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Warming ancient Mars with water clouds

NASA Astrophysics Data System (ADS)

Hartwick, V.; Toon, B.

2017-12-01

High clouds in the present day Mars atmosphere nucleate on interplanetary dust particles (IDPs) that burn up on entry into the Mars atmosphere. Clouds form when superstaturated water vapor condenses on suspended aerosols. Radiatively active water ice clouds may play a crucial role in warming the early Mars climate. Urata and Toon (2011) simulate a stable warm paleo-climate for Mars if clouds form high in the atmosphere and if particles are sufficiently large (r > 10 μm). The annual fluence of micrometeoroids at Mars was larger early on in the evolution of our solar system. Additionally, the water vapor budget throughout the middle and high atmosphere was likely heightened . Both factors should contribute to enhanced nucleation and growth of water ice cloud particles at high altitudes. Here, we use the MarsCAM-CARMA general circulation model (GCM) to examine the radiative impact of high altitude water ice clouds on the early Mars climate and as a possible solution to the faint young sun problem for Mars.

Microcumpter computation of water quality discharges

USGS Publications Warehouse

Helsel, Dennis R.

1983-01-01

A fully prompted program (SEDQ) has been developed to calculate daily and instantaneous water quality (QW) discharges. It is written in a version of BASIC, and requires inputs of gage heights, discharge rating curve, shifts, and water quality concentration information. Concentration plots may be modified interactively using the display screen. Semi-logarithmic plots of concentration and water quality discharge are output to the display screen, and optionally to plotters. A summary table of data is also output. SEDQ could be a model program for micro and minicomputer systems likely to be in use within the Water Resources Division, USGS, in the near future. The daily discharge-weighted mean concentration is one output from SEDQ. It is defined in this report, differentiated from the currently used mean concentration, and designated the ' equivalent concentration. ' (USGS)

Usefulness of warm water and oil assistance in colonoscopy by trainees.

PubMed

Park, Sung Chul; Keum, Bora; Kim, Eun Sun; Jung, Eun Suk; Lee, Sehe Dong; Park, Sanghoon; Seo, Yeon Seok; Kim, Yong Sik; Jeen, Yoon Tae; Chun, Hoon Jai; Um, Soon Ho; Kim, Chang Duck; Ryu, Ho Sang

2010-10-01

Success rate of cecal intubation, endoscopist's difficulty, and procedure-related patient pain are still problems for beginners performing colonoscopy. New methods to aid colonoscopic insertion such as warm water instillation and oil lubrication have been proposed. The aim of this study is to evaluate the feasibility of using warm water or oil in colonoscopy. Colonoscopy was performed in 117 unsedated patients by three endoscopists-in-training. Patients were randomly allocated to three groups, using a conventional method with administration of antispasmodics, warm water instillation, and oil lubrication, respectively. Success rate of total intubation within time limit (15 min), cecal intubation time, degree of endoscopist's difficulty, and level of patient discomfort were compared among the three groups. Cecal intubation time was shorter in the warm water group than in the conventional and oil groups. Degree of procedural difficulty was lower in the warm water group, and patient pain score was higher in the oil lubrication group, compared with the other groups. However, there was no significant difference in success rate of intubation within time limit among the three groups. The warm water method is a simple, safe, and feasible method for beginners. Oil lubrication may not be a useful method compared with conventional and warm water method.

Enhanced submarine ground water discharge form mixing of pore water and estuarine water

USGS Publications Warehouse

Martin, Jonathan B.; Cable, Jaye E.; Swarzenski, Peter W.; Lindenberg, Mary K.

2004-01-01

Submarine ground water discharge is suggested to be an important pathway for contaminants from continents to coastal zones, but its significance depends on the volume of water and concentrations of contaminants that originate in continental aquifers. Ground water discharge to the Banana River Lagoon, Florida, was estimated by analyzing the temporal and spatial variations of Cl− concentration profiles in the upper 230 cm of pore waters and was measured directly by seepage meters. Total submarine ground water discharge consists of slow discharge at depths > ∼70 cm below seafloor (cmbsf) of largely marine water combined with rapid discharge of mixed pore water and estuarine water above ∼70 cmbsf. Cl− profiles indicate average linear velocities of ∼0.014 cm/d at depths > ∼70 cmbsf. In contrast, seepage meters indicate water discharges across the sediment-water interface at rates between 3.6 and 6.9 cm/d. The discrepancy appears to be caused by mixing in the shallow sediment, which may result from a combination of bioirrigation, wave and tidal pumping, and convection. Wave and tidal pumping and convection would be minor because the tidal range is small, the short fetch of the lagoon limits wave heights, and large density contacts are lacking between lagoon and pore water. Mixing occurs to ∼70 cmbsf, which represents depths greater than previously reported. Mixing of oxygenated water to these depths could be important for remineralization of organic matter.

Multidecadal warming of Antarctic waters.

PubMed

Schmidtko, Sunke; Heywood, Karen J; Thompson, Andrew F; Aoki, Shigeru

2014-12-05

Decadal trends in the properties of seawater adjacent to Antarctica are poorly known, and the mechanisms responsible for such changes are uncertain. Antarctic ice sheet mass loss is largely driven by ice shelf basal melt, which is influenced by ocean-ice interactions and has been correlated with Antarctic Continental Shelf Bottom Water (ASBW) temperature. We document the spatial distribution of long-term large-scale trends in temperature, salinity, and core depth over the Antarctic continental shelf and slope. Warming at the seabed in the Bellingshausen and Amundsen seas is linked to increased heat content and to a shoaling of the mid-depth temperature maximum over the continental slope, allowing warmer, saltier water greater access to the shelf in recent years. Regions of ASBW warming are those exhibiting increased ice shelf melt. Copyright © 2014, American Association for the Advancement of Science.

Is Europa's Subsurface Water Ocean Warm?

NASA Technical Reports Server (NTRS)

Melosh, H. J.; Ekholm, A. G.; Showman, A. P.; Lorenz, R. D.

2002-01-01

Europa's subsurface water ocean may be warm: that is, at the temperature of water's maximum density. This provides a natural explanation of chaos melt-through events and leads to a correct estimate of the age of its surface. Additional information is contained in the original extended abstract.

Lessons: Science: "Sinkholes." Students Observe What Happens When Ice-Cold Water Mingles with Warm Water.

ERIC Educational Resources Information Center

VanCleave, Janice

2000-01-01

This intermediate-level science activity has students observe the effect of ice-cold water mingling with warm water. Water's behavior and movement alters with shifts in temperature. Students must try to determine how temperature affects the movement of water. Necessary materials include a pencil, cup, glass jar, masking tape, warm water, ice…

Potential impacts of global warming on water resources in southern California.

PubMed

Beuhler, M

2003-01-01

Global warming will have a significant impact on water resources within the 20 to 90-year planning period of many water projects. Arid and semi-arid regions such as Southern California are especially vulnerable to anticipated negative impacts of global warming on water resources. Long-range water facility planning must consider global climate change in the recommended mix of new facilities needed to meet future water requirements. The generally accepted impacts of global warming include temperature, rising sea levels, more frequent and severe floods and droughts, and a shift from snowfall to rain. Precipitation changes are more difficult to predict. For Southern California, these impacts will be especially severe on surface water supplies. Additionally, rising sea levels will exacerbate salt-water intrusion into freshwater and impact the quality of surface water supplies. Integrated water resources planning is emerging as a tool to develop water supplies and demand management strategies that are less vulnerable to the impacts of global warming. These tools include water conservation, conjunctive use of surface and groundwater and desalination of brackish water and possibly seawater. Additionally, planning for future water needs should include explicit consideration of the potential range of global warming impacts through techniques such as scenario planning.

Warm Rivers Play Role in Arctic Sea Ice Melt

NASA Image and Video Library

2014-03-05

Beaufort Sea surface temperatures where Canada Mackenzie River discharges into the Arctic Ocean, measured by NASA MODIS instrument; warm river waters had broken through a shoreline sea ice barrier to enhance sea ice melt.

Greenhouse warming and the tropical water budget

NASA Technical Reports Server (NTRS)

Betts, Alan K.

1990-01-01

The present work takes issue with some of the theses of Lindzen's (1990) work on global warming, arguing in particular that Lindzen's work is hampered by the use of oversimplified models. Lindzen then presents a detailed reply to these arguments, emphasizing the fundamental importance of the upper tropospheric water-vapor budget to the question of global warming.

Comparison of Distal Limb Warming With Fluidotherapy and Warm Water Immersion for Mild Hypothermia Rewarming.

PubMed

Kumar, Parveen; McDonald, Gerren K; Chitkara, Radhika; Steinman, Alan M; Gardiner, Phillip F; Giesbrecht, Gordon G

2015-09-01

The purpose of the study was to determine the effectiveness of Fluidotherapy rewarming through the distal extremities for mildly hypothermic, vigorously shivering subjects. Fluidotherapy is a dry heat modality in which cellulose particles are suspended by warm air circulation. Seven subjects (2 female) were cooled on 3 occasions in 8˚C water for 60 minutes, or to a core temperature of 35°C. They were then dried and rewarmed in a seated position by 1) shivering only; 2) Fluidotherapy applied to the distal extremities (46 ± 1°C, mean ± SD); or 3) water immersion of the distal extremities (44 ± 1°C). The order of rewarming followed a balanced design. Esophageal temperature, skin temperature, heart rate, oxygen consumption, and heat flux were measured. The warm water produced the highest rewarming rate, 6.1°C·h(-1), 95% CI: 5.3-6.9, compared with Fluidotherapy, 2.2°C·h(-1), 95% CI: 1.4-3.0, and shivering only, 2.0°C·h(-1), 95% CI: 1.2-2.8. The Fluidotherapy and warm water conditions increased skin temperature and inhibited shivering heat production, thus reducing metabolic heat production (166 ± 42 W and 181 ± 45 W, respectively), compared with shivering only (322 ± 142 W). Warm water provided a significantly higher net heat gain (398.0 ± 52 W) than shivering only (288.4 ± 115 W). Fluidotherapy was not as effective as warm water for rewarming mildly hypothermic subjects. Although Fluidotherapy is more portable and technically simpler, it provides a lower rate of rewarming that is similar to shivering only. It does help decrease shivering heat production, lowering energy expenditure and cardiac work, and could be considered in a hospital setting, if convenient. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Using "warm handoffs" to link hospitalized smokers with tobacco treatment after discharge: study protocol of a randomized controlled trial.

PubMed

Richter, Kimber P; Faseru, Babalola; Mussulman, Laura M; Ellerbeck, Edward F; Shireman, Theresa I; Hunt, Jamie J; Carlini, Beatriz H; Preacher, Kristopher J; Ayars, Candace L; Cook, David J

2012-08-01

Post-discharge support is a key component of effective treatment for hospitalized smokers, but few hospitals provide it. Many hospitals and care settings fax-refer smokers to quitlines for follow-up; however, less than half of fax-referred smokers are successfully contacted and enrolled in quitline services. "Warm handoff" is a novel approach to care transitions in which health care providers directly link patients with substance abuse problems with specialists, using face-to-face or phone transfer. Warm handoff achieves very high rates of treatment enrollment for these vulnerable groups. The aim of this study-"EQUIP" (Enhancing Quitline Utilization among In-Patients)-is to determine the effectiveness, and cost-effectiveness, of warm handoff versus fax referral for linking hospitalized smokers with tobacco quitlines. This study employs a two-arm, individually randomized design. It is set in two large Kansas hospitals that have dedicated tobacco treatment interventionists on staff. At each site, smokers who wish to remain abstinent after discharge will be randomly assigned to groups. For patients in the fax group, staff will provide standard in-hospital intervention and will fax-refer patients to the state tobacco quitline for counseling post-discharge. For patients in the warm handoff group, staff will provide brief in-hospital intervention and immediate warm handoff: staff will call the state quitline, notify them that a warm handoff inpatient from Kansas is on the line, then transfer the call to the patients' mobile or bedside hospital phone for quitline enrollment and an initial counseling session. Following the quitline session, hospital staff provides a brief check-back visit. Outcome measures will be assessed at 1, 6, and 12 months post enrollment. Costs are measured to support cost-effectiveness analyses. We hypothesize that warm handoff, compared to fax referral, will improve care transitions for tobacco treatment, enroll more participants in quitline

Improving conservation of Florida manatees (Trichechus manatus latirostris): conceptualization and contributions toward a regional warm-water network management strategy for sustainable winter habitat.

PubMed

Flamm, Richard Owen; Reynolds, John Elliot; Harmak, Craig

2013-01-01

We used southwestern Florida as a case study to lay the groundwork for an intended and organized decision-making process for managing warm-water habitat needed by endangered manatees to survive winters in Florida. Scientists and managers have prioritized (a) projecting how the network of warm-water sites will change over the next 50 years as warmed industrial discharges may expire and as flows of natural springs are reduced through redirection of water for human uses, and (b) mitigating such changes to prevent undue consequences to manatees. Given the complexities introduced by manatee ecology; agency organizational structure; shifting public demands; fluctuating resource availability; and managing within interacting cultural, social, political, and environmental contexts, it was clear that a structured decision process was needed. To help promote such a process, we collected information relevant to future decisions including maps of known and suspected warm-water sites and prototyped a characterization of sites and networks. We propose steps that would lead to models that might serve as core tools in manatee/warm-water decision-making, and we summarized topics relevant for informed decision-making (e.g., manatee spatial cognition, risk of cold-stress morbidity and mortality, and human dimensions). A major impetus behind this effort is to ensure proactively that robust modeling tools are available well in advance of the anticipated need for a critical management decision.

Improving Conservation of Florida Manatees ( Trichechus manatus latirostris): Conceptualization and Contributions Toward a Regional Warm-Water Network Management Strategy for Sustainable Winter Habitat

NASA Astrophysics Data System (ADS)

Flamm, Richard Owen; Reynolds, John Elliot; Harmak, Craig

2013-01-01

We used southwestern Florida as a case study to lay the groundwork for an intended and organized decision-making process for managing warm-water habitat needed by endangered manatees to survive winters in Florida. Scientists and managers have prioritized (a) projecting how the network of warm-water sites will change over the next 50 years as warmed industrial discharges may expire and as flows of natural springs are reduced through redirection of water for human uses, and (b) mitigating such changes to prevent undue consequences to manatees. Given the complexities introduced by manatee ecology; agency organizational structure; shifting public demands; fluctuating resource availability; and managing within interacting cultural, social, political, and environmental contexts, it was clear that a structured decision process was needed. To help promote such a process, we collected information relevant to future decisions including maps of known and suspected warm-water sites and prototyped a characterization of sites and networks. We propose steps that would lead to models that might serve as core tools in manatee/warm-water decision-making, and we summarized topics relevant for informed decision-making (e.g., manatee spatial cognition, risk of cold-stress morbidity and mortality, and human dimensions). A major impetus behind this effort is to ensure proactively that robust modeling tools are available well in advance of the anticipated need for a critical management decision.

Hydrological Responses of Chaobai River Basin under 1.5° and 2.0° Global Warming Using Multi-GCMs and Multi-RCPs

NASA Astrophysics Data System (ADS)

Hao, Y.; Ma, J.

2017-12-01

The global warming of 1.5° and 2.0° proposed in Paris Agreement has became the iconic threshold of climate change impact research and discussion. In order to provide useful reference to the effective water resource management and planning for the capital city of China, this study aims to assessing the potential impact of 1.5° and 2.0° global warming on river discharge in Chaobai River Basin(CRB) which is main water supply source of Beijing. A semi-distributed hydrological model SWAT was driven by climate projections from five General Circulation Models(GCMs) under three Representative Concentration Pathways (RCP4.5, RCP6.0 and RCP8.5) to simulate the future discharge in CRB under 1.5° and 2.0° global warming respectively. On this basis, climate change impact on annual and monthly discharge, seasonal discharge distribution, extreme monthly discharge in CRB were assessed and the uncertainty associated with GCMs and RCPs were analyzed quantitatively. The results indicate that the average annual discharge will increase slightly and more concentrate in midsummer and early autumn under 1.5° global warming. When the global average temperature rise 2°, the annual discharge in CRB show an evident positive tendency with the magnitude increasing by approximate 30% and the extreme monthly runoff will significantly increase. However, the proportion of discharge in summer which is the peak water usage period will decline. It is obvious that the increment of 0.5° will lead to more flood events and bring great challenge to water resource management. There is a certain uncertainty in the projection of temperature, precipitation and discharge, by contrast, uncertainty of discharge projection is far greater than that of other two meteorological elements. Compared with RCPs, GCMs are proved to be the main factor which are responsible for the impact uncertainty in CRB under two global warming horizons. The uncertainty will be larger as the warming magnitude increase. In a word

Ground water recharge and discharge in the central Everglades

USGS Publications Warehouse

Harvey, Judson W.; Krupa, Steven L.; Krest, James M.

2004-01-01

Rates of ground water recharge and discharge are not well known in the central Everglades. Here we report estimates of ground water recharge and discharge at 15 sites in the Everglades Nutrient Removal Project and in Water Conservation Area 2A (WCA-2A), along with measurements of hydraulic properties of peat at 11 sites. A simple hydrogeologic simulation was used to assess how specific factors have influenced recharge and discharge. Simulations and measurements agreed that the highest values of recharge and discharge occur within 600 m of levees, the result of ground water flow beneath levees. There was disagreement in the interior wetlands of WCA-2A (located > 1000 m from levees) where measurements of recharge and discharge were substantially higher than simulated fluxes. A five-year time series (1997 to 2002) of measured fluxes indicated that recharge and discharge underwent reversals in direction on weekly, monthly, and annual timescales at interior sites in WCA-2A. Ground water discharge tended to occur during average to moderately dry conditions when local surface water levels were decreasing. Recharge tended to occur during moderately wet periods or during very dry periods just as water levels began to increase following precipitation or in response to a pulse of surface water released from water-control structures by water managers. Discharge also tended to occur at sites in the wetland interior for ∼1 week preceding the arrival of the surface water pulse. We conclude that ground water recharge and discharge vary cyclically in the interior wetlands of the central Everglades, driven by the differential responses of surface water and ground water to annual, seasonal, and weekly trends in precipitation and operation of water-control structures.

A comparison of thermal infrared to fiber-optic distributed temperature sensing for evaluation of groundwater discharge to surface water

NASA Astrophysics Data System (ADS)

Hare, Danielle K.; Briggs, Martin A.; Rosenberry, Donald O.; Boutt, David F.; Lane, John W.

2015-11-01

Groundwater has a predictable thermal signature that can be used to locate discrete zones of discharge to surface water. As climate warms, surface water with strong groundwater influence will provide habitat stability and refuge for thermally stressed aquatic species, and is therefore critical to locate and protect. Alternatively, these discrete seepage locations may serve as potential point sources of contaminants from polluted aquifers. This study compares two increasingly common heat tracing methods to locate discrete groundwater discharge: direct-contact measurements made with fiber-optic distributed temperature sensing (FO-DTS) and remote sensing measurements collected with thermal infrared (TIR) cameras. FO-DTS is used to make high spatial resolution (typically m) thermal measurements through time within the water column using temperature-sensitive cables. The spatial-temporal data can be analyzed with statistical measures to reveal zones of groundwater influence, however, the personnel requirements, time to install, and time to georeference the cables can be burdensome, and the control units need constant calibration. In contrast, TIR data collection, either from handheld, airborne, or satellite platforms, can quickly capture point-in-time evaluations of groundwater seepage zones across large scales. However the remote nature of TIR measurements means they can be adversely influenced by a number of environmental and physical factors, and the measurements are limited to the surface ;skin; temperature of water features. We present case studies from a range of lentic to lotic aquatic systems to identify capabilities and limitations of both technologies and highlight situations in which one or the other might be a better instrument choice for locating groundwater discharge. FO-DTS performs well in all systems across seasons, but data collection was limited spatially by practical considerations of cable installation. TIR is found to consistently locate

Ecosystem responses to warming and watering in typical and desert steppes.

PubMed

Xu, Zhenzhu; Hou, Yanhui; Zhang, Lihua; Liu, Tao; Zhou, Guangsheng

2016-10-10

Global warming is projected to continue, leading to intense fluctuations in precipitation and heat waves and thereby affecting the productivity and the relevant biological processes of grassland ecosystems. Here, we determined the functional responses to warming and altered precipitation in both typical and desert steppes. The results showed that watering markedly increased the aboveground net primary productivity (ANPP) in a typical steppe during a drier year and in a desert steppe over two years, whereas warming manipulation had no significant effect. The soil microbial biomass carbon (MBC) and the soil respiration (SR) were increased by watering in both steppes, but the SR was significantly decreased by warming in the desert steppe only. The inorganic nitrogen components varied irregularly, with generally lower levels in the desert steppe. The belowground traits of soil total organic carbon (TOC) and the MBC were more closely associated with the ANPP in the desert than in the typical steppes. The results showed that the desert steppe with lower productivity may respond strongly to precipitation changes, particularly with warming, highlighting the positive effect of adding water with warming. Our study implies that the habitat- and year-specific responses to warming and watering should be considered when predicting an ecosystem's functional responses under climate change scenarios.

Ecosystem responses to warming and watering in typical and desert steppes

PubMed Central

Xu, Zhenzhu; Hou, Yanhui; Zhang, Lihua; Liu, Tao; Zhou, Guangsheng

2016-01-01

Global warming is projected to continue, leading to intense fluctuations in precipitation and heat waves and thereby affecting the productivity and the relevant biological processes of grassland ecosystems. Here, we determined the functional responses to warming and altered precipitation in both typical and desert steppes. The results showed that watering markedly increased the aboveground net primary productivity (ANPP) in a typical steppe during a drier year and in a desert steppe over two years, whereas warming manipulation had no significant effect. The soil microbial biomass carbon (MBC) and the soil respiration (SR) were increased by watering in both steppes, but the SR was significantly decreased by warming in the desert steppe only. The inorganic nitrogen components varied irregularly, with generally lower levels in the desert steppe. The belowground traits of soil total organic carbon (TOC) and the MBC were more closely associated with the ANPP in the desert than in the typical steppes. The results showed that the desert steppe with lower productivity may respond strongly to precipitation changes, particularly with warming, highlighting the positive effect of adding water with warming. Our study implies that the habitat- and year-specific responses to warming and watering should be considered when predicting an ecosystem’s functional responses under climate change scenarios. PMID:27721480

Ecosystem responses to warming and watering in typical and desert steppes

NASA Astrophysics Data System (ADS)

Xu, Zhenzhu; Hou, Yanhui; Zhang, Lihua; Liu, Tao; Zhou, Guangsheng

2016-10-01

Global warming is projected to continue, leading to intense fluctuations in precipitation and heat waves and thereby affecting the productivity and the relevant biological processes of grassland ecosystems. Here, we determined the functional responses to warming and altered precipitation in both typical and desert steppes. The results showed that watering markedly increased the aboveground net primary productivity (ANPP) in a typical steppe during a drier year and in a desert steppe over two years, whereas warming manipulation had no significant effect. The soil microbial biomass carbon (MBC) and the soil respiration (SR) were increased by watering in both steppes, but the SR was significantly decreased by warming in the desert steppe only. The inorganic nitrogen components varied irregularly, with generally lower levels in the desert steppe. The belowground traits of soil total organic carbon (TOC) and the MBC were more closely associated with the ANPP in the desert than in the typical steppes. The results showed that the desert steppe with lower productivity may respond strongly to precipitation changes, particularly with warming, highlighting the positive effect of adding water with warming. Our study implies that the habitat- and year-specific responses to warming and watering should be considered when predicting an ecosystem’s functional responses under climate change scenarios.

Warm water and cool nests are best. How global warming might influence hatchling green turtle swimming performance.

PubMed

Booth, David T; Evans, Andrew

2011-01-01

For sea turtles nesting on beaches surrounded by coral reefs, the most important element of hatchling recruitment is escaping predation by fish as they swim across the fringing reef, and as a consequence hatchlings that minimize their exposure to fish predation by minimizing the time spent crossing the fringing reef have a greater chance of surviving the reef crossing. One way to decrease the time required to cross the fringing reef is to maximize swimming speed. We found that both water temperature and nest temperature influence swimming performance of hatchling green turtles, but in opposite directions. Warm water increases swimming ability, with hatchling turtles swimming in warm water having a faster stroke rate, while an increase in nest temperature decreases swimming ability with hatchlings from warm nests producing less thrust per stroke.

Localized rapid warming of West Antarctic subsurface waters by remote winds

NASA Astrophysics Data System (ADS)

Spence, Paul; Holmes, Ryan M.; Hogg, Andrew Mcc.; Griffies, Stephen M.; Stewart, Kial D.; England, Matthew H.

2017-08-01

The highest rates of Antarctic glacial ice mass loss are occurring to the west of the Antarctica Peninsula in regions where warming of subsurface continental shelf waters is also largest. However, the physical mechanisms responsible for this warming remain unknown. Here we show how localized changes in coastal winds off East Antarctica can produce significant subsurface temperature anomalies (>2 °C) around much of the continent. We demonstrate how coastal-trapped barotropic Kelvin waves communicate the wind disturbance around the Antarctic coastline. The warming is focused on the western flank of the Antarctic Peninsula because the circulation induced by the coastal-trapped waves is intensified by the steep continental slope there, and because of the presence of pre-existing warm subsurface water offshore. The adjustment to the coastal-trapped waves shoals the subsurface isotherms and brings warm deep water upwards onto the continental shelf and closer to the coast. This result demonstrates the vulnerability of the West Antarctic region to a changing climate.

Concentrations of /sup 90/Sr and /sup 137/Cs in region of discharge of warm water from the Kola Atomic Power Station

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayanov, N.I.

1982-01-01

The/sup 90/Sr and /sup 137/Cs concentrations in trout cultivated in warm water from the Kola Atomic Power Station (APS) in the period 1974-1979 were 30-70 pCi/kg. This is one-quarter to one-third of the radionuclide concentrations in wild fish living in this region and one-tenth of that in commerical fishes from other waters on the Kola Peninsula. The low radionuclide concentrations can be attributed to the absence of pollution in the coolant reservoir of the Kola APS during this period of operation, and also to the fact that the main mode of entry of radionuclides into the fish's body is throughmore » food. The investigations lead to the very important conclusion that fish-farming based on the warm effluents of atomic power stations is a feasible proposition.« less

Numerical Modeling and Optimization of Warm-water Heat Sinks

NASA Astrophysics Data System (ADS)

Hadad, Yaser; Chiarot, Paul

2015-11-01

For cooling in large data-centers and supercomputers, water is increasingly replacing air as the working fluid in heat sinks. Utilizing water provides unique capabilities; for example: higher heat capacity, Prandtl number, and convection heat transfer coefficient. The use of warm, rather than chilled, water has the potential to provide increased energy efficiency. The geometric and operating parameters of the heat sink govern its performance. Numerical modeling is used to examine the influence of geometry and operating conditions on key metrics such as thermal and flow resistance. This model also facilitates studies on cooling of electronic chip hot spots and failure scenarios. We report on the optimal parameters for a warm-water heat sink to achieve maximum cooling performance.

Bidet toilet seats with warm-water tanks: residual chlorine, microbial community, and structural analyses.

PubMed

Iyo, Toru; Asakura, Keiko; Nakano, Makiko; Yamada, Mutsuko; Omae, Kazuyuki

2016-02-01

Despite the reported health-related advantages of the use of warm water in bidets, there are health-related disadvantages associated with the use of these toilet seats, and the bacterial research is sparse. We conducted a survey on the hygienic conditions of 127 warm-water bidet toilet seats in restrooms on a university campus. The spray water from the toilet seats had less residual chlorine than their tap water sources. However, the total viable microbial count was below the water-quality standard for tap water. In addition, the heat of the toilet seats' warm-water tanks caused heterotrophic bacteria in the source tap water to proliferate inside the nozzle pipes and the warm-water tanks. Escherichia coli was detected on the spray nozzles of about 5% of the toilet seats, indicating that the self-cleaning mechanism of the spray nozzles was largely functioning properly. However, Pseudomonas aeruginosa was detected on about 2% of the toilet seats. P. aeruginosa was found to remain for long durations in biofilms that formed inside warm-water tanks. Infection-prevention measures aimed at P. aeruginosa should receive full consideration when managing warm-water bidet toilet seats in hospitals in order to prevent opportunistic infections in intensive care units, hematology wards, and other hospital locations.

Using thermal-infrared imagery to delineate ground-water discharge

USGS Publications Warehouse

Banks, W.S.L.; Paylor, R.L.; Hughes, W.B.

1996-01-01

On March 8 and 9, 1992, a thermal-infrared-multispectral scanner (TIMS) was flown over two military ordnance disposal facilities at the Edgewood Area of Aberdeen Proving Ground, Maryland. The data, collected bythe National Aeronautics and Space Administration, in cooperation with the U.S. Army and the U.S. Geological Survey, were used to locate ground-water discharge zones in surface water. The images from the flight show areas where ground-water discharge is concentrated, as well as areas of diffuse discharge. Concentrated discharge is predominant in isolated or nearly isolated ponds and creeks in the study area. Diffuse dicharge is found near parts of the shoreline where the study area meets the surrounding estuaries of the Chesapeake Bay and the Gunpowder River. The average temperature for surface water, measured directly in the field, and the average temperature, calculated from atmospherically corrected TIMS images, was 10.6??C (Celsius) at the first of two sites. Potentiometric surface maps of both field sites show discharge toward the nontidal marshes, the estuaries which surround the field sites, and creeks which drain into the estuaries. The average measured temperature of ground water at both sites was 10.7??C. The calculated temperature from the TIMS imagery at both sites where ground-water discharge is concentrated within a surface-water body is 10.4??C. In the estuaries which surround the field sites, field measurements of temperature were made resulting in an average temperature of 9.0??C. The average calculated TIMS temperature from the estuaries was 9.3??C. Along the shoreline at the first site and within 40 to 80 meters of the western and southern shores of the second site, water was 1?? to 2??C warmer than water more than 80 meters away. The pattern of warmer water grading to cooler water in an offshore direction could result from diffuse ground-water discharge. Tonal differences in the TIMS imagery could indicate changes in surface-water

Fat loss in thawed breast milk: comparison between refrigerator and warm water.

PubMed

Thatrimontrichai, A; Janjindamai, W; Puwanant, M

2012-11-01

To compare the fat loss between refrigerator and warm water thawed breast milk. Experimental. Tertiary-care pediatric university hospital. Ninety samples of expressed breast milk were collected from mothers with singleton babies of a gestational age 32-42 weeks. Fat content in fresh breast milk (FM); thawed breast milk by refrigeration (RM); and thawed breast milk by warm water (WM). The mean (SD) total fat content in FM, RM and WM were 2.98 (0.97), 2.76 (0.99) and 2.66 (0.88) g/100 mL, respectively. The mean difference (SD) of the total fat in FM declined significantly after the frozen milk was thawed by refrigeration or warm water at -0.22 (0.50) g/100 mL (P=0.0001) and -0.32 (0.45) g/100 mL (P<0.0001), respectively. The mean (SD) total fat loss of frozen breast milk thawed by refrigeration was less than thawing in warm water at 0.094 (0.38) g/100 mL (P=0.02). The fat loss of thawed breast milk by refrigeration was significantly less than placing it in warm water.

Localized Rapid Warming of West Antarctic Subsurface Waters by Remote Winds

NASA Astrophysics Data System (ADS)

Griffies, S. M.; Spence, P.; Holmes, R.; Hogg, A. M.; Stewart, K. D.; England, M. H.

2017-12-01

The largest rates of Antarctic glacial ice mass loss are occurring tothe west of the Antarctica Peninsula in regions where warming ofsubsurface continental shelf waters is also largest. However, thephysical mechanisms responsible for this warming remain unknown. Herewe show how localized changes in coastal winds off East Antarctica canproduce significant subsurface temperature anomalies (>2C) around theentire continent. We demonstrate how coastal-trapped Kelvin wavescommunicate the wind disturbance around the Antarctic coastline. Thewarming is focused on the western flank of the Antarctic Peninsulabecause the anomalous circulation induced by the coastal-trapped wavesis intensified by the steep continental slope there, and because ofthe presence of pre-existing warm subsurface water. Thecoastal-trapped waves leads to an adjustment of the flow that shoalsisotherms and brings warm deep water upwards onto the continentalshelf and closer to the coast. This result demonstrates the uniquevulnerability of the West Antarctic region to a changing climate.

Warming will alter water resources

NASA Astrophysics Data System (ADS)

Maggs, William Ward

Drastic changes in water resources in all regions of the United States will be the most severe effect of global warming, according to a study reported January 16 at the meeting of the American Association for the Advancement of Science in San Francisco. However, said the scientists on the AAAS panel on climate and U.S. water resources, strong governmental involvement can greatly reduce the water supply problems climate change will bring.The natural variability of present and future climate was the starting point for the AAAS study. The panel pointed out that it is difficult to identify the direction of potential change for many of the possible consequences of the greenhouse effect, partly because recent history provides little evidence of strong responses to such changes.

Multi-spark discharge system for preparation of nutritious water

NASA Astrophysics Data System (ADS)

Nakaso, Tetsushi; Harigai, Toru; Kusumawan, Sholihatta Aziz; Shimomura, Tomoya; Tanimoto, Tsuyoshi; Suda, Yoshiyuki; Takikawa, Hirofumi

2018-01-01

The nitrogen compound concentration in water is increased by atmospheric-pressure plasma discharge treatment. A rod-to-water electrode discharge treatment system using plasma discharge has been developed by our group to obtain water with a high concentration of nitrogen compounds, and this plasma-treated water improves the growth of chrysanthemum roots. However, it is difficult to apply the system to the agriculture because the amount of treated water obtained by using the system too small. In this study, a multi-spark discharge system (MSDS) equipped multiple spark plugs is presented to obtain a large amount of plasma-treated water. The MSDS consisted of inexpensive parts in order to reduce the system introduction cost for agriculture. To suppress the temperature increase of the spark plugs, the 9 spark plugs were divided into 3 groups, which were discharged in order. The plasma-treated water with a NO3- concentration of 50 mg/L was prepared using the MSDS for 90 min, and the treatment efficiency was about 6 times higher than that of our previous system. It was confirmed that the NO2-, O3, and H2O2 concentrations in the water were also increased by treating the water using the MSDS.

Pulsed electrical discharge in gas bubbles in water

NASA Astrophysics Data System (ADS)

Gershman, Sophia

A phenomenological picture of pulsed electrical discharge in gas bubbles in water is produced by combining electrical, spectroscopic, and imaging methods. The discharge is generated by applying one microsecond long 5 to 20 kilovolt pulses between the needle and disk electrodes submerged in water. A gas bubble is generated at the tip of the needle electrode. The study includes detailed experimental investigation of the discharge in argon bubbles and a brief look at the discharge in oxygen bubbles. Imaging, electrical characteristics, and time-resolved optical emission data point to a fast streamer propagation mechanism and formation of a plasma channel in the bubble. Spectroscopic methods based on line intensity ratios and Boltzmann plots of line intensities of argon, atomic hydrogen, and argon ions and the examination of molecular emission bands from molecular nitrogen and hydroxyl radicals provide evidence of both fast beam-like electrons and slow thermalized ones with temperatures of 0.6 -- 0.8 electron-volts. The collisional nature of plasma at atmospheric pressure affects the decay rates of optical emission. Spectroscopic study of rotational-vibrational bands of hydroxyl radical and molecular nitrogen gives vibrational and rotational excitation temperatures of the discharge of about 0.9 and 0.1 electron-volt, respectively. Imaging and electrical evidence show that discharge charge is deposited on the bubble wall and water serves as a dielectric barrier for the field strength and time scales of this experiment. Comparing the electrical and imaging information for consecutive pulses applied at a frequency of 1 Hz indicates that each discharge proceeds as an entirely new process with no memory of the previous discharge aside from long-lived chemical species, such as ozone and oxygen. Intermediate values for the discharge gap and pulse duration, low repetition rate, and unidirectional character of the applied voltage pulses make the discharge process here unique

Low flows and water temperature risks to Asian coal power plants in a warming world

NASA Astrophysics Data System (ADS)

Wang, Y.; Byers, E.; Parkinson, S.; Wanders, N.; Wada, Y.; Bielicki, J. M.

2017-12-01

Thermoelectric power generation requires cooling, normally provided by wet cooling systems. The withdrawal and discharge of cooling water are subject to regulation. Therefore, operation of power plants may be vulnerable to changes in streamflow and rises in water temperatures. In Asia, about 489 GW of coal-fired power plants are currently under construction, permitted, or announced. Using a comprehensive dataset of these planned coal power plants (PCPPs) and cooling water use models, we investigated whether electricity generation at these power plants will be limited by streamflow and water temperature. Daily streamflow and water temperature time series are from the high-resolution (0.08ox0.08o) runs of the PCRGLOBWB hydrological model, driven by downscaled meteorological forcing from five global climate models. We compared three climate change scenarios (1.5oC, 2oC, and 3oC warming in global mean temperature) and three cooling system choice scenarios (freshwater once-through, freshwater cooling tower, and "business-as-usual" - where a PCPP uses the same cooling system as the nearest existing coal power plant). The potential available capacity of the PCPPs increase slightly from the 1.5oC to the 2oC and 3oC warming scenario due to increase in streamflow. The once-through cooling scenario results in virtually zero available capacity at the PCPPs. The other two cooling scenarios result in about 20% of the planned capacity being unavailable under all warming scenarios. Hotspots of the most water-limited PCPPs are in Pakistan, northwestern India, northwestern and north-central China, and northern Vietnam, where most of the PCPPs will face 30% to 90% unavailable nameplate capacity on annual average. Since coal power plants cannot operate effectively when the capacity factor falls below a minimum load level (about 20% to 50%), the actual limitation on generation capacity would be larger. In general, the PCPPs that will have the highest limitation on annual average

Submarine ground-water discharge: nutrient loading and nitrogen transformations

USGS Publications Warehouse

Kroeger, Kevin D.; Swarzenski, Peter W.; Crusius, John; Bratton, John F.; Charette, Matthew A.

2006-01-01

Eutrophication of coastal waters due to nonpoint source land-derived nitrogen (N) loads is a worldwide phenomenon and perhaps the greatest agent of change altering coastal ecology (National Research Council, 2000; Howarth and others, 2000). Within the United States, a majority of estuaries have been determined to be moderately to severely impaired by eutrophication associated with increasing nutrient loads (Bricker and others, 1999).In coastal watersheds with soils of high hydraulic conductivity and permeable coastal sediments, ground water is a major route of transport of freshwater and its solutes from land to sea. Freshwater flowing downgradient from aquifers may either discharge from a seepage face near the intertidal zone, or flow directly into the sea as submarine ground-water discharge (SGD) (fig. 1). In the coastal aquifer, entrainment of saline pore water occurs prior to discharge, producing a gradient in ground-water salinity from land to sea, referred to as a subterranean estuary (Moore, 1999). In addition, processes including density-driven flow and tidal pumping create brackish and saline ground-water circulation. Hence, submarine ground-water discharge often consists of a substantial amount of recirculating seawater. Mixing of fresh and saline ground waters in the context of coastal sediments may alter the chemical composition of the discharging fluid. Depending on the biogeochemical setting, removal of fixed N due to processes leading to N2 (dinitrogen gas) production in the nearshore aquifer and subterranean estuary may significantly attenuate land-derived N loads; or, processes such as ion exchange and tidal pumping in the subterranean estuary may substantially accelerate the transport of both land-derived and sediment re-mineralized N to estuarine water columns.As emphasized by Burnett and others (2001, 2002), a fundamental problem in evaluating the importance of ground-water discharge in marine geochemical budgets is the difficulty of collecting

First-aid with warm water delays burn progression and increases skin survival.

PubMed

Tobalem, M; Harder, Y; Tschanz, E; Speidel, V; Pittet-Cuénod, B; Wettstein, R

2013-02-01

First aid treatment for thermal injuries with cold water removes heat and decreases inflammation. However, perfusion in the ischemic zone surrounding the coagulated core can be compromised by cold-induced vasoconstriction and favor burn progression. The aim of this study is to evaluate the effect of local warming on burn progression in the rat comb burn model. 24 male Wistar rats were randomly assigned to either no treatment (control) or application of cold (17 °C) or warm (37 °C) water applied for 20 min. Evolution of burn depth, interspace necrosis, and microcirculatory perfusion were assessed with histology, planimetry, respectively with Laser Doppler flowmetry after 1 h, as well as 1, 4, and 7 days. Consistent conversion from a superficial to a deep dermal burn within 24 h was obtained in control animals. Warm and cold water significantly delayed burn depth progression, however after 4 days the burn depth was similar in all groups. Interspace necrosis was significantly reduced by warm water treatment (62±4% vs. 69±5% (cold water) and 82±3% (control); p<0.05). This was attributed to the significantly improved perfusion after warming, which was present 1 h after burn induction and was maintained thereafter (103±4% of baseline vs. 91±3% for cold water and 80±2% for control, p<0.05). In order to limit damage after burn injury, burn progression has to be prevented. Besides delaying burn progression, the application of warm water provided an additional benefit by improving the microcirculatory perfusion, which translated into increased tissue survival. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Linking the pacific decadal oscillation to seasonal stream discharge patterns in Southeast Alaska

USGS Publications Warehouse

Neal, E.G.; Todd, Walter M.; Coffeen, C.

2002-01-01

This study identified and examined differences in Southeast Alaskan streamflow patterns between the two most recent modes of the Pacific decadal oscillation (PDO). Identifying relationships between the PDO and specific regional phenomena is important for understanding climate variability, interpreting historical hydrological variability, and improving water-resources forecasting. Stream discharge data from six watersheds in Southeast Alaska were divided into cold-PDO (1947-1976) and warm-PDO (1977-1998) subsets. For all watersheds, the average annual streamflows during cold-PDO years were not significantly different from warm-PDO years. Monthly and seasonal discharges, however, did differ significantly between the two subsets, with the warm-PDO winter flows being typically higher than the cold-PDO winter flows and the warm-PDO summer flows being typically lower than the cold-PDO flows. These results were consistent with and driven by observed temperature and snowfall patterns for the region. During warm-PDO winters, precipitation fell as rain and ran-off immediately, causing higher than normal winter streamflow. During cold-PDO winters, precipitation was stored as snow and ran off during the summer snowmelt, creating greater summer streamflows. The Mendenhall River was unique in that it experienced higher flows for all seasons during the warm-PDO relative to the cold-PDO. The large amount of Mendenhall River discharge caused by glacial melt during warm-PDO summers offset any flow reduction caused by lack of snow accumulation during warm-PDO winters. The effect of the PDO on Southeast Alaskan watersheds differs from other regions of the Pacific Coast of North America in that monthly/seasonal discharge patterns changed dramatically with the switch in PDO modes but annual discharge did not. ?? 2002 Elsevier Science B.V. All rights reserved.

77 FR 17082 - Standards for Living Organisms in Ships' Ballast Water Discharged in U.S. Waters: Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-23

... Organisms in Ships' Ballast Water Discharged in U.S. Waters: Final Programmatic Environmental Impact... entitled ``Standards for Living Organisms in Ships' Ballast Water Discharged in U.S. Waters'' (Docket No... impacts associated with the establishment of a ballast water discharge standard for the allowable...

Improvement of growth rate of plants by bubble discharge in water

NASA Astrophysics Data System (ADS)

Takahata, Junichiro; Takaki, Koichi; Satta, Naoya; Takahashi, Katsuyuki; Fujio, Takuya; Sasaki, Yuji

2015-01-01

The effect of bubble discharge in water on the growth rate of plants was investigated experimentally for application to plant cultivation systems. Spinach (Spinacia oleracea), radish (Raphanus sativus var. sativus), and strawberry (Fragaria × ananassa) were used as specimens to clarify the effect of the discharge treatment on edible parts of the plants. The specimens were cultivated in pots filled with artificial soil, which included chicken manure charcoal. Distilled water was sprayed on the artificial soil and drained through a hole in the pots to a water storage tank. The water was circulated from the water storage tank to the cultivation pots after 15 or 30 min discharge treatment on alternate days. A magnetic compression-type pulsed power generator was used to produce the bubble discharge with a repetition rate of 250 pps. The plant height in the growth phase and the dry weight of the harvested plants were improved markedly by the discharge treatment in water. The soil and plant analyzer development (SPAD) value of the plants also improved in the growth phase of the plants. The concentration of nitrate nitrogen, which mainly contributed to the improvement of the growth rate, in the water increased with the discharge treatment. The Brix value of edible parts of Fragaria × ananassa increased with the discharge treatment. The inactivation of bacteria in the water was also confirmed with the discharge treatment.

Feasibility of potable water generators to meet vessel numeric ballast water discharge limits.

PubMed

Albert, Ryan J; Viveiros, Edward; Falatko, Debra S; Tamburri, Mario N

2017-07-15

Ballast water is taken on-board vessels into ballast water tanks to maintain vessel draft, buoyancy, and stability. Unmanaged ballast water contains aquatic organisms that, when transported and discharged to non-native waters, may establish as invasive species. Technologies capable of achieving regulatory limits designed to decrease the likelihood of invasion include onboard ballast water management systems. However, to date, the treatment development and manufacturing marketplace is limited to large vessels with substantial ballast requirements. For smaller vessels or vessels with reduced ballast requirements, we evaluated the feasibility of meeting the discharge limits by generating ballast water using onboard potable water generators. Case studies and parametric analyses demonstrated the architectural feasibility of installing potable water generators onboard actual vessels with minimal impacts for most vessel types evaluated. Furthermore, land-based testing of a potable water generator demonstrated capability to meet current numeric discharge limits for living organisms in all size classes. Published by Elsevier Ltd.

Warm fog dissipation using large volume water sprays

NASA Technical Reports Server (NTRS)

Keller, Vernon W. (Inventor)

1988-01-01

To accomplish the removal of warm fog about an area such as an airport runway, a plurality of nozzles along a line adjacent the area propelled water jets through the fog to heights of approximately twenty-five meters. Each water jet breaks up forming a water drop size distribution that falls through the fog overtaking, colliding, and coalescing with individual fog droplets and thereby removes the fog. A water retrieval system is used to collect the water and return it to reservoirs for pumping it to the nozzles once again.

The Summertime Warming Trends in Surface Water Temperature of the Great Lakes

NASA Astrophysics Data System (ADS)

Sugiyama, N.; Kravtsov, S.; Roebber, P.

2014-12-01

Over the past 30 years, the Laurentian Great Lakes have exhibited summertime warming trends in surface water temperature which were greater than those in surface air temperature of the surrounding land, by as much as an order of magnitude over some of the regions. For the years 1995-2012, Lake Superior exhibited the most dramatic warming trend in July-mean temperature, of 0.27±0.15 deg. C yr-1, based on the NOAA's GLSEA satellite observations. Shallower lakes, such as Lake Erie, exhibited smaller warming trends. In addition, within each lake, the warming was also the greatest in the regions of larger water depth; for example, some regions of Lake Superior deeper than 200m exhibited surface-water July-mean warming trends which exceeded 0.3 deg. C yr-1. We used a three-column lake model based on the one developed by Hostetler and Barnstein (1990) coupled with a two-layer atmospheric energy balance model to explore the physics behind these warming trends. We found that, as suggested by Austin and Colman (2007), the ice-albedo feedback plays an important role in amplifying the overlake warming trends. Our particular emphasis was on the question of whether the ice-albedo feedback alone is enough to account for lacustrine amplification of surface warming observed over the Great Lakes region. We found that the answer to this question depends on a number of model parameters, including the diffusion and light attenuation coefficients, which greatly affect the model's skill in reproducing the observed ice coverage of the deep lakes.

Tree water dynamics in a drying and warming world: Future tree water dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grossiord, Charlotte; Sevanto, Sanna; Borrego, Isaac

Disentangling the relative impacts of precipitation reduction and vapour pressure deficit (VPD) on plant water dynamics and determining whether acclimation may influence these patterns in the future is an important challenge. Here, we report sap flux density (FD), stomatal conductance (Gs), hydraulic conductivity (KL) and xylem anatomy in piñon pine (Pinus edulis) and juniper (Juniperus monosperma) trees subjected to five years of precipitation reduction, atmospheric warming (elevated VPD) and their combined effects. No acclimation occurred under precipitation reduction: lower Gs and FD were found for both species compared to ambient conditions. Warming reduced the sensibility of stomata to VPD formore » both species but resulted in the maintenance of Gs and FD to ambient levels only for piñon. For juniper, reduced soil moisture under warming negated benefits of stomatal adjustments and resulted in reduced FD, Gs and KL. Although reduced stomatal sensitivity to VPD also occurred under combined stresses, reductions in Gs, FD and KL took place to similar levels as under single stresses for both species. Our results show that stomatal conductance adjustments to high VPD could minimize but not entirely prevent additive effects of warming and drying on water use and carbon acquisition of trees in semi-arid regions.« less

Tree water dynamics in a drying and warming world

DOE PAGES

Grossiord, Charlotte; Sevanto, Sanna Annika; Borrego, Isaac Anthony; ...

2017-05-26

Disentangling the relative impacts of precipitation reduction and vapour pressure deficit ( VPD) on plant water dynamics and determining whether acclimation may influence these patterns in the future is an important challenge. Here, we report sap flux density ( FD), stomatal conductance ( Gs), hydraulic conductivity ( KL) and xylem anatomy in piñon pine ( Pinus edulis) and juniper ( Juniperus monosperma) trees subjected to five years of precipitation reduction, atmospheric warming (elevated VPD) and their combined effects. No acclimation occurred under precipitation reduction: lower Gs and FD were found for both species compared to ambient conditions. Warming reduced themore » sensibility of stomata to VPD for both species but resulted in the maintenance of Gs and FD to ambient levels only for piñon. For juniper, reduced soil moisture under warming negated benefits of stomatal adjustments and resulted in reduced FD, Gs and KL. Although reduced stomatal sensitivity to VPD also occurred under combined stresses, reductions in Gs, FD and KL took place to similar levels as under single stresses for both species. Here our results show that stomatal conductance adjustments to high VPD could minimize but not entirely prevent additive effects of warming and drying on water use and carbon acquisition of trees in semi-arid regions.« less

Tree water dynamics in a drying and warming world

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grossiord, Charlotte; Sevanto, Sanna Annika; Borrego, Isaac Anthony

Disentangling the relative impacts of precipitation reduction and vapour pressure deficit ( VPD) on plant water dynamics and determining whether acclimation may influence these patterns in the future is an important challenge. Here, we report sap flux density ( FD), stomatal conductance ( Gs), hydraulic conductivity ( KL) and xylem anatomy in piñon pine ( Pinus edulis) and juniper ( Juniperus monosperma) trees subjected to five years of precipitation reduction, atmospheric warming (elevated VPD) and their combined effects. No acclimation occurred under precipitation reduction: lower Gs and FD were found for both species compared to ambient conditions. Warming reduced themore » sensibility of stomata to VPD for both species but resulted in the maintenance of Gs and FD to ambient levels only for piñon. For juniper, reduced soil moisture under warming negated benefits of stomatal adjustments and resulted in reduced FD, Gs and KL. Although reduced stomatal sensitivity to VPD also occurred under combined stresses, reductions in Gs, FD and KL took place to similar levels as under single stresses for both species. Here our results show that stomatal conductance adjustments to high VPD could minimize but not entirely prevent additive effects of warming and drying on water use and carbon acquisition of trees in semi-arid regions.« less

Computer programs for describing the recession of ground-water discharge and for estimating mean ground-water recharge and discharge from streamflow records-update

USGS Publications Warehouse

Rutledge, A.T.

1998-01-01

The computer programs included in this report can be used to develop a mathematical expression for recession of ground-water discharge and estimate mean ground-water recharge and discharge. The programs are intended for analysis of the daily streamflow record of a basin where one can reasonably assume that all, or nearly all, ground water discharges to the stream except for that which is lost to riparian evapotranspiration, and where regulation and diversion of flow can be considered to be negligible. The program RECESS determines the master reces-sion curve of streamflow recession during times when all flow can be considered to be ground-water discharge and when the profile of the ground-water-head distribution is nearly stable. The method uses a repetitive interactive procedure for selecting several periods of continuous recession, and it allows for nonlinearity in the relation between time and the logarithm of flow. The program RORA uses the recession-curve displacement method to estimate the recharge for each peak in the streamflow record. The method is based on the change in the total potential ground-water discharge that is caused by an event. Program RORA is applied to a long period of record to obtain an estimate of the mean rate of ground-water recharge. The program PART uses streamflow partitioning to estimate a daily record of base flow under the streamflow record. The method designates base flow to be equal to streamflow on days that fit a requirement of antecedent recession, linearly interpolates base flow for other days, and is applied to a long period of record to obtain an estimate of the mean rate of ground-water discharge. The results of programs RORA and PART correlate well with each other and compare reasonably with results of the corresponding manual method.

A two-dimensional modeling of the warm-up phase of a high-pressure mercury discharge lamp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Araoud, Z.; Ben Ahmed, R.; Ben Hamida, M. B.

2010-06-15

The main objective of this work is to provide a better understanding of the warm-up phase of high-intensity discharge lamps. As an example of application, we chose the high-pressure mercury lamp. Based on two-dimensional fluid model parameters, such as the electric current, the length and the diameter of the burner are modified and the effect of the convective transport is studied. This allows us to obtain a thorough understanding of the physics of these lamps in their transitory phase. The simulation of the warm-up phase is a must for the proper predictions of the lamp behavior and can be conductedmore » by solving the energy balance, momentum, and Laplace's equations for the plasma, using the frame of the local thermodynamic equilibrium coupled with the energy balance of the wall.« less

Climate-induced warming of lakes can be either amplified or suppressed by trends in water clarity

USGS Publications Warehouse

Rose, Kevin C.; Winslow, Luke A.; Read, Jordan S.; Hansen, Gretchen J. A.

2016-01-01

Climate change is rapidly warming aquatic ecosystems including lakes and reservoirs. However, variability in lake characteristics can modulate how lakes respond to climate. Water clarity is especially important both because it influences the depth range over which heat is absorbed, and because it is changing in many lakes. Here, we show that simulated long-term water clarity trends influence how both surface and bottom water temperatures of lakes and reservoirs respond to climate change. Clarity changes can either amplify or suppress climate-induced warming, depending on lake depth and the direction of clarity change. Using a process-based model to simulate 1894 north temperate lakes from 1979 to 2012, we show that a scenario of decreasing clarity at a conservative yet widely observed rate of 0.92% yr−1 warmed surface waters and cooled bottom waters at rates comparable in magnitude to climate-induced warming. For lakes deeper than 6.5 m, decreasing clarity was sufficient to fully offset the effects of climate-induced warming on median whole-lake mean temperatures. Conversely, a scenario increasing clarity at the same rate cooled surface waters and warmed bottom waters relative to baseline warming rates. Furthermore, in 43% of lakes, increasing clarity more than doubled baseline bottom temperature warming rates. Long-term empirical observations of water temperature in lakes with and without clarity trends support these simulation results. Together, these results demonstrate that water clarity trends may be as important as rising air temperatures in determining how waterbodies respond to climate change.

Transpiration Dominates Ecosystem Water-Use Efficiency in Response to Warming in an Alpine Meadow

NASA Astrophysics Data System (ADS)

Quan, Quan; Zhang, Fangyue; Tian, Dashuan; Zhou, Qingping; Wang, Lixin; Niu, Shuli

2018-02-01

As a key linkage of C and water cycles, water-use efficiency (WUE) quantifies how much water an ecosystem uses for carbon gain. Although ecosystem C and water fluxes have been intensively studied, yet it remains unclear how ecosystem WUE responds to climate warming and which processes dominate the response of WUE. To answer these questions, we examined canopy WUE (WUEc), ecosystem WUE (WUEe) and their components including gross ecosystem productivity, ecosystem evapotranspiration (ET), soil evaporation (E), and plant canopy transpiration (T), in response to warming in an alpine meadow by using a manipulative warming experiment in 2015 and 2016. As expected, low- and high-level warming treatments increased soil temperature (Tsoil) at 10 cm on average by 1.65 and 2.77°C, but decreased soil moisture (Msoil) by 2.52 and 7.6 vol %, respectively, across the two years. Low- and high-level warming increased WUEe by 7.7 and 9.3% over the two years, but rarely changed WUEc in either year. T/ET ratio determined the differential responses of WUEc and WUEe. Larger T/ET led to less difference between WUEc and WUEe. By partitioning WUEc and WUEe into different carbon and water fluxes, we found that T rather than gross ecosystem productivity or E dominated the responses of WUEc and WUEe to warming. This study provides empirical insights into how ecosystem WUE responds to warming and illustrates the importance of plant transpiration in regulating ecosystem WUE under future climate change.

Warming by immersion or exercise affects initial cooling rate during subsequent cold water immersion.

PubMed

Scott, Chris G; Ducharme, Michel B; Haman, François; Kenny, Glen P

2004-11-01

We examined the effect of prior heating, by exercise and warm-water immersion, on core cooling rates in individuals rendered mildly hypothermic by immersion in cold water. There were seven male subjects who were randomly assigned to one of three groups: 1) seated rest for 15 min (control); 2) cycling ergometry for 15 min at 70% Vo2 peak (active warming); or 3) immersion in a circulated bath at 40 degrees C to an esophageal temperature (Tes) similar to that at the end of exercise (passive warming). Subjects were then immersed in 7 degrees C water to a Tes of 34.5 degrees C. Initial Tes cooling rates (initial approximately 6 min cooling) differed significantly among the treatment conditions (0.074 +/- 0.045, 0.129 +/- 0.076, and 0.348 +/- 0.117 degrees C x min(-1) for control, active, and passive warming conditions, respectively); however, secondary cooling rates (rates following initial approximately 6 min cooling to the end of immersion) were not different between treatments (average of 0.102 +/- 0.085 degrees C x min(-1)). Overall Tes cooling rates during the full immersion period differed significantly and were 0.067 +/- 0.047, 0.085 +/- 0.045, and 0.209 +/- 0.131 degrees C x min(-1) for control, active, and passive warming, respectively. These results suggest that prior warming by both active and, to a greater extent, passive warming, may predispose a person to greater heat loss and to experience a larger decline in core temperature when subsequently exposed to cold water. Thus, functional time and possibly survival time could be reduced when cold water immersion is preceded by whole-body passive warming, and to a lesser degree by active warming.

Characteristics of pulse corona discharge over water surface

NASA Astrophysics Data System (ADS)

Fujii, Tomio; Arao, Yasushi; Rea, Massimo

2008-12-01

Production of ozone and OH radical is required to advance the plasma chemical reactions in the NOx removal processes for combustion gas treatment. The corona discharge to the water surface is expected to induce the good conditions for the proceeding of the NO oxidation and the NO2 dissolution removal into water. In order to get the fundamental data of the corona discharge over the water surface, the positive and negative V-I characteristics and the ozone production were measured with the multi needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both the DC and the pulse corona to the water surface showed a stable and almost the same V-I characteristics as to plate electrodes though the surface of water was waved by corona wind. The positive streamer corona showed more ozone production than the negative one both in the DC and in the pulse corona.

Rapid and highly variable warming of lake surface waters around the globe

USGS Publications Warehouse

O'Reilly, Catherine; Sharma, Sapna; Gray, Derek; Hampton, Stephanie; Read, Jordan S.; Rowley, Rex J.; Schneider, Philipp; Lenters, John D.; McIntyre, Peter B.; Kraemer, Benjamin M.; Weyhenmeyer, Gesa A.; Straile, Dietmar; Dong, Bo; Adrian, Rita; Allan, Mathew G.; Anneville, Orlane; Arvola, Lauri; Austin, Jay; Bailey, John L.; Baron, Jill S.; Brookes, Justin D; de Eyto, Elvira; Dokulil, Martin T.; Hamilton, David P.; Havens, Karl; Hetherington, Amy L.; Higgins, Scott N.; Hook, Simon; Izmest'eva, Lyubov R.; Jöhnk, Klaus D.; Kangur, Külli; Kasprzak, Peter; Kumagai, Michio; Kuusisto, Esko; Leshkevich, George; Livingstone, David M.; MacIntyre, Sally; May, Linda; Melack, John M.; Mueller-Navara, Doerthe C.; Naumenko, Mikhail; Noges, Peeter; Noges, Tiina; North, Ryan P.; Plisnier, Pierre-Denis; Rigosi, Anna; Rimmer, Alon; Rogora, Michela; Rudstam, Lars G.; Rusak, James A.; Salmaso, Nico; Samal, Nihar R.; Schindler, Daniel E.; Schladow, Geoffrey; Schmid, Martin; Schmidt, Silke R.; Silow, Eugene A.; Soylu, M. Evren; Teubner, Katrin; Verburg, Piet; Voutilainen, Ari; Watkinson, Andrew; Williamson, Craig E.; Zhang, Guoqing

2015-01-01

In this first worldwide synthesis of in situ and satellite-derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade−1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors—from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade−1) to ice-free lakes experiencing increases in air temperature and solar radiation (0.53°C decade−1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes.

Optimal design of zero-water discharge rinsing systems.

PubMed

Thöming, Jorg

2002-03-01

This paper is about zero liquid discharge in processes that use water for rinsing. Emphasis was given to those systems that contaminate process water with valuable process liquor and compounds. The approach involved the synthesis of optimal rinsing and recycling networks (RRN) that had a priori excluded water discharge. The total annualized costs of the RRN were minimized by the use of a mixed-integer nonlinear program (MINLP). This MINLP was based on a hyperstructure of the RRN and contained eight counterflow rinsing stages and three regenerator units: electrodialysis, reverse osmosis, and ion exchange columns. A "large-scale nickel plating process" case study showed that by means of zero-water discharge and optimized rinsing the total waste could be reduced by 90.4% at a revenue of $448,000/yr. Furthermore, with the optimized RRN, the rinsing performance can be improved significantly at a low-cost increase. In all the cases, the amount of valuable compounds reclaimed was above 99%.

ESTIMATING FLOW AND FLUX OF GROUND-WATER DISCHARGE USING WATER TEMPERATURE AND VELOCITY. (R827961)

EPA Science Inventory

The nature of ground water discharge to a stream has important implications for nearby ground water flow, especially with respect to contaminant transport and well-head protection. Measurements of ground water discharge were accomplished in this study using (1) differences bet...

Ballast Water Discharges into the Great Lakes from Overseas Vessels

EPA Pesticide Factsheets

Analysis of Ballast Water Discharges into the Great Lakes from Overseas Vessels from 2010 to 2013 - An assessment of the volume, location, and global port origins of ballast water discharges in the Great Lakes (May 2015).

Simulation of ground-water discharge to Biscayne Bay, southeastern Florida

USGS Publications Warehouse

Langevin, Christian David

2001-01-01

As part of the Place-Based Studies Program, the U.S. Geological Survey initiated a project in 1996, in cooperation with the U.S. Army Corps of Engineers, to quantify the rates and patterns of submarine ground-water discharge to Biscayne Bay. Project objectives were achieved through field investigations at three sites (Coconut Grove, Deering Estate, and Mowry Canal) along the coastline of Biscayne Bay and through the development and calibration of variable-density, ground-water flow models. Two-dimensional, vertical cross-sectional models were developed for steady-state conditions for the Coconut Grove and Deering Estate transects to quantify local-scale ground-water discharge patterns to Biscayne Bay. A larger regional-scale model was developed in three dimensions to simulate submarine ground-water discharge to the entire bay. The SEAWAT code, which is a combined version of MODFLOW and MT3D, was used to simulate the complex variable-density flow patterns. Field data suggest that ground-water discharge to Biscayne Bay relative to the shoreline is restricted to within 300 meters at Coconut Grove, 600 to 1,000 meters at Deering Estate, and 100 meters at Mowry Canal. The vertical cross-sectional models, which were calibrated to the field data using the assumption of steady state, tend to focus ground-water discharge to within 50 to 200 meters of the shoreline. With homogeneous distributions for aquifer parameters and a constant-concentration boundary for Biscayne Bay, the numerical models could not reproduce the lower ground-water salinities observed beneath the bay, which suggests that further research may be necessary to improve the accuracy of the numerical simulations. Results from the cross-sectional models, which were able to simulate the approximate position of the saltwater interface, suggest that longitudinal dispersivity ranges between 1 and 10 meters, and transverse dispersivity ranges from 0.1 to 1 meter for the Biscayne aquifer. The three

Warming of the Global Ocean: Spatial Structure and Water-Mass Trends

NASA Technical Reports Server (NTRS)

Hakkinen, Sirpa; Rhines, Peter B.; Worthen, Denise L.

2016-01-01

This study investigates the multidecadal warming and interannual-to-decadal heat content changes in the upper ocean (0-700 m), focusing on vertical and horizontal patterns of variability. These results support a nearly monotonic warming over much of the World Ocean, with a shift toward Southern Hemisphere warming during the well-observed past decade. This is based on objectively analyzed gridded observational datasets and on a modeled state estimate. Besides the surface warming, a warming climate also has a subsurface effect manifesting as a strong deepening of the midthermocline isopycnals, which can be diagnosed directly from hydrographic data. This deepening appears to be a result of heat entering via subduction and spreading laterally from the high-latitude ventilation regions of subtropical mode waters. The basin-average multidecadal warming mainly expands the subtropical mode water volume, with weak changes in the temperature-salinity (u-S) relationship (known as ''spice'' variability). However, the spice contribution to the heat content can be locally large, for example in Southern Hemisphere. Multidecadal isopycnal sinking has been strongest over the southern basins and weaker elsewhere with the exception of the Gulf Stream/North Atlantic Current/subtropical recirculation gyre. At interannual to decadal time scales, wind-driven sinking and shoaling of density surfaces still dominate ocean heat content changes, while the contribution from temperature changes along density surfaces tends to decrease as time scales shorten.

Characteristics and applications of diffuse discharge of water electrode in air

NASA Astrophysics Data System (ADS)

Wenzheng, LIU; Tahan, WANG; Xiaozhong, CHEN; Chuanlong, MA

2018-01-01

Plasma water treatment technology, which aims to produce strong oxidizing reactive particles that act on the gas-liquid interface by way of discharging, is used to treat the organic pollutants that do not degrade easily in water. This paper presents a diffuse-discharge plasma water treatment method, which is realized by constructing a conical air gap through an uneven medium layer. The proposed method uses water as one electrode, and a dielectric barrier discharge electrode is constructed by using an uneven dielectric. The electric field distribution in the discharge space will be uneven, wherein the long gap electric field will have a smaller intensity, while the short one will have a larger intensity. A diffuse glow discharge is formed in the cavity. With this type of plasma water treatment equipment, a methyl orange solution with a concentration of 10 mg l-1 was treated, and the removal rate was found to reach 88.96%.

Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems.

PubMed

Rix, Laura; de Goeij, Jasper M; Mueller, Christina E; Struck, Ulrich; Middelburg, Jack J; van Duyl, Fleur C; Al-Horani, Fuad A; Wild, Christian; Naumann, Malik S; van Oevelen, Dick

2016-01-07

Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrients in DOM to higher trophic levels on Caribbean reefs via the so-called sponge loop. Coral mucus may be a major DOM source for the sponge loop, but mucus uptake by sponges has not been demonstrated. Here we used laboratory stable isotope tracer experiments to show the transfer of coral mucus into the bulk tissue and phospholipid fatty acids of the warm-water sponge Mycale fistulifera and cold-water sponge Hymedesmia coriacea, demonstrating a direct trophic link between corals and reef sponges. Furthermore, 21-40% of the mucus carbon and 32-39% of the nitrogen assimilated by the sponges was subsequently released as detritus, confirming a sponge loop on Red Sea warm-water and north Atlantic cold-water coral reefs. The presence of a sponge loop in two vastly different reef environments suggests it is a ubiquitous feature of reef ecosystems contributing to the high biogeochemical cycling that may enable coral reefs to thrive in nutrient-limited (warm-water) and energy-limited (cold-water) environments.

Warming combined with more extreme precipitation regimes modifies the water sources used by trees.

PubMed

Grossiord, Charlotte; Sevanto, Sanna; Dawson, Todd E; Adams, Henry D; Collins, Adam D; Dickman, Lee T; Newman, Brent D; Stockton, Elizabeth A; McDowell, Nate G

2017-01-01

The persistence of vegetation under climate change will depend on a plant's capacity to exploit water resources. We analyzed water source dynamics in piñon pine and juniper trees subjected to precipitation reduction, atmospheric warming, and to both simultaneously. Piñon and juniper exhibited different and opposite shifts in water uptake depth in response to experimental stress and background climate over 3 yr. During a dry summer, juniper responded to warming with a shift to shallow water sources, whereas piñon pine responded to precipitation reduction with a shift to deeper sources in autumn. In normal and wet summers, both species responded to precipitation reduction, but juniper increased deep water uptake and piñon increased shallow water uptake. Shifts in the utilization of water sources were associated with reduced stomatal conductance and photosynthesis, suggesting that belowground compensation in response to warming and water reduction did not alleviate stress impacts for gas exchange. We have demonstrated that predicted climate change could modify water sources of trees. Warming impairs juniper uptake of deep sources during extended dry periods. Precipitation reduction alters the uptake of shallow sources following extended droughts for piñon. Shifts in water sources may not compensate for climate change impacts on tree physiology. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Warm waters, bleached corals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, L.

1990-10-12

Two researchers, Tom Goreau of the Discovery Laboratory in Jamaica and Raymond Hayes of Howard University, claim that they have evidence that nearly clinches the temperature connection to the bleached corals in the Caribbean and that the coral bleaching is an indication of Greenhouse warming. The incidents of scattered bleaching of corals, which have been reported for decades, are increasing in both intensity and frequency. The researchers based their theory on increased temperature of the seas measured by satellites. However, some other scientists feel that the satellites measure the temperature of only the top few millimeters of the water andmore » that since corals lie on reefs perhaps 60 to 100 feet below the ocean surface, the elevated temperatures are not significant.« less

Water resources data Virginia water year 2005 Volume 1. Surface-water discharge and surface-water quality records

USGS Publications Warehouse

Wicklein, Shaun M.; Powell, Eugene D.; Guyer, Joel R.; Owens, Joseph A.

2006-01-01

Water-resources data for the 2005 water year for Virginia includes records of stage, discharge, and water quality of streams and stage, contents, and water quality of lakes and reservoirs. This volume contains records for water discharge at 172 gaging stations; stage only at 2 gaging stations; elevation at 2 reservoirs and 2 tide gages; contents at 1 reservoir, and water quality at 25 gaging stations. Also included are data for 50 crest-stage partial-record stations. Locations of these sites are shown on figures 4A-B and 5A-B. Miscellaneous hydrologic data were collected at 128 measuring sites and 19 water-quality sampling sites not involved in the systematic data-collection program. The data in this report represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Virginia.

Functioning of a Shallow-Water Sediment System during Experimental Warming and Nutrient Enrichment

PubMed Central

Alsterberg, Christian; Sundbäck, Kristina; Hulth, Stefan

2012-01-01

Effects of warming and nutrient enrichment on intact unvegetated shallow-water sediment were investigated for 5 weeks in the autumn under simulated natural field conditions, with a main focus on trophic state and benthic nitrogen cycling. In a flow-through system, sediment was exposed to either seawater at ambient temperature or seawater heated 4°C above ambient, with either natural or nutrient enriched water. Sediment–water fluxes of oxygen and inorganic nutrients, nitrogen mineralization, and denitrification were measured. Warming resulted in an earlier shift to net heterotrophy due to increased community respiration; primary production was not affected by temperature but (slightly) by nutrient enrichment. The heterotrophic state was, however, not further strengthened by warming, but was rather weakened, probably because increased mineralization induced a shortage of labile organic matter. Climate-related warming of seawater during autumn could therefore, in contrast to previous predictions, induce shorter but more intensive heterotrophic periods in shallow-water sediments, followed by longer autotrophic periods. Increased nitrogen mineralization and subsequent effluxes of ammonium during warming suggested a preferential response of organisms driving nitrogen mineralization when compared to sinks of ammonium such as nitrification and algal assimilation. Warming and nutrient enrichment resulted in non-additive effects on nitrogen mineralization and denitrification (synergism), as well as on benthic fluxes of phosphate (antagonism). The mode of interaction appears to be related to the trophic level of the organisms that are the main drivers of the affected processes. Despite the weak response of benthic microalgae to both warming and nutrient enrichment, the assimilation of nitrogen by microalgae was similar in magnitude to rates of nitrogen mineralization. This implies a sustained filter function and retention capacity of nutrients by the sediment. PMID

Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems

PubMed Central

Rix, Laura; de Goeij, Jasper M.; Mueller, Christina E.; Struck, Ulrich; Middelburg, Jack J.; van Duyl, Fleur C.; Al-Horani, Fuad A.; Wild, Christian; Naumann, Malik S.; van Oevelen, Dick

2016-01-01

Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrients in DOM to higher trophic levels on Caribbean reefs via the so-called sponge loop. Coral mucus may be a major DOM source for the sponge loop, but mucus uptake by sponges has not been demonstrated. Here we used laboratory stable isotope tracer experiments to show the transfer of coral mucus into the bulk tissue and phospholipid fatty acids of the warm-water sponge Mycale fistulifera and cold-water sponge Hymedesmia coriacea, demonstrating a direct trophic link between corals and reef sponges. Furthermore, 21–40% of the mucus carbon and 32–39% of the nitrogen assimilated by the sponges was subsequently released as detritus, confirming a sponge loop on Red Sea warm-water and north Atlantic cold-water coral reefs. The presence of a sponge loop in two vastly different reef environments suggests it is a ubiquitous feature of reef ecosystems contributing to the high biogeochemical cycling that may enable coral reefs to thrive in nutrient-limited (warm-water) and energy-limited (cold-water) environments. PMID:26740019

76 FR 57646 - Final Withdrawal of Certain Federal Aquatic Life Water Quality Criteria Applicable to Wisconsin

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-16

... limits in National Pollutant Discharge Elimination System (NPDES) permits, and may affect Clean Water Act... the final Water Quality Guidance for the Great Lakes System (Guidance), required by CWA Section 118(c... waters of the Great Lakes System in Wisconsin designated as Warm Water Sportfish and Warm Water Forage...

TOPEX/El Nino Watch - El Nino Warm Water Pool Decreasing, Jan, 08, 1998

NASA Technical Reports Server (NTRS)

1998-01-01

This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Jan. 8, 1998, and sea surface height is an indicator of the heat content of the ocean. The volume of the warm water pool related to the El Nino has decreased by about 40 percent since its maximum in early November, but the area of the warm water pool is still about one and a half times the size of the continental United States. The volume measurements are computed as the sum of all the sea surface height changes as compared to normal ocean conditions. In addition, the maximum water temperature in the eastern tropical Pacific, as measured by the National Oceanic and Atmospheric Administration (NOAA), is still higher than normal. Until these high temperatures diminish, the El Nino warm water pool still has great potential to disrupt global weather because the high water temperatures directly influence the atmosphere. Oceanographers believe the recent decrease in the size of the warm water pool is a normal part of El Nino's natural rhythm. TOPEX/Poseidon has been tracking these fluctuations of the El Nino warm pool since it began in early 1997. These sea surface height measurements have provided scientists with their first detailed view of how El Nino's warm pool behaves because the TOPEX/Poseidon satellite measures the changing sea surface height with unprecedented precision. In this image, the white and red areas indicate unusual patterns of heat storage; in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal; in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level.

The El Nino phenomenon is thought to be triggered when the steady westward blowing trade winds

Risk assessment for produced water discharges to Louisiana open bays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinhold, A.F.; Holtzman, S.; DePhillips, M.P.

1995-11-01

Potential human health and environmental impacts from discharge of produced water to the Gulf of Mexico concern regulators at the State and Federal levels, environmental interest groups, industry and the public. Current regulations in the United States require or propose azero discharge limit for coastal facilities based primarily on studies performed in low energy,poorly flushed environments. Produced water discharges in coastal Louisiana, however,include a number located in open bays, where potential and impacts are likely to be larger than the minimal impacts associated with offshore discharges, but smaller than those demonstrated in low-energy canal environments. This paper summarizes results ofmore » a conservative screening-level health and ecological assessment for contaminants discharged in produced water to open bays in Louisiana, and reports results of a probabilistic human health risk assessment for radium and lead. The initial human health and ecological risk assessments consisted of conservative screening analyses that identified potentially important contaminants and excluded others from further consideration. A more quantitative probabilistic risk assessment was completed for the human health effects of the two contaminants identified in this screen: radium and lead. This work is part of a series of studies on the health and ecological risks from discharges of produced water to the Gulf of Mexico, supported by the United States Department of Energy (USDOE).« less

Monitoring Environmental Recovery at Terminated Produced Water Discharge Sites in Coastal Louisiana Waters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Continental Shelf Associates, Inc.

1999-08-16

This report presents the results of a study of terminated produced water discharge sites in the coastal waters of Louisiana. Environmental recovery at the sites is documented by comparing pre-termination and post-termination (six months and one year) data. Produced water, sediments, and sediment interstitial water samples were analyzed for radionuclides, metals, and hydrocarbons. Benthic infauna were identified from samples collected in the vicinity of the discharge and reference sites. Radium isotope activities were determined in fish and crustacean samples. In addition, an environmental risk assessment is made on the basis of the concentrations of metals and hydrocarbons determined in themore » samples.« less

Continuous tonic spike activity in spider warm cells in the absence of sensory input.

PubMed

Gingl, E; Tichy, H

2006-09-01

The warm cells of the spider tarsal organ respond very sensitively to low-amplitude changes in temperature and discharge continuously as the rate of change in temperature reaches zero. To test whether the continuous tonic discharge remains without sensory input, we blocked the warm cell's receptive region by Epoxy glue. The activity continued in this situation, but its dependence on temperature changes was strongly reduced. We interpret this to mean that the warm cells exhibit specific intrinsic properties that underlie the generation of the tonic discharge. Experiments with electrical stimulation confirmed the observation that the warm cells persist in activity without an external drive. In warm cells with blocked receptive region, the response curves describing the relationship between the tonic discharge and the level of depolarization is the same for different temperatures. In warm cells with intact receptive region, the curves are shifted upward with rising temperature, as if the injected current is simply added to the receptor current. This indicates a modulating effect of the receptor current on the tonic discharge. Stimulation causes a change in the tonic discharge rate and thereby enables individual warm cells to signal the direction in addition to the magnitude of temperature changes.

Fine-Water-Mist Multiple-Orientation-Discharge Fire Extinguisher

NASA Technical Reports Server (NTRS)

Butz, James R.; Turchi, Craig S.; Kimball, Amanda; McKinnon, Thomas; Riedel, Edward

2010-01-01

A fine-water-mist fire-suppression device has been designed so that it can be discharged uniformly in any orientation via a high-pressure gas propellant. Standard fire extinguishers used while slightly tilted or on their side will not discharge all of their contents. Thanks to the new design, this extinguisher can be used in multiple environments such as aboard low-gravity spacecraft, airplanes, and aboard vehicles that may become overturned prior to or during a fire emergency. Research in recent years has shown that fine water mist can be an effective alternative to Halons now banned from manufacture. Currently, NASA uses carbon dioxide for fire suppression on the International Space Station (ISS) and Halon chemical extinguishers on the space shuttle. While each of these agents is effective, they have drawbacks. The toxicity of carbon dioxide requires that the crew don breathing apparatus when the extinguishers are deployed on the ISS, and Halon use in future spacecraft has been eliminated because of international protocols on substances that destroy atmospheric ozone. A major advantage to the new system on occupied spacecraft is that the discharged system is locally rechargeable. Since the only fluids used are water and nitrogen, the system can be recharged from stores of both carried aboard the ISS or spacecraft. The only support requirement would be a pump to fill the water and a compressor to pressurize the nitrogen propellant gas. This system uses a gaseous agent to pressurize the storage container as well as to assist in the generation of the fine water mist. The portable fire extinguisher hardware works like a standard fire extinguisher with a single storage container for the agents (water and nitrogen), a control valve assembly for manual actuation, and a discharge nozzle. The design implemented in the proof-of-concept experiment successfully extinguished both open fires and fires in baffled enclosures.

Identification of ballast water discharge profiles of a port to enable effective ballast water management and environmental studies

NASA Astrophysics Data System (ADS)

David, Matej; Gollasch, Stephan; Penko, Ludvik

2018-03-01

Information about the profile of ballast water discharges in a port is one of the basic elements of the decision making process in ballast water risk assessment and management, and supports the evaluation of dimensions and processes of aquatic species invasions with vessels ballast water. In the lack of ballast water reporting, ballast water discharge assessments need to be conducted. In this study we have assessed and compared ballast water discharge profiles of two ports with different maritime traffic and cargo profiles, the Port of Hamburg (Germany) and the Muuga Harbour, Port of Tallinn (Estonia). This study shows methods and approaches which can be used to assess volumes and donor ports of ballast water discharges for a port at the level of each vessel call. These methods and approaches can be applied to any port to support the implementation of feasible and efficient ballast water management measures and to enable environmental studies including long-term accumulation risks of disinfection by-products from ballast water management systems making use of active substances, as well as for discharges of other chemical compounds.

Generation of ozone by pulsed corona discharge over water surface in hybrid gas liquid electrical discharge reactor

NASA Astrophysics Data System (ADS)

Lukes, Petr; Clupek, Martin; Babicky, Vaclav; Janda, Vaclav; Sunka, Pavel

2005-02-01

Ozone formation by a pulse positive corona discharge generated in the gas phase between a planar high voltage electrode made from reticulated vitreous carbon and a water surface with an immersed ground stainless steel plate electrode was investigated under various operating conditions. The effects of gas flow rate (0.5-3 litre min-1), discharge gap spacing (2.5-10 mm), applied input power (2-45 W) and gas composition (oxygen containing argon or nitrogen) on ozone production were determined. Ozone concentration increased with increasing power input and with increasing discharge gap. The production of ozone was significantly affected by the presence of water vapour formed through vaporization of water at the gas-liquid interface by the action of the gas phase discharge. The highest energy efficiency for ozone production was obtained using high voltage pulses of approximately 150 ns duration in Ar/O2 mixtures with the maximum efficiency (energy yield) of 23 g kW h-1 for 40% argon content.

Ultraviolet radiation from the pulsed corona discharge in water

NASA Astrophysics Data System (ADS)

Lukes, Petr; Clupek, Martin; Babicky, Vaclav; Sunka, Pavel

2008-05-01

Quantitative analysis of ultraviolet radiation from the pulsed corona discharge in water with needle-plate electrode geometry (~1-3 J pulse-1) was performed using the potassium ferrioxalate actinometry. Photon flux J190-280 and radiant energy Q190-280 of the UV light emitted from the discharge at spectral region 190-280 nm was determined in dependence on the applied voltage (17-29 kV, positive polarity) and the solution conductivity (100-500 µS cm-1). The intensity of the UV radiation strongly increased with increasing water conductivity and applied voltage. Depending on the applied voltage the determined photon flux varied by more than two orders of magnitude within the range of solution conductivities 100-500 µS cm-1. It was found that photon flux from the discharge may be directly related to the discharge pulse mean power Pp as J190-280 = 44.33 P_p^{2.11} (quanta pulse-1). A significant role of UV radiation in the production of hydrogen peroxide and bacterial inactivation by the corona discharge in water has been identified. As the solution conductivity increased the yield of H2O2 produced by the discharge decreased due to increasing photolysis of H2O2 accounting for up to 14% of the total decomposition rate of H2O2. As regards bactericidal effects, it was estimated that the UV radiation contributes about 30% to the overall inactivation of Escherichia coli.

Ground-penetrating radar methods used in surface-water discharge measurements

USGS Publications Warehouse

Haeni, F.P.; Buursink, Marc L.; Costa, John E.; Melcher, Nick B.; Cheng, Ralph T.; Plant, William J.

2000-01-01

In 1999, an experiment was conducted to see if a combination of complementary radar methods could be used to calculate the discharge of a river without having any of the measuring equipment in the water. The cross-sectional area of the 183-meter wide Skagit River in Washington State was measured using a ground-penetrating radar (GPR) system with a single 100-MHz antenna. A van-mounted, side-looking pulsed-Doppler radar system was used to collect water-surface velocity data across the same section of the river. The combined radar data sets were used to calculate the river discharge and the results compared closely to the discharge measurement made by using the standard in-water measurement techniques.

Plasma processes in water under effect of short duration pulse discharges

NASA Astrophysics Data System (ADS)

Gurbanov, Elchin

2013-09-01

It is very important to get a clear water without any impurities and bacteria by methods, that don't change the physical and chemical indicators of water now. In this article the plasma processes during the water treatment by strong electric fields and short duration pulse discharges are considered. The crown discharge around an electrode with a small radius of curvature consists of plasma leader channels with a high conductivity, where the thermo ionization processes and UV-radiation are taken place. Simultaneously the partial discharges around potential electrode lead to formation of atomic oxygen and ozone. The spark discharge arises, when plasma leader channels cross the all interelectrode gap, where the temperature and pressure are strongly grown. As a result the shock waves and dispersing liquid streams in all discharge gap are formed. The plasma channels extend, pressure inside it becomes less than hydrostatic one and the collapse and UV-radiation processes are started. The considered physical processes can be successfully used as a basis for development of pilot-industrial installations for conditioning of drinking water and to disinfecting of sewage.

Are Sierran Lakes Warming as a Result of Climate Change? The Effects of Climate Warming and Variation in Precipitation on Water Temperature in a Snowmelt-Dominated Lake

NASA Astrophysics Data System (ADS)

Sadro, S.; Melack, J. M.; Sickman, J. O.; Skeen, K.

2016-12-01

Water temperature regulates a broad range of fundamental ecosystem processes in lakes. While climate can be an important factor regulating lake temperatures, heterogeneity in the warming response of lakes is large, and variation in precipitation is rarely considered. We analyzed three decades of climate and water temperature data from a high-elevation catchment in the southern Sierra Nevada of California to illustrate the magnitude of warming taking place during different seasons and the role of precipitation in regulating lake temperatures. Significant climate warming trends were evident during all seasons except spring. Nighttime rates of climate warming were approximately 25% higher than daytime rates. Spatial patterns in warming were elevation dependent, with rates of temperature increase higher at sites above 2800 m.a.s.l. than below. Although interannual variation in snow deposition was high, the frequency and severity of recent droughts has contributed to a significant 3.4 mm year -1 decline in snow water equivalent over the last century. Snow accumulation, more than any other climate factor, regulated lake temperature; 94% of variation in summer lake temperature was regulated by precipitation as snow. For every 100 mm decrease in snow water equivalent there was a 0.62 ° increase in lake temperature. Drought years amplify warming in lakes by reducing the role of cold spring meltwaters in lake energy budgets and prolonging the ice-free period during which lakes warm. The combination of declining winter snowpack and warming air temperatures has the capacity to amplify the effect of climate warming on lake temperatures during drought years. Interactions among climatic factors need to be considered when evaluating ecosystem level effects, especially in mountain regions. For mountain lakes already affected by drought, continued climate warming during spring and autumn has the greatest potential to impact mean lake temperatures.

33 CFR 151.2030 - Ballast water discharge standard (BWDS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... possibly prevent the introduction and spread of non-indigenous aquatic invasive species. ... COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in Waters... maximum extent practicable that aquatic nuisance species are not discharged into waters of the United...

33 CFR 151.2030 - Ballast water discharge standard (BWDS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... possibly prevent the introduction and spread of non-indigenous aquatic invasive species. ... COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in Waters... maximum extent practicable that aquatic nuisance species are not discharged into waters of the United...

33 CFR 151.2030 - Ballast water discharge standard (BWDS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... possibly prevent the introduction and spread of non-indigenous aquatic invasive species. ... COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in Waters... maximum extent practicable that aquatic nuisance species are not discharged into waters of the United...

Fresh-water discharge salinity relations in the tidal Delaware River

USGS Publications Warehouse

Keighton, Walter B.

1966-01-01

Sustained flows of fresh water greater than 3,500, 4,400, and 5,300 cubic feet per second into the Delaware River estuary at Trenton, NJ assure low salinity at League Island, Eddystone, and Marcus Hook, respectively. When the discharge at Trenton is less than these critical values, salinity is very sensitive to change in discharge, so that a relatively small decrease in fresh-water discharge results in a relatively great increase in salinity. Comparison of the discharge-salinity relations observed for the 14-year period August 1949-December 1963 with relations proposed by other workers but based on other time periods indicate that such relations change with time and that salinity is affected not only by discharge but also by dredging; construction of breakwater, dikes, and tidal barriers; changing sea level; tidal elevation; tidal range; and wind intensity and direction.

Water Quality Outlet Works Prototype Tests, Warm Springs Dam Dry Creek, Russian River Basin Sonoma County, California

DTIC Science & Technology

1989-03-01

34.4* TECHNICAL REPORT HL-89-4 WATER QUALITY OUTLET WORKS PROTOTYPE TESTS, WARM SPRINGS DAM DRY CREEK, RUSSIAN RIVER BASIN AD-A207 058 SONOMA COUNTY , CALIFORNIA...Clawflcation) [7 Water Quality Outlet Works Prototype Tests, Warm Springs Dam, Dry Creek, Russian River Basin, Sonoma County , California 12. PERSONAL...Cointogobvil Be,,pesso Figur 1. iciniyama Pealm WATER QUALITY OUTLET WORKS PROTOTYPE TESTS WARM SPRINGS DAM, DRY CREEK, RUSSIAN RIVER BASIN SONOMA COUNTY , CALIFORNIA

Extratropical Influence of Upper Tropospheric Water Vapor on Greenhouse Warming

NASA Technical Reports Server (NTRS)

Hu, H.; Liu, W.

1998-01-01

The purpose of this paper is to re-examine the impact of upper tropospheric water vapor on greenhouse warming in midlatitudes by analyzing the recent observations of the upper tropospheric water vapor from the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS), in conjuction with other space-based measurement and model simulation products.

Water Availability in a Warming World

NASA Astrophysics Data System (ADS)

Aminzade, Jennifer

As climate warms during the 21st century, the resultant changes in water availability are a vital issue for society, perhaps even more important than the magnitude of warming itself. Yet our climate models disagree in their forecasts of water availability, limiting our ability to plan accordingly. This thesis investigates future water availability projections from Coupled Ocean-Atmosphere General Circulation Models (GCMs), primarily using two water availability measures: soil moisture and the Supply Demand Drought Index (SDDI). Chapter One introduces methods of measuring water availability and explores some of the fundamental differences between soil moisture, SDDI and the Palmer Drought Severity Index (PDSI). SDDI and PDSI tend to predict more severe future drought conditions than soil moisture; 21st century projections of SDDI show conditions rivaling North American historic mega-droughts. We compare multiple potential evapotranspiration (EP) methods in New York using input from the GISS Model ER GCM and local station data from Rochester, NY, and find that they compare favorably with local pan evaporation measurements. We calculate SDDI and PDSI values using various EP methods, and show that changes in future projections are largest when using EP methods most sensitive to global warming, not necessarily methods producing EP values with the largest magnitudes. Chapter Two explores the characteristics and biases of the five GCMs and their 20th and 21st century climate projections. We compare atmospheric variables that drive water availability changes globally, zonally, and geographically among models. All models show increases in both dry and wet extremes for SDDI and soil moisture, but increases are largest for extreme drying conditions using SDDI. The percentage of gridboxes that agree on the sign of change of soil moisture and SDDI between models is very low, but does increase in the 21st century. Still, differences between models are smaller than differences

Micro electrical discharge milling using deionized water as a dielectric fluid

NASA Astrophysics Data System (ADS)

Chung, Do Kwan; Kim, Bo Hyun; Chu, Chong Nam

2007-05-01

In electrical discharge machining, dielectric fluid is an important factor affecting machining characteristics. Generally, kerosene and deionized water have been used as dielectric fluids. In micro electrical discharge milling, which uses a micro electrode as a tool, the wear of the tool electrode decreases the machining accuracy. However, the use of deionized water instead of kerosene can reduce the tool wear and increase the machining speed. This paper investigates micro electrical discharge milling using deionized water. Deionized water with high resistivity was used to minimize the machining gap. Machining characteristics such as the tool wear, machining gap and machining rate were investigated according to resistivity of deionized water. As the resistivity of deionized water decreased, the tool wear was reduced, but the machining gap increased due to electrochemical dissolution. Micro hemispheres were machined for the purpose of investigating machining efficiency between dielectric fluids, kerosene and deionized water.

TOPEX/El Nino Watch - Warm Water Pool is Increasing, Nov. 10, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S./French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Nov. 10, 1997. The volume of extra warm surface water (shown in white) in the core of the El Nino continues to increase, especially in the area between 15 degrees south latitude and 15 degrees north latitude in the eastern Pacific Ocean. The area of low sea level (shown in purple) has decreased somewhat from late October. The white and red areas indicate unusual patterns of heat storage; in the white areas, the sea surface is between 14 centimeters and 32 cm (6 inches to 13 inches) above normal; in the red areas, it is about 10 centimeters (4 inches) above normal. The surface area covered by the warm water mass is about one-and-one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21 to 30 degrees Celsius (70 to 85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level.

The El Nino phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white areas) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmospheric system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and

Water-Quality Assessment of Southern Florida - Wastewater Discharges and Runoff

USGS Publications Warehouse

Marella, Richard L.

1998-01-01

Nearly 800 million gallons per day of treated wastewater was discharged in the Southern Florida National Water-Quality Assessment (NAWQA) study unit in 1990, most to the Atlantic Ocean (44 percent) and to deep, saline aquifers (25 percent). About 9 percent was discharged to fresh surface waters and about 22 percent to shallow ground water, of which septic tanks accounted for 9 percent. Runoff from agricultural and urban lands, though not directly measured, is a large source of wastewater in southern Florida.

Changing forest water yields in response to climate warming: results from long-term experimental watershed sites across North America.

PubMed

Creed, Irena F; Spargo, Adam T; Jones, Julia A; Buttle, Jim M; Adams, Mary B; Beall, Fred D; Booth, Eric G; Campbell, John L; Clow, Dave; Elder, Kelly; Green, Mark B; Grimm, Nancy B; Miniat, Chelcy; Ramlal, Patricia; Saha, Amartya; Sebestyen, Stephen; Spittlehouse, Dave; Sterling, Shannon; Williams, Mark W; Winkler, Rita; Yao, Huaxia

2014-10-01

Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment's change in actual ET divided by P [AET/P; evaporative index (EI)] coincident with a shift from a cool to a warm period - a positive d indicates an upward shift in EI and smaller than expected water yields, and a negative d indicates a downward shift in EI and larger than expected water yields. Elasticity was defined as the ratio of interannual variation in potential ET divided by P (PET/P; dryness index) to interannual variation in the EI - high elasticity indicates low d despite large range in drying index (i.e., resilient water yields), low elasticity indicates high d despite small range in drying index (i.e., nonresilient water yields). Although the data needed to fully evaluate ecosystems based on these metrics are limited, we were able to identify some characteristics of response among forest types. Alpine sites showed the greatest sensitivity to climate warming with any warming leading to increased water yields. Conifer forests included catchments with lowest elasticity and stable to larger water yields. Deciduous forests included catchments with intermediate elasticity and stable to smaller water yields. Mixed coniferous/deciduous forests included catchments with highest elasticity and stable water yields. Forest type appeared to influence the resilience of catchment water yields to climate warming, with conifer and deciduous catchments more susceptible to

Changing forest water yields in response to climate warming: results from long-term experimental watershed sites across North America

PubMed Central

Creed, Irena F; Spargo, Adam T; Jones, Julia A; Buttle, Jim M; Adams, Mary B; Beall, Fred D; Booth, Eric G; Campbell, John L; Clow, Dave; Elder, Kelly; Green, Mark B; Grimm, Nancy B; Miniat, Chelcy; Ramlal, Patricia; Saha, Amartya; Sebestyen, Stephen; Spittlehouse, Dave; Sterling, Shannon; Williams, Mark W; Winkler, Rita; Yao, Huaxia

2014-01-01

Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment's change in actual ET divided by P [AET/P; evaporative index (EI)] coincident with a shift from a cool to a warm period – a positive d indicates an upward shift in EI and smaller than expected water yields, and a negative d indicates a downward shift in EI and larger than expected water yields. Elasticity was defined as the ratio of interannual variation in potential ET divided by P (PET/P; dryness index) to interannual variation in the EI – high elasticity indicates low d despite large range in drying index (i.e., resilient water yields), low elasticity indicates high d despite small range in drying index (i.e., nonresilient water yields). Although the data needed to fully evaluate ecosystems based on these metrics are limited, we were able to identify some characteristics of response among forest types. Alpine sites showed the greatest sensitivity to climate warming with any warming leading to increased water yields. Conifer forests included catchments with lowest elasticity and stable to larger water yields. Deciduous forests included catchments with intermediate elasticity and stable to smaller water yields. Mixed coniferous/deciduous forests included catchments with highest elasticity and stable water yields. Forest type appeared to influence the resilience of catchment water yields to climate warming, with conifer and deciduous catchments more susceptible to

Density matters: Review of approaches to setting organism-based ballast water discharge standards

USGS Publications Warehouse

Lee II,; Frazier,; Ruiz,

2010-01-01

As part of their effort to develop national ballast water discharge standards under NPDES permitting, the Office of Water requested that WED scientists identify and review existing approaches to generating organism-based discharge standards for ballast water. Six potential approaches were identified and the utility and uncertainties of each approach was evaluated. During the process of reviewing the existing approaches, the WED scientists, in conjunction with scientists at the USGS and Smithsonian Institution, developed a new approach (per capita invasion probability or "PCIP") that addresses many of the limitations of the previous methodologies. THE PCIP approach allows risk managers to generate quantitative discharge standards using historical invasion rates, ballast water discharge volumes, and ballast water organism concentrations. The statistical power of sampling ballast water for both the validation of ballast water treatment systems and ship-board compliance monitoring with the existing methods, though it should be possible to obtain sufficient samples during treatment validation. The report will go to a National Academy of Sciences expert panel that will use it in their evaluation of approaches to developing ballast water discharge standards for the Office of Water.

Assessing the magnitude and timing of anthropogenic warming of a shallow aquifer: example from Virginia Beach, USA

USGS Publications Warehouse

Eggleston, John R.; McCoy, Kurt J.

2015-01-01

Groundwater temperature measurements in a shallow coastal aquifer in Virginia Beach, Virginia, USA, suggest groundwater warming of +4.1 °C relative to deeper geothermal gradients. Observed warming is related to timing and depth of influence of two potential thermal drivers—atmospheric temperature increases and urbanization. Results indicate that up to 30 % of groundwater warming at the water table can be attributed to atmospheric warming while up to 70 % of warming can be attributed to urbanization. Groundwater temperature readings to 30-m depth correlate positively with percentage of impervious cover and negatively with percentage of tree canopy cover; thus, these two land-use metrics explain up to 70 % of warming at the water table. Analytical and numerical modeling results indicate that an average vertical groundwater temperature profile for the study area, constructed from repeat measurement at 11 locations over 15 months, is consistent with the timing of land-use change over the past century in Virginia Beach. The magnitude of human-induced warming at the water table (+4.1 °C) is twice the current seasonal temperature variation, indicating the potential for ecological impacts on wetlands and estuaries receiving groundwater discharge from shallow aquifers.

Preliminary Evidence for the Amplification of Global Warming in Shallow, Intertidal Estuarine Waters

EPA Science Inventory

Over the past 50 years, mean annual water temperature in northeastern U.S. estuaries has increased by approximately 1.2°C, with most of the warming recorded in the winter and early spring. We hypothesize that this warming may be amplified in the shallow (<2m), nearshore portions ...

Characteristics of produced water discharged to the Gulf of Mexico hypoxiczone.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veil, J. A.; Kimmell, T. A.; Rechner, A. C.

2005-08-24

Each summer, an area of low dissolved oxygen (the hypoxic zone) forms in the shallow nearshore Gulf of Mexico waters from the Mississippi River Delta westward to near the Texas/Louisiana border. Most scientists believe that the leading contributor to the hypoxic zone is input of nutrients (primarily nitrogen and phosphorus compounds) from the Mississippi and Atchafalaya Rivers. The nutrients stimulate growth of phytoplankton. As the phytoplankton subsequently die, they fall to the bottom waters where they are decomposed by microorganisms. The decomposition process consumes oxygen in the bottom waters to create hypoxic conditions. Sources other than the two rivers mentionedmore » above may also contribute significant quantities of oxygen-demanding pollutants. One very visible potential source is the hundreds of offshore oil and gas platforms located within or near the hypoxic zone. Many of these platforms discharge varying volumes of produced water. However, only limited data characterizing oxygen demand and nutrient concentration and loading from offshore produced water discharges have been collected. No comprehensive and coordinated oxygen demand data exist for produced water discharges in the Gulf of Mexico. This report describes the results of a program to sample 50 offshore oil and gas platforms located within the Gulf of Mexico hypoxic zone. The program was conducted in response to a requirement in the U.S. Environmental Protection Agency (EPA) general National Pollutant Discharge Elimination System (NPDES) permit for offshore oil and gas discharges. EPA requested information on the amount of oxygen-demanding substances contained in the produced water discharges. This information is needed as inputs to several water quality models that EPA intends to run to estimate the relative contributions of the produced water discharges to the occurrence of the hypoxic zone. Sixteen platforms were sampled 3 times each at approximately one-month intervals to give an

Water isotope tracers of tropical hydroclimate in a warming world

NASA Astrophysics Data System (ADS)

Konecky, B. L.; Noone, D.; Nusbaumer, J. M.; Cobb, K. M.; Di Nezio, P. N.; Otto-Bliesner, B. L.

2016-12-01

The tropical water cycle is projected to undergo substantial changes under a warming climate, but direct meteorological observations to contextualize these changes are rare prior to the 20th century. Stable oxygen and hydrogen isotope ratios (δ18O, δD) of environmental waters preserved in geologic archives are increasingly being used to reconstruct terrestrial rainfall over many decades to millions of years. However, a rising number of new, modern-day observations and model simulations have challenged previous interpretations of these isotopic signatures. This presentation systematically evaluates the three main influences on the δ18O and δD of modern precipitation - rainfall amount, cloud type, and moisture transport - from terrestrial stations throughout the tropics, and uses this interpretive framework to understand past changes in terrestrial tropical rainfall. Results indicate that cloud type and moisture transport have a larger influence on modern δ18O and δD of tropical precipitation than previously believed, indicating that isotope records track changes in cloud characteristics and circulation that accompany warmer and cooler climate states. We use our framework to investigate isotopic records of the land-based tropical rain belt during the Last Glacial Maximum, the period of warming following the Little Ice Age, and the 21st century. Proxy and observational data are compared with water isotope-enabled simulations with the Community Earth System Model in order to discuss how global warming and cooling may influence tropical terrestrial hydroclimate.

Changing forest water yields in response to climate warming: results from long-term experimental watershed sites across North America

Treesearch

Irena F. Creed; Adam T. Spargo; Julia A. Jones; Jim M. Buttle; Mary B. Adams; Fred D. Beall; Eric G. Booth; John L. Campbell; Dave Clow; Kelly Elder; Mark B. Green; Nancy B. Grimm; Chelcy Miniat; Patricia Ramlal; Amartya Saha; Stephen Sebestyen; Dave Spittlehouse; Shannon Sterling; Mark W. Williams; Rita Winkler; Huaxia Yao

2014-01-01

Climate warming is projected to affect forest water yields but the effects are expected to vary.We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm...

Acute vascular effects of carbonated warm water lower leg immersion in healthy young adults.

PubMed

Ogoh, Shigehiko; Nagaoka, Ryohei; Mizuno, Takamasa; Kimura, Shohei; Shidahara, Yasuhiro; Ishii, Tomomi; Kudoh, Michinari; Iwamoto, Erika

2016-12-01

Endothelial dysfunction is associated with increased cardiovascular mortality and morbidity; however, this dysfunction may be ameliorated by several therapies. For example, it has been reported that heat-induced increases in blood flow and shear stress enhance endothelium-mediated vasodilator function. Under these backgrounds, we expect that carbon dioxide (CO 2 )-rich water-induced increase in skin blood flow improves endothelium-mediated vasodilation with less heat stress. To test our hypothesis, we measured flow-mediated dilation (FMD) before and after acute immersion of the lower legs and feet in mild warm (38°C) normal or CO 2 -rich tap water (1000 ppm) for 20 min in 12 subjects. Acute immersion of the lower legs and feet in mild warm CO 2 -rich water increased FMD (P < 0.01) despite the lack of change in this parameter upon mild warm normal water immersion. In addition, FMD was positively correlated with change in skin blood flow regardless of conditions (P < 0.01), indicating that an increase in skin blood flow improves endothelial-mediated vasodilator function. Importantly, the temperature of normal tap water must reach approximately 43°C to achieve the same skin blood flow level as that obtained during mild warm CO 2 -rich water immersion (38°C). These findings suggest that CO 2 -rich water-induced large increases in skin blood flow may improve endothelial-mediated vasodilator function while causing less heat stress. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Environmental policy constraints for acidic exhaust gas scrubber discharges from ships.

PubMed

Ülpre, H; Eames, I

2014-11-15

Increasingly stringent environmental legislation on sulphur oxide emissions from the combustion of fossil fuels onboard ships (International Maritime Organization (IMO) Regulation 14) can be met by either refining the fuel to reduce sulphur content or by scrubbing the exhaust gases. Commonly used open loop marine scrubbers discharge warm acidic exhaust gas wash water into the sea, depressing its pH. The focus on this paper is on the physics and chemistry behind the disposal of acidic discharges in seawater. The IMO Marine Environment Protection Committee (MEPC 59/24/Add.1 Annex 9) requires the wash water to reach a pH greater than 6.5 at a distance of 4m from the point of discharge. We examine the engineering constraints, specifically size and number of ports, to identify the challenges of meeting regulatory compliance. Copyright © 2014. Published by Elsevier Ltd.

33 CFR 151.1511 - Ballast water discharge standard (BWDS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in the... maximum extent practicable that aquatic nuisance species are not discharged into waters of the United..., practicable, and/or may possibly prevent the introduction and spread of non-indigenous aquatic invasive...

33 CFR 151.1511 - Ballast water discharge standard (BWDS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in the... maximum extent practicable that aquatic nuisance species are not discharged into waters of the United..., practicable, and/or may possibly prevent the introduction and spread of non-indigenous aquatic invasive...

33 CFR 151.1511 - Ballast water discharge standard (BWDS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in the... maximum extent practicable that aquatic nuisance species are not discharged into waters of the United..., practicable, and/or may possibly prevent the introduction and spread of non-indigenous aquatic invasive...

Estimated ground-water discharge by evapotranspiration from Death Valley, California, 1997-2001

USGS Publications Warehouse

DeMeo, Guy A.; Laczniak, Randell J.; Boyd, Robert A.; Smith, J. LaRue; Nylund, Walter E.

2003-01-01

The U.S. Geological Survey, in cooperation with the National Park Service and Inyo County, Calif., collected field data from 1997 through 2001 to accurately estimate the amount of annual ground-water discharge by evapotranspiration (ET) from the floor of Death Valley, California. Multispectral satellite-imagery and National Wetlands Inventory data are used to delineate evaporative ground-water discharge areas on the Death Valley floor. These areas are divided into five general units where ground-water discharge from ET is considered to be significant. Based upon similarities in soil type, soil moisture, vegetation type, and vegetation density; the ET units are salt-encrusted playa (21,287 acres), bare-soil playa (75,922 acres), low-density vegetation (6,625 acres), moderate-density vegetation (5,019 acres), and high-density vegetation (1,522 acres). Annual ET was computed for ET units with micrometeorological data which were continuously measured at six instrumented sites. Total ET was determined at sites that were chosen for their soil- and vegetated-surface conditions, which include salt-encrusted playa (extensive salt encrustation) 0.17 feet per year, bare-soil playa (silt and salt encrustation) 0.21 feet per year, pickleweed (pickleweed plants, low-density vegetation) 0.60 feet per year, Eagle Borax (arrowweed plants and salt grass, moderate-density vegetation) 1.99 feet per year, Mesquite Flat (mesquite trees, high-density vegetation) 2.86 feet per year, and Mesquite Flat mixed grasses (mixed meadow grasses, high-density vegetation) 3.90 feet per year. Precipitation, flooding, and ground-water discharge satisfy ET demand in Death Valley. Ground-water discharge is estimated by deducting local precipitation and flooding from cumulative ET estimates. Discharge rates from ET units were not estimated directly because the range of vegetation units far exceeded the five specific vegetation units that were measured. The rate of annual ground-water discharge by ET for

Winter cold of eastern continental boundaries induced by warm ocean waters.

PubMed

Kaspi, Yohai; Schneider, Tapio

2011-03-31

In winter, northeastern North America and northeastern Asia are both colder than other regions at similar latitudes. This has been attributed to the effects of stationary weather systems set by elevated terrain (orography), and to a lack of maritime influences from the prevailing westerly winds. However, the differences in extent and orography between the two continents suggest that further mechanisms are involved. Here we show that this anomalous winter cold can result in part from westward radiation of large-scale atmospheric waves--nearly stationary Rossby waves--generated by heating of the atmosphere over warm ocean waters. We demonstrate this mechanism using simulations with an idealized general circulation model, with which we show that the extent of the cold region is controlled by properties of Rossby waves, such as their group velocity and its dependence on the planetary rotation rate. Our results show that warm ocean waters contribute to the contrast in mid-latitude winter temperatures between eastern and western continental boundaries not only by warming western boundaries, but also by cooling eastern boundaries.

Is Detrusor Contraction during Rapid Bladder Filling Caused by Cold or Warm Water? A Randomized, Controlled, Double-Blind Trial.

PubMed

Kozomara, Marko; Mehnert, Ulrich; Seifert, Burkhardt; Kessler, Thomas M

2018-01-01

We investigated whether detrusor contraction during rapid bladder filling is provoked by cold or warm water. Patients with neurogenic lower urinary tract dysfunction were included in this randomized, controlled, double-blind trial. At the end of a standard urodynamic investigation patients underwent 2 bladder fillings using a 4C ice water test or a 36C warm water test saline solution at a filling speed of 100 ml per minute. The order was randomly selected, and patients and investigators were blinded to the order. The primary outcome measure was detrusor overactivity, maximum detrusor pressure and maximum bladder filling volume during the ice and warm water tests. Nine women and 31 men were the subject of data analysis. Neurogenic lower urinary tract dysfunction was caused by spinal cord injury in 33 patients and by another neurological disorder in 7. Irrespective of test order detrusor overactivity occurred significantly more often during the ice water test than during the warm water test (30 of 40 patients or 75% vs 25 of 40 or 63%, p = 0.02). When comparing the ice water test to the warm water test, maximum detrusor pressure was significantly higher and maximum bladder filling volume was significantly lower during the ice water test (each p <0.001). The order of performing the tests (ice water first vs warm water first) had no effect on the parameters. Our findings imply that the more frequent detrusor overactivity, higher maximum detrusor pressure and lower bladder filling volume during the ice water test compared to the warm water test were caused by cold water. This underlies the theory of a C-fiber mediated bladder cooling reflex in humans. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Changing Waters: Are Climate-Driven Changes in Discharge Regimes Increasing Eutrophication Risk in the Great Lakes Basin?

NASA Astrophysics Data System (ADS)

Van Meter, K. J.; Basu, N. B.

2017-12-01

In recent decades, the Great Lakes Basin (GLB) has experienced increasing precipitation, warming temperatures, and earlier spring thaws. During this same period, the region has been plagued by problems of water quality, with Lake Erie, in particular, experiencing a re-emergence of major eutrophication events, including an increased incidence of Harmful Algal Blooms. Although the prevailing paradigm is that eutrophication of inland waters is directly correlated with total phosphorus (P) inputs, recent decades have seen a decrease in the total P being delivered to the lakes from contributing watersheds. This apparent disconnect between inputs and outputs, i.e. decreasing P inputs but increased eutrophication, has led some to speculate that loading of total P is an insufficient metric of eutrophication risk and that increasing ratios of soluble reactive P (SRP) in relation to the total P (TP) entering inland water bodies may be a more important driver of algal growth. We hypothesize that changes in seasonal discharge patterns may be contributing to changes in the forms of P being delivered to the lakes, potentially due to changes in delivery pathways-for example surface pathways are more dominant in spring snowmelt, while shallow subsurface and tile pathways are more dominant during winter freeze-thaw events. To test this hypothesis, we have utilized data from more than 200 gaging stations across the GLB to explore the influences of climate and changing hydrologic patterns on biogeochemical processing and transport within the GLB. More specifically, we have asked the following questions: 1) How are discharge patterns changing across the GLB? 2) Are SRP:TP ratios increasing in subwatersheds of the GLB, and what are the spatial patterns in these changes? 3) Are climate-related changes in seasonality, e.g. earlier snowmelt, decreasing snowfall, longer growing seasons, linked to increased ratios of bioavailable P? Our results suggest that changes in precipitation as well

Estimation of the discharges of the multiple water level stations by multi-objective optimization

NASA Astrophysics Data System (ADS)

Matsumoto, Kazuhiro; Miyamoto, Mamoru; Yamakage, Yuzuru; Tsuda, Morimasa; Yanami, Hitoshi; Anai, Hirokazu; Iwami, Yoichi

2016-04-01

This presentation shows two aspects of the parameter identification to estimate the discharges of the multiple water level stations by multi-objective optimization. One is how to adjust the parameters to estimate the discharges accurately. The other is which optimization algorithms are suitable for the parameter identification. Regarding the previous studies, there is a study that minimizes the weighted error of the discharges of the multiple water level stations by single-objective optimization. On the other hand, there are some studies that minimize the multiple error assessment functions of the discharge of a single water level station by multi-objective optimization. This presentation features to simultaneously minimize the errors of the discharges of the multiple water level stations by multi-objective optimization. Abe River basin in Japan is targeted. The basin area is 567.0km2. There are thirteen rainfall stations and three water level stations. Nine flood events are investigated. They occurred from 2005 to 2012 and the maximum discharges exceed 1,000m3/s. The discharges are calculated with PWRI distributed hydrological model. The basin is partitioned into the meshes of 500m x 500m. Two-layer tanks are placed on each mesh. Fourteen parameters are adjusted to estimate the discharges accurately. Twelve of them are the hydrological parameters and two of them are the parameters of the initial water levels of the tanks. Three objective functions are the mean squared errors between the observed and calculated discharges at the water level stations. Latin Hypercube sampling is one of the uniformly sampling algorithms. The discharges are calculated with respect to the parameter values sampled by a simplified version of Latin Hypercube sampling. The observed discharge is surrounded by the calculated discharges. It suggests that it might be possible to estimate the discharge accurately by adjusting the parameters. In a sense, it is true that the discharge of a water

Field evaluation of shallow-water acoustic doppler current profiler discharge measurements

USGS Publications Warehouse

Rehmel, M.S.

2007-01-01

In 2004, the U.S. Geological Survey (USGS) Office of Surface Water staff and USGS Water Science employees began testing the StreamPro, an acoustic Doppler current profiler (ADCP) for shallow-water discharge measurements. Teledyne RD Instruments introduced the StreamPro in December of 2003. The StreamPro is designed to make a "moving boat" discharge measurement in streams with depths between 0.15 and 2 m. If the StreamPro works reliably in these conditions, it will allow for use of ADCPs in a greater number of streams than previously possible. Evaluation sites were chosen to test the StreamPro over a range of conditions. Simultaneous discharge measurements with mechanical and other acoustic meters, along with stable rating curves at established USGS streamflow-gaging stations, were used for comparisons. The StreamPro measurements ranged in mean velocity from 0.076 to 1.04 m/s and in discharge from 0.083 m 3/s to 43.4 m 3/s. Tests indicate that discharges measured with the StreamPro compare favorably to the discharges measured with the other meters when the mean channel velocity is greater than 0.25 m/s. When the mean channel velocity is less than 0.25 m/s, the StreamPro discharge measurements for individual transects have greater variability than those StreamPro measurements where the mean channel velocity is greater than 0.25 m/s. Despite this greater variation in individual transects, there is no indication that the StreamPro measured discharges (the mean discharge for all transects) are biased, provided that enough transects are used to determine the mean discharge. ?? 2007 ASCE.

Density Matters: Review of Approaches to Setting Organism-Based Ballast Water Discharge Standards

EPA Science Inventory

As part of their effort to develop national ballast water discharge standards under NPDES permitting, the Office of Water requested that WED scientists identify and review existing approaches to generating organism-based discharge standards for ballast water. Six potential appro...

Partitioning the effects of Global Warming on the Hydrological Cycle with Stable Isotopes in Water Vapor

NASA Astrophysics Data System (ADS)

Dee, S. G.; Russell, J. M.; Nusbaumer, J. M.; Konecky, B. L.; Buenning, N. H.; Lee, J. E.; Noone, D.

2016-12-01

General circulation models (GCMs) suggest that much of the global hydrological cycle's response to anthropogenic warming will be caused by increased lower-tropospheric water vapor concentrations and associated feedbacks. However, fingerprinting changes in the global hydrological cycle due to anthropogenic warming remains challenging. Held and Soden (2006) predicted that as lower-tropospheric water vapor increases, atmospheric circulation will weaken as climate warms to maintain the surface energy budget. Unfortunately, the strength of this feedback and the fallout for other branches of the hydrological cycle is difficult to constrain in situ or with GCMs alone. We demonstrate the utility of stable hydrogen isotope ratios in atmospheric water vapor to quantitatively trace changes in atmospheric circulation and convective mass flux in a warming world. We compare water isotope-enabled GCM experiments for control (present-day) CO2 vs. high CO2(2x, 4x) atmospheres in two GCMs, IsoGSM and iCAM5. We evaluate changes in the distribution of water vapor, vertical velocity (omega), and the stream function between these experiments in order to identify spatial patterns of circulation change over the tropical Pacific (where vertical motion is strong) and map the δD of water vapor associated with atmospheric warming. We also probe the simulations to isolate isotopic signatures associated with water vapor residence time, precipitation efficiency, divergence, and cloud physics. We show that there are robust mechanisms that moisten the troposphere and weaken convective mass flux, and that these mechanisms can be tracked using the δD of water vapor. Further, we find that these responses are most pronounced in the upper troposphere. These findings provide a framework to develop new metrics for the detection of global warming impacts to the hydrological cycle. Further, currently available satellite missions measure δD in the atmospheric boundary layer, the free atmosphere, or the

Study of a DC gas discharge with a copper cathode in a water flow

NASA Astrophysics Data System (ADS)

Tazmeev, G. Kh.; Timerkaev, B. A.; Tazmeev, Kh. K.

2017-07-01

A dc gas discharge between copper electrodes in the current range of 5-20 A was studied experimentally. The discharge gap length was varied within 45-70 mm. The cathode was a 10-mm-diameter rod placed in the water flowing out from a dielectric tube. Three discharge configurations differing in the position of the cathode upper end with respect to the water surface were considered: (i) above water; (ii) flush with the water surface, and (iii) under water. The electric and optical characteristics of the discharge in the second configuration were studied in more detail. It is established that the discharge properties are similar to those of an electric arc. Considerable cathode erosion was observed in the third configuration. It is revealed that fine-dispersed copper grains form in the course of erosion.

Analyzing Conductivity Profiles in Stream Waters Influenced by Mine Water Discharges

NASA Astrophysics Data System (ADS)

Räsänen, Teemu; Hämäläinen, Emmy; Hämäläinen, Matias; Turunen, Kaisa; Pajula, Pasi; Backnäs, Soile

2015-04-01

Conductivity is useful as a general measure of stream water quality. Each stream inclines to have a quite constant range of conductivity that can be used as a baseline for comparing and detecting influence of contaminant sources. Conductivity in natural streams and rivers is affected primarily by the geology of the watershed. Thus discharges from ditches and streams affect not only the flow rate in the river but also the water quality and conductivity. In natural stream waters, the depth and the shape of the river channel change constantly, which changes also the water flow. Thus, an accurate measuring of conductivity or other water quality indicators is difficult. Reliable measurements are needed in order to have holistic view about amount of contaminants, sources of discharges and seasonal variation in mixing and dilution processes controlling the conductivity changes in river system. We tested the utility of CastAway-CTD measuring device (SonTek Inc) to indicate the influence of mine waters as well as mixing and dilution occurring in the recipient river affected by treated dewatering and process effluent water discharges from a Finnish gold mine. The CastAway-CTD measuring device is a small, rugged and designed for profiling of depths of up to 100m. Device measures temperature, salinity, conductivity and sound of speed using 5 Hz response time. It has also built-in GPS which produces location information. CTD casts are normally used to produce vertical conductivity profile for rather deep waters like seas or lakes. We did seasonal multiple Castaway-CTD measurements during 2013 and 2014 and produced scaled vertical and horizontal profiles of conductivity and water temperature at the river. CastAway-CTD measurement pinpoints how possible contaminants behave and locate in stream waters. The conductivity profiles measured by CastAway-CTD device show the variation in maximum conductivity values vertically in measuring locations and horizontally in measured cross

Discharge Characteristics of DC Arc Water Plasma for Environmental Applications

NASA Astrophysics Data System (ADS)

Li, Tianming; Sooseok, Choi; Takayuki, Watanabe

2012-12-01

A water plasma was generated by DC arc discharge with a hafnium embedded rod-type cathode and a nozzle-type anode. The discharge characteristics were examined by changing the operation parameter of the arc current. The dynamic behavior of the arc discharge led to significant fluctuations in the arc voltage and its frequency. Analyses of the high speed image and the arc voltage waveform showed that the arc discharge was in the restrike mode and its frequency varied within several tens of kilohertz according to the operating conditions. The larger thermal plasma volume was generated by the higher flow from the forming steam with a higher restrike frequency in the higher arc current conditions. In addition, the characteristics of the water plasma jet were investigated by means of optical emission spectroscopy to identify the abundant radicals required in an efficient waste treatment process.

Passive thermal refugia provided warm water for Florida manatees during the severe winter of 2009-2010

USGS Publications Warehouse

Stith, B.M.; Slone, D.H.; de Wit, M.; Edwards, H.H.; Langtimm, C.A.; Swain, E.D.; Soderqvist, L.E.; Reid, J.P.

2012-01-01

Haloclines induced by freshwater inflow over tidal water have been identified as an important mechanism for maintaining warm water in passive thermal refugia (PTR) used by Florida manatees Trichechus manatus latirostris during winter in extreme southwestern Florida. Record-setting cold during winter 2009–2010 resulted in an unprecedented number of manatee deaths, adding to concerns that PTR may provide inadequate thermal protection during severe cold periods. Hydrological data from 2009–2010 indicate that 2 canal systems in the Ten Thousand Islands (TTI) region acted as PTR and maintained warm bottom-water temperatures, even during severe and prolonged cold periods. Aerial survey counts of live and dead manatees in TTI during the winter of 2009–2010 suggest that these PTR were effective at preventing mass mortality from hypothermia, in contrast to the nearby Everglades region, which lacks similar artificial PTR and showed high manatee carcass counts. Hydrological data from winter 2008–2009 confirmed earlier findings that without haloclines these artificial PTR may become ineffective as warm-water sites. Tidal pumping of groundwater appears to provide additional heat to bottom water during low tide cycles, but the associated thermal inversion is not observed unless salinity stratification is present. The finding that halocline-driven PTR can maintain warm water even under extreme winter conditions suggests that they may have significant potential as warm-water sites. However, availability and conflicting uses of freshwater and other management issues may make halocline-driven PTR unreliable or difficult to manage during winter.

Atmospheric-pressure electric discharge as an instrument of chemical activation of water solutions

NASA Astrophysics Data System (ADS)

Rybkin, V. V.; Shutov, D. A.

2017-11-01

Results of experimental studies and numerical simulations of physicochemical characteristics of plasmas generated in different types of atmospheric-pressure discharges (pulsed streamer corona, gliding electric arc, dielectric barrier discharge, glow-discharge electrolysis, diaphragmatic discharge, and dc glow discharge) used to initiate various chemical processes in water solutions are analyzed. Typical reactor designs are considered. Data on the power supply characteristics, plasma electron parameters, gas temperatures, and densities of active particles in different types of discharges excited in different gases and their dependences on the external parameters of discharges are presented. The chemical composition of active particles formed in water is described. Possible mechanisms of production and loss of plasma particles are discussed.

Water withdrawals, use, discharge, and trends in Florida, 2000

USGS Publications Warehouse

Marella, Richard L.

2004-01-01

River, Lake Okeechobee and associated canals, and the canals associated with the headwaters of the Upper St. Johns River. Freshwater withdrawals increased 46 percent and saline water withdrawals increased 25 percent in Florida between 1970 and 2000. Ground-water withdrawals increased 82 percent, and surface-water withdrawals increased 10 percent during this period. Between 1970 and 2000, total freshwater withdrawals increased for public supply by 176 percent and for agricultural self-supplied by 87 percent; withdrawals for commercial-industrial self-supplied decreased by 37 percent, and power generation (thermoelectric) decreased by 57 percent. Recreational irrigation withdrawals increased 127 percent between 1985 and 2000. Between 1995 and 2000, freshwater withdrawals increased 13 percent, and saline withdrawals increased 9 percent. An estimated 52 percent of the freshwater withdrawn in Florida was consumed; the remaining 48 percent was returned for further use. Domestic wastewater discharged in 2000 totaled 1,495 Mgal/d, of which 44 percent was discharged to surface waters, 34 percent to the ground through land application systems, and 22 percent to deep injection wells. Domestic wastewater discharge increased by 33 percent between 1985 and 2000, but decreased by 3 percent between 1995 and 2000. An estimated 11.21 million people were served by domestic wastewater systems in 2000, whereas the remaining 4.77 million people discharged wastewater to more than 1.95 million septic tanks. Discharge from the septic tanks was estimated to be 263 Mgal/d in 2000.

Approaches to setting organism-based ballast water discharge standards

EPA Science Inventory

As a major vector by which foreign species invade coastal and freshwater waterbodies, ballast water discharge from ships is recognized as a major environmental threat. The International Maritime Organization (IMO) drafted an international ballast water treaty establishing ballast...

[Desulphurization with multi-needle-water film electrodes by corona discharge].

PubMed

Huang, Xu-ran; Li, Guo-feng; Li, Jie; Wu, Yan

2008-09-01

The study of this paper adopted stainless steel multi-needle as a high voltage electrode system, and water film as low voltage electrode. The electrodes were supplied with negative DC high voltage. Polluted gas containing sulfur dioxide (SO2) flowed into the corona discharge field from the center of the high voltage electrode system in an axis direction, then get across the water surface. Under the effect of corona discharge plasma and water absorption, SO2 was removed by converting it into sulfuric acid. The effect of the three factors which were the applied voltage, SO2 inlet concentration and duration of the exposure to the corona discharge on desulphurization efficiency has been studied mostly. Moreover, the concentrations of SO3(2-) and SO4(2-) ions in the water were measured and the mechanism of desulphurization was analyzed. The results showed that there was a synergistic effect on the removal of SO2 when combining corona discharge and water absorption, and both the desulphurization efficiency and the amount of sulfuric acid increased evidently. As the applied voltage and the duration increased, the desulphurization efficiency increased. Also, the SO2 inlet concentration had effect on desulphurization efficiency. When the SO2 inlet concentration was 430 x 10(-6), the voltage was 14.5 kV and the duration was 7.5 s, a desulphurization efficiency of more than 90% could be attained.

Direct evidence of warm water access to the Totten Glacier sub-ice shelf cavity

NASA Astrophysics Data System (ADS)

Orsi, A. H.; Rintoul, S. R.; Silvano, A.; van Wijk, E.; Pena-Molino, B.; Rosenberg, M. A.

2015-12-01

The Totten Glacier holds enough ice to raise global sea level by 3.5 m, is thinning according to (some) satellite data, and is grounded well below sea level on a retrograde bed and hence is potentially unstable. Basal melt driven by ocean heat flux has been linked to ice shelf thinning elsewhere in Antarctica, but no oceanographic measurements had been made near the Totten. In January 2015 the RSV Aurora Australis was the first ship to reach the Totten calving front. Observations from ship-board CTD, moorings and profiling floats provide direct confirmation that warm water reaches the ice shelf cavity. Warm water is present near the sea floor at every station deeper than 300 m depth, with maximum temperatures at mid-shelf >0.5°C. Mooring data confirm that the warm water is present year-round. A deep (>1100 m) channel at the calving front allows warm water (-0.4°C, >2°C above the local freezing point) to access the ice shelf cavity. The contrast between the oceanographic conditions near the Totten and near the Mertz Glacier is stark, although they are separated by only 30 degrees of longitude. East Antarctic ice shelves have often been assumed to behave in a similar manner and to be invulnerable to ocean change; these measurements suggest these assumptions need to be reconsidered.

Warm water vapour in the sooty outflow from a luminous carbon star.

PubMed

Decin, L; Agúndez, M; Barlow, M J; Daniel, F; Cernicharo, J; Lombaert, R; De Beck, E; Royer, P; Vandenbussche, B; Wesson, R; Polehampton, E T; Blommaert, J A D L; De Meester, W; Exter, K; Feuchtgruber, H; Gear, W K; Gomez, H L; Groenewegen, M A T; Guélin, M; Hargrave, P C; Huygen, R; Imhof, P; Ivison, R J; Jean, C; Kahane, C; Kerschbaum, F; Leeks, S J; Lim, T; Matsuura, M; Olofsson, G; Posch, T; Regibo, S; Savini, G; Sibthorpe, B; Swinyard, B M; Yates, J A; Waelkens, C

2010-09-02

The detection of circumstellar water vapour around the ageing carbon star IRC +10216 challenged the current understanding of chemistry in old stars, because water was predicted to be almost absent in carbon-rich stars. Several explanations for the water were postulated, including the vaporization of icy bodies (comets or dwarf planets) in orbit around the star, grain surface reactions, and photochemistry in the outer circumstellar envelope. With a single water line detected so far from this one carbon-rich evolved star, it is difficult to discriminate between the different mechanisms proposed. Here we report the detection of dozens of water vapour lines in the far-infrared and sub-millimetre spectrum of IRC +10216 using the Herschel satellite. This includes some high-excitation lines with energies corresponding to approximately 1,000 K, which can be explained only if water is present in the warm inner sooty region of the envelope. A plausible explanation for the warm water appears to be the penetration of ultraviolet photons deep into a clumpy circumstellar envelope. This mechanism also triggers the formation of other molecules, such as ammonia, whose observed abundances are much higher than hitherto predicted.

Warming trend in the western Mediterranean deep water

NASA Astrophysics Data System (ADS)

Bethoux, J. P.; Gentili, B.; Raunet, J.; Tailliez, D.

1990-10-01

THE western Mediterranean Sea comprises three water masses: a surface layer (from 0 to ~150 m depth), an intermediate layer (~150-400 m) issuing from the eastern basin, and a deep water mass at depths below 400 m. The deep water is homogeneous and has maintained a more or less constant temperature and salinity from the start of the century until recently1. Here we report measurements from the Medatlante cruises of December 1988 and August 1989, which show the deep layer to be 0.12 °C warmer and ~0.03 p.s.u. more saline than in 1959. Taking these data together with those from earlier cruises, we find a trend of continuously increasing temperatures over the past three decades. These deep-water records reflect the averaged evolution of climate conditions at the surface during the winter, when the deep water is formed. Consideration of the heat budget and water flux in the Mediterranean2,3 leads to the possibility that the deep-water temperature trend may be the result of greenhouse-gas-induced local warming.

[Removal of SO2 from flue gas by water vapor DC corona discharge].

PubMed

Sun, Ming; Wu, Yan

2006-07-01

The influence of several factors on removal rate of SO2 from flue gas in unsaturated water vapor DC corona discharge was researched. Furthermore, the experiments of the removal rate of SO2 in pulsed discharge increased by water vapor DC corona discharge plasma were conducted. The experiment system is supplied with multi-nozzle-plate electrodes and the flow of simulated flue gas is under 70 m3/h. The results show that removal rate of SO2 can be improved by increasing the concentration of water vapor, intensity of electric field or decreasing flow of simulated flue gas. In unsaturated water vapor DC corona discharge, removal rate of SO2 can be improved by 10%, when NH3 is added as NH3 and SO2 is in a mole ratio of two to one, it can reach 60%. The removal rate of SO2 can be increased by 5% in pulsed corona discharge and reach above 90%.

Pathways of warm water to the Northeast Greenland outlet glaciers

NASA Astrophysics Data System (ADS)

Schaffer, Janin; Timmermann, Ralph; Kanzow, Torsten; Arndt, Jan Erik; Mayer, Christoph; Schauer, Ursula

2015-04-01

The ocean plays an important role in modulating the mass balance of the Greenland Ice Sheet by delivering heat to the marine-terminating outlet glaciers surrounding the Greenland coast. The warming and accumulation of Atlantic Water in the subpolar North Atlantic has been suggested to be a potential driver of the glaciers' retreat over the last decades. The shelf regions thus play a critical role for the transport of Atlantic Water towards the glaciers, but also for the transfer of freshwater towards the deep ocean. A key region for the mass balance of the Greenland Ice Sheet is the Northeast Greenland Ice Stream. This large ice stream drains the second-largest basin of the Greenland Ice Sheet and feeds three outlet glaciers. The largest one is Nioghalvfjerdsfjorden (79°N-Glacier) featuring an 80 km long floating ice tongue. Both the ocean circulation on the continental shelf off Northeast Greenland and the circulation in the cavity below the ice tongue are weakly constrained so far. In order to study the relevant processes of glacier-ocean interaction we combine observations and model work. Here we focus on historic and recent hydrographic observations and on the complex bathymetry in the Northeast Greenland shelf region, which is thought to steer the flux of warm Atlantic water onto the continental shelf and into the sub-ice cavity beneath the 79°N-Glacier. We present a new global topography data set, RTopo-2, which includes the most recent surveys on the Northeast Greenland continental shelf and provides a detailed bathymetry for all around Greenland. In addition, RTopo-2 contains ice and bedrock surface topographies for Greenland and Antarctica. Based on the updated ocean bathymetry and a variety of hydrographic observations we show the water mass distribution on the continental shelf off Northeast Greenland. These maps enable us to discuss possible supply pathways of warm modified Atlantic waters on the continental shelf and thus potential ways of heat

Understanding the causes of recent warming of mediterranean waters. How much could be attributed to climate change?

PubMed

Macias, Diego; Garcia-Gorriz, Elisa; Stips, Adolf

2013-01-01

During the past two decades, Mediterranean waters have been warming at a rather high rate resulting in scientific and social concern. This warming trend is observed in satellite data, field data and model simulations, and affects both surface and deep waters throughout the Mediterranean basin. However, the warming rate is regionally different and seems to change with time, which has led to the question of what causes underlie the observed trends. Here, we analyze available satellite information on sea surface temperature (SST) from the last 25 years using spectral techniques and find that more than half of the warming tendency during this period is due to a non-linear, wave-like tendency. Using a state of the art hydrodynamic model, we perform a hindcast simulation and obtain the simulated SST evolution of the Mediterranean basin for the last 52 years. These SST results show a clear sinusoidal tendency that follows the Atlantic Multidecadal Oscillation (AMO) during the simulation period. Our results reveal that 58% of recent warming in Mediterranean waters could be attributed to this AMO-like oscillation, being anthropogenic-induced climate change only responsible for 42% of total trend. The observed acceleration of water warming during the 1990s therefore appears to be caused by a superimposition of anthropogenic-induced warming with the positive phase of the AMO, while the recent slowdown of this tendency is likely due to a shift in the AMO phase. It has been proposed that this change in the AMO phase will mask the effect of global warming in the forthcoming decades, and our results indicate that the same could also be applicable to the Mediterranean Sea. Henceforth, natural multidecadal temperature oscillations should be taken into account to avoid underestimation of the anthropogenic-induced warming of the Mediterranean basin in the future.

Power Plant Bromide Discharges and Downstream Drinking Water Systems in Pennsylvania.

PubMed

Good, Kelly D; VanBriesen, Jeanne M

2017-10-17

Coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems have been implicated in increasing bromide levels and subsequent increases in disinfection byproducts at downstream drinking water plants. Bromide was not included as a regulated constituent in the recent steam electric effluent limitations guidelines and standards (ELGs) since the U.S. EPA analysis suggested few drinking water facilities would be affected by bromide discharges from power plants. The present analysis uses a watershed approach to identify Pennsylvania drinking water intakes downstream of wet FGD discharges and to assess the potential for bromide discharge effects. Twenty-two (22) public drinking water systems serving 2.5 million people were identified as being downstream of at least one wet FGD discharge. During mean August conditions (generally low-flow, minimal dilution) in receiving rivers, the median predicted bromide concentrations contributed by wet FGD at Pennsylvania intake locations ranged from 5.2 to 62 μg/L for the Base scenario (including only natural bromide in coal) and from 16 to 190 μg/L for the Bromide Addition scenario (natural plus added bromide for mercury control); ranges depend on bromide loads and receiving stream dilution capacity.

Increasing water cycle extremes in California and in relation to ENSO cycle under global warming.

PubMed

Yoon, Jin-Ho; Wang, S-Y Simon; Gillies, Robert R; Kravitz, Ben; Hipps, Lawrence; Rasch, Philip J

2015-10-21

Since the winter of 2013-2014, California has experienced its most severe drought in recorded history, causing statewide water stress, severe economic loss and an extraordinary increase in wildfires. Identifying the effects of global warming on regional water cycle extremes, such as the ongoing drought in California, remains a challenge. Here we analyse large-ensemble and multi-model simulations that project the future of water cycle extremes in California as well as to understand those associations that pertain to changing climate oscillations under global warming. Both intense drought and excessive flooding are projected to increase by at least 50% towards the end of the twenty-first century; this projected increase in water cycle extremes is associated with a strengthened relation to El Niño and the Southern Oscillation (ENSO)--in particular, extreme El Niño and La Niña events that modulate California's climate not only through its warm and cold phases but also its precursor patterns.

Increasing water cycle extremes in California and in relation to ENSO cycle under global warming

PubMed Central

Yoon, Jin-Ho; Wang, S-Y Simon; Gillies, Robert R.; Kravitz, Ben; Hipps, Lawrence; Rasch, Philip J.

2015-01-01

Since the winter of 2013–2014, California has experienced its most severe drought in recorded history, causing statewide water stress, severe economic loss and an extraordinary increase in wildfires. Identifying the effects of global warming on regional water cycle extremes, such as the ongoing drought in California, remains a challenge. Here we analyse large-ensemble and multi-model simulations that project the future of water cycle extremes in California as well as to understand those associations that pertain to changing climate oscillations under global warming. Both intense drought and excessive flooding are projected to increase by at least 50% towards the end of the twenty-first century; this projected increase in water cycle extremes is associated with a strengthened relation to El Niño and the Southern Oscillation (ENSO)—in particular, extreme El Niño and La Niña events that modulate California's climate not only through its warm and cold phases but also its precursor patterns. PMID:26487088

Increasing water cycle extremes in California and in relation to ENSO cycle under global warming

NASA Astrophysics Data System (ADS)

Yoon, Jin-Ho; Wang, S.-Y. Simon; Gillies, Robert R.; Kravitz, Ben; Hipps, Lawrence; Rasch, Philip J.

2015-10-01

Since the winter of 2013-2014, California has experienced its most severe drought in recorded history, causing statewide water stress, severe economic loss and an extraordinary increase in wildfires. Identifying the effects of global warming on regional water cycle extremes, such as the ongoing drought in California, remains a challenge. Here we analyse large-ensemble and multi-model simulations that project the future of water cycle extremes in California as well as to understand those associations that pertain to changing climate oscillations under global warming. Both intense drought and excessive flooding are projected to increase by at least 50% towards the end of the twenty-first century; this projected increase in water cycle extremes is associated with a strengthened relation to El Niño and the Southern Oscillation (ENSO)--in particular, extreme El Niño and La Niña events that modulate California's climate not only through its warm and cold phases but also its precursor patterns.

Ballast water regulations and the move toward concentration-based numeric discharge limits.

PubMed

Albert, Ryan J; Lishman, John M; Saxena, Juhi R

2013-03-01

Ballast water from shipping is a principal source for the introduction of nonindigenous species. As a result, numerous government bodies have adopted various ballast water management practices and discharge standards to slow or eliminate the future introduction and dispersal of these nonindigenous species. For researchers studying ballast water issues, understanding the regulatory framework is helpful to define the scope of research needed by policy makers to develop effective regulations. However, for most scientists, this information is difficult to obtain because it is outside the standard scientific literature and often difficult to interpret. This paper provides a brief review of the regulatory framework directed toward scientists studying ballast water and aquatic invasive species issues. We describe different approaches to ballast water management in international, U.S. federal and state, and domestic ballast water regulation. Specifically, we discuss standards established by the International Maritime Organization (IMO), the U.S. Coast Guard and U.S. Environmental Protection Agency, and individual states in the United States including California, New York, and Minnesota. Additionally, outside the United States, countries such as Australia, Canada, and New Zealand have well-established domestic ballast water regulatory regimes. Different approaches to regulation have recently resulted in variations between numeric concentration-based ballast water discharge limits, particularly in the United States, as well as reliance on use of ballast water exchange pending development and adoption of rigorous science-based discharge standards. To date, numeric concentration-based discharge limits have not generally been based upon a thorough application of risk-assessment methodologies. Regulators, making decisions based on the available information and methodologies before them, have consequently established varying standards, or not established standards at all. The

Warm Handoff Versus Fax Referral for Linking Hospitalized Smokers to Quitlines.

PubMed

Richter, Kimber P; Faseru, Babalola; Shireman, Theresa I; Mussulman, Laura M; Nazir, Niaman; Bush, Terry; Scheuermann, Taneisha S; Preacher, Kristopher J; Carlini, Beatriz H; Magnusson, Brooke; Ellerbeck, Edward F; Cramer, Carol; Cook, David J; Martell, Mary J

2016-10-01

Few hospitals treat patients' tobacco dependence. To be effective, hospital-initiated cessation interventions must provide at least 1 month of supportive contact post-discharge. Individually randomized clinical trial. Recruitment commenced July 2011; analyses were conducted October 2014-June 2015. The study was conducted in two large Midwestern hospitals. Participants included smokers who were aged ≥18 years, planned to stay quit after discharge, and spoke English or Spanish. Hospital-based cessation counselors delivered the intervention. For patients randomized to warm handoff, staff immediately called the quitline from the bedside and handed the phone to participants for enrollment and counseling. Participants randomized to fax were referred on the day of hospital discharge. Outcomes at 6 months included quitline enrollment/adherence, medication use, biochemically verified cessation, and cost effectiveness. Significantly more warm handoff than fax participants enrolled in quitline (99.6% vs 59.6%; relative risk, 1.67; 95% CI=1.65, 1.68). One in four (25.4% warm handoff, 25.3% fax) were verified to be abstinent at 6-month follow-up; this did not differ significantly between groups (relative risk, 1.02; 95% CI=0.82, 1.24). Cessation medication use in the hospital and receipt of a prescription for medication at discharge did not differ between groups; however, significantly more fax participants reported using cessation medication post-discharge (32% vs 25%, p=0.01). The average incremental cost-effectiveness ratio of enrolling participants into warm handoff was $0.14. Hospital-borne costs were significantly lower in warm handoff than in fax ($5.77 vs $9.41, p<0.001). One in four inpatient smokers referred to quitline by either method were abstinent at 6 months post-discharge. Among motivated smokers, fax referral and warm handoff are efficient and comparatively effective ways to link smokers with evidence-based care. For hospitals, warm handoff is a less

Effects of a Circulating-water Garment and Forced-air Warming on Body Heat Content and Core Temperature

PubMed Central

Taguchi, Akiko; Ratnaraj, Jebadurai; Kabon, Barbara; Sharma, Neeru; Lenhardt, Rainer; Sessler, Daniel I.

2005-01-01

Background: Forced-air warming is sometimes unable to maintain perioperative normothermia. We therefore compared heat transfer, regional heat distribution, and core rewarming of forced-air warming with a novel circulating-water garment. Methods: Nine volunteers were each evaluated on two randomly ordered study days. They were anesthetized and cooled to a core temperature near 34°C. The volunteers were subsequently warmed for 2.5 hours with either a circulating-water garment or forced-air cover. Overall, heat balance was determined from the difference between cutaneous heat loss (thermal flux transducers) and metabolic heat production (oxygen consumption). Average arm and leg (peripheral) tissue temperatures were determined from 18 intramuscular needle thermocouples, 15 skin thermal flux transducers, and “deep” arm and foot thermometers. Results: Heat production (≈ 60 kcal/h) and loss (≈45 kcal/h) were similar with each treatment before warming. The increase in heat transfer across anterior portions of the skin surface was similar with each warming system (≈65 kcal/h). Forced-air warming had no effect on posterior heat transfer whereas circulating-water transferred 21 ± 9 kcal/h through the posterior skin surface after a half hour of warming. Over 2.5 h, circulating-water thus increased body heat content 56% more than forced air. Core temperatures thus increased faster than with circulating water than forced air, especially during the first hour, with the result that core temperature was 1.1 ± 0.7°C greater after 2.5 h (P < 0.001). Peripheral tissue heat content increased twice as much as core heat content with each device, but the core-to-peripheral tissue temperature gradient remained positive throughout the study. Conclusions: The circulating-water system transferred more heat than forced air, with the difference resulting largely from posterior heating. Circulating water rewarmed patients 0.4°C/h faster than forced air. A substantial peripheral

NPDES (National Pollution Discharge & Elimination System) Minor Dischargers

EPA Pesticide Factsheets

As authorized by the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating point sources that discharge pollutants into waters of the United States. The NPDES permit program regulates direct discharges from municipal and industrial wastewater treatment facilities that discharge directly into surface waters. The NPDES permit program is part of the Permit Compliance System (PCS) which issues, records, tracks, and regulates point source discharge facilities. Individual homes that are connected to a municipal system, use a septic system, or do not have a surface discharge do not need an NPDES permit. Facilities in PCS are identified as either major or minor. Within the major/minor classification, facilities are grouped into municipals or non-municipals. In many cases, non-municipals are industrial facilities. This data layer contains Minor dischargers. Major municipal dischargers include all facilities with design flows of greater than one million gallons per day; minor dischargers are less that one million gallons per day. Essentially, a minor discharger does not meet the discharge criteria for a major. Since its introduction in 1972, the NPDES permit program is responsible for significant improvements to our Nation's water quality.

Soil warming increased whole-tree water use of Pinus cembra at the treeline in the Central Tyrolean Alps

PubMed Central

Wieser, Gerhard; Grams, Thorsten E.E.; Matysssek, Rainer; Oberhuber, Walter; Gruber, Andreas

2016-01-01

The study quantified the effect of soil warming on sap flow density (Qs) of Pinus cembra at treeline in the Central Tyrolean Alps. To enhance soil temperature we installed a transparent roof construction above the forest floor around six trees. Six other trees served as controls in the absence of any manipulation. Roofing enhanced growing season mean soil temperature by 1.6, 1.3, and 1.0 °C at 5, 10, and 20 cm soil depth, respectively, while soil water availability was not affected. Sap flow density (using Granier-type thermal dissipation probes) and environmental parameters were monitored throughout three growing seasons. During the first year of treatment, no warming effect was detected on Qs. However, soil warming caused Qs to increase significantly by 11 and 19% above levels in control trees during the second and third year, respectively. This effect appeared to result from warming-induced root production, a reduction in viscosity and perhaps an increase also in root hydraulic conductivity. Hardly affected were leaf-level net CO2 uptake rate and conductance for water vapor, so that water-use efficiency stayed unchanged as confirmed by needle δ13C analysis. We conclude that tree water loss will increase with soil warming, which may alter the water balance within the treeline ecotone of the Central Austrian Alps in a future warming environment. PMID:25737326

Characterization of water quality and suspended sediment during cold-season flows, warm-season flows, and stormflows in the Fountain and Monument Creek watersheds, Colorado, 2007–2015

USGS Publications Warehouse

Miller, Lisa D.; Stogner, Sr., Robert W.

2017-09-01

From 2007 through 2015, the U.S. Geological Survey, in cooperation with Colorado Springs City Engineering, conducted a study in the Fountain and Monument Creek watersheds, Colorado, to characterize surface-water quality and suspended-sediment conditions for three different streamflow regimes with an emphasis on characterizing water quality during storm runoff. Data collected during this study were used to evaluate the effects of stormflows and wastewater-treatment effluent discharge on Fountain and Monument Creeks in the Colorado Springs, Colorado, area. Water-quality samples were collected at 2 sites on Upper Fountain Creek, 2 sites on Monument Creek, 3 sites on Lower Fountain Creek, and 13 tributary sites during 3 flow regimes: cold-season flow (November–April), warm-season flow (May–October), and stormflow from 2007 through 2015. During 2015, additional samples were collected and analyzed for Escherichia coli (E. coli) during dry weather conditions at 41 sites, located in E. coli impaired stream reaches, to help identify source areas and scope of the impairment.Concentrations of E. coli, total arsenic, and dissolved copper, selenium, and zinc in surface-water samples were compared to Colorado in-stream standards. Stormflow concentrations of E. coli frequently exceeded the recreational use standard of 126 colonies per 100 milliliters at main-stem and tributary sites by more than an order of magnitude. Even though median E. coli concentrations in warm-season flow samples were lower than median concentrations in storm-flow samples, the water quality standard for E. coli was still exceeded at most main-stem sites and many tributary sites during warm-season flows. Six samples (three warm-season flow and three stormflow samples) collected from Upper Fountain Creek, upstream from the confluence of Monument Creek, and two stormflow samples collected from Lower Fountain Creek, downstream from the confluence with Monument Creek, exceeded the acute water

COLD WATER PATCHES IN WARM STREAMS: PHYSICOCHEMICAL CHARACTERISTICS AND THE INFLUENCE OF SHADING

EPA Science Inventory

Discrete coldwater patches within the surface waters of summer-warm streams afford potential thermal refuge for coldwater fishes during periods of heat stress. This analysis focused on reach-scale heterogeneity in water temperatures as influenced by local influx of cooler subsur...

Requiring Pollutant Discharge Permits for Pesticide Applications that Deposit Residues in Surface Waters

PubMed Central

Centner, Terence; Eberhart, Nicholas

2014-01-01

Agricultural producers and public health authorities apply pesticides to control pests that damage crops and carry diseases. Due to the toxic nature of most pesticides, they are regulated by governments. Regulatory provisions require pesticides to be registered and restrictions operate to safeguard human health and the environment. Yet pesticides used near surface waters pose dangers to non-target species and drinking water supplies leading some governments to regulate discharges of pesticides under pollution discharge permits. The dual registration and discharge permitting provisions are burdensome. In the United States, agricultural interest groups are advancing new legislation that would exempt pesticide residues from water permitting requirements. An analysis of the dangers posed by pesticide residues in drinking water leads to a conclusion that both pesticide registration and pollutant discharge permitting provisions are needed to protect human health and aquatic species. PMID:24814945

The estimation for ballast water discharged to China from 2007 to 2014.

PubMed

Zhang, Xiaofang; Bai, Mindong; Tian, Yiping; Du, Huan; Zhang, Zhitao

2017-11-15

Ballast water has been identified as one of the main causes for worldwide transfer of non-indigenous marine species. The volume and source of ballast water are the fundamental elements for an evaluation of the risk posed. However, it is difficult to obtain the volume of ballast water discharged to China, because of the absence of information platform, and until now there is no public report. In this paper, the total volume of ballast water discharged to China and Chinese five major port-groups were estimated. Results showed: the total volume of ballast water exhibited a trend of slow increase from 2007 to 2014, and reached 311 million tons in 2014. Yangtze River Delta received the highest volume of ballast water among all port-groups. The information provided in this research may play an important role in helping policy decision-makers manage such coastal discharges. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessing water quality of the Chesapeake Bay by the impact of sea level rise and warming

NASA Astrophysics Data System (ADS)

Wang, P.; Linker, L.; Wang, H.; Bhatt, G.; Yactayo, G.; Hinson, K.; Tian, R.

2017-08-01

The influence of sea level rise and warming on circulation and water quality of the Chesapeake Bay under projected climate conditions in 2050 were estimated by computer simulation. Four estuarine circulation scenarios in the estuary were run using the same watershed load in 1991-2000 period. They are, 1) the Base Scenario, which represents the current climate condition, 2) a Sea Level Rise Scenario, 3) a Warming Scenario, and 4) a combined Sea Level Rise and Warming Scenario. With a 1.6-1.9°C increase in monthly air temperatures in the Warming Scenario, water temperature in the Bay is estimated to increase by 0.8-1°C. Summer average anoxic volume is estimated to increase 1.4 percent compared to the Base Scenario, because of an increase in algal blooms in the spring and summer, promotion of oxygen consumptive processes, and an increase of stratification. However, a 0.5-meter Sea Level Rise Scenario results in a 12 percent reduction of anoxic volume. This is mainly due to increased estuarine circulation that promotes oxygen-rich sea water intrusion in lower layers. The combined Sea Level Rise and Warming Scenario results in a 10.8 percent reduction of anoxic volume. Global warming increases precipitation and consequently increases nutrient loads from the watershed by approximately 5-7 percent. A scenario that used a 10 percent increase in watershed loads and current estuarine circulation patterns yielded a 19 percent increase in summer anoxic volume, while a scenario that used a 10 percent increase in watershed loads and modified estuarine circulation patterns by the aforementioned sea level rise and warming yielded a 6 percent increase in summer anoxic volume. Impacts on phytoplankton, sediments, and water clarity were also analysed.

Approaches to setting organism-based ballast water discharge standards

USGS Publications Warehouse

Lee, Henry; Reusser, Deborah A.; Frazier, Melanie

2013-01-01

As a vector by which foreign species invade coastal and freshwater waterbodies, ballast water discharge from ships is recognized as a major environmental threat. The International Maritime Organization (IMO) drafted an international treaty establishing ballast water discharge standards based on the number of viable organisms per volume of ballast discharge for different organism size classes. Concerns that the IMO standards are not sufficiently protective have initiated several state and national efforts in the United States to develop more stringent standards. We evaluated seven approaches to establishing discharge standards for the >50-μm size class: (1) expert opinion/management consensus, (2) zero detectable living organisms, (3) natural invasion rates, (4) reaction–diffusion models, (5) population viability analysis (PVA) models, (6) per capita invasion probabilities (PCIP), and (7) experimental studies. Because of the difficulty in synthesizing scientific knowledge in an unbiased and transparent fashion, we recommend the use of quantitative models instead of expert opinion. The actual organism concentration associated with a “zero detectable organisms” standard is defined by the statistical rigor of its monitoring program; thus it is not clear whether such a standard is as stringent as other standards. For several reasons, the natural invasion rate, reaction–diffusion, and experimental approaches are not considered suitable for generating discharge standards. PVA models can be used to predict the likelihood of establishment of introduced species but are limited by a lack of population vital rates for species characteristic of ballast water discharges. Until such rates become available, PVA models are better suited to evaluate relative efficiency of proposed standards rather than predicting probabilities of invasion. The PCIP approach, which is based on historical invasion rates at a regional scale, appears to circumvent many of the indicated problems

Pulsed Power Discharges in Water

NASA Astrophysics Data System (ADS)

Kratel, Axel Wolf Hendrik

An Electrohydraulic Discharge Process (EHD) for the treatment of hazardous chemical wastes in water has been developed. Liquid waste in a 4 L EHD reactor is directly exposed to high-energy pulsed electrical discharges between two submerged electrodes. The high-temperature (> 14,000 K) plasma channel created by an EHD discharge emits ultraviolet radiation, and produces an intense shock wave as it expands against the surrounding water. A simulation of the EHD process is presented along with experimental results. The simulation assumes a uniform plasma channel with a plasma that obeys the ideal gas law and the Spitzer conductivity law. The results agree with previously published data. The simulation is used to predict the total energy efficiency, energy partitioning, maximum plasma channel temperature and pressure for the Caltech Pulsed Power Facility (CPPF). The simulation shows that capacitance, initial voltage and gap length can be used to control the efficiency of the discharge. The oxidative degradation of 4-chlorophenol (4 -CP), 3,4-dichloroaniline (3,4-DCA), and 2,4,6 trinitrotoluene (TNT) in an EHD reactor was explored. The initial rates of degradation for the three substrates are described by a first-order rate equation, where k_{ it 0/} is the zero-order rate constant that accounts for direct photolysis; and k_ {it 1/} is the first-order term that accounts for oxidation in the plasma channel region. For 4-CP in the 4.0 L reactor, the values of these two rate constants are k_{it 0/} = 0.73 +/- 0.08 mu M, and k_{ it 1/} =(9.4 +/- 1.4) times 10^{-4}. For a 200 mu M 4-CP solution this corresponds to an overall intrinsic zero-order rate constant of 0.022 M s^{it -1/} , and a G-value of 4.45 times 10^{-3}. Ozone increases the rate and extent of degradation of the substrates in the EHD reactor. Combined EHD/ozone treatment of a 160 mu M TNT solution resulted in the complete degradation of TNT, and a 34% reduction of the total organic carbon (TOC). The intrinsic

Preliminary Evidence for the Amplification of Global Warming in Shallow, Intertidal Estuarine Waters.

PubMed

Oczkowski, Autumn; McKinney, Richard; Ayvazian, Suzanne; Hanson, Alana; Wigand, Cathleen; Markham, Erin

2015-01-01

Over the past 50 years, mean annual water temperature in northeastern U.S. estuaries has increased by approximately 1.2°C, with most of the warming recorded in the winter and early spring. A recent survey and synthesis of data from four locations in Southern Rhode Island has led us to hypothesize that this warming may be amplified in the shallow (<1 m), nearshore portions of these estuaries. While intertidal areas are not typically selected as locations for long-term monitoring, we compiled data from published literature, theses, and reports that suggest that enhanced warming may be occurring, perhaps at rates three times higher than deeper estuarine waters. Warmer spring waters may be one of the factors influencing biota residing in intertidal regions both in general as well as at our specific sites. We observed greater abundance of fish, and size of Menidia sp., in recent (2010-2012) seine surveys compared to similar collections in 1962. While any linkages are speculative and data are preliminary, taken together they suggest that shallow intertidal portions of estuaries may be important places to look for the effects of climate change.

Characteristics of ultraviolet light and radicals formed by pulsed discharge in water

NASA Astrophysics Data System (ADS)

Sun, Bing; Kunitomo, Shinta; Igarashi, Chiaki

2006-09-01

In this investigation, the ultraviolet light characteristics and OH radical properties produced by a pulsed discharge in water were studied. For the plate-rod reactor, it was found that the ultraviolet light energy has a 3.2% total energy injected into the reactor. The ultraviolet light changed with the peak voltage and electrode distance. UV characteristics in tap water and the distilled water are given. The intensity of the OH radicals was the highest for the 40 mm electrode distance reactor. In addition, the properties of hydrogen peroxide and ozone were also studied under arc discharge conditions. It was found that the OH radicals were in the ground state and the excited state when a pulsed arc discharge was used. The ozone was produced by the arc discharge even if the oxygen gas is not bubbled into the reactor. The ozone concentration produces a maximum value with treatment time.

The effects of sewage discharge on water quality and phytoplankton of Hawai'ian coastal waters.

PubMed

Parnell, P Ed

2003-05-01

The effects of sewage discharge on algal populations and the quality of Hawai'ian coastal waters were investigated. Two outfalls were studied. One discharges primary treated sewage and the other discharges secondary treated sewage but are otherwise similar. This enabled comparisons of the effects of these different levels of treatment on the water quality and algal productivity of receiving waters. Plumes were followed and repeatedly sampled in a time-series manner. Rhodamine dye was used as a conservative tracer to compare the dilution behavior of the plume constituents MRP, NO(3)+NO(2), NH(4), Silicate, TDP, TDN, total bacteria, PC, and PN. Rates of initial dilution ranged from two to almost three orders of magnitude, and were in reasonable agreement with engineering model predictions. Dilution of plume constituents approximated that of Rhodamine until background concentrations were reached, typically within 10 min of discharge. Chl a concentrations did not increase through time in the primary sewage plume but did increase up to 30% in the secondary sewage plume. However, rates of far-field dilution were so rapid that the increase could not have been due to algal growth. The increase was attributed to the plume mixing with a water mass whose relative chl a concentrations were greater. Rates of secondary dilution ranged from 2 to 3 orders of magnitude resulting in total dilutions of 10(5)-10(6) within 3 h of discharge. These rates of secondary dilution were much greater than model predictions. From a nutrient standpoint, secondary treatment exhibited no advantages over primary treatment because dilutions were so rapid. Copyright 2002 Elsevier Science B.V.

Effect of land cover, stream discharge, and precipitation on water quality in Puerto Rico

NASA Astrophysics Data System (ADS)

Hall, J. S.; Uriarte, M.

2017-12-01

In 2015, Puerto Rico experienced one of the worst droughts in its history, causing widespread water rationing and sparking concerns for future resources. The drought represents precipitation extremes that provide valuable insight into the effects of land cover (LC), on modulating discharge and water quality indices at varying spatial scales. We used data collected from 38 water quality and 55 precipitation monitoring stations in Puerto Rico from 2005 to 2016, paired with a 2010 land cover map to (1) determine whether temporal variability in discharge, precipitation, or antecedent precipitation was a better predictor of water quality, (2) find the spatial scale where LC has the greatest impact on water quality, and (3) quantify impacts of LC on water quality indices, including dissolved oxygen (mg/L), total nitrogen (mg/L), phosphorous (mg/L), turbidity (NTRU), fecal coliforms (colony units/100mL) and instantaneous discharge (ft3/s). The resulting linear mixed effects models account for between 36-68% of the variance in water quality. Preliminary results indicate that phosphorous and nitrogen were best predicted from instantaneous stream discharge, the log of discharge was the better predictor for turbidity and fecal coliforms, and summed 2 and 14-day antecedent precipitation indices were better predictors for dissolved oxygen and discharge, respectively. Increased urban and pasture area reliably decreased water quality in relation to forest cover, while agriculture and wetlands had little or mixed effects. Turbidity and nitrogen responded to a watershed level LC, while phosphorous, fecal coliforms, and discharge responded to LC in 60 m riparian buffers at the watershed scale. Our results indicate that LC modulates changing precipitation regimes and the ensuing impacts on water quality at a range of spatial scales.

Water vapor changes under global warming and the linkage to present-day interannual variabilities in CMIP5 models

NASA Astrophysics Data System (ADS)

Takahashi, Hanii; Su, Hui; Jiang, Jonathan H.

2016-12-01

The fractional water vapor changes under global warming across 14 Coupled Model Intercomparison Project Phase 5 simulations are analyzed. We show that the mean fractional water vapor changes under global warming in the tropical upper troposphere between 300 and 100 hPa range from 12.4 to 28.0 %/K across all models while the fractional water vapor changes are about 5-8 %/K in other regions and at lower altitudes. The "upper-tropospheric amplification" of the water vapor change is primarily driven by a larger temperature increase in the upper troposphere than in the lower troposphere per degree of surface warming. The relative contributions of atmospheric temperature and relative humidity changes to the water vapor change in each model vary between 71.5 to 131.8 % and 24.8 to -20.1 %, respectively. The inter-model differences in the water vapor change is primarily caused by differences in temperature change, except over the inter-tropical convergence zone within 10°S-10°N where the model differences due to the relative humidity change are significant. Furthermore, we find that there is generally a positive correlation between the rates of water vapor change for long-tem surface warming and those on the interannual time scales. However, the rates of water vapor change under long-term warming have a systematic offset from those on the inter-annual time scales and the dominant contributor to the differences also differs for the two time scales, suggesting caution needs to be taken when inferring long-term water vapor changes from the observed interannual variations.

Time-resolved processes in a pulsed electrical discharge in argon bubbles in water

NASA Astrophysics Data System (ADS)

Gershman, S.; Belkind, A.

2010-12-01

A phenomenological picture of a pulsed electrical discharge in gas bubbles in water is produced by combining electrical, spectroscopic, and imaging characterization methods. The discharge is generated by applying 1 μ s pulses of 5 to 20 kV between a needle and a disk electrode submerged in water. An Ar gas bubble surrounds the tip of the needle electrode. Imaging, electrical characteristics, and time-resolved optical emission spectroscopic data suggest a fast streamer propagation mechanism and the formation of a plasma channel in the bubble. Comparing the electrical and imaging data for consecutive pulses applied to the bubble at a frequency of 1 Hz indicates that each discharge proceeds as an entirely new process with no memory of the previous discharge aside from the presence of long-lived chemical species, such as ozone and oxygen. Imaging and electrical data show the presence of two discharge events during each applied voltage pulse, a forward discharge near the beginning of the applied pulse depositing charge on the surface of the bubble and a reverse discharge removing the accumulated charge from the water/gas interface when the applied voltage is turned off. The pd value of ~ 300-500 torr cm, the 1 μs long pulse duration, low repetition rate, and unidirectional character of the applied voltage pulses make the discharge process here unique compared to the traditional corona or dielectric barrier discharges.

Warm water and life beneath the grounding zone of an Antarctic outlet glacier

NASA Astrophysics Data System (ADS)

Sugiyama, Shin; Sawagaki, Takanobu; Fukuda, Takehiro

2013-04-01

Ice-ocean interaction plays a key role in rapidly changing Antarctic ice sheet margins. Recent studies demonstrated that warming ocean is eroding floating part of the ice sheet, resulting in thinning, retreat and acceleration of ice shelves and outlet glaciers. Field data are necessary to understand such processes, but direct observations at the interface of ice and the ocean are lacking, particularly beneath the grounding zone. To better understand the interaction of Antarctic ice sheet and the ocean, we performed subglacial measurements through boreholes drilled in the grounding zone of Langhovde Glacier, an outlet glacier in East Antarctica. Langhovde Glacier is located at 69°12'S, 39°48'E, approximately 20 km south of a Japanese research station Syowa. The glacier discharges ice into Lützow-holm Bay through a 3-km-wide floating terminus at a rate of 130 m a-1. Fast flowing feature is confined by bedrock to the west and slow moving ice to the east, and it extends about 10 km upglacier from the calving front. In 2011/12 austral summer season, we operated a hot water drilling system to drill through the glacier at 2.5 and 3 km from the terminus. Inspections of the boreholes revealed the ice was underlain by a shallow saline water layer. Ice and water column thicknesses were found to be 398 and 24 m at the first site, and 431 and 10 m at the second site. Judging from ice surface and bed elevations, the drilling sites were situated at within a several hundred meters from the grounding line. Sensors were lowered into the boreholes to measure temperature, salinity and current within the subglacial water layer. Salinity and temperature from the two sites were fairly uniform (34.25±0.05 PSU and -1.45±0.05°C), indicating vertical and horizontal mixing in the layer. The measured temperature was >0.7°C warmer than the in-situ freezing point, and very similar to the values measured in the open ocean near the glacier front. Subglacial current was up to 3 cm/s, which

Attribution of the United States "warming hole": aerosol indirect effect and precipitable water vapor.

PubMed

Yu, Shaocai; Alapaty, Kiran; Mathur, Rohit; Pleim, Jonathan; Zhang, Yuanhang; Nolte, Chris; Eder, Brian; Foley, Kristen; Nagashima, Tatsuya

2014-11-06

Aerosols can influence the climate indirectly by acting as cloud condensation nuclei and/or ice nuclei, thereby modifying cloud optical properties. In contrast to the widespread global warming, the central and south central United States display a noteworthy overall cooling trend during the 20(th) century, with an especially striking cooling trend in summertime daily maximum temperature (Tmax) (termed the U.S. "warming hole"). Here we used observations of temperature, shortwave cloud forcing (SWCF), longwave cloud forcing (LWCF), aerosol optical depth and precipitable water vapor as well as global coupled climate models to explore the attribution of the "warming hole". We find that the observed cooling trend in summer Tmax can be attributed mainly to SWCF due to aerosols with offset from the greenhouse effect of precipitable water vapor. A global coupled climate model reveals that the observed "warming hole" can be produced only when the aerosol fields are simulated with a reasonable degree of accuracy as this is necessary for accurate simulation of SWCF over the region. These results provide compelling evidence of the role of the aerosol indirect effect in cooling regional climate on the Earth. Our results reaffirm that LWCF can warm both winter Tmax and Tmin.

Water in embedded low-mass protostars: cold envelopes and warm outflows

NASA Astrophysics Data System (ADS)

Kristensen, Lars E.; van Dishoeck, Ewine; Mottram, Joseph; Schmalzl, Markus; Visser, Ruud

2015-08-01

As stars form, gas from the parental cloud is transported through the molecular envelope to the protostellar disk from which planets eventually form. Water plays a crucial role in such systems: it forms the backbone of the oxygen chemistry, it is a unique probe of warm and hot gas, and it provides a unique link between the grain surface and gas-phase chemistries. The distribution of water, both as ice and gas, is a fundamental question to our understanding of how planetary systems, such as the Solar System, form.The Herschel Space Observatory observed many tens of embedded low-mass protostars in a suite of gas-phase water transitions in several programs (e.g. Water in Star-forming regions with Herschel, WISH, and the William Herschel Line Legacy Survey, WILL), and related species (e.g. CO in Protostars with HIFI, COPS-HIFI). I will summarize what Herschel has revealed about the water distribution in the cold outer molecular envelope of low-mass protostars, and the warm gas in outflows, the two components predominantly traced by Herschel observations. I will present our current understanding of where the water vapor is in protostellar systems and the underlying physical and chemical processes leading to this distribution. Through these dedicated observational surveys and complementary modeling efforts, we are now at a stage where we can quantify where the water is during the early stages of star formation.

Effects of Mackenzie River Discharge and Bathymetry on Sea Ice in the Beaufort Sea

NASA Technical Reports Server (NTRS)

Nghiem, S. V.; Hall, D. K.; Rigor, I. G; Li, P.; Neumann, G.

2014-01-01

Mackenzie River discharge and bathymetry effects on sea ice in the Beaufort Sea are examined in 2012 when Arctic sea ice extent hit a record low. Satellite-derived sea surface temperature revealed warmer waters closer to river mouths. By 5 July 2012, Mackenzie warm waters occupied most of an open water area about 316,000 sq km. Surface temperature in a common open water area increased by 6.5 C between 14 June and 5 July 2012, before and after the river waters broke through a recurrent landfast ice barrier formed over the shallow seafloor offshore the Mackenzie Delta. In 2012, melting by warm river waters was especially effective when the strong Beaufort Gyre fragmented sea ice into unconsolidated floes. The Mackenzie and other large rivers can transport an enormous amount of heat across immense continental watersheds into the Arctic Ocean, constituting a stark contrast to the Antarctic that has no such rivers to affect sea ice.

Bio-Decontamination of Water and Surfaces by DC Discharges in Atmospheric Air

NASA Astrophysics Data System (ADS)

Machala, Zdenko; Tarabová, Barbora; Pelach, Michal; Šipoldová, Zuzana; Hensel, Karol; Janda, Mário; Šikurová, Libuša

Two types of DC-driven atmospheric air discharges, including a streamer corona and a transient spark with short high current pulses of limited energy, were employed for bio-decontamination of water and various surfaces (agar plates, plastic foils, human teeth) contaminated by bacteria or spores (Salmonella typhimurium, Bacillus cereus). Both discharges generate cold non-equilibrium plasma. The discharges combined with the electro-spraying of the treated water through the needle electrode lead to fast and efficient bio-decontamination. Experiments comparing direct and indirect plasma effects, oxidation stress measurements in the cell membranes, and chemical changes induced in the treated water enable assessment of the plasma agents being responsible for microbial inactivation. Radicals and reactive oxygen species seem to be dominant biocidal agents, although deeper understanding of the plasma-induced water chemistry and of the temporal evolution of the bio-inactivation processes is needed.

Statistical considerations in estimating organism concentrations in ballast water discharges

EPA Science Inventory

Sampling probabilities may affect the practical use of different ballast water performance standards which establish the acceptable concentration of organisms in ballast discharges. The International Maritime Organization (IMO) has initiated a ballast water standard of <10 viabl...

Formation of well-mixed warm water column in central Bohai Sea during summer: Role of high-frequency atmospheric forcing

NASA Astrophysics Data System (ADS)

Ma, Weiwei; Wan, Xiuquan; Wang, Zhankun; Liu, Yulong; Wan, Kai

2017-12-01

The influence of high-frequency atmospheric forcing on the formation of a well-mixed summer warm water column in the central Bohai Sea is investigated comparing model simulations driven by daily surface forcing and those using monthly forcing data. In the absence of high-frequency atmospheric forcing, numerical simulations have repeatedly failed to reproduce this vertically uniform column of warm water measured over the past 35 years. However, high-frequency surface forcing is found to strongly influence the structure and distribution of the well-mixed warm water column, and simulations are in good agreement with observations. Results show that high frequency forcing enhances vertical mixing over the central bank, intensifies downward heat transport, and homogenizes the water column to form the Bohai central warm column. Evidence presented shows that high frequency forcing plays a dominant role in the formation of the well-mixed warm water column in summer, even without the effects of tidal and surface wave mixing. The present study thus provides a practical and rational way of further improving the performance of oceanic simulations in the Bohai Sea and can be used to adjust parameterization schemes of ocean models.

Potential water-quality effects of coal-bed methane production water discharged along the upper Tongue River, Wyoming and Montana

USGS Publications Warehouse

Kinsey, Stacy M.; Nimick, David A.

2011-01-01

Water quality in the upper Tongue River from Monarch, Wyoming, downstream to just upstream from the Tongue River Reservoir in Montana potentially could be affected by discharge of coal-bed methane (CBM) production water (hereinafter referred to as CBM discharge). CBM discharge typically contains high concentrations of sodium and other ions that could increase dissolved-solids (salt) concentrations, specific conductance (SC), and sodium-adsorption ratio (SAR) in the river. Increased inputs of sodium and other ions have the potential to alter the river's suitability for agricultural irrigation and aquatic ecosystems. Data from two large tributaries, Goose Creek and Prairie Dog Creek, indicate that these tributaries were large contributors to the increase in SC and SAR in the Tongue River. However, water-quality data were not available for most of the smaller inflows, such as small tributaries, irrigation-return flows, and CBM discharges. Thus, effects of these inflows on the water quality of the Tongue River were not well documented. Effects of these small inflows might be subtle and difficult to determine without more extensive data collection to describe spatial patterns. Therefore, synoptic water-quality sampling trips were conducted in September 2005 and April 2006 to provide a spatially detailed profile of the downstream changes in water quality in this reach of the Tongue River. The purpose of this report is to describe these downstream changes in water quality and to estimate the potential water-quality effects of CBM discharge in the upper Tongue River. Specific conductance of the Tongue River through the study reach increased from 420 to 625 microsiemens per centimeter (.μS/cm; or 49 percent) in the downstream direction in September 2005 and from 373 to 543 .μS/cm (46 percent) in April 2006. Large increases (12 to 24 percent) were measured immediately downstream from Goose Creek and Prairie Dog Creek during both sampling trips. Increases attributed to

Warm Water Compress as an Alternative for Decreasing the Degree of Phlebitis.

PubMed

Annisa, Fitri; Nurhaeni, Nani; Wanda, Dessie

Intravenous fluid therapy is an invasive procedure which may increase the risk of patient complications. One of the most common of these is phlebitis, which may cause discomfort and tissue damage. Therefore, a nursing intervention is needed to effectively treat phlebitis. The purpose of this study was to investigate the effectiveness of applying a warm compression intervention to reduce the degree of phlebitis. A quasi-experimental pre-test and post-test design was used, with a non-equivalent control group. The total sample size was 32 patients with degrees of phlebitis ranging from 1 to 4. The total sample was divided into 2 interventional groups: those patients that were given 0.9% NaCl compresses and those given warm water compresses. The results showed that both compresses were effective in reducing the degree of phlebitis, with similar p values (p = .000). However, there was no difference in the average reduction score between the two groups (p = .18). Therefore, a warm water compress is valuable in the treatment of phlebitis, and could decrease the degree of phlebitis both effectively and inexpensively.

Plants as indicators of focused ground water discharge to a northern Minnesota lake

USGS Publications Warehouse

Rosenberry, D.O.; Striegl, Robert G.; Hudson, D.C.

2000-01-01

Determining the discharge of ground water to Shingobee Lake (66 ha), north-central Minnesota, is complicated by the presence of numerous springs situated adjacent to the lake and in the shallow portion of the lakebed. Springs first had to be located before these areas of more rapid discharge could be quantified. Two methods that rely on the distribution of aquatic plants are useful for locating springs. One method identifies areas of the near-shore lakebed where floating-leaf and emergent aquatic vegetation are absent. The second method uses the distribution of marsh marigold (Caltha palustris L.) to locate springs that discharge on land near the shoreline of the lake. Marsh marigold produces large (2 to 4 cm diameter) yellow flowers that provide a ready marker for locating ground water springs. Twice as many springs (38) were identified using this method as were identified using the lack of near-shore vegetation. A portable weir was used to measure discharge from onshore springs, and seepage meters were used to measure discharge from near-shore springs. Of the total 56.7 L s-1 that enters the lake from ground water, approximately 30% comes from onshore and near-shore springs.Determining the discharge of ground water to Shingobee Lake (66 ha), north-central Minnesota, is complicated by the presence of numerous springs situated adjacent to the lake and in the shallow portion of the lakebed. Springs first had to be located before these areas of more rapid discharge could be quantified. Two methods that rely on the distribution of aquatic plants are useful for locating springs. One method identifies areas of the near-shore lakebed where floating-leaf and emergent aquatic vegetation are absent. The second method uses the distribution of marsh marigold (Caltha palustris L.) to locate springs that discharge on land near the shoreline of the lake. Marsh marigold produces large (2 to 4 cm diameter) yellow flowers that provide a ready marker for locating ground water

Coastal water monitoring using a vertical profiler

NASA Astrophysics Data System (ADS)

Kim, Dong Guk; Seo, Seongbong; Park, Young-Gyu; Min, Hong Sik

2017-04-01

Using a profiler system, the Aqualog, composed of a moored wire and a carrier in which a CTD was installed, we have been monitoring coastal water in Korea since August 2016. With this monitoring system, we were able to observe rapid warming of surface water that resulted in large damage to fish farms. The profiles showed that the warming was associated with low salinity water due to the fresh water discharge from the Yangtze River. We also observed change in water properties due to a typhoon. Along the Korean coast there are many aquafarms, which are becoming more vulnerable to environmental change. With the data from the profiler we would be able to help the aquafarms to sustain.

Soil warming increased whole-tree water use of Pinus cembra at the treeline in the Central Tyrolean Alps.

PubMed

Wieser, Gerhard; Grams, Thorsten E E; Matyssek, Rainer; Oberhuber, Walter; Gruber, Andreas

2015-03-01

This study quantified the effect of soil warming on sap flow density (Qs) of Pinus cembra L. at the treeline in the Central Tyrolean Alps. To enhance soil temperature we installed a transparent roof construction above the forest floor around six trees. Six other trees served as controls in the absence of any manipulation. Roofing enhanced growing season mean soil temperature by 1.6, 1.3 and 1.0 °C at 5, 10 and 20 cm soil depth, respectively, while soil water availability was not affected. Sap flow density (using Granier-type thermal dissipation probes) and environmental parameters were monitored throughout three growing seasons. During the first year of treatment, no warming effect was detected on Qs. However, soil warming caused Qs to increase significantly by 11 and 19% above levels in control trees during the second and third year, respectively. This effect appeared to result from warming-induced root production, a reduction in viscosity and perhaps an increase also in root hydraulic conductivity. Hardly affected were leaf-level net CO2 uptake rate and conductance for water vapour, so that water-use efficiency stayed unchanged as confirmed by needle δ(13)C analysis. We conclude that tree water loss will increase with soil warming, which may alter the water balance within the treeline ecotone of the Central Austrian Alps in a future warming environment. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Role of Stratospheric Water Vapor in Global Warming from GCM Simulations Constrained by MLS Observation

NASA Astrophysics Data System (ADS)

Wang, Y.; Stek, P. C.; Su, H.; Jiang, J. H.; Livesey, N. J.; Santee, M. L.

2014-12-01

Over the past century, global average surface temperature has warmed by about 0.16°C/decade, largely due to anthropogenic increases in well-mixed greenhouse gases. However, the trend in global surface temperatures has been nearly flat since 2000, raising a question regarding the exploration of the drivers of climate change. Water vapor is a strong greenhouse gas in the atmosphere. Previous studies suggested that the sudden decrease of stratospheric water vapor (SWV) around 2000 may have contributed to the stall of global warming. Since 2004, the SWV observed by Microwave Limb Sounder (MLS) on Aura satellite has shown a slow recovery. The role of recent SWV variations in global warming has not been quantified. We employ a coupled atmosphere-ocean climate model, the NCAR CESM, to address this issue. It is found that the CESM underestimates the stratospheric water vapor by about 1 ppmv due to limited representations of the stratospheric dynamic and chemical processes important for water vapor variabilities. By nudging the modeled SWV to the MLS observation, we find that increasing SWV by 1 ppmv produces a robust surface warming about 0.2°C in global-mean when the model reaches equilibrium. Conversely, the sudden drop of SWV from 2000 to 2004 would cause a surface cooling about -0.08°C in global-mean. On the other hand, imposing the observed linear trend of SWV based on the 10-year observation of MLS in the CESM yields a rather slow surface warming, about 0.04°C/decade. Our model experiments suggest that SWV contributes positively to the global surface temperature variation, although it may not be the dominant factor that drives the recent global warming hiatus. Additional sensitivity experiments show that the impact of SWV on surface climate is mostly governed by the SWV amount at 100 hPa in the tropics. Furthermore, the atmospheric model simulations driven by observed sea surface temperature (SST) show that the inter-annual variation of SWV follows that of SST

The use of warmed water treatment to induce protective immunity against the bacterial cold-water disease pathogen Flavobacterium psychrophilum in ayu (Plecoglossus altivelis).

PubMed

Sugahara, K; Eguchi, M

2012-03-01

We investigated the induction of protective immunity against bacterial cold-water disease (BCWD) caused by Flavobacterium psychrophilum by warmed water treatment in ayu (Plecoglossus altivelis). Fish were immersed in a live bacterial suspension (10⁷ CFU mL⁻¹) for 30 min and placed in 700 L concrete tanks. The 28 °C warmed water treatment lasted 3 days and began 1, 6, and 24 h after immersion in the live bacterial suspension. A naïve control fish group was immersed in a sterilized modified Cytophaga (MCY) broth instead of the bacterial suspension. Fourteen days after the immersion, agglutination antibody titers against F. psychrophilum were measured by using micro-titer methods. Fish were then exposed to a bacterial bath to infect them with live F. psychrophilum, and cumulative mortality was monitored. Fish treated with warmed water at 1, 6, and 24 h after immersion in the live bacterial suspension had cumulative mortalities of 36%, 30%, and 18%, respectively, all of which were significantly lower than the cumulative mortality of the naïve control fish (90%). Treated fish also showed high antibody titers against F. psychrophilum in agglutination tests. These results demonstrate that warmed water treatment could not only cure BCWD but also immunize the fish against the causative agent F. psychrophilum. Copyright © 2011 Elsevier Ltd. All rights reserved.

Field Evaluation Of Arsenic Transport Across The Ground-Water/Surface Water Interface: Ground-Water Discharge And Iron Oxide Precipitation

EPA Science Inventory

A field investigation was conducted to examine the distribution of arsenic in ground water, surface water, and sediments at a Superfund Site in the northeastern United States (see companion presentation by K. G. Scheckel et al). Ground-water discharge into the study area was cha...

Electric discharge in water as a source of UV radiation, ozone and hydrogen peroxide

NASA Astrophysics Data System (ADS)

Anpilov, A. M.; Barkhudarov, E. M.; Bark, Yu B.; Zadiraka, Yu V.; Christofi, M.; Kozlov, Yu N.; Kossyi, I. A.; Kop'ev, V. A.; Silakov, V. P.; Taktakishvili, M. I.; Temchin, S. M.

2001-03-01

Results are presented from investigations of multispark electric discharge in water excited along multielectrode metal-dielectric systems with gas supply into the interelectrode gaps. The intensity distribution of discharge radiation in the region covering the biologically active soft UV (190≤λ≤430 nm) has been determined and the absolute number of quanta in this wavelength interval has been measured. The potentiality of the slipping surface discharge in water for its disinfection is analysed. The energy expenditure for water cleansing is estimated to be as low as ~10-4 kWh l-1.

Partitioning Hydrologic and Biological Drivers of Discharge Loss in Arctic Headwater Streams

NASA Astrophysics Data System (ADS)

Koch, J. C.; Carey, M.; O'Donnell, J. A.; Records, M. K.; Sjoberg, Y.; Zimmerman, C. E.

2017-12-01

The Arctic-Boreal transition (ABT) zone of Alaska is experiencing unprecedented warming, leading to permafrost thaw and vegetation change. Both of these processes are likely to affect streams and stream ecosystems, but there is little direct empirical evidence regarding the magnitude of these effects and their relative importance. To understand how permafrost thaw and vegetation are affecting streams at the ABT, we monitored 8 first-order streams that drain catchments varying in elevation, aspect, and vegetation cover. Data were obtained from meteorological stations, continuous stream discharge, seepage runs, and stream tracer experiments. Hydrograph analysis indicated that runoff ratios in south-facing catchments were lower than north-facing catchments and decreased over the season. Seepage runs indicated that south-facing catchments lost a large portion of water (up to 50% per km stream reach) in the late summer, while north-facing catchments were gaining water. All streams displayed diel variability in discharge, but with different daily and seasonal trends related to aspect and elevation. South-facing, forested catchment streams showed diel discharge timing consistent with cycles in evapotranspiration rates, while the signal in north-facing catchments and those dominated by tundra was more consistent with thermal controls on water viscosity and groundwater discharge to streams. Together, these signals indicate that the warmer, south-facing catchments are losing a large portion of water to a combination of infiltration and evapotranspiration. The seasonal trends are consistent with higher infiltration rates beneath south-facing streams as the ground thaws over the summer. The magnitude and seasonal dynamics of the diel signatures help separate biological (i.e. evapotranspiration) vs. physical controls (i.e. frozen ground hydrology) on stream-catchment interactions, which vary depending on aspect, elevation, and vegetation cover. Warming, and subsequent increases

Recent Warming of Lake Kivu

PubMed Central

Katsev, Sergei; Aaberg, Arthur A.; Crowe, Sean A.; Hecky, Robert E.

2014-01-01

Lake Kivu in East Africa has gained notoriety for its prodigious amounts of dissolved methane and dangers of limnic eruption. Being meromictic, it is also expected to accumulate heat due to rising regional air temperatures. To investigate the warming trend and distinguish between atmospheric and geothermal heating sources, we compiled historical temperature data, performed measurements with logging instruments, and simulated heat propagation. We also performed isotopic analyses of water from the lake's main basin and isolated Kabuno Bay. The results reveal that the lake surface is warming at the rate of 0.12°C per decade, which matches the warming rates in other East African lakes. Temperatures increase throughout the entire water column. Though warming is strongest near the surface, warming rates in the deep waters cannot be accounted for solely by propagation of atmospheric heat at presently assumed rates of vertical mixing. Unless the transport rates are significantly higher than presently believed, this indicates significant contributions from subterranean heat sources. Temperature time series in the deep monimolimnion suggest evidence of convection. The progressive deepening of the depth of temperature minimum in the water column is expected to accelerate the warming in deeper waters. The warming trend, however, is unlikely to strongly affect the physical stability of the lake, which depends primarily on salinity gradient. PMID:25295730

Recent warming of lake Kivu.

PubMed

Katsev, Sergei; Aaberg, Arthur A; Crowe, Sean A; Hecky, Robert E

2014-01-01

Lake Kivu in East Africa has gained notoriety for its prodigious amounts of dissolved methane and dangers of limnic eruption. Being meromictic, it is also expected to accumulate heat due to rising regional air temperatures. To investigate the warming trend and distinguish between atmospheric and geothermal heating sources, we compiled historical temperature data, performed measurements with logging instruments, and simulated heat propagation. We also performed isotopic analyses of water from the lake's main basin and isolated Kabuno Bay. The results reveal that the lake surface is warming at the rate of 0.12°C per decade, which matches the warming rates in other East African lakes. Temperatures increase throughout the entire water column. Though warming is strongest near the surface, warming rates in the deep waters cannot be accounted for solely by propagation of atmospheric heat at presently assumed rates of vertical mixing. Unless the transport rates are significantly higher than presently believed, this indicates significant contributions from subterranean heat sources. Temperature time series in the deep monimolimnion suggest evidence of convection. The progressive deepening of the depth of temperature minimum in the water column is expected to accelerate the warming in deeper waters. The warming trend, however, is unlikely to strongly affect the physical stability of the lake, which depends primarily on salinity gradient.

Processes Controlling Baseflow and Climatic Warming Effects in Merced River, Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Liu, F.; Conklin, M. H.; Shaw, G.; Bales, R. C.; Conrad, M. E.; Rice, R.

2006-12-01

Sources of streamflow in Merced River were determined using stable isotopes and chemical tracers in order to improve our understanding of hydrologic controls on streamflow and their relationship with climatic warming in the region. Samples were collected from streamflow, groundwater, and natural springs from 2003 to 2006. Both stable isotopes and specific conductivity in streamflow showed a strong seasonality, with lower values from April to July during the snowmelt season, higher values from August to October during dry season, and intermediate values from November to March during winter rainfall and snowfall. Two components controlling baseflow (streamflow from August to October) in the Upper Merced River were identified: shallow subsurface runoff from snowmelt infiltration and groundwater from fractured bedrock. Conductivity in baseflow increased rapidly with discharge, following a power law (R2 > 0.96, p < 0.05), and peaked in October, indicating that the contribution of shallow subsurface runoff to baseflow was significant but decreased rapidly from August to October. Baseflow appears to be very sensitive to the snowmelt timing and regime. From 1976 to 2005, during a period of increasing temperature in the region, streamflow tended to decrease significantly during October (p < 0.05) and increase during March (p < 0.05). However, total annual precipitation did not change significantly, indicating that the shift in baseflow discharge is a result of the early onset of snowmelt due to climatic warming. If climatic warming continues in the region, baseflow in the Sierra Nevada may continue decreasing and water supply may suffer increased stress during the late summer, high water-demand period.

Desalination Brine Discharge Impacts on Coastal Biology and Water Chemistry - A Case Study from Carlsbad Southern California

NASA Astrophysics Data System (ADS)

Petersen, K. L.; Heck, N.; Potts, D. C.; Paytan, A.

2017-12-01

Fresh water demand is increasing world-wide due to on-going droughts, climate change and increasing human population and associated demand for food and water. Desalination of seawater is a reliable source of potable water; however the effects of byproduct brine discharge from desalination plants on coastal areas have not been thoroughly assessed. Here we report results from in-situmeasurements of the effects of brine discharge on water chemistry and coastal biology from a desalination plant in Carlsbad, Southern California. We compared select parameters in the coastal zone around the discharge site before and after operation began and conducted additional controlled laboratory incubations with key coastal species and brine effluent. Our in-situ data shows differences in salinity and temperature between the discharge area and a control site both before and after the desalination plant started operation. The discharge water is warmer by 3-5 Co than the ambient seawater and a temperature gradient is seen around the discharge channel. This is likely a result of mixing of the desalination brine with power plant cooling water for dilution prior to discharge and the higher temperatures are not directly attributed to the desalination. Our post-discharge results show a decipherable salinity plume at the bottom of the water column ( 6 m depth) reaching up to 600 m offshore from the discharge site. This indicates inefficient mixing of the brine in the coastal discharge zone. No significant differences are found in nutrient levels, organic carbon or chlorophyll a concentrations around the discharge. The benthic biology assemblage post-discharge is significantly different from the pre-discharge organisms' assemblage. However, the role of seasonal changes in temperature may also have impacted the data as the sampling was conducted during different seasons. Controlled incubation experiments of brittle stars (Ophiothrix spiculata) shows no significant difference in growth or

Characterizing hydrology and the importance of ground-water discharge in natural and constructed wetlands

USGS Publications Warehouse

Hunt, Randall J.; Walker, John F.; Krabbenhoft, David P.

1999-01-01

Although considered the most important component for the establishment and persistence of wetlands, hydrology has been hard to characterize and linkages between hydrology and other environmental conditions are often poorly understood. In this work, methods for characterizing a wetland’s hydrology from hydrographs were developed, and the importance of ground water to the physical and geochemical conditions in the root zone was investigated. Detailed sampling of nearly continuous hydrographs showed that sites with greater ground-water discharge had higher water tables and more stable hydrographs. Subsampling of the continuous hydrograph failed to characterize the sites correctly, even though the wetland complex is located in a strong regional ground-water-discharge area. By comparing soil-moisture-potential measurements to the water-table hydrograph at one site, we noted that the amount of root-zone saturation was not necessarily driven by the water-table hydrograph but can be a result of other soil parameters (i.e., soil texture and associated capillary fringe). Ground-water discharge was not a significant determinant of maximum or average temperatures in the root zone. High ground-water discharge was associated with earliest date of thaw and shortest period of time that the root zone was frozen, however. Finally, the direction and magnitude of shallow ground-water flow was found to affect the migration and importance of a geochemical species. Areas of higher ground-water discharge had less downward penetration of CO2 generated in the root zone. In contrast, biotically derived CO2 was able to penetrate the deeper ground-water system in areas of ground-water recharge. Although ground-water flows are difficult to characterize, understanding these components is critical to the success of wetland restoration and creation efforts.

Risk assessment for produced water discharges to Louisiana Open Bays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinhold, A.F.; DePhillips, M.P.; Holtzman, S.

Data were collected prior to termination of discharge at three sites (including two open bay sites at Delacroix Island and Bay De Chene) for the risk assessments. The Delacroix Island Oil and Gas Field has been in production since the first well drilling in 1940; the Bay De Chene Field, since 1942. Concentrations of 226Ra, 228Ra, 210Po, and 228Th were measured in discharges. Radium conc. were measured in fish and shellfish tissues. Sediment PAH and metal conc. were also available. Benthos sampling was conducted. A survey of fishermen was conducted. The tiered risk assessment showed that human health risks frommore » radium in produced water appear to be small; ecological risk from radium and other radionuclides in produced water also appear small. Many of the chemical contaminants discharged to open Louisiana bays appear to present little human health or ecological risk. A conservative screening analysis suggested potential risks to human health from Hg and Pb and a potential risk to ecological receptors from total effluent, Sb, Cd, Cu, Pb, Ni, Ag, Zn, and phenol in the water column and PAHs in sediment; quantitiative risk assessments are being done for these contaminants.« less

Warming combined with more extreme precipitation regimes modifies the water sources used by trees

DOE PAGES

Grossiord, Charlotte; Sevanto, Sanna; Dawson, Todd E.; ...

2016-09-09

The persistence of vegetation under climate change will depend on a plant's capacity to exploit water resources. In addition, we analyzed water source dynamics in piñon pine and juniper trees subjected to precipitation reduction, atmospheric warming, and to both simultaneously.

Warming combined with more extreme precipitation regimes modifies the water sources used by trees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grossiord, Charlotte; Sevanto, Sanna; Dawson, Todd E.

The persistence of vegetation under climate change will depend on a plant's capacity to exploit water resources. In addition, we analyzed water source dynamics in piñon pine and juniper trees subjected to precipitation reduction, atmospheric warming, and to both simultaneously.

Century-Long Warming Trends in the Upper Water Column of Lake Tanganyika.

PubMed

Kraemer, Benjamin M; Hook, Simon; Huttula, Timo; Kotilainen, Pekka; O'Reilly, Catherine M; Peltonen, Anu; Plisnier, Pierre-Denis; Sarvala, Jouko; Tamatamah, Rashid; Vadeboncoeur, Yvonne; Wehrli, Bernhard; McIntyre, Peter B

2015-01-01

Lake Tanganyika, the deepest and most voluminous lake in Africa, has warmed over the last century in response to climate change. Separate analyses of surface warming rates estimated from in situ instruments, satellites, and a paleolimnological temperature proxy (TEX86) disagree, leaving uncertainty about the thermal sensitivity of Lake Tanganyika to climate change. Here, we use a comprehensive database of in situ temperature data from the top 100 meters of the water column that span the lake's seasonal range and lateral extent to demonstrate that long-term temperature trends in Lake Tanganyika depend strongly on depth, season, and latitude. The observed spatiotemporal variation in surface warming rates accounts for small differences between warming rate estimates from in situ instruments and satellite data. However, after accounting for spatiotemporal variation in temperature and warming rates, the TEX86 paleolimnological proxy yields lower surface temperatures (1.46 °C lower on average) and faster warming rates (by a factor of three) than in situ measurements. Based on the ecology of Thaumarchaeota (the microbes whose biomolecules are involved with generating the TEX86 proxy), we offer a reinterpretation of the TEX86 data from Lake Tanganyika as the temperature of the low-oxygen zone, rather than of the lake surface temperature as has been suggested previously. Our analyses provide a thorough accounting of spatiotemporal variation in warming rates, offering strong evidence that thermal and ecological shifts observed in this massive tropical lake over the last century are robust and in step with global climate change.

Century-Long Warming Trends in the Upper Water Column of Lake Tanganyika

PubMed Central

Kraemer, Benjamin M.; Hook, Simon; Huttula, Timo; Kotilainen, Pekka; O’Reilly, Catherine M.; Peltonen, Anu; Plisnier, Pierre-Denis; Sarvala, Jouko; Tamatamah, Rashid; Vadeboncoeur, Yvonne; Wehrli, Bernhard; McIntyre, Peter B.

2015-01-01

Lake Tanganyika, the deepest and most voluminous lake in Africa, has warmed over the last century in response to climate change. Separate analyses of surface warming rates estimated from in situ instruments, satellites, and a paleolimnological temperature proxy (TEX86) disagree, leaving uncertainty about the thermal sensitivity of Lake Tanganyika to climate change. Here, we use a comprehensive database of in situ temperature data from the top 100 meters of the water column that span the lake’s seasonal range and lateral extent to demonstrate that long-term temperature trends in Lake Tanganyika depend strongly on depth, season, and latitude. The observed spatiotemporal variation in surface warming rates accounts for small differences between warming rate estimates from in situ instruments and satellite data. However, after accounting for spatiotemporal variation in temperature and warming rates, the TEX86 paleolimnological proxy yields lower surface temperatures (1.46 °C lower on average) and faster warming rates (by a factor of three) than in situ measurements. Based on the ecology of Thaumarchaeota (the microbes whose biomolecules are involved with generating the TEX86 proxy), we offer a reinterpretation of the TEX86 data from Lake Tanganyika as the temperature of the low-oxygen zone, rather than of the lake surface temperature as has been suggested previously. Our analyses provide a thorough accounting of spatiotemporal variation in warming rates, offering strong evidence that thermal and ecological shifts observed in this massive tropical lake over the last century are robust and in step with global climate change. PMID:26147964

Clusters of deep-sea egg-brooding octopods associated with warm fluid discharge: An ill-fated fragment of a larger, discrete population?

NASA Astrophysics Data System (ADS)

Hartwell, Anne M.; Voight, Janet R.; Wheat, C. Geoffrey

2018-05-01

Benthic octopods cluster on bare rock on Dorado Outcrop, a 3000 m deep basalt exposure. The outcrop hosts intermittent discharge of relatively cool (up to 12.3 °C) hydrothermal fluid that carries about half as much oxygen as bottom seawater ( 54 μM vs. 108 μM). We analyzed 231 h of video footage and still images taken by sub-sea vehicles in 2013 and 2014 that documented the clustered octopods, members of the poorly-known genus Muusoctopus. The largest cluster (102 octopods) occurred in a 19 m2 area of fluid discharge, where the basalt was sediment-free; individual octopods were also seen across the outcrop. The clustered octopods appeared to be brooding eggs and a total of 11 egg clutches were confirmed. None of the 186 eggs closely examined showed embryonic development. The intermittent fluid discharge may clear the basalt of sediment and attract gravid octopods which then spawn. However, the increased temperature and limited oxygen of the discharging fluids may threaten the octopods' survival. Octopods in/near areas of discharging fluid had significantly higher estimated respiration rates (3.1-9.8 contractions/min) than did octopods away from discharging fluid (0.8-6.0 contractions/min). Warm fluids likely increase the octopods' metabolic rate and thus their oxygen demand but provide only limited oxygen. The resultant physiological stress is hypothesized to eventually kill eggs near fluid discharge. We hypothesize, because these eggs do not survive, the population is sustained by a larger pool of undetectable females that brood their eggs inside cool conduits of this and perhaps other, unstudied basalt outcrops.

Produced water discharges to the Gulf of Mexico: Background information for ecological risk assessments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinhold, A.F.; Holtzman, S.; DePhillips, M.P.

1996-06-01

This report reviews ecological risk assessment concepts and methods; describes important biological resources in the Gulf of Mexico of potential concern for produced water impacts; and summarizes data available to estimate exposure and effects of produced water discharges. The emphasis is on data relating to produced water discharges in the central and western Gulf of Mexico, especially in Louisiana. Much of the summarized data and cited literature are relevant to assessments of impacts in other regions. Data describing effects on marine and estuarine fishes, mollusks, crustaceans and benthic invertebrates are emphasized. This review is part of a series of studiesmore » of the health and ecological risks from discharges of produced water to the Gulf of Mexico. These assessments will provide input to regulators in the development of guidelines and permits, and to industry in the use of appropriate discharge practices.« less

Water withdrawals, use, discharge, and trends in Florida, 1995

USGS Publications Warehouse

Marella, R.L.

1999-01-01

, Lake Apopka, Lake Okeechobee and associated canals, and the St. Johns River. Freshwater withdrawals increased nearly 29 percent in Florida between 1970 and 1995. Ground-water withdrawals increased 56 percent, and surface-water withdrawals increased 2 percent during this period. Between 1990 and 1995, freshwater withdrawals decreased 5 percent. Fresh ground-water withdrawals decreased 7 percent, and fresh surface-water withdrawals decreased 1 percent during this period. Saline water withdrawals increased 13 percent between 1970 and 1995, and increased 6 percent between 1990 and 1995. An estimated 39 percent of the freshwater withdrawn in Florida was consumed; the remaining 61 percent was returned for use again. Wastewater discharged from the 615 treatment facilities inventoried in 1995 totaled 1,836 Mgal/d, of which 84 percent was from domestic wastewater facilities and the remaining 16 percent was from industrial facilities. Domestic wastewater discharge increased 37 percent between 1985 and 1995, while industrial wastewater discharge increased 7 percent during this period.

Asetek's Warm-Water Liquid Cooling System Yields Energy Cost Savings at

Science.gov Websites

NREL | Energy Systems Integration Facility | NREL Asetek Asetek's Warm-Water Liquid Cooling System Yields Energy Cost Savings at NREL Asetek's RackCDU liquid cooling system was installed and tested at the Energy Systems Integration Facility's (ESIF's) ultra-energy-efficient high-performance

Moving in extreme environments: open water swimming in cold and warm water

PubMed Central

2014-01-01

Open water swimming (OWS), either ‘wild’ such as river swimming or competitive, is a fast growing pastime as well as a part of events such as triathlons. Little evidence is available on which to base high and low water temperature limits. Also, due to factors such as acclimatisation, which disassociates thermal sensation and comfort from thermal state, individuals cannot be left to monitor their own physical condition during swims. Deaths have occurred during OWS; these have been due to not only thermal responses but also cardiac problems. This paper, which is part of a series on ‘Moving in Extreme Environments’, briefly reviews current understanding in pertinent topics associated with OWS. Guidelines are presented for the organisation of open water events to minimise risk, and it is concluded that more information on the responses to immersion in cold and warm water, the causes of the individual variation in these responses and the precursors to the cardiac events that appear to be the primary cause of death in OWS events will help make this enjoyable sport even safer. PMID:24921042

Ultraviolet-B radiation induced cross-linking improves physical properties of cold- and warm-water fish gelatin gels and films.

PubMed

Otoni, Caio G; Avena-Bustillos, Roberto J; Chiou, Bor-Sen; Bilbao-Sainz, Cristina; Bechtel, Peter J; McHugh, Tara H

2012-09-01

Cold- and warm-water fish gelatin granules were exposed to ultraviolet-B radiation for doses up to 29.7 J/cm(2). Solutions and films were prepared from the granules. Gel electrophoresis and refractive index were used to examine changes in molecular weight of the samples. Also, the gel strength and rheological properties of the solutions as well as the tensile and water vapor barrier properties of the films were characterized. SDS-PAGE and refractive index results indicated cross-linking of gelatin chains after exposure to radiation. Interestingly, UV-B treated samples displayed higher gel strengths, with cold- and warm-water fish gelatin having gel strength increases from 1.39 to 2.11 N and from 7.15 to 8.34 N, respectively. In addition, both gelatin samples exhibited an increase in viscosity for higher UV doses. For gelatin films, the cold-water fish gelatin samples made from irradiated granules showed greater tensile strength. In comparison, the warm-water gelatin films made from irradiated granules had lower tensile strength, but better water vapor barrier properties. This might be due to the UV induced cross-linking in warm-water gelatin that disrupted helical structures. Journal of Food Science copy; 2012 Institute of Food Technologists® No claim to original US government works.

TOPEX/El Nino Watch - Warm Water Pool is Thinning, Feb, 5, 1998

NASA Technical Reports Server (NTRS)

1998-01-01

This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Feb. 5, 1998 and sea surface height is an indicator of the heat content of the ocean. The area and volume of the El Nino warm water pool that is affecting global weather patterns remains extremely large, but the pool has thinned along the equator and near the coast of South America. This 'thinning' means that the warm water is not as deep as it was a few months ago. Oceanographers indicate this is a classic pattern, typical of a mature El Nino condition that they would expect to see during the ocean's gradual transition back to normal sea level. In this image, the white and red areas indicate unusual patterns of heat storage; in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal; in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Nino phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using satellite imagery, buoy and ship data, and a forecasting model of the ocean-atmosphere system, the National Oceanic and Atmospheric Administration, (NOAA), has continued to issue an advisory indicating the so-called El Nino weather conditions that have impacted much of the United States and the world are expected to remain through

Characterization of fish hold effluent discharged from commercial fishing vessels into harbor waters.

PubMed

Albert, Ryan J; McLaughlin, Christine; Falatko, Debra

2014-10-15

Fish hold effluent and the effluent produced from the cleaning of fish holds may contain organic material resulting from the degradation of seafood and cleaning products (e.g., soaps and detergents). This effluent is often discharged by vessels into near shore waters and, therefore, could have the potential to contribute to water pollution in bays and estuaries. We characterized effluent from commercial fishing vessels with holds containing refrigerated seawater, ice slurry, or chipped ice. Concentrations of trace heavy metals, wet chemistry parameters, and nutrients in effluent were compared to screening benchmarks to determine if there is a reasonable potential for effluent discharge to contribute to nonattainment of water quality standards. Most analytes (67%) exceeded their benchmark concentration and, therefore, may have the potential to pose risk to human health or the environment if discharges are in significant quantities or there are many vessels discharging in the same areas. Published by Elsevier Ltd.

Water resources of the Warm Springs Indian Reservation, Oregon

USGS Publications Warehouse

Robison, J.H.; Laenen, Antonius

1976-01-01

Water-resources data for the 1,000-square-mile Warm Springs Indian Reservation in north-central Oregon were obtained and evaluated. The area is bounded on the west by the crest of the Cascade Range and on the south and east by the Metolius and Deschutes Rivers. The mountainous western part is underlain by young volcanic rocks, and the plateaus and valleys of the eastern part are underlain by basalt, tuff, sand, and gravel of Tertiary and Quaternary ages. There are numerous springs, some developed for stock use, and about 50 domestic and community wells; yields are small, ranging from less than 1 to as much as 25 gallons per minute. Chemical quality of most ground water is suitable for stock or human consumption and for irrigation. Average flows of the Warm Springs River, Metolius River, and Deschutes River are 440, 1,400, and 4,040 cubic feet per second (cfs), respectively. Shitike Creek, which has an average flow of 108 cfs had a peak of 4,000 cfs in January 1974. Most streams have fewer than 100 milligrams per liter (mg/liter) of dissolved solids. Chemical and biological quality of the mountain lakes is also good; of 10 lakes studied, all had fewer than 50 mg/liter of dissolved solids and none had measurable fecal coliform bacteria. (Woodard-USGS)

Assessing natural and anthropogenic influences on water discharge and sediment load in the Yangtze River, China.

PubMed

Zhao, Yifei; Zou, Xinqing; Liu, Qing; Yao, Yulong; Li, Yali; Wu, Xiaowei; Wang, Chenglong; Yu, Wenwen; Wang, Teng

2017-12-31

The water discharge and sediment load of rivers are changing substantially under the impacts of climate change and human activities, becoming a hot issue in hydro-environmental research. In this study, the water discharge and sediment load in the mainstream and seven tributaries of the Yangtze River were investigated by using long-term hydro-meteorological data from 1953 to 2013. The non-parametric Mann-Kendall test and double mass curve (DMC) were used to detect trends and abrupt change-points in water discharge and sediment load and to quantify the effects of climate change and human activities on water discharge and sediment load. The results are as follows: (1) the water discharge showed a non-significant decreasing trend at most stations except Hukou station. Among these, water discharge at Dongting Lake and the Min River basin shows a significant decreasing trend with average rates of -13.93×10 8 m 3 /year and -1.8×10 8 m 3 /year (P<0.05), respectively. However, the sediment load exhibited a significant decreasing trend in all tributaries of the Yangtze River. (2) No significant abrupt change-points were detected in the time series of water discharge for all hydrological stations. In contrast, significant abrupt change-points were detected in sediment load, most of these changes appeared in the late 1980s. (3) The water discharge was mainly influenced by precipitation in the Yangtze River basin, whereas sediment load was mainly affected by climate change and human activities; the relative contribution ratios of human activities were above 70% for the Yangtze River. (4) The decrease of sediment load has directly impacted the lower Yangtze River and the delta region. These results will provide a reference for better resource management in the Yangtze River Basin. Copyright © 2017 Elsevier B.V. All rights reserved.

Discharge of oilfield-produced water in Nueces Bay, Texas: A case study

USGS Publications Warehouse

D'Unger, Claude; Chapman, Duane C.; Carr, R. Scott

1996-01-01

During oil and gas production, water is often extracted from geological formations along with the hydrocarbons. These “produced waters” have been discharged to Nueces Bay since the turn of the century. These effluents were found to be highly toxic, and sediments in the vicinity of the discharges were also toxic. We developed a map of wells and produced-water discharge sites in the vicinity of Nueces Bay and identified numerous unplugged wells suitable for conversion to produced water disposal wells. An economic analysis of conversion to subterranean injection of produced water indicates that most of the wells currently in production could pay out the cost of conversion to injection in one to three years. The use of one injection well for two or more water-producing wells could yield greater savings. Wells that could not support the cost of injection are small producers, and their loss would not constitute a major loss of jobs or dollars to the area. This study could serve as a useful model for evaluating the economic feasibility of conversion to injection in other areas of Texas and Louisiana.

A cascade of warming impacts brings bluefin tuna to Greenland waters.

PubMed

MacKenzie, Brian R; Payne, Mark R; Boje, Jesper; Høyer, Jacob L; Siegstad, Helle

2014-08-01

Rising ocean temperatures are causing marine fish species to shift spatial distributions and ranges, and are altering predator-prey dynamics in food webs. Most documented cases of species shifts so far involve relatively small species at lower trophic levels, and consider individual species in ecological isolation from others. Here, we show that a large highly migratory top predator fish species has entered a high latitude subpolar area beyond its usual range. Bluefin tuna, Thunnus thynnus Linnaeus 1758, were captured in waters east of Greenland (65°N) in August 2012 during exploratory fishing for Atlantic mackerel, Scomber scombrus Linnaeus 1758. The bluefin tuna were captured in a single net-haul in 9-11 °C water together with 6 tonnes of mackerel, which is a preferred prey species and itself a new immigrant to the area. Regional temperatures in August 2012 were historically high and contributed to a warming trend since 1985, when temperatures began to rise. The presence of bluefin tuna in this region is likely due to a combination of warm temperatures that are physiologically more tolerable and immigration of an important prey species to the region. We conclude that a cascade of climate change impacts is restructuring the food web in east Greenland waters. © 2014 John Wiley & Sons Ltd.

Quantification of excess water loss in plant canopies warmed with infrared heating

USDA-ARS?s Scientific Manuscript database

Here we investigate the extent to which infrared heating used to warm plant canopies in climate manipulation experiments increases transpiration. Concerns regarding the impact of the infrared heater technique on the water balance have been raised before, but a quantification is lacking. We calculate...

Quantifying time-varying ground-water discharge and recharge in wetlands of the northern Florida Everglades

USGS Publications Warehouse

Choi, J.; Harvey, J.W.

2000-01-01

Developing a more thorough understanding of water and chemical budgets in wetlands depends in part on our ability to quantify time-varying interactions between ground water and surface water. We used a combined water and solute mass balance approach to estimate time-varying ground-water discharge and recharge in the Everglades Nutrient Removal project (ENR), a relatively large constructed wetland (1544 hectare) built for removing nutrients from agricultural drainage in the norther Everglades in South Florida, USA. Over a 4-year period (1994 through 1998), ground-water recharge averaged 13.4 hectare-meter per day (ha-m/day) or 0.9 cm/day, which is approximately 31% of surface water pumped into the ENR for treatment. In contrast, ground-water discharge was much smaller (1.4 ha-m/day, or 0.09 cm/day, or 2.8% of water input to ENR for treatment). Using a water-balance approach alone only allowed net ground-water exchange (discharge - recharge) to be estimated (-12 ?? 2.4 ha-ma/day). Disharge and recharge were individually determined by combining a chloride mass balance with the water balance. For a variety of reasons, the ground-water discharge estimated by the combined mass balance approach was not reliable (1.4 ?? 37 ha-m/day). As a result, ground-water interactions could only be reliably estimated by comparing the mass-balance results with other independent approaches, including direct seepage-meter measurements and previous estimates using ground-water modeling. All three independent approaches provided similar estimates of average ground-water recharge, ranging from 13 to 14 ha-m/day. There was also relatively good agreement between ground-water discharge estimates for the mass balance and seepage meter methods, 1.4 and 0.9 ha-m/day, respectively. However, ground-water-flow modeling provided an average discharge estimate that was approximately a factor of four higher (5.4 ha-m/day) than the other two methods. Our study developed an initial understanding of how the

Projected increase in lightning strikes in the United States due to global warming

NASA Astrophysics Data System (ADS)

Romps, David M.; Seeley, Jacob T.; Vollaro, David; Molinari, John

2014-11-01

Lightning plays an important role in atmospheric chemistry and in the initiation of wildfires, but the impact of global warming on lightning rates is poorly constrained. Here we propose that the lightning flash rate is proportional to the convective available potential energy (CAPE) times the precipitation rate. Using observations, the product of CAPE and precipitation explains 77% of the variance in the time series of total cloud-to-ground lightning flashes over the contiguous United States (CONUS). Storms convert CAPE times precipitated water mass to discharged lightning energy with an efficiency of 1%. When this proxy is applied to 11 climate models, CONUS lightning strikes are predicted to increase 12 ± 5% per degree Celsius of global warming and about 50% over this century.

Physicochemical properties of the AC-excited helium discharges using a water electrode

NASA Astrophysics Data System (ADS)

Hafiz, Imran Ahmad QAZI; Yiying, XIN; Muhammad Ajmal, KHAN; Heping, LI; Lu, ZHOU; Chengyu, BAO

2018-07-01

In this paper, the AC-excited helium discharges generated between the powered needle electrode enclosed in a conical quartz tube and the grounded de-ionized water electrode are investigated. The current and voltage waveforms exhibit a transition from the glow-like to streamer-like mode discharges, which forms a stable cone-shaped structure at the gas–liquid interface. In this region, the air and water vapor diffusion initiate various physical–chemical processes leading to substantial changes of the primary species emission intensities (e.g., OH, N2, NO, and O) and the rotational temperatures. The experimentally measured rotational temperature at the gas–liquid interface is 870 K from the N2(C–B) band with a power input of 26 W. With the prolongation of the discharge time, significant changes in the discharge voltage and current, discharge emission patterns, instantaneous concentrations of the secondary species (e.g., H2O2, {{{NO}}}2-, and {{{NO}}}3-) in the liquid phase, pH values and electrical conductivities of the liquids are observed experimentally. The present study is helpful for deepening the understandings to the basic physical–chemical processes in the discharges in contact with liquids, especially to those occurring in the vicinity of the gas–liquid interface, and also for promoting existing and potential applications of such type of discharges in the fields of environmental protection, biomedicine, agriculture, and so on.

Simulated long-term changes in river discharge and soil moisture due to global warming

USGS Publications Warehouse

Manabe, S.; Milly, P.C.D.; Wetherald, R.

2004-01-01

By use of a coupled ocean atmosphere-land model, this study explores the changes of water availability, as measured by river discharge and soil moisture, that could occur by the middle of the 21st century in response to combined increases of greenhouse gases and sulphate aerosols based upon the "IS92a" scenario. In addition, it presents the simulated change in water availability that might be realized in a few centuries in response to a quadrupling of CO2 concentration in the atmosphere. Averaging the results over extended periods, the radiatively forced changes, which are very similar between the two sets of experiments, were successfully extracted. The analysis indicates that the discharges from Arctic rivers such as the Mackenzie and Ob' increase by up to 20% (of the pre-Industrial Period level) by the middle of the 21st century and by up to 40% or more in a few centuries. In the tropics, the discharges from the Amazonas and Ganga-Brahmaputra rivers increase substantially. However, the percentage changes in runoff from other tropical and many mid-latitude rivers are smaller, with both positive and negative signs. For soil moisture, the results of this study indicate reductions during much of the year in many semiarid regions of the world, such as the southwestern region of North America, the northeastern region of China, the Mediterranean coast of Europe, and the grasslands of Australia and Africa. As a percentage, the reduction is particularly large during the dry season. From middle to high latitudes of the Northern Hemisphere, soil moisture decreases in summer but increases in winter.

National water quality assessment of the Georgia-Florida Coastal Plain study unit; water withdrawals and treated wastewater discharges, 1990

USGS Publications Warehouse

Marella, R.L.; Fanning, J.L.

1996-01-01

,293 million gallons per day, of which 69 percent was ground water and 31 percent was surface water. An estimated 1.254 millon acres were irrigated within the study unit during 1990. Water withdrawn for thermoelectric power generation in the study unit in 1990 totaled 1,552 million gallons per day, of which 99 percent was surface water and 1 percent was ground water. An additional 6,919 million gallons per day of saline surface water were withdrawn for thermoelectric power generation in 1990, solely for cooling purposes. Treated wastewater discharged within the Georgia-Florida Coastal Plain study unit totaled nearly 1,187 million gallons per day in 1990. Of the total water discharged, 58 percent was discharged directly into surface water and the remaining 42 percent was discharged to ground water (through drain fields, injection wells, percolation ponds or spray fields). Domestic wastewater facilities discharged in the study unit totaled nearly 789 million gallons per day, industrial wastewater facilities discharged 213 million gallons per day, and releases from septic tanks was estimated at 185 million gallons per day. More than 1.3 million septic tanks were estimated in use within the study unit in 1990.

Warming shifts 'worming': effects of experimental warming on invasive earthworms in northern North America.

PubMed

Eisenhauer, Nico; Stefanski, Artur; Fisichelli, Nicholas A; Rice, Karen; Rich, Roy; Reich, Peter B

2014-11-03

Climate change causes species range shifts and potentially alters biological invasions. The invasion of European earthworm species across northern North America has severe impacts on native ecosystems. Given the long and cold winters in that region that to date supposedly have slowed earthworm invasion, future warming is hypothesized to accelerate earthworm invasions into yet non-invaded regions. Alternatively, warming-induced reductions in soil water content (SWC) can also decrease earthworm performance. We tested these hypotheses in a field warming experiment at two sites in Minnesota, USA by sampling earthworms in closed and open canopy in three temperature treatments in 2010 and 2012. Structural equation modeling revealed that detrimental warming effects on earthworm densities and biomass could indeed be partly explained by warming-induced reductions in SWC. The direction of warming effects depended on the current average SWC: warming had neutral to positive effects at high SWC, whereas the opposite was true at low SWC. Our results suggest that warming limits the invasion of earthworms in northern North America by causing less favorable soil abiotic conditions, unless warming is accompanied by increased and temporally even distributions of rainfall sufficient to offset greater water losses from higher evapotranspiration.

Ground-water discharge determined from estimates of evapotranspiration, Death Valley regional flow system, Nevada and California

USGS Publications Warehouse

Laczniak, Randell J.; Smith, J. LaRue; Elliott, Peggy E.; DeMeo, Guy A.; Chatigny, Melissa A.; Roemer, Gaius J.

2001-01-01

The Death Valley regional flow system (DVRFS) is one of the larger ground-water flow systems in the southwestern United States and includes much of southern Nevada and the Death Valley region of eastern California. Centrally located within the ground-water flow system is the Nevada Test Site (NTS). The NTS, a large tract covering about 1,375 square miles, historically has been used for testing nuclear devices and currently is being studied as a potential repository for the long-term storage of high-level nuclear waste generated in the United States. The U.S. Department of Energy, as mandated by Federal and State regulators, is evaluating the risk associated with contaminants that have been or may be introduced into the subsurface as a consequence of any past or future activities at the NTS. Because subsurface contaminants can be transported away from the NTS by ground water, components of the ground-water budget are of great interest. One such component is regional ground-water discharge. Most of the ground water leaving the DVRFS is limited to local areas where geologic and hydrologic conditions force ground water upward toward the surface to discharge at springs and seeps. Available estimates of ground-water discharge are based primarily on early work done as part of regional reconnaissance studies. These early efforts covered large, geologically complex areas and often applied substantially different techniques to estimate ground-water discharge. This report describes the results of a study that provides more consistent, accurate, and scientifically defensible measures of regional ground-water losses from each of the major discharge areas of the DVRFS. Estimates of ground-water discharge presented in this report are based on a rigorous quantification of local evapotranspiration (ET). The study identifies areas of ongoing ground-water ET, delineates different ET areas based on similarities in vegetation and soil-moisture conditions, and determines an ET rate for

Temperature-induced water stress in high-latitude forests in response to natural and anthropogenic warming.

PubMed

Trahan, Matthew W; Schubert, Brian A

2016-02-01

The Arctic is particularly sensitive to climate change, but the independent effects of increasing atmospheric CO2 concentration (pCO2 ) and temperature on high-latitude forests are poorly understood. Here, we present a new, annually resolved record of stable carbon isotope (δ(13) C) data determined from Larix cajanderi tree cores collected from far northeastern Siberia in order to investigate the physiological response of these trees to regional warming. The tree-ring record, which extends from 1912 through 1961 (50 years), targets early twentieth-century warming (ETCW), a natural warming event in the 1920s to 1940s that was limited to Northern hemisphere high latitudes. Our data show that net carbon isotope fractionation (Δ(13) C), decreased by 1.7‰ across the ETCW, which is consistent with increased water stress in response to climate warming and dryer soils. To investigate whether this signal is present across the northern boreal forest, we compiled published carbon isotope data from 14 high-latitude sites within Europe, Asia, and North America. The resulting dataset covered the entire twentieth century and spanned both natural ETCW and anthropogenic Late Twentieth-Century Warming (~0.7 °C per decade). After correcting for a ~1‰ increase in Δ(13) C in response to twentieth century pCO2 rise, a significant negative relationship (r = -0.53, P < 0.0001) between the average, annual Δ(13) C values and regional annual temperature anomalies is observed, suggesting a strong control of temperature on the Δ(13) C value of trees growing at high latitudes. We calculate a 17% increase in intrinsic water-use efficiency within these forests across the twentieth century, of which approximately half is attributed to a decrease in stomatal conductance in order to conserve water in response to drying conditions, with the other half being attributed to increasing pCO2 . We conclude that annual tree-ring records from northern high-latitude forests record the effects of

Seawater/Saline Agriculture for Energy, Warming, Water, Rainfall, Land, Food and Minerals

NASA Technical Reports Server (NTRS)

Bushnell, Dennis

2006-01-01

The combination of the incipient demise of cheap oil and increasing evidence of Global Warming due to anthropogenic fossil carbon release has reinvigorated the need for and efforts on Renewable energy sources, especially for transportation applications. Biomass/Bio-diesel appears to have many benefits compared to Hydrogen, the only other major renewable transportation fuel candidate. Biomass Production is currently limited by available arable land and fresh water. Halophyte Plants and seawater irrigation proffer a wholly new biomass production mantra using wastelands and very plentiful seawater. Such an approach addresses many-to-most of the major emerging Societal Problems including Land, Water, Food, Warming and Energy. For many reasons, including seawater agriculture, portions of the Sahara appear to be viable candidates for future Biomass Production. The apparent nonlinearity between vegetation cover and atmospheric conditions over North Africa necessitates serious coupled boundary layer Meteorology and Global Circulation Modeling to ensure that this form of Terra Forming is Favorable and to avoid adverse Unintended Consequences.

Discharge, sediment, and water chemistry in Clear Creek, western Nevada, water years 2013–16

USGS Publications Warehouse

Huntington, Jena M.; Riddle, Daniel J.; Paul, Angela P.

2018-05-01

Clear Creek is a small stream that drains the eastern Carson Range near Lake Tahoe, flows roughly parallel to the Highway 50 corridor, and discharges to the Carson River near Carson City, Nevada. Historical and ongoing development in the drainage basin is thought to be affecting Clear Creek and its sediment-transport characteristics. Previous studies from water years (WYs) 2004 to 2007 and from 2010 to 2012 evaluated discharge, selected water-quality parameters, and suspended-sediment concentrations, loads, and yields at three Clear Creek sampling sites. This report serves as a continuation of the data collection and analyses of the Clear Creek discharge regime and associated water-chemistry and sediment concentrations and loads during WYs 2013–16.Total annual sediment loads ranged from 870 to 5,300 tons during WYs 2004–07, from 320 to 1,770 tons during WYs 2010–12, and from 50 to 200 tons during WYs 2013–16. Ranges in annual loads during the three study periods were not significantly different; however, total loads were greater during 2004–07 than they were during 2013–16. Annual suspended-sediment loads in WYs 2013–16 showed no significant change since WYs 2010–12 at sites 1 (U.S. Geological Survey reference site 10310485; Clear Creek above Highway 50, near Spooner Summit, Nevada) or 2 (U.S. Geological Survey streamgage 10310500; Clear Creek above Highway 50, near Spooner Summit, Nevada), but significantly lower loads at site 3 (U.S. Geological Survey site 10310518; Clear Creek at Fuji Park, at Carson City, Nevada), supporting the theory of sediment deposition between sites 2 and 3 where the stream gradient becomes more gradual. Currently, a threshold discharge of about 3.3 cubic feet per second is required to mobilize streambed sediment (bedload) from site 2 in Clear Creek. Mean daily discharge was significantly lower in 2010–12 than in 2004–07 and also significantly lower in 2013–16 than in 2010–12. During this study, lower bedload, and

Amino acid and proximate composition of fish bone gelatin from different warm-water species: A comparative study

NASA Astrophysics Data System (ADS)

Atma, Y.

2017-03-01

Research on fish bone gelatin has been increased in the last decade. The quality of gelatin depends on its physicochemical properties. Fish bone gelatin from warm-water fishes has a superior amino acid composition than cold-water fishes. The composition of amino acid can determine the strength and stability of gelatin. Thus, it is important to analyze the composition of amino acid as well as proximate composition for potential gelatin material. The warm water fish species used in this study were Grass carp, Pangasius catfish, Catfish, Lizard fish, Tiger-toothed croaker, Pink perch, Red snapper, Brown spotted grouper, and King weakfish. There werre five dominant amino acid in fish bone gelatin including glycine (21.2-36.7%), proline (8.7-11.7%), hydroxyproline (5.3-9.6%), alanine (8.48-12.9%), and glutamic acid (7.23-10.15%). Different warm-water species has some differences in amino acid composition. The proximate composition showed that fishbone gelatin from Pangasius catfish has the highest protein content. The water composition of all fishbone gelatin was well suited to the standard. Meanwhile, based on ash content, only gelatin from gelatin Pangasius catfish met the standard for food industries.

Temporal modelling of ballast water discharge and ship-mediated invasion risk to Australia

PubMed Central

Cope, Robert C.; Prowse, Thomas A. A.; Ross, Joshua V.; Wittmann, Talia A.; Cassey, Phillip

2015-01-01

Biological invasions have the potential to cause extensive ecological and economic damage. Maritime trade facilitates biological invasions by transferring species in ballast water, and on ships' hulls. With volumes of maritime trade increasing globally, efforts to prevent these biological invasions are of significant importance. Both the International Maritime Organization and the Australian government have developed policy seeking to reduce the risk of these invasions. In this study, we constructed models for the transfer of ballast water into Australian waters, based on historic ballast survey data. We used these models to hindcast ballast water discharge over all vessels that arrived in Australian waters between 1999 and 2012. We used models for propagule survival to compare the risk of ballast-mediated propagule transport between ecoregions. We found that total annual ballast discharge volume into Australia more than doubled over the study period, with the vast majority of ballast water discharge and propagule pressure associated with bulk carrier traffic. As such, the ecoregions suffering the greatest risk are those associated with the export of mining commodities. As global marine trade continues to increase, effective monitoring and biosecurity policy will remain necessary to combat the risk of future marine invasion events. PMID:26064643

Time-delayed transition of normal-to-abnormal glow in pin-to-water discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, S.-Y.; Byeon, Y.-S.; Yoo, S.

2016-08-15

Time-delayed transition of normal-to-abnormal glow was investigated in discharge between spoke-like pins and ultrapure water by applying AC-driven power at a frequency of 14.3 kHz at atmospheric pressure. The normal-to-abnormal transition can be recognized from the slope changes of current density, gas temperature, electrode temperature, and OH density. The slope changes took place in tens of minutes rather than just after discharge, in other words, the transition was delayed. The time-delay of the transition was caused by the interaction between the plasma and water. The plasma affected water properties, and then the water affected plasma properties.

Study of Wastewater Treatment by OH Radicals Using DC and Pulsed Corona Discharge over Water

NASA Astrophysics Data System (ADS)

Tochikubo, Fumiyoshi; Furuta, Yasutomo; Uchida, Satoshi; Watanabe, Tsuneo

2006-04-01

Water treatment by OH radicals is studied using dc and pulsed corona discharge over water at atmospheric pressure and reduced pressure. In particular, we pay attention to the influence of discharge configuration on the efficiency of wastewater treatment. Experiment is carried out in N2 to clarify the contribution of OH radicals. Needle-cylinder electrodes are designed expecting the efficient generation of OH radicals close to the water surface. N,N-dimethyl- p-nitrosoaniline (RNO) solution is used as a persistent test pollutant. The results strongly suggest that OH radical production close to the water surface is a key factor for efficient wastewater treatment. The use of pulsed discharge at reduced pressure is effective in improving RNO reduction efficiency because of the rapid diffusion of OH radicals to the water surface.

Discrete simulations of spatio-temporal dynamics of small water bodies under varied stream flow discharges

NASA Astrophysics Data System (ADS)

Daya Sagar, B. S.

2005-01-01

Spatio-temporal patterns of small water bodies (SWBs) under the influence of temporally varied stream flow discharge are simulated in discrete space by employing geomorphologically realistic expansion and contraction transformations. Cascades of expansion-contraction are systematically performed by synchronizing them with stream flow discharge simulated via the logistic map. Templates with definite characteristic information are defined from stream flow discharge pattern as the basis to model the spatio-temporal organization of randomly situated surface water bodies of various sizes and shapes. These spatio-temporal patterns under varied parameters (λs) controlling stream flow discharge patterns are characterized by estimating their fractal dimensions. At various λs, nonlinear control parameters, we show the union of boundaries of water bodies that traverse the water body and non-water body spaces as geomorphic attractors. The computed fractal dimensions of these attractors are 1.58, 1.53, 1.78, 1.76, 1.84, and 1.90, respectively, at λs of 1, 2, 3, 3.46, 3.57, and 3.99. These values are in line with general visual observations.

Ground-water discharge determined from measurements of evapotranspiration, other available hydrologic components, and shallow water-level changes, Oasis Valley, Nye County, Nevada

USGS Publications Warehouse

Reiner, S.R.; Laczniak, R.J.; DeMeo, G.A.; Smith, J. LaRue; Elliott, P.E.; Nylund, W.E.; Fridrich, C.J.

2002-01-01

Oasis Valley is an area of natural ground-water discharge within the Death Valley regional ground-water flow system of southern Nevada and adjacent California. Ground water discharging at Oasis Valley is replenished from inflow derived from an extensive recharge area that includes the northwestern part of the Nevada Test Site (NTS). Because nuclear testing has introduced radionuclides into the subsurface of the NTS, the U.S. Department of Energy currently is investigating the potential transport of these radionuclides by ground water flow. To better evaluate any potential risk associated with these test-generated contaminants, a number of studies were undertaken to accurately quantify discharge from areas downgradient in the regional ground-water flow system from the NTS. This report refines the estimate of ground-water discharge from Oasis Valley. Ground-water discharge from Oasis Valley was estimated by quantifying evapotranspiration (ET), estimating subsurface outflow, and compiling ground-water withdrawal data. ET was quantified by identifying areas of ongoing ground-water ET, delineating areas of ET defined on the basis of similarities in vegetation and soil-moisture conditions, and computing ET rates for each of the delineated areas. A classification technique using spectral-reflectance characteristics determined from satellite imagery acquired in 1992 identified eight unique areas of ground-water ET. These areas encompass about 3,426 acres of sparsely to densely vegetated grassland, shrubland, wetland, and open water. Annual ET rates in Oasis Valley were computed with energy-budget methods using micrometeorological data collected at five sites. ET rates range from 0.6 foot per year in a sparse, dry saltgrass environment to 3.1 feet per year in dense meadow vegetation. Mean annual ET from Oasis Valley is estimated to be about 7,800 acre-feet. Mean annual ground-water discharge by ET from Oasis Valley, determined by removing the annual local precipitation

Norovirus Dynamics in Wastewater Discharges and in the Recipient Drinking Water Source: Long-Term Monitoring and Hydrodynamic Modeling.

PubMed

Dienus, Olaf; Sokolova, Ekaterina; Nyström, Fredrik; Matussek, Andreas; Löfgren, Sture; Blom, Lena; Pettersson, Thomas J R; Lindgren, Per-Eric

2016-10-04

Norovirus (NoV) that enters drinking water sources with wastewater discharges is a common cause of waterborne outbreaks. The impact of wastewater treatment plants (WWTPs) on the river Göta älv (Sweden) was studied using monitoring and hydrodynamic modeling. The concentrations of NoV genogroups (GG) I and II in samples collected at WWTPs and drinking water intakes (source water) during one year were quantified using duplex real-time reverse-transcription polymerase chain reaction. The mean (standard deviation) NoV GGI and GGII genome concentrations were 6.2 (1.4) and 6.8 (1.8) in incoming wastewater and 5.3 (1.4) and 5.9 (1.4) log 10 genome equivalents (g.e.) L -1 in treated wastewater, respectively. The reduction at the WWTPs varied between 0.4 and 1.1 log 10 units. In source water, the concentration ranged from below the detection limit to 3.8 log 10 g.e. L -1 . NoV GGII was detected in both wastewater and source water more frequently during the cold than the warm period of the year. The spread of NoV in the river was simulated using a three-dimensional hydrodynamic model. The modeling results indicated that the NoV GGI and GGII genome concentrations in source water may occasionally be up to 2.8 and 1.9 log 10 units higher, respectively, than the concentrations measured during the monitoring project.

Bottom Water Acidification and Warming on the Western Eurasian Arctic Shelves: Dynamical Downscaling Projections

NASA Astrophysics Data System (ADS)

Wallhead, P. J.; Bellerby, R. G. J.; Silyakova, A.; Slagstad, D.; Polukhin, A. A.

2017-10-01

The impacts of oceanic CO2 uptake and global warming on the surface ocean environment have received substantial attention, but few studies have focused on shelf bottom water, despite its importance as habitat for benthic organisms and demersal fisheries such as cod. We used a downscaling ocean biogeochemical model to project bottom water acidification and warming on the western Eurasian Arctic shelves. A model hindcast produced 14-18 year acidification trends that were largely consistent with observational estimates at stations in the Iceland and Irminger Seas. Projections under SRES A1B scenario revealed a rapid and spatially variable decline in bottom pH by 0.10-0.20 units over 50 years (2.5%-97.5% quantiles) at depths 50-500 m on the Norwegian, Barents, Kara, and East Greenland shelves. Bottom water undersaturation with respect to aragonite occurred over the entire Kara shelf by 2040 and over most of the Barents and East Greenland shelves by 2070. Shelf acidification was predominantly driven by the accumulation of anthropogenic CO2, and was concurrent with warming of 0.1-2.7°C over 50 years. These combined perturbations will act as significant multistressors on the Barents and Kara shelves. Future studies should aim to improve the resolution of shelf bottom processes in models, and should consider the Kara Sea and Russian shelves as possible bellwethers of shelf acidification.

Effects of air temperature and discharge on Upper Mississippi River summer water temperatures

USGS Publications Warehouse

Gray, Brian R.; Robertson, Dale M.; Rogala, James T.

2018-01-01

Recent interest in the potential effects of climate change has prompted studies of air temperature and precipitation associations with water temperatures in rivers and streams. We examined associations between summer surface water temperatures and both air temperature and discharge for 5 reaches of the Upper Mississippi River during 1994–2011. Water–air temperature associations at a given reach approximated 1:1 when estimated under an assumption of reach independence but declined to approximately 1:2 when water temperatures were permitted to covary among reaches and were also adjusted for upstream air temperatures. Estimated water temperature–discharge associations were weak. An apparently novel feature of this study is that of addressing changes in associations between water and air temperatures when both are correlated among reaches.

The source, discharge, and chemical characteristics of water from Agua Caliente Spring, Palm Springs, California

USGS Publications Warehouse

Brandt, Justin; Catchings, Rufus D.; Christensen, Allen H.; Flint, Alan L.; Gandhok, Gini; Goldman, Mark R.; Halford, Keith J.; Langenheim, V.E.; Martin, Peter; Rymer, Michael J.; Schroeder, Roy A.; Smith, Gregory A.; Sneed, Michelle; Martin, Peter

2011-01-01

Agua Caliente Spring, in downtown Palm Springs, California, has been used for recreation and medicinal therapy for hundreds of years and currently (2008) is the source of hot water for the Spa Resort owned by the Agua Caliente Band of the Cahuilla Indians. The Agua Caliente Spring is located about 1,500 feet east of the eastern front of the San Jacinto Mountains on the southeast-sloping alluvial plain of the Coachella Valley. The objectives of this study were to (1) define the geologic structure associated with the Agua Caliente Spring; (2) define the source(s), and possibly the age(s), of water discharged by the spring; (3) ascertain the seasonal and longer-term variability of the natural discharge, water temperature, and chemical characteristics of the spring water; (4) evaluate whether water-level declines in the regional aquifer will influence the temperature of the spring discharge; and, (5) estimate the quantity of spring water that leaks out of the water-collector tank at the spring orifice.

Heated Discharge Control and Management Alternatives: Small Water Bodies and Rivers.

ERIC Educational Resources Information Center

MacLaren, James F.

Basic concepts of waste heat management on shallow and deep small water bodies and rivers are reviewed and examples are given. This study defines a small water body as a body in which the far field hydrothermal effects of a heated discharge can be detected in a major portion or practically all of the water body. Environmental effects due to…

Warming shifts ‘worming': effects of experimental warming on invasive earthworms in northern North America

PubMed Central

Eisenhauer, Nico; Stefanski, Artur; Fisichelli, Nicholas A.; Rice, Karen; Rich, Roy; Reich, Peter B.

2014-01-01

Climate change causes species range shifts and potentially alters biological invasions. The invasion of European earthworm species across northern North America has severe impacts on native ecosystems. Given the long and cold winters in that region that to date supposedly have slowed earthworm invasion, future warming is hypothesized to accelerate earthworm invasions into yet non-invaded regions. Alternatively, warming-induced reductions in soil water content (SWC) can also decrease earthworm performance. We tested these hypotheses in a field warming experiment at two sites in Minnesota, USA by sampling earthworms in closed and open canopy in three temperature treatments in 2010 and 2012. Structural equation modeling revealed that detrimental warming effects on earthworm densities and biomass could indeed be partly explained by warming-induced reductions in SWC. The direction of warming effects depended on the current average SWC: warming had neutral to positive effects at high SWC, whereas the opposite was true at low SWC. Our results suggest that warming limits the invasion of earthworms in northern North America by causing less favorable soil abiotic conditions, unless warming is accompanied by increased and temporally even distributions of rainfall sufficient to offset greater water losses from higher evapotranspiration. PMID:25363633

Carbon dioxide flux and net primary production of a boreal treed bog: responses to warming and water table manipulations

NASA Astrophysics Data System (ADS)

Munir, T. M.; Perkins, M.; Kaing, E.; Strack, M.

2014-09-01

Mid-latitude treed bogs are significant carbon (C) stocks and are highly sensitive to global climate change. In a dry continental treed bog, we compared three sites; control, recent (1-3 years; experimental) and older drained (10-13 years; drained) with water levels at 38, 74 and 120 cm below the surface, respectively. At each site we measured carbon dioxide (CO2) fluxes and tree root respiration (Rr) (across hummock-hollow microtopography of the forest floor) and net primary production (NPP) of trees during the growing seasons (May to October) of 2011-2013. The carbon (C) balance was calculated by adding net CO2 exchange of the forest floor (NEff-Rr) to the NPP of the trees. From cooler and wetter 2011 to driest and warmest 2013, The control site was a~C sink of 92, 70 and 76 g m-2, experimental site was a C source of 14, 57 and 135 g m-2, and drained site was a progressively smaller source of 26, 23 and 13 g m-2, respectively. Although all microforms at the experimental site had large net CO2 emissions, the longer-term drainage and deeper water level at the drained site resulted in the replacement of mosses with vascular plants (shrubs) at the hummocks and lichens at the hollows leading to the highest CO2 uptake at drained hummocks and significant losses at hollows. The tree NPP was highest at the drained site. We also quantified the impact of climatic warming at all water table treatments by equipping additional plots with open-top chambers (OTCs) that caused a passive warming on average of ∼1 °C and differential air warming of ∼6 °C (at mid-day full sun) across the study years. Warming significantly enhanced the shrub growth and CO2 sink function of the drained hummocks (exceeding the cumulative respiration losses at hollows induced by the lowered water level × warming). There was an interaction of water level with warming across hummocks that resulted in largest net CO2 uptake at warmed drained hummocks. Thus in 2013, the warming treatment enhanced

Laboratory evaluation of warm mix asphalt.

DOT National Transportation Integrated Search

2011-09-14

"Hot Mix Asphalt (HMA) has been traditionally produced at a discharge temperature of between : 280F (138C) and 320 F (160C), resulting in high energy (fuel) costs and generation of greenhouse : gases. The goal for Warm Mix Asphalt (WMA) is to...

Development testing of large volume water sprays for warm fog dispersal

NASA Technical Reports Server (NTRS)

Keller, V. W.; Anderson, B. J.; Burns, R. A.; Lala, G. G.; Meyer, M. B.; Beard, K. V.

1986-01-01

A new brute-force method of warm fog dispersal is described. The method uses large volume recycled water sprays to create curtains of falling drops through which the fog is processed by the ambient wind and spray induced air flow. Fog droplets are removed by coalescence/rainout. The efficiency of the technique depends upon the drop size spectra in the spray, the height to which the spray can be projected, the efficiency with which fog laden air is processed through the curtain of spray, and the rate at which new fog may be formed due to temperature differences between the air and spray water. Results of a field test program, implemented to develop the data base necessary to assess the proposed method, are presented. Analytical calculations based upon the field test results indicate that this proposed method of warm fog dispersal is feasible. Even more convincingly, the technique was successfully demonstrated in the one natural fog event which occurred during the test program. Energy requirements for this technique are an order of magnitude less than those to operate a thermokinetic system. An important side benefit is the considerable emergency fire extinguishing capability it provides along the runway.

Grey mullet (Mugilidae) as possible indicators of global warming in South African estuaries and coastal waters.

PubMed

James, Nicola C; Whitfield, Alan K; Harrison, Trevor D

2016-12-01

The grey mullet usually occur in large numbers and biomass in the estuaries of all three South African biogeographic regions, thus making it an ideal family to use in terms of possibly acting as an environmental indicator of global warming. In this analysis the relative estuarine abundance of the dominant three groups of mugilids, namely tropical, warm-water and cool-water endemics, were related to sea surface coastal temperatures. The study suggests a strong link between temperature and the distribution and abundance of the three mullet groups within estuaries and indicates the potential of this family to act as an indicator for future climate change within these systems and adjacent coastal waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Temperature inverted haloclines provide winter warm-water refugia for manatees in southwest Florida

USGS Publications Warehouse

Stith, Bradley M.; Reid, James P.; Langtimm, Catherine A.; Swain, Eric D.; Doyle, Terry J.; Slone, Daniel H.; Decker, Jeremy D.; Soderqvist, Lars E.

2010-01-01

Florida manatees (Trichechus manatus latirostris) overwintering in the Ten Thousand Islands and western Everglades have no access to power plants or major artesian springs that provide warm-water refugia in other parts of Florida. Instead, hundreds of manatees aggregate at artificial canals, basins, and natural deep water sites that act as passive thermal refugia (PTR). Monitoring at two canal sites revealed temperature inverted haloclines, which provided warm salty bottom layers that generally remained above temperatures considered adverse for manatees. At the largest PTR, the warmer bottom layer disappeared unless significant salt stratification was maintained by upstream freshwater inflow over a persistent tidal wedge. A detailed three-dimensional hydrology model showed that salinity stratification inhibited vertical convection induced by atmospheric cooling. Management or creation of temperature inverted haloclines may be a feasible and desirable option for resource managers to provide passive thermal refugia for manatees and other temperature sensitive aquatic species.

Natural Attenuation of Chlorinated Solvent Ground-Water Plumes Discharging into Wetlands

DTIC Science & Technology

2003-09-01

ground water in highly saline wetlands (Swanson et al., 1984), and the distribution of marsh marigold (Caltha palustris L.) has been used to map...seeps and springs next to a lake and in wetlands in Minnesota (Rosenberry et al., 2000). Marsh marigold favors ground-water discharge areas across the

Predicting the occurrence of cold water patches at intermittent and ephemeral tributary confluences with warm rivers

EPA Science Inventory

Small, cold tributary streams can provide important thermal refuge habitat for cold-water fishes such as Pacific salmon (Oncorhynchus spp.) residing in warm, downstream receiving waters. We investigated the potential function of small perennial and non-perennial tributary stream...

Spatio-temporal variation of water flow and sediment discharge in the Mahanadi River, India

NASA Astrophysics Data System (ADS)

Bastia, Fakira; Equeenuddin, Sk. Md.

2016-09-01

The transport of sediments by rivers to the oceans represents an important link between the terrestrial and marine ecosystem. Therefore, this work aims to study spatio-temporal variation of the sediment discharge and erosion rate in the Mahanadi river, one of the biggest rivers in India, over past three decades vis-à-vis their controlling factors. To understand the sediment load variation, the trend analysis in the time series data of rainfall, water and sediment discharge of the Mahanadi river were also attempted. The non-parametric Mann-Kendall and Sen's methods were used to determine whether there was a positive or negative trend in the time series data with their statistical significance. The occurrence of abrupt changes was detected using Pettitt test. The trend test result represents that sediment load delivered from the Mahanadi river to the global ocean has decreased sharply at the rate of 0.515 × 106 tons/year between 1980 and 2010. Water discharge and rainfall in the basin showed no significant decreasing trend except at only one tributary. The decline in sediment discharge from the basin to the Bay of Bengal is mainly due to the increase in the number of dams, which has recorded the increase from 70 to 253 during the period of 1980 to 2010. Over the past 30 years the Mahanadi river has discharged about 49.0 ± 20.5 km3 of water and 17.4 ± 12.7 × 106 tons of sediment annually to the Bay of Bengal whereas the mean erosional rate is 265 ± 125 tons/km2/year over the period of 30 years in the basin. Based on the current data (2000-2001 to 2009-2010), sediment flux and water discharge to the ocean are 12 ± 5 × 106 tons/year and 49 ± 16 km3/year respectively; and ranking Mahanadi river second in terms of water discharge and sediment flux to the ocean among the peninsular rivers in India.

Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules.

PubMed

Hensel, Karol; Kučerová, Katarína; Tarabová, Barbora; Janda, Mário; Machala, Zdenko; Sano, Kaori; Mihai, Cosmin Teodor; Ciorpac, Mitică; Gorgan, Lucian Dragos; Jijie, Roxana; Pohoata, Valentin; Topala, Ionut

2015-06-06

Atmospheric pressure DC-driven self-pulsing transient spark (TS) discharge operated in air and pulse-driven dielectric barrier discharge plasma jet (PJ) operated in helium in contact with water solutions were used for inducing chemical effects in water solutions, and the treatment of bacteria (Escherichia coli), mammalian cells (Vero line normal cells, HeLa line cancerous cells), deoxyribonucleic acid (dsDNA), and protein (bovine serum albumin). Two different methods of water solution supply were used in the TS: water electrode system and water spray system. The effects of both TS systems and the PJ were compared, as well as a direct exposure of the solution to the discharge with an indirect exposure to the discharge activated gas flow. The chemical analysis of water solutions was performed by using colorimetric methods of UV-VIS absorption spectrophotometry. The bactericidal effects of the discharges on bacteria were evaluated by standard microbiological plate count method. Viability, apoptosis and cell cycle were assessed in normal and cancerous cells. Viability of cells was evaluated by trypan blue exclusion test, apoptosis by Annexin V-FITC/propidium iodide assay, and cell cycle progression by propidium iodide/RNase test. The effect of the discharges on deoxyribonucleic acid and protein were evaluated by fluorescence and UV absorption spectroscopy. The results of bacterial and mammalian cell viability, apoptosis, and cell cycle clearly show that cold plasma can inactivate bacteria and selectively target cancerous cells, which is very important for possible future development of new plasma therapeutic strategies in biomedicine. The authors found that all investigated bio-effects were stronger with the air TS discharge than with the He PJ, even in indirect exposure.

Discharge, water quality, and native fish abundance in the Virgin River, Utah, Nevada, and Arizona, in support of Pah Tempe Springs discharge remediation efforts

USGS Publications Warehouse

Miller, Matthew P.; Lambert, Patrick M.; Hardy, Thomas B.

2014-01-01

Pah Tempe Springs discharge hot, saline, low dissolved-oxygen water to the Virgin River in southwestern Utah, which is transported downstream to Lake Mead and the Colorado River. The dissolved salts in the Virgin River negatively influence the suitability of this water for downstream agricultural, municipal, and industrial use. Therefore, various remediation scenarios to remove the salt load discharged from Pah Tempe Springs to the Virgin River are being considered. One concern about this load removal is the potential to impact the ecology of the Virgin River. Specifically, information is needed regarding possible impacts of Pah Tempe Springs remediation scenarios on the abundance, distribution, and survival of native fish in the Virgin River. Future efforts that aim to quantitatively assess how various remediation scenarios to reduce the load of dissolved salts from Pah Tempe Springs into the Virgin River may influence the abundance, distribution, and survival of native fish will require data on discharge, water quality, and native fish abundance. This report contains organized accessible discharge, water quality, and native fish abundance data sets from the Virgin River, documents the compilation of these data, and discusses approaches for quantifying relations between abiotic physical and chemical conditions, and fish abundance.

Water- and Plant-Mediated Responses of Ecosystem Carbon Fluxes to Warming and Nitrogen Addition on the Songnen Grassland in Northeast China

PubMed Central

Jiang, Li; Guo, Rui; Zhu, Tingcheng; Niu, Xuedun; Guo, Jixun; Sun, Wei

2012-01-01

Background Understanding how grasslands are affected by a long-term increase in temperature is crucial to predict the future impact of global climate change on terrestrial ecosystems. Additionally, it is not clear how the effects of global warming on grassland productivity are going to be altered by increased N deposition and N addition. Methodology/Principal Findings In-situ canopy CO2 exchange rates were measured in a meadow steppe subjected to 4-year warming and nitrogen addition treatments. Warming treatment reduced net ecosystem CO2 exchange (NEE) and increased ecosystem respiration (ER); but had no significant impacts on gross ecosystem productivity (GEP). N addition increased NEE, ER and GEP. However, there were no significant interactions between N addition and warming. The variation of NEE during the four experimental years was correlated with soil water content, particularly during early spring, suggesting that water availability is a primary driver of carbon fluxes in the studied semi-arid grassland. Conclusion/Significance Ecosystem carbon fluxes in grassland ecosystems are sensitive to warming and N addition. In the studied water-limited grassland, both warming and N addition influence ecosystem carbon fluxes by affecting water availability, which is the primary driver in many arid and semiarid ecosystems. It remains unknown to what extent the long-term N addition would affect the turn-over of soil organic matter and the C sink size of this grassland. PMID:23028848

Response of bean cultures' water use efficiency against climate warming in semiarid regions of China.

PubMed

Guoju, Xiao; Fengju, Zhang; Juying, Huang; Chengke, Luo; Jing, Wang; Fei, Ma; Yubi, Yao; Runyuan, Wang; Zhengji, Qiu

2016-07-31

Farm crop growing and high efficiency water resource utilizing are directly influenced by global warming, and a new challenge will be given to food and water resource security. A simulation experiment by farm warming with infrared ray radiator was carried out, and the result showed photosynthesis of broad bean was significantly faster than transpiration during the seedling stage, ramifying stage, budding stage, blooming stage and podding stage when the temperate was increased by 0.5-1.5 °C. But broad bean transpiration was faster than photosynthesis during the budding stage, blooming stage and podding stage when the temperature was increased by 1.5 °C above. The number of grain per hill and hundred-grain weight were significantly increased when the temperature was increased by 0.5-1.0 °C. But they significantly dropped and finally the yield decreased when the temperature was increased by 1.0 °C above. The broad bean yield decreased by 39.2-88.4% when the temperature was increased by 1.5-2.0 °C. The broad bean water use efficiency increased and then decreased with temperature rising. The water use efficiency increased when the temperature was increased by 1.0 °C below, and it quickly decreased when the temperature was increased by 1.0 °C above. In all, global warming in the future will significantly influence the growth, yield and water use efficiency of bean cultures in China's semiarid regions.

Plasma Discharges in Gas Bubbles in Liquid Water: Breakdown Mechanisms and Resultant Chemistry

NASA Astrophysics Data System (ADS)

Gucker, Sarah M. N.

The use of atmospheric pressure plasmas in gases and liquids for purification of liquids has been investigated by numerous researchers, and is highly attractive due to their strong potential as a disinfectant and sterilizer. However, the fundamental understanding of plasma production in liquid water is still limited. Despite the decades of study dedicated to electrical discharges in liquids, many physical aspects of liquids, such as the high inhomogeneity of liquids, complicate analyses. For example, the complex nonlinearities of the fluid have intricate effects on the electric field of the propagating streamer. Additionally, the liquid material itself can vaporize, leading to discontinuous liquid-vapor boundaries. Both can and do often lead to notable hydrodynamic effects. The chemistry of these high voltage discharges on liquid media can have circular effects, with the produced species having influence on future discharges. Two notable examples include an increase in liquid conductivity via charged species production, which affects the discharge. A second, more complicated scenario seen in some liquids (such as water) is the doubling or tripling of molecular density for a few molecule layers around a high voltage electrode. These complexities require technological advancements in optical diagnostics that have only recently come into being. This dissertation investigates several aspects of electrical discharges in gas bubbles in liquids. Two primary experimental configurations are investigated: the first allows for single bubble analysis through the use of an acoustic trap. Electrodes may be brought in around the bubble to allow for plasma formation without physically touching the bubble. The second experiment investigates the resulting liquid phase chemistry that is driven by the discharge. This is done through a dielectric barrier discharge with a central high voltage surrounded by a quartz discharge tube with a coil ground electrode on the outside. The plasma

Differential Inactivation of Fungal Spores in Water and on Seeds by Ozone and Arc Discharge Plasma

PubMed Central

Kang, Min Ho; Pengkit, Anchalee; Choi, Kihong; Jeon, Seong Sil; Choi, Hyo Won; Shin, Dong Bum; Choi, Eun Ha; Uhm, Han Sup; Park, Gyungsoon

2015-01-01

Seed sterilization is essential for preventing seed borne fungal diseases. Sterilization tools based on physical technologies have recently received much attention. However, available information is very limited in terms of efficiency, safety, and mode of action. In this study, we have examined antifungal activity of ozone and arc discharge plasma, potential tools for seed sterilization. In our results, ozone and arc discharge plasma have shown differential antifungal effects, depending on the environment associated with fungal spores (freely submerged in water or infected seeds). Ozone inactivates Fusarium fujikuroi (fungus causing rice bakanae disease) spores submerged in water more efficiently than arc discharge plasma. However, fungal spores associated with or infecting rice seeds are more effectively deactivated by arc discharge plasma. ROS generated in water by ozone may function as a powerful fungicidal factor. On the other hand, shockwave generated from arc discharge plasma may have greatly contributed to antifungal effects on fungus associated with rice seeds. In support of this notion, addition of ultrasonic wave in ozone generating water has greatly increased the efficiency of seed disinfection. PMID:26406468

Detection of coastal and submarine discharge on the Florida Gulf Coast with an airborne thermal-infrared mapping system

USGS Publications Warehouse

Raabe, Ellen; Stonehouse, David; Ebersol, Kristin; Holland, Kathryn; Robbins, Lisa

2011-01-01

Along the Gulf Coast of Florida north of Tampa Bay lies a region characterized by an open marsh coast, low topographic gradient, water-bearing limestone, and scattered springs. The Floridan aquifer system is at or near land surface in this region, discharging water at a consistent 70-72°F. The thermal contrast between ambient water and aquifer discharge during winter months can be distinguished using airborne thermal-infrared imagery. An airborne thermal-infrared mapping system was used to collect imagery along 126 miles of the Gulf Coast from Jefferson to Levy County, FL, in March 2009. The imagery depicts a large number of discharge locations and associated warm-water plumes in ponds, creeks, rivers, and nearshore waters. A thermal contrast of 6°F or more was set as a conservative threshold for identifying sites, statistically significant at the 99% confidence interval. Almost 900 such coastal and submarine-discharge locations were detected, averaging seven to nine per mile along this section of coast. This represents approximately one hundred times the number of previously known discharge sites in the same area. Several known coastal springs in Taylor and Levy Counties were positively identified with the imagery and were used to estimate regional discharge equivalent to one 1st-order spring, discharging 100 cubic feet per second or more, for every two miles of coastline. The number of identified discharge sites is a conservative estimate and may represent two-thirds of existing features due to low groundwater levels at time of overflight. The role of aquifer discharge in coastal and estuarine health is indisputable; however, mapping and quantifying discharge in a complex karst environment can be an elusive goal. The results of this effort illustrate the effectiveness of the instrument and underscore the influence of coastal springs along this stretch of the Florida coast.

Inactivation of MS2 bacteriophage by streamer corona discharge in water.

PubMed

Lee, Changha; Kim, Jaeeun; Yoon, Jeyong

2011-02-01

Electrical discharge processes are emerging as water treatment technologies applicable to both the degradation of organic contaminants as well as inactivation of pathogens. Particularly as a disinfection technology, electrical discharge processes do not produce toxic byproducts, and effectively inactivate a wide spectrum of microorganisms by multiple lethal actions generated by the formation of plasma channels. This study demonstrates the inactivation of a virus using the streamer corona discharge process (SCDP) with MS2 phage as a surrogate. A rapid inactivation of MS2 phage (i.e., approximately 4 log inactivation in 5 min) was observed in all experimental runs conducted. Discharge conditions such as applied voltage and storage capacitance significantly affected the inactivation efficiency of MS2 phage, whereas the influence of water quality parameters was minor. In order to elucidate the mechanism of MS2 phage inactivation, potentially lethal factors that can be generated by the SCDP were selected, and their roles in the inactivation of MS2 phage were examined. As a result, effects of UV radiation, chemical oxidants, and pulsed electric fields were found to be insignificant. The shockwave generated upon plasma channel formation appears to be the most important factor responsible for MS2 phage inactivation. Copyright © 2010 Elsevier Ltd. All rights reserved.

Estimates of Nutrient Loading by Ground-Water Discharge into the Lynch Cove Area of Hood Canal, Washington

USGS Publications Warehouse

Simonds, F. William; Swarzenski, Peter W.; Rosenberry, Donald O.; Reich, Christopher D.; Paulson, Anthony J.

2008-01-01

Low dissolved oxygen concentrations in the waters of Hood Canal threaten marine life in late summer and early autumn. Oxygen depletion in the deep layers and landward reaches of the canal is caused by decomposition of excess phytoplankton biomass, which feeds on nutrients (primarily nitrogen compounds) that enter the canal from various sources, along with stratification of the water column that prevents mixing and replenishment of oxygen. Although seawater entering the canal is the largest source of nitrogen, ground-water discharge to the canal also contributes significant quantities, particularly during summer months when phytoplankton growth is most sensitive to nutrient availability. Quantifying ground-water derived nutrient loads entering an ecologically sensitive system such as Hood Canal is a critical component of constraining the total nutrient budget and ultimately implementing effective management strategies to reduce impacts of eutrophication. The amount of nutrients entering Hood Canal from ground water was estimated using traditional and indirect measurements of ground-water discharge, and analysis of nutrient concentrations. Ground-water discharge to Hood Canal is variable in space and time because of local geology, variable hydraulic gradients in the ground-water system adjacent to the shoreline, and a large tidal range of 3 to 5 meters. Intensive studies of ground-water seepage and hydraulic-head gradients in the shallow, nearshore areas were used to quantify the freshwater component of submarine ground-water discharge (SGD), whereas indirect methods using radon and radium geochemical tracers helped quantify total SGD and recirculated seawater. In areas with confirmed ground-water discharge, shore-perpendicular electrical resistivity profiles, continuous electromagnetic seepage-meter measurements, and continuous radon measurements were used to visualize temporal variations in ground-water discharge over several tidal cycles. The results of these

A high-frequency warm shallow water acoustic communications channel model and measurements.

PubMed

Chitre, Mandar

2007-11-01

Underwater acoustic communication is a core enabling technology with applications in ocean monitoring using remote sensors and autonomous underwater vehicles. One of the more challenging underwater acoustic communication channels is the medium-range very shallow warm-water channel, common in tropical coastal regions. This channel exhibits two key features-extensive time-varying multipath and high levels of non-Gaussian ambient noise due to snapping shrimp-both of which limit the performance of traditional communication techniques. A good understanding of the communications channel is key to the design of communication systems. It aids in the development of signal processing techniques as well as in the testing of the techniques via simulation. In this article, a physics-based channel model for the very shallow warm-water acoustic channel at high frequencies is developed, which are of interest to medium-range communication system developers. The model is based on ray acoustics and includes time-varying statistical effects as well as non-Gaussian ambient noise statistics observed during channel studies. The model is calibrated and its accuracy validated using measurements made at sea.

Ecosystem under pressure: ballast water discharge into Galveston Bay, Texas (USA) from 2005 to 2010.

PubMed

Steichen, Jamie L; Windham, Rachel; Brinkmeyer, Robin; Quigg, Antonietta

2012-04-01

Ballast water exchange processes facilitate the dispersal and unnatural geographic expansion of phytoplankton, including harmful algal bloom species. From 2005 to 2010, over 45,000 vessels (≈ 8000 annually) travelled across Galveston Bay (Texas, USA) to the deep-water ports of Houston (10th largest in the world), Texas City and Galveston. These vessels (primarily tankers and bulkers) discharged ≈ 1.2 × 10(8) metrictons of ballast water; equivalent to ≈ 3.4% of the total volume of the Bay. Over half of the ballast water discharged had a coastwise origin, 96% being from US waters. Galveston Bay has fewer non-indigenous species but receives a higher volume of ballast water discharge, relative to the highly invaded Chesapeake and San Francisco Bays. Given the magnitude of shipping traffic, the role of Galveston Bay, both as a recipient and donor region of non-indigenous phytoplankton species is discussed here in terms of the invasibility risk to this system by way of ballast water. Copyright © 2012 Elsevier Ltd. All rights reserved.

Decline of cold-water fish species in the Bay of Somme (English Channel, France) in response to ocean warming

NASA Astrophysics Data System (ADS)

Auber, Arnaud; Gohin, Francis; Goascoz, Nicolas; Schlaich, Ivan

2017-04-01

A growing number of studies have documented increasing dominance of warm-water fish species ("tropicalisation") in response to ocean warming. Such reorganization of communities is starting to occur in a multitude of local ecosystems, implying that tropicalisation of marine communities could become a global phenomenon. Using 32 years of trawl surveys in the Bay of Somme (English Channel, France), we aimed to investigate the existence of a tropicalisation in the fish community at the local scale of the estuary during the mid-1990s, a period where an exceptional temperature rise occurred in Northeast Atlantic. A long-term response occurred (with a major transition over 6 years) that was characterized by a marked diminution in the abundance of cold-water species in parallel to a temperature rise generated by the ocean-scale phenomenon, the Atlantic Multidecadal Oscillation, which switched from a cool to a warm phase during the late 1990s. Despite finding no significant increase in the dominance of warm-water species, the long-term diminution of cold-water species suggests that the restructuring of the fish community was mainly influenced by global-scale environmental conditions rather than local ones and that indirect effects may also occurred through biological interactions.

Effects of warming on groundwater flow in mountainous snowmelt-dominated catchments

NASA Astrophysics Data System (ADS)

Evans, S. G.; Ge, S.; Molotch, N. P.

2015-12-01

In mountainous regions, warmer air temperatures have led to an earlier onset of spring snowmelt and lower snowmelt rates; i.e. because snowmelt has shifted earlier when energy availability is lower. These changes to snowmelt will likely affect the partitioning of snowmelt water between surface runoff and groundwater flow, and therefore, the lag time between snowmelt and streamflow. While the connection between snowmelt and surface runoff has been well-studied, the impact of snowmelt variability on groundwater flow processes has received limited attention, especially in mountainous catchments. We construct a two-dimensional, finite element, coupled flow and heat transport hydrogeologic model to evaluate how changes in snowmelt onset and rate may alter groundwater discharge to streams in mountainous catchments. The coupled hydrogeologic model simulates seasonally frozen ground by incorporating permeability variation as a function of temperature and allows for modeling of pore water freeze and thaw. We apply the model to the Green Lakes Valley (GLV) watershed in the Rocky Mountains of Colorado, a representative snowmelt-dominated catchment. Snowmelt for the GLV catchment is reconstructed from a 12 year (1996-2007) dataset of hydrometeorological records and satellite-derived snow covered area. Modeling results suggest that on a yearly cycle, groundwater infiltration and discharge is limited by the seasonally frozen subsurface. Under average conditions from 1996 to 2007, maximum groundwater discharge to the surface lags maximum snowmelt by approximately two months. Ongoing modeling is exploring how increasing air temperatures affect lag times between snowmelt and groundwater discharge to streams. This study has implications for water resource availability and its temporal variability in a warming global climate.

Post-Wildfire Peak Discharge Prediction Methods in Northern New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronstadt, Jackie A.

Recent changes in climate have resulted in a decrease in precipitation and snowpack amounts and increased temperatures in the western United States. As the climate warms, there are also changes to runoff amounts and water availability. Drier and warmer conditions coupled with forest management practices have led to an increase in the frequency and size of forest fires. The 2000 Cerro Grande fire in Los Alamos, New Mexico burned over 43,000 acres and 200 structures. Eleven years later, the Las Conchas fire burned over 156,000 acres and 100 structures, including areas previously burned in 2000, and was considered the largestmore » fire in New Mexico’s history. Both fires burned ponderosa, juniper, piñon and mixed conifer forests, resulting in dramatic decreases in vegetation, changes to surface soils, and alterations to the hydrologic cycle (decreased evapotranspiration, decreased infiltration, increased runoff volume and peak discharge, and decreased time to peak discharge) in surrounding watersheds. The frequency of large, intense “mega-fires” are predicted to increase, thus there is a potential for more post-fire flood damage and more surface water resources to be altered due to water quality issues.« less

Evaluation of the potentials of humic acid removal in water by gas phase surface discharge plasma.

PubMed

Wang, Tiecheng; Qu, Guangzhou; Ren, Jingyu; Yan, Qiuhe; Sun, Qiuhong; Liang, Dongli; Hu, Shibin

2016-02-01

Degradation of humic acid (HA), a predominant type of natural organic matter in ground water and surface waters, was conducted using a gas phase surface discharge plasma system. HA standard and two surface waters (Wetland, and Weihe River) were selected as the targets. The experimental results showed that about 90.9% of standard HA was smoothly removed within 40 min's discharge plasma treatment at discharge voltage 23.0 kV, and the removal process fitted the first-order kinetic model. Roles of some active species in HA removal were studied by evaluating the effects of solution pH and OH radical scavenger; and the results presented that O3 and OH radical played significant roles in HA removal. Scanning electron microscope (SEM) and FTIR analysis showed that HA surface topography and molecular structure were changed during discharge plasma process. The mineralization of HA was analyzed by UV-Vis spectrum, dissolved organic carbon (DOC), specific UV absorbance (SUVA), UV absorption ratios, and excitation-emission matrix (EEM) fluorescence. The formation of disinfection by-products during HA sample chlorination was also identified, and CHCl3 was detected as the main disinfection by-product, but discharge plasma treatment could suppress its formation to a certain extent. In addition, approximately 82.3% and 67.9% of UV254 were removed for the Weihe River water and the Wetland water after 40 min of discharge plasma treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Estimation of combined sewer overflow discharge: a software sensor approach based on local water level measurements.

PubMed

Ahm, Malte; Thorndahl, Søren; Nielsen, Jesper E; Rasmussen, Michael R

2016-12-01

Combined sewer overflow (CSO) structures are constructed to effectively discharge excess water during heavy rainfall, to protect the urban drainage system from hydraulic overload. Consequently, most CSO structures are not constructed according to basic hydraulic principles for ideal measurement weirs. It can, therefore, be a challenge to quantify the discharges from CSOs. Quantification of CSO discharges are important in relation to the increased environmental awareness of the receiving water bodies. Furthermore, CSO discharge quantification is essential for closing the rainfall-runoff mass-balance in combined sewer catchments. A closed mass-balance is an advantage for calibration of all urban drainage models based on mass-balance principles. This study presents three different software sensor concepts based on local water level sensors, which can be used to estimate CSO discharge volumes from hydraulic complex CSO structures. The three concepts were tested and verified under real practical conditions. All three concepts were accurate when compared to electromagnetic flow measurements.

To what extent is water responsible for the maintenance of the life for warm-blooded organisms?

PubMed

Fisenko, Anatoliy I; Malomuzh, Nikolay P

2009-05-22

In this work, attention is mainly focused on those properties of water which are essentially changed in the physiological temperature range of warm-blooded organisms. Studying in detail the half-width of the diffusion peak in the quasi-elastic incoherent neutron scattering, the behavior of the entropy and the kinematic shear viscosity, it is shown that the character of the translational and rotational thermal motions in water radically change near T(H) ~ 315 K, which can be interpreted as the temperature of the smeared dynamic phase transition. These results for bulk pure water are completed by the analysis of the isothermic compressibility and the NMR-spectra for water-glycerol solutions. It was noted that the non-monotone temperature dependence of the isothermic compressibility (beta(T)) takes also place for the water-glycerol solutions until the concentration of glycerol does not exceed 30 mol%. At that, the minimum of beta(T) shifts at left when the concentration increases. All these facts give us some reasons to assume that the properties of the intracellular and extracellular fluids are close to ones for pure water. Namely therefore, we suppose that the upper temperature limit for the life of warm-blooded organisms [T(D) = (315 +/- 3) K] is tightly connected with the temperature of the dynamic phase transition in water. This supposition is equivalent to the assertion that the denaturation of proteins at T > or = T(H) is mainly provoked by the rebuilding of the H-bond network in the intracellular and extracellular fluids, which takes place at T > or = T(H). A question why the heavy water cannot be a matrix for the intracellular and extracellular fluids is considered. The lower physiological pH limit for the life of warm-blooded organisms is discussed.

Initial studies of submarine groundwater discharge in Mississippi coastal waters

NASA Astrophysics Data System (ADS)

Shiller, A. M.; Moore, W. S.; Joung, D. J.; Box, H.; Ho, P.; Whitmore, L. M.; Gilbert, M.; Anderson, H.

2017-12-01

Submarine groundwater discharge (SGD) is a critical component of coastal ecosystems, affecting biogeochemistry and productivity. The SGD flux and effect on the ecosystem of the Mississippi (MS) Bight has not previously been studied. We have determined Ba, δ18O of water, and Ra-isotopes, together with nutrients, chlorophyll, and dissolved oxygen (DO) during multiple cruises from fall 2015 to summer 2016. Water isotope distributions (δ18O) show that, although the MS River Delta bounds the western side of the Bight, nonetheless, Mobile Bay and other local rivers are the Bight's dominant freshwater sources. But elevated dissolved Ba and Ra isotopes cannot be explained by river input. Spatially, SGD in the MS Bight occurs over a wide area, with hot spots near the barrier islands (e.g., Chandeleurs, Horn and Dauphin Islands) and the mouth of Mobile Bay, probably in association with old buried river channels, or dredged ship channels. Based on their high concentrations in saline groundwaters sampled on the barrier islands, the elevated Ba and Ra in MS Bight water are likely due to SGD. In subsurface waters, long-lived Ra isotopes were negatively correlated with DO during spring and summer 2016, suggesting direct discharge of DO-depleted groundwater and/or accumulation of SGD-derived Ra and microbial DO consumption under strongly stratified conditions. Our ongoing study suggests that seasonal variability in flushing, water stratification, and SGD input play important roles in biological production and bottom water hypoxia in the MS Bight.

Final Report: Risk assessment for produced water discharges to Louisiana open bays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinhold, A.F.; DePhillips, M.P.; Holtzman, S.

1996-03-01

Potential human health and environmental impacts from discharges of produced water to the Gulf of Mexico are of concern to regulators at the State and Federal levels, the public, environmental interest groups and industry. Current and proposed regulations require a zero discharge limit for coastal facilities, based primarily on studies in low energy, poorly flushed environments. However, produced water discharges in coastal Louisiana include a number of open bay sites, where potential human health and environmental impacts are likely to be smaller than those demonstrated for low energy canal environments, but greater than the minimal impacts associated with offshore discharges.more » Additional data and assessments are needed to support risk managers at the State and Federal levels in the development of regulations that protect human health and the environment without unnecessary cost to the economic welfare of the region and the nation. This project supports the Natural Gas and Oil Initiative objectives to: (1) improve coordination on environmental research; (2) streamline State and Federal regulation; (3) enhance State, and Federal regulatory decision making capability; (4) enhance dialogue through industry/government/public partnerships; and (5) work with States and Native American Tribes.« less

Subsurface North Atlantic warming as a trigger of rapid cooling events: evidences from the Early Pleistocene (MIS 31-19)

NASA Astrophysics Data System (ADS)

Hernández-Almeida, I.; Sierro, F.-J.; Cacho, I.; Flores, J.-A.

2014-10-01

Subsurface water column dynamics in the subpolar North Atlantic were reconstructed in order to improve the understanding of the cause of abrupt IRD events during cold periods of the Early Pleistocene. We used Mg / Ca-based temperatures of deep-dwelling (Neogloboquadrina pachyderma sinistral) planktonic foraminifera and paired Mg / Ca-δ18O measurements to estimate the subsurface temperatures and δ18O of seawater at Site U1314. Carbon isotopes on benthic and planktonic foraminifera from the same site provide information about the ventilation and water column nutrient gradient. Mg / Ca-based temperatures and δ18O of seawater suggest increased temperatures and salinities during ice-rafting, likely due to enhanced northward subsurface transport of subtropical waters during periods of AMOC reduction. Planktonic carbon isotopes support this suggestion, showing coincident increased subsurface ventilation during deposition of ice-rafted detritus (IRD). Warm waters accumulated at subsurface would result in basal warming and break-up of ice-shelves, leading to massive iceberg discharges in the North Atlantic. Release of heat and salt stored at subsurface would help to restart the AMOC. This mechanism is in agreement with modelling and proxy studies that observe a subsurface warming in the North Atlantic in response to AMOC slowdown during the MIS3.

Eastern and Central Pacific ENSO and their relationships to the recharge/discharge oscillator paradigm

NASA Astrophysics Data System (ADS)

Singh, Awnesh; Delcroix, Thierry

2013-12-01

One of the leading theories to explain the oscillatory nature of the El Niño Southern Oscillation is the recharge-discharge oscillator paradigm, which roots on warm waters exchanged between the equatorial and off-equatorial regions. This study tests the relevance of this theory to account for the Eastern and recently mediated Central Pacific El Niño events. The recharge-discharge of the equatorial Pacific, measured here as changes in Warm (>20 °C) Water Volume (WWV), is analysed using monthly 1993-2010 sea level anomaly (a proxy for WWV) obtained from altimetry, and a validated 1958-2007 DRAKKAR simulation. An Agglomerative Hierarchical Clustering (AHC) technique performed on the observed and modelled WWV tendency shows the existence of five distinct clusters, which characterise the Eastern Pacific (EP) and Central Pacific (CP) El Niño, La Niña, after EP El Niño and neutral conditions. The AHC results, complemented with an analysis of lagged-regression analysis, and 3-month averages of typical EP and CP El Niño events, indicate that the equatorial band WWV discharge during CP is not as pronounced as during EP El Niño. To understand the differences, we analysed the balance of horizontal mass transports accounting for changes in WWV tendency. The analysis indicates an overall poleward transport during EP El Niño, which is not the case during CP El Niño. Instead, a compensating effect with a poleward (equatorward) transport occurring in the western (eastern) Pacific is evident, in line with changes in the zonal thermocline slopes occurring in the western (eastern) half of the basin. The WWV changes are discussed with respect to the conceptual phases of the recharge-discharge oscillator paradigm.

Oligocene sea water temperatures offshore Wilkes Land (Antarctica) indicate warm and stable glacial-interglacial variation and show no 'late Oligocene warming'

NASA Astrophysics Data System (ADS)

Hartman, Julian; Bijl, Peter; Peterse, Francien; Schouten, Stefan; Salabarnada, Ariadna; Bohaty, Steven; Escutia, Carlota; Brinkhuis, Henk; Sangiorgi, Francesca

2017-04-01

At present, warming of the waters below the Antarctic ice shelves is a major contributor to the instability of the Antarctic cryosphere. In order to get insight into future melt behavior of the Antarctic ice sheet, it is important to look at past warm periods that can serve as an analogue for the future. The Oligocene ( 34-23 Ma) is a period within the range of CO2 concentrations predicted by the latest IPCC report for the coming century and is characterized by a very dynamic Antarctic ice sheet, as suggested by benthic δ18O records from ice-distal sites. We suspect that, like today, environmental changes in the Southern Ocean are in part responsible for this dynamicity. To gain more insight into this, we have reconstructed sea water temperatures (SWT) based on Thaumarchaeotal lipids (TEX86) for the Oligocene record obtained from the ice-proximal Site U1356 (Integrated Ocean Drilling Program), offshore Wilkes Land. Part of our record shows a strong coupling between the lithology and SWT, which we attribute to glacial-interglacial variation. Our data shows that both glacial and interglacial temperatures are relatively warm throughout the Oligocene: 14°C and 18°C respectively, which is consistent with previously published estimates based on UK'37 and clumped isotopes for the early Oligocene. Our SST records show only a minor decline between 30 and 24 Ma, and thus show no evidence for a 'late Oligocene warming' as was suggested based on benthic δ18O records from low latitudes. Instead, the discrepancy between our SST trend and the δ18O trend suggests that the late-Oligocene benthic δ18O decrease is likely related to a decline in ice volume. After 24 Ma, however, glacial-interglacial temperature variation appears to increase. In particular, some large temperature drops occur, one of which can be related to the Mi-1 event and a major expansion of the Antarctic ice sheet.

Projected Increase in Lightning Strikes in the United States Due to Global Warming

NASA Astrophysics Data System (ADS)

Romps, D. M.; Seeley, J.; Vollaro, D.; Molinari, J.

2014-12-01

Lightning plays an important role in atmospheric chemistry and in the initiation of wildfires, but the impact of global warming on lightning rates is poorly constrained. The lightning flash rate is proposed here to be proportional to the convective available potential energy (CAPE) times the precipitation rate. Using observations, the product of CAPE and precipitation is found to explain the majority of variance in the time series of total cloud-to-ground lightning flashes over the contiguous United States (CONUS) on timescales ranging from diurnal to seasonal. The observations reveal that storms convert the CAPE of water mass to discharged lightning energy with an efficiency of about 1%. This proxy can be applied to global climate models, which provide predictions for the increase in lightning due to global warming. Results from 11 GCMs will be shown.

Growth decline linked to warming-induced water limitation in hemi-boreal forests.

PubMed

Wu, Xiuchen; Liu, Hongyan; Guo, Dali; Anenkhonov, Oleg A; Badmaeva, Natalya K; Sandanov, Denis V

2012-01-01

Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal forests, based on ring width measurements from three dominant tree-species (Pinus sylvestris, Larix sibirica and Larix gmelinii), sampled from eight sites in the region. We found that regional tree growth has become increasingly limited by low soil water content in the pre- and early-growing season (from October of the previous year to July of the current year) over the past 80 years. A warming-induced reduction in soil water content has also increased the climate sensitivity of these three tree species. Beginning in the mid-1980s, a clear decline in growth is evident for both the pine forests and the larch forests, although there are increasing trends in the proxy of soil water use efficiencies. Our findings are consistent with those from other parts of the world and provide valuable insights into the regional carbon cycle and vegetation dynamics, and should be useful for devising adaptive forest management strategies.

Benefit of warm water immersion on biventricular function in patients with chronic heart failure

PubMed Central

Grüner Sveälv, Bente; Cider, Åsa; Täng, Margareta Scharin; Angwald, Eva; Kardassis, Dimitris; Andersson, Bert

2009-01-01

Background Regular physical activity and exercise are well-known cardiovascular protective factors. Many elderly patients with heart failure find it difficult to exercise on land, and hydrotherapy (training in warm water) could be a more appropriate form of exercise for such patients. However, concerns have been raised about its safety. The aim of this study was to investigate, with echocardiography and Doppler, the acute effect of warm water immersion (WWI) and effect of 8 weeks of hydrotherapy on biventricular function, volumes and systemic vascular resistance. A secondary aim was to observe the effect of hydrotherapy on brain natriuretic peptide (BNP). Methods Eighteen patients [age 69 ± 8 years, left ventricular ejection fraction 31 ± 9%, peakVO2 14.6 ± 4.5 mL/kg/min] were examined with echocardiography on land and in warm water (34°C). Twelve of these patients completed 8 weeks of control period followed by 8 weeks of hydrotherapy twice weekly. Results During acute WWI, cardiac output increased from 3.1 ± 0.8 to 4.2 ± 0.9 L/min, LV tissue velocity time integral from 1.2 ± 0.4 to 1.7 ± 0.5 cm and right ventricular tissue velocity time integral from 1.6 ± 0.6 to 2.5 ± 0.8 cm (land vs WWI, p < 0.0001, respectively). Heart rate decreased from 73 ± 12 to 66 ± 11 bpm (p < 0.0001), mean arterial pressure from 92 ± 14 to 86 ± 16 mmHg (p < 0.01), and systemic vascular resistance from 31 ± 7 to 22 ± 5 resistant units (p < 0.0001). There was no change in the cardiovascular response or BNP after 8 weeks of hydrotherapy. Conclusion Hydrotherapy was well tolerated by all patients. The main observed cardiac effect during acute WWI was a reduction in heart rate, which, together with a decrease in afterload, resulted in increases in systolic and diastolic biventricular function. Although 8 weeks of hydrotherapy did not improve cardiac function, our data support the concept that exercise in warm water is an acceptable regime for patients with heart failure. PMID

Application of Microsecond Voltage Pulses for Water Disinfection by Diaphragm Electric Discharge

NASA Astrophysics Data System (ADS)

Kakaurov, S. V.; Suvorov, I. F.; Yudin, A. S.; Solovyova, T. L.; Kuznetsova, N. S.

2015-11-01

The paper presents the dependence of copper and silver ions formation on the duration of voltage pulses of diaphragm electric discharge and on the pH of treated liquid medium. Knowing it allows one to create an automatic control system to control bactericidal agent's parameters obtained in diaphragm electric discharge reactor. The current-voltage characteristic of the reactor with a horizontal to the diaphragm membrane water flow powered from the author's custom pulse voltage source is also presented. The results of studies of the power consumption of diaphragm electric discharge depending on temperature of the treated liquid medium are given.

Invasive forb benefits from water savings by native plants and carbon fertilization under elevated CO2 and warming.

PubMed

Blumenthal, Dana M; Resco, Víctor; Morgan, Jack A; Williams, David G; Lecain, Daniel R; Hardy, Erik M; Pendall, Elise; Bladyka, Emma

2013-12-01

As global changes reorganize plant communities, invasive plants may benefit. We hypothesized that elevated CO2 and warming would strongly influence invasive species success in a semi-arid grassland, as a result of both direct and water-mediated indirect effects. To test this hypothesis, we transplanted the invasive forb Linaria dalmatica into mixed-grass prairie treated with free-air CO2 enrichment and infrared warming, and followed survival, growth, and reproduction over 4 yr. We also measured leaf gas exchange and carbon isotopic composition in L. dalmatica and the dominant native C3 grass Pascopyrum smithii. CO2 enrichment increased L. dalmatica biomass 13-fold, seed production 32-fold, and clonal expansion seven-fold, while warming had little effect on L. dalmatica biomass or reproduction. Elevated CO2 decreased stomatal conductance in P. smithii, contributing to higher soil water, but not in L. dalmatica. Elevated CO2 also strongly increased L. dalmatica photosynthesis (87% versus 23% in P. smithii), as a result of both enhanced carbon supply and increased soil water. More broadly, rapid growth and less conservative water use may allow invasive species to take advantage of both carbon fertilization and water savings under elevated CO2 . Water-limited ecosystems may therefore be particularly vulnerable to invasion as CO2 increases. No claim to original US goverment works. New Phytologist © 2013 New Phytologist Trust.

Thermal ground-water discharge and associated convective heat flux, Bruneau-Grand View area, southwest Idaho

USGS Publications Warehouse

Young, H.W.; Lewis, R.E.; Backsen, R.L.

1979-01-01

The Bruneau-Grand View area occupies about 1,100 square miles in southwest Idaho. The area has a rural population dependent on ground-water irrigation. Temperature of the ground water ranges from 15 C to more than 80 C. Ground water for irrigation is obtained from flowing and pumped wells. Discharge of thermal ground water from 104 irrigation wells and from 5 hot springs in 1978 was about 50,500 acre-feet. Convective heat flux from the geothermal system associated with this discharge was 4.97 x 10 to the 7th power calories per second. (Woodard-USGS)

Discharge indices for water quality loads

USGS Publications Warehouse

Vogel, Richard M.; Stedinger, Jery R.; Hooper, Richard P.

2003-01-01

Effective discharge has been used to describe the streamflow level that is responsible for transporting the most sediment over the long term. Careful inspection reveals that this concept may not have been well defined, and different interpretations have led to conflicting representations. Because total load is ultimately the quantity of interest, we define a new index, the half‐load discharge, which is that discharge above and below which half the total long‐term load is transported. The value of the half‐load discharge is derived for a reasonable model of flows and constituent concentration. The effective discharge has generally been thought to be a relatively common or frequent flood. The half‐load discharge is generally a much greater and less frequent flow than commonly used estimators of the effective discharge. Relations provided here for the frequency and magnitude of the half‐load discharge provide evidence that it is relatively rare floods that transport most of the sediment over the long term. These ideas apply to other constituents as well.

Estimates of ground-water discharge as determined from measurements of evapotranspiration, Ash Meadows area, Nye County, Nevada

USGS Publications Warehouse

Laczniak, R.J.; DeMeo, G.A.; Reiner, S.R.; Smith, J. LaRue; Nylund, W.E.

1999-01-01

Ash Meadows is one of the major discharge areas within the regional Death Valley ground-water flow system of southern Nevada and adjacent California. Ground water discharging at Ash Meadows is replenished from inflow derived from an extensive recharge area that includes the eastern part of the Nevada Test Site (NTS). Currently, contaminants introduced into the subsurface by past nuclear testing at NTS are the subject of study by the U.S. Department of Energy's Environmental Restoration Program. The transport of any contaminant in contact with ground water is controlled in part by the rate and direction of ground-water flow, which itself depends on the location and quantity of ground water discharging from the flow system. To best evaluate any potential risk associated with these test-generated contaminants, studies were undertaken to accurately quantify discharge from areas downgradient from the NTS. This report presents results of a study to refine the estimate of ground-water discharge at Ash Meadows. The study estimates ground-water discharge from the Ash Meadows area through a rigorous quantification of evapotranspiration (ET). To accomplish this objective, the study identifies areas of ongoing ground-water ET, delineates unique areas of ET defined on the basis of similarities in vegetation and soil-moisture conditions, and computes ET rates for each of the delineated areas. A classification technique using spectral-reflectance characteristics determined from satellite images recorded in 1992 identified seven unique units representing areas of ground-water ET. The total area classified encompasses about 10,350 acres dominated primarily by lush desert vegetation. Each unique area, referred to as an ET unit, generally consists of one or more assemblages of local phreatophytes. The ET units identified range from sparse grasslands to open water. Annual ET rates are computed by energy-budget methods from micrometeorological measurements made at 10 sites within six

ARSENIC CYCLING WITHIN THE WATER COLUMN OF A SMALL LAKE RECEIVING CONTAMINATED GROUND WATER DISCHARGE

EPA Science Inventory

The fate of arsenic discharged from contaminated ground water to a small, shallow lake at a hazardous waste site is controlled, in part, by the rate of ferrous iron oxidation-precipitation and arsenic sorption occurring near the lake chemocline. Laboratory experiments were condu...

Asynchronous warming and δ18O evolution of deep Atlantic water masses during the last deglaciation

NASA Astrophysics Data System (ADS)

Zhang, Jiaxu; Liu, Zhengyu; Brady, Esther C.; Oppo, Delia W.; Clark, Peter U.; Jahn, Alexandra; Marcott, Shaun A.; Lindsay, Keith

2017-10-01

The large-scale reorganization of deep ocean circulation in the Atlantic involving changes in North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) played a critical role in regulating hemispheric and global climate during the last deglaciation. However, changes in the relative contributions of NADW and AABW and their properties are poorly constrained by marine records, including δ18O of benthic foraminiferal calcite (δ18Oc). Here, we use an isotope-enabled ocean general circulation model with realistic geometry and forcing conditions to simulate the deglacial water mass and δ18O evolution. Model results suggest that, in response to North Atlantic freshwater forcing during the early phase of the last deglaciation, NADW nearly collapses, while AABW mildly weakens. Rather than reflecting changes in NADW or AABW properties caused by freshwater input as suggested previously, the observed phasing difference of deep δ18Oc likely reflects early warming of the deep northern North Atlantic by ˜1.4 °C, while deep Southern Ocean temperature remains largely unchanged. We propose a thermodynamic mechanism to explain the early warming in the North Atlantic, featuring a strong middepth warming and enhanced downward heat flux via vertical mixing. Our results emphasize that the way that ocean circulation affects heat, a dynamic tracer, is considerably different from how it affects passive tracers, like δ18O, and call for caution when inferring water mass changes from δ18Oc records while assuming uniform changes in deep temperatures.

Asynchronous warming and δ18O evolution of deep Atlantic water masses during the last deglaciation

NASA Astrophysics Data System (ADS)

Zhang, J.; Liu, Z.; Brady, E. C.; Oppo, D.; Clark, P. U.; Jahn, A.; Marcott, S. A.; Lindsay, K. T.

2017-12-01

The large-scale reorganization of deep-ocean circulation in the Atlantic involving changes in North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) played a critical role in regulating hemispheric and global climate during the last deglaciation. However, changes in the relative contributions of NADW and AABW and their properties are poorly constrained by marine records, including δ18O of benthic foraminiferal calcite (δ18Oc). Here we use an isotope-enabled ocean general circulation model with realistic geometry and forcing conditions to simulate the deglacial water mass and δ18O evolution. Model results suggest that in response to North Atlantic freshwater forcing during the early phase of the last deglaciation, NADW nearly collapses while AABW mildly weakens. Rather than reflecting changes in NADW or AABW properties due to freshwater input as suggested previously, the observed phasing difference of deep δ18Oc likely reflects early warming of the deep northern North Atlantic by 1.4°C while deep Southern Ocean temperature remains largely unchanged. We propose a thermodynamic mechanism to explain the early warming in the North Atlantic, featuring a strong mid-depth warming and enhanced downward heat flux via vertical mixing. Our results emphasize that the way ocean circulation affects heat, a dynamic tracer, is considerably different than how it affects passive tracers like δ18O, and call for caution when inferring water mass changes from δ18Oc records while assuming uniform changes in deep temperatures.

Wastewater discharge impact on drinking water sources along the Yangtze River (China).

PubMed

Wang, Zhuomin; Shao, Dongguo; Westerhoff, Paul

2017-12-01

Unplanned indirect (de facto) wastewater reuse occurs when wastewater is discharged into surface waters upstream of potable drinking water treatment plant intakes. This paper aims to predict percentages and trends of de facto reuse throughout the Yangtze River watershed in order to understand the relative contribution of wastewater discharges into the river and its tributaries towards averting water scarcity concerns. The Yangtze River is the third longest in the world and supports more than 1/15 of the world's population, yet the importance of wastewater on the river remains ill-defined. Municipal wastewater produced in the Yangtze River Basin increased by 41% between 1998 and 2014, from 2580m 3 /s to 3646m 3 /s. Under low flow conditions in the Yangtze River near Shanghai, treated wastewater contributions to river flows increased from 8% in 1998 to 14% in 2014. The highest levels of de facto reuse appeared along a major tributary (Han River) of the Yangtze River, where de facto reuse can exceed 20%. While this initial analysis of de facto reuse used water supply and wastewater data from 110 cities in the basin and 11 gauging stations with >50years of historic streamflow data, the outcome was limited by the lack of gauging stations at more locations (i.e., data had to be predicted using digital elevation mapping) and lack of precise geospatial location of drinking water intakes or wastewater discharges. This limited the predictive capability of the model relative to larger datasets available in other countries (e.g., USA). This assessment is the first analysis of de facto wastewater reuse in the Yangtze River Basin. It will help identify sections of the river at higher risk for wastewater-related pollutants due to presence of-and reliance on-wastewater discharge that could be the focus of field studies and model predictions of higher spatial and temporal resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

Climate change. Projected increase in lightning strikes in the United States due to global warming.

PubMed

Romps, David M; Seeley, Jacob T; Vollaro, David; Molinari, John

2014-11-14

Lightning plays an important role in atmospheric chemistry and in the initiation of wildfires, but the impact of global warming on lightning rates is poorly constrained. Here we propose that the lightning flash rate is proportional to the convective available potential energy (CAPE) times the precipitation rate. Using observations, the product of CAPE and precipitation explains 77% of the variance in the time series of total cloud-to-ground lightning flashes over the contiguous United States (CONUS). Storms convert CAPE times precipitated water mass to discharged lightning energy with an efficiency of 1%. When this proxy is applied to 11 climate models, CONUS lightning strikes are predicted to increase 12 ± 5% per degree Celsius of global warming and about 50% over this century. Copyright © 2014, American Association for the Advancement of Science.

Discharge, water temperature, and selected meteorological data for Vancouver Lake, Vancouver, Washington, water years 2011-13

USGS Publications Warehouse

Foreman, James R.; Marshall, Cameron A.; Sheibley, Rich W.

2014-01-01

The U.S. Geological Survey partnered with the Vancouver Lake Watershed Partnership in a 2-year intensive study to quantify the movement of water and nutrients through Vancouver Lake in Vancouver, Washington. This report is intended to assist the Vancouver Lake Watershed Partnership in evaluating potential courses of action to mitigate seasonally driven blooms of harmful cyanobacteria and to improve overall water quality of the lake. This report contains stream discharge, lake water temperature, and selected meteorological data for water years 2011, 2012, and 2013 that were used to develop the water and nutrient budgets for the lake.

Characterization of a dielectric barrier discharge in contact with liquid and producing a plasma activated water

NASA Astrophysics Data System (ADS)

Neretti, G.; Taglioli, M.; Colonna, G.; Borghi, C. A.

2017-01-01

In this work a low-temperature plasma source for the generation of plasma activated water (PAW) is developed and characterized. The plasma reactor was operated by means of an atmospheric-pressure air dielectric barrier discharge (DBD). The plasma generated is in contact with the water surface and is able to chemically activate the liquid medium. Electrodes were supplied by both sinusoidal and nanosecond-pulsed voltage waveforms. Treatment times were varied from 2 to 12 min to increase the energy dose released to the water by the DBD plasma. The physics of the discharge was studied by means of electrical, spectroscopic and imaging diagnostics. The interaction between the plasma and the liquid was investigated as well. Temperature and composition of the treated water were detected. Images of the discharges showed a filamentary behaviour in the sinusoidal case and a more homogeneous behaviour in the nanosecond-pulsed one. The images and the electrical measurements allowed to evaluate an average electron number density of about 4  ×  1019 and 6  ×  1017 m-3 for the sinusoidal and nanosecond-pulsed discharges respectively. Electron temperatures in the range of 2.1÷2.6 eV were measured by using spectroscopic diagnostics. Rotational temperatures in the range of 318-475 K were estimated by fitting synthetic spectra with the measured ones. Water temperature and pH level did not change significantly after the exposure to the DBD plasma. The production of ozone and hydrogen peroxide within the water was enhanced by increasing the plasma treatment time and the energy dose. Numerical simulations of the nanosecond-pulsed discharge were performed by using a self-consistent coupling of state-to-state kinetics of the air mixture with the Boltzmann equation of free electron kinetics. Temporal evolution of the electron energy distribution function shows departure from the Maxwellian distribution especially during the afterglow phase of the discharge. When

Risk assessment for produced water discharges to Louisiana open bays. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinhold, A.F.; DePhillips, M.P.; Holtzman, S.

1996-03-22

The US Department of Energy (USDOE) has a program of research in the environmental aspects of oil and gas extraction. This sampling project will characterize the environmental impacts associated with the discharge of naturally occurring radioactive materials (NORM), metals and organics in produced water. This report is part of a series of studies of the health and ecological risks from discharges of produced water to the Gulf of Mexico, supported by the USDOE. These assessments are being coordinated with the field study, using the collected data to perform human health and ecological risk assessments. These assessments will provide input tomore » regulators in the development of guidelines and permits, and to industry in the development and use of appropriate discharge practices. The initial human health and ecological risk assessments consist of conservative screening analyses meant to identify potentially important contaminants, and to eliminate others from further consideration. More quantitative assessments were done for contaminants identified, in the screening analysis, as being of potential concern. Section 2 gives an overview of human health and ecological risk assessment to help put the analyses presented here in perspective. Section 3 provides the hazard assessment portion of the risk assessment, and identifies the important receptors and pathways of concern. Section 3 also outlines the approach taken to the risk assessments presented in the rest of the report. The remaining sections (4 through 9) present the human health and ecological risk assessments for discharges of produced water to open bays in Louisiana.« less

A preliminary study of the tropical water cycle and its sensitivity to surface warming

NASA Technical Reports Server (NTRS)

Lau, K. M.; Sui, C. H.; Tao, W. K.

1993-01-01

The Goddard Cumulus Ensemble Model (GCEM) has been used to demonstrate that cumulus-scale dynamics and microphysics play a major role in determining the vertical distribution of water vapor and clouds in the tropical atmosphere. The GCEM is described and is the basic structure of cumulus convection. The long-term equilibrium response to tropical convection to surface warming is examined. A picture of the water cycle within tropical cumulus clusters is developed.

Modeling discharge, temperature, and water quality in the Tualatin River, Oregon

USGS Publications Warehouse

Rounds, Stewart A.; Wood, Tamara M.; Lynch, Dennis D.

1999-01-01

The discharge, water temperature, and water quality of the Tualatin River in northwestern Oregon was simulated with CE-QUAL-W2, a two-dimensional, laterally averaged model developed by the U.S. Army Corps of Engineers. The model was calibrated for May through October periods of 1991, 1992, and 1993. Nine hypothetical scenarios were tested with the model to provide insight for river managers and regulators.

Grafted cellulose for PAHs removal present in industrial discharge waters

NASA Astrophysics Data System (ADS)

Euvrard, Elise; Druart, Coline; Poupeney, Amandine; Crini, Nadia; Vismara, Elena; Lanza, Tommaso; Torri, Giangiacomo; Gavoille, Sophie; Crini, Gregorio

2014-05-01

Keywords: cellulose; biosorbent; PAHs; polycontaminated wastewaters; trace levels. Polycyclic aromatic hydrocarbons (PAHs), chemicals essentially formed during incomplete combustion of organic materials from anthropogenic activities, were present in all compartments of the ecosystem, air, water and soil. Notably, a part of PAHs found in aquatic system was introduced through industrial discharge waters. Since the Water Framework Directive has classified certain PAHs as priority hazardous substances, industrials are called to take account this kind of organic pollutants in their global environmental concern. Conventional materials such as activated carbons definitively proved their worth as finishing treatment systems but remained costly. In this study, we proposed to use cellulose grafted with glycidyl methacrylate [1] for the removal of PAHs present in discharge waters of surface treatment industries. Firstly, to develop the device, we worked with synthetic solutions containing 16 PAHs at 500 ng/L. Two types of grafted cellulose were tested over a closed-loop column with a concentration of 4g cellulose/L: cellulose C2 with a hydroxide group and cellulose C4 with an amine group. No PAH was retained by the raw cellulose whereas abatement percentages of PAHs were similar between C2 and C4 (94% and 98%, respectively, for the sum of the 16 PAHs) with an experiment duration of 400 min (corresponding to about 20 cycles through grafted cellulose). Secondly, to determine the shorter time to abate the amount maximum of PAHs through the system, a kinetic was realized from 20 min (one cycle) to 400 min with C4. The steady state (corresponding to about 95% of abatement of the total PAHs) was reached at 160 min. Finally, the system was then tested with real industrial discharge waters containing both mineral and organic compounds. The results indicated that the abatement percentage of PAHs was similar between C2 and C4, corroborating the tests with synthetic solution. In return

Quantifying the impacts of climate and human activities on water and sediment discharge in a karst region of southwest China

NASA Astrophysics Data System (ADS)

Li, Zhenwei; Xu, Xianli; Yu, Bofu; Xu, Chaohao; Liu, Meixian; Wang, Kelin

2016-11-01

Quantifying the impacts of climate and human activities on water and sediment discharge has become a central topic in climate and hydrologic research. This issue, however, has so far received little attention in karst regions around the world. Seven karst catchments located in southwest China were chosen to explore water and sediment discharge responses to different driving factors during the period from the 1950s to 2011. The non-parametric Mann-Kendall test was used to detect both the trends and abrupt changes in water and sediment discharge. The double mass curve method was used to quantify the effects of climate and human activities on water and sediment discharge. Results indicated that the annual water discharge showed a decreasing trend in all catchments (-0.21 to -3.68 × 108 m3 yr-1), and the sediment discharge exhibited a significant decreasing trend (-7 to -101 × 104 t yr-1) for six out of the seven catchments. A rapid decline (abrupt change) in sediment discharge occurred since 2000 for all except Liujiang catchment where the sediment discharge has a slight increase since 1983 as no large dams were constructed in this catchment. Specifically, the magnitude of reduction in sediment discharge (%) significantly increases with the extent of flow regulation as measured by the ratio of the area upstream the dam to the total catchment area for the seven catchments (R2 = 0.98, P < 0.01). This study demonstrated that water discharge was mainly influenced by precipitation, while sediment discharge was mainly influenced by human activities (relative contribution 70-111%, regardless of whether the effect is negative or positive). Ecological restoration played somehow important roles in the decrease in sediment discharge (negative relationships of sediment discharge with the Normalized Differential Vegetation Index (NDVI)), but dam construction was likely to be the principal cause of the significant decrease in sediment discharge. This study is of use for better

Understanding why the volume of suboxic waters does not increase over centuries of global warming in an Earth System Model

NASA Astrophysics Data System (ADS)

Gnanadesikan, A.; Dunne, J. P.; John, J.

2012-03-01

Global warming is expected to reduce oxygen solubility and vertical exchange in the ocean, changes which would be expected to result in an increase in the volume of hypoxic waters. A simulation made with a full Earth System model with dynamical atmosphere, ocean, sea ice and biogeochemical cycling (the Geophysical Fluid Dynamics Laboratory's Earth System Model 2.1) shows that this holds true if the condition for hypoxia is set relatively high. However, the volume of the most hypoxic (i.e., suboxic) waters does not increase under global warming, as these waters actually become more oxygenated. We show that the rise in dissolved oxygen in the tropical Pacific is associated with a drop in ventilation time. A term-by-term analysis within the least oxygenated waters shows an increased supply of dissolved oxygen due to lateral diffusion compensating an increase in remineralization within these highly hypoxic waters. This lateral diffusive flux is the result of an increase of ventilation along the Chilean coast, as a drying of the region under global warming opens up a region of wintertime convection in our model. The results highlight the potential sensitivity of suboxic waters to changes in subtropical ventilation as well as the importance of constraining lateral eddy transport of dissolved oxygen in such waters.

Environmental impacts of produced water and drilling waste discharges from the Norwegian offshore petroleum industry.

PubMed

Bakke, Torgeir; Klungsøyr, Jarle; Sanni, Steinar

2013-12-01

Operational discharges of produced water and drill cuttings from offshore oil and gas platforms are a continuous source of contaminants to continental shelf ecosystems. This paper reviews recent research on the biological effects of such discharges with focus on the Norwegian Continental Shelf. The greatest concern is linked to effects of produced water. Alkylphenols (AP) and polyaromatic hydrocarbons (PAH) from produced water accumulate in cod and blue mussel caged near outlets, but are rapidly metabolized in cod. APs, naphtenic acids, and PAHs may disturb reproductive functions, and affect several chemical, biochemical and genetic biomarkers. Toxic concentrations seem restricted to <2 km distance. At the peak of discharge of oil-contaminated cuttings fauna disturbance was found at more than 5 km from some platforms, but is now seldom detected beyond 500 m. Water-based cuttings may seriously affect biomarkers in filter feeding bivalves, and cause elevated sediment oxygen consumption and mortality in benthic fauna. Effects levels occur within 0.5-1 km distance. The stress is mainly physical. The risk of widespread, long term impact from the operational discharges on populations and the ecosystem is presently considered low, but this cannot be verified from the published literature. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Increasing water cycle extremes in California and relation to ENSO cycle under global warming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, Jin -Ho; Wang, S. -Y. Simon; Gillies, Robert R.

California has experienced its most severe drought in recorded history since the winter of 2013-2014. The long duration of drought has stressed statewide water resources and the economy, while fueling an extraordinary increase in wildfires. The effects of global warming on the regional climate include a hotter and drier climate, as well as earlier snowmelt, both of which exacerbate drought conditions. However, connections between a changing climate and how climate oscillations modulate regional water cycle extremes are not well understood. Here we analyze large-ensemble simulations of future climate change in California using the Community Earth System Model version 1 (CESM1)more » and multiple climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5). Both intense drought and excessive flooding are projected to increase by at least 50% toward the end of the 21st century. Furthermore, the projected increase in water cycle extremes is associated with tighter relation to El Niño and Southern Oscillation (ENSO), particularly extreme El Niño and La Niña events, which modulates California’s climate not only through its warm and cold phases, but also ENSO’s precursor patterns.« less

Increasing water cycle extremes in California and relation to ENSO cycle under global warming

DOE PAGES

Yoon, Jin -Ho; Wang, S. -Y. Simon; Gillies, Robert R.; ...

2015-10-21

California has experienced its most severe drought in recorded history since the winter of 2013-2014. The long duration of drought has stressed statewide water resources and the economy, while fueling an extraordinary increase in wildfires. The effects of global warming on the regional climate include a hotter and drier climate, as well as earlier snowmelt, both of which exacerbate drought conditions. However, connections between a changing climate and how climate oscillations modulate regional water cycle extremes are not well understood. Here we analyze large-ensemble simulations of future climate change in California using the Community Earth System Model version 1 (CESM1)more » and multiple climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5). Both intense drought and excessive flooding are projected to increase by at least 50% toward the end of the 21st century. Furthermore, the projected increase in water cycle extremes is associated with tighter relation to El Niño and Southern Oscillation (ENSO), particularly extreme El Niño and La Niña events, which modulates California’s climate not only through its warm and cold phases, but also ENSO’s precursor patterns.« less

Estimates of natural ground-water discharge and characterization of water quality in Dry Valley, Washoe County, West-Central Nevada, 2002-2003

USGS Publications Warehouse

Berger, David L.; Maurer, Douglas K.; Lopes, Thomas J.; Halford, Keith J.

2004-01-01

The Dry Valley Hydrographic Area is being considered as a potential source area for additional water supplies for the Reno-Sparks area, which is about 25 miles south of Dry Valley. Current estimates of annual ground-water recharge to Dry Valley have a considerable range. In undeveloped valleys, such as Dry Valley, long-term ground-water discharge can be assumed the same as long-term ground-water recharge. Because estimating ground-water discharge has more certainty than estimating ground-water recharge from precipitation, the U.S. Geological Survey, in cooperation with Washoe County, began a three-year study to re-evaluate the ground-water resources by estimating natural ground-water discharge and characterize ground-water quality in Dry Valley. In Dry Valley, natural ground-water discharge occurs as subsurface outflow and by ground-water evapotranspiration. The amount of subsurface outflow from the upper part of Dry Valley to Winnemucca and Honey Lake Valleys likely is small. Subsurface outflow from Dry Valley westward to Long Valley, California was estimated using Darcy's Law. Analysis of two aquifer tests show the transmissivity of poorly sorted sediments near the western side of Dry Valley is 1,200 to 1,500 square feet per day. The width of unconsolidated sediments is about 4,000 feet between exposures of tuffaceous deposits along the State line, and decreases to about 1,500 feet (0.5 mile) west of the State line. The hydraulic gradient east and west of the State line ranges from 0.003 to 0.005 foot per foot. Using these values, subsurface outflow to Long Valley is estimated to be 50 to 250 acre-feet per year. Areas of ground-water evapotranspiration were field mapped and partitioned into zones of plant cover using relations derived from Landsat imagery acquired July 8, 2002. Evapotranspiration rates for each plant-cover zone were multiplied by the corresponding area and summed to estimate annual ground-water evapotranspiration. About 640 to 790 acre-feet per

Effect of climate change on the irrigation and discharge scheme for winter wheat in Huaibei Plain, China

NASA Astrophysics Data System (ADS)

Zhu, Y.; Ren, L.; Lü, H.

2017-12-01

On the Huaibei Plain of Anhui Province, China, winter wheat (WW) is the most prominent crop. The study area belongs to transitional climate, with shallow water table. The original climate change is complex, in addition, global warming make the climate change more complex. The winter wheat growth period is from October to June, just during the rainless season, the WW growth always depends on part of irrigation water. Under such complex climate change, the rainfall varies during the growing seasons, and water table elevations also vary. Thus, water tables supply variable moisture change between soil water and groundwater, which impact the irrigation and discharge scheme for plant growth and yield. In Huaibei plain, the environmental pollution is very serious because of agricultural use of chemical fertilizer, pesticide, herbicide and etc. In order to protect river water and groundwater from pollution, the irrigation and discharge scheme should be estimated accurately. Therefore, determining the irrigation and discharge scheme for winter wheat under climate change is important for the plant growth management decision-making. Based on field observations and local weather data of 2004-2005 and 2005-2006, the numerical model HYDRUS-1D was validated and calibrated by comparing simulated and measured root-zone soil water contents. The validated model was used to estimate the irrigation and discharge scheme in 2010-2090 under the scenarios described by HadCM3 (1970 to 2000 climate states are taken as baselines) with winter wheat growth in an optimum state indicated by growth height and LAI.

Growth Decline Linked to Warming-Induced Water Limitation in Hemi-Boreal Forests

PubMed Central

Wu, Xiuchen; Liu, Hongyan; Guo, Dali; Anenkhonov, Oleg A.; Badmaeva, Natalya K.; Sandanov, Denis V.

2012-01-01

Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal forests, based on ring width measurements from three dominant tree-species (Pinus sylvestris, Larix sibirica and Larix gmelinii), sampled from eight sites in the region. We found that regional tree growth has become increasingly limited by low soil water content in the pre- and early-growing season (from October of the previous year to July of the current year) over the past 80 years. A warming-induced reduction in soil water content has also increased the climate sensitivity of these three tree species. Beginning in the mid-1980s, a clear decline in growth is evident for both the pine forests and the larch forests, although there are increasing trends in the proxy of soil water use efficiencies. Our findings are consistent with those from other parts of the world and provide valuable insights into the regional carbon cycle and vegetation dynamics, and should be useful for devising adaptive forest management strategies. PMID:22916142

Phosphorus in a ground-water contaminant plume discharging to Ashumet Pond, Cape Cod, Massachusetts, 1999

USGS Publications Warehouse

McCobb, Timothy D.; LeBlanc, Denis R.; Walter, Donald A.; Hess, Kathryn M.; Kent, Douglas B.; Smith, Richard L.

2003-01-01

The discharge of a plume of sewagecontaminated ground water emanating from the Massachusetts Military Reservation to Ashumet Pond on Cape Cod, Massachusetts, has caused concern about excessive loading of nutrients, particularly phosphorus, to the pond. The U.S. Air Force is considering remedial actions to mitigate potentially adverse effects on the ecological characteristics of the pond from continued phosphorus loading. Concentrations as great as 3 milligrams per liter of dissolved phosphorus (as P) are in ground water near the pond's shoreline; concentrations greater than 5 milligrams per liter of phosphorus are in ground water farther upgradient. Temporary drive-point wells were used to collect water samples from 2 feet below the pond bottom to delineate concentration distributions in the pore waters of the pond-bottom sediments. Measurements in the field of specific conductance and colorimetrically determined orthophosphate concentrations provided real-time data to guide the sampling. The contaminant plume discharges to the Fishermans Cove area of Ashumet Pond as evidenced by elevated levels of specific conductance and boron, which are chemically conservative indicators of the sewage-contaminated ground water. Concentrations of nonconservative species, such as dissolved phosphorus, manganese, nitrate, and ammonium, also were elevated above background levels in ground water discharging to the pond, but in spatially complex distributions that reflect their distributions in ground water upgradient of the pond. Phosphorus concentrations exceeded background levels (greater than 0.10 milligram per liter) in the pond-bottom pore water along 875 feet of shoreline. Greatest concentrations (greater than 2 milligrams per liter) occurred within 30 feet of the shore in an area about 225 feet long. Calculations of phosphorus flux in the aquifer upgradient of Ashumet Pond, as determined from water-flux estimates from a steady-state ground-water-flow model and phosphorus

A High-Resolution Record of Warm Water Inflow and Iceberg Calving in Upernavik Isfjord During the Past 150 Years.

NASA Astrophysics Data System (ADS)

Vermassen, F.; Andresen, C. S.; Sabine, S.; Holtvoeth, J.; Cordua, A. E.; Wangner, D. J.; Dyke, L. M.; Kjaer, K. H.; Kokfelt, U.; Haubner, K.

2016-12-01

There is a growing body of evidence demonstrating that changes in warm water inflow to Greenlandic fjords are linked to the rapid retreat of marine-terminating outlet glaciers. This process is thought to be responsible for a substantial component of the increased mass loss from the Greenland Ice Sheet over the last two decades. Sediment cores from glaciated fjords provide high-resolution sedimentological and biological proxy records which can be used to evaluate the interplay of warm water inflow and glacier calving over recent time scales. In this study, multiple short cores ( 2 m) from Upernavik Isfjord, West Greenland, were analysed to establish a multi-proxy record of glacier behaviour and oceanographic conditions that spans the past 150 years. The down-core variation in the amount of ice-rafted debris reveals periods of increased glacier calving, and biomarker proxies are used to reconstruct variability in the inflow of warm, Atlantic-sourced water to the fjord. Measurements of the sortable silt grain size are used to reconstruct bottom-current strength; periods of vigorous current flow are assumed to be due to enhanced warm water inflow. Finally, a record of glacier terminus position changes, derived from historical observations and satellite imagery, allows comparison of our new proxy records with the retreat of the ice margin from 1849 onwards. We use these data to assess the relative importance of mechanisms controlling the (rapid) retreat of marine-terminating glaciers in Upernavik Isfjord.

Inferring Discharge at River Mouths from Water Surface Height Measurements

NASA Astrophysics Data System (ADS)

Branch, R.; Horner-Devine, A.; Chickadel, C. C.

2016-02-01

Numerical model results suggest that a relationship exists between river discharge and surface height anomalies near the mouth of rivers, which presents an opportunity to use satellite elevation data to measure discharge remotely. Here we investigate whether such a relationship can be observed in the field using airborne lidar data at the mouth of the Columbia River. Airborne Lidar data were used because current NASA altimeter data does not have high enough spatial resolution to image surface elevation along a river. NASA's Surface Water and Ocean Topography, SWOT, sensor is planned to have a spatial resolution of less than 100 m and maximum height precision of 1 cm. The magnitude and temporal duration of the elevation signal found in the lidar data will be used to determine if SWOT will have the resolution and precision capabilities to measure discharge from space. Lidar data were acquired during a range of tidal conditions and discharge rates from May through September of 2013. Our results suggest that there is a measurable surface height anomaly at the river mouth during part of the tidal cycle. A 0.7 m surface depression was found during ebb tide and a uniform surface tilt was found at slack tide. The variation of the anomaly over the tidal period presents a challenge for decoupling the tidal component from that due to the discharge.

Discharge mode transition and temporal-spatial evolution of an air-water plasma jet generated by pulsating DC power

NASA Astrophysics Data System (ADS)

Lei, J.; Geng, Y.; Liu, K.; Zhu, W.; Zheng, Z.; Hu, H.

2017-12-01

In this paper, pulsating direct current air-water plasma jet, which can increase the production of •OH and decrease the temperature, is studied. The results show that the discharge mode changes in one cycle from corona discharge with steep Trichel current pulse to glow-like discharge. It is unknown whether the different discharge modes and water ratio have an effect on the transient process of the excited O and •OH production and the mechanism of plasma propagation. So, a series of experiments are done in this paper. The results show that the changing rules of both the excited state O and the discharge current reach their two peak values synchronously. And its maximum appears at the time of the first peak current value in corona mode. However, the change of the excited state •OH is different. It increases to its maximum at the time of the second peak current value in glow-like mode. Besides, the intensified charge coupled device photographs show that the luminous intensity of the discharge zone at the first peak current value in corona mode is stronger than the second peak current value in glow-like mode. At the same time, the discharge area of the former is larger than the latter. Nevertheless, with the increase in water ratio, the discharge area change reversed. Additionally, the air plasma plume propagation depends on the gas flow. The initial propagation velocity decreases with the increase in water ratio.

Dependency of high coastal water level and river discharge at the global scale

NASA Astrophysics Data System (ADS)

Ward, P.; Couasnon, A.; Haigh, I. D.; Muis, S.; Veldkamp, T.; Winsemius, H.; Wahl, T.

2017-12-01

It is widely recognized that floods cause huge socioeconomic impacts. From 1980-2013, global flood losses exceeded $1 trillion, with 220,000 fatalities. These impacts are particularly hard felt in low-lying densely populated deltas and estuaries, whose location at the coast-land interface makes them naturally prone to flooding. When river and coastal floods coincide, their impacts in these deltas and estuaries are often worse than when they occur in isolation. Such floods are examples of so-called `compound events'. In this contribution, we present the first global scale analysis of the statistical dependency of high coastal water levels (and the storm surge component alone) and river discharge. We show that there is statistical dependency between these components at more than half of the stations examined. We also show time-lags in the highest correlation between peak discharges and coastal water levels. Finally, we assess the probability of the simultaneous occurrence of design discharge and design coastal water levels, assuming both independence and statistical dependence. For those stations where we identified statistical dependency, the probability is between 1 and 5 times greater, when the dependence structure is accounted for. This information is essential for understanding the likelihood of compound flood events occurring at locations around the world as well as for accurate flood risk assessments and effective flood risk management. The research was carried out by analysing the statistical dependency between observed coastal water levels (and the storm surge component) from GESLA-2 and river discharge using gauged data from GRDC stations all around the world. The dependence structure was examined using copula functions.

Probability-based classifications for spatially characterizing the water temperatures and discharge rates of hot springs in the Tatun Volcanic Region, Taiwan.

PubMed

Jang, Cheng-Shin

2015-05-01

Accurately classifying the spatial features of the water temperatures and discharge rates of hot springs is crucial for environmental resources use and management. This study spatially characterized classifications of the water temperatures and discharge rates of hot springs in the Tatun Volcanic Region of Northern Taiwan by using indicator kriging (IK). The water temperatures and discharge rates of the springs were first assigned to high, moderate, and low categories according to the two thresholds of the proposed spring classification criteria. IK was then used to model the occurrence probabilities of the water temperatures and discharge rates of the springs and probabilistically determine their categories. Finally, nine combinations were acquired from the probability-based classifications for the spatial features of the water temperatures and discharge rates of the springs. Moreover, various combinations of spring water features were examined according to seven subzones of spring use in the study region. The research results reveal that probability-based classifications using IK provide practicable insights related to propagating the uncertainty of classifications according to the spatial features of the water temperatures and discharge rates of the springs. The springs in the Beitou (BT), Xingyi Road (XYR), Zhongshanlou (ZSL), and Lengshuikeng (LSK) subzones are suitable for supplying tourism hotels with a sufficient quantity of spring water because they have high or moderate discharge rates. Furthermore, natural hot springs in riverbeds and valleys should be developed in the Dingbeitou (DBT), ZSL, Xiayoukeng (XYK), and Macao (MC) subzones because of low discharge rates and low or moderate water temperatures.

Generation of reactive species in atmospheric pressure dielectric barrier discharge with liquid water

NASA Astrophysics Data System (ADS)

Zelong, ZHANG; Jie, SHEN; Cheng, CHENG; Zimu, XU; Weidong, XIA

2018-04-01

Atmospheric pressure helium/water dielectric barrier discharge (DBD) plasma is used to investigate the generation of reactive species in a gas-liquid interface and in a liquid. The emission intensity of the reactive species is measured by optical emission spectroscopy (OES) with different discharge powers at the gas-liquid interface. Spectrophotometry is used to analyze the reactive species induced by the plasma in the liquid. The concentration of OH radicals reaches 2.2 μm after 3 min of discharge treatment. In addition, the concentration of primary long-lived reactive species such as H2O2, {{{{NO}}}3}- and O3 are measured based on plasma treatment time. After 5 min of discharge treatment, the concentration of H2O2, {{{{NO}}}3}-, and O3 increased from 0 mg · L-1 to 96 mg · L-1, 19.5 mg · L-1, and 3.5 mg · L-1, respectively. The water treated by plasma still contained a considerable concentration of reactive species after 6 h of storage. The results will contribute to optimizing the DBD plasma system for biological decontamination.

How Were Southwest Pacific Pelagic Ecosystems Affected by Extreme Global Warming During the Initial Eocene Thermal Maximum?

NASA Astrophysics Data System (ADS)

Hollis, C. J.; Crouch, E. M.; Dickens, G. R.

2004-12-01

Four sections in eastern New Zealand provide the only South Pacific record of the initial Eocene thermal maximum (IETM): a siliciclastic outer shelf section (Tawanui, Hawkes Bay) and three pelagic-hemipelagic sections forming an outer shelf-upper slope transect across a carbonate ramp (Muzzle, Dee and Mead Streams, Clarence Valley). Although the rocks are too indurated to yield reliable oxygen isotope data, the IETM is identified by bulk carbonate carbon isotopes as a sharp negative excursion followed by gradual recovery over 0.6 to 4.0 m. In all sections, the excursion is mirrored by terrigenous sediment concentration, due to reduced biogenic (carbonate and silica) input and increased terrigenous input. Increased precipitation under warm humid conditions appears to have increased terrestrial discharge, recorded by deposition of smectitic marl in pelagic settings and illite/kaolinite-bearing smectitic mudstone in neritic settings. Eutrophic conditions are inferred for the IETM interval at Tawanui based on dysoxia, carbonate dissolution, an acme for the peridinioid dinocyst Apectodinium and abundant Toweius spp in nannofossil assemblages. Continued abundance of Toweius and replacement of Apectodinium by peridinioids of the Deflandrea complex suggests that eutrophic, albeit cooler, conditions persisted for at least 0.5 Ma after the IETM. In contrast, the IETM in Clarence Valley is marked by reduced biogenic silica content but little change in carbonate, and no evidence for carbonate dissolution. Sparse, poorly preserved palynomorphs assemblages suggest organic matter was oxidised under fully oxic conditions. Reduced numbers of upwelling indicators in the siliceous microfossil assemblage and common warm-water planktic foraminifera (Morozovella spp.), nannoplankton (Discoaster spp.) and radiolarians (e.g. Podocyrtis and Theocorys spp.) signal a switch from eutrophic to oligotrophic conditions and significant warming of near-surface waters. A progressive increase in

Water-elevation, stream-discharge, and ground-water quality data in the Alaska Railroad Industrial Area, Fairbanks, Alaska, May 1993 to May 1995

USGS Publications Warehouse

Kriegler, A.T.; Lilly, M.R.

1995-01-01

From May 1993 to May 1995, the U.S. Geological Survey in cooperation with the Alaska Department of Natural Resources, Division of Mining and Water Management collected data on ground-water and surface-water elevations, stream discharge, and ground-water quality in the Alaska Railroad Industrial area in Fairbanks, Alaska. The data- collection efforts were coordinated with environmental efforts being made in the study area by the Alaska Railroad Corporation. These data were collected as part of an effort to characterize the hydrogeology of the Alaska Railroad Industrial area and to define the extent of petroleum hydrocarbons in the area. Ground-water data were collected at 52 observation wells, surface-water data at 12 sites, stream discharge data at 9 sites, and chemical water-quality data at 32 observation wells.

Evaluation of the depth-integration method of measuring water discharge in large rivers

USGS Publications Warehouse

Moody, J.A.; Troutman, B.M.

1992-01-01

The depth-integration method oor measuring water discharge makes a continuos measurement of the water velocity from the water surface to the bottom at 20 to 40 locations or verticals across a river. It is especially practical for large rivers where river traffic makes it impractical to use boats attached to taglines strung across the river or to use current meters suspended from bridges. This method has the additional advantage over the standard two- and eight-tenths method in that a discharge-weighted suspended-sediment sample can be collected at the same time. When this method is used in large rivers such as the Missouri, Mississippi and Ohio, a microwave navigation system is used to determine the ship's position at each vertical sampling location across the river, and to make accurate velocity corrections to compensate for shift drift. An essential feature is a hydraulic winch that can lower and raise the current meter at a constant transit velocity so that the velocities at all depths are measured for equal lengths of time. Field calibration measurements show that: (1) the mean velocity measured on the upcast (bottom to surface) is within 1% of the standard mean velocity determined by 9-11 point measurements; (2) if the transit velocity is less than 25% of the mean velocity, then average error in the mean velocity is 4% or less. The major source of bias error is a result of mounting the current meter above a sounding weight and sometimes above a suspended-sediment sampling bottle, which prevents measurement of the velocity all the way to the bottom. The measured mean velocity is slightly larger than the true mean velocity. This bias error in the discharge is largest in shallow water (approximately 8% for the Missouri River at Hermann, MO, where the mean depth was 4.3 m) and smallest in deeper water (approximately 3% for the Mississippi River at Vickbsurg, MS, where the mean depth was 14.5 m). The major source of random error in the discharge is the natural

Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31-19)

NASA Astrophysics Data System (ADS)

Hernández-Almeida, I.; Sierro, F.-J.; Cacho, I.; Flores, J.-A.

2015-04-01

Subsurface water column dynamics in the subpolar North Atlantic were reconstructed in order to improve the understanding of the cause of abrupt ice-rafted detritus (IRD) events during cold periods of the early Pleistocene. We used paired Mg / Ca and δ18O measurements of Neogloboquadrina pachyderma (sinistral - sin.), deep-dwelling planktonic foraminifera, to estimate the subsurface temperatures and seawater δ18O from a sediment core from Gardar Drift, in the subpolar North Atlantic. Carbon isotopes of benthic and planktonic foraminifera from the same site provide information about the ventilation and water column nutrient gradient. Mg / Ca-based temperatures and seawater δ18O suggest increased subsurface temperatures and salinities during ice-rafting, likely due to northward subsurface transport of subtropical waters during periods of weaker Atlantic Meridional Overturning Circulation (AMOC). Planktonic carbon isotopes support this suggestion, showing coincident increased subsurface ventilation during deposition of IRD. Subsurface accumulation of warm waters would have resulted in basal warming and break-up of ice-shelves, leading to massive iceberg discharges in the North Atlantic. The release of heat stored at the subsurface to the atmosphere would have helped to restart the AMOC. This mechanism is in agreement with modelling and proxy studies that observe a subsurface warming in the North Atlantic in response to AMOC slowdown during Marine Isotope Stage (MIS) 3.

Asynchronous warming and δ 18O evolution of deep Atlantic water masses during the last deglaciation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Jiaxu; Liu, Zhengyu; Brady, Esther C.

The large-scale reorganization of deep ocean circulation in the Atlantic involving changes in North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) played a critical role in regulating hemispheric and global climate during the last deglaciation. However, changes in the relative contributions of NADW and AABW and their properties are poorly constrained by marine records, including δ 18O of benthic foraminiferal calcite (δ 18Oc). Here in this study, we use an isotope-enabled ocean general circulation model with realistic geometry and forcing conditions to simulate the deglacial water mass and δ 18O evolution. Model results suggest that, in response tomore » North Atlantic freshwater forcing during the early phase of the last deglaciation, NADW nearly collapses, while AABW mildly weakens. Rather than reflecting changes in NADW or AABW properties caused by freshwater input as suggested previously, the observed phasing difference of deep δ 18O c likely reflects early warming of the deep northern North Atlantic by ~1.4 °C, while deep Southern Ocean temperature remains largely unchanged. We propose a thermodynamic mechanism to explain the early warming in the North Atlantic, featuring a strong middepth warming and enhanced downward heat flux via vertical mixing. Our results emphasize that the way that ocean circulation affects heat, a dynamic tracer, is considerably different from how it affects passive tracers, like δ 18O, and call for caution when inferring water mass changes from δ 18O c records while assuming uniform changes in deep temperatures.« less

Asynchronous warming and δ18O evolution of deep Atlantic water masses during the last deglaciation.

PubMed

Zhang, Jiaxu; Liu, Zhengyu; Brady, Esther C; Oppo, Delia W; Clark, Peter U; Jahn, Alexandra; Marcott, Shaun A; Lindsay, Keith

2017-10-17

The large-scale reorganization of deep ocean circulation in the Atlantic involving changes in North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) played a critical role in regulating hemispheric and global climate during the last deglaciation. However, changes in the relative contributions of NADW and AABW and their properties are poorly constrained by marine records, including δ 18 O of benthic foraminiferal calcite (δ 18 O c ). Here, we use an isotope-enabled ocean general circulation model with realistic geometry and forcing conditions to simulate the deglacial water mass and δ 18 O evolution. Model results suggest that, in response to North Atlantic freshwater forcing during the early phase of the last deglaciation, NADW nearly collapses, while AABW mildly weakens. Rather than reflecting changes in NADW or AABW properties caused by freshwater input as suggested previously, the observed phasing difference of deep δ 18 O c likely reflects early warming of the deep northern North Atlantic by ∼1.4 °C, while deep Southern Ocean temperature remains largely unchanged. We propose a thermodynamic mechanism to explain the early warming in the North Atlantic, featuring a strong middepth warming and enhanced downward heat flux via vertical mixing. Our results emphasize that the way that ocean circulation affects heat, a dynamic tracer, is considerably different from how it affects passive tracers, like δ 18 O, and call for caution when inferring water mass changes from δ 18 O c records while assuming uniform changes in deep temperatures.

Asynchronous warming and δ 18O evolution of deep Atlantic water masses during the last deglaciation

DOE PAGES

Zhang, Jiaxu; Liu, Zhengyu; Brady, Esther C.; ...

2017-10-02

The large-scale reorganization of deep ocean circulation in the Atlantic involving changes in North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) played a critical role in regulating hemispheric and global climate during the last deglaciation. However, changes in the relative contributions of NADW and AABW and their properties are poorly constrained by marine records, including δ 18O of benthic foraminiferal calcite (δ 18Oc). Here in this study, we use an isotope-enabled ocean general circulation model with realistic geometry and forcing conditions to simulate the deglacial water mass and δ 18O evolution. Model results suggest that, in response tomore » North Atlantic freshwater forcing during the early phase of the last deglaciation, NADW nearly collapses, while AABW mildly weakens. Rather than reflecting changes in NADW or AABW properties caused by freshwater input as suggested previously, the observed phasing difference of deep δ 18O c likely reflects early warming of the deep northern North Atlantic by ~1.4 °C, while deep Southern Ocean temperature remains largely unchanged. We propose a thermodynamic mechanism to explain the early warming in the North Atlantic, featuring a strong middepth warming and enhanced downward heat flux via vertical mixing. Our results emphasize that the way that ocean circulation affects heat, a dynamic tracer, is considerably different from how it affects passive tracers, like δ 18O, and call for caution when inferring water mass changes from δ 18O c records while assuming uniform changes in deep temperatures.« less

Gas exchange and water relations responses of spring wheat to full-season infrared warming

USDA-ARS?s Scientific Manuscript database

Gas exchange and water relations responses to full-season in situ infrared (IR) warming were evaluated for hard red spring wheat (Triticum aestivum L. cv. Yecora Rojo) grown in an open field in a semi-arid desert region of the Southwest USA. A Temperature Free-Air Controlled Enhancement (T-FACE) ap...

Gas Exchange and Water Relations Responses of Spring Wheat to Full-Season Infrared Warming

USDA-ARS?s Scientific Manuscript database

Gas exchange and water relations were evaluated under full-season in situ infrared (IR) warming for hard red spring wheat (Triticum aestivum L. cv. Yecora Rojo) grown in an open field in a semiarid desert region of the southwest USA. A temperature free-air controlled enhancement (T-FACE) apparatus u...

Trans-Himalayan water contributions to river discharge

NASA Astrophysics Data System (ADS)

Andermann, Christoff; Stieglitz, Thomas; Schuessler, Jan A.; Parajouli, Binod

2017-04-01

Hydrological processes in high mountains are not well understood. Groundwater is commonly considered to be of little importance in the mountain water balance, while direct runoff, snow and ice melt are thought to be the principal hydrological buffer. We present new insights into hydrological fluxes between major reservoirs in a trans-Himalayan catchment. The study area is the Kali Gandaki catchment, rising in the dry Tibetan interior, carving through the high Himalayas and draining the full width of the foothills to the Ganges foreland. The catchment has a well-defined monsoon climate, with pronounced annual wet and dry seasons and a clear separation of wind- and leeward regions. We have sampled the main river and its tributaries as well as several springs during the four hydrological seasons (winter, pre-monsoon, monsoon, post-monsoon). We have measured major element abundances as well as 222Rn in situ, as a tracer for groundwater contribution. These measurements are placed in a context of topographic analyses as well as continuous discharge and precipitation measurements. Furthermore, we have equipped two sites with continuous water samplers, sampling over > 4 monsoon seasons, allowing us to resolve the seasonal hydrological dynamic range on a very high temporal resolution. Chemical fluxes vary spatially over several orders of magnitude, showing a systematic downstream dilution trend for most major elements during all hydrological seasons. High initial concentrations derive from evaporite deposits in the uppermost part of the catchment, constituting a large scale, natural salt tracer experiment. The well-defined decline of solute concentrations along the main river, paired with constraints on the composition of lateral water inputs downstream allow the calculation of the spatial distribution of additional hydrological fluxes, by applying end member mixing modeling. Continuous river stage and bulk dissolved load (electrical conductivity) monitoring depict well

Effect of inflow discharges on the development of matric suction and volumetric water content for dike during overtopping tests

NASA Astrophysics Data System (ADS)

Hassan, Marwan A.; Ismail, Mohd A. M.

2017-10-01

The point of this review is to depict the impact of various inflow discharge rate releases on the instruments of matric suction and volumetric water content during an experimental test of spatial overtopping failure at school of civil engineering in universiti Sains of Malaysia. A dry sand dike was conducted inside small flume channel with twelve sensors of tensiometer and Time-Domain Reflectometer (TDR). Instruments are installed in the soil at different locations in downstream and upstream slopes of the dike for measuring the response of matric suction and volumetric water content, respectively. Two values of inflow discharge rates of 30 and 40 L/min are utilized as a part of these experiments to simulate the effectiveness of water reservoirs in erosion mechanism. The outcomes demonstrate that the matric suction and volumetric water content are decreased and increased, respectively for both inflow discharges. The higher inflow discharges accelerate the saturation of dike soil and the erosion process faster than that for the lower inflow discharges.

Longevity of acid discharges from underground mines located above the regional water table.

PubMed

Demchak, J; Skousen, J; McDonald, L M

2004-01-01

The duration of acid mine drainage flowing out of underground mines is important in the design of watershed restoration and abandoned mine land reclamation projects. Past studies have reported that acid water flows from underground mines for hundreds of years with little change, while others state that poor drainage quality may last only 20 to 40 years. More than 150 above-drainage (those not flooded after abandonment) underground mine discharges from Pittsburgh and Upper Freeport coal seams were located and sampled during 1968 in northern West Virginia, and we revisited 44 of those sites in 1999-2000 and measured water flow, pH, acidity, Fe, sulfate, and conductivity. We found no significant difference in flows between 1968 and 1999-2000. Therefore, we felt the water quality data could be compared and the data represented real changes in pollutant concentrations. There were significant water quality differences between year and coal seam, but no effect of disturbance. While pH was not significantly improved, average total acidity declined 79% between 1968 and 1999-2000 in Pittsburgh mines (from 66.8 to 14 mmol H+ L(-1)) and 56% in Upper Freeport mines (from 23.8 to 10.4 mmol H+ L(-1)). Iron decreased an average of about 80% across all sites (from an average of 400 to 72 mg L(-1)), while sulfate decreased between 50 and 75%. Pittsburgh seam discharge water was much worse in 1968 than Upper Freeport seam water. Twenty of our 44 sites had water quality information in 1980, which served as a midpoint to assess the slope of the decline in acidity and metal concentrations. Five of 20 sites (25%) showed an apparent exponential rate of decline in acidity and iron, while 10 of 20 sites (50%) showed a more linear decline. Drainage from five Upper Freeport sites increased in acidity and iron. While it is clear that surface mines and below-drainage underground mines improve in discharge quality relatively rapidly (20-40 years), above-drainage underground mines are not as

Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water.

PubMed

Darelius, E; Fer, I; Nicholls, K W

2016-08-02

The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing.

Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water

PubMed Central

Darelius, E.; Fer, I.; Nicholls, K. W.

2016-01-01

The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing. PMID:27481659

Water quality and discharge data for St. Joseph Bay, Florida, 1997-98

USGS Publications Warehouse

Berndt, M.P.; Franklin, M.A.

1999-01-01

Historical data were compiled on water quality and water levels for the St. Joseph Bay area to assess quality of possible sources of land-derived water into the Bay. Ground-water quality data were compiled from Florida Department of Environmental Protection and surface-water quality data were compiled from U.S.Geological Survey files. Water-quality and water-level data were measured during two sample collection periods in October 1997 and March 1998 to determine water-quality and discharge rates in St. Joseph Bay under two sets of flow conditions. Measurements in the Bay included water level, temperature, pH, specific conductance, dissolved oxygen, and turbidity. Median pH in water from the surficial, intermediate and Floridan aquifer systems ranged from 4.8 to 7.8, and median specific conductance values were less than 500 microsiemens per centimeter. Median nutrient concentrations-- nitrate plus nitrite, ammonia and phosphorus--in the three aquifers were less than 0.5 milligrams per liter. The median pH was 7.0 and the median specific conductance was 81 microsiemens per centimeter for two samples from the Chipola River distribution canal. Water level data were obtained for several wells near St. Joseph Bay but only two wells yielded sufficient data to plot hydrographs. Measurements in St. Joseph Bay during the October and March collection periods were similar for pH and turbidity but differed for temperature, specific conductance and dissolved oxygen. The median temperature was 20.6 degrees Celsius in October and 15.4 degrees Celsius in March, median specific conductance was 39,500 microsiemens per centimeter in October and 43,300 microsiemens per centimeter in March, and median dissolved oxygen was 7.6 milligrams per liter in October and 8.3 milligrams per liter in March. The range in water levels over a tidal cycle in St. Joseph Bay on October 29, 1997 was about 1 foot. During a 24-hour tidal cycle on October 29, 1997, estimated hourly discharge varied from

Water-discharge determinations for the tidal reach of the Willamette River from Ross Island Bridge to Mile 10.3, Portland, Oregon

USGS Publications Warehouse

Dempster, G.R.; Lutz, Gale A.

1968-01-01

Water-discharge, velocity, and slope variations for a 3.7-mile-Iong tidal reach of the Willamette River at Portland, Oreg., were defined from discharge measurements and river stage data collected between July 1962 and January 1965. Observed water discharge during tide-affected flows, during floods, and during backwater from the Columbia River and recorded stages at each end of the river reach were used to determine water discharge from two mathematical models. These models use a finite-difference method to solve the equations of moderately unsteady open-channel streamflow, and discharges are computed by an electronic digital computer. Discharges computed by using the mathematical models compare satisfactorily with observed discharges, except during the period of backwater from the annual flood of the Columbia River. The flow resistance coefficients used in the models vary with discharge; for one model, the coefficients for discharges above 30,000 cfs (cubic feet per second) are 12 and 24 percent less than the coefficient used for discharges below 30,000 cfs. Daily mean discharges were determined by use of one mathematical model for approximately two-thirds of the water year, October 1963 through September 1964. Agreement of computed with routed daily mean discharges is fair; above 30,000 cfs, average differences between the two discharges are about 10 percent, and below 30,000 cfs, computed daily discharges are consistently greater (by as much as 25 percent) than routed discharges. The other model was used to compute discharges for the unusually high flood flows of December 1964.

57. LOOKING UP TAILRACE OF PLANE 2 EAST. WATER DISCHARGING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

57. LOOKING UP TAILRACE OF PLANE 2 EAST. WATER DISCHARGING FROM CULVERT ON LEFT HAD JUST PASSED THROUGH THE FLUME AND POWER HOUSE IN ORDER TO OPERATE THE LIFT MACHINERY. TAILRACE ON RIGHT IS A BYPASS FLUME SO THAT LEVEL OF CANAL BELOW PLANE 2 EAST CAN BE MAINTAINED. - Morris Canal, Phillipsburg, Warren County, NJ

Comparing the Life Cycle Energy Consumption, Global Warming and Eutrophication Potentials of Several Water and Waste Service Options

EPA Science Inventory

Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG...

Atmospheric Pressure Glow Discharge for Point-of-Use Water Treatment

NASA Astrophysics Data System (ADS)

Lindsay, Alexander; Byrns, Brandon; Shannon, Steven; Knappe, Detlef

2012-10-01

Treatment of biological and chemical contaminants is an area of growing global interest where atmospheric pressure plasmas can make a significant contribution. Addressing key challenges of volume processing and operational cost, a large volume 162 MHz coaxial air-plasma source has been developed.footnotetextByrns (2012) J. Phys. D: Appl. Phys. 45 (2012) 195204 Because of VHF ballasting effects, the electric discharge is maintained at a steady glow, allowing formation of critical non-equilibrium chemistry. High densities, ne = 10^11-10^12, have been recorded. The atmospheric nature of the device permits straightforward and efficient treatment of water samples. [H^+] concentrations in 150 milliliter tap water samples have been shown to increase by 10^5 after five minutes of discharge exposure. Recent literature has demonstrated that increasing acidity is strongly correlated with a solution's ability to deactivate microbial contaminants.footnotetextTraylor (2011) J. Phys. D: Appl. Phys. 44 (2011) 472001 The work presented here will explore the impact of treatment gas, system configuration, and power density on water disinfection and PFC abatement. An array of plasma diagnostics, including OES and electrical measurements, are combined with post-process water analysis, including GC-MS and QT analysis of coliform and E.coli bacteria. Development of volume processing atmospheric plasma disinfection methods offers promise for point-of-use treatments in developing areas of the world, potentially supplementing or replacing supply and weather-dependent disinfection methods.

Pilot study of natural attenuation of arsenic in well water discharged to the Little River above Lake Thunderbird, Norman, Oklahoma, 2012

USGS Publications Warehouse

Andrews, William J.; Masoner, Jason R.; Rendon, Samuel H.; Smith, Kevin A.; Greer, James R.; Chatterton, Logan A.

2013-01-01

The City of Norman, Oklahoma, wanted to augment its water supplies to meet the needs of an increasing population. Among the city’s potential water sources are city wells that produce water that exceeds the 10 micrograms per liter primary drinking-water standard for arsenic. The City of Norman was interested in investigating low-cost means of using natural attenuation to remove arsenic from well water and augment the water supply of Lake Thunderbird, the primary water source for the city. The U.S. Geological Survey, in cooperation with the City of Norman, conducted a preliminary investigation (pilot study) to determine if discharge of water from those wells into the Little River over a 12-day period would reduce arsenic concentrations through natural-attenuation processes. Water in the Little River flows into Lake Thunderbird, the principal water source for the city, so the discharged well water would improve the water balance of that reservoir. During this pilot study, 150–250 gallons per minute from each of six city wells were discharged to the Little River over a 12-day period. Water-quality samples were collected from the wells during discharge and from the river before, during, and after well discharges. Streambed-sediment samples were collected at nine sites in the river before and after the well-discharge period. Water discharge from the six wells added 0.3 kilogram per day of arsenic to the river at the nearest downstream streamflow-gaging station. Dissolved arsenic concentration in the Little River at the closest downstream sampling site from the wells increased from about 4 micrograms per liter to as much as 24 micrograms per liter. Base flow in the river increased by about 1.7 cubic feet per second at the nearest downstream streamflow-gaging station. Streamflow in the river was two-thirds of that expected from the amount of water discharged from the wells because of seepage to soils and evapotranspiration of well water along drainage ways to the river

Multi-species collapses at the warm edge of a warming sea

PubMed Central

Rilov, Gil

2016-01-01

Even during the current biodiversity crisis, reports on population collapses of highly abundant, non-harvested marine species were rare until very recently. This is starting to change, especially at the warm edge of species’ distributions where populations are more vulnerable to stress. The Levant basin is the southeastern edge of distribution of most Mediterranean species. Coastal water conditions are naturally extreme, and are fast warming, making it a potential hotspot for species collapses. Using multiple data sources, I found strong evidence for major, sustained, population collapses of two urchins, one large predatory gastropod and a reef-building gastropod. Furthermore, of 59 molluscan species once-described in the taxonomic literature as common on Levant reefs, 38 were not found in the present-day surveys, and there was a total domination of non-indigenous species in molluscan assemblages. Temperature trends indicate an exceptional warming of the coastal waters in the past three decades. Though speculative at this stage, the fast rise in SST may have helped pushing these invertebrates beyond their physiological tolerance limits leading to population collapses and possible extirpations. If so, these collapses may indicate the initiation of a multi-species range contraction at the Mediterranean southeastern edge that may spread westward with additional warming. PMID:27853237

Report: State Enforcement of Clean Water Act Dischargers Can Be More Effective

EPA Pesticide Factsheets

Report #2001-P-00013, August 14, 2001. We believe that state enforcement programs could be much more effective in deterring noncompliance with discharge permits and, ultimately, improving the quality of the nation’s water.

Decline of Yangtze River water and sediment discharge: Impact from natural and anthropogenic changes

PubMed Central

Yang, S. L.; Xu, K. H.; Milliman, J. D.; Yang, H. F.; Wu, C. S.

2015-01-01

The increasing impact of both climatic change and human activities on global river systems necessitates an increasing need to identify and quantify the various drivers and their impacts on fluvial water and sediment discharge. Here we show that mean Yangtze River water discharge of the first decade after the closing of the Three Gorges Dam (TGD) (2003–2012) was 67 km3/yr (7%) lower than that of the previous 50 years (1950–2002), and 126 km3/yr less compared to the relatively wet period of pre-TGD decade (1993–2002). Most (60–70%) of the decline can be attributed to decreased precipitation, the remainder resulting from construction of reservoirs, improved water-soil conservation and increased water consumption. Mean sediment flux decreased by 71% between 1950–1968 and the post-TGD decade, about half of which occurred prior to the pre-TGD decade. Approximately 30% of the total decline and 65% of the decline since 2003 can be attributed to the TGD, 5% and 14% of these declines to precipitation change, and the remaining to other dams and soil conservation within the drainage basin. These findings highlight the degree to which changes in riverine water and sediment discharge can be related with multiple environmental and anthropogenic factors. PMID:26206169

Effects of pulse frequency of input power on the physical and chemical properties of pulsed streamer discharge plasmas in water

NASA Astrophysics Data System (ADS)

Ruma; Lukes, P.; Aoki, N.; Spetlikova, E.; Hosseini, S. H. R.; Sakugawa, T.; Akiyama, H.

2013-03-01

A repetitive pulsed-power modulator, which employs a magnetic pulse compression circuit with a high-speed thyristor switch, was used to study the effects of the pulse repetition rate of input power on the physical and chemical properties of pulsed discharges in water. Positive high-voltage pulses of 20 kV with repetition rates of up to 1 kHz were used to generate a discharge in water using the point-to-plane electrode geometry. By varying the pulse repetition rate, two distinct modes of the discharge plasma were formed in water. The first mode was characterized by the formation of a corona-like discharge propagating through water in the form of streamer channels. The second mode was formed typically above 500 Hz, when the formation of streamer channels in water was suppressed and all plasmas occurred inside a spheroidal aggregate of very fine gas bubbles surrounding the tip of the high-voltage electrode. The production of hydrogen peroxide, degradation of organic dye Acid Orange 7 (AO7) and inactivation of bacteria Escherichia coli by the discharge in water were studied under different discharge plasma modes in dependence on the pulse repetition rate of input power. The efficiency of both chemical and biocidal processes induced by the plasma in water decreased significantly with pulse repetition rates above 500 Hz.

Subsurface warming in the subpolar North Atlantic during rapid climate events in the Early and Mid-Pleistocene

NASA Astrophysics Data System (ADS)

Hernández-Almeida, Iván; Sierro, Francisco; Cacho, Isabel; Abel Flores, José

2014-05-01

A new high-resolution reconstruction of the temperature and salinity of the subsurface waters using paired Mg/Ca-δ18O measurements on the planktonic foraminifera Neogloboquadrina pachyderma sinistrorsa (sin.) was conducted on a deep-sea sediment core in the subpolar North Atlantic (Site U1314). This study aims to reconstruct millennial-scale subsurface hydrography variations during the Early and Mid-Pleistocene (MIS 31-19). These rapid climate events are characterized by abrupt shifts between warm/cold conditions, and ice-sheet oscillations, as evidenced by major ice rafting events recorded in the North Atlantic sediments (Hernández-Almeida et al., 2012), similar to those found during the Last Glacial period (Marcott et al, 2011). The Mg/Ca derived paleotemperature and salinity oscillations prior and during IRD discharges at Site U1314 are related to changes in intermediate circulation. The increases in Mg/Ca paleotemperatures and salinities during the IRD event are preceded by short episodes of cooling and freshening of subsurface waters. The response of the AMOC to this perturbation is an increased of warm and salty water coming from the south, transported to high latitudes in the North Atlantic beneath the thermocline. This process is accompanied by a southward shift in the convection cell from the Nordic Seas to the subpolar North Atlantic and better ventilation of the North Atlantic at mid-depths. Poleward transport of warm and salty subsurface subtropical waters causes intense basal melting and thinning of marine ice-shelves, that culminates in large-scale instability of the ice sheets, retreat of the grounding line and iceberg discharge. The mechanism proposed involves the coupling of the AMOC with ice-sheet dynamics, and would explain the presence of these fluctuations before the establishment of high-amplitude 100-kyr glacial cycles. Hernández-Almeida, I., Sierro, F.J., Cacho, I., Flores, J.A., 2012. Impact of suborbital climate changes in the North

Impact of Leachate Discharge from Cipayung Landfill on Water Quality of Pesanggrahan River, Indonesia

NASA Astrophysics Data System (ADS)

Noerfitriyani, Eki; Hartono, Djoko M.; Moersidik, Setyo S.; Gusniani, Irma

2018-03-01

The landfill operation can cause environmental problems due to solid waste decomposition in the form of leachate. The evaluation of environmental impacts related with solid waste landfilling is needed to ensure that leachate discharge to water bodies does not exceed the standard limit to prevent contamination of the environment. This study aims to analyze the impact of leachate discharge from Cipayung Landfill on water quality of Pesanggrahan River. The data were analyzed based on leachate samples taken from influent and effluent treatment unit, and river water samples taken from upstream, stream at leachate discharge, and downstream. All samples were taken three times under rainy season condition from April to May 2017. The results show the average leachate quality temperature is 34,81 °C, TSS 72.33 mg/L, pH 7.83, BOD 3,959.63 mg/L, COD 6,860 mg/L, TN 373.33 mg/L, Hg 0.0016 mg/L. The BOD5/COD ratio 0.58 indicated that leachate characteristics was biodegradable and resemble intermediate landfill due to the mixing of young leachate and old leachate. The effluent of leachate treatment plant exceeds the leachate standard limit for BOD, COD, and TN parameters. Statistical results from independent T-test showed significant differences (p<0,05) between upstream and downstream influenced with leachate discharge for DO parameter.

Reconnaissance investigations of the discharge and water quality of the Amazon River

USGS Publications Warehouse

Oltman, Roy Edwin

1968-01-01

effect reaches upstream to Obidos at extremely low flows, the distribution of velocities in stream verticals is affected by large-scale turbulence, the standard procedure of basing mean velocity in vertical on the average of point velocities measured at 20 and 80 percent of the total depth is valid, and there is a low Manning roughness coefficient of 0.019 (English units). Samples of suspended sediment taken with a point sampler at various depths in selected verticals show, for the Obidos site, a variation in concentration from 300 to 340 mg/l (milligram per liter) near the streambed to 50 to 70 mg/l in the upper part of the verticals. Median diameter of bed material at Obidos averaged about 0.20 mm (millimeter) in a range of 0.15 to 0.25 ram. Analyses of water samples collected at Obidos in July and November 1963 and August 1964 are presented. The reconnaissance measurements of 1963-64 provide a well-supported value of mean annual water discharge of Amazon River at Obidos and the mouth. Many more measurements of flow and water-quality characteristics are needed to obtain more exact values of discharge, suspended sediment, and salt load.

River Discharge and Bathymetry Estimation from Hydraulic Inversion of Surface Currents and Water Surface Elevation Observations

NASA Astrophysics Data System (ADS)

Simeonov, J.; Holland, K. T.

2015-12-01

We developed an inversion model for river bathymetry and discharge estimation based on measurements of surface currents, water surface elevation and shoreline coordinates. The model uses a simplification of the 2D depth-averaged steady shallow water equations based on a streamline following system of coordinates and assumes spatially uniform bed friction coefficient and eddy viscosity. The spatial resolution of the predicted bathymetry is related to the resolution of the surface currents measurements. The discharge is determined by minimizing the difference between the predicted and the measured streamwise variation of the total head. The inversion model was tested using in situ and remote sensing measurements of the Kootenai River east of Bonners Ferry, ID. The measurements were obtained in August 2010 when the discharge was about 223 m3/s and the maximum river depth was about 6.5 m. Surface currents covering a 10 km reach with 8 m spatial resolution were estimated from airborne infrared video and were converted to depth-averaged currents using acoustic Doppler current profiler (ADCP) measurements along eight cross-stream transects. The streamwise profile of the water surface elevation was measured using real-time kinematic GPS from a drifting platform. The value of the friction coefficient was obtained from forward calibration simulations that minimized the difference between the predicted and measured velocity and water level along the river thalweg. The predicted along/cross-channel water depth variation was compared to the depth measured with a multibeam echo sounder. The rms error between the measured and predicted depth along the thalweg was found to be about 60cm and the estimated discharge was 5% smaller than the discharge measured by the ADCP.

Growth strategies and threshold responses to water deficit modulate effects of warming on tree seedlings from forest to alpine

USGS Publications Warehouse

Lazarus, Brynne E.; Castanha, Cristina; Germino, Matthew; Kueppers, Lara M.; Moyes, Andrew B.

2018-01-01

1.Predictions of upslope range shifts for tree species with warming are based on assumptions of moisture stress at lower elevation limits and low temperature stress at high elevation limits. However, recent studies have shown that warming can reduce tree seedling establishment across the entire gradient from subalpine forest to alpine via moisture limitation. Warming effects also vary with species, potentially resulting in community shifts in high elevation forests. 2.We examined the growth and physiology underlying effects of warming on seedling demographic patterns. We evaluated dry mass (DM), root length, allocation above- and belowground, and relative growth rate (RGR) of whole seedlings, and their ability to avoid or endure water stress via water-use efficiency and resisting turgor loss, for Pinus flexilis, Picea engelmannii and Pinus contorta seeded below, at, and above treeline in experimentally warmed, watered, and control plots in the Rocky Mountains, USA. We expected that growth and allocation responses to warming would relate to moisture status and that variation in drought tolerance traits would explain species differences in survival rates. 3.Across treatments and elevations, seedlings of all species had weak turgor-loss resistance, and growth was marginal with negative RGR in the first growth phase (-0.01 to -0.04 g/g/d). Growth was correlated with soil moisture, particularly in the relatively small-seeded P. contorta and P. engelmannii. P. flexilis, known to have the highest survivorship, attained the greatest DM and longest root but was also the slowest growing and most water-use-efficient. This was likely due to its greater reliance on seed reserves. Seedlings developed 15% less total DM, 25% less root DM, and 11% shorter roots in heated compared to unheated plots. Higher temperatures slightly increased DM, root length and RGR where soils were wettest, but more strongly decreased these variables under drier conditions. 4.Synthesis: The surprising

Corona discharges with water electrospray for Escherichia coli biofilm eradication on a surface.

PubMed

Kovalova, Zuzana; Leroy, Magali; Kirkpatrick, Michael J; Odic, Emmanuel; Machala, Zdenko

2016-12-01

Low-temperature plasma (cold), a new method for the decontamination of surfaces, can be an advantageous alternative to the traditional chemical methods, autoclave or dry heat. Positive and negative corona discharges in air were tested for the eradication of 48-h Escherichia coli biofilms grown on glass slides. The biofilms were treated by cold corona discharge plasma for various exposure times. Water electrospray from the high voltage electrode was applied in some experiments. Thermostatic cultivation of the biofilm, and confocal laser scanning microscopy (CLSM) of the biofilm stained with fluorescent dyes were used for biocidal efficiency quantification. Up to 5 log10 reduction of bacterial concentration in the biofilm was measured by thermostatic cultivation after exposure to both corona discharges for 15min. This decontamination efficiency was significantly enhanced by simultaneous water electrospray through the plasma. CLSM showed that the live/dead ratio after treatment remained almost constant inside the biofilm; only cells on the top layers of the biofilm were affected. DAPI fluorescence showed that biofilm thickness was reduced by about 1/3 upon exposure to the corona discharges with electrospray for 15min. The biofilm biomass loss by about 2/3 was confirmed by crystal violet assay. Copyright © 2016 Elsevier B.V. All rights reserved.

Environmental and economic factors can increase the risk of exotic species introductions to the Arctic region through increased ballast water discharge.

PubMed

Niimi, Arthur J

2004-05-01

The effects of global warming can increase the risk of exotic species introductions in eastern Canadian Arctic waters by reducing surface ice cover and allow increased access to commercial vessels. Ballast water discharged by incoming overseas vessels is an important means for introducing species on a global scale. Analyses of air temperatures at Churchill, Manitoba between 1943 and 2002 indicated an increase in mean temperature within the past decade. Churchill is the only major northern port in this region where grain has been exported on a limited basis due to the short navigation season. Economic analyses of grain exported from Canadian and U.S. ports indicated some cost advantages for using northern ports. The Hudson Bay region is vulnerable to increased exotic species introductions because of its southerly location. Current ballast water exchange measures to reduce the risk of introductions may not be effective because most vessels enter the region with ballast, and the ballast exchange zone is located relatively close to coastal areas where the habitat could be favorable for an introduced species to become established. The probability of a large crab species introduced to this region from northern European waters is discussed. The risk of ballast water-related exotic species introduction to this region may be reduced by expanding the types of cargo handled and developing a strong import market. This approach would accommodate an increase in the number of vessels with cargo, and substantially reduce the volume of ballast carried to this region.

Water Treatment Using Plasma Discharge with Variation of Electrode Materials

NASA Astrophysics Data System (ADS)

Chanan, N.; Kusumandari; Saraswati, T. E.

2018-03-01

This research studied water treatment using plasma discharge. Plasma generated in this study produced active species that played a role in organic compound decomposition. The plasma reactor consisted of two needle electrodes made from stainless steel, tungsten, aluminium and grafit. It placed approximately 2 mm above the solution and connected with high-AC voltage. A solution of methylene blue used as an organic solution model. Plasma treatment times were 2, 4, 6, 8 and 10 min. The absorbance, temperature and pH of the solution were measured before and after treatment using various electrodes. The best electrode used in plasma discharging for methylene blue absorbance reduction was the graphite electrode, which provided the highest degradation efficiency of 98% at 6 min of treatment time.

Warm Water Entrainment Impacts and Environmental Life Cycle Assessment of a Proposed Ocean Thermal Energy Conversion Pilot Plant Offshore Oahu, Hawaii

NASA Astrophysics Data System (ADS)

Hauer, Whitney Blanchard

Ocean thermal energy conversion (OTEC) is a marine renewable energy technology that uses the temperature difference of large volumes of cold deep and warm surface seawater in tropical regions to generate electricity. One anticipated environmental impact of OTEC operations is the entrainment and subsequent mortality of ichthyoplankton (fish eggs and larvae) from the withdrawal of cold and warm seawater. The potential ichthyoplankton loss from the warm water intake was estimated for a proposed 10 MW OTEC pilot plant offshore Oahu, HI based on ambient vertical distribution data. The estimated losses due to entrainment from the warm water intake were 8.418E+02 larvae/1000 m3, 3.26E+06 larvae/day, and 1.19E+09 larvae/year. The potential entrained larvae/year is 1.86 X greater than at the Kahe Generating Station (Kapolei, HI), a 582 MW oil-fired power plant. Extrapolating to age-1 equivalence (9.2E+02 and 2.9E+02 yellowfin and skipjack tuna, respectively), the estimated yearly losses from warm water entrainment of yellowfin and skipjack tuna fish eggs and larvae represent 0.25-0.26 % and 0.09-0.11 % of Hawaii's commercial yellowfin and skipjack tuna industry in 2011 and 2012. An environmental life cycle assessment (LCA) was developed for the proposed OTEC plant operating for 20 and 40 years with availability factors of 0.85, 0.95, and 1.0 to determine the global warming potential (GWP) and cumulative energy demand (CED) impacts. For a 20 year operational OTEC plant, the GWP, CED, energy return on investment (EROI), and energy payback time (EPBT) ranged from 0.047 to 0.055 kg CO2eq/kWh, 0.678 to 0.798 MJ/kWh, 4.51 to 5.31 (unitless), and 3.77 to 4.43 years, respectively. For a 40 year operational OTEC plant, the GWP, CED, EROI, and EBPT ranged from 0.036 to 0.043 kg CO2eq/kWh, 0.527 to 0.620 MJ/kWh, 5.81 to 6.83 (unitless), and 5.85 to 6.89 years, respectively. The GWP impacts are within the range of renewable energy technologies and less than conventional electricity

Potential Impacts of Climate Warming on Water Supply Reliability in the Tuolumne and Merced River Basins, California

PubMed Central

Kiparsky, Michael; Joyce, Brian; Purkey, David; Young, Charles

2014-01-01

We present an integrated hydrology/water operations simulation model of the Tuolumne and Merced River Basins, California, using the Water Evaluation and Planning (WEAP) platform. The model represents hydrology as well as water operations, which together influence water supplied for agricultural, urban, and environmental uses. The model is developed for impacts assessment using scenarios for climate change and other drivers of water system behavior. In this paper, we describe the model structure, its representation of historical streamflow, agricultural and urban water demands, and water operations. We describe projected impacts of climate change on hydrology and water supply to the major irrigation districts in the area, using uniform 2°C, 4°C, and 6°C increases applied to climate inputs from the calibration period. Consistent with other studies, we find that the timing of hydrology shifts earlier in the water year in response to temperature warming (5–21 days). The integrated agricultural model responds with increased water demands 2°C (1.4–2.0%), 4°C (2.8–3.9%), and 6°C (4.2–5.8%). In this sensitivity analysis, the combination of altered hydrology and increased demands results in decreased reliability of surface water supplied for agricultural purposes, with modeled quantity-based reliability metrics decreasing from a range of 0.84–0.90 under historical conditions to 0.75–0.79 under 6°C warming scenario. PMID:24465455

Review of the methods to form hydrogen peroxide in electrical discharge plasma with liquid water

NASA Astrophysics Data System (ADS)

Locke, Bruce R.; Shih, Kai-Yuan

2011-06-01

This paper presents a review of the literature dealing with the formation of hydrogen peroxide from plasma processes. Energy yields for hydrogen peroxide generation by plasma from water span approximately three orders of magnitude from 4 × 10-2 to 80 g kWh-1. A wide range of plasma processes from rf to pulsed, ac, and dc discharges directly in the liquid phase have similar energy yields and may thus be limited by radical quenching processes at the plasma-liquid interface. Reactor modification using discharges in bubbles and discharges over the liquid phase can provide modest improvements in energy yield over direct discharge in the liquid, but the interpretation is complicated by additional chemical reactions of gas phase components such as ozone and nitrogen oxides. The highest efficiency plasma process utilizes liquid water droplets that may enhance efficiency by sequestering hydrogen peroxide in the liquid and by suppressing decomposition reactions by radicals from the gas and at the interface. Kinetic simulations of water vapor reported in the literature suggest that plasma generation of hydrogen peroxide should approach 45% of the thermodynamics limit, and this fact coupled with experimental studies demonstrating improvements with the presence of the condensed liquid phase suggest that further improvements in energy yield may be possible. Plasma generation of hydrogen peroxide directly from water compares favorably with a number of other methods including electron beam, ultrasound, electrochemical and photochemical methods, and other chemical processes.

Classification of a hypervirulent Aeromonas hydrophila pathotype responsible for epidemic outbreaks in warm-water fishes

USDA-ARS?s Scientific Manuscript database

Lineages of hypervirulent Aeromonas hydrophila (vAh) are the cause of persistent outbreaks of motile Aeromonas septicemia in warm-water fishes worldwide. Over the last decade, this virulent lineage of A. hydrophila has resulted in annual losses of millions of tons of farmed carp and catfish in the P...

Water-surface elevation and discharge measurement data for the Red River of the North and its tributaries near Fargo, North Dakota, water years 2014–15

USGS Publications Warehouse

Damschen, William C.; Galloway, Joel M.

2016-08-25

The U.S. Geological Survey, in cooperation with the Fargo Diversion Board of Authority, collected water-surface elevations during a range of discharges needed for calibration of hydrologic and hydraulic models for specific reaches of interest in water years 2014–15. These water-surface elevation and discharge measurement data were collected for design planning of diversion structures on the Red River of the North and Wild Rice River and the aqueduct/diversion structures on the Sheyenne and Maple Rivers. The Red River of the North and Sheyenne River reaches were surveyed six times, and discharges ranged from 276 to 6,540 cubic feet per second and from 166 to 2,040 cubic feet per second, respectively. The Wild Rice River reach also was surveyed six times during 2014 and 2015, and discharges ranged from 13 to 1,550 cubic feet per second. The Maple River reach was surveyed four times, and discharges ranged from 16.4 to 633 cubic feet per second. Water-surface elevation differences from upstream to downstream in the reaches ranged from 0.33 feet in the Red River of the North reach to 9.4 feet in the Maple River reach.

Discharge, suspended sediment, bedload, and water quality in Clear Creek, western Nevada, water years 2010-12

USGS Publications Warehouse

Huntington, Jena M.; Savard, Charles S.

2015-09-30

During this study, total annual sediment loads ranged from 355 tons per year in 2010 to 1,768 tons per year in 2011 and were significantly lower than the previous study (water years 2004–07). Bedload represented between 29 and 38 percent of total sediment load in water years 2010–12, and between 72 and 90 percent of the total sediment load in water years 2004–07, which indicates a decrease in bedload between study periods. Annual suspended-sediment loads in water years 2010–12 indicated no significant change from water years 2004–07. Mean daily discharge was significantly lower in water years 2010–12 than in waters years 2004–07 and may be the reason for the decrease in bedload that resulted in a lower total sediment load.

Global lake response to the recent warming hiatus

NASA Astrophysics Data System (ADS)

Winslow, Luke A.; Leach, Taylor H.; Rose, Kevin C.

2018-05-01

Understanding temporal variability in lake warming rates over decadal scales is important for understanding observed change in aquatic systems. We analyzed a global dataset of lake surface water temperature observations (1985‑2009) to examine how lake temperatures responded to a recent global air temperature warming hiatus (1998‑2012). Prior to the hiatus (1985‑1998), surface water temperatures significantly increased at an average rate of 0.532 °C decade‑1 (±0.214). In contrast, water temperatures did not change significantly during the hiatus (average rate ‑0.087 °C decade‑1 ±0.223). Overall, 83% of lakes in our dataset (129 of 155) had faster warming rates during the pre-hiatus period than during the hiatus period. These results demonstrate that lakes have exhibited decadal-scale variability in warming rates coherent with global air temperatures and represent an independent line of evidence for the recent warming hiatus. Our analyses provide evidence that lakes are sentinels of broader climatological processes and indicate that warming rates based on datasets where a large proportion of observations were collected during the hiatus period may underestimate longer-term trends.

Spatial-temporal evolution of self-organized loop-patterns on a water surface and a diffuse discharge in the gap

NASA Astrophysics Data System (ADS)

Li, Xuechen; Geng, Jinling; Jia, Pengying; Zhang, Panpan; Zhang, Qi; Li, Yaru

2017-11-01

Excited by an alternating current voltage, a patterned discharge and a diffuse discharge are generated in a needle to liquid configuration. Using an intensified charge-coupled device (ICCD), temporal evolution of the discharge between the two electrodes is investigated for the diffuse mode and the patterned mode, respectively. For the diffuse mode, the positive discharge is in a glow regime, and the negative discharge is in a Townsend discharge regime. For the patterned mode, the discharge always belongs to the Townsend discharge regime. Moreover, in the patterned mode, various patterns including the single loop, single loop with the surrounding corona, triple loops, and concentric loops with a central spot are observed on the water surface with the increasing positive peak-value of the applied voltage (Upp). Temporally resolved images of the loop-patterns are captured on the water surface. From the electrical measurements and the ICCD imaging, it is found that the loop pattern emerges after the discharge bridges the two electrodes. Then, it begins to evolve and finally degenerates with the decrease in the discharge current. The pattern does not disappear until the discharge quenches. Formation of the loop-patterns is attributed to the role of negative ions.

Multi-Model Assessment of Global Hydropower and Cooling Water Discharge Potential Under Climate Change

NASA Technical Reports Server (NTRS)

van Vliet, M. T. H.; van Beek, L. P. H.; Eisener, S.; Wada, Y.; Bierkens, M. F. P.

2016-01-01

Worldwide, 98% of total electricity is currently produced by thermoelectric power and hydropower. Climate change is expected to directly impact electricity supply, in terms of both water availability for hydropower generation and cooling water usage for thermoelectric power. Improved understanding of how climate change may impact the availability and temperature of water resources is therefore of major importance. Here we use a multi-model ensemble to show the potential impacts of climate change on global hydropower and cooling water discharge potential. For the first time, combined projections of streamflow and water temperature were produced with three global hydrological models (GHMs) to account for uncertainties in the structure and parametrization of these GHMs in both water availability and water temperature. The GHMs were forced with bias-corrected output of five general circulation models (GCMs) for both the lowest and highest representative concentration pathways (RCP2.6 and RCP8.5). The ensemble projections of streamflow and water temperature were then used to quantify impacts on gross hydropower potential and cooling water discharge capacity of rivers worldwide. We show that global gross hydropower potential is expected to increase between +2.4% (GCM-GHM ensemble mean for RCP 2.6) and +6.3% (RCP 8.5) for the 2080s compared to 1971-2000. The strongest increases in hydropower potential are expected for Central Africa, India, central Asia and the northern high-latitudes, with 18-33% of the world population living in these areas by the 2080s. Global mean cooling water discharge capacity is projected to decrease by 4.5-15% (2080s). The largest reductions are found for the United States, Europe, eastern Asia, and southern parts of South America, Africa and Australia, where strong water temperature increases are projected combined with reductions in mean annual streamflow. These regions are expected to affect 11-14% (for RCP2.6 and the shared socioeconomic

Trend analysis of ground-water levels and spring discharge in the Yucca Mountain Region, Nevada and California, 1960-2000

USGS Publications Warehouse

Fenelon, Joseph M.; Moreo, Michael T.

2002-01-01

Ground-water level and discharge data from 1960 to 2000 were analyzed for the Yucca Mountain region of southern Nevada and eastern California. Included were water-level data from 37 wells and a fissure (Devils Hole) and discharge data from five springs and from a flowing well. Data were evaluated for variability and for upward, downward, or cyclic trends with an emphasis on the period 1992-2000. Potential factors causing trends in water levels and discharge include ground-water withdrawal, infiltration of precipitation, earthquakes, evapotranspiration, barometric pressure, and earth tides. Statistically significant trends in ground-water levels or spring discharge from 1992 to 2000 were upward at 12 water-level sites and downward at 14 water-level sites and 1 spring-discharge site. In general, the magnitude of the change in water level from 1992 to 2000 was small (less than 2 feet), except where influenced by pumping or local effects such as possible equilibration from well construction or diversion of nearby surface water. Seasonal trends are superimposed on some of the long-term (1992-2000) trends in water levels and discharge. Factors causing seasonal trends include barometric pressure, evapotranspiration, and pumping. The magnitude of seasonal change in water level can vary from as little as 0.05 foot in regional aquifers to greater than 5 feet in monitoring wells near large supply wells in the Amargosa Farms area. Three major episodes of earthquake activity affected water levels in wells in the Yucca Mountain region between 1992 and 2000: the Landers/Little Skull Mountain, Northridge, and Hector Mine earthquakes. The Landers/Little Skull Mountain earthquakes, in June 1992, had the largest observed effect on water levels and on discharge during the study period. Monthly measurements of wells in the study network show that earthquakes affected water levels from a few tenths of a foot to 3.5 feet. In the Ash Meadows area, water levels remained relatively stable

Statistical prediction of seasonal discharge in the Naryn basin for water resources planning in Central Asia

NASA Astrophysics Data System (ADS)

Apel, Heiko; Gafurov, Abror; Gerlitz, Lars; Unger-Shayesteh, Katy; Vorogushyn, Sergiy; Merkushkin, Aleksandr; Merz, Bruno

2016-04-01

The semi-arid regions of Central Asia crucially depend on the water resources supplied by the mountainous areas of the Tien-Shan and Pamirs. During the summer months the snow and glacier melt water of the rivers originating in the mountains provides the only water resource available for agricultural production but also for water collection in reservoirs for energy production in winter months. Thus a reliable seasonal forecast of the water resources is crucial for a sustainable management and planning of water resources.. In fact, seasonal forecasts are mandatory tasks of national hydro-meteorological services in the region. Thus this study aims at a statistical forecast of the seasonal water availability, whereas the focus is put on the usage of freely available data in order to facilitate an operational use without data access limitations. The study takes the Naryn basin as a test case, at which outlet the Toktogul reservoir stores the discharge of the Naryn River. As most of the water originates form snow and glacier melt, a statistical forecast model should use data sets that can serve as proxy data for the snow masses and snow water equivalent in late spring, which essentially determines the bulk of the seasonal discharge. CRU climate data describing the precipitation and temperature in the basin during winter and spring was used as base information, which was complemented by MODIS snow cover data processed through ModSnow tool, discharge during the spring and also GRACE gravimetry anomalies. For the construction of linear forecast models monthly as well as multi-monthly means over the period January to April were used to predict the seasonal mean discharge of May-September at the station Uchterek. An automatic model selection was performed in multiple steps, whereas the best models were selected according to several performance measures and their robustness in a leave-one-out cross validation. It could be shown that the seasonal discharge can be predicted with

Quantity and quality of ground-water discharge to the South Platte River, Denver to Fort Lupton, Colorado, August 1992 through July 1993

USGS Publications Warehouse

McMahon, P.B.; Lull, K.J.; Dennehy, K.F.; Collins, J.A.

1995-01-01

Water-quality studies conducted by the Metro Wastewater Reclamation District have indicated that during low flow in segments of the South Platte River between Denver and Fort Lupton, concentrations of dissolved oxygen are less than minimum concen- trations set by the State of Colorado. Low dissolved-oxygen concentrations are observed in two reaches of the river-they are about 3.3 to 6.4 miles and 17 to 25 miles downstream from the Metro Waste- water Reclamation District effluent outfalls. Concentrations of dissolved oxygen recover between these two reaches. Studies conducted by the U.S. Geological Survey have indicated that ground-water discharge to the river may contribute to these low dissolved-oxygen concentrations. As a result, an assessment was made of the quantity and quality of ground-water discharge to the South Platte River from Denver to Fort Lupton. Measurements of surface- water and ground-water discharge and collections of surface water and ground water for water-quality analyses were made from August 1992 through January 1993 and in May and July 1993. The quantity of ground-water discharge to the South Platte River was determined indirectly by mass balance of surface-water inflows and outflows and directly by instantaneous measurements of ground-water discharge across the sediment/water interface in the river channel. The quality of surface water and ground water was determined by sampling and analysis of water from the river and monitoring wells screened in the alluvial aquifer adjacent to the river and by sampling and analysis of water from piezometers screened in sediments underlying the river channel. The ground-water flow system was subdivided into a large-area and a small-area flow system. The precise boundaries of the two flow systems are not known. However, the large-area flow system is considered to incorporate all alluvial sediments in hydrologic connection with the South Platte River. The small- area flow system is considered to incorporate

Stable Isotope Evidence for North Pacific Deep Water Formation during the mid-Pliocene Warm Period

NASA Astrophysics Data System (ADS)

Ford, H. L.; Burls, N.; Hodell, D. A.

2017-12-01

Only intermediate water forms in the North Pacific today because of a strong halocline. A recent climate modeling study suggests that conditions during the mid-Pliocene warm period ( 3 Ma), a time interval used as pseudo-analogue for future climate change, could have supported a Pacific Meridional Overturning Circulation (PMOC) in the North Pacific. This modeled PMOC is of comparable strength to the modern Atlantic Meridional Overturning Circulation. To investigate the possibility of a mid-Pliocene PMOC, we studied a depth transect of sites between 2400 to 3400 m water depth on Shatsky Rise by measuring δ18O and δ13C of Cibicidoides wuellerstorfi and comparing these new results with previously published records. Today, the vertical δ13C gradient has lower values at mid-depths because of the presence of aged water at the "end of the ocean conveyor belt." We find that the vertical δ13C gradient was reduced, and slightly reversed during the Pliocene interval on Shatsky Rise relative to modern. This δ13C data supports the modeling results that there was deep water formation in the North Pacific. On the Shatsky Rise, the mid-depth δ18O values are high relative to the deep site and other high-resolution records in the Equatorial Pacific. This suggests the PMOC water mass was colder and/or had a more enriched seawater δ18O than the surrounding waters. Planned future work includes minor and trace element analyses to determine the temperature and ΔCO32- characteristics of the PMOC water mass. Our results suggest a ventilated North Pacific during the globally warm mid-Pliocene.

Recycled Coarse Aggregate Produced by Pulsed Discharge in Water

NASA Astrophysics Data System (ADS)

Namihira, Takao; Shigeishi, Mitsuhiro; Nakashima, Kazuyuki; Murakami, Akira; Kuroki, Kaori; Kiyan, Tsuyoshi; Tomoda, Yuichi; Sakugawa, Takashi; Katsuki, Sunao; Akiyama, Hidenori; Ohtsu, Masayasu

In Japan, the recycling ratio of concrete scraps has been kept over 98 % after the Law for the Recycling of Construction Materials was enforced in 2000. In the present, most of concrete scraps were recycled as the Lower Subbase Course Material. On the other hand, it is predicted to be difficult to keep this higher recycling ratio in the near future because concrete scraps increase rapidly and would reach to over 3 times of present situation in 2010. In addition, the demand of concrete scraps as the Lower Subbase Course Material has been decreased. Therefore, new way to reuse concrete scraps must be developed. Concrete scraps normally consist of 70 % of coarse aggregate, 19 % of water and 11 % of cement. To obtain the higher recycling ratio, the higher recycling ratio of coarse aggregate is desired. In this paper, a new method for recycling coarse aggregate from concrete scraps has been developed and demonstrated. The system includes a Marx generator and a point to hemisphere mesh electrode immersed in water. In the demonstration, the test piece of concrete scrap was located between the electrodes and was treated by the pulsed discharge. After discharge treatment of test piece, the recycling coarse aggregates were evaluated under JIS and TS and had enough quality for utilization as the coarse aggregate.

Nonthermal Biological Treatments Using Discharge Plasma Produced by Pulsed Power 4. Cleaning of Lakes and Marshes by Pulsed Power Produced Streamer Discharges in Water

NASA Astrophysics Data System (ADS)

Akiyama, Hidenori; Katsuki, Sunao; Namihira, Takao; Ishibashi, Kazuo; Kiyosaki, Noriaki

Pulsed power has been used to produce non-thermal plasmas in atmospheric pressure gases that generate a high electric field at the tips of streamer discharges, where high energy electrons, free radicals, ultraviolet rays, and ozone are produced. These manifestations of streamer discharges have been used in the treatment of exhaust gases, removal of volatile and toxic compounds such as dioxin, and the sterilization of microorganisms. Here, large volume streamer discharges in water are described. These streamer discharges in liquids are able to produce a high electric field, high energy electrons, ozone, chemically active species, ultraviolet rays, and shock waves, which readily sterilize microorganisms and decompose molecules and materials. An application of this phenomenon to the cleaning of lakes and marshes is also described.

Temporal 222Rn distributions to reveal groundwater discharge into desert lakes: Implication of water balance in the Badain Jaran Desert, China

NASA Astrophysics Data System (ADS)

Luo, Xin; Jiao, Jiu Jimmy; Wang, Xu-sheng; Liu, Kun

2016-03-01

How lake systems are maintained and water is balanced in the lake areas in the Badain Jaran Desert (BJD), northeast of China have been debated for about a decade. In this study, continuous 222Rn measurement is used to quantify groundwater discharge into two representative fresh and brine water lakes in the desert using a steady-state mass-balance model. Two empirical equations are used to calculate atmospheric evasion loss crossing the water-air interface of the lakes. Groundwater discharge rates yielded from the radon mass balance model based on the two empirical equations are well correlated and of almost the same values, confirming the validity of the model. The fresh water and brine lakes have a daily averaged groundwater discharge rate of 7.6 ± 1.7 mm d-1 and 6.4 ± 1.8 mm d-1, respectively. The temporal fluctuations of groundwater discharge show similar patterns to those of the lake water level, suggesting that the lakes are recharged from nearby groundwater. Assuming that all the lakes have the same discharge rate as the two studied lakes, total groundwater discharge into all the lakes in the desert is estimated to be 1.59 × 105 m3 d-1. A conceptual model of water balance within a desert lake catchment is proposed to characterize water behaviors within the catchment. This study sheds lights on the water balance in the BJD and is of significance in sustainable regional water resource utilization in such an ecologically fragile area.

Stratification of living organisms in ballast tanks: how do organism concentrations vary as ballast water is discharged?

PubMed

First, Matthew R; Robbins-Wamsley, Stephanie H; Riley, Scott C; Moser, Cameron S; Smith, George E; Tamburri, Mario N; Drake, Lisa A

2013-05-07

Vertical migrations of living organisms and settling of particle-attached organisms lead to uneven distributions of biota at different depths in the water column. In ballast tanks, heterogeneity could lead to different population estimates depending on the portion of the discharge sampled. For example, concentrations of organisms exceeding a discharge standard may not be detected if sampling occurs during periods of the discharge when concentrations are low. To determine the degree of stratification, water from ballast tanks was sampled at two experimental facilities as the tanks were drained after water was held for 1 or 5 days. Living organisms ≥50 μm were counted in discrete segments of the drain (e.g., the first 20 min of the drain operation, the second 20 min interval, etc.), thus representing different strata in the tank. In 1 and 5 day trials at both facilities, concentrations of organisms varied among drain segments, and the patterns of stratification varied among replicate trials. From numerical simulations, the optimal sampling strategy for stratified tanks is to collect multiple time-integrated samples spaced relatively evenly throughout the discharge event.

Global Warming: A Reduced Threat?.

NASA Astrophysics Data System (ADS)

Michaels, Patrick J.; Stooksbury, David E.

1992-10-01

One popular and apocalyptic vision of the world influenced by increasing concentrations of infrared-absorbing trace gases is that of ecological disaster brought about by rapidly rising temperatures, sea level, and evaporation rates. This vision developed from a suite of climate models that have since considerably changed in both their dynamics and their estimates of prospective warming. Observed temperatures indicate that much more warming should already have taken place than predicted by earlier models in the Northern Hemisphere, and that night, rather than day, readings in that hemisphere show a relative warming. A high-latitude polar-night warming or a general night warming could be either benign or beneficial. A large number of plant species show both increased growth and greater water-use efficiency under enhanced carbon dioxide.An extensive body of evidence now indicates that anthropo-generated sulfate emissions are mitigating some of the warming, and that increased cloudiness as a result of these emissions will further enhance night, rather than day, warming. The sulfate emissions, though, are not sufficient to explain all of the night warming. However, the sensitivity of climate to anthropogenerated aerosols, and the general lack of previously predicted warming, could drastically alter the debate on global warming in favor of less expensive policies.

Microbial dynamics in acetate-enriched ballast water at different temperatures.

PubMed

Stehouwer, Peter Paul; van Slooten, Cees; Peperzak, Louis

2013-10-01

The spread of invasive species through ships' ballast water is considered as a major ecological threat to the world's oceans. For that reason, the International Maritime Organization (IMO) has set performance standards for ballast water discharge. Ballast water treatment systems have been developed that employ either UV-radiation or 'active substances' to reduce the concentration of living cells to below the IMOs standards. One such active substance is a chemical mixture known as Peraclean(®) Ocean. The residual of Peraclean(®) Ocean is acetate that might be present at high concentrations in discharged ballast water. In cold coastal waters the breakdown of acetate might be slow, causing a buildup of acetate concentrations in the water if regularly discharged by ships. To study the potential environmental impact, microbial dynamics and acetate degradation were measured in discharge water from a Peraclean(®) Ocean treatment system in illuminated microcosms. In addition, microbial dynamics and acetate degradation were studied at -1, 4, 10, 15 and 25°C in dark microcosms that simulated enclosed ballast water tanks. Acetate breakdown indeed occurred faster at higher temperatures. At 25°C the highest bacteria growth, fastest nutrient and oxygen consumption and highest DOC reduction occurred. On the other hand, at -1°C bacterial growth was strongly delayed, only starting to increase after 12 days. Furthermore, at 25°C the acetate pool was not depleted, probably due to nutrient and oxygen limitation. This means that not all acetate will be broken down in ballast water tanks, even during long voyages in warm waters. In addition, at low temperatures acetate breakdown in ballast water tanks and in discharged water will be extremely slow. Therefore, regular discharge of acetate enriched ballast water in harbors and bays may cause eutrophication and changes in the microbial community, especially in colder regions. Copyright © 2013 Elsevier Inc. All rights reserved.

The risk of water scarcity at different levels of global warming

NASA Astrophysics Data System (ADS)

Schewe, Jacob; Sharpe, Simon

2015-04-01

Water scarcity is a threat to human well-being and economic development in many countries today. Future climate change is expected to exacerbate the global water crisis by reducing renewable freshwater resources different world regions, many of which are already dry. Studies of future water scarcity often focus on most-likely, or highest-confidence, scenarios. However, multi-model projections of water resources reveal large uncertainty ranges, which are due to different types of processes (climate, hydrology, human) and are therefore not easy to reduce. Thus, central estimates or multi-model mean results may be insufficient to inform policy and management. Here we present an alternative, risk-based approach. We use an ensemble of multiple global climate and hydrological models to quantify the likelihood of crossing a given water scarcity threshold under different levels of global warming. This approach allows assessing the risk associated with any particular, pre-defined threshold (or magnitude of change that must be avoided), regardless of whether it lies in the center or in the tails of the uncertainty distribution. We show applications of this method on the country and river basin scale, illustrate the effects of societal processes on the resulting risk estimates, and discuss the further potential of this approach for research and stakeholder dialogue.

Residence times and nitrate transport in ground water discharging to streams in the Chesapeake Bay Watershed

USGS Publications Warehouse

Lindsey, Bruce D.; Phillips, Scott; Donnelly, Colleen A.; Speiran, Gary K.; Plummer, Niel; Bohlke, John Karl; Focazio, Michael J.; Burton, William C.; Busenberg, Eurybiades

2003-01-01

One of the major water-quality problems in the Chesapeake Bay is an overabundance of nutrients from the streams and rivers that discharge to the Bay. Some of these nutrients are from nonpoint sources such as atmospheric deposition, agricultural manure and fertilizer, and septic systems. The effects of efforts to control nonpoint sources, however, can be difficult to quantify because of the lag time between changes at the land surface and the response in the base-flow (ground water) component of streams. To help resource managers understand the lag time between implementation of management practices and subsequent response in the nutrient concentrations in the base-flow component of streamflow, a study of ground-water discharge, residence time, and nitrate transport in springs throughout the Chesapeake Bay Watershed and in four smaller watersheds in selected hydrogeomorphic regions (HGMRs) was conducted. The four watersheds were in the Coastal Plain Uplands, Piedmont crystalline, Valley and Ridge carbonate, and Valley and Ridge siliciclastic HGMRs.A study of springs to estimate an apparent age of the ground water was based on analyses for concentrations of chlorofluorocarbons in water samples collected from 48 springs in the Chesapeake Bay Watershed. Results of the analysis indicate that median age for all the samples was 10 years, with the 25th percentile having an age of 7 years and the 75th percentile having an age of 13 years. Although the number of samples collected in each HGMR was limited, there did not appear to be distinct differences in the ages between the HGMRs. The ranges were similar between the major HGMRs above the Fall Line (modern to about 50 years), with only two HGMRs of small geographic extent (Piedmont carbonate and Mesozoic Lowland) having ranges of modern to about 10 years. The median values of all the HGMRs ranged from 7 to 11 years. Not enough samples were collected in the Coastal Plain for comparison. Spring samples showed slightly younger

Desert Amplification in a Warming Climate

PubMed Central

Zhou, Liming

2016-01-01

Here I analyze the observed and projected surface temperature anomalies over land between 50°S-50°N for the period 1950–2099 by large-scale ecoregion and find strongest warming consistently and persistently seen over driest ecoregions such as the Sahara desert and the Arabian Peninsula during various 30-year periods, pointing to desert amplification in a warming climate. This amplification enhances linearly with the global mean greenhouse gases(GHGs) radiative forcing and is attributable primarily to a stronger GHGs-enhanced downward longwave radiation forcing reaching the surface over drier ecoregions as a consequence of a warmer and thus moister atmosphere in response to increasing GHGs. These results indicate that desert amplification may represent a fundamental pattern of global warming associated with water vapor feedbacks over land in low- and mid- latitudes where surface warming rates depend inversely on ecosystem dryness. It is likely that desert amplification might involve two types of water vapor feedbacks that maximize respectively in the tropical upper troposphere and near the surface over deserts, with both being very dry and thus extremely sensitive to changes of water vapor. PMID:27538725

Digital-model analysis of the effects of water-use alternatives on spring discharges Gooding and Jerome Counties, Idaho

USGS Publications Warehouse

Moreland, Joe A.

1976-01-01

Springs discharging from the Snake Plain aquifer contribute approximately 6,000 cubic feet per second (170 cubic metres per second) to flow in the Snake River between Milner and King Hill. Before irrigation began on the Snake River Plain north and east of the springs, total spring discharge was about 4,200 cubic feet per second (120 cubic meters per second). Increasing amounts of irrigated acreage from the early 1900's to the mid-1940's contributed more irrigation-return water to the aquifer resulting in increased discharge at the springs. Maximum discharge of about 6,800 cubic feet per second (190 cubic metres per second) occurred during the late 1940's and early 1950's. Increased use of pumped ground water for irrigation and changing irrigation practices have since resulted in a decline in spring discharge.

Potential health implications of water resources depletion and sewage discharges in the Republic of Macedonia.

PubMed

Hristovski, Kiril D; Pacemska-Atanasova, Tatjana; Olson, Larry W; Markovski, Jasmina; Mitev, Trajce

2016-08-01

Potential health implications of deficient sanitation infrastructure and reduced surface water flows due to climate change are examined in the case study of the Republic of Macedonia. Changes in surface water flows and wastewater discharges over the period 1955-2013 were analyzed to assess potential future surface water contamination trends. Simple model predictions indicated a decline in surface water hydrology over the last half century, which caused the surface waters in Macedonia to be frequently dominated by >50% of untreated sewage discharges. The surface water quality deterioration is further supported by an increasing trend in modeled biochemical oxygen demand trends, which correspond well with the scarce and intermittent water quality data that are available. Facilitated by the climate change trends, the increasing number of severe weather events is already triggering flooding of the sewage-dominated rivers into urban and non-urban areas. If efforts to develop a comprehensive sewage collection and treatment infrastructure are not implemented, such events have the potential to increase public health risks and cause epidemics, as in the 2015 case of a tularemia outbreak.

Characteristics of the cold-water belt formed off Soya Warm Current

NASA Astrophysics Data System (ADS)

Ishizu, Miho; Kitade, Yujiro; Matsuyama, Masaji

2008-12-01

We examined the data obtained by acoustic Doppler current profiler, conductivity-temperature-depth profiler, and expendable bathythermograph observations, which were collected in the summers of 2000, 2001, and 2002, to clarify the characteristics of the cold-water belt (CWB), i.e., lower-temperature water than the surrounding water extending from the southwest coast of Sakhalin along the offshore side of Soya Warm Current (SWC) and to confirm one of the formation mechanisms of the CWB as suggested by our previous study, i.e., the upwelling due to the convergence of bottom Ekman transport off the SWC region. The CWB was observed at about 30 km off the coast, having a thickness of 14 m and a minimum temperature of 12°C at the sea surface. The CWB does not have the specific water mass, but is constituted of three representative water types off the northeast coast of Hokkaido in summer, i.e., SWC water, Fresh Surface Okhotsk Sea Water, and Okhotsk Sea Intermediate Water. In a comparison of the horizontal distributions of current and temperature, the CWB region is found to be advected to the southeast at an average of 40 ± 29% of the maximum current velocity of the SWC. The pumping speed due to the convergence of the bottom Ekman transport is estimated as (1.5-3.0) × 10-4 m s-1. We examined the mixing ratio of the CWB, and the results implied that the water mass of the CWB is advected southeastward and mixes with a water mass upwelling in a different region off SWC.

Overvoltage effect on electrical discharge type in medium-conductivity water in inhomogeneous pulsed electric field

NASA Astrophysics Data System (ADS)

Panov, V. A.; Vasilyak, L. M.; Pecherkin, V. Ya; Vetchinin, S. P.; Son, E. E.

2018-01-01

The transition between thermal and streamer discharges has been observed experimentally in water solution with conductivity 100 μS/cm applying positive voltage pulses to pin-to-rod electrodes. The transition happens at five-fold pulse amplitude. Considering streamer propagation as an ionization wave helped to establish relation between the parameters governing transition from one to another discharge mechanism.

Developing a methodology for real-time trading of water withdrawal and waste load discharge permits in rivers.

PubMed

Soltani, Maryam; Kerachian, Reza

2018-04-15

In this paper, a new methodology is proposed for the real-time trading of water withdrawal and waste load discharge permits in agricultural areas along the rivers. Total Dissolved Solids (TDS) is chosen as an indicator of river water quality and the TDS load that agricultural water users discharge to the river are controlled by storing a part of return flows in some evaporation ponds. Available surface water withdrawal and waste load discharge permits are determined using a non-linear multi-objective optimization model. Total available permits are then fairly reallocated among agricultural water users, proportional to their arable lands. Water users can trade their water withdrawal and waste load discharge permits simultaneously, in a bilateral, step by step framework, which takes advantage of differences in their water use efficiencies and agricultural return flow rates. A trade that would take place at each time step results in either more benefit or less diverted return flow. The Nucleolus cooperative game is used to redistribute the benefits generated through trades in different time steps. The proposed methodology is applied to PayePol region in the Karkheh River catchment, southwest Iran. Predicting that 1922.7 Million Cubic Meters (MCM) of annual flow is available to agricultural lands at the beginning of the cultivation year, the real-time optimization model estimates the total annual benefit to reach 46.07 million US Dollars (USD), which requires 6.31 MCM of return flow to be diverted to the evaporation ponds. Fair reallocation of the permits, changes these values to 35.38 million USD and 13.69 MCM, respectively. Results illustrate the effectiveness of the proposed methodology in the real-time water and waste load allocation and simultaneous trading of permits. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantifying Ground-Water and Surface-Water Discharge from Evapotranspiration Processes in 12 Hydrographic Areas of the Colorado Regional Ground-Water Flow System, Nevada, Utah, and Arizona

USGS Publications Warehouse

DeMeo, Guy A.; Smith, J. LaRue; Damar, Nancy A.; Darnell, Jon

2008-01-01

Rapid population growth in southern Nevada has increased the demand for additional water supplies from rural areas of northern Clark and southern Lincoln counties to meet projected water-supply needs. Springs and rivers in these undeveloped areas sustain fragile riparian habitat and may be susceptible to ground-water withdrawals. Most natural ground-water and surface-water discharge from these basins occurs by evapotranspiration (ET) along narrow riparian corridors that encompassed about 45,000 acres or about 1 percent of the study area. This report presents estimates of ground- and surface-water discharge from ET across 3.5 million acres in 12 hydrographic areas of the Colorado Regional Ground-Water Flow System. Ground-and surface-water discharge from ET were determined by identifying areas of ground- and surface-water ET, delineating areas of similar vegetation and soil conditions (ET units), and computing ET rates for each of these ET units. Eight ET units were identified using spectral-reflectance characteristics determined from 2003 satellite imagery, high-resolution aerial photography, and land classification cover. These ET units are dense meadowland vegetation (200 acres), dense woodland vegetation (7,200 acres), moderate woodland vegetation (6,100 acres), dense shrubland vegetation (5,800 acres), moderate shrubland vegetation (22,600 acres), agricultural fields (3,100 acres), non-phreatophytic areas (3,400,000 acres), and open water (300 acres). ET from diffuse ground-water and channelized surface-water is expressed as ETgs and is equal to the difference between total annual ET and precipitation. Total annual ET rates were calculated by the Bowen ratio and eddy covariance methods using micrometeorological data collected from four sites and estimated at 3.9 ft at a dense woodland site (February 2003 to March 2005), 3.6 ft at a moderate woodland site (July 2003 to October 2006), 2.8 ft at a dense shrubland site (June 2005 to October 2006), and 1.5 ft at a

Warm water deuterium fractionation in IRAS 16293-2422. The high-resolution ALMA and SMA view

NASA Astrophysics Data System (ADS)

Persson, M. V.; Jørgensen, J. K.; van Dishoeck, E. F.

2013-01-01

Context. Measuring the water deuterium fractionation in the inner warm regions of low-mass protostars has so far been hampered by poor angular resolution obtainable with single-dish ground- and space-based telescopes. Observations of water isotopologues using (sub)millimeter wavelength interferometers have the potential to shed light on this matter. Aims: To measure the water deuterium fractionation in the warm gas of the deeply-embedded protostellar binary IRAS 16293-2422. Methods: Observations toward IRAS 16293-2422 of the 53,2 - 44,1 transition of H218O at 692.07914 GHz from Atacama Large Millimeter/submillimeter Array (ALMA) as well as the 31,3 - 22,0 of H218O at 203.40752 GHz and the 31,2 - 22,1 transition of HDO at 225.89672 GHz from the Submillimeter Array (SMA) are presented. Results: The 692 GHz H218O line is seen toward both components of the binary protostar. Toward one of the components, "source B", the line is seen in absorption toward the continuum, slightly red-shifted from the systemic velocity, whereas emission is seen off-source at the systemic velocity. Toward the other component, "source A", the two HDO and H218O lines are detected as well with the SMA. From the H218O transitions the excitation temperature is estimated at 124 ± 12 K. The calculated HDO/H2O ratio is (9.2 ± 2.6) × 10-4 - significantly lower than previous estimates in the warm gas close to the source. It is also lower by a factor of ~5 than the ratio deduced in the outer envelope. Conclusions: Our observations reveal the physical and chemical structure of water vapor close to the protostars on solar-system scales. The red-shifted absorption detected toward source B is indicative of infall. The excitation temperature is consistent with the picture of water ice evaporation close to the protostar. The low HDO/H2O ratio deduced here suggests that the differences between the inner regions of the protostars and the Earth's oceans and comets are smaller than previously thought

30 CFR 250.248 - What solid and liquid wastes and discharges information and cooling water intake information must...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What solid and liquid wastes and discharges...) § 250.248 What solid and liquid wastes and discharges information and cooling water intake information must accompany the DPP or DOCD? The following solid and liquid wastes and discharges information and...

Predicted effects of climate warming on the distribution of 50 stream fishes in Wisconsin, USA.

PubMed

Lyons, J; Stewart, J S; Mitro, M

2010-11-01

Summer air and stream water temperatures are expected to rise in the state of Wisconsin, U.S.A., over the next 50 years. To assess potential climate warming effects on stream fishes, predictive models were developed for 50 common fish species using classification-tree analysis of 69 environmental variables in a geographic information system. Model accuracy was 56·0-93·5% in validation tests. Models were applied to all 86 898 km of stream in the state under four different climate scenarios: current conditions, limited climate warming (summer air temperatures increase 1° C and water 0·8° C), moderate warming (air 3° C and water 2·4° C) and major warming (air 5° C and water 4° C). With climate warming, 23 fishes were predicted to decline in distribution (three to extirpation under the major warming scenario), 23 to increase and four to have no change. Overall, declining species lost substantially more stream length than increasing species gained. All three cold-water and 16 cool-water fishes and four of 31 warm-water fishes were predicted to decline, four warm-water fishes to remain the same and 23 warm-water fishes to increase in distribution. Species changes were predicted to be most dramatic in small streams in northern Wisconsin that currently have cold to cool summer water temperatures and are dominated by cold-water and cool-water fishes, and least in larger and warmer streams and rivers in southern Wisconsin that are currently dominated by warm-water fishes. Results of this study suggest that even small increases in summer air and water temperatures owing to climate warming will have major effects on the distribution of stream fishes in Wisconsin. © 2010 The Authors. Journal of Fish Biology © 2010 The Fisheries Society of the British Isles.

Verification of 1921 peak discharge at Skagit River near Concrete, Washington, using 2003 peak-discharge data

USGS Publications Warehouse

Mastin, M.C.; Kresch, D.L.

2005-01-01

The 1921 peak discharge at Skagit River near Concrete, Washington (U.S. Geological Survey streamflow-gaging station 12194000), was verified using peak-discharge data from the flood of October 21, 2003, the largest flood since 1921. This peak discharge is critical to determining other high discharges at the gaging station and to reliably estimating the 100-year flood, the primary design flood being used in a current flood study of the Skagit River basin. The four largest annual peak discharges of record (1897, 1909, 1917, and 1921) were used to determine the 100-year flood discharge at Skagit River near Concrete. The peak discharge on December 13, 1921, was determined by James E. Stewart of the U.S. Geological Survey using a slope-area measurement and a contracted-opening measurement. An extended stage-discharge rating curve based on the 1921 peak discharge was used to determine the peak discharges of the three other large floods. Any inaccuracy in the 1921 peak discharge also would affect the accuracies of the three other largest peak discharges. The peak discharge of the 1921 flood was recalculated using the cross sections and high-water marks surveyed after the 1921 flood in conjunction with a new estimate of the channel roughness coefficient (n value) based on an n-verification analysis of the peak discharge of the October 21, 2003, flood. The n value used by Stewart for his slope-area measurement of the 1921 flood was 0.033, and the corresponding calculated peak discharge was 240,000 cubic feet per second (ft3/s). Determination of a single definitive water-surface profile for use in the n-verification analysis was precluded because of considerable variation in elevations of surveyed high-water marks from the flood on October 21, 2003. Therefore, n values were determined for two separate water-surface profiles thought to bracket a plausible range of water-surface slopes defined by high-water marks. The n value determined using the flattest plausible slope was 0

A model for water discharge based on energy consumption data (WATEN).

NASA Astrophysics Data System (ADS)

Moyano, María Carmen; Tornos, Lucía; Juana, Luis

2014-05-01

As the need for water conservation is becoming a major water concern, a lumped model entitled WATEN has been proposed to analyse the water balance in the B-XII Irrigation Sector of the Lower Guadalquivir Irrigated Area, one of the largest irrigated areas in Spain. The aim of this work is to approach the hydrological study of an irrigation district lacking of robust data in such a manner that the water balance is performed from less to more process complexity. WATEN parameters are the total and readily available moisture in the soil, a fix percentage for effective precipitation, and the irrigation efficiency. The Sector presents six different drainage pumping stations, with particular pumping groups and with no water flow measurement devices. Energy consumption depends on the working pumping stations and groups, and on the variable water level to discharge. Energy consumed in the drainage pumping stations has been used for calibration The study has relied on two monthly series of data: the volume of drainage obtained from the model and the energy consumed in the pumping stations. A double mass analysis has permitted the detection of data tendencies. The two resulting series of data have been compared to assess model performance, particularly the Pearson's product moment correlation coefficient and the Nash-Sutcliffe coefficient of efficiency, e2, determined for monthly data and for annual and monthly average data. For model calibration, we have followed a classical approach based on objective functions optimization, and a robust approach based on Markov chain Monte Carlo simulation process, driven in a similar manner to genetic algorithms, entitled Parameters Estimation on Driven Trials (PEDT), and aiming to reduce computational requirements. WATEN has been parameterised maintaining its physical and conceptual rationality. The study approach is outlined as a progressive introduction of data. In this manner, we can observe its effect on the studied objective

Warming and elevated CO2 interact to alter seasonality and reduce variability of soil water in a semiarid grassland

USDA-ARS?s Scientific Manuscript database

Global changes that alter the amount and timing of plant-available water may have profound effects on arid and semi-arid ecosystems. In addition to predicted changes in precipitation, both elevated CO2 and warming can alter water availability, often in opposite ways. Few studies, however, have measu...

Increased future ice discharge from Antarctica owing to higher snowfall

NASA Astrophysics Data System (ADS)

Winkelmann, Ricarda; Levermann, Anders; Martin, Maria A.; Frieler, Katja

2013-04-01

Anthropogenic climate change is likely to cause continuing global sea-level rise, but some processes within the Earth system may mitigate the magnitude of the projected effect. Regional and global climate models simulate enhanced snowfall over Antarctica, which would provide a direct offset of the future contribution to global sea level rise from cryospheric mass loss and ocean expansion. Uncertainties exist in modelled snowfall, but even larger uncertainties exist in the potential changes of dynamic ice discharge from Antarctica. Here we show that snowfall and discharge are not independent, but that future ice discharge will increase by up to three times as a result of additional snowfall under global warming. Our results, based on an ice-sheet model forced by climate simulations through to the end of 2500, show that the enhanced discharge effect exceeds the effect of surface warming as well as that of basal ice-shelf melting, and is due to the difference in surface elevation change caused by snowfall on grounded versus floating ice. Although different underlying forcings drive ice loss from basal melting versus increased snowfall, similar ice dynamical processes are nonetheless at work in both; therefore results are relatively independent of the specific representation of the transition zone. In an ensemble of simulations designed to capture ice-physics uncertainty, the additional dynamic ice loss along the coastline compensates between 30 and 65 per cent of the ice gain due to enhanced snowfall over the entire continent. This results in a dynamic ice loss of up to 1.25 metres in the year 2500 for the strongest warming scenario.

Changes in river water temperature between 1980 and 2012 in Yongan watershed, eastern China: Magnitude, drivers and models

NASA Astrophysics Data System (ADS)

Chen, Dingjiang; Hu, Minpeng; Guo, Yi; Dahlgren, Randy A.

2016-02-01

Climate warming is expected to have major impacts on river water quality, water column/hyporheic zone biogeochemistry and aquatic ecosystems. A quantitative understanding of spatio-temporal air (Ta) and water (Tw) temperature dynamics is required to guide river management and to facilitate adaptations to climate change. This study determined the magnitude, drivers and models for increasing Tw in three river segments of the Yongan watershed in eastern China. Over the 1980-2012 period, Tw in the watershed increased by 0.029-0.046 °C yr-1 due to a ∼0.050 °C yr-1 increase of Ta and changes in local human activities (e.g., increasing developed land and population density and decreasing forest area). A standardized multiple regression model was developed for predicting annual Tw (R2 = 0.88-0.91) and identifying/partitioning the impact of the principal drivers on increasing Tw:Ta (76 ± 1%), local human activities (14 ± 2%), and water discharge (10 ± 1%). After normalizing water discharge, climate warming and local human activities were estimated to contribute 81-95% and 5-19% of the observed rising Tw, respectively. Models forecast a 0.32-1.76 °C increase in Tw by 2050 compared with the 2000-2012 baseline condition based on four future scenarios. Heterogeneity of warming rates existed across seasons and river segments, with the lower flow river and dry season demonstrating a more pronounced response to climate warming and human activities. Rising Tw due to changes in climate, local human activities and hydrology has a considerable potential to aggravate river water quality degradation and coastal water eutrophication in summer. Thus it should be carefully considered in developing watershed management strategies in response to climate change.

Examining Submarine Ground-Water Discharge into Florida Bay by using 222Rn and Continuous Resistivity Profiling

USGS Publications Warehouse

Swarzenski, Peter; Reich, Chris; Rudnick, David

2009-01-01

Estimates of submarine ground-water discharge (SGD) into Florida Bay remain one of the least understood components of a regional water balance. To quantify the magnitude and seasonality of SGD into upper Florida Bay, research activities included the use of the natural geochemical tracer, 222Rn, to examine potential SGD hotspots (222Rn surveys) and to quantify the total (saline + fresh water component) SGD rates at select sites (222Rn time-series). To obtain a synoptic map of the 222Rn distribution within our study site in Florida Bay, we set up a flow-through system on a small boat that consisted of a Differential Global Positioning System, a calibrated YSI, Inc CTD sensor with a sampling rate of 0.5 min, and a submersible pump (z = 0.5 m) that continuously fed water into an air/water exchanger that was plumbed simultaneously into four RAD7 222Rn air monitors. To obtain local advective ground-water flux estimates, 222Rn time-series experiments were deployed at strategic positions across hydrologic and geologic gradients within our study site. These time-series stations consisted of a submersible pump, a Solinist DIVER (to record continuous CTD parameters) and two RAD7 222Rn air monitors plumbed into an air/water exchanger. Repeat time-series 222Rn measurements were conducted for 3-4 days across several tidal excursions. Radon was also measured in the air during each sampling campaign by a dedicated RAD7. We obtained ground-water discharge information by calculating a 222Rn mass balance that accounted for lateral and horizontal exchange, as well as an appropriate ground-water 222Rn end member activity. Another research component utilized marine continuous resistivity profiling (CRP) surveys to examine the subsurface salinity structure within Florida Bay sediments. This system consisted of an AGI SuperSting 8 channel receiver attached to a streamer cable that had two current (A,B) electrodes and nine potential electrodes that were spaced 10 m apart. A separate DGPS

Phosphonate removal from discharged circulating cooling water using iron-carbon micro-electrolysis.

PubMed

Zhou, Zhen; Qiao, Weimin; Lin, Yangbo; Shen, Xuelian; Hu, Dalong; Zhang, Jianqiao; Jiang, Lu-Man; Wang, Luochun

2014-01-01

Phosphonate is a commonly used corrosion and scale inhibitor for a circulating cooling water (CCW) system. Its discharge could cause eutrophication of receiving waters. The iron-carbon (Fe/C) micro-electrolysis technology was used to degrade and remove phosphonate from discharged CCW. The influences of initial pH, Fe/C ratio (FCR) and temperature on phosphonate removal were investigated in a series of batch tests and optimized by response surface methodology. The quadratic model of phosphonate removal was obtained with satisfactory degrees of fitness. The optimum conditions with total phosphorus removal efficiency of 95% were obtained at pH 7.0, FCR of 1.25, and temperature of 45 °C. The phosphonate removal mechanisms were also studied. Phosphonate removal occurred predominantly via two consecutive reactive phases: the degradation of phosphonate complexes (Ca-phosphonate) and the precipitation of Fe/C micro-electrolysis products (PO₄(3-), Ca²⁺ and Fe³⁺).

Considering the summation of the effect of harmful substances during the calculation of the environmentally safe waste water discharge

NASA Astrophysics Data System (ADS)

Sokolov, A. K.

2017-09-01

This article presents the technique of assessing the maximum allowable (standard) discharge of waste waters with several harmful substances into a water reservoir. The technique makes it possible to take into account the summation of their effect provided that the limiting harmful indices are the same. The expressions for the determination of the discharge limit of waste waters have been derived from the conditions of admissibility of the effect of several harmful substances on the waters of a reservoir. Mathematical conditions of admissibility of the effect of wastewaters on a reservoir are given for the characteristic combinations of limiting harmful indices and hazard classes of several substances. The conditions of admissibility of effects are presented in the form of logical products of the sums of relative concentrations that should not exceed the value of 1. It is shown that the calculation of the process of wastewater dilution in a flowing water reservoir is possible only on the basis of a numerical method to assess the wastewater discharge limit. An example of the numerical calculation of the standard limit of industrial enterprise wastewater discharges that contain polysulfide oil, flocculant VPK-101, and fungicide captan is given to test this method. In addition to these three harmful substances, the water reservoir also contained a fourth substance, namely, Zellek-Super herbicide, above the waste discharge point. The summation of the harmful effect was taken into account for VPK-101, captan, and Zellek-Super. The reliability of the technique was tested by the calculation of concentrations of the four substances in the control point of the flowing reservoir during the estimated maximum allowable wastewater discharge. It is shown that the value of the maximum allowable discharge limit was almost two times higher for the example under consideration, taking into account that the effect of harmful substances was unidirectional, which provides a higher level

Inactivation of Bacteria in Oil Field Injected Water by a Pulsed Plasma Discharge Process

NASA Astrophysics Data System (ADS)

Xin, Qing; Li, Zhongjian; Lei, Lecheng; Yang, Bin

2016-09-01

Pulsed plasma discharge was employed to inactivate bacteria in the injection water for an oil field. The effects of water conductivity and initial concentration of bacteria on elimination efficiency were investigated in the batch and continuous flow modes. It was demonstrated that Fe2+ contained in injection water could enhance the elimination efficiency greatly. The addition of reducing agent glutathione (GSH) indicated that active radicals generated by pulsed plasma discharges played an important role in the inactivation of bacteria. Moreover, it was found that the microbial inactivation process for both batch and continuous flow mode well fitted the model based on the Weibull's survival function. supported by Zhejiang Province Welfare Technology Applied Research Project of China (No. 2014C31137), National Natural Science Foundation of China (Nos. 21436007 and U1462201), and the Fundamental Research Funds for the Central Universities of China (No. 2015QNA4032)

Suspended-sediment and fresh-water discharges in the Ob and Yenisey rivers, 1960-1988

USGS Publications Warehouse

Meade, R.H.; Bobrovitskaya, N.N.; Babkin, V.I.

2000-01-01

Of the world's great rivers, the Ob and Yenisey rank among the largest suppliers of fresh water and among the smallest suppliers of suspended sediment to the coastal ocean. Sediment in the middle reaches of the rivers is mobilized from bordering terraces and exchanged between channels and flood plains. Sediment in the lower reaches of these great rivers is deposited and stored (permanently, on a millennial time scale) in flood plains. Sediment discharges, already small under natural conditions, are diminished further by large manmade reservoirs that trap significant proportions of the moving solids. The long winter freeze and sudden spring breakup impose a peakedness in seasonal water runoff and sediment discharge that contrasts markedly with that in rivers of the tropics and more temperate climates. Very little sediment from the Ob and Yenisey rivers is being transported to the open waters of the Arctic Ocean under present conditions.

Pulsed dielectric barrier discharge for Bacillus subtilis inactivation in water

NASA Astrophysics Data System (ADS)

Hernández-Arias, A. N.; Rodríguez-Méndez, B. G.; López-Callejas, R.; Valencia-Alvarado, R.; Mercado-Cabrera, A.; Peña-Eguiluz, R.; Barocio, S. R.; Muñoz-Castro, A. E.; de la Piedad Beneitez, A.

2012-06-01

The inactivation of Bacillus subtilis bacteria in water has been experimentally studied by means of a pulsed dielectric barrier discharge (PDBD) in a coaxial reactor endowed with an alumina dielectric. The plasma source is capable of operating at atmospheric pressure with gas, water or hybrid gas-liquid media at adjustable 25 kV pulses, 30 μs long and at a 500 Hz frequency. In order to evaluate the inactivation efficiency of the system, a set of experiments were designed on the basis of oxygen flow control. The initial data have showed a significant bacterial rate reduction of 103-107 CFU/mL. Additional results proved that applying an oxygen flow for a few seconds during the PDBD treatment inactivates the Bacillus subtilis population with 99.99% effectiveness. As a reference, without gas flow but with the same exposure times, this percentage is reduced to ~90%. The analysis of the relationship between inactivation rate and chemical species in the discharge has been carried out using optical emission spectroscopy as to identifying the main reactive species. Reactive oxygen species such as atomic oxygen and ozone tuned out to be the dominant germicidal species. Some proposed inactivation mechanisms of this technique are discussed.

Temporal variability in domestic point source discharges and their associated impact on receiving waters.

PubMed

Richards, Samia; Withers, Paul J A; Paterson, Eric; McRoberts, Colin W; Stutter, Marc

2016-11-15

Discharges from the widely distributed small point sources of pollutants such as septic tanks contribute to microbial and nutrient loading of streams and can pose risks to human health and stream ecology, especially during periods of ecological sensitivity. Here we present the first comprehensive data on the compositional variability of septic tank effluents (STE) as a potential source of water pollution during different seasons and the associated links to their influence on stream waters. To determine STE parameters and nutrient variations, the biological and physicochemical properties of effluents sampled quarterly from 12 septic tank systems were investigated with concurrent analyses of upstream and downstream receiving waters. The study revealed that during the warmer dryer months of spring and summer, effluents were similar in composition, as were the colder wetter months of autumn and winter. However, spring/summer effluents differed significantly (P<0.05) from autumn/winter for concentrations of biological oxygen demand (BOD), arsenic, barium (Ba), cobalt, chromium, manganese, strontium (Sr), titanium, tungsten (W) and zinc (Zn). With the exception of BOD, Ba and Sr which were greater in summer and spring, the concentrations of these parameters were greater in winter. Receiving stream waters also showed significant seasonal variation (P≤0.05) in alkalinity, BOD, dissolved organic carbon, sulphate, sulphur, lithium, W, Zn and Escherichiacoli abundance. There was a clear significant influence of STE on downstream waters relative to upstream from the source (P<0.05) for total suspended solids, total particulate P and N, ammonium-N, coliforms and E. coli. The findings of this study found seasonal variation in STE and place effluent discharges as a factor affecting adjacent stream quality and call for appropriate measures to reduce or redirect STE discharges away from water courses. Copyright © 2016 Elsevier B.V. All rights reserved.