01

    The greenhouse effect is calculated for a series of Titanian atmosphere models with different proportions of methane, hydrogen, helium, and ammonia. A computer program is used in temperature-structure calculations based on radiative-convective thermal transfer considerations. A brightness temperature spectrum is derived for Titan and is compared with available observational data. It is concluded that the greenhouse effect on Titan is generated by pressure-induced transitions of methane and hydrogen. The helium-to-hydrogen ratio is found to have a maximum of about 1.5. The surface pressure is estimated to be at least 0.4 atm, with a daytime temperature of about 155 K at the surface. The presence of methane clouds in the upper troposphere is indicated. The clouds have a significant optical depth in the visible, but not in the thermal, infrared.

  13. On the relationship between the greenhouse effect, atmospheric photochemistry, and species distribution

    NASA Technical Reports Server (NTRS)

    Callis, L. B.; Boughner, R. E.; Natarajan, M.

    1983-01-01

    The coupling that exists between infrared opacity changes and tropospheric (and to a lesser extent stratospheric) chemistry is explored in considerable detail, and the effects arising from various perturbations are examined. The studies are carried out with a fully coupled one-dimensional radiative-convective-photochemical model (RCP) that extends from the surface to 53.5 km and has the capability of calculating surface temperature changes due to both chemical and radiative perturbations. The model encompasses contemporary atmospheric chemistry and photochemistry involving the O(x), HO(x), NO(x), and Cl(x) species.

  14. Overview of global greenhouse effects

    SciTech Connect

    Reck, R.A.

    1993-09-01

    This report reviews the factors that influence the evolution of climate and climate change. Recent studies have confirmed that CO{sub 2}, O{sub 3}, N{sub 2}O, CH{sub 4}, and chlorofluorocarbos are increasing in abundance in the atmosphere and can alter the radiation balance by means of the so-called greenhouse effect. The greenhouse effect is as well-accepted phenomenon, but the prediction of its consequences is much less certain. Attempts to detect a human-caused temperature change are still inconclusive. This report presents a discussion of the scientific basis for the greenhouse effect, its relationship to the abundances of greenhouse gases, and the evidence confirming the increases in the abundances. The basis for climate modeling is presented together with an example of the model outputs from one of the most sophisticated modeling efforts. Uncertainties in the present understanding of climate are outlined.

  15. Observational determination of the greenhouse effect

    NASA Technical Reports Server (NTRS)

    Raval, A.; Ramanathan, V.

    1989-01-01

    Satellite measurements are used to quantify the atmospheric greenhouse effect, defined here as the infrared radiation energy trapped by atmospheric gases and clouds. The greenhouse effect is found to increase significantly with sea surface temperature. The rate of increase gives compelling evidence for the positive feedback between surface temperature, water vapor and the greenhouse effect; the magnitude of the feedback is consistent with that predicted by climate models. This study demonstrates an effective method for directly monitoring, from space, future changes in the greenhouse effect.

  16. Runaway greenhouse atmospheres: Applications to Earth and Venus

    NASA Technical Reports Server (NTRS)

    Kasting, James F.

    1991-01-01

    Runaway greenhouse atmospheres are discussed from a theoretical standpoint and with respect to various practical situation in which they might occur. The following subject areas are covered: (1) runaway greenhouse atmospheres; (2) moist greenhouse atmospheres; (3) loss of water from Venus; (4) steam atmosphere during accretion; and (5) the continuously habitable zone.

  17. (Limiting the greenhouse effect)

    SciTech Connect

    Rayner, S.

    1991-01-07

    Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

  18. A Hiatus of the Greenhouse Effect.

    PubMed

    Song, Jinjie; Wang, Yuan; Tang, Jianping

    2016-01-01

    The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth's surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (Ga and Gs) are estimated to represent the radiative warming effects of the atmosphere and the surface in the infrared range from 1979 to 2014. The atmospheric and surface greenhouse effect over the tropical monsoon-prone regions is found to contribute substantially to the global total. Furthermore, the downward tendency of cloud activity leads to a greenhouse effect hiatus after the early 1990 s, prior to the warming pause. Additionally, this pause in the greenhouse effect is mostly caused by the high number of La Niña events between 1991 and 2014. A strong La Niña indicates suppressed convection in the tropical central Pacific that reduces atmospheric water vapor content and cloud volume. This significantly weakened regional greenhouse effect offsets the enhanced warming influence in other places and decelerates the rising global greenhouse effect. This work suggests that the greenhouse effect hiatus can be served as an additional factor to cause the recent global warming slowdown. PMID:27616203

  19. A Hiatus of the Greenhouse Effect.

    PubMed

    Song, Jinjie; Wang, Yuan; Tang, Jianping

    2016-09-12

    The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth's surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (Ga and Gs) are estimated to represent the radiative warming effects of the atmosphere and the surface in the infrared range from 1979 to 2014. The atmospheric and surface greenhouse effect over the tropical monsoon-prone regions is found to contribute substantially to the global total. Furthermore, the downward tendency of cloud activity leads to a greenhouse effect hiatus after the early 1990 s, prior to the warming pause. Additionally, this pause in the greenhouse effect is mostly caused by the high number of La Niña events between 1991 and 2014. A strong La Niña indicates suppressed convection in the tropical central Pacific that reduces atmospheric water vapor content and cloud volume. This significantly weakened regional greenhouse effect offsets the enhanced warming influence in other places and decelerates the rising global greenhouse effect. This work suggests that the greenhouse effect hiatus can be served as an additional factor to cause the recent global warming slowdown.

  20. A Hiatus of the Greenhouse Effect

    PubMed Central

    Song, Jinjie; Wang, Yuan; Tang, Jianping

    2016-01-01

    The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth’s surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (Ga and Gs) are estimated to represent the radiative warming effects of the atmosphere and the surface in the infrared range from 1979 to 2014. The atmospheric and surface greenhouse effect over the tropical monsoon-prone regions is found to contribute substantially to the global total. Furthermore, the downward tendency of cloud activity leads to a greenhouse effect hiatus after the early 1990 s, prior to the warming pause. Additionally, this pause in the greenhouse effect is mostly caused by the high number of La Niña events between 1991 and 2014. A strong La Niña indicates suppressed convection in the tropical central Pacific that reduces atmospheric water vapor content and cloud volume. This significantly weakened regional greenhouse effect offsets the enhanced warming influence in other places and decelerates the rising global greenhouse effect. This work suggests that the greenhouse effect hiatus can be served as an additional factor to cause the recent global warming slowdown. PMID:27616203

  1. A Hiatus of the Greenhouse Effect

    NASA Astrophysics Data System (ADS)

    Song, Jinjie; Wang, Yuan; Tang, Jianping

    2016-09-01

    The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth’s surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surface greenhouse effect parameters (Ga and Gs) are estimated to represent the radiative warming effects of the atmosphere and the surface in the infrared range from 1979 to 2014. The atmospheric and surface greenhouse effect over the tropical monsoon-prone regions is found to contribute substantially to the global total. Furthermore, the downward tendency of cloud activity leads to a greenhouse effect hiatus after the early 1990 s, prior to the warming pause. Additionally, this pause in the greenhouse effect is mostly caused by the high number of La Niña events between 1991 and 2014. A strong La Niña indicates suppressed convection in the tropical central Pacific that reduces atmospheric water vapor content and cloud volume. This significantly weakened regional greenhouse effect offsets the enhanced warming influence in other places and decelerates the rising global greenhouse effect. This work suggests that the greenhouse effect hiatus can be served as an additional factor to cause the recent global warming slowdown.

  2. The Greenhouse and Anti-Greenhouse Effects on Titan

    NASA Technical Reports Server (NTRS)

    McKay, C. P.; Cuzzi, Jeffrey N. (Technical Monitor)

    1994-01-01

    Titan is the largest moon of Saturn and is the only moon in the solar system with a substantial atmosphere. Its atmosphere is mostly made of nitrogen, with a few percent CH4, 0.1% H2 and an uncertain level of Ar (less than 10%). The surface pressure is 1.5 atms and the surface temperature is 95 K, decreasing to 71 at the tropopause before rising to stratospheric temperatures of 180 K. In pressure and composition Titan's atmosphere is the closest twin to Earth's. The surface of Titan remains unknown, hidden by the thick smog layer, but it may be an ocean of liquid methane and ethane. Titan's atmosphere has a greenhouse effect which is much stronger than the Earth's - 92% of the surface warming is due to greenhouse radiation. However an organic smog layer in the upper atmosphere produces an anti-greenhouse effect that cuts the greenhouse warming in half - removing 35% of the incoming solar radiation. Models suggest that during its formation Titan's atmosphere was heated to high temperatures due to accretional energy. This was followed by a cold Triton-like period which gradually warmed to the present conditions. The coupled greenhouse and haze anti-greenhouse may be relevant to recent suggestions for haze shielding of a CH4 - NH3 early atmosphere on Earth or Mars. When the NASA/ESA mission to the Saturn System, Cassini, launches in a few years it will carry a probe that will be sent to the surface of Titan and show us this world that is strange and yet in many ways similar to our own.

  3. The Greenhouse Effect and Climate Feedbacks

    NASA Astrophysics Data System (ADS)

    Covey, C.; Haberle, R. M.; McKay, C. P.; Titov, D. V.

    2012-06-01

    We review the theory of the greenhouse effect and climate feedback. We also compare the theory with observations, using examples taken from all four known terrestrial worlds with substantial atmospheres: Venus, Earth, Mars, and Titan.

  4. Cosmic-Ray Reaction and Greenhouse Effect of Halogenated Molecules: Culprits for Atmospheric Ozone Depletion and Global Climate Change

    NASA Astrophysics Data System (ADS)

    Lu, Q.-B.

    2013-07-01

    This study is focused on the effects of cosmic rays (solar activity) and halogen-containing molecules (mainly chlorofluorocarbons — CFCs) on atmospheric ozone depletion and global climate change. Brief reviews are first given on the cosmic-ray-driven electron-induced-reaction (CRE) theory for O3 depletion and the warming theory of halogenated molecules for climate change. Then natural and anthropogenic contributions to these phenomena are examined in detail and separated well through in-depth statistical analyses of comprehensive measured datasets of quantities, including cosmic rays (CRs), total solar irradiance, sunspot number, halogenated gases (CFCs, CCl4 and HCFCs), CO2, total O3, lower stratospheric temperatures and global surface temperatures. For O3 depletion, it is shown that an analytical equation derived from the CRE theory reproduces well 11-year cyclic variations of both polar O3 loss and stratospheric cooling, and new statistical analyses of the CRE equation with observed data of total O3 and stratospheric temperature give high linear correlation coefficients ≥ 0.92. After the removal of the CR effect, a pronounced recovery by 20 25 % of the Antarctic O3 hole is found, while no recovery of O3 loss in mid-latitudes has been observed. These results show both the correctness and dominance of the CRE mechanism and the success of the Montreal Protocol. For global climate change, in-depth analyses of the observed data clearly show that the solar effect and human-made halogenated gases played the dominant role in Earth's climate change prior to and after 1970, respectively. Remarkably, a statistical analysis gives a nearly zero correlation coefficient (R = -0.05) between corrected global surface temperature data by removing the solar effect and CO2 concentration during 1850-1970. In striking contrast, a nearly perfect linear correlation with coefficients as high as 0.96-0.97 is found between corrected or uncorrected global surface temperature and total

  5. Titan's greenhouse and antigreenhouse effects

    NASA Technical Reports Server (NTRS)

    Mckay, Christopher P.; Pollack, James B.; Courtin, Regis

    1992-01-01

    Thermal mechanisms active in Titan's atmosphere are discussed in a brief review of data obtained during the Voyager I flyby in 1980. Particular attention is given to the greenhouse effect (GHE) produced by atmospheric H2, N2, and CH4; this GHE is stronger than that on earth, with CH4 and H2 playing roles similar to those of H2O and CO2 on earth. Also active on Titan is an antigreenhouse effect, in which dark-brown and orange organic aerosols block incoming solar light while allowing IR radiation from the Titan surface to escape. The combination of GHE and anti-GHE leads to a surface temperature about 12 C higher than it would be if Titan had no atmosphere.

  6. The Greenhouse Effect and Climate Feedbacks

    NASA Astrophysics Data System (ADS)

    Covey, C.; Haberle, R. M.; McKay, C. P.; Titov, D. V.

    This chapter reviews the theory of the greenhouse effect and climate feedback. It also compares the theory with observations, using examples taken from all four known terrestrial worlds with substantial atmospheres: Venus, Earth, Mars, and Titan. The greenhouse effect traps infrared radiation in the atmosphere, thereby increasing surface temperature. It is one of many factors that affect a world's climate. (Others include solar luminosity and the atmospheric scattering and absorption of solar radiation.) A change in these factors — defined as climate forcing — may change the climate in a way that brings other processes — defined as feedbacks — into play. For example, when Earth's atmospheric carbon dioxide increases, warming the surface, the water vapor content of the atmosphere increases. This is a positive feedback on global warming because water vapor is itself a potent greenhouse gas. Many positive and negative feedback processes are significant in determining Earth's climate, and probably the climates of our terrestrial neighbors.

  7. The greenhouse and antigreenhouse effects on Titan

    NASA Technical Reports Server (NTRS)

    Mckay, Christopher P.; Pollack, James B.; Courtin, Regis

    1991-01-01

    The parallels between the atmospheric thermal structure of the Saturnian satellite Titan and the hypothesized terrestrial greenhouse effect can serve as bases for the evaluation of competing greenhouse theories. Attention is presently drawn to the similarity between the roles of H2 and CH4 on Titan and CO2 and H2O on earth. Titan also has an antigreenhouse effect due to a high-altitude haze layer which absorbs at solar wavelengths, while remaining transparent in the thermal IR; if this haze layer were removed, the antigreenhouse effect would be greatly reduced, exacerbating the greenhouse effect and raising surface temperature by over 20 K.

  8. Greenhouse effect due to chlorofluorocarbons - Climatic implications

    NASA Technical Reports Server (NTRS)

    Ramanathan, V.

    1975-01-01

    The infrared bands of chlorofluorocarbons and chlorocarbons enhance the atmospheric greenhouse effect. This enhancement may lead to an appreciable increase in the global surface temperature if the atmospheric concentrations of these compounds reach values of the order of 2 parts per billion.

  9. The earth's radiation budget and its relation to atmospheric hydrology. I - Observations of the clear sky greenhouse effect. II - Observations of cloud effects

    NASA Technical Reports Server (NTRS)

    Stephens, Graeme L.; Greenwald, Thomas J.

    1991-01-01

    The clear-sky components of the earth's radiation budget (ERB), the relationship of these components to the sea surface temperature (SST), and microwave-derived water-vapor amount are analyzed in an observational study along with the relationship between the cloudy-sky components of ERB and space/time coincident observations of SST, microwave-derived cloud liquid water, and cloud cover. The purpose of the study is to use these observations for establishing an understanding of the couplings between radiation and the atmosphere that are important to understanding climate feedback. A strategy for studying the greenhouse effect of earth by analyzing the emitted clear-sky longwave flux over the ocean is proposed. It is concluded that the largest observed influence of clouds on ERB is more consistent with macrophysical properties of clouds as opposed to microphysical properties. The analysis for clouds and the greenhouse effect of clouds is compared quantitatively with the clear sky results. Land-ocean differences and tropical-midlatitude differences are shown and explained in terms of the cloud macrostructure.

  10. Scientists' internal models of the greenhouse effect

    NASA Astrophysics Data System (ADS)

    Libarkin, J. C.; Miller, H.; Thomas, S. R.

    2013-12-01

    A prior study utilized exploratory factor analysis to identify models underlying drawings of the greenhouse effect made by entering university freshmen. This analysis identified four archetype models of the greenhouse effect that appear within the college enrolling population. The current study collected drawings made by 144 geoscientists, from undergraduate geoscience majors through professionals. These participants scored highly on a standardized assessment of climate change understanding and expressed confidence in their understanding; many also indicated that they teach climate change in their courses. Although geoscientists held slightly more sophisticated greenhouse effect models than entering freshmen, very few held complete, explanatory models. As with freshmen, many scientists (44%) depict greenhouse gases in a layer in the atmosphere; 52% of participants depicted this or another layer as a physical barrier to escaping energy. In addition, 32% of participants indicated that incoming light from the Sun remains unchanged at Earth's surface, in alignment with a common model held by students. Finally, 3-20% of scientists depicted physical greenhouses, ozone, or holes in the atmosphere, all of which correspond to non-explanatory models commonly seen within students and represented in popular literature. For many scientists, incomplete models of the greenhouse effect are clearly enough to allow for reasoning about climate change. These data suggest that: 1) better representations about interdisciplinary concepts, such as the greenhouse effect, are needed for both scientist and public understanding; and 2) the scientific community needs to carefully consider how much understanding of a model is needed before necessary reasoning can occur.

  11. Effects of ploughing on land-atmosphere exchange of greenhouse gases in a managed temperate grassland in central Scotland

    NASA Astrophysics Data System (ADS)

    Helfter, Carole; Drewer, Julia; Anderson, Margaret; Scholtes, Bob; Rees, Bob; Skiba, Ute

    2015-04-01

    Grasslands are important ecosystems covering > 20% and > 30% of EU and Scotland's land area respectively. Management practices such as grazing, fertilisation and ploughing can have significant short- and long-term effects on greenhouse gas exchange. Here we report on two separate ploughing events two years apart in adjacent grasslands under common management. The Easter Bush grassland, located 10 km south of Edinburgh (55° 52'N, 3° 2'W), comprises two fields separated by a fence and is used for grazing by sheep and cattle. The vegetation is predominantly Lolium perenne (> 90%) growing on poorly drained clay loam. The fields receive several applications of mineral fertiliser a year in spring and summer. Net ecosystem exchange (NEE) of carbon dioxide (CO2) has been monitored continuously by eddy-covariance (EC) since 2002 which has demonstrated that the site is a consistent yet variable sink of atmospheric CO2. The EC system comprises a LI-COR 7000 closed-path analyser and a Gill Instruments Windmaster Pro ultrasonic anemometer mounted atop a 2.5 m mast located along the fence line separating the fields. In addition, fluxes of nitrous oxide (N2O), methane (CH4)and CO2were measured with static chambers installed along transects in each field. Gas samples collected from the chambers were analysed by gas chromatography and fluxes calculated for each 60-minute sampling period. The ploughing events in 2012 and 2014 exhibited multiple similarities in terms of NEE. The light response (i.e. relationship between CO2 flux, and photosynthetically active radiation, PAR) of the NF and SF during the month preceding each ploughing event was of comparable magnitude in both years. Following ploughing, CO2 uptake ceased in the ploughed field for approximately one month and full recovery of the photosynthetic potential was observed after ca. 2 months. During the month following the 2014 ploughing event, the ploughed NF released on average 333 ± 17 mg CO2-C m-2 h-1. In contrast, the

  12. A carbon dioxide/methane greenhouse atmosphere on early Mars

    NASA Technical Reports Server (NTRS)

    Brown, L. L.; Kasting, J. F.

    1993-01-01

    One explanation for the formation of fluvial surface features on early Mars is that the global average surface temperature was maintained at or above the freezing point of water by the greenhouse warming of a dense CO2 atmosphere; however, Kasting has shown that CO2 alone is insufficient because the formation of CO2 clouds reduces the magnitude of the greenhouse effect. It is possible that other gases, such as NH3 and CH4, were present in the early atmosphere of Mars and contributed to the greenhouse effect. Kasting et al. investigated the effect of NH3 in a CO2 atmosphere and calculated that an NH3 mixing ratio of approximately 5 x 10 (exp -4) by volume, combined with a CO2 partial pressure of 4-5 bar, could generate a global average surface temperature of 273 K near 3.8 b.y. ago when the fluvial features are believed to have formed. Atmospheric NH3 is photochemically converted to N2 by ultraviolet radiation at wavelengths shortward of 230 nm; maintenance of sufficient NH3 concentrations would therefore require a source of NH3 to balance the photolytic destruction. We have used a one-dimensional photochemical model to estimate the magnitude of the NH3 source required to maintain a given NH3 concentration in a dense CO2 atmosphere. We calculate that an NH3 mixing ratio of 10(exp -4) requires a flux of NH3 on the order of 10(exp 12) molecules /cm-s. This figure is several orders of magnitude greater than estimates of the NH3 flux on early Mars; thus it appears that NH3 with CO2 is not enough to keep early Mars warm.

  13. Observations of seasonal variations in atmospheric greenhouse trapping and its enhancement at high sea surface temperature

    NASA Technical Reports Server (NTRS)

    Hallberg, Robert; Inamdar, Anand K.

    1993-01-01

    Greenhouse trapping is examined theoretically using a version of the radiative transfer equations that demonstrates how atmospheric greenhouse trapping can vary. Satellite observations of atmospheric greenhouse trapping are examined for four months representing the various seasons. The cause of the super greenhouse effect at the highest SSTs is examined, and four processes are found to contribute. The middle and upper troposphere must be particularly moist and the temperature lapse rate must be increasingly unstable over the warmest regions to explain the observed distribution of atmospheric greenhouse trapping. Since the highest SSTs are generally associated with deep convection, this suggests that deep convection acts to moisten the middle and upper troposphere in regions of the highest SSTs relative to other regions. The tropical atmospheric circulation acts to both increase the temperature lapse rate and greatly increase the atmospheric water vapor concentration with spatially increasing SST.

  14. Heat flow vs. atmospheric greenhouse on early Mars

    NASA Technical Reports Server (NTRS)

    Fanale, F. P.; Postawko, S. E.

    1991-01-01

    Researchers derived a quantitative relationship between the effectiveness of an atmospheric greenhouse and internal heat flow in producing the morphological differences between earlier and later Martian terrains. The derivation is based on relationships previously derived by other researchers. The reasoning may be stated as follows: the CO2 mean residence time in the Martian atmosphere is almost certainly much shorter than the total time span over which early climate differences are thought to have been sustained. Therefore, recycling of previously degassed CO2 quickly becomes more important than the ongoing supply of juvenile CO2. If so, then the atmospheric CO2 pressure, and thereby the surface temperature, may be approximated mathematically as a function of the total degassed CO2 in the atmosphere plus buried material and the ratio of the atmospheric and regolith mean residence times. The latter ratio can also be expressed as a function of heat flow. Hence, it follows that the surface temperature may be expressed as a function of heat flow and the total amount of available CO2. However, the depth to the water table can simultaneously be expressed as a function of heat flow and the surface temperature (the boundary condition). Therefore, for any given values of total available CO2 and regolith conductivity, there exist coupled independent equations which relate heat flow, surface temperature, and the depth to the water table. This means we can now derive simultaneous values of surface temperature and the depth of the water table for any value of the heat flow. The derived relationship is used to evaluate the relative importance of the atmospheric greenhouse effect and the internal regolith thermal gradient in producing morphological changes for any value of the heat flow, and to assess the absolute importance of each of the values of the heat flow which are thought to be reasonable on independent geophysical grounds.

  15. Atmospheric sulfur hexafluoride - Sources, sinks and greenhouse warming

    NASA Technical Reports Server (NTRS)

    Ko, Malcolm K. W.; Sze, Nien D.; Wang, Wei-Chyung; Shia, George; Goldman, Aaron; Murcray, Frank J.; Murcray, David G.; Rinsland, Curtis P.

    1993-01-01

    An estimate is obtained of worldwide production of SF6, from which a global emission rate is derived and extrapolated for the next 20 years. The atmospheric lifetime of SF6 is then estimated based on a known mechanism (e.g., photolysis and atmospheric oxidation) and/or on the mass balance method. Finally, the radiative forcing of SF6 is calculated based on recent laboratory IR absorption data, and the expected warming over the time period 1950-2010 is computed for several emission scenarios. Calculations showed that SF6 is 3 times more effective as a greenhouse gas compared to CFC 11 on a per-molecule basis. However, based on projected emission scenarios, the expected warming from SF6 through 2010 is small (0.004 C), compared to the warming from CO2 and other trace gases (0.8 C).

  16. Integrated model shows that atmospheric brown clouds and greenhouse gases have reduced rice harvests in India

    PubMed Central

    Auffhammer, Maximilian; Ramanathan, V.; Vincent, Jeffrey R.

    2006-01-01

    Previous studies have found that atmospheric brown clouds partially offset the warming effects of greenhouse gases. This finding suggests a tradeoff between the impacts of reducing emissions of aerosols and greenhouse gases. Results from a statistical model of historical rice harvests in India, coupled with regional climate scenarios from a parallel climate model, indicate that joint reductions in brown clouds and greenhouse gases would in fact have complementary, positive impacts on harvests. The results also imply that adverse climate changes due to brown clouds and greenhouse gases contributed to the slowdown in harvest growth that occurred during the past two decades. PMID:17158795

  17. Integrated model shows that atmospheric brown clouds and greenhouse gases have reduced rice harvests in India.

    PubMed

    Auffhammer, Maximilian; Ramanathan, V; Vincent, Jeffrey R

    2006-12-26

    Previous studies have found that atmospheric brown clouds partially offset the warming effects of greenhouse gases. This finding suggests a tradeoff between the impacts of reducing emissions of aerosols and greenhouse gases. Results from a statistical model of historical rice harvests in India, coupled with regional climate scenarios from a parallel climate model, indicate that joint reductions in brown clouds and greenhouse gases would in fact have complementary, positive impacts on harvests. The results also imply that adverse climate changes due to brown clouds and greenhouse gases contributed to the slowdown in harvest growth that occurred during the past two decades.

  18. Integrated model shows that atmospheric brown clouds and greenhouse gases have reduced rice harvests in India

    SciTech Connect

    Auffhammer, M.; Ramanathan, V.; Vincent, J.R.

    2007-12-26

    Previous studies have found that atmospheric brown clouds partially offset the warming effects of greenhouse gases. This finding suggests a tradeoff between the impacts of reducing emissions of aerosols and greenhouse gases. Results from a statistical model of historical rice harvests in India, coupled with regional climate scenarios from a parallel climate model, indicate that joint reductions in brown clouds and greenhouse gases would in fact have complementary, positive impacts on harvests. The results also imply that adverse climate change due to brown clouds and greenhouse gases contributed to the slowdown in harvest growth that occurred during the past two decades.

  19. Biomarker response to galactic cosmic ray-induced NOx and the methane greenhouse effect in the atmosphere of an Earth-like planet orbiting an M dwarf star.

    PubMed

    Grenfell, John Lee; Griessmeier, Jean-Mathias; Patzer, Beate; Rauer, Heike; Segura, Antigona; Stadelmann, Anja; Stracke, Barbara; Titz, Ruth; Von Paris, Philip

    2007-02-01

    Planets orbiting in the habitable zone of M dwarf stars are subject to high levels of galactic cosmic rays (GCRs), which produce nitrogen oxides (NOx) in Earth-like atmospheres. We investigate to what extent these NO(Mx) species may modify biomarker compounds such as ozone (O3) and nitrous oxide (N2O), as well as related compounds such as water (H2O) (essential for life) and methane (CH4) (which has both abiotic and biotic sources). Our model results suggest that such signals are robust, changing in the M star world atmospheric column due to GCR NOx effects by up to 20% compared to an M star run without GCR effects, and can therefore survive at least the effects of GCRs. We have not, however, investigated stellar cosmic rays here. CH4 levels are about 10 times higher on M star worlds than on Earth because of a lowering in hydroxyl (OH) in response to changes in the ultraviolet. The higher levels of CH4 are less than reported in previous studies. This difference arose partly because we used different biogenic input. For example, we employed 23% lower CH4 fluxes compared to those studies. Unlike on Earth, relatively modest changes in these fluxes can lead to larger changes in the concentrations of biomarker and related species on the M star world. We calculate a CH4 greenhouse heating effect of up to 4K. O3 photochemistry in terms of the smog mechanism and the catalytic loss cycles on the M star world differs considerably compared with that of Earth.

  20. Greenhouse Effect Detection Experiment (GEDEX). Selected data sets

    NASA Technical Reports Server (NTRS)

    Olsen, Lola M.; Warnock, Archibald, III

    1992-01-01

    This CD-ROM contains selected data sets compiled by the participants of the Greenhouse Effect Detection Experiment (GEDEX) workshop on atmospheric temperature. The data sets include surface, upper air, and/or satellite-derived measurements of temperature, solar irradiance, clouds, greenhouse gases, fluxes, albedo, aerosols, ozone, and water vapor, along with Southern Oscillation Indices and Quasi-Biennial Oscillation statistics.

  1. Comment on "Cosmic-ray-driven reaction and greenhouse effect of halogenated molecules: Culprits for atmospheric ozone depletion and global climate change"

    NASA Astrophysics Data System (ADS)

    Nuccitelli, Dana; Cowtan, Kevin; Jacobs, Peter; Richardson, Mark; Way, Robert G.; Blackburn, Anne-Marie; Stolpe, Martin B.; Cook, John

    2014-04-01

    Lu (2013) (L13) argued that solar effects and anthropogenic halogenated gases can explain most of the observed warming of global mean surface air temperatures since 1850, with virtually no contribution from atmospheric carbon dioxide (CO2) concentrations. Here we show that this conclusion is based on assumptions about the saturation of the CO2-induced greenhouse effect that have been experimentally falsified. L13 also confuses equilibrium and transient response, and relies on data sources that have been superseeded due to known inaccuracies. Furthermore, the statistical approach of sequential linear regression artificially shifts variance onto the first predictor. L13's artificial choice of regression order and neglect of other relevant data is the fundamental cause of the incorrect main conclusion. Consideration of more modern data and a more parsimonious multiple regression model leads to contradiction with L13's statistical results. Finally, the correlation arguments in L13 are falsified by considering either the more appropriate metric of global heat accumulation, or data on longer timescales.

  2. The greenhouse effect: science and policy.

    PubMed

    Schneider, S H

    1989-02-10

    Global warming from the increase in greenhouse gases has become a major scientific and political issue during the past decade. That infrared radiation is trapped by greenhouse gases and particles in a planetary atmosphere and that the atmospheric CO(2) level has increased by some 25 percent since 1850 because of fossil fuel combustion and land use (largely deforestation) are not controversial; levels of other trace greenhouse gases such as methane and chlorofluorocarbons have increased by even larger factors. Estimates of present and future effects, however, have significant uncertainties. There have also recently been controversial claims that a global warming signal has been detected. Results from most recent climatic models suggest that global average surface temperatures will increase by some 2 degrees to 6 degrees C during the next century, but future changes in greenhouse gas concentrations and feedback processes not properly accounted for in the models could produce greater or smaller increases. Sea level rises of 0.5 to 1.5 meters are typically projected for the next century, but there is a small probability of greater or even negative change. Forecasts of the distribution of variables such as soil moisture or precipitation patterns have even greater uncertainties. Policy responses range from engineering countermeasures to passive adaptation to prevention and a "law of the atmosphere." One approach is to implement those policies now that will reduce emissions of greenhouse gases and have additional societal benefits. Whether the uncertainties are large enough to suggest delaying policy responses is not a scientific question per se, but a value judgment.

  3. (Limiting the greenhouse effect)

    SciTech Connect

    Fulkerson, W.

    1991-01-10

    The Dahlem Conference on controlling CO{sub 2} in the atmosphere focused on research needs broadly defined. The RD D needs discussed tended to be social-institutional rather than technically oriented perhaps because of the propensity of most attendees, but many important ideas emerged, including those related to questions on technology adoption by both developed, emerging, or transition economics. The European attendees appeared to be strongly devoted to reducing emissions, and doing it soon using efficiency improvement and ultimately renewables. The importance of efficiency improvement was universally accepted, but the extent to which it can be relied upon is a major uncertainty for everyone except the most zealous. There was no detailed discussion of what could be done to encourage the more rapid adoption of renewables. Most attendees seemed to have discounted nuclear, but, at any rate, the problems of reviving nuclear worldwide were not discussed in detail.

  4. Atmospheric Sulfur Hexafluoride: Sources, Sinks and Greenhouse Warming

    NASA Technical Reports Server (NTRS)

    Sze, Nien Dak; Wang, Wei-Chyung; Shia, George; Goldman, Aaron; Murcray, Frank J.; Murcray, David G.; Rinsland, Curtis P.

    1993-01-01

    Model calculations using estimated reaction rates of sulfur hexafluoride (SF6) with OH and 0('D) indicate that the atmospheric lifetime due to these processes may be very long (25,000 years). An upper limit for the UV cross section would suggest a photolysis lifetime much longer than 1000 years. The possibility of other removal mechanisms are discussed. The estimated lifetimes are consistent with other estimated values based on recent laboratory measurements. There appears to be no known natural source of SF6. An estimate of the current production rate of SF6 is about 5 kt/yr. Based on historical emission rates, we calculated a present-day atmospheric concentrations for SF6 of about 2.5 parts per trillion by volume (pptv) and compared the results with available atmospheric measurements. It is difficult to estimate the atmospheric lifetime of SF6 based on mass balance of the emission rate and observed abundance. There are large uncertainties concerning what portion of the SF6 is released to the atmosphere. Even if the emission rate were precisely known, it would be difficult to distinguish among lifetimes longer than 100 years since the current abundance of SF6 is due to emission in the past three decades. More information on the measured trends over the past decade and observed vertical and latitudinal distributions of SF6 in the lower stratosphere will help to narrow the uncertainty in the lifetime. Based on laboratory-measured IR absorption cross section for SF6, we showed that SF6 is about 3 times more effective as a greenhouse gas compared to CFC 11 on a per molecule basis. However, its effect on atmospheric warming will be minimal because of its very small concentration. We estimated the future concentration of SF6 at 2010 to be 8 and 10 pptv based on two projected emission scenarios. The corresponding equilibrium warming of 0.0035 C and 0.0043 C is to be compared with the estimated warming due to CO2 increase of about 0.8 C in the same period.

  5. Habitability of waterworlds: runaway greenhouses, atmospheric expansion, and multiple climate states of pure water atmospheres.

    PubMed

    Goldblatt, Colin

    2015-05-01

    There are four different stable climate states for pure water atmospheres, as might exist on so-called "waterworlds." I map these as a function of solar constant for planets ranging in size from Mars-sized to 10 Earth-mass. The states are as follows: globally ice covered (Ts ⪅ 245 K), cold and damp (270 ⪅ Ts ⪅ 290 K), hot and moist (350 ⪅ Ts ⪅ 550 K), and very hot and dry (Tsx2A86;900 K). No stable climate exists for 290 ⪅ T s ⪅ 350 K or 550 ⪅ Ts ⪅ 900 K. The union of hot moist and cold damp climates describes the liquid water habitable zone, the width and location of which depends on planet mass. At each solar constant, two or three different climate states are stable. This is a consequence of strong nonlinearities in both thermal emission and the net absorption of sunlight. Across the range of planet sizes, I account for the atmospheres expanding to high altitudes as they warm. The emitting and absorbing surfaces (optical depth of unity) move to high altitude, making their area larger than the planet surface, so more thermal radiation is emitted and more sunlight absorbed (the former dominates). The atmospheres of small planets expand more due to weaker gravity; the effective runaway greenhouse threshold is about 35 W m(-2) higher for Mars, 10 W m(-2) higher for Earth or Venus, but only a few W m(-2) higher for a 10 Earth-mass planet. There is an underlying (expansion-neglected) trend of increasing runaway greenhouse threshold with planetary size (40 W m(-2) higher for a 10 Earth-mass planet than for Mars). Summing these opposing trends means that Venus-sized (or slightly smaller) planets are most susceptible to a runaway greenhouse. The habitable zone for pure water atmospheres is very narrow, with an insolation range of 0.07 times the solar constant. A wider habitable zone requires background gas and greenhouse gas: N2 and CO2 on Earth, which are biologically controlled. Thus, habitability depends on inhabitance. PMID:25984919

  6. Habitability of waterworlds: runaway greenhouses, atmospheric expansion, and multiple climate states of pure water atmospheres.

    PubMed

    Goldblatt, Colin

    2015-05-01

    There are four different stable climate states for pure water atmospheres, as might exist on so-called "waterworlds." I map these as a function of solar constant for planets ranging in size from Mars-sized to 10 Earth-mass. The states are as follows: globally ice covered (Ts ⪅ 245 K), cold and damp (270 ⪅ Ts ⪅ 290 K), hot and moist (350 ⪅ Ts ⪅ 550 K), and very hot and dry (Tsx2A86;900 K). No stable climate exists for 290 ⪅ T s ⪅ 350 K or 550 ⪅ Ts ⪅ 900 K. The union of hot moist and cold damp climates describes the liquid water habitable zone, the width and location of which depends on planet mass. At each solar constant, two or three different climate states are stable. This is a consequence of strong nonlinearities in both thermal emission and the net absorption of sunlight. Across the range of planet sizes, I account for the atmospheres expanding to high altitudes as they warm. The emitting and absorbing surfaces (optical depth of unity) move to high altitude, making their area larger than the planet surface, so more thermal radiation is emitted and more sunlight absorbed (the former dominates). The atmospheres of small planets expand more due to weaker gravity; the effective runaway greenhouse threshold is about 35 W m(-2) higher for Mars, 10 W m(-2) higher for Earth or Venus, but only a few W m(-2) higher for a 10 Earth-mass planet. There is an underlying (expansion-neglected) trend of increasing runaway greenhouse threshold with planetary size (40 W m(-2) higher for a 10 Earth-mass planet than for Mars). Summing these opposing trends means that Venus-sized (or slightly smaller) planets are most susceptible to a runaway greenhouse. The habitable zone for pure water atmospheres is very narrow, with an insolation range of 0.07 times the solar constant. A wider habitable zone requires background gas and greenhouse gas: N2 and CO2 on Earth, which are biologically controlled. Thus, habitability depends on inhabitance.

  7. Habitability of Waterworlds: Runaway Greenhouses, Atmospheric Expansion, and Multiple Climate States of Pure Water Atmospheres

    PubMed Central

    2015-01-01

    Abstract There are four different stable climate states for pure water atmospheres, as might exist on so-called “waterworlds.” I map these as a function of solar constant for planets ranging in size from Mars-sized to 10 Earth-mass. The states are as follows: globally ice covered (Ts⪅245 K), cold and damp (270⪅Ts⪅290 K), hot and moist (350⪅Ts⪅550 K), and very hot and dry (Tsx2A86;900 K). No stable climate exists for 290⪅Ts ⪅350 K or 550⪅Ts⪅900 K. The union of hot moist and cold damp climates describes the liquid water habitable zone, the width and location of which depends on planet mass. At each solar constant, two or three different climate states are stable. This is a consequence of strong nonlinearities in both thermal emission and the net absorption of sunlight. Across the range of planet sizes, I account for the atmospheres expanding to high altitudes as they warm. The emitting and absorbing surfaces (optical depth of unity) move to high altitude, making their area larger than the planet surface, so more thermal radiation is emitted and more sunlight absorbed (the former dominates). The atmospheres of small planets expand more due to weaker gravity; the effective runaway greenhouse threshold is about 35 W m−2 higher for Mars, 10 W m−2 higher for Earth or Venus, but only a few W m−2 higher for a 10 Earth-mass planet. There is an underlying (expansion-neglected) trend of increasing runaway greenhouse threshold with planetary size (40 W m−2 higher for a 10 Earth-mass planet than for Mars). Summing these opposing trends means that Venus-sized (or slightly smaller) planets are most susceptible to a runaway greenhouse. The habitable zone for pure water atmospheres is very narrow, with an insolation range of 0.07 times the solar constant. A wider habitable zone requires background gas and greenhouse gas: N2 and CO2 on Earth, which are biologically controlled. Thus, habitability depends on inhabitance. Key Words

  8. The Greenhouse Effect: Science and Policy.

    ERIC Educational Resources Information Center

    Schneider, Stephen H.

    1989-01-01

    Discusses many of the scientific questions surrounding the greenhouse effect debate and the issue of plausible responses. Discussion includes topics concerning projecting emissions and greenhouse gas concentrations, estimating global climatic response, economic, social, and political impacts, and policy responses. (RT)

  9. The Greenhouse Effect and Built Environment Education.

    ERIC Educational Resources Information Center

    Greenall Gough, Annette; Gough, Noel

    The greenhouse effect has always existed. Without the greenhouse effect, Earth could well have the oven-like environment of Venus or the deep-freeze environment of Mars. There is some debate about how much the Earth's surface temperature will rise given a certain amount of increase in the amount of greenhouse gases such as carbon dioxide, nitrous…

  10. Height of convective layer in planetary atmospheres with condensable and non-condensable greenhouse substances

    NASA Astrophysics Data System (ADS)

    Makarieva, A. M.; Gorshkov, V. G.; Pujol, T.

    2003-12-01

    Convection reduces greenhouse effect by transporting a certain amount of non-radiative dynamic energy to the upper atmosphere, where this energy dissipates and radiates into space without interaction with greenhouse substances in the lower atmosphere. In this paper we show that the height of the convective layer zc is finite and independent of atmospheric optical thickness τs at large values of the latter. We derive an analytical formula for zc at large values of τs for condensable and non-condensable greenhouse substances. The formula obtained yields reasonable quantitative estimates of the observed height of convective layer on Venus and at low latitudes on Earth, where atmospheric thickness of water vapor is maximum. The dissipative power of dynamic convective processes is limited by the incoming flux of solar radiation. Height of convective layer being finite, values of optical depth at the top of the convective layer and at the mean height of convective energy dissipation increase proportionally to the atmospheric optical thickness, while the contribution of convective energy fluxes to formation of the outgoing flux of thermal radiation proportionally diminishes. As far as optical thickness of condensable greenhouse substances grows exponentially with increasing surface temperature, the obtained results lead to the conclusion that the outgoing thermal radiation into space in the presence of convection tends exponentially to zero with increasing surface temperature, instead of reaching a finite plateau as suggested by earlier radiative-convective studies.

  11. Measuring solar- and greenhouse radiation profiles in the atmosphere using upper-air radiosondes

    NASA Astrophysics Data System (ADS)

    Philipona, R.; Kräuchi, A.

    2012-04-01

    Solar shortwave and thermal longwave irradiance is usually measured at the Earth's surface with ground radiation stations and at the top of the atmosphere with satellites. Here we show for the first time radiative flux profiles and the radiation budget in the atmosphere measured with radiosondes ascending from the Earth's surface to 35 km into the stratosphere. During two-hour flights solar shortwave and thermal longwave irradiance, downward and upward, is measured with four individual sensors at one-second resolution, along with standard PTU radiosonde profiles. Nighttime longwave radiation measurements are contrasted to daytime measurements and 24 hours means of radiation budget- and total net radiation profiles are shown. Of particular interest for greenhouse effect investigations are in situ measured longwave greenhouse radiation profiles and their vertical changes in relation to temperature, clouds, water vapour and other greenhouse gases.

  12. U.S. regional greenhouse gas emissions analysis comparing highly resolved vehicle miles traveled and CO2 emissions: mitigation implications and their effect on atmospheric measurements

    NASA Astrophysics Data System (ADS)

    Mendoza, D. L.; Gurney, K. R.

    2010-12-01

    Carbon dioxide (CO2) is the most abundant anthropogenic greenhouse gas and projections of fossil fuel energy demand show CO2 concentrations increasing indefinitely into the future. After electricity production, the transportation sector is the second largest CO2 emitting economic sector in the United States, accounting for 32.3% of the total U.S. emissions in 2002. Over 80% of the transport sector is composed of onroad emissions, with the remainder shared by the nonroad, aircraft, railroad, and commercial marine vessel transportation. In order to construct effective mitigation policy for the onroad transportation sector and more accurately predict CO2 emissions for use in transport models and atmospheric measurements, analysis must incorporate the three components that determine the CO2 onroad transport emissions: vehicle fleet composition, average speed of travel, and emissions regulation strategies. Studies to date, however, have either focused on one of these three components, have been only completed at the national scale, or have not explicitly represented CO2 emissions instead relying on the use of vehicle miles traveled (VMT) as an emissions proxy. National-level projections of VMT growth is not sufficient to highlight regional differences in CO2 emissions growth due to the heterogeneity of vehicle fleet and each state’s road network which determines the speed of travel of vehicles. We examine how an analysis based on direct CO2 emissions and an analysis based on VMT differ in terms of their emissions and mitigation implications highlighting potential biases introduced by the VMT-based approach. This analysis is performed at the US state level and results are disaggregated by road and vehicle classification. We utilize the results of the Vulcan fossil fuel CO2 emissions inventory which quantified emissions for the year 2002 across all economic sectors in the US at high resolution. We perform this comparison by fuel type,12 road types, and 12 vehicle types

  13. Modern inhalation anesthetics: Potent greenhouse gases in the global atmosphere

    NASA Astrophysics Data System (ADS)

    Vollmer, Martin K.; Rhee, Tae Siek; Rigby, Matt; Hofstetter, Doris; Hill, Matthias; Schoenenberger, Fabian; Reimann, Stefan

    2015-03-01

    Modern halogenated inhalation anesthetics undergo little metabolization during clinical application and evaporate almost completely to the atmosphere. Based on their first measurements in a range of environments, from urban areas to the pristine Antarctic environment, we detect a rapid accumulation and ubiquitous presence of isoflurane, desflurane, and sevoflurane in the global atmosphere. Over the past decade, their abundances in the atmosphere have increased to global mean mole fractions in 2014 of 0.097ppt, 0.30ppt, and 0.13ppt (parts per trillion, 10-12, in dry air), respectively. Emissions of these long-lived greenhouse gases inferred from the observations suggest a global combined release to the atmosphere of 3.1 ± 0.6 million t CO2 equivalent in 2014 of which ≈80% stems from desflurane. We also report on halothane, a previously widely used anesthetic. Its global mean mole fraction has declined to 9.2ppq (parts per quadrillion, 10-15) by 2014. However, the inferred present usage is still 280 ±120t yr-1.

  14. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere

    NASA Astrophysics Data System (ADS)

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M.; Canadell, Josep G.; Saikawa, Eri; Huntzinger, Deborah N.; Gurney, Kevin R.; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward; Friedlingstein, Pierre; Melillo, Jerry; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald; Saunois, Marielle; Schwalm, Christopher R.; Wofsy, Steven C.

    2016-03-01

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change.

  15. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere

    DOE PAGES

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M.; Canadell, Josep G.; Saikawa, Eri; Huntzinger, Deborah N.; Gurney, Kevin R; Sitch, Stephen; Zhang, Bowen; et al

    2016-03-09

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate1. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change2, 3. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively4, 5, 6, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain.more » Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Lastly, our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change.« less

  16. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere.

    PubMed

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M; Canadell, Josep G; Saikawa, Eri; Huntzinger, Deborah N; Gurney, Kevin R; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward; Friedlingstein, Pierre; Melillo, Jerry; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald; Saunois, Marielle; Schwalm, Christopher R; Wofsy, Steven C

    2016-03-10

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change. PMID:26961656

  17. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere.

    PubMed

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M; Canadell, Josep G; Saikawa, Eri; Huntzinger, Deborah N; Gurney, Kevin R; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward; Friedlingstein, Pierre; Melillo, Jerry; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald; Saunois, Marielle; Schwalm, Christopher R; Wofsy, Steven C

    2016-03-10

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change.

  18. Remote sensing of atmospheric greenhouse gases: bridging spatial scales

    NASA Astrophysics Data System (ADS)

    Humpage, N.; Boesch, H.; Parker, R.; Hewson, W.; Sembhi, H.; Somkuti, P.; Webb, A.; Palmer, P. I.; Feng, L.

    2015-12-01

    Observed atmospheric variations of greenhouse gases (GHG) are determined by surface-atmosphere exchange, and atmospheric chemistry and transport. These processes occur over a wide spectrum of spatial and temporal scales. Confronting atmospheric transport models and ultimately improving the fidelity of surface flux estimates demands an integrated observing system that captures these scales. We will discuss using data the role of GHG remote sensing instruments and argue that our ability to deploy them from the ground and to fly them on satellite, aircraft, and unmanned airborne vehicles (UAV) mean that they represent the ideal technology to bridge the observed scales of variability. We will discuss a five-year record of global-scale column observations of CO2 and CH4 from the Japanese GOSAT satellite instrument that is available from University of Leicester as part of the ESA Climate Change Initiative. We will showcase new CO2 and CH4 column data that was collected by our shortwave infrared spectrometer GHOST oboard the NASA Global Hak during a regional survey over the eastern Pacific during early spring 2015, which included coincident overpasses from GOSAT and the NASA OCO-2. These data are being used to test atmospheric transport models over remote regions and to help validate satellite observations over the oceans. We will also discuss GHOST data collected on the UK Dornier 226 research aircraft to measure local-scale measurements over Leicester city centre, a major power plant, and downwind of a controlled Cumbrian heathland fire. Finally, we will report preliminary results from a new ground-based Fourier transform spectrometer station at Harwell (80 km west of London). We anticipate that this site will eventually join the TCCON network, which has been used to validation of satellite observations.

  19. Atmospheric aerosols versus greenhouse gases in the twenty-first century.

    PubMed

    Andreae, Meinrat O

    2007-07-15

    Looked at in a simplistic way, aerosols have counteracted the warming effects of greenhouse gases (GHG) over the past century. This has not only provided some 'climate protection', but also prevented the true magnitude of the problem from becoming evident. In particular, it may have resulted in an underestimation of the sensitivity of the climate system to the effect of GHG. Over the present century, the role of aerosols in opposing global warming will wane, as there are powerful policy reasons to reduce their emissions and their atmospheric lifetimes are short in contrast to those of the GHG. On the other hand, aerosols will continue to play a role in regional climate change, especially with regard to the water cycle. The end of significant climate protection by atmospheric aerosols, combined with the potentially very high sensitivity of the climate system, makes sharp and prompt reductions in greenhouse gas emissions, especially CO2, very urgent.

  20. Greenhouse effect may not be all bad

    SciTech Connect

    Senft, D.

    1990-10-01

    Evidence is presented that indicates US temperatures decreased by a fraction of a degree during the past 70 years contrary to the estimates of some researchers concerned with the greenhouse effect. There is general agreement that the carbon dioxide concentrations in the atmosphere will double by the late or mid 21st century. Experiments on cotton growth under increased temperature and carbon dioxide concentrations indicate sizeable gains in yield. This increased yield is exhibited by citrus trees and is projected for other crops. There is a concomitant need for more water and fertilizer. Increased populations of parasitic mites and insects also occur. Climatic changes are seen as being more gradual than previously thought. The possible increases in food production under these changes in climate are one positive element in the emerging scenario.

  1. Direct Demonstration of the Greenhouse Effect

    NASA Astrophysics Data System (ADS)

    Jaffe, D. A.; Malashanka, S.; Call, K.; Bernays, N.

    2012-12-01

    Consider these three "theories:" climate change, evolution, and gravity. Why are two of them hotly debated by non-scientists, but not gravity? In part, the answer is that climate change and evolution are more complex processes and not readily observable over short time scales to most people. In contrast, the "theory of gravity" is tested every day by billions of people world-wide and is therefore not challenged. While there are numerous "demonstrations" of the greenhouse effect available online, unfortunately, many of them are based on poor understanding of the physical principles involved. For this reason, we sought to develop simple and direct experiments that would demonstrate aspects of the greenhouse effect that would be suitable for museums, K-12, and/or college classrooms. We will describe two experiments. In the first, we use a simple plexiglass tube, approximately 12 cm long, with IR transparent windows. The tube is first filled with dry nitrogen and exposed to an IR heat lamp. Following this, the tube is filled with pure, dry CO2. Both tubes warm up, but the tube filled with CO2 ends up about 0.7 degrees C warmer. It is useful to compare this 12 cm column of CO2 to the column in the earth's atmosphere, which is equivalent to approximately 2.7 meters of pure CO2. This demonstration would be suitable for museum exhibits to demonstrate the physical basis of CO2 heating in the atmosphere. In the second experiment, we use FTIR spectroscopy to quantify the CO2 content of ambient air and indoor/classroom air. For this experiment, we use a commercial standard of 350 ppm CO2 to calibrate the absorption features. Once the CO2 content of ambient air is found, it is useful for students to compare their observed value to background data (e.g. NOAA site in Hawaii) and/or the "Keeling Curve". This leads into a discussion on causes for local variations and the long-term trends. This experiment is currently used in our general chemistry class but could be used in many

  2. The state of greenhouse gases in the atmosphere using global observations through 2014

    NASA Astrophysics Data System (ADS)

    Tarasova, Oksana; Koide, Hiroshi; Dlugokencky, Ed

    2016-04-01

    Oceanic and Atmospheric Administration (NOAA) Annual Greenhouse Gas Index shows that from 1990 to 2014 radiative forcing by long-lived greenhouse gases increased by 36%, with CO2 accounting for about 80% of this increase. The radiative forcing by all long-lived greenhouse gases in 2013 corresponded to a CO2-equivalent mole fraction of 481 ppm (http://www.esrl.noaa.gov/gmd/aggi). The Bulletin cover story explains the role of the water vapor in the greenhouse effect. In spite of water vapor being a strong greenhouse gas, it is the non-condensable greenhouse gases affected by human activities that serve as climate forcing agents; water vapor and clouds act as fast feedbacks. The strong water vapor feedback means that for a doubling of CO2 abundance from preindustrial conditions (from about 280 to 560 ppm), water vapor and clouds lead to a global increase in surface thermal energy that is about three times that of long-lived (non-condensable) greenhouse gases.

  3. Can increased atmospheric CO2 levels trigger a runaway greenhouse?

    PubMed

    Ramirez, Ramses M; Kopparapu, Ravi Kumar; Lindner, Valerie; Kasting, James F

    2014-08-01

    Recent one-dimensional (globally averaged) climate model calculations by Goldblatt et al. (2013) suggest that increased atmospheric CO(2) could conceivably trigger a runaway greenhouse on present Earth if CO(2) concentrations were approximately 100 times higher than they are today. The new prediction runs contrary to previous calculations by Kasting and Ackerman (1986), which indicated that CO(2) increases could not trigger a runaway, even at Venus-like CO(2) concentrations. Goldblatt et al. argued that this different behavior is a consequence of updated absorption coefficients for H(2)O that make a runaway more likely. Here, we use a 1-D climate model with similar, up-to-date absorption coefficients, but employ a different methodology, to show that the older result is probably still valid, although our model nearly runs away at ∼12 preindustrial atmospheric levels of CO(2) when we use the most alarmist assumptions possible. However, we argue that Earth's real climate is probably stable given more realistic assumptions, although 3-D climate models will be required to verify this result. Potential CO(2) increases from fossil fuel burning are somewhat smaller than this, 10-fold or less, but such increases could still cause sufficient warming to make much of the planet uninhabitable by humans.

  4. Can increased atmospheric CO2 levels trigger a runaway greenhouse?

    PubMed

    Ramirez, Ramses M; Kopparapu, Ravi Kumar; Lindner, Valerie; Kasting, James F

    2014-08-01

    Recent one-dimensional (globally averaged) climate model calculations by Goldblatt et al. (2013) suggest that increased atmospheric CO(2) could conceivably trigger a runaway greenhouse on present Earth if CO(2) concentrations were approximately 100 times higher than they are today. The new prediction runs contrary to previous calculations by Kasting and Ackerman (1986), which indicated that CO(2) increases could not trigger a runaway, even at Venus-like CO(2) concentrations. Goldblatt et al. argued that this different behavior is a consequence of updated absorption coefficients for H(2)O that make a runaway more likely. Here, we use a 1-D climate model with similar, up-to-date absorption coefficients, but employ a different methodology, to show that the older result is probably still valid, although our model nearly runs away at ∼12 preindustrial atmospheric levels of CO(2) when we use the most alarmist assumptions possible. However, we argue that Earth's real climate is probably stable given more realistic assumptions, although 3-D climate models will be required to verify this result. Potential CO(2) increases from fossil fuel burning are somewhat smaller than this, 10-fold or less, but such increases could still cause sufficient warming to make much of the planet uninhabitable by humans. PMID:25061956

  5. The greenhouse effect: Physiological changes in plants

    SciTech Connect

    Beard, R.; Harrison, M. )

    1990-05-01

    Elevated atmospheric carbon dioxide is timely topic of study for all biology students at all levels. The stimulatory effect of elevated atmospheric carbon dioxide (700 {mu}l/l) on plant growth, flower induction, protein production and the Calvin-Benson cycle can be easily demonstrated in seedlings in student laboratories. In our lab, the shoot growth of rapid cycling brassicas (Wisconsin fast plants) was measured under ambient and elevated CO{sub 2} conditions for three weeks. Plants grown under elevated CO{sub 2} conditions were significantly taller and showed earlier flower development. These plants also contained greater protein content per gram fresh weight. Crude leaf extracts was used as a source of pentose-5-isomerase which controls the conversion of ribose-5-phosphate to ribulose-5-phosphate in carbon fixation. The activity of this enzyme was measured spectrophotometrically and found to be somewhat greater in plants grown under the higher CO{sub 2} conditions. These physiological changes associated with elevated CO{sub 2} can be used as an introduction to the greenhouse effect as well as to study the regulation of carbon fixation.

  6. Atmospheric expansion in runaway greenhouse atmospheres: the inner edge of the habitable zone depends on planet mass

    NASA Astrophysics Data System (ADS)

    Goldblatt, C.; Zahnle, K. J.

    2014-12-01

    As a wet planet becomes hot, evaporation of the ocean provides a thick steam atmosphere. As the atmosphere thickens, the level at which optical depth is unity (whence radiative emission and absorption dominantly occur) rises into the atmosphere, first for thermal wavelengths and later for solar wavelengths. Consequently, two radiation limits emerge. First, an asymptotic limit on the thermal radiation, as the level at which thermal emission occurs tends towards a fixed temperature, decoupled from surface temperature. Next, a limit the albedo of the planet, as all incoming sunlight is either reflected or absorbed in the atmosphere and almost none reaches the surface. A runaway greenhouse occurs when the product of co-albedo and area-averaged incoming sunlight exceeds the thermal radiation limit. Earth today is perilously close to this [1].Returning to the first sentence, we generate a thick atmosphere: the height of optical depth of unity becomes a non-trivial fraction of the planetary radius. Hence the area of the absorbing and emitting surfaces increase. Thermal emission wins slightly, as this occurs higher, increasing thermal emission in all cases. The underlying tendency is for a larger thermal limit for heavier planets due to pressure effects, making these appear more resistant to a runaway. However, atmospheric expansion affects light planets more, making these seem much more resilient. The least resilient planet would be between Mars-size and Venus-size (Figure 1). It would be foolish to regard small planets as habitable. As the atmospheres become large, so does the problem of atmospheric escape. Theoretical considerations show hydrodynamic escape to happen disastrously for a Europa-size planet. The observation is that Mars is too feeble to hold on to any hefty atmosphere, even far from the Sun as it is, is probably relevant too. The take home points for habitable zone nerds are: (1) planet size matters (2) for small planets, atmospheric escape from a "moist

  7. A mental picture of the greenhouse effect - A pedagogic explanation

    NASA Astrophysics Data System (ADS)

    Benestad, Rasmus E.

    2016-01-01

    The popular picture of the greenhouse effect emphasises the radiation transfer but fails to explain the observed climate change. An old conceptual model for the greenhouse effect is revisited and presented as a useful resource in climate change communication. It is validated against state-of-the-art data, and nontraditional diagnostics show a physically consistent picture. The earth's climate is constrained by well-known and elementary physical principles, such as energy balance, flow, and conservation. Greenhouse gases affect the atmospheric optical depth for infrared radiation, and increased opacity implies higher altitude from which earth's equivalent bulk heat loss takes place. Such an increase is seen in the reanalyses, and the outgoing long-wave radiation has become more diffuse over time, consistent with an increased influence of greenhouse gases on the vertical energy flow from the surface to the top of the atmosphere. The reanalyses further imply increases in the overturning in the troposphere, consistent with a constant and continuous vertical energy flow. The increased overturning can explain a slowdown in the global warming, and the association between these aspects can be interpreted as an entanglement between the greenhouse effect and the hydrological cycle, where reduced energy transfer associated with increased opacity is compensated by tropospheric overturning activity.

  8. The Greenhouse Effect in a Vial.

    ERIC Educational Resources Information Center

    Golden, Richard; Sneider, Cary

    1989-01-01

    Presents an example of a greenhouse-effect experiment from the Climate Protection Institute. Analyzes the amount of carbon dioxide in ambient air, human exhalation, automobile exhaust, and nearly pure carbon dioxide by titrating with ammonia and bromthymol blue. (MVL)

  9. Reply to "comment on 'falsification of the Atmospheric CO2 Greenhouse Effects Within the Frame of Physics' by Joshua B. Halpern, Christopher M. Colose, Chris Ho-Stuart Joel D. Shore, Arthur P. Smith, JÖRG Zimmermann"

    NASA Astrophysics Data System (ADS)

    Gerlich, Gerhard; Tscheuschner, Ralf D.

    It is shown that the notorious claim by Halpern et al. recently repeated in their comment that the method, logic, and conclusions of our "Falsification Of The CO2 Greenhouse Effects Within The Frame Of Physics" would be in error has no foundation. Since Halpern et al. communicate our arguments incorrectly, their comment is scientifically vacuous. In particular, it is not true that we are "trying to apply the Clausius statement of the Second Law of Thermodynamics to only one side of a heat transfer process rather than the entire process" and that we are "systematically ignoring most non-radiative heat flows applicable to Earth's surface and atmosphere". Rather, our falsification paper discusses the violation of fundamental physical and mathematical principles in 14 examples of common pseudo-derivations of fictitious greenhouse effects that are all based on simplistic pictures of radiative transfer and their obscure relation to thermodynamics, including but not limited to those descriptions (a) that define a "Perpetuum Mobile Of The 2nd Kind", (b) that rely on incorrectly calculated averages of global temperatures, (c) that refer to incorrectly normalized spectra of electromagnetic radiation. Halpern et al. completely missed an exceptional chance to formulate a scientifically well-founded antithesis. They do not even define a greenhouse effect that they wish to defend. We take the opportunity to clarify some misunderstandings, which are communicated in the current discussion on the non-measurable, i.e., physically non-existing influence of the trace gas CO2 on the climates of the Earth.

  10. The detection of climate change due to the enhanced greenhouse effect

    NASA Technical Reports Server (NTRS)

    Schiffer, Robert A.; Unninayar, Sushel

    1991-01-01

    The greenhouse effect is accepted as an undisputed fact from both theoretical and observational considerations. In Earth's atmosphere, the primary greenhouse gas is water vapor. The specific concern today is that increasing concentrations of anthropogenically introduced greenhouse gases will, sooner or later, irreversibly alter the climate of Earth. Detecting climate change has been complicated by uncertainties in historical observations and measurements. Thus, the primary concern for the GEDEX project is how can climate change and enhanced greenhouse effects be unambiguously detected and quantified. Specifically examined are the areas of: Earth surface temperature; the free atmosphere (850 millibars and above); space-based measurements; measurement uncertainties; and modeling the observed temperature record.

  11. Micrometeorites in the Post-lunar Greenhouse Effect

    NASA Astrophysics Data System (ADS)

    Maurette, Michel

    On the Earth, an astonishing balance between the absorption and scattering of solar radiation by the early Earth produced the remarkable benign greenhouse effect favourable to the origin and evolution of life. Indeed, the first constraint on any scenario is that the early oceans were not boiling or freezing! It is generally considered that the temperature has to be sufficiently high to prevent freezing at a time when the solar luminosity was smaller than today. But it has to be kept sufficiently low by some mysterious feedback effect, in order to protect the Earth from a runaway greenhouse effect, which led to a surface temperature of about 450 °C on Venus. In fact, the long-lasting micrometeorite thermospheric volcanism effective after the Moon-forming impact, should have ruled the post-lunar greenhouse effect that was critical for the birth of life. Indeed, this impact eradicated at once all atmospheric ingredients of the pre-lunar greenhouse effect at a time when the young Earth was already almost fully outgassed. Subsequently, micrometeorites released simultaneously greenhouse gases for heating and smoke particles for cooling. These micrometeorite ashes resided temporarily within a kind of giant thermospheric cocoon, which might have functioned as a self-regulating IR heater during the period of low solar luminosity. Indeed, it was simultaneously heated up from the inside through the aerodynamical braking of micrometeorites.

  12. CO2 greenhouse in the early martian atmosphere: SO2 inhibits condensation.

    PubMed

    Yung, Y L; Nair, H; Gerstell, M F

    1997-01-01

    Many investigators of the early martian climate have suggested that a dense carbon dioxide atmosphere was present and warmed the surface above the melting point of water (J.B. Pollack, J.F. Kasting, S.M. Richardson, and K. Poliakoff 1987. Icarus 71, 203-224). However, J.F. Kasting (1991. Icarus 94, 1-13) pointed out that previous thermal models of the primitive martian atmosphere had not considered the condensation of CO2. When this effect was incorporated, Kasting found that CO2 by itself is inadequate to warm the surface. SO2 absorbs strongly in the near UV region of the solar spectrum. While a small amount of SO2 may have a negligible effect by itself on the surface temperature, it may have significantly warmed the middle atmosphere of early Mars, much as ozone warms the terrestrial stratosphere today. If this region is kept warm enough to inhibit the condensation of CO2, then CO2 remains a viable greenhouse gas. Our preliminary radiative modeling shows that the addition of 0.1 ppmv of SO2 in a 2 bar CO2 atmosphere raises the temperature of the middle atmosphere by approximately 10 degrees, so that the upper atmosphere in a 1 D model remains above the condensation temperature of CO2. In addition, this amount of SO2 in the atmosphere provides an effective UV shield for a hypothetical biosphere on the martian surface.

  13. CO2 greenhouse in the early martian atmosphere: SO2 inhibits condensation

    NASA Technical Reports Server (NTRS)

    Yung, Y. L.; Nair, H.; Gerstell, M. F.

    1997-01-01

    Many investigators of the early martian climate have suggested that a dense carbon dioxide atmosphere was present and warmed the surface above the melting point of water (J.B. Pollack, J.F. Kasting, S.M. Richardson, and K. Poliakoff 1987. Icarus 71, 203-224). However, J.F. Kasting (1991. Icarus 94, 1-13) pointed out that previous thermal models of the primitive martian atmosphere had not considered the condensation of CO2. When this effect was incorporated, Kasting found that CO2 by itself is inadequate to warm the surface. SO2 absorbs strongly in the near UV region of the solar spectrum. While a small amount of SO2 may have a negligible effect by itself on the surface temperature, it may have significantly warmed the middle atmosphere of early Mars, much as ozone warms the terrestrial stratosphere today. If this region is kept warm enough to inhibit the condensation of CO2, then CO2 remains a viable greenhouse gas. Our preliminary radiative modeling shows that the addition of 0.1 ppmv of SO2 in a 2 bar CO2 atmosphere raises the temperature of the middle atmosphere by approximately 10 degrees, so that the upper atmosphere in a 1 D model remains above the condensation temperature of CO2. In addition, this amount of SO2 in the atmosphere provides an effective UV shield for a hypothetical biosphere on the martian surface.

  14. CO2 greenhouse in the early martian atmosphere: SO2 inhibits condensation.

    PubMed

    Yung, Y L; Nair, H; Gerstell, M F

    1997-01-01

    Many investigators of the early martian climate have suggested that a dense carbon dioxide atmosphere was present and warmed the surface above the melting point of water (J.B. Pollack, J.F. Kasting, S.M. Richardson, and K. Poliakoff 1987. Icarus 71, 203-224). However, J.F. Kasting (1991. Icarus 94, 1-13) pointed out that previous thermal models of the primitive martian atmosphere had not considered the condensation of CO2. When this effect was incorporated, Kasting found that CO2 by itself is inadequate to warm the surface. SO2 absorbs strongly in the near UV region of the solar spectrum. While a small amount of SO2 may have a negligible effect by itself on the surface temperature, it may have significantly warmed the middle atmosphere of early Mars, much as ozone warms the terrestrial stratosphere today. If this region is kept warm enough to inhibit the condensation of CO2, then CO2 remains a viable greenhouse gas. Our preliminary radiative modeling shows that the addition of 0.1 ppmv of SO2 in a 2 bar CO2 atmosphere raises the temperature of the middle atmosphere by approximately 10 degrees, so that the upper atmosphere in a 1 D model remains above the condensation temperature of CO2. In addition, this amount of SO2 in the atmosphere provides an effective UV shield for a hypothetical biosphere on the martian surface. PMID:11541436

  15. From Anti-greenhouse Effect of Solar Absorbers to Cooling Effect of Greenhouse Gases: A 1-D Radiative Convective Model Study

    NASA Astrophysics Data System (ADS)

    Shia, R.

    2012-12-01

    The haze layer in Titan's upper atmosphere absorbs 90% of the solar radiation, but is inefficient for trapping infrared radiation generated by the surface. Its existence partially compensates for the greenhouse warming and keeps the surface approximately 9°C cooler than would otherwise be expected from the greenhouse effect alone. This is the so called anti-greenhouse effect (McKay et al., 1991). This effect can be used to alleviate the warming caused by the increasing level of greenhouse gases in the Earth's atmosphere. A one-dimensional radiative convective model (Kasting et al., 2009 and references listed there) is used to investigate the anti-greenhouse effect in the Earth atmosphere. Increasing of solar absorbers, e.g. aerosols and ozone, in the stratosphere reduces the surface solar flux and cool the surface. However, the absorption of the solar flux also increases the temperature in the upper atmosphere, while reduces the temperature at the surface. Thus, the temperature profile of the atmosphere changes and the regions with positive vertical temperature gradient are expanded. According to Shia (2010) the radiative forcing of greenhouse gases is directly related to the vertical temperature gradient. Under the new temperature profile increases of greenhouse gases should have less warming effect. When the solar absorbers keep increasing, eventually most of the atmosphere has positive temperature gradient and increasing greenhouse gases would cool the surface (Shia, 2011). The doubling CO2 scenario in the Earth atmosphere is simulated for different levels of solar absorbers using the 1-D RC model. The model results show that if the solar absorber increases to a certain level that less than 50% solar flux reaching the surface, doubling CO2 cools the surface by about 2 C. This means if the snowball Earth is generated by solar absorbers in the stratosphere, increasing greenhouse gases would make it freeze even more (Shia, 2011). References: Kasting, J. et al

  16. The passenger car and the greenhouse effect

    SciTech Connect

    Amann, C.A.

    1990-01-01

    This paper reports that concern is mounting over the possibility of global warming from the greenhouse effect. Carbon dioxide from the combustion of fossil fuel is a major greenhouse gas, and automobile exhaust is one of the contributors. The only way to decrease carbon dioxide emissions from a car consuming carbonaceous fuel is to decrease its fuel consumption. The best alternative fossil fuels offer a carbon dioxide reduction of about 20%. Without introducing any new greenhouse-gas controls, it is projected that the total greenhouse-gas contribution of the average car will be halved from recent levels just through fleet turnover and already planned elimination of the current air-conditioning refrigerant. If global warming develops into a serious problem, cars can be operated without fossil fuel. Leading options include battery-electric cars using nuclear power and engine-propelled cars burning biomass-derived alcohol or hydrogen extracted from water with solar cells or nuclear power.

  17. Greenhouse effect and the global climate. (Latest citations from the Aerospace database). Published Search

    SciTech Connect

    Not Available

    1993-09-01

    The bibliography contains citations concerning terrestrial climatic changes known as the greenhouse effect. The greenhouse effect is an accumulation of carbon dioxide and other gases that retain solar-induced heat, thereby increasing the average global temperature. Modeling studies, measurements of atmospheric gases, pollutants and temperatures, studies of climatic records for occurrence of similar changes (paleoclimatology), prediction of environmental changes due to the greenhouse effect, government energy policy as a result of possible climate change, and the contributions of manmade and natural pollutants to the greenhouse effect are among the topics discussed. (Contains a minimum of 52 citations and includes a subject term index and title list.)

  18. Fighting global warming by greenhouse gas removal: destroying atmospheric nitrous oxide thanks to synergies between two breakthrough technologies.

    PubMed

    Ming, Tingzhen; de Richter, Renaud; Shen, Sheng; Caillol, Sylvain

    2016-04-01

    Even if humans stop discharging CO2 into the atmosphere, the average global temperature will still increase during this century. A lot of research has been devoted to prevent and reduce the amount of carbon dioxide (CO2) emissions in the atmosphere, in order to mitigate the effects of climate change. Carbon capture and sequestration (CCS) is one of the technologies that might help to limit emissions. In complement, direct CO2 removal from the atmosphere has been proposed after the emissions have occurred. But, the removal of all the excess anthropogenic atmospheric CO2 will not be enough, due to the fact that CO2 outgases from the ocean as its solubility is dependent of its atmospheric partial pressure. Bringing back the Earth average surface temperature to pre-industrial levels would require the removal of all previously emitted CO2. Thus, the atmospheric removal of other greenhouse gases is necessary. This article proposes a combination of disrupting techniques to transform nitrous oxide (N2O), the third most important greenhouse gas (GHG) in terms of current radiative forcing, which is harmful for the ozone layer and possesses quite high global warming potential. Although several scientific publications cite "greenhouse gas removal," to our knowledge, it is the first time innovative solutions are proposed to effectively remove N2O or other GHGs from the atmosphere other than CO2. PMID:26805926

  19. Fighting global warming by greenhouse gas removal: destroying atmospheric nitrous oxide thanks to synergies between two breakthrough technologies.

    PubMed

    Ming, Tingzhen; de Richter, Renaud; Shen, Sheng; Caillol, Sylvain

    2016-04-01

    Even if humans stop discharging CO2 into the atmosphere, the average global temperature will still increase during this century. A lot of research has been devoted to prevent and reduce the amount of carbon dioxide (CO2) emissions in the atmosphere, in order to mitigate the effects of climate change. Carbon capture and sequestration (CCS) is one of the technologies that might help to limit emissions. In complement, direct CO2 removal from the atmosphere has been proposed after the emissions have occurred. But, the removal of all the excess anthropogenic atmospheric CO2 will not be enough, due to the fact that CO2 outgases from the ocean as its solubility is dependent of its atmospheric partial pressure. Bringing back the Earth average surface temperature to pre-industrial levels would require the removal of all previously emitted CO2. Thus, the atmospheric removal of other greenhouse gases is necessary. This article proposes a combination of disrupting techniques to transform nitrous oxide (N2O), the third most important greenhouse gas (GHG) in terms of current radiative forcing, which is harmful for the ozone layer and possesses quite high global warming potential. Although several scientific publications cite "greenhouse gas removal," to our knowledge, it is the first time innovative solutions are proposed to effectively remove N2O or other GHGs from the atmosphere other than CO2.

  20. Studying the Greenhouse Effect: A Simple Demonstration.

    ERIC Educational Resources Information Center

    Papageorgiou, G.; Ouzounis, K.

    2000-01-01

    Studies the parameters involved in a presentation of the greenhouse effect and describes a simple demonstration of this effect. Required equipment includes a 100-120 watt lamp, a 250mL beaker, and a thermometer capable of recording 0-750 degrees Celsius together with a small amount of chloroform. (Author/SAH)

  1. The Runaway Greenhouse Effect on Earth and other Planets

    NASA Technical Reports Server (NTRS)

    Rabbette, Maura; Pilewskie, Peter; McKay, Christopher; Young, Robert

    2001-01-01

    Water vapor is an efficient absorber of outgoing longwave infrared radiation on Earth and is the primary greenhouse gas. Since evaporation increases with increasing sea surface temperature, and the increase in water vapor further increases greenhouse warming, there is a positive feedback. The runaway greenhouse effect occurs if this feedback continues unchecked until all the water has left the surface and enters the atmosphere. For Mars and the Earth the runaway greenhouse was halted when water vapor became saturated with respect to ice or liquid water respectively. However, Venus is considered to be an example of a planet where the runaway greenhouse effect did occur, and it has been speculated that if the solar luminosity were to increase above a certain limit, it would also occur on the Earth. Satellite data acquired during the Earth Radiation Budget Experiment (ERBE) under clear sky conditions shows that as the sea surface temperature (SST) increases, the rate of outgoing infrared radiation at the top of the atmosphere also increases, as expected. Over the pacific warm pool where the SST exceeds 300 K the outgoing radiation emitted to space actually decreases with increasing SST, leading to a potentially unstable system. This behavior is a signature of the runaway greenhouse effect on Earth. However, the SST never exceeds 303K, thus the system has a natural cap which stops the runaway. According to Stefan-Boltzmann's law the amount of heat energy radiated by the Earth's surface is proportional to (T(sup 4)). However, if the planet has a substantial atmosphere, it can absorb all infrared radiation from the lower surface before the radiation penetrates into outer space. Thus, an instrument in space looking at the planet does not detect radiation from the surface. The radiation it sees comes from some level higher up. For the earth#s atmosphere the effective temperature (T(sub e)) has a value of 255 K corresponding to the middle troposphere, above most of the

  2. Assessing Greenhouse Gas emissions in the Greater Toronto Area using atmospheric observations (Invited)

    NASA Astrophysics Data System (ADS)

    Vogel, F. R.; Chan, E.; Huang, L.; Levin, I.; Worthy, D.

    2013-12-01

    Urban areas are said to be responsible for approximately 75% of anthropogenic Greenhouse Gases (GHGs) emissions while comprising only two percent of the land area [1]. This limited spatial expansion should facilitate a monitoring of anthropogenic GHGs from atmospheric observations. As major sources of emissions, cities also have a huge potential to drive emissions reductions. To effectively manage emissions, cities must however, first measure and report these publicly [2]. Modelling studies and measurements of CO2 from fossil fuel burning (FFCO2) in densely populated areas does, however, pose several challenges: Besides continuous in-situ observations, i.e. finding an adequate atmospheric transport model, a sufficiently fine-grained FFCO2 emission model and the proper background reference observations to distinguish the large-scale from the local/urban contributions to the observed FFCO2 concentration offsets ( ΔFFCO2) are required. Pilot studies which include the data from two 'sister sites*' in the vicinity of Toronto, Canada helped to derive flux estimates for Non-CO2 GHGs [3] and improve our understanding of urban FFCO2 emissions. Our 13CO2 observations reveal that the contribution of natural gas burning (mostly due to domestic heating) account for 80%×7% of FFCO2 emissions in the Greater Toronto Area (GTA) during winter. Our 14CO2 observations in the GTA, furthermore, show that the local offset of CO2 (ΔCO2) between our two sister sites can be largely attributed to urban FFCO2 emissions. The seasonal cycle of the observed ΔFFCO2 in Toronto, combined with high-resolution atmospheric modeling, helps to independently assess the contribution from different emission sectors (transportation, primary energy and industry, domestic heating) as predicted by a dedicated city-scale emission inventory, which deviates from a UNFCCC-based inventory. [1] D. Dodman. 2009. Blaming cities for climate change? An analysis of urban greenhouse gas emissions inventories

  3. Revisiting the Scattering Greenhouse Effect of CO2 Ice Clouds

    NASA Astrophysics Data System (ADS)

    Kitzmann, D.

    2016-02-01

    Carbon dioxide ice clouds are thought to play an important role for cold terrestrial planets with thick CO2 dominated atmospheres. Various previous studies showed that a scattering greenhouse effect by carbon dioxide ice clouds could result in a massive warming of the planetary surface. However, all of these studies only employed simplified two-stream radiative transfer schemes to describe the anisotropic scattering. Using accurate radiative transfer models with a general discrete ordinate method, this study revisits this important effect and shows that the positive climatic impact of carbon dioxide clouds was strongly overestimated in the past. The revised scattering greenhouse effect can have important implications for the early Mars, but also for planets like the early Earth or the position of the outer boundary of the habitable zone.

  4. Production of Greenhouse Gases in The Atmosphere of Early Mars

    NASA Technical Reports Server (NTRS)

    Kress, Monika E.; McKay, Christopher P.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Mars was much warmer and wetter 3.5 to 4 billion years ago than it is today, suggesting that its climate was able to support life in the distant past. Carbon dioxide and methane are greenhouse gases which may have kept Mars warm during this time. We explore the possibility that these gases were produced via grain-catalyzed reactions in the warm, dusty aftermath of large comet and/or asteroid impacts which delivered Mars, volatile inventory.

  5. Physics of greenhouse effect and convection in warm oceans

    NASA Technical Reports Server (NTRS)

    Inamdar, A. K.; Ramanathan, V.

    1994-01-01

    Sea surface temperature (SST) in roughly 50% of the tropical Pacific Ocean is warm enough (SST greater than 300 K) to permit deep convection. This paper examines the effects of deep convection on the climatological mean vertical distributions of water vapor and its greenhouse effect over such warm oceans. The study, which uses a combination of satellite radiation budget observations, atmospheric soundings deployed from ships, and radiation model calculations, also examines the link between SST, vertical distribution of water vapor, and its greenhouse effect in the tropical oceans. Since the focus of the study is on the radiative effects of water vapor, the radiation model calculations do not include the effects of clouds. The data are grouped into nonconvective and convective categories using SST as an index for convective activity. On average, convective regions are more humid, trap significantly more longwave radiation, and emit more radiation to the sea surface. The greenhouse effect in regions of convection operates as per classical ideas, that is, as the SST increases, the atmosphere traps the excess longwave energy emitted by the surface and reradiates it locally back to the ocean surface. The important departure from the classical picture is that the net (up minus down) fluxes at the surface and at the top of the atmosphere decrease with an increase in SST; that is, the surface and the surface-troposphere column lose the ability to radiate the excess energy to space. The cause of this super greenhouse effect at the surface is the rapid increase in the lower-troposphere humidity with SST; that of the column is due to a combination of increase in humidity in the entire column and increase in the lapse rate within the lower troposphere. The increase in the vertical distribution of humidity far exceeds that which can be attributed to the temperature dependence of saturation vapor pressure; that is, the tropospheric relative humidity is larger in convective

  6. The runaway greenhouse: implications for future climate change, geoengineering and planetary atmospheres.

    PubMed

    Goldblatt, Colin; Watson, Andrew J

    2012-09-13

    The ultimate climate emergency is a 'runaway greenhouse': a hot and water-vapour-rich atmosphere limits the emission of thermal radiation to space, causing runaway warming. Warming ceases only after the surface reaches approximately 1400 K and emits radiation in the near-infrared, where water is not a good greenhouse gas. This would evaporate the entire ocean and exterminate all planetary life. Venus experienced a runaway greenhouse in the past, and we expect that the Earth will in around 2 billion years as solar luminosity increases. But could we bring on such a catastrophe prematurely, by our current climate-altering activities? Here, we review what is known about the runaway greenhouse to answer this question, describing the various limits on outgoing radiation and how climate will evolve between these. The good news is that almost all lines of evidence lead us to believe that is unlikely to be possible, even in principle, to trigger full a runaway greenhouse by addition of non-condensible greenhouse gases such as carbon dioxide to the atmosphere. However, our understanding of the dynamics, thermodynamics, radiative transfer and cloud physics of hot and steamy atmospheres is weak. We cannot therefore completely rule out the possibility that human actions might cause a transition, if not to full runaway, then at least to a much warmer climate state than the present one. High climate sensitivity might provide a warning. If we, or more likely our remote descendants, are threatened with a runaway greenhouse, then geoengineering to reflect sunlight might be life's only hope. Injecting reflective aerosols into the stratosphere would be too short-lived, and even sunshades in space might require excessive maintenance. In the distant future, modifying Earth's orbit might provide a sustainable solution. The runaway greenhouse also remains relevant in planetary sciences and astrobiology: as extrasolar planets smaller and nearer to their stars are detected, some will be in

  7. The runaway greenhouse: implications for future climate change, geoengineering and planetary atmospheres.

    PubMed

    Goldblatt, Colin; Watson, Andrew J

    2012-09-13

    The ultimate climate emergency is a 'runaway greenhouse': a hot and water-vapour-rich atmosphere limits the emission of thermal radiation to space, causing runaway warming. Warming ceases only after the surface reaches approximately 1400 K and emits radiation in the near-infrared, where water is not a good greenhouse gas. This would evaporate the entire ocean and exterminate all planetary life. Venus experienced a runaway greenhouse in the past, and we expect that the Earth will in around 2 billion years as solar luminosity increases. But could we bring on such a catastrophe prematurely, by our current climate-altering activities? Here, we review what is known about the runaway greenhouse to answer this question, describing the various limits on outgoing radiation and how climate will evolve between these. The good news is that almost all lines of evidence lead us to believe that is unlikely to be possible, even in principle, to trigger full a runaway greenhouse by addition of non-condensible greenhouse gases such as carbon dioxide to the atmosphere. However, our understanding of the dynamics, thermodynamics, radiative transfer and cloud physics of hot and steamy atmospheres is weak. We cannot therefore completely rule out the possibility that human actions might cause a transition, if not to full runaway, then at least to a much warmer climate state than the present one. High climate sensitivity might provide a warning. If we, or more likely our remote descendants, are threatened with a runaway greenhouse, then geoengineering to reflect sunlight might be life's only hope. Injecting reflective aerosols into the stratosphere would be too short-lived, and even sunshades in space might require excessive maintenance. In the distant future, modifying Earth's orbit might provide a sustainable solution. The runaway greenhouse also remains relevant in planetary sciences and astrobiology: as extrasolar planets smaller and nearer to their stars are detected, some will be in

  8. Quantifying greenhouse-gas emissions from atmospheric measurements: a critical reality check for climate legislation.

    PubMed

    Weiss, Ray F; Prinn, Ronald G

    2011-05-28

    Emissions reduction legislation relies upon 'bottom-up' accounting of industrial and biogenic greenhouse-gas (GHG) emissions at their sources. Yet, even for relatively well-constrained industrial GHGs, global emissions based on 'top-down' methods that use atmospheric measurements often agree poorly with the reported bottom-up emissions. For emissions reduction legislation to be effective, it is essential that these discrepancies be resolved. Because emissions are regulated nationally or regionally, not globally, top-down estimates must also be determined at these scales. High-frequency atmospheric GHG measurements at well-chosen station locations record 'pollution events' above the background values that result from regional emissions. By combining such measurements with inverse methods and atmospheric transport and chemistry models, it is possible to map and quantify regional emissions. Even with the sparse current network of measurement stations and current inverse-modelling techniques, it is possible to rival the accuracies of regional 'bottom-up' emission estimates for some GHGs. But meeting the verification goals of emissions reduction legislation will require major increases in the density and types of atmospheric observations, as well as expanded inverse-modelling capabilities. The cost of this effort would be minor when compared with current investments in carbon-equivalent trading, and would reduce the volatility of that market and increase investment in emissions reduction. PMID:21502167

  9. Future atmospheric conditions increase the greenhouse gas intensity of rice production

    NASA Astrophysics Data System (ADS)

    Van Groenigen, K.; Van Kessel, C.; Hungate, B. A.

    2012-12-01

    Elevated levels of atmospheric CO2 and rising temperatures are both expected to alter rice yields and greenhouse gas (GHG) emissions from rice paddies. This is important, because rice cultivation is one of the largest anthropogenic sources of the potent GHG methane (CH4) and rice is the world's second-most produced staple crop. Because global food demand is growing, it makes sense to assess GHG emissions from croplands on the basis of yield rather than land area, so that efforts to reduce GHG emissions occur with taking into consideration the effects on food production. However, it is unclear whether or how the GHG intensity (that is, yield-scaled GHG emissions) of cropping systems will be affected by future atmospheric conditions. Using meta-analysis, we show that elevated atmospheric CO2 (ranging from 550 to 743 ppmV) and warming (ranging from +0.8°C to +6°C) both increase the GHG intensity of rice cultivation. Elevated atmospheric CO2 increased GHG intensity by 31.4%, because CH4 emissions are stimulated more than rice yields. Warming increased GHG intensity by 11.8% per 1°C, largely due to a decrease in yield. Our findings underscore the need for mitigation and adaptation efforts to secure global food supply while at the same time keeping GHG emissions in check.

  10. Greenhouse Gas Emissions of Indianapolis using a High-Density Surface Tower Network and an Atmospheric Inversion

    NASA Astrophysics Data System (ADS)

    Lauvaux, T.; Miles, N. L.; Davis, K. J.; Richardson, S.; Deng, A.; Sarmiento, D. P.; Wu, K.; Sweeney, C.; Karion, A.; Hardesty, R. M.; Brewer, A.; Turnbull, J. C.; Iraci, L. T.; Hillyard, P. W.; Podolske, J. R.; Gurney, K. R.; Patarasuk, R.; Cambaliza, M. O. L.; Shepson, P. B.; Whetstone, J. R.

    2014-12-01

    The Indianapolis Flux Experiment (INFLUX) was designed to develop and evaluate methods of detection and attribution of greenhouse gas fluxes from urban environments. Determination of greenhouse gas fluxes and uncertainty bounds is essential for the evaluation of the effectiveness of mitigation strategies. Indianapolis is intended to serve as a test bed for these methods; the results will inform efforts at measuring emissions from urban centers worldwide, including megacities. The generally accepted method for determining urban greenhouse gas emissions is inventories, which are compiled from records of land use and human activity. Atmospheric methods, in which towers are instrumented with sensors to measure greenhouse gas mole fractions and these data are used in an inversion model, have the potential to provide independent determination of emissions. The current INFLUX observation network includes twelve in-situ tower-based, continuous measurements of CO2. A subset of five towers additionally measure CH4, and a different subset measure CO. The subset measuring CO also include weekly flask samples of a wide variety of trace gases including 14CO2. Here we discuss the observed urban spatial and temporal patterns in greenhouse gas mole fraction in Indianapolis, with the critical result being the detectability of city emissions with this high-density network. We also present the first atmospheric inversion results for both CO2 and CH4, compare these results to inventories, and discuss the effects of critical assumptions in the inversion framework. The construction of unbiased atmospheric modeling systems and well-defined prior errors remains an important step in atmospheric emissions monitoring over urban areas. In order to minimize transport model errors, we developed a WRF-Chem FDDA modeling system ingesting surface and profile measurements of horizontal mean wind, temperature, and moisture. We demonstrate the impact of the meteorological data assimilation system on

  11. Greenhouse warming by CH4 in the atmosphere of early Earth.

    PubMed

    Pavlov, A A; Kasting, J F; Brown, L L; Rages, K A; Freedman, R

    2000-05-25

    Earth appears to have been warm during its early history despite the faintness of the young Sun. Greenhouse warming by gaseous CO2 and H2O by itself is in conflict with constraints on atmospheric CO2 levels derived from paleosols for early Earth. Here we explore whether greenhouse warming by methane could have been important. We find that a CH4 mixing ratio of 10(-4) (100 ppmv) or more in Earth's early atmosphere would provide agreement with the paleosol data from 2.8 Ga. Such a CH4 concentration could have been readily maintained by methanogenic bacteria, which are thought to have been an important component of the biota at that time. Elimination of the methane component of the greenhouse by oxidation of the atmosphere at about 2.3-2.4 Ga could have triggered the Earth's first widespread glaciation.

  12. [Is there a connection between biodiversity and the greenhouse effect].

    PubMed

    Rozanov, S I

    1998-01-01

    It was discussed the role of biodiversity in ecosystems capacity to control CO2 in atmosphere as the main reason not only of "greenhouse effect" but "greenhouse catastrophe". The necessity to perfect the preventive measures has been defined by time factor. This time may be so little for completing the evolution theory and models of biosphere management. The temps of contemporaneous species extinction exceed two orders as minimum ones how it has been known from planet history. It doesn't permit to discharge that evolutional process will be successful to create organisms which have been capable to stabilize biosphere in conditions of its changing status. It's possible that such change may be provocated with the crisis in civilization-biosphere interrelations.

  13. [Is there a connection between biodiversity and the greenhouse effect].

    PubMed

    Rozanov, S I

    1998-01-01

    It was discussed the role of biodiversity in ecosystems capacity to control CO2 in atmosphere as the main reason not only of "greenhouse effect" but "greenhouse catastrophe". The necessity to perfect the preventive measures has been defined by time factor. This time may be so little for completing the evolution theory and models of biosphere management. The temps of contemporaneous species extinction exceed two orders as minimum ones how it has been known from planet history. It doesn't permit to discharge that evolutional process will be successful to create organisms which have been capable to stabilize biosphere in conditions of its changing status. It's possible that such change may be provocated with the crisis in civilization-biosphere interrelations. PMID:10079930

  14. Comment on "Cosmic-ray-driven reaction and greenhouse effect of halogenated molecules: Culprits for atmospheric ozone depletion and global climate change"

    NASA Astrophysics Data System (ADS)

    Müller, Rolf; Grooß, Jens-Uwe

    2014-04-01

    Lu's "cosmic-ray-driven electron-induced reaction (CRE) theory" is based on the assumption that the CRE reaction of halogenated molecules (e.g., chlorofluorocarbons (CFCs), HCl, ClONO2) adsorbed or trapped in polar stratospheric clouds in the winter polar stratosphere is the key step in forming photoactive halogen species that are the cause of the springtime ozone hole. This theory has been extended to a warming theory of halogenated molecules for climate change. In this comment, we discuss the chemical and physical foundations of these theories and the conclusions derived from the theories. First, it is unclear whether the loss rates of halogenated molecules induced by dissociative electron attachment (DEA) observed in the laboratory can also be interpreted as atmospheric loss rates, but even if this were the case, the impact of DEA-induced reactions on polar chlorine activation and ozone loss in the stratosphere is limited. Second, we falsify several conclusions that are reported on the basis of the CRE theory: There is no polar ozone loss in darkness, there is no apparent 11-year periodicity in polar total ozone measurements, the age of air in the polar lower stratosphere is much older than 1-2 years, and the reported detection of a pronounced recovery (by about 20-25%) in Antarctic total ozone measurements by the year 2010 is in error. There are also conclusions about the future development of sea ice and global sea level which are fundamentally flawed because Archimedes' principle is neglected. Many elements of the CRE theory are based solely on correlations between certain datasets which are no substitute for providing physical and chemical mechanisms causing a particular behavior noticeable in observations. In summary, the CRE theory cannot be considered as an independent, alternative mechanism for polar stratospheric ozone loss and the conclusions on recent and future surface temperature and global sea level change do not have a physical basis.

  15. A Simple Experiment to Demonstrate the Effects of Greenhouse Gases

    ERIC Educational Resources Information Center

    Keating, C. F.

    2007-01-01

    The role of greenhouse gases in our atmosphere is the subject of considerable discussion and debate. Global warming is well-documented, as is the continually increasing amount of greenhouse gases that human activity puts in the air. Is there a relationship between the two? The simple experiment described in this paper provides a good demonstration…

  16. Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory

    NASA Astrophysics Data System (ADS)

    Morgan, E. J.; Lavrič, J. V.; Seifert, T.; Chicoine, T.; Day, A.; Gomez, J.; Logan, R.; Sack, J.; Shuuya, T.; Uushona, E. G.; Vincent, K.; Schultz, U.; Brunke, E.-G.; Labuschagne, C.; Thompson, R. L.; Schmidt, S.; Manning, A. C.; Heimann, M.

    2015-06-01

    A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the northern border of the Namib Sand Sea. Atmospheric oxygen is measured with a differential fuel cell analyzer (DFCA). Carbon dioxide and methane are measured with an early-model cavity ring-down spectrometer (CRDS); nitrous oxide and carbon monoxide are measured with an off-axis integrated cavity output spectrometer (OA-ICOS). Instrument-specific water corrections are employed for both the CRDS and OA-ICOS instruments in lieu of drying. The performance and measurement uncertainties are discussed in detail. As the station is located in a remote desert environment, there are some particular challenges, namely fine dust, high diurnal temperature variability, and minimal infrastructure. The gas handling system and calibration scheme were tailored to best fit the conditions of the site. The CRDS and DFCA provide data of acceptable quality when base requirements for operation are met, specifically adequate temperature control in the laboratory and regular supply of electricity. In the case of the OA-ICOS instrument, performance is significantly improved through the implementation of a drift correction through frequent measurements of a reference cylinder.

  17. HFCs contribution to the greenhouse effect. Present and projected estimations

    SciTech Connect

    Libre, J.M.; Elf-Atochem, S.A.

    1997-12-31

    This paper reviews data that can be used to calculate hydrofluorocarbon (HFC) contribution to the greenhouse effect and compare it to other trace gas contributions. Projections are made for 2010 and 2100 on the basis of available emission scenarios. Industrial judgement on the likelihood of those scenarios is also developed. Calculations can be made in two different ways: from Global Warming Potential weighted emissions of species or by direct calculation of radiative forcing based on measured and projected atmospheric concentrations of compounds. Results show that HFCs corresponding to commercial uses have a negligible contribution to the greenhouse effect in comparison with other trace gases. The projected contributions are also very small even if very high emission scenarios are maintained for decades. In 2010 this contribution remains below 1%. Longer term emissions projections are difficult. However, based on the IPCC scenario IS92a, in spite of huge emissions projected for the year 2100, the HFC contribution remains below 3%. Actually many factors indicate that the real UFC contribution to the greenhouse effect will be even smaller than presented here. Low emissive systems and small charges will likely improve sharply in the future and have drastically improved in the recent past. HFC technology implementation is likely to grow in the future, reach a maximum before the middle of the next century; the market will stabilise driven by recycling, closing of systems and competitive technologies. This hypothesis is supported by previous analysis of the demand for HTCs type applications which can be represented by {open_quotes}S{close_quotes} type curves and by recent analysis indicating that the level of substitution of old products by HFCs is growing slowly. On the basis of those data and best industrial judgement, the contribution of HFCs to the greenhouse effect is highly likely to remain below 1% during the next century. 11 refs., 2 figs., 5 tabs.

  18. Greenhouse effects: earth's climate in transition

    SciTech Connect

    Shepard, M.; Hakkarinen, C.; Hansen, A.; Spencer, D.

    1986-06-01

    Many experts are predicting significant change in the earth's climate during the next 50 years as theories of global warming gain broad acceptance in the scientific community. The consequences of accumulating greenhouse gases in the atmosphere may turn out to be the greatest environmental problem of modern times. One of the key uncertainties in projecting temperature change centers on the question of how much of the carbon dioxide (CO/sub 2/) released to the atmosphere will remain there. Scientists do not yet agree on how the CO/sub 2/ is apportioned among the plants and oceans, how much CO/sub 2/ these reservoirs can hold, or how long they can hold it. Climatologists link hundreds of mathematical equations and temperature measurements to develop their climate models, which are limited by their ability to predict regional changes accurately. There is no consensus on whether there is a need to focus on research or on developing an appropriate response. 12 references, 6 figures.

  19. Hydrogen-nitrogen greenhouse warming in Earth's early atmosphere.

    PubMed

    Wordsworth, Robin; Pierrehumbert, Raymond

    2013-01-01

    Understanding how Earth has sustained surface liquid water throughout its history remains a key challenge, given that the Sun's luminosity was much lower in the past. Here we show that with an atmospheric composition consistent with the most recent constraints, the early Earth would have been significantly warmed by H(2)-N(2) collision-induced absorption. With two to three times the present-day atmospheric mass of N(2) and a H(2) mixing ratio of 0.1, H(2)-N(2) warming would be sufficient to raise global mean surface temperatures above 0°C under 75% of present-day solar flux, with CO(2) levels only 2 to 25 times the present-day values. Depending on their time of emergence and diversification, early methanogens may have caused global cooling via the conversion of H(2) and CO(2) to CH(4), with potentially observable consequences in the geological record.

  20. Testing Plant Responses to Rarified Atmospheres for Inflatable Greenhouses

    NASA Technical Reports Server (NTRS)

    Corey, Kenneth A.

    2000-01-01

    Reduced atmospheric pressures will likely be used to minimize mass and engineering requirements for plant growth habitats used in extraterrestrial applications. A chamber with high vacuum capability was used to design and begin construction of a system for testing plant responses to reduced pressure atmospheres. Several preliminary tests were conducted to evaluate chamber suitability for plant tests and to determine performance of thermal and vacuum systems at ambient and reduced pressure atmospheres down to 0.1 atm. The first tests consisted of measurements of internal gas volume and leakage rate. The method for volume determination was quite sensitive and will be needed for plant gas exchange measurements and calculations. This information will also be used in conjunction with the leak rate. Measured leak rates on the order of 0.46 mm Hg/min at 76 mm Hg pressure are low enough to conduct sensitive carbon dioxide exchange rate measurements at reduced pressure given an adequate plant sample (0.5 to 1.0 sq m area). A test rack with lighting provided by three high-pressure sodium vapor lamps was built to accommodate both short-term and long-term plant responses. Initial short-term experiments with lettuce showed that a pressure of 77 mm Hg resulted in a 6.1-fold increase in the rate of water loss compared to water loss at ambient pressure. Plants were severely wilted after 30 minutes exposure to 77 mm Hg. Water loss was found to be inversely correlated with atmospheric pressure over the range of pressures from 0.2 to 1.0 atm; the rate of water loss at 0.2 atm was 4.3 times higher than water loss at ambient pressure. Older leaves showed moderate wilting during exposure to 156 mm Hg, but those exposed to 345 mm, Hg remained turgid. Results suggest a reduced atmospheric pressure limit of 0.2 to 0.3 atm for lettuce grown in a solid medium. Follow-up experiments with carbon dioxide control and control at high relative humidity (> 90 %) will be needed to further confirm

  1. Middle-School Understanding of the Greenhouse Effect using a NetLogo Computer Model

    NASA Astrophysics Data System (ADS)

    Schultz, L.; Koons, P. O.; Schauffler, M.

    2009-12-01

    We investigated the effectiveness of a freely available agent based, modeling program as a learning tool for seventh and eighth grade students to explore the greenhouse effect without added curriculum. The investigation was conducted at two Maine middle-schools with 136 seventh-grade students and 11 eighth-grade students in eight classes. Students were given a pre-test that consisted of a concept map, a free-response question, and multiple-choice questions about how the greenhouse effect influences the Earth's temperature. The computer model simulates the greenhouse effect and allows students to manipulate atmospheric and surface conditions to observe the effects on the Earth’s temperature. Students explored the Greenhouse Effect model for approximately twenty minutes with only two focus questions for guidance. After the exploration period, students were given a post-test that was identical to the pre-test. Parametric post-test analysis of the assessments indicated middle-school students gained in their understanding about how the greenhouse effect influences the Earth's temperature after exploring the computer model for approximately twenty minutes. The magnitude of the changes in pre- and post-test concept map and free-response scores were small (average free-response post-test score of 7.0) compared to an expert's score (48), indicating that students understood only a few of the system relationships. While students gained in their understanding about the greenhouse effect, there was evidence that students held onto their misconceptions that (1) carbon dioxide in the atmosphere deteriorates the ozone layer, (2) the greenhouse effect is a result of humans burning fossil fuels, and (3) infrared and visible light have similar behaviors with greenhouse gases. We recommend using the Greenhouse Effect computer model with guided inquiry to focus students’ investigations on the system relationships in the model.

  2. On the role of atmosphere-ocean interactions in the expected long-term changes of the Earth's ozone layer caused by greenhouse gases

    NASA Astrophysics Data System (ADS)

    Zadorozhny, Alexander; Dyominov, Igor

    It is well known that anthropogenic emissions of greenhouse gases into the atmosphere produce a global warming of the troposphere and a global cooling of the stratosphere. The expected stratospheric cooling essentially influences the ozone layer via increased polar stratospheric cloud formation and via temperature dependences of the gas phase reaction rates. One more mechanism of how greenhouse gases influences the ozone layer is enhanced water evaporation from the oceans into the atmosphere because of increasing temperatures of the ocean surface due to greenhouse effect. The subject of this paper is a study of the influence of anthropogenic pollution of the atmosphere by the greenhouse gases CO2, CH4, N2O and ozone-depleting chlorine and bromine compounds on the expected long-term changes of the ozone layer with taking into account an increase of water vapour content in the atmosphere due to greenhouse effect. The study based on 2-D zonally averaged interactive dynamical radiative-photochemical model of the troposphere and stratosphere. The model allows to self-consistently calculating diabatic circulation, temperature, gaseous composition of the troposphere and stratosphere at latitudes from the South to North Poles, as well as distribution of sulphate aerosol particles and polar stratospheric clouds of two types. It was supposed in the model that an increase of the ocean surface temperature caused by greenhouse effect is similar to calculated increase of atmospheric surface temperature. Evaporation rate from the ocean surface was computed in dependence of latitude. The model time-dependent runs were made for the period from 1975 to 2100 using two IPCC scenarios depicting maximum and average expected increases of greenhouse gases in the atmosphere. The model calculations show that anthropogenic increasing of water vapour abundance in the atmosphere due to heating of the ocean surface caused by greenhouse effect gives a sensible contribution to the expected ozone

  3. Assessment of ground-based atmospheric observations for verification of greenhouse gas emissions from an urban region.

    PubMed

    McKain, Kathryn; Wofsy, Steven C; Nehrkorn, Thomas; Eluszkiewicz, Janusz; Ehleringer, James R; Stephens, Britton B

    2012-05-29

    International agreements to limit greenhouse gas emissions require verification to ensure that they are effective and fair. Verification based on direct observation of atmospheric greenhouse gas concentrations will be necessary to demonstrate that estimated emission reductions have been actualized in the atmosphere. Here we assess the capability of ground-based observations and a high-resolution (1.3 km) mesoscale atmospheric transport model to determine a change in greenhouse gas emissions over time from a metropolitan region. We test the method with observations from a network of CO(2) surface monitors in Salt Lake City. Many features of the CO(2) data were simulated with excellent fidelity, although data-model mismatches occurred on hourly timescales due to inadequate simulation of shallow circulations and the precise timing of boundary-layer stratification and destratification. Using two optimization procedures, monthly regional fluxes were constrained to sufficient precision to detect an increase or decrease in emissions of approximately 15% at the 95% confidence level. We argue that integrated column measurements of the urban dome of CO(2) from the ground and/or space are less sensitive than surface point measurements to the redistribution of emitted CO(2) by small-scale processes and thus may allow for more precise trend detection of emissions from urban regions.

  4. Assessment of ground-based atmospheric observations for verification of greenhouse gas emissions from an urban region

    NASA Astrophysics Data System (ADS)

    McKain, Kathryn; Wofsy, Steven C.; Nehrkorn, Thomas; Eluszkiewicz, Janusz; Ehleringer, James R.; Stephens, Britton B.

    2012-05-01

    International agreements to limit greenhouse gas emissions require verification to ensure that they are effective and fair. Verification based on direct observation of atmospheric greenhouse gas concentrations will be necessary to demonstrate that estimated emission reductions have been actualized in the atmosphere. Here we assess the capability of ground-based observations and a high-resolution (1.3 km) mesoscale atmospheric transport model to determine a change in greenhouse gas emissions over time from a metropolitan region. We test the method with observations from a network of CO2 surface monitors in Salt Lake City. Many features of the CO2 data were simulated with excellent fidelity, although data-model mismatches occurred on hourly timescales due to inadequate simulation of shallow circulations and the precise timing of boundary-layer stratification and destratification. Using two optimization procedures, monthly regional fluxes were constrained to sufficient precision to detect an increase or decrease in emissions of approximately 15% at the 95% confidence level. We argue that integrated column measurements of the urban dome of CO2 from the ground and/or space are less sensitive than surface point measurements to the redistribution of emitted CO2 by small-scale processes and thus may allow for more precise trend detection of emissions from urban regions.

  5. European emissions of halogenated greenhouse gases inferred from atmospheric measurements.

    PubMed

    Keller, Christoph A; Hill, Matthias; Vollmer, Martin K; Henne, Stephan; Brunner, Dominik; Reimann, Stefan; O'Doherty, Simon; Arduini, Jgor; Maione, Michela; Ferenczi, Zita; Haszpra, Laszlo; Manning, Alistair J; Peter, Thomas

    2012-01-01

    European emissions of nine representative halocarbons (CFC-11, CFC-12, Halon 1211, HCFC-141b, HCFC-142b, HCFC-22, HFC-125, HFC-134a, HFC-152a) are derived for the year 2009 by combining long-term observations in Switzerland, Italy, and Ireland with campaign measurements from Hungary. For the first time, halocarbon emissions over Eastern Europe are assessed by top-down methods, and these results are compared to Western European emissions. The employed inversion method builds on least-squares optimization linking atmospheric observations with calculations from the Lagrangian particle dispersion model FLEXPART. The aggregated halocarbon emissions over the study area are estimated at 125 (106-150) Tg of CO(2) equiv/y, of which the hydrofluorocarbons (HFCs) make up the most important fraction with 41% (31-52%). We find that chlorofluorocarbon (CFC) emissions from banks are still significant and account for 35% (27-43%) of total halocarbon emissions in Europe. The regional differences in per capita emissions are only small for the HFCs, while emissions of CFCs and hydrochlorofluorocarbons (HCFCs) tend to be higher in Western Europe compared to Eastern Europe. In total, the inferred per capita emissions are similar to estimates for China, but 3.5 (2.3-4.5) times lower than for the United States. Our study demonstrates the large benefits of adding a strategically well placed measurement site to the existing European observation network of halocarbons, as it extends the coverage of the inversion domain toward Eastern Europe and helps to better constrain the emissions over Central Europe. PMID:22192076

  6. European emissions of halogenated greenhouse gases inferred from atmospheric measurements.

    PubMed

    Keller, Christoph A; Hill, Matthias; Vollmer, Martin K; Henne, Stephan; Brunner, Dominik; Reimann, Stefan; O'Doherty, Simon; Arduini, Jgor; Maione, Michela; Ferenczi, Zita; Haszpra, Laszlo; Manning, Alistair J; Peter, Thomas

    2012-01-01

    European emissions of nine representative halocarbons (CFC-11, CFC-12, Halon 1211, HCFC-141b, HCFC-142b, HCFC-22, HFC-125, HFC-134a, HFC-152a) are derived for the year 2009 by combining long-term observations in Switzerland, Italy, and Ireland with campaign measurements from Hungary. For the first time, halocarbon emissions over Eastern Europe are assessed by top-down methods, and these results are compared to Western European emissions. The employed inversion method builds on least-squares optimization linking atmospheric observations with calculations from the Lagrangian particle dispersion model FLEXPART. The aggregated halocarbon emissions over the study area are estimated at 125 (106-150) Tg of CO(2) equiv/y, of which the hydrofluorocarbons (HFCs) make up the most important fraction with 41% (31-52%). We find that chlorofluorocarbon (CFC) emissions from banks are still significant and account for 35% (27-43%) of total halocarbon emissions in Europe. The regional differences in per capita emissions are only small for the HFCs, while emissions of CFCs and hydrochlorofluorocarbons (HCFCs) tend to be higher in Western Europe compared to Eastern Europe. In total, the inferred per capita emissions are similar to estimates for China, but 3.5 (2.3-4.5) times lower than for the United States. Our study demonstrates the large benefits of adding a strategically well placed measurement site to the existing European observation network of halocarbons, as it extends the coverage of the inversion domain toward Eastern Europe and helps to better constrain the emissions over Central Europe.

  7. CO2 and the greenhouse effect: present assessment and perspectives.

    PubMed

    Oeschger, H

    1993-01-01

    Our present knowledge on the increasing greenhouse effect is based on the 1990 assessment of the Intergovernmental Panel on Climate Change (IPCC) and its 1992 supplement. Model predictions suggest that a doubling of atmospheric CO2 concentration would increase global temperature by 2-4 degrees C. Because time is needed for the upper layers of the oceans to warm up, there is a delay between the realized increase and the estimated equilibrium increase. The 0.5 degrees C increase in global temperature over the past 100 years is in accordance with model predictions but also within the range of natural variability. The IPCC's assessment suggests that if fossil fuel consumption continues according to a 'business as usual' scenario, global temperature will increase at 0.3 degrees C per decade; droughts, flooding and storms would become more frequent and more severe, and sea-level would continue to rise. Analysis of gas in ice cores from Antarctica and Greenland provides estimates of CO2 concentrations in pre-industrial ages; accurate measurement of atmospheric CO2 began in 1958. Atmospheric CO2 concentration has increased from 280 p.p.m. in AD 1800 to 355 p.p.m. at present. Between 1945 and 1973 global emissions of CO2 increased at a rate of 4.4% per year; after 1973 the rate of increase decreased to 1.6% per year. This change permits a test of the CO2 model. Reconstructed CO2 emission agrees within less than 10% with estimated fossil fuel-generated CO2 emission; contributions to CO2 emission from non-fossil fuel sources must be smaller than assumed previously. There are strong indications that in the past changes in atmospheric greenhouse gas concentrations inherent to the glacial-interglacial cycles did play an important climatic role. For example, they were probably responsible for interhemispheric coupling during the major climatic changes. Measures which might stabilize the greenhouse effect include energy conservation and improved energy efficiency, a transition to

  8. CO2 and the greenhouse effect: present assessment and perspectives.

    PubMed

    Oeschger, H

    1993-01-01

    Our present knowledge on the increasing greenhouse effect is based on the 1990 assessment of the Intergovernmental Panel on Climate Change (IPCC) and its 1992 supplement. Model predictions suggest that a doubling of atmospheric CO2 concentration would increase global temperature by 2-4 degrees C. Because time is needed for the upper layers of the oceans to warm up, there is a delay between the realized increase and the estimated equilibrium increase. The 0.5 degrees C increase in global temperature over the past 100 years is in accordance with model predictions but also within the range of natural variability. The IPCC's assessment suggests that if fossil fuel consumption continues according to a 'business as usual' scenario, global temperature will increase at 0.3 degrees C per decade; droughts, flooding and storms would become more frequent and more severe, and sea-level would continue to rise. Analysis of gas in ice cores from Antarctica and Greenland provides estimates of CO2 concentrations in pre-industrial ages; accurate measurement of atmospheric CO2 began in 1958. Atmospheric CO2 concentration has increased from 280 p.p.m. in AD 1800 to 355 p.p.m. at present. Between 1945 and 1973 global emissions of CO2 increased at a rate of 4.4% per year; after 1973 the rate of increase decreased to 1.6% per year. This change permits a test of the CO2 model. Reconstructed CO2 emission agrees within less than 10% with estimated fossil fuel-generated CO2 emission; contributions to CO2 emission from non-fossil fuel sources must be smaller than assumed previously. There are strong indications that in the past changes in atmospheric greenhouse gas concentrations inherent to the glacial-interglacial cycles did play an important climatic role. For example, they were probably responsible for interhemispheric coupling during the major climatic changes. Measures which might stabilize the greenhouse effect include energy conservation and improved energy efficiency, a transition to

  9. Greenhouse effect of chlorofluorocarbons and other trace gases

    NASA Astrophysics Data System (ADS)

    Hansen, James; Lacis, Andrew; Prather, Michael

    1989-11-01

    A comparison is made of the radiative (greenhouse) forcing of the climate system due to changes of atmospheric chlorofluorocarbons and other trace gases. It is found that CFCs, defined to include chlorofluorocarbons, chlorocarbons, and fluorocarbons, now provide about one-quater of current annual increases in anthropogenic greenhouse climate forcing. If the growth rates of CFC production in the early 1970s had continued to the present, current annual growth of climate forcing due to CFCs would exceed that due to CO2.

  10. Greenhouse effect of chlorofluorocarbons and other trace gases

    NASA Technical Reports Server (NTRS)

    Hansen, James; Lacis, Andrew; Prather, Michael

    1989-01-01

    A comparison is made of the radiative (greenhouse) forcing of the climate system due to changes of atmospheric chlorofluorocarbons and other trace gases. It is found that CFCs, defined to include chlorofluorocarbons, chlorocarbons, and fluorocarbons, now provide about one-quater of current annual increases in anthropogenic greenhouse climate forcing. If the growth rates of CFC production in the early 1970s had continued to the present, current annual growth of climate forcing due to CFCs would exceed that due to CO2.

  11. Role of microorganisms for cycling of atmospheric constituents, emphasizing the greenhouse gas methane (Invited)

    NASA Astrophysics Data System (ADS)

    Conrad, R.

    2013-12-01

    Microorganisms have contributed significantly to the formation of the atmosphere and the habitability of Earth. Microbial methanogenesis probably helped overcoming the faint sun problem on young Earth. Later on, cyanobacterial photosynthesis produced oxygen and thus restricted the life zone of methanogenic microbial communities, which nowadays contribute only about 1% to total carbon cycle. Nevertheless, methanogenesis still dominates the budget of atmospheric methane and contributes significantly to the greenhouse effect. There are numerous habitats, which exchange methane with the atmosphere, and even more in which methane is intensively cycled albeit little emitted. Methane can be a byproduct of chemical reactions in plant leaves, or of aerobic methyl phosphonate consumption in ocean water. Most commonly, however, methane is a stoichiometric catabolic product in the degradation of organic matter by anaerobic microorganisms. The degradation is achieved by a complex microbial community consisting of various species of hydrolytic and fermentative Bacteria that produce hydrogen, carbon dioxide and acetate as major end products, and of methanogenic Archaea that eventually convert these compounds to methane and carbon dioxide. The composition of such methanogenic microbial communities, the rates and paths of methane formation, and the isotopic composition of the produced methane all exhibit quite some variability across the different habitats in which methane is produced from organic matter decomposition, such as flooded soils, lake sediments, peatlands, animal gut systems. The structure of the microbial communities often strongly affects their function. It is a challenging task to understand the environmental and biochemical basis of the interactions of abiotic factors and microorganisms shaping the structure and function of the microbial communities in the different methanogenic habitats.

  12. The impacts of recent permafrost thaw on land-atmosphere greenhouse gas exchange

    NASA Astrophysics Data System (ADS)

    Hayes, Daniel J.; Kicklighter, David W.; McGuire, A. David; Chen, Min; Zhuang, Qianlai; Yuan, Fengming; Melillo, Jerry M.; Wullschleger, Stan D.

    2014-04-01

    Permafrost thaw and the subsequent mobilization of carbon (C) stored in previously frozen soil organic matter (SOM) have the potential to be a strong positive feedback to climate. As the northern permafrost region experiences as much as a doubling of the rate of warming as the rest of the Earth, the vast amount of C in permafrost soils is vulnerable to thaw, decomposition and release as atmospheric greenhouse gases. Diagnostic and predictive estimates of high-latitude terrestrial C fluxes vary widely among different models depending on how dynamics in permafrost, and the seasonally thawed ‘active layer’ above it, are represented. Here, we employ a process-based model simulation experiment to assess the net effect of active layer dynamics on this ‘permafrost carbon feedback’ in recent decades, from 1970 to 2006, over the circumpolar domain of continuous and discontinuous permafrost. Over this time period, the model estimates a mean increase of 6.8 cm in active layer thickness across the domain, which exposes a total of 11.6 Pg C of thawed SOM to decomposition. According to our simulation experiment, mobilization of this previously frozen C results in an estimated cumulative net source of 3.7 Pg C to the atmosphere since 1970 directly tied to active layer dynamics. Enhanced decomposition from the newly exposed SOM accounts for the release of both CO2 (4.0 Pg C) and CH4 (0.03 Pg C), but is partially compensated by CO2 uptake (0.3 Pg C) associated with enhanced net primary production of vegetation. This estimated net C transfer to the atmosphere from permafrost thaw represents a significant factor in the overall ecosystem carbon budget of the Pan-Arctic, and a non-trivial additional contribution on top of the combined fossil fuel emissions from the eight Arctic nations over this time period.

  13. The impacts of recent permafrost thaw on land-atmosphere greenhouse gas exchange

    USGS Publications Warehouse

    Hayes, Daniel J.; Kicklighter, David W.; McGuire, Anthony; Chen, Min; Zhuang, Qianlai; Yuan, Fengming; Melillo, Jerry M.; Wullschleger, Stan D.

    2014-01-01

    Permafrost thaw and the subsequent mobilization of carbon (C) stored in previously frozen soil organic matter (SOM) have the potential to be a strong positive feedback to climate. As the northern permafrost region experiences as much as a doubling of the rate of warming as the rest of the Earth, the vast amount of C in permafrost soils is vulnerable to thaw, decomposition and release as atmospheric greenhouse gases. Diagnostic and predictive estimates of high-latitude terrestrial C fluxes vary widely among different models depending on how dynamics in permafrost, and the seasonally thawed 'active layer' above it, are represented. Here, we employ a process-based model simulation experiment to assess the net effect of active layer dynamics on this 'permafrost carbon feedback' in recent decades, from 1970 to 2006, over the circumpolar domain of continuous and discontinuous permafrost. Over this time period, the model estimates a mean increase of 6.8 cm in active layer thickness across the domain, which exposes a total of 11.6 Pg C of thawed SOM to decomposition. According to our simulation experiment, mobilization of this previously frozen C results in an estimated cumulative net source of 3.7 Pg C to the atmosphere since 1970 directly tied to active layer dynamics. Enhanced decomposition from the newly exposed SOM accounts for the release of both CO2 (4.0 Pg C) and CH4 (0.03 Pg C), but is partially compensated by CO2 uptake (0.3 Pg C) associated with enhanced net primary production of vegetation. This estimated net C transfer to the atmosphere from permafrost thaw represents a significant factor in the overall ecosystem carbon budget of the Pan-Arctic, and a non-trivial additional contribution on top of the combined fossil fuel emissions from the eight Arctic nations over this time period.

  14. The state of greenhouse gases in the atmosphere using global observations through 2012

    NASA Astrophysics Data System (ADS)

    Tarasova, Oksana; Koide, Hiroshi; Dlugokencky, Edward; Montzka, Stephen A.; Butler, James H.

    2014-05-01

    The Global Atmosphere Watch (GAW) Programme of the World Meteorological Organization (WMO) provides a framework for global observations and assessment of the state and development of atmospheric composition, including greenhouse gases. It puts stringent requirements on the quality of the observations. These requirements are reviewed by the greenhouse gas science and measurement community at biennial WMO/IAEA Meetings on Carbon Dioxide, Other Greenhouse Gases, and Related Tracer Measurement Techniques. The 17th meeting was held in Beijing, China, on 10 - 14 June 2013 (http://ggmt-2013.cma.gov.cn/dct/page/1). Results of global analysis of the observational data are reported annually in the WMO/GAW Annual Greenhouse Gas Bulletin. Bulletin No. 9 represents an update of the results for the year 2012 (extended version is available at http://www.wmo.int/pages/prog/arep/gaw/ghg/ghg9-en-online.html). The cover story of this bulletin presents the attribution of methane sources in the context of the renewed growth of the global average methane mole fraction in 2007. The bulletin is prepared by the WMO/GAW Scientific Advisory Group for Greenhouse Gases (http://www.wmo.int/pages/prog/www/CBS/Lists_WorkGroups/CAS/opag-epac/gaw%20sag%20ghg) in collaboration with the World Data Center for Greenhouse Gases. Observations used for global analysis are collected at more than 100 marine and terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. Globally averaged dry-air mole fractions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) derived from this network reached new highs in 2012, with CO2 at 393.1±0.1 ppm, CH4 at 1819±1 ppb and N2O at 325.1±0.1 ppb. These values constitute 141%, 260% and 120% of pre-industrial (before 1750) levels, respectively. The increase of the annual mean CO2 mole fraction from 2011 to 2012 amounted to 2.2 ppm, which is greater than the average growth rate for the 1990s (~1.5 ppm yr-1) and for

  15. Dust eruptions by photophoresis and solid state greenhouse effects.

    PubMed

    Wurm, Gerhard; Krauss, Oliver

    2006-04-01

    We carried out experiments that show a gas pressure dependent ability of light to eject particles from a dust bed. Dust eruptions also occur upon removal of the light source. This can be attributed to a solid state greenhouse effect and photophoretic forces. This ejection mechanism works at light intensities larger than 6 kW/m2 but in extreme cases might work as low as 1 kW/m2. It can be applied to sunlit dust on Mars where it aids or triggers dust lift-off from the surface into the atmosphere. It is of importance for dusty bodies at the inner edge of protoplanetary disks where it leads to light induced erosion. The effect also offers a base for technical applications of dust removal in low pressure environments. PMID:16711990

  16. The greenhouse effect: Its implications for industrial and government policy

    SciTech Connect

    Jarrett, J.; Coates, J.F.

    1985-01-01

    Discussions of policy, and scientific investigation also, could benefit from better information on sources and rates of emissions of the other greenhouse gases. Considerable information is available from the chemical industry on the chloroflurocarbons. Thinking about measures to prevent or control effects of climate change has barely begun. Without being impetuous in seeking much less in declaring solutions, there is room for the generation and exploration of fresh ideas. For example, virtually nothing has been done in conceptualizing means to prevent or retard the melting of the polar ice caps, by altering the albedo, or manipulating the circumpolar ocean currents. There is a need to brighten and broaden the future of public debate on the issue, which has been gloomy, at best. The potential for misinformation and misunderstanding on a complex issue is high. However the evolution of educational and participatory tools for the purpose of teaching complex concepts, in the imagining of strategies for managing future issues, for an understanding of the benefits and costs, and in planning for action, make developing a program of public information on atmospheric issues more attractive. At the same time, there is increasing interest in scientific information of all kinds. The trace gas contribution to the greenhouse effect is an especially interesting public policy topic with important consequences for us and our descendants. With positive action it is capable of becoming a model for the global discussion of slow building environmental developments.

  17. STRATOSPHERIC TEMPERATURES AND WATER LOSS FROM MOIST GREENHOUSE ATMOSPHERES OF EARTH-LIKE PLANETS

    SciTech Connect

    Kasting, James F.; Kopparapu, Ravi K.; Chen, Howard E-mail: hwchen@bu.edu

    2015-11-01

    A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a moist greenhouse explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheres are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing inverse climate calculations to determine habitable zone boundaries using 1D models.

  18. An approach for verifying biogenic greenhouse gas emissions inventories with atmospheric CO 2 concentration data

    DOE PAGES

    Ogle, Stephen; Davis, Kenneth J.; Lauvaux, Thomas; Schuh, Andrew E.; Cooley, Dan; West, Tristram O.; Heath, L.; Miles, Natasha; Richardson, S. J.; Breidt, F. Jay; et al

    2015-03-10

    Verifying national greenhouse gas (GHG) emissions inventories is a critical step to ensure that reported emissions data to the United Nations Framework Convention on Climate Change (UNFCCC) are accurate and representative of a country’s contribution to GHG concentrations in the atmosphere. Verification could include a variety of evidence, but arguably the most convincing verification would be confirmation of a change in GHG concentrations in the atmosphere that is consistent with reported emissions to the UNFCCC. We report here on a case study evaluating this option based on a prototype atmospheric CO2 measurement network deployed in the Mid-Continent Region of themore » conterminous United States. We found that the atmospheric CO2 measurement data did verify the accuracy of the emissions inventory within the confidence limits of the emissions estimates, suggesting that this technology could be further developed and deployed more widely in the future for verifying reported emissions.« less

  19. Ideas of Elementary Students about Reducing the "Greenhouse Effect."

    ERIC Educational Resources Information Center

    Francis, Claire; And Others

    1993-01-01

    Presents the results of a questionnaire given to 563 elementary students to study their ideas of actions that would reduce the greenhouse effect. Most of the children (87%) appreciated that planting trees would help reduce global warming. During interviews it was discovered that children were confused between the greenhouse effect and ozone layer…

  20. Overview of atmospheric effects

    NASA Technical Reports Server (NTRS)

    Rote, D. M.

    1980-01-01

    Effluents from the transportation system are the major cause of Satellite Power System related atmospheric effects. These effects are discussed and include inadvertent weather modification, air quality degradation, compositional changes in the stratosphere and mesosphere, formation of noctilucent clouds, plasma density changes, airglow enhancements, and changes in composition and dynamics of the plasmasphere and magnetosphere.

  1. [The greenhouse effect and human health].

    PubMed

    Berger, A

    1991-01-01

    Numerous scenarios describing the potential evolution of man's activities during the next few decades enable to predict the components of the future environmental system. On this basis and using the most reliable models, it may be predicted that, unless we alter our developmental policy, the Earth system will be significantly perturbed during the course of the 21st century. In particular, the greenhouse warming will cause profound changes in climatic zones as we know them to-day and, consequently, in regional climates and in the agricultural, economic, social and health infrastructures associated with them. According to the Intergovernmental Panel of Climate Change, the Business-as-Usual scenario of emission would lead to a warming of about 3 degrees C above the 1990 level by the end of the next century. Sea level will rise due to the thermal expansion of the warmer oceans and potential melting of glaciers with a "best" estimate of 60 cm for the end of the XXIst century. Much more needs to be known about man-made effects on his surroundings, but action must be taken rapidly and effectively to ensure that instead of destroying the basis for human life on Earth, man's ingenuity is applied to saving and improving it.

  2. Is the additional greenhouse effect already evident in the current climate?

    PubMed

    Raschke, E

    2001-11-01

    Several greenhouse gases, which are in part or entirely produced by human activities, have accumulated in the atmosphere since approximately the middle of the 19th century. They are assumed to have an additional greenhouse effect causing a further increase of atmospheric temperatures near the ground and a decrease in the layers above approximately 15 km altitude. The currently observed near-surface warming over nearly the entire globe is already considered by a large fraction of our society to be result of this additional greenhouse effect. Complete justification of this assumption is, however, not yet possible, because there are still too many unknowns in our knowledge of participating processes and in our modeling capabilities.

  3. Runaway and moist greenhouse atmospheres and the evolution of Earth and Venus.

    PubMed

    Kasting, J F

    1988-01-01

    A one-dimensional climate model is used to study the response of an Earth-like atmosphere to large increases in solar flux. For fully saturated, cloud-free conditions, the critical solar flux at which a runaway greenhouse occurs, that is, the oceans evaporate entirely, is found to be 1.4 times the present flux at Earth's orbit (S0). This value is close to the flux expected at Venus' orbit early in solar system history. Is is nearly independent of the amount of CO2 present in the atmosphere, but is sensitive to the H2O absorption coefficient in the 8- to 12-micrometers window region. Clouds should tend to depress the surface temperature on a warm, moist planet; thus, Venus may originally have had oceans if its initial water endowment was close to that of Earth. It lost them early in its history, however, because of rapid photodissociation of water vapor followed by escape of hydrogen to space. The critical solar flux above which water is rapidly lost could be as low as 1.1S0. The surface temperature of a runaway greenhouse atmosphere containing a full ocean's worth of water would have been in excess of 1500 degrees K--above the solidus for silicate rocks. The presence of such a steam atmosphere during accretion may have significantly influenced the early thermal evolution of both Earth and Venus.

  4. Verification of greenhouse gas emission reductions: the prospect of atmospheric monitoring in polluted areas.

    PubMed

    Levin, Ingeborg; Hammer, Samuel; Eichelmann, Elke; Vogel, Felix R

    2011-05-28

    Independent verification of greenhouse gas emissions reporting is a legal requirement of the Kyoto Protocol, which has not yet been fully accomplished. Here, we show that dedicated long-term atmospheric measurements of greenhouse gases, such as carbon dioxide (CO(2)) and methane (CH(4)), continuously conducted at polluted sites can provide the necessary tool for this undertaking. From our measurements at the semi-polluted Heidelberg site in the upper Rhine Valley, we find that in the catchment area CH(4) emissions decreased on average by 32±6% from the second half of the 1990s until the first half of the 2000s, but the observed long-term trend of emissions is considerably smaller than that previously reported for southwest Germany. In contrast, regional fossil fuel CO(2) levels, estimated from high-precision (14)CO(2) observations, do not show any significant decreasing trend since 1986, in agreement with the reported emissions for this region. In order to provide accurate verification, these regional measurements would best be accompanied by adequate atmospheric transport modelling as required to precisely determine the relevant catchment area of the measurements. Furthermore, reliable reconciliation of reported emissions will only be possible if these are known at high spatial resolution in the catchment area of the observations. This information should principally be available in all countries that regularly report their greenhouse gas emissions to the United Nations Framework Convention on Climate Change.

  5. Assessment of Ground-based Atmospheric Observations for Tracking Changes in Greenhouse Gas Emissions from Urban Areas

    NASA Astrophysics Data System (ADS)

    McKain, K.; Wofsy, S. C.; Nehrkorn, T.; Eluszkiewicz, J.

    2011-12-01

    The fairness and effectiveness of agreements to limit greenhouse gas emissions depends on our ability to verify reported changes in emissions using direct atmospheric observations. The goal of this work was to test whether ground-based measurements of greenhouse gases from urban regions can be used to quantify changes in emissions. We performed an atmospheric inversion for Salt Lake City, Utah using an existing dataset of CO2 measurements, prior estimates of emissions, and a high-resolution Lagrangian atmospheric transport model. By comparing simulated and observed CO2 for Salt Lake City, we were able to constrain emissions to within 15%. Substantial improvements in our ability to estimate emissions using urban surface observations are not expected because of limitations imposed by the character of the data, namely the dominance of the stochastic component of the signal and the inverse relationship between the daily cycle of emissions and CO2 concentration enhancements. Based on these results, we believe ground- and space-based measurements of column enhancements in the urban dome offer a superior route for verification purposes.

  6. Trace Gases, CO2, Climate, and the Greenhouse Effect.

    ERIC Educational Resources Information Center

    Aubrecht, Gordon J., II

    1988-01-01

    Reports carbon dioxide and other trace gases can be the cause of the Greenhouse Effect. Discusses some effects of the temperature change and suggests some solutions. Included are several diagrams, graphs, and a table. (YP)

  7. The greenhouse effect and acid rain

    SciTech Connect

    Traeger, R.K.

    1990-01-01

    The concentrations of carbon dioxide, methane, sulfur dioxide, nitrous oxides and chlorofluorocarbons is increasing in the earth's atmosphere. Increased concentrations of these trace gases could lead to global warming, increased acid rain and increased UV radiation on the earth's surface; however, the actual impacts are still uncertain and are also the subject of great debate. Application of clean'' energy sources such as geothermal are obviously desirable for decreasing these effects and improving our overall general environment. This paper briefly summarizes the global environment concerns, providing a backdrop for the following papers which describe the geothermal role in future environmental considerations. 5 refs., 2 figs., 1 tab.

  8. Miniaturized Laser Heterodyne Radiometer (LHR) for Measurements of Greenhouse Gases in the Atmospheric Column

    NASA Technical Reports Server (NTRS)

    Steel, Emily; McLinden, Matthew

    2012-01-01

    This passive laser heterodyne radiometer (LHR) instrument simultaneously measures multiple trace gases in the atmospheric column including carbon dioxide (CO2) and methane (CH4), and resolves their concentrations at different altitudes. This instrument has been designed to operate in tandem with the passive aerosol sensor currently used in AERONET (an established network of more than 450 ground aerosol monitoring instruments worldwide). Because aerosols induce a radiative effect that influences terrestrial carbon exchange, simultaneous detection of aerosols with these key carbon cycle gases offers a uniquely comprehensive measurement approach. Laser heterodyne radiometry is a technique for detecting weak signals that was adapted from radio receiver technology. In a radio receiver, a weak input signal from a radio antenna is mixed with a stronger local oscillator signal. The mixed signal (beat note, or intermediate frequency) has a frequency equal to the difference between the input signal and the local oscillator. The intermediate frequency is amplified and sent to a detector that extracts the audio from the signal. In the LHR instrument described here, sunlight that has undergone absorption by the trace gas is mixed with laser light at a frequency matched to a trace gas absorption feature in the infrared (IR). Mixing results in a beat signal in the RF (radio frequency) region that can be related to the atmospheric concentration. For a one-second integration, the estimated column sensitivities are 0.1 ppmv for CO2, and <1 ppbv for CH4. In addition to producing a standalone ground measurement product, this instrument could be used to calibrate/validate four Earth observing missions: ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons), OCO-2 (Orbiting Carbon Observatory), OCO-3, and GOSAT (Greenhouse gases Observational SATellite). The only network that currently measures CO2 and CH4 in the atmospheric column is TCCON (Total Carbon Column

  9. Climate and site management as driving factors for the atmospheric greenhouse gas exchange of a restored wetland

    NASA Astrophysics Data System (ADS)

    Herbst, M.; Friborg, T.; Schelde, K.; Jensen, R.; Ringgaard, R.; Vasquez, V.; Thomsen, A. G.; Soegaard, H.

    2013-01-01

    The atmospheric greenhouse gas (GHG) budget of a restored wetland in western Denmark was established for the years 2009-2011 from eddy covariance measurements of carbon dioxide (CO2) and methane (CH4) fluxes. The water table in the wetland, which was restored in 2002, was unregulated, and the vegetation height was limited through occasional grazing by cattle and grass cutting. The annual net CO2 uptake varied between 195 and 983 g m-2 and the annual net CH4 release varied between 11 and 17 g m-2. In all three years the wetland was a carbon sink and removed between 42 and 259 g C m-2 from the atmosphere. However, in terms of the full annual GHG budget (assuming that 1 g CH4 is equivalent to 25 g CO2 with respect to the greenhouse effect over a time horizon of 100 years) the wetland was a sink in 2009, a source in 2010 and neutral in 2011. Complementary observations of meteorological factors and management activities were used to explain the large inter-annual variations in the full atmospheric GHG budget of the wetland. The largest impact on the annual GHG fluxes, eventually defining their sign, came from site management through changes in grazing duration and animal stocking density. These changes accounted for half of the observed variability in the CO2 fluxes and about two thirds of the variability in CH4 fluxes. An unusually long period of snow cover in 2010 had the second largest effect on the annual CO2 flux, whose interannual variability was larger than that of the CH4 flux. Since integrated CO2 and CH4 flux data from restored wetlands are still very rare, it is concluded that more long-term flux measurements are needed to quantify the effects of ecosystem disturbance, in terms of management activities and exceptional weather patterns, on the atmospheric GHG budget more accurately.

  10. Increased soil emissions of potent greenhouse gases under increased atmospheric CO2.

    PubMed

    van Groenigen, Kees Jan; Osenberg, Craig W; Hungate, Bruce A

    2011-07-13

    Increasing concentrations of atmospheric carbon dioxide (CO(2)) can affect biotic and abiotic conditions in soil, such as microbial activity and water content. In turn, these changes might be expected to alter the production and consumption of the important greenhouse gases nitrous oxide (N(2)O) and methane (CH(4)) (refs 2, 3). However, studies on fluxes of N(2)O and CH(4) from soil under increased atmospheric CO(2) have not been quantitatively synthesized. Here we show, using meta-analysis, that increased CO(2) (ranging from 463 to 780 parts per million by volume) stimulates both N(2)O emissions from upland soils and CH(4) emissions from rice paddies and natural wetlands. Because enhanced greenhouse-gas emissions add to the radiative forcing of terrestrial ecosystems, these emissions are expected to negate at least 16.6 per cent of the climate change mitigation potential previously predicted from an increase in the terrestrial carbon sink under increased atmospheric CO(2) concentrations. Our results therefore suggest that the capacity of land ecosystems to slow climate warming has been overestimated.

  11. Greenhouse effects due to man-made perturbations of trace gases

    NASA Technical Reports Server (NTRS)

    Wang, W. C.; Yung, Y. L.; Lacis, A. A.; Mo, T.; Hansen, J. E.

    1976-01-01

    Nitrous oxide, methane, ammonia, and a number of other trace constituents of the earth's atmosphere have infrared absorption bands in the spectral range from 7 to 14 microns. Despite their small amounts, these gases can have a significant effect on the thermal structure of the atmosphere by transmitting most of the thermal radiation from the earth's surface to the lower atmosphere. In the present paper, this greenhouse effect is computed for a number of trace gases. The nature and climatic implications of possible changes in the concentrations of N2O, CH4, NH3, and HNO3 are discussed.

  12. Runaway and moist greenhouse atmospheres and the evolution of earth and Venus

    SciTech Connect

    Kasting, J.F.

    1988-06-01

    For the case of fully moisture-saturated and cloud-free conditions, the present one-dimensional climate model for the response of an earthlike atmosphere to large solar flux increases notes the critical solar flux at which runaway greenhouse (total evaporation of oceans) occurs to be 1.4 times the present flux at the earth's orbit, almost independently of the CO2 content of the atmophere. The value is, however, sensitive to the H2O absorption coefficient in the 8-12 micron window. Venus oceans may have been lost early on due to rapid water vapor photodissociation, followed by hydrogen escape into space. 42 references.

  13. Runaway and moist greenhouse atmospheres and the evolution of earth and Venus

    NASA Technical Reports Server (NTRS)

    Kasting, James F.

    1988-01-01

    For the case of fully moisture-saturated and cloud-free conditions, the present one-dimensional climate model for the response of an earthlike atmosphere to large solar flux increases notes the critical solar flux at which runaway greenhouse (total evaporation of oceans) occurs to be 1.4 times the present flux at the earth's orbit, almost independently of the CO2 content of the atmophere. The value is, however, sensitive to the H2O absorption coefficient in the 8-12 micron window. Venus oceans may have been lost early on due to rapid water vapor photodissociation, followed by hydrogen escape into space.

  14. Geological assessment of the greenhouse effect

    SciTech Connect

    Crowley, T.J. )

    1993-12-01

    Geologic studies provide a valuable perspective on the importance of greenhouse forcing for climate change. On both Pleistocene and tectonic time scales, changes in climate are positively correlated with greenhouse gas variations. However, the sensitivity of the system to greenhouse gas changes cannot yet be constrained by paleoclimate data below its present large range. Geologic records do not support one of the major predictions of greenhouse models-namely, that tropical sea surface temperatures will increase. Geologic data also suggest that winter cooling in high-latitude land areas is less than predicted by models. As the above-mentioned predictions appear to be systemic features of the present generation of climate models, some significant changes in model design may be required to reconcile models and geologic data. However, full acceptance of this conclusion requires more measurements and more systematic compilations of existing geologic data. Since progress in data collection in this area has been quite slow, uncertainties associated with these conclusions may persist for some time. 106 refs., 6 figs.

  15. [Effects of solar greenhouse vegetable cultivation on soil physical quality].

    PubMed

    Sun, Yan; Wang, Yi-quan; Liu, Jun; Xia, Fa-sheng; Wang, Jin-gui; Li, Jian-bo

    2011-08-01

    Taking the solar greenhouse heavy loam soil having been planted vegetables for different years at Yunyang Town in Jingyang County of Shaanxi Province as test objects, and with the uncovered vegetable soil adjacent to the greenhouse as the control, this paper studied the effects of solar greenhouse vegetable cultivation on soil physical quality. Solar greenhouse vegetable cultivation had greater effects on the bulk density of 0-30 cm soil layer (an increase in 0-10 cm soil layer and a decrease in 10-30 cm soil layer), but little effects on that of 30-40 cm soil layer. In 0-40 cm solar greenhouse soil profile, the contents of < 0.01 mm physical clay and < 0.001 mm clay were lower in upper layer than in deeper layer, indicating their downward movement, and this phenomenon was more obvious with increasing year of solar greenhouse vegetable cultivation. Within the first 5 years of solar greenhouse vegetable cultivation, soil field water capacity decreased significantly, with a decrement of 13.8%, but remained relatively stable after then.

  16. Elementary Pre-Service Teacher Perceptions of the Greenhouse Effect.

    ERIC Educational Resources Information Center

    Groves, Fred H.; Pugh, Ava F.

    1999-01-01

    Expands on earlier work to examine pre-service teachers' views on environmental issues, especially global warming and the related term "greenhouse effect." Suggests that pre-service elementary teachers hold many misconceptions about environmental issues. (DDR)

  17. Assessment of a multi-species in situ FTIR for precise atmospheric greenhouse gas observations

    NASA Astrophysics Data System (ADS)

    Hammer, S.; Griffith, D. W. T.; Konrad, G.; Vardag, S.; Caldow, C.; Levin, I.

    2013-05-01

    We thoroughly evaluate the performance of a multi-species, in situ Fourier transform infrared (FTIR) analyser with respect to high-accuracy needs for greenhouse gas monitoring networks. The in situ FTIR analyser is shown to measure CO2, CO, CH4 and N2O mole fractions continuously, all with better reproducibility than the inter-laboratory compatibility (ILC) goals, requested by the World Meteorological Organization (WMO) for the Global Atmosphere Watch (GAW) programme. Simultaneously determined δ13CO2 reaches reproducibility as good as 0.03‰. Second-order dependencies between the measured components and the thermodynamic properties of the sample, (temperature, pressure and flow rate) and the cross sensitivities among the sample constituents are investigated and quantified. We describe an improved sample delivery and control system that minimises the pressure and flow rate variations, making post-processing corrections for those quantities non-essential. Temperature disequilibrium effects resulting from the evacuation of the sample cell are quantified and improved by the usage of a faster temperature sensor. The instrument has proven to be linear for all measured components in the ambient concentration range. The temporal stability of the instrument is characterised on different time scales. Instrument drifts on a weekly time scale are only observed for CH4 (0.04 nmol mol-1 day-1) and δ13CO2 (0.02‰ day-1). Based on 10 months of continuously collected quality control measures, the long-term reproducibility of the instrument is estimated to ±0.016 μmol mol-1 CO2, ±0.03‰ δ13CO2, ±0.14 nmol mol-1 CH4, ±0.1 nmol mol-1 CO and ±0.04 nmol mol-1 N2O. We propose a calibration and quality control scheme with weekly calibrations of the instrument that is sufficient to reach WMO-GAW inter-laboratory compatibility goals.

  18. The impacts of permafrost thaw on land-atmosphere greenhouse gas exchange

    SciTech Connect

    Hayes, Daniel J; Kicklighter, David W.; McGuire, A. David; Chen, Min; Zhuang, Qianlai; Yuan, Fengming; Melillo, Jerry; Wullschleger, Stan

    2014-01-01

    Permafrost thaw and the subsequent mobilization of carbon stored in previously frozen soil organic matter (SOM) would be a strong positive feedback to climate1. As the northern permafrost region experiences double the rate of warming as the rest of the Earth2, the vast amount of carbon in permafrost soils3 is vulnerable to thaw, decomposition and release as atmospheric greenhouse gases (GHG). Here, we employ a process-based model simulation experiment to assess the net effect of this so-called permafrost carbon feedback (PCF) in recent decades. Results show a wide-spread increase in the depth to permafrost between 1990 and 2006, with simulated active layer thickness (ALT) capturing the mean and spatial variability of the observational data. Analysis of the simulation experiment provides an estimate of a 2.8 mm/yr increase in permafrost depth, which translates to 281 TgC/yr thawed from previously frozen SOM. Overall, we estimate a net GHG forcing of 534 MtCO2eq/yr directly tied to ALT dynamics, while accounting for CO2 (562 MtCO2eq/yr) and CH4 (52 MtCO2eq/yr) release as well as CO2 uptake by vegetation (-80 MtCO2eq/yr). This net forcing represents a significant factor in the estimated 640 MtCO2eq/yr pan-arctic GHG source4, and an additional 6.9% contribution on top of the combined 7792 MtCO2eq/yr fossil fuel emissions from the eight Arctic nations over this time period5.

  19. An atmospheric photochemical source of the persistent greenhouse gas CF4

    NASA Astrophysics Data System (ADS)

    Jubb, Aaron M.; McGillen, Max R.; Portmann, Robert W.; Daniel, John S.; Burkholder, James B.

    2015-11-01

    A previously uncharacterized atmospheric source of the persistent greenhouse gas tetrafluoromethane, CF4, has been identified in the UV photolysis of trifluoroacetyl fluoride, CF3C(O)F, which is a degradation product of several halocarbons currently present in the atmosphere. CF4 quantum yields in the photolysis of CF3C(O)F were measured at 193, 214, 228, and 248 nm, wavelengths relevant to stratospheric photolysis, to be (75.3 ± 1) × 10-4, (23.7 ± 0.4) × 10-4, (6.6 ± 0.2) × 10-4, and ≤0.4 × 10-4, respectively. A 2-D atmospheric model was used to estimate the contribution of the photochemical source to the global CF4 budget. The atmospheric photochemical production of CF4 from CF3CH2F (HFC-134a), CF3CHFCl (HCFC-124), and CF3CCl2F (CFC-114a) per molecule emitted was calculated to be (1-2.5) × 10-5, 1.0 × 10-4, and 2.8 × 10-3, respectively. Although CF4 photochemical production was found to be relatively minor at the present time, the identified mechanism demonstrates that long-lived products with potential climate impacts can be formed from the atmospheric breakdown of shorter-lived source gases.

  20. Time-dependent Calculations of an Impact-triggered Runaway Greenhouse Atmosphere on Mars

    NASA Technical Reports Server (NTRS)

    Segura, T. L.; Toon, O. B.; Colaprete, A.

    2003-01-01

    Large asteroid and comet impacts result in the production of thick (greater than tens of meters) global debris layers of 1500+ K and the release through precipitation of impact-injected steam and melting ground ice) of large amounts (greater than tens of meters global equivalent thickness) of water on the surface of Mars. Modeling shows that the surface of Mars is still above the freezing point of water after the rainout of the impact-injected steam and melting of subsurface ice. The energy remaining in the hot debris layer will allow evaporation of this water back into the atmosphere where it may rain out at a later time. Given a sufficiently rapid supply of this water to the atmosphere it will initiate a temporary "runaway" greenhouse state.

  1. Atmospheric Removal of Very Long-lived Greenhouse Gases in the Mesosphere

    NASA Astrophysics Data System (ADS)

    Totterdill, A.; Kovacs, T.; Gomez Martin, J.; FENG, W.; Chipperfield, M.; Plane, J. M.

    2013-12-01

    Chlorofluorocarbons are known to have serious ozone depleting and global warming potentials. Perfluorinated compounds such as SF6, NF3, SF5CF3 and CF3CF2Cl which have very long lifetimes (ranging from a few centuries to over 3000 years) are too stable to affect stratospheric ozone but do have among the highest per molecule radiative forcing of any greenhouse pollutant, making them extremely potent greenhouse gases. Due to the stability of these gases in the lower atmosphere, mesospheric loss processes could significantly reduce their estimated atmospheric lifetimes and hence, overall climate impact. Potential sinks include reactions with metals and energetic particles such as electrons or short wavelength photons already present in the upper atmosphere. The metals, in this instance iron, sodium or potassium, are produced by meteoric ablation, while background and energetic electrons have the continuous source of photoionization and auroral precipitation, respectively. In this study we investigate the removal potentials of four very long lived gases (SF6, NF3, SF5CF3 and CF3CF2Cl). First, by four metals (Fe, Mg, Na and K), where rate coefficients are measured using the Fast Flow Tube and Pulsed Laser Flash Photolysis / Laser Induced Fluorescence techniques. Second, removal by electron attachment was investigated using a quadrupole mass spectrometer. measurements. Third, Lyman-alpha (121.56 nm) photolysis was measured in a VUV absorption cell. The resulting removal rate coefficients are currently being input into the Whole Atmosphere Community Climate Model (WACCM) to obtain lifetime measurements for these species.

  2. Applications of fiber lasers for remote sensing of atmospheric greenhouse gases

    NASA Astrophysics Data System (ADS)

    Dobler, Jeremy T.; Braun, Michael; Nagel, James; Temyanko, Valery L.; Zaccheo, T. Scott; Harrison, F. Wallace; Browell, Edward V.; Kooi, Susan A.

    2013-02-01

    In 2004 ITT Exelis developed the Multifunctional Fiber Laser Lidar (MFLL) for measuring atmospheric CO2. This lidar relies on high efficiency telecom laser components and Erbium Doped Fiber Amplifiers (EDFA's) to implement a unique Continuous Wave (CW) Intensity Modulated (IM) differential absorption lidar measurement. This same approach has also been used to measure atmospheric O2 by replacing the EDFA's with fiber Raman amplifier technology. The use of all fiber coupled components results in a highly reliable, flexible and robust instrument. The general architecture of the MFLL, its implementation for greenhouse gas measurements, and as a pseudorandom noise encoded altimeter system is reviewed. Results from a 2011 flight campaign on the NASA DC-8 aircraft which included CO2, O2, and PN altimetry using a single receiver for all three measurements are also discussed. In addition, an introduction to a novel variation of this approach that will enable greenhouse gas monitoring from a geostationary orbit is given. This paper provides a general overview of a set of applications for fiber lasers in the area of active remote sensing that have been developed by Exelis over the past several years.

  3. Effect of Greenhouse Gases Dissolved in Seawater.

    PubMed

    Matsunaga, Shigeki

    2015-12-30

    A molecular dynamics simulation has been performed on the greenhouse gases carbon dioxide and methane dissolved in a sodium chloride aqueous solution, as a simple model of seawater. A carbon dioxide molecule is also treated as a hydrogen carbonate ion. The structure, coordination number, diffusion coefficient, shear viscosity, specific heat, and thermal conductivity of the solutions have been discussed. The anomalous behaviors of these properties, especially the negative pressure dependence of thermal conductivity, have been observed in the higher-pressure region.

  4. Assessment of US, Indian and Chinese Middle School Students' Outlook on the Greenhouse Effect

    NASA Astrophysics Data System (ADS)

    Niyogi, D.; Ganesh, N.; Singh, D.; Liu, X.; Shepardson, D. P.; Roychoudhury, A.; Hirsch, A.; Halversen, C.

    2012-12-01

    When you think of the greenhouse effect and climate change what images and concepts come to mind? Answers to these questions are important to educators and policy makers as they wrestle with the issue of educating and conveying these concepts in class rooms and to the general public. The greenhouse effect (GHE) sustains life on the earth through regulating the temperatures on the planet. Well-mixed greenhouse gases (GHGs) such as water vapor, carbon dioxide, methane, and nitrous oxide absorb outgoing (long wave) radiation from the Earth's surface while allowing passage without absorption of the incoming solar (shortwave) radiation. Increasing the GHG concentration in the atmosphere increases the absorption of long wavelength radiation thereby increasing global temperatures that result in changes in the atmospheric states consistently over multiple decades.The concept of the greenhouse effect is critical to the discussions underway pertaining to climate change and the controls on greenhouse emissions being proposed in different forums. This study sought to (1) investigate students' conceptions about the greenhouse effect, global warming and climate change; (2) determine if there are differences between perceptions for students in US, India and China (Asia)- where there are known differences in the political and scientific approaches; and (3) determine if there any differences, contextual or otherwise, in the way the greenhouse effect is taught in these countries. This study was conducted in select schools in the Midwest US, India and China that volunteered to work with this project. -For US, data from 51 secondary students from three different schools were analyzed, for India the number was 71 from 3 schools, while for China the number is over 100 (and being analyzed) from different classes within a school. Study Hypotheses: 1.Middle school students have a good scientific understanding of greenhouse gases. 2.The U.S and Asian students have the same outlook. Teachers

  5. Increased greenhouse-gas intensity of rice production under future atmospheric conditions

    NASA Astrophysics Data System (ADS)

    van Groenigen, Kees Jan; van Kessel, Chris; Hungate, Bruce A.

    2013-03-01

    Increased atmospheric CO2 and rising temperatures are expected to affect rice yields and greenhouse-gas (GHG) emissions from rice paddies. This is important, because rice cultivation is one of the largest human-induced sources of the potent GHG methane (CH4) and rice is the world's second-most produced staple crop. The need for meeting a growing global food demand argues for assessing GHG emissions from croplands on the basis of yield rather than land area, such that efforts to reduce GHG emissions take into consideration the consequences for food production. However, it is unclear whether or how the GHG intensity (that is, yield-scaled GHG emissions) of cropping systems will be affected by future atmospheric conditions. Here we show, using meta-analysis, that increased atmospheric CO2 (ranging from 550 to 743ppmV) and warming (ranging from +0.8°C to +6°C) both increase the GHG intensity of rice cultivation. Increased atmospheric CO2 increased GHG intensity by 31.4%, because CH4 emissions are stimulated more than rice yields. Warming increased GHG intensity by 11.8% per 1°C, largely owing to a decrease in yield. This analysis suggests that rising CO2 and warming will approximately double the GHG intensity of rice production by the end of the twenty-first century, stressing the need for management practices that optimize rice production while reducing its GHG intensity as the climate continues to change.

  6. Lake-Atmosphere Greenhouse Gas Exchange in Relation to Atmospheric Forcing and Water Clarity

    NASA Astrophysics Data System (ADS)

    Heiskanen, J. J.; Ojala, A.; Mammarella, I.; Vesala, T.

    2015-12-01

    Even though lakes cover only 2 % of the world's land surface, it has been estimated that lakes release about 10 % of the carbon fixed annually by the terrestrial ecosystems back to the atmosphere. A critical parameter in the gas exchange estimates is the gas transfer velocity (k), which is governed by turbulence. The aim of our study was to assess the current global CO2 evasion estimates from lakes to the atmosphere by comparing parameterizations for kand the significance of wind and heat flux to the gas transfer in small lakes. To improve future predictions of gas evasion from lakes, we focused on the changes in water clarity and how they affect water column physics and processes in the air-water interface. We studied a small boreal lake and used the eddy covariance (EC) method for the high precision data needed, and therefore also aimed to improve the EC methodology on lakes. The air-water gas transfer was related to both wind and heat loss during times of seasonal stratification, but only to wind during autumn overturn. When wind-induced thermocline tilting and resulting spatial variability in surface water CO2 concentrations was accounted for, average k derived from the measurements dropped from 6.0 cm h-1 to 5.2 cm h-1. This was still over twice the estimate (2.2 cm h-1) calculated with a widely used model for kin lakes suggesting that the global estimates of gas evasion from lakes might be underestimations. Water clarity was a significant parameter defining the thermal stratification of the lake: a change from clear to dark water would lead to shorter stratification period and lower water column temperatures in small lakes and therefore have significant impact on the lake-atmosphere exchange processes. Figure 1. The isotherms of Lake Kuivajärvi throughout the open-water period 2013. The top left are the measured temperatures and the others are modeled with LAKE model using fixed light extinction coefficient, Kd. The horizontal dashed black line represents

  7. Aerosol lidar observations of atmospheric mixing in Los Angeles: Climatology and implications for greenhouse gas observations

    NASA Astrophysics Data System (ADS)

    Ware, John; Kort, Eric A.; DeCola, Phil; Duren, Riley

    2016-08-01

    Atmospheric observations of greenhouse gases provide essential information on sources and sinks of these key atmospheric constituents. To quantify fluxes from atmospheric observations, representation of transport—especially vertical mixing—is a necessity and often a source of error. We report on remotely sensed profiles of vertical aerosol distribution taken over a 2 year period in Pasadena, California. Using an automated analysis system, we estimate daytime mixing layer depth, achieving high confidence in the afternoon maximum on 51% of days with profiles from a Sigma Space Mini Micropulse LiDAR (MiniMPL) and on 36% of days with a Vaisala CL51 ceilometer. We note that considering ceilometer data on a logarithmic scale, a standard method, introduces, an offset in mixing height retrievals. The mean afternoon maximum mixing height is 770 m Above Ground Level in summer and 670 m in winter, with significant day-to-day variance (within season σ = 220m≈30%). Taking advantage of the MiniMPL's portability, we demonstrate the feasibility of measuring the detailed horizontal structure of the mixing layer by automobile. We compare our observations to planetary boundary layer (PBL) heights from sonde launches, North American regional reanalysis (NARR), and a custom Weather Research and Forecasting (WRF) model developed for greenhouse gas (GHG) monitoring in Los Angeles. NARR and WRF PBL heights at Pasadena are both systematically higher than measured, NARR by 2.5 times; these biases will cause proportional errors in GHG flux estimates using modeled transport. We discuss how sustained lidar observations can be used to reduce flux inversion error by selecting suitable analysis periods, calibrating models, or characterizing bias for correction in post processing.

  8. The clear-sky greenhouse effect sensitivity to a sea surface temperature change

    NASA Technical Reports Server (NTRS)

    Duvel, J. PH.; Breon, F. M.

    1991-01-01

    The clear-sky greenhouse effect response to a sea surface temperature (SST or Ts) change is studied using outgoing clear-sky longwave radiation measurements from the Earth Radiation Budget Experiment. Considering geographical distributions for July 1987, the relation between the SST, the greenhouse effect (defined as the outgoing infrared flux trapped by atmospheric gases), and the precipitable water vapor content (W), estimated by the Special Sensor Microwave Imager, is analyzed first. A fairly linear relation between W and the normalized greenhouse effect g, is found. On the contrary, the SST dependence of both W and g exhibits nonlinearities with, especially, a large increase for SST above 25 C. This enhanced sensitivity of g and W can be interpreted in part by a corresponding large increase of atmospheric water vapor content related to the transition from subtropical dry regions to equatorial moist regions. Using two years of data (1985 and 1986), the normalized greenhouse effect sensitivity to the sea surface temperature is computed from the interannual variation of monthly mean values.

  9. Solar effect: sunspaces and greenhouses, behavior and health

    SciTech Connect

    Moskal, S.; Brandt, B.

    1981-01-01

    Sunspaces and solar greenhouses can be low-cost additions to existing buildings which by their very nature add to the living space of the dwelling unit into which they are incorporated, thereby influencing the residents' lifestyle. The implications of these solar spaces for their users and the larger community are our focus. Solar greenhouses and sunspaces influence the physical and mental health of the resident, particularly persons who can use the space during the day and those on fixed incomes. Increased sunlight and warmth, and in greenhouses, humidity and food production, directly influence health, while changes in interaction patterns, social status, independence and self-esteem are indirect results. These factors have a beneficial effect on the individual, the family, and the community. With increasing availability and use of solar sunspaces and greenhouses, these wide-ranging benefits could result in changes in demand for human services and have definite implications for public policy.

  10. The state of greenhouse gases in the atmosphere using global observations through 2013

    NASA Astrophysics Data System (ADS)

    Tarasova, Oksana; Koide, Hiroshi; Dlugokencky, Ed; Montzka, Stephen A.; Keeling, Ralph; Tanhua, Toste; Lorenzoni, Laura

    2015-04-01

    We present results from the tenth annual Greenhouse Gas Bulletin (http://www.wmo.int/pages/prog/arep/gaw/ ghg/GHGbulletin.html) of the World Meteorological Organization (WMO). The results are based on research and observations performed by laboratories contributing to the WMO Global Atmosphere Watch (GAW) Programme (www.wmo.int/gaw). The Bulletin presents results of global analyses of observational data collected according to GAW recommended practices and submitted to the World Data Center for Greenhouse Gases (WDCGG), and for the first time, it includes a summary of ocean acidification. Bulletins are prepared by the WMO/GAW Scientific Advisory Group for Greenhouse Gases (http://www.wmo.int/pages/prog/arep/gaw/ScientificAdvisoryGroups.html) in collaboration with WDCGG. The summary of ocean acidification and trends in ocean pCO2 was jointly produced by the International Ocean Carbon Coordination Project (IOCCP) of the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO), the Scientific Committee on Oceanic Research (SCOR), and the Ocean Acidification International Coordination Centre (OA-ICC) of the International Atomic Energy Agency (IAEA). The tenth Bulletin included a special edition published prior to the United Nations Climate Summit in September 2014. The scope of this edition was to demonstrate the level of emission reduction necessary to stabilize radiative forcing by long-lived greenhouse gases. It shows in particular that a reduction in radiative forcing from its current level (2.92 W m-2 in 2013) requires significant reductions in anthropogenic emissions of all major greenhouse gases. Observations used for global analysis are collected at more than 100 marine and terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. Globally averaged dry-air mole fractions of carbon dioxide, methane and nitrous oxide derived from this network reached new highs in 2013, with CO2 at 396.0 ± 0.1 ppm, CH4 at

  11. Greenhouse effect of trace gases, 1970-1980

    NASA Technical Reports Server (NTRS)

    Lacis, A.; Hansen, J.; Lee, P.; Lebedeff, S.; Mitchell, T.

    1981-01-01

    Increased abundances were measured for several trace atmospheric gases in the decade 1970-1980. The equilibrium greenhouse warming for the measured increments of CH4, chlorofluorocarbons and N2O is between 50% and 100% of the equilibrium warming for the measured increase of atmospheric CO2 during the same 10 years. The combined warming of CO2 and trace gases should exceed natural global temperature variability in the 1980's and cause the global mean temperature to rise above the maximum of the late 1930's.

  12. Variations in the tropical greenhouse effect during El Nino

    SciTech Connect

    Soden, B.J.

    1997-05-01

    Observations of the clear-sky outgoing longwave radiation and sea surface temperature are combined to examine the evolution of the tropical greenhouse effect from colder La Nina conditions in early 1985 to warmer El Nino conditions in late 1987. Although comparison of individual months can suggest a decrease in greenhouse trapping from cold to warm conditions, when the entire 4-yr record is considered a distinct increase in tropical-mean greenhouse trapping of {approximately}2 W m{sup -2} is observed in conjunction with a {approximately}0.4 K increase in tropical-mean sea surface temperature. This observed increase compares favorably with GCM simulations of the change in the clear-sky greenhouse effect during El Nifio-Southern Oscillation (ENSO). Superimposed on top of the SST-driven change in greenhouse trapping are dynamically induced changes in tropical moisture apparently associated with a redistribution of SST during ENSO. The GCM simulations also successfully reproduce this feature, providing reassurance in the ability of GCMs to predict both dynamically and thermodynamically driven changes in greenhouse trapping. 25 refs., 3 figs., 1 tab.

  13. Detecting Methane From Leaking Pipelines and as Greenhouse Gas in the Atmosphere

    NASA Technical Reports Server (NTRS)

    Riris, Haris; Numata, Kenji; Li, Steven; Wu, Stewart; Ramanathan, Anand; Dawsey, Martha

    2012-01-01

    Laser remote sensing measurements of trace gases from orbit can provide unprecedented information about important planetary science and answer critical questions about planetary atmospheres. Methane (CH4) is the second most important anthropogenically produced greenhouse gas. Though its atmospheric abundance is much less than that of CO2 (1.78 ppm vs. 380 ppm), it has much larger greenhouse heating potential. CH4 also contributes to pollution in the lower atmosphere through chemical reactions, leading to ozone production. Atmospheric CH4 concentrations have been increasing as a result of increased fossil fuel production, rice farming, livestock, and landfills. Natural sources of CH4 include wetlands, wild fires, and termites, and perhaps other unknown sources. Important sinks for CH4 include non-saturated soils and oxidation by hydroxyl radicals in the atmosphere. Remotely measuring CH4 and other biogenic molecules (such as ethane and formaldehyde) on Mars also has important implications on the existence of life on Mars. Measuring CH4 at very low (ppb) concentrations from orbit will dramatically improve the sensitivity and spatial resolution in the search for CH4 vents and sub-surface life on other planets. A capability has been developed using lasers and spectroscopic detection techniques for the remote measurements of trace gases in open paths. Detection of CH4, CO2, H2O, and CO in absorption cells and in open paths, both in the mid- IR and near-IR region, has been demonstrated using an Optical Parametric Amplifier laser transmitter developed at GSFC. With this transmitter, it would be possible to develop a remote sensing methane instrument. CH4 detection also has very important commercial applications. Pipeline leak detection from an aircraft or a helicopter can significantly reduce cost, response time, and pinpoint the location. The main advantage is the ability to rapidly detect CH4 leaks remotely. This is extremely important for the petrochemical industry

  14. An approach for verifying biogenic greenhouse gas emissions inventories with atmospheric CO2 concentration data

    NASA Astrophysics Data System (ADS)

    Ogle, Stephen M.; Davis, Kenneth; Lauvaux, Thomas; Schuh, Andrew; Cooley, Dan; West, Tristram O.; Heath, Linda S.; Miles, Natasha L.; Richardson, Scott; Breidt, F. Jay; Smith, James E.; McCarty, Jessica L.; Gurney, Kevin R.; Tans, Pieter; Denning, A. Scott

    2015-03-01

    Verifying national greenhouse gas (GHG) emissions inventories is a critical step to ensure that reported emissions data to the United Nations Framework Convention on Climate Change (UNFCCC) are accurate and representative of a country’s contribution to GHG concentrations in the atmosphere. Furthermore, verifying biogenic fluxes provides a check on estimated emissions associated with managing lands for carbon sequestration and other activities, which often have large uncertainties. We report here on the challenges and results associated with a case study using atmospheric measurements of CO2 concentrations and inverse modeling to verify nationally-reported biogenic CO2 emissions. The biogenic CO2 emissions inventory was compiled for the Mid-Continent region of United States based on methods and data used by the US government for reporting to the UNFCCC, along with additional sources and sinks to produce a full carbon balance. The biogenic emissions inventory produced an estimated flux of -408 ± 136 Tg CO2 for the entire study region, which was not statistically different from the biogenic flux of -478 ± 146 Tg CO2 that was estimated using the atmospheric CO2 concentration data. At sub-regional scales, the spatial density of atmospheric observations did not appear sufficient to verify emissions in general. However, a difference between the inventory and inversion results was found in one isolated area of West-central Wisconsin. This part of the region is dominated by forestlands, suggesting that further investigation may be warranted into the forest C stock or harvested wood product data from this portion of the study area. The results suggest that observations of atmospheric CO2 concentration data and inverse modeling could be used to verify biogenic emissions, and provide more confidence in biogenic GHG emissions reporting to the UNFCCC.

  15. Atmospheric CO2 concentrations during ancient greenhouse climates were similar to those predicted for A.D. 2100.

    PubMed

    Breecker, D O; Sharp, Z D; McFadden, L D

    2010-01-12

    Quantifying atmospheric CO(2) concentrations ([CO(2)](atm)) during Earth's ancient greenhouse episodes is essential for accurately predicting the response of future climate to elevated CO(2) levels. Empirical estimates of [CO(2)](atm) during Paleozoic and Mesozoic greenhouse climates are based primarily on the carbon isotope composition of calcium carbonate in fossil soils. We report that greenhouse [CO(2)](atm) have been significantly overestimated because previously assumed soil CO(2) concentrations during carbonate formation are too high. More accurate [CO(2)](atm), resulting from better constraints on soil CO(2), indicate that large (1,000s of ppmV) fluctuations in [CO(2)](atm) did not characterize ancient climates and that past greenhouse climates were accompanied by concentrations similar to those projected for A.D. 2100.

  16. Improving estimations of greenhouse gas transfer velocities by atmosphere-ocean couplers in Earth-System and regional models

    NASA Astrophysics Data System (ADS)

    Vieira, V. M. N. C. S.; Sahlée, E.; Jurus, P.; Clementi, E.; Pettersson, H.; Mateus, M.

    2015-09-01

    Earth-System and regional models, forecasting climate change and its impacts, simulate atmosphere-ocean gas exchanges using classical yet too simple generalizations relying on wind speed as the sole mediator while neglecting factors as sea-surface agitation, atmospheric stability, current drag with the bottom, rain and surfactants. These were proved fundamental for accurate estimates, particularly in the coastal ocean, where a significant part of the atmosphere-ocean greenhouse gas exchanges occurs. We include several of these factors in a customizable algorithm proposed for the basis of novel couplers of the atmospheric and oceanographic model components. We tested performances with measured and simulated data from the European coastal ocean, having found our algorithm to forecast greenhouse gas exchanges largely different from the forecasted by the generalization currently in use. Our algorithm allows calculus vectorization and parallel processing, improving computational speed roughly 12× in a single cpu core, an essential feature for Earth-System models applications.

  17. Biological methanogenesis and the CO2 greenhouse effect

    NASA Technical Reports Server (NTRS)

    Guthrie, P. D.

    1986-01-01

    It is well established that plants tend to increase net photosynthesis under increased carbon dioxide. It is also well established that a large fraction of atmospheric methane is produced by microbial metabolism of organic sediments in paddies and freshwater wetlands, where a major source of organic debris is local plant growth. As CO2 increases, it may lead to increased methane production and a resulting enhancement of the expected greenhouse warming. A rough estimate of the present rate of this biologically mediated feedback on the climate system indicates that it might account for as much as 30 percent of the observed methane increase and speed up the greenhouse forcing by as much as 15 percent.

  18. Knowledge about the 'Greenhouse Effect': Have College Students Improved?

    ERIC Educational Resources Information Center

    Jeffries, Helen; Stanisstreet, Martin; Boyes, Edward

    2001-01-01

    The ideas of Year I undergraduate biology students about the consequences, causes, and cures of the 'greenhouse effect' was determined using a closed-form questionnaire, and results were compared with a parallel study undertaken nearly 10 years ago. Many of the students in the present survey were unaware of the potential effect of global warming…

  19. The super greenhouse effect in a warming world: the role of dynamics and thermodynamics

    NASA Astrophysics Data System (ADS)

    Kashinath, Karthik; O'Brien, Travis; Collins, William

    2016-04-01

    Over warm tropical oceans the increase in greenhouse trapping with increasing SST can be faster than that of the surface emission, resulting in a decrease in clear sky outgoing longwave radiation at the top of the atmosphere (OLR) when SST increases, also known as the super greenhouse effect (SGE). If the SGE is directly linked to SST changes, there are profound implications for positive climate feedbacks in the tropics. We show that CMIP5 models perform well in simulating the observed clear-sky greenhouse effect in the present day. Using global warming experiments we show that the onset and shutdown SST of the SGE, as well as the magnitude of the SGE, increase as the convective threshold SST increases. To account for an increasing convective threshold SST we use an invariant coordinate for convection proposed in a recent study [Williams et al., GRL (2009)]. However, even after accounting for the increase in tropical SST (by normalizing the SGE by surface emission) and accounting for the increase in the threshold temperature for convection (by using the invariant coordinate) we find that the models predict a distinct increase in the clear-sky greenhouse effect in a warmed world. This suggests that thermodynamics (i.e. SST) plays a crucial role in regulating the increasing clear sky greenhouse effect in a warming world. We use theoretical arguments to estimate this increase in SGE and derive its dependence on SST. Finally, as shown in previous studies, we confirm that the increase in the clear-sky greenhouse effect is primarily due to upper tropospheric moistening. Although the absolute increase in upper tropospheric water vapor is small compared to that of the lower troposphere, since the absorptivity scales with fractional changes in water vapor, the contribution of the upper troposphere is more significant, as shown by Chung et al., PNAS (2014).

  20. Demonstration of the greenhouse effect for elementary school students

    NASA Astrophysics Data System (ADS)

    Radovanovic, Jelena

    2014-05-01

    The school where I work is part of the "Step by step towards the sustainable development school" project. Project activities are partly directed towards the popularization of science. As a physics teacher, I have had the opportunity to engage in designing interactive workshops, aiming to introduce younger students to simple experiments which illustrate different natural phenomena, and also in organization, preparation and implementation of school and city science festival (in 2012 and 2013). Numerous displays, workshops and experiments served to introduce a large number of visitors to different topics in the area of science and technology. One of the subjects of forthcoming science festival, planned for May of 2014, is the climate change. To that effect, eight grade students will hold a demonstration and explanation of the greenhouse effect. Although the terms greenhouse effect and global warming are widely used in media, most of the elementary school students in Serbia have poor understanding of the underlying scientific concepts. The experiment with analysis and discussion will first be implemented in one eight-grade class (14 years of age). After that, a group of students from this class will present their newly-acquired knowledge to their peers and younger students at the science fair. Activity objectives: • Explain how atmosphere affects the surface temperature of Earth • Conduct an experiment to demonstrate the greenhouse effect • Analyze the consequences of climate changes Experiment description: Take two empty, transparent containers and add a layer of garden soil. Use cardboard or similar material to make housings for the thermometers. Hang them in the containers, so that they don't touch the soil. Cover one container with a glass panel, and leave the other one open. Place identical incandescent light bulbs at the same distance above each container. Turn the light bulbs on. The students should mark the thermometer readings every 2 minutes, for 20

  1. The contribution from emissions of different gases to the enhanced greenhouse effect. Appendix B

    SciTech Connect

    Wigley, T.M.L.

    1993-01-01

    The main purpose of this paper is to compare the different contributions, that mankind has made to perturbing the atmosphere`s radiative balance. We have, and will continue to perturb both the balance of outgoing long-wave radiation and the balance of incoming short-wave radiation. Human activities since preindustrial times have caused a substantial enhancement of the greenhouse effect, a process involving the absorption of outgoing long-wave radiation which leads to a warming of the lower atmosphere. Because the atmosphere`s short-wave radiative balance is affected by the presence of small particles (aerosols) produced by the oxidation of sulphur compounds, anthropogenic emissions of sulphur dioxide (SO{sub 2}) have also caused a perturbation of the overall balance. The greenhouse gases we will consider are, in order of importance: carbon dioxide (CO{sub 2}), Methane (CH{sub 4}), nitrous oxide (N{sub 2}O) and the halocarbons. We use observed and model-based concentration data together with the most recent information relating concentrations to radiative forcing to estimate the individual contributions of the different gases to the changing radiative balance of the atmosphere. We also estimate the ranges of uncertainty in each of these estimates. We base all results on the 1992 IPCC emissions scenarios IS92a-f. We begin with a summary of 1990 conditions, then consider each gas separately (but lumping the halocarbons into a single group), to compare their relative importance.

  2. Regional climatic effects of atmospheric SO2 on Mars

    NASA Technical Reports Server (NTRS)

    Postawko, S. E.; Fanale, F. P.

    1992-01-01

    The conditions under which the valley networks on Mars may have formed remains controversial. The magnitude of an atmospheric greenhouse effect by an early massive CO2 atmosphere has recently been questioned by Kasting. Recent calculations indicate that if solar luminosity were less than about 86 percent of its current value, formation of CO2 clouds in the Martian atmosphere would depress the atmospheric lapse rate and reduce the magnitude of surface warming. In light of recent revisions of magma generation on Mars during each Martian epoch, and the suggestions by Wanke et al. that the role of liquid SO2 should be more carefully explored, we have recalculated the potential greenhouse warming by atmospheric SO2 on Mars, with an emphasis on more localized effects. In the vicinity of an active eruption, the concentration of atmospheric SO2 will be higher than if it is assumed that the erupted SO2 is instantaneously globally distributed. The local steady-state concentration of SO2 is a function of the rate at which it is released, its atmospheric lifetime, and the rate at which local winds act to disperse the SO2. We have made estimates of eruption rates, length of eruption, and dispersion rates of volcanically released SO2, for a variety of atmospheric conditions and atmospheric lifetimes of SO2 to explore the maximum regional climatic effect of SO2.

  3. Reply to "Comment on 'Cosmic-ray-driven reaction and greenhouse effect of halogenated molecules: Culprits for atmospheric ozone depletion and global climate change' by Dana Nuccitelli et al."

    NASA Astrophysics Data System (ADS)

    Lu, Q.-B.

    2014-04-01

    In the Comment by Nuccitelli et al., they make many false and invalid criticisms of the CFC-warming theory in my recent paper, and claim that their anthropogenic forcings including CO2 would provide a better explanation of the observed global mean surface temperature (GMST) data over the past 50 years. First, their arguments for no significant discrepancy between modeled and observed GMST changes and for no pause in recent global warming contradict the widely accepted fact and conclusion that were reported in the recent literature extensively. Second, their criticism that the key data used in my recent paper would be "outdated" and "flawed" is untrue as these data are still used in the recent or current literature including the newest (2013) IPCC Report and there is no considerable difference between the UK Met Office HadRCUT3 and HadRCUT4 GMST datasets. The use of even more recently computer-reconstructed total solar irradiance data (whatever have large uncertainties) for the period prior to 1976 would not change any of the conclusions in my paper, where quantitative analyses were emphasized on the influences of humans and the Sun on global surface temperature after 1970 when direct measurements became available. For the latter, the solar effect has been well shown to play only a negligible role in global surface temperature change since 1970, which is identical to the conclusion made in the 2013 IPCC Report. Third, their argument that the solar effect would not play a major role in the GMST rise of 0.2°C during 1850-1970 even contradicts the data and conclusion presented in a recent paper published in their Skeptical Science by Nuccitelli himself. Fourth, their comments also indicate their lack of understandings of the basic radiation physics of the Earth system as well as of the efficacies of different greenhouse gases in affecting global surface temperature. Their listed "methodological errors" are either trivial or non-existing. Fifth, their assertion that

  4. ObsPack: a framework for the preparation, delivery, and attribution of atmospheric greenhouse gas data

    NASA Astrophysics Data System (ADS)

    Masarie, K. A.; Peters, W.; Jacobson, A. R.; Tans, P. P.

    2014-09-01

    Observation Package (ObsPack) is a framework designed to bring together atmospheric greenhouse gas observations from a variety of sampling platforms, prepare them with specific applications in mind, and package and distribute them in a self-consistent and well-documented product. Data products created using the ObsPack framework (called "ObsPack products") are intended to support carbon cycle modeling studies and represent the next generation of value-added greenhouse gas observation products modeled after the cooperative GLOBALVIEW products introduced in 1996. Depending on intended use, ObsPack products may include data in their original form reformatted using the ObsPack framework or may contain derived data consisting of averages, subsets or smoothed representations of original data. All products include extensive ancillary information (metadata) intended to help ensure the data are used appropriately, their calibration and quality assurance history are clearly described, and that individuals responsible for the measurements (data providers or principal investigators (PIs)) are properly acknowledged for their work. ObsPack products are made freely available using a distribution strategy designed to improve communication between data providers and product users. The strategy includes a data usage policy that requires users to directly communicate with data providers and an automated e-mail notification system triggered when a product is accessed. ObsPack products will be assigned a unique Digital Object Identifier (DOI) to ensure each product can be unambiguously identified in scientific literature. Here we describe the ObsPack framework and its potential role in supporting the evolving needs of both data providers and product users.

  5. ObsPack: a framework for the preparation, delivery, and attribution of atmospheric greenhouse gas measurements

    NASA Astrophysics Data System (ADS)

    Masarie, K. A.; Peters, W.; Jacobson, A. R.; Tans, P. P.

    2014-12-01

    Observation Package (ObsPack) is a framework designed to bring together atmospheric greenhouse gas observations from a variety of sampling platforms, prepare them with specific applications in mind, and package and distribute them in a self-consistent and well-documented product. Data products created using the ObsPack framework (called "ObsPack products") are intended to support carbon cycle modeling studies and represent a next generation of value-added greenhouse gas observation products modeled after the cooperative GLOBALVIEW products introduced in 1996. Depending on intended use, ObsPack products may include data in their original form reformatted using the ObsPack framework or may contain derived data consisting of averages, subsets, or smoothed representations of original data. All products include extensive ancillary information (metadata) intended to help ensure the data are used appropriately, their calibration and quality assurance history are clearly described, and that individuals responsible for the measurements (data providers or principal investigators (PIs)) are properly acknowledged for their work. ObsPack products are made freely available using a distribution strategy designed to improve communication between data providers and product users. The strategy includes a data usage policy that requires users to directly communicate with data providers and an automated e-mail notification system triggered when a product is accessed. ObsPack products will be assigned a unique digital object identifier (DOI) to ensure each product can be unambiguously identified in scientific literature. Here we describe the ObsPack framework and its potential role in supporting the evolving needs of both data providers and product users.

  6. Exploring the Greenhouse Effect through Physics-Oriented Activities

    ERIC Educational Resources Information Center

    Browne, Kerry P.; Laws, Priscilla W.

    2003-01-01

    We are developing a new activity-based unit on global warming and the environment as part of the "Explorations in Physics Curriculum." We describe the current status of this unit, which focuses on helping students understand the greenhouse effect and its relationship to global warming. We outline several problems encountered in testing the unit…

  7. The Physics behind a Simple Demonstration of the Greenhouse Effect

    ERIC Educational Resources Information Center

    Buxton, Gavin A.

    2014-01-01

    A simple, and popular, demonstration of the greenhouse effect involves a higher temperature being observed in a container with an elevated concentration of CO[subscript 2] inside than in a container with just air enclosed, when subject to direct light. The CO[subscript 2] absorbs outgoing thermal radiation and causes the air inside the container…

  8. Seventh Grade Students' Mental Models of the Greenhouse Effect

    ERIC Educational Resources Information Center

    Shepardson, Daniel P.; Choi, Soyoung; Niyogi, Dev; Charusombat, Umarporn

    2011-01-01

    This constructivist study investigates 225 student drawings and explanations from three different schools in the midwest in the US, to identify seventh grade students' mental models of the greenhouse effect. Five distinct mental models were derived from an inductive analysis of the content of the students' drawings and explanations: Model 1, a…

  9. Climatic effects due to halogenated compounds in the earth's atmosphere

    NASA Technical Reports Server (NTRS)

    Wang, W.-C.; Pinto, J. P.; Yung, Y. L.

    1980-01-01

    Using a one-dimensional radiative-convective model, a sensitivity study is performed of the effect of ozone depletion in the stratosphere on the surface temperature. There could be a cooling of the surface temperature by approximately 0.2 K due to chlorofluoromethane-induced ozone depletion at steady state (assuming 1973 release rates). This cooling reduces significantly the greenhouse effect due to the presence of chlorofluoromethanes. Carbon tetrafluoride has a strong nu sub 3 band at 7.8 microns, and the atmospheric greenhouse effect is shown to be 0.07 and 0.12 K/ppbv with and without taking into account overlap with CH4 and N2O bands. At concentrations higher than 1 ppbv, absorption by the nu sub 3 band starts to saturate and the greenhouse effect becomes less efficient.

  10. Estimation of the atmosphere-ocean fluxes of greenhouse gases and aerosols at the finer resolution of the coastal ocean.

    NASA Astrophysics Data System (ADS)

    Vieira, Vasco; Sahlée, Erik; Jurus, Pavel; Clementi, Emanuela; Pettersson, Heidi; Mateus, Marcos

    2016-04-01

    The balances and fluxes of greenhouse gases and aerosols between atmosphere and ocean are fundamental for Earth's heat budget. Hence, the scientific community needs to know and simulate them with accuracy in order to monitor climate change from Earth-Observation satellites and to produce reliable estimates of climate change using Earth-System Models (ESM). So far, ESM have represented earth's surface with coarser resolutions so that each cell of the marine domain is dominated by the open ocean. In such case it is enough to use simple algorithms considering the wind speed 10m above sea-surface (u10) as sole driver of the gas transfer velocity. The formulation by Wanninkhof (1992) is broadly accepted as the best. However, the ESM community is becoming increasingly aware of the need to model with finer resolutions. Then, it is no longer enough to only consider u10 when modelling gas transfer velocities across the coastal oceans' surfaces. More comprehensive formulations are required that adjust better to local conditions by also accounting for the effects of sea-surface agitation, wave breaking, atmospheric stability of the Surface Boundary Layer, current drag with the bottom, surfactants and rain. Accurate algorithms are also fundamental to monitor atmosphere and ocean greenhouse gas concentrations using satellite data and reverse modelling. Past satellite missions ERS, Envisat, Jason-2, Aqua, Terra and Metop, have already been remotely sensing the ocean's surface at much finer resolutions than ESM using instruments like MERIS, MODIS, AMR, AATSR, MIPAS, Poseidon-3, SCIAMACHY, SeaWiFS, and IASI. The planned new satellite missions Sentinel-3, OCO-2 and GOSAT will further increase the resolutions. We developed a framework to congregate competing formulations for the estimation of the solubility and transfer velocity of virtually any gas on the biosphere taking into consideration the atmosphere and ocean fundamental variables and their derived geophysical processes

  11. Laser Atmospheric Transmitter Receiver-Network (LAnTeRN): A new approach for active measurement of atmospheric greenhouse gases

    NASA Astrophysics Data System (ADS)

    Dobler, J. T.; Braun, M.; Zaccheo, T.

    2012-12-01

    The Laser Atmospheric Transmitter Receiver-Network (LAnTeRN) is a new measurement concept that will enable local, regional and continental determination of key greenhouse gases, with unparalleled accuracy and precision. This new approach will offer the ability to make low bias, high precision, quasi-continuous, measurements to the accuracies required for separating anthropogenic and biogenic sources and sinks. In 2004 ITT Exelis developed an airborne demonstration unit, based on an intensity modulated continuous wave (IM-CW) lidar approach, for actively measuring atmospheric CO2 and O2. The multi-functional fiber laser lidar (MFLL) system relies on low peak power, high reliability, and efficient telecom laser components to implement this unique measurement approach. While evaluating methods for discriminating against thin clouds for the MFLL instrument, a new measurement concept was conceived. LAnTeRN has several fundamental characteristics in common with the MFLL instrument, but is a fundamentally different implementation and capability. The key difference is that LAnTeRN operates in transmission rather than in the traditional backscatter lidar configuration, which has several distinct advantages. Operating as a forward scatter, bistatic lidar system, LAnTeRN enables consideration of continuous monitoring from a geostationary orbit to multiple locations on the ground. Having the receivers on the ground significantly lowers cost and risk compared to an all space based mission, and allows the transmitter subsystem to be implemented, near term, as a hosted payload. Furthermore, the LAnTeRN measurement approach is also applicable for ground to ground measurements where high precision measurements over a long open path is required, such as facilities monitoring, or monitoring of passive volcanoes and fault lines. Using narrow linewidth laser sources allows flexibility to select the position on the absorption feature being probed. This feature allows for weighting the

  12. Potential effects of anthropogenic greenhouse gases on avian habitats and populations in the northern Great Plains

    USGS Publications Warehouse

    Larson, Diane L.

    1994-01-01

    Biotic response to the buildup of greenhouse gases in Earth's atmosphere is considerably more complex than an adjustment to changing temperature and precipitation. The fertilization effect carbon dioxide has on some plants, the impact UVB radiation has on health and productivity of organisms, and the resulting changes in competitive balance and trophic structure must also be considered. The intent of this paper is to review direct and indirect effects of anthropogenic greenhouse gases on wildlife, and to explore possible effects on populations of birds and their habitats in the northern Great Plains.Many of the potential effects of increasing greenhouse gases, such as declining plant nutritional value, changes in timing of insect emergence, and fewer and saltier wetlands, foreshadow a decline in avian populations on the Great Plains. However, other possible effects such as increased drought resistance and water use efficiency of vegetation, longer growing seasons, and greater overall plant biomass promise at least some mitigation. Effects of multiple simultaneous perturbations such as can be expected under doubled carbon dioxide scenarios will require substantial basic research to clarify.

  13. Children's Models of Understanding of Two Major Global Environmental Issues (Ozone Layer and Greenhouse Effect).

    ERIC Educational Resources Information Center

    Boyes, Edward; Stanisstreet, Martin

    1997-01-01

    Aims to quantify the models that 13- and 14 year-old students hold about the causes of the greenhouse effect and ozone layer depletion. Assesses the prevalence of those ideas that link the two phenomena. Twice as many students think that holes in the ozone layer cause the greenhouse effect than think the greenhouse effect causes ozone depletion.…

  14. An approach for verifying biogenic greenhouse gas emissions inventories with atmospheric CO 2 concentration data

    SciTech Connect

    Ogle, Stephen; Davis, Kenneth J.; Lauvaux, Thomas; Schuh, Andrew E.; Cooley, Dan; West, Tristram O.; Heath, L.; Miles, Natasha; Richardson, S. J.; Breidt, F. Jay; Smith, Jim; McCarty, Jessica L.; Gurney, Kevin R.; Tans, P. P.; Denning, Scott

    2015-03-10

    Verifying national greenhouse gas (GHG) emissions inventories is a critical step to ensure that reported emissions data to the United Nations Framework Convention on Climate Change (UNFCCC) are accurate and representative of a country’s contribution to GHG concentrations in the atmosphere. Verification could include a variety of evidence, but arguably the most convincing verification would be confirmation of a change in GHG concentrations in the atmosphere that is consistent with reported emissions to the UNFCCC. We report here on a case study evaluating this option based on a prototype atmospheric CO2 measurement network deployed in the Mid-Continent Region of the conterminous United States. We found that the atmospheric CO2 measurement data did verify the accuracy of the emissions inventory within the confidence limits of the emissions estimates, suggesting that this technology could be further developed and deployed more widely in the future for verifying reported emissions.

  15. Global Warming: Understanding and Teaching the Forecast. Part A The Greenhouse Effect.

    ERIC Educational Resources Information Center

    Andrews, Bill

    1993-01-01

    Provides information necessary for an interdisciplinary analysis of the greenhouse effect, enhanced greenhouse effect, global warming, global climate change, greenhouse gases, carbon dioxide, and scientific study of global warming for students grades 4-12. Several activity ideas accompany the information. (LZ)

  16. El Nino-southern oscillation: A coupled response to the greenhouse effect?

    SciTech Connect

    Sun, De-Zheng

    1997-11-01

    The purpose of this article to elucidate the link between the El Nino-Southern Oscillation (ENSO) and radiative forcing (of which the greenhouse effect is a major part). A unified theory for the tropical Pacific climate is developed by considering the response of the coupled ocean-atmosphere to a changing radiative forcing. The hypothesis is that both the zonal surface sea temperature (SST) gradients and ENSO are a coupled response to the strong radiative heating or the tropical warmth. Owing to ocean-atmosphere interaction, the stronger the radiative heating, the larger the zonal SST gradients. When the SST gradients exceed a critical value, however, the ocean-atmosphere interaction in the cold-tongue region is too strong for the coupled system to hold steady. Consequently, the coupled system enters an oscillatory state. These coupled dynamics are examined in a simple mathematical model whose behavior is consistent with the hypothesis. With a linear temperature profile throughout the depth of subsurface ocean, the model predicts that both the magnitude and period of the oscillation increase with increases in radiative forcing or the greenhouse effect. The increase in the magnitude of the oscillation largely comes from an enhancement of the magnitude of the cold anomalies, while the increase in the period mostly comes from a prolonged duration of the warm events. With a profile in which the lapse rate decreases with depth, the sensitivity is more moderate. The simplicity of the model prevents a quantitative simulation of the sensitivity of ENSO to increases in the greenhouse effect, but qualitatively the model results support the empirical interpretation of the prolonged duration of the 1990-1995 ENSO event. 5 refs., 7 figs.

  17. The radiative-adiabatic model of 2-component (2 + 2) greenhouse effect is applicable for wide range of planetary environment

    NASA Astrophysics Data System (ADS)

    Karnaukhov, A. V.

    In earlier works (1) it is shown that the radiative-adiabatic model make it possible the analytical solution for the 2-component (2 + 2) greenhouse effect in the case of the optical dense atmosphere (Earth, Venus). Now we have obtained the analytical estimation of greenhouse effect not only for the planets with the high optical density of atmosphere but also for the low optical density of atmosphere (Mars) too. These estimations demonstrate a good accordance with the different types of observation data. The detailed analysis of the radiative-adiabatic model of greenhouse effect bring us to conclusion that the greenhouse effect is the most important internal factor for the planetary environment and climate forming. The role of greenhouse effect can be compared with the role of such important external factor as the intensity of incident radiation from the central star (Sun). The evidence of the sharp and significant changes in the climate history of the Mars (the trace of water erosion) and Venus (the anomaly in D/H ratio) give us the proof of the extremely important role of greenhouse effect. Indeed, this changes shift temperature of that planets in different directions (Mars now is colder and Venus is warmer than in the past). So, these changes can not be caused by an external parameter, such as the solar luminosity for example. In the present work we use the radiative-adiabatic model in the investigation of the planetary climate evolution for the planets of the Earth's group (Venus, Earth, and Mars). We show that the observed changes in the Mars and the Venus climate can be easily explained by the assumption of the significant changes of the concentration of the greenhouse gases in atmospheres of that planets. For the Earth we show that it is the role of biosphere's mechanisms that make the parameters of the Earth's climate so stable. We discuss also the possibility of the destruction of the biosphere's mechanisms of the Earth' climate stabilisation. In that case

  18. Summer fluxes of atmospheric greenhouse gases N2O, CH4 and CO2 from mangrove soil in South China.

    PubMed

    Chen, G C; Tam, N F Y; Ye, Y

    2010-06-01

    The atmospheric fluxes of N(2)O, CH(4) and CO(2) from the soil in four mangrove swamps in Shenzhen and Hong Kong, South China were investigated in the summer of 2008. The fluxes ranged from 0.14 to 23.83 micromol m(-2)h(-1), 11.9 to 5168.6 micromol m(-2)h(-1) and 0.69 to 20.56 mmol m(-2)h(-1) for N(2)O, CH(4) and CO(2), respectively. Futian mangrove swamp in Shenzhen had the highest greenhouse gas fluxes, followed by Mai Po mangrove in Hong Kong. Sha Kong Tsuen and Yung Shue O mangroves in Hong Kong had similar, low fluxes. The differences in both N(2)O and CH(4) fluxes among different tidal positions, the landward, seaward and bare mudflat, in each swamp were insignificant. The N(2)O and CO(2) fluxes were positively correlated with the soil organic carbon, total nitrogen, total phosphate, total iron and NH(4)(+)-N contents, as well as the soil porosity. However, only soil NH(4)(+)-N concentration had significant effects on CH(4) fluxes.

  19. Estimating greenhouse gas emissions at the soil-atmosphere interface in forested watersheds of the US Northeast.

    PubMed

    Gomez, Joshua; Vidon, Philippe; Gross, Jordan; Beier, Colin; Caputo, Jesse; Mitchell, Myron

    2016-05-01

    Although anthropogenic emissions of greenhouse gases (GHG: CO2, CH4, N2O) are unequivocally tied to climate change, natural systems such as forests have the potential to affect GHG concentration in the atmosphere. Our study reports GHG emissions as CO2, CH4, N2O, and CO2eq fluxes across a range of landscape hydrogeomorphic classes (wetlands, riparian areas, lower hillslopes, upper hillslopes) in a forested watershed of the Northeastern USA and assesses the usability of the topographic wetness index (TWI) as a tool to identify distinct landscape geomorphic classes to aid in the development of GHG budgets at the soil atmosphere interface at the watershed scale. Wetlands were hot spots of GHG production (in CO2eq) in the landscape owing to large CH4 emission. However, on an areal basis, the lower hillslope class had the greatest influence on the net watershed CO2eq efflux, mainly because it encompassed the largest proportion of the study watershed (54 %) and had high CO2 fluxes relative to other land classes. On an annual basis, summer, fall, winter, and spring accounted for 40, 27, 9, and 24 % of total CO2eq emissions, respectively. When compared to other approaches (e.g., random or systematic sampling design), the TWI landscape classification method was successful in identifying dominant landscape hydrogeomorphic classes and offered the possibility of systematically accounting for small areas of the watershed (e.g., wetlands) that have a disproportionate effect on total GHG emissions. Overall, results indicate that soil CO2eq efflux in the Archer Creek Watershed may exceed C uptake by live trees under current conditions. PMID:27085717

  20. Estimating greenhouse gas emissions at the soil-atmosphere interface in forested watersheds of the US Northeast.

    PubMed

    Gomez, Joshua; Vidon, Philippe; Gross, Jordan; Beier, Colin; Caputo, Jesse; Mitchell, Myron

    2016-05-01

    Although anthropogenic emissions of greenhouse gases (GHG: CO2, CH4, N2O) are unequivocally tied to climate change, natural systems such as forests have the potential to affect GHG concentration in the atmosphere. Our study reports GHG emissions as CO2, CH4, N2O, and CO2eq fluxes across a range of landscape hydrogeomorphic classes (wetlands, riparian areas, lower hillslopes, upper hillslopes) in a forested watershed of the Northeastern USA and assesses the usability of the topographic wetness index (TWI) as a tool to identify distinct landscape geomorphic classes to aid in the development of GHG budgets at the soil atmosphere interface at the watershed scale. Wetlands were hot spots of GHG production (in CO2eq) in the landscape owing to large CH4 emission. However, on an areal basis, the lower hillslope class had the greatest influence on the net watershed CO2eq efflux, mainly because it encompassed the largest proportion of the study watershed (54 %) and had high CO2 fluxes relative to other land classes. On an annual basis, summer, fall, winter, and spring accounted for 40, 27, 9, and 24 % of total CO2eq emissions, respectively. When compared to other approaches (e.g., random or systematic sampling design), the TWI landscape classification method was successful in identifying dominant landscape hydrogeomorphic classes and offered the possibility of systematically accounting for small areas of the watershed (e.g., wetlands) that have a disproportionate effect on total GHG emissions. Overall, results indicate that soil CO2eq efflux in the Archer Creek Watershed may exceed C uptake by live trees under current conditions.

  1. [Errors Analysis and Correction in Atmospheric Methane Retrieval Based on Greenhouse Gases Observing Satellite Data].

    PubMed

    Bu, Ting-ting; Wang, Xian-hua; Ye, Han-han; Jiang, Xin-hua

    2016-01-01

    High precision retrieval of atmospheric CH4 is influenced by a variety of factors. The uncertainties of ground properties and atmospheric conditions are important factors, such as surface reflectance, temperature profile, humidity profile and pressure profile. Surface reflectance is affected by many factors so that it is difficult to get the precise value. The uncertainty of surface reflectance will cause large error to retrieval result. The uncertainties of temperature profile, humidity profile and pressure profile are also important sources of retrieval error and they will cause unavoidable systematic error. This error is hard to eliminate only using CH4 band. In this paper, ratio spectrometry method and CO2 band correction method are proposed to reduce the error caused by these factors. Ratio spectrometry method can decrease the effect of surface reflectance in CH4 retrieval by converting absolute radiance spectrometry into ratio spectrometry. CO2 band correction method converts column amounts of CH4 into column averaged mixing ratio by using CO2 1.61 μm band and it can correct the systematic error caused by temperature profile, humidity profile and pressure profile. The combination of these two correction methods will decrease the effect caused by surface reflectance, temperature profile, humidity profile and pressure profile at the same time and reduce the retrieval error. GOSAT data were used to retrieve atmospheric CH4 to test and validate the two correction methods. The results showed that CH4 column averaged mixing ratio retrieved after correction was close to GOSAT Level2 product and the retrieval precision was up to -0.24%. The studies suggest that the error of CH4 retrieval caused by the uncertainties of ground properties and atmospheric conditions can be significantly reduced and the retrieval precision can be highly improved by using ratio spectrometry method and CO2 hand correction method.

  2. [Errors Analysis and Correction in Atmospheric Methane Retrieval Based on Greenhouse Gases Observing Satellite Data].

    PubMed

    Bu, Ting-ting; Wang, Xian-hua; Ye, Han-han; Jiang, Xin-hua

    2016-01-01

    High precision retrieval of atmospheric CH4 is influenced by a variety of factors. The uncertainties of ground properties and atmospheric conditions are important factors, such as surface reflectance, temperature profile, humidity profile and pressure profile. Surface reflectance is affected by many factors so that it is difficult to get the precise value. The uncertainty of surface reflectance will cause large error to retrieval result. The uncertainties of temperature profile, humidity profile and pressure profile are also important sources of retrieval error and they will cause unavoidable systematic error. This error is hard to eliminate only using CH4 band. In this paper, ratio spectrometry method and CO2 band correction method are proposed to reduce the error caused by these factors. Ratio spectrometry method can decrease the effect of surface reflectance in CH4 retrieval by converting absolute radiance spectrometry into ratio spectrometry. CO2 band correction method converts column amounts of CH4 into column averaged mixing ratio by using CO2 1.61 μm band and it can correct the systematic error caused by temperature profile, humidity profile and pressure profile. The combination of these two correction methods will decrease the effect caused by surface reflectance, temperature profile, humidity profile and pressure profile at the same time and reduce the retrieval error. GOSAT data were used to retrieve atmospheric CH4 to test and validate the two correction methods. The results showed that CH4 column averaged mixing ratio retrieved after correction was close to GOSAT Level2 product and the retrieval precision was up to -0.24%. The studies suggest that the error of CH4 retrieval caused by the uncertainties of ground properties and atmospheric conditions can be significantly reduced and the retrieval precision can be highly improved by using ratio spectrometry method and CO2 hand correction method. PMID:27228765

  3. [Anesthetic gases, the ozone layer and the greenhouse effect. How harmful are the anesthetic emissions for the global environment?].

    PubMed

    Dale, O; Dale, T

    1991-06-30

    During the last decade, world society has acknowledged the harmful effects on the environment of the greenhouse effect and of depletion of the ozone layer, caused by industrial emissions of man-made compounds. Ozone depletion is caused mainly by chlorine compounds or nitrogen oxides released by degradation in the stratosphere. The greenhouse effect is caused by increased trapping of terrestrial heat radiation. Degradation of the anaesthetic vapours halothane, enflurane and isoflurane releases chlorine, and nitrous oxide degradation produces reactive nitrogen oxides. Nitrous oxide in particular, but also the vapours, absorb terrestrial radiation. The total discharge of anaesthetic vapours contributes to less than 0.01% of the total atmospheric chlorine load, and the annual Norwegian release of approximately two tons accounts for 0.2% of the world total. It is estimated that the total amount of nitrous oxide released from anaesthetics accounts for 0.05% of the greenhouse effect, while annual Norwegian emissions of nitrous oxide (less than 160 tons) comprise 0.2-0.4% of world total. Because of their favourable clinical properties and their modest contribution to ozone depletion and the greenhouse effect, medical use of inhalational anaesthetic agents should not be banned. However, low flow anaesthetic techniques should be employed, in order to reduce their negative impacts on the atmosphere.

  4. Household carbon dioxide production in relation to the greenhouse effect

    SciTech Connect

    Stokes, D.; Lindsay, A.; Marinopoulos, J.; Treloar, A.; Wescott, G. )

    1994-03-01

    A survey of 655 households from eastern suburbs of Melbourne was undertaken to determine householders[prime] attitudes to, and understanding of, the greenhouse effect. Carbon dioxide emissions resulting from car, electricity and gas use were computed and household actions which could reduce CO[sub 2] emissions were addressed. Preliminary analysis of the results indicates that householders in this area are aware of, and concerned about, the greenhouse effect, although their understanding of its causes is often poor. Many appreciate the contribution of cars, but are unclear about the relative importance of other household activities. Carbon dioxide emissions from the three sources examined averaged 21[center dot]2 tonnes/year per household and 7[center dot]4 tonnes/year per person. Electricity was the largest contributor (8[center dot]6 tonnes/year), cars the next largest (7[center dot]7 tonnes/year) and gas third (5[center dot] tonnes/year) per household. Emissions varied considerably from household to household. There was a strong positive correlation between availability of economic resources and household CO[sub 2] output from all sources. Carbon dioxide production, particularly from car use, was greater from households which were most distant from a railway station, and from larger households, and numbers of children in the household had little effect on emissions. There were also some economics of scale for households containing more adults. Understanding the causes of the greenhouse bore little relation to change in CO[sub 2] emissions; being concerned about it was associated with a small reduction; but actual actions to reduce car use and household heating, however motivated, produced significant reductions. 12 refs., 9 figs., 6 tabs.

  5. A space parasol as a countermeasure against the greenhouse effect

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.

    1991-01-01

    It is suggested that the deployment of a 'space parasol' at the L1 Langrangian point of the earth-sun system would serve to intercept some desired fraction of the solar radiant energy, thereby lessening the impact of the greenhouse effect. The parasol satellites are described and possible orbit configurations are discussed. Orbital possibilities include Low Earth Orbit, Geosynchronous orbit, and L1 which appears to be the best option. Structural strength, control, and use of extraterrestrial material in the construction of the parasol are discussed.

  6. THE MECHANICAL GREENHOUSE: BURIAL OF HEAT BY TURBULENCE IN HOT JUPITER ATMOSPHERES

    SciTech Connect

    Youdin, Andrew N.; Mitchell, Jonathan L.

    2010-10-01

    The intense irradiation received by hot Jupiters suppresses convection in the outer layers of their atmospheres and lowers their cooling rates. 'Inflated' hot Jupiters, i.e., those with anomalously large transit radii, require additional sources of heat or suppressed cooling. We consider the effect of forced turbulent mixing in the radiative layer, which could be driven by atmospheric circulation or by another mechanism. Due to stable stratification in the atmosphere, forced turbulence drives a downward flux of heat. Weak turbulent mixing slows the cooling rate by this process, as if the planet were irradiated more intensely. Stronger turbulent mixing buries heat into the convective interior, provided the turbulence extends to the radiative-convective boundary. This inflates the planet until a balance is reached between the heat buried into and radiated from the interior. We also include the direct injection of heat due to the dissipation of turbulence or other effects. Such heating is already known to slow planetary cooling. We find that dissipation also enhances heat burial from mixing by lowering the threshold for turbulent mixing to drive heat into the interior. Strong turbulent mixing of heavy molecular species such as TiO may be necessary to explain stratospheric thermal inversions. We show that the amount of mixing required to loft TiO may overinflate the planet by our mechanism. This possible refutation of the TiO hypothesis deserves further study. Our inflation mechanism requires a deep stratified layer that only exists when the absorbed stellar flux greatly exceeds the intrinsic emitted flux. Thus, it would be less effective for more luminous brown dwarfs and for longer period gas giants, including Jupiter and Saturn.

  7. [Preliminary assessment of the potential of biochar technology in mitigating the greenhouse effect in China].

    PubMed

    Jiang, Zhi-Xiang; Zheng, Hao; Li, Feng-Min; Wang, Zhen-Yu

    2013-06-01

    The production of biochar by pyrolysis and its application to soil can sequester the CO2 which was absorbed by plants from atmosphere into soil, in addition it can also bring multiple benefits for agriculture production. On the basis of the available potential survey of the biomass residues from agriculture and forestry section, life cycle assessment was employed to quantify the potential of biochar technology in mitigation of greenhouse gases in our country. The results showed: In China, the amount of available biomass resource was 6.04 x 10(8) t every year and its net greenhouse effect potential was 5.32 x 10(8) t CO(2e) (CO(2e): CO2 equivalent), which was equivalent to 0.88 t CO(2e) for every ton biomass. The greatest of contributor to the total potential was plant carbon sequestration in soil as the form of biochar which accounts for 73.94%, followed by production of renewable energy and its percentage was 23.85%. In summary, production of biochar from agriculture and forestry biomass residues had a significant potential for our country to struggle with the pressure of greenhouse gas emission.

  8. The effect of low ancient greenhouse climate temperature gradients on the ocean's overturning circulation

    NASA Astrophysics Data System (ADS)

    Sijp, Willem P.; England, Matthew H.

    2016-02-01

    We examine whether the reduced meridional temperature gradients of past greenhouse climates might have reduced oceanic overturning, leading to a more quiescent subsurface ocean. A substantial reduction of the pole-to-Equator temperature difference is achieved in a coupled climate model via an altered radiative balance in the atmosphere. Contrary to expectations, we find that the meridional overturning circulation and deep ocean kinetic energy remain relatively unaffected. Reducing the wind strength also has remarkably little effect on the overturning. Instead, overturning strength depends on deep ocean density gradients, which remain relatively unaffected by the surface changes, despite an overall decrease in ocean density. Ocean poleward heat transport is significantly reduced only in the Northern Hemisphere, as now the circulation operates across a reduced temperature gradient, suggesting a sensitivity of Northern Hemisphere heat transport in greenhouse climates to the overturning circulation. These results indicate that climate models of the greenhouse climate during the Cretaceous and early Paleogene may yield a reasonable overturning circulation, despite failing to fully reproduce the extremely reduced temperature gradients of those time periods.

  9. Atmospheric effects on oblique impacts

    NASA Technical Reports Server (NTRS)

    Schultz, P. H.

    1991-01-01

    Laboratory experiments and theoretical calculations often use vertical impact angles (90 deg) in order to avoid the complicating effect of asymmetry. Nevertheless, oblique impacts represent the most likely starting condition for planetary cratering. Changing both impact angles and atmospheric pressure not only allows testing previous results for vertical impacts but also reveals phenomena whose signatures would otherwise be masked in the planetary cratering record. The laboratory studies were performed for investigating impact cratering processes. Impact angles can be increased from 0 to 90 deg in 15 deg increments while maintaining a flat target surface. Different atmospheres (nitrogen, argon, and helium) characterized the effects of both gas density and Mach number. Targets varied according to purpose. Because of the complexities in atmosphere-impactor-ejecta interactions, no single combination allows direct simulation of a planetary-scale (10-100 km) event. Nevertheless, fundamental processes and observed phenomena allow formulating first-order models at such broad scales.

  10. Comparison of the observed and calculated clear sky greenhouse effect - Implications for climate studies

    NASA Technical Reports Server (NTRS)

    Kiehl, J. T.; Briegleb, B. P.

    1992-01-01

    The clear sky greenhouse effect is defined in terms of the outgoing longwave clear sky flux at the top of the atmosphere. Recently, interest in the magnitude of the clear sky greenhouse effect has increased due to the archiving of the clear sky flux quantity through the Earth Radiation Budget Experiment (ERBE). The present study investigates to what degree of accuracy this flux can be analyzed by using independent atmospheric and surface data in conjunction with a detailed longwave radiation model. The conclusion from this comparison is that for most regions over oceans the analyzed fluxes agree to within the accuracy of the ERBE-retrieved fluxes (+/- 5 W/sq m). However, in regions where deep convective activity occurs, the ERBE fluxes are significantly higher (10-15 W/sq m) than the calculated fluxes. This bias can arise from either cloud contamination problems or variability in water vapor amount. It is argued that the use of analyzed fluxes may provide a more consistent clear sky flux data set for general circulation modeling validation. Climate implications from the analyzed fluxes are explored. Finally, results for obtaining longwave surface fluxes over the oceans are presented.

  11. Atmospheric observations for quantifying emissions of point-source synthetic greenhouse gases (CF4, NF3 and HFC-23)

    NASA Astrophysics Data System (ADS)

    Arnold, Tim; Manning, Alistair J.; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Fraser, Paul J.; Mitrevski, Blagoj; Steele, L. Paul; Krummel, Paul B.; Mühle, Jens; Weiss, Ray F.

    2016-04-01

    The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacement compounds that are emitted from fugitive and mobile emission sources, these gases are largely emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane factories (HFC-23). In this work we show the potential for atmospheric measurements to understand regional sources of these gases and to highlight emission 'hotspots'. We target our analysis on measurements from two Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites that are particularly sensitive to regional emissions of these gases: Gosan on Jeju Island in the Republic of Korea and Cape Grim on Tasmania in Australia. These sites measure CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over a decade (2005-2015) at high spatial resolution. At present these gases make a small contribution to global radiative forcing, however, given that their impact could rise significantly and that point sources of such gases can be mitigated, atmospheric monitoring could be an important tool for aiding emissions reduction policy.

  12. Organic Amendment Effects on Greenhouse Gas Emissions from Long-Term Stockpiled Soils

    NASA Astrophysics Data System (ADS)

    Zvomuya, F.; Laskosky, J.

    2014-12-01

    In oil sands projects in Alberta, Canada, salvaged soils are often placed in large stockpiles where they are stored for the duration of the project, typically 20-30 years. Alberta regulations require that topsoil and subsoil are salvaged in two distinct operations - a process known as two-lifting. Reclamation using long-term stockpiled soils often gives poor results, characterized by lower soil organic carbon and nitrogen concentrations compared with equivalent natural, undisturbed soils. It is thought that the change from an aerobic to an anaerobic environment during soil stockpiling and back again to aerobic during placement are largely responsible for the low carbon and nitrogen due to microbial activity transforming C and N in the soil into CO2, CH4 and N2O and releasing them to the atmosphere. Evidence from recent studies indicates that biochar improves soil physical, chemical and biological properties, and hence could mitigate C and N losses due to greenhouse gas emissions from the soil indirectly. We postulate that documented improvements in soil physical, chemical, and biological properties in soils treated with amendments such as biochar may help mitigate C and N losses due to greenhouse gas emissions from the soil indirectly. This laboratory incubation experiment tested the effects of differential rates (0, 10, 20, and 40 g biochar carbon equivalents kg-1 dry soil) of biochar, peat, and humalite on greenhouse gas emissions from a 25-year old two-lift stockpiled soil. The soils were fertilized according to standard practice, placed in 120-mL plastic containers, and incubated at 25°C for 45 days. Gas samples were taken at 1- to 7-day intervals and analyzed for CO2, CH4, and N2O. Data on treatment differences in emissions will be presented. Results from this experiment will provide an insight into the potential for organic amendments to mitigate greenhouse gas emission during reclamation using degraded soils.

  13. The effect of floating vegetation on denitrification and greenhouse gas production in wetland mesocosms

    NASA Astrophysics Data System (ADS)

    Jacobs, A. E.; Harrison, J. A.

    2012-12-01

    Anthropogenic intensification of nitrogen (N) loading to aquatic ecosystems is widespread and can lead to the degradation of these systems. Wetlands are important sites for N removal via denitrification, the microbially mediated reduction of reactive nitrate to inert N2 gas, but they can also produce high levels of greenhouse gases. Floating plants play an important role in encouraging denitrification, since they create low oxygen conditions that may favor denitrification. We investigated whether wetland sediments with floating plant cover had higher denitrification and greenhouse gas production rates than wetland sediments without floating plants. Replicate flow-through mesocosms with wetland sediment and water were constructed in a growth chamber to mimic the wetland where the sediment and water were collected. Mesocosm treatments were covered with floating vegetation (duckweed), an opaque tarp, or no cover to determine how cover type affects denitrification and greenhouse gas production and whether biotic or abiotic factors are likely responsible for observed differences. Denitrification and greenhouse gas production rates were calculated by measuring excess N2 gas, methane, and nitrous oxide concentrations in the water column and measuring the gas exchange rates between the water column and the atmosphere. Gas exchange rates were measured using an inert volatile tracer added to the water column and accumulation of gas in the mesocosm headspace. Additional mesocosm experiments were performed to determine how duckweed-dominated wetland systems respond to nitrogen loading and which mechanism for lowering dissolved oxygen concentrations is important in affecting denitrification under floating vegetation. Mesocosms with floating vegetation had lower dissolved oxygen than no cover or tarp-covered mesocosms, which is consistent with field and literature observations. Water flowing out of the mesocosms had statistically lower total nitrogen and nitrate concentrations

  14. Climate-chemical interactions and greenhouse effects of trace gases

    NASA Technical Reports Server (NTRS)

    Shi, Guang-Yu; Fan, Xiao-Biao

    1994-01-01

    A completely coupled one-dimensional radiative-convective (RC) and photochemical-diffusion (PC) model has been developed recently and used to study the climate-chemical interactions. The importance of radiative-chemical interactions within the troposphere and stratosphere has been examined in some detail. We find that increases of radiatively and/or chemically active trace gases such as CO2, CH4 and N2O have both the direct effects and the indirect effects on climate change by changing the atmospheric O3 profile through their interaction with chemical processes in the atmosphere. It is also found that the climatic effect of ozone depends strongly on its vertical distribution throughout the troposphere and stratosphere, as well on its column amount in the atmosphere.

  15. Effects of cirrus composition on atmospheric radiation budgets

    NASA Technical Reports Server (NTRS)

    Kinne, Stefan; Liou, Kuo-Nan

    1988-01-01

    A radiative transfer model that can be used to determine the change in solar and infrared fluxes caused by variations in the composition of cirrus clouds was used to investigate the importance of particle size and shape on the radiation budget of the Earth-atmosphere system. Even though the cloud optical thickness dominates the radiative properties of ice clouds, the particle size and nonsphericity of ice crystals are also important in calculations of the transfer of near-IR solar wavelengths. Results show that, for a given optical thickness, ice clouds composed of larger particles would produce larger greenhouse effects than those composed of smaller particles. Moreover, spherical particles with equivalent surface areas, frequently used for ice crystal clouds, would lead to an overestimation of the greenhouse effect.

  16. Equity effects of economic instruments for greenhouse gas abatement

    SciTech Connect

    Harrison, D. Jr.

    1994-12-31

    This paper discusses the equity effects of using economic instruments--such as a carbon tax or carbon emissions trading program--to regulate greenhouse gas emissions. Determining these equity effects is more complicated than assessing overall costs and benefits, although some of the same issues arise. Among the key issues are the following: (1) benchmark for evaluating impacts of economic instruments (status quo or regulatory program that achieves the same emission reductions); (2) use of any government revenues collected, which are transfers overall but affect gains and losses; (3) time period (long-term or transitional impacts); and (4) groupings (income groups, sectors or regions). Empirical studies suggest that a national tax is regressive in the US but may be less so in other countries. The equity impacts of an international carbon tax or emissions trading program differ greatly depending upon the specific elements. The paper considers options to compensate or mitigate adverse effects to income groups, sectors, or regions of the world. Although impossible to avoid all losses to every group, it would be possible to avoid major equity effects if carbon taxes or carbon trading programs were used to control global warming.

  17. "Home Made" Model to Study the Greenhouse Effect and Global Warming

    ERIC Educational Resources Information Center

    Onorato, P.; Mascheretti, P.; DeAmbrosis, A.

    2011-01-01

    In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of…

  18. Using Interactive Technology to Support Students' Understanding of the Greenhouse Effect and Global Warming

    ERIC Educational Resources Information Center

    Varma, Keisha; Linn, Marcia C.

    2012-01-01

    In this work, we examine middle school students' understanding of the greenhouse effect and global warming. We designed and refined a technology-enhanced curriculum module called "Global Warming: Virtual Earth". In the module activities, students conduct virtual experiments with a visualization of the greenhouse effect. They analyze data and draw…

  19. Rich soil carbon and nitrogen but low atmospheric greenhouse gas fluxes from North Sulawesi mangrove swamps in Indonesia.

    PubMed

    Chen, Guang C; Ulumuddin, Yaya I; Pramudji, Sastro; Chen, Shun Y; Chen, Bin; Ye, Yong; Ou, Dan Y; Ma, Zhi Y; Huang, Hao; Wang, Jing K

    2014-07-15

    The soil to atmosphere fluxes of greenhouse gases N2O, CH4 and CO2 and their relationships with soil characteristics were investigated in three tropical oceanic mangrove swamps (Teremaal, Likupang and Kema) in North Sulawesi, Indonesia. Mangrove soils in North Sulawesi were rich in organic carbon and nitrogen, but the greenhouse gas fluxes were low in these mangroves. The fluxes ranged -6.05-13.14 μmol m(-2)h(-1), -0.35-0.61 μmol m(-2)h(-1) and -1.34-3.88 mmol m(-2)h(-1) for N2O, CH4 and CO2, respectively. The differences in both N2O and CH4 fluxes among different mangrove swamps and among tidal positions in each mangrove swamp were insignificant. CO2 flux was influenced only by mangrove swamps and the value was higher in Kema mangrove. None of the measured soil parameters could explain the variation of CH4 fluxes among the sampling plots. N2O flux was negatively related to porewater salinity, while CO2 flux was negatively correlated with water content and organic carbon. This study suggested that the low gas emissions due to slow metabolisms would lead to the accumulations of organic matters in North Sulawesi mangrove swamps. PMID:24784732

  20. Rich soil carbon and nitrogen but low atmospheric greenhouse gas fluxes from North Sulawesi mangrove swamps in Indonesia.

    PubMed

    Chen, Guang C; Ulumuddin, Yaya I; Pramudji, Sastro; Chen, Shun Y; Chen, Bin; Ye, Yong; Ou, Dan Y; Ma, Zhi Y; Huang, Hao; Wang, Jing K

    2014-07-15

    The soil to atmosphere fluxes of greenhouse gases N2O, CH4 and CO2 and their relationships with soil characteristics were investigated in three tropical oceanic mangrove swamps (Teremaal, Likupang and Kema) in North Sulawesi, Indonesia. Mangrove soils in North Sulawesi were rich in organic carbon and nitrogen, but the greenhouse gas fluxes were low in these mangroves. The fluxes ranged -6.05-13.14 μmol m(-2)h(-1), -0.35-0.61 μmol m(-2)h(-1) and -1.34-3.88 mmol m(-2)h(-1) for N2O, CH4 and CO2, respectively. The differences in both N2O and CH4 fluxes among different mangrove swamps and among tidal positions in each mangrove swamp were insignificant. CO2 flux was influenced only by mangrove swamps and the value was higher in Kema mangrove. None of the measured soil parameters could explain the variation of CH4 fluxes among the sampling plots. N2O flux was negatively related to porewater salinity, while CO2 flux was negatively correlated with water content and organic carbon. This study suggested that the low gas emissions due to slow metabolisms would lead to the accumulations of organic matters in North Sulawesi mangrove swamps.

  1. Effect of tropospheric aerosols upon atmospheric infrared cooling rates

    NASA Technical Reports Server (NTRS)

    Harshvardhan, MR.; Cess, R. D.

    1978-01-01

    The effect of tropospheric aerosols on atmospheric infrared cooling rates is investigated by the use of recent models of infrared gaseous absorption. A radiative model of the atmosphere that incorporates dust as an absorber and scatterer of infrared radiation is constructed by employing the exponential kernel approximation to the radiative transfer equation. Scattering effects are represented in terms of a single scattering albedo and an asymmetry factor. The model is applied to estimate the effect of an aerosol layer made of spherical quartz particles on the infrared cooling rate. Calculations performed for a reference wavelength of 0.55 microns show an increased greenhouse effect, where the net upward flux at the surface is reduced by 10% owing to the strongly enhanced downward emission. There is a substantial increase in the cooling rate near the surface, but the mean cooling rate throughout the lower troposphere was only 10%.

  2. A new index to assess chemicals increasing the greenhouse effect based on their toxicity to algae.

    PubMed

    Wang, Ting; Zhang, Xiaoxian; Tian, Dayong; Gao, Ya; Lin, Zhifen; Liu, Ying; Kong, Lingyun

    2015-11-01

    CO2, as the typical greenhouse gas causing the greenhouse effect, is a major global environmental problem and has attracted increasing attention from governments. Using algae to eliminate CO2, which has been proposed as an effective way to reduce the greenhouse effect in the past decades, can be disturbed by a growing number of artificial chemicals. Thus, seven types of chemicals and Selenastrum capricornutum (algae) were examined in this study, and the good consistency between the toxicity of artificial chemicals to algae and the disturbance of carbon fixation by the chemicals was revealed. This consistency showed that the disturbance of an increasing number of artificial chemicals to the carbon fixation of algae might be a "malware" worsening the global greenhouse effect. Therefore, this study proposes an original, promising index to assess the risk of deepening the greenhouse effect by artificial chemicals before they are produced and marketed. PMID:26520250

  3. A new index to assess chemicals increasing the greenhouse effect based on their toxicity to algae.

    PubMed

    Wang, Ting; Zhang, Xiaoxian; Tian, Dayong; Gao, Ya; Lin, Zhifen; Liu, Ying; Kong, Lingyun

    2015-11-01

    CO2, as the typical greenhouse gas causing the greenhouse effect, is a major global environmental problem and has attracted increasing attention from governments. Using algae to eliminate CO2, which has been proposed as an effective way to reduce the greenhouse effect in the past decades, can be disturbed by a growing number of artificial chemicals. Thus, seven types of chemicals and Selenastrum capricornutum (algae) were examined in this study, and the good consistency between the toxicity of artificial chemicals to algae and the disturbance of carbon fixation by the chemicals was revealed. This consistency showed that the disturbance of an increasing number of artificial chemicals to the carbon fixation of algae might be a "malware" worsening the global greenhouse effect. Therefore, this study proposes an original, promising index to assess the risk of deepening the greenhouse effect by artificial chemicals before they are produced and marketed.

  4. Primary Student-Teachers' Conceptual Understanding of the Greenhouse Effect: A mixed method study

    NASA Astrophysics Data System (ADS)

    Ratinen, Ilkka Johannes

    2013-04-01

    The greenhouse effect is a reasonably complex scientific phenomenon which can be used as a model to examine students' conceptual understanding in science. Primary student-teachers' understanding of global environmental problems, such as climate change and ozone depletion, indicates that they have many misconceptions. The present mixed method study examines Finnish primary student-teachers' understanding of the greenhouse effect based on the results obtained via open-ended and closed-form questionnaires. The open-ended questionnaire considers primary student-teachers' spontaneous ideas about the greenhouse effect depicted by concept maps. The present study also uses statistical analysis to reveal respondents' conceptualization of the greenhouse effect. The concept maps and statistical analysis reveal that the primary student-teachers' factual knowledge and their conceptual understanding of the greenhouse effect are incomplete and even misleading. In the light of the results of the present study, proposals for modifying the instruction of climate change in science, especially in geography, are presented.

  5. Future atmospheric methane concentrations in the context of the stabilization of greenhouse gas concentrations

    NASA Astrophysics Data System (ADS)

    Kheshgi, Haroon S.; Jain, Atul K.; Kotamarthi, V. R.; Wuebbles, Donald J.

    1999-08-01

    Tropospheric CH4 concentration depends, according to modeled tropospheric processes, on many factors, including emissions of CH4 as well as NOx and CO. Illustrative analyses of the relation between emissions and CH4 concentration give some guidance on the role of CH4 in the stabilization of greenhouse gas concentrations. The contribution of CH4 to radiative forcing at the time of stabilization is expected to be modest, provided CH4 and CO emissions do not go far beyond current rates. However, in cases leading to stabilization the potential mitigation of increases in radiative forcing by methane control could be comparable to that of CO2 control over the next century. Whether or not this potential is realized will depend partially on the cost of deep reductions of CH4, NOx, CO, or CO2 emissions over the next century, which is not known.

  6. A Cloud Greenhouse Effect on Mars: Significant Climate Change in the Recent Past

    NASA Technical Reports Server (NTRS)

    Haberle, Robert M.; Kahre, Melinda A.; Schaeffer, James R.; Montmessin, Frank; Phillips, R J.

    2012-01-01

    The large variations in Mars orbit parameters are known to be significant drivers of climate change on the Red planet. The recent discovery of buried CO2 ice at the South Pole adds another dimension to climate change studies. In this paper we present results from the Ames GCM that show within the past million years it is possible that clouds from a greatly intensified Martian hydrological cycle may have produced a greenhouse effect strong enough to raise global mean surface temperatures by several tens of degrees Kelvin. It is made possible by the ability of the Martian atmosphere to transport water to high altitudes where cold clouds form, reduce the outgoing longwave radiation, and drive up surface temperatures to maintain global energy balance.

  7. The Impact of Upper Tropospheric Humidity from Microwave Limb Sounder on the Midlatitude Greenhouse Effect

    NASA Technical Reports Server (NTRS)

    Hu, Hua; Liu, W. Timothy

    1998-01-01

    This paper presents an analysis of upper tropospheric humidity, as measured by the Microwave Limb Sounder, and the impact of the humidity on the greenhouse effect in the midlatitudes. Enhanced upper tropospheric humidity and an enhanced greenhouse effect occur over the storm tracks in the North Pacific and North Atlantic. In these areas, strong baroclinic activity and the large number of deep convective clouds transport more water vapor to the upper troposphere, and hence increase greenhouse trapping. The greenhouse effect increases with upper tropospheric humidity in areas with a moist upper troposphere (such as areas over storm tracks), but it is not sensitive to changes in upper tropospheric humidity in regions with a dry upper troposphere, clearly demonstrating that there are different mechanisms controlling the geographical distribution of the greenhouse effect in the midlatitudes.

  8. A Three-Tier Diagnostic Test to Assess Pre-Service Teachers' Misconceptions about Global Warming, Greenhouse Effect, Ozone Layer Depletion, and Acid Rain

    ERIC Educational Resources Information Center

    Arslan, Harika Ozge; Cigdemoglu, Ceyhan; Moseley, Christine

    2012-01-01

    This study describes the development and validation of a three-tier multiple-choice diagnostic test, the atmosphere-related environmental problems diagnostic test (AREPDiT), to reveal common misconceptions of global warming (GW), greenhouse effect (GE), ozone layer depletion (OLD), and acid rain (AR). The development of a two-tier diagnostic test…

  9. The Impact of Secondary School Students' Preconceptions on the Evolution of Their Mental Models of the Greenhouse Effect and Global Warming

    ERIC Educational Resources Information Center

    Reinfried, Sibylle; Tempelmann, Sebastian

    2014-01-01

    This paper provides a video-based learning process study that investigates the kinds of mental models of the atmospheric greenhouse effect 13-year-old learners have and how these mental models change with a learning environment, which is optimised in regard to instructional psychology. The objective of this explorative study was to observe and…

  10. Improved Estimates of Clear Sky Longwave Flux and Application to the Tropical Greenhouse Effect

    NASA Technical Reports Server (NTRS)

    Collins, W. D.

    1997-01-01

    The first objective of this investigation is to eliminate the clear-sky offset introduced by the scene-identification procedures developed for the Earth Radiation Budget Experiment (ERBE). Estimates of this systematic bias range from 10 to as high as 30 W/sq m. The initial version of the ScaRaB data is being processed with the original ERBE algorithm. Since the ERBE procedure for scene identification is based upon zonal flux averages, clear scenes with longwave emission well below the zonal mean value are mistakenly classified as cloudy. The erroneous classification is more frequent in regions with deep convection and enhanced mid- and upper-tropospheric humidity. We will develop scene identification parameters with zonal and/or time dependence to reduce or eliminate the bias in the clear- sky data. The modified scene identification procedure could be used for the ScaRaB-specific version of the Earth-radiation products. The second objective is to investigate changes in the clear-sky Outgoing Longwave Radiation (OLR) associated with decadal variations in the tropical and subtropical climate. There is considerable evidence for a shift in the climate state starting in approximately 1977. The shift is accompanied by higher SSTs in the equatorial Pacific, increased tropical convection, and higher values of atmospheric humidity. Other evidence indicates that the humidity in the tropical troposphere has been steadily increasing over the last 30 years. It is not known whether the atmospheric greenhouse effect has increased during this period in response to these changes in SST and precipitable water. We will investigate the decadal-scale fluctuations in the greenhouse effect using Nimbus-7, ERBE, and ScaRaB measurements spaning 1979 to the present. The data from the different satellites will be intercalibrated by comparison with model calculations based upon ship radiosonde observations. The fluxes calculated from the radiation model will also be used for validation of the

  11. Atmospheric Effects in IR Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released August 3, 2004 This image shows two representations of the same infra-red image covering parts of Ius Chasma and Oudemans Crater. On the left is a grayscale image showing surface temperature, and on the right is a false-color composite made from 3 individual THEMIS bands. The false-color image is colorized using a technique called decorrelation stretch (DCS), which emphasizes the spectral differences between the bands to highlight compositional variations.

    This image is dominated by atmospheric effects. The pink/magenta colors inside the canyon show areas with a large amount of atmospheric dust. In the bottom half of the image, the patchy blue/cyan colors indicate the presence of water ice clouds out on the plains. Water ice clouds and high amounts of dust do not generally occur at the same place and time on Mars because the dust absorbs sunlight and heats the atmosphere. The more dust that is present, the warmer the atmosphere becomes, sublimating the water ice into water vapor and dissipating any clouds.

    Image information: IR instrument. Latitude -8.2, Longitude 267.9 East (92.1.West). 100 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is

  12. Biochar alters manure's effect on nitrogen cycling and greenhouse gas emissions in a calcareous soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few multiyear field studies have examined the impacts of a one-time biochar application on net N mineralization and greenhouse gas emissions in an irrigated, calcareous soil; yet such applications are hypothesized as a means of sequestering atmospheric CO2 and improving soil quality. We fall-applie...

  13. Assessment of a multi-species in-situ FTIR for precise atmospheric greenhouse gas observations

    NASA Astrophysics Data System (ADS)

    Hammer, S.; Griffith, D. W. T.; Konrad, G.; Vardag, S.; Caldow, C.; Levin, I.

    2012-05-01

    We thoroughly evaluate the performance of a multi-species, in-situ FTIR analyser with respect to high accuracy needs for greenhouse gas monitoring networks. The in-situ FTIR analyser measures CO2, CO, CH4 and N2O mole fractions continuously, all with better reproducibility than requested by the WMO-GAW inter-laboratory compatibility (ILC) goal. Simultaneously determined δ13CO2 reaches reproducibility as good as 0.03‰. This paper focuses on the quantification of residual dependencies between the measured components and the thermodynamic properties of the sample as well as the cross-sensitivities among the sample constituents. The instrument has proven to be linear for all components in the ambient range. The temporal stability of the instrument was investigated by 10 months of continuously collected quality control measures. Based on these measures we conclude that for moderately stable laboratory conditions weekly calibrations of the instrument are sufficient to reach WMO-GAW ILC goals.

  14. The Role of Carbon Management Technologies in Addressing Atmospheric Stabilization of Greenhouse Gases

    SciTech Connect

    Edmonds, James A. ); Freund, Paul F.; Dooley, James J. ); David Williams, Bob Durie, et. al.

    2002-08-10

    Recent progress in decarbonization processes and engineered storage systems for CO2, together with preliminary cost estimates for these technologies, indicate that capture and storage of CO2 will have a major role to play in achieving deep reductions in emissions. These technologies hold the potential to reduce the cost of stabilizing the concentration of greenhouse gases, the ultimate objective of the UN Framework Convention on Climate Change (FCCC). Their value rises as the allowable level of cumulative carbon emissions declines. The value of these technologies is robust regardless of whether the world's economically recoverable oil and gas resources are eventually found to be large or small. This paper considers the economic implication of those advances in the context of long-term, global climate change mitigation strategies. This indicates the need for a broad, robust research and development strategy to reduce the cost of separating CO2 and to make accessible the widest range of storage reservoirs. It is also important to demonstrate excellent security of storage, in order to win public acceptance of the use of capture and storage techniques.

  15. A Miniaturized Laser Heterodyne Radiometer for Greenhouse Gas Measurements in the Atmospheric Column

    NASA Technical Reports Server (NTRS)

    Steel, Emily Wilson

    2015-01-01

    Laser Heterodyne Radiometry is a technique adapted from radio receiver technology has been used to measure trace gases in the atmosphere since the 1960s.By leveraging advances in the telecommunications industry, it has been possible to miniaturize this technology.The mini-LHR (Miniaturized Laser Heterodyne Radiometer) has been under development at NASA Goddard Space flight Center since 2009. This sun-viewing instrument measures carbon dioxide and methane in the atmospheric column and operates in tandem with an AERONET sun photometer producing a simultaneous measure of aerosols. The mini-LHR has been extensively field tested in a range of locations ranging in the continental US as well as Alaska and Hawaii and now operates autonomously with sensitivities of approximately 0.2 ppmv and approximately10 ppbv, for carbon dioxide and methane respectively, for 10 averaged scans under clear sky conditions.

  16. Initial Results from an Atmospheric Validation of Urban Greenhouse Gas Budget Estimates for the US Northeast Corridor

    NASA Astrophysics Data System (ADS)

    Nehrkorn, T.; Wofsy, S. C.; Hutyra, L.; Decola, P.; Callahan, W.; Sargent, M. R.; McKain, K.; Barrera, Y.; Jones, T.; Gately, C.; Hardiman, B. S.; Mountain, M. E.; Henderson, J.; Collatz, G. J.; Schaaf, C. L.; Miller, C. E.; Long, A.; Sloop, C.; Prinzivalli, S.

    2015-12-01

    The world's population is increasingly concentrated in urban areas. Urbanization has a profound impact on carbon dynamics, leading to higher anthropogenic carbon dioxide (CO2) emissions and lower biogenic fluxes. We describe a model-data analysis framework that is designed to validate and improve greenhouse gas (GHG) budget estimates for the US Northeast (Washington DC to Boston) urban corridor. It encompasses an observational network of GHG in-situ measurements (at near surface sites, on tall buildings, and on towers), column amount measurements from ground-based and satellite sensors, miniMPL measurements of the planetary boundary layer structure, a high-resolution emission inventory, and a modeling framework for atmospheric transport and diffusion that is comprised of a mesoscale atmospheric model and a Lagrangian particle dispersion model. We present selected results from different aspects of the modeling-data framework, including emission inventories at high spatio-temporal resolution, verification of meteorological simulation using conventional and novel (e.g., miniMPL) observations, and aspects of the inversion methodology.

  17. Natural flux of greenhouse methane from the Timor Sea to the atmosphere

    NASA Astrophysics Data System (ADS)

    Brunskill, G. J.; Burns, K. A.; Zagorskis, I.

    2011-06-01

    Methane gas bubbles from the Cornea Seep were sampled at the sea surface in the Timor Sea continental shelf area in June 2005. Total bubble gas flux was 0.076 to 0.76 L m-2 h-1 during the 6 h d-1 periods of low neap tides in June 2005. This bubble gas contained an average of 26 mmol CH4 L-1 and about 0.16 and 0.006 mmol L-1 of ethane and propane. We estimate the daily flux from the sea surface to the atmosphere to be 0.012 to 0.12 mol CH4 m-2 d-1 or 0.13 to 1.3 t CH4 d-1 from an area of about 0.7 km2. This methane flux came from a 500 × 1400 m carbonate pavement dome on the seafloor at 84 m water depth. The seep hard ground was swath mapped, and 3.5 kHz subbottom profile data indicate that the seep dome was strongly reflective with poor penetration into the subsurface, consistent with the presence of a carbonate hard ground. Carbon and deuterium isotope ratios (δ13C = -41 to -42‰, δD = -157 to -158‰) of the seep bubble gas indicate that this methane had a thermogenic origin and was in the same isotopic range as gas within the Late Cretaceous Cornea oil and gas field. We could not detect inputs of fluids containing nutrients or short-lived radium isotopes at this site, commonly associated with other cold seeps. Tens to a hundred of kilometers seaward from the Cornea seep site, water column dissolved methane concentrations in this sector of the Timor Sea shelf and slope were 100-500 times supersaturated with respect to the atmosphere, and thus the water column is expected to be degassing additional methane to the atmosphere. Perhaps there are thousands of other methane seeps (of similar magnitude to the Cornea Seep) on this shelf and slope to account for all the excess dissolved methane (˜86,000 t) measured in the water column. These measured and calculated fluxes provide evidence for the hypothesis that shallow sea seeps may be a significant source of atmospheric methane, in contrast to deep sea vents, where most of the methane is dissolved and oxidized in

  18. Changes in Arctic Vegetation Amplify High-Latitude Warming Through Greenhouse Effect

    NASA Astrophysics Data System (ADS)

    Swann, A.; Fung, I.; Levis, S.; Bonan, G. B.; Doney, S. C.

    2009-12-01

    Changes in vegetation cover are recognized to modify climate and the energy budget of the Earth through changes in albedo in high latitudes and evapotranspiration (ET) in the tropics. In snow-covered regions, the springtime growth of leaves enhances solar absorption because surface albedo is reduced from the albedo of snow (~0.8) towards the albedo of leaves (~0.1). Leaves also play a hydrologic role, transpiring soil water to the atmosphere. It has been suggested that broad-leaf deciduous trees may invade warming tundra more effectively than boreal evergreen trees and these trees have higher rates of transpiration than needle-leaf trees. Here we use a global climate model with an interactive biosphere to investigate the effects of adding deciduous trees on bare ground at high northern latitudes. We find that the top-of-atmosphere radiative imbalance from enhanced transpiration (associated with the expanded forest cover) is 2.4 times larger than the direct forcing due to albedo change from the forest. Albedo change is considered to be the dominant mechanism by which trees directly modify climate at high-latitudes, but our findings suggest an additional mechanism through transpiration. Furthermore, the greenhouse warming by additional water vapor melts sea ice and triggers a positive feedback through changes in ocean albedo and evaporation. Vegetation feedbacks through albedo and transpiration produce a strong warming if they act in combination with sea-ice processes.

  19. New Broadband LIDAR for Greenhouse Carbon Dioxide Gas Sensing in the Earth's Atmosphere

    NASA Technical Reports Server (NTRS)

    Georgieva, Elena; Heaps, William S.; Huang,Wen

    2011-01-01

    We present demonstration of a novel broadband lidar technique capable of dealing with the atmospherically induced variations in CO2 absorption using a Fabry-Perot based detector and a broadband laser. The Fabry-Perot solid etalon in the receiver part is tuned to match the wavelength of several CO2 absorption lines simultaneously. The broadband technique tremendously reduces the requirement for source wavelength stability, instead putting this responsibility on the Fabry- Perot based receiver. The instrument technology we are developing has a clear pathway to space and realistic potential to become a robust, low risk space measurement system.

  20. Advection from the North Atlantic as the Forcing of Winter Greenhouse Effect Over Europe

    NASA Technical Reports Server (NTRS)

    Otterman, Jay; Angell, J.; Atlas, Robert; Bungato, D.; Schubert, S.; Starr, D.; Susskind, J.; Wu, M.-L. C.

    2001-01-01

    In winter, large interannual fluctuations in the surface skin temperature are observed over central Europe: we observe a difference of 9.8 K comparing warm February 1990 with cold February 1996 for the region 50-60 degrees N; 5-35 degrees E. Previous studies show that advection from the North Atlantic constitutes the forcing to such fluctuations. The advection is quantified by Index I(sub na), the average of the ocean-surface wind speed over the eastern North Atlantic when the direction is from the southwest (when the wind is from another direction, it counts as a zero speed to the average). Average Ina for February 1990 was 10.6 in s(exp -1), but for February 1996 I(sub na) was only 2.4 m s(exp -1). A large value of I(sub na) means a strong southwesterly flow which brings warm and moist air into Europe at low level, producing a steeper tropospheric lapse rate. Strong ascending motions result, which we observe in February 1990 at 700 mb. The near-surface moisture rises to higher (and cooler) levels, producing clouds and precipitation. Total preciptable water and cloud-cover fraction have larger values in February 1990 than in 1996. The difference in the greenhouse effect between these two scenarios can be translated into a virtual irradiating source of 2.6 W m(exp -2) above the February 1990 atmosphere, which, as an order of magnitude estimate, contributes to the warming of the surface by 2.6 K. If we accept this estimate as numerically pertinent, the direct effect stands as 7.2 K (9.8 K - 2.6 K), and therefore its greenhouse-effect reinforcement is by 36%. This constitutes a substantial positive feedback to the direct effect, which is the inflow of warm air to the low troposphere over Europe.

  1. Greenhouse effect: temperature of a metal sphere surrounded by a glass shell and heated by sunlight

    NASA Astrophysics Data System (ADS)

    Nguyen, Phuc H.; Matzner, Richard A.

    2012-01-01

    We study the greenhouse effect on a model satellite consisting of a tungsten sphere surrounded by a thin spherical, concentric glass shell, with a small gap between the sphere and the shell. The system sits in vacuum and is heated by sunlight incident along the z-axis. This development is a generalization of the simple treatment of the greenhouse effect given by Kittel and Kroemer (1980 Thermal Physics (San Francisco: Freeman)) and can serve as a very simple model demonstrating the much more complex Earth greenhouse effect. Solution of the model problem provides an excellent pedagogical tool at the Junior/Senior undergraduate level.

  2. Effect of tropospheric aerosols upon atmospheric infrared cooling rates

    NASA Technical Reports Server (NTRS)

    Harshvardhan, MR.; Cess, R. D.

    1978-01-01

    An investigation has been made of the impact of wind-blown dust particles upon local climate of arid regions. The case of Northwest India is specifically considered, where a dense layer of dust persists for several months during the summer. In order to examine the effect of this dust layer on the infrared radiative flux and cooling rates, a method is presented for calculating the IR flux within a dusty atmosphere which allows the use of gaseous band models and is applicable in the limit of small single scattering albedo and pronounced forward scattering. The participating components of the atmosphere are assumed to be water vapor and spherical quartz particles only. The atmospheric window is partially filled by including the water vapor continuum bands for which empirically obtained transmission functions have been used. It is shown that radically different conclusions may be drawn on dust effects if the continuum absorption is not considered. The radiative transfer model, when applied to a dusty atmosphere, indicates that there is a moderate enhancement in the atmospheric greenhouse and a 10% increase in the mean IR radiative cooling rate, relative to the dust free case, within the lower troposphere. These results have been compared with previous work by other authors in the context of the possibility of dust layers inhibiting local precipitation.

  3. Soil Carbon Sequestration and the Greenhouse Effect (2nd Edition)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This volume is a second edition of the book “Soil Carbon Sequestration and The Greenhouse Effect”. The first edition was published in 2001 as SSSA Special Publ. #57. The present edition is an update of the concepts, processes, properties, practices and the supporting data. All chapters are new co...

  4. Simultaneous retrieval of atmospheric CO2 and light path modification from space-based spectroscopic observations of greenhouse gases: methodology and application to GOSAT measurements over TCCON sites.

    PubMed

    Oshchepkov, Sergey; Bril, Andrey; Yokota, Tatsuya; Yoshida, Yukio; Blumenstock, Thomas; Deutscher, Nicholas M; Dohe, Susanne; Macatangay, Ronald; Morino, Isamu; Notholt, Justus; Rettinger, Markus; Petri, Christof; Schneider, Matthias; Sussman, Ralf; Uchino, Osamu; Velazco, Voltaire; Wunch, Debra; Belikov, Dmitry

    2013-02-20

    This paper presents an improved photon path length probability density function method that permits simultaneous retrievals of column-average greenhouse gas mole fractions and light path modifications through the atmosphere when processing high-resolution radiance spectra acquired from space. We primarily describe the methodology and retrieval setup and then apply them to the processing of spectra measured by the Greenhouse gases Observing SATellite (GOSAT). We have demonstrated substantial improvements of the data processing with simultaneous carbon dioxide and light path retrievals and reasonable agreement of the satellite-based retrievals against ground-based Fourier transform spectrometer measurements provided by the Total Carbon Column Observing Network (TCCON).

  5. Simultaneous retrieval of atmospheric CO2 and light path modification from space-based spectroscopic observations of greenhouse gases: methodology and application to GOSAT measurements over TCCON sites.

    PubMed

    Oshchepkov, Sergey; Bril, Andrey; Yokota, Tatsuya; Yoshida, Yukio; Blumenstock, Thomas; Deutscher, Nicholas M; Dohe, Susanne; Macatangay, Ronald; Morino, Isamu; Notholt, Justus; Rettinger, Markus; Petri, Christof; Schneider, Matthias; Sussman, Ralf; Uchino, Osamu; Velazco, Voltaire; Wunch, Debra; Belikov, Dmitry

    2013-02-20

    This paper presents an improved photon path length probability density function method that permits simultaneous retrievals of column-average greenhouse gas mole fractions and light path modifications through the atmosphere when processing high-resolution radiance spectra acquired from space. We primarily describe the methodology and retrieval setup and then apply them to the processing of spectra measured by the Greenhouse gases Observing SATellite (GOSAT). We have demonstrated substantial improvements of the data processing with simultaneous carbon dioxide and light path retrievals and reasonable agreement of the satellite-based retrievals against ground-based Fourier transform spectrometer measurements provided by the Total Carbon Column Observing Network (TCCON). PMID:23435008

  6. Effect of the greenhouse gases (CO2, H2O, SO2) on Martian paleoclimate

    NASA Technical Reports Server (NTRS)

    Postawko, S. E.; Kuhn, W. R.

    1986-01-01

    There is general agreement that certain surface features on Mars are indicative of the presence of liquid water at various times in the geologic past. In particular, the valley networks are difficult to explain by a mechanism other than the flow of liquid water. It has been suggested in several studies that a thick CO2 atmosphere on Mars early in its history could have provided a greenhouse warming that would have allowed the flow of water either on the surface or just below the surface. However, this effect was examined with a detailed radiation model, and it was found that if reduced solar luminosity early in the history of the solar system is taken into account, even three bars of CO2 will not provide sufficient greeenhouse warming. The addition of water vapor and sulflur dioxide (both plausible gases that may have been emitted by Martian volcanoes) to the atmosphere also fail to warm the surface above 273 K for reduced solar luminosity conditions. The increase in temperature may be large enough, however, for the formation of these features by brines.

  7. The Anthropogenic `Greenhouse Effect': Greek Prospective Primary Teachers' Ideas About Causes, Consequences and Cures

    NASA Astrophysics Data System (ADS)

    Ikonomidis, Simos; Papanastasiou, Dimitris; Melas, Dimitris; Avgoloupis, Stavros

    2012-12-01

    This study explores the ideas of Greek prospective primary teachers about the anthropogenic greenhouse effect, particularly about its causes, consequences and cures. For this purpose, a survey was conducted: 265 prospective teachers completed a closed-form questionnaire. The results showed serious misconceptions in all areas (causes, consequences and cures). The most prominent misconception found by this survey is the conflation between the greenhouse effect and the ozone layer depletion, which is widely reported in the literature. There is also the notion that `good things' (like clean beaches) can help ameliorate the greenhouse effect, whereas `bad things' (like insecticides) can enhance it. One of the secondary results of the survey is that prospective teachers' main source of information about the greenhouse effect is school. This calls for educational interventions to fight misconceptions at the source. Some suggestions are presented in this paper. The results of this study are compared with the results of two similar studies conducted in the UK and in Turkey.

  8. Models of Students' Thinking Concerning the Greenhouse Effect and Teaching Implications.

    ERIC Educational Resources Information Center

    Koulaidis, Vasilis; Christidou, Vasilia

    1999-01-01

    Primary school students (n=40) ages 11 and 12 years were interviewed concerning their conceptions of the greenhouse effect. Analysis of the data led to the formation of seven distinct models of thinking regarding this phenomenon. (Author/CCM)

  9. The role of forestry development in China in alleviating greenhouse effects

    SciTech Connect

    Liu Hong

    1996-12-31

    Forestry development in China has gained great achievements and made great progress in realizing sustainable forest management and alleviating global climate change. The main measures to mitigate greenhouse effects through the means of forestry development include afforestation to increase the forested area, fuel wood forest development, management improvement, wise utilization, international cooperation, investment increase, forest related scientific research, strengthening the forest law enforcement system. Climate change as well as how to alleviate the greenhouse effects is a hot topic at present. This paper describes the achievements of China`s forestry development and its role to alleviate the greenhouse effects, and puts forward the measures to mitigate greenhouse effects through the means of forestry development.

  10. What Light through Yonder Window Breaks?--The Greenhouse Effect Revisited.

    ERIC Educational Resources Information Center

    Bohren, Craig F.

    1992-01-01

    Presents three experiments exploring aspects of the greenhouse effect. Topics and discussion includes radiation in energy transfer, emissivity and absorptivity, the irrelevance of reflectivity, a digression on insulators and convection, climate change, and radiative energy balance. (MCO)

  11. Changing risks of resonance in extreme weather events for higher atmospheric greenhouse gas concentrations

    NASA Astrophysics Data System (ADS)

    Huntingford, Chris; Mitchell, Dann; Osprey, Scott

    2015-04-01

    A recent paper by Petoukhov et al (2013) demonstrates that many of the recent major extreme events in the NH may have been caused by resonant conditions driving very high meridional winds around slowly moving centres-of-action. Besides high amplitudes of planetary wave numbers 6,7 and 8, additional features are identified through 4 further conditions that trigger system resonance. These make the potential for high amplitude waves more likely as well as the possibility of more persistent events. A concern is that human-induced climate change could create conditions more conducive to tropospheric Rossby wave resonance, thereby forcing any periods of extreme weather to become more commonplace and longer lasting. Whilst the CMIP5 ensemble provides much information on expected changes, to fully address changing probabilities of extreme event occurrence - which by definition are relatively rare - is, though, best approached through a massive ensemble modeling framework. The climateprediction-dot-net citizen-science massive ensemble GCM modeling framework provides order 104 simulations for sea-surface temperature, sea-ice extent and atmospheric gas composition representative of both pre-industrial and contemporary conditions. Here we present what these families of simulations imply in terms of the changing likelihood of conditions for mid-latitude resonance, and implications for amplitudes of Rossby waves

  12. Investigation of the relationship between atmospheric mercury and concentrations of key greenhouse gases at a mountainous monitoring site.

    PubMed

    Kim, Ki-Hyun; Pandey, Sudhir Kumar; Brown, Richard J C; Sheu, Guey Rong; Jeon, Eui-Chan; Jung, Kweon; Kang, Chang-Hee

    2015-03-01

    The concentration of total gaseous mercury (TGM) was monitored, together with some key greenhouse gases (GHGs: carbon dioxide (CO2), methane (CH4), and water (H2O) vapor) at hourly intervals at a mountainous monitoring site close to the highly industrialized city of Seoul, Korea. Correlations between the concentrations of Hg and those of the greenhouse gases were examined to assess their source characteristics and responses to changes in meteorological conditions. The mean Hg levels in this study (3.58 ± 2.13 ng m(-3)) were considerably lower (by, e.g., 24.3%) than those measured previously in other comparable sites during 1999-2006 (4.73 ± 1.34 ng m(-3)). Accordingly, such a reduction in Hg levels suggests the effectiveness of the regulatory measures enforced over the years. The mean Hg level observed in this study is also lower (by approximately 5%) than those in other Asian locations. In contrast, the mean concentrations of the two most important GHGs (CO2 and CH4) were moderately higher than those of other locations across the world (by approximately 4-9%). The results of our analysis indicate that the behavior of Hg is strongly correlated with water vapor and CH4 in terms of their source characteristics, despite notable differences in their diurnal patterns.

  13. [Effects of sunken depth of energy-saving solar greenhouse on the diurnal variation and spatial distribution of environmental factors in the greenhouse].

    PubMed

    Li, Qing-ming; Zi, Xi-zhen; Yu, Xian-chang

    2011-08-01

    Taking the energy-saving solar greenhouses with the same infrastructure but different sunken depths (0, 0.5, 1.0, and 1.5 m) in Tai' an of Shandong Province as test objects, this paper analyzed the intercepted amount of direct solar radiation energy, and studied the diurnal variation and spatial distribution patterns of environmental factors in the greenhouses on winter solstice (December 20-24, 2009) and summer solstice (June 19-23, 2010). With the increase of sunken depth, the shadow areas in the greenhouses caused by sunken profiles increased gradually, the direct solar radiation energy into the interior of the greenhouses shifted from south to north, and the ratio of ground radiation to back wall radiation decreased gradually. Within the range of 0-1.0 m sunken depth, the air temperature and soil temperature in the greenhouses increased significantly with increasing sunken depth; but when the sunken depth was 1.5 m, the warming effect declined significantly, and the deviation of the lowest soil temperature increased. The deeper the sunken depth, the lower the light intensity and the higher the relative humidity in the greenhouses were. In considering of both lighting and heat preservation, the appropriate sunken depth of energy-saving sunlight greenhouses with a span of 10 m in Tai' an region should be less than 1.0 m.

  14. Carbon Dioxide and the Greenhouse Effect: A Problem Evaluation Activity.

    ERIC Educational Resources Information Center

    Brewer, Carol A.; Beiswenger, Jane M.

    1993-01-01

    Describes exercises to examine the global carbon cycle. Students are asked to predict consequences of increased carbon dioxide emissions into the atmosphere and to suggest ways to mitigate problems associated with these higher levels of atmospheric carbon dioxide. A comparison modeling exercise examines some of the variables related to the success…

  15. Greenhouse gases: What is their role in climate change

    SciTech Connect

    Edmonds, J.A.; Chandler, W.U. ); Wuebbles, D. )

    1990-12-01

    This paper summarizes information relevant to understanding the role of greenhouse gases in the atmosphere. It examines the nature of the greenhouse effect, the Earth's radiation budget, the concentrations of these gases in the atmosphere, how these concentrations have been changing, natural processes which regulate these concentrations of greenhouse gases, residence times of these gases in the atmosphere, and the rate of release of gases affecting atmospheric composition by human activities. We address the issue of the greenhouse effect itself in the first section. In the second section we examine trends in atmospheric concentration of greenhouse gases and emissions sources. In the third section, we examine the natural carbon cycle and its role in determining the atmospheric residence time of carbon dioxide (CO{sub 2}). In the fourth section, we examine the role atmospheric chemistry plays in the determining the concentrations of greenhouse gases. This paper is not intended to be an exhaustive treatment of these issues. Exhaustive treatments can be found in other volumes, many of which are cited throughout this paper. Rather, this paper is intended to summarize some of the major findings, unknowns, and uncertainties associated with the current state of knowledge regarding the role of greenhouse gases in the atmosphere. 57 refs., 11 figs., 11 tabs.

  16. Our Changing Atmosphere.

    ERIC Educational Resources Information Center

    Clearing, 1988

    1988-01-01

    Summarizes what is known about two major variables involved in certain types of chemical pollution that seem to be changing the structure of the Earth's atmosphere. Discusses the greenhouse effect and the ozone layer. (TW)

  17. [Effects of superphosphate addition on NH3 and greenhouse gas emissions during vegetable waste composting].

    PubMed

    Yang, Yan; Sun, Qin-ping; Li, Ni; Liu, Chun-sheng; Li, Ji-jin; Liu, Ben-sheng; Zou, Guo-yuan

    2015-01-01

    To study the effects of superphosphate (SP) on the NH, and greenhouse gas emissions, vegetable waste composting was performed for 27 days using 6 different treatments. In addition to the controls, five vegetable waste mixtures (0.77 m3 each) were treated with different amounts of the SP additive, namely, 5%, 10%, 15%, 20% and 25%. The ammonia volatilization loss and greenhouse gas emissions were measured during composting. Results indicated that the SP additive significantly decreased the ammonia volatilization and greenhouse gas emissions during vegetable waste composting. The additive reduced the total NH3 emission by 4.0% to 16.7%. The total greenhouse gas emissions (CO2-eq) of all treatments with SP additives were decreased by 10.2% to 20.8%, as compared with the controls. The NH3 emission during vegetable waste composting had the highest contribution to the greenhouse effect caused by the four different gases. The amount of NH3 (CO2-eq) from each treatment ranged from 59.90 kg . t-1 to 81.58 kg . t-1; NH3(CO2-eq) accounted for 69% to 77% of the total emissions from the four gases. Therefore, SP is a cost-effective phosphorus-based fertilizer that can be used as an additive during vegetable waste composting to reduce the NH3 and greenhouse gas emissions as well as to improve the value of compost as a fertilizer.

  18. [Effects of superphosphate addition on NH3 and greenhouse gas emissions during vegetable waste composting].

    PubMed

    Yang, Yan; Sun, Qin-ping; Li, Ni; Liu, Chun-sheng; Li, Ji-jin; Liu, Ben-sheng; Zou, Guo-yuan

    2015-01-01

    To study the effects of superphosphate (SP) on the NH, and greenhouse gas emissions, vegetable waste composting was performed for 27 days using 6 different treatments. In addition to the controls, five vegetable waste mixtures (0.77 m3 each) were treated with different amounts of the SP additive, namely, 5%, 10%, 15%, 20% and 25%. The ammonia volatilization loss and greenhouse gas emissions were measured during composting. Results indicated that the SP additive significantly decreased the ammonia volatilization and greenhouse gas emissions during vegetable waste composting. The additive reduced the total NH3 emission by 4.0% to 16.7%. The total greenhouse gas emissions (CO2-eq) of all treatments with SP additives were decreased by 10.2% to 20.8%, as compared with the controls. The NH3 emission during vegetable waste composting had the highest contribution to the greenhouse effect caused by the four different gases. The amount of NH3 (CO2-eq) from each treatment ranged from 59.90 kg . t-1 to 81.58 kg . t-1; NH3(CO2-eq) accounted for 69% to 77% of the total emissions from the four gases. Therefore, SP is a cost-effective phosphorus-based fertilizer that can be used as an additive during vegetable waste composting to reduce the NH3 and greenhouse gas emissions as well as to improve the value of compost as a fertilizer. PMID:25985667

  19. Mars Greenhouses: Concepts and Challenges. Proceedings from a 1999 Workshop

    NASA Technical Reports Server (NTRS)

    Wheeler, Ray M. (Editor); Martin-Brennan, Cindy (Editor)

    2000-01-01

    Topic covered include :Plants on Mars: On the Next Mission and in the Long Term Future; Bubbles in the Rocks: Natural and Artificial Caves and Cavities as Like Support Structures; Challenges for Bioregenerative Life Support on Mars; Cost Effectiveness Issues; Low Pressure Systems for Plant Growth; Plant Responses to Rarified Atmospheres; Can CO2 be Used as a Pressurizing Gas for Mars Greenhouses?; Inflatable Habitats Technology Development; Development of an Inflatable Greenhouse for a Modular Crop Production System; Mars Inflatable Greenhouse Workshop; Design Needs for Mars Deployable Greenhouse; Preliminary Estimates of the Possibilities for Developing a Deployable Greenhouse for a Planetary Surface Mars; Low Pressure Greenhouse Concepts for Mars; Mars Greenhouse Study: Natural vs. Artificial Lighting; and Wire Culture for an Inflatable Mars Greenhouse and Other Future Inflatable Space Growth Chambers.

  20. Influence of Organic Agriculture on the Net Greenhouse Effect in the Red River Valley, Minnesota

    NASA Astrophysics Data System (ADS)

    Phillips, R. L.

    2004-12-01

    Fluxes for the suite of biologically-produced greenhouse gases (CH4, N2O and CO2) are strongly influenced by agriculture, yet the influence of organic agriculture on all three gases, which comprise the net greenhouse effect (GHE), is not clear in the context of large-scale agricultural production. Greenhouse gas mitigation potential will depend upon the net balance for all three gases [GHE balance (CO2 equiv.)= CO2 flux+ 23CH4flux + 296N2Oflux]. On-farm, field-scale experiments were performed to test the hypothesis that the net GHE at the soil-atmosphere interface is reduced under organic wheat production, compared with conventional, and that effects vary inter-seasonally. Trace gas fluxes were measured at the soil-atmosphere interface for organic and conventional wheat farms in the Red River Valley, Minnesota, one of the most productive agricultural regions in the US. We utilized 40-60 ha field pairs planted with hard red spring wheat (Triticum aestivum L.). Treatment pairs were located 6km apart and consisted of fields continuously cropped for wheat/soybean/sugar beet production for over 20 yr. Ten random, permanent points were generated for each 8.1 ha sub-plot nested inside each field. Each field pair was similar with respect to crop, climate, cultivation history, tillage, rotation, soil texture, pH, macronutrients, bulk density, and water holding capacity. Differences between treatments for the last five years were soil amendments (compost or urea) and herbicide/fungicide application versus mechanical weed control. We collected gas fluxes at each of the 41 points from April (wheat emergence) until the end of July (maturity) to determine the hourly and seasonally integrated net GHE for each management practice, given similar soil/plant/climatic conditions. Moreover, we analyzed inter-seasonal variability to determine the relationship between wheat phenology and flux under field conditions for soil temperature and moisture (water-filled pore space). The net GHE

  1. Atmospheric Effects of Biomass Burning

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.

    2000-01-01

    Biomass fires are both natural and anthropogenic in origin. The natural trigger is lightning, which leads to mid- and high-latitude fires and episodes of smoke and pollution associated with them. Lightning is also prominent in tropical regions when the dry season gives way to the wet season and lightning in convective systems ignites dry vegetation. Atmospheric consequences of biomass fires are complex. When considering the impacts of fires for a given ecosystem, inputs of fires must be compared to other process that emit trace gases and particles into the atmosphere. Other processes include industrial activity, fires for household purposes and biogenic sources which may themselves interact with fires. That is, fires may promote or restrict biogenic processes. Several books have presented various aspects of fire interactions with atmospheric chemistry and a cross-disciplinary review of a 1992 fire-oriented experiment appears in SAFARI: The Role of southern African Fires in Atmospheric and Ecological Environments. The IGAC/BIBEX core activity (see acronyms at end of Chapter) has sponsored field campaigns that integrate multiple aspects of fires ground-based measurements with an ecological perspective, atmospheric measurements with chemical and meteorological components, and remote sensing. This Chapter presents two aspects of biomass fires and the environment. Namely, the relationship between biomass burning and ozone is described, starting with a brief description of the chemical reactions involved and illustrative measurements and interpretation. Second, because of the need to observe biomass burning and its consequences globally, a summary of remote sensing approaches to the study of fires and trace gases is given. Examples in this Chapter are restricted to tropical burning for matters of brevity and because most burning activity globally is within this zone.

  2. Effects of UV-absorbing plastic films on greenhouse whitefly (Homoptera: Aleyrodidae).

    PubMed

    Mutwiwa, Urbanus N; Borgemeister, Christian; von Elsner, Burkhard; Tantau, Hans-Juergen

    2005-08-01

    Studies were conducted to investigate the effects of ultraviolet (UV)-absorbing plastic films on the orientation and distribution behavior of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). In field experiments, small tunnels were constructed and covered with either an UV-transmitting (Thermilux) or UV-absorbing (K-Rose) plastic film. Results show that significantly more whiteflies were recorded in the tunnels with high compared with those with low UV intensities. Moreover, whitefly penetration and dispersion were less inside the UV-deficient tunnels. These results suggest that the type of plastic film used for greenhouse covers may have a significant influence on both the initial immigration and distribution of T. vaporariorum into greenhouses. The possibilities of using UV-absorbing plastic films for whitefly integrated pest management in greenhouses are discussed.

  3. Carbon dioxide emissions from Deccan volcanism and a K/T boundary greenhouse effect

    NASA Technical Reports Server (NTRS)

    Caldeira, Ken; Rampino, Michael R.

    1990-01-01

    A greenhouse warming caused by increased emissions of carbon dioxide from the Deccan Traps volcanism has been suggested as the cause of the terminal Cretaceous extinctions on land and in the sea. Total eruptive and noneruptive CO2 output by the Deccan eruptions (from 6 to 20 x 10 to the 16th moles) over a period of several hundred thousand years is estimated based on best estimates of the CO2 weight fraction of the original basalts and basaltic melts, the fraction of CO2 degassed, and the volume of the Deccan Traps eruptions. Results of a model designed to estimate the effects of increased CO2 on climate and ocean chemistry suggest that increases in atmospheric pCO2 due to Deccan Traps CO2 emissions would have been less than 75 ppm, leading to a predicted global warming of less than 1 C over several hundred thousand years. It is concluded that the direct climate effects of CO2 emissions from the Deccan eruptions would have been too weak to be an important factor in the end-Cretaceous mass extinctions.

  4. Carbon dioxide emissions from Deccan volcanism and a K/T boundary greenhouse effect

    NASA Astrophysics Data System (ADS)

    Caldeira, Ken; Rampino, Michael R.

    1990-08-01

    A greenhouse warming caused by increased emissions of carbon dioxide from the Deccan Traps volcanism has been suggested as the cause of the terminal Cretaceous extinctions on land and in the sea. Total eruptive and noneruptive CO2 output by the Deccan eruptions (from 6 to 20 x 10 to the 16th moles) over a period of several hundred thousand years is estimated based on best estimates of the CO2 weight fraction of the original basalts and basaltic melts, the fraction of CO2 degassed, and the volume of the Deccan Traps eruptions. Results of a model designed to estimate the effects of increased CO2 on climate and ocean chemistry suggest that increases in atmospheric pCO2 due to Deccan Traps CO2 emissions would have been less than 75 ppm, leading to a predicted global warming of less than 1 C over several hundred thousand years. It is concluded that the direct climate effects of CO2 emissions from the Deccan eruptions would have been too weak to be an important factor in the end-Cretaceous mass extinctions.

  5. [Effects of fertilizer application on greenhouse vegetable yield: a case study of Shouguang].

    PubMed

    Liu, Ping; Li, Yan; Jiang, Li-Hua; Liu, Zhao-Hui; Gao, Xin-Hao; Lin, Hai-Tao; Zheng, Fu-Li; Shi, Jing

    2014-06-01

    Data collected from 51 representative greenhouses of Shouguang through questionnaire survey were analyzed to investigate the effect of chemical fertilizers on vegetable yield, relationship between application of organic manure and yield, and influence factors and evolution rule of fertilizer application rate. The results showed that averages of 3338 kg N x hm(-2), 1710 kg P2O5 x hm(-2) 3446 kg K2O x hm(-2) were applied to greenhouse vegetables annually in Shouguang, 6-14 times as that in the local wheat-maize rotation system. The application rates of chemical N, P, and K fertilizers accounted for about 35%, 49% and 42% of the total input. Increasing application of chemical fertilizers had no significant effect on vegetable yields, while organic manure input significantly increased the vegetable yields. With the increase of greenhouse cultivating time, no significant changes in the input of chemical N, P, and K fertilizers were observed in greenhouse vegetable production while organic manure input decreased significantly. Differences in vegetable species, planting pattern and cultivating time of greenhouses was one of the reasons for large variations in nutrient application rate. In recent more than ten years, organic manure nutrient input increased significantly, chemical N and P fertilizer input presented a downward trend, chemical K fertilizer input increased significantly, and the N/P/K ratio became more and more reasonable in greenhouse vegetable production in Shouguang.

  6. An investigation of a super-Earth exoplanet with a greenhouse-gas atmosphere using a general circulation model

    NASA Astrophysics Data System (ADS)

    Zalucha, Angela M.; Michaels, Timothy I.; Madhusudhan, Nikku

    2013-11-01

    We use the Massachusetts Institute of Technology general circulation model (GCM) dynamical core, in conjunction with a Newtonian relaxation scheme that relaxes to a gray, analytical solution of the radiative transfer equation, to simulate a tidally locked, synchronously orbiting super-Earth exoplanet. This hypothetical exoplanet is simulated under the following main assumptions: (1) the size, mass, and orbital characteristics of GJ 1214b (Charbonneau, D. [2009]. Nature 462, 891-894), (2) a greenhouse-gas dominated atmosphere, (3), the gas properties of water vapor, and (4) a surface. We have performed a parameter sweep over global mean surface pressure (0.1, 1, 10, and 100 bar) and global mean surface albedo (0.1, 0.4, and 0.7). Given assumption (1) above, the period of rotation of this exoplanet is 1.58 Earth-days, which we classify as the rapidly rotating regime. Our parameter sweep differs from Heng and Vogt (Heng, K., Vogt, S.S. [2011]. Mon. Not. R. Astron. Soc. 415, 2145-2157), who performed their study in the slowly rotating regime and using Held and Suarez (Held, I.M., Suarez, M.J. [1994]. Bull. Am. Meteorol. Soc. 75 (10), 1825-1830) thermal forcing. This type of thermal forcing is a prescribed function, not related to any radiative transfer, used to benchmark Earth’s atmosphere. An equatorial, westerly, superrotating jet is a robust feature in our GCM results. This equatorial jet is westerly at all longitudes. At high latitudes, the flow is easterly. The zonal winds do show a change with global mean surface pressure. As global mean surface pressure increases, the speed of the equatorial jet decreases between 9 and 15 h local time (substellar point is located at 12 h local time). The latitudinal extent of the equatorial jet increases on the nightside. For the two greatest initial surface pressure cases, an increasingly westerly component of flow develops at middle to high latitudes between 11 and 18 h local time. On the nightside, the easterly flow in the

  7. Warming effects on greenhouse gas fluxes in peatlands are modulated by vegetation composition.

    PubMed

    Ward, Susan E; Ostle, Nicholas J; Oakley, Simon; Quirk, Helen; Henrys, Peter A; Bardgett, Richard D

    2013-10-01

    Understanding the effects of warming on greenhouse gas feedbacks to climate change represents a major global challenge. Most research has focused on direct effects of warming, without considering how concurrent changes in plant communities may alter such effects. Here, we combined vegetation manipulations with warming to investigate their interactive effects on greenhouse gas emissions from peatland. We found that although warming consistently increased respiration, the effect on net ecosystem CO2 exchange depended on vegetation composition. The greatest increase in CO2 sink strength after warming was when shrubs were present, and the greatest decrease when graminoids were present. CH4 was more strongly controlled by vegetation composition than by warming, with largest emissions from graminoid communities. Our results show that plant community composition is a significant modulator of greenhouse gas emissions and their response to warming, and suggest that vegetation change could alter peatland carbon sink strength under future climate change.

  8. Climate Change and the Greenhouse Effect - Nature and Humans

    NASA Astrophysics Data System (ADS)

    Alevizos, Anastasios; Zygouras, Grigorios

    2014-05-01

    In this project twenty A grade students of Lyceum (age 16) were involved (2011-12) and had been learning to give answers to questions about greenhouse gases, their origin and the processes forming them with regard to human activity on our planet and our dependence on fossil fuels. They had considered whether and how this dependence affects global warming, how this dependence can be reduced by changing attitudes and using renewable energy sources and further more they had put questions and doubts about anthropogenic global warming existence. The student dialogues during a '' TV series debate '' concerning the views, questions and answers of three groups, the ''IPCCs'', the ''CLIMATE SCEPTICS'' and the '' REALISTS'' are exposed on a poster.

  9. Changes in Arctic vegetation amplify high-latitude warming through the greenhouse effect

    PubMed Central

    Swann, Abigail L.; Fung, Inez Y.; Levis, Samuel; Bonan, Gordon B.; Doney, Scott C.

    2010-01-01

    Arctic climate is projected to change dramatically in the next 100 years and increases in temperature will likely lead to changes in the distribution and makeup of the Arctic biosphere. A largely deciduous ecosystem has been suggested as a possible landscape for future Arctic vegetation and is seen in paleo-records of warm times in the past. Here we use a global climate model with an interactive terrestrial biosphere to investigate the effects of adding deciduous trees on bare ground at high northern latitudes. We find that the top-of-atmosphere radiative imbalance from enhanced transpiration (associated with the expanded forest cover) is up to 1.5 times larger than the forcing due to albedo change from the forest. Furthermore, the greenhouse warming by additional water vapor melts sea-ice and triggers a positive feedback through changes in ocean albedo and evaporation. Land surface albedo change is considered to be the dominant mechanism by which trees directly modify climate at high-latitudes, but our findings suggest an additional mechanism through transpiration of water vapor and feedbacks from the ocean and sea-ice. PMID:20080628

  10. Changes in Arctic vegetation amplify high-latitude warming through the greenhouse effect.

    PubMed

    Swann, Abigail L; Fung, Inez Y; Levis, Samuel; Bonan, Gordon B; Doney, Scott C

    2010-01-26

    Arctic climate is projected to change dramatically in the next 100 years and increases in temperature will likely lead to changes in the distribution and makeup of the Arctic biosphere. A largely deciduous ecosystem has been suggested as a possible landscape for future Arctic vegetation and is seen in paleo-records of warm times in the past. Here we use a global climate model with an interactive terrestrial biosphere to investigate the effects of adding deciduous trees on bare ground at high northern latitudes. We find that the top-of-atmosphere radiative imbalance from enhanced transpiration (associated with the expanded forest cover) is up to 1.5 times larger than the forcing due to albedo change from the forest. Furthermore, the greenhouse warming by additional water vapor melts sea-ice and triggers a positive feedback through changes in ocean albedo and evaporation. Land surface albedo change is considered to be the dominant mechanism by which trees directly modify climate at high-latitudes, but our findings suggest an additional mechanism through transpiration of water vapor and feedbacks from the ocean and sea-ice.

  11. Operation GREENHOUSE-1951. Final report

    SciTech Connect

    Berkhouse, L.; Davis, S.E.; Gladeck, F.R.; Hallowell, J.H.; Jones, C.B.

    1983-06-15

    GREENHOUSE was a four-detonation atmospheric nuclear weapon's test series conducted in the Marshall Islands at Enewetak Atoll in April and May 1951. This is a report of DOD personnel in GREENHOUSE with an emphasis on operational radiological safety.

  12. Advection from the North Atlantic as the Forcing of Winter Greenhouse Effect Over Europe

    NASA Technical Reports Server (NTRS)

    Otterman, J.; Angell, J.; Atlas, R.; Bungato, D.; Shubert, S.; Starr, David OC.; Susskind, J.; Wu, M.-L. C.

    2002-01-01

    In winter, large interannual fluctuations in the surface temperature are observed over central Europe. Comparing warm February 1990 with cold February 1996, a satellite-retrieved surface (skin) temperature difference of 9.8 K is observed for the region 50-60 degrees N; 5-35 degrees E. Previous studies show that advection from the North Atlantic constitutes the forcing to such fluctuations. The advection is quantified by Index I(sub na), the average of the ocean-surface wind speed over the eastern North Atlantic when the direction is from the southwest (when the wind is from another direction, it counts as a zero speed to the average). Average I(sub na) for February 1990 was 10.6 m/s, but for February 1996 I(sub na) was only 2.4 m/s. A large value of I(sub na) means a strong southwesterly flow which brings warm and moist air into central Europe at low level, producing a steeper tropospheric lapse rate. Strong ascending motions at 700 mb are observed in association with the occurrence of enhanced warm, moist advection from the ocean in February 1990 producing clouds and precipitation. Total precipitable water and cloud-cover fraction have larger values in February 1990 than in 1996. The difference in the greenhouse effect between these two scenarios, this reduction in heat loss to space, can be translated into a virtual radiative heating of 2.6 W/square m above the February 1990 surface/atmosphere system, which contributes to a warming of the surface on the order of 2.6 K. Accepting this estimate as quantitatively meaningful, we evaluate the direct effect, the rise in the surface temperature in Europe as a result of maritime-air inflow, as 7.2 K (9.8 K-2.6 K). Thus, fractional reinforcement by the greenhouse effect is 2.6/7.2, or 36%, a substantial positive feedback.

  13. Atmospheric effect on spectral signature - measurements

    NASA Astrophysics Data System (ADS)

    Kaufman, Yoram J.

    In order to improve the quality of remote sensing there is a need to estimate the atmospheric effect on the remotely sensed image, from the image itself. This can be done by recognition of some surface features with known radiative characteristics. For this purpose measurements of the atmospheric effect on the spectral signature of surface cover were conducted during hazy conditions. Simultaneous measurements of the aerosol optical thickness and its vertical distribution were carried. The results of the measurements are used here to study the spectral dependence of the atmospheric effect on remote sensing of vegetated fields (forest, corn field etc.) and water bodies, and to verify theoretical predictions. It is suggested that the radiances over dark areas (e.g. water in the near IR and forest in the visible) can be used to derive the aerosol optical thickness. Combined with climatological information, the derived optical thickness can be used to perform corrections of the atmospheric effect (not given here).

  14. Atmospheric effects in multispectral remote sensor data

    NASA Technical Reports Server (NTRS)

    Turner, R. E.

    1975-01-01

    The problem of radiometric variations in multispectral remote sensing data which occur as a result of a change in geometric and environmental factors is studied. The case of spatially varying atmospheres is considered and the effect of atmospheric scattering is analyzed for realistic conditions. Emphasis is placed upon a simulation of LANDSAT spectral data for agricultural investigations over the United States. The effect of the target-background interaction is thoroughly analyzed in terms of various atmospheric states, geometric parameters, and target-background materials. Results clearly demonstrate that variable atmospheres can alter the classification accuracy and that the presence of various backgrounds can change the effective target radiance by a significant amount. A failure to include these effects in multispectral data analysis will result in a decrease in the classification accuracy.

  15. Atmospheric effects on the underground muon intensity

    NASA Technical Reports Server (NTRS)

    Fenton, A. G.; Fenton, K. B.; Humble, J. E.; Hyland, G. B.

    1985-01-01

    It has previously been reported that the barometric pressure coefficient observed for muons at Poatina (vertical absorber depth 357 hg/sq cm) appears to be appreciably higher than would be expected from atmospheric absorption alone. There is a possibility that the effect is due to an upper atmospheric temperature effect arising from an inverse correlation of surface pressure with stratospheric temperature. A new proportional telescope is discussed which has been operating at Poatina since about the beginning of 83 and which has a long term stability suitable for studying variations of atmospheric origin.

  16. Atmospheric propagation effects relevant to optical communications

    NASA Technical Reports Server (NTRS)

    Shaik, K. S.

    1988-01-01

    A number of atmospheric phenomena affect the propagation of light. The effects of clear air turbulence are reviewed as well as atmospheric turbidity on optical communications. Among the phenomena considered are astronomical and random refraction, scintillation, beam broadening, spatial coherence, angle of arrival, aperture averaging, absorption and scattering, and the effect of opaque clouds. An extensive reference list is also provided for further study. Useful information on the atmospheric propagation of light in relation to optical deep space communications to an earth based receiving station is available, however, further data must be generated before such a link can be designed with committed performance.

  17. Atmospheric Propagation Effects Relevant to Optical Communications

    NASA Technical Reports Server (NTRS)

    Shaik, K. S.

    1988-01-01

    A number of atmospheric phenomena affect the propagation of light. This article reviews the effects of clear-air turbulence as well as atmospheric turbidity on optical communications. Among the phenomena considered are astronomical and random refraction, scintillation, beam broadening, spatial coherence, angle of arrival, aperture averaging, absorption and scattering, and the effect of opaque clouds. An extensive reference list is also provided for further study, Useful information on the atmospheric propagation of light in resolution to optical deep-space communications to an earth-based receiving station is available, however, further data must be generated before such a link can be designed with committed performance.

  18. [Effects of spent mushroom compost on greenhouse cabbage growth under soil salt stress].

    PubMed

    Wang, Qiu-Ling; Wu, Liang-Huan; Dong, Lan-Xue; Chen, Zai-Ming; Wang, Zhong-Qiang

    2011-05-01

    A pot experiment was conducted to study the effect of spent mushroom compost (SMC) in alleviating greenhouse soil secondary salinization and cabbage salt stress. With the amendment of SMC, the salinized soil after 60 day cabbage cultivation had a pH value close to 7.0, its organic matter and available phosphorous contents increased significantly, and the increment of total water-soluble salt content reduced, compared with the control. When the amendment amount of SMC was 10 g x kg(-1), the increment of soil water soluble salt content was the least, suggesting that appropriate amendment with SMC could reduce the salt accumulation in greenhouse soil. Amendment with SMC increased the cabbage seed germination rate, plant height, plant fresh mass, chlorophyll SPAD value, and vitamin C content, and decreased the proline content significantly. All the results indicated that SMC could improve the growth environment of greenhouse cabbage, and effectively alleviate the detrimental effect of salt stress.

  19. [Effects of spent mushroom compost on greenhouse cabbage growth under soil salt stress].

    PubMed

    Wang, Qiu-Ling; Wu, Liang-Huan; Dong, Lan-Xue; Chen, Zai-Ming; Wang, Zhong-Qiang

    2011-05-01

    A pot experiment was conducted to study the effect of spent mushroom compost (SMC) in alleviating greenhouse soil secondary salinization and cabbage salt stress. With the amendment of SMC, the salinized soil after 60 day cabbage cultivation had a pH value close to 7.0, its organic matter and available phosphorous contents increased significantly, and the increment of total water-soluble salt content reduced, compared with the control. When the amendment amount of SMC was 10 g x kg(-1), the increment of soil water soluble salt content was the least, suggesting that appropriate amendment with SMC could reduce the salt accumulation in greenhouse soil. Amendment with SMC increased the cabbage seed germination rate, plant height, plant fresh mass, chlorophyll SPAD value, and vitamin C content, and decreased the proline content significantly. All the results indicated that SMC could improve the growth environment of greenhouse cabbage, and effectively alleviate the detrimental effect of salt stress. PMID:21812296

  20. Greenhouse investigations on the effect of guava on infestations of Asian citrus psyllid in grapefruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reports from Vietnam indicate interplanting guava with citrus dramatically reduces infestations of Asian citrus psyllid (Diaphorina citri). We therefore conducted greenhouse studies to assess the effect of different guava cultivars on adult psyllids. The effects of cotton and tomato were also evalu...

  1. Can intense forest fertilization be considered a sustainable management practice in the context of greenhouse gas exchange between soils and the atmosphere?

    NASA Astrophysics Data System (ADS)

    Oquist, Mats G.; Egnell, Gustaf; Nilsson, Mats

    2016-04-01

    The demand for forest biomass is increasing and there is large potential for increasing biomass production of northern forest ecosystems by various management strategies involving N fertilization. Increased biomass production also leads to more atmospheric carbon sequestration that potentially can mitigate climate change. N fertilization has been shown to increase biomass production and to decrease soil respiration rates. However, the potential increase in N2O emissions following N addition may counteract the sustainability of such management practices in terms of its impact on the sink/source relationship of greenhouse gases. Here we evaluate the effect of various N addition intensities on the soil-atmosphere exchange of CO2 and N2O in a long-term field experiment in a boreal Scots pine (Pinus sylvestris) forest stand. The stand was planted in 1953 and the experiment was established in 1974 with annual N addition at four levels (N0, N1, N2, and N3 receiving 0, 35, 70, and 110 kg N ha-1 year-1, respectively) organized in a randomized block design (n=3) in plots of 30x30m. The high (N3) and intermediate (N2) N addition levels were terminated in 1990 and 2006, respectively, and offered an opportunity to investigate recovery of greenhouse gas exchange following high N loading. Soil-atmosphere exchange of GHGs were estimated weekly during 2010-2011 based on static chamber measurements during the snow free period and snow concentration gradients during winter. In the ongoing treatment (N1) the annual N2O emissions were 25 mg N2O m-2 yr-1, as compared to 6 mg N2O m-2 yr-1 in the control plots, representing a ca 4-fold significant increase due to N-addition. The N2O-N loss from the treatment corresponded to ca 0.5% of the annually added N (35 kg N ha-1). In the N2 treatment (terminated in 2006) annual N2O emissions were 15 mg N2O m-2 yr-1, while in the N3 treatment N2O emissions were the same as in the control plots with no N-additions. Thus the system has capacity to

  2. On the average temperature of airless spherical bodies and the magnitude of Earth's atmospheric thermal effect.

    PubMed

    Volokin, Den; ReLlez, Lark

    2014-01-01

    The presence of atmosphere can appreciably warm a planet's surface above the temperature of an airless environment. Known as a natural Greenhouse Effect (GE), this near-surface Atmospheric Thermal Enhancement (ATE) as named herein is presently entirely attributed to the absorption of up-welling long-wave radiation by greenhouse gases. Often quoted as 33 K for Earth, GE is estimated as a difference between planet's observed mean surface temperature and an effective radiating temperature calculated from the globally averaged absorbed solar flux using the Stefan-Boltzmann (SB) radiation law. This approach equates a planet's average temperature in the absence of greenhouse gases or atmosphere to an effective emission temperature assuming ATE ≡ GE. The SB law is also routinely employed to estimating the mean temperatures of airless bodies. We demonstrate that this formula as applied to spherical objects is mathematically incorrect owing to Hölder's inequality between integrals and leads to biased results such as a significant underestimation of Earth's ATE. We derive a new expression for the mean physical temperature of airless bodies based on an analytic integration of the SB law over a sphere that accounts for effects of regolith heat storage and cosmic background radiation on nighttime temperatures. Upon verifying our model against Moon surface temperature data provided by the NASA Diviner Lunar Radiometer Experiment, we propose it as a new analytic standard for evaluating the thermal environment of airless bodies. Physical evidence is presented that Earth's ATE should be assessed against the temperature of an equivalent airless body such as the Moon rather than a hypothetical atmosphere devoid of greenhouse gases. Employing the new temperature formula we show that Earth's total ATE is ~90 K, not 33 K, and that ATE = GE + TE, where GE is the thermal effect of greenhouse gases, while TE > 15 K is a thermodynamic enhancement independent of the

  3. On the average temperature of airless spherical bodies and the magnitude of Earth's atmospheric thermal effect.

    PubMed

    Volokin, Den; ReLlez, Lark

    2014-01-01

    The presence of atmosphere can appreciably warm a planet's surface above the temperature of an airless environment. Known as a natural Greenhouse Effect (GE), this near-surface Atmospheric Thermal Enhancement (ATE) as named herein is presently entirely attributed to the absorption of up-welling long-wave radiation by greenhouse gases. Often quoted as 33 K for Earth, GE is estimated as a difference between planet's observed mean surface temperature and an effective radiating temperature calculated from the globally averaged absorbed solar flux using the Stefan-Boltzmann (SB) radiation law. This approach equates a planet's average temperature in the absence of greenhouse gases or atmosphere to an effective emission temperature assuming ATE ≡ GE. The SB law is also routinely employed to estimating the mean temperatures of airless bodies. We demonstrate that this formula as applied to spherical objects is mathematically incorrect owing to Hölder's inequality between integrals and leads to biased results such as a significant underestimation of Earth's ATE. We derive a new expression for the mean physical temperature of airless bodies based on an analytic integration of the SB law over a sphere that accounts for effects of regolith heat storage and cosmic background radiation on nighttime temperatures. Upon verifying our model against Moon surface temperature data provided by the NASA Diviner Lunar Radiometer Experiment, we propose it as a new analytic standard for evaluating the thermal environment of airless bodies. Physical evidence is presented that Earth's ATE should be assessed against the temperature of an equivalent airless body such as the Moon rather than a hypothetical atmosphere devoid of greenhouse gases. Employing the new temperature formula we show that Earth's total ATE is ~90 K, not 33 K, and that ATE = GE + TE, where GE is the thermal effect of greenhouse gases, while TE > 15 K is a thermodynamic enhancement independent of the

  4. Tree species influence soil-atmosphere fluxes of the greenhouse gases CO2, CH4 and N2O

    NASA Astrophysics Data System (ADS)

    Steffens, Christina; Vesterdal, Lars; Pfeiffer, Eva-Maria

    2016-04-01

    In the temperate zone, forests are the greatest terrestrial sink for atmospheric CO2, and tree species affect soil C stocks and soil CO2 emissions. When considering the total greenhouse gas (GHG) balance of the forest soil, the relevant GHGs CH4 and N2O should also be considered as they have a higher global warming potential than CO2. The presented data are first results from a field study in a common garden site in Denmark where tree species with ectomycorrhizal colonization (beech - Fagus sylvatica, oak - Quercus robur) and with arbuscular mycorrhizal colonization (maple - Acer pseudoplatanus, ash - Fraxinus excelsior) have been planted in monocultures in adjacent blocks of about 0.25 ha in the year 1973 on former arable land. The soil-atmosphere fluxes of all three gases were measured every second week since August 2015. The hypothesis is that the total GHG efflux from forest soil would differ between species, and that these differences could be related to the type of mycorrhizal association and leaf litter quality. Preliminary results (August to December 2015) indicate that tree species influence the fluxes (converted to CO2-eq) of the three GHGs. Total soil CO2 efflux was in the low end of the range reported for temperate broadleaved forests but similar to the measurements at the same site approximately ten years ago. It was highest under oak (9.6±2.4 g CO2 m-2 d-1) and lowest under maple (5.2±1.6 g CO2 m-2 d-1). In contrast, soil under oak was a small but significant sink for CH4(-0.005±0.003 g CO2-eq m-2 d-1), while there were almost no detectable CH4 fluxes in maple. Emissions of N2O were highest under beech (0.6±0.6 g CO2-eq m-2 d-1) and oak (0.2±0.09 g CO2-eq m-2 d-1) and lowest under ash (0.03±0.04 g CO2-eq m-2 d-1). In the total GHG balance, soil CH4 uptake was negligible (≤0.1% of total emissions). Emissions of N2O (converted to CO2-eq) contributed <1% (ash) to 8% (beech) to total GHG emissions. Summing up all GHG emissions, the tree species

  5. Tree species influence soil-atmosphere fluxes of the greenhouse gases CO2, CH4 and N2O

    NASA Astrophysics Data System (ADS)

    Steffens, Christina; Vesterdal, Lars; Pfeiffer, Eva-Maria

    2016-04-01

    In the temperate zone, forests are the greatest terrestrial sink for atmospheric CO2, and tree species affect soil C stocks and soil CO2 emissions. When considering the total greenhouse gas (GHG) balance of the forest soil, the relevant GHGs CH4 and N2O should also be considered as they have a higher global warming potential than CO2. The presented data are first results from a field study in a common garden site in Denmark where tree species with ectomycorrhizal colonization (beech - Fagus sylvatica, oak - Quercus robur) and with arbuscular mycorrhizal colonization (maple - Acer pseudoplatanus, ash - Fraxinus excelsior) have been planted in monocultures in adjacent blocks of about 0.25 ha in the year 1973 on former arable land. The soil-atmosphere fluxes of all three gases were measured every second week since August 2015. The hypothesis is that the total GHG efflux from forest soil would differ between species, and that these differences could be related to the type of mycorrhizal association and leaf litter quality. Preliminary results (August to December 2015) indicate that tree species influence the fluxes (converted to CO2-eq) of the three GHGs. Total soil CO2 efflux was in the low end of the range reported for temperate broadleaved forests but similar to the measurements at the same site approximately ten years ago. It was highest under oak (9.6±2.4 g CO2 m‑2 d‑1) and lowest under maple (5.2±1.6 g CO2 m‑2 d‑1). In contrast, soil under oak was a small but significant sink for CH4(-0.005±0.003 g CO2-eq m‑2 d‑1), while there were almost no detectable CH4 fluxes in maple. Emissions of N2O were highest under beech (0.6±0.6 g CO2-eq m‑2 d‑1) and oak (0.2±0.09 g CO2-eq m‑2 d‑1) and lowest under ash (0.03±0.04 g CO2-eq m‑2 d‑1). In the total GHG balance, soil CH4 uptake was negligible (≤0.1% of total emissions). Emissions of N2O (converted to CO2-eq) contributed <1% (ash) to 8% (beech) to total GHG emissions. Summing up all GHG

  6. Climatic effects of atmospheric water vapor distribution through volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Yim, W. W.

    2011-12-01

    Volcanic eruptions play an important role in changing the water vapor distribution of the atmosphere. In comparison with the emission of carbon dioxide released during the consumption of fossil fuel, water vapor's role in climate change has been grossly underestimated. Studies made of modern volcanic eruptions, including satellite images and meteorological records, have revealed climatic effects in different parts of the globe through the migration of volcanic clouds, depending mainly on their timing, location, Volcanic Explosivity Index (VEI) and composition. The climatic effects of volcanic eruptions include: (1) Reduction in solar heating because of the particulates discharged. (2) Interference with the 'normal' atmospheric circulation and/or oceanic circulation. (3) The ash particles and aerosols provide condensation nuclei for water. (4) The transfer from the troposphere into the stratosphere of water vapor which act as a greenhouse gas more important than carbon dioxide. (5) Variability in regional rainfall including the occurrence of droughts, floods, landslides salinization and crop failures. (6) Anomalous regional wind and rain storms. (7) Acid rain. Selected volcanic eruptions will be used as examples to illustrate the different climatic effects.

  7. Noxious gases in greenhouses.

    PubMed

    Likas, C; Exarchou, V; Gourgoulianis, K; Giaglaras, P; Gemptos, T; Kittas, K; Molyvdas, P A

    2001-01-01

    The concentration of NO(2) and SO(2) was measured in a commercial greenhouse from 23/9/1999 25/01/2000. The measurements showed that the level of the two gases is very high in the greenhouse atmosphere. Lung function tests in 42 workers showed that temporary work did not influence significantly the respiratory health status. PMID:11426932

  8. Effects of compost and manure additions on the greenhouse gas dynamics of managed grasslands

    NASA Astrophysics Data System (ADS)

    DeLonge, M. S.; Silver, W. L.

    2013-12-01

    Grasslands cover approximately 30% of the terrestrial land surface, and have significant potential to increase soil C storage and thus lower atmospheric CO2 concentrations. Organic matter amendments (e.g., compost, manure) have been shown to be effective at increasing grassland soil C both through direct addition and by increasing net primary productivity. However, organic matter additions can also increase N2O and CH4 fluxes. The effects of organic matter amendments on both soil C and greenhouse gas emissions are dependent on their physical and chemical qualities. To explore the impacts of organic matter amendments of different chemical and physical qualities on soil C and greenhouse gas emissions we established research plots on three managed annual grasslands in California. Three replicate blocks were established at each site and included an untreated control, a manure treatment, and a compost treatment. At one site, an additional compost with a lower nitrogen content was also tested. In October 2011, a 1 cm layer of the designated amendment was added to each plot. All plots were sampled for soil (C and N, bulk density, temperature, moisture) and plant (community, aboveground biomass) properties, prior to and for two years following treatment. Plots were also sampled intensively for N2O, CH4, and CO2 fluxes using static chambers on over 35 days throughout the two rainy seasons, where sampling days were selected to target pulses following rain events. Results show that the amendments differentially affected soil C and greenhouse gases among the treatments. One year after treatment, C concentrations in the top 10 cm of soils had increased at all three sites by a mean of 0.5-1% on plots that received either compost treatment, but not on those that received manure. Lower in the profile (10-30 cm), C concentrations were increased by a smaller amount (<0.3%) and only in two of the sites. The untreated grassland soils were a small source of N2O during the first few

  9. Residue placement and rate, crop species, and nitrogen fertilization effects on soil greenhouse gas emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High variability due to soil heterogeneity and climatic conditions challenge measurement of greenhouse gas (GHG) emissions as influenced by management practices in the field. To reduce this variability, we examined the effect of management practices on CO2, N2O, and CH4 fluxes and soil temperature a...

  10. Greenhouse Effect: Temperature of a Metal Sphere Surrounded by a Glass Shell and Heated by Sunlight

    ERIC Educational Resources Information Center

    Nguyen, Phuc H.; Matzner, Richard A.

    2012-01-01

    We study the greenhouse effect on a model satellite consisting of a tungsten sphere surrounded by a thin spherical, concentric glass shell, with a small gap between the sphere and the shell. The system sits in vacuum and is heated by sunlight incident along the "z"-axis. This development is a generalization of the simple treatment of the…

  11. Energy balance in ice layers - the solid-state greenhouse effect at the Mars polar caps

    NASA Astrophysics Data System (ADS)

    Kaufmann, E.; Kömle, N. I.; Kargl, G.

    Icy surfaces like the polar caps of Mars or the surfaces of the outer Galilean satellites behave different than rock and soil surfaces when they are irradiated by solar light The latter ones absorb and reflect incoming solar radiation immediately at the surface In contrast ices are partially transparent in the visible spectral range and opaque in the infrared Due to this property it is possible for the solar radiation to reach a certain depth and raise the temperature of the ice layer below the surface This internal temperature rise is called solid-state greenhouse effect It may play an important role in the energy balance of icy surfaces in the solar system as already suggested in previous theoretical investigations One possible consequence of the solid-state greenhouse effect are the Martian spiders observed at the cryptic region on Mars by Mars Global Surveyor In the frame of a project performed at the Space Research Institute in Graz the solid-state greenhouse effect was investigated experimentally and theoretically A couple of experiments were performed including diverse samples with the main focus on layered samples with a covering coat consisting of pure H 2 O-ice Different samples were irradiated under cryo-vacuum conditions by a solar simulator The temperature distributions inside the samples were measured and compared with the results of theoretical modelling In addition models describing the influence of the solid-state greenhouse effect on Mars where the surface is partially covered by CO 2 -ice were developed

  12. Student Teacher Understanding of the Greenhouse Effect, Ozone Layer Depletion, and Acid Rain.

    ERIC Educational Resources Information Center

    Dove, Jane

    1996-01-01

    Describes the results of a survey designed to ascertain details of student teachers' knowledge and misconceptions about the greenhouse effect, acid rain, and ozone layer depletion. Results indicate familiarity with the issues but little understanding of the concepts involved and many commonly held misconceptions. (JRH)

  13. Greenhouse Effect in the Classroom: A Project- and Laboratory-Based Curriculum.

    ERIC Educational Resources Information Center

    Lueddecke, Susann B.; Pinter, Nicholas; McManus, Scott A.

    2001-01-01

    Tests a multifaceted curriculum for use in introductory earth science classes from the secondary school to the introductory undergraduate level. Simulates the greenhouse effect with two fish tanks, heat lamps, and thermometers. Uses a hands-on science approach to develop a deeper understanding of the climate system among students. (Contains 28…

  14. Discussing the Greenhouse Effect: Children's Collaborative Discourse Reasoning and Conceptual Change.

    ERIC Educational Resources Information Center

    Mason, Lucia; Santi, Marina

    1998-01-01

    Investigates fifth-grade students' conceptual changes toward the greenhouse effect and global warming due to sociocognitive interaction developed in small and large group discussion in an authentic classroom context during an environmental education unit. Classroom discussions led the children to integrate new scientific knowledge into their…

  15. Spaceship Nigeria: A Topic Study for Global Warming, Greenhouse Effect and Ozone Layer Depletion.

    ERIC Educational Resources Information Center

    Okebukola, Peter; Akpan, Ben B.

    1997-01-01

    Explains the concept of a topic study, how it meets the needs of teachers seeking to integrate their teaching, and how it is especially well suited for environmental education. Outlines curriculum for a topic study on the greenhouse effect and ozone layer depletion. (DDR)

  16. The Anthropogenic "Greenhouse Effect": Greek Prospective Primary Teachers' Ideas about Causes, Consequences and Cures

    ERIC Educational Resources Information Center

    Ikonomidis, Simos; Papanastasiou, Dimitris; Melas, Dimitris; Avgoloupis, Stavros

    2012-01-01

    This study explores the ideas of Greek prospective primary teachers about the anthropogenic greenhouse effect, particularly about its causes, consequences and cures. For this purpose, a survey was conducted: 265 prospective teachers completed a closed-form questionnaire. The results showed serious misconceptions in all areas (causes, consequences…

  17. Australian Students' Appreciation of the Greenhouse Effect and the Ozone Hole.

    ERIC Educational Resources Information Center

    Fisher, Brian

    1998-01-01

    Examines students' explanations of the greenhouse effect and the hole in the ozone layer, using a life-world and scientific dichotomy. Illuminates ideas often expressed in classrooms and sheds light on the progression in students' developing powers of explanation. Contains 17 references. (DDR)

  18. The Greenhouse Effect: A Selected Bibliography. Bibliography Series Twenty-two.

    ERIC Educational Resources Information Center

    O'Neill, Gertrudis, Comp.

    The purpose of this bibliography is to provide listings of articles, books, and documents which are available in the Robert E. Kennedy Library, California Polytechnic State University, and other libraries on the problem of the greenhouse effect published since 1980. Listings are organized as: (1) "Subject Headings"; (2) "Carbon Dioxide…

  19. Factor Analysis of Drawings: Application to College Student Models of the Greenhouse Effect

    ERIC Educational Resources Information Center

    Libarkin, Julie C.; Thomas, Stephen R.; Ording, Gabriel

    2015-01-01

    Exploratory factor analysis was used to identify models underlying drawings of the greenhouse effect made by over 200 entering university freshmen. Initial content analysis allowed deconstruction of drawings into salient features, with grouping of these features via factor analysis. A resulting 4-factor solution explains 62% of the data variance,…

  20. Experimental research on the effects of water application on greenhouse gas emissions from beef cattle feedlots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of water application (e.g., through rainfall or sprinkler system) on emissions of greenhouse gases (GHGs), such as nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2), from pen surfaces of open-lot beef cattle feedlots was evaluated under controlled laboratory conditions. Soil/ma...

  1. Mass Media and Global Warming: A Public Arenas Model of the Greenhouse Effect's Scientific Roots.

    ERIC Educational Resources Information Center

    Neuzil, Mark

    1995-01-01

    Uses the Public Arenas model to examine the historical roots of the greenhouse effect issue as communicated in scientific literature from the early 1800s to modern times. Utilizes a constructivist approach to discuss several possible explanations for the rise and fall of global warming as a social problem in the scientific arena. (PA)

  2. Understanding the Greenhouse Effect by Embodiment - Analysing and Using Students' and Scientists' Conceptual Resources

    NASA Astrophysics Data System (ADS)

    Niebert, Kai; Gropengießer, Harald

    2014-01-01

    Over the last 20 years, science education studies have reported that there are very different understandings among students of science regarding the key aspects of climate change. We used the cognitive linguistic framework of experientialism to shed new light on this valuable pool of studies to identify the conceptual resources of understanding climate change. In our study, we interviewed 35 secondary school students on their understanding of the greenhouse effect and analysed the conceptions of climate scientists as drawn from textbooks and research reports. We analysed all data by metaphor analysis and qualitative content analysis to gain insight into students' and scientists' resources for understanding. In our analysis, we found that students and scientists refer to the same schemata to understand the greenhouse effect. We categorised their conceptions into three different principles the conceptions are based on: warming by more input, warming by less output, and warming by a new equilibrium. By interrelating students' and scientists' conceptions, we identified the students' learning demand: First, our students were afforded with experiences regarding the interactions of electromagnetic radiation and CO2. Second, our students reflected about the experience-based schemata they use as source domains for metaphorical understanding of the greenhouse effect. By uncovering the-mostly unconscious-deployed schemata, we gave students access to their source domains. We implemented these teaching guidelines in interventions and evaluated them in teaching experiments to develop evidence-based and theory-guided learning activities on the greenhouse effect.

  3. The Effect of Greenhouse Gas Mitigation on Drought Impacts in the U.S.

    EPA Science Inventory

    In this paper, we present a methodology for analyzing the economic benefits in the U.S. of changes in drought frequency and severity due to global greenhouse gas (GHG) mitigation. We construct reduced-form models of the effect of drought on agriculture and reservoir recreation i...

  4. Potato (Solanum tuberosum) greenhouse tuber production as an assay for asexual reproduction effects from herbicides

    EPA Science Inventory

    The present study determined whether young potato plants can be used as an assay to indicate potential effects of pesticides on asexual reproduction. Solanum tuberosum (Russet Burbank) plants were grown from seed pieces in a mineral soil in pots under greenhouse conditions. Plant...

  5. Improving Students' Conceptual Understanding of the Greenhouse Effect Using Theory-Based Learning Materials that Promote Deep Learning

    ERIC Educational Resources Information Center

    Reinfried, Sibylle; Aeschbacher, Urs; Rottermann, Benno

    2012-01-01

    Students' everyday ideas of the greenhouse effect are difficult to change. Environmental education faces the challenge of developing instructional settings that foster students' conceptual understanding concept of the greenhouse effect in order to understand global warming. To facilitate students' conceptual development with regard to the…

  6. Precipitation rates and atmospheric heat transport during the Cenomanian greenhouse warming in North America: Estimates from a stable isotope mass-balance model

    USGS Publications Warehouse

    Ufnar, David F.; Ludvigson, Greg A.; Gonzalez, L.; Grocke, D.R.

    2008-01-01

    Stable isotope mass-balance modeling results of meteoric ??18O values from the Cenomanian Stage of the Cretaceous Western Interior Basin (KWIB) suggest that precipitation and evaporation fluxes were greater than that of the present and significantly different from simulations of Albian KWIB paleohydrology. Sphaerosiderite meteoric ??18O values have been compiled from the Lower Tuscaloosa Formation of southwestern Mississippi (25??N paleolatitude), The Dakota Formation Rose Creek Pit, Fairbury Nebraska (35??N) and the Dunvegan Formation of eastern British Columbia (55??N paleolatitude). These paleosol siderite ??18O values define a paleolatitudinal gradient ranging from - 4.2??? VPDB at 25??N to - 12.5??? VPDB at 55??N. This trend is significantly steeper and more depleted than a modern theoretical siderite gradient (25??N: - 1.7???; 65??N: - 5.6??? VPDB ), and a Holocene meteoric calcite trend (27??N: - 3.6???; 67??N: - 7.4??? VPDB). The Cenomanian gradient is also comparatively steeper than the Albian trend determined for the KWIB in the mid- to high latitudes. The steep latitudinal trend in meteoric ??18O values may be the result of increased precipitation and evaporation fluxes (amount effects) under a more vigorous greenhouse-world hydrologic cycle. A stable-isotope mass-balance model has been used to generate estimates of precipitation and evaporation fluxes and precipitation rates. Estimates of Cenomanian precipitation rates based upon the mass-balance modeling of the KWIB range from 1400??mm/yr at 25??N paleolatitude to 3600??mm/yr at 45??N paleolatitude. The precipitation-evaporation (P-E) flux values were used to delineate zones of moisture surplus and moisture deficit. Comparisons between Cenomanian P-E and modern theoretical siderite, and Holocene calcite latitudinal trends shows an amplification of low-latitude moisture deficits between 5-25??N paleolatitude and moisture surpluses between 40-60??N paleolatitude. The low-latitude moisture deficits

  7. The atmospheric effects of stratospheric aircraft

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S. (Editor); Wesoky, Howard L. (Editor)

    1993-01-01

    This document presents a second report from the Atmospheric Effects of Stratospheric Aircraft (AESA) component of NASA's High-Speed Research Program (HSRP). This document presents a second report from the Atmospheric Effects of Stratospheric Aircraft (AESA) component of NASA's High Speed Research Program (HSRP). Market and technology considerations continue to provide an impetus for high-speed civil transport research. A recent United Nations Environment Program scientific assessment has shown that considerable uncertainty still exists about the possible impact of aircraft on the atmosphere. The AESA was designed to develop the body of scientific knowledge necessary for the evaluation of the impact of stratospheric aircraft on the atmosphere. The first Program report presented the basic objectives and plans for AESA. This second report presents the status of the ongoing research as reported by the principal investigators at the second annual AESA Program meeting in May 1992: Laboratory studies are probing the mechanism responsible for many of the heterogeneous reactions that occur on stratospheric particles. Understanding how the atmosphere redistributes aircraft exhaust is critical to our knowing where the perturbed air will go and for how long it will remain in the stratosphere. The assessment of fleet effects is dependent on the ability to develop scenarios which correctly simulate fleet operations.

  8. Retrieval of atmospheric methane from high spectral resolution satellite measurements: a correction for cirrus cloud effects.

    PubMed

    Bril, Andrey; Oshchepkov, Sergey; Yokota, Tatsuya

    2009-04-10

    We assessed the accuracy of methane (CH(4)) retrievals from synthetic radiance spectra particular to Greenhouse Gases Observing Satellite observations. We focused on estimating the CH(4) vertical column amount from an atmosphere that includes thin cirrus clouds, taking into account uncertain meteorological conditions. A photon path-length probability density function (PPDF)-based method was adapted to correct for atmospheric scattering effects in CH(4) retrievals. This method was shown to provide similar retrieval accuracy as compared to a carbon dioxide (CO(2))-proxy-based correction approach. It infers some advantages of PPDF-based method for methane retrievals under high variability of CO(2) abundance.

  9. Climate-chemical interactions and effects of changing atmospheric trace gases

    SciTech Connect

    Ramanathan, V.; Callis, L.; Cess, R.; Hansen, J.; Isaksen, I.; Kuhn, W.; Lacis, A.; Luther, F.; Mahlman, J.; Reck, R.; and others

    1987-08-01

    The problem concerning the greenhouse effects of human activities has broadened in scope from the CO2-climate problem to the trace gas-climate problem. The climate effects of non-CO2 trace gases are strongly governed by interactions between chemistry, radiation, and dynamics. We discuss in detail the nature of the trace gas radiative heating and describe the importance of radiative-chemical interactions within the troposphere and the stratosphere. We make an assessment of the trace gas effects on troposphere-stratosphere temperature trends for the period covering the preindustrial era to the present and for the next several decades. Non-CO2 greenhouse gases in the atmosphere are now adding to the greenhouse effect by an amount comparable to the effect of CO2. The rate of decadal increase of the total greenhouse forcing is now 3--6 times greater than the mean rate for the period 1850--1960. Time-dependent calculations with a simplified one-dimensional diffusive ocean model suggest that a surface warming about 0.4--0.8 K should have occurred during 1850 to 1980. For the various trace gas scenarios considered in this study, the equilibrium surface warming for the period 1980 to 2030 ranges from 0.8 to 4.1 K. This wide range in the projected warming is due to the range in the assumed scenario as well as due to the threefold uncertainty in the sensitivity of climate models.

  10. Effects of biochar addition on greenhouse gas emissions and microbial responses in a short-term laboratory experiment.

    PubMed

    Yoo, Gayoung; Kang, Hojeong

    2012-01-01

    Biochar application to soil has drawn much attention as a strategy to sequester atmospheric carbon in soil ecosystems. The applicability of this strategy as a climate change mitigation option is limited by our understanding of the mechanisms responsible for the observed changes in greenhouse gas emissions from soils, microbial responses, and soil fertility changes. We conducted an 8-wk laboratory incubation using soils from PASTURE (silt loam) and RICE PADDY (silt loam) sites with and without two types of biochar (biochar from swine manure [CHAR-M] and from barley stover [CHAR-B]). Responses to addition of the different biochars varied with the soil source. Addition of CHAR-B did not change CO and CH evolution from the PASTURE or the RICE PADDY soils, but there was a decrease in NO emissions from the PASTURE soil. The effects of CHAR-M addition on greenhouse gas emissions were different for the soils. The most substantial change was an increase in NO emissions from the RICE PADDY soil. This result was attributed to a combination of abundant denitrifiers in this soil and increased net nitrogen mineralization. Soil phosphatase and N-acetylglucosaminidase activity in the CHAR-B-treated soils was enhanced compared with the controls for both soils. Fungal biomass was higher in the CHAR-B-treated RICE PADDY soil. From our results, we suggest CHAR-B to be an appropriate amendment for the PASTURE and RICE PADDY soils because it provides increased nitrogen availability and microbial activity with no net increase in greenhouse gas emissions. Application of CHAR-M to RICE PADDY soils could result in excess nitrogen availability, which may increase NO emissions and possible NO leaching problems. Thus, this study confirms that the ability of environmentally sound biochar additions to sequester carbon in soils depends on the characteristics of the receiving soil as well as the nature of the biochar.

  11. Effects of biochar addition on greenhouse gas emissions and microbial responses in a short-term laboratory experiment.

    PubMed

    Yoo, Gayoung; Kang, Hojeong

    2012-01-01

    Biochar application to soil has drawn much attention as a strategy to sequester atmospheric carbon in soil ecosystems. The applicability of this strategy as a climate change mitigation option is limited by our understanding of the mechanisms responsible for the observed changes in greenhouse gas emissions from soils, microbial responses, and soil fertility changes. We conducted an 8-wk laboratory incubation using soils from PASTURE (silt loam) and RICE PADDY (silt loam) sites with and without two types of biochar (biochar from swine manure [CHAR-M] and from barley stover [CHAR-B]). Responses to addition of the different biochars varied with the soil source. Addition of CHAR-B did not change CO and CH evolution from the PASTURE or the RICE PADDY soils, but there was a decrease in NO emissions from the PASTURE soil. The effects of CHAR-M addition on greenhouse gas emissions were different for the soils. The most substantial change was an increase in NO emissions from the RICE PADDY soil. This result was attributed to a combination of abundant denitrifiers in this soil and increased net nitrogen mineralization. Soil phosphatase and N-acetylglucosaminidase activity in the CHAR-B-treated soils was enhanced compared with the controls for both soils. Fungal biomass was higher in the CHAR-B-treated RICE PADDY soil. From our results, we suggest CHAR-B to be an appropriate amendment for the PASTURE and RICE PADDY soils because it provides increased nitrogen availability and microbial activity with no net increase in greenhouse gas emissions. Application of CHAR-M to RICE PADDY soils could result in excess nitrogen availability, which may increase NO emissions and possible NO leaching problems. Thus, this study confirms that the ability of environmentally sound biochar additions to sequester carbon in soils depends on the characteristics of the receiving soil as well as the nature of the biochar. PMID:22751062

  12. Effect of shade on atmospheric oxidants (smog)

    SciTech Connect

    Stewart, W.S.; Wilken, D.H.

    1985-01-01

    A series of experiments utilizing atmospheric smog were conducted comparing simultaneously the oxidant level in sunlight and under shade. From the results of the experiments, it is suggested that the undesirable effects of smog in a localized area may be reduced by the planting of shade trees, vines, shrubs and encouraging a denser growth of vegetation.

  13. Student Mental Models of the Greenhouse Effect: Retention Months After Interventions

    NASA Astrophysics Data System (ADS)

    Harris, S. E.; Gold, A. U.

    2013-12-01

    Individual understanding of climate science, and the greenhouse effect in particular, is one factor important for societal decision-making. Ideally, learning opportunities about the greenhouse effect will not only move people toward expert-like ideas but will also have long-lasting effects for those individuals. We assessed university students' mental models of the greenhouse effect before and after specific learning experiences, on a final exam, then again a few months later. Our aim was to measure retention after students had not necessarily been thinking about, nor studying, the greenhouse effect recently. How sticky were the ideas learned? 164 students in an introductory science course participated in a sequence of two learning activities and assessments regarding the greenhouse effect. The first lesson involved the full class, then, for the second lesson, half the students completed a simulation-based activity and the other half completed a data-driven activity. We assessed student thinking through concept sketches, multiple choice and short answer questions. All students generated concept sketches four times, and completed a set of multiple choice (MCQs) and short answer questions twice. Later, 3-4 months after the course ended, 27 students ('retention students') completed an additional concept sketch and answered the questions again, as a retention assessment. These 27 students were nearly evenly split between the two contrasting second lessons in the sequence and included both high and low-achieving students. We then compared student sketches and scores to 'expert' answers. The general pattern over time showed a significant increase in student scores from before the lesson sequence to after, both on concept sketches and MCQs, then an additional increase in concept sketch score on the final exam (MCQs were not asked on the final exam). The scores for the retention students were not significantly different from the full class. Within the retention group

  14. Magnetic effects in hot Jupiter atmospheres

    SciTech Connect

    Rogers, T. M.; Komacek, T. D.

    2014-10-20

    We present magnetohydrodynamic simulations of the atmospheres of hot Jupiters ranging in temperature from 1100 to 1800 K. Magnetic effects are negligible in atmospheres with temperatures ≲1400 K. At higher temperatures winds are variable and, in many cases, mean equatorial flows can become westward, opposite to their hydrodynamic counterparts. Ohmic dissipation peaks at temperatures ∼1500-1600 K, depending on field strength, with maximum values ∼10{sup 18} W at 10 bars, substantially lower than previous estimates. Based on the limited parameter study done, this value cannot be increased substantially with increasing winds, higher temperatures, higher field strengths, different boundary conditions, or lower diffusivities. Although not resolved in these simulations, there is modest evidence that a magnetic buoyancy instability may proceed in hot atmospheres.

  15. Determining solar effects in Neptune's atmosphere.

    PubMed

    Aplin, K L; Harrison, R G

    2016-01-01

    Long-duration observations of Neptune's brightness at two visible wavelengths provide a disk-averaged estimate of its atmospheric aerosol. Brightness variations were previously associated with the 11-year solar cycle, through solar-modulated mechanisms linked with either ultraviolet or galactic cosmic ray (GCR) effects on atmospheric particles. Here, we use a recently extended brightness data set (1972-2014), with physically realistic modelling to show, rather than alternatives, ultraviolet and GCR are likely to be modulating Neptune's atmosphere in combination. The importance of GCR is further supported by the response of Neptune's atmosphere to an intermittent 1.5- to 1.9-year periodicity, which occurred preferentially in GCR (not ultraviolet) during the mid-1980s. This periodicity was detected both at Earth, and in GCR measured by Voyager 2, then near Neptune. A similar coincident variability in Neptune's brightness suggests nucleation onto GCR ions. Both GCR and ultraviolet mechanisms may occur more rapidly than the subsequent atmospheric particle transport. PMID:27417301

  16. Determining solar effects in Neptune's atmosphere

    PubMed Central

    Aplin, K. L.; Harrison, R. G.

    2016-01-01

    Long-duration observations of Neptune's brightness at two visible wavelengths provide a disk-averaged estimate of its atmospheric aerosol. Brightness variations were previously associated with the 11-year solar cycle, through solar-modulated mechanisms linked with either ultraviolet or galactic cosmic ray (GCR) effects on atmospheric particles. Here, we use a recently extended brightness data set (1972–2014), with physically realistic modelling to show, rather than alternatives, ultraviolet and GCR are likely to be modulating Neptune's atmosphere in combination. The importance of GCR is further supported by the response of Neptune's atmosphere to an intermittent 1.5- to 1.9-year periodicity, which occurred preferentially in GCR (not ultraviolet) during the mid-1980s. This periodicity was detected both at Earth, and in GCR measured by Voyager 2, then near Neptune. A similar coincident variability in Neptune's brightness suggests nucleation onto GCR ions. Both GCR and ultraviolet mechanisms may occur more rapidly than the subsequent atmospheric particle transport. PMID:27417301

  17. Determining solar effects in Neptune's atmosphere

    NASA Astrophysics Data System (ADS)

    Aplin, K. L.; Harrison, R. G.

    2016-07-01

    Long-duration observations of Neptune's brightness at two visible wavelengths provide a disk-averaged estimate of its atmospheric aerosol. Brightness variations were previously associated with the 11-year solar cycle, through solar-modulated mechanisms linked with either ultraviolet or galactic cosmic ray (GCR) effects on atmospheric particles. Here, we use a recently extended brightness data set (1972-2014), with physically realistic modelling to show, rather than alternatives, ultraviolet and GCR are likely to be modulating Neptune's atmosphere in combination. The importance of GCR is further supported by the response of Neptune's atmosphere to an intermittent 1.5- to 1.9-year periodicity, which occurred preferentially in GCR (not ultraviolet) during the mid-1980s. This periodicity was detected both at Earth, and in GCR measured by Voyager 2, then near Neptune. A similar coincident variability in Neptune's brightness suggests nucleation onto GCR ions. Both GCR and ultraviolet mechanisms may occur more rapidly than the subsequent atmospheric particle transport.

  18. Elevated CO2 and warming effects on soil carbon sequestration and greenhouse gas exchange in agroecosystems: A review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrations of CO2 and other greenhouse gases (GHGs) have been increasing dramatically in earth’s atmosphere since the industrial revolution, and are expected to continue increasing from ~385 ppmv today to more than 600 ppmv by the end of this century. Global surface temperatures are expected to ...

  19. Biochar and manure effects on net nitrogen mineralization and greenhouse gas emissions from calcareous soil under corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few multiyear field studies have examined the impacts of a one-time biochar application on net N mineralization and greenhouse gas emissions in an irrigated, calcareous soil; yet such applications are hypothesized as a means of sequestering atmospheric CO2 and improving soil quality. We fall-applie...

  20. Effects of 17β-estradiol on emissions of greenhouse gases in simulative natural water body.

    PubMed

    Ruan, Aidong; Zhao, Ying; Liu, Chenxiao; Zong, Fengjiao; Yu, Zhongbo

    2015-05-01

    Environmental estrogens are widely spread across the world and are increasingly thought of as serious contaminators. The present study looks at the influence of different concentrations of 17β-estradiol on greenhouse gas emissions (CO2 , CH4 , and N2 O) in simulated systems to explore the relationship between environmental estrogen-pollution and greenhouse gas emissions in natural water bodies. The present study finds that 17β-estradiol pollution in simulated systems has significant promoting effects on the emissions of CH4 and CO2 , although no significant effects on N2 O emissions. The present study indicates that 17β-estradiol has different effects on the different elements cycles; the mechanism of microbial ecology is under review.

  1. Atmospheric station Křešín u Pacova, Czech Republic - a Central European research infrastructure for studying greenhouse gases, aerosols and air quality

    NASA Astrophysics Data System (ADS)

    Dvorská, A.; Sedlák, P.; Schwarz, J.; Fusek, M.; Hanuš, V.; Vodička, P.; Trusina, J.

    2015-05-01

    Long-lasting research infrastructures covering the research areas of atmospheric chemistry, meteorology and climatology are of highest importance. The Atmospheric Station (AS) Křešín u Pacova, central Czech Republic, is focused on monitoring of the occurence and long-range transport of greenhouse gases, atmospheric aerosols, selected gaseous atmospheric pollutants and basic meteorological characteristics. The AS and its 250 m tall tower was built according to the recommendations of the Integrated Carbon Observation System (ICOS) and cooperates with numerous national and international projects and monitoring programmes. First measurements conducted at ground started in 2012, vertical profile measurements were added in 2013. A seasonal variability with slightly higher autumn and winter concentrations of elemental and organic carbon was revealed. The suitability of the doubly left-censored Weibull distribution for modelling and interpretation of elemental carbon concentrations, which are often lower than instrumental quantification limits, was verified. Initial data analysis also suggests that in summer, the tower top at 250 m is frequently above the nocturnal surface inversions, thus being decoupled from local influences.

  2. Effects of air temperature on atmospheric CO sub 2 -plant growth relationships

    SciTech Connect

    Allen, S.G.; Idson, S.B.; Kimball, B.A. . Water Conservation Lab.); Baker, J.T.; Allen, L.H. Jr. Florida Univ., Gainesville, FL ); Mauney, J.R.; Radin, J.W. ); Anderson, M.G. )

    1990-04-01

    The carbon dioxide concentration of the earth's atmosphere is increasing and expected to double some time during the middle of the next century. In addition, climate models predict that due to the greenhouse effect'', increased atmospheric CO{sub 2} may cause a warming of the earth's surface of 1.5 to 4.5{degree}C. The separate effects of atmospheric CO{sub 2} concentration and temperature on plant processes has been studied extensively. In general, a doubling of CO{sub 2} results in about a one-third increase in productivity of C{sub 3} plants, although a wide range of responses have been reported. This report reviews research concerned with the CO{sub 2} by temperature interaction effects on plants, with an emphasis on experiments conducted in outdoor, CO{sub 2}-enriched environments. 102 refs., 28 figs., 4 tabs.

  3. MEAD Marine Effects of Atmospheric Deposition

    NASA Astrophysics Data System (ADS)

    Jickells, T.; Spokes, L.

    2003-04-01

    The coastal seas are one of the most valuable resources on the planet but they are threatened by human activity. We rely on the coastal area for mineral resources, waste disposal, fisheries and recreation. In Europe, high population densities and high levels of industrial activity mean that the pressures arising from these activities are particularly acute. One of the main problems concerning coastal seas is the rapid increase in the amounts of nitrogen-based pollutants entering the water. They come from many sources, the most important ones being traffic, industry and agriculture. These pollutants can be used by algae as nutrients. The increasing concentrations of these nutrients have led to excessive growth of algae, some of which are harmful. When algae die and decay, oxygen in the water is used up and the resulting lower levels of oxygen may lead to fish kills. Human activity has probably doubled the amount of chemically and biologically reactive nitrogen present globally. In Europe the increases have been greater than this, leading to real concern over the health of coastal waters. Rivers have, until recently, been thought to be the most important source of reactive nitrogen to the coastal seas but we now know that inputs from the atmosphere are large and can equal, or exceed, those from the rivers. Our initial hypothesis was that atmospheric inputs are important and potentially different in their effect on coastal ecosystems to riverine inputs and hence require different management strategies. However, we had almost no information on the direct effects of atmospheric deposition on marine ecosystems, though clearly such a large external nitrogen input should lead to enhanced phytoplankton growth The aim of this European Union funded MEAD project has been to determine how inputs of nitrogen from the atmosphere affect the chemistry and biology of coastal waters. To try to answer this, we have conducted field experiments in the Kattegat, an area where we know

  4. Volcanic Effects in the Upper Atmosphere

    NASA Astrophysics Data System (ADS)

    Chiti, A.; Zhang, S.; Holt, J. M.

    2013-12-01

    Large volcanic eruptions have a well observed impact on the lower atmosphere and climate. In the past forty years, two eruptions, El Chichon in 1982 and Pinatubo in 1991, released significant amounts of aerosols. The effects of these two volcanos have been studied in the stratosphere (10km - 50km), but not in the upper atmosphere. This project attempted to find traces of the two eruptions at altitudes of 250km to 500km through temperature trend studies of long-term observations of the upper atmosphere. An ion temperature trend model was refined and then used to subtract solar, geomagnetic, annual, semi-annual, and correlated effects from Millstone Hill Incoherent Scatter Radar (ISR) data, which span more than 3 solar cycles starting in 1970s. After subtraction, the ion temperature residuals were studied around the years 1982 and 1991 for anomalous dips. This modeling technique was then applied to the Sondrestrom (1990-) and St. Santin (1966-1987) ISR sites to validate temperature trends and volcanic effects at different locations., Effects of the 1982 El Chichon eruption appeared to exist with a visible ion temperature drop in Millstone Hill and St. Santin measurements. The 1991 Pinatubo eruption was not immediately present until up to 2 years later over Millstone Hill and Sondrestrom, but this result contains large uncertainty due to solar and magnetic activities. Further study is needed to understand the theoretical effects of volcanic activity at those altitudes and gauge the significance of the observed temperature residuals.

  5. Effects of meteorite impacts on the atmospheric evolution of Mars.

    PubMed

    Pham, Lê Binh San; Karatekin, Ozgür; Dehant, Véronique

    2009-01-01

    Early in its history, Mars probably had a denser atmosphere with sufficient greenhouse gases to sustain the presence of stable liquid water at the surface. Impacts by asteroids and comets would have played a significant role in the evolution of the martian atmosphere, not only by causing atmospheric erosion but also by delivering material and volatiles to the planet. We investigate the atmospheric loss and the delivery of volatiles with an analytical model that takes into account the impact simulation results and the flux of impactors given in the literature. The atmospheric loss and the delivery of volatiles are calculated to obtain the atmospheric pressure evolution. Our results suggest that the impacts alone cannot satisfactorily explain the loss of significant atmospheric mass since the Late Noachian (approximately 3.7-4 Ga). A period with intense bombardment of meteorites could have increased the atmospheric loss; but to explain the loss of a speculative massive atmosphere in the Late Noachian, other factors of atmospheric erosion and replenishment also need to be taken into account. PMID:19317624

  6. False advertising in the greenhouse?

    NASA Astrophysics Data System (ADS)

    Banse, K.

    1991-12-01

    Most scientists are convinced of the importance of their own research subjects. Broecker [1991] has deplored the temptation, if not the tendency, to go overboard and exaggerate this importance once funding enters the mind. In particular, he alleges inflated or even false claims by biological (and other) oceanographers regarding the relevance of their research to the "greenhouse effect," caused by the anthropogenic enhancement of the atmospheric CO2 content. He writes [Broecker, 1991, p. 191]: "In my estimation, on any list of subjects requiring intense study with regard to the prediction of the consequences of CO2 buildup in the atmosphere, I would place marine biological cycles near the bottom."

  7. Studying the Physical Basis of Global Warming: Thermal Effects of the Interaction between Radiation and Matter and Greenhouse Effect

    ERIC Educational Resources Information Center

    Besson, Ugo; De Ambrosis, Anna; Mascheretti, Paolo

    2010-01-01

    We present a teaching module dealing with the thermal effects of interaction between radiation and matter, the infrared emission of bodies and the greenhouse effect devoted to university level and teacher education. The module stresses the dependence of the optical properties of materials (transparency, absorptivity and emissivity) on radiation…

  8. Volatile anaesthetics and the atmosphere: atmospheric lifetimes and atmospheric effects of halothane, enflurane, isoflurane, desflurane and sevoflurane.

    PubMed

    Langbein, T; Sonntag, H; Trapp, D; Hoffmann, A; Malms, W; Röth, E P; Mörs, V; Zellner, R

    1999-01-01

    The atmospheric lifetimes of the halogenated anaesthetics halothane, enflurane, isoflurane, desflurane and sevoflurane with respect to reaction with the hydroxyl radical (OH.) and UV photolysis have been determined from observations of OH. reaction kinetics and UV absorption spectra. Rate coefficients for the reaction with OH radicals for all halogenated anaesthetics investigated ranged from 0.44 to 2.7 x 10(-14) cm3 molec-1 s-1. Halothane, enflurane and isoflurane showed distinct UV absorption in the range 200-350 nm. In contrast, no absorption in this wavelength range was detected for desflurane or sevoflurane. The total atmospheric lifetimes, as derived from both OH. reactivity and photolysis, were 4.0-21.4 yr. It has been calculated that up to 20% of anaesthetics enter the stratosphere. As a result of chlorine and bromine content, the ozone depletion potential (ODP) relative to chlorofluorocarbon CFC-11 varies between 0 and 1.56, leading to a contribution to the total ozone depletion in the stratosphere of approximately 1% for halothane and 0.02% for enflurane and isoflurane. Estimates of the greenhouse warming potential (GWP) relative to CFC-12 yield values of 0.02-0.14, resulting in a relative contribution to global warming of all volatile anaesthetics of approximately 0.03%. The stratospheric impact of halothane, isoflurane and enflurane and their influence on ozone depletion is of increasing importance because of decreasing chlorofluorocarbons globally. However, the influence of volatile anaesthetics on greenhouse warming is small.

  9. Effects of land-use change on the greenhouse gas exchange in Western Siberia

    NASA Astrophysics Data System (ADS)

    Fleischer, Elisa; Lokys, Hanna; Paas, Bastian; Tibebe, Degefie; El-Madany, Tarek; Klemm, Otto

    2013-04-01

    The interface between the steppe and the northern forest zone in Western Siberia plays a significant role in the global carbon cycle. Induced by changing climate and by changing socio-economic conditions, agricultural expansion and other fundamental land-use changes are expected in these regions. Such changes will exhibit a strong impact on the budgets of the greenhouse gases (GHGs) carbon dioxide and methane, which are the most important long-lived GHGs in the atmosphere. Nevertheless, hardly any research concerning this topic has been done in these regions. In the framework of the research project SASCHA (Sustainable land management and adaptation strategies to climate change for the Western Siberian corn-belt), which is funded by the BMBF, the turbulent exchange of water vapor, carbon dioxide and methane between the surface and the atmospheric boundary layer, and the surface energy balance were measured over a grassland near the city of Tyumen in the Tyumen Oblast. Therefore, an eddy covariance station was operated from July to September 2012, which was equipped with a Gill R3-50 sonic anemometer (Gill Instruments, UK), a LI-7200 enclosed CO2/H2O analyzer (LI-COR Biosciences, USA), and a LI-7700 open-path methane analyzer (LI-COR Biosciences, USA). The grassland around the station was ploughed in mid-September in order to prepare it for crop production. Before ploughing, the CO2 fluxes showed daily courses, mostly with negative fluxes during daytime due to photosynthesis, and emissions during the night because of respiration. However, after the ploughing process, positive CO2 fluxes throughout the days resulted because photosynthesis was inhibited. During the whole measurement period a positive CO2 balance was found, for the period before ploughing as well as for the period after. The fluxes of water vapor also showed clear diurnal courses with intense evapotranspiration from the surface to the atmosphere during daytime, and a small deposition flux during the

  10. Comparison of radiative and physiological effects of doubled atmospheric CO{sub 2} on climate

    SciTech Connect

    Sellers, P.J.; Collatz, G.J.; Los, S.O.

    1996-03-08

    The physiological response of terrestrial vegetation when directly exposed to an increase in atmospheric carbon dioxide (CO{sub 2}) concentration could result in warming over the continents in addition to that due to the conventional CO{sub 2} {open_quotes}greenhouse effect.{close_quotes} Results from a coupled biosphere-atmosphere model (SiB2-GCM) indicate that, for doubled CO{sub 2} conditions, evapotranspiration will drop and air temperature will increase over the tropical continents, amplifying the changes resulting from atmospheric radiative effects. The range of responses in surface air temperature and terrestrial carbon uptake due to increased CO{sub 2} are projected to be inversely related in the tropics year-round and inversely related during the growing season elsewhere. 21 refs., 4 figs., 2 tabs.

  11. Counteracting the climate effects of volcanic eruptions using short-lived greenhouse gases

    NASA Astrophysics Data System (ADS)

    Fuglestvedt, Jan S.; Samset, Bjørn H.; Shine, Keith P.

    2014-12-01

    A large volcanic eruption might constitute a climate emergency, significantly altering global temperature and precipitation for several years. Major future eruptions will occur, but their size or timing cannot be predicted. We show, for the first time, that it may be possible to counteract these climate effects through deliberate emissions of short-lived greenhouse gases, dampening the abrupt impact of an eruption. We estimate an emission pathway countering a hypothetical eruption 3 times the size of Mount Pinatubo in 1991. We use a global climate model to evaluate global and regional responses to the eruption, with and without counteremissions. We then raise practical, financial, and ethical questions related to such a strategy. Unlike the more commonly discussed geoengineering to mitigate warming from long-lived greenhouse gases, designed emissions to counter temporary cooling would not have the disadvantage of needing to be sustained over long periods. Nevertheless, implementation would still face significant challenges.

  12. [Effects of understory removal on soil greenhouse gas emissions in Carya cathayensis stands].

    PubMed

    Liu, Juan; Chen, Xue-shuang; Wu, Jia-sen; Jiang, Pei-kun; Zhou, Guo-mo; Li, Yong-fu

    2015-03-01

    CO2, N2O and CH4 are important greenhouse gases, and soils in forest ecosystems are their important sources. Carya cathayensis is a unique tree species with seeds used for high-grade dry fruit and oil production. Understory vegetation management plays an important role in soil greenhouse gases emission of Carya cathayensis stands. A one-year in situ experiment was conducted to study the effects of understory removal on soil CO2, N2O and CH4 emissions in C. cathayensis plantation by closed static chamber technique and gas chromatography method. Soil CO2 flux had a similar seasonal trend in the understory removal and preservation treatments, which was high in summer and autumn, and low in winter and spring. N2O emission occurred mainly in summer, while CH4 emission showed no seasonal trend. Understory removal significantly decreased soil CO, emission, increased N2O emission and CH4 uptake, but had no significant effect on soil water soluble organic carbon and microbial biomass carbon. The global warming potential of soil greenhouse gases emitted in the understory removal. treatment was 15.12 t CO2-e . hm-2 a-1, which was significantly lower than that in understory preservation treatment (17.04 t CO2-e . hm-2 . a-1). PMID:26211046

  13. [Effects of understory removal on soil greenhouse gas emissions in Carya cathayensis stands].

    PubMed

    Liu, Juan; Chen, Xue-shuang; Wu, Jia-sen; Jiang, Pei-kun; Zhou, Guo-mo; Li, Yong-fu

    2015-03-01

    CO2, N2O and CH4 are important greenhouse gases, and soils in forest ecosystems are their important sources. Carya cathayensis is a unique tree species with seeds used for high-grade dry fruit and oil production. Understory vegetation management plays an important role in soil greenhouse gases emission of Carya cathayensis stands. A one-year in situ experiment was conducted to study the effects of understory removal on soil CO2, N2O and CH4 emissions in C. cathayensis plantation by closed static chamber technique and gas chromatography method. Soil CO2 flux had a similar seasonal trend in the understory removal and preservation treatments, which was high in summer and autumn, and low in winter and spring. N2O emission occurred mainly in summer, while CH4 emission showed no seasonal trend. Understory removal significantly decreased soil CO, emission, increased N2O emission and CH4 uptake, but had no significant effect on soil water soluble organic carbon and microbial biomass carbon. The global warming potential of soil greenhouse gases emitted in the understory removal. treatment was 15.12 t CO2-e . hm-2 a-1, which was significantly lower than that in understory preservation treatment (17.04 t CO2-e . hm-2 . a-1).

  14. The Role of the Ozone Hole and Elevated Greenhouse Gases as Drivers of Antarctic Sea Ice Extent Increase Via Changes in Atmospheric Circulation

    NASA Astrophysics Data System (ADS)

    Pope, J. O.; Orr, A.; Marshall, G.; Abraham, N. L.

    2015-12-01

    Antarctic sea ice extent has displayed an overall increase across the duration of the 35-year satellite record. However, the cause of this increase is uncertain, with both anthropogenic and natural forcing changes proposed as drivers. Here, we investigate two possible anthropogenic forcings that could influence sea ice extent via changes in the near-surface wind field over the Southern Ocean; (i) ozone depletion and (ii) greenhouse gas increases. We employ an atmosphere-only version of the UK Met Office model, HadGEM3, with prescribed sea surface temperatures and sea ice coupled to the UKCA interactive climate-chemistry model. Starting from a pre-industrial control simulation, two additional simulations were spun off, one investigating the forcing from increased 21st century greenhouse gases and one investigating the forcing from the ozone hole. Based on the work of Holland & Kwok (2012) we analyse the changes in Antarctic circulation, in particular the surface wind properties which have been shown to correlate with sea ice extent. We examine changes in the surface wind field in these two model simulations relative to that in the pre-industrial control simulation, compare them to observed changes during the satellite record, and assess their potential role in driving a response in sea ice extent at both continental and regional scales.

  15. Reservoir Greenhouse Gas Emissions at Russian HPP

    SciTech Connect

    Fedorov, M. P.; Elistratov, V. V.; Maslikov, V. I.; Sidorenko, G. I.; Chusov, A. N.; Atrashenok, V. P.; Molodtsov, D. V.; Savvichev, A. S.; Zinchenko, A. V.

    2015-05-15

    Studies of greenhouse-gas emissions from the surfaces of the world’s reservoirs, which has demonstrated ambiguity of assessments of the effect of reservoirs on greenhouse-gas emissions to the atmosphere, is analyzed. It is recommended that greenhouse- gas emissions from various reservoirs be assessed by the procedure “GHG Measurement Guidelines for Fresh Water Reservoirs” (2010) for the purpose of creating a data base with results of standardized measurements. Aprogram for research into greenhouse-gas emissions is being developed at the St. Petersburg Polytechnic University in conformity with the IHA procedure at the reservoirs impounded by the Sayano-Shushenskaya and Mainskaya HPP operated by the RusHydro Co.

  16. Model evaluation of the radiative and temperature effects of the ozone content changes in the global atmosphere of 1980's

    NASA Technical Reports Server (NTRS)

    Karol, Igor L.; Frolkis, Victor A.

    1994-01-01

    Radiative and temperature effects of the observed ozone and greenhouse gas atmospheric content changes in 1980 - 1990 are evaluated using the two-dimensional energy balance radiative-convective model of the zonally and annually averaged troposphere and stratosphere. Calculated radiative flux changes for standard conditions quantitatively agree with their estimates in WMO/UNEP 1991 review. Model estimates indicate rather small influence of ozone depletion in the lower stratosphere on the greenhouse tropospheric warming rate, being more significant in the non-tropical Southern Hemisphere. The calculated cooling of the lower stratosphere is close to the observed temperature trends there in the last decade.

  17. Effect of reed canary grass cultivation on greenhouse gas emission from peat soil at controlled rewetting

    NASA Astrophysics Data System (ADS)

    Karki, S.; Elsgaard, L.; Lærke, P. E.

    2014-09-01

    Cultivation of bioenergy crops in rewetted peatland (paludiculture) is considered as a possible land use option to mitigate greenhouse gas (GHG) emissions. However, bioenergy crops like reed canary grass (RCG) can have a complex influence on GHG fluxes. Here we determined the effect of RCG cultivation on GHG emission from peatland rewetted to various extents. Mesocosms were manipulated to three different ground water levels (GWL), i.e., 0, -10 and -20 cm below the soil surface in a controlled semi-field facility. Emissions of CO2 (ecosystem respiration, ER), CH4 and N2O from mesocosms with RCG and bare soil were measured at weekly to fortnightly intervals with static chamber techniques for a period of one year. Cultivation of RCG increased both ER and CH4 emissions, but decreased the N2O emissions. The presence of RCG gave rise to 69, 75 and 85% of total ER at -20, -10 and 0 cm GWL, respectively However, this difference was due to decreased soil respiration at the rising GWL as the plant-derived CO2 flux was similar at all three GWL. For methane, 70-95% of the total emission was due to presence of RCG, with the highest contribution at -20 cm GWL. In contrast, cultivation of RCG decreased N2O emission by 33-86% with the major reductions at -10 and -20 cm GWL. In terms of global warming potential, the increase in CH4 emissions due to RCG cultivation was more than off-set by the decrease in N2O emissions at -10 and -20 cm GWL; at 0 cm GWL the CH4 emissions was offset only by 23%. CO2 emissions from ER obviously were the dominant RCG-derived GHG flux, but above-ground biomass yields, and preliminary measurements of gross photosynthetic production, show that ER could be more than balanced due to the uptake of CO2 by RCG. Our results support that RCG cultivation could be a good land use option in terms of mitigating GHG emission from rewetted peatlands, potentially turning these ecosystems into a sink of atmospheric CO2.

  18. Effect of reed canary grass cultivation on greenhouse gas emission from peat soil at controlled rewetting

    NASA Astrophysics Data System (ADS)

    Karki, S.; Elsgaard, L.; Lærke, P. E.

    2015-01-01

    Cultivation of bioenergy crops in rewetted peatland (paludiculture) is considered as a possible land use option to mitigate greenhouse gas (GHG) emissions. However, bioenergy crops like reed canary grass (RCG) can have a complex influence on GHG fluxes. Here we determined the effect of RCG cultivation on GHG emission from peatland rewetted to various extents. Mesocosms were manipulated to three different ground water levels (GWLs), i.e. 0, -10 and -20 cm below the soil surface in a controlled semi-field facility. Emissions of CO2 (ecosystem respiration, ER), CH4 and N2O from mesocosms with RCG and bare soil were measured at weekly to fortnightly intervals with static chamber techniques for a period of 1 year. Cultivation of RCG increased both ER and CH4 emissions, but decreased the N2O emissions. The presence of RCG gave rise to 69, 75 and 85% of total ER at -20, -10 and 0 cm GWL, respectively. However, this difference was due to decreased soil respiration at the rising GWL as the plant-derived CO2 flux was similar at all three GWLs. For methane, 70-95% of the total emission was due to presence of RCG, with the highest contribution at -20 cm GWL. In contrast, cultivation of RCG decreased N2O emission by 33-86% with the major reductions at -10 and -20 cm GWL. In terms of global warming potential, the increase in CH4 emissions due to RCG cultivation was more than offset by the decrease in N2O emissions at -10 and -20 cm GWL; at 0 cm GWL the CH4 emissions was offset only by 23%. CO2 emissions from ER were obviously the dominant RCG-derived GHG flux, but above-ground biomass yields, and preliminary measurements of gross photosynthetic production, showed that ER could be more than balanced due to the photosynthetic uptake of CO2 by RCG. Our results support that RCG cultivation could be a good land use option in terms of mitigating GHG emission from rewetted peatlands, potentially turning these ecosystems into a sink of atmospheric CO2.

  19. Interannual Atmospheric Oscillations and Their Gravitational Effects

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.; Au, A. Y.

    2000-01-01

    Past studies have examined the effects of the interannual atmospheric oscillations (IAO), or often called teleconnection patterns, on the Earth's rotation, such as El Nino/Southern Oscillation (ENSO), the quasi-biennial oscillation, and to a lesser extent the North Atlantic Oscillation (NAO). The present study focuses on IAO's effects on the gravitational field and geocenter; the purpose is to be able to identify and isolate the contributions of each prominent IAO in relation to the total contribution of the atmosphere, in terms of their magnitudes, their geographical patterns, and their interannual time history. We use the 40-year NCEP reanalysis of the monthly, global atmospheric surface pressure field as our basic data set. The method we apply to isolate the IAOs is the empirical orthogonal function (EOF) decomposition which is widely used in meteorological investigations. We do the EOF analysis first on IAOs' seasonal signals (by "collapsing" the 40-year series into 12 mean-months for each grid point) and obtain estimates for their respective contributions. Then we remove these seasonal signals from the data to focus on the (broad-band) interannual EOFs. We examine ENSO, NAO, North Pacific Oscillation, and other less prominent IAOs that can be identified from our data set, and compute their respective contributions to the variation of global gravitational field and geocenter motion. Finally, we compare the results with the available observational data, and discuss the implications w.r.t. the upcoming space missions such as GRACE.

  20. Compensation for atmospheric effects in LANDSAT data

    NASA Technical Reports Server (NTRS)

    Lambeck, P. F.; Potter, J. F. (Principal Investigator)

    1979-01-01

    Preprocessing algorithms were developed to remove or reduce the variations in multispectral data caused by variations in Sun angle and by changes in the atmospheric aerosol and water vapor levels. The two most significant algorithms developed by using mathematical models to define interrelations between the required multiplicative and additive correction factors so that just a few statistical characteristics of a LANDSAT distribution model would be sufficient to drive the mathematical model and to calculate the preprocessing corrections are examined. These are the atmospheric correction (ATCOR) computer program and the XSTAR haze correction algorithm. Neither the ATCOR nor the XSTAR algorithm provides an explicit compensation for the effects of changing LANDSAT view angle. Development efforts are underway to address this aspect of the preprocessing problem.

  1. Effects of land use intensity on the full greenhouse gas balance in an Atlantic peat bog

    NASA Astrophysics Data System (ADS)

    Beetz, S.; Liebersbach, H.; Glatzel, S.; Jurasinski, G.; Buczko, U.; Höper, H.

    2012-06-01

    The assessment of emission factors for many peatlands is difficult, and reliable data on the exchange of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) between soil and atmosphere of these areas is particularly scarce. Reasons for this are the multitude of soil and land use combinations that control greenhouse gas exchange and the high effort associated with data acquisition. We investigated the greenhouse gas exchange of a peat bog restoration sequence over a period of 2 yr (July 2007-June 2009) in an Atlantic raised bog in Northwest Germany. We set up three sites representing different land use intensities: intensive grassland (mineral fertilizer, cattle manure and 4-5 cuts per year); extensive grassland (no fertilizer or manure, maximal 1 cutting per year); near-natural peat bog (almost no anthropogenic influence). We obtained seasonal and annual estimates of greenhouse gas exchange based on closed chamber measurements. CH4 and N2O fluxes were recorded bi-weekly, CO2 NEE determinations were carried out 3-4 weekly. To get annual sums the CH4 and N2O fluxes were interpolated linearly while NEE was modelled. The intensive grassland site emitted 548 ± 169 g CO2-C m-2 in the first and 817 ± 140 g CO2-C m-2 in the second year. The extensive grassland site showed a slight uptake in the first year (-148 ± 143 g CO2-C m-2), and a small emission of 88 ± 146 g CO2-C m-2 in the second year. In contrast to these agriculturally used sites, the near-natural site took up CO2-C in both years (-8 ± 68 g CO2-C m-2 and -127 ± 53 g CO2-C m-2). Under consideration of N2O and CH4 exchange, the total average greenhouse warming potential (GWP) for 2008 amounts to 441 ± 157 g m-2, 14 ± 152 g m-2 and 31 ± 68 g m-2 CO2-C-equivalent for the intensive grassland, the extensive grassland and the near-natural site, respectively. Despite inter-annual variability, rewetting contributes considerably to mitigating GHG emission from formerly drained peatlands. Already

  2. FETC Programs for Reducing Greenhouse Gas Emissions

    SciTech Connect

    Ruether, J.A.

    1998-02-01

    Mark Twain once quipped that everyone talks about the weather but no one does anything about it. With interest in global climate change on the rise, researchers in the fossil-energy sector are feeling the heat to provide new technology to permit continued use of fossil fuels but with reduced emissions of so-called `greenhouse gases.` Three important greenhouse gases, carbon dioxide, methane, and nitrous oxide, are released to the atmosphere in the course of recovering and combusting fossil fuels. Their importance for trapping radiation, called forcing, is in the order given. In this report, we briefly review how greenhouse gases cause forcing and why this has a warming effect on the Earth`s atmosphere. Then we discuss programs underway at FETC that are aimed at reducing emissions of methane and carbon dioxide.

  3. [Effects of urea and coated urea on harmful gases concentrations in plastic greenhouse].

    PubMed

    Zhou, Xihong; Zeng, Qingru; Mao, Xiaoyun; Zhang, Litian; Liao, Bohan; Tie, Baiqing; Liao, Zongwen

    2006-09-01

    With simulation test and plastic greenhouse experiment, this paper studied the effects of urea and minerals- coated urea on the soil pH and harmful gases concentrations in plastic greenhouse. The results showed that under simulated condition, the application of these'two N fertilizers led to an initial increase of soil pH, which reached the maximum (an increment of > 50%) within the first week and dropped to the initial level by the end of the fifth week. In plastic greenhouse, applying urea and coated urea resulted in the increase of NH3, NO2 and O3 concentrations. The daily volatilization amount of NH3 and NO2 was higher in urea treatment than in coated urea treatment, and the highest value in urea treatment was 42.36 microg x m(-3) x d(-1) for NH3, 41.95 microg x m(-3) x d(-1) for NO2, and 86.00 microg x m(-3) x d(-1) for O3. The volatilization intensity of NH3 and NO2 was influenced by temperature and sunlight, while the O3 concentration was influenced by sunlight. PMID:17147165

  4. Effects of nitrogen fertilization on the acidity and salinity of greenhouse soils.

    PubMed

    Han, Jiangpei; Shi, Jiachun; Zeng, Lingzao; Xu, Jianming; Wu, Laosheng

    2015-02-01

    A greenhouse pot experiment was conducted to study the effects of conventional nitrogen fertilization on soil acidity and salinity. Three N rates (urea; N0, 0 kg N ha(-1); N1, 600 kg N ha(-1); and N2, 1,200 kg N ha(-1)) were applied in five soils with different greenhouse cultivation years to evaluate soil acidification and salinization rate induced by nitrogen fertilizer in lettuce production. Both soil acidity and salinity increased significantly as N input increased after one season, with pH decrease ranging from 0.45 to 1.06 units and electrolytic conductivity increase from 0.24 to 0.68 mS cm(-1). An estimated 0.92 mol H(+) was produced for 1 mol (NO2 (-) + NO3 (-))-N accumulation in soil. The proton loading from nitrification was 14.3-27.3 and 12.1-58.2 kmol H(+) ha(-1) in the center of Shandong Province under N1 and N2 rate, respectively. However, the proton loading from the uptake of excess bases by lettuces was only 0.3-4.5 % of that from nitrification. Moreover, the release of protons induced the direct release of base cations and accelerated soil salinization. The increase of soil acidity and salinity was attributed to the nitrification of excess N fertilizer. Compared to the proton loading by lettuce, nitrification contributed more to soil acidification in greenhouse soils. PMID:25226832

  5. Effects of nitrogen fertilization on the acidity and salinity of greenhouse soils.

    PubMed

    Han, Jiangpei; Shi, Jiachun; Zeng, Lingzao; Xu, Jianming; Wu, Laosheng

    2015-02-01

    A greenhouse pot experiment was conducted to study the effects of conventional nitrogen fertilization on soil acidity and salinity. Three N rates (urea; N0, 0 kg N ha(-1); N1, 600 kg N ha(-1); and N2, 1,200 kg N ha(-1)) were applied in five soils with different greenhouse cultivation years to evaluate soil acidification and salinization rate induced by nitrogen fertilizer in lettuce production. Both soil acidity and salinity increased significantly as N input increased after one season, with pH decrease ranging from 0.45 to 1.06 units and electrolytic conductivity increase from 0.24 to 0.68 mS cm(-1). An estimated 0.92 mol H(+) was produced for 1 mol (NO2 (-) + NO3 (-))-N accumulation in soil. The proton loading from nitrification was 14.3-27.3 and 12.1-58.2 kmol H(+) ha(-1) in the center of Shandong Province under N1 and N2 rate, respectively. However, the proton loading from the uptake of excess bases by lettuces was only 0.3-4.5 % of that from nitrification. Moreover, the release of protons induced the direct release of base cations and accelerated soil salinization. The increase of soil acidity and salinity was attributed to the nitrification of excess N fertilizer. Compared to the proton loading by lettuce, nitrification contributed more to soil acidification in greenhouse soils.

  6. [Effects of urea and coated urea on harmful gases concentrations in plastic greenhouse].

    PubMed

    Zhou, Xihong; Zeng, Qingru; Mao, Xiaoyun; Zhang, Litian; Liao, Bohan; Tie, Baiqing; Liao, Zongwen

    2006-09-01

    With simulation test and plastic greenhouse experiment, this paper studied the effects of urea and minerals- coated urea on the soil pH and harmful gases concentrations in plastic greenhouse. The results showed that under simulated condition, the application of these'two N fertilizers led to an initial increase of soil pH, which reached the maximum (an increment of > 50%) within the first week and dropped to the initial level by the end of the fifth week. In plastic greenhouse, applying urea and coated urea resulted in the increase of NH3, NO2 and O3 concentrations. The daily volatilization amount of NH3 and NO2 was higher in urea treatment than in coated urea treatment, and the highest value in urea treatment was 42.36 microg x m(-3) x d(-1) for NH3, 41.95 microg x m(-3) x d(-1) for NO2, and 86.00 microg x m(-3) x d(-1) for O3. The volatilization intensity of NH3 and NO2 was influenced by temperature and sunlight, while the O3 concentration was influenced by sunlight.

  7. [Effects of transplanting date and density on appearance quality of greenhouse single-flower cut chrysanthemum].

    PubMed

    Li, Xiang-mao; Dai, Jian-feng; Luo, Wei-hong; Chen, Fa-di; Gu, Jun-jie; Lu, Jin-hua

    2007-05-01

    Transplanting date and density are the important factors affecting the appearance quality of chrysanthemum. The study on the greenhouse single-flower cut chrysanthemum (Chrysanthemum morifolium cv. Shenma) showed that within the ranges of test transplanting date and density, the plant height and neck length increased, while the leaf number per plant, stem diameter, plant fresh mass and flower diameter decreased with the delay of transplanting date and the increase of transplanting density. No effect of transplanting density was observed on plant height. For the production of single-flower cut chrysanthemum in non-heated greenhouse in Shanghai, the optimal transplanting date and density to achieve the top rank of quality (rank A) were the middle ten days of August and 64 plants x m(-2), and those to achieve the second rank of quality (rank B) were from mid August to early September and 72-80 plants x m(-2), respectively. The results obtained in this study offered references in establishing the prediction model of greenhouse single-flower cut chrysanthemum appearance quality based on light, temperature, and transplanting date and density.

  8. A Green Planet versus a Desert World: Estimating the Effect of Vegetation Extremes on the Atmosphere.

    NASA Astrophysics Data System (ADS)

    Fraedrich, Klaus; Kleidon, Axel; Lunkeit, Frank

    1999-10-01

    The effect of vegetation extremes on the general circulation is estimated by two atmospheric GCM simulations using global desert and forest boundary conditions over land. The difference between the climates of a `green planet' and a `desert world' is dominated by the changes of the hydrological cycle, which is intensified substantially. Enhanced evapotranspiration over land reduces the near-surface temperatures; enhanced precipitation leads to a warmer mid- and upper troposphere extending from the subtropics (induced by ITCZ, monsoon, and Hadley cell dynamics) to the midlatitudes (over the cyclogenesis area of Northern Hemisphere storm tracks). These regional changes of the surface water and energy balances, and of the atmospheric circulation, have potential impact on the ocean and the atmospheric greenhouse.

  9. Ozone, Climate, and Global Atmospheric Change.

    ERIC Educational Resources Information Center

    Levine, Joel S.

    1992-01-01

    Presents an overview of global atmospheric problems relating to ozone depletion and global warming. Provides background information on the composition of the earth's atmosphere and origin of atmospheric ozone. Describes causes, effects, and evidence of ozone depletion and the greenhouse effect. A vignette provides a summary of a 1991 assessment of…

  10. Extratropical influence of upper tropospheric water vapor on Greenhouse warming

    NASA Technical Reports Server (NTRS)

    Liu, W. Timothy; Hu, Hua

    1997-01-01

    Despite its small quantity, the importance of upper tropospheric water vapor is its ability to trap the longwave radiation emitted from the Earth's surface, namely the greenhouse effect. The greenhouse effect is defined quantitatively as the difference between the longwave flux emitted by the Earth's surface and the outgoing longwave radiation (OLR) flux emitted from the top of the atmosphere (TOA) (Raval and Ramanathan 1989).

  11. Anthropogenic effects on the subtropical jet in the Southern Hemisphere: aerosols versus long-lived greenhouse gases

    NASA Astrophysics Data System (ADS)

    Rotstayn, L. D.; Collier, M. A.; Jeffrey, S. J.; Kidston, J.; Syktus, J. I.; Wong, K. K.

    2013-03-01

    We use single-forcing historical simulations with a coupled atmosphere-ocean global climate model to compare the effects of anthropogenic aerosols (AAs) and increasing long-lived greenhouse gases (LLGHGs) on simulated winter circulation in the Southern Hemisphere (SH). Our primary focus is on the subtropical jet, which is an important source of baroclinic instability, especially in the Australasian region, where the speed of the jet is largest. For the period 1950 to 2005, our simulations suggest that AAs weaken the jet, whereas increasing LLGHGs strengthen the jet. The different responses are explained in terms of thermal wind balance: increasing LLGHGs preferentially warm the tropical mid-troposphere and upper troposphere, whereas AAs have a similar effect of opposite sign. In the mid-troposphere, the warming (cooling) effect of LLGHGs (AAs) is maximal between 20S and 30S; this coincides with the descending branch of the Hadley circulation, which may advect temperature changes from the tropical upper troposphere to the subtropics of the SH. It follows that LLGHGs (AAs) increase (decrease) the mid-tropospheric temperature gradient between low latitudes and the SH mid-latitudes. The strongest effects are seen at longitudes where the southward branches of the Hadley cell in the upper troposphere are strongest, notably at those that correspond to Asia and the western Pacific warm pool.

  12. Effects of organic matter amendments on net primary productivity and greenhouse gas emissions in annual grasslands.

    PubMed

    Ryals, Rebecca; Silver, Whendee L

    2013-01-01

    Most of the world's grasslands are managed for livestock production. A critical component of the long-term sustainability and profitability of rangelands (e.g., grazed grassland ecosystems) is the maintenance of plant production. Amending grassland soils with organic waste has been proposed as a means to increase net primary productivity (NPP) and ecosystem carbon (C) storage, while mitigating greenhouse gas emissions from waste management. Few studies have evaluated the effects of amendments on the C balance and greenhouse gas dynamics of grasslands. We used field manipulations replicated within and across two rangelands (a valley grassland and a coastal grassland) to determine the effects of a single application of composted green waste amendments on NPP and greenhouse gas emissions over three years. Amendments elevated total soil respiration by 18% +/- 4% at both sites but had no effect on nitrous oxide or methane emissions. Carbon losses were significantly offset by greater and sustained plant production. Amendments stimulated both above- and belowground NPP by 2.1 +/- 0.8 Mg C/ha to 4.7 +/- 0.7 Mg C/ha (mean +/- SE) over the three-year study period. Net ecosystem C storage increased by 25-70% without including the direct addition of compost C. The estimated magnitude of net ecosystem C storage was sensitive to estimates of heterotrophic soil respiration but was greater than controls in five out of six fields that received amendments. The sixth plot was the only one that exhibited lower soil moisture than the control, suggesting an important role of water limitation in these seasonally dry ecosystems. Treatment effects persisted over the course of the study, which were likely derived from increased water-holding capacity in most plots, and slow-release fertilization from compost decomposition. We conclude that a single application of composted organic matter can significantly increase grassland C storage, and that effects of a single application are likely to

  13. Effects of organic matter amendments on net primary productivity and greenhouse gas emissions in annual grasslands.

    PubMed

    Ryals, Rebecca; Silver, Whendee L

    2013-01-01

    Most of the world's grasslands are managed for livestock production. A critical component of the long-term sustainability and profitability of rangelands (e.g., grazed grassland ecosystems) is the maintenance of plant production. Amending grassland soils with organic waste has been proposed as a means to increase net primary productivity (NPP) and ecosystem carbon (C) storage, while mitigating greenhouse gas emissions from waste management. Few studies have evaluated the effects of amendments on the C balance and greenhouse gas dynamics of grasslands. We used field manipulations replicated within and across two rangelands (a valley grassland and a coastal grassland) to determine the effects of a single application of composted green waste amendments on NPP and greenhouse gas emissions over three years. Amendments elevated total soil respiration by 18% +/- 4% at both sites but had no effect on nitrous oxide or methane emissions. Carbon losses were significantly offset by greater and sustained plant production. Amendments stimulated both above- and belowground NPP by 2.1 +/- 0.8 Mg C/ha to 4.7 +/- 0.7 Mg C/ha (mean +/- SE) over the three-year study period. Net ecosystem C storage increased by 25-70% without including the direct addition of compost C. The estimated magnitude of net ecosystem C storage was sensitive to estimates of heterotrophic soil respiration but was greater than controls in five out of six fields that received amendments. The sixth plot was the only one that exhibited lower soil moisture than the control, suggesting an important role of water limitation in these seasonally dry ecosystems. Treatment effects persisted over the course of the study, which were likely derived from increased water-holding capacity in most plots, and slow-release fertilization from compost decomposition. We conclude that a single application of composted organic matter can significantly increase grassland C storage, and that effects of a single application are likely to

  14. Effects of Nitrogen Fertilization of Boreal Forest Land on Greenhouse Gas Flows

    NASA Astrophysics Data System (ADS)

    Gustavsson, L.; Sathre, R. C.

    2011-12-01

    Forest growth on mineral soils in boreal regions is often limited by a low availability of nitrogen (N), and fertilization has shown particular promise in increasing yields in productive boreal forests. In this study we analyze the greenhouse gas (GHG) implications of increasing forest biomass production through N fertilization and using the increased production for bioenergy and biomaterials in place of non-renewable fuels and materials. We begin with a stand-level analysis of the radiative forcing implications of forest fertilization and biomass substitution, with explicit consideration of the temporal patterns of GHG emissions to and removals from the atmosphere. We model and compare the production and use of biomass from a hectare of fertilized and non-fertilized forest land in northern Sweden. We calculate the annual net emissions of CO2, N2O and CH4 for each system, over a 225-year period with 1-year time steps. We calculate the annual atmospheric concentration decay of each of these emissions, and calculate the resulting annual changes in instantaneous and cumulative radiative forcing. We find that forest fertilization can significantly increase biomass production, which increases the potential for material and energy substitution. The average carbon stock in tree biomass, forest soils and wood products all increase when fertilization is used. The additional GHG emissions due to fertilizer production and application are small compared to increases in carbon stock and substitution benefits. By the end of the 225-year simulation period, the cumulative radiative forcing reduction of the fertilized stand is over twice that of the non-fertilized stand. We then consider a steady-state landscape-level scenario where 10% of Swedish forest land is fertilized. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net GHG benefits

  15. An example of fingerprint detection of greenhouse climate changes

    SciTech Connect

    Karoly, D.J.; Cohen, J.A.; Meehl, G.A.

    1994-07-01

    As an example of the technique of fingerprint detection of greenhouse climate change, a multivariate signal or fingerprint of the enhanced greenhouse effect is defined using the zonal mean atmospheric temperature change as a function of height and latitude between equilibrium climate model simulations with control and doubled CO{sub 2} concentrations. This signal is compared with observed atmospheric temperature variations over the period 1963 to 1988 from radiosonde-based global analyses. There is a signiificant increase of this greenhouse signal in the observational data over this period. These results must be treated with caution. Upper air data are available for a short period only, possibly, to be able to resolve any real greenhouse climate change. The greenhouse fingerprint used in this study may not be unique to the enhanced greenhouse effect and may be due to other forcing mechanisms. However, it is shown that the patterns of atmospheric temperature change associated with uniform global increases of sea surface temperature, with El Nino-Southern Oscillation events and with decreases of stratospheric ozone concentrations individually are different from the greenhouse fingerprint used here. 30 refs., 6 figs., 2 tabs.

  16. Global Change Could Amplify Fire Effects on Soil Greenhouse Gas Emissions

    PubMed Central

    Niboyet, Audrey; Brown, Jamie R.; Dijkstra, Paul; Blankinship, Joseph C.; Leadley, Paul W.; Le Roux, Xavier; Barthes, Laure; Barnard, Romain L.; Field, Christopher B.; Hungate, Bruce A.

    2011-01-01

    Background Little is known about the combined impacts of global environmental changes and ecological disturbances on ecosystem functioning, even though such combined impacts might play critical roles in shaping ecosystem processes that can in turn feed back to climate change, such as soil emissions of greenhouse gases. Methodology/Principal Findings We took advantage of an accidental, low-severity wildfire that burned part of a long-term global change experiment to investigate the interactive effects of a fire disturbance and increases in CO2 concentration, precipitation and nitrogen supply on soil nitrous oxide (N2O) emissions in a grassland ecosystem. We examined the responses of soil N2O emissions, as well as the responses of the two main microbial processes contributing to soil N2O production – nitrification and denitrification – and of their main drivers. We show that the fire disturbance greatly increased soil N2O emissions over a three-year period, and that elevated CO2 and enhanced nitrogen supply amplified fire effects on soil N2O emissions: emissions increased by a factor of two with fire alone and by a factor of six under the combined influence of fire, elevated CO2 and nitrogen. We also provide evidence that this response was caused by increased microbial denitrification, resulting from increased soil moisture and soil carbon and nitrogen availability in the burned and fertilized plots. Conclusions/Significance Our results indicate that the combined effects of fire and global environmental changes can exceed their effects in isolation, thereby creating unexpected feedbacks to soil greenhouse gas emissions. These findings highlight the need to further explore the impacts of ecological disturbances on ecosystem functioning in the context of global change if we wish to be able to model future soil greenhouse gas emissions with greater confidence. PMID:21687708

  17. Effect of atmospherics on beamforming accuracy

    NASA Technical Reports Server (NTRS)

    Alexander, Richard M.

    1990-01-01

    Two mathematical representations of noise due to atmospheric turbulence are presented. These representations are derived and used in computer simulations of the Bartlett Estimate implementation of beamforming. Beamforming is an array processing technique employing an array of acoustic sensors used to determine the bearing of an acoustic source. Atmospheric wind conditions introduce noise into the beamformer output. Consequently, the accuracy of the process is degraded and the bearing of the acoustic source is falsely indicated or impossible to determine. The two representations of noise presented here are intended to quantify the effects of mean wind passing over the array of sensors and to correct for these effects. The first noise model is an idealized case. The effect of the mean wind is incorporated as a change in the propagation velocity of the acoustic wave. This yields an effective phase shift applied to each term of the spatial correlation matrix in the Bartlett Estimate. The resultant error caused by this model can be corrected in closed form in the beamforming algorithm. The second noise model acts to change the true direction of propagation at the beginning of the beamforming process. A closed form correction for this model is not available. Efforts to derive effective means to reduce the contributions of the noise have not been successful. In either case, the maximum error introduced by the wind is a beam shift of approximately three degrees. That is, the bearing of the acoustic source is indicated at a point a few degrees from the true bearing location. These effects are not quite as pronounced as those seen in experimental results. Sidelobes are false indications of acoustic sources in the beamformer output away from the true bearing angle. The sidelobes that are observed in experimental results are not caused by these noise models. The effects of mean wind passing over the sensor array as modeled here do not alter the beamformer output as

  18. High chance that current atmospheric greenhouse concentrations commit to warmings greater than 1.5 °C over land.

    PubMed

    Huntingford, Chris; Mercado, Lina M

    2016-01-01

    The recent Paris UNFCCC climate meeting discussed the possibility of limiting global warming to 2 °C since pre-industrial times, or possibly even 1.5 °C, which would require major future emissions reductions. However, even if climate is stabilised at current atmospheric greenhouse gas (GHG) concentrations, those warming targets would almost certainly be surpassed in the context of mean temperature increases over land only. The reason for this is two-fold. First, current transient warming lags significantly below equilibrium or "committed" warming. Second, almost all climate models indicate warming rates over land are much higher than those for the oceans. We demonstrate this potential for high eventual temperatures over land, even for contemporary GHG levels, using a large set of climate models and for which climate sensitivities are known. Such additional land warming has implications for impacts on terrestrial ecosystems and human well-being. This suggests that even if massive and near-immediate emissions reductions occur such that atmospheric GHGs increase further by only small amounts, careful planning is needed by society to prepare for higher land temperatures in an eventual equilibrium climatic state. PMID:27461560

  19. High chance that current atmospheric greenhouse concentrations commit to warmings greater than 1.5 °C over land

    PubMed Central

    Huntingford, Chris; Mercado, Lina M.

    2016-01-01

    The recent Paris UNFCCC climate meeting discussed the possibility of limiting global warming to 2 °C since pre-industrial times, or possibly even 1.5 °C, which would require major future emissions reductions. However, even if climate is stabilised at current atmospheric greenhouse gas (GHG) concentrations, those warming targets would almost certainly be surpassed in the context of mean temperature increases over land only. The reason for this is two-fold. First, current transient warming lags significantly below equilibrium or “committed” warming. Second, almost all climate models indicate warming rates over land are much higher than those for the oceans. We demonstrate this potential for high eventual temperatures over land, even for contemporary GHG levels, using a large set of climate models and for which climate sensitivities are known. Such additional land warming has implications for impacts on terrestrial ecosystems and human well-being. This suggests that even if massive and near-immediate emissions reductions occur such that atmospheric GHGs increase further by only small amounts, careful planning is needed by society to prepare for higher land temperatures in an eventual equilibrium climatic state. PMID:27461560

  20. High chance that current atmospheric greenhouse concentrations commit to warmings greater than 1.5 °C over land

    NASA Astrophysics Data System (ADS)

    Huntingford, Chris; Mercado, Lina M.

    2016-07-01

    The recent Paris UNFCCC climate meeting discussed the possibility of limiting global warming to 2 °C since pre-industrial times, or possibly even 1.5 °C, which would require major future emissions reductions. However, even if climate is stabilised at current atmospheric greenhouse gas (GHG) concentrations, those warming targets would almost certainly be surpassed in the context of mean temperature increases over land only. The reason for this is two-fold. First, current transient warming lags significantly below equilibrium or “committed” warming. Second, almost all climate models indicate warming rates over land are much higher than those for the oceans. We demonstrate this potential for high eventual temperatures over land, even for contemporary GHG levels, using a large set of climate models and for which climate sensitivities are known. Such additional land warming has implications for impacts on terrestrial ecosystems and human well-being. This suggests that even if massive and near-immediate emissions reductions occur such that atmospheric GHGs increase further by only small amounts, careful planning is needed by society to prepare for higher land temperatures in an eventual equilibrium climatic state.

  1. The greenhouse gambit

    SciTech Connect

    Dogan, D. . Environmental Information Service)

    1992-01-01

    While forecasts of the economic costs and benefits of ameliorating global warming remain speculative, so, too, are the climate change projections that gird the debate. The consensus among most of the scientific community is that a doubling of atmospheric carbon dioxide is likely to raise the mean global temperature of the Earth 3 to 8 degrees Fahrenheit by 2050. To put this forecast in some perspective, the planet was about 10 degrees cooler during the last Great Ice Age and about 10 degrees warmer dozing the Age of the Dinsosaurs. Accordingly, the warming could bring about dramatic changes in climate. But a prudent investor must be careful not to invest too much in pat assumptions about the greenhouse effect. The climate may have many surprises in store. Indeed, it has surprised climate forecasters already by not warming nearly as fast as their general circulation models have suggested it would. This book examines four industries with the most at stake in the greenhouse debate: agriculture, forest products, automobiles and electric power. All of these industries essentially face two choices: Act now to blunt the possible momentum of climate change, or wait and see if the basic forecast is correct, accommodating any change as it occurs. These choices involve a trade-off between further information-gathering to ensure a proper course of action and implementing a strategy, quickly to its intended effect. Such a trade-off is the essence of risk, the stuff of investing. For the purposes of this book, it defines the greenhouse gambit.''

  2. Engineering concepts for inflatable Mars surface greenhouses.

    PubMed

    Hublitz, I; Henninger, D L; Drake, B G; Eckart, P

    2004-01-01

    A major challenge of designing a bioregenerative life support system for Mars is the reduction of the mass, volume, power, thermal and crew-time requirements. Structural mass of the greenhouse could be saved by operating the greenhouse at low atmospheric pressure. This paper investigates the feasibility of this concept. The method of equivalent system mass is used to compare greenhouses operated at high atmospheric pressure to greenhouses operated at low pressure for three different lighting methods: natural, artificial and hybrid lighting.

  3. Sterilization effects of atmospheric cold plasma brush

    SciTech Connect

    Yu, Q.S.; Huang, C.; Hsieh, F.-H.; Huff, H.; Duan Yixiang

    2006-01-02

    This study investigated the sterilization effects of a brush-shaped plasma created at one atmospheric pressure. A population of 1.0x10{sup 4}-1.0x10{sup 5} Escherichia coli or Micrococcus luteus bacteria was seeded in filter paper media and then subjected to Ar and/or Ar+O{sub 2} plasmas. A complete kill of the Micrococcus luteus required about 3 min argon plasma exposures. With oxygen addition into the argon plasma gas streams, a complete kill of the bacteria needed only less than 1 min plasma exposure for Micrococcus luteus and about 2 min exposure for Escherichia coli. The plasma treatment effects on the different bacteria cell structures were examined using scanning electron microscopy.

  4. Effects of different regulatory methods on improvement of greenhouse saline soils, tomato quality, and yield.

    PubMed

    Maomao, Hou; Xiaohou, Shao; Yaming, Zhai

    2014-01-01

    To identify effective regulatory methods scheduling with the compromise between the soil desalination and the improvement of tomato quality and yield, a 3-year field experiment was conducted to evaluate and compare the effect of straw mulching and soil structure conditioner and water-retaining agent on greenhouse saline soils, tomato quality, and yield. A higher salt removing rate of 80.72% in plough layer with straw mulching was obtained based on the observation of salt mass fraction in 0 ~ 20 cm soil layer before and after the experiment. Salts were also found to move gradually to the deeper soil layer with time. Straw mulching enhanced the content of soil organic matter significantly and was conductive to reserve soil available N, P, and K, while available P and K in soils of plough layer with soil structure conditioner decreased obviously; thus a greater usage of P fertilizer and K fertilizer was needed when applying soil structure conditioner. Considering the evaluation indexes including tomato quality, yield, and desalination effects of different regulatory methods, straw mulching was recommended as the main regulatory method to improve greenhouse saline soils in south China. Soil structure conditioner was the suboptimal method, which could be applied in concert with straw mulching.

  5. Effects of different regulatory methods on improvement of greenhouse saline soils, tomato quality, and yield.

    PubMed

    Maomao, Hou; Xiaohou, Shao; Yaming, Zhai

    2014-01-01

    To identify effective regulatory methods scheduling with the compromise between the soil desalination and the improvement of tomato quality and yield, a 3-year field experiment was conducted to evaluate and compare the effect of straw mulching and soil structure conditioner and water-retaining agent on greenhouse saline soils, tomato quality, and yield. A higher salt removing rate of 80.72% in plough layer with straw mulching was obtained based on the observation of salt mass fraction in 0 ~ 20 cm soil layer before and after the experiment. Salts were also found to move gradually to the deeper soil layer with time. Straw mulching enhanced the content of soil organic matter significantly and was conductive to reserve soil available N, P, and K, while available P and K in soils of plough layer with soil structure conditioner decreased obviously; thus a greater usage of P fertilizer and K fertilizer was needed when applying soil structure conditioner. Considering the evaluation indexes including tomato quality, yield, and desalination effects of different regulatory methods, straw mulching was recommended as the main regulatory method to improve greenhouse saline soils in south China. Soil structure conditioner was the suboptimal method, which could be applied in concert with straw mulching. PMID:25147873

  6. Effects of Different Regulatory Methods on Improvement of Greenhouse Saline Soils, Tomato Quality, and Yield

    PubMed Central

    Xiaohou, Shao; Yaming, Zhai

    2014-01-01

    To identify effective regulatory methods scheduling with the compromise between the soil desalination and the improvement of tomato quality and yield, a 3-year field experiment was conducted to evaluate and compare the effect of straw mulching and soil structure conditioner and water-retaining agent on greenhouse saline soils, tomato quality, and yield. A higher salt removing rate of 80.72% in plough layer with straw mulching was obtained based on the observation of salt mass fraction in 0~20 cm soil layer before and after the experiment. Salts were also found to move gradually to the deeper soil layer with time. Straw mulching enhanced the content of soil organic matter significantly and was conductive to reserve soil available N, P, and K, while available P and K in soils of plough layer with soil structure conditioner decreased obviously; thus a greater usage of P fertilizer and K fertilizer was needed when applying soil structure conditioner. Considering the evaluation indexes including tomato quality, yield, and desalination effects of different regulatory methods, straw mulching was recommended as the main regulatory method to improve greenhouse saline soils in south China. Soil structure conditioner was the suboptimal method, which could be applied in concert with straw mulching. PMID:25147873

  7. The greenhouse of Titan.

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1973-01-01

    Analysis of non-gray radiative equilibrium and gray convective equilibrium on Titan suggests that a massive molecular-hydrogen greenhouse effect may be responsible for the disagreement between the observed IR temperatures and the equilibrium temperature of an atmosphereless Titan. Calculations of convection indicate a probable minimum optical depth of 14 which corresponds to a molecular hydrogen shell of substantial thickness with total pressures of about 0.1 bar. It is suggested that there is an equilibrium between outgassing and blow-off on the one hand and accretion from the protons trapped in a hypothetical Saturnian magnetic field on the other, in the present atmosphere of Titan. It is believed that an outgassing equivalent to the volatilization of a few kilometers of subsurface ice is required to maintain the present blow-off rate without compensation for all geological time. The presence of an extensive hydrogen corona around Titan is postulated, with surface temperatures up to 200 K.

  8. Methane Emissions from the Arctic OCean to the Atmosphere: Present and Future Climate Effects (MOCA)

    NASA Astrophysics Data System (ADS)

    Durant, A. J.; Lund-Myhre, C.; Mienert, J.; Myhre, G.; Stohl, A.; Isaksen, I.; Pisso, I.; Greinert, J.; Nisbet, E.; Paris, J.; Pyle, J. A.; Belan, B. D.; Ruppel, C. D.; Schlager, H.; Spahni, R.

    2013-12-01

    Methane hydrates (MH) in ocean seabed sediments are a potential source of methane (CH4) to the atmosphere, where CH4 has potential to act as a powerful greenhouse gas. Recent scientific studies show diversity in the flux of CH4 that actually reaches the atmosphere. MH are potentially susceptible to ocean warming, which could trigger a positive feedback resulting in rapid climate warming. MOCA is a new project funded by the Norwegian Research Council that will apply advanced measurements and modelling to quantify the amount and present atmospheric impact of CH4 originating from MH. Furthermore, the project will investigate potential future climate effects from destabilisation of MH deposits in a warming climate, and will focus on scenarios in 2050 and 2100. This presentation will provide an overview of the planned measurement campaigns, which aim to improve understanding of the fate of methane released at the ocean seabed, and its presence in the ocean water column and atmosphere. These measurement data will be used in combination with inversion modeling to quantify the present-day CH4 emissions from marine seabed seep sites west of Prince Carl Forland (Svalbard) to the atmosphere, and to identify the main influences on the atmospheric fraction. The project is anticipated to generate new knowledge on the entire Earth system and climate change using the region around Svalbard as an experimental test bed to study polar processes.

  9. Effect of the irrigation with waste water on two different mediterranean soils under greenhouse conditions

    NASA Astrophysics Data System (ADS)

    Pina, S.; Garcia-Orenes, F.; Mataix, J.; Jordan, M. M.; Mataix-Solera, J.

    2009-04-01

    The semi-arid zones as the Mediterranean coast are densely populated and their aquifers are being hardly exploited. The use of waste water for irrigation is an alternative for the water shortage. Consequently, it is considered necessary to improve the efforts to investigate changes of soil properties. The main objective of this work was to compare the short-term effects of irrigation with waste water on two different Mediterranean soils. It was used flowerpots with loquat (Eriobotrya japonica Lindl) under greenhouse conditions. Two different Mediterranean soils were selected from Alicante, SE of Spain, one gypsiferous soil and one calcareous soil with similar texture, to evaluate the different behaviour against waste water irrigation. The flowerpots were irrigated with two different treatments: fresh water (control) and treated waste water from secondary treatment. The experience lasted twelve months, the first six to adapt the plants into the greenhouse and then the soils were irrigated twice a week. Two soil sampling were taking in the beginning and in the end of the experiment to determinate EC, Na, P, OC and N. In both soils our results show a slight increase in electrical conductivity, being deeper in the calcareous soil as it is easier to drain. However it was found a higher increase of sodium concentrations in the gypsiferous soil. Fertility analysis in the secondary treatment of both soils presented an improvement in potassium and available phosphorus levels. In the other hand, organic carbon and nitrogen do not seem to change; the reason could be an enhancement in biological activity caused by irrigation. This biological activity and greenhouse conditions speed up organic matter mineralization. According to the short-term results in the soils studied parameters, except for electrical conductivity and sodium content, there is not a notable negative impact. Nevertheless, it must be necessary to extend the experience for long-term conclusions.

  10. Effect of duckweed cover on greenhouse gas emissions and odour release from waste stabilisation ponds.

    PubMed

    van der Steen, N P; Nakiboneka, P; Mangalika, L; Ferrer, A V M; Gijzen, H J

    2003-01-01

    Treatment of wastewater in stabilisation pond systems prevents the negative environmental impact of uncontrolled disposal of sewage. However, even a natural treatment system may generate secondary negative environmental impacts in terms of energy consumption, emission of greenhouse gases and emission of odorous compounds. Whereas natural systems have an advantage over electro-mechanical systems in that they use less hardware and less energy, it is not yet known whether secondary environmental effects in the form of greenhouse gas emissions are lower for these systems. This research intends to be a first step in the direction of answering this question by assessing gas emissions from two types of natural systems, namely algae-based and duckweed-based stabilisation ponds. The H2S volatilisation from laboratory scale pond-reactors has been determined by drawing the air above the water surface continuously through a solution of 1 M NaOH for absorption of sulphide. The amount of H2S that volatilised from the algae pond-reactor, and was trapped in the NaOH trap, was found to be 2.5-86 mg/m2/day. The H2S volatilisation from the duckweed pond-reactor was found to be negligible, even though the sulphide concentration was 9.7 mg/l S(2-). The duckweed cover was a physical barrier for volatilisation, since bubbles were trapped in the cover. In addition the duckweed layer was found to be afavourable environment for both aerobic sulphide oxidisers (Beggiatoa gigantae) as well as for photosynthetic purple sulphur bacteria belonging to the genus Chromatium. These may also have contributed to the prevention of H2S volatilisation. Results on methane emissions were not conclusive so far, but the same mechanisms that prevent H2S volatilisation may also prevent methane volatilisation. Therefore it was concluded that duckweed covers on stabilisation ponds may reduce the emission of both odorous and greenhouse gases.

  11. Titan's Greenhouse Effect And Climate: Lessons From The Earth's Cooler Cousin

    NASA Astrophysics Data System (ADS)

    Nixon, Conor A.; Titan Climate White Paper Proposal Team

    2009-12-01

    We argue that continuing scientific study of Earth's `distant cousin’ Titan can provide a greater understanding and insight into the energy balance of our own planet's atmosphere. Titan's Earth-like properties have been recognized for some time, from the discovery of its atmosphere in 1907, through the Voyager 1 encounter in 1980 that showed Titan's atmosphere is mostly nitrogen gas with a surface pressure within a factor of two of terrestrial. Calculation shows that Titan's atmosphere causes `greenhouse’ warming of the surface, an effect similar to that seen on the Earth, Mars, and Venus. In the 1990s, direct imaging from the Earth by adaptive optics revealed that Titan's ubiquitous haze layer is slowly changing in apparent response to the seasons that occur due to the Saturn system's obliquity. The NASA Cassini mission that arrived in Saturnian orbit in 2004, and the ESA Huygens Titan probe of 2005, have returned a flood of new data regarding this intriguing world. For the first time, we are building a detailed picture of weather in the lower atmosphere, where condensable methane takes on the role played by water in the Earth's atmosphere, leading to methane rainfall, rivers and lakes. We examine parallels between the atmospheres of Earth and of Titan, including the possibilities for dramatic climate change. Extending the duration of the Cassini spacecraft mission during the next decade will provide part of the needed picture, but in addition we urge planning for a future new mission focused on Titan's climate, and other measures.

  12. A Greenhouse Assay on the Effect of Applied Urea Amount on the Rhizospheric Soil Bacterial Communities.

    PubMed

    Shang, Shuanghua; Yi, Yanli

    2015-12-01

    The rhizospheric bacteria play key role in plant nutrition and growth promotion. The effects of increased nitrogen inputs on plant rhizospheric soils also have impacted on whole soil microbial communities. In this study, we analyzed the effects of applied nitrogen (urea) on rhizospheric bacterial composition and diversity in a greenhouse assay using the high-throughput sequencing technique. To explore the environmental factors driving the abundance, diversity and composition of soil bacterial communities, the relationship between soil variables and the bacterial communities were also analyzed using the mantel test as well as the redundancy analysis. The results revealed significant bacterial diversity changes at different amounts of applied urea, especially between the control treatment and the N fertilized treatments. Mantel tests showed that the bacterial communities were significantly correlated with the soil nitrate nitrogen, available nitrogen, soil pH, ammonium nitrogen and total organic carbon. The present study deepened the understanding about the rhizospheric soil microbial communities under different amounts of applied urea in greenhouse conditions, and our work revealed the environmental factors affecting the abundance, diversity and composition of rhizospheric bacterial communities.

  13. A Greenhouse Assay on the Effect of Applied Urea Amount on the Rhizospheric Soil Bacterial Communities.

    PubMed

    Shang, Shuanghua; Yi, Yanli

    2015-12-01

    The rhizospheric bacteria play key role in plant nutrition and growth promotion. The effects of increased nitrogen inputs on plant rhizospheric soils also have impacted on whole soil microbial communities. In this study, we analyzed the effects of applied nitrogen (urea) on rhizospheric bacterial composition and diversity in a greenhouse assay using the high-throughput sequencing technique. To explore the environmental factors driving the abundance, diversity and composition of soil bacterial communities, the relationship between soil variables and the bacterial communities were also analyzed using the mantel test as well as the redundancy analysis. The results revealed significant bacterial diversity changes at different amounts of applied urea, especially between the control treatment and the N fertilized treatments. Mantel tests showed that the bacterial communities were significantly correlated with the soil nitrate nitrogen, available nitrogen, soil pH, ammonium nitrogen and total organic carbon. The present study deepened the understanding about the rhizospheric soil microbial communities under different amounts of applied urea in greenhouse conditions, and our work revealed the environmental factors affecting the abundance, diversity and composition of rhizospheric bacterial communities. PMID:26543266

  14. Factor Analysis of Drawings: Application to college student models of the greenhouse effect

    NASA Astrophysics Data System (ADS)

    Libarkin, Julie C.; Thomas, Stephen R.; Ording, Gabriel

    2015-09-01

    Exploratory factor analysis was used to identify models underlying drawings of the greenhouse effect made by over 200 entering university freshmen. Initial content analysis allowed deconstruction of drawings into salient features, with grouping of these features via factor analysis. A resulting 4-factor solution explains 62% of the data variance, suggesting that 4 archetype models of the greenhouse effect dominate thinking within this population. Factor scores, indicating the extent to which each student's drawing aligned with representative models, were compared to performance on conceptual understanding and attitudes measures, demographics, and non-cognitive features of drawings. Student drawings were also compared to drawings made by scientists to ascertain the extent to which models reflect more sophisticated and accurate models. Results indicate that student and scientist drawings share some similarities, most notably the presence of some features of the most sophisticated non-scientific model held among the study population. Prior knowledge, prior attitudes, gender, and non-cognitive components are also predictive of an individual student's model. This work presents a new technique for analyzing drawings, with general implications for the use of drawings in investigating student conceptions.

  15. NASA's Atmospheric Effects of Aviation Project

    NASA Technical Reports Server (NTRS)

    Cofer, W. Randy, III; Anderson, Bruce E.; Connors, V. S.; Wey, C. C.; Sanders, T.; Winstead, E. L.; Pui, C.; Chen, Da-ren; Hagen, D. E.; Whitefield, P.

    2001-01-01

    During August 1-14, 1999, NASA's Atmospheric Effects of Aviation Project (AEAP) convened a workshop at the NASA Langley Research Center to try to determine why such a wide variation in aerosol emissions indices and chemical and physical properties has been reported by various independent AEAP-supported research teams trying to characterize the exhaust emissions of subsonic commercial aircraft. This workshop was divided into two phases, a laboratory phase and a field phase. The laboratory phase consisted of supplying known particle number densities (concentrations) and particle size distributions to a common manifold for the participating research teams to sample and analyze. The field phase was conducted on an aircraft run-up pad. Participating teams actually sampled aircraft exhaust generated by a Langley T-38 Talon aircraft at 1 and 9 m behind the engine at engine powers ranging from 48 to 100 percent. Results from the laboratory phase of this intercomparison workshop are reported in this paper.

  16. Global atmospheric changes.

    PubMed Central

    Piver, W T

    1991-01-01

    Increasing concentrations of CO2 and other greenhouse gases in the atmosphere can be directly related to global warming. In terms of human health, because a major cause of increasing atmospheric concentrations of CO2 is the increased combustion of fossil fuels, global warming also may result in increases in air pollutants, acid deposition, and exposure to ultraviolet (UV) radiation. To understand better the impacts of global warming phenomena on human health, this review emphasizes the processes that are responsible for the greenhouse effect, air pollution, acid deposition, and increased exposure to UV radiation. PMID:1820255

  17. Global atmospheric changes.

    PubMed

    Piver, W T

    1991-12-01

    Increasing concentrations of CO2 and other greenhouse gases in the atmosphere can be directly related to global warming. In terms of human health, because a major cause of increasing atmospheric concentrations of CO2 is the increased combustion of fossil fuels, global warming also may result in increases in air pollutants, acid deposition, and exposure to ultraviolet (UV) radiation. To understand better the impacts of global warming phenomena on human health, this review emphasizes the processes that are responsible for the greenhouse effect, air pollution, acid deposition, and increased exposure to UV radiation.

  18. Runaway greenhouse effect on exomoons due to irradiation from hot, young giant planets

    NASA Astrophysics Data System (ADS)

    Heller, R.; Barnes, R.

    2015-04-01

    The Kepler space telescope has proven capable of detecting transits of objects almost as small as the Earth's Moon. Some studies suggest that moons as small as 0.2 Earth masses can be detected in the Kepler data by transit timing variations and transit duration variations of their host planets. If such massive moons exist around giant planets in the stellar habitable zone (HZ), then they could serve as habitats for extraterrestrial life. While earlier studies on exomoon habitability assumed the host planet to be in thermal equilibrium with the absorbed stellar flux, we here extend this concept by including the planetary luminosity from evolutionary shrinking. Our aim is to assess the danger of exomoons to be in a runaway greenhouse state due to extensive heating from the planet. We apply pre-computed evolution tracks for giant planets to calculate the incident planetary radiation on the moon as a function of time. Added to the stellar flux, the total illumination yields constraints on a moon's habitability. Ultimately, we include tidal heating to evaluate a moon's energy budget. We use a semi-analytical formula to parameterize the critical flux for the moon to experience a runaway greenhouse effect. Planetary illumination from a 13-Jupiter-mass planet onto an Earth-sized moon at a distance of ten Jupiter radii can drive a runaway greenhouse state on the moon for about 200 million years (Myr). When stellar illumination equivalent to that received by Earth from the Sun is added, then the runaway greenhouse holds for about 500 Myr. After 1000 Myr, the planet's habitable edge has moved inward to about six Jupiter radii. Exomoons in orbits with eccentricities of 0.1 experience strong tidal heating; they must orbit a 13-Jupiter-mass host beyond 29 or 18 Jupiter radii after 100 Myr (at the inner and outer boundaries of the stellar HZ, respectively), and beyond 13 Jupiter radii (in both cases) after 1000 Myr to be habitable. If a roughly Earth-sized, Earth-mass moon would

  19. Part I. Development of a concept inventory addressing students' beliefs and reasoning difficulties regarding the greenhouse effect, Part II. Distribution of chlorine measured by the Mars Odyssey Gamma Ray Spectrometer

    NASA Astrophysics Data System (ADS)

    Keller, John Michael

    This work presents two research efforts, one involving planetary science education research and a second involving the surface composition of Mars. In the former, student beliefs and reasoning difficulties associated with the greenhouse effect were elicited through student interviews and written survey responses from >900 US undergraduate non-science majors. This guided the development of the Greenhouse Effect Concept Inventory (GECI), an educational research tool designed to assess pre- and post-instruction conceptual understanding of the greenhouse effect. Three versions of this multiple-choice instrument were administered to >2,500 undergraduates as part of the development and validation process. In contrast to previous research efforts regarding causes, consequences, and solutions to the enhanced greenhouse effect, the GECI focuses primarily on the physics of energy flow through Earth's atmosphere. The GECI is offered to the science education community as a research tool for assessing instructional strategies on this topic. It was confirmed that the study population subscribes to several previously identified beliefs. These include correct understandings that carbon dioxide is an important greenhouse gas and the greenhouse effect increases planetary surface temperatures. Students also commonly associate the greenhouse effect with increased penetration of sunlight into and trapping of solar energy in the atmosphere. Students intermix concepts associated with the greenhouse effect, global warming, and ozone depletion. Reinforcing the latter concept, a majority believe that the Sun radiates most of its energy as ultraviolet light. Students also describe inaccurate and incomplete trapping models, which include permanent trapping, trapping through reflection, and trapping of gases and pollution. Another reasoning difficulty involves the idea that Earth's surface radiates energy primarily during the nighttime. The second research effort describes the distribution of

  20. Effects of plant size, temperature, and light intensity on flowering of Phalaenopsis hybrids in Mediterranean greenhouses.

    PubMed

    Paradiso, Roberta; De Pascale, Stefania

    2014-01-01

    Mediterranean greenhouses for cultivation of Phalaenopsis orchids reproduce the warm, humid, and shaded environment of tropical underbrush. Heating represents the highest production cost, due to the high thermal requirements and the long unproductive phase of juvenility, in which plants attain the critical size for flowering. Our researches aimed to investigate the effect of plant size, temperature, and light intensity, during the phase of flower induction, on flowering of modern genotypes selected for Mediterranean greenhouses. Three experiments were carried out to compare (i) plant size: reduced size versus size considered optimal for flowering (hybrids "Sogo Yukidian," "Chain Xen Diamond," and "Pinlong"); (ii) temperature: moderate reduction of temperature versus standard thermal regime (hybrid "Premium"); (iii) light intensity: supplemental lighting versus reference light intensity (hybrid "Premium"). The premature exposure of plants to the inductive treatment delayed the beginning of flowering and reduced the flower stem quality, in all the tested hybrids. In "Premium," the lower temperature did not affect flowering earliness and commercial quality of flower stems compared to the standard regime, whereas it promoted stem branching. In the same hybrid, supplemental lighting anticipated flowering and promoted the emission of the second stem and the stem branching, compared to the reference light regime.

  1. High salinity effect on bioremediation of pretreated pesticide lixiviates from greenhouses.

    PubMed

    Micó, María M; González, Óscar; Bacardit, Jordi; Malfeito, Jorge; Sans, Carme

    2015-01-01

    Hydroponics culture greenhouses usually work in closed and semi-closed irrigation systems for nutrients and water-saving purposes. Photo-Fenton reaction has been revealed as an efficient way to depollute that kind of recycled effluents containing pesticides, even for high salinity concentrations. However, the inefficacy of organic matter chemical depletion imposes the use of a subsequent treatment. This work proposes the suitability of an integration of advanced oxidation process with a subsequent bioreactor to treat greenhouse lixiviates effluents at high or extremely high conductivity (salts concentration: up to 42 g L⁻¹). As a first step in this study, the performance of a series of sequencing batch reactors was monitored in order to check the biocompatibility of photo-Fenton pretreated effluents depending on their salinity content. In the second step, those same pretreated effluents were loaded to a biofiltration column filled with expanded clay. Finally, bacterial 16S rRNA gene sequencing was carried out to analyse microbial diversity of the biomass developed in the column. Results stated that the chemical-biological coupled system is effective for the treatment of water effluents containing pesticides. The integrated system is able to deplete more than 80% of the organic load, even under extremely high salinity. PMID:26041507

  2. High salinity effect on bioremediation of pretreated pesticide lixiviates from greenhouses.

    PubMed

    Micó, María M; González, Óscar; Bacardit, Jordi; Malfeito, Jorge; Sans, Carme

    2015-01-01

    Hydroponics culture greenhouses usually work in closed and semi-closed irrigation systems for nutrients and water-saving purposes. Photo-Fenton reaction has been revealed as an efficient way to depollute that kind of recycled effluents containing pesticides, even for high salinity concentrations. However, the inefficacy of organic matter chemical depletion imposes the use of a subsequent treatment. This work proposes the suitability of an integration of advanced oxidation process with a subsequent bioreactor to treat greenhouse lixiviates effluents at high or extremely high conductivity (salts concentration: up to 42 g L⁻¹). As a first step in this study, the performance of a series of sequencing batch reactors was monitored in order to check the biocompatibility of photo-Fenton pretreated effluents depending on their salinity content. In the second step, those same pretreated effluents were loaded to a biofiltration column filled with expanded clay. Finally, bacterial 16S rRNA gene sequencing was carried out to analyse microbial diversity of the biomass developed in the column. Results stated that the chemical-biological coupled system is effective for the treatment of water effluents containing pesticides. The integrated system is able to deplete more than 80% of the organic load, even under extremely high salinity.

  3. Small Impacts on Mars: Atmospheric Effects

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Nemtchinov, Ivan V.

    2002-01-01

    The objectives of this investigation were to study the interaction of the atmosphere with the surface of Mars through the impact of small objects that would generate dust and set the dust into motion in the atmosphere. The approach involved numerical simulations of impacts and experiments under controlled conditions. Attachment: Atmospheric disturbances and radiation impulses caused by large-meteoroid impact in the surface of Mars.

  4. Atmospheric CO2: principal control knob governing Earth's temperature.

    PubMed

    Lacis, Andrew A; Schmidt, Gavin A; Rind, David; Ruedy, Reto A

    2010-10-15

    Ample physical evidence shows that carbon dioxide (CO(2)) is the single most important climate-relevant greenhouse gas in Earth's atmosphere. This is because CO(2), like ozone, N(2)O, CH(4), and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does. Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO(2) and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state.

  5. Atmospheric CO2: Principal Control Knob Governing Earth's Temperature

    NASA Technical Reports Server (NTRS)

    Lacis, Andrew A.; Schmidt, Gavin A.; Rind, David; Ruedy, Reto A.

    2010-01-01

    Ample physical evidence shows that carbon dioxide (CO2) is the single most important climate-relevant greenhouse gas in Earth s atmosphere. This is because CO2, like ozone, N2O, CH4, and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does. Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO2 and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state.

  6. Atmospheric CO2: principal control knob governing Earth's temperature.

    PubMed

    Lacis, Andrew A; Schmidt, Gavin A; Rind, David; Ruedy, Reto A

    2010-10-15

    Ample physical evidence shows that carbon dioxide (CO(2)) is the single most important climate-relevant greenhouse gas in Earth's atmosphere. This is because CO(2), like ozone, N(2)O, CH(4), and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does. Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO(2) and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state. PMID:20947761

  7. Atmospheric Dispersion Effects in Weak Lensing Measurements

    SciTech Connect

    Plazas, Andrés Alejandro; Bernstein, Gary

    2012-10-01

    The wavelength dependence of atmospheric refraction causes elongation of finite-bandwidth images along the elevation vector, which produces spurious signals in weak gravitational lensing shear measurements unless this atmospheric dispersion is calibrated and removed to high precision. Because astrometric solutions and PSF characteristics are typically calibrated from stellar images, differences between the reference stars' spectra and the galaxies' spectra will leave residual errors in both the astrometric positions (dr) and in the second moment (width) of the wavelength-averaged PSF (dv) for galaxies.We estimate the level of dv that will induce spurious weak lensing signals in PSF-corrected galaxy shapes that exceed the statistical errors of the DES and the LSST cosmic-shear experiments. We also estimate the dr signals that will produce unacceptable spurious distortions after stacking of exposures taken at different airmasses and hour angles. We also calculate the errors in the griz bands, and find that dispersion systematics, uncorrected, are up to 6 and 2 times larger in g and r bands,respectively, than the requirements for the DES error budget, but can be safely ignored in i and z bands. For the LSST requirements, the factors are about 30, 10, and 3 in g, r, and i bands,respectively. We find that a simple correction linear in galaxy color is accurate enough to reduce dispersion shear systematics to insignificant levels in the r band for DES and i band for LSST,but still as much as 5 times than the requirements for LSST r-band observations. More complex corrections will likely be able to reduce the systematic cosmic-shear errors below statistical errors for LSST r band. But g-band effects remain large enough that it seems likely that induced systematics will dominate the statistical errors of both surveys, and cosmic-shear measurements should rely on the redder bands.

  8. Atmospheric Dispersion Effects in Weak Lensing Measurements

    DOE PAGES

    Plazas, Andrés Alejandro; Bernstein, Gary

    2012-10-01

    The wavelength dependence of atmospheric refraction causes elongation of finite-bandwidth images along the elevation vector, which produces spurious signals in weak gravitational lensing shear measurements unless this atmospheric dispersion is calibrated and removed to high precision. Because astrometric solutions and PSF characteristics are typically calibrated from stellar images, differences between the reference stars' spectra and the galaxies' spectra will leave residual errors in both the astrometric positions (dr) and in the second moment (width) of the wavelength-averaged PSF (dv) for galaxies.We estimate the level of dv that will induce spurious weak lensing signals in PSF-corrected galaxy shapes that exceed themore » statistical errors of the DES and the LSST cosmic-shear experiments. We also estimate the dr signals that will produce unacceptable spurious distortions after stacking of exposures taken at different airmasses and hour angles. We also calculate the errors in the griz bands, and find that dispersion systematics, uncorrected, are up to 6 and 2 times larger in g and r bands,respectively, than the requirements for the DES error budget, but can be safely ignored in i and z bands. For the LSST requirements, the factors are about 30, 10, and 3 in g, r, and i bands,respectively. We find that a simple correction linear in galaxy color is accurate enough to reduce dispersion shear systematics to insignificant levels in the r band for DES and i band for LSST,but still as much as 5 times than the requirements for LSST r-band observations. More complex corrections will likely be able to reduce the systematic cosmic-shear errors below statistical errors for LSST r band. But g-band effects remain large enough that it seems likely that induced systematics will dominate the statistical errors of both surveys, and cosmic-shear measurements should rely on the redder bands.« less

  9. Stability of the boreal forest-tundra ecotone: A test for the greenhouse effect

    SciTech Connect

    Nichols, H. . Dept. of EPO Biology)

    1993-09-01

    The Greenhouse Warming hypothesis predicts that high northern latitudes will experience greater temperature increases than lower latitudes over the next century. Arctic meteorological data indicates some recent surface warmings, while tropospheric level cooling has occurred over the last 40 years, over the North American arctic. These equivocal signals indicate the need to examine the reproductive status of the arctic tree-line, which integrates the climatic trends of the circumpolar regions. The boundary between the boreal forest and the arctic tundra is sensitive to climate change according to climatic theory, and it is expected to respond to global atmospheric warming, as demonstrated by paleo-ecological studies of the forest limit during the last several thousand years. Much of the forest edge and the dwarf spruce true islands'' in the arctic tundra are currently infertile and reproduce by vegetative layering, due to insufficient summer warmth, but are expected to produce ripened seed and pollen when sufficient warming occurs. Since weather observatories are few and far between in the arctic, these tree islands act as quasi-meteorological stations to give us early warning of climatic change. These clonal trees will act as beacons'' throughout the circumpolar areas to indicate climatic warming, and will need to be monitored by ground survey using pollen and seed collections. Then sensitivity of northern ecosystems and human cultures to climatic change require the collaboration of several arctic nations in field and remote-sensing studies to assess these dichotomous possibilities.

  10. Knowledge about the Greenhouse Effect and the Effects of the Ozone Layer among Norwegian Pupils Finishing Compulsory Education in 1989, 1993, and 2005—What Now?

    NASA Astrophysics Data System (ADS)

    Kirkeby Hansen, Pål J.

    2010-02-01

    The greenhouse effect and the effects of the ozone layer have been in the media and public focus for more than two decades. During the same period, Norwegian compulsory schools have had four national curricula. The two last-mentioned prescribe explicitly the two topics. Media and public discourse might have been sources of information causing informal learning among pupils. The point of departure for this questionnaire-based examination of the development of pupils' knowledge about the greenhouse effect and the effects of the ozone layer from 1989 to 2005 is the changing curricula and formal and informal learning. In 2005 the trends seem to be that more pupils confuse the greenhouse effect with the effects of the ozone layer. At the same time, specific knowledge about the greenhouse effect is improving. This article will discuss some possible causes for these trends, and give some recommendations for teaching the topics in accordance with the last national curriculum implemented in 2006.

  11. Empirical Quantification of the Runaway Greenhouse Limit on Earth

    NASA Astrophysics Data System (ADS)

    Goldblatt, C.; Dewey, M. C.

    2015-12-01

    There have been many modeling studies of the runaway greenhouse effect and the conditions required to produce one on an Earth-like planet, however these models have not been verified with empirical evidence. It has been suggested that the Earth's tropics may be near a state of localized runaway greenhouse, meaning the surface temperature and atmospheric composition in those areas could cause runaway greenhouse, were it not for the tempering effects of meridional heat transport and circulation (Pierrehumbert, 1995). Using the assumption that some areas of the Earth's tropics may be under these conditions, this study uses measurements of the atmospheric properties, surface properties, and radiation budgets of these areas to quantify a radiation limit for runaway greenhouse on Earth, by analyzing the dependence of outgoing longwave radiation (OLR) at the top of the atmosphere on surface temperature and total column water vapour. An upper limit on OLR for clear-sky conditions was found between 289.8 W/m2 and 292.2 W/m2, which occurred at surface temperatures near 300K. For surface temperatures above this threshold, total column water vapour increased, but OLR initially decreased and then remained relatively constant, between 273.6 W/m2 and 279.7 W/m2. These limits are in good agreement with recent modeling results (Goldblatt et al., 2013), supporting the idea that some of the Earth's tropics may be in localized runaway greenhouse, and that radiation limits for runaway greenhouse on Earth can be empirically derived. This research was done as part of Maura Dewey's undergraduate honours thesis at the University of Victoria. Refs: Robert T. Pierrehumbert. Thermostats, radiator fins, and the local runaway greenhouse. Journal of Atmospheric Sciences, 52(10):1784-1806, 1995. Colin Goldblatt, Tyler D. Robinson, Kevin J. Zahnle, and David Crisp. Low simulated radiation limit for runaway greenhouse climates. Nature Geoscience, 6:661-667, 2013.

  12. Amplifying effects of land-use change on future atmospheric CO2 levels

    NASA Astrophysics Data System (ADS)

    Gitz, Vincent; Ciais, Philippe

    2003-03-01

    We constructed a model to analyze the interactions between land-use change and atmospheric CO2 during the recent past and for the future. The primary impact of the conversion of forested lands to cultivated lands is to increase atmospheric CO2, via losses of biomass and soil carbon to the atmosphere. This increase is likely to continue in the next decades, but its magnitude can vary according to each land-use scenario. We show that this first-order effect is further amplified by the correlated diminution of terrestrial sinks, because when croplands replace forests, the turnover time of excess carbon in the biosphere decreases, and hence the sink capacity of terrestrial ecosystems decreases. This effect acts to further increase by up to 100 ppm the CO2 level reached by 2100, and it is of the same order of magnitude, although smaller, than climate-carbon feedbacks. Uncertainties on the magnitude of this land-use induced effect are large, because of uncertainties in the sink role of terrestrial ecosystems in the future and because of uncertainties inherent to the modeling of land-use induced carbon emissions. Such an extra rise in atmospheric CO2 is however partially offset by the ocean reservoir and by sinks operating over undisturbed, pristine ecosystems, suggesting that conserving pristine forests with long turnover times might be efficient in mitigating the greenhouse effect.

  13. Effects of stabilizing atmospheric CO2 on global climate in the next two centuries

    NASA Astrophysics Data System (ADS)

    Dai, Aiguo; Wigley, T. M. L.; Meehl, G. A.; Washington, W. M.

    Previous coupled ocean-atmosphere model simulations showed that the reduction in global warming is only moderate by year 2100 under CO2 stabilization (STA) scenarios compared with that under business-as-usual (BAU) scenarios. To further illustrate the long-term effect of stabilizing CO2 on global climate, we integrated a coupled ocean-atmosphere model from 1870 to 2200 forced by historical and projected CO2, SO2 and other greenhouse gases under newly updated BAU and STA scenarios. Our results show that the reduction in global warming resulting from CO2 stabilization could be large (∼1.5°C globally, and up to 12°C in DJF at northern high-latitudes) by the later part of the 22nd century. Stabilizing the CO2 level also results in reduced changes in precipitation, soil moisture and diurnal temperature range. BAU and STA patterns of change are similar for all variables examined.

  14. The Greenhouse Effect and the Destruction of the Ozone Shield: Implications for Rhetoric and Criticism.

    NASA Astrophysics Data System (ADS)

    Stoller, Martin Reid

    Rhetoric, in the Aristotelian sense of "the available means of persuasion," is a crucial, often determining component of the process of making public policy generally, and environmental policy specifically. Environmental crises which have been addressed by the governmental, industrial, and social policy -making establishments have tended to be treated in a manner similar to that in which social, political, economic, military, and other problems have been commonly treated, utilizing a traditional rhetoric, including long-proven persuasive language and arguments. Such problems as air pollution and water pollution have been, to some degree, successfully addressed in this manner. A new and fundamentally different cluster of environmental problems has recently been recognized by elements of the policy making establishment as a legitimate candidate for consideration and policy formation. These environmental problems differ from the more familiar type in a variety of ways, each of which, to a greater or lesser degree, make problematic for those activists concerned with these crises the production of an effective crisis-oriented rhetoric. This study addresses two such closely related phenomena, the Greenhouse Effect and ozone depletion, and identifies those characteristics which contribute to their rhetorical complexity. Using traditional techniques of rhetorical examination, primarily neo-Aristotelian analysis, this study demonstrates the inadequacy of current crisis-oriented rhetoric, and identifies the causes of this rhetorical ineffectiveness. The study concludes that the mediation of such crises as the Greenhouse Effect and ozone depletion cannot be significantly facilitated by traditional environmental-oriented rhetoric, and may in fact be hindered by the use of rhetoric associated with fundamentally different (i.e., easier to solve) environmental problems.

  15. The effectiveness of measures to reduce the man-made greenhouse effect. The application of a Climate-policy Model

    NASA Astrophysics Data System (ADS)

    Jain, A. K.; Bach, W.

    1994-06-01

    In this paper we briefly describe the characteristics and the performance of our 1-D Muenster Climate Model. The model system consists of coupled models including gas cycle models, an energy balance model and a sea level rise model. The chemical feedback mechanisms among greenhouse gases are not included. This model, which is a scientifically-based parameterized simulation model, is used here primarily to help assess the effectiveness of various plausible policy options in mitigating the additional man-made greenhouse warming and the resulting sea level rise. For setting priorities it is important to assess the effectiveness of the various measures by which the greenhouse effect can be reduced. To this end we take a Scenario Business-as-Usual as a reference case (Leggett et al., 1992) and study the mitigating effects of the following four packages of measures: The Copenhagen Agreements on CFC, HCFC, and halon reduction (GECR, 1992), the Tropical Forest Preservation Plan of the Climate Enquete-Commission of the German Parliament on CO2 reduction (ECGP, 1990), a detailed reduction scheme for energy-related CO2 (ECGP, 1990), and a preliminary scheme for CH4, CO, and N2O reduction (Bach and Jain, 1992 1993). The required reduction depends, among others, on the desired climate and ecosystem protection. This is defined by the Enquete-Commission and others as a mean global rate of surface temperature change of ca. 0.1 °C per decade — assumed to be critical to many ecosystems — and a mean global warming ceiling of ca. 2 °C in 2100 relative to 1860. Our results show that the Copenhagen Agreements, the Tropical Forest Preservation Plan, the energy-related CO2 reduction scheme, and the CH4 and N2O reduction schemes could mitigate the anthropogenic greenhouse warming by ca. 12%, 6%, 35%, and 9% respectively. Taken together, all four packages of measures could reduce the man-made greenhouse effect by more than 60% until 2100; i.e. over the climate sensitivity range 2.5

  16. High-precision quasi-continuous atmospheric greenhouse gas measurements at Trainou tower (Orléans forest, France)

    NASA Astrophysics Data System (ADS)

    Schmidt, M.; Lopez, M.; Yver Kwok, C.; Messager, C.; Ramonet, M.; Wastine, B.; Vuillemin, C.; Truong, F.; Gal, B.; Parmentier, E.; Cloué, O.; Ciais, P.

    2014-07-01

    Results from the Trainou tall tower measurement station installed in 2006 are presented for atmospheric measurements of CO2, CH4, N2O, SF6, CO, H2 mole fractions and radon-222 activity. Air is sampled from four sampling heights (180, 100, 50 and 5 m) of the Trainou 200 m television tower in the Orléans forest in France (47°57'53" N, 2°06'45" E, 131 m a.s.l.). The station is equipped with a custom-built CO2 analyser (CARIBOU), which is based on a commercial non-dispersive, infrared (NDIR) analyser (Licor 6252), and a coupled gas chromatography (GC) system equipped with an electron capture detector (ECD) and a flame ionization detector (FID) (HP6890N, Agilent) and a reduction gas detector (PP1, Peak Performer). Air intakes, pumping and air drying system are shared between the CARIBOU and the GC systems. The ultimately achieved short-term repeatability (1 sigma, over several days) for the GC system is 0.05 ppm for CO2, 1.4 ppb for CH4, 0.25 ppb for N2O, 0.08 ppb for SF6, 0.88 ppb for CO and 3.8 for H2. The repeatability of the CARIBOU CO2 analyser is 0.06 ppm. In addition to the in situ measurements, weekly flask sampling is performed, and flask air samples are analysed at the Laboratoire des Sciences du Climat et de l'Environnement (LSCE) central laboratory for the same species as well for stable isotopes of CO2. The comparison between in situ measurements and the flask sampling showed averaged differences of 0.08 ± 1.40 ppm for CO2, 0.7 ± 7.3 ppb for CH4, 0.6 ± 0.6 ppb for N2O, 0.01 ± 0.10 ppt for SF6, 1.5± 5.3 ppb for CO and 4.8± 6.9 ppb for H2 for the years 2008-2012. At Trainou station, the mean annual increase rates from 2007 to 2011 at the 180 m sampling height were 2.2 ppm yr-1 for CO2, 4 ppb yr-1 for CH4, 0.78 ppb yr-1 for N2O and 0.29 ppt yr-1 for SF6. For all species, the 180 m sampling level showed the smallest diurnal variation. Mean diurnal gradients between the 50 m and the 180 m sampling level reached up to 30 ppm CO2, 15 ppm CH4 or 0.5 ppb N2

  17. Greenhouse gas emissions from solid waste in Beijing: The rising trend and the mitigation effects by management improvements.

    PubMed

    Yu, Yongqiang; Zhang, Wen

    2016-04-01

    Disposal of solid waste poses great challenges to city managements. Changes in solid waste composition and disposal methods, along with urbanisation, can certainly affect greenhouse gas emissions from municipal solid waste. In this study, we analysed the changes in the generation, composition and management of municipal solid waste in Beijing. The changes of greenhouse gas emissions from municipal solid waste management were thereafter calculated. The impacts of municipal solid waste management improvements on greenhouse gas emissions and the mitigation effects of treatment techniques of greenhouse gas were also analysed. Municipal solid waste generation in Beijing has increased, and food waste has constituted the most substantial component of municipal solid waste over the past decade. Since the first half of 1950s, greenhouse gas emission has increased from 6 CO2-eq Gg y(-1)to approximately 200 CO2-eq Gg y(-1)in the early 1990s and 2145 CO2-eq Gg y(-1)in 2013. Landfill gas flaring, landfill gas utilisation and energy recovery in incineration are three techniques of the after-emission treatments in municipal solid waste management. The scenario analysis showed that three techniques might reduce greenhouse gas emissions by 22.7%, 4.5% and 9.8%, respectively. In the future, if waste disposal can achieve a ratio of 4:3:3 by landfill, composting and incineration with the proposed after-emission treatments, as stipulated by the Beijing Municipal Waste Management Act, greenhouse gas emissions from municipal solid waste will decrease by 41%.

  18. Greenhouse gas emissions from solid waste in Beijing: The rising trend and the mitigation effects by management improvements.

    PubMed

    Yu, Yongqiang; Zhang, Wen

    2016-04-01

    Disposal of solid waste poses great challenges to city managements. Changes in solid waste composition and disposal methods, along with urbanisation, can certainly affect greenhouse gas emissions from municipal solid waste. In this study, we analysed the changes in the generation, composition and management of municipal solid waste in Beijing. The changes of greenhouse gas emissions from municipal solid waste management were thereafter calculated. The impacts of municipal solid waste management improvements on greenhouse gas emissions and the mitigation effects of treatment techniques of greenhouse gas were also analysed. Municipal solid waste generation in Beijing has increased, and food waste has constituted the most substantial component of municipal solid waste over the past decade. Since the first half of 1950s, greenhouse gas emission has increased from 6 CO2-eq Gg y(-1)to approximately 200 CO2-eq Gg y(-1)in the early 1990s and 2145 CO2-eq Gg y(-1)in 2013. Landfill gas flaring, landfill gas utilisation and energy recovery in incineration are three techniques of the after-emission treatments in municipal solid waste management. The scenario analysis showed that three techniques might reduce greenhouse gas emissions by 22.7%, 4.5% and 9.8%, respectively. In the future, if waste disposal can achieve a ratio of 4:3:3 by landfill, composting and incineration with the proposed after-emission treatments, as stipulated by the Beijing Municipal Waste Management Act, greenhouse gas emissions from municipal solid waste will decrease by 41%. PMID:26873911

  19. Nitrogen supply modulates the effect of changes in drying-rewetting frequency on soil C and N cycling and greenhouse gas exchange.

    PubMed

    Morillas, Lourdes; Durán, Jorge; Rodríguez, Alexandra; Roales, Javier; Gallardo, Antonio; Lovett, Gary M; Groffman, Peter M

    2015-10-01

    Climate change and atmospheric nitrogen (N) deposition are two of the most important global change drivers. However, the interactions of these drivers have not been well studied. We aimed to assess how the combined effect of soil N additions and more frequent soil drying-rewetting events affects carbon (C) and N cycling, soil:atmosphere greenhouse gas (GHG) exchange, and functional microbial diversity. We manipulated the frequency of soil drying-rewetting events in soils from ambient and N-treated plots in a temperate forest and calculated the Orwin & Wardle Resistance index to compare the response of the different treatments. Increases in drying-rewetting cycles led to reductions in soil NO3- levels, potential net nitrification rate, and soil : atmosphere GHG exchange, and increases in NH4+ and total soil inorganic N levels. N-treated soils were more resistant to changes in the frequency of drying-rewetting cycles, and this resistance was stronger for C- than for N-related variables. Both the long-term N addition and the drying-rewetting treatment altered the functionality of the soil microbial population and its functional diversity. Our results suggest that increasing the frequency of drying-rewetting cycles can affect the ability of soil to cycle C and N and soil : atmosphere GHG exchange and that the response to this increase is modulated by soil N enrichment.

  20. Nitrogen supply modulates the effect of changes in drying-rewetting frequency on soil C and N cycling and greenhouse gas exchange.

    PubMed

    Morillas, Lourdes; Durán, Jorge; Rodríguez, Alexandra; Roales, Javier; Gallardo, Antonio; Lovett, Gary M; Groffman, Peter M

    2015-10-01

    Climate change and atmospheric nitrogen (N) deposition are two of the most important global change drivers. However, the interactions of these drivers have not been well studied. We aimed to assess how the combined effect of soil N additions and more frequent soil drying-rewetting events affects carbon (C) and N cycling, soil:atmosphere greenhouse gas (GHG) exchange, and functional microbial diversity. We manipulated the frequency of soil drying-rewetting events in soils from ambient and N-treated plots in a temperate forest and calculated the Orwin & Wardle Resistance index to compare the response of the different treatments. Increases in drying-rewetting cycles led to reductions in soil NO3- levels, potential net nitrification rate, and soil : atmosphere GHG exchange, and increases in NH4+ and total soil inorganic N levels. N-treated soils were more resistant to changes in the frequency of drying-rewetting cycles, and this resistance was stronger for C- than for N-related variables. Both the long-term N addition and the drying-rewetting treatment altered the functionality of the soil microbial population and its functional diversity. Our results suggest that increasing the frequency of drying-rewetting cycles can affect the ability of soil to cycle C and N and soil : atmosphere GHG exchange and that the response to this increase is modulated by soil N enrichment. PMID:25916277

  1. Spatial interactions in a modified Daisyworld model: Heat diffusivity and greenhouse effects.

    PubMed

    Alberti, T; Primavera, L; Vecchio, A; Lepreti, F; Carbone, V

    2015-11-01

    In this work we investigate a modified version of the Daisyworld model, originally introduced by Lovelock and Watson to describe in a simple way the interactions between an Earth-like planet, its biosphere, and the incoming solar radiation. Here a spatial dependency on latitude is included, and both a variable heat diffusivity along latitudes and a simple greenhouse effect description are introduced in the model. We show that the spatial interactions between the variables of the system can locally stabilize the coexistence of the two vegetation types. The feedback on albedo is able to generate equilibrium solutions which can efficiently self-regulate the planet climate, even for values of the solar luminosity relatively far from the current Earth conditions.

  2. Global sea level rise and the greenhouse effect: might they be connected

    SciTech Connect

    Peltier, W.R.; Tushingham, A.M.

    1989-03-21

    Secular sea level trends extracted from tide gauge records of appropriately long duration demonstrate that global sea level may be rising at a rate in excess of 1 millimeter per year. However, because global coverage of the oceans by the tide gauge network is highly nonuniform and the tide gauge data reveal considerable spatial variability, there has been a well-founded reluctance to interpret the observed secular sea level rise as representing a signal of global scale that might be related to the greenhouse effect. When the tide gauge data are filtered so as to remove the contribution of ongoing glacial isostatic adjustment to the local sea level trend at each location, then the individual tide gauge records reveal sharply reduced geographic scatter and suggest that there is a globally coherent signal of strength 2.4 {+-} 0.90 millimeters per year that is active in the system. This signal could constitute an indication of global climate warming.

  3. Global sea level rise and the greenhouse effect: might they be connected?

    PubMed

    Peltier, W R; Tushingham, A M

    1989-05-19

    Secular sea level trends extracted from tide gauge records of appropriately long duration demonstrate that global sea level may be rising at a rate in excess of 1 millimeter per year. However, because global coverage of the oceans by the tide gauge network is highly nonuniform and the tide gauge data reveal considerable spatial variability, there has been a well-founded reluctance to interpret the observed secular sea level rise as representing a signal of global scale that might be related to the greenhouse effect. When the tide gauge data are filtered so as to remove the contribution of ongoing glacial isostatic adjustment to the local sea level trend at each location, then the individual tide gauge records reveal sharply reduced geographic scatter and suggest that there is a globally coherent signal of strength 2.4 +/- 0.90 millimeters per year that is active in the system. This signal could constitute an indication of global climate warming.

  4. Effect of a plant fortifier (Boundary) on pests and predators of greenhouse vegetable crops.

    PubMed

    Sannino, Luigi; Piro, Filippo

    2015-01-01

    Boundary, a plant fortifier composed of extracts of Sophora flavescens Aiton and brown algae, was tested for control of the leaf miner Tuta absoluta (Meyrick) on tomato (three trials) and of the red spider mite Tetranychus urticae Koch on eggplant (one trial) and for side effects on the whitefly predator Macrolophus pygmaeus (Kambur) (two trials) on tomato and on the thrips predators Orius laevigatus (Fieber) and Amblyseius swirskii Athias-Henriot (two trials) on pepper, all in cold greenhouses in South Italy. Control rates for T. absoluta were moderate (40-70%) in the autumn crop but very high and comparable to those for emamectin benzoate in the spring crops (96-100%). Boundary compared well with abamectin against T. urticae, with near complete control. M. pygmaeus was moderately injured in late autumn, but not in early autumn. At the tested application rate and predator population density Boundary was safe for O. laevigatus and A. swirskii. PMID:25631629

  5. Effects of Nitrogen Deposition on Greenhouse-Gas Fluxes for Forests and Grasslands of North America

    EPA Science Inventory

    Human activities have substantially elevated the atmospheric deposition of reactive nitrogen (N) onto terrestrial ecosystems of North America. Some of this N can stimulate carbon (C) storage in terrestrial ecosystems, but the fertilization effect of added N can be diminished by e...

  6. Large-eddy simulation, atmospheric measurement and inverse modeling of greenhouse gas emissions at local spatial scales

    NASA Astrophysics Data System (ADS)

    Nottrott, Anders Andelman

    non-volatile switching of magnetization would be more promising for information storage or MERAM devices with lower energy consumption and the magnetic state can be further controlled by voltage impulse. In this work, we first study the equivalent of direct and converse magnetoelectric effects. The resonant direct and converse magnetoelectric (ME) effects have been investigated experimentally and theoretically in FeGa/PZT/FeGa sandwich laminate composites. The frequency responses of direct and converse magnetoelectric effects were measured under the same electric and magnetic bias conditions. The resonant direct ME effect (DME) occurs at an antiresonance frequency, while resonant converse ME effect (CME) occurs at a resonance frequency. The antiresonance and resonance frequencies have close but different values under identical bias conditions. The magnitudes of resonant effective ME coefficients for direct and converse ME effects are also not equal. Based on different sets of constitutive equations of the materials for DME and CME, a new model was developed to describe the frequency response of DME and CME in laminate composite, which was in good agreement with the experimental results. Inequivalence of resonant ME effects is ascribed to the different mechanical and electrical boundary conditions for DME and CME. On the other hand, similar bias E and H field dependence was observed for both DME and CME resonance frequencies and resonant coefficients, indicating consistency between DME and CME effects. In the study of the frequency response of DME and CME, the linear piezoelectric effect is used. However, this linear piezoelectric effect in converse magnetoelectric coupling would lead to "butter-fly" like magnetization vs. electric field curve which leads to a "volatile" behavior in magnetic memory system. In the presented study, a unique ferroelastic switching pathway in ferroelectric substrates is utilized to produce two distinct, reversible and stable lattice strain

  7. The effects of carbon tax on the Oregon economy and state greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Rice, A. L.; Butenhoff, C. L.; Renfro, J.; Liu, J.

    2014-12-01

    Of the numerous mechanisms to mitigate greenhouse gas emissions on statewide, regional or national scales in the United States, a tax on carbon is perhaps one of the simplest. By taxing emissions directly, the costs of carbon emissions are incorporated into decision-making processes of market actors including consumers, energy suppliers and policy makers. A carbon tax also internalizes the social costs of climate impacts. In structuring carbon tax revenues to reduce corporate and personal income taxes, the negative incentives created by distortionary income taxes can be reduced or offset entirely. In 2008, the first carbon tax in North America across economic sectors was implemented in British Columbia through such a revenue-neutral program. In this work, we investigate the economic and environmental effects of a carbon tax in the state of Oregon with the goal of informing the state legislature, stakeholders and the public. The study investigates 70 different economic sectors in the Oregon economy and six geographical regions of the state. The economic model is built upon the Carbon Tax Analysis Model (C-TAM) to provide price changes in fuel with data from: the Energy Information Agency National Energy Modeling System (EIA-NEMS) Pacific Region Module which provides Oregon-specific energy forecasts; and fuel price increases imposed at different carbon fees based on fuel-specific carbon content and current and projected regional-specific electricity fuel mixes. CTAM output is incorporated into the Regional Economic Model (REMI) which is used to dynamically forecast economic impacts by region and industry sector including: economic output, employment, wages, fiscal effects and equity. Based on changes in economic output and fuel demand, we further project changes in greenhouse gas emissions resulting from economic activity and calculate revenue generated through a carbon fee. Here, we present results of this modeling effort under different scenarios of carbon fee and

  8. Single Event Effects: Space and Atmospheric Environments

    NASA Technical Reports Server (NTRS)

    Barth, Janet L.

    2003-01-01

    The paper discusses the following: 1. Sun-Earth connections. 2. Heavy ions: galactic cosmic rays; solar particle events. 3. Protons: solar particle events; trapped. 4. Atmospheric neutrons. 5. Summary.

  9. Atmospheric aerosols: Their Optical Properties and Effects

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Measured properties of atmospheric aerosol particles are presented. These include aerosol size frequency distribution and complex retractive index. The optical properties of aerosols are computed based on the presuppositions of thermodynamic equilibrium and of Mie-theory.

  10. Moisture effects on greenhouse gases generation in nitrifying gas-phase compost biofilters.

    PubMed

    Maia, Guilherme D N; Day, George B; Gates, Richard S; Taraba, Joseph L; Coyne, Mark S

    2012-06-01

    Gas-phase compost biofilters are extensively used in concentrated animal feeding operations to remove odors and, in some cases, ammonia from air sources. The expected biochemical pathway for these predominantly aerobic systems is nitrification. However, non-uniform media with low oxygen levels can shift biofilter microbial pathways to denitrification, a source of greenhouse gases. Several factors contribute to the formation of anoxic/anaerobic zones: media aging, media and particle structure, air velocity distribution, compaction, biofilm thickness, and moisture content (MC) distribution. The present work studies the effects of media moisture conditions on ammonia (NH(3)) removal and greenhouse gas generation (nitrous oxide, N(2)O and methane, CH(4)) for gas-phase compost biofilters subject to a 100-day controlled drying process. Continuous recordings were made for the three gases and water vapor (2.21-h sampling cycle, each cycle consisted of three gas species, and water vapor, for a total of 10,050 data points). Media moisture conditions were classified into three corresponding media drying rate (DR) stages: Constant DR (wetter media), falling DR, and stable-dry system. The first-half of the constant DR period (0-750 h; MC=65-52%, w.b.) facilitated high NH(3) removal rates, but higher N(2)O generation and no CH(4) generation. At the drier stages of the constant DR (750-950 h; MC=52-48%, w.b.) NH(3) removal remained high but N(2)O net generation decreased to near zero. In the falling DR stage (1200-1480 h; MC=44-13%) N(2)O generation decreased, CH(4) increased, and NH(3) was no longer removed. No ammonia removal or greenhouse gas generation was observed in the stable-dry system (1500-2500 h; MC=13%). These results indicate that media should remain toward the drier region of the constant DR (in close proximity to the falling DR stage; MC=50%, approx.), to maintain high levels of NH(3) removal, reduced levels of N(2)O generation, and nullify levels of CH(4

  11. Effect of Atmospheric Conditions on LIBS Spectra

    PubMed Central

    Effenberger, Andrew J.; Scott, Jill R.

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) is typically performed at ambient Earth atmospheric conditions. However, interest in LIBS in other atmospheric conditions has increased in recent years, especially for use in space exploration (e.g., Mars and Lunar) or to improve resolution for isotopic signatures. This review focuses on what has been reported about the performance of LIBS in reduced pressure environments as well as in various gases other than air. PMID:22399914

  12. Quantifying Regional Greenhouse Gas Emissions of HFC-134a From Atmospheric Measurements at the Trinidad Head (California), Cape Grim (Tasmania) and Mace Head (Ireland) Remote AGAGE Sites.

    NASA Astrophysics Data System (ADS)

    Manning, A. J.; Weiss, R. F.; Mühle, J.; Fraser, P. J.; Krummel, P. B.; O'Doherty, S.; Simmonds, P. G.

    2008-12-01

    Atmospheric measurement-based "top-down" approaches to emissions estimation provide a method of validating reported inventory-based "bottom-up" emissions assessments. At the AGAGE (Advanced Global Atmospheric Gases Experiment) measurement stations at Trinidad Head (THD) on the Northern California coast (41°N, 124°W), Cape Grim (CGM) on the northwestern tip of Tasmania (41°S, 145°E), and Mace Head (MHD) on the western coast of Ireland (53°N, 10°W), Medusa GC/MS and GC/ECD/FID instrumentation measure a wide range of trace gases in ambient air at high temporal resolution and high precision. Here, the western US, northwestern European and southern Australian emissions of the greenhouse gas (GHG) HFC-134a are estimated using the HFC-134a measurements, an atmospheric dispersion model (NAME), and an inversion methodology. NAME (Numerical Atmospheric dispersion Modelling Environment) is a Lagrangian atmospheric dispersion model that uses 3D meteorology from the UK Met Office numerical weather prediction model. Mid-latitude Northern and Southern Hemisphere baseline concentrations of HFC-134a are determined using NAME and statistical post- processing of the observations, and this baseline is used to generate a time series of "polluted" (above baseline) observations. In this application NAME is run backwards in time for ten days for each 3-hour interval in 1995-2008 for MHD, 2003-2008 for CGM and 2005-2008 for THD releasing thousands of model particles at each observing site. A map is then produced estimating all of the surface (0-100m) contributions within ten days of travel arriving at each site during each interval. The resulting matrix describes the dilution in concentration that occurs from a unit release from each grid as it travels to the measurement site. Iterative inversion modeling is then carried out to generate an emission estimate that provides the best statistical match between the modeled time series and the observations. Uncertainty in the emission

  13. [Effects of vegetable cultivation years on microbial biodiversity and abundance of nitrogen cycling in greenhouse soils].

    PubMed

    Wang, Ya-Nan; Zeng, Xi-Bai; Wang, Yu-Zhong; Bai, Ling-Yu; Su, Shi-Ming; Wu, Cui-Xia; Li, Lian-Fang; Duan, Ran

    2014-04-01

    The effects of facility vegetable cultivation years (three, nine, fourteen or seventeen years) on biodiversity and abundance of soil microorganisms, such as bacteria, ammonia oxidizing bacteria (AOB) and nirK type denitrifying bacteria, in the greenhouse soils in Wuwei of Gansu Province, China were determined by the combined analyses of terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR. The results showed that the dominant population structure and abundance of bacteria, AOB, nirK type denitrifying bacteria in the soils were significantly different from those in the farmland fields. The dominant population also changed with the cultivation years. With the increase of vegetable cultivation years, the abundance of 16S rRNA and nirK gene in the 0-20 cm soil layer first increased and then decreased, with the maximum values of 9.67 x 10(9) and 2.30 x 10(7) copies x g(-1) soil at year 14 and year 9, being as 1.51 and 1.52 times of that of the 3-year, respectively. However, the abundance of amoA gene showed an opposite trend. The amoA gene copy number in the 14-year sample was 3.28 x 10(7) copies x g(-1) soil, which was only 45.7% of that of the 3-year. These results illustrated that the ecological adaptation mechanisms of the different functional microorganisms involved in nitrogen cycling had significant differences in the facility vegetable soils, and provided a base for further researches on exploring and explaining the characteristics and adaptation mechanisms of microorganisms in greenhouse soil.

  14. [Effects of vegetable cultivation years on microbial biodiversity and abundance of nitrogen cycling in greenhouse soils].

    PubMed

    Wang, Ya-Nan; Zeng, Xi-Bai; Wang, Yu-Zhong; Bai, Ling-Yu; Su, Shi-Ming; Wu, Cui-Xia; Li, Lian-Fang; Duan, Ran

    2014-04-01

    The effects of facility vegetable cultivation years (three, nine, fourteen or seventeen years) on biodiversity and abundance of soil microorganisms, such as bacteria, ammonia oxidizing bacteria (AOB) and nirK type denitrifying bacteria, in the greenhouse soils in Wuwei of Gansu Province, China were determined by the combined analyses of terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR. The results showed that the dominant population structure and abundance of bacteria, AOB, nirK type denitrifying bacteria in the soils were significantly different from those in the farmland fields. The dominant population also changed with the cultivation years. With the increase of vegetable cultivation years, the abundance of 16S rRNA and nirK gene in the 0-20 cm soil layer first increased and then decreased, with the maximum values of 9.67 x 10(9) and 2.30 x 10(7) copies x g(-1) soil at year 14 and year 9, being as 1.51 and 1.52 times of that of the 3-year, respectively. However, the abundance of amoA gene showed an opposite trend. The amoA gene copy number in the 14-year sample was 3.28 x 10(7) copies x g(-1) soil, which was only 45.7% of that of the 3-year. These results illustrated that the ecological adaptation mechanisms of the different functional microorganisms involved in nitrogen cycling had significant differences in the facility vegetable soils, and provided a base for further researches on exploring and explaining the characteristics and adaptation mechanisms of microorganisms in greenhouse soil. PMID:25011307

  15. [Effects of canopy shapes of grape on canopy microenvironment, leaf and fruit quality in greenhouse].

    PubMed

    Shi, Xiang-bin; Liu, Feng-zhi; Cheng, Cun-gang; Wang, Xiao-di; Wang, Bao-liang; Zheng, Xiao-cui; Wang, Hai-bo

    2015-12-01

    The effects of three canopy shapes, i.e., vertical canopy, V-shaped canopy and horizontal canopy, on canopy microenvironment, quality of leaves and fruits were studied in the 3-year-old grape 'Jingmi' grafted on ' Beta' in greenhouse. The results showed that gap fraction and openness of vertical canopy were significantly higher than that of V-shaped canopy and horizontal canopy, and leaf area index, light interception rate and canopy temperature difference between day and night were significantly lower than those of V-shaped canopy and horizontal canopy. There was no significant difference between the latter two treatments. The palisade thickness of V-shaped canopy was significantly greater than that of vertical canopy, and horizontal canopy was in the middle. The chlorophyll and carotenoid contents of V-shaped canopy were significantly higher than those of vertical canopy and horizontal canopy, and those in the latter two treatments had no significant difference. The fruit quality of V-shaped canopy was the best, and that of horizontal canopy was the worst. The results of GC-MS analysis showed that 29 types of volatile aroma compounds were detected in V-shaped canopy, but just 17 and 16 in vertical canopy and horizontal canopy, respectively. In V-shaped canopy, the characteristic aroma in grape 'Jingmi' was higher, except ethanol, trans-2- hexene-1-alcohol, 2-octyl ketone and formic acid ester. The linalool content in vertical canopy and V-shaped canopy was higher than that in horizontal canopy. The nerol content in V-shaped canopy was higher than that in vertical canopy and horizontal canopy, and the leaf alcohol content in V-shaped canopy and horizontal canopy was higher than that in vertical canopy. The citronellol was de-tected only in V-shaped canopy. In greenhouse, the fruit aroma of V-shaped canopy grape was stronger, and well reflected the variety characteristics. PMID:27112012

  16. [Effects of canopy shapes of grape on canopy microenvironment, leaf and fruit quality in greenhouse].

    PubMed

    Shi, Xiang-bin; Liu, Feng-zhi; Cheng, Cun-gang; Wang, Xiao-di; Wang, Bao-liang; Zheng, Xiao-cui; Wang, Hai-bo

    2015-12-01

    The effects of three canopy shapes, i.e., vertical canopy, V-shaped canopy and horizontal canopy, on canopy microenvironment, quality of leaves and fruits were studied in the 3-year-old grape 'Jingmi' grafted on ' Beta' in greenhouse. The results showed that gap fraction and openness of vertical canopy were significantly higher than that of V-shaped canopy and horizontal canopy, and leaf area index, light interception rate and canopy temperature difference between day and night were significantly lower than those of V-shaped canopy and horizontal canopy. There was no significant difference between the latter two treatments. The palisade thickness of V-shaped canopy was significantly greater than that of vertical canopy, and horizontal canopy was in the middle. The chlorophyll and carotenoid contents of V-shaped canopy were significantly higher than those of vertical canopy and horizontal canopy, and those in the latter two treatments had no significant difference. The fruit quality of V-shaped canopy was the best, and that of horizontal canopy was the worst. The results of GC-MS analysis showed that 29 types of volatile aroma compounds were detected in V-shaped canopy, but just 17 and 16 in vertical canopy and horizontal canopy, respectively. In V-shaped canopy, the characteristic aroma in grape 'Jingmi' was higher, except ethanol, trans-2- hexene-1-alcohol, 2-octyl ketone and formic acid ester. The linalool content in vertical canopy and V-shaped canopy was higher than that in horizontal canopy. The nerol content in V-shaped canopy was higher than that in vertical canopy and horizontal canopy, and the leaf alcohol content in V-shaped canopy and horizontal canopy was higher than that in vertical canopy. The citronellol was de-tected only in V-shaped canopy. In greenhouse, the fruit aroma of V-shaped canopy grape was stronger, and well reflected the variety characteristics.

  17. Atmospheric Effects on InSAR Measurements and Their Mitigation

    PubMed Central

    Ding, Xiao-li; Li, Zhi-wei; Zhu, Jian-jun; Feng, Guang-cai; Long, Jiang-ping

    2008-01-01

    Interferometric Synthetic Aperture Radar (InSAR) is a powerful technology for observing the Earth surface, especially for mapping the Earth's topography and deformations. InSAR measurements are however often significantly affected by the atmosphere as the radar signals propagate through the atmosphere whose state varies both in space and in time. Great efforts have been made in recent years to better understand the properties of the atmospheric effects and to develop methods for mitigating the effects. This paper provides a systematic review of the work carried out in this area. The basic principles of atmospheric effects on repeat-pass InSAR are first introduced. The studies on the properties of the atmospheric effects, including the magnitudes of the effects determined in the various parts of the world, the spectra of the atmospheric effects, the isotropic properties and the statistical distributions of the effects, are then discussed. The various methods developed for mitigating the atmospheric effects are then reviewed, including the methods that are based on PSInSAR processing, the methods that are based on interferogram modeling, and those that are based on external data such as GPS observations, ground meteorological data, and satellite data including those from the MODIS and MERIS. Two examples that use MODIS and MERIS data respectively to calibrate atmospheric effects on InSAR are also given.

  18. Effects of Experimental Warming on Net Greenhouse Gas Fluxes from a New England Salt Marsh

    NASA Astrophysics Data System (ADS)

    Carey, J.; Kroeger, K. D.; Morkeski, K.; Chen, X.; Tang, J.

    2014-12-01

    Salt marsh ecosystems face a variety of anthropogenic stressors, including rising temperature, increasing rate of relative sea level rise, changing sediment loads, and increasing nitrogen loads. In this study, we focus on the role of increased temperatures in altering net greenhouse gas fluxes (CO2, CH4, N2O) in a relatively undisturbed New England salt marsh (Waquoit Bay National Estuarine Research Reserve, USA). Salt marshes are considered large net sinks of carbon (C), due in part to the high rates of primary production and relatively slow decomposition rates. However, increased temperature as a result of climate change may alter the net carbon balance of these ecosystems, due to changes in relative rates of respiration and photosynthesis. In addition to altering the net C balance, nitrous oxide (N2O) is produced in part via microbially-mediated processes that also respond to temperature (e.g. nitrification, denitrification). Thus, we hypothesize that higher temperatures may increase the fluxes of this potent GHG from marshes to the atmosphere. To examine the role of warming in altering net GHG fluxes, we installed six open-top-chambers (OTCs) in both the high and low marsh during July of 2014. We used the cavity ring-down spectroscopy method (Picarro and LGR) to measure in-situ fluxes of CO2, CH4, N2O monthly in light and dark conditions. We will present data demonstrating that our OTCs successfully warmed the air temperature in the plots at least 5 ˚C and evaluate how this temperature increase altered GHG net ecosystem exchange in the marsh.

  19. High-sensitivity remote detection of atmospheric pollutants and greenhouse gases at low ppm levels using near-infrared tunable diode lasers

    NASA Astrophysics Data System (ADS)

    Roy, Anirban; Upadhyay, Abhishek; Chakraborty, Arup Lal

    2016-05-01

    The concentration of atmospheric pollutants and greenhouse gases needs to be precisely monitored for sustainable industrial development and to predict the climate shifts caused by global warming. Such measurements are made on a continuous basis in ecologically sensitive and urban areas in the advanced countries. Tunable diode laser spectroscopy (TDLS) is the most versatile non-destructive technology currently available for remote measurements of multiple gases with very high selectivity (low cross-sensitivity), very high sensitivity (on the order of ppm and ppb) and under hazardous conditions. We demonstrate absolute measurements of acetylene, methane and carbon dioxide using a fielddeployable fully automated TDLS system that uses calibration-free 2f wavelength modulation spectroscopy (2f WMS) techniques with sensitivities of low ppm levels. A 40 mW, 1531.52 nm distributed feedback (DFB) diode laser, a 10 mW, 1650 nm DFB laser and a 1 mW, 2004 nm vertical cavity surface emitting laser (VCSEL) are used in the experiments to probe the P9 transition of acetylene, R4 transition of methane and R16 transition of carbon dioxide respectively. Data acquisition and on-board analysis comprises a Raspberry Pi-based embedded system that is controllable over a wireless connection. Gas concentration and pressure are simultaneously extracted by fitting the experimental signals to 2f WMS signals simulated using spectroscopic parameters obtained from the HITRAN database. The lowest detected concentration is 11 ppm for acetylene, 275 ppm for methane and 285 ppm for carbon dioxide using a 28 cm long single-pass gas cell.

  20. Global Warming & the Greenhouse Effect. Grades 7-10. Teacher's Guide. Great Explorations in Math and Science (GEMS).

    ERIC Educational Resources Information Center

    Hocking, Colin; And Others

    This series of educational activities is intended to help teachers communicate basic scientific concepts related to global warming and the greenhouse effect to students grades 7-10. Seven sessions provide laboratory activities, simulations, and discussions that can be used to improve student understanding of a number of important scientific…

  1. Global Warming and the Greenhouse Effect: January 1986-January 1992. Quick Bibliography Series: QB 92-36.

    ERIC Educational Resources Information Center

    MacLean, Jayne T.

    This bibliography contains 442 journal article, book, and audiovisual citations on global warming and the greenhouse effect entered into the National Agricultural Library's AGRICOLA database between January 1979 and March 1992. The bibliography contains an author and subject index as well as information on obtaining documents. (LZ)

  2. Physiological effects of Meloidogyne incognita infection on cotton genotypes with differing levels of resistance in the greenhouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greenhouse tests were conducted to evaluate 1) the effect of Meloidogyne incognita infection in cotton on plant growth and physiology including the height-to-node ratio, chlorophyll content, dark adapted quantum yield of photosystem II, and leaf area, and 2) the extent to which moderate or high leve...

  3. The Impact of Secondary School Students' Preconceptions on the Evolution of their Mental Models of the Greenhouse effect and Global Warming

    NASA Astrophysics Data System (ADS)

    Reinfried, Sibylle; Tempelmann, Sebastian

    2014-01-01

    This paper provides a video-based learning process study that investigates the kinds of mental models of the atmospheric greenhouse effect 13-year-old learners have and how these mental models change with a learning environment, which is optimised in regard to instructional psychology. The objective of this explorative study was to observe and analyse the learners' learning pathways according to their previous knowledge in detail and to understand the mental model formation processes associated with them more precisely. For the analysis of the learning pathways, drawings, texts, video and interview transcripts from 12 students were studied using qualitative methods. The learning pathways pursued by the learners significantly depend on their domain-specific previous knowledge. The learners' preconceptions could be typified based on specific characteristics, whereby three preconception types could be formed. The 'isolated pieces of knowledge' type of learners, who have very little or no previous knowledge about the greenhouse effect, build new mental models that are close to the target model. 'Reduced heat output' type of learners, who have previous knowledge that indicates compliances with central ideas of the normative model, reconstruct their knowledge by reorganising and interpreting their existing knowledge structures. 'Increasing heat input' type of learners, whose previous knowledge consists of subjective worldly knowledge, which has a greater personal explanatory value than the information from the learning environment, have more difficulties changing their mental models. They have to fundamentally reconstruct their mental models.

  4. Students' Understanding of the Greenhouse Effect, the Societal Consequences of Reducing CO2 Emissions and the Problem of Ozone Layer Depletion.

    ERIC Educational Resources Information Center

    Andersson, Bjorn; Wallin, Anita

    2000-01-01

    Contributes to the growing body of knowledge about students' conceptions and views of environmental and natural resource issues. Questions 9th and 12th grade Swedish students' understandings of the greenhouse effect, reduction of CO2 emissions, and the depletion of the ozone layer. Observes five models of the greenhouse effect that appear among…

  5. Anthropogenic effects on greenhouse gas (CH4 and N2O) emissions in the Guadalete River Estuary (SW Spain).

    PubMed

    Burgos, M; Sierra, A; Ortega, T; Forja, J M

    2015-01-15

    Coastal areas are subject to a great anthropogenic pressure because more than half of the world's population lives in its vicinity causing organic matter inputs, which intensifies greenhouse gas emissions into the atmosphere. Dissolved concentrations of CH4 and N2O have been measured seasonally during 2013 in the Guadalete River Estuary, which flows into the Cadiz Bay (southwestern Spanish coast). It has been intensely contaminated since 1970. Currently it receives wastewater effluents from cities and direct discharges from nearby agriculture crop. Eight sampling stations have been established along 18 km of the estuary. CH4 and N2O were measured using a gas chromatograph connected to an equilibration system. Additional parameters such as organic matter, dissolved oxygen, nutrients and chlorophyll were determinate as well, in order to understand the relationship between physicochemical and biological processes. Gas concentrations increased from the River mouth toward the inner part, closer to the wastewater treatment plant discharge. Values varied widely within 21.8 and 3483.4 nM for CH4 and between 9.7 and 147.6 nM for N2O. Greenhouse gas seasonal variations were large influenced by the precipitation regime, masking the temperature influence. The Guadatete Estuary acted as a greenhouse gas source along the year, with mean fluxes of 495.7 μmol m(-2)d(-1) and 92.8 μmol m(-2)d(-1) for CH4 and N2O, respectively.

  6. The Effect of Gravity Waves on Jupiter's Middle Atmosphere

    NASA Astrophysics Data System (ADS)

    Yelle, R. V.; Young, L. A.; Young, R. E.

    1998-09-01

    The temperature profile of Jupiter's middle atmosphere exhibits numerous fluctuations that are likely the manifestation of gravity waves. The amplitude of the temperature perturbations are large enough for non-linear effects on the wave propagation, the interaction among waves, and the interaction between waves and the background atmosphere to be important. As a consequence wave propagation and dissipation affects the energy balance, momentum balance, and diffusion of trace species in the middle atmosphere. We adapt theories for wave-wave interaction developed for the terrestrial atmosphere to Jupiter's atmosphere and extend them to include dissipation by molecular viscosity and thermal conduction. Although definitive conclusions are limited by our knowledge of the wave spectrum on Jupiter, we find that wave-wave interactions in the presence of these molecular effects can explain the observed levels of turbulent mixing and dynamical heating in the middle atmosphere.

  7. Atmospheric Effects on the Combustion of Detonating Aluminized Explosives

    NASA Astrophysics Data System (ADS)

    Carney, Joel

    2005-07-01

    The detonation and subsequent combustion of aluminized explosive formulations depend heavily on the reactions of aluminum and oxygen. Fuel-rich formulations require oxygen from an external source (nominally an oxygen-containing atmosphere) to burn the fuel to completion. Dynamic spectroscopic measurements were made for two different aluminized explosives (PBXIH-135 and PBXN-111) to investigate the effect of changing atmospheres on the combustion properties of aluminum. Both explosive formulations were tested under normal atmospheric conditions and in an atmosphere of nitrogen. Light emission (from 350-550 nm) from the explosive events was collected in a spectrometer and dispersed temporally in a streak camera. New, nitrogen-containing species (near 387 and 416 nm) arise in the nitrogen atmosphere experiments for both formulations that seem to replace aluminum monoxide as a primary intermediate product for the fuel. The peak assignments and global kinetics of each species will be presented and the implications of these results on atmospheric effects will be discussed.

  8. Cost-effectiveness analysis of policy instruments for greenhouse gas emission mitigation in the agricultural sector.

    PubMed

    Bakam, Innocent; Balana, Bedru Babulo; Matthews, Robin

    2012-12-15

    Market-based policy instruments to reduce greenhouse gas (GHG) emissions are generally considered more appropriate than command and control tools. However, the omission of transaction costs from policy evaluations and decision-making processes may result in inefficiency in public resource allocation and sub-optimal policy choices and outcomes. This paper aims to assess the relative cost-effectiveness of market-based GHG mitigation policy instruments in the agricultural sector by incorporating transaction costs. Assuming that farmers' responses to mitigation policies are economically rationale, an individual-based model is developed to study the relative performances of an emission tax, a nitrogen fertilizer tax, and a carbon trading scheme using farm data from the Scottish farm account survey (FAS) and emissions and transaction cost data from literature metadata survey. Model simulations show that none of the three schemes could be considered the most cost effective in all circumstances. The cost effectiveness depends both on the tax rate and the amount of free permits allocated to farmers. However, the emissions trading scheme appears to outperform both other policies in realistic scenarios. PMID:22868381

  9. Cost-effectiveness analysis of policy instruments for greenhouse gas emission mitigation in the agricultural sector.

    PubMed

    Bakam, Innocent; Balana, Bedru Babulo; Matthews, Robin

    2012-12-15

    Market-based policy instruments to reduce greenhouse gas (GHG) emissions are generally considered more appropriate than command and control tools. However, the omission of transaction costs from policy evaluations and decision-making processes may result in inefficiency in public resource allocation and sub-optimal policy choices and outcomes. This paper aims to assess the relative cost-effectiveness of market-based GHG mitigation policy instruments in the agricultural sector by incorporating transaction costs. Assuming that farmers' responses to mitigation policies are economically rationale, an individual-based model is developed to study the relative performances of an emission tax, a nitrogen fertilizer tax, and a carbon trading scheme using farm data from the Scottish farm account survey (FAS) and emissions and transaction cost data from literature metadata survey. Model simulations show that none of the three schemes could be considered the most cost effective in all circumstances. The cost effectiveness depends both on the tax rate and the amount of free permits allocated to farmers. However, the emissions trading scheme appears to outperform both other policies in realistic scenarios.

  10. The size and range effect: lifecycle greenhouse gas emissions of electric vehicles

    NASA Astrophysics Data System (ADS)

    Ager-Wick Ellingsen, Linda; Singh, Bhawna; Hammer Strømman, Anders

    2016-05-01

    The primary goal of this study is to investigate the effect of increasing battery size and driving range to the environmental impact of electric vehicles (EVs). To this end, we compile cradle-to-grave inventories for EVs in four size segments to determine their climate change potential. A second objective is to compare the lifecycle emissions of EVs to those of conventional vehicles. For this purpose, we collect lifecycle emissions for conventional vehicles reported by automobile manufacturers. The lifecycle greenhouse gas emissions are calculated per vehicle and over a total driving range of 180 000 km using the average European electricity mix. Process-based attributional LCA and the ReCiPe characterisation method are used to estimate the climate change potential from the hierarchical perspective. The differently sized EVs are compared to one another to find the effect of increasing the size and range of EVs. We also point out the sources of differences in lifecycle emissions between conventional- and electric vehicles. Furthermore, a sensitivity analysis assesses the change in lifecycle emissions when electricity with various energy sources power the EVs. The sensitivity analysis also examines how the use phase electricity sources influences the size and range effect.

  11. Effect of Biochar on Greenhouse Gas Emissions and Nitrogen Cycling in Laboratory and Field Experiments

    NASA Astrophysics Data System (ADS)

    Hagemann, Nikolas; Harter, Johannes; Kaldamukova, Radina; Ruser, Reiner; Graeff-Hönninger, Simone; Kappler, Andreas; Behrens, Sebastian

    2014-05-01

    The extensive use of nitrogen (N) fertilizers in agriculture is a major source of anthropogenic N2O emissions contributing 8% to global greenhouse gas emissions. Soil biochar amendment has been suggested as a means to reduce both CO2 and non-CO2 greenhouse gas emissions. The reduction of N2O emissions by biochar has been demonstrated repeatedly in field and laboratory experiments. However, the mechanisms of the reduction remain unclear. Further it is not known how biochar field-weathering affects GHG emissions and how agro-chemicals, such as the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP), that is often simultaneously applied together with commercial N-fertilizers, impact nitrogen transformation and N2O emissions from biochar amended soils. In order investigate the duration of the biochar effect on soil N2O emissions and its susceptibility to DMPP application we performed a microcosm and field study with a high-temperature (400 ° C) beech wood derived biochar (60 t ha-1 and 5 % (w/w) biochar in the field and microcosms, respectively). While the field site contained the biochar already for three years, soil and biochar were freshly mixed for the laboratory microcosm experiments. In both studies we quantified GHG emissions and soil nitrogen speciation (nitrate, nitrite, ammonium). While the field study was carried out over the whole vegetation period of the sunflower Helianthus annuus L., soil microcosm experiments were performed for up to 9 days at 28° C. In both experiments a N-fertilizer containing DMPP was applied either before planting of the sunflowers or at the beginning of soil microcosms incubation. Laboratory microcosm experiments were performed at 60% water filled pore space reflecting average field conditions. Our results show that biochar effectively reduced soil N2O emissions by up to 60 % in the field and in the soil microcosm experiments. No significant differences in N2O emission mitigation potential between field-aged and fresh

  12. Greenhouse Gases

    MedlinePlus

    ... Greenhouse Gases Come From Outlook for Future Emissions Recycling and Energy Nonrenewable Sources Oil and Petroleum Products ... Power Wave Power Ocean Thermal Energy Conversion Biomass Wood and Wood Waste Waste-to-Energy (MSW) Landfill ...

  13. Solar greenhouse

    SciTech Connect

    Baldwin, R.E.

    1980-04-01

    A solar greenhouse is disclosed wherein plants are grown and utilized as collectors to absorb solar radiation and produce heat laden humidified air through the process of evapotranspiration. This humidified air is then further heated by solar energy. Energy is then extracted from the humidified air by cooling the air and condensing the water vapor within the air. The extracted heat can then be stored and utilized as required to heat the greenhouse and plants.

  14. Titan is to Earth's Hydrological Cycle what Venus is to its Greenhouse Effect

    NASA Astrophysics Data System (ADS)

    Lorenz, R. D.

    2012-06-01

    Titan serves as an extreme extrapolation of Earth's possible present trend toward more violent rainstorms interspersed by long droughts, much as Venus has acted as a bogeyman to illustrate the perils of enhanced greenhouse warming.

  15. Effect of elevated atmospheric CO2 on carbon allocation patterns in Eriphorum vaginatum

    NASA Astrophysics Data System (ADS)

    Strom, L.

    2013-12-01

    Greenhouse gases of particular importance to the human induced greenhouse effect are, e.g., CO2 and CH4. Natural and agricultural wetlands together contribute with over 40 % of the annual atmospheric emissions of CH4 and are, therefore, considered to be the largest single contributor of this gas to the troposphere. There is a growing concern that increasing atmospheric concentrations of CO2 will stimulate CH4 production and emission from wetland ecosystems, resulting in feedback mechanisms that in future will increase the radiative forcing of these ecosystems. The aim of this study was to elucidate the effect of elevated atmospheric CO2 on fluxes of CO2 and CH4, biomass allocation patterns and amount of labile substrates (i.e. low molecular weight organic acids, OAs) for CH4 production in the root vicinity of Eriophorum vaginatum. Eriophorum cores and plants were collected at Fäjemyr, a temperate ombrotrophic bog situated in the south of Sweden. These were cultivated under controlled environmental conditions in an atmosphere of 390 or 800 ppm of CO2 (n=5 per treatment). After a one month development period gas fluxes were measured twice per week over one month using a Fourier Transform Infrared spectrometer (Gasmet Dx-4030) and OAs using a liquid chromatography-ionspray tandem mass spectrometry system (Dionex ICS-2500 and Applied Biosystems 2000 Q-Trap triple quadrupole MS). The results clearly show that elevated CO2 significantly affects all measured parts of the carbon cycle. Greenhouse gas fluxes were significantly (repeated measures test) higher under elevated CO2 conditions, NEE p < 0.0001, Reco p = 0.005, GPP p = 0.012 and CH4 p = 0.022. As were biomass of leaves, roots and concentration of OAs around the roots of plants, p = 0.045, p = 0 = 0.045 and p = 0.045 respectively (Kruskal wallis 1-way anova). The study shows higher CH4 emissions under elevated CO2 and that this may be due to a priming effect, due to input of fresh labile-C via living roots and

  16. Estimating the Health Effects of Greenhouse Gas Mitigation Strategies: Addressing Parametric, Model, and Valuation Challenges

    PubMed Central

    Hess, Jeremy J.; Ebi, Kristie L.; Markandya, Anil; Balbus, John M.; Wilkinson, Paul; Haines, Andy; Chalabi, Zaid

    2014-01-01

    Background: Policy decisions regarding climate change mitigation are increasingly incorporating the beneficial and adverse health impacts of greenhouse gas emission reduction strategies. Studies of such co-benefits and co-harms involve modeling approaches requiring a range of analytic decisions that affect the model output. Objective: Our objective was to assess analytic decisions regarding model framework, structure, choice of parameters, and handling of uncertainty when modeling health co-benefits, and to make recommendations for improvements that could increase policy uptake. Methods: We describe the assumptions and analytic decisions underlying models of mitigation co-benefits, examining their effects on modeling outputs, and consider tools for quantifying uncertainty. Discussion: There is considerable variation in approaches to valuation metrics, discounting methods, uncertainty characterization and propagation, and assessment of low-probability/high-impact events. There is also variable inclusion of adverse impacts of mitigation policies, and limited extension of modeling domains to include implementation considerations. Going forward, co-benefits modeling efforts should be carried out in collaboration with policy makers; these efforts should include the full range of positive and negative impacts and critical uncertainties, as well as a range of discount rates, and should explicitly characterize uncertainty. We make recommendations to improve the rigor and consistency of modeling of health co-benefits. Conclusion: Modeling health co-benefits requires systematic consideration of the suitability of model assumptions, of what should be included and excluded from the model framework, and how uncertainty should be treated. Increased attention to these and other analytic decisions has the potential to increase the policy relevance and application of co-benefits modeling studies, potentially helping policy makers to maximize mitigation potential while

  17. Effects of Fuel Ethanol Use on Fuel-Cycle Energy and Greenhouse Gas Emissions

    SciTech Connect

    C. Saricks; D. Santini; M. Wang

    1999-02-08

    We estimated the effects on per-vehicle-mile fuel-cycle petroleum use, greenhouse gas (GHG) emissions, and energy use of using ethanol blended with gasoline in a mid-size passenger car, compared with the effects of using gasoline in the same car. Our analysis includes petroleum use, energy use, and emissions associated with chemicals manufacturing, farming of corn and biomass, ethanol production, and ethanol combustion for ethanol; and petroleum use, energy use, and emissions associated with petroleum recovery, petroleum refining, and gasoline combustion for gasoline. For corn-based ethanol, the key factors in determining energy and emissions impacts include energy and chemical usage intensity of corn farming, energy intensity of the ethanol plant, and the method used to estimate energy and emissions credits for co-products of corn ethanol. The key factors in determining the impacts of cellulosic ethanol are energy and chemical usage intensity of biomass farming, ethanol yield per dry ton of biomass, and electricity credits in cellulosic ethanol plants. The results of our fuel-cycle analysis for fuel ethanol are listed below. Note that, in the first half of this summary, the reductions cited are per-vehicle-mile traveled using the specified ethanol/gasoline blend instead of conventional (not reformulated) gasoline. The second half of the summary presents estimated changes per gallon of ethanol used in ethanol blends. GHG emissions are global warming potential (GWP)-weighted, carbon dioxide (CO2)-equivalent emissions of CO2, methane (CH4), and nitrous oxide (N2O).

  18. [Effects of DMPP-compound fertilizer on greenhouse celery growth and nutritional quality].

    PubMed

    Wu, Shao-fu; Wu, Liang-huan; Yin, Yi-meng; Yang, Shu-dong; Chen, Xian-you

    2007-02-01

    A field study with greenhouse celery (Apium graveolens L. ) showed that compared with basal application of ordinary compound fertilizer, one-time basal application of DMPP-compound fertilizer ( ENTEC , 12-12-17) at the rates of 67. 5 kg N x hm(-2) and 54. 0 kg N x hm(-2) increased the yield by 5. 78% and 10. 14% , respectively. The application of ENTEC also improved the nutritional quality of edible parts, e. g. , the Vc, amino acid, soluble sugar, N and P contents increased, while nitrate content decreased. Compared with basal plus side dressing applications, appropriately reducing the application rate and times of ENTEChad more beneficial effects on celery yield and quality, and reduced the production costs. ENTEC could suppress the transformation of soil NH4+ -N to NO3 - -N effectively, and thus, its application could retain soil residual N more in NH4+ -N than in NO3- -N form after celery harvested, resulting in a reduction of nitrate leaching.

  19. The Effect of Natural Gas Supply on US Renewable Energy and Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Shearer, C.; Bistline, J.; Inman, M.; Davis, S. J.

    2014-12-01

    Increased use of natural gas has been promoted as a means of decarbonizing the US power sector, because of superior generator efficiency and lower CO2 emissions per unit of electricity than coal. We model the effect of different gas supplies on the US power sector and greenhouse gas (GHG) emissions. Across a range of climate policies, we find that more abundant natural gas decreases use of both coal and renewable energy technologies in the future. Without a climate policy, overall energy use also increases as the gas supply increases. With reduced deployment of lower-carbon renewable energies and increased electricity consumption, the effect of higher gas supplies on GHG emissions is small: cumulative emissions 2013-2055 in our high gas supply scenario are 2% less than in our low gas supply scenario, when there are no new climate policies and a methane leakage rate of 1.5% is assumed. Assuming leakage rates of 0 or 3% does not substantially alter this finding. In our results, only climate policies bring about a significant reduction in future CO2 emissions within the US electricity sector. Our results suggest that without strong limits on GHG emissions or policies that explicitly encourage renewable energy, more abundant natural gas may actually slow the process of decarbonization, primarily by delaying deployment of renewable energy technologies.

  20. Atmospheric effects on CO2 laser propagation

    NASA Technical Reports Server (NTRS)

    Murty, S. S. R.; Bilbro, J. W.

    1978-01-01

    An investigation was made of the losses encountered in the propagation of CO2 laser radiation through the atmosphere, particularly as it applies to the NASA/Marshall Space Flight Center Pulsed Laser Doppler System. As such it addresses three major areas associated with signal loss: molecular absorption, refractive index changes in a turbulent environment, and aerosol absorption and scattering. In particular, the molecular absorption coefficients of carbon dioxide, water vapor, and nitrous oxide are calculated for various laser lines in the region of 10.6 mu m as a function of various pressures and temperatures. The current status in the physics of low-energy laser propagation through a turbulent atmosphere is presented together with the analysis and evaluation of the associated heterodyne signal power loss. Finally, aerosol backscatter and extinction coefficients are calculated for various aerosol distributions and the results incorporated into the signal-to-noise ratio equation for the Marshall Space Flight Center system.

  1. Effects of atmospheric moisture on rock resistivity.

    NASA Technical Reports Server (NTRS)

    Alvarez, R.

    1973-01-01

    This study examines the changes in resistivity of rock samples as induced by atmospheric moisture. Experiments were performed on samples of hematitic sandstone, pyrite, and galena. The sandstone underwent a change in resistivity of four orders of magnitude when it was measured in a vacuum of 500 ntorr and in air of 37% relative humidity. Pyrite and galena showed no variations in resistivity when they were measured under the same conditions. These results, plus others obtained elsewhere, indicate that rocks of the resistive type are affected in their electrical properties by atmospheric moisture, whereas rocks of the conductive type are not. The experimental evidence obtained is difficult to reconcile with a model of aqueous electrolytic conduction on the sample surface. It is instead suggested that adsorbed water molecules alter the surface resistivity in a manner similar to that observed in semiconductors and insulators.

  2. Solar wind effects on atmosphere evolution at Venus and Mars

    NASA Technical Reports Server (NTRS)

    Luhmann, Janet G.; Bauer, S. J.

    1992-01-01

    The weak intrinsic magnetism of Venus and Mars leaves these planets subject to some unique atmospheric loss processes. This paper reviews the ways in which material seems to be removed by the solar wind interaction, including atmospheric ion pickup by the solar wind, bulk removal and outflow of ionospheric plasma, and atmospheric sputtering by pickup ions. The factors in the planets' and sun's histories, such as planetary magnetism, solar luminosity, and past solar wind properties, that must ultimately be folded into considerations of the effects of the solar wind interaction on atmosphere evolution are discussed.

  3. Direct and ozone-mediated forcing of the Southern Annular Mode by greenhouse gases

    NASA Astrophysics Data System (ADS)

    Morgenstern, Olaf; Zeng, Guang; Dean, Sam M.; Joshi, Manoj; Abraham, N. Luke; Osprey, Annette

    2014-12-01

    We assess the roles of long-lived greenhouse gases and ozone depletion in driving meridional surface pressure gradients in the southern extratropics; these gradients are a defining feature of the Southern Annular Mode. Stratospheric ozone depletion is thought to have caused a strengthening of this mode during summer, with increasing long-lived greenhouse gases playing a secondary role. Using a coupled atmosphere-ocean chemistry-climate model, we show that there is cancelation between the direct, radiative effect of increasing greenhouse gases by the also substantial indirect—chemical and dynamical—feedbacks that greenhouse gases have via their impact on ozone. This sensitivity of the mode to greenhouse gas-induced ozone changes suggests that a consistent implementation of ozone changes due to long-lived greenhouse gases in climate models benefits the simulation of this important aspect of Southern Hemisphere climate.

  4. Atmospheric turbulence effects on aircraft noise propagation

    NASA Technical Reports Server (NTRS)

    Chapkis, R. L.

    1979-01-01

    The Brown and Clifford model for the apparent sound attenuation cuased by atmospheric turbulence was reviewed and extended. Calculations, based on the model, were made for the predicted sound attenuation for a tower-mounted loudspeaker-type sound source and for an airplane sound source. The important parameters in the model are identified and discussed. A model for sound fluctuations is also presented and a practical experimental program to validate the models described.

  5. [Research advances in the effects of elevated atmospheric carbon dioxide and ozone on biogenic VOCs emission].

    PubMed

    Li, Dewen; Yi, Shi; He, Xingyua

    2005-12-01

    The increasing concentrations of CO2 and O3 in the troposphere have become a focus of both the domestic and foreign researchers, and the emissions of biogenic volatile organic compounds (BVOCs) can be affected by the change of concentrations. The BVOCs with high chemical reactivity may affect the chemical compositions of lower atmosphere, and promote photochemistry air pollution. At one time, the greenhouse effect and global environment changes will be influenced by the BVOCs. The effects of single and joint action of CO2 and 03 on the emitting characteristics of biogenic volatile organic compounds (BVOCs) were summarized and further researches on this field, especially that of trees in urban areas under the condition of multiple environmental stresses were perspected in this paper.

  6. Calculation of turbulence effects in an upward-refracting atmosphere

    NASA Astrophysics Data System (ADS)

    Gilbert, Kenneth E.; di, Xiao; Raspet, Richard

    1990-06-01

    The effect of atmospheric turbulence on sound propagation was investigated for both nonrefractive and refractive atmospheres, using the parabolic equation method of Gilbert and White (1989) in conjunction with a two-dimensional atmospheric turbulence model. The calculations for a nonrefractive atmosphere gave good agreement with experimental data and with Daigle's (1979) theory, while calculations for an upward-refractive atmosphere gave reasonable agreement with the data of Weiner and Keast (1959). It is concluded that, for a receiver deep in a shadow zone and for frequencies greater than a few hundred hertz, the measured sound-pressure level is due almost entirely to the sound scattered into the shadow zone by atmospheric turbulence. Consequently, for upward refraction and frequencies above a few hundred hertz, turbulence must be included in long-range propagation calculations.

  7. Terrestrial nitrous oxide cycles and atmospheric effects

    NASA Technical Reports Server (NTRS)

    Whitten, R. C.; Lawless, J. G.; Banin, A.

    1984-01-01

    The basic processes that cause N2O emission from soils are briefly discussed, and the rate of the processes is shown to vary widely in space and time, depending on soil, climate, and agrotechnical conditions. Although significant amounts of N2O are indeed emitted from the land, the complexity of the soil processes involved and the wide variation of measured rates still prevents the quantitative evaluation, global budgeting, and reliable prediction of atmospheric N2O. Increased atmospheric N2O abundance increases the levels of odd-nitrogen in the stratosphere, which, in turn, decreases the stratospheric ozone density via a catalytic cycle. Using appropriate atmospheric models and current chemical kinetic data, it has been found that the dependence of ozone reduction on N2O increase is nearly linear; a simulated doubling of N2O leads to a predicted decrease of about 14 percent in total ozone column density. A 10 percent increase in N2O yields a predicted increase in nonmelanoma skin cancer of several percent, and a possible raising of surface temperature of 0.03 K.

  8. Eutrophication effects on greenhouse gas fluxes from shallow-lake mesocosms override those of climate warming.

    PubMed

    Davidson, Thomas A; Audet, Joachim; Svenning, Jens-Christian; Lauridsen, Torben L; Søndergaard, Martin; Landkildehus, Frank; Larsen, Søren E; Jeppesen, Erik

    2015-12-01

    Fresh waters make a disproportionately large contribution to greenhouse gas (GHG) emissions, with shallow lakes being particular hot spots. Given their global prevalence, how GHG fluxes from shallow lakes are altered by climate change may have profound implications for the global carbon cycle. Empirical evidence for the temperature dependence of the processes controlling GHG production in natural systems is largely based on the correlation between seasonal temperature variation and seasonal change in GHG fluxes. However, ecosystem-level GHG fluxes could be influenced by factors, which while varying seasonally with temperature are actually either indirectly related (e.g. primary producer biomass) or largely unrelated to temperature, for instance nutrient loading. Here, we present results from the longest running shallow-lake mesocosm experiment which demonstrate that nutrient concentrations override temperature as a control of both the total and individual GHG flux. Furthermore, testing for temperature treatment effects at low and high nutrient levels separately showed only one, rather weak, positive effect of temperature (CH4 flux at high nutrients). In contrast, at low nutrients, the CO2 efflux was lower in the elevated temperature treatments, with no significant effect on CH4 or N2 O fluxes. Further analysis identified possible indirect effects of temperature treatment. For example, at low nutrient levels, increased macrophyte abundance was associated with significantly reduced fluxes of both CH4 and CO2 for both total annual flux and monthly observation data. As macrophyte abundance was positively related to temperature treatment, this suggests the possibility of indirect temperature effects, via macrophyte abundance, on CH4 and CO2 flux. These findings indicate that fluxes of GHGs from shallow lakes may be controlled more by factors indirectly related to temperature, in this case nutrient concentration and the abundance of primary producers. Thus, at ecosystem

  9. Eutrophication effects on greenhouse gas fluxes from shallow-lake mesocosms override those of climate warming.

    PubMed

    Davidson, Thomas A; Audet, Joachim; Svenning, Jens-Christian; Lauridsen, Torben L; Søndergaard, Martin; Landkildehus, Frank; Larsen, Søren E; Jeppesen, Erik

    2015-12-01

    Fresh waters make a disproportionately large contribution to greenhouse gas (GHG) emissions, with shallow lakes being particular hot spots. Given their global prevalence, how GHG fluxes from shallow lakes are altered by climate change may have profound implications for the global carbon cycle. Empirical evidence for the temperature dependence of the processes controlling GHG production in natural systems is largely based on the correlation between seasonal temperature variation and seasonal change in GHG fluxes. However, ecosystem-level GHG fluxes could be influenced by factors, which while varying seasonally with temperature are actually either indirectly related (e.g. primary producer biomass) or largely unrelated to temperature, for instance nutrient loading. Here, we present results from the longest running shallow-lake mesocosm experiment which demonstrate that nutrient concentrations override temperature as a control of both the total and individual GHG flux. Furthermore, testing for temperature treatment effects at low and high nutrient levels separately showed only one, rather weak, positive effect of temperature (CH4 flux at high nutrients). In contrast, at low nutrients, the CO2 efflux was lower in the elevated temperature treatments, with no significant effect on CH4 or N2 O fluxes. Further analysis identified possible indirect effects of temperature treatment. For example, at low nutrient levels, increased macrophyte abundance was associated with significantly reduced fluxes of both CH4 and CO2 for both total annual flux and monthly observation data. As macrophyte abundance was positively related to temperature treatment, this suggests the possibility of indirect temperature effects, via macrophyte abundance, on CH4 and CO2 flux. These findings indicate that fluxes of GHGs from shallow lakes may be controlled more by factors indirectly related to temperature, in this case nutrient concentration and the abundance of primary producers. Thus, at ecosystem

  10. [Effects of fertilization on the P accumulation and leaching in vegetable greenhouse soil].

    PubMed

    Zhao, Ya-jie; Zhao, Mu-qiu; Lu, Cai-yan; Shi, Yi; Chen, Xin

    2015-02-01

    A packed soil column experiment was conducted to investigate the effect of different fertilization practices on phosphorus (P) accumulation and leaching potential in a vegetable greenhouse soil with different fertility levels. The results showed that the leaching loss of total P in the leachates elevated with the increment of leaching time while the accumulative leaching loss of total P was relatively low, indicating P was mainly accumulated in the soil instead of in the leachate. At the end of the leaching experiment, soil fertility and fertilization treatment affected the content of total phosphorus and Olsen-P significantly. Compared with the low-level-fertility soil, the contents of total P and Olsen-P increased by 14.3% and 12.2% in the medium-level-fertility soil, 33.3% and 37.7% in the high-level-fertility soil. Total P in the combined application of poultry manure and chemical fertilizer (M+NPK) was elevated by 5.7% and 4.3%, compared with the NPK and M treatment. Compared with NPK treatment, Olsen-P in M and M + NPK treatments augmented by 13.0% and 3.1%, respectively. Soil total P and Olsen-P mainly accumulated in the 0-10 cm and 10-20 cm soil layers, and much less in the 20-40 cm soil layer. PMID:26094462

  11. Global sea level rise and the greenhouse effect: Might they be connected

    SciTech Connect

    Peltier, W.R.; Tushingham, A.M. )

    1989-05-19

    Secular sea level trends extracted from tide gauge records of appropriately long duration demonstrate that global sea level may be rising at a rate in excess of 1 millimeter per year. However, because global coverage of the oceans by the tide gauge network is highly nonuniform and the tide gauge data reveal considerable spatial variability, there has been a well-founded reluctance to interpret the observed secular sea level rise as representing a signal of global scale that might be related to the greenhouse effect. When the tide gauge data are filtered so as to remove the contribution of ongoing glacial isostatic adjustement to the local sea level trend at each location, then the individual tide gauge records reveal sharply reduced geographic scatter and suggest that there is a globally coherent signal of strength 2.4 {plus minus} 0.90 millimeters per year that is active in the system. This signal could constitute an indication of global climate warming. 15 refs., 8 figs.

  12. [Effects of nutrition medium on cucumber growth and soil microenvironment in greenhouse under continuous cropping].

    PubMed

    Wu, Chun-Cheng; Li, Tian-Lai; Cao, Xia; Meng, Si-Da; Zhang, Yong-Yong; Yang, Li-Juan

    2014-05-01

    An experiment of continuous cropping of cucumber in nutrition medium (composted with straw, rural soil and puffed chicken manure) or soil was conducted in greenhouse in order to study the effects of medium type on the cucumber growth and soil microenvironment, respectively. The results showed that the two treatments both displayed different levels of obstacles resulted from continuous cropping. In the same cropping season, the nutrient content, soil invertase and urease activities and B/F (bacteria/fungi) ratio in the nutrition medium were obviously higher but fungi quantity was lower than in the soil medium, suggesting the use of nutrition medium changed the bacterial population structure as to improve the cucumber growth and yield. Under continuous cropping, correlation analysis showed that the bacterial quantity was significantly positively related with plant height and root dry mass, and markedly significantly positive correlation exited between the aboveground dry mass and yield of cucumber. The urease activity was also significantly positively related with the cucumber yield. Compared with the soil medium, the nutrition medium could greatly improve soil microenvironment and alleviate the continuous cropping obstacle. PMID:25129942

  13. Counteracting the climate effects of volcanic eruptions using short-lived greenhouse gases

    NASA Astrophysics Data System (ADS)

    Samset, B. H.; Fuglestvedt, J.; Shine, K. P.

    2014-12-01

    A large volcanic eruption might constitute a climate emergency, significantly altering global temperature and precipitation for several years. Major future eruptions will occur, but their size or timing cannot be predicted. How could global society prepare for, and react to, such emergencies? One possibility is deliberate, coordinated emissions of short-lived greenhouse gases, along a pathway designed to match the climate responses to the eruption. We estimate such an emission pathway, countering a hypothetical eruption three times the size of Mt Pinatubo in 1991. Using a global climate model to evaluate global and regional responses to the eruption, with and without counter emissions, we show that it may be possible to counteract its climate effects, significantly dampening the abrupt impact of the eruption. We then raise practical, financial and ethical aspects related to such a strategy. Designed emissions to counter temporary global cooling would not have the disadvantages associated with more commonly discussed geoengineering to avoid long-term warming. Nevertheless, implementation would still face significant challenges.

  14. Temperature effects on net greenhouse gas production and bacterial communities in arctic thaw ponds.

    PubMed

    Negandhi, Karita; Laurion, Isabelle; Lovejoy, Connie

    2016-08-01

    One consequence of High Arctic permafrost thawing is the formation of small ponds, which release greenhouse gases (GHG) from stored carbon through microbial activity. Under a climate with higher summer air temperatures and longer ice-free seasons, sediments of shallow ponds are likely to become warmer, which could influence enzyme kinetics or select for less cryophilic microbes. There is little data on the direct temperature effects on GHG production and consumption or on microbial communities' composition in Arctic ponds. We investigated GHG production over 16 days at 4°C and 9°C in sediments collected from four thaw ponds. Consistent with an enzymatic response, production rates of CO2 and CH4 were significantly greater at higher temperatures, with Q10 varying from 1.2 to 2.5. The bacterial community composition from one pond was followed through the incubation by targeting the V6-V8 variable regions of the 16S rRNA gene and 16S rRNA. Several rare taxa detected from rRNA accounted for significant community compositional changes. At the higher temperature, the relative community contribution from Bacteroidetes decreased by 15% with compensating increases in Betaproteobacteria, Alphaproteobacteria, Firmicutes, Acidobacteria, Verrucomicrobia and Actinobacteria. The increase in experimental GHG production accompanied by changes in community indicates an additional factor to consider in sediment environments when evaluating future climate scenarios. PMID:27288196

  15. Effects of vermicomposts produced from food waste on the growth and yields of greenhouse peppers.

    PubMed

    Arancon, Norman Q; Edwards, Clive A; Atiyeh, Rola; Metzger, James D

    2004-06-01

    Vermicomposts, produced commercially from food wastes, were substituted at a range of different concentrations into a soil-less commercial bedding plant container medium, Metro-Mix 360 (MM360), to evaluate their effects on the growth and yields of peppers in the greenhouse. Six-week-old peppers (Capsicum annum L. var. California) were transplanted into 100%, 80%, 60%, 40%, 20% or 10% MM360 substituted with 0%, 10%, 20%, 40%, 60%, 80% and 100% vermicompost. All plants were watered three times weekly with 200 ppm Peter's Nutrient Solution from the time of transplanting up to 107 days. Peppers grown in potting mixtures containing 40% food waste vermicomposts and 60% MM360 yielded 45% more fruit weights and had 17% greater mean number of fruits than those grown in MM360 only. The mean heights, numbers of buds and numbers of flowers of peppers grown in potting mixtures containing 10-80% vermicompost although greater did not differ significantly from those of peppers grown in MM360. There were no positive correlations between the increases in pepper yields, and the amounts of mineral-N and microbial biomass-N in the potting mixtures, or the concentrations of nitrogen in the shoot tissues of peppers. Factors such as: an improvement of the physical structure of the potting medium, increases in populations of beneficial microorganisms and the potential availability of plant growth-influencing-substances produced by microorganisms in vermicomposts, could have contributed to the increased pepper yields obtained. PMID:15051075

  16. Effect of Rotation Crops on Heterodera glycines Population Density in a Greenhouse Screening Study

    PubMed Central

    Warnke, S.A.; Chen, S.Y.; Wyse, D.L.; Johnson, G.A.; Porter, P.M.

    2006-01-01

    Crop rotation is a common means of reducing pathogen populations in soil. Several rotation crops have been shown to reduce soybean cyst nematode (Heterodera glycines) populations, but a comprehensive study of the optimal crops is needed. A greenhouse study was conducted to determine the effect of growth and decomposition of 46 crops on population density of H. glycines. Crops were sown in soil infested with H. glycines. Plants were maintained until 75 days after planting, when the soil was mixed, a sample of the soil removed to determine egg density, and shoots and roots chopped and mixed into the soil. After 56 days, soil samples were again taken for egg counts, and a susceptible soybean (‘Sturdy’) was planted in the soil as a bioassay to determine egg viability. Sunn hemp (Crotalaria juncea), forage pea (Pisum sativum), lab-lab bean (Lablab purpureus), Illinois bundleflower (Desman-thus illinoensis), and alfalfa (Medicago sativa) generally resulted in smaller egg population density in soil or number of cysts formed on soybean in the bioassay than the fallow control. Sunn hemp most consistently showed the lowest numbers of eggs and cysts. As a group, legumes resulted in lower egg population densities than monocots, Brassica species, and other dicots. PMID:19259545

  17. Potato (Solanum tuberosum) greenhouse tuber production as an assay for asexual reproduction effects from herbicides.

    PubMed

    Olszyk, David; Pfleeger, Thomas; Lee, E Henry; Plocher, Milton

    2010-01-01

    The present study determined whether young potato plants can be used as an assay to indicate potential effects of pesticides on asexual reproduction. Solanum tuberosum (Russet Burbank) plants were grown from seed pieces in a mineral soil in pots under greenhouse conditions. Plants were treated with herbicides (cloransulam, dicamba, glyphosate, imazapyr, primsulfuron, sulfometuron, or tribenuron) at simulated drift levels [effective concentrations producing a 25% potato tuber fresh weight (EC25) of 0.00038, 0.0016, and 0.0021 x f.a.r. of 1,124, 52, and 9 g active ingredient hectare(-1) (g a.i. HA(-1)), respectively. Primisulfuron, dicamba, and cloransulam also significantly reduced tuber fresh weight, but with higher EC25 values of 0.011, 0.07, and 0.010 to 0.2 x f.a.r. of 40, 558, and 18 g a.i. HA(-1), respectively. Glyphosate had little effect on tuber fresh weight, with a significant reduction in only one experiment. Sulfometuron reduced tuber fresh weight at an EC25 value lower than the EC25 values for shoot dry weight or plant height. For other herbicides, the reduction in tuber fresh weight occurred within the range of EC25 values for other responses. Although additional experiments are required to develop further a phytotoxicity test, these results indicated that tuber production in young potato plants (harvested approximately 42 DAE) may be an effective assay for below-ground asexual reproductive responses to herbicides, especially acetolactate synthase inhibitors.

  18. Thermal balance of the lower Venus atmosphere: radiative and dynamical effects

    NASA Astrophysics Data System (ADS)

    Afanasenko, T. S.; Rodin, A. V.

    2003-04-01

    The current state and recent evolution of Venus climate is believed to be controlled by greenhouse effect variations in response to modified composition of the atmosphere. The quantitative assessment of the thermal regime of the lower Venus atmosphere is, however, highly complicated due to major uncertaintues in its spectral properties, in particular, spectral line profile, which shape is dependent on temperature, pressure, and specific molecular transition. We present a comprehensive, high-resolution model of the thermal radiation and 1D calculations of the thermal balance, involving both radiative and dynamical heat transfer. Spectroscopic model is based on the war-wing approximation for molecular absorption, and self-consistent micorphysical model of the cloud layer. In the lower atmospheric layers simulated radiative fluxes are concentrated within the windows in between absorption bands and reveal high sensitivity to the far-wing spectral line formfactor. Radiation flux effectively generated at 30-40 km is absorbed at the lower boundary of the cloud deck, with the excess heat being removed by convection and large-scale circulation. Sensitivities of the thermal state and dynamical fluxes to minor constituents and aerosol properties are explored. This work has been supported by RFBR grant #01-02-17481

  19. The effects of biomass burning on the concentration of trace gases in the atmosphere

    NASA Technical Reports Server (NTRS)

    Donaldson, Leon M.

    1988-01-01

    Over the past several years, there has been considerable interest concerning the global effects of biomass burning on concentrations of trace gases in the atmosphere. The paucity of reported studies and investigations into the effects of the Greenhouse Gases such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), up until about a decade ago, would suggest that the topic was not then one of universal concern. Efforts are now being made to understand the biogenic, anthropogenic and photochemical sources of atmospheric trace gases. Biomass burning which includes the burning of forests for clearing, the burning of vegetative stubble after harvesting, and lightning and human-induced wildfires is but one consideration under the general paradigm of atmospheric perturbations. A team of researchers from the Langley Research Center, along with the Canadian Forest Ministry, Ontario, Canada collaborated in an experiment in a deforestration effort through a prescribed burn. Through a specially designed experimental modeling and instrumentation, a substantial pre-burn data set was collected. The primary focus of the pre-burn experimental activities was the emission of nitrous oxide (N2O) gas from selected sites.

  20. [Effects of planting years of vegetable solar greenhouse on soil microbial flora and enzyme activities].

    PubMed

    Yang, Qin; Li, Liang

    2013-09-01

    Taking the vegetable solar greenhouses having been planted for 2, 4, 6, 11, 13, 16, and 19 years as test objects, and with the open vegetable field as the control, this paper studied the variations of soil microbial flora and enzyme activities. With the increasing years of planting, the numbers of soil bacteria, actinomycetes, and total microbes in vegetable solar greenhouses decreased after an initial increase, and reached the maximum in the greenhouse of 11 years planting, with a significant increment of 54.8%, 63.7%, and 55.4%, respectively, as compared to the control. The number of soil fungi in the vegetable solar greenhouses increased steadily with increasing planting years, being about 2.2 times higher in the greenhouse of 11 years planting. Among the microbial physiological groups, the numbers of aerobic cellulose-decomposer, aerobic azotobacter, nitrite bacteria, denitrifier, and sulphur reducer showed the same variation trend as the soil bacteria's, and those in the greenhouse of 11 years planting being 1.5, 1.6, 1.9, 1.4, and 1.1 times of the control, respectively. The number of ammonifiers increased after an initial decrease, reached the minimum in the greenhouse of 13 years planting, being only 56.0% of the control. The enzyme activities of soil urease, polyphenol oxidase, sucrase, protease, cellulase, and alkaline phosphatase increased firstly and then decreased with the increasing years of planting, but soil catalase activity was relatively stable. Correlation analysis showed that the numbers of soil bacteria, actinomycetes, and total microbes were significantly positively correlated with all test soil enzyme activities, while the number of soil fungi had significant negative correlation with the activity of soil catalase. PMID:24417112

  1. [Effects of planting years of vegetable solar greenhouse on soil microbial flora and enzyme activities].

    PubMed

    Yang, Qin; Li, Liang

    2013-09-01

    Taking the vegetable solar greenhouses having been planted for 2, 4, 6, 11, 13, 16, and 19 years as test objects, and with the open vegetable field as the control, this paper studied the variations of soil microbial flora and enzyme activities. With the increasing years of planting, the numbers of soil bacteria, actinomycetes, and total microbes in vegetable solar greenhouses decreased after an initial increase, and reached the maximum in the greenhouse of 11 years planting, with a significant increment of 54.8%, 63.7%, and 55.4%, respectively, as compared to the control. The number of soil fungi in the vegetable solar greenhouses increased steadily with increasing planting years, being about 2.2 times higher in the greenhouse of 11 years planting. Among the microbial physiological groups, the numbers of aerobic cellulose-decomposer, aerobic azotobacter, nitrite bacteria, denitrifier, and sulphur reducer showed the same variation trend as the soil bacteria's, and those in the greenhouse of 11 years planting being 1.5, 1.6, 1.9, 1.4, and 1.1 times of the control, respectively. The number of ammonifiers increased after an initial decrease, reached the minimum in the greenhouse of 13 years planting, being only 56.0% of the control. The enzyme activities of soil urease, polyphenol oxidase, sucrase, protease, cellulase, and alkaline phosphatase increased firstly and then decreased with the increasing years of planting, but soil catalase activity was relatively stable. Correlation analysis showed that the numbers of soil bacteria, actinomycetes, and total microbes were significantly positively correlated with all test soil enzyme activities, while the number of soil fungi had significant negative correlation with the activity of soil catalase.

  2. TESTING SIDE-EFFECTS OF COMMON PESTICIDES ON A. SWIRSKII UNDER GREENHOUSE CIRCUMSTANCES.

    PubMed

    Audenaert, J; Vissers, M; Gobin, B

    2014-01-01

    If a grower uses predatory mites, and should use chemical compounds, he needs to be very careful in his choice of products. The selected products have to be efficient against the target pest and at the same time compatible with the present beneficial's. Useful tools for such product selection under greenhouse circumstances are side effects lists. These lists are freely available on the websites of producing companies of biological control agents. But not all products (e.g. newly developed ones) have been tested for side effects. Moreover the information already available in these tables is not based on field tests. For this reason, we have developed a protocol for quick screening of side effects of chemical plant protection products under field conditions. For these experiments we have chosen the predatory mite Amblyseius swirskii as test organism, because this is an often used phytoseiid mite, which is very sensitive to pesticides. Hibiscus rosa sinensis is the standard reference plant in our side effects trials because the chosen predatory mite has shown very good control of pests on this plant species. The experimental design consists of eight test objects in 4 replications. Test object 1 is a positive reference (water spray) and test object 2 a negative reference (deltamethrin spray, a product with long residual activity against beneficial organisms). The plot size is 0,68 m2 and each plot contains 32 Hibiscus plants. The greenhouse temperature is set at 20±2°C. The test strategy has the following sequence: introduction of an overdose of Amblyseius swirskii mites 14 days before spraying the pesticides > precount of predatory mites 4 days before application (4DBA) > spray application (A) for the 6 test products and for the 2 references > counting's after application (1, 2, 4, 8 en 12 weeks after application = 1 till 12WAA). The counting's of the number of predatory mites are performed on 20 Hibiscus leaves/plot under a binocular. Because of the absence of any

  3. Effects of physical agitation on yield of greenhouse-grown soybean

    NASA Technical Reports Server (NTRS)

    Jones, R. S.; Mitchell, C. A.

    1992-01-01

    Agronomic and horticultural crop species experience reductions in growth and harvestable yield after exposure to physical agitation (also known as mechanical stress), as by wind or rain. A greenhouse study was conducted to test the influence of mechanical stress on soybean yield and to determine if exposure to mechanical stress during discrete growth periods has differential effects on seed yield. A modified rotatory shaker was used to apply seismic (i.e., shaking) stress. Brief, periodic episodes of seismic stress reduced stem length, total seed dry weight, and seed number of soybean [Glycine max (L.) Merr.]. Lodging resistance was greater for plants stressed during vegetative growth or throughout vegetative and reproductive growth than during reproductive growth only. Seed dry weight yield was reduced regardless of the timing or duration of stress application, but was lowest when applied during reproductive development. Seismic stress applied during reproductive growth stages R1 to R2 (Days 3 to 4) was as detrimental to seed dry weight accumulation as was stress applied during growth stages R1 to R6 (Days 39 to 42). Seed dry weight per plant was highly correlated with seed number per plant, and seed number was correlated with the seed number of two- and three-seeded pods. Dry weight per 100 seeds was unaffected by seismic-stress treatment. Growth and yield reductions resulting from treatments applied only during the vegetative stage imply that long-term mechanical effects were induced, from which the plants did not fully recover. It is unclear which yield-controlling physiological processes were affected by mechanical stress. Both transient and long-term effects on yield-controlling processes remain to be elucidated.

  4. Assessing global greenhouse effect and its variability through regional analysis of satellite data

    SciTech Connect

    Otterman, J.; Anyamba, E.; Susskind, J.

    1997-11-01

    This paper presents a preliminary study of the greenhouse factor (G) and its seasonal, interannual, and short-term variability on regional and global scales. The analysis uses satellite observations, the Pathfinder Path A set, for both outgoing longware radiation (OLR) and and surface emission (SE). Satellite data from a 4-year period was used to examine G, with a focus on regions that are likely to contribute significantly to the observed global variability. A higher seasonal change in global G (as compared to OLR) was found; in comparison, OLR varies from half the G variance range. The March-April 1987 El Nino region anomaly of the greenhouse factor correlated quite well with a cloud fraction anomaly, but at other times cloud fraction anomalies were observed without a G anomaly. The interannual anomalies of G tend to be of opposite sign in the equatorial east Pacific and equatorial Atlantic. The results of regional analysis are presented for the smoothed greenhouse factor, the greenhouse factor interannual anomaly, the greenhouse factor short-term variability, the cloud fraction interannual anomaly, and the precipitable water interannual anomaly. 7 refs., 5 figs.

  5. Energy, atmospheric chemistry, and global climate

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1991-01-01

    Global atmospheric changes due to ozone destruction and the greenhouse effect are discussed. The work of the Intergovernmental Panel on Climate Change is reviewed, including its judgements regarding global warming and its recommendations for improving predictive capability. The chemistry of ozone destruction and the global atmospheric budget of nitrous oxide are reviewed, and the global sources of nitrous oxide are described.

  6. Atmospheric Science: It's More than Meteorology.

    ERIC Educational Resources Information Center

    Smith, David R.; Krockover, Gerald H.

    1988-01-01

    Indicates that atmospheric science is not just forcasting the weather. Gives an overview of current topics in meteorology including ozone depletion, acid precipitation, winter cyclones, severe local storms, the greenhouse effect, wind shear and microbursts. Outlines the Atmospheric Sciences Education Program at Purdue University to produce…

  7. Effects of pollutant atmospheres on surface receptors of pulmonary macrophages

    SciTech Connect

    Prasad, S.B.; Rao, V.S.; Mannix, R.C.; Phalen, R.F.

    1988-01-01

    The effects of two multicomponent pollutant atmospheres on the surface receptors (FcR) and phagocytic activity of rat pulmonary alveolar macrophages have been studied. FcR are crucial for the macrophages to become cytotoxic against target cells. The atmospheres were composed of pollutants that are prevalent in the South Coast Air Basin of southern California. Rats were exposed nose-only to a 7-component oxidant-and sulfate-containing atmosphere for 4 h/d for either 7 or 21 consecutive days. In another experiment rats were exposed 5 h/d for 5 consecutive days to another pollutant combination--acid droplets plus carbon-containing dilute diesel engine exhaust. In both experiments matched rats were exposed nose-only to purified air to be used as controls. Each of the atmospheres studied significantly reduced FcR activity for at least 3 d following the exposure, with the group of rats exposed to the 7-component atmosphere for 21 d exhibiting the most pronounced effect. Macrophages from rats exposed to the diesel exhaust plus acid atmosphere and the 7-component atmosphere for 7 d had significantly reduced phagocytic activity for at least 3 d postexposure, while the macrophages from rats exposed to the latter atmosphere for 21 d had phagocytic activity near control values. The decrease in phagocytosis and inhibition of FcR of macrophages suggests an impairment of macrophage function that probably renders the host vulnerable to bacterial and/or viral infections.

  8. [The influence of the greenhouse effect on vegetation--results of studies in England].

    PubMed

    Burga, C A

    1992-03-10

    Studies on the effects of an increased concentration of carbon dioxide on terrestrial ecosystems have produced results on plant growth in general and on growth of forests in particular. Deciduous trees and conifers react differently to increased atmospheric CO2. In most instances, an increased growth rate can be expected. Higher CO2 concentrations can thus compensate for or alleviate other environmental stresses. Economically important species (e.g. cotton) exhibit growth retardation in the presence of increased CO2 concentrations. Raised temperatures stimulate not only growth of trees but also of typical weeds. A few scenarios of expected changes in future vegetations following a global raise in temperature are depicted.

  9. Memory efficient atmospheric effects modeling for infrared scene generators

    NASA Astrophysics Data System (ADS)

    Kavak, Çaǧlar; Özsaraç, Seçkin

    2015-05-01

    The infrared (IR) energy radiated from any source passes through the atmosphere before reaching the sensor. As a result, the total signature captured by the IR sensor is significantly modified by the atmospheric effects. The dominant physical quantities that constitute the mentioned atmospheric effects are the atmospheric transmittance and the atmospheric path radiance. The incoming IR radiation is attenuated by the transmittance and path radiance is added on top of the attenuated radiation. In IR scene simulations OpenGL is widely used for rendering purposes. In the literature there are studies, which model the atmospheric effects in an IR band using OpenGLs exponential fog model as suggested by Beers law. In the standard pipeline of OpenGL, the related fog model needs single equivalent OpenGL variables for the transmittance and path radiance, which actually depend on both the distance between the source and the sensor and also on the wavelength of interest. However, in the conditions where the range dependency cannot be modeled as an exponential function, it is not accurate to replace the atmospheric quantities with a single parameter. The introduction of OpenGL Shading Language (GLSL) has enabled the developers to use the GPU more flexible. In this paper, a novel method is proposed for the atmospheric effects modeling using the least squares estimation with polynomial fitting by programmable OpenGL shader programs built with GLSL. In this context, a radiative transfer model code is used to obtain the transmittance and path radiance data. Then, polynomial fits are computed for the range dependency of these variables. Hence, the atmospheric effects model data that will be uploaded in the GPU memory is significantly reduced. Moreover, the error because of fitting is negligible as long as narrow IR bands are used.

  10. Outward atmospheric scintillation effects and inward atmospheric scintillation effects comparisons for direct detection ladar applications

    NASA Astrophysics Data System (ADS)

    Youmans, Douglas G.

    2014-06-01

    Atmospheric turbulence produces intensity modulation or "scintillation" effects on both on the outward laser-mode path and on the return backscattered radiation path. These both degrade laser radar (ladar) target acquisition, ranging, imaging, and feature estimation. However, the finite sized objects create scintillation averaging on the outgoing path and the finite sized telescope apertures produce scintillation averaging on the return path. We expand on previous papers going to moderate to strong turbulence cases by starting from a 20kft altitude platform and propagating at 0° elevation (with respect to the local vertical) for 100km range to a 1 m diameter diffuse sphere. The outward scintillation and inward scintillation effects, as measured at the focal plane detector array of the receiving aperture, will be compared. To eliminate hard-body surface speckle effects in order to study scintillation, Goodman's M-parameter is set to 106 in the analytical equations and the non-coherent imaging algorithm is employed in Monte Carlo realizations. The analytical equations of the signal-to-noise ratio (SNRp), or mean squared signal over a variance, for a given focal plane array pixel window of interest will be summarized and compared to Monte Carlo realizations of a 1m diffuse sphere.

  11. [Effect of Biochar on Soil Greenhouse Gas Emissions in Semi-arid Region].

    PubMed

    Guo, Yan-liang; Wang, Dan-dan; Zheng, Ji-yong; Zhao, Shi-wei; Zhang, Xing-chang

    2015-09-01

    This study aimed to investigate the effects of biochar addition on the emission of greenhouse gases from farmland soil in semi-arid region. Through an in-situ experiments, the influence of sawdust biochar(J) and locust tree skin biochar (H) at three doses (1%, 3%, and 5% of quality percentage) on C2, CH4 and N2O emissions were studied within the six months in the south of Ningxiaprovince. The results indicated that soil CO2 emission flux was slightly increased with the addition doses for both biochars, and the averaged CO2 emission flux for sawdust and locust tree skin biochar was enhanced by 1. 89% and 3. 34% compared to the control, but the difference between treatments was not statistically significant. The soil CH4 emission was decreased with the increasing of biochar doses, by 1. 17%, 2. 55%, 4. 32% for J1, J3, J5 and 2. 35%, 5. 83%, 7. 32% for H1, H3, H5, respectively. However, the difference was statistically significant only for J5, H3 and H5 treatments (P <0. 05). Across addition doses, there was no apparent effect on soil N2O emission. Our study indicated that the biochar has no significant influence on soil CO2 and N2O emissions within six months in semi-arid region and can significantly influence soil CH4 emissions (P < 0. 05). As for biochar type, the locust tree skin biochar is significantly better than the sawdust biochar in terms of restraining CH4 emission(P = 0. 048). PMID:26717703

  12. [Effect of Biochar on Soil Greenhouse Gas Emissions in Semi-arid Region].

    PubMed

    Guo, Yan-liang; Wang, Dan-dan; Zheng, Ji-yong; Zhao, Shi-wei; Zhang, Xing-chang

    2015-09-01

    This study aimed to investigate the effects of biochar addition on the emission of greenhouse gases from farmland soil in semi-arid region. Through an in-situ experiments, the influence of sawdust biochar(J) and locust tree skin biochar (H) at three doses (1%, 3%, and 5% of quality percentage) on C2, CH4 and N2O emissions were studied within the six months in the south of Ningxiaprovince. The results indicated that soil CO2 emission flux was slightly increased with the addition doses for both biochars, and the averaged CO2 emission flux for sawdust and locust tree skin biochar was enhanced by 1. 89% and 3. 34% compared to the control, but the difference between treatments was not statistically significant. The soil CH4 emission was decreased with the increasing of biochar doses, by 1. 17%, 2. 55%, 4. 32% for J1, J3, J5 and 2. 35%, 5. 83%, 7. 32% for H1, H3, H5, respectively. However, the difference was statistically significant only for J5, H3 and H5 treatments (P <0. 05). Across addition doses, there was no apparent effect on soil N2O emission. Our study indicated that the biochar has no significant influence on soil CO2 and N2O emissions within six months in semi-arid region and can significantly influence soil CH4 emissions (P < 0. 05). As for biochar type, the locust tree skin biochar is significantly better than the sawdust biochar in terms of restraining CH4 emission(P = 0. 048).

  13. Effect of pest controlling neem and mata-raton leaf extracts on greenhouse gas emissions from urea-amended soil cultivated with beans: a greenhouse experiment.

    PubMed

    Méndez-Bautista, Joaquín; Fernández-Luqueño, Fabián; López-Valdez, Fernando; Mendoza-Cristino, Reyna; Montes-Molina, Joaquín A; Gutierrez-Miceli, Federico A; Dendooven, L

    2010-10-01

    In a previous laboratory experiment, extracts of neem (Azadirachta indica A. Juss.) and Gliricidia sepium Jacquin, locally known as mata-raton, used to control pests on crops, inhibited emissions of CO(2) from a urea-amended soil, but not nitrification and N(2)O emissions. We investigated if these extracts when applied to beans (Phaseolus vulgaris L.) affected their development, soil characteristics and emissions of carbon dioxide (CO(2)) and nitrous oxide (N(2)O) in a greenhouse environment. Untreated beans and beans planted with lambda-cyhalothrin, a commercial insecticide, served as controls. After 117days, shoots of plants cultivated in soil amended with urea or treated with lambda-cyhalothrin, or extracts of neem or G. sepium were significantly higher than when cultivated in the unamended soil, while the roots were significantly longer when plants were amended with urea or treated with leaf extracts of neem or G. sepium than when treated with lambda-cyhalothrin. The number of pods, fresh and dry pod weight and seed yield was significantly higher when bean plants were treated with leaf extracts of neem or G. sepium treatments than when left untreated and unfertilized. The number of seeds was similar for the different treatments. The number of nodules was lower in plants fertilized with urea, treated with leaf extracts of neem or G. sepium, or with lambda-cyhalothrin compared to the unfertilized plants. The concentrations of NH(4)(+), NO(2)(-) and NO(3)(-) decreased significantly over time with the lowest concentrations generally found at harvest. Treatment had no significant effect on the concentrations of NH(4)(+) and NO(2)(-), but the concentration of NO(3)(-) was significantly lower in the unfertilized soil compared to the other treatments. It was found that applying extracts of neem or G. sepium leaves to beans favored their development when compared to untreated plants, but had no significant effect on nitrification in soil.

  14. Effect of pest controlling neem and mata-raton leaf extracts on greenhouse gas emissions from urea-amended soil cultivated with beans: a greenhouse experiment.

    PubMed

    Méndez-Bautista, Joaquín; Fernández-Luqueño, Fabián; López-Valdez, Fernando; Mendoza-Cristino, Reyna; Montes-Molina, Joaquín A; Gutierrez-Miceli, Federico A; Dendooven, L

    2010-10-01

    In a previous laboratory experiment, extracts of neem (Azadirachta indica A. Juss.) and Gliricidia sepium Jacquin, locally known as mata-raton, used to control pests on crops, inhibited emissions of CO(2) from a urea-amended soil, but not nitrification and N(2)O emissions. We investigated if these extracts when applied to beans (Phaseolus vulgaris L.) affected their development, soil characteristics and emissions of carbon dioxide (CO(2)) and nitrous oxide (N(2)O) in a greenhouse environment. Untreated beans and beans planted with lambda-cyhalothrin, a commercial insecticide, served as controls. After 117days, shoots of plants cultivated in soil amended with urea or treated with lambda-cyhalothrin, or extracts of neem or G. sepium were significantly higher than when cultivated in the unamended soil, while the roots were significantly longer when plants were amended with urea or treated with leaf extracts of neem or G. sepium than when treated with lambda-cyhalothrin. The number of pods, fresh and dry pod weight and seed yield was significantly higher when bean plants were treated with leaf extracts of neem or G. sepium treatments than when left untreated and unfertilized. The number of seeds was similar for the different treatments. The number of nodules was lower in plants fertilized with urea, treated with leaf extracts of neem or G. sepium, or with lambda-cyhalothrin compared to the unfertilized plants. The concentrations of NH(4)(+), NO(2)(-) and NO(3)(-) decreased significantly over time with the lowest concentrations generally found at harvest. Treatment had no significant effect on the concentrations of NH(4)(+) and NO(2)(-), but the concentration of NO(3)(-) was significantly lower in the unfertilized soil compared to the other treatments. It was found that applying extracts of neem or G. sepium leaves to beans favored their development when compared to untreated plants, but had no significant effect on nitrification in soil. PMID:20692019

  15. "Atmospheric Measurements by Ultra-Light SpEctrometer" (AMULSE) dedicated to vertical profile measurements of greenhouse gases (CO2, CH4) under stratospheric balloons: instrumental development and field application.

    NASA Astrophysics Data System (ADS)

    Maamary, Rabih; Joly, Lilian; Decarpenterie, Thomas; Cousin, Julien; Dumelié, Nicolas; Grouiez, Bruno; Albora, Grégory; Chauvin, Nicolas; Miftah-El-Khair, Zineb; Legain, Dominique; Tzanos, Diane; Barrié, Joel; Moulin, Eric; Ramonet, Michel; Bréon, François-Marie; Durry, Georges

    2016-04-01

    Human activities disrupt natural biogeochemical cycles such as the carbon and contribute to an increase in the concentrations of the greenhouse gases (carbone dioxide and methane) in the atmosphere. The current atmospheric transport modeling (the vertical trade) still represents an important source of uncertainty in the determination of regional flows of greenhouse gases, which means that a good knowledge of the vertical distribution of CO2 is necessary to (1) make the link between the ground measurements and spatial measurements that consider an integrated concentration over the entire column of the atmosphere, (2) validate and if possible improve CO2 transport model to make the link between surface emissions and observed concentration. The aim of this work is to develop a lightweight instrument (based on mid-infrared laser spectrometry principles) for in-situ measuring at high temporal/spatial resolution (5 Hz) the vertical profiles of the CO2 and the CH4 using balloons (meteorological and BSO at high precision levels (< 1 ppm in 1 second integration time for the CO2 sensor, and smaller than several tenths of ppb in 1 second integration time for the CH4 sensor). The instrument should be lighter than 2.5 kg in order to facilitate authorizations, costs and logistics flights. These laser spectrometers are built on recent instrumental developments. Several flights were successfully done in the region Champagne-Ardenne and in Canada recently. Aknowledgments: The authors acknowledge financial supports from CNES, CNRS défi instrumental and the region Champagne-Ardenne.

  16. Greenhouse gas and soil nutrient dynamics at Haliburton Forest: nitrogen and phosphorous amendments to soils to study the effects of high nitrogen deposition

    NASA Astrophysics Data System (ADS)

    Winsborough, C. L.; Basiliko, N.

    2011-12-01

    Many of Canada's forests are currently experiencing a major environmental disturbance in the form of atmospheric nitrogen (N) deposition from fossil fuel burning and agricultural practices. Nitrogen is a major nutrient required for plants and soil microorganisms and is normally in short supply relative to biological demands. However, when N is in excess various negative impacts result including nutrient leaching, increased nitrous oxide (N2O) emissions, and disturbances to carbon and methane (CH4) cycling. Introducing soil amendments might have the potential to mitigate the negative impacts of excess N in forest soils. Previous research at Haliburton Forest in southeastern Ontario, Canada has demonstrated that N is no longer a limiting nutrient for plants, but rather phosphorous (P), where the addition of P resulted in rapid increased growth in sugar maple trees. We characterized long term (>5 years) and more immediate/short-term effects of P additions and short-term effects of N and N+P additions to soils at Haliburton Forest on the exchange of greenhouse gases (CH4, N2O, CO2) and cycling of N and P to determine the extent of excess N impact and potential N saturation. Long-term effects of P addition demonstrated suppressed levels of CH4 uptake likely due to an N limitation of CH4 oxidizing bacteria. Decreased pools of N with P addition suggest that P additions alleviate P limitation and induce N uptake, however overall low inorganic N pools suggest that N saturation has not yet appeared. Immediate effects demonstrated increased N2O and CO2 efflux and suppressed CH4 uptake in N amended plots while P amended plots remained similar to control plots. 1- and 2-year post-application greenhouse gas and nutrient data will help to elucidate these findings.

  17. Engineering concepts for inflatable Mars surface greenhouses

    NASA Technical Reports Server (NTRS)

    Hublitz, I.; Henninger, D. L.; Drake, B. G.; Eckart, P.

    2004-01-01

    A major challenge of designing a bioregenerative life support system for Mars is the reduction of the mass, volume, power, thermal and crew-time requirements. Structural mass of the greenhouse could be saved by operating the greenhouse at low atmospheric pressure. This paper investigates the feasibility of this concept. The method of equivalent system mass is used to compare greenhouses operated at high atmospheric pressure to greenhouses operated at low pressure for three different lighting methods: natural, artificial and hybrid lighting. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  18. Engineering concepts for inflatable Mars surface greenhouses.

    PubMed

    Hublitz, I; Henninger, D L; Drake, B G; Eckart, P

    2004-01-01

    A major challenge of designing a bioregenerative life support system for Mars is the reduction of the mass, volume, power, thermal and crew-time requirements. Structural mass of the greenhouse could be saved by operating the greenhouse at low atmospheric pressure. This paper investigates the feasibility of this concept. The method of equivalent system mass is used to compare greenhouses operated at high atmospheric pressure to greenhouses operated at low pressure for three different lighting methods: natural, artificial and hybrid lighting. PMID:15846884

  19. Potential effects of clean coal technologies on acid precipitation, greenhouse gases, and solid waste disposal

    SciTech Connect

    Blasing, T.J.; Miller, R.L.; McCold, L.N.

    1993-11-01

    The US Department of Energy`s (DOE`s) Clean Coal Technology Demonstration Program (CCTDP) was initially funded by Congress to demonstrate more efficient, economically feasible, and environmentally acceptable coal technologies. Although the environmental focus at first was on sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) because their relationship to acid precipitation, the CCTDP may also lead to reductions in carbon dioxide (CO{sub 2}) emissions and in the volume of solid waste produced, compared with conventional technologies. The environmental effects of clean coal technologies (CCTs) depend upon which (if any) specific technologies eventually achieve high acceptance in the marketplace. In general, the repowering technologies and a small group of retrofit technologies show the most promise for reducing C0{sub 2} emissions and solid waste. These technologies also compare favorably with other CCTs in terms of SO{sub 2} and NO{sub x} reductions. The upper bound for CO{sup 2} reductions in the year 2010 is only enough to reduce global ``greenhouse`` warming potential by about 1%. However, CO{sub 2} emissions come from such variety of sources around the globe that no single technological innovation or national policy change could realistically be expected to reduce these emissions by more than a few percent. Particular CCTs can lead to either increases or decreases in the amount of solid waste produced. However, even if decreases are not achieved, much of the solid waste from clean coal technologies would be dry and therefore easier to dispose of than scrubber sludge.

  20. The effect of agency budgets on minimizing greenhouse gas emissions from road rehabilitation policies

    NASA Astrophysics Data System (ADS)

    Reger, Darren; Madanat, Samer; Horvath, Arpad

    2015-11-01

    Transportation agencies are being urged to reduce their greenhouse gas (GHG) emissions. One possible solution within their scope is to alter their pavement management system to include environmental impacts. Managing pavement assets is important because poor road conditions lead to increased fuel consumption of vehicles. Rehabilitation activities improve pavement condition, but require materials and construction equipment, which produce GHG emissions as well. The agency’s role is to decide when to rehabilitate the road segments in the network. In previous work, we sought to minimize total societal costs (user and agency costs combined) subject to an emissions constraint for a road network, and demonstrated that there exists a range of potentially optimal solutions (a Pareto frontier) with tradeoffs between costs and GHG emissions. However, we did not account for the case where the available financial budget to the agency is binding. This letter considers an agency whose main goal is to reduce its carbon footprint while operating under a constrained financial budget. A Lagrangian dual solution methodology is applied, which selects the optimal timing and optimal action from a set of alternatives for each segment. This formulation quantifies GHG emission savings per additional dollar of agency budget spent, which can be used in a cap-and-trade system or to make budget decisions. We discuss the importance of communication between agencies and their legislature that sets the financial budgets to implement sustainable policies. We show that for a case study of Californian roads, it is optimal to apply frequent, thin overlays as opposed to the less frequent, thick overlays recommended in the literature if the objective is to minimize GHG emissions. A promising new technology, warm-mix asphalt, will have a negligible effect on reducing GHG emissions for road resurfacing under constrained budgets.

  1. [Effects of irrigation amount and various fertigation methods on yield and quality of cucumber in greenhouse].

    PubMed

    Fang, Dong-ping; Zhang, Fu-cang; Li, Jing; Wang, Hai-dong; Xiang, You-zhen; Zhang, Yan

    2015-06-01

    Taking cucumber as experimental plant, an experiment was conducted to study the effects of irrigation amount and fertigation methods on growth, yield and quality of cucumber in greenhouse. The experiment had designed two irrigation levels, i.e. 100% ET0 (W1) and 75% ET0 (W2), and four fertigation fertilization ratios, i.e. 100%, 66.6%, 33.3% and 0% (Z100, Z66 , Z33, Z0) fertigation of a total amount of (360:180:540 kg · hm(-2)) (N:P2O5:K2O) by 8 times with the corresponding remainders (0%, 33.3%, 66.6% and 100%) were applied to soil as basic fertilization before the planting according to the recommended fertilization rate, and no fertilizer treatment was set up as the control (CK). Results showed that irrigation and fertilization levels had positive correlations with plant height, leaf areas, dry mass, yield and quality of cucumber. Yield at W1Z100 was the highest, reaching 67760 kg · hm(-2). W2 treatment increased the mean water use efficiency (WUE) by 9.4% compared to W1. W2Z100 treatment had the highest WUE, reaching 47.13 kg · m(-3). Yield at W2Z100 was only 3.4% lower than the maximum, but saved 25% of water. Yield and dry matter at Z100 were 15.3% and 16.8% higher than at Z0, respectively, the cucumber fruit vitamin C, soluble protein and soluble sugar contents were increased, and the water use efficiency was increased by 19.1%. W2Z100 treatment was the best treatment which could enable cucumber to obtain both the high-yield and the high-quality. PMID:26572026

  2. [Effects of antiseptic on the analysis of greenhouse gases concentrations in lake water].

    PubMed

    Xiao, Qi-Tao; Hu, Zheng-Hu; James, Deng; Xiao, Wei; Liu, Shou-Dong; Li, Xu-Hui

    2014-01-01

    To gain insight into antiseptic effects on the concentrations of CO2, CH4, and N2O in lake water, antisepetic (CuSO4 and HgCl2) were added into water sample, and concentrations of greenhouse gases were measured by the gas chromatography based on water equilibrium method. Experiments were conducted as following: the control group without antisepetic (CK), the treatment group with 1 mL CuSO4 solution (T1), the treatment group with 5 mL CuSO4 solution (T2), and the treatment group with 0.5 mL HgCl2 solution (T3). All groups were divided into two batches: immediately analysis (I), and after 2 days analysis (II). Results showed that CuSO4 and HgCl2 significantly increased CO2 concentration, the mean CO2 concentration (Mco2) of CK (I) and CK (II) were (11.5 +/- 1.47) micromol x L(-1) and (14.38 +/- 1.59) micromol x L(-1), respectively; the Mco2 of T1 (I) and T1 (II) were (376 +/- 70) micromol x L(-1) and (448 +/- 246.83) micromol x L(-1), respectively; the Mco2 of T2 (I) and T2 (II) were (885 +/- 51.53) micromol x L(-1) and (988.83 +/- 101.96) micromol x L(-1), respectively; the Mco2 of T3 (I) and T3 (II) were (287.19 +/- 30.01) micromol x L(-1) and (331.33 +/- 22.06) micromol x L(-1), respectively. The results also showed that there was no difference in CH4 and N2O concentrations among treatments. Water samples should be analyzed as soon as possible after pretreatment. Our findings suggest that adding antiseptic may lead an increase in CO2 concentration.

  3. Biochar and hydrochar effects on greenhouse gas (carbon dioxide, nitrous oxide, and methane) fluxes from soils.

    PubMed

    Kammann, Claudia; Ratering, Stefan; Eckhard, Christian; Müller, Christoph

    2012-01-01

    With a growing world population and global warming, we are challenged to increase food production while reducing greenhouse gas (GHG) emissions. We studied the effects of biochar (BC) and hydrochar (HC) produced via pyrolysis or hydrothermal carbonization, respectively, on GHG fluxes in three laboratory incubation studies. In the first experiment, ryegrass was grown in sandy loam mixed with equal amounts of a nitrogen-rich peanut hull BC, compost, BC+compost, double compost, or no addition (control); wetting-drying cycles and N fertilization were applied. Biochar with or without compost significantly reduced NO emissions and did not change the CH uptake, whereas ryegrass yield was significantly increased. In the second experiment, 0% (control) or 8% (w/w) of BC (peanut hull, maize, wood chip, or charcoal) or 8% HC (beet chips or bark) was mixed into a soil and incubated at 65% water-holding capacity (WHC) for 140 d. Treatments included simulated plowing and N fertilization. All BCs reduced NO emissions by ∼60%. Hydrochars reduced NO emissions only initially but significantly increased them after N fertilization to 302% (HC-beet) and 155% (HC-bark) of the control emissions, respectively. Large HC-associated CO emissions suggested that microbial activity was stimulated and that HC was less stable than BC. In the third experiment, nutrient-rich peanut hull BC addition and incubation over 1.5 yr at high WHCs did not promote NO emissions. However, NO emissions were significantly increased with BC after NHNO addition. In conclusion, BC reduced NO emissions and improved the GHG-to-yield ratio under field-relevant conditions. However, the risk of increased NO emissions with HC addition must be carefully evaluated.

  4. Health effects of adopting low greenhouse gas emission diets in the UK

    PubMed Central

    Milner, James; Green, Rosemary; Dangour, Alan D; Haines, Andy; Chalabi, Zaid; Spadaro, Joseph; Markandya, Anil; Wilkinson, Paul

    2015-01-01

    Objective Dietary changes which improve health are also likely to be beneficial for the environment by reducing emissions of greenhouse gases (GHG). However, previous analyses have not accounted for the potential acceptability of low GHG diets to the general public. This study attempted to quantify the health effects associated with adopting low GHG emission diets in the UK. Design Epidemiological modelling study. Setting UK. Participants UK population. Intervention Adoption of diets optimised to achieve the WHO nutritional recommendations and reduce GHG emissions while remaining as close as possible to existing dietary patterns. Main outcome Changes in years of life lost due to coronary heart disease, stroke, several cancers and type II diabetes, quantified using life tables. Results If the average UK dietary intake were optimised to comply with the WHO recommendations, we estimate an incidental reduction of 17% in GHG emissions. Such a dietary pattern would be broadly similar to the current UK average. Our model suggests that it would save almost 7 million years of life lost prematurely in the UK over the next 30 years and increase average life expectancy by over 8 months. Diets that result in additional GHG emission reductions could achieve further net health benefits. For emission reductions greater than 40%, improvements in some health outcomes may decrease and acceptability will diminish. Conclusions There are large potential benefits to health from adopting diets with lower associated GHG emissions in the UK. Most of these benefits can be achieved without drastic changes to existing dietary patterns. However, to reduce emissions by more than 40%, major dietary changes that limit both acceptability and the benefits to health are required. PMID:25929258

  5. The ice-core record - Climate sensitivity and future greenhouse warming

    NASA Technical Reports Server (NTRS)

    Lorius, C.; Raynaud, D.; Jouzel, J.; Hansen, J.; Le Treut, H.

    1990-01-01

    The prediction of future greenhouse-gas-warming depends critically on the sensitivity of earth's climate to increasing atmospheric concentrations of these gases. Data from cores drilled in polar ice sheets show a remarkable correlation between past glacial-interglacial temperature changes and the inferred atmospheric concentration of gases such as carbon dioxide and methane. These and other palaeoclimate data are used to assess the role of greenhouse gases in explaining past global climate change, and the validity of models predicting the effect of increasing concentrations of such gases in the atmosphere.

  6. The ice-core record - Climate sensitivity and future greenhouse warming

    NASA Astrophysics Data System (ADS)

    Lorius, C.; Raynaud, D.; Jouzel, J.; Hansen, J.; Le Treut, H.

    1990-09-01

    The prediction of future greenhouse-gas-warming depends critically on the sensitivity of earth's climate to increasing atmospheric concentrations of these gases. Data from cores drilled in polar ice sheets show a remarkable correlation between past glacial-interglacial temperature changes and the inferred atmospheric concentration of gases such as carbon dioxide and methane. These and other palaeoclimate data are used to assess the role of greenhouse gases in explaining past global climate change, and the validity of models predicting the effect of increasing concentrations of such gases in the atmosphere.

  7. PROTOTYPE TOOL FOR EVALUATING THE COST AND EFFECTIVENESS OF GREENHOUSE GAS MITIGATION TECHNOLOGIES

    EPA Science Inventory

    The paper introduces the structure of a tool, being developed by the U.S. EPA's Office of Research and Development, that will be able to analyze the benefits of new technologies and strategies for controlling greenhouse gas (GHG) emissions. When completed, the tool will be able ...

  8. NASA atmospheric effects of aviation projects: Status and plans

    NASA Technical Reports Server (NTRS)

    Wesoky, Howard L.; Thompson, Anne M.; Stolarski, Richard S.

    1994-01-01

    NASA's Atmospheric Effects of Aviation Project is developing a scientific basis for assessment of the atmospheric impact of subsonic and supersonic aviation. Issues addressed include predicted ozone changes and climatic impact, and related uncertainties. A primary goal is to assist assessments of United Nations scientific organizations and, hence, consideration of emission standards by the International Civil Aviation Organization. Project focus is on simulation of atmospheric processes by computer models, but studies of aircraft operations, laboratory studies, and remote and in situ observations of chemical, dynamic, and radiative processes are also included.

  9. Evidence for an earlier greenhouse cooling effect in the stratosphere before 1980 over the Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    Zerefos, C. S.; Tourpali, K.; Zanis, P.; Eleftheratos, K.; Repapis, C.; Goodman, A.; Wuebbles, D.; Isaksen, I. S. A.; Luterbacher, J.

    2014-08-01

    processes reduce the statistical significance of these trends. Model results are in line with reanalysis and the observations, indicating a persistent cooling (-0.33 °C decade-1) in the lower stratosphere during summer before and after 1980; a feature that is also seen throughout the year. However, the lower stratosphere CESM1-WACCM modelled trends are generally lower than reanalysis and the observations. The contrasting effects of ozone depletion at polar latitudes in winter/spring and the anticipated strengthening of the Brewer-Dobson circulation from man-made global warming at polar latitudes are discussed. Our results provide additional evidence for an early greenhouse cooling signal in the lower stratosphere before 1980, which appears well in advance relative to the tropospheric greenhouse warming signal. The suitability of early warning signals in the stratosphere relative to the troposphere is supported by the fact that the stratosphere is less sensitive to changes due to cloudiness, humidity and man-made aerosols. Our analysis also indicates that the relative contribution of the lower stratosphere versus the upper troposphere low-frequency variability is important for understanding the added value of the long-term tropopause variability related to human-induced global warming.

  10. [Effects of combined application of biogas residues and chemical fertilizers on greenhouse tomato's growth and its fruit yield and quality].

    PubMed

    Xie, Jing-huan; Chen, Gang; Yuan, Qiao-xia; Lin, Gui-ying; Wang, Zhi-shan; Guo, Cong-ying; Zhong, Hui

    2010-09-01

    With randomized block design, a field experiment was conducted in greenhouse to study the effects of combined application of biogas residues and chemical fertilizers on the tomato growth and its fruit yield and quality. The combined application of biogas residues and chemical fertilizers benefited the tomato growth and its fruit yield and quality. The yield of the combined application of 60% biogas residues and 40% chemical fertilizers were higher than the other treatments. The fruit quality under the application of 60% biogas residue and 40% chemical fertilizers also improved significantly, with the Vc content (91.09 mg x kg(-1)) and total sugar content being 21.32 mg x kg(-1) and 2.13% higher than the control, respectively. Among the test fertilization combinations, 60% biogas residue combined with 40% chemical fertilizers was the best one for greenhouse tomato's growth and its fruit yield and quality. PMID:21265160

  11. Geologic signatures of atmospheric effects on impact cratering on Venus

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Highlights of the research include geologic signatures of impact energy and atmospheric response to crater formation. Laboratory experiments were performed at the NASA Ames Vertical Gun Range (AVGR) to assess the interaction between disrupted impactor and atmosphere during entry, and to assess the energy coupling between impacts and the surrounding atmosphere. The Schlieren imaging at the AVGR was used in combination with Magellan imaging and theoretical studies to study the evolution of the impactor following impact. The Schlieren imaging documented the downrange blast front created by vaporization during oblique impacts. Laboratory experiments allowed assessing the effect of impact angle on coupling efficiency with an atmosphere. And the impact angle's effect on surface blasts and run-out flows allowed the distinction of crater clusters created by simultaneous impacts from those created by isolated regions of older age.

  12. Knowledge about the Greenhouse Effect and the Effects of the Ozone Layer among Norwegian Pupils Finishing Compulsory Education in 1989, 1993, and 2005--What Now?

    ERIC Educational Resources Information Center

    Hansen, Pal J. Kirkeby

    2010-01-01

    The greenhouse effect and the effects of the ozone layer have been in the media and public focus for more than two decades. During the same period, Norwegian compulsory schools have had four national curricula. The two last-mentioned prescribe explicitly the two topics. Media and public discourse might have been sources of information causing…

  13. Efficiency of energy recovery from municipal solid waste and the resultant effect on the greenhouse gas balance.

    PubMed

    Gohlke, Oliver

    2009-11-01

    Global warming is a focus of political interest and life-cycle assessment of waste management systems reveals that energy recovery from municipal solid waste is a key issue. This paper demonstrates how the greenhouse gas effects of waste treatment processes can be described in a simplified manner by considering energy efficiency indicators. For evaluation to be consistent, it is necessary to use reasonable system boundaries and to take the generation of electricity and the use of heat into account. The new European R1 efficiency criterion will lead to the development and implementation of optimized processes/systems with increased energy efficiency which, in turn, will exert an influence on the greenhouse gas effects of waste management in Europe. Promising technologies are: the increase of steam parameters, reduction of in-plant energy consumption, and the combined use of heat and power. Plants in Brescia and Amsterdam are current examples of good performance with highly efficient electricity generation. Other examples of particularly high heat recovery rates are the energy-from-waste (EfW) plants in Malmö and Gothenburg. To achieve the full potential of greenhouse gas reduction in waste management, it is necessary to avoid landfilling combustible wastes, for example, by means of landfill taxes and by putting incentives in place for increasing the efficiency of EfW systems.

  14. Assessment of the greenhouse effect impact of technologies used for energy recovery from municipal waste: a case for England.

    PubMed

    Papageorgiou, A; Barton, J R; Karagiannidis, A

    2009-07-01

    Waste management activities contribute to global greenhouse gas emissions approximately by 4%. In particular the disposal of waste in landfills generates methane that has high global warming potential. Effective mitigation of greenhouse gas emissions is important and could provide environmental benefits and sustainable development, as well as reduce adverse impacts on public health. The European and UK waste policy force sustainable waste management and especially diversion from landfill, through reduction, reuse, recycling and composting, and recovery of value from waste. Energy from waste is a waste management option that could provide diversion from landfill and at the same time save a significant amount of greenhouse gas emissions, since it recovers energy from waste which usually replaces an equivalent amount of energy generated from fossil fuels. Energy from waste is a wide definition and includes technologies such as incineration of waste with energy recovery, or combustion of waste-derived fuels for energy production or advanced thermal treatment of waste with technologies such as gasification and pyrolysis, with energy recovery. The present study assessed the greenhouse gas emission impacts of three technologies that could be used for the treatment of Municipal Solid Waste in order to recover energy from it. These technologies are Mass Burn Incineration with energy recovery, Mechanical Biological Treatment via bio-drying and Mechanical Heat Treatment, which is a relatively new and uninvestigated method, compared to the other two. Mechanical Biological Treatment and Mechanical Heat Treatment can turn Municipal Solid Waste into Solid Recovered Fuel that could be combusted for energy production or replace other fuels in various industrial processes. The analysis showed that performance of these two technologies depends strongly on the final use of the produced fuel and they could produce GHG emissions savings only when there is end market for the fuel. On the

  15. [Treatment effect of biological filtration and vegetable floating-bed combined system on greenhouse turtle breeding wastewater].

    PubMed

    Chen, Chong-Jun; Zhang, Rui; Xiang, Kun; Wu, Wei-Xiang

    2014-08-01

    Unorganized discharge of greenhouse turtle breeding wastewater has brought several negative influences on the ecological environment in the rural area of Yangtze River Delta. Biological filtration and vegetable floating-bed combined system is a potential ecological method for greenhouse turtle breeding wastewater treatment. In order to explore the feasibility of this system and evaluate the contribution of vegetable uptake of nitrogen (N) and phosphorus (P) in treating greenhouse turtle breeding wastewater, three types of vegetables, including Ipomoea aquatica, lettuce and celery were selected in this study. Results showed the combined system had a high capacity in simultaneous removal of organic matter, N and P. The removal efficiencies of COD, NH4(+)-N, TN and TP from the wastewater reached up to 93.2%-95.6%, 97.2%-99.6%, 73.9%-93.1% and 74.9%-90.0%, respectively. System with I. aquatica had the highest efficiencies in N and P removal, followed by lettuce and celery. However, plant uptake was not the primary pathway for TN arid TP removal in the combined system. The vegetable uptake of N and P accounted for only 9.1%-25.0% of TN and TP removal from the wastewater while the effect of microorganisms would be dominant for N and P removal. In addition, the highest amounts of N and P uptake in I. aquatica were closely related with the biomass of plant. Results from the study indicated that the biological filtration and vegetable floating-bed combined system was an effective approach to treating greenhouse turtle breeding wastewater in China. PMID:25509094

  16. [Treatment effect of biological filtration and vegetable floating-bed combined system on greenhouse turtle breeding wastewater].

    PubMed

    Chen, Chong-Jun; Zhang, Rui; Xiang, Kun; Wu, Wei-Xiang

    2014-08-01

    Unorganized discharge of greenhouse turtle breeding wastewater has brought several negative influences on the ecological environment in the rural area of Yangtze River Delta. Biological filtration and vegetable floating-bed combined system is a potential ecological method for greenhouse turtle breeding wastewater treatment. In order to explore the feasibility of this system and evaluate the contribution of vegetable uptake of nitrogen (N) and phosphorus (P) in treating greenhouse turtle breeding wastewater, three types of vegetables, including Ipomoea aquatica, lettuce and celery were selected in this study. Results showed the combined system had a high capacity in simultaneous removal of organic matter, N and P. The removal efficiencies of COD, NH4(+)-N, TN and TP from the wastewater reached up to 93.2%-95.6%, 97.2%-99.6%, 73.9%-93.1% and 74.9%-90.0%, respectively. System with I. aquatica had the highest efficiencies in N and P removal, followed by lettuce and celery. However, plant uptake was not the primary pathway for TN arid TP removal in the combined system. The vegetable uptake of N and P accounted for only 9.1%-25.0% of TN and TP removal from the wastewater while the effect of microorganisms would be dominant for N and P removal. In addition, the highest amounts of N and P uptake in I. aquatica were closely related with the biomass of plant. Results from the study indicated that the biological filtration and vegetable floating-bed combined system was an effective approach to treating greenhouse turtle breeding wastewater in China.

  17. Co-effect of increased humidity and meteorological conditions on greenhouse gas fluxes in a young hybrid aspen forest

    NASA Astrophysics Data System (ADS)

    Hansen, Raili; Mander, Ülo; Kupper, Priit; Soosaar, Kaido; Maddison, Martin; Sõber, Jaak; Lõhmus, Krista

    2014-05-01

    Due to the climate change, higher precipitation and an increase in air humidity is expected in northern Europe in the near future (IPCC 2007). There are some studies about irrigation, elevated CO2 and O3 etc., but still we have too little knowledge about the humidity effect on the deciduous forest ecosystem. In 2006 a free-air humidity manipulation (FAHM) facility was established in Estonia and in 2008 we started to artificially increase the air humidity in young hybrid aspen (Populus tremula L. x P. tremuloides Michx.) forest trials on an Endogleyic Planosol of former arable land. Air humidity was raised on average about 7% compared to ambient condition (Tullus et al., 2012). We measured the carbon dioxide, methane and nitrous oxide fluxes from the FAHM system using closed static chamber and gas-chromatograph techniques from July 2009 to November 2012 during snow free periods. Flux measurements were done once a month in three humidification (h) plots and in three control (c) plots. We monitored soil temperature, soil water potential (SWP), precipitation and relative humidity. The vegetation period was rainy in 2009, droughty in 2010 and 2011 (according to SWP the drought was severe in 2011) and cold in 2012. Soil respiration was the lowest in 2011 both in c and h plots; however it was significantly higher in h. Most of the time the soil was a sink for methane, but less CH4 was oxidized in the soil of h plots. Emission of N2O did not have good correlation with air humidity, although one could observe a clear tendency of bigger N2O fluxes when soil was continuously water-saturated. Expectedly, soil respiration had strong positive correlations with soil temperature and CH4 emission demonstrated strong positive correlation with SWP. Hence, interaction of humidification and precipitation affected greenhouse gas fluxes. IPCC, Climate Change 2007: The Physical Science Basis. Cambridge University Press, Cambridge. 2007. Tullus A, Kupper P, Sellin A, Parts L, Sõber J

  18. Influence of Sea Surface Temperature, Tropospheric Humidity and Lapse Rate on the Annual Cycle of the Clear-Sky Greenhouse Effect

    NASA Technical Reports Server (NTRS)

    Hu, H.; Liu, W.

    2000-01-01

    The implication of this work will provide modeling study a surrogate of annual cycle of the greenhouse effect. For example, the model should be able to simulate the annual cycle before it can be used for global change study.

  19. Effectivity of atmospheric electricity on launch availability

    NASA Technical Reports Server (NTRS)

    Ernst, John A.

    1991-01-01

    Thunderstorm days at KSC; percentage of frequency of thunderstorms (1957-1989); effect of lightning advisory on ground operations; Shuttle launch history; Shuttle launch weather history; applied meteorology unit; and goals/operational benefits. This presentation is represented by viewgraphs.

  20. The effect of lactation length on greenhouse gas emissions from the national dairy herd.

    PubMed

    Wall, E; Coffey, M P; Pollott, G E

    2012-11-01

    Many governments have signed up to greenhouse gas emission (GHGE) reduction programmes under their national climate change obligations. Recently, it has been suggested that the use of extended lactations in dairy herds could result in reduced GHGE. Dairy GHGE were modelled on a national basis and the model was used to compare emissions from lactations of three different lengths (305, 370 and 440 days), and a current 'base' scenario on the basis of maintaining current milk production levels. In addition to comparing GHGE from the average 'National Herd' under these scenarios, results were used to investigate how accounting for lactations of different lengths might alter the estimation of emissions calculated from the National Inventory methodology currently recommended by Intergovernmental Panel on Climate Change. Data for the three lactation length scenarios were derived from nationally recorded dairy performance information and used in the GHGE model. Long lactations required fewer milking cows and replacements to maintain current milk yield levels than short ones, but GHGEs were found to rise from 1214 t of CO2 equivalent (CE)/farm per year for lactations of 305 days to 1371 t CE/farm per year for 440-day lactations. This apparent anomaly can be explained by the less efficient milk production (kg milk produced per kg cow weight) found in later lactation, a more pronounced effect in longer lactations. The sensitivity of the model to changes in replacement rate, persistency and level of milk yield was investigated. Changes in the replacement rate from 25% to 20% and in persistency by −10% to +20% resulted in very small changes in GHGE. Differences in GHGE due to the level of milk yield were much more dramatic with animals in the top 10% for yield, producing about 25% less GHGE/year than the average animal. National Inventory results were investigated using a more realistic spread of lactation lengths than recommended for such calculations using emissions

  1. Exploring the Effects of Solar Radiation Management on Water Cycling in a Coupled Land-Atmosphere Model

    NASA Astrophysics Data System (ADS)

    Dagon, K.; Schrag, D. P.

    2015-12-01

    Solar radiation management (SRM) has been proposed as a form of geoengineering to reduce the warming effects of anthropogenic greenhouse gas emissions. Modeling studies have concluded that SRM roughly compensates for global mean temperature changes induced by greenhouse gas forcing, while large-scale hydrologic cycle changes persist. This is driven by both the sensitivity of surface energy fluxes to changes in shortwave versus longwave radiation, and the physiological effect of carbon dioxide on vegetation. We explore the impact of SRM on the hydrologic cycle that may contribute to local and regional temperature and temperature variability. Regional and seasonal changes are examined under simulations using the Community Land Model, version 4, with reductions in solar radiation relative to simulations with present-day and elevated CO2 concentrations. There are significant regional impacts due to vegetation-climate interactions that are not compensated under SRM, including changes in evapotranspiration, soil moisture, and runoff. In the tropics, evapotranspiration decreases due to increased vegetation water use efficiency, increasing soil moisture. In northern mid-latitudes, decreases in evapotranspiration do not always translate to increases in soil moisture due in part to the precipitation response. These results imply that SRM does not compensate for higher greenhouse gas concentrations when one considers land-atmosphere interactions.

  2. Effects of atmospheric drag in swing-by trajectory

    NASA Astrophysics Data System (ADS)

    De Almeida Prado, Antonio Fernando Bertachini; Broucke, Roger

    In this paper, we study the effects of the atmospheric drag in swing-by maneuvers. Our goal is to simulate a large variety of initial conditions for those orbits and study them according to the effects caused by this close approach. The practical importance of this topic is to allow mission designers to explore close approaches with planets, as well as to take advantage of the atmospheric effects, when it is possible. We use the well-known planar restricted circular three-body problem plus atmospheric drag as our model. We integrate numerically the equations of motion forward and backward in time, until the spacecraft is in a distance that we can neglect the planet's effect and consider the system formed by the Sun and the spacecraft as a two-body system. At these two points we can use the two body celestial mechanics to compute energy, angular momentum and the Jacobian constant before and after the close approach.

  3. Superrotation observed in Venus atmosphere

    NASA Astrophysics Data System (ADS)

    Matsuda, Yoshihisa; Takagi, Masahiro

    2005-01-01

    Venus has a dense and high-temperature atmosphere with 92 atm and 730K at the surface. The high temperature near the surface is maintained by the greenhouse effect due to a huge amount of carbon dioxide, which is a main constituent of the atmosphere. It is observed that the Venus atmosphere rotates in the same direction with the solid part (its rotation period is 243 Earth days) and at 70 km altitude this atmospheric rotation is 60 times faster than the solid part. This superrotation is introduced in detail.

  4. Energy and greenhouse gas emission effects of corn and cellulosic ethanol with technology improvements and land use changes.

    SciTech Connect

    Wang, M.; Han, J.; Haq, Z; Tyner, .W.; Wu, M.; Elgowainy, A.

    2011-05-01

    Use of ethanol as a transportation fuel in the United States has grown from 76 dam{sup 3} in 1980 to over 40.1 hm{sup 3} in 2009 - and virtually all of it has been produced from corn. It has been debated whether using corn ethanol results in any energy and greenhouse gas benefits. This issue has been especially critical in the past several years, when indirect effects, such as indirect land use changes, associated with U.S. corn ethanol production are considered in evaluation. In the past three years, modeling of direct and indirect land use changes related to the production of corn ethanol has advanced significantly. Meanwhile, technology improvements in key stages of the ethanol life cycle (such as corn farming and ethanol production) have been made. With updated simulation results of direct and indirect land use changes and observed technology improvements in the past several years, we conducted a life-cycle analysis of ethanol and show that at present and in the near future, using corn ethanol reduces greenhouse gas emission by more than 20%, relative to those of petroleum gasoline. On the other hand, second-generation ethanol could achieve much higher reductions in greenhouse gas emissions. In a broader sense, sound evaluation of U.S. biofuel policies should account for both unanticipated consequences and technology potentials. We maintain that the usefulness of such evaluations is to provide insight into how to prevent unanticipated consequences and how to promote efficient technologies with policy intervention.

  5. HYDROGEN GREENHOUSE PLANETS BEYOND THE HABITABLE ZONE

    SciTech Connect

    Pierrehumbert, Raymond; Gaidos, Eric E-mail: gaidos@hawaii.edu

    2011-06-10

    We show that collision-induced absorption allows molecular hydrogen to act as an incondensible greenhouse gas and that bars or tens of bars of primordial H{sub 2}-He mixtures can maintain surface temperatures above the freezing point of water well beyond the 'classical' habitable zone defined for CO{sub 2} greenhouse atmospheres. Using a one-dimensional radiative-convective model, we find that 40 bars of pure H{sub 2} on a three Earth-mass planet can maintain a surface temperature of 280 K out to 1.5 AU from an early-type M dwarf star and 10 AU from a G-type star. Neglecting the effects of clouds and of gaseous absorbers besides H{sub 2}, the flux at the surface would be sufficient for photosynthesis by cyanobacteria (in the G star case) or anoxygenic phototrophs (in the M star case). We argue that primordial atmospheres of one to several hundred bars of H{sub 2}-He are possible and use a model of hydrogen escape to show that such atmospheres are likely to persist further than 1.5 AU from M stars, and 2 AU from G stars, assuming these planets have protecting magnetic fields. We predict that the microlensing planet OGLE-05-390Lb could have retained an H{sub 2}-He atmosphere and be habitable at {approx}2.6 AU from its host M star.

  6. Greenhouse gas policy influences climate via direct effects of land-use change

    SciTech Connect

    Jones, Andrew D.; Collins, William D.; Edmonds, James A.; Torn, Margaret S.; Janetos, Anthony C.; Calvin, Katherine V.; Thomson, Allison M.; Chini, Louise M.; Mao, Jiafu; Shi, Xiaoying; Thornton, Peter; Hurtt, George; Wise, Marshall A.

    2013-06-01

    Proposed climate mitigation measures do not account for direct biophysical climate impacts of land-use change (LUC), nor do the stabilization targets modeled for the 5th Climate Model Intercomparison Project (CMIP5) Representative Concentration Pathways (RCPs). To examine the significance of such effects on global and regional patterns of climate change, a baseline and alternative scenario of future anthropogenic activity are simulated within the Integrated Earth System Model, which couples the Global Change Assessment Model, Global Land-use Model, and Community Earth System Model. The alternative scenario has high biofuel utilization and approximately 50% less global forest cover compared to the baseline, standard RCP4.5 scenario. Both scenarios stabilize radiative forcing from atmospheric constituents at 4.5 W/m2 by 2100. Thus, differences between their climate predictions quantify the biophysical effects of LUC. Offline radiative transfer and land model simulations are also utilized to identify forcing and feedback mechanisms driving the coupled response. Boreal deforestation is found to strongly influence climate due to increased albedo coupled with a regional-scale water vapor feedback. Globally, the alternative scenario yields a 21st century warming trend that is 0.5 °C cooler than baseline, driven by a 1 W/m2 mean decrease in radiative forcing that is distributed unevenly around the globe. Some regions are cooler in the alternative scenario than in 2005. These results demonstrate that neither climate change nor actual radiative forcing are uniquely related to atmospheric forcing targets such as those found in the RCP’s, but rather depend on particulars of the socioeconomic pathways followed to meet each target.

  7. The atmospheric effects of stratospheric aircraft: A third program report

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S. (Editor); Wesoky, Howard L. (Editor)

    1993-01-01

    A third report from the Atmospheric Effects of Stratospheric Aircraft (AESA) component of NASA's High-Speed Research Program (HSRP) is presented. Market and technology considerations continue to provide an impetus for high-speed civil transport research. A recent United Nations Environment Program scientific assessment showed that considerable uncertainty still exists about the possible impact of aircraft on the atmosphere. The AESA was designed to develop the body of scientific knowledge necessary for the evaluation of the impact of stratospheric aircraft on the atmosphere. The first Program report presented the basic objectives and plans for AESA. This third report marks the midpoint of the program and presents the status of the ongoing research on the impact of stratospheric aircraft on the atmosphere as reported at the third annual AESA Program meeting in June 1993. The focus of the program is on predicted atmospheric changes resulting from projected HSCT emissions. Topics reported on cover how high-speed civil transports (HSCT) might affect stratospheric ozone, emissions scenarios and databases to assess potential atmospheric effects from HSCT's, calculated results from 2-D zonal mean models using emissions data, engine trace constituent measurements, and exhaust plume/aircraft wake vortex interactions.

  8. Nuclear effects in atmospheric and accelerator neutrino experiments

    SciTech Connect

    Chauhan, S.; Athar, M. Sajjad; Singh, S. K.

    2010-11-24

    We have studied the nuclear medium effects in the neutrino (antineutrino) induced interactions in nuclei at intermediate energy region. We have applied this study to calculate the event rates for atmospheric and accelerator neutrino experiments. The study of the nuclear effects has been done for the quasielastic lepton production and the charged current incoherent and coherent pion production processes.

  9. Aerosol speckle effects on atmospheric pulsed lidar backscattered signals

    NASA Technical Reports Server (NTRS)

    Murty, S. R.

    1989-01-01

    Lidar systems using atmospheric aerosols as targets exhibit return signal amplitude and power fluctuations which indicate speckle effects. The effects of refractive turbulence along the path on the aerosol speckle field propagation and on the decorrelation time are studied for coherent pulsed lidar systems.

  10. Simulation of atmospheric temperature effects on cosmic ray muon flux

    SciTech Connect

    Tognini, Stefano Castro; Gomes, Ricardo Avelino

    2015-05-15

    The collision between a cosmic ray and an atmosphere nucleus produces a set of secondary particles, which will decay or interact with other atmosphere elements. This set of events produced a primary particle is known as an extensive air shower (EAS) and is composed by a muonic, a hadronic and an electromagnetic component. The muonic flux, produced mainly by pions and kaons decays, has a dependency with the atmosphere’s effective temperature: an increase in the effective temperature results in a lower density profile, which decreases the probability of pions and kaons to interact with the atmosphere and, consequently, resulting in a major number of meson decays. Such correlation between the muon flux and the atmosphere’s effective temperature was measured by a set of experiments, such as AMANDA, Borexino, MACRO and MINOS. This phenomena can be investigated by simulating the final muon flux produced by two different parameterizations of the isothermal atmospheric model in CORSIKA, where each parameterization is described by a depth function which can be related to the muon flux in the same way that the muon flux is related to the temperature. This research checks the agreement among different high energy hadronic interactions models and the physical expected behavior of the atmosphere temperature effect by analyzing a set of variables, such as the height of the primary interaction and the difference in the muon flux.

  11. Highly physical penumbra solar radiation pressure modeling with atmospheric effects

    NASA Astrophysics Data System (ADS)

    Robertson, Robert; Flury, Jakob; Bandikova, Tamara; Schilling, Manuel

    2015-10-01

    We present a new method for highly physical solar radiation pressure (SRP) modeling in Earth's penumbra. The fundamental geometry and approach mirrors past work, where the solar radiation field is modeled using a number of light rays, rather than treating the Sun as a single point source. However, we aim to clarify this approach, simplify its implementation, and model previously overlooked factors. The complex geometries involved in modeling penumbra solar radiation fields are described in a more intuitive and complete way to simplify implementation. Atmospheric effects are tabulated to significantly reduce computational cost. We present new, more efficient and accurate approaches to modeling atmospheric effects which allow us to consider the high spatial and temporal variability in lower atmospheric conditions. Modeled penumbra SRP accelerations for the Gravity Recovery and Climate Experiment (GRACE) satellites are compared to the sub-nm/s2 precision GRACE accelerometer data. Comparisons to accelerometer data and a traditional penumbra SRP model illustrate the improved accuracy which our methods provide. Sensitivity analyses illustrate the significance of various atmospheric parameters and modeled effects on penumbra SRP. While this model is more complex than a traditional penumbra SRP model, we demonstrate its utility and propose that a highly physical model which considers atmospheric effects should be the basis for any simplified approach to penumbra SRP modeling.

  12. Effect of different agronomic management practices on greenhouse gas emissions and nutrient cycling in a long-term field trial

    NASA Astrophysics Data System (ADS)

    Koal, Philipp; Schilling, Rolf; Gerl, Georg; Pritsch, Karin; Munch, Jean Charles

    2015-04-01

    In order to achieve a reduction of greenhouse gas emissions, modern agronomic management practices need to be established. Therefore, to assess the effect of different farming practices on greenhouse gas emissions, reliable data are required. The experiment covers and compares two main aspects of agricultural management for a better implementation of sustainable land use. The focus lies on the determination and interpretation of greenhouse gas emissions, however, regarding in each case a different agricultural management system, namely an organic farming system and an integrated farming system where the effect of diverse tillage systems and fertilisation practices are observed. In addition, with analysis of the alterable biological, physical and chemical soil properties a link between the impact of different management systems on greenhouse gas emissions and the observed cycle of matter in the soil, especially the nitrogen and carbon cycle, will be enabled. Measurements have been carried out on long-term field trials at the Research Farm Scheyern located in a Tertiary hilly landscape approximately 40 km north of Munich (South Germany). The long-term field trials of the organic and integrated farming system were started in 1992. Since then parcels of land (each around 0.2-0.4 ha) with a particular interior plot set-up have been conducted with the same crop rotation, tillage and fertilisation practice referring to organic and integrated farming management. Thus, the management impacts on the soil of more than 20 years are being examined. Fluxes of CH4, N2O and CO2 have been monitored since 2007 for the integrated farming system trial and since 2012 for the organic farming system trial using an automated system which consists of chambers (0.4 m2 area) with a motor-driven lid, an automated gas sampling unit, an on-line gas chromatographic analysis system, and a control and data logging unit. Precipitation and temperature data have been observed for each experimental

  13. SPS environmental effects on the upper atmosphere

    SciTech Connect

    Duncan, L.M.

    1980-01-01

    The ionospheric effects and associated environmental impacts which may be produced during the construction and operation of a solar power satellite system are reviewed. Propellant emissions from heavy lift-launch vehicles are predicted to cause widespread ionospheric depletions in electron and ion densities. Collisional damping of the microwave power beam in the lower ionosphere can significantly enhance the local free electron temperatures. Thermal self-focusing of the power beam in the ionosphere may excite variations in the beam power-flux density and create large-scale field-aligned electron density irregularities. These large-scale irregularities may also trigger the formation of small-scale plasma striations. Ionospheric modifications can lead to the development of potentially serious telecommunications and climate impacts. A comprehensive research program is being conducted to understand the physical interactions driving these ionospheric effects and to determine the scope and magnitude of the associated environmental impacts.

  14. Distinguishing Solar Cycle Effects in Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    Aplin, K. L.; Harrison, R. G.

    2008-12-01

    As solar radiation decreases with distance from the Sun, other sources of energy, such as ionization from galactic cosmic rays (GCR), assume a greater relative importance than at the terrestrial planets. Charged particle effects could therefore be more relevant to the formation of clouds and haze at the outer planets. The long-term solar modulation of Neptune's albedo is thought to be caused by either ion-induced nucleation of cloud-forming particles, or ultraviolet (UV) radiation effects on the colour of the clouds. On the basis of the 11 year solar cycle, the statistical evidence was slightly in favour of the UV mechanism, however distinguishing unambiguously between the two mechanisms will require more than the solar cycle variation alone. A 1.68 year quasi-periodicity, uniquely present at some times from heliospheric modulation of GCR, has previously been used to discriminate between solar UV and GCR effects in terrestrial data. The cosmic ray proton monitor data from both the Voyager spacecraft show this 1.68 year modulation during the 1980s when the spacecraft were close to the outer planets, indicating the possibility for applying a similar technique as far out as Neptune.

  15. The Atmospheric Effects of Stratospheric Aircraft: a First Program Report

    NASA Technical Reports Server (NTRS)

    Prather, Michael J.; Wesoky, Howard L.; Miake-Lye, Richard C.; Douglass, Anne R.; Turco, Richard P.; Wuebbles, Donald J.; Ko, Malcolm K. W.; Schmeltekopf, Arthur L.

    1992-01-01

    Studies have indicated that, with sufficient technology development, high speed civil transport aircraft could be economically competitive with long haul subsonic aircraft. However, uncertainty about atmospheric pollution, along with community noise and sonic boom, continues to be a major concern; and this is addressed in the planned 6 yr HSRP begun in 1990. Building on NASA's research in atmospheric science and emissions reduction, the AESA studies particularly emphasizing stratospheric ozone effects. Because it will not be possible to directly measure the impact of an HSCT aircraft fleet on the atmosphere, the only means of assessment will be prediction. The process of establishing credibility for the predicted effects will likely be complex and involve continued model development and testing against climatological patterns. Lab simulation of heterogeneous chemistry and other effects will continue to be used to improve the current models.

  16. The atmospheric effects of stratospheric aircraft: A first program report

    SciTech Connect

    Prather, M.J.; Wesoky, H.L.; Miake-lye, R.C.; Douglass, A.R.; Turco, R.P.; Wuebbles, D.J.; Ko, M.K.W.; Schmeltekopf, A.L.

    1992-01-01

    Studies have indicated that, with sufficient technology development, high speed civil transport aircraft could be economically competitive with long haul subsonic aircraft. However, uncertainty about atmospheric pollution, along with community noise and sonic boom, continues to be a major concern; and this is addressed in the planned 6 yr HSRP begun in 1990. Building on NASA's research in atmospheric science and emissions reduction, the AESA studies particularly emphasizing stratospheric ozone effects. Because it will not be possible to directly measure the impact of an HSCT aircraft fleet on the atmosphere, the only means of assessment will be prediction. The process of establishing credibility for the predicted effects will likely be complex and involve continued model development and testing against climatological patterns. Lab simulation of heterogeneous chemistry and other effects will continue to be used to improve the current models.

  17. Effects of ingested atmospheric turbulence on measured tail rotor acoustics

    NASA Technical Reports Server (NTRS)

    Signor, David B.; Yamauchi, Gloria K.; Mosher, Marianne; Hagen, Martin J.; George, Albert R.

    1992-01-01

    Results from an outdoor hover test of a full-scale Lynx tail rotor are presented. The investigation was designed to further the understanding of the acoustics of an isolated tail rotor hovering out-of-ground effect in atmospheric turbulence, without the effects of the main rotor wake or other helicopter components. Measurements include simultaneous rotor performance, noise, inflow, and far-field atmospheric turbulence. Results with grid-generated inflow turbulence are also presented. The effects of turbulence ingestion on rotor noise are quantified. Turbulence ingestion noise is found to be the dominant noise mechanism at locations near the rotor axis. At these locations, the sound radiated by the hovering rotor increases with both increasing atmospheric wind speed and ingested rms turbulent velocity.

  18. Measurements of atmospheric turbulence effects on tail rotor acoustics

    NASA Technical Reports Server (NTRS)

    Hagen, Martin J.; Yamauchi, Gloria K.; Signor, David B.; Mosher, Marianne

    1994-01-01

    Results from an outdoor hover test of a full-scale Lynx tail rotor are presented. The investigation was designed to further the understanding of the acoustics of an isolated tail rotor hovering out-of-ground effect in atmospheric turbulence, without the effects of the main rotor wake or other helicopter components. Measurements include simultaneous rotor performance, noise, inflow, and far-field atmospheric turbulence. Results with grid-generated inflow turbulence are also presented. The effects of atmospheric turbulence ingestion on rotor noise are quantified. In contradiction to current theories, increasing rotor inflow and rotor thrust were found to increase turbulence ingestion noise. This is the final report of Task 13A--Helicopter Tail Rotor Noise, of the NASA/United Kingdom Defense Research Agency cooperative Aeronautics Research Program.

  19. Effect of standard of living on energy consumption and the CO{sub 2} greenhouse effect

    SciTech Connect

    Hung-Yee Shu; Ming-Chin Chang; Shaw, H.

    1996-12-31

    Per capita energy growth patterns were lumped into 6 global regions of similar sociopolitical background, and used to project the rate of growth of atmospheric CO{sub 2}. The 6 key global regions specifically considered were: (1) North America (U.S. and Canada) [NA], (2) Middle East (North Africa and Persian Gulf States) [ME], (3) Commonwealth of Independent States and Eastern Europe [CISEE], (4) China and other centrally planned Asiatic economies [CPAE], (5) Industrialized Countries (including Western Europe, Australia, New Zealand, Israel, Japan, and South Africa) [IC], (6) Less Developed Countries (including all of South and Central America, Central Africa, and the rest of Asia) [LDC]. LDC population will grow 2.7 times from 50 to 67% of world population from 1990 to 2100. Over the same period, world population will grow from 5.2 to 11.9 billion people, and energy use from 15 to 60 TW. LDC energy use will grow disproportionately faster from 20 to 40%, and that in IC will slow from 30 to 22% of world energy. Data on the gross domestic product (GDP) from the World Bank were used as surrogates for standard of living (SOL) to relate world energy consumption with SOL. Per capita energy consumption varied linearly with per capita GDP for the LDC, but was independent of GDP for IC. The per capita energy consumption was multiplied by the population to project the total world energy consumption. We projected that non-fossil energy sources consisting mostly of nuclear energy will overtake fossil energy consisting mostly of coal derived products in the year 2075. The growth of CO{sub 2} emissions from 6 to 18.2 GtC/a will result in an average global temperature increase of 3{degrees}C due to this source only. However, CO{sub 2} is only about half the problem. When all infrared absorbing gases are considered, an average increase of 5.6 {degrees}C is projected for 2100. 7 figs., 1 tab.

  20. Effects of Syn-Pandemic Reforestation on Atmospheric Carbon Dioxide From 1500 to 1700 A.D.

    NASA Astrophysics Data System (ADS)

    Nevle, R. J.; Bird, D. K.

    2005-12-01

    Recent analysis of paleoclimate proxies suggests that biomass burning by humans during the past eight millennia produced quantities of CO2 sufficient to counteract the effects of decreasing insolation driven by orbital variations and thus prevented ice sheet expansion. Correlation between periods of declining population and biomass burning, such as implied by the synchroneity of the American pandemics and decreasing atmospheric CO2 concentration during the 16th-18th centuries, provides an important test of the extent to which pre-industrial anthropogenic activity affected the atmospheric greenhouse gas budget. Numerous studies have attributed the ~5 ppm decline of atmospheric CO2 concentration, as well as the synchronous ~0.1 per mil increase of the δ13C of atmospheric CO2 between 1500 and 1700 A.D., to the effects of Little Ice Age cooling. However, this interpretation is not supported by recent multiproxy-based surface temperature reconstructions, which demonstrate a diminutive global temperature anomaly of ~0.1 C that was unlikely to have independently produced the distinct effect observed in atmospheric CO2 concentration. Alternatively, it is possible that a decline in CO2 concentration driven by massive reforestation produced cooling as a by-product. The timing and magnitude of changes in both the concentration and carbon-isotope composition of atmospheric CO2 recorded by globally distributed climate proxies from the tropics (sponges), temperate latitudes (tree rings), and polar regions (ice cores) are compatible with fixation of >10 Gt C due to reforestation. Reforestation, which explains pre-industrial atmospheric CO2 variations between 1500 and 1700 A.D. in a manner more consistent with the global surface temperature record than explanations requiring substantial cooling, presumably occurred on lands that were cultivated and seasonally burned, then subsequently abandoned, by indigenous Americans who perished in pandemics during European conquest. The