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Sample records for change 1990-2001 emission

  1. INVENTORY OF U.S. GREENHOUSE GAS EMISSIONS AND SINKS: 1990-2001

    EPA Science Inventory

    The inventory report presents estimates by the United States government of U.S. anthropogenic greenhouse gas emissions and sinks for the years 1990 through 2001. The emission estimates in the tables are presented on both a full molecular mass basis and on a Global Warming Potent...

  2. Correlates of Alaska Native Fatal and Nonfatal Suicidal Behaviors 1990-2001

    ERIC Educational Resources Information Center

    Wexler, Lisa; Hill, Ryan; Bertone-Johnson, Elizabeth; Fenaughty, Andrea

    2008-01-01

    Factors correlated with suicidal behavior in a predominately Alaska Native region of Alaska are described, and the correlates relating to fatal and nonfatal suicide behaviors in this indigenous population are distinguished. Suicide data from the region (1990-2001) were aggregated and compared to 2000 U.S. Census Data using chi-squared tests.…

  3. Emergency department capacity and access in California, 1990-2001: an economic analysis.

    PubMed

    Melnick, Glenn A; Nawathe, Amar C; Bamezai, Anil; Green, Lois

    2004-01-01

    Media report that hospitals are closing their emergency departments (EDs) and reducing access to ED services, raising concerns that EDs are not sustainable under competition and managed care. We analyzed financial, economic, capacity, and utilization data for California EDs for 1990-2001. We found that contrary to media reports, hospitals are not abandoning the ED market. Rather, our results show a robust market, where hospitals are adding ED capacity to meet increased demand and to maintain access. Supporting economic analyses show that EDs are sustainable since they generate a sizable and growing portion of inpatient admissions, which contribute to overall economic viability. PMID:15451990

  4. Teaching migration routes to canada geese and trumpeter swans using ultralight aircraft, 1990-2001

    USGS Publications Warehouse

    Sladen, William J. L.; Lishman, W.A.; Ellis, D.H.; Shire, G.G.; Rininger, D.L.

    2002-01-01

    This paper summarizes eleven years (1990-2001) of experiments to teach Canada Geese (Branta canadensis) and Trumpeter Swans (Cygnus buccinator) pre-selected migration routes using ultralight aircraft. When Canada Geese were trained to follow an ultralight aircraft for southward autumn migrations of 680 or 1,320 km, 81% (83/103) returned on their own in the next spring to near their place of training. In contrast, none returned of 21 similarly raised geese that were transported south in a closed truck over a route of 680 km. Trumpeter Swans have proven more difficult to train. However, in two experiments in which Trumpeter Swans followed an ultralight for the entire pre-selected route, one of three and two of four returned close to their training area. A stage-by-stage method, in which swans were transported in trucks between stops, flown in the vicinity and penned with a view of the night sky, has shown some promise. So far an established migration route (north and south twice) has been confirmed in only two geese

  5. Emissions versus climate change

    EPA Science Inventory

    Climate change is likely to offset some of the improvements in air quality expected from reductions in pollutant emissions. A comprehensive analysis of future air quality over North America suggests that, on balance, the air will still be cleaner in coming decades.

  6. CLIMATE CHANGE AND GLOBAL ISOPRENE EMISSIONS

    EPA Science Inventory

    Emission of isoprene from vegetation affects tropospheric chemistry at the regional and global scales. rojected global climate change will potentially alter emission rates, with corresponding influences on concentrations of ozone and other radiatively important trace gases. rogre...

  7. Observational Constraints on Changing Arctic Methane Emissions

    NASA Astrophysics Data System (ADS)

    Dlugokencky, E. J.; Bruhwiler, L.; Lang, P. M.; Masarie, K.; Crotwell, A. M.; Crotwell, M.; Lowry, D.; Fisher, R. E.; Nisbet, E. G.

    2012-12-01

    Methane (CH4) is the second-most important greenhouse gas influenced by human activities. Its chemistry results in additional indirect climate effects from production of tropospheric O3, which also affects air quality, and stratospheric H2O. Because methane's atmospheric lifetime is relatively short (~9 yr) and ~70% of its emissions are anthropogenic, reductions in its emissions provide a potential cost-effective opportunity to slow the rate of increase of radiative forcing. Some fraction of decreased anthropogenic emissions may be canceled by potentially strong feed-backs to natural emissions. Because natural emissions of CH4 are diffuse, relatively weak, and highly-variable in space and time, quantifying changes for large spatial regions is difficult from small-scale field studies alone. Atmosphere observations at well-chosen sites integrate these emissions over large zonal regions and can be particularly useful for detecting changes in emissions. Paleo-climate studies indicate that CH4 emissions from Arctic wetlands are sensitive to climate and may provide a strong positive feedback as the Arctic warms. Measurements of atmospheric CH4 from the NOAA Global Monitoring Division's, Global Cooperative Air Sampling Network began in 1983. These high-precision observations offer key constraints on changes in Arctic CH4 emissions. During 2007, the CH4 growth rate increased in the Arctic, but was nearly zero during 2008. Use of the data in a chemical transport model suggest anomalous emissions of about 2 Tg CH4 during 2007, but returning to long-term average emissions after that. Another potential source affected by climate is emissions from methane clathrates. Measurements of methane's isotopic composition in the Arctic have been useful in showing that CH4 enhancements in Arctic air result from wetlands, not clathrates. Both potential sources are also constrained by spatial patterns in observed CH4, which indicate that, so far, changes in emissions of Arctic CH4 over the

  8. CLIMATE CHANGE AND ISOPRENE EMISSIONS FROM VEGETATION

    EPA Science Inventory

    A global model was developed for estimating spatial and temporal patterns in the emission of isoprene from vegetation under the current climate and used to estimate emissions under doubled-CO2 climate scenarios. urrent emissions were estimated on the basis of vegetation type, fol...

  9. Impact of Changes in Barometric Pressure on Landfill Methane Emission

    NASA Astrophysics Data System (ADS)

    McDermitt, Dayle; Xu, Liukang; Lin, Xiaomao; Amen, Jim; Welding, Karla

    2013-04-01

    Landfill methane emissions were measured continuously using the eddy covariance method from June to December 2010. The study site was located at the Bluff Road Landfill in Lincoln, Nebraska USA. Methane emissions strongly depended on changes in barometric pressure; rising barometric pressure suppressed the emission, while falling barometric pressure enhanced the emission. Emission rates were systematically higher in December than during the summer period. Higher methane emission rates were associated with changes in barometric pressure that were larger in magnitude and longer in duration in winter than in summer, and with lower mean temperatures, which appeared to reduce methane oxidation rates. Sharp changes in barometric pressure caused up to 35-fold variation in day-to-day methane emissions. Power spectrum and ogive analysis showed that continuous measurements over a period of at least 10 days were needed in order to capture 90% of total variance in the methane emission time series at our site. Our results suggest that point-in-time methane emission rate measurements taken at monthly or even longer time intervals using techniques such as the tracer plume method, the mass balance method, or the closed-chamber method may be subject to large variations because of the strong dependence of methane emissions on changes in barometric pressure. Estimates of long-term integrated methane emissions from landfills based on such measurements will inevitably yield large uncertainties. Our results demonstrate the value of continuous measurements for quantifying total annual methane emission from a landfill.

  10. Emission control devices, fuel additive, and fuel composition changes.

    PubMed Central

    Piver, W T

    1977-01-01

    Emission control devices are installed to meet the exhaust standards of the Clean Air Act for carbon monoxide and hydrocarbons, and it is necessary to know, from a public health point of view, how exhaust emissions may be affected by changes in fuel additives and fuel composition. Since these topics are concerned with developing technologies, the available literature on exhaust emission characteristics and the limited information on health effects, is reviewed. PMID:71235

  11. Emission control devices, fuel additive, and fuel composition changes.

    PubMed

    Piver, W T

    1977-08-01

    Emission control devices are installed to meet the exhaust standards of the Clean Air Act for carbon monoxide and hydrocarbons, and it is necessary to know, from a public health point of view, how exhaust emissions may be affected by changes in fuel additives and fuel composition. Since these topics are concerned with developing technologies, the available literature on exhaust emission characteristics and the limited information on health effects, is reviewed. PMID:71235

  12. Attributing land-use change carbon emissions to exported biomass

    SciTech Connect

    Saikku, Laura; Soimakallio, Sampo; Pingoud, Kim

    2012-11-15

    In this study, a simple, transparent and robust method is developed in which land-use change (LUC) emissions are retrospectively attributed to exported biomass products based on the agricultural area occupied for the production. LUC emissions account for approximately one-fifth of current greenhouse gas emissions. Increasing agricultural exports are becoming an important driver of deforestation. Brazil and Indonesia are used as case studies due to their significant deforestation in recent years. According to our study, in 2007, approximately 32% and 15% of the total agricultural land harvested and LUC emissions in Brazil and Indonesia respectively were due to exports. The most important exported single items with regard to deforestation were palm oil for Indonesia and bovine meat for Brazil. To reduce greenhouse gas (GHG) emissions effectively worldwide, leakage of emissions should be avoided. This can be done, for example, by attributing embodied LUC emissions to exported biomass products. With the approach developed in this study, controversial attribution between direct and indirect LUC and amortization of emissions over the product life cycle can be overcome, as the method operates on an average basis and annual level. The approach could be considered in the context of the UNFCCC climate policy instead of, or alongside with, other instruments aimed at reducing deforestation. However, the quality of the data should be improved and some methodological issues, such as the allocation procedure in multiproduct systems and the possible dilution effect through third parties not committed to emission reduction targets, should be considered. - Highlights: Black-Right-Pointing-Pointer CO{sub 2} emissions from land use changes are highly important. Black-Right-Pointing-Pointer Attribution of land use changes for products is difficult. Black-Right-Pointing-Pointer Simple and robust method is developed to attribute land use change emissions.

  13. Data trimming, nuclear emissions, and climate change.

    PubMed

    Shrader-Frechette, Kristin Sharon

    2009-03-01

    Ethics requires good science. Many scientists, government leaders, and industry representatives support tripling of global-nuclear-energy capacity on the grounds that nuclear fission is "carbon free" and "releases no greenhouse gases." However, such claims are scientifically questionable (and thus likely to lead to ethically questionable energy choices) for at least 3 reasons. (i) They rely on trimming the data on nuclear greenhouse-gas emissions (GHGE), perhaps in part because flawed Kyoto Protocol conventions require no full nuclear-fuel-cycle assessment of carbon content. (ii) They underestimate nuclear-fuel-cycle releases by erroneously assuming that mostly high-grade uranium ore, with much lower emissions, is used. (iii) They inconsistently compare nuclear-related GHGE only to those from fossil fuels, rather than to those from the best GHG-avoiding energy technologies. Once scientists take account of (i)-(iii), it is possible to show that although the nuclear fuel cycle releases (per kWh) much fewer GHG than coal and oil, nevertheless it releases far more GHG than wind and solar-photovoltaic. Although there may be other, ethical, reasons to support nuclear tripling, reducing or avoiding GHG does not appear to be one of them. PMID:18937054

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

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

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

  15. Climate Change Technology Scenarios: Energy, Emissions, and Economic Implications

    SciTech Connect

    Placet, Marylynn; Humphreys, Kenneth K.; Mahasenan, N Maha

    2004-08-15

    This report describes three advanced technology scenarios and various illustrative cases developed by staff of Pacific Northwest National Laboratory (PNNL) for the U.S. Climate Change Technology Program. These scenarios and illustrative cases explore the energy, emissions and economic implications of using advanced energy technologies and other climate change related technologies to reduce future emissions of greenhouse gases (GHGs). The cases were modeled using the Mini Climate Assessment Model (MiniCAM) developed by PNNL. The report describes the scenarios, the specifications for the cases, and the results. The report also provides background information on current emissions of GHGs and issues associated with stabilizing GHG concentrations.

  16. Impact of changes in barometric pressure on landfill methane emission

    NASA Astrophysics Data System (ADS)

    Xu, Liukang; Lin, Xiaomao; Amen, Jim; Welding, Karla; McDermitt, Dayle

    2014-07-01

    Landfill methane emissions were measured continuously using the eddy covariance method from June to December 2010. The study site was located at the Bluff Road Landfill in Lincoln, Nebraska, USA. Our results show that landfill methane emissions strongly depended on changes in barometric pressure; rising barometric pressure suppressed the emission, while falling barometric pressure enhanced the emission, a phenomenon called barometric pumping. There was up to a 35-fold variation in day-to-day methane emissions due to changes in barometric pressure. Wavelet coherence analysis revealed a strong spectral coherency between variations of barometric pressure and methane emission at periodicities ranging from 1 day to 8 days. Power spectrum and ogive analysis showed that at least 10 days of continuous measurements was needed in order to capture 90% of the total variance in the methane emission time series at our landfill site. From our results, it is clear that point-in-time measurements taken at monthly or longer time intervals using techniques such as the trace plume method, the mass balance method, or the closed-chamber method will be subject to large variations in measured emission rates because of the barometric pumping phenomenon. Estimates of long-term integrated methane emissions from landfills based on such measurements could yield uncertainties, ranging from 28.8% underestimation to 32.3% overestimation. Our results demonstrate a need for continuous measurements to quantify annual total landfill emissions. This conclusion may apply to the study of methane emissions from wetlands, peatlands, lakes, and other environmental contexts where emissions are from porous media or ebullition. Other implications from the present study for hazard gas monitoring programs are also discussed.

  17. Beyond 'dangerous' climate change: emission scenarios for a new world.

    PubMed

    Anderson, Kevin; Bows, Alice

    2011-01-13

    The Copenhagen Accord reiterates the international community's commitment to 'hold the increase in global temperature below 2 degrees Celsius'. Yet its preferred focus on global emission peak dates and longer-term reduction targets, without recourse to cumulative emission budgets, belies seriously the scale and scope of mitigation necessary to meet such a commitment. Moreover, the pivotal importance of emissions from non-Annex 1 nations in shaping available space for Annex 1 emission pathways received, and continues to receive, little attention. Building on previous studies, this paper uses a cumulative emissions framing, broken down to Annex 1 and non-Annex 1 nations, to understand the implications of rapid emission growth in nations such as China and India, for mitigation rates elsewhere. The analysis suggests that despite high-level statements to the contrary, there is now little to no chance of maintaining the global mean surface temperature at or below 2°C. Moreover, the impacts associated with 2°C have been revised upwards, sufficiently so that 2°C now more appropriately represents the threshold between 'dangerous' and 'extremely dangerous' climate change. Ultimately, the science of climate change allied with the emission scenarios for Annex 1 and non-Annex 1 nations suggests a radically different framing of the mitigation and adaptation challenge from that accompanying many other analyses, particularly those directly informing policy. PMID:21115511

  18. ARS NP212 Climate change, soils and emissions program update

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Agricultural Research Service National Program 212 (Climate Change, Soils, and Emissions) has a significant component focused on air quality studies. Presented here for the Agricultural Air Quality Task Force is an update on the status of ARS programs with focus on air quality. National Program ...

  19. Climate impacts of changing aerosol emissions since 1996

    NASA Astrophysics Data System (ADS)

    Kühn, T.; Partanen, A.-I.; Laakso, A.; Lu, Z.; Bergman, T.; Mikkonen, S.; Kokkola, H.; Korhonen, H.; Räisänen, P.; Streets, D. G.; Romakkaniemi, S.; Laaksonen, A.

    2014-07-01

    Increases in Asian aerosol emissions have been suggested as one possible reason for the hiatus in global temperature increase during the past 15 years. We study the effect of sulphur and black carbon (BC) emission changes between 1996 and 2010 on the global energy balance. We find that the increased Asian emissions have had very little regional or global effects, while the emission reductions in Europe and the U.S. have caused a positive radiative forcing. In our simulations, the global-mean aerosol direct radiative effect changes by 0.06 W/m2 during 1996 to 2010, while the effective radiative forcing (ERF) is 0.42 W/m2. The rather large ERF arises mainly from changes in cloudiness, especially in Europe. In Asia, the BC warming due to sunlight absorption has largely offset the cooling caused by sulphate aerosols. Asian BC concentrations have increased by a nearly constant fraction at all altitudes, and thus, they warm the atmosphere also in cloudy conditions.

  20. Emissions pathways, climate change, and impacts on California.

    PubMed

    Hayhoe, Katharine; Cayan, Daniel; Field, Christopher B; Frumhoff, Peter C; Maurer, Edwin P; Miller, Norman L; Moser, Susanne C; Schneider, Stephen H; Cahill, Kimberly Nicholas; Cleland, Elsa E; Dale, Larry; Drapek, Ray; Hanemann, R Michael; Kalkstein, Laurence S; Lenihan, James; Lunch, Claire K; Neilson, Ronald P; Sheridan, Scott C; Verville, Julia H

    2004-08-24

    The magnitude of future climate change depends substantially on the greenhouse gas emission pathways we choose. Here we explore the implications of the highest and lowest Intergovernmental Panel on Climate Change emissions pathways for climate change and associated impacts in California. Based on climate projections from two state-of-the-art climate models with low and medium sensitivity (Parallel Climate Model and Hadley Centre Climate Model, version 3, respectively), we find that annual temperature increases nearly double from the lower B1 to the higher A1fi emissions scenario before 2100. Three of four simulations also show greater increases in summer temperatures as compared with winter. Extreme heat and the associated impacts on a range of temperature-sensitive sectors are substantially greater under the higher emissions scenario, with some interscenario differences apparent before midcentury. By the end of the century under the B1 scenario, heatwaves and extreme heat in Los Angeles quadruple in frequency while heat-related mortality increases two to three times; alpine/subalpine forests are reduced by 50-75%; and Sierra snowpack is reduced 30-70%. Under A1fi, heatwaves in Los Angeles are six to eight times more frequent, with heat-related excess mortality increasing five to seven times; alpine/subalpine forests are reduced by 75-90%; and snowpack declines 73-90%, with cascading impacts on runoff and streamflow that, combined with projected modest declines in winter precipitation, could fundamentally disrupt California's water rights system. Although interscenario differences in climate impacts and costs of adaptation emerge mainly in the second half of the century, they are strongly dependent on emissions from preceding decades. PMID:15314227

  1. Emissions pathways, climate change, and impacts on California

    USGS Publications Warehouse

    Hayhoe, K.; Cayan, D.; Field, C.B.; Frumhoff, P.C.; Maurer, E.P.; Miller, N.L.; Moser, S.C.; Schneider, S.H.; Cahill, K.N.; Cleland, E.E.; Dale, L.; Drapek, R.; Hanemann, R.M.; Kalkstein, L.S.; Lenihan, J.; Lunch, C.K.; Neilson, R.P.; Sheridan, S.C.; Verville, J.H.

    2004-01-01

    The magnitude of future climate change depends substantially on the greenhouse gas emission pathways we choose. Here we explore the implications of the highest and lowest Intergovernmental Panel on Climate Change emissions pathways for climate change and associated impacts in California. Based on climate projections from two state-of-the-art climate models with low and medium sensitivity (Parallel Climate Model and Hadley Centre Climate Model, version 3, respectively), we find that annual temperature increases nearly double from the lower B1 to the higher A1fi emissions scenario before 2100. Three of four simulations also show greater increases in summer temperatures as compared with winter. Extreme heat and the associated impacts on a range of temperature-sensitive sectors are substantially greater under the higher emissions scenario, with some interscenario differences apparent before midcentury. By the end of the century under the B1 scenario, heatwaves and extreme heat in Los Angeles quadruple in frequency while heat-related mortality increases two to three times; alpine/subalpine forests are reduced by 50-75%; and Sierra snowpack is reduced 30-70%. Under A1fi, heatwaves in Los Angeles are six to eight times more frequent, with heat-related excess mortality increasing five to seven times; alpine/subalpine forests are reduced by 75-90%; and snowpack declines 73-90%, with cascading impacts on runoff and streamflow that, combined with projected modest declines in winter precipitation, could fundamentally disrupt California's water rights system. Although interscenario differences in climate impacts and costs of adaptation emerge mainly in the second half of the century, they are strongly dependent on emissions from preceding decades.

  2. Emissions pathways, climate change, and impacts on California

    SciTech Connect

    Hayhoe, Katharine; Cayan, Daniel; Field, Christopher B.; Frumhoff, Peter C.; Maurer, Edwin P.; Miller, Norman L.; Moser, Susanne C.; Schneider, Stephen H.; Cahill, Kimberly Nicholas; Cleland, Elsa E.; Dale, Larry; Drapek, Ray; Hanemann, R. Michael; Kalkstein, Laurence S.; Lenihan, James; Lunch, Claire K.; Neilson, Ronald P.; Sheridan, Scott C.; Verville, Julia H.

    2004-06-01

    The magnitude of future climate change depends substantially on the greenhouse gas emission pathways we choose. Here we explore the implications of the highest and lowest Intergovernmental Panel on Climate Change emissions pathways for climate change and associated impacts in California. Based on climate projections from two state-of-the-art climate models with low and medium sensitivity (Parallel Climate Model and Hadley Centre Climate Model, version 3, respectively), we find that annual temperature increases nearly double from the lower B1 to the higher A1fi emissions scenario before 2100. Three of four simulations also show greater increases in summer temperatures as compared with winter. Extreme heat and the associated impacts on a range of temperature-sensitive sectors are substantially greater under the higher emissions scenario, with some interscenario differences apparent before midcentury. By the end of the century under the B1 scenario, heatwaves and extreme heat in Los Angeles quadruple in frequency while heat-related mortality increases two to three times; alpine/subalpine forests are reduced by 50-75 percent; and Sierra snowpack is reduced 30-70 percent. Under A1fi, heatwaves in Los Angeles are six to eight times more frequent, with heat-related excess mortality increasing five to seven times; alpine/subalpine forests are reduced by 75-90 percent; and snowpack declines 73-90 percent, with cascading impacts on runoff and streamflow that, combined with projected modest declines in winter precipitation, could fundamentally disrupt California's water rights system. Although interscenario differences in climate impacts and costs of adaptation emerge mainly in the second half of the century, they are strongly dependent on emissions from preceding decades.

  3. Impact of carbonaceous aerosol emissions on regional climate change

    NASA Astrophysics Data System (ADS)

    Roeckner, E.; Stier, P.; Feichter, J.; Kloster, S.; Esch, M.; Fischer-Bruns, I.

    2006-11-01

    The past and future evolution of atmospheric composition and climate has been simulated with a version of the Max Planck Institute Earth System Model (MPI-ESM). The system consists of the atmosphere, including a detailed representation of tropospheric aerosols, the land surface, and the ocean, including a model of the marine biogeochemistry which interacts with the atmosphere via the dust and sulfur cycles. In addition to the prescribed concentrations of carbon dioxide, ozone and other greenhouse gases, the model is driven by natural forcings (solar irradiance and volcanic aerosol), and by emissions of mineral dust, sea salt, sulfur, black carbon (BC) and particulate organic matter (POM). Transient climate simulations were performed for the twentieth century and extended into the twenty-first century, according to SRES scenario A1B, with two different assumptions on future emissions of carbonaceous aerosols (BC, POM). In the first experiment, BC and POM emissions decrease over Europe and China but increase at lower latitudes (central and South America, Africa, Middle East, India, Southeast Asia). In the second experiment, the BC and POM emissions are frozen at their levels of year 2000. According to these experiments the impact of projected changes in carbonaceaous aerosols on the global mean temperature is negligible, but significant changes are found at low latitudes. This includes a cooling of the surface, enhanced precipitation and runoff, and a wetter surface. These regional changes in surface climate are caused primarily by the atmospheric absorption of sunlight by increasing BC levels and, subsequently, by thermally driven circulations which favour the transport of moisture from the adjacent oceans. The vertical redistribution of solar energy is particularly large during the dry season in central Africa when the anomalous atmospheric heating of up to 60 W m-2 and a corresponding decrease in surface solar radiation leads to a marked surface cooling, reduced

  4. Changes in Carbon Emissions in Colombian Savannas Derived From Recent Land use and Land Cover Change

    NASA Astrophysics Data System (ADS)

    Etter, A.; Sarmiento, A.

    2007-12-01

    The global contribution of carbon emissions from land use dynamics and change to the global carbon (C) cycle is still uncertain, a major concern in global change modeling. Carbon emission from fires in the tropics is significant and represents 9% of the net primary production, and 50% of worldwide C emissions from fires are attributable to savanna fires. Such emissions may vary significantly due to differences in ecosystem types. Most savanna areas are devoted to grazing land uses making methane emissions also important in savanna ecosystems. Land use change driven by intensification of grazing and cropping has become a major factor affecting C emission dynamics from savanna regions. Colombia has some 17 MHa of mesic savannas which have been historically burned. Due to changes in market demands and improved accessibility during the last 20 years, important areas of savannas changed land use from predominantly extensive grazing to crops and intensive grazing systems. This research models and evaluates the impacts of such land use changes on the spatial and temporal burning patterns and C emissions in the Orinoco savannas of Colombia. We address the effects of land use change patterns using remote sensing data from MODIS and Landsat, ecosystem mapping products, and spatial GIS analysis. First we map the expansion of the agricultural frontier from the 1980s-2000s. We then model the changes in land use from the 1980s using a statistical modeling approach to analyze and quantify the impact of accessibility, ecosystem type and land tenure. We calculate the effects on C emissions from fire regimes and other sources of C based on patterns and extent of burned areas in the 2000s for different savanna ecosystem types and land uses. In the Llanos the fire regime exhibits a marked seasonal variability with most fire events occurring during the dry season between December-March. Our analysis shows that fire frequencies vary consistently between 0.6 and 2.8 fires.yr-1 per 2

  5. Transient simulations of historical climate change including interactive carbon emissions from land-use change.

    NASA Astrophysics Data System (ADS)

    Matveev, A.; Matthews, H. D.

    2009-04-01

    Carbon fluxes from land conversion are among the most uncertain variables in our understanding of the contemporary carbon cycle, which limits our ability to estimate both the total human contribution to current climate forcing and the net effect of terrestrial biosphere changes on atmospheric CO2 increases. The current generation of coupled climate-carbon models have made significant progress in simulating the coupled climate and carbon cycle response to anthropogenic CO2 emissions, but do not typically include land-use change as a dynamic component of the simulation. In this work we have incorporated a book-keeping land-use carbon accounting model into the University of Victoria Earth System Climate Model (UVic ESCM), and intermediate-complexity coupled climate-carbon model. The terrestrial component of the UVic ESCM allows an aerial competition of five plant functional types (PFTs) in response to climatic conditions and area availability, and tracks the associated changes in affected carbon pools. In order to model CO2 emissions from land conversion in the terrestrial component of the model, we calculate the allocation of carbon to short and long-lived wood products following specified land-cover change, and use varying decay timescales to estimate CO2 emissions. We use recently available spatial datasets of both crop and pasture distributions to drive a series of transient simulations and estimate the net contribution of human land-use change to historical carbon emissions and climate change.

  6. Possible climate change over Eurasia under different emission scenarios

    NASA Astrophysics Data System (ADS)

    Sokolov, A. P.; Monier, E.; Scott, J. R.; Forest, C. E.; Schlosser, C. A.

    2011-12-01

    In an attempt to evaluate possible climate change over EURASIA, we analyze results of six AMIP type simulations with CAM version 3 (CAM3) at 2x2.5 degree resolution. CAM3 is driven by time series of sea surface temperatures (SSTs) and sea ice obtained by running the MIT IGSM2.3, which consists of a 3D ocean GCM coupled to a zonally-averaged atmospheric climate-chemistry model. In addition to changes in SSTs, CAM3 is forced by changes in greenhouse gases and ozone concentrations, sulfate aerosol forcing and black carbon loading calculated by the IGSM2.3. An essential feature of the IGSM is the possibility to vary its climate sensitivity (using a cloud adjustment technique) and the strength of the aerosol forcing. For consistency, new modules were developed in CAM3 to modify its climate sensitivity and aerosol forcing to match those used in the simulations with the IGSM2.3. The simulations presented in this paper were carried out for two emission scenarios, a "Business as usual" scenario and a 660 ppm of CO2-EQ stabilization, which are similar to the RCP8.5 and RCP4.5 scenarios, respectively. Values of climate sensitivity used in the simulations within the IGSM-CAM framework are median and the bounds of the 90% probability interval of the probability distribution obtained by comparing the 20th century climate simulated by different versions of the IGSM with observations. The associated strength of the aerosol forcing was chosen to ensure a good agreement with the observed climate change over the 20th century. Because the concentration of sulfate aerosol significantly decreases over the 21st century in both emissions scenarios, climate changes obtained in these simulations provide a good approximation for the median, and the 5th and 95th percentiles of the probability distribution of 21st century climate change.

  7. Possible climate change over Eurasia under different emission scenarios

    NASA Astrophysics Data System (ADS)

    Sokolov, A. P.; Monier, E.; Gao, X.

    2012-12-01

    In an attempt to evaluate possible climate change over EURASIA, we analyze results of six AMIP type simulations with CAM version 3 (CAM3) at 2x2.5 degree resolution. CAM3 is driven by time series of sea surface temperatures (SSTs) and sea ice obtained by running the MIT IGSM2.3, which consists of a 3D ocean GCM coupled to a zonally-averaged atmospheric climate-chemistry model. In addition to changes in SSTs, CAM3 is forced by changes in greenhouse gases and ozone concentrations, sulfate aerosol forcing and black carbon loading calculated by the IGSM2.3. An essential feature of the IGSM is the possibility to vary its climate sensitivity (using a cloud adjustment technique) and the strength of the aerosol forcing. For consistency, new modules were developed in CAM3 to modify its climate sensitivity and aerosol forcing to match those used in the simulations with the IGSM2.3. The simulations presented in this paper were carried out for two emission scenarios, a "Business as usual" scenario and a 660 ppm of CO2-EQ stabilization, which are similar to the RCP8.5 and RCP4.5 scenarios, respectively. Values of climate sensitivity used in the simulations within the IGSM-CAM framework are median and the bounds of the 90% probability interval of the probability distribution obtained by comparing the 20th century climate simulated by different versions of the IGSM with observations. The associated strength of the aerosol forcing was chosen to ensure a good agreement with the observed climate change over the 20th century. Because the concentration of sulfate aerosol significantly decreases over the 21st century in both emissions scenarios, climate changes obtained in these simulations provide a good approximation for the median, and the 5th and 95th percentiles of the probability distribution of 21st century climate change.

  8. Irreversible climate change due to carbon dioxide emissions.

    PubMed

    Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

    2009-02-10

    The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450-600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the "dust bowl" era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4-1.0 m if 21st century CO(2) concentrations exceed 600 ppmv and 0.6-1.9 m for peak CO(2) concentrations exceeding approximately 1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer. PMID:19179281

  9. Irreversible climate change due to carbon dioxide emissions

    PubMed Central

    Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

    2009-01-01

    The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450–600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the “dust bowl” era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4–1.0 m if 21st century CO2 concentrations exceed 600 ppmv and 0.6–1.9 m for peak CO2 concentrations exceeding ≈1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer. PMID:19179281

  10. Springtime microwave emissivity changes in the southern Kara Sea

    NASA Technical Reports Server (NTRS)

    Crane, Robert G.; Anderson, Mark R.

    1994-01-01

    Springtime microwave brightness temperatures over first-year ice are examined for the southern Kara Sea. Snow emissivity changes are revealed by episodic drops in the 37- to 18-GHz brightness temperature gradient ratio measured by the Nimbus 7 scanning multichannel microwave radiometer. We suggest that the negative gradient ratios in spring 1982 result from increased scatter at 37 GHz due to the formation of a near-surface hoar layer. This interpretation is supported by the results of a surface radiation balance model that shows the melt signature occurring at below freezing temperatures but under clear-sky conditions with increased solar input to the surface. Published observations from the Greenland ice cap show a surface hoar layer forming under similar atmospheric conditions owing to the increased penetration and absorption of solar radiation just below the surface layer. In spring/early summer 1984 similar gradient ratio signatures occur. They appear to be due to several days of freeze-thaw cycling following the movement of a low-pressure system through the region. These changes in surface emissivity represent the transition from winter to summer conditions (as defined by the microwave response) and are shown to be regional in extent and to vary with the synoptic circulations.

  11. Can we attribute changes in risk to anthropogenic emissions?

    NASA Astrophysics Data System (ADS)

    Stone, D. A.; Huggel, C.; Hansen, G.

    2014-12-01

    Losses and damages associated with extreme weather events have been receiving attention lately within the context of anthropogenic climate change, whether in discussions in the public, international negotiations, or legal arenas. Investigations of the role of anthropogenic emissions in this loss and damage have so far taken two forms. On the one hand, so-called "event attribution" studies have examined the role of anthropogenic emissions in the occurrence of the extreme weather event, usually in terms of the chance of the event. On the other hand, a different line of research has been primarily concerned with how losses related to extreme weather events have varied over time, by examining trends in disaster databases. According to these latter studies, the increase in asset values and in exposure are the main drivers of the strong increase of economic losses over the past several decades in many areas.Here we propose a better integration of these existing lines of research in detection and attribution of extreme weather events and disasters by applying a risk framework, where risk is considered a function of the probability of occurrence of an extreme weather event as well as the associated consequences of that event. Attribution of risk thus requires consideration of intensity of the physical event, exposure and value of assets, and vulnerability. Through analysis of trends in these contributors for select case study events, as well as comparative analysis of repeated events, we examine the feasibility of considering the role of anthropogenic emissions against other factors in contributing to long-term trends in risk.

  12. Impacts of Land Cover Change on Biomass Burning Emissions of Mercury

    NASA Astrophysics Data System (ADS)

    Kumar, A.; Wu, S.; Huang, Y.

    2014-12-01

    Mercury is a toxic pollutant in the global environment. It can be deposited from the atmosphere to water bodies where conversion to the highly toxic methyl mercury occurs. Biomass burning is an important source of mercury to the atmosphere with emissions affected by vegetation type and density. We investigate the impacts of 2000-2050 land cover change on biomass burning emissions of mercury associated with the changes in wildfire activities and mercury emission factors. Our results show that the changes in mercury emission factors driven by vegetation change would significantly affect the mercury emissions from biomass burning over some regions, although little change in the global mercury emissions is calculated. Accounting for the changes in wildfire activities driven by land cover change by 2050 leads to an increase by 14% in the global total mercury emissions from biomass burning with even larger regional perturbations.

  13. Predicting Changes in the Radio Emission Fluxes of Extragalactic Sources

    NASA Astrophysics Data System (ADS)

    Sukharev, A. L.; Ryabov, M. I.; Donskikh, G. I.

    2016-06-01

    Data from long-term monitoring with the 26-m University of Michigan radio telescope at a frequency of 14.5 GHz (1974-2011) is used to predict changes in the radio emission fluxes from the extragalactic sources 3C273, 3C120, 3C345, 3C446, 3C454.3, OJ287, OT081, and BLLac. The predictions are based on data on the major periods of variability and their durations obtained by wavelet analysis. The radio emission fluxes from the sources 3C345, 3C446, and 3C454.3, which have complicated variabilities, are predicted using an autoregression linear prediction method. This yields a forecast of the flux variations extending up to 5 years. Harmonic prediction is used for another group of sources, BLLac, OJ287, and OT081, with rapid variability. This approach yielded forecasts extending 4-9 years. For the sources 3C273 and 3C120, which have stable long periods, the harmonic method was also used and yielded a forecast extending up to 16 years. The reliability of the prediction was confirmed by independent observational data from the MOJAVE program for 2011-2015.

  14. On the proportionality between global temperature change and cumulative CO2 emissions during periods of net negative CO2 emissions

    NASA Astrophysics Data System (ADS)

    Zickfeld, Kirsten; MacDougall, Andrew H.; Damon Matthews, H.

    2016-05-01

    Recent research has demonstrated that global mean surface air warming is approximately proportional to cumulative CO2 emissions. This proportional relationship has received considerable attention, as it allows one to calculate the cumulative CO2 emissions (‘carbon budget’) compatible with temperature targets and is a useful measure for model inter-comparison. Here we use an Earth system model to explore whether this relationship persists during periods of net negative CO2 emissions. Negative CO2 emissions are required in the majority of emissions scenarios limiting global warming to 2 °C above pre-industrial, with emissions becoming net negative in the second half of this century in several scenarios. We find that for model simulations with a symmetric 1% per year increase and decrease in atmospheric CO2, the temperature change (ΔT) versus cumulative CO2 emissions (CE) relationship is nonlinear during periods of net negative emissions, owing to the lagged response of the deep ocean to previously increasing atmospheric CO2. When corrected for this lagged response, or if the CO2 decline is applied after the system has equilibrated with the previous CO2 increase, the ΔT versus CE relationship is close to linear during periods of net negative CO2 emissions. A proportionality constant—the transient climate response to cumulative carbon emissions (TCRE)‑ can therefore be calculated for both positive and net negative CO2 emission periods. We find that in simulations with a symmetric 1% per year increase and decrease in atmospheric CO2 the TCRE is larger on the upward than on the downward CO2 trajectory, suggesting that positive CO2 emissions are more effective at warming than negative emissions are at subsequently cooling. We also find that the cooling effectiveness of negative CO2 emissions decreases if applied at higher atmospheric CO2 concentrations.

  15. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 60—Determination of Emission Rate Change 1.Introduction 1.1The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 7 2011-07-01 2011-07-01 false Determination of Emission Rate Change...

  16. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 60—Determination of Emission Rate Change 1.Introduction 1.1The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 7 2010-07-01 2010-07-01 true Determination of Emission Rate Change...

  17. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 60—Determination of Emission Rate Change 1.Introduction 1.1The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 8 2013-07-01 2013-07-01 false Determination of Emission Rate Change...

  18. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 60—Determination of Emission Rate Change 1.Introduction 1.1The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 8 2012-07-01 2012-07-01 false Determination of Emission Rate Change...

  19. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 60—Determination of Emission Rate Change 1. Introduction 1.1 The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 8 2014-07-01 2014-07-01 false Determination of Emission Rate Change...

  20. Air quality in postunification Erfurt, East Germany: associating changes in pollutant concentrations with changes in emissions.

    PubMed Central

    Ebelt, S; Brauer, M; Cyrys, J; Tuch, T; Kreyling, W G; Wichmann, H E; Heinrich, J

    2001-01-01

    The unification of East and West Germany in 1990 resulted in sharp decreases in emissions of major air pollutants. This change in air quality has provided an opportunity for a natural experiment to evaluate the health impacts of air pollution. We evaluated airborne particle size distribution and gaseous co-pollutant data collected in Erfurt, Germany, throughout the 1990s and assessed the extent to which the observed changes are associated with changes in the two major emission sources: coal burning for power production and residential heating, and motor vehicles. Continuous data for sulfur dioxide, total suspended particulates (TSP), nitric oxide, carbon monoxide, and meteorologic parameters were available for 1990-1999, and size-selective particle number and mass concentration measurements were made during winters of 1991 and 1998. We used hourly profiles of pollutants and linear regression analyses, stratified by year, weekday/weekend, and hour, using NO and SO(2) as markers of traffic- and heating-related combustion sources, respectively, to study the patterns of various particle size fractions. Supplementary data on traffic and heating-related sources were gathered to support hypotheses linking these sources with observed changes in ambient air pollution levels. Substantially decreased (19-91%) concentrations were observed for all pollutants, with the exception of particles in the 0.01-0.03 microm size range (representing the smallest ultrafine particles that were measured). The number concentration for these particles increased by 115% between 1991 and 1998. The ratio of these ultrafine particles to TSP also increased by more than 500%, indicating a dramatic change in the size distribution of airborne particles. Analysis of hourly concentration patterns indicated that in 1991, concentrations of SO(2) and larger particle sizes were related to residential heating with coal. These peaks were no longer evident in 1998 due to decreases in coal consumption and

  1. CHANGES TO THE BIOGENIC EMISSION INVENTORY SYSTEM VERSION 3 (BEIS3)

    EPA Science Inventory

    This extended abstract describes recent changes to the Biogenic Emissions Inventory System (BEIS3) that were completed in preparation for the 2005 release of the Community Multiscale Air Quality model. Changes to the model affect the calculated emissions of isoprene and monoterp...

  2. Assessing Land Management Change Effects on Forest Carbon and Emissions Under Changing Climate

    NASA Astrophysics Data System (ADS)

    Law, B. E.

    2014-12-01

    There has been limited focus on fine-scale land management change effects on forest carbon under future environmental conditions (climate, nitrogen deposition, increased atmospheric CO2). Forest management decisions are often made at the landscape to regional levels before analyses have been conducted to determine the potential outcomes and effectiveness of such actions. Scientists need to evaluate plausible land management actions in a timely manner to help shape policy and strategic land management. Issues of interest include species-level adaptation to climate, resilience and vulnerability to mortality within forested landscapes and regions. Efforts are underway to improve land system model simulation of future mortality related to climate, and to develop and evaluate plausible land management options that could help mitigate or avoid future die-offs. Vulnerability to drought-related mortality varies among species and with tree size or age. Predictors of species ability to survive in specific environments are still not resolved. A challenge is limited observations for fine-scale (e.g. 4 km2) modeling, particularly physiological parameters. Uncertainties are primarily associated with future land management and policy decisions. They include the interface with economic factors and with other ecosystem services (biodiversity, water availability, wildlife habitat). The outcomes of future management scenarios should be compared with business-as-usual management under the same environmental conditions to determine the effects of management changes on forest carbon and net emissions to the atmosphere. For example, in the western U.S., land system modeling and life cycle assessment of several management options to reduce impacts of fire reduced long-term forest carbon gain and increased carbon emissions compared with business-as-usual management under future environmental conditions. The enhanced net carbon uptake with climate and reduced fire emissions after thinning

  3. Climate change-induced vegetation change as a driver of increased subarctic biogenic volatile organic compound emissions

    PubMed Central

    Valolahti, Hanna; Kivimäenpää, Minna; Faubert, Patrick; Michelsen, Anders; Rinnan, Riikka

    2015-01-01

    Emissions of biogenic volatile organic compounds (BVOCs) have been earlier shown to be highly temperature sensitive in subarctic ecosystems. As these ecosystems experience rapidly advancing pronounced climate warming, we aimed to investigate how warming affects the BVOC emissions in the long term (up to 13 treatment years). We also aimed to assess whether the increased litterfall resulting from the vegetation changes in the warming subarctic would affect the emissions. The study was conducted in a field experiment with factorial open-top chamber warming and annual litter addition treatments on subarctic heath in Abisko, northern Sweden. After 11 and 13 treatment years, BVOCs were sampled from plant communities in the experimental plots using a push–pull enclosure technique and collection into adsorbent cartridges during the growing season and analyzed with gas chromatography–mass spectrometry. Plant species coverage in the plots was analyzed by the point intercept method. Warming by 2 °C caused a 2-fold increase in monoterpene and 5-fold increase in sesquiterpene emissions, averaged over all measurements. When the momentary effect of temperature was diminished by standardization of emissions to a fixed temperature, warming still had a significant effect suggesting that emissions were also indirectly increased. This indirect increase appeared to result from increased plant coverage and changes in vegetation composition. The litter addition treatment also caused significant increases in the emission rates of some BVOC groups, especially when combined with warming. The combined treatment had both the largest vegetation changes and the highest BVOC emissions. The increased emissions under litter addition were probably a result of a changed vegetation composition due to alleviated nutrient limitation and stimulated microbial production of BVOCs. We suggest that the changes in the subarctic vegetation composition induced by climate warming will be the major factor

  4. Relative changes in CO emissions over megacities based on observations from space

    NASA Astrophysics Data System (ADS)

    Pommier, Matthieu; McLinden, Chris A.; Deeter, Merritt

    2013-07-01

    Urban areas are large sources of several air pollutants, with carbon monoxide (CO) among the largest. Yet measurement from space of their CO emissions remains elusive due to its long lifetime. Here we introduce a new method of estimating relative changes in CO emissions over megacities. A new multichannel Measurements of Pollution in the Troposphere (MOPITT) CO data product, offering improved sensitivity to the boundary layer, is used to estimate this relative change over eight megacities: Moscow, Paris, Mexico, Tehran, Baghdad, Los Angeles, Sao Paulo, and Delhi. By combining MOPITT observations with wind information from a meteorological reanalysis, changes in the CO upwind-downwind difference are used as a proxy for changes in emissions. Most locations show a clear reduction in CO emission between 2000-2003 and 2004-2008, reaching -43% over Tehran and -47% over Baghdad. There is a contrasted agreement between these results and the MACCity and Emission Database for Global Atmospheric Research v4.2 inventories.

  5. Greenhouse gas emissions from soil under changing environmental conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This manuscript is the Guest Editors’ Introduction to a special issue on greenhouse gas emissions from agriculture. The papers were assembled following presentation at EuroSoil 2012. Exchange of greenhouse gases between soils and the atmosphere is a natural consequence of several ecosystem process...

  6. Distinctive timing of US historical surface ozone change determined by climate and anthropogenic emissions

    NASA Astrophysics Data System (ADS)

    Yan, Yingying; Lin, Jintai

    2016-04-01

    Future changes in surface ozone in a warming climate is an important question for the United States. Analyses of historical ozone change in response to climate change, although useful for validating theories regarding future ozone changes, are complicated by concurrent changes in anthropogenic emissions. Here we find that the individual contributions of climate and precursor emissions to US historical ozone changes over 1990-2014 can be distinguished by contrasting the changes in daytime versus nighttime ozone, based on an analysis of observed and simulated annual mean ozone time series. In particular, climate variability has determined ozone interannual variability, particularly for the daytime ozone, while reductions of anthropogenic NOx emissions have primarily driven an increase in the nighttime ozone. Our results have important implications for future ozone change studies and ozone mitigation.

  7. Development of North American emission inventories for air quality modeling under climate change

    SciTech Connect

    Jung-Hun Woo; Shan He; Efthimios Tagaris; Kuo-Jen Liao; Kasemsan Manomaiphiboon; Praveen Amar; Armistead G. Russell

    2008-11-15

    An approach that integrates the impact of both the current regulations and the longer-term national and global trends is developed to construct an emissions inventory (EI) for North America for the mid-century in support of a regional modeling study of ozone and particulate matter (PM) less than or equal to 2.5 {mu}m (PM2.5). Because the time horizon of such a distant projection is beyond that of EIs used in typical modeling studies, it is necessary to identify a practical approach that allows the emission projections to account for emission controls and climatic and energy-use changes. However, a technical challenge arises because this requires integration of various different types of information with which emissions from human activities are associated. The method developed here is based on data availability, spatiotemporal coverage and resolution, and future-scenario consistency (i.e., Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios A1B), and consists of two major steps: (1) near-future EI projection (to the year 2020), and (2) longer-term EI projection (to mid-century). For the United States, the year-2050 emissions for nitrogen oxides (NOx), sulfur dioxide (SO{sub 2}), PM2.5, anthropogenic volatile organic compounds (VOCs), and ammonia are projected to change by 55, 55, 30, 40, and 20%, respectively, compared with 2001. NOx and SO{sub 2} Emission changes are very similar in total amount but different in sectoral contribution. The projected emission trends for Canada and Mexico differ considerably. After taking into account the modeled climate changes, biogenic VOC emission increases from three countries overwhelm the decreases in anthropogenic VOC emissions, leading to a net small increase (2%) in overall VOC emissions. 16 refs., 8 figs., 4 tabs.

  8. Future Arctic temperature change resulting from a range of aerosol emissions scenarios

    NASA Astrophysics Data System (ADS)

    Wobus, Cameron; Flanner, Mark; Sarofim, Marcus C.; Moura, Maria Cecilia P.; Smith, Steven J.

    2016-06-01

    The Arctic temperature response to emissions of aerosols -- specifically black carbon (BC), organic carbon (OC), and sulfate -- depends on both the sector and the region where these emissions originate. Thus, the net Arctic temperature response to global aerosol emissions reductions will depend strongly on the blend of emissions sources being targeted. We use recently published equilibrium Arctic temperature response factors for BC, OC, and sulfate to estimate the range of present-day and future Arctic temperature changes from seven different aerosol emissions scenarios. Globally, Arctic temperature changes calculated from all of these emissions scenarios indicate that present-day emissions from the domestic and transportation sectors generate the majority of present-day Arctic warming from BC. However, in all of these scenarios, this warming is more than offset by cooling resulting from SO2 emissions from the energy sector. Thus, long-term climate mitigation strategies that are focused on reducing carbon dioxide (CO2) emissions from the energy sector could generate short-term, aerosol-induced Arctic warming. A properly phased approach that targets BC-rich emissions from the transportation sector as well as the domestic sectors in key regions -- while simultaneously working toward longer-term goals of CO2 mitigation -- could potentially avoid some amount of short-term Arctic warming.

  9. U.S. EPA'S GLOBAL CLIMATE CHANGE PROGRAM - LANDFILL EMISSIONS AND MITIGATION

    EPA Science Inventory

    The paper discusses the U.S. EPA's global climate change program, concentrating on global landfill methane (CH4) emissions and mitigation research. he EPA's Air and Energy Engineering Research Laboratory (AEERL) has begun research on developing more reliable emission estimates of...

  10. DETECTING LAND COVER CHANGE AT THE JORNADA EXPERIMENT RANGE, NEW MEXICO, WITH ASTER EMISSIVITIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multispectral thermal infrared remote sensing of surface emissivities can detect and monitor long term land cover changes over arid regions. The technique is based on the association between broadband emissivity and density of sparsely covered terrains. The association exists regardless of plant col...

  11. Trends in future N₂O emissions due to land use change.

    PubMed

    Nol, Linda; Verburg, Peter H; Moors, Eddy J

    2012-02-01

    Better insight in the possible range of future N₂O emissions can help to construct mitigation and adaptation strategies and to adapt land use planning and management to climate objectives. The Dutch fen meadow landscape is a hotspot of N₂O emission due to high nitrogen inputs combined with moist peat soils due to land use change. Socio-economic developments in the area are expected to have major impacts on N₂O emission. The goals of this study are to estimate changes in N₂O emissions for the period 2006-2040 under three different scenarios for the Dutch fen meadow landscape (rural production, rural fragmentation, and rural multifunctionality) and to quantify the share of different emission sources. Three scenarios were constructed and quantified based on the Story-And-Simulation approach. The rural production and the rural fragmentation scenarios are characterized by globalization and a market-oriented economy; in the rural production scenario dairy farming has a strong competitive position in the study region, while under the rural fragmentation scenario agriculture is declining. Under the rural multifunctionality scenario, the global context is characterized by regionalization and stronger regulation toward environmental issues. The N₂O emission decreased between 2006 and 2040 under all scenarios. Under the rural production scenario, the N₂O emission decreased by 7%. Due to measures to limit peat mineralization and policies to reduce agricultural emissions, the rural multifunctionality scenario showed the largest decrease in N₂O emissions (44%). Under the rural fragmentation scenario, in which the dairy farming sector is diminished, the emission decreased by 33%. Compared to other uncertainties involved in N₂O emission estimates, the uncertainty due to possible future land use change is relatively large and assuming a constant emission with time is therefore not appropriate. PMID:21940095

  12. Chemical changes in secondary electron emission during oxidation of nickel /100/ and /111/ crystal surfaces

    NASA Technical Reports Server (NTRS)

    Holloway, P. H.; Hudson, J. B.

    1975-01-01

    Changes in the secondary electron spectra (which include chemical shifts of Auger transitions) between 0-70 eV during the oxidation of both (100) and (111) nickel surfaces are reported. The reaction sequence between oxygen and nickel is also briefly described. Emission rate changes are correlated with changes in the work function of the solid.

  13. Sub-surface soil carbon changes affects biofuel greenhouse gas emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in direct soil organic carbon (SOC) can have a major impact on overall greenhouse gas (GHG) emissions from biofuels when using life-cycle assessment (LCA). Estimated changes in SOC, when accounted for in an LCA, are typically derived from near-surface soil depths (<30 cm). Changes in subsurf...

  14. Allowable CO2 emissions based on projected changes in regional extremes and related impacts

    NASA Astrophysics Data System (ADS)

    Seneviratne, Sonia I.; Donat, Markus; Pitman, Andy; Knutti, Reto; Wilby, Robert

    2016-04-01

    Global temperature targets, such as the widely accepted 2°C and 1.5° limits, may fail to communicate the urgency of reducing CO2 emissions. Translation of CO2 emissions into regional- and impact-related climate targets could be more powerful because they resonate better with national interests. We illustrate this approach using regional changes in extreme temperatures and precipitation. These scale robustly with global temperature across scenarios, and thus with cumulative CO2 emissions. This is particularly relevant for changes in regional extreme temperatures on land, which are much greater than changes in the associated global mean. Linking cumulative CO2 emission targets to regional consequences, such as changing climate extremes, would be of particular benefit for political decision making, both in the context of climate negotiations and adaptation.

  15. ABRUPT LONGITUDINAL MAGNETIC FIELD CHANGES AND ULTRAVIOLET EMISSIONS ACCOMPANYING SOLAR FLARES

    SciTech Connect

    Johnstone, B. M.; Petrie, G. J. D.; Sudol, J. J.

    2012-11-20

    We have used Transition Region and Coronal Explorer 1600 A images and Global Oscillation Network Group (GONG) magnetograms to compare ultraviolet (UV) emissions from the chromosphere to longitudinal magnetic field changes in the photosphere during four X-class solar flares. An abrupt, significant, and persistent change in the magnetic field occurred across more than 10 pixels in the GONG magnetograms for each flare. These magnetic changes lagged the GOES flare start times in all cases, showing that they were consequences and not causes of the flares. Ultraviolet emissions were spatially coincident with the field changes. The UV emissions tended to lag the GOES start times for the flares and led the changes in the magnetic field in all pixels except one. The UV emissions led the photospheric field changes by 4 minutes on average with the longest lead being 9 minutes; however, the UV emissions continued for tens of minutes, and more than an hour in some cases, after the field changes were complete. The observations are consistent with the picture in which an Alfven wave from the field reconnection site in the corona propagates field changes outward in all directions near the onset of the impulsive phase, including downward through the chromosphere and into the photosphere, causing the photospheric field changes, whereas the chromosphere emits in the UV in the form of flare kernels, ribbons, and sequential chromospheric brightenings during all phases of the flare.

  16. Signaling of metabolic changes in algae by means of light emission variations

    NASA Astrophysics Data System (ADS)

    Jaskowska, Anna; Gorski, Zbigniew; Dudziak, Andrzej

    2004-08-01

    This work deals with light emission changes from Characeae cells induced in them by mechanical injury, metabolites e.g. ascorbic acid (AsA) and local anaesthetic (LA) - lignocaine. Two optoelectronic methods: (1) the single photon counting (SPC) with an EMI Thorn 9558A (340 - 800 nm) photomultiplier, and (2) the single photon imaging (SPCI) using Molecular Light Imager "Night Owl" LB 981 EG&G Berthold were employed for ultraweak light emission changes record. These methods were used as the complementary ones. Spontaneous ultraweak emission from plants (kept in darkness) as a photonic response to the perturbation of their oxidative metabolism was studied. The reagents used here are antioxidants quenching singlet oxygen 1O2*, and lignocaine is an efficient scavenger of OH*. An increase of the emission intensity was observed both in the case of the mechanical injury and action of AsA or LA. It is pointed out that the use of the SPC is justifiable for samples requiring a high time resolution while the use of the SPCI for samples requiring determination of the space-distribution of emission. The procedure of analysis of temporal-spatial changes in the light emission by objects with a complex shape has been elaborated. It is suggested that ultraweak light emission changes could be considered as an optical determinant of homeostasis security state in plant cells.

  17. Effect of dramatic land use change on gaseous pollutant emissions from biomass burning in Northeastern China

    NASA Astrophysics Data System (ADS)

    Zhao, Hongmei; Tong, Daniel Q.; Gao, Chuanyu; Wang, Guoping

    2015-02-01

    Biomass burning contributes a substantial amount of gas and particle emissions to the atmosphere. As China's breadbasket, northeast China has experienced dramatic land use change in the past century, converting approximately 55 × 104 ha of wetland into farmland to feed a rapidly growing population. This study combines measured emission factors of dominant crops (rice and soybean) and wetland plants (Calamagrostis angu-stifolia, Carex lasiocarpa, Carex pseudo-curaica) and remote sensing land use data to estimate the effect of the unprecedented land use change on gaseous pollutants emissions from biomass burning. Our biomass burning emission estimates resulting from land use changes have increased because of increased post-harvest crop residue burning and decreased burning of wetland plants. From 1986 to 2005, the total emissions of CO2, CO, CXHY, SO2 and NO have increased by 18.6%, 35.7%, 26.8%, 66.2% and 33.2%, respectively. We have found two trends in agricultural burning: increased dryland crop residue burning and decreased wetland (rice paddy) burning. Our results revealed that the large scale land use change in northeastern China has induced more active biomass-burning emissions. The regional emission inventory of gaseous pollutants derived from this work may be used to support further examination of the subsequent effects on regional climate and air quality simulations with numerical atmospheric models.

  18. Emission energy control of semiconductor quantum dots using phase change material

    NASA Astrophysics Data System (ADS)

    Kanazawa, Shohei; Sato, Yu; Yamamura, Ariyoshi; Saiki, Toshiharu

    2015-03-01

    Semiconductor quantum dots have paid much attention as it is a promising candidate for quantum, optical devices, such as quantum computer and quantum dot laser. We propose a local emission energy control method of semiconductor quantum dots using applying strain by volume expansion of phase change material. Phase change material can change its phase crystalline to amorphous, and the volume expand by its phase change. This method can control energy shift direction and amount by amorphous religion and depth. Using this method, we matched emission energy of two InAs/InP quantum dots. This achievement can connect to observing superradiance phenomenon and quantum dot coupling effect.

  19. Global mismatch between greenhouse gas emissions and the burden of climate change

    NASA Astrophysics Data System (ADS)

    Althor, Glenn; Watson, James E. M.; Fuller, Richard A.

    2016-02-01

    Countries export much of the harm created by their greenhouse gas (GHG) emissions because the Earth’s atmosphere intermixes globally. Yet, the extent to which this leads to inequity between GHG emitters and those impacted by the resulting climate change depends on the distribution of climate vulnerability. Here, we determine empirically the relationship between countries’ GHG emissions and their vulnerability to negative effects of climate change. In line with the results of other studies, we find an enormous global inequality where 20 of the 36 highest emitting countries are among the least vulnerable to negative impacts of future climate change. Conversely, 11 of the 17 countries with low or moderate GHG emissions, are acutely vulnerable to negative impacts of climate change. In 2010, only 28 (16%) countries had an equitable balance between emissions and vulnerability. Moreover, future emissions scenarios show that this inequality will significantly worsen by 2030. Many countries are manifestly free riders causing others to bear a climate change burden, which acts as a disincentive for them to mitigate their emissions. It is time that this persistent and worsening climate inequity is resolved, and for the largest emitting countries to act on their commitment of common but differentiated responsibilities.

  20. Global mismatch between greenhouse gas emissions and the burden of climate change

    PubMed Central

    Althor, Glenn; Watson, James E. M.; Fuller, Richard A.

    2016-01-01

    Countries export much of the harm created by their greenhouse gas (GHG) emissions because the Earth’s atmosphere intermixes globally. Yet, the extent to which this leads to inequity between GHG emitters and those impacted by the resulting climate change depends on the distribution of climate vulnerability. Here, we determine empirically the relationship between countries’ GHG emissions and their vulnerability to negative effects of climate change. In line with the results of other studies, we find an enormous global inequality where 20 of the 36 highest emitting countries are among the least vulnerable to negative impacts of future climate change. Conversely, 11 of the 17 countries with low or moderate GHG emissions, are acutely vulnerable to negative impacts of climate change. In 2010, only 28 (16%) countries had an equitable balance between emissions and vulnerability. Moreover, future emissions scenarios show that this inequality will significantly worsen by 2030. Many countries are manifestly free riders causing others to bear a climate change burden, which acts as a disincentive for them to mitigate their emissions. It is time that this persistent and worsening climate inequity is resolved, and for the largest emitting countries to act on their commitment of common but differentiated responsibilities. PMID:26848052

  1. The evolution of shipping emissions and the costs of regulation changes in the northern EU area

    NASA Astrophysics Data System (ADS)

    Johansson, L.; Jalkanen, J.-P.; Kalli, J.; Kukkonen, J.

    2013-11-01

    An extensive inventory of marine exhaust emissions is presented in the northern European emission control area (ECA) in 2009 and 2011. The emissions of SOx, NOx, CO2, CO and PM2.5 were evaluated using the Ship Traffic Emission Assessment Model (STEAM). We have combined the information on individual vessel characteristics and position reports generated by the automatic identification system (AIS). The emission limitations from 2009 to 2011 have had a significant impact on reducing the emissions of both SOx and PM2.5. The predicted emissions of SOx originated from IMO (International Maritime Organization)-registered marine traffic have been reduced by 29%, from 320 kt to 231 kt, in the ECA from 2009 to 2011. The corresponding predicted reduction of PM2.5 emissions was 17%, from 72 kt to 61 kt. The highest CO2 and PM2.5 emissions in 2011 were located in the vicinity of the coast of the Netherlands, in the English Channel, near the south-eastern UK and along the busiest shipping lines in the Danish Straits and the Baltic Sea. The changes of emissions and the financial costs caused by various regulative actions since 2005 were also evaluated, based on the increased direct fuel costs. We also simulated the effects and direct costs associated with the forthcoming switch to low-sulfur distillate fuels in 2015. According to the projections for the future, there will be a reduction of 87% in SOx emissions and a reduction of 48% in PM2.5 emissions in 2015, compared with the corresponding shipping emissions in 2011 in the ECA. The corresponding relative increase in fuel costs for all IMO-registered shipping varied between 13% and 69%, depending on the development of the prices of fuels and the use of the sulfur scrubber equipment.

  2. Changes in otoacoustic emissions during selective auditory and visual attention.

    PubMed

    Walsh, Kyle P; Pasanen, Edward G; McFadden, Dennis

    2015-05-01

    Previous studies have demonstrated that the otoacoustic emissions (OAEs) measured during behavioral tasks can have different magnitudes when subjects are attending selectively or not attending. The implication is that the cognitive and perceptual demands of a task can affect the first neural stage of auditory processing-the sensory receptors themselves. However, the directions of the reported attentional effects have been inconsistent, the magnitudes of the observed differences typically have been small, and comparisons across studies have been made difficult by significant procedural differences. In this study, a nonlinear version of the stimulus-frequency OAE (SFOAE), called the nSFOAE, was used to measure cochlear responses from human subjects while they simultaneously performed behavioral tasks requiring selective auditory attention (dichotic or diotic listening), selective visual attention, or relative inattention. Within subjects, the differences in nSFOAE magnitude between inattention and attention conditions were about 2-3 dB for both auditory and visual modalities, and the effect sizes for the differences typically were large for both nSFOAE magnitude and phase. These results reveal that the cochlear efferent reflex is differentially active during selective attention and inattention, for both auditory and visual tasks, although they do not reveal how attention is improved when efferent activity is greater. PMID:25994703

  3. Changes in otoacoustic emissions during selective auditory and visual attention

    PubMed Central

    Walsh, Kyle P.; Pasanen, Edward G.; McFadden, Dennis

    2015-01-01

    Previous studies have demonstrated that the otoacoustic emissions (OAEs) measured during behavioral tasks can have different magnitudes when subjects are attending selectively or not attending. The implication is that the cognitive and perceptual demands of a task can affect the first neural stage of auditory processing—the sensory receptors themselves. However, the directions of the reported attentional effects have been inconsistent, the magnitudes of the observed differences typically have been small, and comparisons across studies have been made difficult by significant procedural differences. In this study, a nonlinear version of the stimulus-frequency OAE (SFOAE), called the nSFOAE, was used to measure cochlear responses from human subjects while they simultaneously performed behavioral tasks requiring selective auditory attention (dichotic or diotic listening), selective visual attention, or relative inattention. Within subjects, the differences in nSFOAE magnitude between inattention and attention conditions were about 2–3 dB for both auditory and visual modalities, and the effect sizes for the differences typically were large for both nSFOAE magnitude and phase. These results reveal that the cochlear efferent reflex is differentially active during selective attention and inattention, for both auditory and visual tasks, although they do not reveal how attention is improved when efferent activity is greater. PMID:25994703

  4. Metrics for linking emissions of gases and aerosols to global precipitation changes

    NASA Astrophysics Data System (ADS)

    Shine, K. P.; Allan, R. P.; Collins, W. J.; Fuglestvedt, J. S.

    2015-08-01

    Recent advances in understanding have made it possible to relate global precipitation changes directly to emissions of particular gases and aerosols that influence climate. Using these advances, new indices are developed here called the Global Precipitation-change Potential for pulse (GPPP) and sustained (GPPS) emissions, which measure the precipitation change per unit mass of emissions. The GPP can be used as a metric to compare the effects of different emissions. This is akin to the global warming potential (GWP) and the global temperature-change potential (GTP) which are used to place emissions on a common scale. Hence the GPP provides an additional perspective of the relative or absolute effects of emissions. It is however recognised that precipitation changes are predicted to be highly variable in size and sign between different regions and this limits the usefulness of a purely global metric. The GPPP and GPPS formulation consists of two terms, one dependent on the surface temperature change and the other dependent on the atmospheric component of the radiative forcing. For some forcing agents, and notably for CO2, these two terms oppose each other - as the forcing and temperature perturbations have different timescales, even the sign of the absolute GPPP and GPPS varies with time, and the opposing terms can make values sensitive to uncertainties in input parameters. This makes the choice of CO2 as a reference gas problematic, especially for the GPPS at time horizons less than about 60 years. In addition, few studies have presented results for the surface/atmosphere partitioning of different forcings, leading to more uncertainty in quantifying the GPP than the GWP or GTP. Values of the GPPP and GPPS for five long- and short-lived forcing agents (CO2, CH4, N2O, sulphate and black carbon - BC) are presented, using illustrative values of required parameters. The resulting precipitation changes are given as the change at a specific time horizon (and hence they are

  5. The impacts of population change on carbon emissions in China during 1978-2008

    SciTech Connect

    Zhu Qin Peng Xizhe

    2012-09-15

    This study examines the impacts of population size, population structure, and consumption level on carbon emissions in China from 1978 to 2008. To this end, we expanded the stochastic impacts by regression on population, affluence, and technology model and used the ridge regression method, which overcomes the negative influences of multicollinearity among independent variables under acceptable bias. Results reveal that changes in consumption level and population structure were the major impact factors, not changes in population size. Consumption level and carbon emissions were highly correlated. In terms of population structure, urbanization, population age, and household size had distinct effects on carbon emissions. Urbanization increased carbon emissions, while the effect of age acted primarily through the expansion of the labor force and consequent overall economic growth. Shrinking household size increased residential consumption, resulting in higher carbon emissions. Households, rather than individuals, are a more reasonable explanation for the demographic impact on carbon emissions. Potential social policies for low carbon development are also discussed. - Highlights: Black-Right-Pointing-Pointer We examine the impacts of population change on carbon emissions in China. Black-Right-Pointing-Pointer We expand the STIRPAT model by containing population structure factors in the model. Black-Right-Pointing-Pointer The population structure includes age structure, urbanization level, and household size. Black-Right-Pointing-Pointer The ridge regression method is used to estimate the model with multicollinearity. Black-Right-Pointing-Pointer The population structure plays a more important role compared with the population size.

  6. Syntheses of wetland methane emissions at high latitudes: exploring sensitivities to climate change and permafrost thaw.

    NASA Astrophysics Data System (ADS)

    Olefeldt, D.; Turetsky, M. R.

    2014-12-01

    Climate change and associated permafrost thaw has the potential to increase methane emissions from high latitude wetlands, thus amplifying human-caused climate change. Methane monitoring at high latitude wetlands have been carried out since the 1970s, and at this time there are published data from a large number of sites and some individual sites have data that span more than a decade. By synthesizing data both across and within sites it is possible to improve our understanding of environmental and physical controls on methane emissions. It is clear from comparing mean growing season methane emissions across sites that site wetness, soil temperature and vegetation composition have strong and interacting effects. At individual sites it is also evident that soil temperatures and wetness co-vary at inter-annual scales as a result of physical processes, with compounding influences on methane emissions. Further the presence of certain sedge species, often found in fens at high latitudes strongly influence sensitivities to soil temperature and wetness. Shifts in functional relationships as related to ecosystem structure is central for methane emissions at high latitude wetlands, given the hydrological and ecological changes that occur with permafrost thaw and thermokarst landform development. Hence, in order to more accurately project future methane emissions from high latitudes at a pan-arctic scale, it is necessary to include a spatial representation of thermokarst development as well as ecosystem-appropriate functional relationships between emissions and environmental variables.

  7. Changes in Emissions in Megacities during the Past Decades: Impact on the Distribution of Atmospheric Compounds

    NASA Astrophysics Data System (ADS)

    Doumbia, E. H. T.; Granier, C.; Sindelarova, K.; Tilmes, S.; Bouarar, I.; Richter, A.; Hilboll, A.; Conley, A. J.; Garcia, R. R.; Kinnison, D. E.; Lamarque, J. F.; Marsh, D. R.; Smith, A. K.; Neely, R.; Turnock, S.

    2015-12-01

    The surface emissions of atmospheric compounds have changed dramatically in many world regions during the past decades. We will evaluate these changes through an analysis of different global and regional anthropogenic emissions inventories, focusing on several megacities. In European and North American megacities, surface emissions of chemical compounds have decreased significantly, while they have increased in many other megacities in different parts of the world. Simulations performed with the CAM4-Chem Community Earth System Model will be used to evaluate the impact of the changes in emissions on the distributions chemical compounds in different megacities. These simulations were performed as part of the Chemistry-Climate Model Initiative (CCMI), a project of the International Global Atmospheric Chemistry Project (IGAC). The analysis of the simulations will focus more particularly on nitrogen dioxide: this species has been observed by satellite measurements since the late 1990s. Model results and satellite observations will be analysed for everal megacities in Europe and North America, where strong emission controls have been implemented. Other megacities in China, India, Africa and South America, where few emission regulations have been enforced have seen large increases in their emissions: we will evaluate the consistency of the model simulations and satellite observations of NO2 in these cities.

  8. Metrics for linking emissions of gases and aerosols to global precipitation changes

    NASA Astrophysics Data System (ADS)

    Shine, K. P.; Allan, R. P.; Collins, W. J.; Fuglestvedt, J. S.

    2015-04-01

    Recent advances in understanding have made it possible to relate global precipitation changes more directly to emissions of particular gases and aerosols that influence climate. Using these advances, a new index is developed here called the Global Precipitation-change Potential (GPP), which measures the precipitation change per unit mass of emissions. It is recognised that precipitation changes are predicted to be highly variable in size and sign between different regions, and ultimately climate change impacts will be more dependent on these regional changes. Nevertheless, the GPP presents a useful measure of the global-mean role of emissions of individual forcing agents. Results are presented for pulse (GPPP) and sustained (GPPS) emissions for selected long- and short-lived forcing agents (CO2, CH4, N2O, sulphate and black carbon - BC) using illustrative values of required parameters. The GPP can be used as a metric to compare the importance of emissions. This is akin to the global warming potential (GWP) and the global temperature-change potential (GTP) which are used to place emissions on a common scale. The GPP is further down the cause-effect chain from emissions to impacts than the GWP and GTP, and so provides an additional perspective. One key parameter needed for the GPP is the surface-atmosphere partitioning of radiative forcing. Few studies have presented results for this partitioning for different forcings, leading to more uncertainty in quantification of the GPP than the GWP or GTP. Using CO2 as references gas, the pulse and sustained GPP values for the non-CO2 species are larger than the corresponding GTP values, because the CO2 GPP is the sum of two quite strongly opposing terms. For BC emissions, the atmospheric forcing is sufficiently strong that the GPPS is opposite in sign to the GTPS. The choice of CO2 as a reference gas is problematic, especially for the GPPS at time horizons less than about 60 years, because the opposing terms make the CO2 GPPS

  9. Changes in motor vehicle emissions on diurnal to decadal time scales and effects on atmospheric composition.

    PubMed

    Harley, Robert A; Marr, Linsey C; Lehner, Jaime K; Giddings, Sarah N

    2005-07-15

    Emissions from gasoline and diesel engines vary on time scales including diurnal, weekly, and decadal. Temporal patterns differ for these two engine types that are used predominantly for passenger travel and goods movement, respectively. Rapid growth in diesel fuel use and decreasing NOx emission rates from gasoline engines have led to altered emission profiles. During the 1990s, on-road use of diesel fuel grew 3 times faster than gasoline. Over the same time period, the NOx emission rate from gasoline engines in California was reduced by a factor of approximately 2, while the NOx emission rate from diesel engines decreased only slightly. Diesel engines therefore grew in both relative and absolute terms as a source of NOx, accounting for about half of all on-road NO, emissions as of 2000. Diesel truck emissions decrease by 60-80% on weekends. Counterintuitive responses to these emission changes are seen in measured concentrations of ozone. In contrast, elemental carbon (EC) concentrations decrease on weekends as expected. Weekly and diurnal patterns in diesel truck activity contribute to variability in the ratio of organic carbon (OC) to EC in primary source emissions, and this could be a source of bias in assessments of the importance of secondary organic aerosol. PMID:16082967

  10. Decadal change in carbon monoxide to nitrogen oxide ratio in U.S. vehicular emissions

    NASA Astrophysics Data System (ADS)

    Parrish, D. D.; Trainer, M.; Hereid, D.; Williams, E. J.; Olszyna, K. J.; Harley, R. A.; Meagher, J. F.; Fehsenfeld, F. C.

    2002-06-01

    Accurate emission inventories and their temporal trends must be incorporated into pollutant inventories to allow for reliable modeling of the country's past, present, and future air quality. Measured carbon monoxide (CO) and nitrogen oxide (NOx) concentrations from two urban areas show that the CO/NOx vehicular emission ratio has decreased at an average rate of 7-9% per year from 1987 to 1999. This amounts to a factor of nearly 3 over the 12 years. The current U.S. Environmental Protection Agency tabulations of estimated pollutant emission trends indicate a rate of decrease smaller by a factor of 2-3. The trend in maximum ambient CO levels in U.S. cities suggests a 5.2 +/- 0.8% per year average annual decrease in CO vehicular emissions, which implies a 2-3% annual increase in NOx emissions from vehicles. Thus over the decade of the 1990s, annual U.S. CO emissions from vehicles have decreased from ~65 to ~38 Tg, representing approximate decreases of 6 and 3% in the annual global fuel-use CO emissions and in total global anthropogenic CO emissions, respectively. It is expected that the volatile organic compound (VOC)/NOx vehicular exhaust emission ratio has decreased similarly, implying that the character of atmospheric photochemistry in U.S. urban areas has changed significantly over the decade.

  11. Variations in European ammonia emissions due to daily weather fluctuations and climate change

    NASA Astrophysics Data System (ADS)

    Ambelas Skjøth, C.; Geels, C.

    2012-04-01

    Ammonia plays an important role in atmospheric processes. It is the main alkaline component in the atmosphere and is highly reactive in forming either aerosols or by depositing fast to most surfaces including sensitive ecosystems. The geographical distribution of ammonia emission has been highly studied, while the temporal variations have been somewhat neglected. Climate and daily meteorology affects the temporal distribution and the amount of ammonia emissions. This forms an important feed-back mechanism e.g. by changing ammonia emissions thus affecting aerosol composition and the sensitive ecosystems through associated nitrogen depositions. This feed-back mechanism has so far been overlooked in climate change and earth system science studies. Here we assess annual variations in ammonia emissions in central and Northern Europe as well as emission changes due to projected temperature changes in the future. We use the dynamical ammonia emission model (Skjøth et al., 2011) within the DAMOS system (Geels et al., 2012) with focus on the period 2000-2100. The model use hourly meteorological data from the MM5 model and bias-corrected climate data from the ENSEMBLES project. The model reproduces hourly changes in ammonia emissions due to climate and is also capable of taking into account changes in production methods as well as policy measures. Here we study the effect of climate change on five main agricultural sources to ammonia: 1) heated stables, 2) open cattle barns, 3) storage facilities, 4) animal waste and mineral fertilizer 5) grazing animals. Climate change increase emissions due to increased temperatures. The expected increase in ammonia emissions is typically 20-40% for cattle barns, storage facilities and application of manure in form of animal waste. Heated stables (e.g. pigs and poultry) are only marginally affected by climatic changes as these sources typically are heated to maintain a constant temperature. The heated stables therefore have a more or less

  12. Climate change and N2O emissions from South West England grasslands: A modelling approach

    NASA Astrophysics Data System (ADS)

    Abalos, Diego; Cardenas, Laura M.; Wu, Lianhai

    2016-05-01

    Unravelling the impacts of climate change on agriculture becomes increasingly important, as the rates and magnitude of its effects are accelerating. Current estimates of the consequences of climate change on nitrous oxide (N2O) emissions remain largely uncertain; there is a need for more consistent and comprehensive assessments of this impact. In this study we explored the implications of two IPCC climate change projections (high and medium emissions scenarios) on N2O emissions from South West England grasslands for the time slices of a baseline, the 2020s, the 2050s and the 2080s, employing a process-based model (SPACSYS). The model was initially calibrated and validated using datasets collected from three grassland sites of the region. Statistical analysis showed that simulated results had no significant total error or bias compared to measured values. We found a consistent increase in N2O emissions of up to 94% under future climate change scenarios compared to those under the baseline, and warming rather than precipitation variability was the overriding factor controlling the N2O rise. Modelling fertilizer forms showed that replacing ammonium-nitrate fertilizers with urea or slurry significantly reduced N2O emissions (c. 30%). Our study highlights the urgent necessity to adopt viable N2O mitigation measures now in order to avoid higher emissions in the future.

  13. Long-term changes in Jovian synchrotron radio emission - Intrinsic variations or effects of viewing geometry?

    NASA Astrophysics Data System (ADS)

    Hood, L. L.

    1993-04-01

    Possible causes of the observed long-term variation of Jovian synchrotron radio emission, including both intrinsic changes in the Jovian radiation belts and apparent changes due to variations in the Jovigraphic declination of the earth, DE, are investigated. An increase in diffusion rate with other parameters held constant results in an inward displacement of the peak emission radial distance that is not observed. Effects of viewing geometry changes are examined. The possible importance of such effects is suggested by a correlation between the total decimetric radio flux and DE, which varies between -3.3 and +3.3 deg during one Jovian orbital period. Because the Jovian central meridian longitudes where the magnetic latitude passes through zero during a given Jovian rotation change substantially with DE and since significant longitudinal asymmetries exist in both the volume emissivity and the latitudinal profile of the beam, the total intensity should be at least a partial function of D sub E.

  14. Opportunities to change development pathways toward lower greenhouse gas emissions through energy efficiency

    SciTech Connect

    Alterra, Swart; Masanet, Eric; Lecocq, Franck; Najam, Adil; Schaeffer, Robert; Winkler, Harald; Sathaye, Jayant

    2008-07-04

    There is a multiplicity of development pathways in which low energy sector emissions are not necessarily associated with low economic growth. However, changes in development pathways can rarely be imposed from the top. On this basis, examples of energy efficiency opportunities to change development pathways toward lower emissions are presented in this paper. We review opportunities at the sectoral and macro level. The potential for action on nonclimate policies that influence energy use and emissions are presented. Examples are drawn from policies already adopted and implemented in the energy sector. The paper discusses relationships between energy efficiency policies and their synergies and tradeoffs with sustainable development and greenhouse gas emissions. It points to ways that energy efficiency could be mainstreamed into devel?opment choices.

  15. Carbon cycle and climate change, a tale of increasing emissions and uncertain future sinks

    NASA Astrophysics Data System (ADS)

    Ciais, P.; Sabine, C. L.

    2013-12-01

    CO2 has increased by 40% in the atmosphere above pre-industrial levels, and is reaching close to 400 ppm. It's a fact that the increase of CO2 is due to human-caused emissions from land use change and fossil fuel use. Yet, an average of 54% of these human emissions was removed from the atmosphere by CO2 sinks in the ocean and the land biosphere. In the IPCC AR5 report, an update of the global carbon budget is provided, together with CH4 sources and sinks, over the last 3 decades. The first finding is the recent acceleration of fossil fuel CO2 emissions during the last decade, and the fact that sinks have increased proportionally with emissions. Future projections of the coupled climate-carbon cycle system using CMIP5 models, translated into compatible emissions for each RCP pathway radiative forcing trajectory will be presented. When the carbon cycle is coupled to simulations of climate change, the sinks weaken, causing a positive feedback on warming, but uncertainties on the magnitude of this feedback and on the role of each regions, remain very high, as shown by the large spread between models. The second finding concerns additional feedbacks, most likely of positive sign, such as CO2 and CH4 emissions from thawed permafrost and nutrient limitations on land carbon storage. These feedbacks were not included in the CMIP5 models and represent a large (but uncertain) source of extra warming for any given economic scenario of anthropogenic emissions

  16. Differentiating Climate Change and Emissions Influence on Future Ozone and Health

    NASA Astrophysics Data System (ADS)

    Stowell, J.; Kim, Y. M.; Gao, Y.; Fu, J. S.; Chang, H. H.; Liu, Y.

    2015-12-01

    From the advent of coal burning and the subsequent industrial revolution to the present, human activities continue to influence ground-level ozone (O3) concentrations. Besides the obvious environmental and climate implications, studies have shown convincing links between O3 exposure and health. These adverse health outcomes range from impaired lung function and cardiovascular stress to premature death. However, little is known concerning the potential impacts of future mitigation policies on O3 and health. Applying novel modeling strategies, we provide evidence of the impact of mitigation on O3 attributable to both climate change and anthropogenic emissions. We employ the latest emission scenarios for both low and high emissions (Representative Concentration Pathways or RCPs) and include population projections to estimate excess mortality associated with each source separate from one another. We found that, by the mid-21st century, U.S. O3 could increase by 0.9% per year under a low emission future and by 1.6% under high emission settings. We predict excess mortality from high emission-induced O3 to increase annually by over 1,200 deaths. Conversely, excess deaths from lower emissions may decrease by over 1,600 annually. Taken together, these results indicate that mitigation efforts may significantly offset the effect of climate change on O3-related mortality.

  17. The effectiveness of net negative carbon dioxide emissions in reversing anthropogenic climate change

    NASA Astrophysics Data System (ADS)

    Tokarska, Katarzyna B.; Zickfeld, Kirsten

    2015-09-01

    Artificial removal of CO2 from the atmosphere (also referred to as negative emissions) has been proposed as a means to restore the climate system to a desirable state, should the impacts of climate change become ‘dangerous’. Here we explore whether negative emissions are indeed effective in reversing climate change on human timescales, given the potentially counteracting effect of natural carbon sinks and the inertia of the climate system. We designed a range of CO2 emission scenarios, which follow a gradual transition to a zero-carbon energy system and entail implementation of various amounts of net-negative emissions at technologically plausible rates. These scenarios are used to force an Earth System Model of intermediate complexity. Results suggest that while it is possible to revert to a desired level of warming (e.g. 2 °C above pre-industrial) after different levels of overshoot, thermosteric sea level rise is not reversible for at least several centuries, even under assumption of large amounts of negative CO2 emissions. During the net-negative emission phase, artificial CO2 removal is opposed by CO2 outgassing from natural carbon sinks, with the efficiency of CO2 removal—here defined as the drop in atmospheric CO2 per unit negative emission—decreasing with the total amount of negative emissions.

  18. Fuel characteristics and emissions from biomass burning and land-use change in Nigeria.

    PubMed

    Isichei, A O; Muoghalu, J I; Akeredolu, F A; Afolabi, O A

    1995-01-01

    Nigeria is one of the 13 low-latitude countries that have significant biomass burning activities. Biomass burning occurs in moist savanna, dry forests, and forest plantations. Fires in the forest zone are associated with slash-and-burn agriculture; the areal extent of burning is estimated to be 80% of the natural savanna. In forest plantations, close to 100% of litter is burned. Current estimates of emissions from land-use change are based on a 1976 national study and extrapolations from it. The following non-carbon dioxide (CO2) trace gas emissions were calculated from savanna burning: methane (CH4), 145 gigagrams (Gg); carbon monoxide (CO), 3831 Gg; nitrous oxide (N2O), 2 Gg; and nitrogen oxides (NOx), 49 Gg. Deforestation rates in forests and woodlands are 300 × 10(3) ha (kilohectare, or kha) and 200 × kha per year, respectively. Trace gas emissions from deforestation were estimated to be 300 Gg CH4, 2.4 Gg N2O, and 24 Gg NOx. CO2 emissions from burning, decay of biomass, and long-term emissions from soil totaled 125 561 Gg. These estimates should be viewed as preliminary, because greenhouse gas emission inventories from burning, deforestation, and land-use change require two components: fuel load and emission factors. Fuel load is dependent on the areal extent of various land uses, and the biomass stocking and some of these data in Nigeria are highly uncertain. PMID:24197951

  19. Land-use change and greenhouse gas emissions from corn and cellulosic ethanol

    PubMed Central

    2013-01-01

    Background The greenhouse gas (GHG) emissions that may accompany land-use change (LUC) from increased biofuel feedstock production are a source of debate in the discussion of drawbacks and advantages of biofuels. Estimates of LUC GHG emissions focus mainly on corn ethanol and vary widely. Increasing the understanding of LUC GHG impacts associated with both corn and cellulosic ethanol will inform the on-going debate concerning their magnitudes and sources of variability. Results In our study, we estimate LUC GHG emissions for ethanol from four feedstocks: corn, corn stover, switchgrass, and miscanthus. We use new computable general equilibrium (CGE) results for worldwide LUC. U.S. domestic carbon emission factors are from state-level modelling with a surrogate CENTURY model and U.S. Forest Service data. This paper investigates the effect of several key domestic lands carbon content modelling parameters on LUC GHG emissions. International carbon emission factors are from the Woods Hole Research Center. LUC GHG emissions are calculated from these LUCs and carbon content data with Argonne National Laboratory’s Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) model. Our results indicate that miscanthus and corn ethanol have the lowest (−10 g CO2e/MJ) and highest (7.6 g CO2e/MJ) LUC GHG emissions under base case modelling assumptions. The results for corn ethanol are lower than corresponding results from previous studies. Switchgrass ethanol base case results (2.8 g CO2e/MJ) were the most influenced by assumptions regarding converted forestlands and the fate of carbon in harvested wood products. They are greater than miscanthus LUC GHG emissions because switchgrass is a lower-yielding crop. Finally, LUC GHG emissions for corn stover are essentially negligible and insensitive to changes in model assumptions. Conclusions This research provides new insight into the influence of key carbon content modelling variables on LUC GHG emissions

  20. Can biofuels be a solution to climate change? The implications of land use change-related emissions for policy

    PubMed Central

    Khanna, Madhu; Crago, Christine L.; Black, Mairi

    2011-01-01

    Biofuels have gained increasing attention as an alternative to fossil fuels for several reasons, one of which is their potential to reduce the greenhouse gas (GHG) emissions from the transportation sector. Recent studies have questioned the validity of claims about the potential of biofuels to reduce GHG emissions relative to the liquid fossil fuels they are replacing when emissions owing to direct (DLUC) and indirect land use changes (ILUC) that accompany biofuels are included in the life cycle GHG intensity of biofuels. Studies estimate that the GHG emissions released from ILUC could more than offset the direct GHG savings by producing biofuels and replacing liquid fossil fuels and create a ‘carbon debt’ with a long payback period. The estimates of this payback period, however, vary widely across biofuels from different feedstocks and even for a single biofuel across different modelling assumptions. In the case of corn ethanol, this payback period is found to range from 15 to 200 years. We discuss the challenges in estimating the ILUC effect of a biofuel and differences across biofuels, and its sensitivity to the assumptions and policy scenarios considered by different economic models. We also discuss the implications of ILUC for designing policies that promote biofuels and seek to reduce GHG emissions. In a first-best setting, a global carbon tax is needed to set both DLUC and ILUC emissions to their optimal levels. However, it is unclear whether unilateral GHG mitigation policies, even if they penalize the ILUC-related emissions, would increase social welfare and lead to optimal emission levels. In the absence of a global carbon tax, incentivizing sustainable land use practices through certification standards, government regulations and market-based pressures may be a viable option for reducing ILUC. PMID:22482030

  1. Future fire emissions associated with projected land use change in Sumatra.

    PubMed

    Marlier, Miriam E; DeFries, Ruth; Pennington, Derric; Nelson, Erik; Ordway, Elsa M; Lewis, Jeremy; Koplitz, Shannon N; Mickley, Loretta J

    2015-01-01

    Indonesia has experienced rapid land use change over the last few decades as forests and peatswamps have been cleared for more intensively managed land uses, including oil palm and timber plantations. Fires are the predominant method of clearing and managing land for more intensive uses, and the related emissions affect public health by contributing to regional particulate matter and ozone concentrations and adding to global atmospheric carbon dioxide concentrations. Here, we examine emissions from fires associated with land use clearing and land management on the Indonesian island of Sumatra and the sensitivity of this fire activity to interannual meteorological variability. We find ~80% of 2005-2009 Sumatra emissions are associated with degradation or land use maintenance instead of immediate land use conversion, especially in dry years. We estimate Sumatra fire emissions from land use change and maintenance for the next two decades with five scenarios of land use change, the Global Fire Emissions Database Version 3, detailed 1-km2 land use change maps, and MODIS fire radiative power observations. Despite comprising only 16% of the original study area, we predict that 37-48% of future Sumatra emissions from land use change will occur in fuel-rich peatswamps unless this land cover type is protected effectively. This result means that the impact of fires on future air quality and climate in Equatorial Asia will be decided in part by the conservation status given to the remaining peatswamps on Sumatra. Results from this article will be implemented in an atmospheric transport model to quantify the public health impacts from the transport of fire emissions associated with future land use scenarios in Sumatra. PMID:25044917

  2. Estimation of Energy Consumption and Greenhouse Gas Emissions considering Aging and Climate Change in Residential Sector

    NASA Astrophysics Data System (ADS)

    Lee, M.; Park, C.; Park, J. H.; Jung, T. Y.; Lee, D. K.

    2015-12-01

    The impacts of climate change, particularly that of rising temperatures, are being observed across the globe and are expected to further increase. To counter this phenomenon, numerous nations are focusing on the reduction of greenhouse gas (GHG) emissions. Because energy demand management is considered as a key factor in emissions reduction, it is necessary to estimate energy consumption and GHG emissions in relation to climate change. Further, because South Korea is the world's fastest nation to become aged, demographics have also become instrumental in the accurate estimation of energy demands and emissions. Therefore, the purpose of this study is to estimate energy consumption and GHG emissions in the residential sectors of South Korea with regard to climate change and aging to build more accurate strategies for energy demand management and emissions reduction goals. This study, which was stablished with 2010 and 2050 as the base and target years, respectively, was divided into a two-step process. The first step evaluated the effects of aging and climate change on energy demand, and the second estimated future energy use and GHG emissions through projected scenarios. First, aging characteristics and climate change factors were analyzed by using the logarithmic mean divisia index (LMDI) decomposition analysis and the application of historical data. In the analysis of changes in energy use, the effects of activity, structure, and intensity were considered; the degrees of contribution were derived from each effect in addition to their relations to energy demand. Second, two types of scenarios were stablished based on this analysis. The aging scenarios are business as usual and future characteristics scenarios, and were used in combination with Representative Concentration Pathway (RCP) 2.6 and 8.5. Finally, energy consumption and GHG emissions were estimated by using a combination of scenarios. The results of these scenarios show an increase in energy consumption

  3. Impact on Climate due to Changes in Radiative Forcing from Stratospheric Aircraft Emissions

    NASA Astrophysics Data System (ADS)

    Dutta, M.; Wuebbles, D. J.; Herman, R.; Baughcum, S. L.

    2004-05-01

    Aircraft emissions can affect climate both directly and indirectly. The 1999 Intergovernmental Panel on Climate Change report on Aviation and The Global Atmosphere estimated that emissions from a fleet of one thousand High Speed Civil Transport aircraft (flying at Mach 2.4) could produce a non-negligible impact on the radiative forcing driving changes in climate. In this study we reexamine the radiative forcing from fleets of aircraft flying at stratospheric altitudes and predominantly in the northern hemisphere mid-latitude regions. We use our narrowband radiative transfer model in these studies, along with model calculations of calculated changes in ozone and water vapor from our zonally-averaged model of atmospheric chemical and physical processes. The radiative transfer model has higher resolution in the tropopause and lower stratosphere region than the models used in the 1999 IPCC assessment. Our results suggest that the radiative forcing for the water vapor emissions from aircraft was overestimated previously.

  4. Impacts of future climate and emission changes on U.S. air quality

    NASA Astrophysics Data System (ADS)

    Penrod, Ashley; Zhang, Yang; Wang, Kai; Wu, Shiang-Yuh; Leung, L. Ruby

    2014-06-01

    Changes in climate and emissions will affect future air quality. In this work, simulations of regional air quality during current (2001-2005) and future (2026-2030) winter and summer are conducted with the newly released CMAQ version 5.0 to examine the impacts of simulated future climate and anthropogenic emission projections on air quality over the U.S. Current meteorological and chemical predictions are evaluated against observations to assess the model's capability in reproducing the seasonal differences. WRF and CMAQ capture the overall observational spatial patterns and seasonal differences. Biases in model predictions are attributed to uncertainties in emissions, boundary conditions, and limitations in model physical and chemical treatments as well as the use of a coarse grid resolution. Increased temperatures (up to 3.18 °C) and decreased ventilation (up to 157 m in planetary boundary layer height) are found in both future winter and summer, with more prominent changes in winter. Increases in future temperatures result in increased isoprene and terpene emissions in winter and summer, driving the increase in maximum 8-h average O3 (up to 5.0 ppb) over the eastern U.S. in winter while decreases in NOx emissions drive the decrease in O3 over most of the U.S. in summer. Future PM2.5 concentrations in winter and summer and many of its components decrease due to decreases in primary anthropogenic emissions and the concentrations of secondary anthropogenic pollutants as well as increased precipitation in winter. Future winter and summer dry and wet deposition fluxes are spatially variable and increase with decreasing surface resistance and precipitation, respectively. They decrease with a decrease in ambient particulate concentrations. Anthropogenic emissions play a more important role in summer than in winter for future O3 and PM2.5 levels, with a dominance of the effects of significant emission reductions over those of climate change on future PM2.5 levels.

  5. Future fire emissions associated with projected land use change in Indonesia

    NASA Astrophysics Data System (ADS)

    Marlier, M. E.; DeFries, R. S.; Pennington, D.; Ordway, E.; Nelson, E.; Mickley, L.; Koplitz, S.

    2013-12-01

    Indonesia has experienced rapid land use change in past decades as forests and peatlands are cleared for agricultural development, including oil palm and timber plantations1. Fires are the predominant method of clearing and the subsequent emissions can have important public health impacts by contributing to regional particulate matter and ozone concentrations2. This regional haze was dramatically seen in Singapore during June 2013 due to the transport of emissions from fires in Sumatra. Our study is part of a larger project that will quantify the public health impact of various land use development scenarios for Sumatra over the coming decades. Here, we describe how we translate economic projections of land use change into future fire emissions inventories for GEOS-Chem atmospheric transport simulations. We relate past GFED3 fire emissions3 to detailed 1-km land use change data and MODIS fire radiative power observations, and apply these relationships to future estimates of land use change. The goal of this interdisciplinary project is to use modeling results to interact with policy makers and influence development strategies in ways that protect public health. 1Miettinen et al. 2011. Deforestation rates in insular Southeast Asia between 2000 and 2010. Glob. Change Biol.,17 (7), 2261-2270. 2Marlier et al. 2013. El Niño and health risks from landscape fire emissions in southeast Asia. Nature Clim. Change, 3, 131-136. 3van der Werf et al. 2010. Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997-2009). Atmos. Chem. Physics, 10 (23), 11707-11735.

  6. LINKING CHANGES IN UTILITY NO X EMISSIONS TO CHANGE IN OZONE AIR QUALITY

    EPA Science Inventory

    The NOx State Implementation Plan (SIP) Call was designed to reduce Northeastern U.S. NOx emissions from utilities. With these reductions, it was anticipated that the amount of ozone attributed to transport from other states would in turn be reduced. In th...

  7. Correlation between ethylene emission and skin colour changes during papaya (Carica papaya L.) fruit ripening

    NASA Astrophysics Data System (ADS)

    da Silva, M. G.; Oliveira, J. G.; Vitoria, A. P.; Corrêa, S. F.; Pereira, M. G.; Campostrini, E.; Santos, E. O.; Cavalli, A.; Vargas, H.

    2005-06-01

    The skin colour changes and ethylene emission rates were monitored during papaya (C. papaya L.) fruit ripening. Two groups of papaya (‘Formosa’ and ‘Solo’) were applied in this study. The total colour difference was used as measured parameter and the corresponding half time of its saturation was used as correlation parameter. A high correlation factor between the saturation half time and corresponding climacteric peak time was found. It was concluded that high ethylene emission rate in ‘Solo’ fruit promotes a quick change of the total colour difference.

  8. Maturational changes in cerebral function in infants determined by /sup 18/FDG positron emission tomography

    SciTech Connect

    Chugani, H.T.; Phelps, M.E.

    1986-02-21

    2-Deoxy-2(/sup 18/F)fluro-D-glucose positron emission tomography performed in human infants during development revealed progressive changes in local cerebral glucose utilization. In infants 5 weeks of age and younger, glucose utilization was highest in the sensorimotor cortex, thalamus, midbrain-brainstem, and cerebellar vermis. By 3 months, glucose metabolic activity had increased in the parietal, temporal, and occipital cortices and the basal ganglia, with subsequent increases in frontal and various association regions occurring by 8 months. These functional changes measured with positron emission tomography are in agreement with behavioral, neurophysiological, and anatomical alterations known to occur during infant development. 32 references, 2 figures, 1 table.

  9. Isoprene emissions over Asia 1979-2012: impact of climate and land-use changes

    NASA Astrophysics Data System (ADS)

    Stavrakou, T.; Müller, J.-F.; Bauwens, M.; De Smedt, I.; Van Roozendael, M.; Guenther, A.; Wild, M.; Xia, X.

    2014-05-01

    Due to the scarcity of observational constraints and the rapidly changing environment in East and Southeast Asia, isoprene emissions predicted by models are expected to bear substantial uncertainties. The aim of this study is to improve upon the existing bottom-up estimates, and to investigate the temporal evolution of the fluxes in Asia over 1979-2012. To this purpose, we calculate the hourly emissions at 0.5°×0.5° resolution using the MEGAN-MOHYCAN model driven by ECMWF ERA-Interim climatology. In order to remedy for known biases identified in previous studies, and to improve the simulation of interannual variability and trends in emissions, this study incorporates (i) changes in land use, including the rapid expansion of oil palms, (ii) meteorological variability according to ERA-Interim, (iii) long-term changes in solar radiation (dimming/brightening) constrained by surface network radiation measurements, and (iv) recent experimental evidence that South Asian tropical forests are much weaker isoprene emitters than previously assumed, and on the other hand, that oil palms have a strong isoprene emission capacity. These effects lead to a significant lowering (factor of 2) in the total isoprene fluxes over the studied domain, and to emission reductions reaching a factor of 3.5 in Southeast Asia. The bottom-up annual isoprene emissions for 2005 are estimated at 7.0, 4.8, 8.3, and 2.9 Tg in China, India, Indonesia and Malaysia, respectively. The isoprene flux anomaly over the whole domain and studied period is found to be strongly correlated with the Oceanic Niño Index (r = 0.73), with positive (negative) anomalies related to El Niño (La Niña) years. Changes in temperature and solar radiation are the major drivers of the interannual variability and trends in the emissions, except over semi-arid areas such as northwestern China, Pakistan and Kazakhstan, where soil moisture is by far the main cause of interannual emission changes. In our base simulation, annual

  10. Isoprene emissions over Asia 1979–2012: impact of climate and land-use changes

    SciTech Connect

    Stavrakou, T.; Müller, J. -F.; Bauwens, M.; De Smedt, I.; Van Roozendael, M.; Guenther, A.; Wild, M.; Xia, X.

    2014-01-01

    Due to the scarcity of observational constraints and the rapidly changing environment in East and Southeast Asia, isoprene emissions predicted by models are expected to bear substantial uncertainties. The aim of this study is to improve upon the existing bottom-up estimates, and to investigate the temporal evolution of the fluxes in Asia over 1979–2012. To this purpose, we calculate the hourly emissions at 0.5°×0.5° resolution using the MEGAN–MOHYCAN model driven by ECMWF ERA-Interim climatology. In order to remedy for known biases identified in previous studies, and to improve the simulation of interannual variability and trends in emissions, this study incorporates (i) changes in land use, including the rapid expansion of oil palms, (ii) meteorological variability according to ERA-Interim, (iii) long-term changes in solar radiation (dimming/brightening) constrained by surface network radiation measurements, and (iv) recent experimental evidence that South Asian tropical forests are much weaker isoprene emitters than previously assumed, and on the other hand, that oil palms have a strong isoprene emission capacity. These effects lead to a significant lowering (factor of 2) in the total isoprene fluxes over the studied domain, and to emission reductions reaching a factor of 3.5 in Southeast Asia. The bottom-up annual isoprene emissions for 2005 are estimated at 7.0, 4.8, 8.3, and 2.9 Tg in China, India, Indonesia and Malaysia, respectively. The isoprene flux anomaly over the whole domain and studied period is found to be strongly correlated with the Oceanic Niño Index (r = 0.73), with positive (negative) anomalies related to El Niño (La Niña) years. Changes in temperature and solar radiation are the major drivers of the interannual variability and trends in the emissions, except over semi-arid areas such as northwestern China, Pakistan and Kazakhstan, where soil moisture is by far the main cause of interannual emission changes. In our base simulation

  11. Biofuels, land use change, and greenhouse gas emissions: some unexplored variables.

    PubMed

    Kim, Hyungtae; Kim, Seungdo; Dale, Bruce E

    2009-02-01

    Greenhouse gas release from land use change (the so-called "carbon debt") has been identified as a potentially significant contributor to the environmental profile of biofuels. The time required for biofuels to overcome this carbon debt due to land use change and begin providing cumulative greenhouse gas benefits is referred to as the "payback period" and has been estimated to be 100-1000 years depending on the specific ecosystem involved in the land use change event. Two mechanisms for land use change exist: "direct" land use change, in which the land use change occurs as part of a specific supply chain for a specific biofuel production facility, and "indirect" land use change, in which market forces act to produce land use change in land that is not part of a specific biofuel supply chain, including, for example, hypothetical land use change on another continent. Existing land use change studies did not consider many of the potentially important variables that might affect the greenhouse gas emissions of biofuels. We examine here several variables that have not yet been addressed in land use change studies. Our analysis shows that cropping management is a key factor in estimating greenhouse gas emissions associated with land use change. Sustainable cropping management practices (no-till and no-till plus cover crops) reduce the payback period to 3 years for the grassland conversion case and to 14 years for the forest conversion case. It is significant that no-till and cover crop practices also yield higher soil organic carbon (SOC) levels in corn fields derived from former grasslands or forests than the SOC levels that result if these grasslands or forests are allowed to continue undisturbed. The United States currently does not hold any of its domestic industries responsible for its greenhouse gas emissions. Thus the greenhouse gas standards established for renewable fuels such as corn ethanol in the Energy Independence and Security Act (EISA) of 2007 set a

  12. Response of global particulate-matter-related mortality to changes in local precursor emissions.

    PubMed

    Lee, Colin J; Martin, Randall V; Henze, Daven K; Brauer, Michael; Cohen, Aaron; Donkelaar, Aaron van

    2015-04-01

    Recent Global Burden of Disease (GBD) assessments estimated that outdoor fine-particulate matter (PM2.5) is a causal factor in over 5% of global premature deaths. PM2.5 is produced by a variety of direct and indirect, natural and anthropogenic processes that complicate PM2.5 management. This study develops a proof-of-concept method to quantify the effects on global premature mortality of changes to PM2.5 precursor emissions. Using the adjoint of the GEOS-Chem chemical transport model, we calculated sensitivities of global PM2.5-related premature mortality to emissions of precursor gases (SO2, NOx, NH3) and carbonaceous aerosols. We used a satellite-derived ground-level PM2.5 data set at approximately 10 × 10 km(2) resolution to better align the exposure with population density. We used exposure-response functions from the GBD project to relate mortality to exposure in the adjoint calculation. The response of global mortality to changes in local anthropogenic emissions varied spatially by several orders of magnitude. The largest reductions in mortality for a 1 kg km(-2) yr(-1) decrease in emissions were for ammonia and carbonaceous aerosols in Eastern Europe. The greatest reductions in mortality for a 10% decrease in emissions were found for secondary inorganic sources in East Asia. In general, a 10% decrease in SO2 emissions was the most effective source to control, but regional exceptions were found. PMID:25730303

  13. Greenhouse gas emission mitigation relevant to changes in municipal solid waste management system.

    PubMed

    Pikoń, Krzysztof; Gaska, Krzysztof

    2010-07-01

    Standard methods for assessing the environmental impact of waste management systems are needed to underpin the development and implementation of sustainable waste management practice. Life cycle assessment (LCA) is a tool for comprehensively ensuring such assessment and covers all impacts associated with waste management. LCA is often called "from cradle to grave" analysis. This paper integrates information on the greenhouse gas (GHG) implications of various management options for some of the most common materials in municipal solid waste (MSW). Different waste treatment options for MSW were studied in a system analysis. Different combinations of recycling (cardboard, plastics, glass, metals), biological treatment (composting), and incineration as well as land-filling were studied. The index of environmental burden in the global warming impact category was calculated. The calculations are based on LCA methodology. All emissions taking place in the whole life cycle system were taken into account. The analysis included "own emissions," or emissions from the system at all stages of the life cycle, and "linked emissions," or emissions from other sources linked with the system in an indirect way. Avoided emissions caused by recycling and energy recovery were included in the analysis. Displaced emissions of GHGs originate from the substitution of energy or materials derived from waste for alternative sources. The complex analysis of the environmental impact of municipal waste management systems before and after application of changes in MSW systems according to European Union regulations is presented in this paper. The evaluation is made for MSW systems in Poland. PMID:20681425

  14. The Impact of Changing Climate on Ammonia Emissions from Agriculture and the Associated Climate Forcings

    NASA Astrophysics Data System (ADS)

    Ward, D. S.; Riddick, S. N.; Hess, P. G. M.

    2015-12-01

    Agriculture is the largest anthropogenic source of ammonia (NH3) on a global scale with major contributions from the application of synthetic fertilizer and manure from livestock. While strict controls are placed on the emissions of many industrial pollutants, NH3 concentrations are expected to increase this century. In addition to future expansion of agricultural activities that could lead to greater NH3 emissions, NH3 emissions are affected by changes in temperature and precipitation. Here we use a newly developed agricultural N pathways model running in a global terrestrial model (Community Land Model v4.0) to estimate future NH3 emissions from manure and synthetic fertilizer application, and the impact of changing climate on these emissions and other N pathways (runoff, denitrification, etc.). We include future increases in the application of manure and synthetic fertilizer that are consistent with a middle-of-the-road projection of population growth and per capita caloric intake. Combined with atmospheric forcing that follows RCP8.5, NH3 emissions increase by about 50% and 90% between years 2010 and 2100 from synthetic fertilizer and manure, respectively. Roughly 25% of this increase can be attributed to the changing climate, mainly increased global temperatures over the 21st century. We show associated changes in ammonium nitrate and ammonium sulfate aerosol concentrations and radiative forcings, the results of a set of additional simulations using the Community Atmosphere Model v5.0 and an offline radiative transfer scheme. This work suggests that projections of global NH3 concentrations need to take changes in climate into account.

  15. Health Expenditure Trends in OECD Countries, 1990-2001

    PubMed Central

    Huber, Manfred; Orosz, Eva

    2003-01-01

    This article presents data on health care spending for 30 OECD countries from OECD Health Data 2003, the latest edition of OECD's annual data collection on health systems across industrialized countries. OECD data show health care expenditures as a proportion of gross domestic product at an all-time high, due to both increased expenditures and overall economic slowdown. The article discusses similarities and differences across countries in how health care expenditures are funded and how the health care dollar is spent among types of services. PMID:14997690

  16. Structural and technological changes of greenhouse gas emissions during the transition period in Polish industry

    NASA Astrophysics Data System (ADS)

    Pasierb, Slawomir; Niedziela, Karol; Wojtulewicz, Jerzy

    1996-01-01

    We analyzed the patterns of energy use and greenhouse gas (GHG) emissions in Polish industry arising during the transition from a centrally planned economy to a market economy. A method of analyzing industry energy use and GHG emissions is discussed. Using this method, the impact of changes in industrial production value, the share of specific industry branches in the total industrial production, energy intensity, and the mix of the energy carriers in the 1989 1993 period has been analyzed. The last year of the analyzed period shows favorable trends in efficiency and signs of production structure shift to a less energy-intensive one. Economic reform implemented after 1989, which released energy carriers' prices from government control, had important effects on the industrial sector. Energy efficiency and emission intensity trends of 1992 1994 were favorable; if they continue, production will return to 1989 levels with much lower energy consumption and significantly decreased GHG emissions.

  17. The integrated global temperature change potential (iGTP) and relationships between emission metrics

    NASA Astrophysics Data System (ADS)

    Peters, Glen P.; Aamaas, Borgar; Berntsen, Terje; Fuglestvedt, Jan S.

    2011-12-01

    The Kyoto Protocol compares greenhouse gas emissions (GHGs) using the global warming potential (GWP) with a 100 yr time-horizon. The GWP was developed, however, to illustrate the difficulties in comparing GHGs. In response, there have been many critiques of the GWP and several alternative emission metrics have been proposed. To date, there has been little focus on understanding the linkages between, and interpretations of, different emission metrics. We use an energy balance model to mathematically link the absolute GWP, absolute global temperature change potential (AGTP), absolute ocean heat perturbation (AOHP), and integrated AGTP. For pulse emissions, energy conservation requires that AOHP = AGWP - iAGTP/λ and hence AGWP and iAGTP are closely linked and converge as AOHP decays to zero. When normalizing the metrics with CO2 (GWP, GTP, and iGTP), we find that the iGTP and GWP are similar numerically for a wide range of GHGs and time-horizons, except for very short-lived species. The similarity between the iGTPX and GWPX depends on how well a pulse emission of CO2 can substitute for a pulse emission of X across a range of time-horizons. The ultimate choice of emission metric(s) and time-horizon(s) depends on policy objectives. To the extent that limiting integrated temperature change over a specific time-horizon is consistent with the broader objectives of climate policy, our analysis suggests that the GWP represents a relatively robust, transparent and policy-relevant emission metric.

  18. Rate and velocity of climate change caused by cumulative carbon emissions

    NASA Astrophysics Data System (ADS)

    LoPresti, Anna; Charland, Allison; Woodard, Dawn; Randerson, James; Diffenbaugh, Noah S.; Davis, Steven J.

    2015-09-01

    International climate mitigation efforts are focused on limiting increase in global mean temperature, which has been shown to be proportional to cumulative CO2 emissions. However, the ability of natural and human systems to successfully adapt to climatic changes depends on both the magnitude and rate of change, the latter of which will depend on how quickly a given level of cumulative emissions occurs. We show that cumulative CO2 emissions of 4620 Gt CO2 (reached in 2100 in RCP4.5 and 2057 in RCP8.5) produce globally averaged warming rates that are nearly twice as fast in RCP8.5 than RCP4.5 (0.34 ± 0.08 °C per decade versus 0.19 ± 0.05 °C per decade, respectively). Similarly, the globally averaged velocity of climate change calculated according to the ‘nearest equivalent climate’ is greater by a factor of ˜2 in RCP8.5 than in RCP4.5 (2.51 ± 0.67 km yr-1 versus 1.32 ± 0.39 km yr-1, respectively), despite equivalent cumulative emissions. These differences in the projected velocity of climate change represent uncertainty for ecosystems that may be unable to adapt to the faster changes. Particularly at risk are boreal forests, of which 48% are projected to experience rates of change beyond their expected adaptive capacity (i.e. >0.3 °C per decade) in RCP4.5, compared with 95% in RCP8.5. Thus, the same budget of cumulative carbon emissions may result in critically different impacts on natural and human systems, depending on the amount of time over which that budget is expended.

  19. Rate and Velocity of Climate Change Caused by Cumulative Carbon Emissions

    NASA Astrophysics Data System (ADS)

    Davis, S. J.; LoPresti, A.; Diffenbaugh, N. S.; Randerson, J. T.; Woodard, D.; Charland, A.

    2015-12-01

    International climate mitigation efforts are focused on limiting increase in global mean temperature, which has been shown to be proportional to cumulative CO2 emissions. However, the ability of natural and human systems to successfully adapt to climatic changes depends on both the magnitude and rate of change, the latter of which will depend on how quickly a given level of cumulative emissions occurs. We show that cumulative CO2 emissions of 4,620 Gt CO2 (reached in 2100 in RCP4.5 and 2057 in RCP8.5) produce globally averaged warming rates that are nearly twice as fast in RCP8.5 than RCP4.5 (0.34±0.08°C per decade versus 0.19±0.05°C per decade, respectively). Similarly, the globally averaged velocity of climate change calculated according to the "nearest equivalent climate" is greater by a factor of ~2 in RCP8.5 than in RCP4.5 (2.51±0.67 km y-1 versus 1.32 ± 0.39 km y-1, respectively), despite equivalent cumulative emissions. These differences in the projected velocity of climate change represent uncertainty for ecosystems that may be unable to adapt to the faster changes. Particularly at risk are boreal forests, of which 48% are projected to experience rates of change beyond their expected adaptive capacity (i.e. >0.3°C per decade) in RCP4.5, compared with 95% in RCP8.5. Thus, the same budget of cumulative carbon emissions may result in critically different impacts on natural and human systems, depending on the amount of time over which that budget is expended.

  20. Acoustic emission from single point machining: Part 2, Signal changes with tool wear. Revised

    SciTech Connect

    Heiple, C.R.; Carpenter, S.H.; Armentrout, D.L.; McManigle, A.P.

    1989-12-31

    Changes in acoustic emission signal characteristics with tool wear were monitored during single point machining of 4340 steel and Ti-6Al-4V heat treated to several strength levels, 606l-T6 aluminum, 304 stainless steel, 17-4PH stainless steel, 410 stainless steel, lead, and teflon. No signal characteristic changed in the same way with tool wear for all materials tested. A single change in a particular AE signal characteristic with tool wear valid for all materials probably does not exist. Nevertheless, changes in various signal characteristic with wear for a given material may be sufficient to be used to monitor tool wear.

  1. Acoustic emission from single point machining: Part 2, Signal changes with tool wear

    SciTech Connect

    Heiple, C.R.; Carpenter, S.H.; Armentrout, D.L.; McManigle, A.P.

    1989-01-01

    Changes in acoustic emission signal characteristics with tool wear were monitored during single point machining of 4340 steel and Ti-6Al-4V heat treated to several strength levels, 606l-T6 aluminum, 304 stainless steel, 17-4PH stainless steel, 410 stainless steel, lead, and teflon. No signal characteristic changed in the same way with tool wear for all materials tested. A single change in a particular AE signal characteristic with tool wear valid for all materials probably does not exist. Nevertheless, changes in various signal characteristic with wear for a given material may be sufficient to be used to monitor tool wear.

  2. Trend and uncertainty analysis of simulated climate change impacts with multiple GCMs and emission scenarios

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Impacts of climate change on hydrology, soil erosion, and wheat production during 2010-2039 at El Reno in central Oklahoma, USA, were simulated using the Water Erosion Prediction Project (WEPP) model. Projections from four GCMs (CCSR/NIES, CGCM2, CSIRO-Mk2, and HadCM3) under three emissions scenari...

  3. Downscaling socioeconomic and emissions scenarios for global environmental change research:a review

    SciTech Connect

    Van Vuuren, Detlet; Smith, Steven J.; Riahi, Keywan

    2010-05-01

    Abstract: Global change research encompasses global to local scale analysis. Impacts analysis in particular often requires spatial downscaling, whereby socio-economic and emissions variables specified at relatively large spatial scales are translated to values at a country or grid level. The methods used for spatial downscaling are reviewed, classified, and current applications discussed.

  4. Isoprene emissions over Asia 1979-2012: impact of climate and land use changes

    NASA Astrophysics Data System (ADS)

    Stavrakou, T.; Müller, J.-F.; Bauwens, M.; De Smedt, I.; Van Roozendael, M.; Guenther, A.; Wild, M.; Xia, X.

    2013-11-01

    Due to the scarcity of observational constraints and the rapidly changing environment in East and Southeast Asia, isoprene emissions predicted by models are expected to bear substantial uncertainties. The aim of this study is to improve upon the existing bottom-up estimates, and investigate the temporal evolution of the fluxes in Asia over 1979-2012. To this purpose, we calculate the hourly emissions at 0.5° × 0.5° resolution using the MEGAN-MOHYCAN model driven by ECMWF ERA-Interim climatology. This study incorporates (i) changes in land use, including the rapid expansion of oil palms, (ii) meteorological variability according to ERA-Interim, (iii) long-term changes in solar radiation (dimming/brightening) constrained by surface network radiation measurements, and (iv) recent experimental evidence that South Asian tropical forests are much weaker isoprene emitters than previously assumed, and on the other hand, that oil palms hold a strong isoprene emission capacity. These effects lead to a significant lowering (factor of two) in the total isoprene fluxes over the studied domain, and to emission reductions reaching a~factor of 3.5 in Southeast Asia. The bottom-up annual isoprene emissions for 2005 are estimated at 7.0, 4.8, 8.3, 2.9 Tg in China, India, Indonesia and Malaysia, respectively. Changes in temperature and solar radiation are the major drivers of the interannual variability and trend in the emissions. An annual positive flux trend of 0.2% and 0.52% is found in Asia and China, respectively, through the entire period, related to positive trend in temperature and solar radiation. The impact of oil palm expansion in Indonesia and Malaysia is to enhance the trends over that region, e.g. from 1.17% to 1.5% in 1979-2005 in Malaysia. A negative emission trend is derived in India (-0.4%), owing to the negative trend in solar radiation data associated to the strong dimming effect likely due to increasing aerosol loadings. The bottom-up emissions are evaluated

  5. The sum of the parts: can we really reduce carbon emissions through individual behaviour change?

    PubMed

    Reynolds, Lucy

    2010-01-01

    Individuals are increasingly being urged to 'do their bit' in the fight against climate change, with governments and pro-environmentalists insisting that the collective impact of small behaviour changes will result in a meaningful reduction in global carbon emissions. The following paper considers this debate, as well as offering personal contributions from two leading environmentalists: Dr Doug McKenzie-Mohr, environmental psychologist and author of Fostering Sustainable Behavior: Community-Based Social Marketing; and Dr Tom Crompton, change strategist for WWF and co-author of Meeting Environmental Challenges: The Role of Human Identity, who argues for the role of intrinsic value systems in achieving sustainable behaviour change. As well as considering the responsibility of the individual in mitigating climate change, the paper introduces the discipline of social marketing as an effective tool for facilitating individual behaviour change, drawing on evidence from the field to recommend the key characteristics of effective behaviour change programmes. PMID:20333949

  6. Detecting Long-term Changes in Point Source Fossil CO2 Emissions with Tree Ring Archives

    NASA Astrophysics Data System (ADS)

    Keller, E. D.; Turnbull, J. C.; Norris, M. W.

    2015-12-01

    We examine the utility of tree ring 14C archives for detecting long term changes in fossil CO2 emissions from a point source. Trees assimilate carbon from the atmosphere during photosynthesis, in the process faithfully recording the average atmospheric 14C content over the growing season in each annual tree ring. Using 14C as a proxy for fossil CO2, we examine interannual variability over six years of fossil CO2 observations between 2004 and 2012 from two trees growing near the Kapuni Natural Gas Plant in rural Taranaki, New Zealand. We quantify the amount of variability that can be attributed to transport and meteorology by simulating constant point source fossil CO2 emissions over the observation period with the atmospheric transport model WindTrax. We then calculate the amount of change in emissions that we can detect with new observations over annual or multi-year time periods given both measurement uncertainty of 1ppm and the modelled variation in transport. In particular, we ask, what is the minimum amount of change in emissions that we can detect using this method, given a reference period of six years? We find that changes of 42% or more could be detected in a new sample from one year at the pine tree, or 22% in the case of four years of new samples. This threshold lowers and the method becomes more practical with a larger signal; for point sources 10 times the magnitude of the Kapuni plant (a typical size for large electricity generation point sources worldwide), it would be possible to detect sustained emissions changes on the order of 10% given suitable meteorology and observations.

  7. Air quality impacts of European wildfire emissions in a changing climate

    NASA Astrophysics Data System (ADS)

    Knorr, Wolfgang; Dentener, Frank; Hantson, Stijn; Jiang, Leiwen; Klimont, Zbigniew; Arneth, Almut

    2016-05-01

    Wildfires are not only a threat to human property and a vital element of many ecosystems, but also an important source of air pollution. In this study, we first review the available evidence for a past or possible future climate-driven increase in wildfire emissions in Europe. We then introduce an ensemble of model simulations with a coupled wildfire-dynamic-ecosystem model, which we combine with published spatial maps of both wildfire and anthropogenic emissions of several major air pollutants to arrive at air pollutant emission projections for several time slices during the 21st century. The results indicate moderate wildfire-driven emission increases until 2050, but there is a possibility of large increases until the last decades of this century at high levels of climate change. We identify southern and north-eastern Europe as potential areas where wildfires may surpass anthropogenic pollution sources during the summer months. Under a scenario of high levels of climate change (Representative Concentration Pathway, RCP, 8.5), emissions from wildfires in central and northern Portugal and possibly southern Italy and along the west coast of the Balkan peninsula are projected to reach levels that could affect annual mean particulate matter concentrations enough to be relevant for meeting WHO air quality targets.

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

  9. Monitoring vegetation cover changes over a semi-arid rangeland with multispectral ASTER thermal infrared emissivities

    NASA Astrophysics Data System (ADS)

    French, A. N.; Schmugge, T.; Ritchie, J.; Hsu, A.; Jacob, F.; Ogawa, K.; Inamdar, A.

    2006-12-01

    Observations of land surface temperatures with thermal infrared are an important and crucial application of satellite remote sensing that the value of multispectral thermal infrared emissivities, a measurement component, may be overlooked. Spectral emissivities, retrievable from sensors such as ASTER and MODIS provide indispensable data for more accurate land surface temperature estimates and characterization of land surface cover. This study addresses the latter issue, whereby long-term changes in vegetation canopy densities can be detected in a way independent of more conventional vegetation indices such as NDVI. Thermal emissivities are dependent upon the surface geometry and are especially variable over sparse vegetation. When viewing such terrain, emissivities range in values from 0.8-0.9 represent dry soils and up to 0.98-0.99 represent vegetation. Using ASTER's 90 m multispectral thermal infrared capability, a sequence of 21 scenes were acquired for 2001-2003 over the New Mexico semi-arid rangeland, Jornada. These were calibrated, atmospherically corrected, georegistered, then converted to spectral and broadband emissivities. Analysis of the scenes reveals spatially coherent patches of grass and shrubland showing decreasing emissivities on the order of 1% per 3 years. The observed patterns could be due to long-term soil surface texture or moisture changes, but a more likely explanation is decreased vegetation density. A significant benefit of emissivity monitoring, particularly at 8-9.5 μm wavelengths, is its independence from vegetation greenness, which means thermal infrared assessments can be a useful canopy density estimator year-round. When used in conjunction with NDVI, thermal data can help discriminate soils from both green and senescent vegetation.

  10. Reducing The Risk Of Abrupt Climate Change: Emission Corridors Preserving The Thermohaline Circulation

    NASA Astrophysics Data System (ADS)

    Zickfeld, K.

    Paleo-reconstructions have shown that large and abrupt climate changes have occurred throughout the last ice-age cycles. This evidence, supplemented by insights into the complex and nonlinear nature of the climate system, gives raise to the concern that anthropogenic forcing may trigger such events in the future. A prominent example for such a potential climatic shift is the collapse of the North Atlantic thermohaline circu- lation (THC), which would cause a major cooling of the northern North Atlantic and north-western Europe and considerable regional sea level rise, with possibly severe consequences on, e.g., fisheries, agriculture and ecosystems. In this paper we present emission corridors for the 21st century preserving the THC. Emission corridors embrace the range of future emissions beyond which either the THC collapses or the mitigation burden becomes intolerable. They are calculated along the conceptual and methodological lines of the tolerable windows approach. We investigate the sensitivity of the emission corridors to the main uncertain parame- ters (climate and North Atlantic hydrological sensitivities as well as emissions of non CO_2 greenhouse gases). Results show a high dependence of the size of the emis- sion corridors on hydrological and climate sensitivities. For the best-guess values of both parameters we find that the emission corridors are wider than the range spanned by the SRES emissions scenarios. Thus, no immediate mitigation seems necessary in order to preserve the THC. For high but still realistic values of the sensitivities, however, even the low SRES emissions scenarios transgress the corridor boundaries. These findings imply that under 'business as usual' a non-negligible risk of either a THC collapse or an intolerable mitigation burden exists.

  11. Response of Arctic Temperature to Changes in Emissions of Short-Lived Climate Forcers

    NASA Astrophysics Data System (ADS)

    Sand, M.; Berntsen, T.; von Salzen, K.; Flanner, M.; Langner, J.; Victor, D. G.

    2014-12-01

    There is growing scientific and political interest in the impacts of climate change and anthropogenic emissions on the Arctic. Over recent decades temperatures in the Arctic have increased twice the global rate, largely due to ice albedo and temperature feedbacks. While deep cuts in global CO2 emissions are required to slow this warming, there is also growing interest in the potential for reducing short lived climate forcers (SLCFs). Politically, action on SLCFs may be particularly promising because the benefits of mitigation appear promptly and there are large co-benefits in terms of improved air quality. This study is the first to systematically quantify the Arctic climate impact of regional SLCF emissions, taking into account BC, sulphur dioxide (SO2), nitrogen oxides (NOx), volatile hydrocarbons (VOC), organic carbon (OC) and tropospheric ozone, their transport processes and transformations in the atmosphere. Using several chemical transport models we perform detailed radiative forcing calculations from emissions of these species. Geographically we separate emissions into seven source regions that correspond with the national groupings of the Arctic Council, the leading body organizing international policy in the region (the United States, Canada, the Nordic countries, the rest of Europe, Russia, East and South Asia, and the rest of the world). We look at six main sectors known to account for [nearly all] of these emissions: households (domestic), energy/industry/waste, transport, agricultural fires, grass/forest fires, and gas flaring. We find that the largest Arctic warming source is from emissions within the Asian nations. However, the Arctic is most sensitive, per unit mass emitted, to SLCFs emissions from a small number of activities within the Arctic nations themselves. A stringent, but technically feasible SLCFs mitigation scenario, phased in from 2015 through 2030, can cut warming by 0.2 K in 2050.

  12. Response of Arctic Temperature to Changes in Emissions of Short-Lived Climate Forcers

    NASA Astrophysics Data System (ADS)

    Sand, M.; Berntsen, T.; von Salzen, K.; Flanner, M.; Langner, J.; Victor, D. G.

    2015-12-01

    There is growing scientific and political interest in the impacts of climate change and anthropogenic emissions on the Arctic. Over recent decades temperatures in the Arctic have increased twice the global rate, largely due to ice albedo and temperature feedbacks. While deep cuts in global CO2 emissions are required to slow this warming, there is also growing interest in the potential for reducing short lived climate forcers (SLCFs). Politically, action on SLCFs may be particularly promising because the benefits of mitigation appear promptly and there are large co-benefits in terms of improved air quality. This study is the first to systematically quantify the Arctic climate impact of regional SLCF emissions, taking into account BC, sulphur dioxide (SO2), nitrogen oxides (NOx), volatile hydrocarbons (VOC), organic carbon (OC) and tropospheric ozone, their transport processes and transformations in the atmosphere. Using several chemical transport models we perform detailed radiative forcing calculations from emissions of these species. Geographically we separate emissions into seven source regions that correspond with the national groupings of the Arctic Council, the leading body organizing international policy in the region (the United States, Canada, the Nordic countries, the rest of Europe, Russia, East and South Asia, and the rest of the world). We look at six main sectors known to account for [nearly all] of these emissions: households (domestic), energy/industry/waste, transport, agricultural fires, grass/forest fires, and gas flaring. We find that the largest Arctic warming source is from emissions within the Asian nations. However, the Arctic is most sensitive, per unit mass emitted, to SLCFs emissions from a small number of activities within the Arctic nations themselves. A stringent, but technically feasible SLCFs mitigation scenario, phased in from 2015 through 2030, can cut warming by 0.2 K in 2050.

  13. Air pollution response to changing weather and power plant emissions in the eastern United States

    NASA Astrophysics Data System (ADS)

    Bloomer, Bryan Jaye

    Air pollution in the eastern United States causes human sickness and death as well as damage to crops and materials. NOX emission reduction is observed to improve air quality. Effectively reducing pollution in the future requires understanding the connections between smog, precursor emissions, weather, and climate change. Numerical models predict global warming will exacerbate smog over the next 50 years. My analysis of 21 years of CASTNET observations quantifies a climate change penalty. I calculate, for data collected prior to 2002, a climate penalty factor of ˜3.3 ppb O3/°C across the power plant dominated receptor regions in the rural, eastern U.S. Recent reductions in NOX emissions decreased the climate penalty factor to ˜2.2 ppb O3/°C. Prior to 1995, power plant emissions of CO2, SO2, and NOX were estimated with fuel sampling and analysis methods. Currently, emissions are measured with continuous monitoring equipment (CEMS) installed directly in stacks. My comparison of the two methods show CO 2 and SO2 emissions are ˜5% lower when inferred from fuel sampling; greater differences are found for NOX emissions. CEMS are the method of choice for emission inventories and commodity trading and should be the standard against which other methods are evaluated for global greenhouse gas trading policies. I used CEMS data and applied chemistry transport modeling to evaluate improvements in air quality observed by aircraft during the North American electrical blackout of 2003. An air quality model produced substantial reductions in O3, but not as much as observed. The study highlights weaknesses in the model as commonly used for evaluating a single day event and suggests areas for further investigation. A new analysis and visualization method quantifies local-daily to hemispheric-seasonal scale relationships between weather and air pollution, confirming improved air quality despite increasing temperatures across the eastern U.S. Climate penalty factors indicate

  14. Isoprene emissions over Asia 1979-2012 : impact of climate and land use changes

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Due to the scarcity of observational contraints and the rapidly changing environment in East and Southeast Asia, isoprene emissions predicted by models are expected to bear substantial uncertainties. This study aims at improving upon current bottom-up estimates, and investigate the temporal evolution of isoprene fluxes in Asia over 1979-2012. For that, we use the MEGAN model and incorporate (i) changes in land use, including the rapid expansion of oil palms, (ii) meteorological variability, (iii) long-term changes in solar radiation constrained by surface network measurements, and (iv) recent experimental evidence that South Asian forests are much weaker isoprene emitters than previously assumed. These effects lead to a significant reduction of the total isoprene fluxes over the studied domain compared to the standard simulation. The bottom-up emissions are evaluated using satellite-based emission estimates derived from inverse modelling constrained by GOME-2/MetOp-A formaldehyde columns through 2007-2012. The top-down estimates support our assumptions and confirm the lower isoprene emission rate in tropical forests of Indonesia and Malaysia.

  15. Change of Auger-electron emission from Ni-Pd alloys under magnetic phase transition

    NASA Astrophysics Data System (ADS)

    Elovikov, S. S.; Zykova, E. Y.; Gvozdover, R. S.; Colligon, J. S.; Yurasova, V. E.

    2006-04-01

    The change of Auger-electron emission from polycrystals of disordered ferromagnetic NiPd 3 and Ni 3 Pd alloys, under ferro- to paramagnetic transition, has been studied experimentally. It has been shown that the intensity of the Auger-lines, which are formed because of transition of valent zone 3d 3/2 and 3d 5/2 electrons, has local maxima near the Curie point T C for the alloys. Thus, the sensitivity of Auger-electron emission to a magnetic state of the alloy has been established.

  16. Transient climate changes in a perturbed parameter ensemble of emissions-driven earth system model simulations

    NASA Astrophysics Data System (ADS)

    Murphy, James M.; Booth, Ben B. B.; Boulton, Chris A.; Clark, Robin T.; Harris, Glen R.; Lowe, Jason A.; Sexton, David M. H.

    2014-11-01

    We describe results from a 57-member ensemble of transient climate change simulations, featuring simultaneous perturbations to 54 parameters in the atmosphere, ocean, sulphur cycle and terrestrial ecosystem components of an earth system model (ESM). These emissions-driven simulations are compared against the CMIP3 multi-model ensemble of physical climate system models, used extensively to inform previous assessments of regional climate change, and also against emissions-driven simulations from ESMs contributed to the CMIP5 archive. Members of our earth system perturbed parameter ensemble (ESPPE) are competitive with CMIP3 and CMIP5 models in their simulations of historical climate. In particular, they perform reasonably well in comparison with HadGEM2-ES, a more sophisticated and expensive earth system model contributed to CMIP5. The ESPPE therefore provides a computationally cost-effective tool to explore interactions between earth system processes. In response to a non-intervention emissions scenario, the ESPPE simulates distributions of future regional temperature change characterised by wide ranges, and warm shifts, compared to those of CMIP3 models. These differences partly reflect the uncertain influence of global carbon cycle feedbacks in the ESPPE. In addition, the regional effects of interactions between different earth system feedbacks, particularly involving physical and ecosystem processes, shift and widen the ESPPE spread in normalised patterns of surface temperature and precipitation change in many regions. Significant differences from CMIP3 also arise from the use of parametric perturbations (rather than a multimodel ensemble) to represent model uncertainties, and this is also the case when ESPPE results are compared against parallel emissions-driven simulations from CMIP5 ESMs. When driven by an aggressive mitigation scenario, the ESPPE and HadGEM2-ES reveal significant but uncertain impacts in limiting temperature increases during the second half

  17. The effects of potential changes in United States beef production on global grazing systems and greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Dumortier, Jerome; Hayes, Dermot J.; Carriquiry, Miguel; Dong, Fengxia; Du, Xiaodong; Elobeid, Amani; Fabiosa, Jacinto F.; Martin, Pamela A.; Mulik, Kranti

    2012-06-01

    We couple a global agricultural production and trade model with a greenhouse gas model to assess leakage associated with modified beef production in the United States. The effects on emissions from agricultural production (i.e., methane and nitrous oxide emissions from livestock and crop management) as well as from land-use change, especially grazing system, are assessed. We find that a reduction of US beef production induces net carbon emissions from global land-use change ranging from 37 to 85 kg CO2-equivalent per kg of beef annualized over 20 years. The increase in emissions is caused by an inelastic domestic demand as well as more land-intensive cattle production systems internationally. Changes in livestock production systems such as increasing stocking rate could partially offset emission increases from pasture expansion. In addition, net emissions from enteric fermentation increase because methane emissions per kilogram of beef tend to be higher globally.

  18. Detection and Monitoring of Changing Natural Methane Emissions in the Arctic

    NASA Astrophysics Data System (ADS)

    Bruhwiler, L.; Sweeney, C.; Dlugokencky, E. J.; Miller, J. B.; Karion, A.; Miller, C. E.

    2012-12-01

    Climate models suggest that the future Arctic climate will continue to warm and become wetter as well. This implies increased emissions of CH4 from wetlands, however, the future of Arctic hydrology is uncertain given expected melting of permafrost. In addition, vast stores of organic carbon are thought to be frozen in Arctic soils; as much as 1,700 billion tonnes of carbon, several times the amount emitted by fossil fuel use to date and about equal to known coal reserves. If mobilized to the atmosphere, this carbon would have significant impacts on global climate, especially if emitted as CH4. NOAA ESRL, Environment Canada, and other agencies have collected observations of greenhouse gases in the Arctic and the rest of the world for at least several decades. Analysis of this data does not currently support increased Arctic emissions of CO2 or CH4. However, it is difficult to detect changes in Arctic emissions because of transport from lower latitudes and high inter-annual variability. Arctic surface emissions are also especially difficult to detect from space, and current satellite platforms do not provide useful information about greenhouse gas budgets in the lower Arctic troposphere. Modeling/assimilation systems, such as NOAA's CarbonTracker-CH4 system can help untangle the Arctic budget and trends of greenhouse gases. On the other hand, the CarbonTracker is dependent on assumptions about prior fluxes and wetland distributions and source estimates are highly uncertain. We address the plausibility of monitoring the Arctic greenhouse gas emission trends. How large would Arctic emission trends have to be before they could be identified in network observations? What spatial information could be recovered? How would the spatial density of observations affect our ability to perceive and attribute trends in Arctic emissions? Could emission have already been increasing during the close of the 20th century? Trends in emissions need to be large before they can be

  19. Impacts of Regional Climate Change on Biogenic Emissions and Air Quality

    SciTech Connect

    Zhang, Yang; Hu, X.-M.; Leung, Lai R.; Gustafson, William I.

    2008-09-25

    Regional air quality simulations are conducted for four summers (2001, 2002, 2051, and 2052) to examine the sensitivity of air quality to potential regional climate change in the U.S. In response to the predicted warmer climate in 2051/2052, emissions of isoprene and terpene increase by 20-92.1% and 20-56%, respectively, over most of the domain. Surface O3, which is sensitive to changes in temperature and solar radiation but relatively insensitive to changes in PBL height and cloud fraction, increase by up to 19-20%. PM2.5, its compositions, and visibility exhibit an overall negative sensitivity (decrease by up to 40%), resulting from the competition of the negative temperature effect and positive emission/temperature effects. While the response of dry deposition is governed by the negative sensitivity of surface resistances, that of wet deposition is either positive or negative, depending on the relative dominancy of changes in PM2.5 and precipitation. Overall the net climatic effect dominates changes in O3, PM2.5, wet and total deposition, and the net biogenic emission effect is important for isoprene, organic matter, visibility, and dry deposition over several regions. Models that do not include secondary organic aerosol formation from isoprene photooxidation may underestimate by at least 20% the air quality responses to future climate changes over many areas of the modeling domain. Both regional climate and air quality exhibit interannual variability, particularly in temperature, isoprene emissions, and PM2.5 concentrations, indicating a need for long-term simulations to predict future air quality.

  20. Can an influence of changing aerosol emissions be detected in the pattern of surface temperature change between 1970 and 2000?

    NASA Astrophysics Data System (ADS)

    Ekman, Annica; Anna, Lewinschal; Hamish, Struthers

    2013-04-01

    Since the 1970's, there has been a rapid change in the magnitude and spatial distribution of anthropogenic aerosol particle and precursor emissions in the world with a significant decrease over e.g. Europe and North America and a substantial increase over large parts of Asia. During the same time period, there has been a significant increase in global greenhouse gas concentrations. In the present study, the global climate model CAM-Oslo is used to examine if the shift in aerosol emissions between 1970 and present day results in a clear fingerprint in the modeled atmospheric circulation, precipitation and temperature change patterns. CAM-Oslo includes a comprehensive module of the atmospheric aerosol cycle as well as descriptions of the direct and indirect effects of aerosol particles on radiation, cloud reflectivity and precipitation. We also examine if the temperature response pattern differs when aerosol effects are considered separately or simultaneously with a change in greenhouse gas concentration. To evaluate the simulations, we make use of observations and re-analysis data of surface temperature, precipitation and 300 hPa geopotential. We investigate if the modeled results correspond better or worse with the observations when aerosol and greenhouse effects are included or excluded. For a few selected regions, we also examine more closely the underlying processes that determine the surface temperature anomaly pattern and if the importance of different processes change when greenhouse effects and aerosol effects are considered separately or simultaneously.

  1. Simulated carbon emissions from land-use change are substantially enhanced by accounting for agricultural management

    NASA Astrophysics Data System (ADS)

    Pugh, T. A. M.; Arneth, A.; Olin, S.; Ahlström, A.; Bayer, A. D.; Klein Goldewijk, K.; Lindeskog, M.; Schurgers, G.

    2015-12-01

    It is over three decades since a large terrestrial carbon sink (S T) was first reported. The magnitude of the net sink is now relatively well known, and its importance for dampening atmospheric CO2 accumulation, and hence climate change, widely recognised. But the contributions of underlying processes are not well defined, particularly the role of emissions from land-use change (E LUC) versus the biospheric carbon uptake (S L; S T = S L - E LUC). One key aspect of the interplay of E LUC and S L is the role of agricultural processes in land-use change emissions, which has not yet been clearly quantified at the global scale. Here we assess the effect of representing agricultural land management in a dynamic global vegetation model. Accounting for harvest, grazing and tillage resulted in cumulative E LUC since 1850 ca. 70% larger than in simulations ignoring these processes, but also changed the timescale over which these emissions occurred and led to underestimations of the carbon sequestered by possible future reforestation actions. The vast majority of Earth system models in the recent IPCC Fifth Assessment Report omit these processes, suggesting either an overestimation in their present-day S T, or an underestimation of S L, of up to 1.0 Pg C a-1. Management processes influencing crop productivity per se are important for food supply, but were found to have little influence on E LUC.

  2. Decadal changes in carbon Emissions and sinks optimized using a Bayesian fusion of multiple observations.

    NASA Astrophysics Data System (ADS)

    Ciais, P.

    2015-12-01

    A better understanding of current human perturbation global carbon cycle is fundamental to support the projection of future climate change and designing better informed climate policy. making. Here, we develop a Bayesian approach that fuses different data-streams to optimize fossil fuel emission (F), land use change emission (L), land sink (B) and ocean sink (O) at a 5-year time step from 1980 to 2014. Here we show that the optimization decreases uncertainties compared with those of the carbon budget established by Global Carbon Project (GCP) and the IPCC where single datasets are used and the land sink deduced as a residual from other terms. Uncertainties of F, L, B and O are reduced by 11%, 26, 36% and 40% compared to those of the GCP budget. Fossil fuel and land use change emissions show a significantly increasing and decreasing trend, respectively, while no significant trend is detected for land and ocean uptakes. We infer with a 93% confidence that the net biosphere uptake with land use change (BL) has increased since 1980. After a further decomposition of the net land flux, sum of L and B, into gross terrestrial fluxes of primary productivity (GPP) and ecosystem respiration (TER), we attribute the increase of B+L to a faster growth of GPP than TER from 1980~1984 to 1990~1994 and a lower decreasing rate of GPP than TER in the 2000s. This approach can be potentially implemented on a yearly basis in future with growing observation-based datasets.

  3. Impacts of Future Climate and Emission Changes on U.S. Air Quality

    SciTech Connect

    Penrod, Ashley; Zhang, Yang; Wang, K.; Wu, Shiang Yuh; Leung, Lai-Yung R.

    2014-06-01

    Changes in climate and emissions will affect future air quality. In this work, simulations of present (2001-2005) and future (2026-2030) regional air quality are conducted with the newly released CMAQ version 5.0 to examine the individual and combined impacts of simulated future climate and anthropogenic emission projections on air quality over the U.S. Current (2001-2005) meteorological and chemical predictions are evaluated against observational data to assess the model’s capability in reproducing the seasonal differences. Overall, WRF and CMAQ perform reasonably well. Increased temperatures (up to 3.18 °C) and decreased ventilation (up to 157 m in planetary boundary layer height) are found in both future winter and summer, with more prominent changes in winter. Increases in future temperatures result in increased isoprene and terpene emissions in winter and summer, driving the increase in maximum 8-h average O3 (up to 5.0 ppb) over the eastern U.S. in winter while decreases in NOx emissions drive the decrease in O3 over most of the U.S. in summer. Future concentrations of PM2.5 in winter and summer and many of its components including organic matter in winter, ammonium and nitrate in summer, and sulfate in winter and summer, decrease due to decreases in primary anthropogenic emissions and the concentrations of secondary anthropogenic pollutants and increased precipitation in winter. Future winter and summer dry and wet deposition fluxes are spatially variable and increase with increasing surface resistance and precipitation (e.g., NH4+ and NO3- dry and wet deposition fluxes increase in winter over much of the U.S.), respectively, and decrease with a decrease in ambient particulate concentrations (e.g., SO42- dry and wet deposition fluxes decrease over the eastern U.S. in summer and winter). Sensitivity simulations show that anthropogenic emission projections dominate over changes in climate in their impacts on the U.S. air quality in the near future. Changes

  4. Changes in US background ozone due to global anthropogenic emissions from 1970 to 2020

    NASA Astrophysics Data System (ADS)

    Nopmongcol, Uarporn; Jung, Jaegun; Kumar, Naresh; Yarwood, Greg

    2016-09-01

    Estimates of North American and US Background (NAB and USB) ozone (O3) are critical in setting and implementing the US National Ambient Air Quality Standards (NAAQS) and therefore influence population exposure to O3 across the US. NAB is defined as the O3 concentration in the absence of anthropogenic O3 precursor emissions from North America whereas USB excludes anthropogenic emissions inside the US alone. NAB and USB vary geographically and with time of year. Analyses of O3 trends at rural locations near the west coast suggest that background O3 is rising in response to increasing non-US emissions. As the O3 NAAQS is lowered, rising background O3 would make attaining the NAAQS more difficult. Most studies of changing US background O3 have inferred trends from observations whereas air quality management decisions tend to rely on models. Thus, it is important that the models used to develop O3 management strategies are able to represent the changes in background O3 in order to increase confidence that air quality management strategies will succeed. We focus on how changing global emissions influence USB rather than the effects of inter-annual meteorological variation or long-term climate change. We use a regional model (CAMx) nested within a global model (GEOS-Chem) to refine our grid resolution over high terrain in the western US and near US borders where USB tends to be higher. We determine USB from CAMx simulations that exclude US anthropogenic emissions. Over five decades, from 1970 to 2020, estimated USB for the annual fourth highest maximum daily 8-h average O3 (H4MDA8) in the western US increased from mostly in the range of 40-55 ppb to 45-60 ppb, but remained below 45 ppb in the eastern US. USB increases in the southwestern US are consistent with rising emissions in Asia and Mexico. USB decreases in the northeast US after 1990 follow declining Canadian emissions. Our results show that the USB increases both for the top 30 MDA8 days and the H4MDA8 (the former

  5. Contribution of Soil Carbonates to CO2 Emissions Following Land Use Change

    NASA Astrophysics Data System (ADS)

    Grand, S.; Rothstein, D.

    2014-12-01

    Land disturbance is known to contribute to carbon dioxide emission through accelerated decomposition of soil organic matter. Many soils also contain large stocks of potentially reactive inorganic C (Ci) in the form of carbonate minerals. Under strong acidification conditions, as can be generated by nitrification and other biogeochemical reactions, carbonate weathering has the potential to generate CO2 emissions on a short time scale; yet little is known about the contribution of this process to disturbance-related C emissions. Information is particularly scarce for high-latitude alkaline soils. The objective of this study is to determine the contribution of Ci to total greenhouse gas emissions from soil following a land disturbance event. The perturbation consisted of the conversion of long-idled agricultural land to a woody bioenergy plantation. We hypothesized that this land use change would intensify acidification processes and increase the release of Ci. We tested this hypothesis by monitoring greenhouse gas emissions during the establishment of a poplar plantation on soils developed from limestone-derived glacial drift in northern Michigan, USA. We used 13C natural abundance to estimate the contribution of Ci to soil C emissions. We found that carbonates were abundant in the soil profile despite the leaching associated with the humid climate. Carbonate-C concentration averaged 2 g/kg in the topsoil and 15 to 25 g/kg in the deep subsoil. The persistence of measurable carbonate concentrations above the expected weathering front was likely due to biological translocation processes. Using a Bayesian isotopic mixing model accounting for endmember uncertainties, we detected a significant contribution of Ci to total soil CO2 emissions at the plot scale. There was a significant interaction between disturbance and season. In the spring, Ci emissions were three times higher in newly established poplar plots than in control plots. In the summer, Ci emissions in control

  6. Changes in soil aggregation and dust emission potential in response to aeolian processes

    NASA Astrophysics Data System (ADS)

    swet, Nitzan; Katra, Itzhak

    2016-04-01

    Aeolian (wind) dust emission has high environmental and socioeconomic significances due to loss of natural soil and air pollution. Dust emission involves complex interactions between the airflow and the soil surface. The soil aggregates were dust particles are held determine the topsoil erodibility in aeolian erosion. Although the key role of soil aggregation in dust emission mechanisms, information on changes in soil aggregate size distribution (ASD) due to aeolian erosion is lucking. This study is focused on quantitative ASD analyses before and after aeolian processes (saltation). Aeolian experiments and soil analyses were conducted on semiarid loess topsoils with different initial conditions of aggregation. The results show that saltation rates and PM emissions depend on the initial ASD and shear velocity. In all initial soil conditions, the content of aggregates at saltator-sized 63-250 μm was increased by 10-34 % following erosion of macro-aggregates > 500 μm. It revealed that the aggregate-saltator production increases with the shear velocity (up to 0.61 m s-1) for soils with available macro-aggregates. The findings highlight the dynamics in soil aggregation in response to aeolian transport and therefore its significance for determining the mechanisms of dust emission from soil aggregates.

  7. Impacts of Land Use Change on Energy Usage and Ghg Emissions

    NASA Astrophysics Data System (ADS)

    Jeyachandran, I.; Eltrop, L.; Jenssen, T.; Marathe, S. D.

    2014-12-01

    Urbanization has a profound impact on landscape modification and subsequent impacts on energy usage and associated Green House Gas (GHG) emissions. In this paper, a methodology to assess the impact of land use change on energy demand and Green House Gas emissions using remote sensing data is presented. The methodology development was carried out using region of Stuttgart, Germany as the case study for the time period of 1990 to 2006. The first step involved using Corine land cover corresponding to the years 1990, 2000 and 2006 in conjunction with the administrative boundary map of the region of Stuttgart to assess the land use change from 1990 to 2006. The second step of the methodology involved using ATKIS building data of 2004 in conjunction with the land use data of 1990, and 2000 to identify the buildings in 1990 and 2000 and assess the land use conversion to built areas due to urbanization. Also the building types were identified, and the energy usage for heating and cooling was modeled using local guidelines. As the final step, the GHG emissions associated with heating and energy demand was estimated for the years 1990, 2000 and 2004 using the empirical relation set by Öko-Institute (2011). The results of the study indicate that there has been a significant increase in urban residential built surfaces (17%) and decrease in urban greenery, forest and agricultural areas during the time period of 1990 to 2004. The increase in residential built surfaces has resulted in an increase of electricity and heating demand and a subsequent increase in GHG emissions(14%). The methodology presented in this paper brings forth the use of remote sensing to estimate and predict GHG emissions resulting from land use changes.

  8. Decadal Changes in Ozone and Emissions in Central California and Current Issues

    NASA Astrophysics Data System (ADS)

    Tanrikulu, S.; Beaver, S.; Soong, S.; Tran, C.; Cordova, J.; Palazoglu, A.

    2011-12-01

    The relationships among ozone, emissions, and meteorology are very complex in central California, and must be well studied and understood in order to facilitate better air quality planning. Factors significantly impacting changes in emissions such as economic and population growth, and adopted emission controls make the matter even more complex. Here we review the history of ozone pollution in central California since the 1970s to plan for the future. Since the 1970s, changes in emissions have been accompanied by likewise dramatic changes in region-to-region differences in air quality. We focus on the coastal San Francisco Bay Area (SFBA) and the inland San Joaquin Valley (SJV). In the 1970s, the SFBA population was approaching 5 million people while the considerably larger and more rural SJV population remained below 2 million. The SFBA population was mostly confined to coastal locations. Peak ozone levels occurred mostly around the population centers and especially over the Bay itself. Hourly average ozone levels routinely approached 160 ppb. These high ozone levels promoted regulations under which SFBA emissions were continuously reduced through the present. By the 1990s, SFBA emissions had been reduced considerably despite the region's population growing to around 6 million. Relative to the 1970s, in 1990s the SFBA had lower peak ozone levels that were shifted to inland locations where much of the population growth was occurring. The SFBA still exceeded the federal 1-hour standard. A rapidly changing economic landscape in the 1970s promoted vast changes in the central California population distribution. In the SJV, the OPEC oil crisis promoted significant development of petroleum resources. Meanwhile, family farms were quickly being replaced with commercial-scale farming operations. The SJV population rapidly expanded to around 3 million people by the early 1990s. During this time, SJV emissions increased considerably, largely from increases in mobile source

  9. Transformative Reduction of Transportation Greenhouse Gas Emissions. Opportunities for Change in Technologies and Systems

    SciTech Connect

    Vimmerstedt, Laura; Brown, Austin; Newes, Emily; Markel, Tony; Schroeder, Alex; Zhang, Yimin; Chipman, Peter; Johnson, Shawn

    2015-04-30

    The transportation sector is changing, influenced by concurrent, ongoing, dynamic trends that could dramatically affect the future energy landscape, including effects on the potential for greenhouse gas emissions reductions. Battery cost reductions and improved performance coupled with a growing number of electric vehicle model offerings are enabling greater battery electric vehicle market penetration, and advances in fuel cell technology and decreases in hydrogen production costs are leading to initial fuel cell vehicle offerings. Radically more efficient vehicles based on both conventional and new drivetrain technologies reduce greenhouse gas emissions per vehicle-mile. Net impacts also depend on the energy sources used for propulsion, and these are changing with increased use of renewable energy and unconventional fossil fuel resources. Connected and automated vehicles are emerging for personal and freight transportation systems and could increase use of low- or non-emitting technologies and systems; however, the net effects of automation on greenhouse gas emissions are uncertain. The longstanding trend of an annual increase in transportation demand has reversed for personal vehicle miles traveled in recent years, demonstrating the possibility of lower-travel future scenarios. Finally, advanced biofuel pathways have continued to develop, highlighting low-carbon and in some cases carbon-negative fuel pathways. We discuss the potential for transformative reductions in petroleum use and greenhouse gas emissions through these emerging transportation-sector technologies and trends and present a Clean Transportation Sector Initiative scenario for such reductions, which are summarized in Table ES-1.

  10. Mitigating methane emission from paddy soil with rice-straw biochar amendment under projected climate change.

    PubMed

    Han, Xingguo; Sun, Xue; Wang, Cheng; Wu, Mengxiong; Dong, Da; Zhong, Ting; Thies, Janice E; Wu, Weixiang

    2016-01-01

    Elevated global temperatures and increased concentrations of carbon dioxide (CO2) in the atmosphere associated with climate change will exert profound effects on rice cropping systems, particularly on their greenhouse gas emitting potential. Incorporating biochar into paddy soil has been shown previously to reduce methane (CH4) emission from paddy rice under ambient temperature and CO2. We examined the ability of rice straw-derived biochar to reduce CH4 emission from paddy soil under elevated temperature and CO2 concentrations expected in the future. Adding biochar to paddy soil reduced CH4 emission under ambient conditions and significantly reduced emissions by 39.5% (ranging from 185.4 mg kg(-1) dry weight soil, dws season(-1) to 112.2 mg kg(-1) dws season(-1)) under simultaneously elevated temperature and CO2. Reduced CH4 release was mainly attributable to the decreased activity of methanogens along with the increased CH4 oxidation activity and pmoA gene abundance of methanotrophs. Our findings highlight the valuable services of biochar amendment for CH4 control from paddy soil in a future that will be shaped by climate change. PMID:27090814

  11. Mitigating methane emission from paddy soil with rice-straw biochar amendment under projected climate change

    NASA Astrophysics Data System (ADS)

    Han, Xingguo; Sun, Xue; Wang, Cheng; Wu, Mengxiong; Dong, Da; Zhong, Ting; Thies, Janice E.; Wu, Weixiang

    2016-04-01

    Elevated global temperatures and increased concentrations of carbon dioxide (CO2) in the atmosphere associated with climate change will exert profound effects on rice cropping systems, particularly on their greenhouse gas emitting potential. Incorporating biochar into paddy soil has been shown previously to reduce methane (CH4) emission from paddy rice under ambient temperature and CO2. We examined the ability of rice straw-derived biochar to reduce CH4 emission from paddy soil under elevated temperature and CO2 concentrations expected in the future. Adding biochar to paddy soil reduced CH4 emission under ambient conditions and significantly reduced emissions by 39.5% (ranging from 185.4 mg kg‑1 dry weight soil, dws season‑1 to 112.2 mg kg‑1 dws season‑1) under simultaneously elevated temperature and CO2. Reduced CH4 release was mainly attributable to the decreased activity of methanogens along with the increased CH4 oxidation activity and pmoA gene abundance of methanotrophs. Our findings highlight the valuable services of biochar amendment for CH4 control from paddy soil in a future that will be shaped by climate change.

  12. Mitigating methane emission from paddy soil with rice-straw biochar amendment under projected climate change

    PubMed Central

    Han, Xingguo; Sun, Xue; Wang, Cheng; Wu, Mengxiong; Dong, Da; Zhong, Ting; Thies, Janice E.; Wu, Weixiang

    2016-01-01

    Elevated global temperatures and increased concentrations of carbon dioxide (CO2) in the atmosphere associated with climate change will exert profound effects on rice cropping systems, particularly on their greenhouse gas emitting potential. Incorporating biochar into paddy soil has been shown previously to reduce methane (CH4) emission from paddy rice under ambient temperature and CO2. We examined the ability of rice straw-derived biochar to reduce CH4 emission from paddy soil under elevated temperature and CO2 concentrations expected in the future. Adding biochar to paddy soil reduced CH4 emission under ambient conditions and significantly reduced emissions by 39.5% (ranging from 185.4 mg kg−1 dry weight soil, dws season−1 to 112.2 mg kg−1 dws season−1) under simultaneously elevated temperature and CO2. Reduced CH4 release was mainly attributable to the decreased activity of methanogens along with the increased CH4 oxidation activity and pmoA gene abundance of methanotrophs. Our findings highlight the valuable services of biochar amendment for CH4 control from paddy soil in a future that will be shaped by climate change. PMID:27090814

  13. Changes in Regional Nitric Oxide Emissions from Savanna Soils Associated with Woody Encroachment

    NASA Astrophysics Data System (ADS)

    Martin, R. E.; Asner, G. P.

    2002-12-01

    Mesquite has been rapidly increasing over the past 100 years resulting in documented changes to the biophysical and biogeochemical structure of savanna ecosystems world-wide. Some of these changes include increases in plant and soil C and N stores and cycling rates as well as isotopic shifts in these pools (Archer et al. 2001, Boutton et al. 1998, Hibbard et al.2001). However, there is no information about the impacts of woody encroachment on soil N oxides emissions. The objective of this study is to determine that remotely sensed variables of vegetation, soil type, and climate alone can be used to estimate N oxide emissions. N oxide fluxes and related parameters were measured at nine study sites across a range of woody canopy cover on two soil types. Spatially, woody canopy cover was the best predictor of NO emissions while temporally temperature was the dominant control given adequate soil moisture. Through linking these biogeochemical relationships with spatially explicit data derived from remote sensing data it is possible to extend these plot-scale measurements to the landscape and regional scales. This method allows better determination of the spatial distribution of N oxide emissions and associated variability.

  14. Land cover change mapping using MODIS time series to improve emissions inventories

    NASA Astrophysics Data System (ADS)

    López-Saldaña, Gerardo; Quaife, Tristan; Clifford, Debbie

    2016-04-01

    MELODIES is an FP7 funded project to develop innovative and sustainable services, based upon Open Data, for users in research, government, industry and the general public in a broad range of societal and environmental benefit areas. Understanding and quantifying land surface changes is necessary for estimating greenhouse gas and ammonia emissions, and for meeting air quality limits and targets. More sophisticated inventories methodologies for at least key emission source are needed due to policy-driven air quality directives. Quantifying land cover changes on an annual basis requires greater spatial and temporal disaggregation of input data. The main aim of this study is to develop a methodology for using Earth Observations (EO) to identify annual land surface changes that will improve emissions inventories from agriculture and land use/land use change and forestry (LULUCF) in the UK. First goal is to find the best sets of input features that describe accurately the surface dynamics. In order to identify annual and inter-annual land surface changes, a times series of surface reflectance was used to capture seasonal variability. Daily surface reflectance images from the Moderate Resolution Imaging Spectroradiometer (MODIS) at 500m resolution were used to invert a Bidirectional Reflectance Distribution Function (BRDF) model to create the seamless time series. Given the limited number of cloud-free observations, a BRDF climatology was used to constrain the model inversion and where no high-scientific quality observations were available at all, as a gap filler. The Land Cover Map 2007 (LC2007) produced by the Centre for Ecology & Hydrology (CEH) was used for training and testing purposes. A land cover product was created for 2003 to 2015 and a bayesian approach was created to identified land cover changes. We will present the results of the time series development and the first exercises when creating the land cover and land cover changes products.

  15. Historical land use change and associated carbon emissions in Brazil from 1940 to 1995

    NASA Astrophysics Data System (ADS)

    Leite, Christiane Cavalcante; Costa, Marcos Heil; Soares-Filho, Britaldo Silveira; de Barros Viana Hissa, Letícia

    2012-06-01

    The evaluation of impacts of land use change is in general limited by the knowledge of past land use conditions. Most publications on the field present only a vague description of the earlier patterns of land use, which is usually insufficient for more comprehensive studies. Here we present the first spatially explicit reconstruction of historical land use patterns in Brazil, including both croplands and pasturelands, for the period between 1940 and 1995. This reconstruction was obtained by merging satellite imagery with census data, and provides a 5' × 5' yearly data set of land use for three different categories (cropland, natural pastureland and planted pastureland) for Brazil. The results show that important land use changes occurred in Brazil. Natural pasture dominated in the 1950s and 1960s, but since the beginning of 1970s it has been gradually replaced by planted pasture, especially in southeast and center west of Brazil. The croplands began its expansion in the 1960s reaching extensive areas in almost all states in 1980. Carbon emissions from historical land use changes were calculated by superimposing a composite biomass map on grids of a weighted average of the fractions of the vegetation types and the replacement land uses. Net emissions from land use changes between 1940 and 1995 totaled 17.2 ± 9.0 Pg-C (90% confidence range), averaging 0.31 ± 0.16 Pg-C yr-1, but reaching up to 0.47 ± 0.25 Pg-C yr-1 during the 1960s and through 1986-1995. Despite international concerns about Amazon deforestation emissions, 72% of Brazil's carbon emissions during the period actually came from deforestation in the Atlantic Forest and Cerrado biomes. Brazil's carbon emissions from land use change are about 11 times larger than its emissions from fossil fuel burning, although only about 18.1% of the native biomass has been lost due to agricultural expansion, which is similar to the global mean (17.7%).

  16. Dynamic control of light emission faster than the lifetime limit using VO2 phase-change

    NASA Astrophysics Data System (ADS)

    Cueff, Sébastien; Li, Dongfang; Zhou, You; Wong, Franklin J.; Kurvits, Jonathan A.; Ramanathan, Shriram; Zia, Rashid

    2015-10-01

    Modulation is a cornerstone of optical communication, and as such, governs the overall speed of data transmission. Currently, the two main strategies for modulating light are direct modulation of the excited emitter population (for example, using semiconductor lasers) and external optical modulation (for example, using Mach-Zehnder interferometers or ring resonators). However, recent advances in nanophotonics offer an alternative approach to control spontaneous emission through modifications to the local density of optical states. Here, by leveraging the phase-change of a vanadium dioxide nanolayer, we demonstrate broadband all-optical direct modulation of 1.5 μm emission from trivalent erbium ions more than three orders of magnitude faster than their excited state lifetime. This proof-of-concept demonstration shows how integration with phase-change materials can transform widespread phosphorescent materials into high-speed optical sources that can be integrated in monolithic nanoscale devices for both free-space and on-chip communication.

  17. More frequent moments in the climate change debate as emissions continue

    NASA Astrophysics Data System (ADS)

    Huntingford, Chris; Friedlingstein, Pierre

    2015-12-01

    Recent years have witnessed unprecedented interest in how the burning of fossil fuels may impact on the global climate system. Such visibility of this issue is in part due to the increasing frequency of key international summits to debate emissions levels, including the 2015 21st Conference of Parties meeting in Paris. In this perspective we plot a timeline of significant climate meetings and reports, and against metrics of atmospheric greenhouse gas changes and global temperature. One powerful metric is cumulative CO2 emissions that can be related to past and future warming levels. That quantity is analysed in detail through a set of papers in this ERL focus issue. We suggest it is an open question as to whether our timeline implies a lack of progress in constraining climate change despite multiple recent keynote meetings—or alternatively—that the increasing level of debate is encouragement that solutions will be found to prevent any dangerous warming levels?

  18. Dynamic control of light emission faster than the lifetime limit using VO2 phase-change.

    PubMed

    Cueff, Sébastien; Li, Dongfang; Zhou, You; Wong, Franklin J; Kurvits, Jonathan A; Ramanathan, Shriram; Zia, Rashid

    2015-01-01

    Modulation is a cornerstone of optical communication, and as such, governs the overall speed of data transmission. Currently, the two main strategies for modulating light are direct modulation of the excited emitter population (for example, using semiconductor lasers) and external optical modulation (for example, using Mach-Zehnder interferometers or ring resonators). However, recent advances in nanophotonics offer an alternative approach to control spontaneous emission through modifications to the local density of optical states. Here, by leveraging the phase-change of a vanadium dioxide nanolayer, we demonstrate broadband all-optical direct modulation of 1.5 μm emission from trivalent erbium ions more than three orders of magnitude faster than their excited state lifetime. This proof-of-concept demonstration shows how integration with phase-change materials can transform widespread phosphorescent materials into high-speed optical sources that can be integrated in monolithic nanoscale devices for both free-space and on-chip communication. PMID:26489436

  19. Analysis of Power Plant NOx Emission Changes and Their Impact on Ozone in the Eastern United States

    NASA Astrophysics Data System (ADS)

    Frost, G.; Kim, S.; McKeen, S.; Hsie, E. Y.; Trainer, M.; Peckham, S.; Grell, G.

    2005-12-01

    Changes in NOx emissions from electric power generation plants due to the implementation of pollution controls are measured by Continuous Emission Monitoring Systems (CEMS) and compiled by the EPA. Eastern US power plant NOx emissions decreased between 1999 and 2004 by about 50 percent during the summer ozone season (May - September). CEMS data for the 1999 - 2004 period are analyzed to understand the extent of these emission changes and their temporal and spatial variability. CEMS data are used to construct a nationwide 2004 update to the power plant portion of the EPA's NEI 1999, the most recent final emission inventory available for air quality models. O3 concentrations during the 2004 ozone season are simulated by the Weather Research and Forecasting Chemistry (WRF-Chem) model, with a base emission scenario using the NEI 1999 and a perturbation scenario using the updated 2004 inventory. The impact of these NOx emission trends on O3 in the Eastern US is described.

  20. Climate change and pollutant emissions impacts on air quality in 2050 over Portugal

    NASA Astrophysics Data System (ADS)

    Sá, E.; Martins, H.; Ferreira, J.; Marta-Almeida, M.; Rocha, A.; Carvalho, A.; Freitas, S.; Borrego, C.

    2016-04-01

    Changes in climate and air pollutant emissions will affect future air quality from global to urban scale. In this study, regional air quality simulations for historical and future periods are conducted, with CAMx version 6.0, to investigate the impacts of future climate and anthropogenic emission projections on air quality over Portugal and the Porto metropolitan area in 2050. The climate and the emission projections were derived from the Representative Concentrations Pathways (RCP8.5) scenario. Modelling results show that climate change will impact NO2, PM10 and O3 concentrations over Portugal. The NO2 and PM10 annual means will increase in Portugal and in the Porto municipality, and the maximum 8-hr daily O3 value will increase in the Porto suburban areas (approximately 5%) and decrease in the urban area (approximately 2%). When considering climate change and projected anthropogenic emissions, the NO2 annual mean decreases (approximately 50%); PM10 annual mean will increase in Portugal and decrease in Porto municipality (approximately 13%); however PM10 and O3 levels increase and extremes occur more often, surpassing the currently legislated annual limits and displaying a higher frequency of daily exceedances. This air quality degradation is likely to be related with the trends found for the 2046-2065 climate, which implies warmer and dryer conditions, and with the increase of background concentrations of ozone and particulate matter. The results demonstrate the need for Portuguese authorities and policy-makers to design and implement air quality management strategies that take climate change impacts into account.

  1. Positron emission tomography displacement sensitivity: predicting binding potential change for positron emission tomography tracers based on their kinetic characteristics.

    PubMed

    Morris, Evan D; Yoder, Karmen K

    2007-03-01

    There is great interest in positron emission tomography (PET) as a noninvasive assay of fluctuations in synaptic neurotransmitter levels, but questions remain regarding the optimal choice of tracer for such a task. A mathematical method is proposed for predicting the utility of any PET tracer as a detector of changes in the concentration of an endogenous competitor via displacement of the tracer (a.k.a., its 'vulnerability' to competition). The method is based on earlier theoretical work by Endres and Carson and by the authors. A tracer-specific predictor, the PET Displacement Sensitivity (PDS), is calculated from compartmental model simulations of the uptake and retention of dopaminergic radiotracers in the presence of transient elevations of dopamine (DA). The PDS predicts the change in binding potential (DeltaBP) for a given change in receptor occupancy because of binding by the endogenous competitor. Simulations were performed using estimates of tracer kinetic parameters derived from the literature. For D(2)/D(3) tracers, the calculated PDS indices suggest a rank order for sensitivity to displacement by DA as follows: raclopride (highest sensitivity), followed by fallypride, FESP, FLB, NMSP, and epidepride (lowest). Although the PDS takes into account the affinity constant for the tracer at the binding site, its predictive value cannot be matched by either a single equilibrium constant, or by any one rate constant of the model. Values for DeltaBP have been derived from published studies that employed comparable displacement paradigms with amphetamine and a D(2)/D(3) tracer. The values are in good agreement with the PDS-predicted rank order of sensitivity to displacement. PMID:16788713

  2. Spin change of a proto-neutron star by the emission of neutrinos

    NASA Astrophysics Data System (ADS)

    Ryu, Chung-Yeol; Maruyama, Tomoyuki; Kajino, Toshitaka; Mathews, Grant J.; Cheoun, Myung-Ki

    2012-04-01

    We investigate the structure of proto-neutron stars (PNSs) with trapped neutrinos by using a quark-meson coupling model. We adopt a phenomenological lepton density which is diffuse near the surface. We calculate the populations of baryons and leptons, the equations of state, and the mass-radius relation for isentropic PNS models. In addition, the moment of inertia is calculated for both PNS and cold-neutron-star (CNS) models as a means to study the change of the spin period due to the neutrino emission from a PNS. Neutrino emission from a hyperonic neutron star is shown to increase the spin by about 10% of the initial spin, while the spin of a nucleonic neutron star with a central density above ρC≈5ρ0 is decreased by a few % by the emission of neutrinos. Therefore, the spin change owing to the leakage of neutrinos from a PNS is a small (<10%) correction compared to other processes related to the spin change.

  3. Estimates of Geographically Explicit Future CO2 Emissions From Land Cover/ Land Use Changes

    NASA Astrophysics Data System (ADS)

    Richardson, T.; Yang, X.; Jain, A.; O'Neill, B.

    2007-12-01

    Land cover and land use change activities, such as deforestation, afforestation, and agriculture management, are important sources of not only CO2, but also non-CO2 GHGs and aerosols. The objective of this paper is to evaluate the potential contribution of future GHGs and reactive GHGs emissions via changes in regional land use-related activities at a 0.5 degree by 0.5 degree resolution. Regional land use is downscaled to the grid cell level based on socioeconomic, biophysical, and biogeochemical factors. Socio-economic factors include population density at the grid zone level. Land sustainability and attainable crop yields, as well as terrain conditions, are biophysical and biogeochemical factors that were also determined at each grid zone level. The productivity of land was determined by the length of growing period (LGP) using the biophysical and biochemical cycles of the Integrated Science Assessment Model (ISAM). Agro-ecological and economic indexes were constructed using historical and current-day cropping practices at the grid zone levels. In the future, the distribution of LGPs may be altered due to changes in carbon, nutrients, and climate. This paper uses two IPCC SRES (A2 and B1) emissions and land use scenarios during the time period 2000-2050 to evaluate the relative importance of land use emissions to future net terrestrial CO2 uptakes.

  4. The impacts of emissions, meteorology and climate change on pollution transport

    NASA Astrophysics Data System (ADS)

    Fang, Yuanyuan

    Long-range transport (LRT) of pollutants is known to exacerbate local and regional air quality problems. Questions remain, however, as to the spatial and temporal variation of intercontinental influence and its importance relative to pollution produced at the local or regional scales at present and in the future. A global chemical transport model (MOZART), a general circulation model (AM3) as well as recent field observations are applied to investigate the impacts of pollutant emissions, synoptic meteorology and climate change on the magnitude and variability of LRT. Surface O3 is a key air pollutant and it is mainly controlled by the supply of NOx on the global or regional scale. U.S. anthropogenic NOx emissions decreased notably since the 1990s due to emission regulations to improve the O3 air quality. Model sensitivity studies show a less-than-linear response of NOy (NOx and its oxidation products) export to NOx emission controls during summer time and suggest a need to control a larger percentage of emissions for a desired change in O3 precursor export. Recent observations suggest that northern mid-latitudes lightning NOx source may be underestimated in the current generation of models. If these models are used to estimate the contribution of O3 LRT, they will likely overestimate the fractional contribution of PAN to total NOy export and the northern mid-latitudinal regional mean O3 production efficiency per unit NOx. The resulting O3 response to foreign anthropogenic emissions will be overestimated. Future observational studies of lightning NOx are needed to constrain model estimates of the O3 response to anthropogenic NOx changes. Field campaigns over the past decades have identified cyclone passages and associated warm conveyor belts as key mechanisms for pollutant export from the United States. Using MOZART simulated CO as a tracer of pollution, a quantitative relationship between strong daily export events and migratory mid-latitude cyclones is established

  5. Response of Arctic temperature to changes in emissions of short-lived climate forcers

    NASA Astrophysics Data System (ADS)

    Sand, M.; Berntsen, T. K.; von Salzen, K.; Flanner, M. G.; Langner, J.; Victor, D. G.

    2016-03-01

    There is growing scientific and political interest in the impacts of climate change and anthropogenic emissions on the Arctic. Over recent decades temperatures in the Arctic have increased at twice the global rate, largely as a result of ice-albedo and temperature feedbacks. Although deep cuts in global CO2 emissions are required to slow this warming, there is also growing interest in the potential for reducing short-lived climate forcers (SLCFs; refs ,). Politically, action on SLCFs may be particularly promising because the benefits of mitigation are seen more quickly than for mitigation of CO2 and there are large co-benefits in terms of improved air quality. This Letter is one of the first to systematically quantify the Arctic climate impact of regional SLCFs emissions, taking into account black carbon (BC), sulphur dioxide (SO2), nitrogen oxides (NOx), volatile organic compounds (VOCs), organic carbon (OC) and tropospheric ozone (O3), and their transport processes and transformations in the atmosphere. This study extends the scope of previous works by including more detailed calculations of Arctic radiative forcing and quantifying the Arctic temperature response. We find that the largest Arctic warming source is from emissions within the Asian nations owing to the large absolute amount of emissions. However, the Arctic is most sensitive, per unit mass emitted, to SLCFs emissions from a small number of activities within the Arctic nations themselves. A stringent, but technically feasible mitigation scenario for SLCFs, phased in from 2015 to 2030, could cut warming by 0.2 (+/-0.17) K in 2050.

  6. Metabolomic changes in murine serum following inhalation exposure to gasoline and diesel engine emissions.

    PubMed

    Brower, Jeremy B; Doyle-Eisele, Melanie; Moeller, Benjamin; Stirdivant, Steven; McDonald, Jacob D; Campen, Matthew J

    2016-04-01

    The adverse health effects of environmental exposure to gaseous and particulate components of vehicular emissions are a major concern among urban populations. A link has been established between respiratory exposure to vehicular emissions and the development of cardiovascular disease (CVD), but the mechanisms driving this interaction remain unknown. Chronic inhalation exposure to mixed vehicle emissions has been linked to CVD in animal models. This study evaluated the temporal effects of acute exposure to mixed vehicle emissions (MVE; mixed gasoline and diesel emissions) on potentially active metabolites in the serum of exposed mice. C57Bl/6 mice were exposed to a single 6-hour exposure to filtered air (FA) or MVE (100 or 300 μg/m(3)) by whole body inhalation. Immediately after and 18 hours after the end of the exposure period, animals were sacrificed for serum and tissue collection. Serum was analyzed for metabolites that were differentially present between treatment groups and time points. Changes in metabolite levels suggestive of increased oxidative stress (oxidized glutathione, cysteine disulfide, taurine), lipid peroxidation (13-HODE, 9-HODE), energy metabolism (lactate, glycerate, branched chain amino acid catabolites, butrylcarnitine, fatty acids), and inflammation (DiHOME, palmitoyl ethanolamide) were observed immediately after the end of exposure in the serum of animals exposed to MVE relative to those exposed to FA. By 18 hours post exposure, serum metabolite differences between animals exposed to MVE versus those exposed to FA were less pronounced. These findings highlight complex metabolomics alterations in the circulation following inhalation exposure to a common source of combustion emissions. PMID:27017952

  7. Changes in inorganic fine particulate matter sensitivities to precursors due to large-scale US emissions reductions.

    PubMed

    Holt, Jareth; Selin, Noelle E; Solomon, Susan

    2015-04-21

    We examined the impact of large US emissions changes, similar to those estimated to have occurred between 2005 and 2012 (high and low emissions cases, respectively), on inorganic PM2.5 sensitivities to further NOx, SO2, and NH3 emissions reductions using the chemical transport model GEOS-Chem. Sensitivities to SO2 emissions are larger year-round and across the US in the low emissions case than the high emissions case due to more aqueous-phase SO2 oxidation. Sensitivities to winter NOx emissions are larger in the low emissions case, more than 2× those of the high emissions case in parts of the northern Midwest. Sensitivities to NH3 emissions are smaller (∼40%) in the low emissions case, year-round, and across the US. Differences in NOx and NH3 sensitivities indicate an altered atmospheric acidity. Larger sensitivities to SO2 and NOx in the low emissions case imply that reducing these emissions may improve air quality more now than they would have in 2005; conversely, NH3 reductions may not improve air quality as much as previously assumed. PMID:25816113

  8. The impact of changing nitrogen oxide emissions on wet and dry nitrogen deposition in the northeastern USA

    NASA Astrophysics Data System (ADS)

    Butler, Thomas J.; Likens, Gene E.; Vermeylen, Francoise M.; Stunder, Barbara J. B.

    This study is an attempt to quantify the relation between changes in NO x emissions and nitric acid (HNO 3) in the northeastern USA. From this relation, and previous work relating NO x emission changes and wet NO 3- deposition, we can estimate how changing NO x emissions may impact total (wet+dry) measured nitrogen (N) deposition. Electric utility emissions account for {1}/{4}, and vehicle emissions account for over {1}/{2} of the total NO x emissions in the eastern USA. Canadian NO x emissions from the seven easternmost provinces (Manitoba and east) represent less than 10% (1.2 teragrams (Tg) NO x) of the NO x emissions compared with those from the eastern USA. Emissions from eastern Canada are dominated by vehicle NO x emissions, which account for {2}/{3} of the total NO x emissions from eastern Canada. Data from the EPA National Emissions Inventory show, for the period 1991-2001, that nitrogen oxide (NO x) emissions in the eastern USA have declined by 17% to from 16.1 to 13.1 Tg. Large declines in vehicle emissions in 2001 may be questionable. If 2001 data are excluded the decline in total NO x is only 7%. A recent assessment of EPA's emissions estimates suggest that vehicle NO x emissions may be underestimated, and total NO x emissions reductions may be less than what is reported by the EPA. The CASTNet (Clean Air Status and Trends Network) measurements of N dry deposition include HNO 3, particulate NO 3- and NH 4+. The dominant N dry deposition product measured is HNO 3, which represents 80% of measured N dry deposition for the sites used in this study. Amounts of NH 3, NO 2, organic nitrate and PAN dry deposition are not measured by CASTNet. The NH 3 and NO 2 deposition are probably significant, and may be major N dry deposition components in some areas. Random coefficient models with total NO x emissions as the independent variable, and HNO 3 concentrations as the dependent variable, show that reducing total NO x emissions by 50% should reduce HNO 3

  9. Assessments of the contribution of land use change to the dust emission in Central Asia

    NASA Astrophysics Data System (ADS)

    Xi, X.; Sokolik, I. N.

    2015-12-01

    While the dust emission from arid and semi-arid regions is known as a natural process induced by wind erosion, human may affect the dust emission directly through land use disturbances and indirectly by climate change. There has been much debate on the relative importance of climate change and land use to the global dust budget, as past estimates on the proportion of dust contributed by land use, in particular agricultural practices, remains very uncertain. This to the large extent stems from the way how human-made dust sources are identified and how they are treated in models. This study attempts to assess the land use contribution to the dust emission in Central Asia during 2000-2014 by conducting multiple experiments on the total emission in the WRF-Chem-DuMo model, and applying two methods to separate the natural and anthropogenic sources. The model experiments include realistic treatments of agriculture (e.g., expansion and abandonment) and water body changes (e.g., Aral Sea desiccation) in the land cover map of WRF-Chem-DuMo, but impose no arbitrary labeling of dust source type or adjustment to the erosion threshold. Intercomparison of the model experiments will be focused on the magnitude, interannual variability, and climate sensitivity of dust fluxes resulting from the selections of surface input data and dust flux parameterizations. Based on annual land use intensity maps, the sensitivity of the anthropogenic dust proportion to selection of the threshold value will be evaluated. In conjunction with the empirical method, satellite-derived annual land classifications will be used to track the land cover dynamics, and separate potential human-made source areas.

  10. Annual land cover change mapping using MODIS time series to improve emissions inventories.

    NASA Astrophysics Data System (ADS)

    López Saldaña, G.; Quaife, T. L.; Clifford, D.

    2014-12-01

    Understanding and quantifying land surface changes is necessary for estimating greenhouse gas and ammonia emissions, and for meeting air quality limits and targets. More sophisticated inventories methodologies for at least key emission source are needed due to policy-driven air quality directives. Quantifying land cover changes on an annual basis requires greater spatial and temporal disaggregation of input data. The main aim of this study is to develop a methodology for using Earth Observations (EO) to identify annual land surface changes that will improve emissions inventories from agriculture and land use/land use change and forestry (LULUCF) in the UK. First goal is to find the best sets of input features that describe accurately the surface dynamics. In order to identify annual and inter-annual land surface changes, a times series of surface reflectance was used to capture seasonal variability. Daily surface reflectance images from the Moderate Resolution Imaging Spectroradiometer (MODIS) at 500m resolution were used to invert a Bidirectional Reflectance Distribution Function (BRDF) model to create the seamless time series. Given the limited number of cloud-free observations, a BRDF climatology was used to constrain the model inversion and where no high-scientific quality observations were available at all, as a gap filler. The Land Cover Map 2007 (LC2007) produced by the Centre for Ecology & Hydrology (CEH) was used for training and testing purposes. A prototype land cover product was created for 2006 to 2008. Several machine learning classifiers were tested as well as different sets of input features going from the BRDF parameters to spectral Albedo. We will present the results of the time series development and the first exercises when creating the prototype land cover product.

  11. Biofuels, causes of land-use change, and the role of fire in greenhouse gas emissions

    SciTech Connect

    Kline, Keith L; Dale, Virginia H

    2008-07-01

    IN THEIR REPORTS IN THE 29 FEBRUARY ISSUE ('LAND CLEARING AND THE BIOFUEL CARBON debt,' J. Fargione et al., p. 1235, and 'Use of U.S. croplands for biofuels increases greenhouse gases through emissions from land-use change,' T. Searchinger et al., p. 1238), the authors do not provide adequate support for their claim that biofuels cause high emissions due to land-use change. The conclusions of both papers depend on the misleading premise that biofuel production causes forests and grasslands to be converted to agriculture. However, field research, including a meta-analysis of 152 case studies, consistently finds that land-use change and associated carbon emissions are driven by interactions among cultural, technological, biophysical, political, economic, and demographic forces within a spatial and temporal context rather than by a single crop market. Searchinger et al. assert that soybean prices accelerate clearing of rainforest based on a single citation for a study not designed to identify the causal factors of land clearing. The study analyzed satellite imagery from a single state in Brazil over a 4-year period and focused on land classification after deforestation. Satellite imagery can measure what changed but does little to tell us why. Similarly, Fargione et al. do not rely on primary empirical studies of causes of land-use change. Furthermore, neither fire nor soil carbon sequestration was properly considered in the Reports. Fire's escalating contribution to global climate change is largely a result of burning in tropical savannas and forests. Searchinger et al. postulate that 10.8 million hectares could be needed for future biofuel, a fraction of the 250 to 400 million hectares burned each year between 2000 and 2005. By offering enhanced employment and incomes, biofuels can help establish economic stability and thus reduce the recurring use of fire on previously cleared land as well as pressures to clear more land. Neither Searchinger et al. nor Fargione et

  12. Historical Responsibility for Climate Change - from countries emissions to contribution to temperature increase

    NASA Astrophysics Data System (ADS)

    Krapp, Mario; Gütschow, Johannes; Rocha, Marcia; Schaeffer, Michiel

    2016-04-01

    The notion of historical responsibility is central to the equity debate and the measure of responsibility as a countries' share of historical global emissions remains one of the essential parameters in so-called equity proposals, which attempt to distribute effort among countries in an equitable manner. The focus of this contribution is on the historical contribution of countries, but it takes it one step further: its general objective lies on estimating countries' contribution directly to the change in climate. The historical responsibility is not based on cumulative emissions but instead measured in terms of the countries' estimated contribution to the increase in global-mean surface-air temperature. This is achieved by (1) compiling a historical emissions dataset for the period from 1850 until 2012 for each individual Kyoto-greenhouse gas and each UNFCCC Party using a consistent methodology and (2) applying those historical emissions to a revised version of the so-called Policy-maker Model put forward by the Ministry of Science and Technology of the Federative Republic of Brazil, which is a simple, yet powerful tool that allows historical GHG emissions of individual countries to be directly related to their effect on global temperature changes. We estimate that the cumulative GHG emissions until 2012 from the USA, the European Union and China contribute to a total temperature increase of about 0.50°C in 2100, which is equivalent to about 50% of the temperature increase from total global GHG emissions by that year (of about 1.0°C). Respectively, the USA, the European Union, and China are responsible for 20.2%, 17.3%, and 12.1% of global temperature increase in 2100. Russian historical emissions are responsible for 0.06°C temperature increase by 2100, ranking as the fourth largest contributor to temperature increase with 6.2% of the total contribution. India ranks fifth: Indian emissions to date would contribute to roughly 0.05°C of global mean temperature

  13. Tuning Eu3+ emission in europium sesquioxide films by changing the crystalline phase

    NASA Astrophysics Data System (ADS)

    Mariscal, A.; Quesada, A.; Camps, I.; Palomares, F. J.; Fernández, J. F.; Serna, R.

    2016-06-01

    We report the growth of europium sesquioxide (Eu2O3) thin films by pulsed laser deposition (PLD) in vacuum at room temperature from a pure Eu2O3 ceramic bulk target. The films were deposited in different configurations formed by adding capping and/or buffer layers of amorphous aluminum oxide (a-Al2O3). The optical properties, refractive index and extinction coefficient of the as deposited Eu2O3 layers were obtained. X-ray photoelectron spectroscopy (XPS) measurements were done to assess its chemical composition. Post-deposition annealing was performed at 500 °C and 850 °C in air in order to achieve the formation of crystalline films and to accomplish photoluminescence emission. According to the analysis of X-ray diffraction (XRD) spectra, cubic and monoclinic phases were formed. It is found that the relative amount of the phases is related to the different film configurations, showing that the control over the crystallization phase can be realized by adequately designing the structures. All the films showed photoluminescence emission peaks (under excitation at 355 nm) that are attributed to the intra 4f-transitions of Eu3+ ions. The emission spectral shape depends on the crystalline phase of the Eu2O3 layer. Specifically, changes in the hypersensitive 5D0 → 7F2 emission confirm the strong influence of the crystal field effect on the Eu3+ energy levels.

  14. Biological implications of longevity in dairy cows: 2. Changes in methane emissions and efficiency with age.

    PubMed

    Grandl, F; Amelchanka, S L; Furger, M; Clauss, M; Zeitz, J O; Kreuzer, M; Schwarm, A

    2016-05-01

    Previous studies indicated that absolute CH4 emissions and CH4 yield might increase and that milk production efficiency might decrease with age in cattle. Both would make strategies to increase longevity in dairy cattle less attractive. These aspects were experimentally determined in Brown Swiss cattle distributed continuously across a large age range. Thirty lactating dairy cows (876-3,648 d of age) received diets consisting of hay, corn silage, and grass pellets supplemented with 0 or 5kg of concentrate per day. Twelve heifers (199-778 d of age) received hay only. Cows and heifers were members of herds subjected to the 2 different feeding regimens (with or without concentrate) for the past 10 yr. Methane emissions were measured individually for 2 d in open-circuit respiration chambers, followed by quantifying individual feed intake and milk yield over 8 d. Additional data on digestibility, rumination time, and passage time of feed of all experimental animals were available. Regression analyses were applied to evaluate effects of age and feeding regimen. Body weight, milk yield, and the hay proportion of forage dry matter intake were considered as covariates. Methane emissions per unit of intake, body weight, and milk yield were significantly related to age. Their development in the cows with age was characterized by an increase to maximum at around 2,000 d of age, followed by a decline. This response was not accompanied by corresponding age-related changes in intake, chewing activity, digesta passage time, and digestibility of organic matter, which would have explained shifts in CH4. However, fiber digestibility showed a similar change with age as methane emissions, resulting in quite stable methane emissions per unit of digestible fiber. As expected, methane emissions intensity per unit of milk produced was greater by 8% without concentrate than with concentrate, but no difference was noted in the response to age when the animals were subjected to different

  15. Quantifying Climate Feedbacks from Abrupt Changes in High-Latitude Trace-Gas Emissions

    SciTech Connect

    Schlosser, Courtney Adam; Walter-Anthony, Katey; Zhuang, Qianlai; Melillo, Jerry

    2013-04-26

    Our overall goal was to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically forced climate warming, and the extent to which these emissions provide a strong feedback mechanism to global climate warming. This goal is motivated under the premise that polar amplification of global climate warming will induce widespread thaw and degradation of the permafrost, and would thus cause substantial changes in the extent of wetlands and lakes, especially thermokarst (thaw) lakes, over the Arctic. Through a coordinated effort of field measurements, model development, and numerical experimentation with an integrated assessment model framework, we have investigated the following hypothesis: There exists a climate-warming threshold beyond which permafrost degradation becomes widespread and thus instigates strong and/or sharp increases in methane emissions (via thermokarst lakes and wetland expansion). These would outweigh any increased uptake of carbon (e.g. from peatlands) and would result in a strong, positive feedback to global climate warming.

  16. Updating soil CO2 emission experiments to assess climate change effects and extracellular soil respiration

    NASA Astrophysics Data System (ADS)

    Vidal Vazquez, Eva; Paz Ferreiro, Jorge

    2014-05-01

    Experimental work is an essential component in training future soil scientists. Soil CO2 emission is a key issue because of the potential impacts of this process on the greenhouse effect. The amount of organic carbon stored in soils worldwide is about 1600 gigatons (Gt) compared to 750 Gt in the atmosphere mostly in the form of CO2. Thus, if soil respiration increased slightly so that just 10% of the soil carbon pool was converted to CO2, atmospheric CO2 concentrations in the atmosphere could increase by one-fifth. General circulation model predictions indicate atmosphere warming between 2 and 5°C (IPCC 2007) and precipitation changes ranging from about -15 to +30%. Traditionally, release of CO2 was thought to occur only in an intracellular environment; however, recently CO2 emissions have been in irradiated soil, in the absence of microorganisms (Maire et al., 2013). Moreover, soil plays a role in the stabilization of respiration enzymes promoting CO2 release after microorganism death. Here, we propose to improve CO2 emission experiments commonly used in soil biology to investigate: 1) effects of climatic factors on soil CO2 emissions, and 2) rates of extracellular respiration in soils and how these rates are affected by environmental factors. Experiment designed to assess the effect of climate change can be conducted either in field conditions under different ecosystems (forest, grassland, cropland) or in a greenhouse using simple soil chambers. The interactions of climate change in CO2 emissions are investigated using climate-manipulation experiment that can be adapted to field or greenhouse conditions (e.g. Mc Daniel et al., 2013). The experimental design includes a control plot (without soil temperature and rain manipulation) a warming treatment as well as wetting and/or drying treatments. Plots are warmed to the target temperature by procedures such as infrared heaters (field) or radiant cable (greenhouse). To analyze extracellular respiration, rates of CO2

  17. Carbon Density and Anthropogenic Land Use Influences on Net Land-Use Change Emissions

    SciTech Connect

    Smith, Steven J.; Rothwell, Andrew J.

    2013-10-08

    We examine historical and future land-use emissions using a simple mechanistic carbon-cycle model with regional and ecosystem specific parameterizations. Our central estimate of net terrestrial land-use change emissions, exclusive of climate feedbacks, is 250 GtC over the last three hundred years. This estimate is most sensitive to assumptions for preindustrial forest and soil carbon densities. We also find that estimates are sensitive to the treatment of crop and pasture lands. These sensitivities also translate into differences in future terrestrial uptake in the RCP4.5 land-use scenario. This estimate of future uptake is lower than the native values from the GCAM integrated assessment model result due to lower net reforestation in the RCP4.5 gridded land-use data product

  18. Volatile interaction between undamaged plants affects tritrophic interactions through changed plant volatile emission.

    PubMed

    Vucetic, Andja; Dahlin, Iris; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben; Ninkovic, Velemir

    2014-01-01

    Volatile interactions between unattacked plants can lead to changes in their volatile emissions. Exposure of potato plants to onion plant volatiles results in increased emission of 2 terpenoids, (E)-nerolidol and TMTT. We investigated whether this is detectable by the ladybird Coccinella septempunctata. The odor of onion-exposed potato was significantly more attractive to ladybirds than that of unexposed potato. Further, a synthetic blend mimicking the volatile profile of onion-exposed potato was more attractive than a blend mimicking that of unexposed potato. When presented individually, TMTT was attractive to ladybirds whereas (E)-nerolidol was repellent. Volatile exchange between unattacked plants and consequent increased attractiveness for ladybirds may be a mechanism that contributes to the increased abundance of natural enemies in complex plant habitats. PMID:25763628

  19. Dynamic evaluation of CMAQ part I: Separating the effects of changing emissions and changing meteorology on ozone levels between 2002 and 2005 in the eastern US

    NASA Astrophysics Data System (ADS)

    Foley, Kristen M.; Hogrefe, Christian; Pouliot, George; Possiel, Norm; Roselle, Shawn J.; Simon, Heather; Timin, Brian

    2015-02-01

    A dynamic evaluation of the Community Multiscale Air Quality (CMAQ) modeling system version 5.0.1 was conducted to evaluate the model's ability to predict changes in ozone levels between 2002 and 2005, a time period characterized by emission reductions associated with the EPA's Nitrogen Oxides State Implementation Plan as well as significant reductions in mobile source emissions. Model results for the summers of 2002 and 2005 were compared to simulations from a previous version of CMAQ to assess the impact of model updates on predicted pollutant response. Changes to the model treatment of emissions, meteorology and chemistry had substantial impacts on the simulated ozone concentrations. While the median bias for high summertime ozone decreased in both years compared to previous simulations, the observed decrease in ozone from 2002 to 2005 in the eastern US continued to be underestimated by the model. Additional "cross" simulations were used to decompose the model predicted change in ozone into the change due to emissions, the change due to meteorology and any remaining change not explained individually by these two components. The decomposition showed that the emission controls led to a decrease in modeled high summertime ozone close to twice as large as the decrease attributable to changes in meteorology alone. Quantifying the impact of retrospective emission controls by removing the impacts of meteorology during the control period can be a valuable approach for communicating to policy makers the net benefit of national control measures.

  20. A spatial modeling framework to evaluate domestic biofuel-induced potential land use changes and emissions.

    PubMed

    Elliott, Joshua; Sharma, Bhavna; Best, Neil; Glotter, Michael; Dunn, Jennifer B; Foster, Ian; Miguez, Fernando; Mueller, Steffen; Wang, Michael

    2014-02-18

    We present a novel bottom-up approach to estimate biofuel-induced land-use change (LUC) and resulting CO2 emissions in the U.S. from 2010 to 2022, based on a consistent methodology across four essential components: land availability, land suitability, LUC decision-making, and induced CO2 emissions. Using high-resolution geospatial data and modeling, we construct probabilistic assessments of county-, state-, and national-level LUC and emissions for macroeconomic scenarios. We use the Cropland Data Layer and the Protected Areas Database to characterize availability of land for biofuel crop cultivation, and the CERES-Maize and BioCro biophysical crop growth models to estimate the suitability (yield potential) of available lands for biofuel crops. For LUC decision-making, we use a county-level stochastic partial-equilibrium modeling framework and consider five scenarios involving annual ethanol production scaling to 15, 22, and 29 BG, respectively, in 2022, with corn providing feedstock for the first 15 BG and the remainder coming from one of two dedicated energy crops. Finally, we derive high-resolution above-ground carbon factors from the National Biomass and Carbon Data set to estimate emissions from each LUC pathway. Based on these inputs, we obtain estimates for average total LUC emissions of 6.1, 2.2, 1.0, 2.2, and 2.4 gCO2e/MJ for Corn-15 Billion gallons (BG), Miscanthus × giganteus (MxG)-7 BG, Switchgrass (SG)-7 BG, MxG-14 BG, and SG-14 BG scenarios, respectively. PMID:24456539

  1. Emission Changes Resulting from the San Pedro Bay, California Ports Truck Retirement Program

    SciTech Connect

    Bishop, G. A.; Schuchmann, B. G.; Stedman, D. H.; Lawson, D. R.

    2012-01-03

    Recent U.S. Environmental Protection Agency emissions regulations have resulted in lower emissions of particulate matter and oxides of nitrogen from heavy-duty diesel trucks. To accelerate fleet turnover the State of California in 2008 along with the Ports of Los Angeles and Long Beach (San Pedro Bay Ports) in 2006 passed regulations establishing timelines forcing the retirement of older diesel trucks. On-road emissions measurements of heavy-duty diesel trucks were collected over a three-year period, beginning in 2008, at a Port of Los Angeles location and an inland weigh station on the Riverside freeway (CA SR91). At the Port location the mean fleet age decreased from 12.7 years in April of 2008 to 2.5 years in May of 2010 with significant reductions in carbon monoxide (30%), oxides of nitrogen (48%) and infrared opacity (a measure of particulate matter, 54%). We also observed a 20-fold increase in ammonia emissions as a result of new, stoichiometrically combusted, liquefied natural gas powered trucks. These results compare with changes at our inland site where the average ages were 7.9 years in April of 2008 and 8.3 years in April of 2010, with only small reductions in oxides of nitrogen (10%) being statistically significant. Both locations have experienced significant increases in nitrogen dioxide emissions from new trucks equipped with diesel particle filters; raising the mean nitrogen dioxide to oxides of nitrogen ratios from less than 10% to more than 30% at the Riverside freeway location.

  2. A spatial modeling framework to evaluate domestic biofuel-induced potential land use changed and emissions

    USGS Publications Warehouse

    Elliot, Joshua; Sharma, Bhavna; Best, Neil; Glotter, Michael; Dunn, Jennifer B.; Foster, Ian; Miguez, Fernando; Mueller, Steffen; Wang, Michael

    2014-01-01

    We present a novel bottom-up approach to estimate biofuel-induced land-use change (LUC) and resulting CO2 emissions in the U.S. from 2010 to 2022, based on a consistent methodology across four essential components: land availability, land suitability, LUC decision-making, and induced CO2 emissions. Using highresolution geospatial data and modeling, we construct probabilistic assessments of county-, state-, and national-level LUC and emissions for macroeconomic scenarios. We use the Cropland Data Layer and the Protected Areas Database to characterize availability of land for biofuel crop cultivation, and the CERES-Maize and BioCro biophysical crop growth models to estimate the suitability (yield potential) of available lands for biofuel crops. For LUC decisionmaking, we use a county-level stochastic partial-equilibrium modeling framework and consider five scenarios involving annual ethanol production scaling to 15, 22, and 29 BG, respectively, in 2022, with corn providing feedstock for the first 15 BG and the remainder coming from one of two dedicated energy crops. Finally, we derive high-resolution above-ground carbon factors from the National Biomass and Carbon Data set to estimate emissions from each LUC pathway. Based on these inputs, we obtain estimates for average total LUC emissions of 6.1, 2.2, 1.0, 2.2, and 2.4 gCO2e/MJ for Corn-15 Billion gallons (BG), Miscanthus × giganteus (MxG)-7 BG, Switchgrass (SG)-7 BG, MxG-14 BG, and SG-14 BG scenarios, respectively.

  3. Changes in CH4 emission from rice fields from 1960 to 1990s. 1. Impacts of modern rice technology

    NASA Astrophysics Data System (ADS)

    van der Gon, Hugo Denier

    2000-03-01

    Four countries (Indonesia, Philippines, Thailand, and Nepal) were taken as an example to assess the impact of changes in rice cultivation on methane emissions from rice fields since the 1960s. The change of rice area by type of culture from 1960-1990s is estimated, and its relative contribution to national harvested rice area is calculated and multiplied with an emission factor, to derive the relative methane emission per unit rice land. Relative methane emission per ha rice land has increased since 1960 for all four countries, largely due to an increase in irrigated rice area and partly due to a decrease in upland rice area. Patterns of rice area changes and related emission changes differ considerably among countries. On the basis of the rice area increases between 1960 and the 1990s, significant increases in methane emissions from rice fields due to increases in total rice cultivated area are not to be expected in the future. The impact of modern rice variety adoption is assessed by relating methane emissions to rice production. The organic matter returned to the paddy soil is largely determined by rice biomass production which, given a certain yield, is different for traditional and modern rice varieties. By calculating total organic matter returned to rice paddy soils and assuming a constant fraction to be emitted as methane, rice production and methane emission can be related. The analysis indicates that (1) up to now, rice yield increases in countries with high modern rice variety adoption have not resulted in increased methane emissions per unit of harvested area and, (2) global annual emission from rice fields may be considerably lower than generally assumed. The introduction of modern rice varieties can be regarded as a historical methane emission mitigation strategy because higher rice yields resulted in lower or equal methane emissions.

  4. Changes in CH4 emission from rice fields from 1960 to 1990s: 1. Impacts of modern rice technology

    NASA Astrophysics Data System (ADS)

    Gon, Hugo Denier

    2000-03-01

    Four countries (Indonesia, Philippines, Thailand, and Nepal) were taken as an example to assess the impact of changes in rice cultivation on methane emissions from rice fields since the 1960s. The change of rice area by type of culture from 1960-1990s is estimated, and its relative contribution to national harvested rice area is calculated and multiplied with an emission factor, to derive the relative methane emission per unit rice land. Relative methane emission per ha rice land has increased since 1960 for all four countries, largely due to an increase in irrigated rice area and partly due to a decrease in upland rice area. Patterns of rice area changes and related emission changes differ considerably among countries. On the basis of the rice area increases between 1960 and the 1990s, significant increases in methane emissions from rice fields due to increases in total rice cultivated area are not to be expected in the future. The impact of modern rice variety adoption is assessed by relating methane emissions to rice production. The organic matter returned to the paddy soil is largely determined by rice biomass production which, given a certain yield, is different for traditional and modern rice varieties. By calculating total organic matter returned to rice paddy soils and assuming a constant fraction to be emitted as methane, rice production and methane emission can be related. The analysis indicates that (1) up to now, rice yield increases in countries with high modern rice variety adoption have not resulted in increased methane emissions per unit of harvested area and, (2) global annual emission from rice fields may be considerably lower than generally assumed. The introduction of modern rice varieties can be regarded as a historical methane emission mitigation strategy because higher rice yields resulted in lower or equal methane emissions.

  5. Ammonia Emissions from the Agriculture Sector of Argentina in a Context of Changing Technologies and Practices

    NASA Astrophysics Data System (ADS)

    Dawidowski, L. E.

    2015-12-01

    Agriculture is a key sector of the Argentinean economy, accounting for 6 to 8 5% of the GDP in the last ten years. Argentina switched in the 90´s from an articulated co-evolution between extensive livestock and crop farming, with annual rotation of crops and livestock, to intensive decoupled practices. Under these new production schemes, ecosystems were supplied with more nutrients, generating increasing levels of wastes. Other changes have also occurred, associated with the shift of the agricultural frontier and the consequent reduction in the cattle stock. In addition, changes related to climate through the strong increase in rainfall in the 80s and 90s in the west Pampas, helped to boost agricultural development. The agriculture sector accounts for practically all NH3 emissions in Argentina, however no inventory has been thus far available. To bridge this gap and particularly to have accurate input information to run coupled atmospheric chemistry models for secondary inorganic aerosols, we estimated 2000-2012 NH3 emissions, both at national and spatially disaggregated levels. Of particular interest for us was also temporal disaggregation as crops growing and temperature exhibit strong seasonal variability. As no NH3 inventory was available we also estimated related N2O emissions to verify our estimates with those of national GHG emission inventory (NEI). National NH3 emissions in 2012 amounted to 309.9 Gg, use of fertilizers accounted for 43.6%, manure management 18,9%, manure in pasture 36,0% and agricultural waste burning 1.5%. Our N2O estimates are in good agreement with the GHG-NEI. NH3 estimates in the EDGAR database for 2008 are 84.0% higher than ours for this year, and exhibit more significant differences per category, namely 113,6% higher for use of fertilizers and about 500% higher for agricultural waste burning. Urea dominates national NH3 emissions, accounting for 32,8% of the total and its use for wheat and corn crops dominates the trend.

  6. Energy and Greenhouse Gas Emissions in China: Growth, Transition, and Institutional Change

    NASA Astrophysics Data System (ADS)

    Kahrl, Fredrich James

    Global energy markets and climate change in the twenty first century depend, to an extraordinary extent, on China. China is now, or will soon be, the world's largest energy consumer. Since 2007, China has been the world's largest emitter of greenhouse gases (GHGs). Despite its large and rapidly expanding influence on global energy markets and the global atmosphere, on a per capita basis energy consumption and GHG emissions in China are low relative to developed countries. The Chinese economy, and with it energy use and GHG emissions, are expected to grow vigorously for at least the next two decades, raising a question of critical historical significance: How can China's economic growth imperative be meaningfully reconciled with its goals of greater energy security and a lower carbon economy? Most scholars, governments, and practitioners have looked to technology---energy efficiency, nuclear power, carbon capture and storage---for answers to this question. Alternatively, this study seeks to root China's future energy and emissions trajectory in the political economy of its multiple transitions, from a centrally planned to a market economy and from an agrarian to a post-industrial society. The study draws on five case studies, each a dedicated chapter, which are organized around three perspectives on energy and GHG emissions: the macroeconomy; electricity supply and demand; and nitrogen fertilizer production and use. Chapters 2 and 3 examine how growth and structural change in China's macroeconomy have shaped energy demand, finding that most of the dramatic growth in the country's energy use over the 2000s was driven by an acceleration of its investment-dominated, energy-intensive growth model, rather than from structural change. Chapters 4 and 5 examine efforts to improve energy efficiency and increase the share of renewable generation in the electric power sector, concluding that China's power system lacks the flexibility in generation, pricing, and demand to

  7. Impacts of future climate change and emissions reductions on nitrogen and sulfur deposition over the United States

    NASA Astrophysics Data System (ADS)

    Tagaris, Efthimios; Liao, Kuo-Jen; Manomaiphiboon, Kasemsan; Woo, Jung-Hun; He, Shan; Amar, Praveen; Russell, Armistead G.

    2008-04-01

    Potential impacts of global climate change and emissions on the total nitrogen and sulfur deposition over the US are investigated. Three future years' annual average deposition rates (i.e., 2049-2051) are compared with historic ones (i.e., 2000-2002) accounting for existing US and individual State's emission regulations and strategies. Impacts of global climate change alone on regional nitrogen and sulfur deposition are small compared to impacts from emission control-related reductions for the projections used in this study. The combined effect of climate change and emission reductions is a decrease in the annual average nitrogen and sulfur deposition over the US. Reduced nitrogen species dominate oxidized nitrogen deposition in the future. Spatial distribution plots for both components show lower deposition rates in the future mainly in the middle and eastern States where reductions in NOx and SO2 emissions are more pronounced.

  8. Nitrogen emissions along the Colorado Front Range: Response to population growth, land and water use change, and agriculture

    NASA Astrophysics Data System (ADS)

    Baron, J. S.; Del Grosso, S.; Ojima, D. S.; Theobald, D. M.; Parton, W. J.

    While N emissions are not commonly linked to land use change, the production of fixed nitrogen is strongly related to activities associated with urbanization, such as construction, production of energy, and development and use of transportation corridors. Agricultural intensification, brought about by application of synthetic N fertilizers and industrial-scale animal feeding operations, is another land use change that increases N emissions. The Colorado Front Range region experienced rapid population growth from 1980 (1.9 million) to 2000 (2.9 million). Emissions from point (power plants and industry) and mobile (highway and off road vehicles) sources were responsible for most of the increase in emissions since 1980. Agriculture (cropped and grazed land and livestock) was the other important source of N emissions. Soil emissions from cropped and grazed lands remained stable while livestock emissions increased slightly due to more cattle and hogs in feedlots. Although cause and effect relationships between increased N emissions and eutrophication of particular ecosystems are difficult to establish, higher N deposition has been observed at alpine sites near the headwaters of the South Platte River commensurate with the rise in emissions. The ecosystem responses of alpine systems to N deposition are likely to be the result, albeit an indirect one, of land use change.

  9. Assessing the implications of human land-use change for the transient climate response to cumulative carbon emissions

    NASA Astrophysics Data System (ADS)

    Simmons, C. T.; Matthews, H. D.

    2016-03-01

    Recent research has shown evidence of a linear climate response to cumulative CO2 emissions, which implies that the source, timing, and amount of emissions does not significantly influence the climate response per unit emission. Furthermore, these analyses have generally assumed that the climate response to land-use CO2 emissions is equivalent to that of fossil fuels under the assumption that, once in the atmosphere, the radiative forcing induced by CO2 is not sensitive to the emissions source. However, land-cover change also affects surface albedo and the strength of terrestrial carbon sinks, both of which have an additional climate effect. In this study, we use a coupled climate-carbon cycle model to assess the climate response to historical and future cumulative land-use CO2 emissions, in order to compare it to the response to fossil fuel CO2. We find that when we isolate the CO2-induced (biogeochemical) temperature changes associated with land-use change, then the climate response to cumulative land-use emissions is equivalent to that of fossil fuel CO2. We show further that the globally-averaged albedo-induced biophysical cooling from land-use change is non-negligible and may be of comparable magnitude to the biogeochemical warming, with the result that the net climate response to land-use change is substantially different from a linear response to cumulative emissions. However, our new simulations suggest that the biophysical cooling from land-use change follows its own independent (negative) linear response to cumulative net land-use CO2 emissions, which may provide a useful scaling factor for certain applications when evaluating the full transient climate response to emissions.

  10. Towards an inventory of methane emissions from manure management that is responsive to changes on Canadian farms

    NASA Astrophysics Data System (ADS)

    VanderZaag, A. C.; MacDonald, J. D.; Evans, L.; Vergé, X. P. C.; Desjardins, R. L.

    2013-09-01

    Methane emissions from manure management represent an important mitigation opportunity, yet emission quantification methods remain crude and do not contain adequate detail to capture changes in agricultural practices that may influence emissions. Using the Canadian emission inventory methodology as an example, this letter explores three key aspects for improving emission quantification: (i) obtaining emission measurements to improve and validate emission model estimates, (ii) obtaining more useful activity data, and (iii) developing a methane emission model that uses the available farm management activity data. In Canada, national surveys to collect manure management data have been inconsistent and not designed to provide quantitative data. Thus, the inventory has not been able to accurately capture changes in management systems even between manure stored as solid versus liquid. To address this, we re-analyzed four farm management surveys from the past decade and quantified the significant change in manure management which can be linked to the annual agricultural survey to create a continuous time series. In the dairy industry of one province, for example, the percentage of manure stored as liquid increased by 300% between 1991 and 2006, which greatly affects the methane emission estimates. Methane emissions are greatest from liquid manure, but vary by an order of magnitude depending on how the liquid manure is managed. Even if more complete activity data are collected on manure storage systems, default Intergovernmental Panel on Climate Change (IPCC) guidance does not adequately capture the impacts of management decisions to reflect variation among farms and regions in inventory calculations. We propose a model that stays within the IPCC framework but would be more responsive to farm management by generating a matrix of methane conversion factors (MCFs) that account for key factors known to affect methane emissions: temperature, retention time and inoculum. This

  11. Modeling GHG Emissions and Carbon Changes in Agricultural and Forest Systems to Guide Mitigation and Adaptation: Synthesis and Future Needs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural production systems and land use change for agriculture and forestry are important sources of anthropogenic greenhouse gas (GHG) emissions. Recent commitments by the European Union, the United States, and China to reduce GHG emissions highlight the need to improve estimates of current em...

  12. PROJECTING FUTURE-YEAR POLLUTANT EMISSIONS: EMERGING APPROACHES FROM THE EPA ORD GLOBAL CHANGE AIR QUALITY ASSESSMENT

    EPA Science Inventory

    The U.S. EPA's Office of Research and Development is exploring approaches for assessing the relative impacts of climate and emissions changes on future-year air quality. A challenge related to this effort is the development of emissions inventories out to the year 2050. This pap...

  13. Climate change and health costs of air emissions from biofuels and gasoline

    PubMed Central

    Hill, Jason; Polasky, Stephen; Nelson, Erik; Tilman, David; Huo, Hong; Ludwig, Lindsay; Neumann, James; Zheng, Haochi; Bonta, Diego

    2009-01-01

    Environmental impacts of energy use can impose large costs on society. We quantify and monetize the life-cycle climate-change and health effects of greenhouse gas (GHG) and fine particulate matter (PM2.5) emissions from gasoline, corn ethanol, and cellulosic ethanol. For each billion ethanol-equivalent gallons of fuel produced and combusted in the US, the combined climate-change and health costs are $469 million for gasoline, $472–952 million for corn ethanol depending on biorefinery heat source (natural gas, corn stover, or coal) and technology, but only $123–208 million for cellulosic ethanol depending on feedstock (prairie biomass, Miscanthus, corn stover, or switchgrass). Moreover, a geographically explicit life-cycle analysis that tracks PM2.5 emissions and exposure relative to U.S. population shows regional shifts in health costs dependent on fuel production systems. Because cellulosic ethanol can offer health benefits from PM2.5 reduction that are of comparable importance to its climate-change benefits from GHG reduction, a shift from gasoline to cellulosic ethanol has greater advantages than previously recognized. These advantages are critically dependent on the source of land used to produce biomass for biofuels, on the magnitude of any indirect land use that may result, and on other as yet unmeasured environmental impacts of biofuels. PMID:19188587

  14. Procedure to diagnose onychomycosis through changes in emissivity on infrared images.

    PubMed

    Villaseñor-Mora, Carlos; Vega, Arturo Gonzalez; Garay-Sevilla, Maria Eugenia; Padilla-Medina, José Alfredo; Arteaga-Murillo, Lauro Ivan

    2013-11-01

    A noninvasive, quick, reliable, and relatively cheap procedure for the diagnosis of onychomycosis is put forward. It is known that a nail may show an abnormal appearance, although only 50% of all the nails having such an appearance may owe it to the presence of onychomycosis; hence, adequate diagnosis of nail disease is needed for appropriate prescription of medication and treatment of the nail. In order to contribute to the process of improvement in the diagnosis, a procedure based on the analysis of medium-range infrared images is presented in which it is possible to observe energy changes mostly due to the changes in emissivity of the nail. As a nail is more affected by onychomycosis, such changes become more intense. Also, it was found that a nail without onychomycosis has a lower temperature than toe skin, but has a higher emission of energy. Fifty percent of the ailments that may a cause a fingernail or toenail to have an abnormal appearance are not considered in the present work. PMID:24193948

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  16. Surface Emissivity Retrieved with Satellite Ultraspectral IR Measurements for Monitoring Global Change

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Larar, Allen M.; Liu, Xu; Smith, William L.; Schluessel, Peter

    2009-01-01

    Surface and atmospheric thermodynamic parameters retrieved with advanced ultraspectral remote sensors aboard Earth observing satellites are critical to general atmospheric and Earth science research, climate monitoring, and weather prediction. Ultraspectral resolution infrared radiance obtained from nadir observations provide atmospheric, surface, and cloud information. Presented here is the global surface IR emissivity retrieved from Infrared Atmospheric Sounding Interferometer (IASI) measurements under "clear-sky" conditions. Fast radiative transfer models, applied to the cloud-free (or clouded) atmosphere, are used for atmospheric profile and surface parameter (or cloud parameter) retrieval. The inversion scheme, dealing with cloudy as well as cloud-free radiances observed with ultraspectral infrared sounders, has been developed to simultaneously retrieve atmospheric thermodynamic and surface (or cloud microphysical) parameters. Rapidly produced surface emissivity is initially evaluated through quality control checks on the retrievals of other impacted atmospheric and surface parameters. Surface emissivity and surface skin temperature from the current and future operational satellites can and will reveal critical information on the Earth s ecosystem and land surface type properties, which can be utilized as part of long-term monitoring for the Earth s environment and global climate change.

  17. Climate and mortality changes due to reductions in household cooking emissions

    NASA Astrophysics Data System (ADS)

    Bergman, Tommi; Mielonen, Tero; Arola, Antti; Kokkola, Harri

    2016-04-01

    Household cooking is a significant cause for health and environmental problems in the developing countries. There are more than 3 billion people who use biomass for fuel in cooking stoves in their daily life. These cooking stoves use inadequate ventilation and expose especially women and children to indoor smoke. To reduce problems of the biomass burning, India launched an initiative to provide affordable and clean energy solutions for the poorest households by providing clean next-generation cooking stoves. The improved cooking stoves are expected to improve outdoor air quality and to reduce the climate-active pollutants, thus simultaneously slowing the climate change. Previous research has shown that the emissions of black carbon can be decreased substantially, as much as 90 % by applying better technology in cooking stoves. We have implemented reasonable (50% decrease) and best case (90% decrease) scenarios of the reductions in black and organic carbon due to improved cooking stoves in India into ECHAM-HAMMOZ aerosol-climate model. The global simulations of the scenarios will be used to study how the reductions of emissions in India affect the pollutant concentrations and radiation. The simulated reductions in particulate concentrations will also be used to estimate the decrease in mortality rates. Furthermore, we will study how the emission reductions would affect the global climate and mortality if a similar initiative would be applied in other developing countries.

  18. Changes in acoustic emission peaks in precipitation strengthened alloys with heat treatment

    SciTech Connect

    Heiple, C.R.; Carpenter, S.H.

    1983-01-01

    Acoustic emission was measured during tensile deformation in a number of precipitation-strengthened alloys as a function of prior heat treatment. The alloys tested included 7075, 6061, and 2219 aluminum; a modified A-286 stainless steel (JBK-75) and an experimental beryllium-containing stainless steel; and Incoloy 903. A rms voltage peak was observed in all the alloys near the onset of plastic flow, and a second peak was usually observed in 7075, 2219, and Incoloy 903 at plastic strains greater than 1%. Some evidence of a second peak was also observed in 6061 aluminum. Changes with heat treatment in the stress and strain at which the second peak occurred were consistent with the peak arising from the fracture of inclusions. The shifts in the location of the peak were in a direction so as to make the stress on the inclusions at the second peak relatively insensitive to prior heat treatment. The amplitude distributions of acoustic emission signals were also consistent with this interpretation. The strain at which the first acoustic emission peak occurred also varied with heat treatment, but the dependence of peak location on prior aging was different for the various alloys.

  19. Non-Kyoto Radiative Forcing in Long-Run Greenhouse Gas Emissions and Climate Change Scenarios

    SciTech Connect

    Rose, Steven K.; Richels, Richard G.; Smith, Steven J.; Riahi, Keywan; Stefler, Jessica; Van Vuuren, Detlef

    2014-04-27

    Climate policies designed to achieve climate change objectives must consider radiative forcing from the Kyoto greenhouse gas, as well as other forcing constituents, such as aerosols and tropospheric ozone. Net positive forcing leads to global average temperature increases. Modeling of non-Kyoto forcing is a relatively new component of climate management scenarios. Five of the nineteen models in the EMF-27 Study model both Kyoto and non-Kyoto forcing. This paper describes and assesses current non-Kyoto radiative forcing modeling within these integrated assessment models. The study finds negative forcing from aerosols masking significant positive forcing in reference non-climate policy projections. There are however large differences across models in projected non-Kyoto emissions and forcing, with differences stemming from differences in relationships between Kyoto and non-Kyoto emissions and fundamental differences in modeling structure and assumptions. Air pollution and non-Kyoto forcing decline in the climate policy scenarios. However, non-Kyoto forcing appears to be influencing mitigation results, including allowable carbon dioxide emissions, and further evaluation is merited. Overall, there is substantial uncertainty related to non-Kyoto forcing that must be considered.

  20. Land cover changes and greenhouse gas emissions in two different soil covers in the Brazilian Caatinga.

    PubMed

    Ribeiro, Kelly; Sousa-Neto, Eráclito Rodrigues de; Carvalho, João Andrade de; Sousa Lima, José Romualdo de; Menezes, Rômulo Simões Cezar; Duarte-Neto, Paulo José; da Silva Guerra, Glauce; Ometto, Jean Pierre Henry Baulbaud

    2016-11-15

    The Caatinga biome covers an area of 844,453km(2) and has enormous endemic biodiversity, with unique characteristics that make it an exclusive Brazilian biome. It falls within the earth's tropical zone and is one of the several important ecoregions of Brazil. This biome undergoes natural lengthy periods of drought that cause losses in crop and livestock productivity, having a severe impact on the population. Due to the vulnerability of this ecosystem to climate change, livestock has emerged as the main livelihood of the rural population, being the precursor of the replacement of native vegetation by grazing areas. This study aimed to measure GHG emissions from two different soil covers: native forest (Caatinga) and pasture in the municipality of São João, Pernambuco State, in the years 2013 and 2014. GHG measurements were taken by using static chamber techniques in both soil covers. According to a previous search, so far, this is the first study measuring GHG emissions using the static chamber in the Caatinga biome. N2O emissions ranged from -1.0 to 4.2mgm(-2)d(-1) and -1.22 to 3.4mgm(-2)d(-1) in the pasture and Caatinga, respectively, and they did not significantly differ from each other. Emissions were significantly higher during dry seasons. Carbon dioxide ranged from -1.1 to 14.1 and 1.2 to 15.8gm(-2)d(-1) in the pasture and Caatinga, respectively. CO2 emissions were higher in the Caatinga in 2013, and they were significantly influenced by soil temperature, showing an inverse relation. Methane emission ranged from 6.6 to 6.8 and -6.0 to 4.8mgm(-2)d(-1) in the pasture and Caatinga, respectively, and was significantly higher only in the Caatinga in the rainy season of 2014. Soil gas fluxes seemed to be influenced by climatic and edaphic conditions as well as by soil cover in the Caatinga biome. PMID:27453133

  1. Changes in nitrogen oxides emissions in California during 2005-2010 indicated from top-down and bottom-up emission estimates

    NASA Astrophysics Data System (ADS)

    Huang, Min; Bowman, Kevin W.; Carmichael, Gregory R.; Chai, Tianfeng; Pierce, R. Bradley; Worden, John R.; Luo, Ming; Pollack, Ilana B.; Ryerson, Thomas B.; Nowak, John B.; Neuman, J. Andrew; Roberts, James M.; Atlas, Elliot L.; Blake, Donald R.

    2014-11-01

    In California, emission control strategies have been implemented to reduce air pollutants. Here we estimate the changes in nitrogen oxides (NOx = NO + NO2) emissions in 2005-2010 using a state-of-the-art four-dimensional variational approach. We separately and jointly assimilate surface NO2 concentrations and tropospheric NO2 columns observed by Ozone Monitoring Instrument (OMI) into the regional-scale Sulfur Transport and dEposition Model (STEM) chemical transport model on a 12 × 12 km2 horizontal resolution grid in May 2010. The assimilation generates grid-scale top-down emission estimates, and the updated chemistry fields are evaluated with independent aircraft measurements during the NOAA California Nexus (CalNex) field experiment. The emission estimates constrained only by NO2 columns, only by surface NO2, and by both indicate statewide reductions of 26%, 29%, and 30% from ~0.3 Tg N/yr in the base year of 2005, respectively. The spatial distributions of the emission changes differ in these cases, which can be attributed to many factors including the differences in the observation sampling strategies and their uncertainties, as well as those in the sensitivities of column and surface NO2 with respect to NOx emissions. The updates in California's NOx emissions reduced the mean error in modeled surface ozone in the Western U.S., even though the uncertainties in some urban areas increased due to their NOx-saturated chemical regime. The statewide reductions in NOx emissions indicated from our observationally constrained emission estimates are also reflected in several independently developed inventories: ~30% in the California Air Resources Board bottom-up inventory, ~4% in the 2008 National Emission Inventory, and ~20% in the annual mean top-down estimates by Lamsal et al. using the global Goddard Earth Observing System (GEOS)-Chem model and OMI NO2 columns. Despite the grid-scale differences among all top-down and bottom-up inventories, they all indicate

  2. Inorganic aerosols responses to emission changes in Yangtze River Delta, China

    SciTech Connect

    Dong, Xinyi; Li, Juan; Fu, Joshua S.; Gao, Yang; Huang, Kan; Zhuang, Guoshun

    2014-05-15

    China announced the Chinese National Ambient Air Quality standards (CH-NAAQS) on Feb. 29th, 2012, and PM2.5 is for the very first time included in the standards as a criteria pollutant. In order to probe into PM2.5 pollution over Yangtze River Delta, which is one of the major urban clusters hosting more than 80 million people in China, the integrated MM5/CMAQ modeling system is applied for a full year simulation to examine the PM2.5 concentration and seasonality, and also the inorganic aerosols responses to precursor emission changes. Both simulation and observation demonstrated that, inorganic aerosols have substantial contributions to PM2.5 over YRD, ranging from 37.1% in November to 52.8% in May. Nocturnal production of nitrate (NO3-) through heterogeneous hydrolysis of N2O5 was found significantly contribute to high NO3-concentration throughout the year. We also found that in winter NO3- was even increased under nitrogen oxides (NOx) emission reduction due to higher production of N2O5 from the excessive ozone (O3) introduced by attenuated titration, which further lead to increase of ammonium (NH4+) and sulfate (SO42-), while other seasons showed decrease response of NO3-. Sensitivity responses of NO3- under anthropogenic VOC emission reduction was examined and demonstrated that in urban areas over YRD, NO3- formation was actually VOC sensitive due to the O3-involved nighttime chemistry of N2O5, while a reduction of NOx emission may have counter-intuitive effect by increasing concentrations of inorganic aerosols.

  3. Inorganic aerosols responses to emission changes in Yangtze River Delta, China.

    PubMed

    Dong, Xinyi; Li, Juan; Fu, Joshua S; Gao, Yang; Huang, Kan; Zhuang, Guoshun

    2014-05-15

    The new Chinese National Ambient Air Quality standards (CH-NAAQS) published on Feb. 29th, 2012 listed PM2.5 as criteria pollutant for the very first time. In order to probe into PM2.5 pollution over Yangtze River Delta, the integrated MM5/CMAQ modeling system is applied for a full year simulation to examine the PM2.5 concentration and seasonality, and also the inorganic aerosols responses to precursor emission changes. Total PM2.5 concentration over YRD was found to have strong seasonal variation with higher values in winter months (up to 89.9 μg/m(3) in January) and lower values in summer months (down to 28.8 μg/m(3) in July). Inorganic aerosols were found to have substantial contribution to PM2.5 over YRD, ranging from 37.1% in November to 52.8% in May. Nocturnal production of nitrate (NO3(-)) through heterogeneous hydrolysis of N2O5 was found significantly contribute to high NO3(-) concentration throughout the year. In winter, NO3(-) was found to increase under nitrogen oxides (NOx) emission reduction due to higher production of N2O5 from the excessive ozone (O3) introduced by attenuated titration, which further lead to increase of ammonium (NH4(+)) and sulfate (SO4(2-)), while other seasons showed decrease response of NO3(-). Sensitivity responses of NO3(-) under anthropogenic VOC emission reduction was examined and demonstrated that in urban areas over YRD, NO3(-) formation was actually more sensitive to VOC than NOx due to the O3-involved nighttime chemistry of N2O5, while a reduction of NOx emission may have counter-intuitive effect by increasing concentrations of inorganic aerosols. PMID:24631615

  4. Exploring the response of West Siberian wetland methane emissions to potential future changes in climate, vegetation, and soil microbial metabolism

    NASA Astrophysics Data System (ADS)

    Bohn, Theodore; Kaplan, Jed; Lettenmaier, Dennis

    2015-04-01

    Methane emissions from northern peatlands depend strongly on environmental conditions, wetland plant species assemblages (via root zone oxidation and plant-aided transport), and soil microbial behavior (via metabolic pathways). While the responses of wetland methane emissions to potential future climate change have been extensively explored, the effects of future changes in plant species and soil microbial metabolism are not as well studied. We ran the Variable Infiltration Capacity (VIC) land surface model over the West Siberian Lowland (WSL), with methane emissions parameters that vary spatially with dominant plant species, and forced with outputs from 32 CMIP5 models for the RCP4.5 scenario. We compared the effects of changes in climate and vegetation (in terms of both leaf area index and species abundances) on predicted wetland CH4 emissions for the period 2071-2100, relative to the period 1981-2010. We also explored possible acclimatization of soil microbial communities to these changes. We evaluated the effects of climate change, potential northward migration of plant species, and potential microbial acclimatization on end-of-century methane emissions over the WSL, in terms of both total annual emissions and the spatial distribution of emissions. Our results suggest that, while microbial acclimatization mitigates the effects of warmer temperatures, the northward migration of plant species enhances the response to warming (due to plant-aided transport), and additionally shifts the location of maximal emissions northward, where the possible release of ancient carbon with permafrost thaw is a concern. Our work indicates the importance of better constraining the responses of wetland plants and soil microbial communities to changes in climate as they are critical determinants of the region's future methane emissions.

  5. Urban ecosystem modeling and global change: potential for rational urban management and emissions mitigation.

    PubMed

    Chen, Shaoqing; Chen, Bin; Fath, Brian D

    2014-07-01

    Urbanization is a strong and extensive driver that causes environmental pollution and climate change from local to global scale. Modeling cities as ecosystems has been initiated by a wide range of scientists as a key to addressing challenging problems concomitant with urbanization. In this paper, 'urban ecosystem modeling (UEM)' is defined in an inter-disciplinary context to acquire a broad perception of urban ecological properties and their interactions with global change. Furthermore, state-of-the-art models of urban ecosystems are reviewed, categorized as top-down models (including materials/energy-oriented models and structure-oriented models), bottom-up models (including land use-oriented models and infrastructure-oriented models), or hybrid models thereof. Based on the review of UEM studies, a future framework for explicit UEM is proposed based the integration of UEM approaches of different scales, guiding more rational urban management and efficient emissions mitigation. PMID:24747346

  6. Acoustic emission from single point machining: Source mechanisms and signal changes with tool wear

    SciTech Connect

    Heiple, C.R.; Carpenter, S.H.; Armentrout, D.L.; McManigle, A.P.

    1994-05-01

    Acoustic emission (AE) was monitored during single point, continuous machining of 4340 steel and Ti-6Al-4V as a function of heat treatment. Heat treatments that increase the strength of 4340 steel substantially increase the amount of AE produced during deformation, while heat treatments that increase the strength of Ti-6Al-4V dramatically decrease the amount of AE produced during deformation. There was little change in root-mean-square (rms) AE level during machining for either alloy as a function of prior heat treatment, demonstrating that chip deformation is not a major source of AE in single point machining. Additional data from a variety of materials suggest that sliding friction between the nose and/or flank of the tool and the newly machined surface is the primary source of AE. Changes in AE signal characteristics with tool wear were also monitored during single point machining. No signal characteristic changed in the same way with tool wear for all materials tested. A single change in a particular AE signal characteristic with tool wear valid for all materials probably does not exist. Nevertheless, changes in various signal characteristics with wear for a given material may be sufficient to be used to monitor tool wear.

  7. Fluid Shifts: Otoacoustical Emission Changes in Response to Posture and Lower Body Negative Pressure

    NASA Technical Reports Server (NTRS)

    Melgoza, R.; Kemp, D.; Ebert, D.; Danielson, R.; Stenger, M.; Hargens, A.; Dulchavsky, S.

    2016-01-01

    INTRODUCTION: The purpose of the NASA Fluid Shifts Study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to correlate these findings with vision changes and other elements of the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. Due to the invasive nature of direct measures of ICP, a noninvasive technique of monitoring ICP is desired for use during spaceflight. The phase angle and amplitude of otoacoustic emissions (OAEs) have been shown to be sensitive to posture change and ICP (1, 2), therefore use of OAEs is an attractive option. OAEs are low-level sounds produced by the sensory cells of the cochlea in response to auditory stimulation. These sounds travel peripherally from the cochlea, through the oval window, to the ear canal where they can be recorded. OAE transmission is sensitive to changes in the stiffness of the oval window, occurring as a result of changes in cochlear pressure. Increased stiffness of the oval window largely affects the transmission of sound from the cochlea at frequencies between 800 Hz and 1600 Hz. OAEs can be self-recorded in the laboratory or on the ISS using a handheld device. Our primary objectives regarding OAE measures in this experiment were to 1) validate this method during preflight testing of each crewmember (while sitting, supine and in head-down tilt position), and 2) determine if OAE measures (and presumably ICP) are responsive to lower body negative pressure and to spaceflight. METHODS: Distortion-product otoacoustic emissions (DPOAEs) and transient evoked otoacoustic emissions (TEOAEs) were recorded preflight using the Otoport Advance OAE system (Otodynamics Ltd., Hatfield, UK). Data were collected in four conditions (seated

  8. Dynamic control of light emission faster than the lifetime limit using VO2 phase-change

    PubMed Central

    Cueff, Sébastien; Li, Dongfang; Zhou, You; Wong, Franklin J.; Kurvits, Jonathan A.; Ramanathan, Shriram; Zia, Rashid

    2015-01-01

    Modulation is a cornerstone of optical communication, and as such, governs the overall speed of data transmission. Currently, the two main strategies for modulating light are direct modulation of the excited emitter population (for example, using semiconductor lasers) and external optical modulation (for example, using Mach–Zehnder interferometers or ring resonators). However, recent advances in nanophotonics offer an alternative approach to control spontaneous emission through modifications to the local density of optical states. Here, by leveraging the phase-change of a vanadium dioxide nanolayer, we demonstrate broadband all-optical direct modulation of 1.5 μm emission from trivalent erbium ions more than three orders of magnitude faster than their excited state lifetime. This proof-of-concept demonstration shows how integration with phase-change materials can transform widespread phosphorescent materials into high-speed optical sources that can be integrated in monolithic nanoscale devices for both free-space and on-chip communication. PMID:26489436

  9. Predicting Greenhouse Gas Emissions and Soil Carbon from Changing Pasture to an Energy Crop

    PubMed Central

    Duval, Benjamin D.; Anderson-Teixeira, Kristina J.; Davis, Sarah C.; Keogh, Cindy; Long, Stephen P.; Parton, William J.; DeLucia, Evan H.

    2013-01-01

    Bioenergy related land use change would likely alter biogeochemical cycles and global greenhouse gas budgets. Energy cane (Saccharum officinarum L.) is a sugarcane variety and an emerging biofuel feedstock for cellulosic bio-ethanol production. It has potential for high yields and can be grown on marginal land, which minimizes competition with grain and vegetable production. The DayCent biogeochemical model was parameterized to infer potential yields of energy cane and how changing land from grazed pasture to energy cane would affect greenhouse gas (CO2, CH4 and N2O) fluxes and soil C pools. The model was used to simulate energy cane production on two soil types in central Florida, nutrient poor Spodosols and organic Histosols. Energy cane was productive on both soil types (yielding 46–76 Mg dry mass⋅ha−1). Yields were maintained through three annual cropping cycles on Histosols but declined with each harvest on Spodosols. Overall, converting pasture to energy cane created a sink for GHGs on Spodosols and reduced the size of the GHG source on Histosols. This change was driven on both soil types by eliminating CH4 emissions from cattle and by the large increase in C uptake by greater biomass production in energy cane relative to pasture. However, the change from pasture to energy cane caused Histosols to lose 4493 g CO2 eq⋅m−2 over 15 years of energy cane production. Cultivation of energy cane on former pasture on Spodosol soils in the southeast US has the potential for high biomass yield and the mitigation of GHG emissions. PMID:23991028

  10. Predicting greenhouse gas emissions and soil carbon from changing pasture to an energy crop.

    PubMed

    Duval, Benjamin D; Anderson-Teixeira, Kristina J; Davis, Sarah C; Keogh, Cindy; Long, Stephen P; Parton, William J; DeLucia, Evan H

    2013-01-01

    Bioenergy related land use change would likely alter biogeochemical cycles and global greenhouse gas budgets. Energy cane (Saccharum officinarum L.) is a sugarcane variety and an emerging biofuel feedstock for cellulosic bio-ethanol production. It has potential for high yields and can be grown on marginal land, which minimizes competition with grain and vegetable production. The DayCent biogeochemical model was parameterized to infer potential yields of energy cane and how changing land from grazed pasture to energy cane would affect greenhouse gas (CO2, CH4 and N2O) fluxes and soil C pools. The model was used to simulate energy cane production on two soil types in central Florida, nutrient poor Spodosols and organic Histosols. Energy cane was productive on both soil types (yielding 46-76 Mg dry mass · ha(-1)). Yields were maintained through three annual cropping cycles on Histosols but declined with each harvest on Spodosols. Overall, converting pasture to energy cane created a sink for GHGs on Spodosols and reduced the size of the GHG source on Histosols. This change was driven on both soil types by eliminating CH4 emissions from cattle and by the large increase in C uptake by greater biomass production in energy cane relative to pasture. However, the change from pasture to energy cane caused Histosols to lose 4493 g CO2 eq · m(-2) over 15 years of energy cane production. Cultivation of energy cane on former pasture on Spodosol soils in the southeast US has the potential for high biomass yield and the mitigation of GHG emissions. PMID:23991028

  11. Effects of changing power plant NOx emissions on ozone in the eastern United States: Proof of concept

    NASA Astrophysics Data System (ADS)

    Frost, G. J.; McKeen, S. A.; Trainer, M.; Ryerson, T. B.; Neuman, J. A.; Roberts, J. M.; Swanson, A.; Holloway, J. S.; Sueper, D. T.; Fortin, T.; Parrish, D. D.; Fehsenfeld, F. C.; Flocke, F.; Peckham, S. E.; Grell, G. A.; Kowal, D.; Cartwright, J.; Auerbach, N.; Habermann, T.

    2006-06-01

    Recent decreases in nitrogen oxide (NOx = NO + NO2) emissions from eastern U.S. power plants and their effects on regional ozone are studied. Using the EPA 1999 National Emission Inventory as a reference emission data set, NOx and sulfur dioxide (SO2) emission rates at selected power plants are updated to their summer 2003 levels using Continuous Emission Monitoring System (CEMS) measurements. The validity of the CEMS data is established by comparison to observations made on the NOAA WP-3 aircraft as part of the 2004 New England Air Quality Study. The impacts of power plant NOx emission decreases on O3 are investigated using the WRF-Chem regional chemical forecast model. Summertime NOx emission rates decreased by approximately 50% between 1999 and 2003 at the subset of power plants studied. The impact of NOx emission reductions on ozone was moderate during summer 2004 because of relatively cool temperatures and frequent synoptic disturbances. Effects in individual plant plumes vary depending on the plant's NOx emission strength, the proximity of other NOx sources, and the availability of volatile organic compounds (VOCs) and sunlight. This study provides insight into the ozone changes that can be anticipated as power plant NOx emission reductions continue to be implemented throughout the United States.

  12. Methane emission from Russian frozen wetlands under conditions of climate change

    NASA Astrophysics Data System (ADS)

    Reneva, S.

    2009-04-01

    There is growing evidence that the climate change will have significant impact on permafrost, leading to warming, thawing, and disappearance of the frozen ground. Arctic soils contain 14%-30% of all the carbon stored in soils worldwide, many of which is accumulated in the Arctic wetlands (Anisimov & Reneva 2006). Wetlands occupy almost 2 million km2 in the circumpolar region, contain about 50 Gt C, and because of the high groundwater levels favour the production of methane in the anaerobic carbon-rich soil layer (Anisimov et al 2005). Methane has 21-times stronger greenhouse effect than the equal amount of CO2, and there are growing concerns that enhanced CH4 emission may have significant effect on the global radiative forcing. The goal of our study was to estimate the potential increase in the methane emission from Russian frozen wetlands under the projected for the mid-21st century climatic conditions and to evaluate the effect it may have on global radiative forcing. We used digital geographically referenced contours of Russian wetlands from 1:1,000,000-scale topographic maps to calculate the total area (350 000 km2) and the fraction of land they occupy in the nodes of 0.5 by 0.5 degree lat/long regular grid spanning permafrost regions. These data were overlaid with the results from predictive permafrost model (Anisimov & Belolutskaia 2003, Anisimov et al 1999) forced by CCC, HadCM3, GFDL, NCAR climatic projections for 2050 under B1 emission scenario (ref. http://ipcc-ddc.cru.uea.ac.uk/ and http://igloo.atmos.uiuc.edu/IPCC/). Ultimately, we calculated the increase in the amount of organic material that may potentially become available for decomposition due to deeper seasonal thawing of wetlands in the Russian part of Arctic. Following (Christensen et al 2003a, Christensen et al 2003b) we hypothesised that the temperature and substrate availability combined explain almost entirely the variations in mean annual methane emissions. We used the results of numerous

  13. Seasonal changes in CH4 emissions from an alpine reservoir, Lake Klöntal, Switzerland

    NASA Astrophysics Data System (ADS)

    Sollberger, S.; Eugster, W.; Schubert, C.; Wehrli, B.

    2012-04-01

    average fluxes, but they do record the magnitude of these changes via different methods. We thus conclude that the variability of CH4 fluxes observed throughout the literature and our study is related to both physical triggers and the method used for measurements. Eddy measurements are continuous but limited spatially, whereas chamber measurements directly spatially cover more of the lake surface but at low and intermittent frequency. The discrepancy between surface concentrations used for flux measurements and chamber emissions may also be due to the fact that sampling did not occur simultaneously at the same spot. This study highlights the necessity for future assessments of CH4 emissions from water bodies to use a combination of methods in order to account for the various sources of CH4 emission.

  14. Effect of land-use change and management on biogenic volatile organic compound emissions--selecting climate-smart cultivars.

    PubMed

    Rosenkranz, Maaria; Pugh, Thomas A M; Schnitzler, Jörg-Peter; Arneth, Almut

    2015-09-01

    Land-use change (LUC) has fundamentally altered the form and function of the terrestrial biosphere. Increasing human population, the drive for higher living standards and the potential challenges of mitigating and adapting to global environmental change mean that further changes in LUC are unavoidable. LUC has direct consequences on climate not only via emissions of greenhouse gases and changing the surface energy balance but also by affecting the emission of biogenic volatile organic compounds (BVOCs). Isoprenoids, which dominate global BVOC emissions, are highly reactive and strongly modify atmospheric composition. The effects of LUC on BVOC emissions and related atmospheric chemistry have been largely ignored so far. However, compared with natural ecosystems, most tree species used in bioenergy plantations are strong BVOC emitters, whereas intensively cultivated crops typically emit less BVOCs. Here, we summarize the current knowledge on LUC-driven BVOC emissions and how these might affect atmospheric composition and climate. We further discuss land management and plant-breeding strategies, which could be taken to move towards climate-friendly BVOC emissions while simultaneously maintaining or improving key ecosystem functions such as crop yield under a changing environment. PMID:25255900

  15. Land use change and biogeochemical controls of nitrogen oxide emissions from soils in eastern Amazonia

    NASA Astrophysics Data System (ADS)

    Verchot, Louis V.; Davidson, Eric A.; Catta‸nio, J. Henrique; Ackerman, Ilse L.; Erickson, Heather E.; Keller, Michael

    1999-03-01

    The objectives of this study were (1) to determine the effects of land use change on N oxide fluxes from soil in seasonally dry, eastern Amazonia and (2) evaluate the "hole-in-the-pipe" model in a field setting where N availability varies among land uses and soil moisture varies among seasons. We measured N oxide flux from an old-growth forest, a 20-year-old secondary forest, an active pasture, and a degraded pasture. We also measured soil water content, soil inorganic N stocks, net N mineralization and nitrification potential. To determine the effects of pasture age on N oxide flux, we measured gas fluxes at a chronosequence of pastures (0-13 years). In the land use study, N2O fluxes followed the order: primary forest (2.4 kg N ha-1 yr-1) > secondary forest (0.9 kg N ha-1 yr-1) > active pasture (0.3 kg N ha-1 yr-1) ≥ degraded pasture (0.1 kg N ha-1 yr-1), and NO fluxes followed the order: primary forest (1.5 kg N ha y-11) > degraded pasture (0.7 kg N ha-1 yr-1) > active pasture (0.5 kg N ha-1 yr-1) ≥ secondary forest (0.3 kg N ha-1 yr-1). In the chronosequence study, no trend in N oxide emissions with pasture age was apparent, but emissions from pastures were lower than from the forest.Total N oxide flux correlated with a laboratory measure of nitrification potential (r2 = 0.85).The ratio N2O:NO correlated with soil water content (r2 = 0.56). Parameterization of the model accounted for variability in N oxide emissions across land uses and seasons and the model application revealed the importance of studying both N oxide gases simultaneously. Model predictions for six independent sites agreed well with observed fluxes, suggesting that the model may be applicable at a broader scale. The consistently low annual emissions of N2O estimated for all of the Amazonian pastures that we studied suggest that conversions of tropical forests to cattle pastures may not in the long term cause a significant increase in the contribution of soil emissions to atmospheric N2O or

  16. The Impacts of Changes in Snowfall on Soil Greenhouse Gas Emissions Using an Automated Chamber System

    NASA Astrophysics Data System (ADS)

    Ruan, L.; Kahmark, K.; Robertson, G.

    2012-12-01

    Snow cover has decreased in many regions of the northern hemisphere and is projected to decrease further in most. The reduced snow cover may enhance soil freezing and increase the depth of frost. The frequency of freeze-thaw cycles is likely to increase due to the reduction of snowpack thickness. Freeze and thaw cycles can strongly affect soil C and N dynamics. The pulses of N2O and CO2 emissions from soil after thawing have been reported in various studies. However, most studies were based on the controlled laboratory conditions or low resolution static chamber methods in situ. Near-continuous automated chambers provide the temporal resolution needed for capturing short-lived pulses of greenhouse gases after intermittent melting events. We investigated the winter and spring response of soil greenhouse gas emissions (CO2, CH4 and N2O) to changes of snow depth using an automated chamber system. This study was established in 2010 at the Kellogg Biological Station (KBS) in southwest Michigan. The plot was no till rotational (corn-soybean-wheat) cropland, most recently in corn. The experiment was a completely randomized design (CRD) with three levels of snow depth: ambient, double, and no snow. Each level had four replicates. Twelve automated chambers were randomly assigned to treatments and greenhouse gas fluxes measured 4 times per day in each plot. There were more freeze-thaw cycles in the no snow treatment than in the ambient and double snow treatments. Soil temperature at 5 cm depth was more variable in the no snow treatment than in the ambient and double snow treatments. CH4 fluxes were uniformly low with no significant difference across three treatments. CO2 showed expected seasonal changes with the highest emission in spring and lowest emissions through the winter. N2O peaks were higher in spring due to freeze thaw effects and cumulative N2O fluxes were substantially higher in the no snow treatment than in the ambient and double snow treatments.

  17. Emissions of greenhouse gases from agriculture, land-use change, and forestry in the Gambia.

    PubMed

    Jallow, B P

    1995-01-01

    The Gambia has successfully completed a national greenhouse gas emissions inventory based on the results of a study funded by the United Nations Environment Programme (UNEP)/Global Environment Facility (GEF) Country Case Study Program. The concepts of multisectoral, multidisciplinary, and interdisciplinary collaboration were most useful in the preparation of this inventory. New data were gathered during the study period, some through regional collaboration with institutions such as Environment and Development in the Third World (ENDA-TM) Energy Program and the Ecological Monitoring Center in Dakar, Senegal, and some through national surveys and the use of remote sensing techniques, as in the Bushfires Survey. Most of the data collected are used in this paper. The Intergovernmental Panel on Climate Change/Organisation for Economic Co-operation and Development/International Energy Agency (IPCC/OECD/IEA) methodology is used to calculate greenhouse gas emissions. Many of the default data in the IPCC/OECD/IEA methodology have also been used. Overall results indicate that in the biomass sectors (agriculture, forestry, and land-use change) carbon dioxide (CO2) is emitted most, with a total of 1.7 Tg. This is followed by methane (CH4), 22.3 Gg; carbon monoxide (CO), 18.7 Gg; nitrogen oxides (NOx), 0.3 Gg; and nitrous oxide (N2O), 0.014 Gg. The Global Warming Potential (GWP) was used as an index to describe the relative effects of the various gases reported here. Based on the emissions in The Gambia in 1993, it was found that CO2 will contribute 75%, CH4 about 24.5%, and N2O 0.2% of the warming expected in the 100-year period beginning in 1993. The results in this analysis are limited by the shortcomings of the IPCC/OECD/IEA methodology and scarce national data. Because the methodology was developed outside of the developing world, most of its emissions factors and coefficients were developed and tested in environments that are very different from The Gambia. This is likely

  18. Estimating Indirect Emissions from Land Use Change Due to Biofuels (Invited)

    NASA Astrophysics Data System (ADS)

    Reilly, J. M.

    2010-12-01

    Interest in biofuels as an alternative fuel has led to the realization that they may not be a viable low greenhouse gas alternative, even if process emissions are low, because expansions of land area in biomass crops may lead to forest destruction and hence carbon emissions.(1,2)If the concern was only direct land use effects—changes in carbon stocks on land directly used for biomass—direct measurement would be an option. However, agricultural economists recognize that if biofuels are produced from crops grown on existing cropland the crops previously grown there will likely be replaced by production elsewhere. Given international markets in agricultural products a diversion of land or part of the corn crop in the US for biofuels would result in higher market prices for corn and other crops, and thus spur land conversion almost anywhere around the world. There have now been a number of estimates of the potential land use emissions, and those estimates vary widely and are sensitive to key parameters of both the economic models used in the analysis and the representation of biophysical processes.(3,4,5)Among the important parameters are those that describe the willingness to convert unmanaged land, the ability to intensify production on existing land, the productivity of new land coming to production compared to existing cropland, demand elasticities for agricultural products, and the representation of carbon and nitrogen cycles and storage.(6,7) 1. J. Fargione, J. et al., Science 319, 1235 (2008). 2. T. Searchinger, T et al., Science 319, 1238 (2008) 3. J.M. Melillo, Science, 326: 1397-1399 (2009) 4. M. Wise et al., Science 324, 1183 (2009). 5. W. E. Tyner, et al., Land Use Changes and Consequent CO2 Emissions due to US Corn Ethanol Production: A Comprehensive Analysis, Department of Agricultural Economics, Purdue University (July 2010). 6. T. W. Hertel, The Global Supply and Demand for Agricultural Land in 2050: A Perfect Storm in the Making? AAEA Presidential

  19. Effects of future climate and land cover changes on biogenic emissions and air quality in the US

    NASA Astrophysics Data System (ADS)

    Chung, S. H.; Gonzalez Abraham, R.; Arroyo, A.; Lamb, B. K.; Duhl, T.; Wiedinmyer, C.; Guenther, A. B.; Zhang, Y.; Salathe, E. P.

    2009-12-01

    Biogenic volatile organic compounds (BVOCs) emitted from vegetations are highly reactive in the atmosphere and contribute to ozone and secondary organic aerosol formation. Climate change influences vegetation distributions and emissions of BVOCs and thereby affects air quality. As part of a comprehensive investigation of the effects of global change on regional air quality in the US, this study examines the effects of future climate and land cover changes on emissions of BVOCs into the atmosphere and air quality in the US. The mesoscale WRF (Weather Research and Forecasting) model is applied at hemispheric (220 km grid cells) and continental US (36 km grid cells) scales for current (1995-2004) and future (2045-2054) decades to downscale climate results from the ECHAM5 global climate model for IPCC SRES scenario A1B. The MEGAN (Model of Emissions of Gases and Aerosols from Nature) model is driven by WRF meteorological results to predict biogenic emissions of VOCs and NOx. MEGAN accounts for vegetation species distributions and environmental factors such as temperature and light. Current decade vegetation distributions are derived from satellite observations. Future vegetation distributions are predicted from MAPSS (Mapped Atmosphere-Plant-Soil System) and the land cover model of IMAGE 2.0 (Integrated Model to Assess the Global Environment). Future land cover changes include the expansion of croplands so that land management changes can also be examined. The CMAQ (Community Multiscale Air Quality Modeling) chemical transport model is used to simulate O3 and aerosol concentrations using current- and future-decade biogenic emissions but with anthropogenic emissions held constant at current-decade levels. Results showing the changes in US air quality due to climate- and landuse-driven changes in biogenic emissions will be presented. These results are compared to previous simulations derived from the IPCC SRES scenario A1 scenario with the PCM (Parallel Climate Model

  20. Land use change emission scenarios: anticipating a forest transition process in the Brazilian Amazon.

    PubMed

    Aguiar, Ana Paula Dutra; Vieira, Ima Célia Guimarães; Assis, Talita Oliveira; Dalla-Nora, Eloi L; Toledo, Peter Mann; Santos-Junior, Roberto Araújo Oliveira; Batistella, Mateus; Coelho, Andrea Santos; Savaget, Elza Kawakami; Aragão, Luiz Eduardo Oliveira Cruz; Nobre, Carlos Afonso; Ometto, Jean Pierre H

    2016-05-01

    Following an intense occupation process that was initiated in the 1960s, deforestation rates in the Brazilian Amazon have decreased significantly since 2004, stabilizing around 6000 km(2) yr(-1) in the last 5 years. A convergence of conditions contributed to this, including the creation of protected areas, the use of effective monitoring systems, and credit restriction mechanisms. Nevertheless, other threats remain, including the rapidly expanding global markets for agricultural commodities, large-scale transportation and energy infrastructure projects, and weak institutions. We propose three updated qualitative and quantitative land-use scenarios for the Brazilian Amazon, including a normative 'Sustainability' scenario in which we envision major socio-economic, institutional, and environmental achievements in the region. We developed an innovative spatially explicit modelling approach capable of representing alternative pathways of the clear-cut deforestation, secondary vegetation dynamics, and the old-growth forest degradation. We use the computational models to estimate net deforestation-driven carbon emissions for the different scenarios. The region would become a sink of carbon after 2020 in a scenario of residual deforestation (~1000 km(2) yr(-1)) and a change in the current dynamics of the secondary vegetation - in a forest transition scenario. However, our results also show that the continuation of the current situation of relatively low deforestation rates and short life cycle of the secondary vegetation would maintain the region as a source of CO2 - even if a large portion of the deforested area is covered by secondary vegetation. In relation to the old-growth forest degradation process, we estimated average gross emission corresponding to 47% of the clear-cut deforestation from 2007 to 2013 (using the DEGRAD system data), although the aggregate effects of the postdisturbance regeneration can partially offset these emissions. Both processes (secondary

  1. Quantifying Climate Feedbacks from Abrupt Changes in High-Latitude Trace-Gas Emissions

    SciTech Connect

    Zhuang, Qianlai

    2012-11-16

    During the three-year project period, Purdue University has specifically accomplished the following: revised the existing Methane Dynamics Model (MDM) to consider the effects of changes of atmospheric pressure; applied the methane dynamics model (MDM) to Siberian region to demonstrate that ebullition estimates could increase previous estimates of regional terrestrial CH{sub 4} emissions 3- to 7-fold in Siberia; Conducted an analysis of the carbon balance of the Arctic Basin from 1997 to 2006 to show that terrestrial areas of the Arctic were a net source of 41.5 Tg CH{sub 4} yr{sup 1} that increased by 0.6 Tg CH{sub 4} yr{sup 1} during the decade of analysis, a magnitude that is comparable with an atmospheric inversion of CH{sub 4}; improved the quantification of CH{sub 4} fluxes in the Arctic with inversion methods; evaluated AIRS CH4 retrieval data with a transport and inversion model and surface flux and aircraft data; to better quantify methane emissions from wetlands, we extended the MDM within a biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to include a large-scale hydrology model, the variable infiltration capacity (VIC) model; more recently, we developed a single box atmospheric chemistry model involving atmospheric methane (CH{sub 4}), carbon monoxide (CO) and radical hydroxyl (OH) to analyze atmospheric CH{sub 4} concentrations from 1984 to 2008.

  2. EPA'S GLOBAL CLIMATE CHANGE PROGRAM--PROGRAM PLAN FOR METHANE EMISSIONS FROM LANDFILLS AND OTHER WASTE DISPOSAL FACILITIES

    EPA Science Inventory

    The paper discusses a portion of EPA's global climate change program, a program plan for methane emissions from landfills and other waste disposal facilities. In response to concerns about global climate change, the U. S. EPA's Office of Research and Development (ORD) has initiat...

  3. Climate Change Impacts on Agriculture and Food Security in 2050 under a Range of Plausible Socioeconomic and Emissions Scenarios

    NASA Astrophysics Data System (ADS)

    Wiebe, K.; Lotze-Campen, H.; Bodirsky, B.; Kavallari, A.; Mason-d'Croz, D.; van der Mensbrugghe, D.; Robinson, S.; Sands, R.; Tabeau, A.; Willenbockel, D.; Islam, S.; van Meijl, H.; Mueller, C.; Robertson, R.

    2014-12-01

    Previous studies have combined climate, crop and economic models to examine the impact of climate change on agricultural production and food security, but results have varied widely due to differences in models, scenarios and data. Recent work has examined (and narrowed) these differences through systematic model intercomparison using a high-emissions pathway to highlight the differences. New work extends that analysis to cover a range of plausible socioeconomic scenarios and emission pathways. Results from three general circulation models are combined with one crop model and five global economic models to examine the global and regional impacts of climate change on yields, area, production, prices and trade for coarse grains, rice, wheat, oilseeds and sugar to 2050. Results show that yield impacts vary with changes in population, income and technology as well as emissions, but are reduced in all cases by endogenous changes in prices and other variables.

  4. Planting Jatropha curcas on Constrained Land: Emission and Effects from Land Use Change

    PubMed Central

    Firdaus, M. S.; Husni, M. H. A.

    2012-01-01

    A study was carried out to assess carbon emission and carbon loss caused from land use change (LUC) of converting a wasteland into a Jatropha curcas plantation. The study was conducted for 12 months at a newly established Jatropha curcas plantation in Port Dickson, Malaysia. Assessments of soil carbon dioxide (CO2) flux, changes of soil total carbon and plant biomass loss and growth were made on the wasteland and on the established plantation to determine the effects of land preparation (i.e., tilling) and removal of the wasteland's native vegetation. Overall soil CO2 flux showed no significant difference (P < 0.05) between the two plots while no significant changes (P < 0.05) on soil total carbon at both plots were detected. It took 1.5 years for the growth of Jatropha curcas to recover the biomass carbon stock lost during land conversion. As far as the present study is concerned, converting wasteland to Jatropha curcas showed no adverse effects on the loss of carbon from soil and biomass and did not exacerbate soil respiration. PMID:22545018

  5. Changes in O3 and NO2 due to emissions from Fracking in the UK.

    NASA Astrophysics Data System (ADS)

    Archibald, Alexander; Ordonez, Carlos

    2016-04-01

    Poor air quality is a problem that affects millions of people around the world. Understanding the driving forces behind air pollution is complicated as the precursor gases which combine to produce air pollutants react in a highly non-linear manner and are subject to a range of atmospheric transport mechanisms compounded by the weather. A great deal of money has been spent on mitigating air pollution and so it's important to assess the impacts that new technologies that emit air pollutant precursors may have on local and regional air pollution. One of the most highly discussed new technologies that could impact air quality is the adoption of wide-scale hydraulic fracturing or "fracking" for natural gas. Indeed in regions of the USA where fracking is commonplace large levels of ozone (O3 - a key air pollutant) have been observed and attributed directly to the fracking process. In this study, a numerical modelling framework was used to assess possible impacts of fracking in the UK where at present no large scale fracking facilities are in operation. A number of emissions scenarios were developed for the principle gas phase air pollution precursors: the oxides of nitrogen (NOx) and volatile organic compounds (VOCs). These emissions scenarios were then used in a state-of-the-art numerical air quality model (the UK Met Office operational air quality forecasting model AQUM) to determine potential impacts related to fracking on UK air quality. Comparison of base model results and observations for the year 2013 of NOx, O3 and VOCs from the UK Automatic Urban and Rural Network (AURN) showed that AQUM has good skill at simulating these gas phase air pollutants (O3 r=0.64, NMGE=0.3; NO2 r=0.62, NMGE=0.51). Analysis of the simulations with fracking emissions demonstrate that there are large changes in 1hr max NO2 (11.6±6.6 ppb) with modest increases in monthly mean NO2, throughout the British Isles (150±100 ppt). These results highlight that stringent measures should be

  6. Carbon Dioxide Emissions and Change in Prevalence of Obesity and Diabetes in the United States: An Ecological Study

    PubMed Central

    Zheutlin, Alexander R.; Adar, Sara D.; Park, Sung Kyun

    2014-01-01

    Recent studies suggest that increasing levels of the greenhouse gas, carbon dioxide (CO2), may influence weight gain and thus may play a role in rising trends in obesity and diabetes. We conducted an ecological study to examine the associations between CO2 emissions from fossil fuel combustion and changes in the prevalence of obesity and diabetes in the United States. County-level data on CO2 emissions, prevalence of obesity and diagnosed diabetes, other sociodemographic factors and neighborhood characteristics related to urbanicity, and fine particles (PM2.5) between 2004 and 2008 were obtained from the Vulcan Project, Centers for Disease Control and Prevention, and American Community Survey. Linear mixed effect modeling of 3019 counties for the associations between average CO2 emissions and changes in diabetes and obesity prevalence between 2004 and 2008 was performed. The average obesity and diabetes prevalence increased between 2004 and 2008 by 3.65% (SD: 1.88%) and 1.65% (SD: 1.70%), respectively. A marginally significant positive association between CO2 emission and changes in obesity prevalence was found with adjustment for sociodemographic factors, indicators of urbanicity and spatial autocorrelation (p-trend=0.06). The association became weaker and nonsignificant with further adjustment for PM2.5 (p-trend=0.17). There was a significant positive association between CO2 emission and changes in diabetes prevalence before controlling for PM2.5 (p-trend=0.05) but the association became null after controlling for PM2.5 (p-trend=0.49), suggesting PM2.5 is a critical confounder in the association between CO2 emission and changes in diabetes prevalence. This study does not support the hypothesis that CO2 emissions, a leading driver of climate change, may be linked to increasing trends in obesity and diabetes, though there was an indication of possible link between CO2 and obesity. PMID:25108606

  7. Global change and the mulga woodlands of southwest Queensland: greenhouse gas emissions, impacts, and adaptation.

    PubMed

    Howden, S M; Moore, J L; McKeon, G M; Carter, J O

    2001-09-01

    The possibility of trading greenhouse gas emission permits as a result of the Kyoto Protocol has spurred interest in developing land-based sinks for greenhouse gases. Extensive grazing lands that have the potential to develop substantial woody biomass are one obvious candidate for such activities. However, such activities need to consider the possible impacts on existing grazing and the possible impacts of continuing CO2 buildup in the atmosphere and resultant climate change. We used simulation models to investigate these issues in the mulga (Acacia aneura) woodlands of southwest Queensland. The simulation results suggest that this system can be managed to act as either a net source or a net sink of greenhouse gases under current climate and CO2 and under a range of global change scenarios. The key component in determining source or sink status is the management of the woody mulga. The most effective means of permanently increasing carbon stores and hence reducing net emissions is to exclude both burning and grazing. There are combinations of management regimes, such as excluding fire with light grazing, which, on average, allows productive grazing but transient carbon storage. The effects of increased CO2 on ecosystem carbon stores were unexpected. Carbon stores increased (7-17%) with doubling of CO2 only in those simulations where burning did not occur, but decreased when burnt. This occurred because the substantial increases in grass growth with doubling of CO2 (34-56%) enabled more fires, killing off the establishing cohorts needed to ensure continued carbon accumulation. On average, the doubling of atmospheric CO2 concentration increased grass growth by 44%, which is identical with mean literature values, suggesting that this result may be applicable in other ecosystems where fire has a similar function. A sensitivity analysis of the CO2 response of mulga showed only minor impacts. We discuss additional uncertainties and shortcomings. PMID:11697664

  8. Attribution of changes in global wetland methane emissions from pre-industrial to present using CLM4.5-BGC

    NASA Astrophysics Data System (ADS)

    Paudel, Rajendra; Mahowald, Natalie M.; Hess, Peter G. M.; Meng, Lei; Riley, William J.

    2016-03-01

    An understanding of potential factors controlling methane emissions from natural wetlands is important to accurately project future atmospheric methane concentrations. Here, we examine the relative contributions of climatic and environmental factors, such as precipitation, temperature, atmospheric CO2 concentration, nitrogen deposition, wetland inundation extent, and land-use and land-cover change, on changes in wetland methane emissions from preindustrial to present day (i.e., 1850-2005). We apply a mechanistic methane biogeochemical model integrated in the Community Land Model version 4.5 (CLM4.5), the land component of the Community Earth System Model. The methane model explicitly simulates methane production, oxidation, ebullition, transport through aerenchyma of plants, and aqueous and gaseous diffusion. We conduct a suite of model simulations from 1850 to 2005, with all changes in environmental factors included, and sensitivity studies isolating each factor. Globally, we estimate that preindustrial methane emissions were higher by 10% than present-day emissions from natural wetlands, with emissions changes from preindustrial to the present of +15%, -41%, and -11% for the high latitudes, temperate regions, and tropics, respectively. The most important change is due to the estimated change in wetland extent, due to the conversion of wetland areas to drylands by humans. This effect alone leads to higher preindustrial global methane fluxes by 33% relative to the present, with the largest change in temperate regions (+80%). These increases were partially offset by lower preindustrial emissions due to lower CO2 levels (10%), shifts in precipitation (7%), lower nitrogen deposition (3%), and changes in land-use and land-cover (2%). Cooler temperatures in the preindustrial regions resulted in our simulations in an increase in global methane emissions of 6% relative to present day. Much of the sensitivity to these perturbations is mediated in the model by changes in

  9. Estimating soil carbon change and biofuel life-cycle greenhouse gas emissions with economic, ecosystem and life-cycle models

    NASA Astrophysics Data System (ADS)

    Qin, Z.; Dunn, J.; Kwon, H. Y.; Mueller, S.; Wander, M.

    2015-12-01

    Land-use change (LUC) resulting from biofuel feedstock production can alter soil organic carbon (SOC) stocks of lands producing those crops and the crops they displace, possibly resulting in greenhouse gas (GHG) emissions. LUC GHG emissions included in biofuel life cycle analysis (LCA) have at times been estimated to be so great that biofuels did not offer a greenhouse gas reduction compared to conventional fossil fuels. To improve the accuracy of emissions estimates, SOC changes must be considered at a finer spatial resolution and take into account climate, soil, land use and management factors. This study reports on the incorporation of global LUC as predicted by a computable general equilibrium model (i.e., GTAP) and spatially-explicit modeled SOC estimates (using surrogate CENTURY) for various biofuel feedstock scenarios into a widely-used LCA model (i.e., GREET). Resulting estimates suggest: SOC changes associated with domestic corn production might contribute 2-6% or offset as much as 5% of total corn ethanol life-cycle GHG emissions. On the other hand, domestic LUC GHG emissions for switchgrass ethanol have the potential offset up to 60% of GHG emissions in the fuel's life cycle. Further, large SOC sequestration is predicted for Miscanthus feedstock production, enabling Miscanthus-based ethanol systems to offset all life-cycle GHG emissions and create a net carbon sink. LUC GHG emissions for ethanol derived from corn stover are small compared to other sources. Total life-cycle GHG emissions (g CO2eq MJ-1, 100cm soil) were estimated to be 59-66 for corn ethanol, 14 for stover ethanol, 18-26 for switchgrass ethanol, and -7 - -0.6 for Miscanthus ethanol.

  10. Changes in Ice Cloud and Gas Emission at Titan's South Pole as Winter Nears

    NASA Astrophysics Data System (ADS)

    Jennings, D. E.; Achterberg, R. K.; Anderson, C. M.; Samuelson, R. E.; Bjoraker, G. L.; Nixon, C. A.; Flasar, F. M.; de Kok, R.; Teanby, N. A.; Coustenis, A.; Vinatier, S.; Bampasidis, G.

    2014-04-01

    As winter approaches in Titan's south, dramatic changes in atmospheric infrared emissions are taking place near the pole. An ice cloud seen only in the north by Voyager and Cassini [1-4] became visible near the South Pole in July 2012 [5]. In the north, emission from the ice cloud located at 220 cm-1 in far-infrared spectra from Cassini's Composite Infrared Spectrometer (CIRS) [6] has been gradually decreasing since the beginning of the mission [4]. In the northern winter shadow when the stratospheric temperature minimum was deepest the ice cloud resided at 100-150 km altitude. The onset of the ice cloud in the south was quite sudden and concurrent with the formation of a polar cloud at higher altitude (360 km) seen by the Imaging Science System (ISS) on Cassini [7]. After 2012 the southern ice cloud grew rapidly and at present has reached an emission intensity rivaling that seen in the winter north at the beginning of the Cassini mission. In mid-2013 the South Pole emission began to exhibit a distinct collar morphology. By early December 2013 the radius of this emission ring was about 10 degrees in latitude.The radius had expanded by 6 degrees between July and December 2013. The ring's center was shifted from the pole toward the Sun by 4 degrees. Minor stratospheric gases had a similar collar structure near the South Pole and also a central peak, again shifted 4 degrees from the pole. At high southern latitudes the temperatures at 1 mbar drop steeply and reach a minimum at 80-90 S. The collar structure we see in the ice cloud and gases might be produced by material concentrated near the pole in combination with a steep drop in temperature toward the pole. The recent amassing of gases and condensables at the South Pole is probably the result of the seasonal reversal of atmospheric circulation. We find that the temperature field in the south as winter nears is also shifted from the pole toward the Sun by 4 degrees. The 4-degree shift of the ice cloud and gas collars

  11. Estimating changes in urban ozone concentrations due to life cycle emissions from hydrogen transportation systems

    NASA Astrophysics Data System (ADS)

    Wang, Guihua; Ogden, Joan M.; Chang, Daniel P. Y.

    Hydrogen has been proposed as a low polluting alternative transportation fuel that could help improve urban air quality. This paper examines the potential impact of introducing a hydrogen-based transportation system on urban ambient ozone concentrations. This paper considers two scenarios, where significant numbers of new hydrogen vehicles are added to a constant number of gasoline vehicles. In our scenarios hydrogen fuel cell vehicles (HFCVs) are introduced in Sacramento, California at market penetrations of 9% and 20%. From a life cycle analysis (LCA) perspective, considering all the emissions involved in producing, transporting, and using hydrogen, this research compares three hypothetical natural gas to hydrogen pathways: (1) on-site hydrogen production; (2) central hydrogen production with pipeline delivery; and (3) central hydrogen production with liquid hydrogen truck delivery. Using a regression model, this research shows that the daily maximum temperature correlates well with atmospheric ozone formation. However, increases in initial VOC and NO x concentrations do not necessarily increase the peak ozone concentration, and may even cause it to decrease. It is found that ozone formation is generally limited by NO x in the summer and is mostly limited by VOC in the fall in Sacramento. Of the three hydrogen pathways, the truck delivery pathway contributes the most to ozone precursor emissions. Ozone precursor emissions from the truck pathway at 9% market penetration can cause additional 3-h average VOC (or NO x) concentrations up to approximately 0.05% (or 1%) of current pollution levels, and at 20% market penetration up to approximately 0.1% (or 2%) of current pollution levels. However, all of the hydrogen pathways would result in very small (either negative or positive) changes in ozone air quality. In some cases they will result in worse ozone air quality (mostly in July, August, and September), and in some cases they will result in better ozone air quality

  12. Natural variability versus human impact: Hydroclimate variability and the role of agriculture in changing dust emissions from Australia.

    NASA Astrophysics Data System (ADS)

    Marx, Samuel; Kamber, Balz; McGowan, Hamish; Hooper, James; Zawadzki, Atun

    2016-04-01

    Broad-scale dust emissions play an important role in Earth systems, for example influencing oceanic productivity via phytoplankton fertilisation. Existing palaeo dust records show that dust emissions vary significantly in time, implying its impact is similarly variable. There remains, however, a paucity of records which quantify variability in dust emissions. This study presents continuous, Holocene-aged, records of dust emissions from Australia, an important global dust source. Records demonstrate that rates of dust export have varied by 8-30 times over the mid to late Holocene. This variability is largely attributed to hydroclimate variability and its associated feedbacks within dust source areas. Significantly, however, a major disruption of dust emission rates is recorded in the past 200 years when dust emissions increased by between 2-10 times rates of natural variability in dust export. This change is concomitant with the arrival of Europeans in Australia and is primarily attributed to the development of agriculture which resulted in unprecedented environmental change in Australia's arid interior. This result broadly accords with the few other existing empirical dust records which both pre-date and post-date the onset of agriculture in various arid and semi-arid regions. Collectively, these records imply the impact of dust in Earth systems has changed as a result of agricultural development.

  13. Changes of Land Cover and Land Use and Greenhouse Gas Emissions in Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Zhuang, Q.; Melillo, J.; Reilly, J.; McGuire, A.; Prinn, R.; Shvidenko, A.; Tchebakova, N.; Sirin, A.; Maksyutov, S.; Peregon, A.

    2009-04-01

    Northern Eurasia accounts for about 20% of the Earth's land surface and 60% of the terrestrial land cover north of 40°N. It contains 70% of the Earth's boreal forests and more than two-thirds of the Earth's land that is underlain by permafrost. The region is covered by vast areas of peatland, complex tundra in the north and semi-deserts and deserts in the south, including the Mongolia plateau. The surface air temperature has increased in the last half century and this increase will continue during this century. We present the results of climate change effects on biogeochemical processes and mechanisms governing the carbon and water dynamics in the region. Future research will address on how patterns of land use in Northern Eurasia may change in the future due to: 1) Economic pressures for providing food, fiber and fuel to a growing global population; 2) Expansion of management of land for cropping, pasture, and forestry into areas that experience a more favorable climate in the future; and 3) Abandonment of management in areas that experience a less favorable climate and the implications of these changes for (1) the exchange of CO2 and CH4 between terrestrial ecosystems and the atmosphere; (2) terrestrial carbon storage and primary productivity; (3) water supply; and (4) radiative forcing of the atmosphere through changes in surface albedo. We use a system of linked models that include the MIT Emissions Prediction and Policy Analysis (EPPA) model of the world economy, the SiBCliM bioclimatic vegetation model, and the Terrestrial Ecosystem Model (TEM) with land-cover/ land-use modeling and biogeochemical modeling based on current relationships as observed through satellite and remote sensing data.

  14. Projected changes of rainfall seasonality and dry spells in a high greenhouse gas emissions scenario

    NASA Astrophysics Data System (ADS)

    Pascale, Salvatore; Lucarini, Valerio; Feng, Xue; Porporato, Amilcare; ul Hasson, Shabeh

    2016-02-01

    In this diagnostic study we analyze changes of rainfall seasonality and dry spells by the end of the twenty-first century under the most extreme IPCC5 emission scenario (RCP8.5) as projected by twenty-four coupled climate models contributing to Coupled Model Intercomparison Project 5 (CMIP5). We use estimates of the centroid of the monthly rainfall distribution as an index of the rainfall timing and a threshold-independent, information theory-based quantity such as relative entropy (RE) to quantify the concentration of annual rainfall and the number of dry months and to build a monsoon dimensionless seasonality index (DSI). The RE is projected to increase, with high inter-model agreement over Mediterranean-type regions—southern Europe, northern Africa and southern Australia—and areas of South and Central America, implying an increase in the number of dry days up to 1 month by the end of the twenty-first century. Positive RE changes are also projected over the monsoon regions of southern Africa and North America, South America. These trends are consistent with a shortening of the wet season associated with a more prolonged pre-monsoonal dry period. The extent of the global monsoon region, characterized by large DSI, is projected to remain substantially unaltered. Centroid analysis shows that most of CMIP5 projections suggest that the monsoonal annual rainfall distribution is expected to change from early to late in the course of the hydrological year by the end of the twenty-first century and particularly after year 2050. This trend is particularly evident over northern Africa, southern Africa and western Mexico, where more than 90 % of the models project a delay of the rainfall centroid from a few days up to 2 weeks. Over the remaining monsoonal regions, there is little inter-model agreement in terms of centroid changes.

  15. Historical Pattern and Future Trajectories of Terrestrial N2O Emission driven by Multi-factor Global Changes

    NASA Astrophysics Data System (ADS)

    Lu, C.; Tian, H.; Yang, J.; Zhang, B.; Xu, R.

    2015-12-01

    Nitrous oxide (N2O) is among the most important greenhouse gases only next to carbon dioxide (CO2) and methane (CH4) due to its long life time and high radiative forcing (with a global warming potential 265 times as much as CO2 at 100-year time horizon). The Atmospheric concentration of N2O has increased by 20% since pre-industrial era, and this increase plays a significant role in shaping anthropogenic climate change. However, compared to CO2- and CH4-related research, fewer studies have been performed in assessing and predicting the spatiotemporal patterns of N2O emission from natural and agricultural soils. Here we used a coupled biogeochemical model, DLEM, to quantify the historical and future changes in global terrestrial N2O emissions resulting from natural and anthropogenic perturbations including climate variability, atmospheric CO2 concentration, nitrogen deposition, land use and land cover changes, and agricultural land management practices (i.e., synthetic nitrogen fertilizer use, manure application, and irrigation etc.) over the period 1900-2099. We focused on inter-annual variation and long-term trend of terrestrial N2O emission driven by individual and combined environmental changes during historical and future periods. The sensitivity of N2O emission to climate, atmospheric composition, and human activities has been examined at biome-, latitudinal, continental and global scales. Future projections were conducted to identify the hot spots and hot time periods of global N2O emission under two emission scenarios (RCP2.6 and RCP8.5). It provides a modeling perspective for understanding human-induced N2O emission growth and developing potential management strategies to mitigate further atmospheric N2O increase and climate warming.

  16. Dynamic evaluation of CMAQ part I: Separating the effects of changing emissions and changing meteorology on ozone levels between 2002 and 2005 in the eastern US

    EPA Science Inventory

    A dynamic evaluation of the Community Multiscale Air Quality (CMAQ) modeling system version 5.0.1 was conducted to evaluate the model's ability to predict changes in ozone levels between 2002 and 2005, a time period characterized by emission reductions associated with the EPA's N...

  17. Greenhouse gas emissions from biofuels' indirect land use change are uncertain but may be much greater than previously estimated.

    PubMed

    Plevin, Richard J; O'Hare, Michael; Jones, Andrew D; Torn, Margaret S; Gibbs, Holly K

    2010-11-01

    The life cycle greenhouse gas (GHG) emissions induced by increased biofuel consumption are highly uncertain: individual estimates vary from each other and each has a wide intrinsic error band. Using a reduced-form model, we estimated that the bounding range for emissions from indirect land-use change (ILUC) from US corn ethanol expansion was 10 to 340 g CO(2) MJ(-1). Considering various probability distributions to model parameters, the broadest 95% central interval, i.e., between the 2.5 and 97.5%ile values, ranged from 21 to 142 g CO(2)e MJ(-1). ILUC emissions from US corn ethanol expansion thus range from small, but not negligible, to several times greater than the life cycle emissions of gasoline. The ILUC emissions estimates of 30 g CO(2) MJ(-1) for the California Air Resources Board and 34 g CO(2)e MJ(-1) by USEPA (for 2022) are at the low end of the plausible range. The lack of data and understanding (epistemic uncertainty) prevents convergence of judgment on a central value for ILUC emissions. The complexity of the global system being modeled suggests that this range is unlikely to narrow substantially in the near future. Fuel policies that require narrow bounds around point estimates of life cycle GHG emissions are thus incompatible with current and anticipated modeling capabilities. Alternative policies that address the risks associated with uncertainty are more likely to achieve GHG reductions. PMID:20942480

  18. Warmer temperature accelerates methane emissions from the Zoige wetland on the Tibetan Plateau without changing methanogenic community composition

    NASA Astrophysics Data System (ADS)

    Cui, Mengmeng; Ma, Anzhou; Qi, Hongyan; Zhuang, Xuliang; Zhuang, Guoqiang; Zhao, Guohui

    2015-06-01

    Zoige wetland, locating on the Tibet Plateau, accounts for 6.2% of organic carbon storage in China. However, the fate of the organic carbon storage in the Zoige wetland remains poorly understood despite the Tibetan Plateau is very sensitive to global climate change. As methane is an important greenhouse gas and methanogenesis is the terminal step in the decomposition of organic matter, understanding how methane emissions from the Zoige wetland is fundamental to elucidate the carbon cycle in alpine wetlands responding to global warming. In this study, microcosms were performed to investigate the effects of temperature and vegetation on methane emissions and microbial processes in the Zoige wetland soil. A positive correlation was observed between temperature and methane emissions. However, temperature had no effect on the main methanogenic pathway—acetotrophic methanogenesis. Moreover, methanogenic community composition was not related to temperature, but was associated with vegetation, which was also involved in methane emissions. Taken together, these results indicate temperature increases methane emissions in alpine wetlands, while vegetation contributes significantly to methanogenic community composition and is associated with methane emissions. These findings suggest that in alpine wetlands temperature and vegetation act together to affect methane emissions, which furthers a global warming feedback loop.

  19. Gaining ground in the modeling of land-use change greenhouse gas emissions associated with biofuel production

    NASA Astrophysics Data System (ADS)

    Dunn, J.; Mueller, S.; Kwon, H.; Wang, M.; Wander, M.

    2012-12-01

    Land-use change (LUC) resulting from biofuel feedstock production and the associated greenhouse gas (GHG) emissions are a hotly-debated aspect of biofuels. Certainly, LUC GHG emissions are one of the most uncertain elements in life cycle analyses (LCA) of biofuels. To estimate LUC GHG emissions, two sets of data are necessary. First, information on the amount and type of land that is converted to biofuel feedstock production is required. These data are typically generated through application of computable general equilibrium (CGE) models such as Purdue University's Global Trade Analysis Project (GTAP) model. Second, soil carbon content data for the affected land types is essential. Recently, Argonne National Laboratory's Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) has been updated with CGE modeling results that estimate the amount and type of LUC world-wide from production of ethanol from corn, corn stover, miscanthus, and switchgrass (Mueller et al. 2012). Moreover, we have developed state-specific carbon content data, determined through modeling with CENTURY, for the two most dominant soil types in the conterminous 48 U.S. states (Kwon et al. 2012) to enable finer-resolution results for domestic LUC GHG emissions for these ethanol production scenarios. Of the feedstocks examined, CCLUB estimates that LUC GHG emissions are highest for corn ethanol (9.1 g CO2e/MJ ethanol) and lowest for miscanthus (-12 g CO2e/MJ ethanol). We will present key observations from CCLUB results incorporated into Argonne National Laboratory's Greenhouse Gases, Regulated Emissions, and Energy use in Transportation (GREET) model, which is a LCA tool for transportation fuels and advanced vehicle technologies. We will discuss selected issues in this modeling, including the sensitivity of domestic soil carbon emission factors to modeling parameters and assumptions about the fate of harvested wood products. Further, we will discuss efforts to update CCLUB with county

  20. Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change

    NASA Astrophysics Data System (ADS)

    Searchinger, Timothy; Heimlich, Ralph; Houghton, R. A.; Dong, Fengxia; Elobeid, Amani; Fabiosa, Jacinto; Tokgoz, Simla; Hayes, Dermot; Yu, Tun-Hsiang

    2008-02-01

    Most prior studies have found that substituting biofuels for gasoline will reduce greenhouse gases because biofuels sequester carbon through the growth of the feedstock. These analyses have failed to count the carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the grain (or cropland) diverted to biofuels. By using a worldwide agricultural model to estimate emissions from land-use change, we found that corn-based ethanol, instead of producing a 20% savings, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years. Biofuels from switchgrass, if grown on U.S. corn lands, increase emissions by 50%. This result raises concerns about large biofuel mandates and highlights the value of using waste products.

  1. Uncertainty in projected climate change caused by methodological discrepancy in estimating CO2 emissions from fossil fuel combustion

    NASA Astrophysics Data System (ADS)

    Quilcaille, Yann; Gasser, Thomas; Ciais, Philippe; Lecocq, Franck; Janssens-Maenhout, Greet; Mohr, Steve; Andres, Robert J.; Bopp, Laurent

    2016-04-01

    There are different methodologies to estimate CO2 emissions from fossil fuel combustion. The term "methodology" refers to the way subtypes of fossil fuels are aggregated and their implied emissions factors. This study investigates how the choice of a methodology impacts historical and future CO2 emissions, and ensuing climate change projections. First, we use fossil fuel extraction data from the Geologic Resources Supply-Demand model of Mohr et al. (2015). We compare four different methodologies to transform amounts of fossil fuel extracted into CO2 emissions based on the methodologies used by Mohr et al. (2015), CDIAC, EDGARv4.3, and IPCC 1996. We thus obtain 4 emissions pathways, for the historical period 1750-2012, that we compare to the emissions timeseries from EDGARv4.3 (1970-2012) and CDIACv2015 (1751-2011). Using the 3 scenarios by Mohr et al. (2015) for projections till 2300 under the assumption of an Early (Low emission), Best Guess or Late (High emission) extraction peaking, we obtain 12 different pathways of CO2 emissions over 1750-2300. Second, we extend these CO2-only pathways to all co-emitted and climatically active species. Co-emission ratios for CH4, CO, BC, OC, SO2, VOC, N2O, NH3, NOx are calculated on the basis of the EDGAR v4.3 dataset, and are then used to produce complementary pathways of non-CO2 emissions from fossil fuel combustion only. Finally, the 12 emissions scenarios are integrated using the compact Earth system model OSCAR v2.2, in order to quantify the impact of the selected driver onto climate change projections. We find historical cumulative fossil fuel CO2 emissions from 1750 to 2012 ranging from 365 GtC to 392 GtC depending upon the methodology used to convert fossil fuel into CO2 emissions. We notice a drastic increase of the impact of the methodology in the projections. For the High emission scenario with Late fuel extraction peaking, cumulated CO2 emissions from 1700 to 2100 range from 1505 GtC to 1685 GtC; this corresponds

  2. Air quality and climate responses to anthropogenic black carbon emission changes from East Asia, North America and Europe

    NASA Astrophysics Data System (ADS)

    Sadiq, Makliyar; Tao, Wei; Liu, Junfeng; Tao, Shu

    2015-11-01

    East Asia, North America and Europe are the world largest emitters of anthropogenic black carbon (BC). In this study, the role of each region's anthropogenic BC emissions on domestic air quality and climate is investigated. A ten-year six-member parallel simulation (i.e., with anthropogenic emissions in each region reduced by 0%, 50% or 100%, or increased by 200%, 500% or 1000%) is conducted based on the state-of-the-art Community Earth System Model (CESM). Linearity of the emission-response relationship is examined for a variety of air quality and climate indicators. Generally, a change in BC emissions tend to linearly influence BC concentrations over both source and nearby downwind regions even taking into account the effect of BC-induced climate perturbations. Aerosol optical depth (AOD) and the net radiative flux perturbation at top of atmosphere (TOA) tend to preserve a similar linear relationship to local BC emission changes, with a robust signal confined only to the source areas. However, the response of temperature in most places is inconsistent to BC emission changes. Though the presence of BC in the atmosphere absorbs solar and terrestrial radiation which has a tendency to warm the atmosphere, the perturbed atmospheric circulation induces substantial meridional exchanges of warm and cold air masses, which overpasses the warming tendency of BC exerted on the atmosphere. This indicates that reducing/increasing regional BC emissions immediately ameliorate/deteriorate local air quality proportionally, but the associated effects on climate perturbation may lack a clear trend within the initial 10-year time span.

  3. Dust emissions from eastern Australia during the mid to late Holocene record changing hydro-climatic conditions and landuse.

    NASA Astrophysics Data System (ADS)

    Marx, S. K.; McGowan, H. A.; Kamber, B. S.

    2014-12-01

    Dust emissions, determined from dust deposition rates in sedimentary archives, are sensitive indicators of landscape change in dust source areas. Changing patterns in dust output are most often interpreted to indicate changing aridity, where increased dust emissions occur in response to increased aridity. However, the controls on the degree of dustiness are complex and in addition to aridity include sediment availability and windiness. Sediment availability is influenced not only by climate, but also landuse. Despite this, dust emissions can be used to reconstruct landscape response through time. Rates of dust deposition downwind of the main dust producing regions of eastern and central Australia are examined in this study. Prior to agricultural development, dust emissions from this region appeared to be driven by changes in the position of synoptic scale circulation features combined with the operation of teleconnections. However, following widespread agricultural development dust output increased significantly, with patterns linked to human activity; although the influence of climate was still apparent. Different dust source regions appear to respond differently to spatial variability in climate. Dust emissions increased from central Australia desert after 4500 cal. BP, interpreted as a response to a northward positioning, and possible strengthening, of the baric ridge. Peak dust emissions from central Australia occurred at around 3500 cal. BP, coincident with a generally dry climate but also apparent peak El Niño Southern Oscillation (ENSO) variability. High ENSO variability is thought to have driven increased dust emissions as rapid changes between wet and dry sequences resupply sediment to dust source areas during wet phases, before it is entrained and transported during subsequent dry periods. By contrast, at the same time in more southerly latitudes (Australia's western Murray-Darling Basin (MDB)) dust emissions were lower than at any other time. This is

  4. Changes in future air quality, deposition, and aerosol-cloud interactions under future climate and emission scenarios

    NASA Astrophysics Data System (ADS)

    Glotfelty, Timothy; Zhang, Yang; Karamchandani, Prakash; Streets, David G.

    2016-08-01

    The prospect of global climate change will have wide scale impacts, such as ecological stress and human health hazards. One aspect of concern is future changes in air quality that will result from changes in both meteorological forcing and air pollutant emissions. In this study, the GU-WRF/Chem model is employed to simulate the impact of changing climate and emissions following the IPCC AR4 SRES A1B scenario. An average of 4 future years (2020, 2030, 2040, and 2050) is compared against an average of 2 current years (2001 and 2010). Under this scenario, by the Mid-21st century global air quality is projected to degrade with a global average increase of 2.5 ppb in the maximum 8-hr O3 level and of 0.3 μg m-3 in 24-hr average PM2.5. However, PM2.5 changes are more regional due to regional variations in primary aerosol emissions and emissions of gaseous precursor for secondary PM2.5. Increasing NOx emissions in this scenario combines with a wetter climate elevating levels of OH, HO2, H2O2, and the nitrate radical and increasing the atmosphere's near surface oxidation state. This differs from findings under the RCP scenarios that experience declines in OH from reduced NOx emissions, stratospheric recovery of O3, and increases in CH4 and VOCs. Increasing NOx and O3 levels enhances the nitrogen and O3 deposition, indicating potentially enhanced crop damage and ecosystem stress under this scenario. The enhanced global aerosol level results in enhancements in aerosol optical depth, cloud droplet number concentration, and cloud optical thickness. This leads to dimming at the Earth's surface with a global average reduction in shortwave radiation of 1.2 W m-2. This enhanced dimming leads to a more moderate warming trend and different trends in radiation than those found in NCAR's CCSM simulation, which does not include the advanced chemistry and aerosol treatment of GU-WRF/Chem and cannot simulate the impacts of changing climate and emissions with the same level of detailed

  5. Sources of Asian dust and role of climate change versus desertification in Asian dust emission

    NASA Astrophysics Data System (ADS)

    Zhang, X. Y.; Gong, S. L.; Zhao, T. L.; Arimoto, R.; Wang, Y. Q.; Zhou, Z. J.

    2003-12-01

    Simulations of Asian dust emissions over the past 43 years are presented based on a size-dependent soil dust emission and transport model (NARCM) along with supporting data from a network of surface stations. The deserts in Mongolia and in western and northern China (mainly the Taklimakan and Badain Juran, respectively) contribute ~70% of the total dust emissions; non-Chinese sources account for ~40% of this. Several areas, especially the Onqin Daga sandy land, Horqin sandy land, and Mu Us Desert, have increased in dust emissions over the past 20 years, but efforts to reduce desertification in these areas may have little effect on Asian dust emission amount because these are not key sources. The model simulations indicate that meteorology and climate have had a greater influence on the Asian dust emissions and associated Asian dust storm occurrences than desertification.

  6. EMISSION REDUCTIONS AIMED AT IMPROVING AIR QUALITY: UNINTENDED CLIMATIC CONSEQUENCES AND THE EFFECT OF CLIMATE CHANGE ON THEIR SUCCESS

    EPA Science Inventory

    This work will provide improved understanding of the role of climate change, both in the recent past and future, on the success of pollutant control strategies, allowing for better planning and accountability of emission reductions. This work will also provide a quantitative a...

  7. EFFECTS OF CHANGING COALS ON THE EMISSIONS OF METAL HAZARDOUS AIR POLLUTANTS FROM THE COMBUSTION OF PULVERIZED COAL

    EPA Science Inventory

    The report discusses tests conducted at EPA's Air Pollution Prevention and Control Division to evaluate the effects of changing coals on emissions of metal hazardous air pollutants from coal-fired boilers. Six coals were burned in a 29 kW (100,000 Btu/hr) down-fired combustor und...

  8. HOUSEHOLDS, CONSUMPTION, AND ENERGY USE: THE ROLE OF DEMOGRAPHIC CHANGE IN FUTURE U.S. GREENHOUSE GAS EMISSIONS

    EPA Science Inventory

    The primary objective of the proposed research is to determine whether expected changes in the composition of the U.S. population by household type over the next 25-100 years will have a substantial influence on total energy demand and carbon dioxide emissions. Specific aims for ...

  9. Developed and developing world contributions to climate system change based on carbon dioxide, methane and nitrous oxide emissions

    NASA Astrophysics Data System (ADS)

    Wei, Ting; Dong, Wenjie; Yan, Qing; Chou, Jieming; Yang, Zhiyong; Tian, Di

    2016-05-01

    One of the key issues in international climate negotiations is the formulation of targets for emissions reduction for all countries based on the principle of "common but differentiated responsibilities". This formulation depends primarily on the quantitative attribution of the responsibilities of developed and developing countries for historical climate change. Using the Commuity Earth System Model (CESM), we estimate the responsibilities of developed countries and developing countries for climatic change from 1850 to 2005 using their carbon dioxide, methane and nitrous oxide emissions. The results indicate that developed countries contribute approximately 53%-61%, and developing countries approximately 39%-47%, to the increase in global air temperature, upper oceanic warming, sea-ice reduction in the NH, and permafrost degradation. In addition, the spatial heterogeneity of these changes from 1850 to 2005 is primarily attributed to the emissions of greenhouse gases (GHGs) in developed countries. Although uncertainties remain in the climate model and the external forcings used, GHG emissions in developed countries are the major contributor to the observed climate system changes in the 20th century.

  10. Changing Land Use to Offset CO2 Emissions: Limited Potential for the Upper Midwest of the U.S.

    NASA Astrophysics Data System (ADS)

    Fissore, C.; Espelata, J. F.; Nater, E. A.; Hobbie, S. E.; Reich, P. B.

    2008-12-01

    Efforts to mitigate increasing carbon (C) emissions are needed, and increasingly more policies point at terrestrial ecosystems as places to sequester atmospheric CO2. Whether terrestrial C sequestration can offset significant CO2 emissions is questionable, particularly in light of (1) increasing pressures on land use from an array of competing sectors including food and biofuel production and urbanization, and (2) a growing concern among scientists that previously published rates of C sequestration attributed to the conversion from conventional tillage to no-till or conservation tillage were overly optimistic. We analyzed the potential to promote terrestrial C sequestration through changes in land use and land cover in the Upper Midwest of the U.S. over a 50-year timeframe based on available data. Although some land use and cover changes, such as restoring forests, grasslands and wetlands, cause substantial carbon storage for a given area of land, conversion of even 10% of the regions agricultural land would offset only a few percent of its carbon emissions. Conversion to no-till agricultural, although popular among policymakers, results in variable and, on average, negligible C sequestration (sequestration rates range from -0.2 to 0.8 Mg C ha-1 y-1). Despite the unquestionable ecological benefits of some of the proposed land use changes, land use change realistically can be only a modest part of a more comprehensive strategy to achieve significant emissions reductions.

  11. An Analysis of Health Impacts Associated with Pollutant Response to Changes in Emissions In Different Regions of Central California

    NASA Astrophysics Data System (ADS)

    Tran, C.; Tanrikulu, S.; Beaver, S.; Hilken, H.

    2011-12-01

    Exposure to ozone and particulate matter has been shown to have considerable human health impacts. Currently major air basins of central California such as the San Francisco Bay Area (SFBA), Sacramento area, and the San Joaquin Valley (SJV) are all designated as in nonattainment of the Federal 8-hour ozone and 24-hour PM2.5 standards, despite California's comprehensive emission control programs for the last fifty years. Although these programs were very effective, decreasing anthropogenic emissions 40 to 50 percent in the region from 1990 to 2010 alone, the ambient response of pollutants was mixed and varied among these three interconnected regions. The purpose of this work was to investigate differences in each region's human health impact response to changes in emissions using the US EPA's BenMAP program. Inputs to BenMAP were prepared using the CMAQ model. Ambient concentrations were simulated for 2005. Then, anthropogenic emissions were reduced 10 to 60 percent across the board in 10 percent increments for the purpose of assessing pollutant responses to changes in emissions. BenMAP was run for each emission reduction scenario. The BenMAP results were normalized by county population to enable comparisons among counties that ranged from rural and agricultural to urban and densely populated. In all regions, the benefits of direct PM emission reductions were greater than those of similar precursor reductions. With respect to mortality rates, direct PM reductions produced the largest benefits in Nevada, Stanislaus, Tuolumne, and San Francisco Counties. For a 40 percent reduction in emissions, reductions in annual mortality rates ranged from 120 to 140 per million for these counties. Precursor emission reductions' benefits were maximized at the southern end of SJV, with Tulare showing the maximum reduction of around 83 mortalities per million. Monetized benefits of avoided mortalities as a result of direct PM emission reductions were significantly higher in

  12. Are vegetation-related roughness changes the cause of the recent decrease in dust emission from the Sahel?

    PubMed Central

    Cowie, Sophie M; Knippertz, Peter; Marsham, John H

    2013-01-01

    [1] Since the 1980s, a dramatic downward trend in North African dustiness and transport to the tropical Atlantic Ocean has been observed by different data sets and methods. The precise causes of this trend have previously been difficult to understand, partly due to the sparse observational record. Here we show that a decrease in surface wind speeds associated with increased roughness due to more vegetation in the Sahel is the most likely cause of the observed drop in dust emission. Associated changes in turbulence and evapotranspiration, and changes in large-scale circulation, are secondary contributors. Past work has tried to explain negative correlations between North African dust and precipitation through impacts on emission thresholds due to changes in soil moisture and vegetation cover. The use of novel diagnostic tools applied here to long-term surface observations suggests that this is not the dominating effect. Our results are consistent with a recently observed global decrease in surface wind speed, known as “stilling”, and demonstrate the importance of representing vegetation-related roughness changes in models. They also offer a new mechanism of how land-use change and agriculture can impact the Sahelian climate. Citation: Cowie, S. M., P. Knippertz, and J. H. Marsham (2013), Are vegetation-related roughness changes the cause of the recent decrease in dust emission from the Sahel?, Geophys. Res. Lett., 40, 1868–1872, doi:10.1002/grl.50273 PMID:25821264

  13. Detecting long-term changes in point-source fossil CO2 emissions with tree ring archives

    NASA Astrophysics Data System (ADS)

    Keller, Elizabeth D.; Turnbull, Jocelyn C.; Norris, Margaret W.

    2016-05-01

    We examine the utility of tree ring 14C archives for detecting long-term changes in fossil CO2 emissions from a point source. Trees assimilate carbon from the atmosphere during photosynthesis, in the process faithfully recording the average atmospheric 14C content in each new annual tree ring. Using 14C as a proxy for fossil CO2, we examine interannual variability over six years of fossil CO2 observations between 2004-2005 and 2011-2012 from two trees growing near the Kapuni Gas Treatment Plant in rural Taranaki, New Zealand. We quantify the amount of variability that can be attributed to transport and meteorology by simulating constant point-source fossil CO2 emissions over the observation period with the atmospheric transport model WindTrax. We compare model simulation results to observations and calculate the amount of change in emissions that we can detect with new observations over annual or multi-year time periods, given both the measurement uncertainty of 1ppm and the modelled variation in transport. In particular, we ask, what is the minimum amount of change in emissions that we can detect using this method, given a reference period of six years? We find that changes of 42 % or more could be detected in a new sample from one year at the same observation location or 22 % in the case of four years of new samples. This threshold is reduced and the method becomes more practical the more the size of the signal increases. For point sources 10 times larger than the Kapuni plant (a more typical size for power plants worldwide), it would be possible to detect sustained emissions changes on the order of 10 %, given suitable meteorology and observations.

  14. Atmospheric So2 Emissions Since the Late 1800s Change Organic Sulfur Forms in Humic Substance Extracts of Soils

    SciTech Connect

    Lehmann,J.; Solomon, D.; Zhao, F.; McGrath, S.

    2008-01-01

    Atmospheric SO2 emissions in the UK and globally increased 6- and 20-fold, respectively, from the mid-1800s to the 1960s resulting in increased S deposition, acid rain, and concurrent acidification of terrestrial and aquatic ecosystems. Structural analyses using synchrotron-based X-ray near-edge spectroscopy (XANES) on humic substance extracts of archived samples from the Rothamsted Park Grass Experiment reveal a significant (R2 = -0.58; P < 0.05; N = 7) shift in soil organic sulfur (S) forms, from reduced to more oxidized organic S between 1876 and 1981, even though soil total S contents remained relatively constant. Over the last 30 years, a decrease in emissions and consequent S deposition has again corresponded with a change of organic S structures of humic extractsreverting in the direction of their early industrial composition. However, the observed reversal lagged behind reductions in emissions by 19 years, which was computed using cross correlations between time series data (R2 = 0.66; P = 0.0024; N = 11). Presently, the ratio of oxidized-to-reduced organic S in humic substance extracts is nearly double that of early industrial times at identical SO2 emission loads. The significant and persistent structural changes of organic S in humic substances as a response to SO2 emissions and S deposition may have effects on recuperation of soils and surface waters from acidification.

  15. Atmospheric SO2 emissions since the late 1800s change organic sulfur forms in humic substance extracts of soils.

    PubMed

    Lehmann, Johannes; Solomon, Dawit; Zhao, Fang-Jie; McGrath, Steve P

    2008-05-15

    Atmospheric SO2 emissions in the UK and globally increased 6- and 20-fold, respectively, from the mid-1800s to the 1960s resulting in increased S deposition, acid rain, and concurrent acidification of terrestrial and aquatic ecosystems. Structural analyses using synchrotron-based X-ray near-edge spectroscopy (XANES) on humic substance extracts of archived samples from the Rothamsted Park Grass Experiment reveal a significant (R2 = -0.58; P < 0.05; N = 7) shift in soil organic sulfur (S) forms, from reduced to more oxidized organic S between 1876 and 1981, even though soil total S contents remained relatively constant. Over the last 30 years, a decrease in emissions and consequent S deposition has again corresponded with a change of organic S structures of humic extracts-reverting in the direction of their early industrial composition. However, the observed reversal lagged behind reductions in emissions by 19 years, which was computed using cross correlations between time series data (R2 = 0.66; P = 0.0024; N = 11). Presently, the ratio of oxidized-to-reduced organic S in humic substance extracts is nearly double that of early industrial times at identical SO2 emission loads. The significant and persistent structural changes of organic S in humic substances as a response to SO2 emissions and S deposition may have effects on recuperation of soils and surface waters from acidification. PMID:18546688

  16. Valuing Non-CO2 GHG Emission Changes in Benefit-Cost Analysis

    EPA Science Inventory

    The climate impacts of greenhouse gas (GHG) emissions impose social costs on society. To date, EPA has not had an approach to estimate the economic benefits of reducing emissions of non-CO2 GHGs (or the costs of increasing them) that is consistent with the methodology underlying...

  17. IMPACTS OF CLIMATE CHANGE AND LAND COVER CHANGE ON BIOGENIC VOLATILE ORGANIC COMPOUNDS (BVOCS) EMISSIONS IN TEXAS

    EPA Science Inventory

    Significant amounts of vegetation and forests in eastern and central Texas are the source of substantial emissions of volatile organic compounds (VOCs) which, when mixed with nitrogen oxides from anthropogenic sources, can lead to ozone formation. The biogenic emis...

  18. DYNAMIC EVALUATION OF REGIONAL AIR QUALITY MODELS: ASSESSING CHANGES TO O 3 STEMMING FROM CHANGES IN EMISSIONS AND METEOROLOGY

    EPA Science Inventory

    Regional-scale air quality models are used to estimate the response of air pollutants to potential emission control strategies as part of the decision-making process. Traditionally, the model predicted pollutant concentrations are evaluated for the “base case” to assess a model’s...

  19. Concurrent changes in methyl jasmonate emission and the expression of its biosynthesis-related genes in Cymbidium ensifolium flowers.

    PubMed

    Huang, Mingkun; Ma, Cuiping; Yu, Rangcai; Mu, Lanling; Hou, Jia; Yu, Yunyi; Fan, Yanping

    2015-04-01

    Methyl jasmonate (MeJA) is one of most abundant scent compounds in Cymbidium ensifolium flowers. In this study, the emission of MeJA and its regulation mechanism were investigated. Our results showed that emission of MeJA in C. ensifolium flowers was controlled developmentally and rhythmically. It occurred in a tissue-specific manner, and high MeJA emission was found in sepals and petals. A group of vital genes involved in the MeJA biosynthesis via the octadecanoid pathway were isolated from C. ensifolium flowers, including CeLOX, CeAOS, CeAOC and CeJMT. MeJA emission was at very low levels in unopened or half-opened C. ensifolium flowers and reached its maximal level between day 4 and 6 and declined from day 7 to 10 postanthesis. The expression of CeLOX, CeAOS, CeAOC and CeJMT increased from day 1 to day 6, and then declined from day 7 to 10 postanthesis, corresponding to the change in MeJA emission. Moreover, the expression of CeLOX, CeAOS, CeAOC and CeJMT oscillated in a rhythmic manner could reach the maximum level between 8:00 h and 16:00 h, which coincided with the MeJA emission. The high level of MeJA emission in sepals and petals coincided with the high transcript levels. The results suggest that MeJA emission in C. ensifolium flower might be directly regulated at the transcription levels. Moreover, the recombinant protein of CeJMT could specifically catalyze the jasmonic acid to form the corresponding ester MeJA. PMID:25214235

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  1. The effect of localized surface plasmon resonance on the emission color change in organic light emitting diodes.

    PubMed

    Lee, Illhwan; Park, Jae Yong; Hong, Kihyon; Son, Jun Ho; Kim, Sungjun; Lee, Jong-Lam

    2016-03-17

    Three primary colors, cyan, yellow, and green, are obtained from Ag nano-dot embedded organic light emitting diodes (OLEDs) by localized surface plasmon resonance (LSPR). By changing the thickness of the Ag film, the size and spacing of Ag nano-dots are controlled. The generated light from the emissive layer in the OLEDs interacts with the free electrons near the surface of the Ag nano-dots, which leads to LSPR absorption and scattering. The UV-visible absorption spectra of glass/ITO/Ag nano-dot samples show intense peaks from 430 nm to 520 nm with an increase of Ag nano-dot size. And also, the Rayleigh scattering spectra results show the plasmon resonance wavelength in the range of 470-550 nm. The effect of the LSPR of Ag nano-dots on the change of emission color in OLEDs is demonstrated using 2 dimensional finite-difference time-domain simulations. The intensity of the electro-magnetic field in the sample with 5 nm-thick Ag is low at the incident wavelength of 500 nm, but it increases with the incident wavelength. This provides evidence that the emission color change in OLEDs originates from LSPR at the Ag nano-dots. As a result, the emission peak wavelength of OLEDs shifted toward longer wavelengths, from cyan to yellow-green, with the increase of Ag nano-dot size. PMID:26934838

  2. Peatland CO2 emissions: Using 13C to quantify responses to land use change

    NASA Astrophysics Data System (ADS)

    Snell, Helen; Robinson, David; Midwood, Andrew J.

    2013-04-01

    Soil is the largest terrestrial carbon reservoir and annually soils emit about 98 billion tonnes of CO2which is derived from plant root and rhizosphere respiration (autotrophically fuelled by photosynthesis) and microbial degradation of soil organic carbon (heterotrophic respiration). These two processes are intrinsically linked by complex physical and biochemical interactions. In order to meet its GHG reductions targets the Scottish Government plans to increase woodland cover from 17 to 25% by the second half of this century which will inevitably lead to significant tree planting on peatland soils. Tree roots and associated mycorrhiza will alter physical and biological conditions in the soil which may affect the heterotrophic contribution to CO2 emissions and consequently the long term landscape-scale carbon balance since the difference between net primary productivity and heterotrophic respiration defines the terrestrial CO2 sink. Significant uncertainties surround the response of peatlands to tree planting and predicted climate changes. At a field site in eastern Scotland we used natural abundance stable isotopes of carbon to partition soil CO2 efflux into its heterotrophic and autotrophic components to determine whether young Scots pine plantations affect heterotrophic respiration rates in peatland soil. Rate and isotopic composition of soil CO2 efflux was measured in plantation areas and in unforested heather moorland; soil and roots were then excavated and separately incubated to establish the isotopic end members of a simple linear mixing model. Isotopic composition of soil efflux varies temporally and spatially across the site; young Scots pine trees do not increase the heterotrophic flux from soil and therefore do not lead to a net loss of soil carbon from these landscapes.

  3. Reduction of the Livestock Ammonia Emission under the Changing Temperature during the Initial Manure Nitrogen Biomineralization

    PubMed Central

    Bagdonienė, Indrė; Baležentienė, Ligita

    2013-01-01

    Experimental data were applied for the modelling optimal cowshed temperature environment in laboratory test bench by a mass-flow method. The principal factor affecting exponent growth of ammonia emission was increasing air and manure surface temperature. With the manure temperature increasing from 4°C to 30°C, growth in the ammonia emission grew fourfold, that is, from 102 to 430 mg m−2h−1. Especial risk emerges when temperature exceeds 20°C: an increase in temperature of 1°C contributes to the intensity of ammonia emission by 17 mg m−2h−1. The temperatures of air and manure surface as well as those of its layers are important when analysing emission processes from manure. Indeed, it affects the processes occurring on the manure surface, namely, dehydration and crust formation. To reduce ammonia emission from cowshed, it is important to optimize the inner temperature control and to manage air circulation, especially at higher temperatures, preventing the warm ambient air from blowing direct to manure. Decrease in mean annual temperature of 1°C would reduce the annual ammonia emission by some 5.0%. The air temperature range varied between −15°C and 30°C in barns. The highest mean annual temperature (14.6°C) and ammonia emission (218 mg m−2h−1) were observed in the semideep cowshed. PMID:24453912

  4. Diurnal changes of PM10-emission from arable soils in NE-Germany

    NASA Astrophysics Data System (ADS)

    Hoffmann, Carsten; Funk, Roger

    2015-06-01

    Repeated loss of fine soil particles by dust emission from arable fields caused by tillage operations, decline soil fertility and reduce air quality. The objective of this study was to quantify the diurnal dynamic of topsoil moisture and the connected PM10-emission of 15 different soils from arable fields around Berlin. As typical for the young moraine landscape in NE Germany, soils from glacial (sand and loam dominated), aeolian (silt loam), and fluvial (organic) sediments were selected. Soil samples were placed outside under hot summer and clear sky conditions for 24 h to reproduce the natural dynamic of soil surface moisture, including dew uptake during the night and evaporation during the day. Dynamic of PM10 emissions of all soils were then measured nine times per day in a stationary wind tunnel. Glacial and fluvial sands showed lowest fine dust emission potential (PM10pot) between 89 and 415 μg PM10 g-1 soil, while PM10pot of loess soils were higher (369-1215 μg PM10 g-1 soil). During the night, the moisture of all samples increased slightly by dew uptake, and fine dust emissions of soil samples were reduced up to 51% directly after sunrise. Highest average reductions in PM10 emissions were found for glacial and fluvial loams. Some hours after sunrise, all soil samples heated up and quickly dried again. Under minimal moisture conditions, highest fine dust emissions were measured between 10 a.m. and 3 p.m.

  5. Methane Emissions From Western Siberian Wetlands: Heterogeneity and Sensitivity to Climate Change

    NASA Astrophysics Data System (ADS)

    Bohn, T. J.; Lettenmaier, D. P.; Podest, E.; McDonald, K. C.; Sathulur, K.; Bowling, L. C.; Friborg, T.

    2007-12-01

    Prediction of methane emissions from high-latitude wetlands is important given concerns about their sensitivity to a warming climate. As a basis for prediction of wetland methane emissions at regional scales, we have coupled the Variable Infiltration Capacity macroscale hydrological model (VIC) with the Biosphere-Energy-Transfer- Hydrology terrestrial ecosystem model (BETHY) and a wetland methane emissions model to make large-scale estimates of methane emissions as a function of soil temperature, water table depth, and net primary productivity (NPP), with a parameterization of the sub-grid heterogeneity of the water table depth based on topographic wetness index. Using landcover classifications derived from L-band satellite synthetic aperture radar imagery, we simulated methane emissions for the Chaya River basin in western Siberia, an area that includes the Bakchar Bog, for a retrospective baseline period of 1980-1999, and evaluated their sensitivity to increases in temperature of 0-5 °C and increases in precipitation of 0-15%. The interactions of temperature and precipitation, through their effects on the water table depth, play an important role in determining methane emissions from these wetlands. The balance between these effects varies spatially, and their net effect depends in part on sub- grid topographic heterogeneity. Higher temperatures alone increase methane production in saturated areas, but cause those saturated areas to shrink in extent, resulting in a net reduction in methane emissions. Higher precipitation alone raises water tables and expands the saturated area, resulting in a net increase in methane emissions. Combining a temperature increase of 3 °C and an increase of 10% in precipitation, to represent the climate conditions likely in western Siberia at the end of this century, results in roughly a doubling of annual methane emissions. This work was carried out at the University of Washington, at Purdue University, and at the Jet Propulsion

  6. Is a change in roughness length the cause of the recent decrease in Sahelian dust emission?

    NASA Astrophysics Data System (ADS)

    Cowie, S.; Knippertz, P.; Marsham, J.

    2012-04-01

    The huge quantity of mineral dust emitted annually from North Africa makes this area crucial to the global dust cycle. Once in the atmosphere, dust aerosols have a significant impact on the global energy and carbon budgets and on air quality. Previous studies have documented changes in the dust output from North Africa on inter-annual to decadal time scales, but the exact reasons for this variability are still a matter of debate. This work uses long-term observations from seven Sahelian surface stations with almost continuous records and frequent dust storms between 1984 and 2010 to explore the trends in mean wind, dust uplift potential (DUP) and dust emission frequency (DEF). DEF is inferred from the present weather codes (WW) of SYNOP reports. The synchronous measurement of wind allows an estimate of a local dust-uplift threshold velocity. DUP is a novel diagnostic that takes into account the non-linear relationship between wind-speed and dust uplift assuming a constant threshold velocity. ECMWF ERA-Interim 10m winds are also used for comparison. There is little evidence in the station data that the increase in vegetation and soil moisture has significantly increased the threshold velocity for dust uplift, suggesting a dominant control by atmospheric processes. Averaged over the seven stations, there is a significant decreasing trend in mean wind over the study period for all seasons, and even more so for DUP and DEF, which are highly correlated. ERA-Interim mean wind, analysed over an area encompassing the seven stations, however, shows a much weaker downward trend, largely confined to the cooler half of the year. It is hypothesized that this cool-season signal is caused by a downward trend in the North Atlantic Oscillation, which is correlated to wind and dust activity on an inter-annual basis during this time of year. The remaining large discrepancies between ERA-Interim and the station observations are unexpected and are thought to be related to recent wetter

  7. Developing spatial inequalities in carbon appropriation: a sociological analysis of changing local emissions across the United States.

    PubMed

    Elliott, James R; Clement, Matthew Thomas

    2015-05-01

    This study examines an overlooked dynamic in sociological research on greenhouse gas emissions: how local areas appropriate the global carbon cycle for use and exchange purposes as they develop. Drawing on theories of place and space, we hypothesize that development differentially drives and spatially decouples use- and exchange-oriented emissions at the local level. To test our hypotheses, we integrate longitudinal, county-level data on residential and industrial emissions from the Vulcan Project with demographic, economic and environmental data from the U.S. Census Bureau and National Land Change Database. Results from spatial regression models with two-way fixed-effects indicate that alongside innovations and efficiencies capable of reducing environmentally harmful effects of development comes a spatial disarticulation between carbon-intensive production and consumption within as well as across societies. Implications for existing theory, methods and policy are discussed. PMID:25769856

  8. Soil Incubation Study to Assess the Impacts of Manure Application and Climate Change on Greenhouse Gas Emissions from Agricultural Soil

    NASA Astrophysics Data System (ADS)

    Schiavone, K.; Barbieri, L.; Adair, C.

    2015-12-01

    Agricultural fields in Vermont's Lake Champlain Basin have problems with the loss of nutrients due to runoff which creates eutrophic conditions in the lakes, ponds and rivers. In efforts to retain nitrogen and other nutrients in the soil farmers have started to inject manure rather than spraying it. Our understanding of the effects this might have on the volatilization of nitrogen into nitrous oxide is limited. Already, agriculture produces 69% of the total nitrous oxide emissions in the US. Understanding that climate change will affect the future of agriculture in Vermont, we set up a soil core incubation test to monitor the emissions of CO₂ and N₂O using a Photoacoustic Gas Sensor (PAS). Four 10 cm soil cores were taken from nine different fertilizer management plots in a No Till corn field; Three Injected plots, three Broadcast plots, and three Plow plots. Frozen soil cores were extracted in early April, and remained frozen before beginning the incubation experiment to most closely emulate three potential spring environmental conditions. The headspace was monitored over one week to get emission rates. This study shows that environmental and fertilizer treatments together do not have a direct correlation to the amount of CO₂ and N₂O emissions from agricultural soil. However, production of CO₂ was 26% more in warmer environmental conditions than in variable(freeze/thaw) environmental conditions. The injected fertilizer produced the most emissions, both CO₂ and N₂O. The total N₂O emissions from Injected soil cores were 2.2x more than from traditional broadcast manure cores. We believe this is likely due to the addition of rich organic matter under anaerobic soil conditions. Although, injected fertilizer is a better application method for reducing nutrient runoff, the global warming potential of N₂O is 298 times that of CO₂. With climate change imminent, assessing the harmful effects and benefits of injected fertilizer is a crucial next step in

  9. Changes in the emission properties of metallic targets upon exposure to repetitively pulsed laser radiation

    NASA Astrophysics Data System (ADS)

    Konov, V. I.; Pimenov, S. M.; Prokhorov, A. M.; Chapliev, N. I.

    1988-02-01

    A scanning electron microscope and a repetitively pulsed CO2 laser are used to reveal the relationships which govern the correlation of the transforming metal surface microrelief with the emission of charged particles and the surface luminescence upon exposure to multipulse laser focusing. It is shown that the effect of sorption and laser-stimulated desorption on the emission signals can manifest itself in different ways depending on the current oscillation mode in the target-vacuum chamber circuit.

  10. The Impact of Future Emissions Changes on Air Pollution Concentrations and Related Human Health Effects

    NASA Astrophysics Data System (ADS)

    Mikolajczyk, U.; Suppan, P.; Williams, M.

    2015-12-01

    Quantification of potential health benefits of reductions in air pollution on the local scale is becoming increasingly important. The aim of this study is to conduct health impact assessment (HIA) by utilizing regionally and spatially specific data in order to assess the influence of future emission scenarios on human health. In the first stage of this investigation, a modeling study was carried out using the Weather Research and Forecasting (WRF) model coupled with Chemistry to estimate ambient concentrations of air pollutants for the baseline year 2009, and for the future emission scenarios in southern Germany. Anthropogenic emissions for the baseline year 2009 are derived from the emission inventory provided by the Netherlands Organization of Applied Scientific Research (TNO) (Denier van der Gon et al., 2010). For Germany, the TNO emissions were replaced by gridded emission data with a high spatial resolution of 1/64 x 1/64 degrees. Future air quality simulations are carried out under different emission scenarios, which reflect possible energy and climate measures in year 2030. The model set-up included a nesting approach, where three domains with horizontal resolution of 18 km, 6 km and 2 km were defined. The simulation results for the baseline year 2009 are used to quantify present-day health burdens. Concentration-response functions (CRFs) for PM2.5 and NO2 from the WHO Health risks of air Pollution in Europe (HRAPIE) project were applied to population-weighted mean concentrations to estimate relative risks and hence to determine numbers of attributable deaths and associated life-years lost. In the next step, future health impacts of projected concentrations were calculated taking into account different emissions scenarios. The health benefits that we assume with air pollution reductions can be used to provide options for future policy decisions to protect public health.

  11. A novel method for quantifying the greenhouse gas emissions of biofuels based on historical land use change

    NASA Astrophysics Data System (ADS)

    Liu, X.; Rhodes, J.; Clarens, A. F.

    2012-12-01

    Land use change (LUC) emissions have been at the center of an ongoing debate about how the carbon footprint of biofuels compare to petroleum-based fuels over their entire life cycle. The debate about LUC has important implications in the US, the EU, and other countries that are working to deploy biofuel policies, informed by life cycle assessment, that promote carbon emission reductions, among other things. LUC calculations often distinguish between direct land use change (DLUC), those that occur onsite, and indirect land use change (ILUC), those that result from market mechanisms leading to emissions that are either spatially or temporally removed from the agricultural activity. These designations are intended to capture the fundamental connection between agricultural production of biofuel feedstock and its physical effects on the land, but both DLUC and ILUC can be difficult to measure and apply broadly. ILUC estimates are especially challenging to quantify because they rely on global economic models to assess how much land would be brought into production in other countries as a consequence of biofuel feedstock cultivation. As a result, ILUC estimates inherently uncertain, are sensitive to complex assumptions, have limited transparency, and have precipitated sufficient controversy to delay development of coherent biofuel policies. To address these shortcomings of conventional LUC methodologies, we have developed a method for estimating land use change emissions that is based on historical emissions from a parcel of land. The method, which we call historical land use change (HLUC) can be readily quantified for any parcel of land in the world using open source datasets of historical emissions. HLUC is easy to use and is directly tied to the physical processes on land used for biofuel production. The emissions from the HLUC calculations are allocated between historical agricultural activity and proposed biofuel feedstock cultivation. This is compatible with

  12. Modeling the response of forest isoprene emissions to future increases in atmospheric CO2 concentration and changes in climate (Invited)

    NASA Astrophysics Data System (ADS)

    Monson, R. K.; Heald, C. L.; Guenther, A. B.; Wilkinson, M.

    2009-12-01

    Isoprene emissions from plants to the atmosphere are sensitive to changes in temperature, light and atmospheric CO2 concentration in both the short- (seconds-to-minutes) and long-term (hours-to-months). We now understand that the different time constants for these responses are due to controls by different sets of biochemical and physiological processes n leaves. Progress has been made in the past few years toward converting this process-level understanding into quantitative models. In this talk, we consider this progress with special emphasis on the short- and long-term responses to atmospheric CO2 concentration and temperature. A new biochemically-based model is presented for describing the CO2 responses, and the model is deployed in a global context to predict interactions between the influences of temperature and CO2 on the global isoprene emission rate. The model is based on the theory of enzyme-substrate kinetics, particularly with regard to those reactions that produce puruvate or glyceraldehyde 3-phosphate, the two chloroplastic substrates for isoprene biosynthesis. In the global model, when we accounted for CO2 inhibition of isoprene emission in the long-term response, we observed little impact on present-day global isoprene emission (increase from 508 to 523 Tg C yr-1). However, the large increases in future isoprene emissions predicted from past models which are due to a projected warmer climate, were entirely offset by including the CO2 effects. The isoprene emission response to CO2 was dominated by the long-term growth environment effect, with modulations of 10% or less from the short-term effect. We use this analysis as a framework for grounding future global models of isoprene emission in biochemical and physiological observations.

  13. Impacts of Global Climate Change and Emissions on Regional Ozone and Fine Particulate Matter Concentrations over United States

    SciTech Connect

    Tagaris, Efthimios; Manomaiphiboon, Kasemsan; Liao, Kuo-Jen; Leung, Lai R.; Woo, Jung-Hun; He, Shan; Amar, Praveen; Russell, Armistead G.

    2007-07-31

    Simulated future summers (i.e., 2049-2051) and annual (i.e., 2050) average regional O 3 and PM2.5 concentrations over North America are compared with historic (i.e., 2000-2002 summers and all of 2001) levels to investigate the potential impacts of global climate change on regional air quality. Meteorological inputs to the CMAQ chemical transport model are developed by downscaling the GISS Global Climate Model simulations using an MM5-based regional climate model. Future-year emissions for North America are developed by growing the US EPA CAIR inventory, Mexican and Canadian emissions and by using the IMAGE model with the IPCC A1B emissions scenario that is also used in projecting future climate. Reductions of more than 50% in NOX and SO2 emissions are forecast. The impacts of global climate change alone on regional air quality are small compared to impacts from emission control-related reductions in the US and Canada. The combined effect of climate change and emission reductions lead to a 20% decrease (regionally varying from -11% to -28% regionally) in the mean summer maximum daily 8-hr ozone levels (M8hO3) over the US, -8% over Canada and -10% over Northern Mexico. The mean annual PM2.5 concentrations are estimated to be 23% lower (varies from -9% to -32%) over the US, -7% and -15% over Western and Eastern Canada, respectively and -25% over Northern Mexico. Major reductions are expected in sulfate, nitrate and ammonium fractions of annually-averaged PM2.5 for all sub-regions. The limited reduction in organic carbon over the US and Northern Mexico and the higher concentrations over Canada suggests that organic carbon will be the dominant component of PM2.5 mass over most of the continent in the future. Regionally, the Eastern US benefits more than the rest of the regions from reductions in both M8hO3 and PM2.5, due to both spatial variations in the meteorological and emissions changes. Reduction in the higher M8hO3 concentrations is also estimated for all sub

  14. Short term changes in methanol emission and pectin methylesterase activity are not directly affected by light in Lycopersicon esculentum

    NASA Astrophysics Data System (ADS)

    Oikawa, P. Y.; Li, L.; Timko, M. P.; Mak, J. E.; Lerdau, M. T.

    2011-04-01

    Plants are an important source of atmospheric methanol (MeOH), the second most abundant organic gas after methane. Factors regulating phytogenic MeOH production are not well constrained in current MeOH emission models. Previous studies have indicated that light may have a direct influence on MeOH production. As light is known to regulate cell wall expansion, it was predicted that light would stimulate MeOH production through the pectin methylesterase (PME) pathway. MeOH emissions normalized for stomatal conductance (gs) did not, however, increase with light over short time scales (20-30 min). After experimentally controlling for gs and temperature, no light activation of PME activity or MeOH emission was observed. The results clearly demonstrate that light does not directly influence short-term changes in MeOH production and emission. Our data suggest that substrate limitation may be important in regulating MeOH production over short time scales. Future investigation of the long-term impacts of light on MeOH production may increase understanding of MeOH emission dynamics at the seasonal time scale.

  15. Short term changes in methanol emission and pectin methylesterase activity are not directly affected by light in Lycopersicon esculentum

    NASA Astrophysics Data System (ADS)

    Oikawa, P. Y.; Li, L.; Timko, M. P.; Mak, J. E.; Lerdau, M. T.

    2011-01-01

    Plants are an important source of atmospheric methanol (MeOH), the second most abundant organic gas after methane. Factors regulating phytogenic MeOH production are not well constrained in current MeOH emission models. Previous studies have indicated that light may have a direct influence on MeOH production. As light is known to regulate cell wall expansion, it was predicted that light would stimulate MeOH production through the pectin methylesterase (PME) pathway. MeOH emissions normalized for stomatal conductance (gs) did not, however, increase with light over short time scales (20-30 min). After experimentally controlling for gs and temperature, no light activation of PME activity or MeOH emission was observed. The results clearly demonstrate that light does not directly influence short-term changes in MeOH production and emission. Our data suggest that substrate limitation may be important in regulating MeOH production over short time scales. Future investigation of the long-term impacts of light on MeOH production may increase understanding of MeOH emission dynamics at the seasonal time scale.

  16. Tracing changes of N2O emission pathways in a permanent grassland under elevated atmospheric CO2 concentrations

    NASA Astrophysics Data System (ADS)

    Gorenflo, Andre; Moser, Gerald; Brenzinger, Kristof; Elias, Dafydd; McNamara, Neill; Clough, Tim; Maček, Irena; Vodnik, Dominik; Braker, Gesche; Schimmelpfennig, Sonja; Gerstner, Judith; Müller, Christoph

    2015-04-01

    The increase of greenhouse gases (GHG) in the atmosphere is of concern due to its effect on global temperatures. Nitrous oxide (N2O) with a Global Warming Potential of 298 over a 100 year period is of particular concern because strong feedback effects of elevated atmospheric CO2 on N2O emissions have been observed. However, so far the changes in processes which are responsible for such a feedback effect are only poorly understood. Our study was carried out in situ in a long-term Free Air Carbon dioxide Enrichment (FACE) study on permanent grassland at atmospheric CO2 concentrations 20% above ambient which expected at the middle of this century. We performed an in situ 15N tracing with differentially labelled NH4NO3 to trace the main N2O emission pathways. Over a period of more than one year we monitored at least weakly the N2O emissions with the closed chamber technique and analyzed the 15N signature of the N2O. The observed gaseous emissions under ambient and elevated atmospheric CO2 were associated with the observed gross N transformations and the microbial activities to identify the main emission pathways under ambient and elevated CO2.

  17. Modeling dust emission variations in Eastern Europe related to North-Atlantic abrupt climate changes of the last glacial period

    NASA Astrophysics Data System (ADS)

    Sima, A.; Kageyama, M.; Rousseau, D.; Ramstein, G.; Schulz, M.; Balkanski, Y.; Antoine, P.; Dulac, F.; Hatte, C.; Lagroix, F.; Gerasimenko, N.

    2010-12-01

    The European loess sequences of the last glacial period (~ 100-15 kyr BP) show periods of strong dust accumulation alternating with episodes of reduced (or no) sedimentation, allowing soil development. For the main loess sedimentation period (~ 40 - 15 kyr BP), data indicate a correlation between these variations and the North Atlantic rapid climate changes: the Dansgaard-Oeschger (DO) and Heinrich (H) events. We use numerical modeling to investigate the relationship between the North-Atlantic abrupt changes and the sedimentation variations in Europe. A first study (Sima et al, QSR, 2009) focused on western Europe, and addressed the impact on dust emission of North-Atlantic SST changes as those associated to DO and H events. It proposed that vegetation played a key role in modulating dust emission variations in western European source areas. Here we focus on eastern Europe, especially on the areas north and north-east of the Carpathian Mountains, where loess deposits have recorded DO and H events (Rousseau et al. Clim. Past D, 2010). As in the previous study, we use the LMDZ AGCM and the SECHIBA land-surface models to simulate a reference glacial state (“stadial”), a cold (“HE”) and a warm (“DO interstadial”) perturbation, all corresponding to Marine Isotope Stage 3 conditions. We follow the same protocol as for the study on the west-European sector to analyze the impact of the climate factors and surface conditions on dust emission. The simulated most active emission areas are compatible with the loess deposit distribution, and the key role of vegetation in stadial-interstadial dust emission variations is confirmed.

  18. 21st century United States emissions mitigation could increase water stress more than the climate change it is mitigating

    PubMed Central

    Hejazi, Mohamad I.; Voisin, Nathalie; Liu, Lu; Bramer, Lisa M.; Fortin, Daniel C.; Hathaway, John E.; Huang, Maoyi; Kyle, Page; Leung, L. Ruby; Li, Hong-Yi; Liu, Ying; Patel, Pralit L.; Pulsipher, Trenton C.; Rice, Jennie S.; Tesfa, Teklu K.; Vernon, Chris R.; Zhou, Yuyu

    2015-01-01

    There is evidence that warming leads to greater evapotranspiration and surface drying, thus contributing to increasing intensity and duration of drought and implying that mitigation would reduce water stresses. However, understanding the overall impact of climate change mitigation on water resources requires accounting for the second part of the equation, i.e., the impact of mitigation-induced changes in water demands from human activities. By using integrated, high-resolution models of human and natural system processes to understand potential synergies and/or constraints within the climate–energy–water nexus, we show that in the United States, over the course of the 21st century and under one set of consistent socioeconomics, the reductions in water stress from slower rates of climate change resulting from emission mitigation are overwhelmed by the increased water stress from the emissions mitigation itself. The finding that the human dimension outpaces the benefits from mitigating climate change is contradictory to the general perception that climate change mitigation improves water conditions. This research shows the potential for unintended and negative consequences of climate change mitigation. PMID:26240363

  19. 21st century United States emissions mitigation could increase water stress more than the climate change it is mitigating.

    PubMed

    Hejazi, Mohamad I; Voisin, Nathalie; Liu, Lu; Bramer, Lisa M; Fortin, Daniel C; Hathaway, John E; Huang, Maoyi; Kyle, Page; Leung, L Ruby; Li, Hong-Yi; Liu, Ying; Patel, Pralit L; Pulsipher, Trenton C; Rice, Jennie S; Tesfa, Teklu K; Vernon, Chris R; Zhou, Yuyu

    2015-08-25

    There is evidence that warming leads to greater evapotranspiration and surface drying, thus contributing to increasing intensity and duration of drought and implying that mitigation would reduce water stresses. However, understanding the overall impact of climate change mitigation on water resources requires accounting for the second part of the equation, i.e., the impact of mitigation-induced changes in water demands from human activities. By using integrated, high-resolution models of human and natural system processes to understand potential synergies and/or constraints within the climate-energy-water nexus, we show that in the United States, over the course of the 21st century and under one set of consistent socioeconomics, the reductions in water stress from slower rates of climate change resulting from emission mitigation are overwhelmed by the increased water stress from the emissions mitigation itself. The finding that the human dimension outpaces the benefits from mitigating climate change is contradictory to the general perception that climate change mitigation improves water conditions. This research shows the potential for unintended and negative consequences of climate change mitigation. PMID:26240363

  20. Future climate change under RCP emission scenarios with GISS ModelE2

    DOE PAGESBeta

    Nazarenko, L.; Schmidt, G. A.; Miller, R. L.; Tausnev, N.; Kelley, M.; Ruedy, R.; Russell, G. L.; Aleinov, I.; Bauer, M.; Bauer, S.; et al

    2015-02-24

    We examine the anthropogenically forced climate response for the 21st century representative concentration pathway (RCP) emission scenarios and their extensions for the period 2101–2500. The experiments were performed with ModelE2, a new version of the NASA Goddard Institute for Space Sciences (GISS) coupled general circulation model that includes three different versions for the atmospheric composition components: a noninteractive version (NINT) with prescribed composition and a tuned aerosol indirect effect (AIE), the TCAD version with fully interactive aerosols, whole-atmosphere chemistry, and the tuned AIE, and the TCADI version which further includes a parameterized first indirect aerosol effect on clouds. Each atmosphericmore » version is coupled to two different ocean general circulation models: the Russell ocean model (GISS-E2-R) and HYCOM (GISS-E2-H). By 2100, global mean warming in the RCP scenarios ranges from 1.0 to 4.5° C relative to 1850–1860 mean temperature in the historical simulations. In the RCP2.6 scenario, the surface warming in all simulations stays below a 2 °C threshold at the end of the 21st century. For RCP8.5, the range is 3.5–4.5° C at 2100. Decadally averaged sea ice area changes are highly correlated to global mean surface air temperature anomalies and show steep declines in both hemispheres, with a larger sensitivity during winter months. By the year 2500, there are complete recoveries of the globally averaged surface air temperature for all versions of the GISS climate model in the low-forcing scenario RCP2.6. TCADI simulations show enhanced warming due to greater sensitivity to CO₂, aerosol effects, and greater methane feedbacks, and recovery is much slower in RCP2.6 than with the NINT and TCAD versions. All coupled models have decreases in the Atlantic overturning stream function by 2100. In RCP2.6, there is a complete recovery of the Atlantic overturning stream function by the year 2500 while with scenario RCP8.5, the

  1. Future climate change under RCP emission scenarios with GISS ModelE2

    SciTech Connect

    Nazarenko, L.; Schmidt, G. A.; Miller, R. L.; Tausnev, N.; Kelley, M.; Ruedy, R.; Russell, G. L.; Aleinov, I.; Bauer, M.; Bauer, S.; Bleck, R.; Canuto, V.; Cheng, Y.; Clune, T. L.; Del Genio, A. D.; Faluvegi, G.; Hansen, J. E.; Healy, R. J.; Kiang, N. Y.; Koch, D.; Lacis, A. A.; LeGrande, A. N.; Lerner, J.; Lo, K. K.; Menon, S.; Oinas, V.; Perlwitz, J.; Puma, M. J.; Rind, D.; Romanou, A.; Sato, M.; Shindell, D. T.; Sun, S.; Tsigaridis, K.; Unger, N.; Voulgarakis, A.; Yao, M. -S.; Zhang, Jinlun

    2015-02-24

    We examine the anthropogenically forced climate response for the 21st century representative concentration pathway (RCP) emission scenarios and their extensions for the period 2101–2500. The experiments were performed with ModelE2, a new version of the NASA Goddard Institute for Space Sciences (GISS) coupled general circulation model that includes three different versions for the atmospheric composition components: a noninteractive version (NINT) with prescribed composition and a tuned aerosol indirect effect (AIE), the TCAD version with fully interactive aerosols, whole-atmosphere chemistry, and the tuned AIE, and the TCADI version which further includes a parameterized first indirect aerosol effect on clouds. Each atmospheric version is coupled to two different ocean general circulation models: the Russell ocean model (GISS-E2-R) and HYCOM (GISS-E2-H). By 2100, global mean warming in the RCP scenarios ranges from 1.0 to 4.5° C relative to 1850–1860 mean temperature in the historical simulations. In the RCP2.6 scenario, the surface warming in all simulations stays below a 2 °C threshold at the end of the 21st century. For RCP8.5, the range is 3.5–4.5° C at 2100. Decadally averaged sea ice area changes are highly correlated to global mean surface air temperature anomalies and show steep declines in both hemispheres, with a larger sensitivity during winter months. By the year 2500, there are complete recoveries of the globally averaged surface air temperature for all versions of the GISS climate model in the low-forcing scenario RCP2.6. TCADI simulations show enhanced warming due to greater sensitivity to CO₂, aerosol effects, and greater methane feedbacks, and recovery is much slower in RCP2.6 than with the NINT and TCAD versions. All coupled models have decreases in the Atlantic overturning stream function by 2100. In RCP2.6, there is a complete recovery of the Atlantic overturning stream function by the year 2500 while with scenario RCP8.5, the E2-R

  2. Greenhouse gas emission response to global change may be limited by vegetation community shifts

    EPA Science Inventory

    Coastal marshes experience a confluence of global changes including climate change, sea level rise, exotic species invasion, and eutrophication. These changes are likely to exert new abiotic stressors and affect interspecific interactions that influence vegetation community stru...

  3. Observations of Geocoronal H-alpha Emission Intensities Over Changing Solar Geophysical Conditions

    NASA Astrophysics Data System (ADS)

    Nossal, S. M.; Roesler, F. L.; Mierkiewicz, E. J.; Reynolds, R. J.; Bishop, J.; Madsen, G.

    2002-05-01

    We will present observations of thermospheric + exospheric hydrogen H-alpha emissions taken by the Wisconsin H-alpha Mapper Fabry-Perot (WHAM) during the time period of 1997 through 2001. WHAM has acquired more than 37,000 spectra to date over about 100 nights. These observations span from near solar minimum through solar maximum conditions. The WHAM Fabry-Perot is located at the Kitt Peak Observatory near Tucson, Arizona and is remotely operable from Wisconsin. WHAM's resolving power is sufficient for the retrieval of the geocoronal H-alpha emission intensity, but not for the resolution of the line profile. The resolution, precision and high signal-to-noise of the WHAM Fabry-Perot facilitate the separation of the terrestrial emission from the galactic emission. Variability in the WHAM geocoronal H-alpha observations over the rise of the solar cycle is limited to within about 35% with higher emissions observed during solar maximum conditions. This result is consistent with observed limits to the variability over the past solar cycle made using similarly designed Fabry-Perot instruments, but with photomultiplier detection, from midlatitude Wisconsin and Haleakala observing sites. These data are also consistent with comparisons made between winter solstice zenith observations taken during the early 1990's from Wisconsin (NSF-CHARM campaign) and WHAM zenith observations.

  4. Reducing abrupt climate change risk using the Montreal Protocol and other regulatory actions to complement cuts in CO2 emissions

    PubMed Central

    Molina, Mario; Zaelke, Durwood; Sarma, K. Madhava; Andersen, Stephen O.; Ramanathan, Veerabhadran; Kaniaru, Donald

    2009-01-01

    Current emissions of anthropogenic greenhouse gases (GHGs) have already committed the planet to an increase in average surface temperature by the end of the century that may be above the critical threshold for tipping elements of the climate system into abrupt change with potentially irreversible and unmanageable consequences. This would mean that the climate system is close to entering if not already within the zone of “dangerous anthropogenic interference” (DAI). Scientific and policy literature refers to the need for “early,” “urgent,” “rapid,” and “fast-action” mitigation to help avoid DAI and abrupt climate changes. We define “fast-action” to include regulatory measures that can begin within 2–3 years, be substantially implemented in 5–10 years, and produce a climate response within decades. We discuss strategies for short-lived non-CO2 GHGs and particles, where existing agreements can be used to accomplish mitigation objectives. Policy makers can amend the Montreal Protocol to phase down the production and consumption of hydrofluorocarbons (HFCs) with high global warming potential. Other fast-action strategies can reduce emissions of black carbon particles and precursor gases that lead to ozone formation in the lower atmosphere, and increase biosequestration, including through biochar. These and other fast-action strategies may reduce the risk of abrupt climate change in the next few decades by complementing cuts in CO2 emissions. PMID:19822751

  5. Changes in the use and management of forests for abating carbon emissions: issues and challenges under the Kyoto Protocol.

    PubMed

    Brown, Sandra; Swingland, Ian R; Hanbury-Tenison, Robin; Prance, Ghillean T; Myers, Norman

    2002-08-15

    The global carbon cycle is significantly influenced by changes in the use and management of forests and agriculture. Humans have the potential through changes in land use and management to alter the magnitude of forest-carbon stocks and the direction of forest-carbon fluxes. However, controversy over the use of biological means to absorb or reduce emissions of CO(2) (often referred to as carbon 'sinks') has arisen in the context of the Kyoto Protocol. The controversy is based primarily on two arguments: sinks may allow developed nations to delay or avoid actions to reduce fossil fuel emissions, and the technical and operational difficulties are too threatening to the successful implementation of land use and forestry projects for providing carbon offsets. Here we discuss the importance of including carbon sinks in efforts to address global warming and the consequent additional social, environmental and economic benefits to host countries. Activities in tropical forest lands provide the lowest cost methods both of reducing emissions and reducing atmospheric concentrations of greenhouse gases. We conclude that the various objections raised as to the inclusion of carbon sinks to ameliorate climate change can be addressed by existing techniques and technology. Carbon sinks provide a practical available method of achieving meaningful reductions in atmospheric concentrations of carbon dioxide while at the same time contribute to national sustainable development goals. PMID:12460486

  6. Changes in timber haul emissions in the context of shifting forest management and infrastructure

    PubMed Central

    Healey, Sean P; Blackard, Jock A; Morgan, Todd A; Loeffler, Dan; Jones, Greg; Songster, Jon; Brandt, Jason P; Moisen, Gretchen G; DeBlander, Larry T

    2009-01-01

    Background Although significant amounts of carbon may be stored in harvested wood products, the extraction of that carbon from the forest generally entails combustion of fossil fuels. The transport of timber from the forest to primary milling facilities may in particular create emissions that reduce the net sequestration value of product carbon storage. However, attempts to quantify the effects of transport on the net effects of forest management typically use relatively sparse survey data to determine transportation emission factors. We developed an approach for systematically determining transport emissions using: 1) -remotely sensed maps to estimate the spatial distribution of harvests, and 2) - industry data to determine landscape-level harvest volumes as well as the location and processing totals of individual mills. These data support spatial network analysis that can produce estimates of fossil carbon released in timber transport. Results Transport-related emissions, evaluated as a fraction of transported wood carbon at 4 points in time on a landscape in western Montana (USA), rose from 0.5% in 1988 to 1.7% in 2004 as local mills closed and spatial patterns of harvest shifted due to decreased logging on federal lands. Conclusion The apparent sensitivity of transport emissions to harvest and infrastructure patterns suggests that timber haul is a dynamic component of forest carbon management that bears further study both across regions and over time. The monitoring approach used here, which draws only from widely available monitoring data, could readily be adapted to provide current and historical estimates of transport emissions in a consistent way across large areas. PMID:19874619

  7. Study of emissivity changes presented by inorganic and organic soil under drying at ambient temperature

    NASA Astrophysics Data System (ADS)

    Villaseñor-Mora, C.; Gonzalez-Vega, A.; Martinez-Torres, P.; Hernández-Arellano, H.

    2015-09-01

    Thermal emissivity can be used to determine the moisture content in soils, but it is strongly influenced by the kind of soil and the organic matter content. These experiments were performed by recording infrared images of the wet soils as a function of water loss. Samples with different organic matter content were wet until reach the field capacity; then, a sequence of thermal images was acquired to follow the different stages of drying process of the studied samples. The emissivity was calculated indirectly by measuring the reflection and absorption of the samples.

  8. Greenhouse gas emissions from agro-ecosystems and their contribution to environmental change in the Indus Basin of Pakistan

    NASA Astrophysics Data System (ADS)

    Iqbal, M. Mohsin; Goheer, M. Arif

    2008-11-01

    There is growing concern that increasing concentrations of greenhouse gases in the atmosphere have been responsible for global warming through their effect on radiation balance and temperature. The magnitude of emissions and the relative importance of different sources vary widely, regionally and locally. The Indus Basin of Pakistan is the food basket of the country and agricultural activities are vulnerable to the effects of global warming due to accelerated emissions of GHGs. Many developments have taken place in the agricultural sector of Pakistan in recent decades in the background of the changing role of the government and the encouragement of the private sector for investment in new ventures. These interventions have considerable GHG emission potential. Unfortunately, no published information is currently available on GHG concentrations in the Indus Basin to assess their magnitude and emission trends. The present study is an attempt to estimate GHG (CO2, CH4 and N2O) emissions arising from different agro-ecosystems of Indus Basin. The GHGs were estimated mostly using the IPCC Guidelines and data from the published literature. The results showed that CH4 emissions were the highest (4.126 Tg yr-1) followed by N2O (0.265 Tg yr-1) and CO2 (52.6 Tg yr-1). The sources of CH4 are enteric fermentation, rice cultivation and cultivation of other crops. N2O is formed by microbial denitrification of NO3 produced from applied fertilizer-N on cropped soils or by mineralization of native organic matter on fallow soils. CO2 is formed by the burning of plant residue and by soil respiration due to the decomposition of soil organic matter.

  9. Estimating national landfill methane emissions: an application of the 2006 Intergovernmental Panel on Climate Change Waste Model in Panama.

    PubMed

    Weitz, Melissa; Coburn, Jeffrey B; Salinas, Edgar

    2008-05-01

    This paper estimates national methane emissions from solid waste disposal sites in Panama over the time period 1990-2020 using both the 2006 Intergovernmental Panel on Climate Change (IPCC) Waste Model spreadsheet and the default emissions estimate approach presented in the 1996 IPCC Good Practice Guidelines. The IPCC Waste Model has the ability to calculate emissions from a variety of solid waste disposal site types, taking into account country- or region-specific waste composition and climate information, and can be used with a limited amount of data. Countries with detailed data can also run the model with country-specific values. The paper discusses methane emissions from solid waste disposal; explains the differences between the two methodologies in terms of data needs, assumptions, and results; describes solid waste disposal circumstances in Panama; and presents the results of this analysis. It also demonstrates the Waste Model's ability to incorporate landfill gas recovery data and to make projections. The former default method methane emissions estimates are 25 Gg in 1994, and range from 23.1 Gg in 1990 to a projected 37.5 Gg in 2020. The Waste Model estimates are 26.7 Gg in 1994, ranging from 24.6 Gg in 1990 to 41.6 Gg in 2020. Emissions estimates for Panama produced by the new model were, on average, 8% higher than estimates produced by the former default methodology. The increased estimate can be attributed to the inclusion of all solid waste disposal in Panama (as opposed to only disposal in managed landfills), but the increase was offset somewhat by the different default factors and regional waste values between the 1996 and 2006 IPCC guidelines, and the use of the first-order decay model with a time delay for waste degradation in the IPCC Waste Model. PMID:18512440

  10. The effect of localized surface plasmon resonance on the emission color change in organic light emitting diodes

    NASA Astrophysics Data System (ADS)

    Lee, Illhwan; Park, Jae Yong; Hong, Kihyon; Son, Jun Ho; Kim, Sungjun; Lee, Jong-Lam

    2016-03-01

    Three primary colors, cyan, yellow, and green, are obtained from Ag nano-dot embedded organic light emitting diodes (OLEDs) by localized surface plasmon resonance (LSPR). By changing the thickness of the Ag film, the size and spacing of Ag nano-dots are controlled. The generated light from the emissive layer in the OLEDs interacts with the free electrons near the surface of the Ag nano-dots, which leads to LSPR absorption and scattering. The UV-visible absorption spectra of glass/ITO/Ag nano-dot samples show intense peaks from 430 nm to 520 nm with an increase of Ag nano-dot size. And also, the Rayleigh scattering spectra results show the plasmon resonance wavelength in the range of 470-550 nm. The effect of the LSPR of Ag nano-dots on the change of emission color in OLEDs is demonstrated using 2 dimensional finite-difference time-domain simulations. The intensity of the electro-magnetic field in the sample with 5 nm-thick Ag is low at the incident wavelength of 500 nm, but it increases with the incident wavelength. This provides evidence that the emission color change in OLEDs originates from LSPR at the Ag nano-dots. As a result, the emission peak wavelength of OLEDs shifted toward longer wavelengths, from cyan to yellow-green, with the increase of Ag nano-dot size.Three primary colors, cyan, yellow, and green, are obtained from Ag nano-dot embedded organic light emitting diodes (OLEDs) by localized surface plasmon resonance (LSPR). By changing the thickness of the Ag film, the size and spacing of Ag nano-dots are controlled. The generated light from the emissive layer in the OLEDs interacts with the free electrons near the surface of the Ag nano-dots, which leads to LSPR absorption and scattering. The UV-visible absorption spectra of glass/ITO/Ag nano-dot samples show intense peaks from 430 nm to 520 nm with an increase of Ag nano-dot size. And also, the Rayleigh scattering spectra results show the plasmon resonance wavelength in the range of 470-550 nm. The

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  13. Spatially-Explicit Estimates of Greenhouse Gas Emissions from Fire and Land-Use Change in the Brazilian Cerrado

    NASA Astrophysics Data System (ADS)

    Galford, G. L.; Spera, S. A.; Coe, M. T.; Costa, C., Jr.

    2014-12-01

    Understanding the multiple types of land-use changes that can occur within an ecosystem provides a comprehensive picture of the human's impact on natural systems. We use the Cerrado (savanna) of Brazil to examine the primary and secondary impacts of land-use change on greenhouse gas emissions. The primary land-use changes include fires for land-clearing, conversions to pasture and row-crop agriculture, and shifting management practices of agricultural lands. Secondary land-use changes include savanna degradation due to fires that escape from intended burn areas. These escape fires typically have a lower combustion completion coefficient than clearing fires, so it is important to distinguish them to correctly estimate the regional greenhouse gas budget. We have created a first-order spatio-temporal model of greenhouse gas emissions that can be easily modified for other savanna regions using globally available data products as inputs. Our data inputs are derived from publically available remote sensing imagery. Initial biomass is estimated by Baccini et al. 2012, which is derived from LiDAR and MODIS imagery. All other input data sets give annual estimates. Clearing of the savanna is documented by LAPIG of Universidade Federal de Goias using MODIS (MOD13Q1), LANDSAT and CBERS images. MODIS burned area products delineate annual fires; in combination with the savanna clearing database we determine primary and escape fires. Pastures and row-crop agriculture are documented by LAPIG and Spera et al. 2014, respectively. The row-crop agriculture dataset enables us to estimate greenhouse gas emissions associated with specific crops (e.g., soy or maize) and management (e.g., fertilizer use). Recent contributions to the literature have provided many in situ measurements from the land-use changes of interest needed to estimate a regional greenhouse gas budget, including combustion coefficients of savanna sub-types, carbon emission soil stocks, nitrogen emissions from fertilizer

  14. Production, management, and environment symposium: Environmental footprint of livestock production - Greenhouse gas emissions and climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This manuscript is the introduction to the 2015 Production, Management, and Environment symposium titled “Environmental Footprint of Livestock Production – Greenhouse Gas Emissions and Climate Change” that was held at the Joint Annual Meeting of the ASAS and ADSA at the Rosen Shingle Creek Resort in...

  15. The Implications of Future Food Demand on Global Land Use, Land-Use Change Emissions, and Climate

    NASA Astrophysics Data System (ADS)

    Calvin, K. V.; Wise, M.; Kyle, P.; Luckow, P.; Clarke, L.; Edmonds, J.; Eom, J.; Kim, S.; Moss, R.; Patel, P.

    2011-12-01

    In 2005, cropland accounted for approximately 10% of global land area. The amount of cropland needed in the future depends on a number of factors including global population, dietary preferences, and agricultural crop yields. In this paper, we explore the effect of various assumptions about global food demand and agricultural productivity between now and 2100 on global land use, land-use change emissions, and climate using the GCAM model. GCAM is a global integrated assessment model, linking submodules of the regionally disaggregated, global economy, energy system, agriculture and land-use, terrestrial carbon cycle, oceans and climate. GCAM simulates supply, demand, and prices for energy and agricultural goods from 2005 to 2100 in 5-year increments. In each time period, the model computes the allocation of land across a variety of land cover types in 151 different regions, assuming that farmers maximize profits and that food demand is relatively inelastic. For this analysis, we look at the effect of alternative socioeconomic pathways, crop yield improvement assumptions, and future meat demand scenarios on the demand for agricultural land. The three socioeconomic pathways explore worlds where global population in 2100 ranges from 6 billion people to 14 billion people. The crop yield improvement assumptions range from a world where yields do not improve beyond today's levels to a world with significantly higher crop productivity. The meat demand scenarios range from a vegetarian world to a world where meat is a dominant source of calories in the global diet. For each of these scenarios, we find that sufficient land exists to feed the global economy. However, rates of deforestation, bioenergy potential, land-use change emissions, and climate change differ across the scenarios. Under less favorable scenarios, deforestation rates, land-use change emissions, and the rate of climate change can be adversely affected.

  16. Mitigating greenhouse gas emissions with agricultural land management changes: What practices hold the best potential?

    NASA Astrophysics Data System (ADS)

    Eagle, A. J.; Olander, L.; Rice, C. W.; Haugen-Kozyra, K.; Henry, L. R.; Baker, J. S.; Jackson, R. B.

    2010-12-01

    Agricultural land management practices within the United States have significant potential to mitigate greenhouse gases (GHGs) in voluntary market or regulatory contexts - by sequestering soil carbon or reducing N2O or CH4 emissions. Before these practices can be utilized in active protocols or within a regulatory or farm bill framework, we need confidence in our ability to determine their impact on GHG emissions. We develop a side-by-side comparison of mitigation potential and implementation readiness for agricultural GHG mitigation practices, with an extensive literature review. We also consider scientific certainty, environmental and social co-effects, economic factors, regional specificity, and possible implementation barriers. Biophysical GHG mitigation potential from agricultural land management activities could reach more than 500 Mt CO2e/yr in the U.S. (7.1% of annual emissions). Up to 75% of the total potential comes from soil C sequestration. Economic potential is lower, given necessary resources to incentivize on-farm adaptations, but lower cost activities such as no-till, fertilizer N management, and cover crops show promise for near-term implementation in certain regions. Scientific uncertainty or the need for more research limit no-till and rice water management in some areas; and technical or other barriers need to be addressed before biochar, advanced crop breeding, and agroforestry can be widely embraced for GHG mitigation. Significant gaps in the current research and knowledge base exist with respect to interactions between tillage and N2O emissions, and with fertilizer application timing impacts on N2O emissions.

  17. Regional air quality management aspects of climate change: impact of climate mitigation options on regional air emissions.

    PubMed

    Rudokas, Jason; Miller, Paul J; Trail, Marcus A; Russell, Armistead G

    2015-04-21

    We investigate the projected impact of six climate mitigation scenarios on U.S. emissions of carbon dioxide (CO2), sulfur dioxide (SO2), and nitrogen oxides (NOX) associated with energy use in major sectors of the U.S. economy (commercial, residential, industrial, electricity generation, and transportation). We use the EPA U.S. 9-region national database with the MARKet Allocation energy system model to project emissions changes over the 2005 to 2050 time frame. The modeled scenarios are two carbon tax, two low carbon transportation, and two biomass fuel choice scenarios. In the lower carbon tax and both biomass fuel choice scenarios, SO2 and NOX achieve reductions largely through pre-existing rules and policies, with only relatively modest additional changes occurring from the climate mitigation measures. The higher carbon tax scenario projects greater declines in CO2 and SO2 relative to the 2050 reference case, but electricity sector NOX increases. This is a result of reduced investments in power plant NOX controls in earlier years in anticipation of accelerated coal power plant retirements, energy penalties associated with carbon capture systems, and shifting of NOX emissions in later years from power plants subject to a regional NOX cap to those in regions not subject to the cap. PMID:25803240

  18. 47 CFR 5.77 - Change in equipment and emission characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... fixed location: (1) Any change that will either increase the height of a structure supporting the radiating portion of the antenna or decrease the height of a lighted antenna structure. (2) Any change...

  19. Impact of land use change on wind erosion and dust emission: scenarios from the central US

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There will be significant changes in land cover and land use throughout the central United States in the coming years, particularly as a result of climate change, changes in US rangeland/farm policy, and increasing exploitation of land-intensive sustainable energy sources. The purpose of this study ...

  20. DETECTING LAND COVER CHANGE AT THE JORNADA EXPERIMENTAL RANGE, NEW MEXICO WITH ASTER EMISSIVITIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Detecting land cover change over semi-arid rangeland is important for monitoring vegetation responses to drought, population expansion, and changing agricultural practices. Such change can be detected using vegetation indices, but these do not represent non-green vegetation and are dominated by seas...

  1. Luminosity-dependent change of the emission diagram in the X-ray pulsar 4U 1626-67

    NASA Astrophysics Data System (ADS)

    Koliopanos, Filippos; Gilfanov, Marat

    2016-03-01

    We detect variability of the Fe K α emission line in the spectrum of X-ray pulsar 4U 1626-67, correlated with changes in its luminosity and in the shape of its pulse profile. Analysis of archival Chandra and RXTE observations revealed the presence of an intrinsically narrow Fe K α emission line in the spectrum obtained during the source's current high-luminosity period. However, the line was not present during an XMM-Newton observation seven years earlier, when the source was ˜three times fainter. The line is resolved by the high-energy grating of Chandra at the 98 per cent confidence level, and its small intrinsic width, σ =36.4_{-11.3}^{+15.3} eV, suggests reflection off an accretion disc at the radius R≈ (7.5_{-3.8}^{+8.2})× 10^8 cm assuming a Keplerian disk, viewed at an inclination angle of 20°. This value is consistent with the radius of the magnetosphere of the pulsar, suggesting that the line originates near the inner edge of a disc that is truncated by the magnetic field of the neutron star. Timing analysis of the XMM-Newton and RXTE data revealed a major change in the pulse profile of the source from a distinct double-peaked shape during the high-luminosity state when the line was present, to a much more complex multipeak structure during the low-luminosity state. We argue that the appearance of the line and the change in the shape of the pulse profile are correlated and are the result of a major change in the emission diagram of the accretion column, from a pencil-beam pattern at low luminosity, to a fan-beam pattern at high luminosity.

  2. Evaluation of blood-brain barrier permeability changes in rhesus monkeys and man using 82Rb and positron emission tomography

    SciTech Connect

    Yen, C.K.; Budinger, T.F.

    1981-12-01

    Dynamic positron tomography of the brain with /sup 82/Rb, obtained from a portable generator (/sup 82/Sr (25 days) - /sup 82/Rb (76 sec)), provides a means of studying blood-brain barrier (BBB) permeability in physiological and clinical investigations. The BBB in rhesus monkeys was opened unilaterally be intracarotid infusion of 3 M urea. This osmotic barrier opening allowed entry into the brain of intravenously administered rubidium chloride. The BBB opening was demonstrated noninvasively using /sup 82/Rb and positron emission tomography and corroborated by the accumulation of /sup 86/Rb in tissue samples. Positron emission tomography studies can be repeated every 5 min and indicate that dynamic tomography or static imaging can be used to study BBB permeability changes induced by a wide variety of noxious stimuli. Brain tumors in human subjects are readily detected because of the usual BBB permeability disruption in and around the tumors.

  3. [Carbon emissions and low-carbon regulation countermeasures of land use change in the city and town concentrated area of central Liaoning Province, China].

    PubMed

    Xi, Feng-ming; Liang, Wen-juan; Niu, Ming-fen; Wang, Jiao-yue

    2016-02-01

    Carbon emissions due to land use change have an important impact on global climate change. Adjustment of regional land use patterns has a great scientific significance to adaptation to a changing climate. Based on carbon emission/absorption parameters suitable for Liaoning Province, this paper estimated the carbon emission of land use change in the city and town concentrated area of central Liaoning Province. The results showed that the carbon emission and absorption were separately 308.51 Tg C and 11.64 Tg C from 1997 to 2010. It meant 3.8% of carbon emission. was offset by carbon absorption. Among the 296.87 Tg C net carbon emission of land use change, carbon emission of remaining land use type was 182.24 Tg C, accounting for 61.4% of the net carbon emission, while the carbon emission of land use transformation was 114.63 Tg C, occupying the rest 38.6% of net carbon emission. Through quantifying the mapping relationship between land use change and carbon emission, it was shown that during 1997-2004 the contributions of remaining construction land (40.9%) and cropland transform ation to construction land (40.6%) to carbon emission were larger, but the greater contributions to carbon absorption came from cropland transformation to forest land (38.6%) and remaining forest land (37.5%). During 2004-2010, the land use types for carbon emission and absorption were the same to the period of 1997-2004, but the contribution of remaining construction land to carbon emission increased to 80.6%, and the contribution of remaining forest land to carbon absorption increased to 71.7%. Based on the carbon emission intensity in different land use types, we put forward the low-carbon regulation countermeasures of land use in two aspects. In carbon emission reduction, we should strict control land transformation to construction land, increase the energy efficiency of construction land, and avoid excessive development of forest land and water. In carbon sink increase, we should

  4. Increased influence of nitrogen limitation on CO2 emissions from future land use and land-use change

    NASA Astrophysics Data System (ADS)

    Jain, A. K.; Meiyappan, P.; House, J.

    2015-12-01

    In the latest projections of future greenhouse gas emissions for the Intergovernmental Panel on Climate Change (IPCC), few Earth System Models included the effect of nitrogen limitation, a key process limiting forest regrowth. We estimate the impacts of nitrogen limitation on the CO2 emissions from land use and land-use change (LULUC), including wood harvest, for the period 1900-2100. We use a land-surface model that includes a fully coupled carbon and nitrogen cycle, and accounts for forest regrowth processes following agricultural abandonment and wood harvest. Future projections are based on the four Representation Concentration Pathways used in the IPCC Fifth Assessment Report, and we account for uncertainty in future climate for each scenario based on ensembles of climate model outputs. Results show that excluding nitrogen limitation will underestimate global LULUC emissions by 34-52 PgC (20-30%) during the 20th century (range across three different historical LULUC reconstructions) and by 128-187 PgC (90-150%) during the 21st century (range across the four IPCC scenarios). The full range for estimated LULUC emissions during the 21st century including climate model uncertainty is 91 to 227 PgC (with nitrogen limitation included). The underestimation increases with time because: (1) Projected annual wood harvest rates from forests summed over the 21st century are 380-1080% higher compared to those of the 20th century, resulting in more regrowing secondary forests, (2) Nitrogen limitation reduces the CO2 fertilization effect on net primary production of regrowing secondary forests following wood harvest and agricultural abandonment, and (3) Nitrogen limitation effect is aggravated by the gradual loss of soil nitrogen from LULUC disturbance. Our study implies that: (1) Nitrogen limitation of CO2 uptake is substantial and sensitive to nitrogen inputs, (2) If LULUC emissions are larger than previously estimated in studies without nitrogen limitation, then meeting

  5. Increased influence of nitrogen limitation on CO2 emissions from future land use and land use change

    NASA Astrophysics Data System (ADS)

    Meiyappan, Prasanth; Jain, Atul K.; House, Joanna I.

    2015-09-01

    In the latest projections of future greenhouse gas emissions for the Intergovernmental Panel on Climate Change (IPCC), few Earth System Models included the effect of nitrogen limitation, a key process limiting forest regrowth. Few included forest management (wood harvest). We estimate the impacts of nitrogen limitation on the CO2 emissions from land use and land use change (LULUC), including wood harvest, for the period 1900-2100. We use a land surface model that includes a fully coupled carbon and nitrogen cycle and accounts for forest regrowth processes following agricultural abandonment and wood harvest. Future projections are based on the four Representation Concentration Pathways used in the IPCC Fifth Assessment Report, and we account for uncertainty in future climate for each scenario based on ensembles of climate model outputs. Results show that excluding nitrogen limitation will underestimate global LULUC emissions by 34-52 PgC (20-30%) during the 20th century (range across three different historical LULUC reconstructions) and by 128-187 PgC (90-150%) during the 21st century (range across the four IPCC scenarios). The full range for estimated LULUC emissions during the 21st century including climate model uncertainty is 91 to 227 PgC (with nitrogen limitation included). The underestimation increases with time because (1) projected annual wood harvest rates from forests summed over the 21st century are 380-1080% higher compared to those of the 20th century, resulting in more regrowing secondary forests; (2) nitrogen limitation reduces the CO2 fertilization effect on net primary production of regrowing secondary forests following wood harvest and agricultural abandonment; and (3) nitrogen limitation effect is aggravated by the gradual loss of soil nitrogen from LULUC disturbance. Our study implies that (1) nitrogen limitation of CO2 uptake is substantial and sensitive to nitrogen inputs; (2) if LULUC emissions are larger than previously estimated in studies

  6. Modeling of global biogenic emissions for key indirect greenhouse gases and their response to atmospheric CO2 increases and changes in land cover and climate

    NASA Astrophysics Data System (ADS)

    Tao, Zhining; Jain, Atul K.

    2005-11-01

    Natural emissions of nonmethane volatile organic compounds (NMVOCs) play a crucial role in the oxidation capacity of the lower atmosphere and changes in concentrations of major greenhouse gases (GHGs), particularly methane and tropospheric ozone. In this study, we integrate a global biogenic model within a terrestrial ecosystem model to investigate the vegetation and soil emissions of key indirect GHGs, e.g., isoprene, monoterpene, other NMVOCs (OVOC), CO, and NOx. The combination of a high-resolution terrestrial ecosystem model with satellite data allows investigation of the potential changes in net primary productivity (NPP) and resultant biogenic emissions of indirect GHGs due to atmospheric CO2 increases and changes in climate and land use practices. Estimated global total annual vegetation emissions for isoprene, monoterpene, OVOC, and CO are 601, 103, 102, and 73 Tg C, respectively. Estimated NOx emissions from soils are 7.51 Tg N. The land cover changes for croplands generally lead to a decline of vegetation emissions for isoprene OVOC, whereas temperature and atmospheric CO2 increases lead to higher vegetation emissions. The modeled global mean isoprene emissions show relatively large seasonal variations over the previous 20 years from 1981 to 2000 (as much as 31% from year to year). Savanna and boreal forests show large seasonal variations, whereas tropical forests with high plant productivity throughout the year show small seasonal variations. Results of biogenic emissions from 1981 to 2000 indicate that the CO2 fertilization effect, along with changes in climate and land use, causes the overall up-trend in isoprene and OVOC emissions over the past 2 decades. This relationship suggests that future emission scenario estimations for NMVOCs should account for effects of CO2 and climate in order to more accurately estimate local, regional, and global chemical composition of the atmosphere, the global carbon budget, and radiation balance of the Earth

  7. Changes in the carbon dioxide emission from soils in the course of postagrogenic succession in the Chernozems forest-steppe

    NASA Astrophysics Data System (ADS)

    Karelin, D. V.; Lyuri, D. I.; Goryachkin, S. V.; Lunin, V. N.; Kudikov, A. V.

    2015-11-01

    The CO2 emission from soils in the course of the long-term postagrogenic succession on Calcic Chernozems under meadow-steppe vegetation was studied. Seasonal dynamics of the emission at different stages of the restoration of natural vegetation and long-term changes in the main pools of carbon in the soils and phytomass were examined. These data were used to create a regression model of the CO2 emission on the basis of data on the soil water content and temperature with a temporal resolution of 3 h. The results were compared with an analogous study of the postagrogenic succession on sandy Agropodzols of southern taiga. It was found that the long-term pattern of the CO2 emission has a bimodal character. The first maximum corresponds to the early stages of the succession (2-8 years) and is ensured by a sharp intensification of respiration in the organomineral soil horizons under the impact of plant species typical of these stages, active growth of their underground parts, and, probably, activation of microbiota in the rhizosphere. The second maximum of the emission is observed at the final stages of the succession and is mainly ensured by the increasing pool of steppe litter. A decrease in the soil temperature because of the thermal insulation of the soil surface by the accumulating litter and organic substances in the topsoil horizons leads to a temporary decrease in the emission intensity at the middle stages of the succession, when the litter pool is still not vary large. The restoration of the initial level of the CO2 emission typical of the natural cenoses is achieved in about 80-100 years after the abandoning of the cultivated fields, i.e., considerably faster than that in the southern taiga zone (150-170 years). The results of modeling suggest that this is caused by the considerable accumulation of steppe litter, organic substances, and phytomass in the topsoil horizons rather than by the somewhat increased heat supply owing to longer duration of vegetation

  8. Innovative approach to retrieve land surface emissivity and land surface temperature in areas of highly dynamic emissivity changes by using thermal infrared data

    NASA Astrophysics Data System (ADS)

    Heinemann, S.

    2015-12-01

    The land surface temperature (LST) is an extremely significant parameter in order to understand the processes of energetic interactions between Earth's surface and atmosphere. This knowledge is significant for various environmental research questions, particularly with regard to the recent climate change. This study shows an innovative approach to retrieve land surface emissivity (LSE) and LST by using thermal infrared (TIR) data from satellite sensors, such as SEVIRI and AATSR. So far there are no methods to derive LSE/LST particularly in areas of highly dynamic emissivity changes. Therefore especially for regions with large surface temperature amplitude in the diurnal cycle such as bare and uneven soil surfaces but also for regions with seasonal changes in vegetation cover including various surface areas such as grassland, mixed forests or agricultural land different methods were investigated to identify the most appropriate one. The LSE is retrieved by using the day/night Temperature-Independent Spectral Indices (TISI) method, and the Generalised Split-Window (GSW) method is used to retrieve the LST. Nevertheless different GSW algorithms show that equal LSEs lead to large LST differences. Additionally LSE is also measured using a NDVI-based threshold method (NDVITHM) to distinguish between soil, dense vegetation cover and pixel composed of soil and vegetation. The data used for this analysis were derived from MODIS TIR. The analysis is implemented with IDL and an intercomparison is performed to determine the most effective methods. To compensate temperature differences between derived and ground truth data appropriate correction terms by comparing derived LSE/LST data with ground-based measurements are developed. One way to calibrate LST retrievals is by comparing the canopy leaf temperature of conifers derived from TIR data with the surrounding air temperature (e.g. from synoptic stations). Prospectively, the derived LSE/LST data become validated with near

  9. Innovative approach to retrieve land surface emissivity and land surface temperature in areas of highly dynamic emissivity changes by using thermal infrared data

    NASA Astrophysics Data System (ADS)

    Heinemann, Sascha; Muro, Javier; Burkart, Andreas; Schultz, Johannes; Thonfeld, Frank; Menz, Gunter

    2016-04-01

    The land surface temperature (LST) is an extremely significant parameter in order to understand the processes of energetic interactions between the Earth's surface and the atmosphere. This knowledge is significant for various environmental research questions, particularly with regard to climate change. The current challenge is to reduce the higher deviations during daytime especially for bare areas with a maximum of 5.7 Kelvin. These temperature differences are time and vegetation cover dependent. This study shows an innovative approach to retrieve land surface emissivity (LSE) and LST by using thermal infrared (TIR) data from satellite sensors, such as SEVIRI and AATSR. So far there are no methods to derive LSE/LST particularly in areas of highly dynamic emissivity changes. Therefore especially for regions with large surface temperature amplitude in the diurnal cycle such as bare and uneven soil surfaces but also for regions with seasonal changes in vegetation cover including various surface areas such as grassland, mixed forests or agricultural land different methods were investigated to identify the most appropriate one. The LSE is retrieved by using the day/night Temperature-Independent Spectral Indices (TISI) method, while the Generalised Split-Window (GSW) method is used to retrieve the LST. Nevertheless different GSW algorithms show that equal LSEs lead to large LST differences. For bare surfaces during daytime the difference is about 6 Kelvin. Additionally LSE is also measured using a NDVI-based threshold method (NDVITHM) to distinguish between soil, dense vegetation cover and pixel composed of soil and vegetation. The data used for this analysis were derived from MODIS TIR. The analysis is implemented with IDL and an intercomparison is performed to determine the most effective methods. To compensate temperature differences between derived and ground truth data appropriate correction terms, by comparing derived LSE/LST data with ground-based measurements

  10. Reduction on NOx emissions on urban areas by changing specific vehicle fleets: effects on NO2 and O3 concentration

    NASA Astrophysics Data System (ADS)

    Goncalves, M.; Jimenez, P.; Baldasano, J.

    2007-12-01

    The largest amount of NOx emissions in urban areas comes from on-road traffic, which is the largest contributor to urban air pollution (Colvile et al., 2001). Currently different strategies are being tested in order to reduce its effects; many of them oriented to the reduction of the unitary vehicles emissions, by alternative fuels use (such as biofuels, natural gas or hydrogen) or introduction of new technologies (such as hybrid electric vehicles or fuel cells). Atmospheric modelling permits to predict their consequences on tropospheric chemistry (Vautard et al., 2007). Hence, this work assesses the changes on NO2 and O3 concentrations when substituting a 10 per cent of the urban private cars fleets by petrol hybrid electric cars (HEC) or by natural gas cars (NGC) in Madrid and Barcelona urban areas (Spain). These two cities are selected in order to highlight the different patterns of pollutants transport (inland vs. coastal city) and the different responses to emissions reductions. The results focus on a typical summertime episode of air pollution, by means of the Eulerian air quality model ARW- WRF/HERMES/CMAQ, applied with high resolution (1-hr, 1km2) since of the complexity of both areas under study. The detailed emissions scenarios are implemented in the HERMES traffic emissions module, based on the Copert III-EEA/EMEP-CORINAIR (Nztiachristos and Samaras, 2000) methodology. The HEC introduction reduces NOx emissions from on-road traffic in a 10.8 per cent and 8.2 per cent; and the NGC introduction in a 10.3 per cent and 7.8 per cent, for Madrid and Barcelona areas, respectively. The scenarios also affect the NMVOCs reduction (ranging from -3.1 to -6.9 per cent), influencing the tropospheric photochemistry through the NOx/NMVOCs ratio. The abatement of the NO photooxidation but also to the reduction on primary NO2 involves a decrease on NO2 levels centred on urban areas. For example, the NO2 24-hr average concentration in downtown areas reduces up to 8 per

  11. Influence of (FeO + TiO2) abundance on the thermal emission from the lunar regolith using Chang'E-2 microwave radiometer data

    NASA Astrophysics Data System (ADS)

    Meng, Zhiguo; Ping, Jinsong; Xu, Yi; Cai, Zhanchuan; Zheng, Yongchun

    Abstract:The microwave radiometer data obtained from Chang’E-2 mission (CELMS data) has provided new opportunity to study the influence of the (FeO+TiO2) abundance on the microwave thermal emission of the lunar regolith. In this paper, the radiative transfer simulation is employed to study the change of the brightness temperature with (FeO+TiO2) abundance at different frequencies and surface temperature. The (FeO+TiO2) abundance are derived from Clementine UV-VIS data and the samples from Apollo, Luna and Surveyor projects. The simulation results along the Equator indicate that the (FeO+TiO2) abundance has strong impact on the microwave thermal emission of the lunar regolith. However, the data along the Longitude 0° shows that the (FeO+TiO2) abundance is not the dominant influential factor of the microwave thermal emission of the lunar regolith. Specifically, the abnormal brightness temperature at 160°W (Unnamed crater), 138°W (Crater Vavilov), 125°W (Crater Hertzsprung), 116°E (Crater Abul Wáfa), 119°E (Crater Heron), 130°E (Crater Catena Gregory) and 140°E (Crater Catena Mendeleev) shows that the (FeO+TiO2) abundance is not the only influential factor for the observed brightness temperature. In addition, the correlations between the four-channel brightness temperature and the (FeO+TiO2) abundance in Apollo landing site and along the Equator both indicate that the (FeO+TiO2) abundance is slightly decreasing with depth. The research is essential for the inversion of the lunar regolith parameters with the microwave radiometer data from Chang’E satellites. Keywords: lunar regolith, microwave thermal emission, CELMS data, (FeO+TiO2) abundance

  12. Including adaptation and mitigation responses to climate change in a multiobjective evolutionary algorithm framework for urban water supply systems incorporating GHG emissions

    NASA Astrophysics Data System (ADS)

    Paton, F. L.; Maier, H. R.; Dandy, G. C.

    2014-08-01

    Cities around the world are increasingly involved in climate action and mitigating greenhouse gas (GHG) emissions. However, in the context of responding to climate pressures in the water sector, very few studies have investigated the impacts of changing water use on GHG emissions, even though water resource adaptation often requires greater energy use. Consequently, reducing GHG emissions, and thus focusing on both mitigation and adaptation responses to climate change in planning and managing urban water supply systems, is necessary. Furthermore, the minimization of GHG emissions is likely to conflict with other objectives. Thus, applying a multiobjective evolutionary algorithm (MOEA), which can evolve an approximation of entire trade-off (Pareto) fronts of multiple objectives in a single run, would be beneficial. Consequently, the main aim of this paper is to incorporate GHG emissions into a MOEA framework to take into consideration both adaptation and mitigation responses to climate change for a city's water supply system. The approach is applied to a case study based on Adelaide's southern water supply system to demonstrate the framework's practical management implications. Results indicate that trade-offs exist between GHG emissions and risk-based performance, as well as GHG emissions and economic cost. Solutions containing rainwater tanks are expensive, while GHG emissions greatly increase with increased desalinated water supply. Consequently, while desalination plants may be good adaptation options to climate change due to their climate-independence, rainwater may be a better mitigation response, albeit more expensive.

  13. 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.

  14. Evaluation of historical land cover, land use, and land-use change emissions in the GCAM integrated assessment model

    NASA Astrophysics Data System (ADS)

    Calvin, K. V.; Wise, M.; Kyle, P.; Janetos, A. C.; Zhou, Y.

    2012-12-01

    Integrated Assessment Models (IAMs) are often used as science-based decision-support tools for evaluating the consequences of climate and energy policies, and their use in this framework is likely to increase in the future. However, quantitative evaluation of these models has been somewhat limited for a variety of reasons, including data availability, data quality, and the inherent challenges in projections of societal values and decision-making. In this analysis, we identify and confront methodological challenges involved in evaluating the agriculture and land use component of the Global Change Assessment Model (GCAM). GCAM is a global integrated assessment model, linking submodules of the regionally disaggregated global economy, energy system, agriculture and land-use, terrestrial carbon cycle, oceans and climate. GCAM simulates supply, demand, and prices for energy and agricultural goods from 2005 to 2100 in 5-year increments. In each time period, the model computes the allocation of land across a variety of land cover types in 151 different regions, assuming that farmers maximize profits and that food demand is relatively inelastic. GCAM then calculates both emissions from land-use practices, and long-term changes in carbon stocks in different land uses, thus providing simulation information that can be compared to observed historical data. In this work, we compare GCAM results, both in recent historic and future time periods, to historical data sets. We focus on land use, land cover, land-use change emissions, and albedo.

  15. Sensitivity of air quality to potential future climate change and emissions in the United States and major cities

    NASA Astrophysics Data System (ADS)

    Trail, M.; Tsimpidi, A. P.; Liu, P.; Tsigaridis, K.; Rudokas, J.; Miller, P.; Nenes, A.; Hu, Y.; Russell, A. G.

    2014-09-01

    Simulated present and future air quality is compared for the years 2006-2010 and 2048-2052 over the contiguous United States (CONUS) using the Community Multi-scale Air Quality (CMAQ) model. Regionally downscaled present and future climate results are developed using GISS and the Weather Research Forecasting (WRF) model. Present and future emissions are estimated using MARKAL 9R model. O3 and PM2.5 sensitivities to precursor emissions for the years 2010 and 2050 are calculated using CMAQ-DDM (Direct Decoupled Method). We find major improvements in future U.S. air quality including generally decreased MDA8 (maximum daily 8-hr average O3) mixing ratios and PM2.5 concentrations and reduced frequency of NAAQS O3 standard exceedances in most major U.S. cities. The Eastern and Pacific U.S. experience the largest reductions in summertime seasonal average MDA8 (up to 12 ppb) with localized decreases in the 4th highest MDA8 of the year, decreasing by up to 25 ppb. Results from a Climate Penalty (CP) scenario isolate the impact of climate change on air quality and show that future climate change tends to increase O3 mixing ratios in some regions of the U.S., with climate change causing increases of over 10 ppb in the annual 4th highest MDA8 in Los Angeles. Seasonal average PM2.5 decreases (2-4 μg m-3) over the Eastern U.S. are accounted for by decreases in sulfate and nitrate concentrations resulting from reduced mobile and point source emissions of NOx and SOx.

  16. Brain dopaminergic system changes in drug addiction: a review of positron emission tomography findings.

    PubMed

    Hou, Haifeng; Wang, Chunyan; Jia, Shaowei; Hu, Shu; Tian, Mei

    2014-10-01

    Dopamine (DA) is considered crucial for the rewarding effects of drugs of abuse, but its role in addiction remains unclear. Positron emission tomography (PET) is the first technology used for in vivo measurement of components of the dopaminergic system in the human brain. In this article, we review the major findings from PET imaging studies on the involvement of DA in drug addiction, including presynaptic DA synthesis, vesicular monoamine transporter 2, the DA transporter, and postsynaptic DA receptors. These results have corroborated the role of DA in addiction and increased the understanding of its underlying mechanisms. PMID:25260796

  17. Scenario analysis on the goal of carbon emission peaking around 2030 of China proposed in the China-U.S. joint statement on climate change

    NASA Astrophysics Data System (ADS)

    Zheng, T.

    2015-12-01

    A goal of carbon (C) emission peaking around 2030 of China was declared in the China-U.S. joint statement on climate change, and emphasized in China's intended nationally determined contributions (INDC). Here, we predicted the carbon emission of China during the period 2011~2050 under seven scenarios, and analyzed the scientific and social implications of realizing the goal. Our results showed that: (1) C emissions of China will reach their peaks at 2022~2045 (with peak values 3.15~5.10 Pg C), and the predicted decay rates of C intensity were 2.1~4.2% in 2011~2050; (2) the precondition that the national C emission reaches the peak before 2030 is that the annual decay rates of C intensity must exceed 3.3% , as decay rates under different scenarios were predicted higher than that except for Past G8 scenario; (3) the national C emission would reach the peak before 2030, if the government of China should realize the C emissions reduction goals of China's 12th five-year plan, climate commitments of Copenhagen and INDC; (4) Chinese government could realize the goal of C emission peaking around 2030 from just controlling C emission intensity , but associated with relatively higher government's burden. In summary, China's C emission may well peak before 2030, meanwhile the combination of emissions reduction and economic macro-control would be demanded to avoid heavier social pressure of C emissions reduction occurred.

  18. Imprint of North-Atlantic abrupt climate changes on western European loess deposits as viewed in a dust emission model

    NASA Astrophysics Data System (ADS)

    Sima, Adriana; Rousseau, Denis-Didier; Kageyama, Masa; Ramstein, Gilles; Schulz, Michael; Balkanski, Yves; Antoine, Pierre; Dulac, François; Hatté, Christine

    2009-12-01

    Western European loess sequences of the last glaciation (˜100,000-15,000 years BP) exhibit strong, cyclic variations of the sedimentation rate, which are coeval to the Greenland stadial/interstadial cycles and the Heinrich events. These North-Atlantic rapid climate changes appear, thus, as a potential cause for the sedimentation variations, via changes in dust intensity cycle. Here we make a first step in testing this hypothesis, by modelling the impact of the North-Atlantic abrupt climate variations on dust emission. Our dust emission calculations use meteorological fields generated by the LMDZ atmospheric general circulation model at a resolution down to 60 km over Western Europe. Three numerical experiments are run, representing a Greenland stadial, an interstadial and a Heinrich event. Orbital parameters and ice-sheet configuration correspond to conditions from Marine Isotope Stage 3 (˜60,000-25,000 years BP), a period characterized by strong millennial-scale climate variability. The only differences we impose in the boundary conditions regard the North-Atlantic surface temperature and sea-ice cover in the latitudinal band 30°-63°N. The changes in wind, precipitation, soil moisture and snow cover from one simulated state to another result in small differences in dust emission intensity. In contrast, when the inhibition of the aeolian erosion by vegetation is taken into account, the dust fluxes for the cold climate states (Greenland stadial and Heinrich event) become generally more than twice higher than those for the relatively warmer Greenland interstadial, in agreement with the loess data. These results support the hypothesis that the North-Atlantic millennial-scale variability is imprinted in Western European loess profiles, and point to vegetation changes as the main factor responsible for millennial-scale sedimentation variations. An analysis for the English Channel and southern North Sea areas, major potential dust sources, shows that the seasonality

  19. Dynamic evaluation of the CMAQv5.0 modeling system: Assessing the model’s ability to simulate ozone changes due to NOx emission reductions

    EPA Science Inventory

    Regional air quality models are frequently used for regulatory applications to predict changes in air quality due to changes in emissions or changes in meteorology. Dynamic model evaluation is thus an important step in establishing credibility in the model predicted pollutant re...

  20. Farm Simulation: a tool for evaluating the mitigation of greenhouse gas emissions and the adaptation of dairy production to climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Farms both produce greenhouse gas emissions that drive human-induced climate change and are impacted by that climate change. Whole farm and global climate models provide useful tools for studying the benefits and costs of greenhouse gas mitigation and the adaptation of farms to changing climate. The...

  1. MercNet: A national monitoring network to assess responses to changing mercury emissions in the United States

    USGS Publications Warehouse

    Schmeltz, D.; Evers, D.C.; Driscoll, C.T.; Artz, R.; Cohen, M.; Gay, D.; Haeuber, R.; Krabbenhoft, D.P.; Mason, R.; Morris, K.; Wiener, J.G.

    2011-01-01

    A partnership of federal and state agencies, tribes, industry, and scientists from academic research and environmental organizations is establishing a national, policy-relevant mercury monitoring network, called MercNet, to address key questions concerning changes in anthropogenic mercury emissions and deposition, associated linkages to ecosystem effects, and recovery from mercury contamination. This network would quantify mercury in the atmosphere, land, water, and biota in terrestrial, freshwater, and coastal ecosystems to provide a national scientific capability for evaluating the benefits and effectiveness of emission controls. Program development began with two workshops, convened to establish network goals, to select key indicators for monitoring, to propose a geographic network of monitoring sites, and to design a monitoring plan. MercNet relies strongly on multi-institutional partnerships to secure the capabilities and comprehensive data that are needed to develop, calibrate, and refine predictive mercury models and to guide effective management. Ongoing collaborative efforts include the: (1) development of regional multi-media databases on mercury in the Laurentian Great Lakes, northeastern United States, and eastern Canada; (2) syntheses and reporting of these data for the scientific and policy communities; and (3) evaluation of potential monitoring sites. The MercNet approach could be applied to the development of other monitoring programs, such as emerging efforts to monitor and assess global mercury emission controls. ?? 2011 Springer Science+Business Media, LLC (outside the USA).

  2. MercNet: a national monitoring network to assess responses to changing mercury emissions in the United States.

    PubMed

    Schmeltz, David; Evers, David C; Driscoll, Charles T; Artz, Richard; Cohen, Mark; Gay, David; Haeuber, Richard; Krabbenhoft, David P; Mason, Robert; Morris, Kristi; Wiener, James G

    2011-10-01

    A partnership of federal and state agencies, tribes, industry, and scientists from academic research and environmental organizations is establishing a national, policy-relevant mercury monitoring network, called MercNet, to address key questions concerning changes in anthropogenic mercury emissions and deposition, associated linkages to ecosystem effects, and recovery from mercury contamination. This network would quantify mercury in the atmosphere, land, water, and biota in terrestrial, freshwater, and coastal ecosystems to provide a national scientific capability for evaluating the benefits and effectiveness of emission controls. Program development began with two workshops, convened to establish network goals, to select key indicators for monitoring, to propose a geographic network of monitoring sites, and to design a monitoring plan. MercNet relies strongly on multi-institutional partnerships to secure the capabilities and comprehensive data that are needed to develop, calibrate, and refine predictive mercury models and to guide effective management. Ongoing collaborative efforts include the: (1) development of regional multi-media databases on mercury in the Laurentian Great Lakes, northeastern United States, and eastern Canada; (2) syntheses and reporting of these data for the scientific and policy communities; and (3) evaluation of potential monitoring sites. The MercNet approach could be applied to the development of other monitoring programs, such as emerging efforts to monitor and assess global mercury emission controls. PMID:21901443

  3. Responding to climate change and the global land crisis: REDD+, market transformation and low-emissions rural development.

    PubMed

    Nepstad, Daniel C; Boyd, William; Stickler, Claudia M; Bezerra, Tathiana; Azevedo, Andrea A

    2013-06-01

    Climate change and rapidly escalating global demand for food, fuel, fibre and feed present seemingly contradictory challenges to humanity. Can greenhouse gas (GHG) emissions from land-use, more than one-fourth of the global total, decline as growth in land-based production accelerates? This review examines the status of two major international initiatives that are designed to address different aspects of this challenge. REDD+ is an emerging policy framework for providing incentives to tropical nations and states that reduce their GHG emissions from deforestation and forest degradation. Market transformation, best represented by agricultural commodity roundtables, seeks to exclude unsustainable farmers from commodity markets through international social and environmental standards for farmers and processors. These global initiatives could potentially become synergistically integrated through (i) a shared approach for measuring and favouring high environmental and social performance of land use across entire jurisdictions and (ii) stronger links with the domestic policies, finance and laws in the jurisdictions where agricultural expansion is moving into forests. To achieve scale, the principles of REDD+ and sustainable farming systems must be embedded in domestic low-emission rural development models capable of garnering support across multiple constituencies. We illustrate this potential with the case of Mato Grosso State in the Brazilian Amazon. PMID:23610173

  4. Responding to climate change and the global land crisis: REDD+, market transformation and low-emissions rural development

    PubMed Central

    Nepstad, Daniel C.; Boyd, William; Stickler, Claudia M.; Bezerra, Tathiana; Azevedo, Andrea A.

    2013-01-01

    Climate change and rapidly escalating global demand for food, fuel, fibre and feed present seemingly contradictory challenges to humanity. Can greenhouse gas (GHG) emissions from land-use, more than one-fourth of the global total, decline as growth in land-based production accelerates? This review examines the status of two major international initiatives that are designed to address different aspects of this challenge. REDD+ is an emerging policy framework for providing incentives to tropical nations and states that reduce their GHG emissions from deforestation and forest degradation. Market transformation, best represented by agricultural commodity roundtables, seeks to exclude unsustainable farmers from commodity markets through international social and environmental standards for farmers and processors. These global initiatives could potentially become synergistically integrated through (i) a shared approach for measuring and favouring high environmental and social performance of land use across entire jurisdictions and (ii) stronger links with the domestic policies, finance and laws in the jurisdictions where agricultural expansion is moving into forests. To achieve scale, the principles of REDD+ and sustainable farming systems must be embedded in domestic low-emission rural development models capable of garnering support across multiple constituencies. We illustrate this potential with the case of Mato Grosso State in the Brazilian Amazon. PMID:23610173

  5. Land Use Change In Australia's Tropical Savanna Woodlands: Greenhouse Gas Emissions From Deforestation And Conversion To Agriculture

    NASA Astrophysics Data System (ADS)

    Hutley, L. B.; Bristow, M.; Beringer, J.; Livesley, S. L.; Arndt, S. K.

    2015-12-01

    Clearing and burning of tropical savanna leads to globally significant emissions of greenhouse gases (GHG), although there is large uncertainty relating to the magnitude of this flux. Australia's tropical savannas are 12% of global savanna extent and are largely intact; however there is currently a focus on agricultural expansion across northern Australia involving clearing for primary production. Eddy covariance and soil chamber methods were used over almost 2 years to quantify CO2 and non-CO2 fluxes from savanna that was cleared and prepared for agriculture (CS). Fluxes from an uncleared site (UC) were also monitored. Carbon fluxes from both sites were similar (NEE -0.23 Mg C ha-1 month-1) for the 5.4 months prior to clearing, a period spanning the late dry to mid-wet season. Fluxes were monitored for a further 17 months through a dry-wet-dry climate cycle and phased land use change which included clearing and a debris curing phase, followed by burning and soil preparation for cropping. Over this period (excluding the managed fire), the CS site was a source of +0.43 Mg C ha-1 month-1 compared to a net sink at the UC site of -0.05 Mg C ha-1 month-1. Woody debris from clearing (30.9 Mg C ha-1) was removed from the site via burning in the late dry season and emission factors were used to calculate emissions of CO2, CH4 and N2O which totalled 138.0 Mg CO2-e ha-1. Over the 17 months of monitoring this land transformation, emissions were +9.7 Mg CO2-e ha-1 month-1 compared to a sink of -0.17 Mg CO2-e from the UC site. Using these emissions and LUC scenarios at catchment to regional scales suggest proposed clearing for agriculture could significantly increase the region's fire-dominated GHG emissions. These data are essential for both land-atmosphere models as well as decision support tools that inform trade-offs between greenhouse gas accounting, conservation and development goals.

  6. Global methane and nitrous oxide emissions from terrestrial ecosystems due to multiple environmental changes

    DOE PAGESBeta

    Tian, Hanqin; Chen, Guangsheng; Lu, Chaoqun; Xu, Xiaofeng; Ren, Wei; Zhang, Bowen; Banger, Kamaljit; Tao, Bo; Pan, Shufen; Chu, Mingliang; et al

    2015-03-16

    Greenhouse gas (GHG)-induced climate change is among the most pressing sustainability challenges facing humanity today, posing serious risks for ecosystem health. Methane (CH4) and nitrous oxide (N2O) are the two most important GHGs after carbon dioxide (CO2), but their regional and global budgets are not well known. In this paper, we applied a process-based coupled biogeochemical model to concurrently estimate the magnitude and spatial and temporal patterns of CH4 and N2O fluxes as driven by multiple environmental changes, including climate variability, rising atmospheric CO2, increasing nitrogen deposition, tropospheric ozone pollution, land use change, and nitrogen fertilizer use.

  7. Trading forests: land-use change and carbon emissions embodied in production and exports of forest-risk commodities

    NASA Astrophysics Data System (ADS)

    Henders, Sabine; Persson, U. Martin; Kastner, Thomas

    2015-12-01

    Production of commercial agricultural commodities for domestic and foreign markets is increasingly driving land clearing in tropical regions, creating links and feedback effects between geographically separated consumption and production locations. Such teleconnections are commonly studied through calculating consumption footprints and quantifying environmental impacts embodied in trade flows, e.g., virtual water and land, biomass, or greenhouse gas emissions. The extent to which land-use change (LUC) and associated carbon emissions are embodied in the production and export of agricultural commodities has been less studied. Here we quantify tropical deforestation area and carbon emissions from LUC induced by the production and the export of four commodities (beef, soybeans, palm oil, and wood products) in seven countries with high deforestation rates (Argentina, Bolivia, Brazil, Paraguay, Indonesia, Malaysia, and Papua New Guinea). We show that in the period 2000-2011, the production of the four analyzed commodities in our seven case countries was responsible for 40% of total tropical deforestation and resulting carbon losses. Over a third of these impacts was embodied in exports in 2011, up from a fifth in 2000. This trend highlights the growing influence of global markets in deforestation dynamics. Main flows of embodied LUC are Latin American beef and soybean exports to markets in Europe, China, the former Soviet bloc, the Middle East and Northern Africa, whereas embodied emission flows are dominated by Southeast Asian exports of palm oil and wood products to consumers in China, India and the rest of Asia, as well as to the European Union. Our findings illustrate the growing role that global consumers play in tropical LUC trajectories and highlight the need for demand-side policies covering whole supply chains. We also discuss the limitations of such demand-side measures and call for a combination of supply- and demand-side policies to effectively limit tropical

  8. Impact of preindustrial to present-day changes in short-lived pollutant emissions on atmospheric composition and climate forcing

    NASA Astrophysics Data System (ADS)

    Naik, Vaishali; Horowitz, Larry W.; Fiore, Arlene M.; Ginoux, Paul; Mao, Jingqiu; Aghedo, Adetutu M.; Levy, Hiram

    2013-07-01

    We describe and evaluate atmospheric chemistry in the newly developed Geophysical Fluid Dynamics Laboratory chemistry-climate model (GFDL AM3) and apply it to investigate the net impact of preindustrial (PI) to present (PD) changes in short-lived pollutant emissions (ozone precursors, sulfur dioxide, and carbonaceous aerosols) and methane concentration on atmospheric composition and climate forcing. The inclusion of online troposphere-stratosphere interactions, gas-aerosol chemistry, and aerosol-cloud interactions (including direct and indirect aerosol radiative effects) in AM3 enables a more complete representation of interactions among short-lived species, and thus their net climate impact, than was considered in previous climate assessments. The base AM3 simulation, driven with observed sea surface temperature (SST) and sea ice cover (SIC) over the period 1981-2007, generally reproduces the observed mean magnitude, spatial distribution, and seasonal cycle of tropospheric ozone and carbon monoxide. The global mean aerosol optical depth in our base simulation is within 5% of satellite measurements over the 1982-2006 time period. We conduct a pair of simulations in which only the short-lived pollutant emissions and methane concentrations are changed from PI (1860) to PD (2000) levels (i.e., SST, SIC, greenhouse gases, and ozone-depleting substances are held at PD levels). From the PI to PD, we find that changes in short-lived pollutant emissions and methane have caused the tropospheric ozone burden to increase by 39% and the global burdens of sulfate, black carbon, and organic carbon to increase by factors of 3, 2.4, and 1.4, respectively. Tropospheric hydroxyl concentration decreases by 7%, showing that increases in OH sinks (methane, carbon monoxide, nonmethane volatile organic compounds, and sulfur dioxide) dominate over sources (ozone and nitrogen oxides) in the model. Combined changes in tropospheric ozone and aerosols cause a net negative top

  9. Simultaneous observations of changes in coronal bright point emission at the 20 cm radio and He Lambda 10830 wavelengths

    NASA Technical Reports Server (NTRS)

    Habbal, Shadia R.; Harvey, Karen L.

    1986-01-01

    Preliminary results of observations of solar coronal bright points acquired simultaneously from ground based observatories at the radio wavelength of 20 cm and in the He I wavelength 10830 line on September 8, 1985, are reported. The impetus for obtaining simultaneous radio and optical data is to identify correlations, if any, in changes of the low transition-coronal signatures of bright points with the evolution of the magnetic field, and to distinguish between intermittent heating and changes in the magnetic field topology. Although simultaneous observations of H alpha emission and the photospheric magnetic field at Big Bear were also made, as well as radio observations from Owen Valley Radio Interferometer and Solar Maximum Mission (SSM) (O VIII line), only the comparison between He 10830 and the Very Large Array (VLA) radio data are presented.

  10. Robust red-emission spectra and yields in firefly bioluminescence against temperature changes

    NASA Astrophysics Data System (ADS)

    Mochizuki, Toshimitsu; Wang, Yu; Hiyama, Miyabi; Akiyama, Hidefumi

    2014-05-01

    We measured the quantitative spectra of firefly (Photinus pyralis) bioluminescence at various temperatures to investigate the temperature dependence of the luciferin-luciferase reaction at 15-34 °C. The quantitative spectra were decomposed very well into red (1.9 eV), orange (2.0 eV), and green (2.2 eV) Gaussian components. The intensity of the green component was the only temperature sensitive quantity that linearly decreased as the temperature increased at pH 7 and 8. We found the quantitative bioluminescence spectra to be robust below 2.0 eV against temperature and other experimental conditions. The revealed robustness of the red emissions should be useful for quantitative applications such as adenosine-5'-triphosphate detection.

  11. Attribution of atmospheric sulfur dioxide over the English Channel to dimethyl sulfide and changing ship emissions

    NASA Astrophysics Data System (ADS)

    Yang, Mingxi; Bell, Thomas G.; Hopkins, Frances E.; Smyth, Timothy J.

    2016-04-01

    Atmospheric sulfur dioxide (SO2) was measured continuously from the Penlee Point Atmospheric Observatory (PPAO) near Plymouth, United Kingdom, between May 2014 and November 2015. This coastal site is exposed to marine air across a wide wind sector. The predominant southwesterly winds carry relatively clean background Atlantic air. In contrast, air from the southeast is heavily influenced by exhaust plumes from ships in the English Channel as well as near Plymouth Sound. A new International Maritime Organization (IMO) regulation came into force in January 2015 to reduce the maximum allowed sulfur content in ships' fuel 10-fold in sulfur emission control areas such as the English Channel. Our observations suggest a 3-fold reduction in ship-emitted SO2 from 2014 to 2015. Apparent fuel sulfur content calculated from coincidental SO2 and carbon dioxide (CO2) peaks from local ship plumes show a high level of compliance to the IMO regulation (> 95 %) in both years (˜ 70 % of ships in 2014 were already emitting at levels below the 2015 cap). Dimethyl sulfide (DMS) is an important source of atmospheric SO2 even in this semi-polluted region. The relative contribution of DMS oxidation to the SO2 burden over the English Channel increased from about one-third in 2014 to about one-half in 2015 due to the reduction in ship sulfur emissions. Our diel analysis suggests that SO2 is removed from the marine atmospheric boundary layer in about half a day, with dry deposition to the ocean accounting for a quarter of the total loss.

  12. TREMOR, OLFACTORY AND MOTOR CHANGES IN ITALIAN ADOLESCENTS EXPOSED TO HISTORICAL FERRO-MANGANESE EMISSION

    PubMed Central

    Lucchini, Roberto G; Guazzetti, Stefano; Zoni, Silvia; Donna, Filippo; Peter, Stephanie; Zacco, Annalisa; Salmistraro, Marco; Bontempi, Elza; Zimmerman, Neil J; Smith, Donald R

    2012-01-01

    Background and Objective Increased prevalence of Parkinsonism was observed in Valcamonica, Italy, a region impacted by ferroalloy plants emissions containing manganese and other metals for a century until 2001. The aim of this study was to assess neurobehavioral functions in adolescents from the impacted region and the reference area of Garda Lake. Methods Adolescents age 11–14 yrs were recruited through the school system for neuro-behavioral testing. Metals including manganese, lead, iron, zinc, copper were measured in airborne particulate matter collected with 24-hour personal samplers, and in soil, tap water, blood, urine and hair. Independent variables included parental education and socio-economic status, children’s body mass index, number of siblings, parity order, smoking and drinking habits. Results A total of 311 subjects (49.2% females), residing in either the exposed (n=154) or the reference (n=157) area participated. Average airborne and soil manganese were respectively 49.5 ng/m3 (median 31.4, range 1.24–517) and 958 ppm (median 897, range 465–1729) in the impacted area, and 27.4 ng/m3 (median 24.7, range 5.3–85.9) ng/m3 and 427 ppm (median 409 range 160–734) in the reference area. Regression models showed significant impairment of motor coordination (Luria-Nebraska test, p=0.0005), hand dexterity (Aiming Pursuit test, p= 0.0115) and odor identification (Sniffin’ task, p=0.003 ) associated with soil manganese. Tremor intensity was positively associated with blood (p=0.005) and hair (p=0.01) manganese. Conclusion Historical environmental exposure to manganese from ferroalloy emission reflected by the concentration in soil and the biomarkers was associated with subclinical deficits in olfactory and motor function among adolescents. PMID:22322213

  13. Emissions of carbon from land use change in sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Houghton, R. A.; Hackler, J. L.

    2006-06-01

    Previous estimates of the flux of carbon from land use change in sub-Saharan Africa have been based on highly aggregated data and have ignored important categories of land use. To improve these estimates, we divided the region into four subregions (east, west, central, and southern Africa), each with six types of natural vegetation and five types of land use (permanent crops, pastures, shifting cultivation, industrial wood harvest, and tree plantations). We reconstructed rates of land use change and rates of wood harvest from country-level statistics reported by the Food and Agriculture Organization (FAO) (1961-2000) and extrapolated the rates from 1961 to 1850 on the basis of qualitative histories of demography, economy, and land use. We used a bookkeeping model to calculate the annual flux of carbon associated with these changes in land use. Country-level estimates of average forest biomass from the FAO, together with changes in biomass calculated from the reconstructed rates of land use change, constrained the average biomass of forests in 1850. Comparison of potential (predisturbance) forest areas with the areas present in 1850 and 2000 suggests that 60% of Africa's forests were lost before 1850 and an additional 10% lost in the last 150 years. The annual net flux of carbon from changes in land use was probably small and variable before the early 1900s but increased to a source of 0.3 ± 0.2 PgC/yr by the end of the century. In the 1990s the source was equivalent to about 15% of the global net flux of carbon from land use change.

  14. Global methane and nitrous oxide emissions from terrestrial ecosystems due to multiple environmental changes

    SciTech Connect

    Tian, Hanqin; Chen, Guangsheng; Lu, Chaoqun; Xu, Xiaofeng; Ren, Wei; Zhang, Bowen; Banger, Kamaljit; Tao, Bo; Pan, Shufen; Chu, Mingliang; Zhang, Chi; Bruhwiler, Lori; Wofsy, Steven

    2015-03-16

    Greenhouse gas (GHG)-induced climate change is among the most pressing sustainability challenges facing humanity today, posing serious risks for ecosystem health. Methane (CH4) and nitrous oxide (N2O) are the two most important GHGs after carbon dioxide (CO2), but their regional and global budgets are not well known. In this paper, we applied a process-based coupled biogeochemical model to concurrently estimate the magnitude and spatial and temporal patterns of CH4 and N2O fluxes as driven by multiple environmental changes, including climate variability, rising atmospheric CO2, increasing nitrogen deposition, tropospheric ozone pollution, land use change, and nitrogen fertilizer use.

  15. Changes in land cover and carbon emissions to 2050 from African tropical forests using policy scenarios

    NASA Astrophysics Data System (ADS)

    Laporte, N.; Galford, G. L.; Soares Filho, B. S.

    2011-12-01

    Africa has the second largest block of rainforest in the world, next to the Amazon basin, with the majority of the carbon being stored in the dense humid forests of the Democratic Republic of the Congo (DRC). Historically, political instability in the DRC kept development and deforestation low, with primary forest uses being extensive logging and small scale agriculture. In the last decade, political stability has opened the country to foreign investment in forested areas, largely for industrial-scale oil palm plantations and more recently to rice production. The DRC ranks worst on the IFPRI global hunger index, scoring "extremely serious" based on the proportion of undernourished population, prevalence of underweight in children under 5 and the mortality rates of children under 5. In fact, DRC saw its hunger score increase (worsen) from 1990 to 2010, with a 66% gain compared to the other 8 worsening countries increasing only 21% or less. This is a critical time for policy in the DRC, where business-as-usual (relatively low deforestation rates) is unlikely to continue given today's relative political stability and economic stabilization compared to the 1990s. The country must examine options for forest conservation in balance with foreign investment for use of forest resources, national development of rural livelihoods and domestic production of food. Here we present deforestation trajectories simulated through the year 2050 under a set of scenarios. The scenarios consider the relative carbon emissions from business-as-usual (no new policy), conservation (policy favoring protection and enforcement for forest areas), and a food security scenario (favoring clearing for industrial agriculture, extractive timber resources and development of new agricultural areas). Carbon emissions for each scenario are estimated with a coupled bookkeeping model. These scenarios are not predictive of the future, rather, they are meant to provide an understanding of the outcomes of

  16. Environmental Changes and Dust Emission in the Dried Bottom of the Aral Sea

    NASA Astrophysics Data System (ADS)

    Orlovsky, L.; Indoitu, R.; Kozhoridze, G.; Batyrbaeva, M.; Orlovsky, N.

    2014-12-01

    Dust storms are common events, and one of the most important manifestations of desertification occurring in the drylands of Middle Asia. This area is characterized by strong winds, scarcity of vegetation cover, continental and Mediterranean type of climate with long dry summers, frequent soil and atmospheric droughts, susceptibility of soils to erosion - all these serves as a basis for formation of dust storms (DS). Additionally to the natural pre-conditions of dust storms development, the large-scale anthropogenic land cover and land use changes favor development of DS in this region. The drastic desiccation of the Aral Sea led to the intensive development of desertification processes and formation of a new desert, the Aralkum. The temporal and spatial distribution of DS for three periods: 1936-1960, 1936-1980, and 1970-2005, based on the data from meteorological network, showed decrease in DS frequency and changes in the source areas. Temperature and rainfall trends also showed significant changes across the region. At the same time in the last few decades the dried bottom of the Aral Sea became the new "hot spot" of dust and salt storms. Dust storms and their source areas have been determined and analyzed by the NOAA AVHRR, TOMS and OMI models. The analysis showed that the Aralkum Desert is one of the most active dust sources in the region, responsible for high aerosol concentrations in the atmosphere. Dust plumes that sweep up from the dried bottom of the Aral Sea have become larger, and dust storms have become more powerful, since the bottom exposure. The land-cover changes in the dried bottom of the Aral Sea were determined by Landsat TM images for 1987 and 2009. The monitoring algorithm have been developed and validated by ground truth data. The main change occurred in the land cover of the dried bottom was the considerable reduction of vegetation and small water bodies, while the areas of solonchaks (salty pans) and sandy massifs increased significantly.

  17. Time dependent changes in Schottky barrier mapping of the W/Si(001) interface utilizing ballistic electron emission microscopy

    SciTech Connect

    Durcan, Chris A.; Balsano, Robert; LaBella, Vincent P.

    2015-06-28

    The W/Si(001) Schottky barrier height is mapped to nanoscale dimensions using ballistic electron emission microscopy (BEEM) over a period of 21 days to observe changes in the interface electrostatics. Initially, the average spectrum is fit to a Schottky barrier height of 0.71 eV, and the map is uniform with 98% of the spectra able to be fit. After 21 days, the average spectrum is fit to a Schottky barrier height of 0.62 eV, and the spatial map changes dramatically with only 27% of the spectra able to be fit. Transmission electron microscopy shows the formation of an ultra-thin tungsten silicide at the interface, which increases in thickness over the 21 days. This increase is attributed to an increase in electron scattering and the changes are observed in the BEEM measurements. Interestingly, little to no change is observed in the I-V measurements throughout the 21 day period.

  18. Impact of hygrometry changes on creep behaviour of a porous rock and associated acoustic emission.

    NASA Astrophysics Data System (ADS)

    Grgic, D.; Amitrano, D.

    2009-04-01

    Static fatigue of a polycrystalline porous rock (iron ore) was studied by performing multi step uniaxial creep tests under partially saturated conditions, and the impact of water saturation was analyzed. The samples were, in a first step set to a partial water saturation of 90%. In a second step, the samples were saturated completely in order to simulate the impact of flooding corresponding to the conditions of abandoned iron mines. We recorded axial and transversal strain and acoustic emission (EA). The experimental results show that the water saturation induces a strong increase in AE activity and dilatant inelastic volumetric strain. This is associated with a notable decrease in Young's modulus and in the b-value of the Gutenberg-Richter law (i.e., the relative number of large-amplitude events increases) as the rock approaches failure, indicating that microfracturing plays an important role in the creep process. Water saturation accelerates static fatigue through hydro-mechanical coupling and subcritical stress corrosion cracking. The chemical reactions involved in the corrosion of iron ore and leading to a decrease in its intrinsic mechanical properties are described. These reactions play a major role in the static fatigue of iron ore, which on a large scale is probably the main mechanism explaining certain collapses in underground iron mines. It is also shown that creep straining of iron ore is partially reversible after stress removal, indicating that it results also from time-dependent viscoplastic mechanism (i.e., dislocation creep).

  19. Consumption, Not CO2 emissions: Reframing Perspectives on Climate Change and Sustainability

    SciTech Connect

    Harriss, Robert; Shui, Bin

    2010-12-01

    A stunning documentary film titled “Mardi Gras: Made in China” provides an insightful and engaging perspective on the globalization of desire for material consumption. Tracing the life cycle of Mardi Gras beads from a small factory in Fuzhou, China to the streets of the Mardi Gras celebration in New Orleans the viewer grasps the near universal human desire to strive for an affluent lifestyle. David Redmon, an independent film maker, follows the beads' genealogy back to the industrial town of Fuzhou, China, to the factory that is the world's largest producer of Mardi Gras beads and related party trinkets. He explores how these frivolous and toxic products affect the people who make them and those who consume them. Redmon captures the daily reality of a Chinese manufacturing facility. It’s workforce of approximately 500 teenage girls, and a handful of boys, live like prisoners in a fenced-in compound. These young people, often working 16-hour days, are constantly exposed to styrene, a chemical known to cause cancer — all for about 10 cents an hour. In addition to indoor pollution, the decrepit coal-fired manufacturing facilities are symbolic of China’s fast rise to the world’s top producer of carbon dioxide (CO2) emissions.1 The process of industrialization and modernization in China is happening at an unprecedented rate and scale.

  20. Polish country study to address climate change: Strategies of the GHG`s emission reduction and adaptation of the Polish economy to the changed climate. Final report

    SciTech Connect

    1996-01-01

    The Polish Country Study Project was initiated in 1992 as a result of the US Country Study Initiative whose objective was to grant the countries -- signatories of the United Nations` Framework Convention on Climate Change -- assistance that will allow them to fulfill their obligations in terms of greenhouse gases (GHG`s) inventory, preparation of strategies for the reduction of their emission, and adapting their economies to the changed climatic conditions. In February 1993, in reply to the offer from the United States Government, the Polish Government expressed interest in participation in this program. The Study proposal, prepared by the Ministry of Environmental Protection, Natural Resources and Forestry was presented to the US partner. The program proposal assumed implementation of sixteen elements of the study, encompassing elaboration of scenarios for the strategy of mission reduction in energy sector, industry, municipal management, road transport, forestry, and agriculture, as well as adaptations to be introduced in agriculture, forestry, water management, and coastal management. The entire concept was incorporated in macroeconomic strategy scenarios. A complementary element was the elaboration of a proposal for economic and legal instruments to implement the proposed strategies. An additional element was proposed, namely the preparation of a scenario of adapting the society to the expected climate changes.

  1. Simulating effects of changing climate and CO(2) emissions on soil carbon pools at the Hubbard Brook experimental forest.

    PubMed

    Dib, Alain E; Johnson, Chris E; Driscoll, Charles T; Fahey, Timothy J; Hayhoe, Katharine

    2014-05-01

    Carbon (C) sequestration in forest biomass and soils may help decrease regional C footprints and mitigate future climate change. The efficacy of these practices must be verified by monitoring and by approved calculation methods (i.e., models) to be credible in C markets. Two widely used soil organic matter models - CENTURY and RothC - were used to project changes in SOC pools after clear-cutting disturbance, as well as under a range of future climate and atmospheric carbon dioxide (CO(2) ) scenarios. Data from the temperate, predominantly deciduous Hubbard Brook Experimental Forest (HBEF) in New Hampshire, USA, were used to parameterize and validate the models. Clear-cutting simulations demonstrated that both models can effectively simulate soil C dynamics in the northern hardwood forest when adequately parameterized. The minimum postharvest SOC predicted by RothC occurred in postharvest year 14 and was within 1.5% of the observed minimum, which occurred in year 8. CENTURY predicted the postharvest minimum SOC to occur in year 45, at a value 6.9% greater than the observed minimum; the slow response of both models to disturbance suggests that they may overestimate the time required to reach new steady-state conditions. Four climate change scenarios were used to simulate future changes in SOC pools. Climate-change simulations predicted increases in SOC by as much as 7% at the end of this century, partially offsetting future CO(2) emissions. This sequestration was the product of enhanced forest productivity, and associated litter input to the soil, due to increased temperature, precipitation and CO(2) . The simulations also suggested that considerable losses of SOC (8-30%) could occur if forest vegetation at HBEF does not respond to changes in climate and CO(2) levels. Therefore, the source/sink behavior of temperate forest soils likely depends on the degree to which forest growth is stimulated by new climate and CO(2) conditions. PMID:24132912

  2. Enhancement of aerosol responses to changes in emissions over East Asia by gas-oxidant-aerosol coupling and detailed aerosol processes

    NASA Astrophysics Data System (ADS)

    Matsui, H.; Koike, M.

    2016-06-01

    We quantify the responses of aerosols to changes in emissions (sulfur dioxide, black carbon (BC), primary organic aerosol, nitrogen oxides (NOx), and volatile organic compounds) over East Asia by using simulations including gas-oxidant-aerosol coupling, organic aerosol (OA) formation, and BC aging processes. The responses of aerosols to NOx emissions are complex and are dramatically changed by simulating gas-phase chemistry and aerosol processes online. Reduction of NOx emissions by 50% causes a 30-40% reduction of oxidant (hydroxyl radical and ozone) concentrations and slows the formation of sulfate and OA by 20-30%. Because the response of OA to changes in NOx emissions is sensitive to the treatment of emission and oxidation of semivolatile and intermediate volatility organic compounds, reduction of the uncertainty in these processes is necessary to evaluate gas-oxidant-aerosol coupling accurately. Our simulations also show that the sensitivity of aerosols to changes in emissions is enhanced by 50-100% when OA formation and BC aging processes are resolved in the model. Sensitivity simulations show that the increase of NOx emissions from 1850 to 2000 explains 70% (40%) of the enhancement of aerosol mass concentrations (direct radiative effects) over East Asia during that period through enhancement of oxidant concentrations and that this estimation is sensitive to the representation of OA formation and BC aging processes. Our results demonstrate the importance of simultaneous simulation of gas-oxidant-aerosol coupling and detailed aerosol processes. The impact of NOx emissions on aerosol formation will be a key to formulating effective emission reduction strategies such as BC mitigation and aerosol reduction policies in East Asia.

  3. Positive and negative feedbacks to climate change associated with methane emissions from arctic permafrost systems (Invited)

    NASA Astrophysics Data System (ADS)

    Walter Anthony, K. M.; Grosse, G.; Jones, B. M.

    2009-12-01

    sensing time series of thermokarst lakes on the Northern Seward Peninsula in Alaska revealed that while lakes are rapidly expanding, an unprecedented number of lakes drained during the past 55 years, suggesting that degradation of permafrost may be accelerating in some regions. Drained basins fill in with new terrestrial vegetation, often becoming wetlands. Although these are a source of methane to the atmosphere when their surface is unfrozen in summer, their total annual emissions are often lower than lakes because of refreezing of the lake thaw bulb. Plant productivity in basins, together with the buildup of peat, serve as a sink of atmospheric carbon and a negative feedback to permafrost thaw. Results presented here aim to improve understanding of microbial and geologic methane emission dynamics related to permafrost degradation in various regions of the Arctic in order to better constrain current and future atmospheric methane budgets and global climate models.

  4. The Effect of Changes in Polar Sea Ice on Emissions of Marine Aerosols

    NASA Astrophysics Data System (ADS)

    Matrai, P.; Gabric, A. J.

    2015-12-01

    Cloud radiative effects remain a major weakness in our understanding of the climate system and consequently in developing accurate climate projections. This is mainly true for Arctic low-level clouds in their key role of regulating surface energy fluxes which affect the freezing and melting of sea ice. The radiative properties of clouds are strongly dependent on the number concentration of airborne water-soluble particles, known as cloud condensation nuclei (CCN). In the Arctic, the aerosol-cloud-radiation relationship is more complex than elsewhere and the clouds constitute a warming factor for climate, rather than cooling, most of the year. This is due to the semi-permanent ice cover, which raises the albedo of the surface, and the clean Arctic air, which decreases the albedo of the clouds. There has been much discussion on the relative magnitude of the biogenic source of polar CCN: Primary organic marine aerosols and/or sulfate-containing aerosols, derived from marine emissions. Regional field measurements and pan- (Ant)Arctic model simulations don't necessarily agree. Arctic CCN are formed primarily by aggregates of marine organic material and may grow in mass by condensation. Southern Ocean aerosols may be dominated by sulfate particles and organic particles at lower and higher Antarctic latitudes, respectively. The interaction of polar marine microorganisms, seasonality, sea ice cover, presence or absence of sea spray, and atmospheric heterogeneous processes combine to control natural aerosol concentrations and mass, thus modulating the sensitivity of cloud properties, including their reflectivity and the resulting regional radiation budget. We discuss Arctic and Antarctic field and satellite observations and establish a strong and fundamental link between the biology at the ocean/sea ice interface, clouds and climate over polar regions.

  5. Composition, seasonal change, and bathymetry of Ligeia Mare, Titan, derived from its microwave thermal emission

    NASA Astrophysics Data System (ADS)

    Le Gall, A.; Malaska, M. J.; Lorenz, R. D.; Janssen, M. A.; Tokano, T.; Hayes, A. G.; Mastrogiuseppe, M.; Lunine, J. I.; Veyssière, G.; Encrenaz, P.; Karatekin, O.

    2016-02-01

    For the last decade, the passive radiometer incorporated in the Cassini RADAR has recorded the 2.2 cm wavelength thermal emission from Titan's seas. In this paper, we analyze the radiometry observations collected from February 2007 to January 2015 over one of these seas, Ligeia Mare, with the goal of providing constraints on its composition, bathymetry, and dynamics. In light of the depth profile obtained by Mastrogiuseppe et al. (2014) and of a two-layer model, we find that the dielectric constant of the sea liquid is <1.8, and its loss tangent is <3.6-2.1+4.3×10-5. Both results point to a composition dominated by liquid methane rather than ethane. A high methane concentration suggests that Ligeia Mare is primarily fed by methane-rich precipitation and/or ethane has been removed from it (e.g., by crustal interaction). Our result on the dielectric constant of the seafloor is less constraining (<2.9-0.9+0.9), but we favor a scenario where the floor of Ligeia Mare is covered by a sludge of compacted and possibly nitrile-rich organic material formed by the deposition of photochemical haze or by rain washing of the nearby shores. We use these results to produce a low-resolution bathymetry map of the sea. We also estimate the temperature variation of the bulk sea between February 2007 and July 2013 to be <2 K, which provides a constraint on its net evaporative cooling currently being explored in ocean circulation models. Lastly, we suggest a lag in the summer warming of the northern polar terrains.

  6. The Change of the North American Monsoon Seasonal Precipitation in the CCSMv.4 under IPCC CO2 Emission Scenarios

    NASA Astrophysics Data System (ADS)

    Hernandez, M.; Tribbia, J. J.; Caron, J.

    2012-12-01

    The North American monsoon (NAM), characterized by distinct seasonal precipitation over western Mexico and the Southwestern United States, is a summertime phenomenon that depends on complex interactions between the Pacific Ocean, Gulf of Mexico, and the North American land mass. Thus, the NAM is strongly influenced by the El Niño Southern Oscillation, a dominant mode of interannual Pacific sea surface temperature (SST) and atmospheric variability, as well as the North Pacific Oscillation, a low-frequency (decadal) Pacific variation. This study assesses present day and projected changes in the NAM precipitation on a yearly and seasonal basis. Observations from the NCEP-NCAR Reanalysis project are compared to the Community Climate System Model version 4 (CCSM) from 1980 to 2000. Spatial patterns agree well, but still show an overestimation in precipitation within the NAM region. Fifteen CCSM ensemble runs, for various IPCC AR4 emission scenarios (A1, B1, and constant CO2), are assessed within each specific scenario and averaged, for comparisons between 1980-2000 and 2080-2100. In the NAM region we find yearly and seasonal decreases in precipitation and increases in temperature for all IPCC emission scenarios. Our analysis further finds statistical significance to the differences in mean precipitation and temperature over the NAM region, due in part to different levels of CO2 in the atmosphere.; Future temperature climate (2080-2100) within a "high emission" scenario is compared to present temperature climate (1980-2000) to create a difference temperature plot throughout the southwestern United States.

  7. Quantifying climate change mitigation potential in Great Plains wetlands for three greenhouse gas emission scenarios

    USGS Publications Warehouse

    Byrd, Kristin B.; Ratliff, Jamie L.; Wein, Anne; Bliss, Norman B.; Sleeter, Benjamin M.; Sohl, Terry L.; Li, Zhengpeng

    2015-01-01

    We examined opportunities for avoided loss of wetland carbon stocks in the Great Plains of the United States in the context of future agricultural expansion through analysis of land-use land-cover (LULC) change scenarios, baseline carbon datasets and biogeochemical model outputs. A wetland map that classifies wetlands according to carbon pools was created to describe future patterns of carbon loss and potential carbon savings. Wetland avoided loss scenarios, superimposed upon LULC change scenarios, quantified carbon stocks preserved under criteria of carbon densities or land value plus cropland suitability. Up to 3420 km2 of wetlands may be lost in the region by 2050, mainly due to conversion of herbaceous wetlands in the Temperate Prairies where soil organic carbon (SOC) is highest. SOC loss would be approximately 0.20 ± 0.15 megagrams of carbon per hectare per year (MgC ha−1 yr−1), depending upon tillage practices on converted wetlands, and total ecosystem carbon loss in woody wetlands would be approximately 0.81 ± 0.41 MgC ha−1 yr−1, based on biogeochemical model results. Among wetlands vulnerable to conversion, wetlands in the Northern Glaciated Plains and Lake Agassiz Plains ecoregions exhibit very high mean SOC and on average, relatively low land values, potentially creating economically competitive opportunities for avoided carbon loss. This mitigation scenarios approach may be adapted by managers using their own preferred criteria to select sites that best meet their objectives. Results can help prioritize field-based assessments, where site-level investigations of carbon stocks, land value, and consideration of local priorities for climate change mitigation programs are needed.

  8. Enhancing light emission efficiency without color change in post-transition metal chalcogenides

    NASA Astrophysics Data System (ADS)

    Wang, Cong; Yang, Shengxue; Cai, Hui; Ataca, Can; Chen, Hui; Zhang, Xinzheng; Xu, Jingjun; Chen, Bin; Wu, Kedi; Zhang, Haoran; Liu, Luqi; Li, Jingbo; Grossman, Jeffrey C.; Tongay, Sefaattin; Liu, Qian

    2016-03-01

    Two-dimensional (2D) materials can take a large amount of mechanical deformation before reaching the fracture limit due to their high Young's modulus, and this in return, provides a way to tune the properties of 2D materials by strain engineering. Previous works have shown that the optical band gap of transition metal chalcogenides (TMDs) can be modulated by strain, resulting in a drift of the photoluminescence (PL) peak position and a decrease (or little change) in PL intensity. Here, we report a member of the post-transition metal chalcogenides (PTMCs), 2D-GaSe sheets, displaying vastly different phenomena under strain. Strained 2D-GaSe emits photons at almost the same wavelength as unstrained material but appears an order of magnitude brighter. In contrast to TMDs, optical spectroscopy measurements reveal that changes in the optical properties are mostly related to the colossal optical absorption anisotropy of GaSe, instead of commonly accepted strain-induced band renormalization. Results suggest that the light-matter interaction and the optical properties of 2D-GaSe can be controlled at will by manipulating the optical absorption.Two-dimensional (2D) materials can take a large amount of mechanical deformation before reaching the fracture limit due to their high Young's modulus, and this in return, provides a way to tune the properties of 2D materials by strain engineering. Previous works have shown that the optical band gap of transition metal chalcogenides (TMDs) can be modulated by strain, resulting in a drift of the photoluminescence (PL) peak position and a decrease (or little change) in PL intensity. Here, we report a member of the post-transition metal chalcogenides (PTMCs), 2D-GaSe sheets, displaying vastly different phenomena under strain. Strained 2D-GaSe emits photons at almost the same wavelength as unstrained material but appears an order of magnitude brighter. In contrast to TMDs, optical spectroscopy measurements reveal that changes in the optical

  9. Historical changes in carbon dioxide (CO2) and dimethyl sulphide (DMS) emissions in the eutrophied Southern North Sea

    NASA Astrophysics Data System (ADS)

    Gypens, N.; Borges, A. V.; Lancelot, C.

    2012-04-01

    Anthropogenic activities after the Second World War have severely increased river nutrient [nitrogen (N) and phosphorus (P)] loads to European coastal areas. The resulting N: P: Si imbalance (compared to phytoplankton requirements) stimulated in the Southern North Sea the growth of Phaeocystis colonies modifying the functioning of the ecosystem and, therefore, the carbon but also the biogenic sulphur cycles. Phaeocystis is a significant producer of DMSP (dimethylsulphide propionate), the precursor of DMS. When emitted to the atmosphere the DMS has a cooling effect on the climate contrarily to the CO2 greenhouse gas. Since the late 1990's specific nutrient reduction policies have however considerably reduced P loads while N is maintained. In this application we explore, with a mathematical tool, the effects of changing N and P loads on air-sea CO2 exchanges and DMS marine emissions. The chosen model is the MIRO-CO2-DMS, a complex biogeochemical model describing carbon, biogenic sulphur and nutrient cycles in the marine domain. Model simulations are performed for the contemporary period since 1950, using real forcing fields for sea surface temperature, wind speed and atmospheric CO2 and RIVERSTRAHLER model simulations for river carbon and nutrient loads. Results are discussing the importance of human activities and river inputs of carbon and nutrients on the eutrophication of coastal areas, their ability to absorb atmospheric CO2 and the importance of DMS emissions associated with phytoplankton blooms, especially Phaeocystis.

  10. Biodiversity losses and carbon emissions in Amazon region - the situation of contemporary period and strategies for reduce these environmental changes

    SciTech Connect

    Freitas, M.A.V. de; Aquino, L.C.; Rosa, L.P.

    1997-12-31

    The forest removal is a major contributor to local, regional and global environmental changes. Many of the tropical`s species are gravely threatened Numerous studies suggest that from 1970 to 1990 between 5 and 20 percent of the tropical`s species were committed to extinction. In 1995, the deforested lands in Brazilian Amazon account an amount Superior to 470,000 Km{sup 2}, old deforestation included, for a total surface of tropical`s rain forest of 3.4 and 3.8 million square kilometres. In 1990`s, the amount of carbon released to the atmosphere (as CO{sub 2}) from Brazilian Amazon deforestation was 3.5 % to 4.9 % and 250 % to 360 % of the World and Brazilian annual emission from fossil fuels, respectively. On the other hand, if deforestation is stopped and replaced with a rational forest management, a reuse of degraded lands for agro-forestry and biomass production for energy and industrial purposes, we can reduce the pressure on forests lands and the net carbon flux will be reversed. In this paper, we discuss the relations with biodiversity losses and carbon emissions in Brazilian Amazon region in the last thirty years and find suggest the principal`s strategies to reduce this environmental`s destruction.

  11. Fast polarization changes in mm microwave emission of weak multistructured solar bursts

    NASA Technical Reports Server (NTRS)

    Kaufmann, P.; Strauss, F. M.; Costa, J. E. R.; Dennis, B. R.

    1982-01-01

    Circular polarization of weak multistructured solar bursts was measured at mm microwaves with unprecedented sensitivity (0.03 sfu rms) and high time resolution (1ms). It was shown that sudden changes occur in the degree of polarization with time scales of 0.04 to 0.3 s. In most cases the degree of polarization attained maximum values before the maximum flux in both mm microwaves and hard X-rays with time scales of 0.04 to 1.0 s. The timing accuracy in determining the degree of polarization was 40 ms. Physical phenomena are discussed invoking one or a combination of various possible causes for the observed effects. The bursts at mm microwaves were weak compared to the contribution of the preexisting active regions, and therefore the changes in magnetoionic propagation conditions for emerging radiation plays an important role in the observed effects. Composite effects due to more than one polarizing mechanism or more than one polarized spots within the antenna beam are discussed.

  12. Dust emission and environmental changes in the dried bottom of the Aral Sea

    NASA Astrophysics Data System (ADS)

    Indoitu, R.; Kozhoridze, G.; Batyrbaeva, M.; Vitkovskaya, I.; Orlovsky, N.; Blumberg, D.; Orlovsky, L.

    2015-06-01

    In the 1990s, the western world became aware of the ecological disaster of what was once the fourth largest lake in the world - the Aral Sea. The drastic desiccation of the Aral Sea led to the intensive development of desertification processes in the region and the formation of a new desert, the Aralkum. In the last few decades, the Aralkum has become the new "hot spot" of dust and salt storms in the region. Dust storms and their source areas have been determined and analyzed by the NOAA AVHRR, TOMS and OMI data. An analysis of the land-cover changes in the dried bottom of the Aral Sea revealed that the north-eastern part of the Aralkum Desert is one of the most active dust sources in the region, responsible for high aerosol concentrations in the atmosphere. Dust plumes that sweep up from the dried bottom of the Aral Sea have become larger, and dust storms have become more powerful, since the bottom exposure. The main change that occurred in the land cover was the considerable reduction of vegetation and small water bodies, while the areas of solonchaks (salty pans) and sandy massifs increased significantly.

  13. Gas bubble transport and emissions for shallow peat from a northern peatland: The role of pressure changes and peat structure

    NASA Astrophysics Data System (ADS)

    Chen, Xi; Slater, Lee

    2015-01-01

    Gas bubbles are an important pathway for methane release from peatlands. The mechanisms controlling gas bubble transport and emissions in peat remain uncertain. The effects of hydrostatic pressure and peat structure on the dynamics of gas bubbles in shallow peat were therefore tested in laboratory experiments. A peat monolith was retrieved from a raised bog and maintained in a saturated state. Three distinct layers were identified from noninvasive permittivity measurements supported by soil physical properties (porosity, bulk density). Phase I of the experiment involved monitoring for the accumulation of gas bubbles under steady pressure and temperature conditions. The data showed evidence for gas bubbles being impeded by a shallow semiconfining layer at depths between 10 and 15 cm. Visible gas bubbles observed on the side of the sample box were recorded over time to estimate changes in the vertical distribution of volumetric gas content. Porosity estimates derived using the Complex Refraction Index Model (CRIM) suggest that gas bubbles enlarge the pore space when the exerted pressure is high enough. Phase II involved triggering release of trapped bubbles by repeatedly increasing and decreasing hydrostatic pressure in an oversaturated condition. Comparison of changes in pressure head and methane density in the head space confirmed that the increasing buoyancy force during drops in pressure is more important for triggering ebullition than increasing mobility during increases in pressure. Our findings demonstrate the importance of changes in hydrostatic pressure on bubble size and variations in resistance of the peat fabric in regulating methane releases from peatlands.

  14. Changing Arctic Ecosystems: Updated forecast: Reducing carbon dioxide (CO2) emissions required to improve polar bear outlook

    USGS Publications Warehouse

    Oakley, Karen L.; Atwood, Todd C.; Mugel, Douglas N.; Rode, Karyn D.; Whalen, Mary E.

    2015-01-01

    The Arctic is warming faster than other regions of the world due to the loss of snow and ice, which increases the amount of solar energy absorbed by the region. The most visible consequence has been the rapid decline in sea ice over the last 3 decades-a decline projected to bring long ice-free summers if greenhouse gas (GHG) emissions are not significantly reduced. The polar bear (Ursus maritimus) depends on sea ice over the biologically productive continental shelves of the Arctic Ocean as a platform for hunting seals. In 2008, the U.S. Fish and Wildlife Service listed the polar bear as threatened under the Endangered Species Act (ESA) due to the threat posed by sea ice loss. The polar bear was the first species to be listed due to forecasted population declines from climate change.

  15. Organic Crystals with Near-Infrared Amplified Spontaneous Emissions Based on 2'-Hydroxychalcone Derivatives: Subtle Structure Modification but Great Property Change.

    PubMed

    Cheng, Xiao; Wang, Kai; Huang, Shuo; Zhang, Houyu; Zhang, Hongyu; Wang, Yue

    2015-07-13

    A series of highly efficient deep red to near-infrared (NIR) emissive organic crystals 1-3 based on the structurally simple 2'-hydroxychalcone derivatives were synthesized through a simple one-step condensation reaction. Crystal 1 displays the highest quantum yield (Φf) of 0.32 among the reported organic single crystals with an emission maximum (λem) over 710 nm. Comparison between the bright emissive crystals 1-3 and the nearly nonluminous compounds 4-7 clearly gives evidence that a subtle structure modification can arouse great property changes, which is instructive in designing new high-efficiency organic luminescent materials. Notably, crystals 1-3 exhibit amplified spontaneous emissions (ASE) with extremely low thresholds. Thus, organic deep red to NIR emissive crystals with very high Φf have been obtained and are found to display the first example of NIR fluorescent crystal ASE. PMID:26036645

  16. Projecting policy-relevant metrics for high summertime ozone pollution events over the eastern United States due to climate and emission changes during the 21st century

    NASA Astrophysics Data System (ADS)

    Rieder, Harald E.; Fiore, Arlene M.; Horowitz, Larry W.; Naik, Vaishali

    2015-01-01

    the eastern United States (EUS), nitrogen oxides (NOx) emission controls have led to improved air quality over the past two decades, but concerns have been raised that climate warming may offset some of these gains. Here we analyze the effect of changing emissions and climate, in isolation and combination, on EUS summertime surface ozone (O3) over the recent past and the 21st century in an ensemble of simulations performed with the Geophysical Fluid Dynamics Laboratory CM3 chemistry-climate model. The simulated summertime EUS O3 is biased high but captures the structure of observed changes in regional O3 distributions following NOx emission reductions. We introduce a statistical bias correction, which allows derivation of policy-relevant statistics by assuming a stationary mean state bias in the model, but accurate simulation of changes at each quantile of the distribution. We contrast two different 21st century scenarios: (i) representative concentration pathway (RCP) 4.5 and (ii) simulations with well-mixed greenhouse gases (WMGG) following RCP4.5 but with emissions of air pollutants and precursors held fixed at 2005 levels (RCP4.5_WMGG). We find under RCP4.5 no exceedance of maximum daily 8 hour average ozone above 75 ppb by mid-21st century, reflecting the U.S. NOx emissions reductions projected in RCP4.5, while more than half of the EUS exceeds this level by the end of the 21st century under RCP4.5_WMGG. Further, we find a simple relationship between the changes in estimated 1 year return levels and regional NOx emission changes, implying that our results can be generalized to estimate changes in the frequency of EUS pollution events under different regional NOx emission scenarios.

  17. Land cover change and carbon emissions over 100 years in an African biodiversity hotspot.

    PubMed

    Willcock, Simon; Phillips, Oliver L; Platts, Philip J; Swetnam, Ruth D; Balmford, Andrew; Burgess, Neil D; Ahrends, Antje; Bayliss, Julian; Doggart, Nike; Doody, Kathryn; Fanning, Eibleis; Green, Jonathan M H; Hall, Jaclyn; Howell, Kim L; Lovett, Jon C; Marchant, Rob; Marshall, Andrew R; Mbilinyi, Boniface; Munishi, Pantaleon K T; Owen, Nisha; Topp-Jorgensen, Elmer J; Lewis, Simon L

    2016-08-01

    Agricultural expansion has resulted in both land use and land cover change (LULCC) across the tropics. However, the spatial and temporal patterns of such change and their resulting impacts are poorly understood, particularly for the presatellite era. Here, we quantify the LULCC history across the 33.9 million ha watershed of Tanzania's Eastern Arc Mountains, using geo-referenced and digitized historical land cover maps (dated 1908, 1923, 1949 and 2000). Our time series from this biodiversity hotspot shows that forest and savanna area both declined, by 74% (2.8 million ha) and 10% (2.9 million ha), respectively, between 1908 and 2000. This vegetation was replaced by a fivefold increase in cropland, from 1.2 million ha to 6.7 million ha. This LULCC implies a committed release of 0.9 Pg C (95% CI: 0.4-1.5) across the watershed for the same period, equivalent to 0.3 Mg C ha(-1)  yr(-1) . This is at least threefold higher than previous estimates from global models for the same study area. We then used the LULCC data from before and after protected area creation, as well as from areas where no protection was established, to analyse the effectiveness of legal protection on land cover change despite the underlying spatial variation in protected areas. We found that, between 1949 and 2000, forest expanded within legally protected areas, resulting in carbon uptake of 4.8 (3.8-5.7) Mg C ha(-1) , compared to a committed loss of 11.9 (7.2-16.6) Mg C ha(-1) within areas lacking such protection. Furthermore, for nine protected areas where LULCC data are available prior to and following establishment, we show that protection reduces deforestation rates by 150% relative to unprotected portions of the watershed. Our results highlight that considerable LULCC occurred prior to the satellite era, thus other data sources are required to better understand long-term land cover trends in the tropics. PMID:26748590

  18. Land-use Changes on Peatlands in Russia and Green House Gas Emissions

    NASA Astrophysics Data System (ADS)

    Sirin, A.; Minaeva, T.; Chistotin, M.; Glagolev, M.; Suvorov, G.

    2009-04-01

    Russia possesses vast areas of peatlands and associated paludified shallow peat lands, over 8 and 20% respectively. The country is the largest World peatland nation, and thus could be responsible for the large part of GHG exchange between peatlands and the atmosphere. Russian peatlands present a high variety of natural conditions from permafrost mires to bogs, fens and swamps within boreal, temperate, steppe and semi-arid zones, which have quite different rates of GHG flux, emitting or absorbing carbon dioxide and methane. Many regions of Russia still contain vast areas of virgin mires but in the central European part of Russia, West Siberia and Far East the appreciable part of peatlands was already modified. Peatlands were used in a broad spectrum of human activities connected with direct water level draw-down: peat extraction for different purposes (up to 1.5 million ha), drainage for agriculture, and drainage for forestry (each over 3 million ha). Many peatlands all the over the country were affected by infrastructure development (by road, pipe line construction etc.) with related changes of their hydrology and GHG fluxes. These land uses are under consideration of LULUFC issues of UNFCCC, and peat excavation is directly included in IPCC 2006 Guidelines as a main wetland/peatland land use activity related to climate change mitigation. General estimates and geographical distribution of peatlands drained for agriculture and forestry as well as peatlands under excavation, extracted or abandoned are given based on existing statistical and sectoral information. GHG fluxes from disturbed peatlands are analyzed using available Russian data and the results of specially organized observations in 2004-2008 in the pilot regions in Central European Russia and West Siberia which included a variety of modified and virgin control sites.

  19. Reviews and syntheses: Soil N2O and NO emissions from land use and land-use change in the tropics and subtropics: a meta-analysis

    NASA Astrophysics Data System (ADS)

    van Lent, J.; Hergoualc'h, K.; Verchot, L. V.

    2015-12-01

    Deforestation and forest degradation in the tropics may substantially alter soil N-oxide emissions. It is particularly relevant to accurately quantify those changes to properly account for them in a REDD+ climate change mitigation scheme that provides financial incentives to reduce the emissions. With this study we provide updated land use (LU)-based emission rates (104 studies, 392 N2O and 111 NO case studies), we determine the trend and magnitude of flux changes with land-use change (LUC) using a meta-analysis approach (44 studies, 135 N2O and 37 NO cases) and evaluate biophysical drivers of N2O and NO emissions and emission changes for the tropics. The average N2O and NO emissions in intact upland tropical forest amounted to 2.0 ± 0.2 (n = 90) and 1.7 ± 0.5 (n = 36) kg N ha-1 yr-1, respectively. In agricultural soils annual N2O emissions were exponentially related to N fertilization rates and average water-filled pore space (WFPS) whereas in non-agricultural sites a Gaussian response to WFPS fit better with the observed NO and N2O emissions. The sum of soil N2O and NO fluxes and the ratio of N2O to NO increased exponentially and significantly with increasing nitrogen availability (expressed as NO3- / [NO3-+NH4+]) and WFPS, respectively; following the conceptual Hole-In-the-Pipe model. Nitrous and nitric oxide fluxes did not increase significantly overall as a result of LUC (Hedges's d of 0.11 ± 0.11 and 0.16 ± 0.19, respectively), however individual LUC trajectories or practices did. Nitrous oxide fluxes increased significantly after intact upland forest conversion to croplands (Hedges's d = 0.78 ± 0.24) and NO increased significantly following the conversion of low forest cover (secondary forest younger than 30 years, woodlands, shrublands) (Hedges's d of 0.44 ± 0.13). Forest conversion to fertilized systems significantly and highly raised both N2O and NO emission rates (Hedges's d of 1.03 ± 0.23 and 0.52 ± 0.09, respectively). Changes in nitrogen

  20. Soil N2O and NO emissions from land use and land-use change in the tropics and subtropics: a meta-analysis

    NASA Astrophysics Data System (ADS)

    van Lent, J.; Hergoualc'h, K.; Verchot, L. V.

    2015-08-01

    Deforestation and forest degradation in the tropics may substantially alter soil N-oxide emissions. It is particularly relevant to accurately quantify those changes to properly account for them in a REDD+ climate change mitigation scheme that provides financial incentives to reduce the emissions. With this study we provide updated land use (LU)-based emission rates (103 studies, 387 N2O and 111 NO case studies), determine the trend and magnitude of flux changes with land-use change (LUC) using a meta-analysis approach (43 studies, 132 N2O and 37 NO cases) and evaluate biophysical drivers of N2O and NO emissions and emission changes for the tropics. The average N2O and NO emissions in intact upland tropical forest amounted to 2.0 ± 0.2 (n = 88) and 1.7 ± 0.5 (n = 36) kg N ha-1 yr-1, respectively. In agricultural soils annual N2O emissions were exponentially related to N fertilization rates and average water-filled pore space (WFPS) whereas in non-agricultural sites a Gaussian response to WFPS fit better the observed NO and N2O emissions. The sum of soil N2O and NO fluxes and the ratio of N2O to NO increased exponentially and significantly with increasing nitrogen availability (expressed as NO3-/[NO3-+NH4+]) and WFPS, respectively; following the conceptual Hole-In-the-Pipe model. Nitrous and nitric oxide fluxes did not overall increase significantly as a result of LUC (Hedges's d of 0.11 ± 0.11 and 0.16 ± 0.19, respectively), however individual LUC trajectories or practices did. Nitrous oxide fluxes increased significantly after intact upland forest conversion to croplands (Hedges's d = 0.78 ± 0.24) and NO increased significantly following the conversion of low forest cover (secondary forest younger than 30 years, woodlands, shrublands) (Hedges's d of 0.44 ± 0.13). Forest conversion to fertilized systems significantly and highly raised both N2O and NO emission rates (Hedges's d of 1.03 ± 0.23 and 0.52 ± 0.09, respectively). Changes in nitrogen availability

  1. Observing Future Changes in the Photochemical Environment over Western North America due to Changes in Foreign Emissions: Lessons from Mount Bachelor

    NASA Astrophysics Data System (ADS)

    Fischer, E. V.; Jaffe, D. A.; Weatherhead, E. C.

    2011-12-01

    There are multiple lines of evidence that springtime O3 mixing ratios are increasing over western North America, and rising O3 precursor emissions in East Asia are cited as potentially responsible. The Asian contribution to background O3 has two components: 1) O3 has a sufficient lifetime in spring such that O3 formed in the Asian boundary layer can cross the Pacific, and 2) O3 can be formed en-route as a result of peroxyacetyl nitrate (PAN) decomposition. To confidently detect a trend in a trace species such as O3, the trend must be large relative to both the natural variability and to the long-term measurement uncertainty, or alternatively one needs many years of observations. Detection of changes to the O3 budget in the air entering North America is challenging because consistent long-term observations are sparse. We report on measurements of PAN and O3 from the summit of Mount Bachelor (43.979°N, 121.687°W; 2.7 km a.s.l). These are the first consistent multi-year springtime measurements of PAN in the free troposphere over the U.S. Pacific Northwest. We combine the observed variability in PAN and O3 at Mount Bachelor with a range of possible future trends in these species to determine the observational requirements to detect such trends. A previous study using a global chemical transport model suggested that rising Asian emissions of nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOCs) will result in a relatively larger positive trend in PAN than O3 over western North America. We show that the timescale for PAN and O3 trend detection is equivalent when the PAN trend is approximately 4 times larger than the O3 trend. This reflects greater observed relative variability in PAN than O3. Our analysis suggests that if the true O3 trend over western North America due to rising Asian precursor emissions is on the order of 1% per year, it could be corroborated at a strategic representative site like Mount Bachelor in a relatively short timeframe

  2. Uncertainties of the extreme high flows under climate change impact due to emission scenarios, hydrological models and parameters

    NASA Astrophysics Data System (ADS)

    Tian, Ye; Booij, Martijn; Zhu, Qian; Pan, Suli; Xu, Yue-Ping

    2013-04-01

    Climate change has exerted a significant impact on the hydrological cycle which is closely related to human's daily life. Due to the fact that the extreme precipitation is happening with increasing frequency and intensity, the study of extreme high flows has been an issue of great importance in recent years. Normally the future discharges are simulated by hydrological models with outputs from the RCMs. However the uncertainties are involved in every step of the processes, including GCMs, emission scenarios, downscaling methods, hydrological models and etc. In this study, the uncertainties in extreme high flows originating from greenhouse gas emission scenarios, hydrological model structures and their parameters were evaluated for the Jinhua River basin, East China. The baseline (1961-1990) climate and future (2011-2040) climate for scenario A1B, A2 and B2 were downscaled by the PRECIS Regional Climate Model with a spatial resolution of 50km×50km from the General Circulation Model (GCM). The outputs of the PRECIS (daily temperature and daily precipitation) were bias corrected by a distribution based method and a linear correction method. Three hydrological models (GR4J, HBV and Xinanjiang) were applied to simulate the daily discharge. The parameter uncertainty in hydrological models were taken into account and quantified by means of the Generalized Likelihood Uncertainty Estimation (GLUE) method. The GLUE was applied for each hydrological model in three emission scenarios. In total 30000 parameter sets were randomly generated within the parameter ranges, in which about 10% parameter sets were above the pre-assigned threshold and represented as the parameter uncertainty. The annual maximum discharge was used for the extreme high flow analysis. There was an overestimation for the monthly precipitation in July, August and September and an overestimation of 6.3-7.8 oC for monthly temperature all year round in the PRECIS output. The biases were reduced after bias

  3. Mitigating GHG emissions from agriculture under climate change constrains - a case study for the State of Saxony, Germany

    NASA Astrophysics Data System (ADS)

    Haas, E.; Kiese, R.; Klatt, S.; Butterbach-Bahl, K.

    2012-12-01

    Mitigating greenhouse gas (N2O, CO2, CH4) emissions from agricultural soils under conditions of projected climate change (IPCC SRES scenarios) is a prerequisite to limit global warming. In this study we used the recently developed regional biogeochemical ecosystem model LandscapeDNDC (Haas et al., 2012, Landscape Ecology) and two time slices for present day (1998 - 2018) and future climate (2078-2098) (regional downscale of IPCC SRES A1B climate simulation) and compared a business as usual agricultural management scenario (winter rape seed - winter barley - winter wheat rotation; fertilization: 170 / 150 / 110 kg-N mineral fertilizer; straw harvest barley/wheat: 90 %) with scenarios where either one or all of the following options were realized: no-till, residue return to fields equal 100%, reduction of fertilization rate s were left on the field or reduction of N fertilization by 10%. The spatial domain is the State of Saxony (1 073 523 hectares of arable land), a typical region for agricultural production in Central Europe. The simulations are based on a high resolution polygonal datasets (5 517 agricultural grid cells) for which relevant information on soil properties is available. The regionalization of the N2O emissions was validated against the IPCC Tier I methodology resulting in N2O emissions of 1 824 / 1 610 / 1 180 [t N2O-N yr-1] for of the baseline years whereas the simulations results in 6 955 / 6 039 / 2 207 [t N2O-N yr-1] for the first three years of the baseline scenarios and ranging between 621 and 6 955 [t N2O-N yr-1] within the following years (mean of 2 923). The influence of climate change (elevated mean temperature of approx. 2°C and minor changes in precipitation) results in an increase of 259 [t N2O-N yr-1] (mean 3 182) or approx. 9 percent on average (with a minimum of 618 and a maximum of 6 553 [t N2O-N yr-1]). Focusing on the mitigation , the recarbonization did result in an increase of soil carbon stocks of 2 585 [kg C/ha] within the

  4. Modeling analyses of the effects of changes in nitrogen oxides emissions from the electric power sector on ozone levels in the eastern United States

    SciTech Connect

    Edith Gego; Alice Gilliland; James Godowitch

    2008-04-15

    In this paper, we examine the changes in ambient ozone concentrations simulated by the Community Multiscale Air Quality (CMAQ) model for summer 2002 under three different nitrogen oxides (NOx) emission scenarios. Two emission scenarios represent best estimates of 2002 and 2004 emissions; they allow assessment of the impact of the NOx emissions reductions imposed on the utility sector by the NOx State Implementation Plan (SIP) Call. The third scenario represents a hypothetical rendering of what NOx emissions would have been in 2002 if no emission controls had been imposed on the utility sector. Examination of the modeled median and 95th percentile daily maximum 8-hr average ozone concentrations reveals that median ozone levels estimated for the 2004 emission scenario were less than those modeled for 2002 in the region most affected by the NOx SIP Call. Comparison of the 'no-control' with the '2002' scenario revealed that ozone concentrations would have been much higher in much of the eastern United States if the utility sector had not implemented NOx emission controls; exceptions occurred in the immediate vicinity of major point sources where increased NO titration tends to lower ozone levels. 13 refs., 8 figs., 2 tabs.

  5. The design, characterization, and comparison of MEMS comb-drive acoustic emission transducers with the principles of area-change and gap-change

    NASA Astrophysics Data System (ADS)

    Kabir, Minoo; Saboonchi, Hossain; Ozevin, Didem

    2015-04-01

    Comb-drive transducers are made of interdigitized fingers formed by the stationary part known as stator and the moving part known as rotor, and based on the transduction principle of capacitance change. They can be designed as area-change or gap-change mechanism to convert the mechanical signal at in-plane direction into electrical output. The comb-drive transducers can be utilized to differentiate the wave motion in orthogonal directions when they are utilized with the outof- plane transducers. However, their sensitivity is weak to detect the wave motion released by newly formed damage surfaces. In this study, Micro-Electro-Mechanical System (MEMS) comb-drive Acoustic Emission (AE) transducer designs with two different mechanisms are designed, characterized and compared for sensing high frequency wave propagation. The MEMS AE transducers are manufactured using MetalMUMPs (Metal Multi-User MEMS Processes), which use electroplating technique for highly elevated microstructure geometries. Each type of the transducers is numerically modeled using COMSOL Multiphysics program in order to determine the sensitivity based on the applied load. The transducers are experimentally characterized and compared to the numerical models. The experiments include laser excitation to control the direction of the wave generation, and actual crack growth monitoring of aluminum 7075 specimens loaded under fatigue. Behavior and responses of the transducers are compared based on the parameters such as waveform signature, peak frequency, damping, sensitivity, and signal to noise ratio. The comparisons between the measured parameters are scaled according to the respective capacitance of each sensor in order to determine the most sensitive design geometry.

  6. LINKING REGIONAL AEROSOL EMISSION CHANGES WITH MULTIPLE IMPACT MEASURES THROUGH DIRECT AND CLOUD-RELATED FORCING ESTIMATES

    EPA Science Inventory

    Outputs expected from this project include improved confidence in direct radiative forcing and cloud radiative forcing, particularly over the United States and with regard to United States emissions publicly available, documented data sets including emission inventories of siz...

  7. Changes in the Diffuse CO2 Emission and Relation to Seismic Activity in and around El Hierro, Canary Islands

    NASA Astrophysics Data System (ADS)

    Padrón, Eleazar; Melián, Gladys; Marrero, Rayco; Nolasco, Dácil; Barrancos, José; Padilla, Germán; Hernández, Pedro A.; Pérez, Nemesio M.

    2008-01-01

    Significant changes in the diffuse emission of carbon dioxide were recorded in a geochemical station located at El Hierro, Canary Islands, before the occurrence of several seismic events during 2004. Two precursory CO2 efflux increases started thirteen and nine days before two seismic events of magnitude 2.3 and 1.7, which took place near El Hierro Island, Canary Islands, on March 23 and April 15, reaching a maximun value of 51.1 and 46.2 g m-2 d-1, respectively, five and eight days before the two seismic events. Other similar increases started thirteen and five days before the occurrence of two seismic events of magnitude 1.3 and 1.5 which took place on October 15 and 21 respectively, reaching the maximum values four and one day before the earthquakes. These changes were not related to variations in atmospheric or soil parameters. The Material Failure Forecast Method (FFM), which analyzes the rate of precursory phenomena, was successfully applied to forecast the first seismic event that took place in El Hierro Island in 2004.

  8. Up/Down trend in the MODIS Aerosol Optical Depth and its relationship to the Sulfur Dioxide Emission Changes in China during 2000 and 2010

    NASA Astrophysics Data System (ADS)

    Itahashi, S.; Uno, I.; Yumimoto, K.; Irie, H.; Osada, K.; Ogata, K.; Fukushima, H.; Wang, Z.; Ohara, T.

    2011-08-01

    Anthropogenic SO2 emissions increased alongside economic development in China at a rate of 12.7 % yr-1 from 2000 to 2005. However, under new Chinese government policy, SO2 emissions declined by 3.9 % yr-1 between 2005 and 2009. Between 2000 and 2010, we found that the variability in the fine-mode (submicron) aerosol optical depth (AOD) over the oceans adjacent to East Asia increased by 4-8 % yr-1 to a peak around 2005-2006 and subsequently decreased by 4-7 % yr-1, based on observations by the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA's Terra satellite and simulations by a chemical transport model. This trend is consistent with ground-based observations of the number-size distribution of aerosol particles at a mountainous background observation site in central Japan. These fluctuations in SO2 emission intensity and AOD are thought to reflect the widespread installation of fuel-gas desulfurization (FGD) devices in power plants in China because aerosol sulfate is a major determinant of the AOD in East Asia. Using a chemical transport model, we confirmed that the above-mentioned fluctuation in AOD is mainly caused by changes in SO2 emission rather than by varying meteorological conditions in East Asia. High correlation was also found between satellite-retrieved SO2 vertical column density and bottom-up SO2 emissions, both of which were also consistent with observed AOD trends. We proposed a simplified approach for evaluating changes in SO2 emissions in China, combining the use of modeled sensitivity coefficients that describe the variation of AOD with changes in SO2 emissions and satellite retrieval. Satellite measurements of the AOD above Sea of Japan marked the 4.1 % yr-1 declining between 2007 and 2010, and this correspond to the SO2 emissions from China decreased by ~9 % yr-1 between the same period.

  9. Strong dependence of CO2 emissions from anthropogenic land cover change on initial land cover and soil carbon parametrization

    NASA Astrophysics Data System (ADS)

    Goll, Daniel S.; Brovkin, Victor; Liski, Jari; Raddatz, Thomas; Thum, Tea; Todd-Brown, Kathe E. O.

    2015-09-01

    The quantification of sources and sinks of carbon from land use and land cover changes (LULCC) is uncertain. We investigated how the parametrization of LULCC and of organic matter decomposition, as well as initial land cover, affects the historical and future carbon fluxes in an Earth System Model (ESM). Using the land component of the Max Planck Institute ESM, we found that the historical (1750-2010) LULCC flux varied up to 25% depending on the fraction of biomass which enters the atmosphere directly due to burning or is used in short-lived products. The uncertainty in the decadal LULCC fluxes of the recent past due to the parametrization of decomposition and direct emissions was 0.6 Pg C yr-1, which is 3 times larger than the uncertainty previously attributed to model and method in general. Preindustrial natural land cover had a larger effect on decadal LULCC fluxes than the aforementioned parameter sensitivity (1.0 Pg C yr-1). Regional differences between reconstructed and dynamically computed land covers, in particular, at low latitudes, led to differences in historical LULCC emissions of 84-114 Pg C, globally. This effect is larger than the effects of forest regrowth, shifting cultivation, or climate feedbacks and comparable to the effect of differences among studies in the terminology of LULCC. In general, we find that the practice of calibrating the net land carbon balance to provide realistic boundary conditions for the climate component of an ESM hampers the applicability of the land component outside its primary field of application.

  10. Changes in the X-Ray Emission from the Magnetar Candidate 1E 2259+586 During its 2002 Outburst

    NASA Technical Reports Server (NTRS)

    Woods, P. M.; Kaspi, V. M.; Thompson, C.; Gavrill, F. P.; Marshall, H. L.; Chakrabarty, D.; Flanagan, K.; Heyl, J.; Hernquist, L.

    2004-01-01

    preglitch value. The changes in the source properties of 1E 2259+586 during its 2002 outburst are shown to be qualitatively similar to changes seen during or following burst activity in two SGRs, thus further solidifying the common nature of SGRs and AXP's as magnetars. The changes in persistent emission properties of 1E 2259+586 suggest that the star underwent a plastic deformation of the crust that simultaneously impacted the superfluid interior (crustal and possibly core superfluid) and the magnetosphere. Finally, the changes in persistent emission properties coincident with burst activity in 1E 2259+586 enabled us to infer previous burst-active episodes from this and other AXP's. The nondetection of these outbursts by all-sky gamma-ray instruments suggests that the number of active magnetar candidates in our Galaxy is larger than previously thought.

  11. Changes in the properties of soils and soil biota in the impact zone of the aerotechnogenic emissions from the Kandalaksha aluminum smelter

    NASA Astrophysics Data System (ADS)

    Evdokimova, G. A.; Korneikova, M. V.; Mozgova, N. P.

    2013-10-01

    A comparative analysis of the changes in the properties of the soils and soil biota in the past ten years along the gradient of pollution with aerotechnogenic emission from the Kandalaksha aluminum smelter in response to a decrease in the emission volume has been performed. The concentrations of fluorine compounds (the priority pollutant) in the emissions and in the organic soil horizons in the impact zone significantly decreased in 2011 relative to 2001. The concentrations of Al decreased only in close vicinity to the smelter (up to 2 km). The concentrations of F, Ca, and Mg in the liquid phase were higher than those in the solid phase, and these elements migrated to greater distances from the source of the contamination (up to 15-20 km). The elements Si, Al, Fe, and P were contained mostly in the solid phase and were mainly deposited within the 5-km zone. The acidity of the litter near the smelter decreased by almost by two pH units in the nearest zone (<2 km). The decrease in the amount of contaminants in the emissions resulted in the narrowing of the zone of the maximum soil contamination from 2.5 to 1.5 km from the emission source; the zones of strong and moderate contamination narrowed by 5 km. The regularities of the changes in the numbers and biomasses of the main groups of microorganisms in the soils of the permanent sampling plots did not change during the past ten years. The emissions inhibited the development of the fungal biota. The prokaryotic part of the soil microbiota and, particularly, the actinomycetes proved to be tolerant to the emitted contaminants. It was suggested that the changes in the structure of the fungal and actinomycetal communities should be used to monitor the state of the soil ecosystems affected by the emissions from the aluminum smelter.

  12. Investigating the direct and indirect influences of light on short-term changes in methanol production and emission in Lycopersicon esculentum

    NASA Astrophysics Data System (ADS)

    Oikawa, P.; Li, L.; Timko, M.; Mak, J. E.; Lerdau, M.

    2010-12-01

    Plant-produced methanol (MeOH) is the largest source of MeOH to the atmosphere where it is the second most abundant organic gas after methane. Current MeOH emission models are limited by their inability to predict changes in MeOH production in plants, a process still not well understood. Previous modeling studies indicated that light may have a direct influence on phytogenic MeOH production. As light is known to regulate cell wall expansion, we predicted light to stimulate MeOH production through the pectin methylesterase (PME) pathway. After normalizing MeOH emissions for stomatal conductance, we were unable to detect a MeOH emission response to light over short time scales (20-30min). After experimentally controlling for stomatal conductance and temperature, no light activation of PME activity or MeOH emission was observed. Our results clearly demonstrate the lack of a direct influence of light on short-term changes in MeOH production and emission. Future investigation of the long-term impacts of light on MeOH production is needed as light history may be an important factor for predicting MeOH emission over diurnal and seasonal time scales.

  13. Study of Reciprocal Effects between Mandatory Pollutant Emissions Reduction Policy and Structural Change within the Manufacturing Sector in a Chinese Coastal Area.

    PubMed

    Guo, Yang; Guo, Xianglin; Tian, Jinping; Chen, Lujun

    2015-11-01

    We develop a multicriteria decision-making model coupled with scenario analysis to quantitatively elucidate the reciprocal effect between a mandatory pollutant emissions reduction policy and industrial structure change within the manufacturing sector on the basis of an in-depth study of a well-developed coastal area in East China, Ningbo City, toward 2020. First, 18 two-digit level industries (TDLIs) in the manufacturing sector are screened out due to intensive emissions of the four pollutants (COD, NH3-N, SO2, and NOx). Second, a model is established to identify the optimal solution for the industrial structure adjustment of the 18 TDLIs under two scenarios, the "business-as-usual" scenario and the "industrial structure adjustment" scenario. Both scenarios are expanded into three subscenarios. Quantitative constraint conditions and two criteria are formulated to screen out the optimal solutions. We propose a coefficient of industrial structure adjustment, Ki, which could clearly reflect the policy preference in terms of industrial development and reallocate the quota of the four-pollutant emission among the 18 TDLIs with regards to the different expectations of economy development in 2020. The model will help local authorities make tailored policies to reduce pollution emissions effectively through industrial structure change by delicately allocating the pollutant emission quota and setting reasonable targets of emission intensity reduction among TDLIs. PMID:26421657

  14. Future Premature Mortality Due to O3, Secondary Inorganic Aerosols and Primary PM in Europe — Sensitivity to Changes in Climate, Anthropogenic Emissions, Population and Building Stock

    PubMed Central

    Geels, Camilla; Andersson, Camilla; Hänninen, Otto; Lansø, Anne Sofie; Schwarze, Per E.; Ambelas Skjøth, Carsten; Brandt, Jørgen

    2015-01-01

    Air pollution is an important environmental factor associated with health impacts in Europe and considerable resources are used to reduce exposure to air pollution through emission reductions. These reductions will have non-linear effects on exposure due, e.g., to interactions between climate and atmospheric chemistry. By using an integrated assessment model, we quantify the effect of changes in climate, emissions and population demography on exposure and health impacts in Europe. The sensitivity to the changes is assessed by investigating the differences between the decades 2000–2009, 2050–2059 and 2080–2089. We focus on the number of premature deaths related to atmospheric ozone, Secondary Inorganic Aerosols and primary PM. For the Nordic region we furthermore include a projection on how population exposure might develop due to changes in building stock with increased energy efficiency. Reductions in emissions cause a large significant decrease in mortality, while climate effects on chemistry and emissions only affects premature mortality by a few percent. Changes in population demography lead to a larger relative increase in chronic mortality than the relative increase in population. Finally, the projected changes in building stock and infiltration rates in the Nordic indicate that this factor may be very important for assessments of population exposure in the future. PMID:25749320

  15. Future premature mortality due to O3, secondary inorganic aerosols and primary PM in Europe--sensitivity to changes in climate, anthropogenic emissions, population and building stock.

    PubMed

    Geels, Camilla; Andersson, Camilla; Hänninen, Otto; Lansø, Anne Sofie; Schwarze, Per E; Skjøth, Carsten Ambelas; Brandt, Jørgen

    2015-03-01

    Air pollution is an important environmental factor associated with health impacts in Europe and considerable resources are used to reduce exposure to air pollution through emission reductions. These reductions will have non-linear effects on exposure due, e.g., to interactions between climate and atmospheric chemistry. By using an integrated assessment model, we quantify the effect of changes in climate, emissions and population demography on exposure and health impacts in Europe. The sensitivity to the changes is assessed by investigating the differences between the decades 2000-2009, 2050-2059 and 2080-2089. We focus on the number of premature deaths related to atmospheric ozone, Secondary Inorganic Aerosols and primary PM. For the Nordic region we furthermore include a projection on how population exposure might develop due to changes in building stock with increased energy efficiency. Reductions in emissions cause a large significant decrease in mortality, while climate effects on chemistry and emissions only affects premature mortality by a few percent. Changes in population demography lead to a larger relative increase in chronic mortality than the relative increase in population. Finally, the projected changes in building stock and infiltration rates in the Nordic indicate that this factor may be very important for assessments of population exposure in the future. PMID:25749320

  16. Modeling the effects of changes in New Source Review on national SO{sub 2} and NOx emissions from electricity-generating units

    SciTech Connect

    David A. Evans; Benjamin F. Hobbs; Craig Oren; Karen L. Palmer

    2007-03-15

    The Clean Air Act establishes New Source Review (NSR) programs that apply to the construction or modification of major stationary emissions sources. In 2002 and 2003, the U.S. Environmental Protection Agency revised its rules to narrow the applicability of NSR to facility renovations. Congress then mandated a National Research Council study of the effects of the rules. An electricity-sector model - the Integrated Planning Model (IPM) - was used to explore the possible effects of the equipment replacement provision (ERP), the principal NSR change that was to affect the power-generation industry. The studies focused in particular on coal-fired electricity generating units, EGUs, for two reasons. First, coal-fired EGUs are important contributors of these pollutants, accounting for approximately 70 and 20% of nations SO{sub 2} and NOx emissions in 2004, respectively. Second, the shares of total capacity of large coal-fired EGUs that lack flue-gas desulfurization to control SO{sub 2} and selective catalytic reduction to reduce NOx emissions are 62 and 63% respectively. Although the analysis cannot predict effects on local emissions, assuming that the Clean Air Interstate Rule (CAIR) is implemented, we find that stringent enforcement of the previous NSR rules would likely lead to no or limited decreases in national emissions compared to policies such as ERP. Our results indicate that tighter emissions caps could achieve further decreases in national emissions more cost-effectively than NSR programs. 15 refs., 3 figs., 1 tab.

  17. Now Read This II: A Guide to Mainstream Fiction, 1990-2001. Genreflecting Advisory Series.

    ERIC Educational Resources Information Center

    Pearl, Nancy

    This book provides a straightforward approach to finding and recommending good novels based on what sparks a reader's interest. With emphasis on award-winning fiction, the guide features more than 500 novels published between 1990 and 2001. This companion title uses the same easy-access organization used in the original "Now Read This: A Guide to…

  18. Research and Statistical Techniques Used in the Journal of Counseling & Development: 1990-2001

    ERIC Educational Resources Information Center

    Bangert, Arthur W.; Baumberger, Julie P.

    2005-01-01

    The "Journal of Counseling & Development" ("JCD") is the principal journal of the American Counseling Association (ACA) and is considered as the premier counseling journal in the world. The Research section of JCD is devoted primarily to publishing empirical investigations related to counseling theory and methods, counselor training and education,…

  19. Spatiotemporal Changes of Built-Up Land Expansion and Carbon Emissions Caused by the Chinese Construction Industry.

    PubMed

    Chuai, Xiaowei; Huang, Xianjin; Lu, Qinli; Zhang, Mei; Zhao, Rongqin; Lu, Junyu

    2015-11-01

    China is undergoing rapid urbanization, enlarging the construction industry, greatly expanding built-up land, and generating substantial carbon emissions. We calculated both the direct and indirect carbon emissions from energy consumption (anthropogenic emissions) in the construction sector and analyzed built-up land expansion and carbon storage losses from the terrestrial ecosystem. According to our study, the total anthropogenic carbon emissions from the construction sector increased from 3,905×10(4) to 103,721.17×10(4) t from 1995 to 2010, representing 27.87%-34.31% of the total carbon emissions from energy consumption in China. Indirect carbon emissions from other industrial sectors induced by the construction sector represented approximately 97% of the total anthropogenic carbon emissions of the sector. These emissions were mainly concentrated in seven upstream industry sectors. Based on our assumptions, built-up land expansion caused 3704.84×10(4) t of carbon storage loss from vegetation between 1995 and 2010. Cropland was the main built-up land expansion type across all regions. The study shows great regional differences. Coastal regions showed dramatic built-up land expansion, greater carbon storage losses from vegetation, and greater anthropogenic carbon emissions. These regional differences were the most obvious in East China followed by Midsouth China. These regions are under pressure for strong carbon emissions reduction. PMID:26421527

  20. Taking advantage of data on N leaching to improve estimates of N2O emission reductions from agriculture in response to management changes

    NASA Astrophysics Data System (ADS)

    Gurwick, N. P.; Tonitto, C.

    2012-12-01

    Estimates of reductions in N2O emissions from agricultural soils associated with different crop management practices often focus on in-field emissions. This is particularly true in the context of policy development for carbon offsets which are highly relevant in California, given the state's global warming protection law (AB 32). However, data sets often do not cover an entire year, missing key times such as spring thaw, and only rarely do they span multiple years even though inter-annual variation can be large. In the most productive grain systems on tile-drained Mollisols in the U.S. there are no long-term data sets of N2O flux, although these agroecosystems have the highest application rates of N fertilizer in grain systems and are prime candidates for large reductions in N2O emissions. In contrast, estimates of the influence of management practices like cover crops are much stronger because more data are available, and downstream N2O emissions should shift proportionally. Nevertheless, these changes in downstream emissions are frequently not included in estimates of N2O flux change. As an example, cereal cover crops reduce N leakage by 70%, and leguminous cover crops reduce N leakage by 40%. These data should inform estimates of downstream N2O emissions from agricultural fields, particularly in the context of protocol development, where project developers or aggregators will have information about basic management of individual crop fields. Even the IPCC default guidelines for simple (Tier 1) emission factors could take this information into account. Despite the complexity of estimating downstream N2O emissions in the absence of site-specific hydrology data, the IPCC estimates that 30% of applied N is lost and that between 0.75% and 1.0 % of lost N is converted to N2O. That single estimate should be refined based on data showing that leaching varies with management practices.

  1. Impact of emission control on PM2.5 and the chemical composition change in Beijing-Tianjin-Hebei during the APEC summit 2014.

    PubMed

    Wen, Wei; Cheng, Shuiyuan; Chen, Xufeng; Wang, Gang; Li, Song; Wang, Xiaoqi; Liu, Xiaoyu

    2016-03-01

    The success of the emission reduction measures undertaken by authorities in the Asia-Pacific Economic Cooperation summit 2014 demonstrated that the Beijing-Tianjin-Hebei air quality can be improved by introducing integrated emission reduction measures. This paper combines observation data, emission reduction measures, and air quality simulations that were applied before, during, and after the emission control measure implement to analyze the chemical composition change and relationship between emissions and concentrations of pollutants in region. The 24-h PM2.5 samples were collected in the city Beijing, Shijiazhuang, and Tangshan during the period of 20 October to 25 November, 2014. The total PM2.5 mass was measured. PM2.5 samples were used for the analysis of inorganic elements, selected ions, and organic carbon (OC) and element carbon (EC). PM2.5 concentrations during the emission control period were decreased. Total PM2.5 concentrations were reduced by 54, 26, and 39 % when compared to non-emission control period in Beijing, Shijiazhuang, and Tangshan. The average element concentrations were reduced significantly by 75 % in Beijing, 37 % in Shijiazhuang, and 36 % in Tangshan. After the Asia-Pacific Economic Cooperation (APEC) conference, the average element concentration increased. At both cities, the concentration secondary water-soluble ions, primary carbon, and element carbon were reduced. However, the concentration of secondary carbon species increased in Beijing due to photochemical oxidants change. More stringent control of regional emissions will be needed for significant reductions of fine particulate pollution in the region to continue to improve air quality. PMID:26514566

  2. Climate Change and Tritrophic Interactions: Will Modifications to Greenhouse Gas Emissions Increase the Vulnerability of Herbivorous Insects to Natural Enemies?

    PubMed

    Boullis, Antoine; Francis, Frederic; Verheggen, François J

    2015-04-01

    Insects are highly dependent on odor cues released into the environment to locate conspecifics or food sources. This mechanism is particularly important for insect predators that rely on kairomones released by their prey to detect them. In the context of climate change and, more specifically, modifications in the gas composition of the atmosphere, chemical communication-mediating interactions between phytophagous insect pests, their host plants, and their natural enemies is likely to be impacted. Several reports have indicated that modifications to plants caused by elevated carbon dioxide and ozone concentrations might indirectly affect insect herbivores, with community-level modifications to this group potentially having an indirect influence on higher trophic levels. The vulnerability of agricultural insect pests toward their natural enemies under elevated greenhouse gases concentrations has been frequently reported, but conflicting results have been obtained. This literature review shows that the higher levels of carbon dioxide, as predicted for the coming century, do not enhance the abundance or efficiency of natural enemies to locate hosts or prey in most published studies. Increased ozone levels lead to modifications in herbivore-induced volatile organic compounds (VOCs) released by damaged plants, which may impact the attractiveness of these herbivores to the third trophic level. Furthermore, other oxidative gases (such as SO2 and NO2) tend to reduce the abundance of natural enemies. The impact of changes in atmospheric gas emissions on plant-insect and insect-insect chemical communication has been under-documented, despite the significance of these mechanisms in tritrophic interactions. We conclude by suggesting some further prospects on this topic of research yet to be investigated. PMID:26313181

  3. Farm simulation: a tool for evaluating the mitigation of greenhouse gas emissions and the adaptation of dairy production to climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Process-level modeling at the farm scale provides a tool for evaluating strategies for both mitigating greenhouse gas emissions and adapting to climate change. The Integrated Farm System Model (IFSM) simulates representative crop, beef or dairy farms over many years of weather to predict performance...

  4. Farm simulation: a tool for evaluating the mitigation of greenhouse gas emissions and the adaptation of dairy production to climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Process-level modeling at the farm scale provides a tool for evaluating both strategies for mitigating greenhouse gas emissions and strategies for adapting to climate change. The Integrated Farm System Model (IFSM) simulates representative crop, beef or dairy farms over many years of weather to pred...

  5. Policy change driven by an AIS-assisted marine emission inventory in Hong Kong and the Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Ng, Simon K. W.; Loh, Christine; Lin, Chubin; Booth, Veronica; Chan, Jimmy W. M.; Yip, Agnes C. K.; Li, Ying; Lau, Alexis K. H.

    2013-09-01

    A new exhaust emission inventory of ocean-going vessels (OGVs) was compiled for Hong Kong by using Automatic Identification System (AIS) data for the first time to determine typical main engine load factors, through vessel speed and operation mode characterization. It was found that in 2007, container vessel was the top emitting vessel type, contributing 9,886, 11,480, 1,173, 521 and 1166 tonnes of SO2, NOx, PM10, VOC and CO, respectively, or about 80%-82% of the emissions. The top five, which also included ocean cruise, oil tanker, conventional cargo vessel and dry bulk carrier, accounted for about 98% of emissions. Emission maps, which add a new spatial dimension to the inventory, show the key emission hot spots in Hong Kong and suggest that a significant portion of emissions were emitted at berth. Scientific evidence about the scale and distribution of ship emissions has contributed in raising public awareness and facilitating stakeholder engagement about the issue. Fair Winds Charter, the world's first industry-led voluntary emissions reduction initiative, is a perfect example of how careful scientific research can be used in public engagement and policy deliberation to help drive voluntary industry actions and then government proposals to control and regulate marine emissions in Hong Kong and the Pearl River Delta region.

  6. Future U.S. ozone projections dependence on regional emissions, climate change, long-range transport and differences in modeling design

    NASA Astrophysics Data System (ADS)

    He, Hao; Liang, Xin-Zhong; Lei, Hang; Wuebbles, Donald J.

    2016-03-01

    A consistent modeling framework with nested global and regional chemical transport models (CTMs) is used to separate and quantitatively assess the relative contributions to projections of future U.S. ozone pollution from the effects of emissions changes, climate change, long-range transport (LRT) of pollutants, and differences in modeling design. After incorporating dynamic lateral boundary conditions (LBCs) from a global CTM, a regional CTM's representation of present-day U.S. ozone pollution is notably improved, especially relative to results from the regional CTM with fixed LBCs or from the global CTM alone. This nested system of global and regional CTMs projects substantial surface ozone trends for the 2050's: 6-10 ppb decreases under the 'clean' A1B scenario and ∼15 ppb increases under the 'dirty' A1Fi scenario. Among the total trends of future ozone, regional emissions changes dominate, contributing negative 25-60% in A1B and positive 30-45% in A1Fi. Comparatively, climate change contributes positive 10-30%, while LRT effects through changing chemical LBCs account for positive 15-20% in both scenarios, suggesting introducing dynamic LBCs could influence projections of the U.S. future ozone pollution with a magnitude comparable to effects of climate change alone. The contribution to future ozone projections due to differences in modeling design, including model formulations, emissions treatments, and other factors between the global and the nested regional CTMs, is regionally dependent, ranging from negative 20% to positive 25%. It is shown that the model discrepancies for present-day simulations between global and regional CTMs can propagate into future U.S. ozone projections systematically but nonlinearly, especially in California and the Southeast. Therefore in addition to representations of emissions change and climate change, accurate treatment of LBCs for the regional CTM is essential for projecting the future U.S. ozone pollution.

  7. Optimal Coordination and Synchronization in Local Air Quality and GHG Emissions: An Economic Study of Multiple Gases Issue in Integrated Assessment of Global Change

    SciTech Connect

    Yang, Zili

    2009-03-19

    In the duration of this project, we finished the main tasks set up in the initial proposal. These tasks include: collecting needed data of regional aerosol emissions (mainly SO2); building the RICES model; conducting preliminary simulation runs on some policy scenarios. We established a unified and transparent IA modeling platform that connecting climate change and local air pollution. The RICES model is the pioneering IA model that treats climate change and local air pollution as correlated global and local stock externalities.

  8. Source Contributions of Urban PM2.5 in the Beijing-Tianjin-Hebei Region: Changes between 2006 and 2013 and Relative Impacts of Emissions and Meteorology

    NASA Astrophysics Data System (ADS)

    Li, X.; Zhang, Q.; Zhang, Y.; Zheng, B.; Li, M.; Wang, K.; Chen, Y.; Wallington, T. J.; Han, W.; Shen, W.; Zhang, X.; He, K.

    2015-12-01

    Anthropogenic emissions in China have been controlled for years to improve ambient air quality. However, severe haze events caused by atmospheric aerosols with aerodynamic diameter less than or equal to 2.5 μm (PM2.5) have continued to occur, especially in the Beijing-Tianjin-Hebei (BTH) region. The Chinese government has set an ambitious goal to reduce urban PM2.5 concentrations by 25% in BTH by 2017 relative to the 2012 levels. Source apportionment (SA) is necessary to the development of the effective emission control strategies. In this work, the Comprehensive Air Quality Model with extensions (CAMx) with the Particulate Source Apportionment Technology (PSAT) is applied to the China domain for the years 2006 and 2013. Ambient surface concentrations of PM2.5 and its components are generally well reproduced. To quantify the contributions of each emission category or region to PM2.5 in BTH, the total emissions are divided into 7 emission categories and 11 source regions. The source contributions determined in this work are generally consistent with results from previous work. In 2013, the industrial (44%) and residential (27%) sectors are the dominant contributors to urban PM2.5 in BTH. The residential sector is the largest contributor in winter; the industry sector dominates in other seasons. A slight increasing trend (+3% for industry and +6% for residential) is found in 2013 relative to 2006, necessitating more attention to these two sectors. Local emissions make the largest contribution (40%-60%) for all receptors. Change of source contribution of PM2.5 in Beijing and northern Hebei are dominate by change of local emission. However, for Tianjin, and central and southern Hebei, change of meteorology condition are as important as change of emission, because regional inflow in these areas is more important than in Beijing and northern Hebei and can increase under unfavorable weather conditions, indicating a strong need for regional joint emission control efforts

  9. Source contributions of urban PM2.5 in the Beijing-Tianjin-Hebei region: Changes between 2006 and 2013 and relative impacts of emissions and meteorology

    NASA Astrophysics Data System (ADS)

    Li, Xin; Zhang, Qiang; Zhang, Yang; Zheng, Bo; Wang, Kai; Chen, Ying; Wallington, Timothy J.; Han, Weijian; Shen, Wei; Zhang, Xiaoye; He, Kebin

    2015-12-01

    Anthropogenic emissions in China have been controlled for years to improve ambient air quality. However, severe haze events caused by atmospheric aerosols with aerodynamic diameter less than or equal to 2.5 μm (PM2.5) have continued to occur, especially in the Beijing-Tianjin-Hebei (BTH) region. The Chinese government has set an ambitious goal to reduce urban PM2.5 concentrations by 25% in BTH by 2017 relative to the 2012 levels. Source apportionment (SA) is necessary to the development of the effective emission control strategies. In this work, the Comprehensive Air Quality Model with extensions (CAMx) with the Particulate Source Apportionment Technology (PSAT) is applied to the China domain for the years 2006 and 2013. Ambient surface concentrations of PM2.5 and its components are generally well reproduced. To quantify the contributions of each emission category or region to PM2.5 in BTH, the total emissions are divided into 7 emission categories and 11 source regions. The source contributions determined in this work are generally consistent with results from previous work. In 2013, the industrial (44%) and residential (27%) sectors are the dominant contributors to urban PM2.5 in BTH. The residential sector is the largest contributor in winter; the industry sector dominates in other seasons. A slight increasing trend (+3% for industry and +6% for residential) is found in 2013 relative to 2006, necessitating more attention to these two sectors. Local emissions make the largest contribution (40%-60%) for all receptors. Change of source contribution of PM2.5 in Beijing and northern Hebei are dominate by change of local emission. However, for Tianjin, and central and southern Hebei, change of meteorology condition are as important as change of emission, because regional inflow in these areas is more important than in Beijing and northern Hebei and can increase under unfavorable weather conditions, indicating a strong need for regional joint emission control efforts

  10. Mid-21st century air quality at the urban scale under the influence of changed climate and emissions: case studies for Paris and Stockholm

    NASA Astrophysics Data System (ADS)

    Markakis, K.; Valari, M.; Engardt, M.; Lacressonnière, G.; Vautard, R.; Andersson, C.

    2015-10-01

    Ozone, PM10 and PM2.5 concentrations over Paris, France and Stockholm, Sweden were modeled at 4 and 1 \\unit{km} horizontal resolutions respectively for the present and 2050 periods employing decade-long simulations. We account for large-scale global climate change (RCP-4.5) and fine resolution bottom-up emission projections developed by local experts and quantify their impact on future pollutant concentrations. Moreover, we identify biases related to the implementation of regional scale emission projections over the study areas by comparing modeled pollutant concentrations between the fine and coarse scale simulations. We show that over urban areas with major regional contribution (e.g., the city of Stockholm) the bias due to coarse emission inventory may be significant and lead to policy misclassification. Our results stress the need to better understand the mechanism of bias propagation across the modeling scales in order to design more successful local-scale strategies. We find that the impact of climate change is spatially homogeneous in both regions, implying strong regional influence. The climate benefit for ozone (daily average and maximum) is up to -5 % for Paris and -2 % for Stockholm city. The joined climate benefit on PM2.5 and PM10 in Paris is between -10 and -5 % while for Stockholm we observe mixed trends up to 3 % depending on season and size class. In Stockholm, emission mitigation leads to concentration reductions up to 15 % for daily average and maximum ozone and 20 % for PM and through a sensitivity analysis we show that this response is entirely due to changes in emissions at the regional scale. On the contrary, over the city of Paris (VOC-limited photochemical regime), local mitigation of NOx emissions increases future ozone concentrations due to ozone titration inhibition. This competing trend between the respective roles of emission and climate change, results in an increase in 2050 daily average ozone by 2.5 % in Paris. Climate and not

  11. Modeling the effects of changes in new source review on national SO2 and NOx emissions from electricity-generating units.

    PubMed

    Evans, David A; Hobbs, Benjamin F; Oren, Craig; Palmer, Karen L

    2008-01-15

    The Clean Air Act establishes New Source Review (NSR) programs that apply to construction or modification of major stationary sources. In 2002 and 2003, EPA revised its rules to narrow NSR's coverage of renovations. Congress mandated a National Research Council study of the revisions' impacts. In that study, we used an electricity-sector model to explore possible effects of the equipment replacement provision (ERP), the principal NSR change directed at power plants. We find that, assuming implementation of the Clean Air Interstate Rule (CAIR), tight enforcement of the prerevision NSR rules would likely lead to no or limited decreases in national emissions compared to policies such as ERP. However, emissions might shift forward in time because the previous NSR rules would depress allowance prices, discouraging banking and encouraging allowance use. Only under the most aggressive prerevision NSR enforcement scenario, in which essentially all coal capacity is compelled to retrofit controls by 2020, do NOx emissions fall below ERP levels. Even then, total 2007-2020 SO2 emissions are unaffected. Further decreases in national emissions could be accomplished more cheaply by tighter emissions caps than through NSR because caps provide incentives for efficient operating strategies, such as fuel switching, as well as retrofits. PMID:18284129

  12. Changing regional emissions of airborne pollutants reflected in the chemistry of snowpacks and wetfall in the Rocky Mountain region, USA, 1993–2012

    USGS Publications Warehouse

    Ingersoll, George P.; Miller, Debra C.; Morris, Kristi H.; McMurray, Jill A.; Port, Garrett M.; Caruso, Brian

    2016-01-01

    Wintertime precipitation sample data from 55 Snowpack sites and 17 National Atmospheric Deposition Program (NADP)/National Trends Network Wetfall sites in the Rocky Mountain region were examined to identify long-term trends in chemical concentration, deposition, and precipitation using Regional and Seasonal Kendall tests. The Natural Resources Conservation Service snow-telemetry (SNOTEL) network provided snow-water-equivalent data from 33 sites located near Snowpack- and NADP Wetfall-sampling sites for further comparisons. Concentration and deposition of ammonium, calcium, nitrate, and sulfate were tested for trends for the period 1993–2012. Precipitation trends were compared between the three monitoring networks for the winter seasons and downward trends were observed for both Snowpack and SNOTEL networks, but not for the NADP Wetfall network. The dry-deposition fraction of total atmospheric deposition, relative to wet deposition, was shown to be considerable in the region. Potential sources of regional airborne pollutant emissions were identified from the U.S. Environmental Protection Agency 2011 National Emissions Inventory, and from long-term emissions data for the period 1996–2013. Changes in the emissions of ammonia, nitrogen oxides, and sulfur dioxide were reflected in significant trends in snowpack and wetfall chemistry. In general, ammonia emissions in the western USA showed a gradual increase over the past decade, while ammonium concentrations and deposition in snowpacks and wetfall showed upward trends. Emissions of nitrogen oxides and sulfur dioxide declined while regional trends in snowpack and wetfall concentrations and deposition of nitrate and sulfate were downward.

  13. Assessing 'Dangerous Climate Change': Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature

    NASA Technical Reports Server (NTRS)

    Hansen, James; Kharecha, Pushker; Sato, Makiko; Masson-Demotte, Valerie; Ackerman, Frank; Beerling, David J.; Hearty, Paul J.; Hoegh-Guldberg, Ove; Hsu, Shi-Ling; Parmesan, Camille; Rockstrum, Johan; Rohling, Eelco J.; Sachs, Jeffrey; Smith, Pete; Steffen, Conrad; VanSusteren, Lise; VonShuckmann, Karina; Zachos, James C.

    2013-01-01

    We assess climate impacts of global warming using ongoing observations and paleoclimate data. We use Earth's measured energy imbalance, paleoclimate data, and simple representations of the global carbon cycle and temperature to define emission reductions needed to stabilize climate and avoid potentially disastrous impacts on today's young people, future generations, and nature. A cumulative industrial-era limit of approx.500 GtC fossil fuel emissions and 100 GtC storage in the biosphere and soil would keep climate close to the Holocene range to which humanity and other species are adapted. Cumulative emissions of approx.1000 GtC, sometimes associated with 2 C global warming, would spur "slow" feedbacks and eventual warming of 3-4 C with disastrous consequences. Rapid emissions reduction is required to restore Earth's energy balance and avoid ocean heat uptake that would practically guarantee irreversible effects. Continuation of high fossil fuel emissions, given current knowledge of the consequences, would be an act of extraordinary witting intergenerational injustice. Responsible policymaking requires a rising price on carbon emissions that would preclude emissions from most remaining coal and unconventional fossil fuels and phase down emissions from conventional fossil fuels.

  14. Long-term changes in CO2 emissions in Austria and Czechoslovakia—Identifying the drivers of environmental pressures

    PubMed Central

    Gingrich, Simone; Kušková, Petra; Steinberger, Julia K.

    2011-01-01

    This study presents fossil-fuel related CO2 emissions in Austria and Czechoslovakia (current Czech Republic and Slovakia) for 1830–2000. The drivers of CO2 emissions are discussed by investigating the variables of the standard Kaya identity for 1920–2000 and conducting a comparative Index Decomposition Analysis. Proxy data on industrial production and household consumption are analysed to understand the role of the economic structure. CO2 emissions increased in both countries in the long run. Czechoslovakia was a stronger emitter of CO2 throughout the time period, but per-capita emissions significantly differed only after World War I, when Czechoslovakia and Austria became independent. The difference in CO2 emissions increased until the mid-1980s (the period of communism in Czechoslovakia), explained by the energy intensity and the composition effects, and higher industrial production in Czechoslovakia. Counterbalancing factors were the income effect and household consumption. After the Velvet revolution in 1990, Czechoslovak CO2 emissions decreased, and the energy composition effect (and industrial production) lost importance. Despite their different political and economic development, Austria and Czechoslovakia reached similar levels of per-capita CO2 emissions in the late 20th century. Neither Austrian “eco-efficiency” nor Czechoslovak restructuring have been effective in reducing CO2 emissions to a sustainable level. PMID:21461052

  15. Assessing "dangerous climate change": required reduction of carbon emissions to protect young people, future generations and nature.

    PubMed

    Hansen, James; Kharecha, Pushker; Sato, Makiko; Masson-Delmotte, Valerie; Ackerman, Frank; Beerling, David J; Hearty, Paul J; Hoegh-Guldberg, Ove; Hsu, Shi-Ling; Parmesan, Camille; Rockstrom, Johan; Rohling, Eelco J; Sachs, Jeffrey; Smith, Pete; Steffen, Konrad; Van Susteren, Lise; von Schuckmann, Karina; Zachos, James C

    2013-01-01

    We assess climate impacts of global warming using ongoing observations and paleoclimate data. We use Earth's measured energy imbalance, paleoclimate data, and simple representations of the global carbon cycle and temperature to define emission reductions needed to stabilize climate and avoid potentially disastrous impacts on today's young people, future generations, and nature. A cumulative industrial-era limit of ∼500 GtC fossil fuel emissions and 100 GtC storage in the biosphere and soil would keep climate close to the Holocene range to which humanity and other species are adapted. Cumulative emissions of ∼1000 GtC, sometimes associated with 2°C global warming, would spur "slow" feedbacks and eventual warming of 3-4°C with disastrous consequences. Rapid emissions reduction is required to restore Earth's energy balance and avoid ocean heat uptake that would practically guarantee irreversible effects. Continuation of high fossil fuel emissions, given current knowledge of the consequences, would be an act of extraordinary witting intergenerational injustice. Responsible policymaking requires a rising price on carbon emissions that would preclude emissions from most remaining coal and unconventional fossil fuels and phase down emissions from conventional fossil fuels. PMID:24312568

  16. A theoretical framework to distinguish direct and indirect anthropogenic perturbations of the terrestrial carbon cycle; and its implications in the definition of "emissions from land-use change"

    NASA Astrophysics Data System (ADS)

    Gasser, Thomas; Ciais, Philippe; Viovy, Nicolas

    2013-04-01

    We present a theoretical analysis of the net land-to-atmosphere CO2 flux, so as to discuss possible definitions of "emissions from land-use change" at global scale. Our work is based on the fact that the terrestrial carbon cycle is affected by two anthropogenic perturbations. The first is the perturbation of the global Carbon-Climate-Nitrogen (CCN) system as observed with elevated CO2, climate change and increased nitrogen deposition; it impacts the intensive parameters of the terrestrial biosphere. The second is the Land-Use and Land-Use Change (LUC) perturbation induced by human activities; impacting the extensive parameters of the biosphere. Previous global carbon budgets tried to separate these two perturbations by defining two CO2 fluxes: the emissions from land-use change (LUC perturbation) and the land sink (CCN perturbation). Here, through successive mathematical demonstrations, we isolate four (not two) generic components of the net land-to-atmosphere CO2 flux. The two first components are the fluxes that would be observed if only one perturbation occurred. The two other components are due to the coupling of the CCN and LUC perturbations, highlighting the non-linear behavior of the terrestrial carbon cycle. Thanks to this, we introduce three possible definitions of "emissions from land-use change", that are indeed used in the scientific literature (often without clear distinctions), and we draw conclusions as for their absolute and relative behaviors. Finally, we illustrate our theoretical results thanks to two models: a simple carbon-climate model using a book-keeping module to estimate emissions from land-use change (named OSCAR), and the spatialized land-surface model ORCHIDEE. Our preliminary results show that comparing results from studies that do not use the same definition can lead to a bias of up to 20% between estimates of "emissions from land-use change". This makes our study of major interest to reconcile modeling and observation of "emissions

  17. Modelling future changes in climate, ozone-depleting substances and ozone precursor emissions using the whole-atmosphere UM-UKCA model

    NASA Astrophysics Data System (ADS)

    Banerjee, A.; Archibald, A. T.; Maycock, A. C.; Abraham, L.; Telford, P.; Braesicke, P.; Pyle, J. A.

    2013-12-01

    Using the recently upgraded whole-atmosphere UM-UKCA chemistry-climate model, we investigate the atmospheric response to future changes in a) greenhouse gases under the RCP4.5 and 8.5 scenarios for climate change, b) ozone-depleting substances (ODS) and a recovery of the ozone layer and c) ozone precursor emissions and tropospheric oxidising capacity. In addition, we combine theses scenarios in order to explore the interactions between individual perturbations. Within this framework, the coupled stratosphere-troposphere system and whole-atmosphere chemistry allows us to study the impacts of changes in composition of the stratosphere on the troposphere and vice versa. Under a scenario for moderate climate change (RCP4.5), we find that by the year 2100: 1) the stratosphere significantly impacts the troposphere via changes in stratosphere-troposphere exchange (STE) but the chemical changes induced in the troposphere do not impact the stratosphere, 2) perturbations are linearly additive with regard to the total ozone column and tropospheric odd oxygen budget, 3) while the Brewer-Dobson circulation strengthens under climate change (with an increase in the tropical upward mass flux at 70hPa of 17%), this strengthening is offset by ozone recovery (which on its own leads to a decrease in the mass flux of 9%) and 4) the tropospheric ozone burden decreases by 10% given mitigation of its precursor emissions but this is offset by climate change and stratospheric ozone recovery (9% and 6% increases in the burden respectively).

  18. Response of fine particulate matter to emission changes of oxides of nitrogen and anthropogenic volatile organic compounds in the eastern United States

    SciTech Connect

    Alexandra P. Tsimpidi; Vlassis A. Karydis; Spyros N. Pandis

    2008-11-15

    A three-dimensional chemical transport model (Particulate Matter Comprehensive Air Quality Model with Extensions) is used to investigate changes in fine particle (PM2.5) concentrations in response to 50% emissions changes of oxides of nitrogen (NOx) and anthropogenic volatile organic compounds (VOCs) during July 2001 and January 2002 in the eastern United States. The reduction of NOx emissions by 50% during the summer results in lower average oxidant levels and lowers PM2.5 (8% on average), mainly because of reductions of sulfate (9-11%), nitrate (45-58%), and ammonium (7-11%). The organic particulate matter (PM) slightly decreases in rural areas, whereas it increases in cities by a few percent when NOx is reduced. Reduction of NOx during winter causes an increase of the oxidant levels and a rather complicated response of the PM components, leading to small net changes. Sulfate increases (8-17%), nitrate decreases (18-42%), organic PM slightly increases, and ammonium either increases or decreases a little. The reduction of VOC emissions during the summer causes on average a small increase of the oxidant levels and a marginal increase in PM2.5. This small net change is due to increases in the inorganic components and decreases of the organic ones. Reduction of VOC emissions during winter results in a decrease of the oxidant levels and a 5-10% reduction of PM2.5 because of reductions in nitrate (4-19%), ammonium (4-10%), organic PM (12-14%), and small reductions in sulfate. Although sulfur dioxide (SO{sub 2}) reduction is the single most effective approach for sulfate control, the coupled decrease of SO{sub 2} and NOx emissions in both seasons is more effective in reducing total PM2.5 mass than the SO{sub 2} reduction alone. 34 refs., 7 figs., 1 tab.

  19. Mid-21st century air quality at the urban scale under the influence of changed climate and emissions - case studies for Paris and Stockholm

    NASA Astrophysics Data System (ADS)

    Markakis, Konstantinos; Valari, Myrto; Engardt, Magnuz; Lacressonniere, Gwendoline; Vautard, Robert; Andersson, Camilla

    2016-02-01

    Ozone, PM10 and PM2.5 concentrations over Paris, France and Stockholm, Sweden were modelled at 4 and 1 km horizontal resolutions respectively for the present and 2050 periods employing decade-long simulations. We account for large-scale global climate change (RCP-4.5) and fine-resolution bottom-up emission projections developed by local experts and quantify their impact on future pollutant concentrations. Moreover, we identify biases related to the implementation of regional-scale emission projections by comparing modelled pollutant concentrations between the fine- and coarse-scale simulations over the study areas. We show that over urban areas with major regional contribution (e.g. the city of Stockholm) the bias related to coarse-scale projections may be significant and lead to policy misclassification. Our results stress the need to better understand the mechanism of bias propagation across the modelling scales in order to design more successful local-scale strategies. We find that the impact of climate change is spatially homogeneous in both regions, implying strong regional influence. The climate benefit for ozone (daily mean and maximum) is up to -5 % for Paris and -2 % for Stockholm city. The climate benefit on PM2.5 and PM10 in Paris is between -5 and -10 %, while for Stockholm we estimate mixed trends of up to 3 % depending on season and size class. In Stockholm, emission mitigation leads to concentration reductions up to 15 % for daily mean and maximum ozone and 20 % for PM. Through a sensitivity analysis we show that this response is entirely due to changes in emissions at the regional scale. On the contrary, over the city of Paris (VOC-limited photochemical regime), local mitigation of NOx emissions increases future ozone concentrations due to ozone titration inhibition. This competing trend between the respective roles of emission and climate change, results in an increase in 2050 daily mean ozone by 2.5 % in Paris. Climate and not emission change

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  1. Interannual variation in the fine-mode MODIS aerosol optical depth and its relationship to the changes in sulfur dioxide emissions in China between 2000 and 2010

    NASA Astrophysics Data System (ADS)

    Itahashi, S.; Uno, I.; Yumimoto, K.; Irie, H.; Osada, K.; Ogata, K.; Fukushima, H.; Wang, Z.; Ohara, T.

    2012-03-01

    Anthropogenic SO2 emissions increased alongside economic development in China at a rate of 12.7% yr-1 from 2000 to 2005. However, under new Chinese government policy, SO2 emissions declined by 3.9% yr-1 between 2005 and 2009. Between 2000 and 2010, we found that the variability in the fine-mode (submicron) aerosol optical depth (AOD) over the oceans adjacent to East Asia increased by 3-8% yr-1 to a peak around 2005-2006 and subsequently decreased by 2-7% yr-1, based on observations by the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA's Terra satellite and simulations by a chemical transport model. This trend is consistent with ground-based observations of aerosol particles at a mountainous background observation site in central Japan. These fluctuations in SO2 emission intensity and fine-mode AOD are thought to reflect the widespread installation of fuel-gas desulfurization (FGD) devices in power plants in China, because aerosol sulfate is a major determinant of the fine-mode AOD in East Asia. Using a chemical transport model, we confirmed that the contribution of particulate sulfate to the fine-mode AOD is more than 70% of the annual mean and that the abovementioned fluctuation in fine-mode AOD is caused mainly by changes in SO2 emission rather than by other factors such as varying meteorological conditions in East Asia. A strong correlation was also found between satellite-retrieved SO2 vertical column density and bottom-up SO2 emissions, both of which were also consistent with observed fine-mode AOD trends. We propose a simplified approach for evaluating changes in SO2 emissions in China, combining the use of modeled sensitivity coefficients that describe the variation of fine-mode AOD with changes in SO2 emissions and satellite retrieval. Satellite measurements of fine-mode AOD above the Sea of Japan marked a 4.1% yr-1 decline between 2007 and 2010, which corresponded to the 9% yr-1 decline in SO2 emissions from China during the same

  2. Inter-annual variability of wintertime PM2.5 chemical composition in Xi'an, China: Evidences of changing source emissions.

    PubMed

    Xu, Hongmei; Cao, Junji; Chow, Judith C; Huang, R-J; Shen, Zhenxing; Chen, L W Antony; Ho, Kin Fai; Watson, John G

    2016-03-01

    Chemical characteristics of PM2.5 in Xi'an in wintertime of 2006, 2008, and 2010 were investigated. Markers of OC2, EC1, and NO3(-)/SO4(2-) ratio were calculated to investigate the changes in PM2.5 emission sources over the 5-year period. Positive matrix factorization (PMF) model was used to identify and quantify the main sources of PM2.5 and their contributions. The results showed that coal combustion, motor vehicular emissions, fugitive dust, and secondary inorganic aerosol accounted for more than 80% of PM2.5 mass. The importance of these major sources to the PM2.5 mass varied yearly: coal combustion was the largest contributor (31.2% ± 5.2%), followed by secondary inorganic aerosol (20.9% ± 5.2%) and motor vehicular emissions (19.3% ± 4.8%) in 2006; the order was still coal combustion emissions (27.6% ± 3.4%), secondary inorganic aerosol (23.2% ± 6.9%), and motor vehicular emissions (20.9% ± 4.6%) in 2008; while coal combustion emission further decreased (24.1% ± 3.1%) with fugitive dust (19.4% ± 5.5%) increasing in 2010. The changes in PM2.5 chemical compositions and source contributions can be attributed to the social and economic developments in Xi'an, China, including energy structure adjustment, energy consumption, the expansion of civil vehicles, and the increase of urban construction activities. PMID:26760274

  3. Carbon dioxide emissions and the overshoot ratio change resulting from the implementation of 2nd Energy Master Plan in South Korea

    NASA Astrophysics Data System (ADS)

    Yeo, M. J.; Kim, Y. P.

    2015-12-01

    The direction of the energy policies of the country is important in the projection of environmental impacts of the country. The greenhouse gases (GHGs) emission of the energy sector in South Korea is very huge, about 600 MtCO2e in 2011. Also the carbon footprint due to the energy consumption contributes to the ecological footprint is also large, more than 60%. Based on the official plans (the national greenhouse gases emission reduction target for 2030 (GHG target for 2030) and the 2nd Energy Master Plan (2nd EMP)), several scenarios were proposed and the sensitivity of the GHG emission amount and 'overshoot ratio' which is the ratio of ecological footprint to biocapacity were estimated. It was found that to meet the GHG target for 2030 the ratio of non-emission energy for power generation should be over 71% which would be very difficult. We also found that the overshoot ratio would increase from 5.9 in 2009 to 7.6 in 2035. Thus, additional efforts are required to reduce the environmental burdens in addition to optimize the power mix configuration. One example is the conversion efficiency in power generation. If the conversion efficiency in power generation rises up 50% from the current level, 40%, the energy demand and resultant carbon dioxide emissions would decrease about 10%. Also the influence on the environment through changes in consumption behavior, for example, the diet choice is expected to be meaningful.

  4. United Kingdom Deriving Emissions linked to Climate Change Network: greenhouse gas and ozone depleting substance measurements from a UK network of tall towers

    NASA Astrophysics Data System (ADS)

    Stanley, Kieran; O'Doherty, Simon; Young, Dickon; Grant, Aoife; Manning, Alistair; Simmonds, Peter; Oram, Dave; Sturges, Bill; Derwent, Richard

    2016-04-01

    Real-time, high-frequency measurement networks are essential for investigating the emissions of gases linked with climate change and stratospheric ozone depletion. These networks can be used to verify greenhouse gas (GHG) and ozone depleting substances (ODS) emission inventories for the Kyoto and Montreal Protocols. Providing accurate and reliable country- and region-specific emissions to the atmosphere are critical for reporting to the UN agencies. The United Kingdom Deriving Emissions linked to Climate Change (UK DECC) Network, operating since 2012, is distinguished by its capability to measure at high-frequency, the influence of all of the important species in the Kyoto and Montreal Protocols from the UK, Ireland and Continental Europe. Data obtained from the UK DECC network are also fed into the European Integrated Carbon Observation System (ICOS). This presentation will give an overview of the UK DECC Network, detailing the analytical techniques used to determine the suite of GHGs and ODSs, as well as the calibration strategy used within the network. Interannual results of key GHGs from the network will also be presented.

  5. Reducing nitrous oxide emissions by changing N fertiliser use from calcium ammonium nitrate (CAN) to urea based formulations.

    PubMed

    Harty, M A; Forrestal, P J; Watson, C J; McGeough, K L; Carolan, R; Elliot, C; Krol, D; Laughlin, R J; Richards, K G; Lanigan, G J

    2016-09-01

    The accelerating use of synthetic nitrogen (N) fertilisers, to meet the world's growing food demand, is the primary driver for increased atmospheric concentrations of nitrous oxide (N2O). The IPCC default emission factor (EF) for N2O from soils is 1% of the N applied, irrespective of its form. However, N2O emissions tend to be higher from nitrate-containing fertilisers e.g. calcium ammonium nitrate (CAN) compared to urea, particularly in regions, which have mild, wet climates and high organic matter soils. Urea can be an inefficient N source due to NH3 volatilisation, but nitrogen stabilisers (urease and nitrification inhibitors) can improve its efficacy. This study evaluated the impact of switching fertiliser formulation from calcium ammonium nitrate (CAN) to urea-based products, as a potential mitigation strategy to reduce N2O emissions at six temperate grassland sites on the island of Ireland. The surface applied formulations included CAN, urea and urea with the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) and/or the nitrification inhibitor dicyandiamide (DCD). Results showed that N2O emissions were significantly affected by fertiliser formulation, soil type and climatic conditions. The direct N2O emission factor (EF) from CAN averaged 1.49% overall sites, but was highly variable, ranging from 0.58% to 3.81. Amending urea with NBPT, to reduce ammonia volatilisation, resulted in an average EF of 0.40% (ranging from 0.21 to 0.69%)-compared to an average EF of 0.25% for urea (ranging from 0.1 to 0.49%), with both fertilisers significantly lower and less variable than CAN. Cumulative N2O emissions from urea amended with both NBPT and DCD were not significantly different from background levels. Switching from CAN to stabilised urea formulations was found to be an effective strategy to reduce N2O emissions, particularly in wet, temperate grassland. PMID:27155080

  6. Simulation and validation of greenhouse gas emissions and SOC stock changes in arable land using the ECOSSE model

    NASA Astrophysics Data System (ADS)

    Khalil, M. I.; Richards, M.; Osborne, B.; Williams, M.; Müller, C.

    2013-12-01

    Model simulations of C and N dynamics, based on country-specific agricultural and environmental conditions, can provide information for compiling national greenhouse gas (GHG) inventories, as well as insights into potential mitigation options. A multi-pool dynamic model, ‘ECOSSE’ (v5 modified), was used to simulate coupled GHGs and soil organic carbon (SOC) stock changes. It was run for an equivalent time frame of 8 years with inputs from conventionally-tilled arable land cropped with spring barley receiving N fertilizer as calcium ammonium nitrate at 135-159 kg N ha-1 and crop residues (3 t ha-1 yr-1). The simulated daily N2O fluxes were consistent with the measured values, with R2 of 0.33 (p < 0.05) and the total error and bias differences were within 95% confidence levels. The measured seasonal N2O losses were 0.39-0.60% of the N applied, with a modelled estimate of 0.23-0.41%. In contrast, the measured annual N2O loss (integrated) was 0.35% and the corresponding simulated value of 0.45% increased to 0.59% when the sum of the daily fluxes was taken into account. This indicates intermittent gas samplings may miss the peak fluxes. On an 8-year average the modelled N2O emission factor (EF) was 0.53 ± 0.03%. The model successfully predicted the daily heterotrophic respiration (RH), with an R2 of 0.45 (p < 0.05) and the total error and bias differences were within the 95% confidence intervals. The simulated and measured total RH (3149 versus 3072 kg C ha-1 yr-1) was within the cropland average values previously reported. The total measured CH4 fluxes indicated that the unfertilized treatments were a small source (-2.29 g C ha-1 yr-1), whilst the fertilized treatments were a sink (+3.64). In contrast, the simulated values suggested a sink (26.61-31.37 g C ha-1 yr-1), demonstrating fertilizer-induced decreases in CH4 oxidation. On average, based on the simulated SOC content a loss of 516 kg C ha-1 yr-1 was indicated, which is within the uncertainty range for

  7. Probabilistic estimation of future emissions of isoprene and surface oxidant chemistry associated with land use change in response to growing food needs

    NASA Astrophysics Data System (ADS)

    Hardacre, C. J.; Palmer, P. I.; Baumanns, K.; Rounsevell, M.; Murray-Rust, D.

    2012-12-01

    We quantify the impact of land use change, determined by our growing need for food and biofuel production, on isoprene emissions and subsequent atmospheric oxidant chemistry in 2015 and 2030, relative to 1990, ignoring compound climate change effects over that period. We estimate isoprene emissions from an ensemble (n = 1000) of land use change realizations from 1990-2050, broadly guided by the IPCC AR4/SRES scenarios A1 and B1. We also superimpose land use change required to address projected biofuel usage using two scenarios: (1) assuming that world governments make no changes to biofuel policy after 2009, and (2) assuming that world governments develop biofuel policy with the aim of keeping equivalent atmospheric CO2 at 450 ppm. We present the median and interquartile range (IQR) statistics of the ensemble and show that land use change between -1.50 × 1012 m2 to +6.06 × 1012 m2 was found to drive changes in the global isoprene burden of -3.5 to +2.8 Tg yr-1 in 2015 and -7.7 to +6.4 Tg yr-1 in 2030. We use land use change realizations corresponding to the median and IQR of these emission estimates to drive the GEOS-Chem global 3-D chemistry transport model to investigate the perturbation to global and regional surface concentrations of isoprene, nitrogen oxides (NO+NO2), and the atmospheric concentration and deposition of ozone (O3). We show that across sub-continental regions the monthly surface O3 increases by 0.1-0.8 ppb, relative to a zero land-use change calculation, driven by increases (decreases) in surface isoprene in high (low) NOx environments. At the local scale (4° × 5°) we find that surface O3 increases by 5-12 ppb over temperate North America, China and Boreal Eurasia, driven by large increases in isoprene emissions from short-rotation coppice crop cultivation for biofuel production.

  8. Probabilistic estimation of future emissions of isoprene and surface oxidant chemistry associated with land-use change in response to growing food needs

    NASA Astrophysics Data System (ADS)

    Hardacre, C. J.; Palmer, P. I.; Baumanns, K.; Rounsevell, M.; Murray-Rust, D.

    2013-06-01

    We quantify the impact of land-use change, determined by our growing demand for food and biofuel production, on isoprene emissions and subsequent atmospheric oxidant chemistry in 2015 and 2030, relative to 1990, ignoring compound climate change effects over that period. We estimate isoprene emissions from an ensemble (n = 1000) of land-use change realizations from 1990-2050, broadly guided by the IPCC AR4/SRES scenarios A1 and B1. We also superimpose land-use change required to address projected biofuel usage using two scenarios: (1) assuming that world governments make no changes to biofuel policy after 2009, and (2) assuming that world governments develop biofuel policy with the aim of keeping equivalent atmospheric CO2 at 450 ppm. We present the median and interquartile range (IQR) statistics of the ensemble and show that land-use change between -1.50 × 1012 m2 to +6.06 × 1012 m2 was found to drive changes in the global isoprene burden of -3.5 to +2.8 Tg yr-1 in 2015 and -7.7 to +6.4 Tg yr-1 in 2030. We use land-use change realizations corresponding to the median and IQR of these emission estimates to drive the GEOS-Chem global 3-D chemistry transport model to investigate the perturbation to global and regional surface concentrations of isoprene, nitrogen oxides (NO+NO2), and the atmospheric concentration and deposition of ozone (O3). We show that across subcontinental regions the monthly surface O3 increases by 0.1-0.8 ppb, relative to a zero land-use change calculation, driven by increases (decreases) in surface isoprene in high (low) NOx environments. At the local scale (4° × 5°) we find that surface O3 increases by 5-12 ppb over temperate North America, China and boreal Eurasia, driven by large increases in isoprene emissions from short-rotation coppice crop cultivation for biofuel production.

  9. Atmospheric concentrations of particulate sulfate and nitrate in Hong Kong during 1995-2008: impact of emission changes in mainland China

    NASA Astrophysics Data System (ADS)

    Nie, W.; Wang, T.; Wang, W.; Wei, X.; Liu, Q.

    2011-12-01

    The release of large amounts of sulfur dioxide (SO2) and nitrogen oxides (NOx) from the burning of fossil fuel leads to regional air pollution phenomena such as haze and acidic deposition. Despite longstanding recognition of the severity of these problems and the numerous studies conducted in China, little is known of long-term trends in particulate sulfate and nitrate and their association with changes in precursor emissions. In this study, we analyze records covering a 14-year period (1995-2008) of coarse particulate (PM10) composition in the subtropical city of Hong Kong, situated in the rapidly developing Pearl River Delta region of southern China. A linear regression method and a Regional Kendall test are employed for trend calculations. In contrast to the decreased levels of SO2 and NOx emissions in Hong Kong, there are increasing overall trends in ambient concentrations of sulfate and nitrate, with the most obvious rise seen during 2001-2005 and relatively steady values recorded thereafter. These increased sulfate and nitrate concentrations have both negated the effect of emission-reduction efforts for coarse particles and increased the acidity of wet deposition in Hong Kong. Backward trajectories are computed to help identify the origin of large-scale air masses arriving in Hong Kong. In air masses dominated by Hong Kong urban sources and ship emissions, no statistically significant trend is apparent in either sulfate or nitrate, results that can be attributed to falling local urban emissions and increasing ship emissions; however, the sharp increases seen in particulate sulfate and nitrate concentrations were observed in air masses originating from eastern China and are generally consistent with changes in emissions of their precursors in eastern China. Examination of PM10 mass data recorded at a pair of upwind-urban sites also indicates that long-range transport makes a large contribution (> 80%) to coarse particulate loadings in Hong Kong. Together with

  10. Land Use Changes and GHG Emissions from Tropical Forest Conversion by Oil Palm Plantations in Riau Province, Indonesia

    PubMed Central

    Ramdani, Fatwa; Hino, Masateru

    2013-01-01

    Increasing prices and demand for biofuel and cooking oil from importer countries have caused a remarkable expansion of oil palm plantations in Indonesia. In this paper, we attempt to monitor the expansion of oil palm plantations on peat land and in tropical forests. We measure the GHG emissions from the land conversion activities at provincial scale. Using Landsat images from three different periods (1990s, 2000s and 2012), we classified LULC of the Riau Province, which is the largest oil palm producing region in Indonesia. A hybrid method of integration, generated by combining automatic processing and manual analysis, yields the best results. We found that the tropical rainforest cover decreased from ∼63% in the 1990s to ∼37% in the 2000s. By 2012, the remaining tropical rainforest cover was only ∼22%. From the 1990s to the 2000s, conversion of forests and peat lands was the primary source of emissions, total CO2 emitted to the atmosphere was estimated at ∼26.6 million tCO2.y-1, with 40.62% and 59.38% of the emissions from conversion of peat lands and forests, respectively. Between 2000 and 2012, the total CO2 emitted to the atmosphere was estimated at ∼5.2 million tCO2. y-1, with 69.94% and 27.62% of the emissions from converted peat lands and converted forests, respectively. The results show that in the Riau Province, the oil palm industry boomed in the period from 1990 to 2000, with transformation of tropical forest and peat land as the primary source of emissions. The decrease of CO2 emissions in the period from 2000 to 2012 is possibly due to the enforcement of a moratorium on deforestation. PMID:23936186

  11. Land use changes and GHG emissions from tropical forest conversion by oil palm plantations in Riau Province, Indonesia.

    PubMed

    Ramdani, Fatwa; Hino, Masateru

    2013-01-01

    Increasing prices and demand for biofuel and cooking oil from importer countries have caused a remarkable expansion of oil palm plantations in Indonesia. In this paper, we attempt to monitor the expansion of oil palm plantations on peat land and in tropical forests. We measure the GHG emissions from the land conversion activities at provincial scale. Using Landsat images from three different periods (1990s, 2000s and 2012), we classified LULC of the Riau Province, which is the largest oil palm producing region in Indonesia. A hybrid method of integration, generated by combining automatic processing and manual analysis, yields the best results. We found that the tropical rainforest cover decreased from ∼63% in the 1990s to ∼37% in the 2000s. By 2012, the remaining tropical rainforest cover was only ∼22%. From the 1990s to the 2000s, conversion of forests and peat lands was the primary source of emissions, total CO2 emitted to the atmosphere was estimated at ∼26.6 million tCO2.y(-1), with 40.62% and 59.38% of the emissions from conversion of peat lands and forests, respectively. Between 2000 and 2012, the total CO2 emitted to the atmosphere was estimated at ∼5.2 million tCO2. y(-1), with 69.94% and 27.62% of the emissions from converted peat lands and converted forests, respectively. The results show that in the Riau Province, the oil palm industry boomed in the period from 1990 to 2000, with transformation of tropical forest and peat land as the primary source of emissions. The decrease of CO2 emissions in the period from 2000 to 2012 is possibly due to the enforcement of a moratorium on deforestation. PMID:23936186

  12. Response of the summertime ground-level ozone trend in the Chicago area to emission controls and temperature changes, 2005-2013

    NASA Astrophysics Data System (ADS)

    Jing, Ping; Lu, Zifeng; Xing, Jia; Streets, David G.; Tan, Qian; O'Brien, Timothy; Kamberos, Joseph

    2014-12-01

    Despite strenuous efforts to reduce the emissions of ozone precursors such as nitrogen oxides (NOx), concentrations of ground-level ozone (O3) still often exceed the National Ambient Air Quality Standard in U.S. cities in summertime, including Chicago. Furthermore, studies have projected a future increase in O3 formation due to global climate change. This study examines the response of summertime O3 to emission controls and temperature change in the Chicago area from 2005 to 2013 by employing observations of O3, O3 precursors, and meteorological variables. We find that meteorology explains about 53% of the O3 variance in Chicago. O3 mixing ratios over Chicago are found to show no clear decline over the 2005-2013 period. The summertime ground-level O3 trend consists of a decrease of 0.08 ppb/year between 2005 and 2009 and an increase of 1.49 ppb/year between 2009 and 2013. Emissions of NOx and concentrations of NO2 have been decreasing steadily from 2005 to 2013 in the Chicago area. Concentrations of volatile organic compounds (VOCs) in Chicago, however, have more than doubled since 2009, even though emission inventories suggest that VOC emissions have decreased. We believe that O3 production in Chicago became more sensitive to VOCs starting in 2008/2009 and may have switched from being NOx-limited to VOC-limited. The warmer climate since 2008 has also contributed to the increasing ozone trend in the Chicago area. Increased attention should be paid to improving the quantification of VOC sources, enhancing the monitoring of reactive VOC concentrations, and designing VOC mitigation measures.

  13. High Resolution Modelling of Climate Change Impacts on Water Supply and Demand, Crop Nutrient Usage and GHG emissions, Similkameen Watershed, British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Mirmasoudi, S.; Byrne, J. M.; Kroebel, R.; MacDonald, R. J.; Johnson, D. L.; McKenzie, R. H.

    2015-12-01

    The Similkameen watershed in southern British Columbia, Canada is expected to warm substantially in the coming decades. A higher proportion of winter rain to snow and an earlier onset of spring snowmelt are likely to result in lower spring stream flow peaks. The reduction in winter water storage, combined with longer, warmer, and drier summers, poses a challenge for water resources in an irrigation-based agricultural watershed. There are already substantial irrigation developments, and water demands are expected to increase to maintain current agricultural production, further stressing a shrinking summer water supply. Agriculture releases significant amounts of CO2, CH4 and N2O to the atmosphere, accounting for approximately 8% of anthropogenic greenhouse gas (GHG) emissions in Canada, excluding CO2 emissions from fuels. Agricultural GHG fluxes are complex but the active management of agricultural systems offers possibilities for mitigating GHG emissions. Although GHG emissions derived from soil have been researched for several decades, there are still geographic regions and agricultural systems that have not been well characterized. This work will address a series of questions for the Similkameen watershed. For a range of climate scenarios, we will: (i) use the GENESYS (GENerate Earth SYstems Science input) hydrometeorological model to simulate historical and future water supplies; (ii) link GENESYS and AquaCrop models to assess climate driven changes in water requirement and associated crop productivity; and (iii) link GENESYS and HOLOS (whole-farm model and software program that estimates GHG emissions) to estimate farm and regional level GHG emissions and seasonal nutrient balance for the crops in the watershed.

  14. Changes in luminescence emission induced by proton irradiation: InGaAs/GaAs quantum wells and quantum dots

    NASA Technical Reports Server (NTRS)

    Leon, R.; Swift, G. M.; Magness, B.; Taylor, W. A.; Tang, Y. S.; Wang, K. L.; Dowd, P.; Zhang, Y. H.

    2000-01-01

    The photoluminescence emission from InGaAs/GaAs quantum-well and quantum-dot (QD) structures are compared after controlled irradiation with 1.5 MeV proton fluxes. Results presented here show a significant enhancement in radiation tolerance with three-dimensional quantum confinement.

  15. 18F-Fluoride bone positron emission tomography demonstrating changes related to finger clubbing and hypertrophic osteoarthropathy.

    PubMed

    Kashyap, Raghava; Ali, Mirza Athar; Nagaraju, Madhusudhan; Muntimadugu, Babaiah

    2014-04-01

    Hypertrophic pulmonary osteoarthropathy is manifested by clubbing and periostitis of bones. We present a very rare documentation of increased F18-sodium fluoride uptake in the distal phalanges of both hands correlating to clubbing of the fingers in a 55-year-old female patient with carcinoma of lung in whom bone positron emission tomography was performed for metastatic work-up. PMID:24761070

  16. Optical and Physical Properties from Primary On-Road Vehicle ParticleEmissions And Their Implications for Climate Change

    SciTech Connect

    Strawa, A.W.; Kirchstetter, T.W.; Hallar, A.G.; Ban-Weiss, G.A.; McLaughlin, J.P.; Harley, R.A.; Lunden, M.M.

    2009-01-23

    During the summers of 2004 and 2006, extinction and scattering coefficients of particle emissions inside a San Francisco Bay Area roadway tunnel were measured using a combined cavity ring-down and nephelometer instrument. Particle size distributions and humidification were also measured, as well as several gas phase species. Vehicles in the tunnel traveled up a 4% grade at a speed of approximately 60 km h{sup -1}. The traffic situation in the tunnel allows the apportionment of emission factors between light duty gasoline vehicles and diesel trucks. Cross-section emission factors for optical properties were determined for the apportioned vehicles to be consistent with gas phase and particulate matter emission factors. The absorption emission factor (the absorption cross-section per mass of fuel burned) for diesel trucks (4.4 {+-} 0.79 m{sup 2} kg{sup -1}) was 22 times larger than for light-duty gasoline vehicles (0.20 {+-} 0.05 m{sup 2} kg{sup -1}). The single scattering albedo of particles - which represents the fraction of incident light that is scattered as opposed to absorbed - was 0.2 for diesel trucks and 0.3 for light duty gasoline vehicles. These facts indicate that particulate matter from motor vehicles exerts a positive (i.e., warming) radiative climate forcing. Average particulate mass absorption efficiencies for diesel trucks and light duty gasoline vehicles were 3.14 {+-} 0.88 m{sup 2} g{sub PM}{sup -1} and 2.9 {+-} 1.07 m{sup 2} g{sub PM}{sup -1}, respectively. Particle size distributions and optical properties were insensitive to increases in relative humidity to values in excess of 90%, reinforcing previous findings that freshly emitted motor vehicle particulate matter is hydrophobic.

  17. Gaseous mercury emissions from soil following forest loss and land use changes: Field experiments in the United States and Brazil

    NASA Astrophysics Data System (ADS)

    Carpi, Anthony; Fostier, Anne H.; Orta, Olivia R.; dos Santos, Jose Carlos; Gittings, Michael

    2014-10-01

    Forest ecosystems are a sink of atmospheric mercury, trapping the metal in the canopy, and storing it in the forest floor after litter fall. Fire liberates a portion of this mercury; however, little is known about the long-term release of mercury post deforestation. We conducted two large-scale experiments to study this phenomenon. In upstate New York, gaseous mercury emissions from soil were monitored continually using a Teflon dynamic surface flux chamber for two-weeks before and after cutting of the canopy on the edge of a deciduous forest. In Brazil, gaseous mercury emissions from soil were monitored in an intact Ombrophilous Open forest and an adjacent field site both before and after the field site was cleared by burning. In the intact forest, gaseous mercury emissions from soil averaged -0.73 ± 1.84 ng m-2 h-1 (24-h monitoring) at the New York site, and 0.33 ± 0.09 ng m-2 h-1 (daytime-only) at the Brazil site. After deforestation, gaseous mercury emissions from soil averaged 9.13 ± 2.08 ng m-2 h-1 in New York and 21.2 ± 0.35 ng m-2 h-1 at the Brazil site prior to burning. Gaseous mercury emissions averaged 74.9 ± 0.73 ng m-2 h-1 after burning of the cut forest in Brazil. Extrapolating our data, measured over several weeks to months, to a full year period, deforested soil is estimated to release an additional 2.30 g ha-1 yr-1 of gaseous mercury to the atmosphere in the Brazilian experiment and 0.41 g ha-1 yr-1 in the New York experiment. In Brazil, this represents an additional 50% of the mercury load released during the fire itself.

  18. How emissions, climate, and land use change will impact mid-century air quality over the United States: a focus on effects at national parks

    NASA Astrophysics Data System (ADS)

    Martin, M. Val; Heald, C. L.; Lamarque, J.-F.; Tilmes, S.; Emmons, L. K.; Schichtel, B. A.

    2015-03-01

    We use a global coupled chemistry-climate-land model (CESM) to assess the integrated effect of climate, emissions and land use changes on annual surface O3 and PM2.5 in the United States with a focus on national parks (NPs) and wilderness areas, using the RCP4.5 and RCP8.5 projections. We show that, when stringent domestic emission controls are applied, air quality is predicted to improve across the US, except surface O3 over the western and central US under RCP8.5 conditions, where rising background ozone counteracts domestic emission reductions. Under the RCP4.5 scenario, surface O3 is substantially reduced (about 5 ppb), with daily maximum 8 h averages below the primary US Environmental Protection Agency (EPA) National Ambient Air Quality Standards (NAAQS) of 75 ppb (and even 65 ppb) in all the NPs. PM2.5 is significantly reduced in both scenarios (4 μg m-3; ~50%), with levels below the annual US EPA NAAQS of 12 μg m-3 across all the NPs; visibility is also improved (10-15 dv; >75 km in visibility range), although some western US parks with Class I status (40-74 % of total sites in the US) are still above the 2050 planned target level to reach the goal of natural visibility conditions by 2064. We estimate that climate-driven increases in fire activity may dominate summertime PM2.5 over the western US, potentially offsetting the large PM2.5 reductions from domestic emission controls, and keeping visibility at present-day levels in many parks. Our study indicates that anthropogenic emission patterns will be important for air quality in 2050. However, climate and land use changes alone may lead to a substantial increase in surface O3 (2-3 ppb) with important consequences for O3 air quality and ecosystem degradation at the US NPs. Our study illustrates the need to consider the effects of changes in climate, vegetation, and fires in future air quality management and planning and emission policy making.

  19. How emissions, climate, and land use change will impact mid-century air quality over the United States: a focus on effects at National Parks

    NASA Astrophysics Data System (ADS)

    Martin, M. Val; Heald, C. L.; Lamarque, J.-F.; Tilmes, S.; Emmons, L. K.; Schichtel, B. A.

    2014-10-01

    We use a global coupled chemistry-climate-land model (CESM) to assess the integrated effect of climate, emissions and land use changes on annual surface O3 and PM2.5 on the United States with a focus on National Parks (NPs) and wilderness areas, using the RCP4.5 and RCP8.5 projections. We show that, when stringent domestic emission controls are applied, air quality is predicted to improve across the US, except surface O3 over the western and central US under RCP8.5 conditions, where rising background ozone counteracts domestic emissions reductions. Under the RCP4.5, surface O3 is substantially reduced (about 5 ppb), with daily maximum 8 h averages below the primary US EPA NAAQS of 75 ppb (and even 65 ppb) in all the NPs. PM2.5 is significantly reduced in both scenarios (4 μg m-3; ~50%), with levels below the annual US EPA NAAQS of 12 μg m-3 across all the NPs; visibility is also improved (10-15 deciviews; >75 km in visibility range), although some parks over the western US (40-74% of total sites in the US) may not reach the 2050 target to restore visibility to natural conditions by 2064. We estimate that climate-driven increases in fire activity may dominate summertime PM2.5 over the western US, potentially offsetting the large PM2.5 reductions from domestic emission controls, and keeping visibility at present-day levels in many parks. Our study suggests that air quality in 2050 will be primarily controlled by anthropogenic emission patterns. However, climate and land use changes alone may lead to a substantial increase in surface O3 (2-3 ppb) with important consequences for O3 air quality and ecosystem degradation at the US NPs. Our study illustrates the need to consider the effects of changes in climate, vegetation, and fires in future air quality management and planning and emission policy making.

  20. Impact of climate change on GHG emissions of (pre-) alpine grassland ecosystems under intensive and extensive management - a climate sequence lysimeter study

    NASA Astrophysics Data System (ADS)

    Kiese, Ralf; Lu, Haiyan; Fu, Jin; Diaz-Pines, Eugenio; Gasche, Rainer; Dannenmann, Michael; Butterbach-Bahl, Klaus

    2015-04-01

    Due to cool and moist climatic conditions alpine grassland soils of moderate elevation are rich in soil organic carbon and associated nitrogen. In the framework of an in-situ climate change experiment we test the hypothesis that soil organic carbon and nitrogen are either volatilized (GHG emissions) or leached with seepage water due to increase in temperature. Field investigations are carried out in the (Pre-) Alpine TERENO Observatory covering several research sites (including ICOS sites) in South-Bavaria, Germany. IMK-IFU has installed 36 weighable lysimeters with undisturbed intact grassland soil cores (diameter 1m, depth 1.4m) and is operating them at three sites differing in altitude and thus climatic conditions (850m, 750m, 600m) since 2011. Lysimeters were partly translocated from higher elevation to sites at lower elevation and other soil cores still staying at the sites as controls. In addition to the space for time in-situ climate change approach the total of 36 lysimeters are split into treatments of intensive and extensive grassland management. GHG exchange was measured by manual (850m site) but also with two novel automatic robot chamber systems (750m, 600m) connected to QCLs for simultaneous detection of CO2, N2O, and CH4 concentration changes in chamber headspace. GHG flux monitoring was supplemented by NEE measurements with transparent chambers since 2014. Climate change, generally stimulated plant growth (according to biomass sampling after cutting events) and soil C and N turnover leading to increased soil CO2 emissions and an increased uptake of atmospheric CH4. N2O emission were generally low and slightly increased in spring, summer and autumn but significantly decreased during the winter period under global change conditions, the latter due to lower intensity and frequency of frost-thaw events. The main gaseous nitrogen component emitted from the grassland ecosystems was N2 which also showed a much stronger increase with climate change than N2O

  1. Response of lightning NOx emissions and ozone production to climate change: Insights from the Atmospheric Chemistry and Climate Model Intercomparison Project

    NASA Astrophysics Data System (ADS)

    Finney, D. L.; Doherty, R. M.; Wild, O.; Young, P. J.; Butler, A.

    2016-05-01

    Results from an ensemble of models are used to investigate the response of lightning nitrogen oxide emissions to climate change and the consequent impacts on ozone production. Most models generate lightning using a parameterization based on cloud top height. With this approach and a present-day global emission of 5 TgN, we estimate a linear response with respect to changes in global surface temperature of +0.44 ± 0.05 TgN K-1. However, two models using alternative approaches give +0.14 and -0.55 TgN K-1 suggesting that the simulated response is highly dependent on lightning parameterization. Lightning NOx is found to have an ozone production efficiency of 6.5 ± 4.7 times that of surface NOx sources. This wide range of efficiencies across models is partly due to the assumed vertical distribution of the lightning source and partly to the treatment of nonmethane volatile organic compound (NMVOC) chemistry. Careful consideration of the vertical distribution of emissions is needed, given its large influence on ozone production.

  2. Interactions of Climate Change and Nitrogen Management for Optimizing Crop Productivity and Food Security while Minimizing Nitrogen Pollution and Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Davidson, E. A.; Suddick, E. C.

    2012-12-01

    Producing food, transportation, and energy for seven billion people has led to huge increases in use of synthetic nitrogen (N) fertilizers and fossil fuels, resulting in large releases of N as air and water pollution. In its numerous chemical forms, N plays a critical role in all aspects of climate change, including mitigation, adaptation, and impacts. Here we report on a multi-authored, interdisciplinary technical report on climate-nitrogen interactions submitted to the US National Climate Assessment as part of a Research Coordination Network activity. Management of the N cycle not only affects emissions of nitrous oxide (N2O) and nitrogen oxides (NOX), but also impacts carbon dioxide (CO2) and methane (CH4), through effects on carbon cycling processes in forests and soils and the effects on atmospheric reactions of ozone (O3) and CH4. While some of these direct and indirect N effects have a short-term cooling effect, the warming effects of N2O dominate at long time scales. The challenges of mitigating N2O emissions are substantially different from those for CO2 and CH4, because N is essential for food production, and over 80% of anthropogenic N2O emissions are from the agricultural sector. On one hand, improved agricultural nutrient management can confer some adaptive capacity of crops to climatic variability, but, on the other hand, increased climatic variability will render the task more difficult to manage nutrients for the optimization of crop productivity while minimizing N losses to the environment. Higher air temperatures will result in a "climate penalty" for air quality mitigation efforts, because larger NOX emissions reductions will be needed to achieve the same reductions of O3 pollution under higher temperatures, thus imposing further challenges to avoid harmful impacts on human health and crop productivity. Changes in river discharge, due to summer drought and to extreme precipitation events, will affect the transport of N from agricultural fields to

  3. Modelling future changes in climate, ozone-depleting substances and ozone precursor emissions using the whole-atmosphere UM-UKCA model

    NASA Astrophysics Data System (ADS)

    Banerjee, Antara; Maycock, Amanda; Archibald, Alexander; Telford, Paul; Abraham, Luke; Braesicke, Peter; Pyle, John

    2014-05-01

    Using the recently upgraded whole-atmosphere UM-UKCA chemistry-climate model, we investigate the atmospheric response to future changes in a) greenhouse gases under the RCP4.5 and 8.5 scenarios for climate change, b) ozone-depleting substances (ODS) and a recovery of the ozone layer and c) ozone precursor emissions and tropospheric oxidising capacity. In addition, we combine these scenarios in order to explore the interactions between individual perturbations. Within this framework, the coupled stratosphere-troposphere system and whole-atmosphere chemistry allows us to study the impact of changes in composition of the stratosphere on the troposphere and vice versa. We find that by the year 2100: 1) the stratosphere significantly impacts the troposphere via changes in stratosphere-troposphere exchange (STE) but the chemical changes induced in the troposphere do not impact the stratosphere, 2) perturbations are linearly additive with regard to the total ozone column and tropospheric odd oxygen budget, 3) while the Brewer-Dobson Circulation strengthens under climate change (with an increase in the DJF 70hPa tropical upwards mass flux of ~20% at RCP4.5 and exceeding 30% at RCP8.5), this strengthening is offset by ozone recovery (which on its own leads to a decrease in the mass flux of ~10%) and 4) tropospheric ozone decreases given mitigation of its precursor emissions (with a 10% decrease in ozone burden) but this can be offset by climate change at both RCP4.5 and 8.5 and stratospheric ozone recovery (increasing the burden by 6-13%).

  4. Evaluation of blood--brain barrier permeability changes in rhesus monkeys and man using /sup 82/Rb and positron emission tomography

    SciTech Connect

    Yen, C.K.; Budinger, T.F.

    1981-12-01

    Dynamic positron tomography of the brain with /sup 82/Rb, obtained from a portable generator (/sup 82/Sr (25 days) -- /sup 82/Rb (76 sec)), provides a means of studying blood-brain barrier (BBB) permeability in physiological and clinical investigations. The BBB in rhesus monkeys was opened unilaterally by intracarotid infusion of 3 M urea. This osmotic barrier opening allowed entry into the brain of intravenously administered rubidium chloride. The BBB opening was demonstrated noninvasively using /sup 82/Rb and positron emission tomography and corroborated by the accumulation of /sup 86/Rb in tissue samples. Positron emission tomography studies can be repeated every 5 min and indicate that dynamic tomography or static imaging can be used to study BBB permeability changes induced by a wide variety of noxious stimuli. Brain tumors in human subjects are readily detected because of the usual BBB permeability disruption in and around the tumors.

  5. The Impact of Emission and Climate Change on Ozone in the United States under Representative Concentration Pathways (RCPs)

    SciTech Connect

    Gao, Yang; Fu, Joshua S.; Drake, John B.; Lamarque, J.-F.; Liu, Yang

    2013-09-27

    Dynamical downscaling was applied in this study to link the global climate-chemistry model Community Atmosphere Model (CAM-Chem) with the regional models: Weather Research and Forecasting (WRF) Model and Community Multi-scale Air Quality (CMAQ). Two Representative Concentration Pathway (RCP) scenarios (RCP 4.5 and RCP 8.5) were used to evaluate the climate impact on ozone concentrations in 2050s. Ozone concentrations in the lower-mid troposphere (surface to ~300 hPa), from mid- to high latitudes in the Northern Hemisphere (NH), show decreasing trends in RCP 4.5 between 2000s and 2050s, with the largest decrease of 4-10 ppbv occurring in the summer and the fall; and increasing trends (2-12 ppbv) in RCP 8.5 resulting from the increased methane emissions. In RCP 8.5, methane emissions increase by ~60% by the end of 2050s, accounting for more than 90% of ozone increases in summer and fall, and 60-80% in spring and winter. Under the RCP 4.5 scenario, in the summer when photochemical reactions are the most active, the large ozone precursor emissions reduction leads to the greatest decrease of downscaled surface ozone concentrations, ranging from 6 to 10 ppbv. However, a few major cities show ozone increases of 3 to 7 ppbv due to weakened NO titration. Under the RCP 8.5 scenario, in winter, downscaled ozone concentrations increase across nearly the entire continental US in winter, ranging from 3 to 10 ppbv due to increased methane emissions and enhanced stratosphere-troposphere exchange (STE). More intense heat waves are projected to occur by the end of 2050s in RCP 8.5, leading to more than 8 ppbv of the maximum daily 8-hour daily average (MDA8) ozone during the heat wave days than other days; this indicates the dramatic impact heat waves exert on high frequency ozone events.

  6. Variability of OH rotational temperatures on time scales from hours to 15 years by kinetic temperature variations, emission layer changes, and non-LTE effects

    NASA Astrophysics Data System (ADS)

    Noll, Stefan

    2016-07-01

    Rotational temperatures derived from hydroxyl (OH) line emission are frequently used to study atmospheric temperatures at altitudes of about 87 km. While the measurement only requires intensities of a few bright lines of an OH band, the interpretation can be complicated. Ground-based temperatures are averages for the entire, typically 8 km wide emission layer. Variations in the rotational temperature are then caused by changes of the kinetic temperature and the OH emission profile. The latter can also be accompanied by differences in the layer-averaged efficiency of the thermalisation of the OH rotational level populations. Since this especially depends on the frequency of collisions with O_2, which is low at high altitudes, the non-local thermodynamic equilibrium (non-LTE) contribution to the measured temperatures can be significant and variable. In order to understand the impact of the different sources of OH rotational temperature variations from time scales of hours to a solar cycle, we have studied spectra from the astronomical echelle spectrographs X-shooter and UVES located at Cerro Paranal in Chile. While the X-shooter data spanning 3.5 years allowed us to measure temperatures for 25 OH and two O_2 bands, the UVES spectra cover no more than 10 OH bands simultaneously but a period of about 15 years. These data have been complemented by kinetic temperature and OH and O_2 emission profiles from the multi-channel radiometer SABER on the TIMED satellite. Taking the O_2 and SABER kinetic temperatures as reference and considering the different band-dependent emission profiles, we could evaluate the contribution of non-LTE effects to the measured OH rotational temperatures depending on line set, band, and time. Non-LTE contributions are significant for most bands and can exceed 10 K. The amplitudes of their average nocturnal and seasonal variation are of the order of 1 to 2 K.

  7. Incorporating Agricultural Management Practices into the Assessment of Soil Carbon Change and Life-Cycle Greenhouse Gas Emissions of Corn Stover Ethanol Production

    SciTech Connect

    Qin, Zhangcai; Canter, Christina E.; Dunn, Jennifer B.; Mueller, Steffen; Kwon, Ho-young; Han, Jeongwoo; Wander, Michelle M.; Wang, Michael

    2015-09-01

    Land management practices such as cover crop adoption or manure application that can increase soil organic carbon (SOC) may provide a way to counter SOC loss upon removal of stover from corn fields for use as a biofuel feedstock. This report documents the data, methodology, and assumptions behind the incorporation of land management practices into corn-soybean systems that dominate U.S. grain production using varying levels of stover removal in the GREETTM (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model and its CCLUB (Carbon Calculator for Land Use change from Biofuels production) module. Tillage (i.e., conventional, reduced and no tillage), corn stover removal (i.e., at 0, 30% and 60% removal rate), and organic matter input techniques (i.e., cover crop and manure application) are included in the analysis as major land management practices. Soil carbon changes associated with land management changes were modeled with a surrogate CENTURY model. The resulting SOC changes were incorporated into CCLUB while GREET was expanded to include energy and material consumption associated with cover crop adoption and manure application. Life-cycle greenhouse gas (GHG) emissions of stover ethanol were estimated using a marginal approach (all burdens and benefits assigned to corn stover ethanol) and an energy allocation approach (burdens and benefits divided between grain and stover ethanol). In the latter case, we considered corn grain and corn stover ethanol to be produced at an integrated facility. Life-cycle GHG emissions of corn stover ethanol are dependent upon the analysis approach selected (marginal versus allocation) and the land management techniques applied. The expansion of CCLUB and GREET to accommodate land management techniques can produce a wide range of results because users can select from multiple scenario options such as choosing tillage levels, stover removal rates, and whether crop yields increase annually or remain constant

  8. Changes in fluorescent emission of cationic fluorophores in the presence of n-alkanes and alcohols in different polarity solvents

    NASA Astrophysics Data System (ADS)

    Delgado-Camón, Arantzazu; Garriga, Rosa; Mateos, Elena; Cebolla, Vicente L.; Galbán, Javier; Membrado, Luis; Marcos, Susana de; Gálvez, Eva M.

    2011-01-01

    Berberine and coralyne experience either fluorescence enhancement or quenching when long hydrocarbon chain compounds (e.g., n-alkanes or alcohols) are added to their solutions, depending on solvent polarity. In polar solvents, as methanol or acetonitrile, the added compounds provide an apolar microenvironment that hinders alternative relaxation mechanisms, favouring fluorescence emission. However, alkane additions produce quenching in dichloromethane, which has been explained taking into account ion pairing between cationic fluorophore and counterion. The strong quenching measured after alcohol additions in dichloromethane suggests reversed micelle formation. Procedures and results described here may find practical applications in the development of analytical methods.

  9. Air pollution and associated human mortality: the role of air pollutant emissions, climate change and methane concentration increases from the preindustrial period to present

    NASA Astrophysics Data System (ADS)

    Fang, Y.; Naik, V.; Horowitz, L. W.; Mauzerall, D. L.

    2013-02-01

    Increases in surface ozone (O3) and fine particulate matter (≤2.5 μm aerodynamic diameter, PM2.5) are associated with excess premature human mortalities. We estimate changes in surface O3 and PM2.5 from pre-industrial (1860) to present (2000) and the global present-day (2000) premature human mortalities associated with these changes. We extend previous work to differentiate the contribution of changes in three factors: emissions of short-lived air pollutants, climate change, and increased methane (CH4) concentrations, to air pollution levels and associated premature mortalities. We use a coupled chemistry-climate model in conjunction with global population distributions in 2000 to estimate exposure attributable to concentration changes since 1860 from each factor. Attributable mortalities are estimated using health impact functions of long-term relative risk estimates for O3 and PM2.5 from the epidemiology literature. We find global mean surface PM2.5 and health-relevant O3 (defined as the maximum 6-month mean of 1-h daily maximum O3 in a year) have increased by 8 ± 0.16 μg m-3 and 30 ± 0.16 ppbv (results reported as annual average ±standard deviation of 10-yr model simulations), respectively, over this industrial period as a result of combined changes in emissions of air pollutants (EMIS), climate (CLIM) and CH4 concentrations (TCH4). EMIS, CLIM and TCH4 cause global population-weighted average PM2.5 (O35) to change by +7.5 ± 0.19 μg m-3 (+25 ± 0.30 ppbv), +0.4 ± 0.17 μg m-3 (+0.5 ± 0.28 ppbv), and 0.04 ± 0.24 μg m-3 (+4.3 ± 0.33 ppbv), respectively. Total global changes in PM2.5 are associated with 1.5 (95% confidence interval, CI, 1.2-1.8) million cardiopulmonary mortalities and 95 (95% CI, 44-144) thousand lung cancer mortalities annually and changes in O3 are associated with 375 (95% CI, 129-592) thousand respiratory mortalities annually. Most air pollution mortality is driven by changes in emissions of short-lived air pollutants and their

  10. Life cycle inventory analysis of regenerative thermal oxidation of air emissions from oriented strand board facilities in Minnesota - a perspective of global climate change

    SciTech Connect

    Nicholson, W.J.

    1997-12-31

    Life cycle inventory analysis has been applied to the prospective operation of regenerative thermal oxidation (RTO) technology at oriented strand board plants at Bemidji (Line 1) and Cook, Minnesota. The net system destruction of VOC`s and carbon monoxide, and at Cook a small quantity of particulate, has a very high environmental price in terms of energy and water use, global warming potential, sulfur and nitrogen oxide emissions, solids discharged to water, and solid waste deposited in landfills. The benefit of VOC destruction is identified as minor in terms of ground level ozone at best and possibly slightly detrimental. Recognition of environmental tradeoffs associated with proposed system changes is critical to sound decision-making. There are more conventional ways to address carbon monoxide emissions than combustion in RTO`s. In an environment in which global warming is a concern, fuel supplemental combustion for environmental control does not appear warranted. Consideration of non-combustion approaches to address air emission issues at the two operations is recommended. 1 ref., 5 tabs.

  11. Land use change emissions from oil palm expansion in Pará, Brazil depend on proper policy enforcement on deforested lands

    NASA Astrophysics Data System (ADS)

    Yui, Sahoko; Yeh, Sonia

    2013-12-01

    Brazil aims to increase palm oil production to meet the growing national and global demand for edible oil and biodiesel while preserving environmentally and culturally significant areas. As land use change (LUC) is the result of complex interactions between socio-economic and biophysical drivers operating at multiple temporal and spatial scales, the type and location of LUC depend on drivers such as neighboring land use, conversion elasticity, access to infrastructure, distance to markets, and land suitability. The purpose of this study is to develop scenarios to measure the impact of land conversion under three different enforcement scenarios (none, some, and strict enforcement). We found that converting 22.5 million hectares of land can produce approximately 29 billion gallons (110 billion liters) of biodiesel a year. Of that, 22-71% of the area can come from forest land, conservation units, wetland and indigenous areas, emitting 14-84 gCO2e MJ-1. This direct land use emission alone can be higher than the carbon intensity of diesel that it intends to displace for lowering greenhouse gas emissions. This letter focuses narrowly on GHG emissions and does not address socio-economic-ecological prospects for these degraded lands for palm oil or for other purposes. Future studies should carefully evaluate these tradeoffs.

  12. CHIANTI—An Atomic Database for Emission Lines. XIII. Soft X-Ray Improvements and Other Changes

    NASA Astrophysics Data System (ADS)

    Landi, E.; Young, P. R.; Dere, K. P.; Del Zanna, G.; Mason, H. E.

    2013-02-01

    The CHIANTI spectral code consists of two parts: an atomic database and a suite of computer programs in Python and IDL. Together, they allow the calculation of the optically thin spectrum of astrophysical objects and provide spectroscopic plasma diagnostics for the analysis of astrophysical spectra. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, ionization, and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7.1 has been released, which includes improved data for several ions, recombination rates, and element abundances. In particular, it provides a large expansion of the CHIANTI models for key Fe ions from Fe VIII to Fe XIV to improve the predicted emission in the 50-170 Å wavelength range. All data and programs are freely available at http://www.chiantidatabase.org and in SolarSoft, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

  13. CHIANTI-AN ATOMIC DATABASE FOR EMISSION LINES. XIII. SOFT X-RAY IMPROVEMENTS AND OTHER CHANGES

    SciTech Connect

    Landi, E.; Young, P. R.; Dere, K. P.; Del Zanna, G.; Mason, H. E.

    2013-02-15

    The CHIANTI spectral code consists of two parts: an atomic database and a suite of computer programs in Python and IDL. Together, they allow the calculation of the optically thin spectrum of astrophysical objects and provide spectroscopic plasma diagnostics for the analysis of astrophysical spectra. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, ionization, and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7.1 has been released, which includes improved data for several ions, recombination rates, and element abundances. In particular, it provides a large expansion of the CHIANTI models for key Fe ions from Fe VIII to Fe XIV to improve the predicted emission in the 50-170 A wavelength range. All data and programs are freely available at http://www.chiantidatabase.org and in SolarSoft, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

  14. Utilizing TEMPO surface estimates to determine changes in emissions, community exposure and environmental impacts from cement kilns across North America using alternative fuels

    NASA Astrophysics Data System (ADS)

    Pegg, M. J.; Gibson, M. D.; Asamany, E.

    2015-12-01

    A major problem faced by all North American (NA) Governments is managing solid waste from residential and non-residential sources. One way to mitigate the need to expand landfill sites across NA is waste diversion for use as alternative fuel in industries such as cement manufacture. Currently, waste plastic, tires, waste shingles and other high carbon content waste destined for landfill are being explored, or currently used, as an alternative supplemental fuels for use in cement kilns across NA. While this is an attractive, environmentally sustainable solution, significant knowledge gaps remain in our fundamental understanding of whether these alternative fuels may lead to increased air pollution emissions from cement kilns across NA. The long-term objective of using TEMPO is to advance fundamental understanding of uncharacterized air pollution emissions and to assess the actual or potential environmental and health impacts of these emissions from cement kilns across NA. TEMPO measurements will be made in concert with in-situ observations augmented by air dispersion, land-use regression and receptor modelling. This application of TEMPO follows on from current research on a series of bench scale and pilot studies for Lafarge Canada Inc., that investigated the change in combustion emissions from various mixtures of coal (C), petroleum coke (PC) and non-recyclable alternative fuels. From our work we demonstrated that using an alternative fuel mixture in a cement kiln has potential to reduce emissions of CO2 by 34%; reduce NOx by 80%, and reduce fuel SO2 emissions by 98%. We also provided evidence that there would be a significant reduction in the formation of secondary ground-level ozone (O3) and secondary PM2.5 in downwind stack plumes if alternative waste derived fuels are used. The application of air dispersion, source apportionment, land use regression; together with remote sensing offers a powerful set of tools with the potential to improve air pollution

  15. Effect of land use change for bioenergy on greenhouse gas emissions from a wet marginal soil in New York State, USA.

    NASA Astrophysics Data System (ADS)

    Stoof, Cathelijne; Mason, Cedric; Steenhuis, Tammo; Richards, Brian

    2013-04-01

    Millions of hectares of marginal lands in the Northeast USA no longer used for agriculture are suitable for production of second-generation cellulosic bioenergy crops, offering the potential for regional bioenergy production without inducing food vs. fuel competition for prime farmland. Abundant water resources, close proximity between production and markets, and compatibility with existing agricultural systems all favor development in the region. Yet, little is known about how sustainable bioenergy crop production on marginal lands is regarding greenhouse gas emissions. In a 10-ha field trial on wet marginal soils in upstate New York, we are assessing the effect of land use change (from fallow land to perennial grass stands) on N2O and CH4 emissions. The deep clay loam is unsuited for row-crop agriculture because it is too dry in summer and too wet in winter. Monthly chamber campaigns were performed from April to November 2012 to monitor large scale (10-20 m resolution) differences caused by land cover type (n=4 for both switchgrass, reed-canary grass and a 50-yr unplowed control) across soil moisture gradients (n=5 soil moisture levels per replicate). Additional weekly campaigns assessed the smaller scale spatial and temporal variability in emissions at meter-scale. Here we present results of both the large and small-scale patterns in greenhouse gas emissions from this marginal soil, and discuss effects of soil properties and hydrologic conditions as potential drivers. Insight gained about the environmental impact of bioenergy crops can be used to assess the sustainability of using this region's underutilized land base for energy production.

  16. IMPACT OF GLOBAL CHANGE ON URBAN AIR QUALITY VIA CHANGES IN MOBILE SOURCE EMISSIONS, BACKGROUND CONCENTRATIONS, AND REGIONAL SCALE METEOROLOGICAL FEEDBACKS

    EPA Science Inventory

    The source profiles measured during the current project will be useful for all future simulations of air pollution in the United States. The specific model predictions created in this project will contribute to the “weight-of-science” evaluation for the effect of Global Chang...

  17. Flare evolution and polarization changes in fine structures of solar radio emission in the 2013 April 11 event

    NASA Astrophysics Data System (ADS)

    Chernov, Gennady; Sych, Robert; Tan, Bao-Lin; Yan, Yi-Hua; Tan, Cheng-Ming; Fu, Qi-Jun; Karlický, Marian; Fomichev, Valery

    2016-02-01

    The measurement of positions and sizes of radio sources in observations is important for understanding of the flare evolution. For the first time, solar radio spectral fine structures in an M6.5 flare that occurred on 2013 April 11 were observed simultaneously by several radio instruments at four different observatories: Chinese Solar Broadband Radio Spectrometer at Huairou (SBRS/Huairou), Ondřejov Radio Spectrograph in the Czech Republic (ORSC/Ondřejov), Badary Broadband Microwave Spectropolarimeter (BMS/Irkutsk), and spectrograph/IZMIRAN (Moscow, Troitsk). The fine structures included microwave zebra patterns (ZPs), fast pulsations and fiber bursts. They were observed during the flare brightening located at the tops of a loop arcade as shown in images taken by the extreme ultraviolet (EUV) telescope onboard NASA's satellite Solar Dynamics Observatory (SDO). The flare occurred at 06:58-07:26 UT in solar active region NOAA 11719 located close to the solar disk center. ZPs appeared near high frequency boundaries of the pulsations, and their spectra observed in Huairou and Ondřejov agreed with each other in terms of details. At the beginning of the flare's impulsive phase, a strong narrowband ZP burst occurred with a moderate left-handed circular polarization. Then a series of pulsations and ZPs were observed in almost unpolarized emission. After 07:00 UT a ZP appeared with a moderate right-handed polarization. In the flare decay phase (at about 07:25 UT), ZPs and fiber bursts become strongly right-hand polarized. BMS/Irkutsk spectral observations indicated that the background emission showed a left-handed circular polarization (similar to SBRS/Huairou spectra around 3 GHz). However, the fine structure appeared in the right-handed polarization. The dynamics of the polarization was associated with the motion of the flare exciter, which was observed in EUV images at 171 Å and 131 Å by the SDO Atmospheric Imaging Assembly (AIA). Combining magnetograms observed by

  18. Effects of ozone exposure on `Golden' papaya fruit by photoacoustic phase-resolved method: Physiological changes associated with carbon dioxide and ethylene emission rates during ripening

    NASA Astrophysics Data System (ADS)

    Corrêa, Savio Figueira; Mota, Leonardo; Paiva, Luisa Brito; Couto, Flávio Mota do; Silva, Marcelo Gomes da; Oliveira, Jurandi Gonçalves de; Sthel, Marcelo Silva; Vargas, Helion; Miklós, András

    2011-06-01

    This work addresses the effects of ozone activity on the physiology of `Golden' papaya fruit. Depth profile analysis of double-layer biological samples was accomplished using the phase-resolved photoacoustic spectroscopy. The feasibility of the method was demonstrated by singling out the spectra of the cuticle and the pigment layers of papaya fruit. The same approach was used to monitor changes occurring on the fruit during ripening when exposed to ozone. In addition, one has performed real time studies of fluorescence parameters and the emission rates of carbon dioxide and ethylene. Finally, the amount of pigments and the changes in waxy cuticle have been monitored. Results indicate that a fruit deliberately subjected to ozone at a level of 6 ppmv underwent ripening sooner (at least 24-48 h) than a fruit stored at ambient conditions. Moreover, ozone caused a reduction in the maximum quantum yield of photosynthetic apparatus located within the skin of papaya fruit.

  19. Effects of ozone exposure on 'Golden' papaya fruit by photoacoustic phase-resolved method: Physiological changes associated with carbon dioxide and ethylene emission rates during ripening

    SciTech Connect

    Correa, Savio Figueira; Brito Paiva, Luisa; Mota do Couto, Flavio; Gomes da Silva, Marcelo; Silva Sthel, Marcelo; Vargas, Helion; Mota, Leonardo; Goncalves de Oliveira, Jurandi; Miklos, Andras

    2011-06-01

    This work addresses the effects of ozone activity on the physiology of 'Golden' papaya fruit. Depth profile analysis of double-layer biological samples was accomplished using the phase-resolved photoacoustic spectroscopy. The feasibility of the method was demonstrated by singling out the spectra of the cuticle and the pigment layers of papaya fruit. The same approach was used to monitor changes occurring on the fruit during ripening when exposed to ozone. In addition, one has performed real time studies of fluorescence parameters and the emission rates of carbon dioxide and ethylene. Finally, the amount of pigments and the changes in waxy cuticle have been monitored. Results indicate that a fruit deliberately subjected to ozone at a level of 6 ppmv underwent ripening sooner (at least 24-48 h) than a fruit stored at ambient conditions. Moreover, ozone caused a reduction in the maximum quantum yield of photosynthetic apparatus located within the skin of papaya fruit.

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

    NASA Astrophysics Data System (ADS)

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

    2006-10-01

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

  1. Modeling high resolution space-time variations in energy demand/CO2 emissions of human inhabited landscapes in the United States under a changing climate

    NASA Astrophysics Data System (ADS)

    Godbole, A. V.; Gurney, K. R.

    2010-12-01

    With urban and exurban areas now accounting for more than 50% of the world's population, projected to increase 20% by 2050 (UN World Urbanization Prospects, 2009), urban-climate interactions are of renewed interest to the climate change scientific community (Karl et. al, 1988; Kalnay and Cai, 2003; Seto and Shepherd, 2009). Until recently, climate modeling efforts treated urban-human systems as independent of the earth system. With studies pointing to the disproportionately large influence of urban areas on their surrounding environment (Small et. al, 2010), modeling efforts have begun to explicitly account for urban processes in land models, like the CLM 4.0 urban layer, for example (Oleson.et. al, 2008, 2010). A significant portion of the urban energy demand comes from the space heating and cooling requirement of the residential and commercial sectors - as much as 51% (DOE, RECS 2005) and 11% (Belzer, D. 2006) respectively, in the United States. Thus, these sectors are both responsible for a significant fraction of fossil fuel CO2 emissions and will be influenced by a changing climate through changes in energy use and energy supply planning. This points to the possibility of interactive processes and feedbacks with the climate system. Space conditioning energy demand is strongly driven by external air temperature (Ruth, M. et.al, 2006) in addition to other socio-economic variables such as building characteristics (age of structure, activity cycle, weekend/weekday usage profile), occupant characteristics (age of householder, household income) and energy prices (Huang, 2006; Santin et. al, 2009; Isaac and van Vuuren, 2009). All of these variables vary both in space and time. Projections of climate change have begun to simulate changes in temperature at much higher resolution than in the past (Diffenbaugh et. al, 2005). Hence, in order to understand how climate change and variability will potentially impact energy use/emissions and energy planning, these two

  2. Composition, seasonal change and bathymetry of Ligeia Mare, Titan, derived from its 2.2-cm thermal emission

    NASA Astrophysics Data System (ADS)

    Le Gall, A.; Lorenz, R. D.; Malaska, M. J.; Tokano, T.; Hayes, A. G.; Mastrogiuseppe, M.; Veyssière, G.

    2015-10-01

    Ligeia Mare is the second largest sea of Saturn's moon Titan. It is also the first extraterritorial sea for which a bathymetry profile was obtained. In this paper, we analyze all data acquired up to July 2013 in the passive mode of the RADAR (i.e., radiometry mode) on board the Cassini probe in order to constrain its composition, seasonal change and bathymetry.

  3. Projected effect of 2000-2050 changes in climate and emissions on aerosol levels in China and associated transboundary transport

    EPA Science Inventory

    We investigate projected 2000–2050 changes in concentrations of aerosols in China and the associated transboundary aerosol transport by using the chemical transport model GEOS-Chem driven by the Goddard Institute for Space Studies (GISS) general circulation model (GCM) 3 at 4° × ...

  4. Time-frequency analysis of stimulus frequency otoacoustic emissions and their changes with efferent stimulation in guinea pigs

    NASA Astrophysics Data System (ADS)

    Berezina-Greene, Maria A.; Guinan, John J.

    2015-12-01

    To aid in understanding their origin, stimulus frequency otoacoustic emissions (SFOAEs) were measured at a series of tone frequencies using the suppression method, both with and without stimulation of medial olivocochlear (MOC) efferents, in anesthetized guinea pigs. Time-frequency analysis showed SFOAE energy peaks in 1-3 delay components throughout the measured frequency range (0.5-12 kHz). One component's delay usually coincided with the phase-gradient delay. When multiple delay components were present, they were usually near SFOAE dips. Below 2 kHz, SFOAE delays were shorter than predicted from mechanical measurements. With MOC stimulation, SFOAE amplitude was decreased at most frequencies, but was sometimes enhanced, and all SFOAE delay components were affected. The MOC effects and an analysis of model data suggest that the multiple SFOAE delay components arise at the edges of the traveling-wave peak, not far basal of the peak. Comparisons with published guinea-pig neural data suggest that the short latencies of low-frequency SFOAEs may arise from coherent reflection from an organ-of-Corti motion that has a shorter group delay than the traveling wave.

  5. Changes.

    ERIC Educational Resources Information Center

    Weikel, William J.

    1999-01-01

    The author, founding editor of the American Mental Health Counselors Association (AMHC) Journal, now the Journal of Mental Health Counseling, examines some of the changes that have taken place in the profession over the past 20 years. Special emphasis is given to the visionary excellence that set the "AMHCA Agenda" over 20 years ago. (Author)

  6. Application of Chang's attenuation correction technique for single-photon emission computed tomography partial angle acquisition of Jaszczak phantom

    PubMed Central

    Saha, Krishnendu; Hoyt, Sean C.; Murray, Bryon M.

    2016-01-01

    The acquisition and processing of the Jaszczak phantom is a recommended test by the American College of Radiology for evaluation of gamma camera system performance. To produce the reconstructed phantom image for quality evaluation, attenuation correction is applied. The attenuation of counts originating from the center of the phantom is greater than that originating from the periphery of the phantom causing an artifactual appearance of inhomogeneity in the reconstructed image and complicating phantom evaluation. Chang's mathematical formulation is a common method of attenuation correction applied on most gamma cameras that do not require an external transmission source such as computed tomography, radionuclide sources installed within the gantry of the camera or a flood source. Tomographic acquisition can be obtained in two different acquisition modes for dual-detector gamma camera; one where the two detectors are at 180° configuration and acquire projection images for a full 360°, and the other where the two detectors are positioned at a 90° configuration and acquire projections for only 180°. Though Chang's attenuation correction method has been used for 360° angle acquisition, its applicability for 180° angle acquisition remains a question with one vendor's camera software producing artifacts in the images. This work investigates whether Chang's attenuation correction technique can be applied to both acquisition modes by the development of a Chang's formulation-based algorithm that is applicable to both modes. Assessment of attenuation correction performance by phantom uniformity analysis illustrates improved uniformity with the proposed algorithm (22.6%) compared to the camera software (57.6%). PMID:27051167

  7. Application of Chang's attenuation correction technique for single-photon emission computed tomography partial angle acquisition of Jaszczak phantom.

    PubMed

    Saha, Krishnendu; Hoyt, Sean C; Murray, Bryon M

    2016-01-01

    The acquisition and processing of the Jaszczak phantom is a recommended test by the American College of Radiology for evaluation of gamma camera system performance. To produce the reconstructed phantom image for quality evaluation, attenuation correction is applied. The attenuation of counts originating from the center of the phantom is greater than that originating from the periphery of the phantom causing an artifactual appearance of inhomogeneity in the reconstructed image and complicating phantom evaluation. Chang's mathematical formulation is a common method of attenuation correction applied on most gamma cameras that do not require an external transmission source such as computed tomography, radionuclide sources installed within the gantry of the camera or a flood source. Tomographic acquisition can be obtained in two different acquisition modes for dual-detector gamma camera; one where the two detectors are at 180° configuration and acquire projection images for a full 360°, and the other where the two detectors are positioned at a 90° configuration and acquire projections for only 180°. Though Chang's attenuation correction method has been used for 360° angle acquisition, its applicability for 180° angle acquisition remains a question with one vendor's camera software producing artifacts in the images. This work investigates whether Chang's attenuation correction technique can be applied to both acquisition modes by the development of a Chang's formulation-based algorithm that is applicable to both modes. Assessment of attenuation correction performance by phantom uniformity analysis illustrates improved uniformity with the proposed algorithm (22.6%) compared to the camera software (57.6%). PMID:27051167

  8. Acoustic emission and dilatometry for non-destructive characterization of microstructural changes in Mg based metal matrix composites submitted to thermal cycling

    SciTech Connect

    Chmelik, R.; Lukac, P.; Kiehn, J.; Kainer, K.U.; Mordike, B.L.

    1997-12-18

    Many Mg-based metal matrix composites (MMCs) have been developed and manufactured during the last decade as prospective light high-performance constructional materials. When a MMC is submitted to temperature changes (cooling down from the temperature of fabrication, cyclic temperature changes during operation of structural parts) thermal stresses arise at the interfaces owing to a considerable mismatch of the thermal expansion coefficient of the matrix and that of the reinforcement. Even slight temperature changes may produce thermal stresses which exceed the matrix yield stress, consequently, generating new dislocations at the interfaces causing microstructural changes and plastic deformation of the matrix. Long-term exposure may also result in fatigue damage. It is noteworthy that the effect of temperature variations is similar to creep under non-stationary loading conditions. Acoustic emission (AE) has been observed during thermal cycling of Mg based MMCs. Since dislocation motion and microstructural damage are generally accepted to produce AE, it is possible by AE measurements to identify and to characterize the microstructural changes and to correlate them with temperature or other parameters. The dilatometry technique enables the degree of matrix plastic deformation which superposing the thermal expansion to be determined by measuring the shape changes during testing. The combination of both methods yields non-destructively, at any instant of the test, information on the structure and operating processes over the entire volume of the specimen. This can also provide valuable information for subsequent investigations by microscopy or internal friction. The object of this paper is to report on the recently developed, combined AE and dilatometry technique and its application in a structural evolution in Mg-based MMCs subjected to thermal cycling.

  9. Changes in CO2, N2O and NO Emissions in Response to Conventional Tillage and No-tillage Management Practices in the State of Rondonia, Brazil

    NASA Astrophysics Data System (ADS)

    Passianoto, C. C.; Ahrens, T. D.; Feigl, B. J.; Steudler, P. A.; Do Carmo, J. B.; Melillo, J. M.

    2002-12-01

    treatment (0.12 kg N ha-1). For the first week following fertilization the percentage of fertilizer N lost as N2O plus NO was 1.0% for the tillage treatment and 3.0% for the no-tillage treatment. Because pasture restoration will continue in Rond“nia and other parts of the Amazon Basin, we can expect changes in CO2, N2O and NO emissions to the atmosphere from the region. For CO2, both the sign and magnitude of these changes will depend on the restoration regime chosen. Nitrogen oxide emission will increase as the rate of pasture restoration increases with the magnitude of the increases being restoration-regime dependent.

  10. Spatio-temporal changes in CO2 emissions during the second ZERT injection, August-September 2008

    SciTech Connect

    Amonette, James E.; Barr, Jonathan L.; Dobeck, Laura M.; Gullickson, Kadie; Walsh, Stephen J.

    2010-01-13

    This study reports the first field test of a multi-channel, auto-dilution, steady-state, soil-CO2 flux monitoring system being developed to help understand the pathways by which fugitive CO2 from a geologic sequestration site migrates to the surface. The test was conducted from late August through mid-October 2008 at the Zero Emissions Research and Technology (ZERT) project site located in Bozeman, MT. Twenty steady-state and five non-steady-state flux chambers were installed in a 10x15 m area, one boundary of which was directly above a shallow (2-m depth) horizontal injection well located 0.5 m below the water table. A total flux of 52 kg CO2 d-1.was injected into the well for 13 days and the efflux from the soil was monitored by the chambers before, during, and for 33 days after the injection. The results showed a rapid increase in soil efflux once injection started, with maximal values reached within 3-7 d in most chambers. Efflux returned to background levels within a similar time period after injection ceased. A radial efflux pattern was observed to at least 2 m from the injection well, and evidence for movement of the CO2 plume during the injection, presumably due to groundwater flow, was seen. The steady-state chambers yielded very stable data, but 3- to 5-fold higher fluxes than the non-steady-state chambers. The higher fluxes were attributed to vacuum induced in the steady-state chambers by narrow vent tubes. High winds resulted in significant decreases in measured soil CO2 efflux, presumably by enhancing efflux from soil outside the chambers.

  11. Volatile Organic Compounds Emissions from Luculia pinceana Flower and Its Changes at Different Stages of Flower Development.

    PubMed

    Li, Yuying; Ma, Hong; Wan, Youming; Li, Taiqiang; Liu, Xiuxian; Sun, Zhenghai; Li, Zhenghong

    2016-01-01

    Luculia plants are famed ornamental plants with sweetly fragrant flowers, of which L. pinceana Hooker, found primarily in Yunnan Province, China, has the widest distribution. Solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) was employed to identify the volatile organic compounds (VOCs) emitted from different flower development stages of L. pinceana for the evaluation of floral volatile polymorphism. Peak areas were normalized as percentages and used to determine the relative amounts of the volatiles. The results showed that a total of 39 compounds were identified at four different stages of L. pinceana flower development, including 26 at the bud stage, 26 at the initial-flowering stage, 32 at the full-flowering stage, and 32 at the end-flowering stage. The most abundant compound was paeonol (51%-83%) followed by (E,E)-α-farnesene, cyclosativene, and δ-cadinene. All these volatile compounds create the unique fragrance of L. pinceana flower. Floral scent emission offered tendency of ascending first and descending in succession, meeting its peak level at the initial-flowering stage. The richest diversity of floral volatile was detected at the third and later periods of flower development. Principal component analysis (PCA) indicated that the composition and its relative content of floral scent differed throughout the whole flower development. The result has important implications for future floral fragrance breeding of Luculia. L. pinceana would be adequate for a beneficial houseplant and has a promising prospect for development as essential oil besides for a fragrant ornamental owing to the main compounds of floral scent with many medicinal properties. PMID:27110758

  12. Soil Carbon Sequestration and Greenhouse Gas Emissions Under a Changing Climate at the Foodshed Scale - Preliminary Results from Diverse Cropping Systems

    NASA Astrophysics Data System (ADS)

    Kong, A. Y.; Shukla, S. P.; Rosenzweig, C.

    2011-12-01

    The term 'foodshed' is an analog to the concept of a 'watershed' and describes "the flow of foodstuffs to consuming markets." Our main goals in identifying a foodshed are to: determine sustainable regional production and develop ideas for regional/local distribution systems that increase market access for producers and fresh food access for consumers, while reducing the carbon footprint of the food choices within the foodshed. The latter can be achieved by establishing policies that protect agricultural land from development, conserve water, and promote the adoption of agricultural management practices that decrease disturbance and/or increase carbon sequestration in soils, all of which can play a role in mitigating climate change. Because few studies relate climate change and agriculture at the regional-scale, we lack a good understanding of which elements of a foodshed are most vulnerable to changes in climate. With this foodshed analysis, our overall aims are to utilize the latest methods of climate and agricultural scenario generation to conduct multi-scale and transdisciplinary assessments of climate change impacts on the production, distribution and consumption of agricultural crops within a foodshed and to evaluate the potential for mitigation [soil carbon sequestration and greenhouse gas (GHG) emissions reduction)] and design the framework for adaptation (policy incentives) to climate change within a foodshed. Here, we present the methodology and preliminary results for an integrated climate/ecosystem modeling approach to look at how agricultural management practices can contribute to climate change mitigation within the Hudson Valley, a sub-region of the New York City foodshed. First, cutting-edge CMIP5 GCMs were validated against historical climatic data (1979-present) to identify which GCMs best simulate the climate of the Northeastern US (which includes the New York City foodshed). Subsequently, the selected GCMs were forced with the IPCC's four newly

  13. Modified Methodology for Projecting Coastal Louisiana Land Changes over the Next 50 Years

    USGS Publications Warehouse

    Hartley, Steve B.

    2009-01-01

    The coastal Louisiana landscape is continually undergoing geomorphologic changes (in particular, land loss); however, after the 2005 hurricane season, the changes were intensified because of Hurricanes Katrina and Rita. The amount of land loss caused by the 2005 hurricane season was 42 percent (562 km2) of the total land loss (1,329 km2) that was projected for the next 50 years in the Louisiana Coastal Area (LCA), Louisiana Ecosystem Restoration Study. The purpose of this study is to provide information on potential changes to coastal Louisiana by using a revised LCA study methodology. In the revised methodology, we used classified Landsat TM satellite imagery from 1990, 2001, 2004, and 2006 to calculate the 'background' or ambient land-water change rates but divided the Louisiana coastal area differently on the basis of (1) geographic regions ('subprovinces') and (2) specific homogeneous habitat types. Defining polygons by subprovinces (1, Pontchartrain Basin; 2, Barataria Basin; 3, Vermilion/Terrebonne Basins; and 4, the Chenier Plain area) allows for a specific erosion rate to be applied to that area. Further subdividing the provinces by habitat type allows for specific erosion rates for a particular vegetation type to be applied. Our modified methodology resulted in 24 polygons rather than the 183 that were used in the LCA study; further, actively managed areas and the CWPPRA areas were not masked out and dealt with separately as in the LCA study. This revised methodology assumes that erosion rates for habitat types by subprovince are under the influence of similar environmental conditions (sediment depletion, subsidence, and saltwater intrusion). Background change rate for three time periods (1990-2001, 1990-2004, and 1990-2006) were calculated by taking the difference in water or land among each time period and dividing it by the time interval. This calculation gives an annual change rate for each polygon per time period. Change rates for each time period

  14. Impacts of ENSO events on cloud radiative effects in preindustrial conditions: Changes in cloud fraction and aerosol emissions, wet scavenging and transport

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Russell, L. M.; Xu, L.; Lou, S.; Lamjiri, M. A.

    2015-12-01

    The impacts of the El Niño-Southern Oscillation (ENSO) events on shortwave and longwave cloud radiative effects (CRESW and CRELW) and the related changes in cloud fraction and aerosol emissions, wet scavenging and transport are quantified using three 150-year simulations for the preindustrial condition from the CESM model. Compared to recent observations from Clouds and the Earth's Radiant Energy System (CERES), the model simulation successfully reproduced larger variations of CRESW over the tropical western and central Pacific, Indonesian regions, and the eastern Pacific, as well as large variations of CRELW located mainly within the tropics. The ENSO cycle is found to dominate interannual variations of cloud radiative effects, especially over the tropics. Relative to those during La Niña events, simulated cooling (warming) effects from CRESW (CRELW) during El Niño events are stronger over tropical western and central Pacific, with the largest difference exceeding 40 Wm-2 (30 Wm-2), and weaker effects of 10-30 Wm-2 over Indonesian regions and the subtropical Pacific. Sensitivity tests show that variations of cloud radiative effects are mainly driven by ENSO-induced changes in cloud fraction. However, changes in natural aerosol concentrations, primarily due to changes in wet scavenging and transport processes, also play an important role in modulating the variations of cloud radiative effects. Because of increased (decreased) precipitation in El Niño (La Niña) events, increased (decreased) wet scavenging and transport of natural aerosols offset about 10% of variations of cloud radiative effects averaged over the tropics, whereas the emission changes enhance the variations by 4-6%. Moreover, the variation in medium and high cloud fraction accounts for about 20-50% of the interannual variations of CRESW over the tropics and almost all of the variations of CRELW between 60°S and 60°N. The variation of low cloud fraction plays a dominant role in contributing

  15. Putting VOC Measurements During SOAS 2013 in Context of Historical Observations: How Have VOC Emissions in the Alabama Region Changed Since the SOS 1990 Study?

    NASA Astrophysics Data System (ADS)

    Olson, K. F.; Koss, A.; De Gouw, J. A.; Goldstein, A. H.

    2013-12-01

    Volatile organic compounds (VOCs) play an important role in atmospheric photochemistry. They react with atmospheric oxidants to form ozone and secondary organic aerosols (SOA). VOCs are emitted from a variety of anthropogenic and biogenic sources. The Southeastern United States (SEUS) is heavily forested with high biogenic VOCs emissions. There are many anthropogenic air pollution sources in the region, including urban centers and power plants. This makes the SEUS an ideal location to study the chemistry of biogenic VOCs in the presence of anthropogenic emissions. The SEUS has hosted several large atmospheric chemistry field campaigns. The Southern Oxidant and Aerosol Study (SOAS) took place in a forested site near Centerville, AL from June 1st to July 15th, 2013. SOAS included a comprehensive suite of instruments measuring VOCs, oxidants, aerosol properties and meteorology. During the campaign, in-situ gas chromatography - mass spectrometry (GC-MS) was used to measure VOCs at the SOAS Centreville ground site. We put these VOC measurements in perspective of measurements from previous campaigns in the SEUS including the Southern Oxidant Study (SOS) campaign in the 1990s as well as measurements during June and July 1990 in a loblolly pine plantation in western Alabama as part of the Rural Oxidants in the Southern Environment program. We analyze how VOC levels vary within the region and how regional photochemistry has changed in recent decades.

  16. Composition, seasonal change and bathymetry of Ligeia Mare, Titan, derived from its 2.2-cm thermal emission

    NASA Astrophysics Data System (ADS)

    Le Gall, A. A.; Malaska, M.; Lorenz, R. D.; Janssen, M. A.; Tokano, T.; Hayes, A.; Lunine, J. I.; Veyssière, G.; Mastrogiuseppe, M.; Karatekin, O.; Encrenaz, P.

    2015-12-01

    For the last 10 years, the Cassini RADAR has been exploring Saturn's moon Titan, the only planetary body besides Earth whose surface presently exhibits significant accumulations of liquids in the forms of lakes and seas. In particular, the passive Radiometer that is incorporated in this instrument has been recording the 2.2 cm-wavelength thermal emission from Titan's three seas. Radiometry observations provide new information beyond the active radar reflection data. In this paper, we analyze the radiometry observations collected from Feb. 2007 to July 2013 over one of these seas, Ligeia Mare, with the goal of providing constrains on its liquid composition, seafloor nature, bathymetry, and dynamics. In light of the two-layer model we have developed for this analysis, we find that the dielectric constant of the sea liquid is most likely smaller than 1.8, suggesting that the composition of Ligeia Mare is dominated by liquid methane rather than liquid ethane (although a ternary methane-ethane-nitrogen mixture cannot be ruled out). This result is further supported by the value we infer for the liquid loss tangent of 3-5×10-5. This value is in agreement with the one first published by Mastrogiuseppe et al. (2014) based on active radar observation. A high methane concentration suggests that Ligeia Mare is either a sea from which ethane has been removed by crustal interaction, or a sea primarely fed by methane-rich precipitation, or both. For the seafloor, a dielectric constant of 2.6-2.9±0.9 is determined. Though this result is not very constraining, we favor a scenario where the floor of Ligeia Mare is covered by a sludge of compacted and possibly nitrile-rich organic material formed by the deposition of photochemical haze or by rain-washing of the nearby shores. These results are then used to convert the radiometry mosaic of Ligeia Mare into a qualitative low-resolution bathymetry map. Lastly, we establish limits on the physical temperature variation of the sea

  17. Scenarios of land use and land cover change in the conterminous United States: Utilizing the special report on emission scenarios at ecoregional scales

    USGS Publications Warehouse

    Sleeter, Benjamin M.; Sohl, Terry L.; Bouchard, Michelle A.; Reker, Ryan R.; Soulard, Christopher E.; Acevedo, William; Griffith, Glenn E.; Sleeter, Rachel R.; Auch, Roger F.; Sayler, Kristi L.; Prisley, Stephen; Zhu, Zhi-Liang

    2012-01-01

    Global environmental change scenarios have typically provided projections of land use and land cover for a relatively small number of regions or using a relatively coarse resolution spatial grid, and for only a few major sectors. The coarseness of global projections, in both spatial and thematic dimensions, often limits their direct utility at scales useful for environmental management. This paper describes methods to downscale projections of land-use and land-cover change from the Intergovernmental Panel on Climate Change's Special Report on Emission Scenarios to ecological regions of the conterminous United States, using an integrated assessment model, land-use histories, and expert knowledge. Downscaled projections span a wide range of future potential conditions across sixteen land use/land cover sectors and 84 ecological regions, and are logically consistent with both historical measurements and SRES characteristics. Results appear to provide a credible solution for connecting regionalized projections of land use and land cover with existing downscaled climate scenarios, under a common set of scenario-based socioeconomic assumptions.