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At least 955 records · Page 53
All sourcesNASA NTRSDOE OSTI
NASA NTRS1999

Global Precipitation during the 1997-98 El Nino and Initiation of the 1998-99 La Nina

The 1997-99 ENSO (El nino Southern Oscillation) cycle was very powerful, but also well observed. The best satellite rainfall estimates combined with gauge observations allow for a global analysis of precipitation anomalies accompanying the 1997-98 El Nino and initiation of the 1998-99 La Nina. For the period April 1997 to March 1998 the central to eastern Pacific, southeastern and western U.S., Argentina, eastern Africa, South China, eastern Russia, and North Atlantic were all more than two standard deviations wetter than normal. During the same year the Maritime Continent, eastern Indian Ocean, subtropical North Pacific, northeastern South America, and much of the mid- latitude southern oceans were more than two standard deviations drier than normal. An analysis of the evolution of the El Nino and accompanying precipitation anomalies revealed that a dry Maritime Continent led the formation of the El Nino SST (Sea Surface Temperature), while in the central Pacific, precipitation anomalies lagged the El Nino SST by a season. A rapid transition from El Nino to La Nina occurred in May 1998, but as early as October-November 1997 precipitation indices captured precursor changes in Pacific rainfall anomalies. Differences were found between observed and modeled [NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis] precipitation anomalies for 1997 and 98. In particular, the model had a bias towards positive precipitation anomalies and the magnitudes of the anomalies in the equatorial Pacific were small compared to the observations. Also, the evolution of the precipitation field, including the drying of the Maritime Continent and eastward progression of rainfall in the equatorial Pacific, was less pronounced for the model compared to the observations. One degree daily estimates of rainfall show clearly the MaddenJulian Oscillation and related westerly wind burst events over the Maritime Continent, which are key indicators for the onset of El Nino.

Curtis, Scott↗
NASA NTRS1997

ENSO Mechanisms

This current leading theory of the El Nino-Southern Oscillation (ENSO) phenomenon involves reflection of equatorial waves on the western ocean boundary to shift the ENSO phase from El Nino to La Nina and vice versa. However, recent satellite altimetry and In situ observations indicate that this theory has several flaws. These include imperfect equatorial wave reflection on the western ocean boundary, a maxima of the simulated coupled wind-sea surface temperature (SST) interaction located too far into the eastern equatorial Pacific, and an excessive role of thermocline displacement on SST in this region. We show that the central equatorial Pacific SST is fundamental in driving the EIVSO ocean-atmosphere coupled system, through the east-west displacement of the eastern edge of the warm pool, perfectly related with ENSO. Within the equatorial wave-guide, the dominance of surface zonal advection in these displacements is demonstrated with four different satellite and in situ data sets and three ocean models. This demonstration is supported by the evidence of a convergence of water masses into the eastern edge of the warm pool, resulting in a well-defined salinity front. All these results lead us to propose a notable modification of the leading delayed-action oscillator theory for the oscillatory nature of ENSO. Simulations with a linearized coupled ocean-atmosphere model result in 3-6 year ENSO-like oscillations, with many Of the variable model parameters found very close to their observed values. This simple model suggests that ocean processes ignored or underestimated in the delayed action oscillator theory, such as zonal current convergence, zonal advection of sea surface temperature and equatorial wave reflection from the eastern-ocean boundary, are fundamental to the development of ENSO, in particular to its manifestations in the central equatorial Pacific.

Picaut, Joel↗
NASA NTRS2009

A GCM Study of Responses of the Atmospheric Water Cycle of West Africa and the Atlantic to Saharan Dust Radiative Forcing

The responses of the atmospheric water cycle and climate of West Africa and the Atlantic to radiative forcing of Saharan dust are studied using the NASA finite volume general circulation model (fvGCM), coupled to a mixed layer ocean. We find evidence of an "elevated heat pump" (EHP) mechanism that underlines the responses of the atmospheric water cycle to dust forcing as follow. During the boreal summerr, as a result of large-scale atmospheric feedback triggered by absorbing dust aerosols, rainfall and cloudiness are ehanIed over the West Africa/Eastern Atlantic ITCZ, and suppressed over the West Atlantic and Caribbean region. Shortwave radiation absorption by dust warms the atmosphere and cools the surface, while longwave has the opposite response. The elevated dust layer warms the air over West Africa and the eastern Atlantic. As the warm air rises, it spawns a large-scale onshore flow carrying the moist air from the eastern Atlantic and the Gulf of Guinea. The onshore flow in turn enhances the deep convection over West Africa land, and the eastern Atlantic. The condensation heating associated with the ensuing deep convection drives and maintains an anomalous large-scale east-west overturning circulation with rising motion over West Africa/eastern Atlantic, and sinking motion over the Caribbean region. The response also includes a strengthening of the West African monsoon, manifested in a northward shift of the West Africa precipitation over land, increased low-level westerlies flow over West Africa at the southern edge of the dust layer, and a near surface westerly jet underneath the dust layer overr the Sahara. The dust radiative forcing also leads to significant changes in surface energy fluxes, resulting in cooling of the West African land and the eastern Atlantic, and warming in the West Atlantic and Caribbean. The EHP effect is most effective for moderate to highly absorbing dusts, and becomes minimized for reflecting dust with single scattering albedo at0.95 or higher.

Lau, K. M.↗
NASA NTRS2014

Toward Improved Land Surface Initialization in Support of Regional WRF Forecasts at the Kenya Meteorological Service (KMS)

Flooding and drought are two key forecasting challenges for the Kenya Meteorological Service (KMS). Atmospheric processes leading to excessive precipitation and/or prolonged drought can be quite sensitive to the state of the land surface, which interacts with the planetary boundary layer (PBL) of the atmosphere providing a source of heat and moisture. The development and evolution of precipitation systems are affected by heat and moisture fluxes from the land surface, particularly within weakly-sheared environments such as in the tropics and sub-tropics. These heat and moisture fluxes during the day can be strongly influenced by land cover, vegetation, and soil moisture content. Therefore, it is important to represent the land surface state as accurately as possible in land surface and numerical weather prediction (NWP) models. Enhanced regional modeling capabilities have the potential to improve forecast guidance in support of daily operations and high-impact weather over eastern Africa. KMS currently runs a configuration of the Weather Research and Forecasting (WRF) NWP model in real time to support its daily forecasting operations, making use of the NOAA/National Weather Service (NWS) Science and Training Resource Center's Environmental Modeling System (EMS) to manage and produce the KMS-WRF runs on a regional grid over eastern Africa. Two organizations at the NASA Marshall Space Flight Center in Huntsville, AL, SERVIR and the Shortterm Prediction Research and Transition (SPoRT) Center, have established a working partnership with KMS for enhancing its regional modeling capabilities through new datasets and tools. To accomplish this goal, SPoRT and SERVIR is providing enhanced, experimental land surface initialization datasets and model verification capabilities to KMS as part of this collaboration. To produce a land-surface initialization more consistent with the resolution of the KMS-WRF runs, the NASA Land Information System (LIS) is run at a comparable resolution to provide real-time, daily soil initialization data in place of data interpolated from the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) model soil moisture and temperature fields. Additionally, realtime green vegetation fraction (GVF) data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (Suomi- NPP) satellite will be incorporated into the KMS-WRF runs, once it becomes publicly available from the National Environmental Satellite Data and Information Service (NESDIS). Finally, model verification capabilities will be transitioned to KMS using the Model Evaluation Tools (MET; Brown et al. 2009) package in conjunction with a dynamic scripting package developed by SPoRT (Zavodsky et al. 2014), to help quantify possible improvements in simulated temperature, moisture and precipitation resulting from the experimental land surface initialization. Furthermore, the transition of these MET tools will enable KMS to monitor model forecast accuracy in near real time. This paper presents preliminary efforts to improve land surface model initialization over eastern Africa in support of operations at KMS. The remainder of this extended abstract is organized as follows: The collaborating organizations involved in the project are described in Section 2; background information on LIS and the configuration for eastern Africa is presented in Section 3; the WRF configuration used in this modeling experiment is described in Section 4; sample experimental WRF output with and without LIS initialization data are given in Section 5; a summary is given in Section 6 followed by acknowledgements and references.

Case, Johnathan L.↗
DOE OSTI2012

WINS. Market Simulation Tool for Facilitating Wind Energy Integration

Integrating 20% or more wind energy into the system and transmitting large sums of wind energy over long distances will require a decision making capability that can handle very large scale power systems with tens of thousands of buses and lines. There is a need to explore innovative analytical and implementation solutions for continuing reliable operations with the most economical integration of additional wind energy in power systems. A number of wind integration solution paths involve the adoption of new operating policies, dynamic scheduling of wind power across interties, pooling integration services, and adopting new transmission scheduling practices. Such practices can be examined by the decision tool developed by this project. This project developed a very efficient decision tool called Wind INtegration Simulator (WINS) and applied WINS to facilitate wind energy integration studies. WINS focused on augmenting the existing power utility capabilities to support collaborative planning, analysis, and wind integration project implementations. WINS also had the capability of simulating energy storage facilities so that feasibility studies of integrated wind energy system applications can be performed for systems with high wind energy penetrations. The development of WINS represents a major expansion of a very efficient decision tool called POwer Market Simulator (POMS), which was developed by IIT and has been used extensively for power system studies for decades. Specifically, WINS provides the following superiorities; (1) An integrated framework is included in WINS for the comprehensive modeling of DC transmission configurations, including mono-pole, bi-pole, tri-pole, back-to-back, and multi-terminal connection, as well as AC/DC converter models including current source converters (CSC) and voltage source converters (VSC); (2) An existing shortcoming of traditional decision tools for wind integration is the limited availability of user interface, i.e., decision results are often text-based demonstrations. WINS includes a powerful visualization tool and user interface capability for transmission analyses, planning, and assessment, which will be of great interest to power market participants, power system planners and operators, and state and federal regulatory entities; and (3) WINS can handle extended transmission models for wind integration studies. WINS models include limitations on transmission flow as well as bus voltage for analyzing power system states. The existing decision tools often consider transmission flow constraints (dc power flow) alone which could result in the over-utilization of existing resources when analyzing wind integration. WINS can be used to assist power market participants including transmission companies, independent system operators, power system operators in vertically integrated utilities, wind energy developers, and regulatory agencies to analyze economics, security, and reliability of various options for wind integration including transmission upgrades and the planning of new transmission facilities. WINS can also be used by industry for the offline training of reliability and operation personnel when analyzing wind integration uncertainties, identifying critical spots in power system operation, analyzing power system vulnerabilities, and providing credible decisions for examining operation and planning options for wind integration. Researches in this project on wind integration included (1) Development of WINS; (2) Transmission Congestion Analysis in the Eastern Interconnection; (3) Analysis of 2030 Large-Scale Wind Energy Integration in the Eastern Interconnection; (4) Large-scale Analysis of 2018 Wind Energy Integration in the Eastern U.S. Interconnection. The research resulted in 33 papers, 9 presentations, 9 PhD degrees, 4 MS degrees, and 7 awards. The education activities in this project on wind energy included (1) Wind Energy Training Facility Development; (2) Wind Energy Course Development.

17 WIND ENERGY↗
DOE OSTI2014

Additional EIPC Study Analysis: Final Report

Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations were developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 14 topics was developed for further analysis. This paper brings together the earlier interim reports of the first 13 topics plus one additional topic into a single final report.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2012

Integrating Wind and Solar Energy in the U.S. Bulk Power System: Lessons from Regional Integration Studies

Two recent studies sponsored by the U.S. Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL) have examined the impacts of integrating high penetrations of wind and solar energy on the Eastern and Western electric grids. The Eastern Wind Integration and Transmission Study (EWITS), initiated in 2007, examined the impact on power system operations of reaching 20% to 30% wind energy penetration in the Eastern Interconnection. The Western Wind and Solar Integration Study (WWSIS) examined the operational implications of adding up to 35% wind and solar energy penetration to the Western Interconnect. Both studies examined the costs of integrating variable renewable energy generation into the grid and transmission and operational changes that might be necessary to address higher penetrations of wind or solar generation. This paper identifies key insights from these regional studies for integrating high penetrations of renewables in the U.S. electric grid. The studies share a number of key findings, although in some instances the results vary due to differences in grid operations and markets, the geographic location of the renewables, and the need for transmission.

14 SOLAR ENERGY↗
DOE OSTI2014

Geochemistry Sampling for Traditional and Multicomponent Equilibrium Geothermometry in Southeast Idaho

The Eastern Snake River Plain (ESRP) is an area of high regional heat flux due the movement of the North American Plate over the Yellowstone Hotspot beginning ca.16 Ma. Temperature gradients between 45-60 °C/km (up to double the global average) have been calculated from deep wells that penetrate the upper aquifer system (Blackwell 1989). Despite the high geothermal potential, thermal signatures from hot springs and wells are effectively masked by the rapid flow of cold groundwater through the highly permeable basalts of the Eastern Snake River Plain aquifer (ESRPA) (up to 500+ m thick). This preliminary study is part of an effort to more accurately predict temperatures of the ESRP deep thermal reservoir while accounting for the effects of the prolific cold water aquifer system above. This study combines the use of traditional geothermometry, mixing models, and a multicomponent equilibrium geothermometry (MEG) tool to investigate the geothermal potential of the ESRP. In March, 2014, a collaborative team including members of the University of Idaho, the Idaho National Laboratory, and the Lawrence Berkeley National Laboratory collected 14 thermal water samples from and adjacent to the Eastern Snake River Plain. The preliminary results of chemical analyses and geothermometry applied to these samples are presented herein.

15 GEOTHERMAL ENERGY↗
DOE OSTI2024

A decade of curtailment studies demonstrates a consistent and effective strategy to reduce bat fatalities at wind turbines in North America

Abstract There is a rapid, global push for wind energy installation. However, large numbers of bats are killed by turbines each year, raising concerns about the impacts of wind energy expansion on bat populations. Preventing turbine blades from spinning at low wind speeds, referred to as curtailment, is a method to reduce bat fatalities, but drawing consistent inference across studies has been challenging. We compiled publicly available studies that evaluated curtailment at six wind energy facilities in North America across 10 years. We used meta‐regression of 29 implemented treatments to determine fatality reduction efficacy as well as sources of variation influencing efficacy. We also estimated species‐specific fatality reduction for three species that comprise most fatalities in North America: hoary bat ( Lasiurus cinereus ), eastern red bat ( Lasiurus borealis ) and silver‐haired bat ( Lasionycteris noctivagans ). We found that curtailment reduced total bat fatalities by 33% with every 1.0 ms −1 increase in curtailment wind speed. Estimates of the efficacy for the three target species were similar (hoary bats: 28% per ms −1 , 95% CI: 0.4%–48%, eastern red bats: 32% per ms −1 , 95% CI: 13%–47% and silver‐haired bats: 32% per ms −1 , 95% CI: 3%–53%). Across multiple facilities and years, a 5.0 ms −1 cut‐in speed was estimated to reduce total bat fatalities by an average of 62% (95% CI: 54%–69%). Mortality reductions at individual facilities in any given year were estimated to fall between 33%–79% (95% prediction interval). Inter‐annual differences rather than inter‐site or turbine characteristics accounted for most of the variation in efficacy rates. Species‐specific average mortality reduction at 5.0 ms −1 curtailment wind speed was 48% (95% CI: 24%–64%) for hoary bats, 61% (95% CI: 42%–74%) for eastern red bats and 52% (95% CI: 30%–66%) for silver‐haired bats. Practical implication . curtailment reduced bat mortality at wind turbines in this North American study. Efficacy increased proportionally as curtailment speed is raised, and patterns and rates of efficacy were similar across species. This indicates that curtailment is an effective strategy to reduce bat fatalities at wind energy facilities, but exploration of further refinements could both minimize bat mortality and maximize energy production.

17 WIND ENERGY↗
DOE OSTI2019

Geographic patterns in morphometric and genetic variation for coyote populations with emphasis on southeastern coyotes

Prior to 1900, coyotes (Canis latrans) were restricted to the western and central regions of North America, but by the early 2000s, coyotes became ubiquitous throughout the eastern United States. Information regarding morphological and genetic structure of coyote populations in the southeastern United States is limited, and where data exist, they are rarely compared to those from other regions of North America. We assessed geographic patterns in morphology and genetics of coyotes with special consideration of coyotes in the southeastern United States. Mean body mass of coyote populations increased along a west-to-east gradient, with southeastern coyotes being intermediate to western and northeastern coyotes. Similarly, principal component analysis of body mass and linear body measurements suggested that southeastern coyotes were intermediate to western and northeastern coyotes in body size but exhibited shorter tails and ears from other populations. Genetic analyses indicated that southeastern coyotes represented a distinct genetic cluster that differentiated strongly from western and northeastern coyotes. We postulate that southeastern coyotes experienced lower immigration from western populations than did northeastern coyotes, and over time, genetically diverged from both western and northeastern populations. Coyotes colonizing eastern North America experienced different selective pressures than did stable populations in the core range, and we offer that the larger body size of eastern coyotes reflects an adaptation that improved dispersal capabilities of individuals in the expanding range.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2018

Oil Biodegradation in Deep Marine Basins

Nine important hydrocarbon (oil) basins where offshore petroleum leases have been licensed are compared. These nine basins (Gulf of Mexico, Eastern Mediterranean’s Nile Deep-Sea Fan, Central Mediterranean and the Sirte Basin, North Sea, Caspian Sea, Angola, Trinidad and Tobago, Great Australian Bight, and Brazil’s Amazonian Deep-Sea Basin) are geographically separated and are impacted by very different water masses. The geochemical parameters of these basins are quite distinct, for example, salinities ranging from 39 psu in the Eastern Mediterranean to 12 psu in the Caspian. Additionally, parameters like temperatures of the bottom water are also very distinct, with the temperature in the deep water of the Eastern Mediterranean being between 12 °C and 14 °C and the temperature of the deep water in the North Sea being -2 °C. Each basin represents a unique ecosystem in which distinct microbes may thrive. These distinct environmental parameters may act to constrain the extent of hydrocarbon degradation in these basins. Another potential constraint on hydrocarbon degradation is the extent of natural hydrocarbon seeps in the area. Though many basins have similar if not 16S rRNA identical strains of oil-degrading bacteria, Colwellia psychrerythraea from different basins showed that a mixture of natural selection and neutral evolution has contributed to the divergence of these. Most if not all deep ocean basin microbial communities are dominated by Thaumarchaeota below 200 m. These microaerophilic, ammonium oxidizer, psychrophiles are very adapted to an oligotrophic lifestyle, and though many in this group will degrade oil, they are rapidly outcompeted by other bacteria in oil or high hydrocarbon intrusions, thus the virtual “canary in the coal mine.” Cometabolic biodegradation of oil is well documented but could be an important natural attenuation mechanism for oil in deep marine basins with episodic methane seeps. Microbial community structure can also predict concentrations of oil in deep basins. Many other synergistic effects require more research in environmental systems biology in deep marine basins.

Hazen, Terry C.↗
DOE OSTI2014

Diagnosis of the Marine Low Cloud Simulation in the NCAR Community Earth System Model (CESM) and the NCEP Global Forecast System (GFS)-Modular Ocean Model v4 (MOM4) coupled model

We present a diagnostic analysis of the marine low cloud climatology simulated by two state-of-the-art coupled atmosphere-ocean models: the NCAR Community Earth System Model (CESM) and the NCEP Global Forecasting System (GFS). In both models, the shallow convection and boundary layer turbulence parameterizations have been recently updated: both models now use a mass-flux scheme for the parameterization of shallow convection, and a turbulence parameterization capable of handling Stratocumulus (Sc)-topped Planetary Boundary Layers (PBLs). For shallow convection, both models employ a convective trigger function based on the concept of convective inhibition and both include explicit convective overshooting/penetrative entrainment formulation. For Sc-topped PBL, both models treat explicitly turbulence mixing and cloud-top entrainment driven by cloud-top radiative cooling. Our focus is on the climatological transition from Sc to shallow Cumulus (Cu)-topped PBL in the subtropical eastern oceans. We show that in the CESM the coastal Sc-topped PBLs in the subtropical Eastern Pacific are well-simulated but the climatological transition from Sc to shallow Cu is too abrupt and happens too close to the coast. By contrast, in the GFS coupled simulation the coastal Sc amount and PBL depth are severely underestimated while the transition from Sc to shallow Cu is ³delayed² and offshore Sc cover is too extensive in the subtropical Eastern Pacific. We discuss the possible connections between such differences in the simulations and differences in the parameterizations of shallow convection and boundary layer turbulence in the two models.

Xiao, Heng↗
DOE OSTI2014

Interannual and intra-annual variability of rainfall in Haiti (1905–2005)

The interannual variability of annual and monthly rainfall in Haiti is examined from a database of 78 rain gauges in 1905–2005. The spatial coherence of annual rainfall is rather low, which is partly due to Haiti’s rugged landscape, complex shoreline, and surrounding warm waters (mean sea surface temperatures >27 °C from May to December). The interannual variation of monthly rainfall is mostly shaped by the intensity of the low-level winds across the Caribbean Sea, leading to a drier- (or wetter-) than-average rainy season associated with easterly (or westerly) anomalies, increasing (or decreasing) winds. The varying speed of low-level easterlies across the Caribbean basin may reflect at least four different processes during the year: (1) an anomalous trough/ridge over the western edge of the Azores high from December to February, peaking in January; (2) a zonal pressure gradient between Eastern Pacific and the tropical Northern Atlantic from May/June to September, with a peak in August (i.e. lower-than-average rainfall in Haiti is associated with positive sea level pressure anomalies over the tropical North Atlantic and negative sea level pressure anomalies over the Eastern Pacific); (3) a local ocean–atmosphere coupling between the speed of the Caribbean Low Level Jet and the meridional sea surface temperature (SST) gradient across the Caribbean basin (i.e. colder-than-average SST in the southern Caribbean sea is associated with increased easterlies and below-average rainfall in Haiti). This coupling is triggered when the warmest Caribbean waters move northward toward the Gulf of Mexico; (4) in October/November, a drier- (or wetter-) than-usual rainy season is related to an almost closed anticyclonic (or cyclonic) anomaly located ENE of Haiti on the SW edge of the Azores high. This suggests a main control of the interannual variations of rainfall by intensity, track and/or recurrence of tropical depressions traveling northeast of Haiti. In conclusion, during this period, the teleconnection of Haitian rainfall with synchronous Atlantic and Eastern Pacific SST is at a minimum.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Changes in global vegetation activity and its driving factors during 1982–2013

Vegetation activity plays a crucial role in the global carbon cycle and climate. Many studies have examined recent changes in vegetation growth and the associated local climatic drivers. They revealed a global greening trend during the recent decades. However, few studies have analyzed how remote oceanic conditions affect land vegetation growth through atmospheric teleconnection, and the causes of the recent greening needs further investigation. Here in this study, we investigate the spatio-temporal variations (including trends) of vegetation activity using satellite data of growing-season normalized difference vegetation index (NDVI gs ), and examine their relationship to local and remote climate oscillations and external anthropogenic forcing by statistical means. As expected, there is an increasing trend in global-mean NDVI gs from 1982–2013, with significant greening over Europe and many other land areas. NDVI gs is temperature-limited at northern high-latitudes, but water-limited in arid and semi-arid regions, and radiation-limited in the Amazon and eastern and southern Asia. Globally, El Niño-Southern Oscillation (ENSO) is the leading climatic driver of interannual variability of NDVI gs , especially over southern and eastern Africa, eastern Australia, northeastern Asia, and northern South America. Consistent with previous modeling studies, a regression-based attribution analysis suggests that historical anthropogenic forcing (mainly increases in greenhouse gases) explains about two thirds of the NDVI gs trend from 1982 to 2013, with the rest coming mainly from the Atlantic Multi-decadal Oscillation (AMO). Contributions to the recent NDVI gs trend from ENSO and Pacific decadal variability and Artctic Oscillation appear to be small.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Health and vitality assessment of two common pine species in the context of climate change in southern Europe

The Mediterranean Basin is expected to be more strongly affected by ongoing climate change than most other regions of the earth. The South-eastern France can be considered as case study for assessing global change impacts on forests. Based on non-parametric statistical tests, the climatic parameters (temperature, relative humidity, rainfall, global radiation) and forest-response indicators (crown defoliation, discoloration and visible foliar ozone injury) of two pine species (Pinus halepensis and Pinus cembra) were analyzed. In the last 20 years, the trend analyses reveal a clear hotter and drier climate along the coastline and slightly rainier inland. In the current climate change context, a reduction in ground-level ozone (O{sub 3}) was found at remote sites and the visible foliar O{sub 3} injury decreased while deterioration of the crown conditions was observed likely due to a drier and warmer climate. Clearly, if such climatic and ecological changes are now being detected when the climate, in South-eastern France, has warmed in the last 20 years (+0.46–1.08 °C), it can be expected that many more impacts on tree species will occur in response to predicted temperature changes by 2100 (+1.95–4.59 °C). Climate change is projected to reduce the benefits of O{sub 3} precursor emissions controls leading to a higher O{sub 3} uptake. However, the drier and warmer climate should induce a soil drought leading to a lower O{sub 3} uptake. These two effects, acting together in an opposite way, could mitigate the harmful impacts of O{sub 3} on forests. The development of coordinated emission abatement strategies is useful to reduce both climate change and O{sub 3} pollution. Climate change will create additional challenges for forest management with substantial socio-economic and biological diversity impacts. However, the development of future sustainable and adaptive forest management strategies has the potential to reduce the vulnerability of forest species to climate change. - Highlights: • We assess climate change impacts on forests: South-eastern France as case study in the last 20 years. • We detect and estimate trends for O{sub 3} concentrations, climatic parameters and visible injury. • We establish a state-of-the-art of the health of 2 common pine species in a context of climate change. • We use two valuable bio-indicator species for O{sub 3} stress: Pinus halepensis and Pinus cembra. • Deterioration of crown conditions: climate change creates additional challenges for forest.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

A conceptual geochemical model of the geothermal system at Surprise Valley, CA

Characterizing the geothermal system at Surprise Valley (SV), northeastern California, is important for determining the sustainability of the energy resource, and mitigating hazards associated with hydrothermal eruptions that last occurred in 1951. Previous geochemical studies of the area attempted to reconcile different hot spring compositions on the western and eastern sides of the valley using scenarios of dilution, equilibration at low temperatures, surface evaporation, and differences in rock type along flow paths. These models were primarily supported using classical geothermometry methods, and generally assumed that fluids in the Lake City mud volcano area on the western side of the valley best reflect the composition of a deep geothermal fluid. In this contribution, we address controls on hot spring compositions using a different suite of geochemical tools, including optimized multicomponent geochemistry (GeoT) models, hot spring fluid major and trace element measurements, mineralogical observations, and stable isotope measurements of hot spring fluids and precipitated carbonates. We synthesize the results into a conceptual geochemical model of the Surprise Valley geothermal system, and show that high-temperature (quartz, Na/K, Na/K/Ca) classical geothermometers fail to predict maximum subsurface temperatures because fluids re-equilibrated at progressively lower temperatures during outflow, including in the Lake City area. We propose a model where hot spring fluids originate as a mixture between a deep thermal brine and modern meteoric fluids, with a seasonally variable mixing ratio. The deep brine has deuterium values at least 3 to 4‰ lighter than any known groundwater or high-elevation snow previously measured in and adjacent to SV, suggesting it was recharged during the Pleistocene when meteoric fluids had lower deuterium values. The deuterium values and compositional characteristics of the deep brine have only been identified in thermal springs and groundwater samples collected in proximity to structures that transmit thermal fluids, suggesting the brine may be thermal in nature. On the western side of the valley at the Lake City mud volcano, the deep brine-meteoric water mixture subsequently boils in the shallow subsurface, precipitates calcite, and re-equilibrates at about 130 °C. On the eastern side of the valley, meteoric fluid mixes to a greater extent with the deep brine, cools conductively without boiling, and the composition is modified as dissolved elements are sequestered by secondary minerals that form along the cooling and outflow path at temperatures <130 °C. Re-equilibration of geothermal fluids at lower temperatures during outflow explains why subsurface temperature estimates based on classical geothermometry methods are highly variable, and fail to agree with temperature estimates based on dissolved sulfate-oxygen isotopes and results of classical and multicomponent geothermometry applied to reconstructed deep well fluids. Furthermore, the proposed model is compatible with the idea suggested by others that thermal fluids on the western and eastern side of the valley have a common source, and supports the hypothesis that low temperature re-equilibration during west to east flow is the major control on hot spring fluid compositions, rather than dilution, evaporation, or differences in rock type.

15 GEOTHERMAL ENERGY↗
DOE OSTI2025

Removal of Antibiotics from Swine Wastewater Using an Environmentally Friendly Biochar: Performance and Mechanisms

Antibiotics used in the swine industry to treat diseases and improve animal growth are poorly absorbed by swine and have been classified as micropollutants due to their occurrence in surface water, wastewater, and soil. This study investigated the capacity of biochar produced from eastern red cedar to remove target antibiotics that have been extensively used in the swine industry. Biochar was produced by pyrolysis from eastern red cedar at 450 °C. The sorption tests were performed by mixing biochar and a solution (1:10 ratio) containing each antibiotic in 100, 300, 600, and 900 μg L –1 concentrations. The results indicate that red cedar biochar was able to effectively remove up to 99.93% tetracycline, 96.23% oxytetracycline, 98.28% chlortetracycline, 76.4% sulfadiazine, and 78.6% sulfamethazine at the lowest concentrations. The removal efficiencies at higher concentrations declined up to 83.52, 47.23, 64.16, 69.8, and 58.4% for tetracycline, oxytetracycline, chlortetracycline, sulfadiazine, and sulfamethazine, respectively. The biochar exhibited stronger adsorption capacity for chlortetracycline and sulfamethazine compared to the other antibiotics. The likely adsorption mechanisms driving the removal of tetracyclines and sulfonamides are hydrogen-bonding and π–π electron-donor–acceptor, supported by FTIR analyses of the biochar itself. Overall, the results highlighted the potential utilization of eastern red cedar biochar for practical applications, mitigating antibiotic residues from swine wastewater in a cost-effective and environmentally friendly manner due to its relatively low pyrolysis temperature (450 °C) and sustainable repurposing of an invasive tree species.

09 BIOMASS FUELS↗
DOE OSTI2018

Ultrafine Mineral Associations in Superhigh-Organic-Sulfur Kentucky Coals

Two high-organic-sulfur Kentucky coals, the eastern Kentucky River Gem coal and the western Kentucky Davis coal, are examined by scanning electron microscopy, (SEM) and transmission electron microscopy (TEM), both including elemental analysis by energy-dispersive spectroscopy (EDS). From the SEM-EDS analysis, it is observed that the western Kentucky coal had areas with Pb and Cd in addition to the expected Fe and S and the eastern Kentucky coal had individual Fe-S-rich areas with La and Ni and with Si, Al, Cr, Ni, and Ti. TEM and selected area electron diffraction (SAED) analyses demonstrate that anglesite with a rim of Pb-bearing amorphous Fe-oxide occurs in the western Kentucky coal. Melanterite, an Fe-sulfate, with minor Al, Si, and K EDS peaks, suggests that clay minerals may be in close association with the sulfate, is also detected in the coal. A polycrystalline metal in the eastern Kentucky sample with a composition similar to stainless steel is adjacent to an Al-rich shard. Euhedral pyrite grains surrounded by kaolinite and gibbsite are detected. Overall, it is noted that element associations should not be assumed to be organic just because minerals cannot be seen with optical microscopy or with standard bulk analytical techniques, such as X-ray diffraction (XRD).

organic sulfur, kentucky coals, geoscience, SEM↗